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A study on prevalence and molecular identification of haemoprotozoan diseases in cattle at Chittagong district
(A thesis submitted in the partial fulfillment of the requirements for the degree of Master of Science in Parasitology Department of Pathology and Parasitology Faculty of Veterinary Medicine Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2014-12) Bary, Md. Akramul
This present survey was conducted to reveal out the prevalence through microscopic examination and molecular identification of haemoprotozoan parasitic diseases in cattle at Chittagong district, Bangladesh. A total 300 blood samples were randomly collected (150 crossbred and 150 local cattle) in three consecutive seasons (summer, rainy and winter) from four selected areas, namely Nasirabad, Patia, Bayezid and Jointika. The effects of topography, season, age and gender were tested in both crossbred and local cattle. Molecular detection technique (PCR) was performed after consequence screening by light microcopy, which exhibited that 22 samples (14 for Anaplasma sp, 6 for Babesia sp and 2 for mixed infections were positive.The overall prevalence of haemoprotozoan diseases were 9.33% in crossbred and 5.33% in local cattle, among these babesiosis, anaplasmosis were recorded 2.66% and 6.00 % in crossbred cattle and 1.33% and 3.33 % in local cattle, respectively. Anaplasmosis was common in all areas.The highest prevalence of anaplasmosis was found in Patia (9.33%) followed by Bayezid (4.00%), Nasirabad (2.67%) and Jointika (2.66%) and babesiosis was recorded in Bayezid (4.00%) followed by Jointika (2.66%) and Patia (1.33%). Moreover, haemoprotozoan diseases occurred more frequently in summer followed by rainy and winter season. Among these seasons the highest prevalence of anaplasmosis was recorded 12.00% in crossbred cattle followed by 6.00% in local cattle in summer whereas frequency of babesiosis was highest in summer which was 4.00% in crossbred cattle followed by 2.00% in local cattle. Prevalence of anaplasmosis increased significantly (P<0.05) with the increase of age in crossbred cattle. The highest prevalence of anaplasmosis was 13.72% and 6.94% in adult crossbred and local cattle, respectively. Occurrence of babesiosis was the highest in adult (5.88%) in crossbred than young (2.78%) in local cattle, respectively. It was observed that, the breed and age were important predictor of haemoprotozoan diseases. It was revealed that haemoprotozoan diseases were more common in female cattle, among these highest prevalence of anaplasmosis was recorded (6.11%) in female crossbred cattle and (4.00%) in local cattle, respectively. Positive samples were analyzed by using RNA gene based PCR technique, where 9 samples were amplified among these 4 samples (1.33%) of Babesia sp and 5 samples (1.67%) of Anaplasma sp. As this study is a new invention under these areas, further investigation is recommended with special emphasis on the identification of available vectors for better understanding of such diseases which will help to take necessary preventive measures.
A study on prevalence, molecular identification and characterization of blood and tissue protozoa of domestic ruminants in Chittagong, Bangladesh
(A thesis submitted in the total fulfillment of the requirements for the degree of Doctor of Philosophy from Department of Pathology and Parasitology Department of Pathology and Parasitology Faculty of Veterinary Medicine Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2017-01) Mannan, Abdul
Blood and tissue parasites infect both the small and large ruminants causing significant economic losses all over the world including Bangladesh. The actual extent of these parasitic diseases and their epidemiologic features is not yet comprehensively studied in Bangladesh. Accurate identification and characterization are essential for any epidemiologic investigation. With the availability of modern DNA based tools and resources, the capacity for accurate and reliable detection of any disease agents are now possible which was not available before. The present study was therefore designed to investigate the prevalence followed by molecular identification of selected hemoparasites (Babesia, Anaplasma, Trypanosoma) of cattle in different geographic areas of the country. In addition, an attempt was made towards the molecular characterization of tissue protozoan (Toxoplasma gondii) in small ruminants in the Chittagong Metropolitan area located in southern part of Bangladesh. Further analyses of the associated risk factors were also done to help to develop necessary prevention and control options against these important protozoa. Blood samples collected from cattle were preserved in the laboratory for further examination with conventional microscopy and modern molecular tools like PCR and DNA sequencing. Sample size varied among different protozoa species and initial screening was aided by Giemsa stained thin smear examinations. A variable numbers of samples were assessed to detect hemoprotozoa including Anaplasma (n=1680), Babesia (n=1680) and Trypanosoma (n=480) where 8.21%, 1.43% and 0.63% prevalence was recorded respectively from different study areas inside Bangladesh. Bovine anaplasmosis was found as an important rickettsial disease with limited reports related to its prevalence inside Bangladesh. Comparative prevalence of this hemoparasitewas recorded as 9.33% in the hilly areas, 9.00% in coastal areas and 5.83% in plain lands inside the country. Further analyses indicated a higher prevalence (P>0.05) in crossbred cattle compared to local or indigenous breeds. Variations in seasonal incidence were also observed with high case numbers recorded in winter season of the year. Age of the animals was also found an important epidemiologic factor where animals aged 18-30 months were more vulnerable to anaplasmosis than other age groups. Housing and floor types also found to be associated with variable prevalence and animals living in non-cemented or soil-type floors were more prone to suffer from anaplasmosis. Molecular characterization through PCR amplification of 16S rRNA gene was achieved where an 80% cases (40 out of 50 samples) were found positive for A. marginale infections. Further amplification of MSP4 gene fragments successfully identified all forty positive cases in 16S rRNA screening. Further DNA sequencing and phylogenetic studies revealed that all the isolates of this present study were closely related to the isolates already reported from countries like Argentina, Australia and China. Bovine babesiosis is an economic important protozoan disease with sporadic reports on its prevalence and incidence in Bangladesh. During this study, prevalence of babesiosis was found as 1.17%, 1.67% and 1.46% in the selected hilly, coastal and xviii plain areas respectively in the study areas. Further data analysis showed crossbred and female animals more vulnerable than local or indigenous cattle and their male counterparts. High number of babesiosis was recorded in summer season compared to other time of the year. Animals aged 6-18 months were more susceptible to babesiosis than other age groups. Molecular identification of the organism were achieved through PCR amplification of 18SrRNA gene fragments where all positive cases (n=24) screened by conventional microscopy were successfully amplified. Further DNA sequencing and phylogenetic analysis revealed that two distinct isolates of Babesia, Babesia bigemina and Babesia ovata were present in the country. Trypanosomiasis is one of the least studied blood parasites of cattle in Bangladesh and thought to be distributed in different parts where relevant vectors are available. During this study out of 480 blood samples, only three were found positive in a single dairy farm located in Chittagong Metropolitan area. All positive cases were recorded in female and Holstein Frisian crossbred cattle and in one farm where previous incidence and disease record was not available. The time of the year when these cases were found was in rainy season and all the animals were aged 6 years or more and none of the younger animals were found positive. Molecular identification was achieved through PCR amplification of 18SrRNA gene fragment following previously published protocols. Sequencing of amplified DNA and further phylogenetic analysis revealed that Trypanosoma evansi were circulating in Bangladesh which is closely related to the isolates reported from countries like Taiwan, Thailand and Japan. Toxoplasmosis is an important zoonotic tissue protozoan disease of small ruminants in Bangladesh and has been documented by a number of publications. Several studies reported variable prevalence rate of toxoplasmosis in different parts of the country. The present study revealed an overall prevalence of toxoplasmosis in sheep and goats as 30.43% and 41.30% respectively. Further statistical analysis of the data indicated that animals aged two years or more were highly seropositive to Toxoplasma gondii. History of abortion and sources of drinking water were found to be significantly associated with toxoplasmosis. Animals with previous history of abortion were highly seropositive compared to the other groups. High seroprevalence was recorded in farms where ponds and municipality supply water are used as water sources for animals. Apart from serodiagnosis, acute and chronic cases of toxoplasmosis are always troublesome to detect hindering their prevention and control efforts. Combined histopathological and molecular approaches were applied during this study to detect the Toxoplasma gondii from several aborted tissues of sheep and goats. Prevalence of T. gondii was detected as high as 25% in sheep (n=4) and 36.84% (n=19) in goats. All the positive cases were detected in animals that aborted at 3.5 months of gestation. Further sequencing of amplified DNA and phylogenetic analysis of the sequences confirms the presence of T. gondii in a single cluster with minimum genetic variations among the four isolates which are closely related to the isolates recorded from countries like India and Iran.
