Assessment of microbial load in fecal sample of fat-tailed sheep with molecular characterization and antibiogram study

Abstract

This study was conducted to observe the microbial load in the rectal swab and in fecal samples of lamb and adult fat-tailed sheep with molecular characterization and antibiogram study of the identified isolates. The study was performed during the period from July, 2017 to December, 2017. A total of 32 samples were collected, of which 16 were from Dinajpur (8 rectal swab and 8 fecal samples) and 16 were from Nilphamari (8 rectal swab and 8 fecal samples). The organisms were isolated by using standard microbiological method. The result revealed that in case of total aerobic count, the microbial load was higher in Dinajpur (1.53×107 ±0.05 CFU) than that of in Nilphamari (1.46×107 ±0.06 CFU) and in case of total anaerobic count, it was also higher in Dinajpur (0.78×107 ±0.012CFU) than that of in Nilphamari (0.62×107 ±0.05). Among the thirty two samples, the prevalence of the isolates were, Escherichia coli 11 (34.37%), Salmonella spp 10 (31.25%), Klebsiella spp 7 (21.87%). and Clostridium spp 4 (12.5%). The bacteria were isolated by using different bacteriological culture media (MacConkey agar, EMB agar, SS agar, BGA agar, brain heart infusion agar, blood agar and Robertson’s cooked meat medium) and identified by different biochemical tests (catalase test, indole test, MR reaction, VP reaction, TSI test, citrate utilization test and MIU test). The bacteria were identified by using Gram’s staining technique and out of four isolates 3 isolates were found to be gram negative rods (Escherichia coli, Salmonella spp, Klebsiella spp.), while one was gram positive, small rod (Clostridium spp.). Among four (4) identified isolates, Klebsiella spp. was characterized by using molecular technique like PCR and electropherogram and it was characterized as Klebsiella pneumoniae. From the antibiogram study it was observed that Escherichia coli, Salmonella spp. and Klebsiella pneumoniae were highly susceptibile to Ofloxacin, while these isolates were individually susceptible to Flumequine, Cefixime and Vancomycin respectively. Colistin was susceptible to Escherichia coli and Klebsiella pneumoniae. Escherichia coli, Salmonella spp. and Klebsiella pneumoniae were resistant to Cefepime, Cefaclor, Tobramycin, Aztreonam and Vancomycin. Clostridium spp. exhibited high susceptibility to Colistin, Ciprofloxacin and Levofloxacin. Gentamycin and showed resistance to Nalidixic Acid, Co-Trimoxazole, Amoxycillin, Erythromycin, Cefalexin, Vancomycin, Cloxacillin and Penicillin. The study suggests that the proper dosing of the antibiotics and maintenance of hygiene should be established in all the farms of fat-tailed sheep in Bangladesh to inhibit the multi drug resistant bacteria to keep the sheep and the individuals directly involved with the rearing sheep safe from all the possible zoonotic diseases.