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    16S rRNA sequence based identification of pathogenic gut microbiota of Rohu Labeo rohita (Hamilton-Buchanan 1822) and Silver carp Hypophthalmichthys molitrix (Valenciennes 1844)
    (University of Dhaka, 2017-01-23) Punom, Nusrat Jahan
    Rohu (Labeo rohita) and Silver carp (Hypophthalmichthys molitrix), both are tropical, most common, popular and commercially important fish of Bangladesh where pathogenic gastrointestinal bacteria of these fish, indicates the acceptability or quality as a whole the economic status of these fish. Current study was, therefore, carried out to investigate and compare the gastrointestinal pathogenic bacteria of these economically important fish of Bangladesh. The experimental fishes were collected from three different fish markets of Dhaka metropolitan city viz. Nobabgonj Bazar, Palashi Bazar and Anando Bazar. In the present study, the gastrointestinal tract of experimental fishes were examined with three replicates. Homogenized samples were then used for bacteriological density enumeration using serial dilution and spread plate techniques with five selective media Luria agar (LA), Thiosulphate citrate bile salt sucrose agar (TCBS), Salmonella- Shigella agar (SS), Aeromonas agar, Mannitol Salt agar (MSA), Eosin Methylene Blue agar (EMB) plate to understand Total Bacterial Count (TBC), Total Vibrio like colony count, Total Salmonella- Shigella count, Total Aeromonas count, Total Staphylococcal count, Total coliform count. Besides conventional culture techniques, Biochemical as well as molecular techniques (16S rRNA sequencing) were performed for the purpose of isolation and identification of gut microbiota. The study was also investigated the antibiotic susceptibility of 14 antibiotics on selected isolates. On an average, TBC of Rohu samples was 5.27 ± 2.01× 107 cfu/g and in Silver carp was 3.02 ± 1.42 × 107 cfu/g; total Vibrio count from Rohu and Silver carp sample was 1.58 ± 3.51 × 106 cfu/g and 2.38 ± 3.63 × 103 cfu/g, respectively; total Salmonella and Shigella was 6.94 ± 7.15 × 106cfu/g from Rohu and 1.11 ± 0.97 × 106 cfu/g from Silver carp. In Rohu, total Aeromonas was 1.31 ± 1.06 × 107 cfu/g and in Silver carp was 6.09 ± 4.61 × 106 cfu/g; total Staphylococcal count was found 1.03 ± 0.52 × 107 cfu/g in Rohu and 5.48 ± 3.98 × 106 cfu/g in Silver carp. For Rohu sample, enteric bacteria with special reference to coliform count was 1.68 ± 0.981 × 107 cfu/g and for Silver carp was 1.39 ± 2.35 × 107 cfu/g. Bacterial density (TBC, Salmonella-Shigella and Staphylococcal count) showed significant difference between species but among markets no significant difference were observed. All types of load counts exceed the ICMSF acceptable limit. 18 different (9 isolates of Rohu and 9 isolates of Silver carp) colonies were selected based on morphology for biochemical identification tests. Among 18 isolates, 3 were gram positive. From Rohu sample, 2 Aeromonas sp. and Pseudomonas sp., 1 Vibrio sp., 1 Proteus sp., 1 Staphylococcus sp., 1 Enterobacter sp. and 1 Klebsiella sp. was provisionally identified. In Silver carp, 1 Vibrio sp., 1 Salmonella sp., 1 Pseudomonas sp., 1 Escherichia sp., 1 Klebsiella sp. and 2 Aeromonas sp. and Staphylococcus sp. were provisionally identified. 10 representative isolates, named as njp1, njp2, njp3, njp4, njp5, njp6, njp7, njp8, njp9 and njp10 were selected for sequencing by 16S rRNA gene and identified as Aeromonas hydrophila subsp. dhakensis, Proteus penneri , Pseudomonas plecoglossicida, Aeromonas caviae, Enterobacter sp., Pseudomonas aeruginosa, Aeromonas sp., Citrobacter freundii, Klebsiella pneumoniae subsp. rhinoscleromatis and Klebsiella pneumoniae subsp. rhinoscleromatis, respectively. Multiple sequence alignment was performed to find out the polymorphic sites among the sequenced strains with considering 1341 bp nucleotides where 1.49% dissimilarities were observed among the identified 3 Aeromonas sp. and 3.88% in 2 Pseudomonas sp.All of the 2 group (njp9 and njp10) were absolutely similar in all positions of the sequence to each other except in 3 positions (338, 361 and 1038) were polymorphic. Phylogenetic analysis also confirmed the taxonomic relations among the identified species. Finally, 6 different group of pathogenic gastrointestinal bacteria were identified by 16S rRNA sequencing whereas biochemical assay provisionally identified 9 different group of pathogenic bacteria. The present study also revealed that, all the isolates including reference strain (E. coli DH5α) were sensitive to Ciprofloxacin and resistant to Sulphamethoxazole. Findings of this study indicate the poor quality and unhygienic condition of the marketed fish which reflects the potential reservoir of pathogenic bacteria causing fish borne disease outbreaks.