Application of different diagnostic techniques in detection and estimation of prevalence of avian influenza in poultry of Chattogram region
(Faculty of Veterinary Medicine, Chattogram Veterinary and Animal Sciences University, Khulshi, Chattogram-4225, Bangladesh, 2025-06) Ara, Jahan
Avian influenza (AI) is an infectious disease of birds caused by influenza A virus, posing a major global public health and economic concern. In Bangladesh, AI outbreaks in commercial and backyard poultry are frequent and cause huge losses in the poultry industry. This study was conducted to detect avian influenza virus (AIV) in layer poultry farms of Chattogram region by using molecular techniques and to study the pathological alterations in AIV-infected birds. A total of 108 pooled samples were collected from 26-layer farms. Gross and histopathological examinations were performed for assessing pathological changes. RNA was extracted and after cDNA conversion subjected to conventional PCR. Real-time RT-PCR was also performed targeting the M gene for AIV detection. Out of 26-layer farms, 3 were found positive for AIV based on rRT-PCR, although 6 farms were positive by conventional PCR. On the other hand, gross lesions suggestive of AIV infection were observed in birds from 8 farms (30.8%). Gross lesions included erythema and congestion in abdominal skin, hemorrhages in trachea and lungs, hemorrhage on the fat of abdomen and coronary groove of heart, enlarged spleen, and necrosis in intestine. In case of laying hen, the ova were hemorrhagic and misshapen. Histopathological changes comprised epithelial desquamation, inflammatory cell infiltration, congestion, hemorrhages, and necrosis in respiratory and digestive organs. This study confirms the AIV in layer poultry of Chattogram and provides valuable insights into the associated pathological alterations. The findings highlight the urgent need for continuous surveillance and effective control strategies against AIV to safeguard poultry health and production in Bangladesh.
Clinicopathological and Molecular Insights into Reproductive Disorder in Dairy Cows: Hematobiochemical, Hormonal and FOXP3 Genotypic Correlations
(Faculty of Veterinary Medicine, Chattogram Veterinary and Animal Sciences University, Khulshi, Chattogram-4225, Bangladesh, 2025-06) Sultana Poly, Nigar
Reproductive efficiency is fundamental to sustainable dairy production but is constantly challenged by multifactorial infertility disorders associated with nutrition, disease, hormonal balance, and genetics. Therefore, this study aims to investigate hematobiochemical, hormonal, and genetic factors underlying cows with reproductive disorders compared to fertile cows. A case control study was conducted from June 2024 to June 2025 across three dairy-producing regions of Bangladesh (Rangpur, Bogura, and Chattogram) to identify hematobiochemical, hormonal, and genetic factors associated with reproductive disorders in dairy cows. Blood samples and fertility data were collected from 97 lactating cows from both commercial farms and smallholder systems classified into control group (conceived ≤2 AIs; n = 57) and case group (≥3 AIs or repeat breeding; n = 40). Hematological indices, serum biochemical markers, and hormonal profiles were measured, alongside molecular genotyping of some fertility-associated genes (APOB, TFB1M, FOXP3, and IARS) using conventional PCR, and TaqMan probe based real-time PCR genotyping assay, with selected confirmation by Sanger sequencing. Statistical analyses were performed using R for non-parametric tests. The results revealed significant alterations in hematobiochemical profiles in case group compared with control group counterparts although some values present within the reference range. Hemoglobin concentrations were significantly lower in case group (9.65 ± 0.93 g/dL) than control group (10.47 ± 1.03 g/dL; p = 0.002), indicating mild anemia. Glucose, total protein, albumin, and calcium, were significantly reduced in case group, suggesting poor nutritional status, altered protein metabolism, and impaired immune response. Conversely, hepatic enzyme activities (ALT and AST) were significantly elevated in case group, indicating possible hepatocellular stress or subclinical hepatic dysfunction. Lipid profiles also revealed marginally elevated LDL in case group, while HDL and triglycerides did not differ significantly. We found a clear association between endocrine imbalance and reproductive inefficiency. Fertile cows had significantly higher serum FSH (3.72 ± 2.08 mIU/ml vs. 1.90 ± 2.41 mIU/ml; p < 0.001), progesterone (3.28 ± 1.40 ng/ml vs. 2.47 ± 1.76 ng/ml; p = 0.01), and AMH (0.20 ± 0.12 ng/ml vs. 0.05 ± 0.04 ng/ml; p = 0.002) compared to case group. These findings suggest that insufficient gonadotropin stimulation, reduced ovarian reserve, and luteal insufficiency contribute to infertility in dairy cows. Cows under poor management and nutrition also exhibited significantly lower Hb, glucose, albumin, and calcium, as well as higher ALT and LDL, compared with cows on balanced diets. This highlights the combined role of inadequate feeding and metabolic derangements in exacerbating reproductive failure. However, real-time PCR identified the presence of allelic variations at the FOXP3 locus (g.87298881A>G) which is recently reported for recurrent infertility in different breeds of cattle except Bangladeshi cows. In our study we identified G allele frequencies ranged from 0.375 to 0.517, with moderate to high prevalence across 97 cows of Jersey, Deshi, Holstein-cross, and Sahiwal breeds. Importantly, the G/G genotype also significantly associated with reduced hemoglobin, lower glucose, higher ALT and CRP, and prolonged calving intervals, days open, and service per conception, indicating a strong correlation between the FOXP3 variant and reproductive inefficiency. Genotypic stratification also revealed that cows with the wild (A/A) and carrier type (A/G) genotype of FOXP3 gene exhibited higher FSH and progesterone levels than those with mutant type (G/G) genotypes, implicating this locus might have pathogenic role in reproductive function regulation. Genetic screening also conducted for APOB gene (1.3kb insertion mutation) for Cholesterol deficiency (CD), TFB1M gene (138 kb deletion mutation) for lethal haplotype 5 (HH5), and IARS gene mutation (c.235G>C) for weak calf syndrome and calf mortality but no carrier or mutant animals found in this cohort. Overall, this study provides the first integrated evidence in Bangladesh linking metabolic dysfunction, hormonal deficits, and the FOXP3 risk allele to poor reproductive performance related to infertility in dairy cows. These findings support integrating routine biomarker screening with genetic testing can enable early identification of at-risk animals, guiding targeted nutritional and breeding interventions to enhance fertility and sustainable productivity.
