Molecular characterization and antimicrobial resistance patterns of spp. and Escherichia coli of laying chicken

Abstract

Multidrug resistant (MDR) Gram-negative bacteria are the most common causes of diseases in commercial poultry, and antibiotic resistance of these organisms is often plasmid mediated. In Bangladesh such types of data are very much scarce. In this study, the antibiogram profile of Salmonella spp and E. coli isolates from 20 either clinically affected or dead laying chicken obtained from 10 commercial layer farms was performed. And MDR pattern was determined by using 7 common antimicrobials followed by isolation of plasmids to correlate between plasmids and drug resistance. Of these tested samples, 70-100% of both Salmonella Spp and E. coli were resistant to β-lactam antibiotics (ampicillin, amoxicillin, and penicillin) cephalexin and cotrimoxazole while 60-90% isolates of both species were susceptible to both ciprofloxacin and gentamicin. Isolates of both Salmonella spp and E. coli contain plasmids above 10 kbp size which might contain MDR genes. This is the first report on the characterization of plasmids found in both Salmonella spp and E. coli isolates obtained from a significant number of commercial layer farms (N=10) in Chittagong District, Bangladesh. The gathered information furthers our understanding of the mechanisms of drug resistance in specific region related to other parts of the country and world. The large plasmids might be potential factors for dissemination of antibiotic resistance genes regionally.

Antimicrobial resistance situation in animal health of Bangladesh

“…All E. coli isolates from apparently healthy broilers of LBMs in Chattogram city carried bla TEM , tet A, and Sul 2 multidrug-resistant genes. Likewise, MDR E. coli was also reported in layer chickens with resistance against the same type of antibiotics as in broiler from different areas of Bangladesh [ 8 , 29 ]. Ubiquitous dissemination of MDR E. coli with resistance against tetracycline (100%), fluoroquinolone (85%), sulfamethoxazole-trimethoprim (85%), aminoglycosides (71%), and nitrofurantoin (21%) was identified in backyard poultry of Bangladesh.…”

“…Multidrug-resistant (MDR) Salmonella species were reported from various types of birds reared in different farming systems. Day-old chicks, dead, sick, and even apparently healthy layer birds harbored MDR Salmonella with resistance against penicillin-G (90-100%), ampicillin (100%), amoxicillin (98-100%), tetracycline (93%), nitrofurantoin (78%), sulfamethoxazole (60%), gentamycin (46%), and ciprofloxacin (20-40%) [ 8 , 36 , 38 , 40 ]. MDR Salmonella spp.…”

“…A total of eight ABR bacterial species were reported in layer, broiler, backyard poultry, ducks, pigeons, and quails in nine different districts of Bangladesh (Table-1) [8,15,16,22,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44]. ABR Escherichia coli was identified in different types of birds from both conventional and unconventional farming systems in different areas of Bangladesh.…”

“…Rising demand for animal-source nutrition in LMICs is working as driving force for shifting of the small-scale animal farming systems to intensive, large-scale, and specialized commercialization. Non-therapeutic use of antimicrobials for prevention and control of disease or as antimicrobial growth promoters (AGP) are common practices in intensive farm-animal production systems [ 8 ]. Use of AGPs at subtherapeutic doses in farm animals exerts selective pressure on circulating beneficial or commensal bacteria which ultimately accelerates the development of AMR [ 9 ].…”

“…The Department of Livestock Services (DLS), Government of Bangladesh is the mandated body to formulate and execute a surveillance program on AMR and implement NAP strategies in the animal health sector of the country. Although the patterns and extent of AMR development in the animal-borne pathogens of Bangladesh have been reported in some studies [ 8 , 18 , 19 , 21 , 22 ], DLS has not yet looked deep into the matter. Before launching an AMR surveillance program in animal health sector of Bangladesh, it is utmost necessary to understand the knowledge gaps by analyzing nature and extent of the problem.…”