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    A comparative analysis of bacterial flora and proximate composition of mud crab (Scylla serrata,Forsskal 1775) collected from different local markets of Dhaka city
    (University of Dhaka, 2015-01-18) Karim, Farhana
    The present study was carried out to investigate the presence of bacterial flora and proximate composition of mud crab (Scylla serrata) meat from the local markets (Mohakhali, Karwan bazar, Farmgate, Basabo and Agora super shop) of Dhaka city. The densities (cfu/g) of total bacterial count (TBC), total coliform (TC), fecal coliform (FC), total Salmonella spp. and Shigella spp. (SS), total E. coli, total Staphylococcusspp. and total Vibriospp. like colonies were counted. Moisture, ash, protein and lipid contents were also determined for the samples of each market. TC, FC, SS, E. coil, and Vibrio spp. were detected in most of the samples except the frozen ones from Agora super shop. The samples from Basabo and Karwan bazar had much higher bacterial load than the others. The highest TBC counts were observed in the samples from Karwan bazar (38.1 ± 1.20 x104cfu/g) and the lowest were from Agora super shop (4.48 ± 0.26 x104cfu/g). The total Vibriospp. counts were found only in two markets; Farmgate and Basabo. The total E. coli countsranged from 1.25± 0.02 x104cfu/gto 4.33± 0.56x104cfu/g. The Salmonella, Shigella (SS) counts variedbetween3.95± 0.28 x104cfu/g for Karwan bazarand 16.76±1.26x104cfu/g for Basabo.Total Staphylococcus spp. counts ranged between 14.4± 1.1 x104cfu/gand 20.01± 1.94 x104cfu/g for normal crab samples and 0.37±0.025x104cfu/g for frozen samples. A total of 47 isolates were recovered from the samples and 10 generawere identified asBacillus,Citrobacter,Alcaligens,Salmonella,Shigella,Vibrio,Escherichia,Klebsiella,Staphylococcus and Enterobacter. Nearly similar nutritional compositions were found in the live crab samples. Whereas,much lower moisture content with higher ash, protein and lipid contents were observed in frozen samples. The results of this study showed that the bacterial load was significantly higher in live crab samples than the frozen ones which arevery useful to evaluate the safety of mud crab for human consumption.Consumption of normal crabs from above mentioned markets can lead to food borne diseases of human, whether the frozen samples can be considered as much safer. This study also revealed that mud crabs can be an alternative source of protein (excluding the bacterial hazards) to the traditional protein sources as its protein content is high.
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    A comparative study of the seab pathogens of potato, sweet potato and sugar beet in Bangladesh
    (© University of Dhaka, 2025-04-27) Flora, Ashrafunnesa
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    A comparative study of values of the adolescent school girls and their teachers
    (© University of Dhaka, 2025-05-04) Quiah, Philomena
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    A comparative study on the contribution of treated and untreated tannery wastes on environment
    (Bangladesh J. Sci. Res., 2008-12) Shabnam, Sohana; Huq, S. M. Imamul; Rahman, Shafiqur
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    A comparative study on the effects of treated and untreated tannery wastes on plant growth
    (Bangladesh Journal of Scientific Research, 2009-12) Shabnam, Sohana; Huq, S. M. Imamul; Rahman, Shafiqur
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    A comparison of extraction methods to assess the available Ca and Mg in some Bangladesh Soil
    (Dacca University Studies, 1977) Anam, K.; Huq, S. M. Imamul; Ahmed, M.; Ahmed, N. U.
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    A pedogenic study of some soils from the Brahmaputra floodplain of Bangladesh
    (© University of Dhaka, 2025-05-06) Mazumder, Md. Aminur Rahman
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    A study of availability of soil nitrogen by various extractants
    (Bangladesh J. Sci. Res., 1989) Hossain, A. K. M. A.; Hoque, S.; Mandal, R.; Khan, T. H.