DEVELOPMENT OF SIMPLEX AND MULTIPLEX PCR ASSAY FOR RELIABLE IDENTIFICATION OF HAEMOPARASITIC DISEASES OF CATTLE, BANGLADESH
(Chattogram Veterinary & Animal Sciences University, Khulshi-Chattogram, 2022-12) Sultana, Ayesha
Bangladesh is a tropical, agro-based developing country. Anaplasmosis, Babesiosis, and Theileriosis are the most common vector-borne haemoparasitic diseases in cattle. This study not only describes the development and evaluation of a multiplex PCR assay for simultaneous detection of haemoparasitic diseases (Theileria annulata, Babesia bigemina, and Anaplasma marginale), but also their prevalence ratio. In the multiplex PCR assay, three sets of pre-designed primers were used that targeted the genes Tams1 for T. annulata, 18S rRNA for B. bigemina, and 16S rRNA for A. marginale, with desired amplicons sizes of 751 bp, 504 bp, and 270 bp, respectively, with the use of 2% agarose gel for electrophoresis of amplified PCR products. A total of 350 blood specimens were collected that were tentatively diagnosed as haemoparastic diseases on the basis of clinical signs from three districts of Bangladesh: Chattogram, Rangpur, and Sylhet. Blood samples were stained and preserved at -20°C for further molecular study. In this study, 52% (out of 350) cases were tentatively diagnosed as positive by microscopic examination, among the isolates A. marginale (30.3%), Babesia sp. (12.9%), and Theileria sp. (9%). (Whereas, 21.7% in Chattogram, 17.1% in Sylhet, and 13.1% in Rangpur.) However, in the simplex PCR assay, 35.7% of the cases (14.9% in Chattogram, 12% in Sylhet, and 8.9% in Rangpur) showed a positive band in electrophoresis. Mixed haemoparasitic infection is very common in cattle. Overall, 13.1% of infections were detected positive by multiplex PCR; among them, 2% were diagnosed as positive for all three haemoparasites and 3.71% were diagnosed as anaplasmosis+Babesiosis and so. The partial gene sequencing and phylogenetic analysis of the nucleotide sequences expressed the fidelity of the primer pairs that were used in multiplex PCR, which was found to be 100% sensitive and 85% specific for the detection of infections. In multiplex PCR, amplification of multiple target sequences in one assay is helpful for diagnosis of multiple organisms at a time. This is also time-saving and costeffective compared to other two methods, but requires several trials for optimization of annealing temperature and shows false negative results in minor errors. Beyond all limitations, multiplex PCR assay is precise and could be used as a robust tool for easy, sensitive, specific, and simultaneous diagnosis of haemoparasitic diseases in cattle.
DNA barcoding and morphotaxonomic analyses of mosquitoes collected from Chittagong Metropolitan area
(A thesis submitted for partial fulfillment of the requirements for the degree of Master of Science in Parasitology Department of Pathology and Parasitology Faculty of Veterinary Medicine Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2018-01) Sarkar, Md. Suruzzaman
Mosquitoes are important vectors for a wide variety of pathogens and parasites. Identification of different mosquito species are crucial for their eventual control. We have used the classical morphometry and modern molecular methods like DNA barcoding approach for reliable identification of mosquitoes that were collected from different locations of Chittagong Metropolitan area of Bangladesh. A total of 20 randomly collected specimens were included in this study. Different morphological features of head, clypeus, vertex, antenna, maxillary palp, thorax, wings, legs and abdomen of the mosquitoes were examined using three-dimensional microscopy. The morphological characteristics of the mosquitoes observed under stereo binocular microscope in the laboratory shown highly similarity with the Aedes aegypti species. Genomic DNA was extracted from all of the 20 samples using commercial kits and specific primers were used for amplification of partial cytochrome oxidase genes for molecular characterization. PCR products were then sequenced and further bioinformatics analyses was accomplished. Sequence similarity based BLASTn and phylogenetic analyses (MEGA 6) of the sequence indicated similarity with three different species namely Aedes aegypti, Culex pipiens and Aedes albopictus. Among these 5 samples, 3 samples were Aedes aegypti, 1 sample was Aedes albopictus and 1 sample was Culex pipiens. The findings were compatible with the morphological data and reliably characterized the mosquito species. The study was first DNA barcoding analyses on mosquito in the country and showed the feasibility of using molecular tools for their characterization. Further study about the origin and vector potential of these mosquitoes will enhance our capacity to improve existing vector surveillance and control program.
Endoparasitic Infection and Antibiotic Resistance Patterns of Escherichia coli and Salmonella Isolated from Pet Birds in Chattogram
(Chattogram Veterinary and Animal Sciences University Chattogram-4225, Bangladesh, 2020-06) Md. Bayzid, Md.
Different parasitic and bacterial diseases are the crucial impediment in the rearing of pet birds. Gastrointestinal tract and blood are the major predilection sites for parasitic infection. The aim of this study was to identify the gastrointestinal (GI), as well as blood parasitic infection and the occurrence of Escherichia coli and Salmonella spp. with antimicrobial resistance (AMR) patterns from pet birds in Bangladesh. Between June, 2019 and March, 2020 a total of 549 (for GI parasite), 150 (for AMR of E. coli and Salmonella spp.) freshly voided faecal samples and 311 blood samples were collected from Chattogram metropolitan area, Bangladesh. For the detection of GI parasites coproscopy were performed and for isolation of E. coli and Salmonella spp. different microbiological tests were conducted followed by antibiotic sensitivity test (AST) and antibiotic resistant genes were identified by molecular technique. Blood samples tested through multiplex PCR method for Haemoproteus, Plasmodium and Leucocytozoon spp. detection. The occurrence of GI parasite was 18.9% (CI=15.7– 22.5%). Among them the protozoal cyst was 10.9% (CI=8.40–13.8%) containing Eimeria 7.7% (CI=5.6-10.2%), Isospora 2.9% (CI=1.7-4.7%), Caryospora 0.4% (CI=0-1.3%). Among nematode, Ascaridia infection rate was 3.5% (CI=2.1-5.4%), Capillaria 1.7% (CI=1-3%), Heterakis 0.91% (CI=0-2%). Within cestode, the Coanotaenia was found 0.36% (CI=0-1%). But no trematode egg was detected. The occurrence of blood parasitic disease was 2.25% (CI=0.91-4.58%). Among them 0.32% (CI=0.4-1.8%) was Haemoproteus, 1.3% (CI=0.35-3.26%) Plasmodium and 0.64% (CI=0.4-2.3%) Leucocytozoon. The overall prevalence of E. coli in pet birds was 48.7% (95% CI=40.4-57). The AST revealed that, the 91.78% isolates were resistant to ceftriaxone, 86.3% to tetracycline and 75.34% to sulfomethoxazole-trimethoprim. To the contrary, 98.63% isolates were sensitive to colistin sulfate followed by 97.26% to gentamicin. Majority of E. coli isolates were multidrug resistant and carried blaTEM, tetA, tetB, sul1, sul2, gyrA, gyrB, parC and CTX-M-2 genes. The overall infection rate of Salmonella spp. in pet birds were 2.7 % (95% CI=0.7-6.7). The AST evolved that the isolates were 100% resistant to ceftriaxone, 75% to azithromycin, 50% to amoxiciline and tetracycline followed by gentamicin 25%. To the contrary, 100% isolates were sensitive to ciprofloxacin, enrofloxacin and colistin sulfate. Different pet bird’s spp. was infected with various types of gastrointestinal and blood parasites. Due to cherished in intensive care with regular anthelmintic therapy, less vector availability, the occurrence of gastrointestinal as well as blood parasitic infections were less. In order to haphazard used of antibiotics, AMR were developed in E. coli and Salmonella spp.
Histopathological and Molecular Characterization of Canine and Feline Neoplasms: An Integrated Approach Using Immunohistochemistry, PCR and qPCR
(Faculty of Veterinary Medicine, Chattogram Veterinary and Animal Sciences University, Khulshi, Chattogram-4225, Bangladesh, 2025-07) Nova, Farnaz Kader
Neoplastic conditions in companion animals are increasingly recognized in clinical veterinary practice, particularly in dogs and cats. These tumors often exhibit diverse biological behaviors, histopathological patterns and clinical outcomes, posing diagnostic and therapeutic challenges. The objective of this study was to comprehensively evaluate four clinical cases of neoplasia-two in dogs and two in cats- using an integrative diagnostic approach that combined histopathology, immunohistochemistry (IHC) and molecular techniques such as polymerase chain reaction (PCR), quantitative real-time PCR (qPCR) and partial sequencing. Here, case 1 featured an 8-year-old female German Shepherd with a chronic mammary gland mass. Histopathology showed ductal and nest-like epithelial arrangements with moderate pleomorphism and stromal desmoplasia. IHC revealed Ki-67 positivity in 13% of tumor cells and P53 expression in 5%. PCR confirmed expression of BCL2, Ki-67, MYC, MMP9 and P53. qPCR demonstrated upregulation of Ki-67, MYC, MMP9 and P53, suggesting transcriptionally active oncogenic pathways. The tumor was diagnosed as an intermediate-grade mammary gland carcinoma. Case 2 was a 9-year-old male local breed dog with a prepubic cutaneous mass. Histological features included squamous epithelial nests with keratin pearls, dyskeratosis and necrosis- typical of well differentiated squamous cell carcinoma. IHC showed 10% Ki-67 positivity and 7% P53 expression, indicative of modest proliferation and limited tumor suppressor involvement. PCR confirmed neoplastic gene expression, but qPCR was not performed. The diagnosis was cutaneous squamous cell carcinoma. Case 3 involved a 1-year-old female cat with a recurrent mammary mass post-surgery. Histopathology revealed papillary and tubular epithelial patterns with low mitotic activity and focal necrosis. IHC results showed only 1% Ki-67 positivity and <1% P53 expression. PCR confirmed the presence of neoplastic markers, but qPCR was not feasible. Despite histological low-grade features, clinical recurrence and rapid progression suggested an aggressive course, possibly due to incomplete resection or multicentric origin and possibly a low grade feline mammary gland carcinoma. Case 4 concerned a 4-year-old male cat with a nasal bridge mass and facial swelling. Histology revealed infiltrative glandular structures with marked atypia and high mitotic activity. Stromal desmoplasia and subcutaneous invasion were also observed. IHC showed 30% Ki-67 positivity, indicating high proliferation, while P53 staining was minimal (<1%). PCR detected all targeted oncogenes. qPCR revealed high expression of Ki-67, MYC and BCL2; MMP9and P53 were also elevated, though less significantly. The diagnosis was high-grade nasal adenocarcinoma. Across all cases, Ki-67 levels strongly correlated with tumor grade. High-grade tumors (Case 4) showed elevated Ki-67 protein and mRNA expression, while low-grade tumors (Cases 2 and 3) showed minimal Ki-67 positivity. MYC expression was notably upregulated in all tumors, indicating its central role in oncogenesis across species. BCL2 was more prominent in feline tumors, particularly in the nasal adenocarcinoma, suggesting species-specific apoptotic regulation. MMP9 was elevated in canine cases, aligning with its known role in tissue invasion and remodeling. P53 expression varied, with discrepancies between IHC and qPCR in some cases (Case 1), potentially reflecting post-translational regulation or degradation. Hematological findings supported these pathological observations. All animals showed elevated erythrocyte sedimentation rates (ESR), indicating chronic inflammation. Lymphocytosis was evident in feline cases, possibly due to prolonged antigenic stimulation from neoplastic processes. Among the amplified genes, only BCL2 produced good-quality sequence data. Several SNPs were detected within the sequenced region of BCL2, with cats showing more variants than dogs. However, as only partial mRNA and CDS regions were obtained, full-length sequencing will be required to confirm and characterize these mutations. Sequencing of other genes (Ki67, MMP9, MYC, and P53) was not successful due to poor-quality reads. This study underscores the utility of a multimodal diagnostic approach in veterinary oncology. Histopathology provided tumor classification and grading; IHC enabled assessment of cell proliferation and tumor suppressor protein involvement; PCR/qPCR offered insights into gene expression and oncogenic activity. In conclusion, integrating histological, immunohistochemical and molecular diagnostics enhances the understanding and classification of tumors in companion animals. This approach supports more precise diagnosis, better prognostication and lays the groundwork for individualized therapeutic strategies. Future research should aim to validate these molecular markers in larger cohorts and further explore their potential in targeted veterinary cancer treatments.
HISTOPATHOLOGICAL AND MOLECULAR DETECTION OF SALMONELLOSIS IN POULTRY IN CHITTAGONG
(Chittagong Veterinary and Animal Sciences University, Khulshi-Chittagong-4225, Bangladesh, 2017-06) Mohajan, Prima
Salmonellosis is one of the most important bacterial diseases of poultry because it causes high economic loss due to mortality and reduced egg production in layer birds. Salmonella infection in poultry can occur in either acute or chronic form by the member of genus Salmonella under Enterobacteriaceae family. There are mainly two biovars of avian species (host) specific Salmonella enterica named Salmonella Gallinarum and Salmonella Pullorum which are responsible for fowl typhoid and pullorum disease respectively. The present study was undertaken with the aim to carry out pathological and molecular identification of Salmonella isolated from commercial chickens in Chittagong. For this purpose a cross sectional survey was done with the collection of 90 different samples from dead chickens (38 Layers, 37 Broilers and 15 Sonali) brought to the department of Pathology and Parasitology, Chittagong Veterinary and Animal Sciences University (CVASU) for postmortem examination. A preformed questionnaire was also used to record additional information such as production type, farm size, vaccination etc. All the postmortem samples were primarily inoculated into selenite cystine broth followed by streaking into XLD agar to determine typical colony characteristics of Salmonella. Out of 90 samples 16 (17.78%, 95% CI 10.5-27.3%) were found primarily positive on XLD agar based on colony morphology which was also tested by Polymerase Chain Reaction (PCR) using previously published primer to detect invA gene specific for Salmonella. After PCR, 13(14.44%) samples were found positive (95% CI 7.9-23.4%) with the amplicon size of 284bp in agarose gel electrophoresis. Additionally liver, lung, spleen, kidney and intestine were also collected and preserved in 10% buffered formalin for histopathological examination. Gross pathological changes observed during necropsy included misshapened ova, unabsorbed yolk sac in chicks, bronze colored liver, haemorrhages and necrotic foci in spleen and intestine. Histopathological investigation showed congestion and hemorrhages in lungs; coagulation necrosis and fatty change in liver; congestion and haemorrhage in kidney which was also associated with coagulation necrosis and fatty change in renal tubule in some cases. Marked destruction of intestinal epithelia with caseous mass in intestinal lumen was found along with haemorrhage and sloughed off villi. Depletion of lymphocytic nodule and lymphocytes along with vascular thickening in spleen was markedly observed in most of the cases. Necrosis, proliferation of Reticuloendothelial (RE) cells and presence of secondary follicles were also noticeable lesions in spleen. Univariable logistic regression was used to identify the effect of different variables on the estimated prevalence (14.44%) of Salmonella. Statistically significant difference (p<0.05) was observed in the prevalence of salmonellosis in different production type of chickens. Prevalence in layer (26%, OR=4) was significantly higher compared to broiler (8%, OR=1). The result of the present study indicates the importance of PCR as a rapid and reliable tool alongside conventional cultural techniques for screening Salmonella. The data of risk factor analysis in this study suggest the prevalence of Salmonella enterica is very high in commercial layers in Chittagong.