    Available nitrogen was determined using 11 extractants on 29 soils covering a wide range of physical and chemical properties. Assessment of 2M KCI (p H 7.0), IN NaCI, IN NaCI (pH 1.0), 2N NaCI, IN Na2S04 ( p H l .O ) , 0.5N NaHCOa ( pH 8.5 ), Morgan’s reagent, O.IN C a C h , 0.5N HCl, 0.7N HCI and 0.5N H2SO4 extractable nitrogen showed that the best efficiency was obtained by IN NaCI. IN NaCI and 2M KCI extractable nitrogen bear significant relationship with soil organic matter and total nitrogen were found to be dependent on the type of soil. Correlation study with nitrogen uptake by BR-4 rice reveals that 2M KCI is superior to IN NaCI and closely followed by IN NaCI. Compared to these two extractants both aerobic and anaerobic incubation methods produced less satisfactory results.
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    A study of depression in adults as related to some socio-economic factors
    (© University of Dhaka, 2025-05-05) Roy, Purabi
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    A study of slow-release N-carrters on rice
    (Journal of Bangladesh Academy of Sciences, 1987) Rashid, M. H.; Islam, A.; Ahmed, I. U.; Islam, M. S.; Mandal, R.
    A field experiment was carried out to monitor the relative efficiency of urea, urea formaldehyde (UF), sulphur coated urea (SCU) and isobutylidene diurea (IBDU) each at the rate of 40, 80 and 120 kg N/ha on growth, yield and chemical composition of rice grown during aman season. Application of nitrogen caused a significant increase in number of tillers, height and yields of straw and grain irrespective of the sources. Among the chemical composition (N, P, K, Ca and Mg) of straw and grain only N content was significantly improved. All these components increased with nitrogen rate. The effectiveness of the N-carriers in increasing the parameters followed the order: SCU> Urea> IB DU > UF. Percent recovery of added nitrogen generally decreased with increasing amount of nitrogen. SCU was found to be superior to conventional urea whereas IBDU and UF were inferior due to slow release of nitrogen. Anaerobic incubation of urea, UF, SCU and IBDU for 4 weeks caused a significant release of NH4-N from 59.9 to 78.2%. An initial rapid production of NH4-N was followed by a gradual release with time. More than 75% urea and SCU decomposed to NH4-N within 2 and 4 weeks respectively. UF was more resistant to decomposition as compared to SCU and IBDU. However, the trend of degradation was similar for all the compounds. Accumulation of a small quantity of NO3-N disappeared rapidly within 2 weeks time.
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    A study of some non-cognitive factors related to academic achievement of secondary school students
    (© University of Dhaka, 2025-05-05) Chowdhury, Mohammad Salim
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    A study on Nosocomial infections and its consequences
    (© University of Dhaka, 2025-05-04)
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    A STUDY ON THE EFFECT OF CONSTANT AND FLUCTUATING TEMPERATURES ON SOME ASPECTS OF BIOLOGY OF NILAPARVATA LUGENS (STAL) AND NEPHOTETTIX VLRSSCEMS (HORV
    (© University of Dhaka, 2025-09-01) KHATUN, JOBEDA
    ITilaparyata lup.SiQS (Stal) and Nephotettix vires cons (Horv ) are the two major rice pest in Bangladesh, Temperature response of these two species was studied in the laboratory. The f avourable range of temperature for preoviposition period was 30®C-l+0®C for both the species. The incubation and developmental period was found to be shortest at i+0®C. The maximum and minimum adult longevity ware at 2?®C and 1+0°C respectively. The maximum hatchability was observed at 30°C and minimum at 20®C in both the species. The maximum survival!ty from egg to adult stage was found in 30°C in 21. lumens and 2?®C in virescens. The duration of the larval periods were 30 days at 20°C in 2J. virescens and 31 days in £[• lunens at the same temperature. The egg viability was maximum in 25°C to 3°°C and minimum at 20®C, The time required for hatching of eggs of both the species was almost same. At 10 and b5°G the development of eggs and larvae did not occur. The time required for development of eggs and larvae was more at fluctuating temperature than the constant temperature
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    A study on two rubber producing soils of Chittagong
    (Bangladesh J. Soil Sci., 1978) Anam, K.; Huq, S. M. Imamul; Aziz, A.; Ahmed, M.
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    A survey of mental disorders in the hospitals and clinics of Bangladesh
    (© University of Dhaka, 2025-04-30) Shammi, Nadira