Histopathological examination and optimization of Multiplex PCR protocol for diagnosis of viral respiratory diseases in commercial poultry
(A thesis submitted in the partial fulfillment of the requirements for the degree of Master of Science (MS) in Pathology Department of Pathology and Parasitology Faculty of Veterinary Medicine Chittagong Veterinary and Animal Sciences University Khulshi, Chittagong-4225, Bangladesh, 2013-06) Pervin, Shahnaj
The present work was to optimize a multiplex PCR protocol for rapid and accurate diagnosis of avian respiratory viral diseases. Four sets of specific oligonucleotide primers were used in this study that amplified products of predicted sizes from each virus in the sRT-PCR as well as in the mPCR assays (1023, 320, 647, 149 bp for AIV, NDV, ILTV, and IBV respectively) with the use of 1% agarose gel electrophoresis for PCR amplified products. A total of 48 specimen samples included trachea, lungs, liver, spleen, proventriculus etc. were collected from different dead birds that were tentatively diagnosed as respiratory viral infection on the basis of anamnesis and postmortem lesions by the expert veterinary clinician. Samples were preserved in 10% buffered formalin for histopathological study and in 100% alcohol with -80oC refrizaration for molecular study like RNA/DNA extraction for PCR or RT-PCR. A questionnaire was used during the period from August 2013 to March 2014 to record additional information and history of the cases such as age and type of birds, litter type, vaccination history, farm category, sex, pathological lesions, histopathology etc. Out of 48 cases 35.42% was tentatively diagnosed as AI, 33.33% was ND and 12.25% was IB where visceral gout was most prominent lesion. No ILT was diagnosed tentatively through necropsy. Mixed infection is common in commercial chicken flock, among the cases 4.17% was diagnosed as AI+ND, 12.25% and 2.08% was diagnosed as AI/ ND and IB/ND respectively. Among 48 test samples both the PCR screening process a total of 33(68.75%) samples showed positive band in 1% agarose gel electrophoresis where 15(31.25%), 16(33.33%) and 2(4.16%) samples were found positive for AI, ND and IB respectively. No ILT was found in this screening. Among the diseases AI was diagnosed accurately in 70.58% cases through necropsy and 81.25% and 33.33% for ND and IB respectively. ILT was not diagnosed tentatively which was also proved by molecular diagnosis that indicates the 100% accuracy of the tentative diagnosis. Microscopically congestion and hemorrhage in trachea, lungs, liver and spleen were found commonly in most of the samples, in addition with exudates in trachea and hemorrhagic kidney with urate crystal in renal tubules in IB infected sample. Hemorrhage in proventriculus is also found in only AI and ND infected cases.
Histopathological Investigation of Selective Neoplasm Found in Dog and Cat
(Chattogram Veterinary and Animal Sciences University, Khulshi-Chattogram-4225, 2023-06) Dhar, Anamika
Histopathological investigation of tumor cells plays a pivotal role in the diagnosis, prognosis, and treatment of various neoplastic conditions in companion animals. This study aims to explore the diverse cellular characteristics of suspected tumor cases includes lipoma in a cat, and a case of lymphoma and mammary gland carcinoma in two individual dogs using histopathological examinations. The tissue samples were collected after the surgical removal of the tumors from the respective animals that were documented at the Shahedul Alam Quadary Teaching Veterinary Hospital (SAQTVH) in Chattogram and the Teaching and Training Pet Hospital and Research Center (TTPHRC) in Dhaka. Grossly a large nodular mass were palpated in intra-abdominal region in a 5 years old local spayed cat and laparotomy was performed at TTPHRC, revealed a yellow, soft, lobulated mass with an oily surface. Besides, a 1.2 years old male Rottweiler dog with an around 5 cm nodular mass in left submandibular region and a local 8 years old unspayed dog with enlarged masses in mammary gland region were admitted in SAQTVH and TTPHRC respectively for surgery. Histopathological examination revealed mature adipocytes with eccentrically placed nuclei and less mitotic figures that indicate benign form of neoplasm in the cat called lipoma. In the Rottweiler dog the tumor tissue showed large number of pleomorphic cells, anisokaryosis, uneven distribution of chromatin materials, increased amount of binucleated cells indicating increased mitotic figure and fibroblast which is characteristics figure of lymphoma. The neoplastic cells also present within the blood vessels suggestive of metastasis and poor prognosis. In mammary gland tumor the ductal epithelial cells were proliferated, resulting in the creation of finger-like projections that extend into the inner space (lumen) and presence of pleomorphic cells with metaplasia within the milk duct indicative of invasive ductal carcinoma in dog. In Bangladesh, very few studies have been conducted on tumor in companion animals. Therefore, it‘s essential to enhance our understanding of tumor biology and providing clinicians with valuable information to make perfect decisions in tumor management. Detailed investigation on the histopathology of abnormal cellular growth in this study will be helpful for diagnosis, prognosis and treatment of such cases in dogs and cats.
Identification of Antimicrobial Resistant (AMR) Gene in Salmonella sp isolated from Broiler Chicken at Chattogram Area
(A thesis submitted in the partial fulfilment of the requirements for the degree of Masters of Pathology Faculty of Veterinary Medicine Department of Pathology and Parasitology Chattogram Veterinary and Animal Sciences University Khulshi, Chattogram-4225, Bangladesh, 2022-12) Rahman, Md. Hafizar
Globally, antimicrobial resistance (AMR) is a public health concern, since antibiotics are among the most prescribed classes of drugs in humans and animals. Random use of antimicrobials in the poultry industry is considered as a contributing factor for AMR that can jeopardize human health through the potential dissemination of AMR pathogens. It is noteworthy that Salmonella is one of the bacterial groups considered to be of high priority in surveillance programs in the food chain and infectious diseases in poultry. Information on the circulation of Salmonella strains at the commercial poultry farm level is limited in many parts of the world. The present study aimed to determine the prevalence and stereotyping of Salmonella strains circulating in the broiler farm environment with their detailed AMR profiling. Pooled cloacal samples were collected randomly from commercial broiler farms in Chattogram district, Bangladesh. Then the standard bacteriological procedure was followed to isolate Salmonella sp, and identification was confirmed by the basis of morphology, cultural characters, and genus-specific polymerase chain reaction (PCR). After phenotypic characterization of the resistance profile against commonly used antibiotics by disc diffusion technique, all strains were screened by PCR for some selected resistance genes. Out of the 105 samples, Salmonella sp was isolated and identified from 8 samples. In antimicrobial sensitivity testing, 100% isolates showed resistance to ampicillin and amoxicillin, and 87.5% to gentamycin followed by tetracycline, and ciprofloxacin (75%), doxycycline (50%), Trimethoprim/Sulfamethoxazole, and Ceftriaxone (25%). The results of PCR assays revealed that all the eight isolates were carrying the tetA gene, the tetB and 16.67% the tetC gene. The prevalence of the isolates bearing the Sul-I gene, blaTEM, blaCTX-M were 100%, 87.5 %, and 50 %, respectively. The present study was conducted to find out the prevalence of poultry Salmonella in broiler chickens and to find out that there is a great risk to securing healthy poultry products due to the circulation of the multi drug resistant (MDR) Salmonella sp.
Isolation & molecular characterization of Campylobacter jejuni and virulent gene associated avian fecal Escherichia coli in broiler, Bangladesh Md. Sirazul
(Chattogram Veterinary and Animal Sciences University Chattogram-4225, Bangladesh, 2020-06) Md. Sirazul Islam, Md. Sirazul
The intestinal environment of broilers is a potential Campylobacter jejuni and avian fecal Escherichia coli (AFEC) reservoir. Understanding the intestinal microbiota in broilers and their subsequent human transmission is a key public health concern here, where C. jejuni and intestinal virulent associated gene (VAG) carriage E. coli are simultaneously studied in apparently healthy birds from broiler farms, live bird markets (LBMs) and supershops. In the period from June 2019 to February 2020, pooled cloacal samples were collected from broiler farms located in 6 districts of Bangladesh and pooled meat samples were collected from LBMs and super shops in Chattogram. Data on farm management, biosecurity, and hygiene practices were collected through a face-to-face interview during sampling using a structured questionnaire. To examine the occurrence of C. jejuni and VAG AFEC in broiler chickens, microbial culture and PCR-based methods were applied. Positive PCR amplicon was confirmed by gene sequencing and phylogenetic analysis was subsequently performed. To evaluate the risk factors, epidemiological data were analyzed using univariable logistic regression models followed by multivariable logistic regression. Among the 216 farms, 27 were positive to C. jejuni; thus, the farm level prevalence was estimated to be 12.5% (95% CI: 8.5%–17.7%). Remarkably, at LBMs and super shops, a higher prevalence of 27.08% (95% CI: 15.28%–41.84%; N=48) of C. jejuni was recorded in broiler meat. In risk factor analysis, downtime of less than 14 days, no separate footwear for shed entry, increased number of flock rotations per shed per year, and entry of more than 1 person to sheds were found to be significantly associated with C. jejuni infection. Phylogenetic analysis showed a close connection between C. jejuni strains isolated from Bangladesh and other strains isolated from humans, pigs and bats of India, South Africa and Grenada. VAGs AFEC was isolated from the apparently healthy chickens with a prevalence of 55.6% (95% CI: 48.7%–62.3%). Virulence Associated Genes; astA, iucD, iss, irp2 and cva/cvi were detected in a rate of 46.3%, 25.5%, 17.6%, 12.9% and 2.8%, respectively. Geographical locations and flock age of less than 21 days were significantly associated with the VAGs AFEC positive status in broilers. The results of this study showed a high level of microbial contamination of zoonotic importance and the presence of pathogenic bacteria in the intestine and meat of Bangladeshi broilers. Potential sources of contamination and anthropogenic factors associated with the alarming occurrence of C. jejuni and VAGs AFEC noted in this study would assist in developing interventions under the 'One Health' banner that includes chickens, humans and environmental perspectives to minimize the increasing risks of broiler-associated pathogens.
Isolation and molecular detection of enteric bacteria from neonatal calf in Chittagong
(A thesis submitted in the partial fulfillment of the requirements for the degree of Master of Science in Pathology Department of Pathology and Parasitology Faculty of Veterinary Medicine Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2016-12) Tofazzal, Md. Rakib
Calf mortality due to neonatal calf diarrhea is a major problem in cattle farming in Bangladesh where certain groups of bacteria play crucial role. The aim of the present study was to carry out pathological and molecular investigation on enterotoxigenic Escherichia coli (ETEC) and Salmonella typhimurium in neonatal calves. During the study, fecal samples were collected from 200 calves (less than 40 days of age) from a total of 64 dairy and beef farms located in Chittagong Metropolitan Area and Patiya Upazila of Chittagong. The study was conducted during June, 2015 to March, 2016 when 5 dead calves with a history of diarrheal illness were examined through necropsy for gross and histopathological screening. Alongside classical culture technique molecular diagnostic tools like Polymerase chain reaction (PCR) was employed to identify the pathogens including E. coli and Salmonella spp. Two separate primer pairs namely ECO and K99 were used during this study where ECO is indicative of E. coli, and K99 is indicative for Enterotoxigenic E. coli (ETEC) K99. Besides, Salmonella spp. was confirmed by InvA gene in PCR. Typh and 104 primers were also used to identify S. typhimurium and multidrug resistant S. typhimurium DT104, respectively. Results indicated 19 (9.5%) cases of ETEC K99 out of 200 isolates, whereas S. typhimurium was recovered from only 8 calves (4%) and S. typhimurium DT104 was recorded from 2 calves. None of the dead animals was found positive for S. typhimurium through PCR. Gross pathological changes observed during necropsy include watery intestinal contents with bad odor, mucus and blood (in two cases) with dilatation of intestinal lumen. Histopathological investigation of intestine showed villous atrophy in all five cases of dead calves. Thickening of intestinal epithelium, sloughing off epithelium, congestion in lamina propria, infiltration of reactive cells were the findings of diarrhea caused by ETEC K99. Two out of five dead calves were found positive for ETEC K99 and one was isolated for mixed infection with E. coli and rotavirus in confirmatory molecular identification. Statistically significant difference (p<0.05) were observed in the prevalence of E. coli and S. typhimurium collected from different locations and herd size. Highest prevalence of ETEC K99 and S. typhimurium were found in Bakalia (30.43%) and Chawkbazar (27.27%), respectively. Compared to female animals, male calves were mostly affected by both ETEC K99 (13.27%) and S. typhimurium (27.27%). Small farms having <10heads had highest prevalence of ETEC K99 (42.86%). But S. typhimurium occurred highest in medium sized farms (5.81%) having 21-50 heads. Multilevel univariable and multivariable logistic regression was used to evaluate the risk factors associated with both infections. E. coli was significantly affected by farm size (OR = 3.54, 95% CI: 1.02, 12.78), population density (OR = 1.02, 95% CI: 1.00, 1.05), age (OR = 5.51, 95% CI: 1.59, 19.04), coexistence of other animal species in same pen (OR = 3.24, 95% CI: 1.12, 9.34), suckling as feeding regime (OR = 5.07, 95% CI: 1.43, 17.16). Interestingly, level of dehydration showed inverse association with prevalence of ETEC K99. Infection with Salmonella spp. was found to be significantly affected by the source of drinking water supply (OR = 32.28, 95% CI: 5.76-180.94), status of antibiotic therapy (OR = 7.03, 95% CI: 1.30, 37.81) and recent introduction of new calf in the farm (OR = 0.09, 95% CI: 0.01, 0.90). The results of the present study indicate the importance of PCR as rapid, effective and reliable tool alongside conventional culture techniques for screening of ETEC and Salmonella spp. when confronted with cases of undifferentiated calf diarrhea. Moreover, identification of the risk factors associated with the spreading of bacteria causing diarrheal illness may be helpful towards developing suitable prevention and control strategies.
Lumpy skin disease outbreak in commercial cattle farms of Chattogram, Bangladesh
(Chattogram Veterinary and Animal Sciences University Chattogram-4225, Bangladesh, 2020-06) Hasib, F. M. Yasir
Lumpy Skin Disease (LSD) is an important viral disease capable of incurring significant economic loss in commercial livestock production. The disease is of major economic importance due to production losses resulting from severe emaciation, lowered milk production, abortion, secondary mastitis, loss of fertility, extensive damage to hides and a loss of draft from lameness. Moreover, death or culling of sick cattle impose indirect losses due to the cattle movement and trade restriction. In mid-2019, an outbreak of LSD was reported in cattle population from different parts of Bangladesh including Chattogram Division. During this study a cross-sectional survey was undertaken from August to December 2019 to investigate the prevalence and associated risk factors of LSD in cattle in Chattogram district. A total of 3327 cattle from 19 commercial farms were investigated for the LSD associated skin lesions and possible risk factors. A total of 120 skin biopsies were collected from the suspected animal for histopathological examination followed by molecular detection through PCR and DNA sequencing. Partial genome sequencing and phylogenetic analyses were also explored on selected specimens. It was revealed that demonstrated that the overall prevalence of LSD in the study population was 10% (95% confidence interval: 9.4 to 11%) where the highest farm level outbreak frequency was 63.33% and lowest 4.22%. Crossbred (OR=3.56) and female (OR=3.56) cattle showed significantly higher susceptibility to the disease compared to their counterparts. Introduction of new animals in any farms was found to be one of the most significant risk factors (OR=2.34) associated with the transmission of the disease. Notably all suspected skin biopsies were positive for LSD virus (LSDV) infection with granulomatous and pyogranulomatous dermatitis as revealed through histopathology. Phylogenetic analysis based on the inverted terminal repeat region of the LSDV genome suggested that the locally circulating strain was closely related to the strains isolated from Middle East and North African countries.
Molecular and Histopathological detection of Cryptosporidiosis in calves in Chittagong
(Chittagong Veterinary and Animal Sciences University, Khulshi-Chittagong-4225, Bangladesh, 2017-06) Parvez, Md. Anwar
Cryptosporidium is an intestinal protozoan parasite of livestock and human and cause cryptosporidiosis which is also a common disease of cattle especially neonatal calves. Cryptosporidiosis is commonly asymptomatic but sometimes associated with persistent diarrhea in calves. The aim of the present study was to carry out pathological and molecular investigation of cryptosporidium infection in calves. The study was conducted during June, 2015 to January, 2016. During the study period fecal sample were collected from 160 calves with less than 45 days age from a total of 50 dairy and beef farms located in Chittagong Metropolitan Area and Patiya Upazilla of Chittagong when 5 dead calves with a history of diarrheal illness were also examined for gross and histopathological examination. The fecal samples were first screened by modified ZiehlNeelsen (Z-N) staining technique for the detection of cryptosporidium oocysts under light microscope which is characterized by pink to bright red spherical bodies and later confirmed by polymerase chain reaction (PCR) using 18s rRNA gene. Z-N positive fecal samples were used for DNA extraction Cryptosporidium spp. was confirmed by amplifying 18srRNA gene primer. The positive samples yielded 580bp band with the use of 1% agarose gel electrophoresis for PCR amplified products. The overall prevalence of Cryptosporidiosis in crossbred calves was 9.37% (15/160) by Z-N techniques and 1.88% (3/160) by nested PCR amplification which is statistically significant (p<0.05). The prevalence of Cryptosporidium was also significantly higher in diarrhoeic calves (42.85%) than non diarrhoeic (7.9%) calves. During necropsy examination bad odors, bloody mucous membrane with fluid filled watery fecal contents were found in two dead calves. For histopathological examination tissue samples were collected from dead calves and preserved in 10% buffered formalin. After tissue processing and routine H&E staining of intestinal tissue section revealed atrophied villi and sloughing of mucosa with reactive cellular infiltration. It is evident that the prevalence of cryptosporidiosis in bovine calves in these areas is under diagnosed and the clinical status of infection was not potentially high. It can be concluded that Cryptosporidium spp. infection is prevalent in Bangladesh and adult cattle could serve as reservoirs for the zoonotic infection in humans.
Molecular identification of babesiosis in stray dog at Chittagong Metropolitan Area
(A thesis submitted in the partial fulfillment of the requirements for the degree of Master of Science in Parasitology Department of Pathology and Parasitological Faculty of Veterinary Medicine Chittagong Veterinary and Animal Sciences University Chittagong-4225, Bangladesh, 2014-12) E-Azam, Md. Nur
An epidemiological study of babesiosis in stray dogs was conducted at Chittagong Metropolitan area, Bangladesh, for six months. Blood samples of 130 stray dogs were collected from nine randomly selected locations along with the information of age and sex. Blood samples were initially examined by Giemsa's stained blood smear method. DNA was extracted from microscopy positive blood samples and Babesia spp were confirmed by amplifying 18S rRNA gene. The prevalence was determined 6.92% in microscopic technique and the percentages of PCR positive samples from the microscopy positive samples were 66.67% (6 out of 9). The highest prevalence of babesiosis was found in Alankar (16.67%) compared to other areas. Significantly higher frequency of babesiosis was found in adult dog than younger (p<0.05). Again, Babesia infection was common in male (11.94%) than female (1.59%) and were statistically significant (p<0.05). Furthermore, we sought to develop a seminested PCR to detect and differentiate Babesia gibsoni (Asia genotype), B. canis subsp. vogeli, B. canis subsp. canis and B. canis subsp. rossi DNA in canine blood samples. An outer primer pair was designed to amplify a 340 bp fragment of the 18S rRNA genes in the seminested primary reaction. Then specific internal primers were designed for B. gibsoni (Asian type) (BgibAsia-F) and B. canis subsp. canis (BCC-F) that were paired with the outer reverse primer in the seminested secondary reaction to amplify 185 bp and 198 bp respectively. Based on seminested PCR and sequencing of the PCR products, all parasitic isolates were identified as Babesia gibsoni (Asian type) and B. canis subsp. canis. These results recommended that Babesia gibsoni (Asian type) and B. canis subsp. canis parasites are widespread in stray dog in Chittagong Metropolitan area, Bangladesh. Further investigations are required to clarify the origin, distribution, vector and pathogenesis of these parasites tracking in dogs in Bangladesh.
Molecular Identification of Tick-Borne Pathogens from Tick Samples of Cattle in Bandarban District, Bangladesh
(Faculty of Veterinary Medicine Chattogram Veterinary and Animal Sciences University Chattogram – 4225, Bangladesh, 2024-06) Khatun, Mst. Mitu
The role of tick-borne pathogen transmission is exacerbated by international cattle trade, leading to significant economic losses through diseases like anaplasmosis, babesiosis, and theileriosis. These diseases hinder cattle health, growth, and production. A cross-sectional study was conducted in the Bandarban district of Bangladesh to identify tick-borne pathogens in cattle. The study aimed to morphologically identify ticks and molecularly identify tick-borne diseases from tick samples. Tick samples (130) were collected from three upazilas: 48 from Bandarban sadar, 44 from Lama, and 38 from Alikadam along with details on each cattle's age, sex, species, and physiological status. Morphological identification under a microscope revealed that Boophilus sp. and Haemaphysalis sp. had an overall prevalence of 92.31% and 7.69%, respectively. Tick infestations were more common in the summer (94.44%) compared to spring (87.5%). Adult cattle showed higher susceptibility to Haemaphysalis sp. (13.33%) compared to young cattle and calves (0%), while Boophilus sp. was more prevalent in young cattle and calves (100%) compared to adults (86.7%). Indigenous breed cattle were more prone to tick infestations (95%) than crossbred cattle (75%). The prevalence of Boophilus sp. was highest in Lama (33.85%), followed by Bandarban Sadar (33.08%) and Alikadam (25.38%). Haemaphysalis sp. was found only in Bandarban Sadar (3.85%) and Alikadam (3.85%). PCR testing of 20 pooled tick samples identified tick-borne pathogens, resulting in three Anaplasma marginale positive samples (one each from Bandarban Sadar, Lama, and Alikadam), one Babesia bigemina positive sample from Alikadam, and one Theileria annulata positive sample from Bandarban Sadar. Sequencing and phylogenetic analysis revealed the presence of Anaplasma marginale, Babesia bigemina, and Theileria annulata in cattle in the Bandarban district, with these pathogens being carried by ticks. The findings of this study are invaluable for veterinarians and cattle farmers in Bandarban, providing insights necessary to develop effective prevention and control measures against tick-borne infections..
Molecular Investigation of Cryptosporidium Spp. in Stray and Pet dog at Chittagong Metropolitan Area
(A thesis submitted in the partial fulfillment of the requirements for the degree of Master of Science (MS) in Pathology Department of Pathology and Parasitology Faculty of Veterinary Medicine Chittagong Veterinary and Animal Sciences University Khulshi, Chittagong-4225, Bangladesh, 2014-06) Islam, Md. Shafiqul
Cryptosporidium is a zoonotic pathogen composed of genetically distinct but morphologically identical genotypes. Recent molecular study indicates that dogs may transmit the cattle genotype, which is known to be pathogenic to humans. The aim of the present study was to evaluate the present condition of Cryptosporidium infection in stray and pet dogs at Chittagong metropolitan area in Bangladesh. One hundred and thirty (130) non diarrheic fecal samples obtained from 98 stray dogs and 32 pet dogs were investigated during the period from January 2014 to May 2014. Initial identification of Cryptosporidium spp. was carried out on stool samples by Ziehl-Neelsen (Z-N) acid fast staining method where Cryptosporidium oocysts were revealed as pink to bright red spherical or slightly ovoid bodies. DNA was extracted from Z-N positive fecal samples and Cryptosporidium spp. were confirmed by amplifying 18srRNA gene. The prevalence was determined to be 8.46% in Z-N techniques and 3.85% by nested PCR amplification of 18srRNA gene. Five fecal samples were found positive in PCR where one sample was found positive from pet dog. Four sets of specific oligonucleotide primers were used in this study that amplified products of predicted sizes for each gene in PCR assays [581, 550, 800, 448 bp for 18srRNA(nested), COWP, Gp60(nested) and HSP70 gene respectively] with the use of 1% agarose gel electrophoresis for PCR amplified products. C. parvum was found to be present in one isolates from stray dog which showed successful amplification of a specific DNA fragment at 550 bp with C. parvum outer wall protein (COWP) gene amplicon which may contain cattle genotype of zoonotic significance but it’s unclear up to further sequence study. There was no significant (p>0.05) difference in the prevalence between male and female stray and pet dogs. There was significant (p<0.05) prevalence in young in compared to adult stray dogs. Results indicate that PCR-based diagnostic methods are useful tool for the accurate diagnosis of Cryptosporidium infection in dogs. Significant raise (p<0.05) in lymphocytic and monocyte counts was found in Cryptosporidium infected dogs. This is the first investigation on the presence of C. parvum among stray dogs in Bangladesh based on COWP gene amplification and it has pointed to existence of a genotype that may play an important role as a source of human and farm animal cryptosporidiosis, although gene sequence of the positive isolates is needed for clear identity of the genotypes. The results of this research give an idea that stray dogs may act as reservoirs for zoonotic intestinal protozoan parasites and should be considered important to public health. So that, it is imperative for human to avoid fecal contamination in streets, public gardens and parks. Also stray dog population should be controlled by euthanasia or by performing neutering of male stray dog, specially in urban areas.
Occurrence of Eimeria spp. in neonatal calves in Chittagong metropolitan area
(Chittagong Veterinary and Animal Sciences University, Khulshi-Chittagong-4225, Bangladesh, 2017-06) Rafiul Hoque, Mohammad
Calf diarrhea is a major problem in cattle farming in Bangladesh where coccidiosis is common phenomenon. The specific objective of the present study was to determine the prevalence of coccidia infection in neonatal calves as well as to assess the risk factors associated with the infection. During the study, fecal samples were collected from 130 calves (less than 45 days of age) from a total of 39 dairy and beef farms located in Chittagong Metropolitan Area and Patiya Upazila of Chittagong. The study was conducted during June, 2015 to December, 2015. The prevalence of Eimeria spp. was found 20.77% in diarrheaic calves in the study area. 26% and 27% prevalence of Eimeria spp. was found considering age in calves between 2-4 weeks and > 4 weeks, respectively. Univariable and multivariable logistic regression models were used to evaluate the risk factors associated with Eimeria spp. infection. In univariable logistic regression analysis, 5 variables (age, flooring of calving pen, source of drinking water, fecal consistency and dehydration test) showed significant (P-value <0.2) association with the prevalence of Eimeria spp. In multivariable analysis, age and fecal consistency were found significantly (P-value <0.05) associated with presence of Eimeria spp. Calves with more than 4 weeks of age and calves with 2 to 4 weeks of age had odds ratio of 9.03 and 6.58, respectively compared to calves with less than 2 weeks of age. Calves with liquid (OR=4.5) and semi-solid (OR=1.4) fecal consistency had higher chance to get the infection compared to calves with solid feces. The results of the present study identified the risk factors associated with occurrence of Eimeria spp. causing diarrhea in neonatal calves will be helpful for developing suitable targeted control program in the study area.