Detection of tetracycline resistance determinant tetA gene and antimicrobial resistance pattern in Escherichia coli isolates recovered from healthy layer chickens

Abstract

Aim:The aim was to study the occurrence of tetracycline resistance determinant tetA gene, and antibacterial resistance pattern in commensal Escherichia coli recovered from healthy non-clinical layer chickens. Materials and Methods:Twenty-four cloacal swabs were obtained from 15 flocks in five different layer farms located at around Namakkal, which is a place of high-intensity layer chicken rearing in south India. Identification of E. coli was carried out by performing cultural and biochemical tests. Antimicrobial resistance test was carried out using disc diffusion method. The polymerase chain reaction employing tetAC forward and tetAC reverse primers were carried out to detect tetA gene conferring resistance to tetracycline.Result: All the collected cloacal swabs yielded E. coli. Twenty-one isolates (88%) were resistant to tetracycline antibiotic in disc diffusion method. All the isolates showed resistance to more than six antibiotics, which implied existence of multidrug resistant microbiota in intestine of poultry. Only seven (29%) isolates showed the presence of tetA gene indicating the involvement of either other one or more efflux gene(s), namely tetB, tetC and tetD or ribosomal protection encoded by tetM, tetO, tetQ and tetS genes than tetA gene. Conclusion:Based on the presence of tetA gene among tetracycline-resistant bacteria in healthy non-clinical food-producing animals such as layer chickens, it can be significant in human medicine as tetA gene could easily be spread to other bacteria. This kind of phenomenon can be extrapolated in transfer of resistance for other antibacterial essential for treating bacterial infections in human. We conclude that preventing the spread of antimicrobial resistance through direct or indirect contact, consumed food/feed and through the environment is empirical in reduction of failures while treating bacterial infections.

Antibiogram of Escherichia coli Isolated from Avian Colibacillosis in Chitwan District of Nepal

“…Neupane et al (2005) reported no resistance against Amikacin in poultry isolates and 90% sensitive showed by Bist et al (2014). Result of sensitivity of Amikacin of this study is contrast to study of Priti and Satish (2014) and Balasubramaniam (2014) in which resistance of Amikacin was 88.33% and 71% respectively. Resistance against Amikacin was observed 10.68% in this study.…”

“…of Co-trimoxazole (sulphamethoxazole+trimethoprim) was found 86.40% and got similarities of finding of Balasubramaniam et al, (2014) 83%, Salehi and Bonab (2006) 80% and Bukhrosh and Hamdi (2013) 82.2 %. Haghighi and Peighambari (2005) also reported 94% resistance in COT which is also similar to this study.…”

Comparison of antibiotic resistant Escherichia coli obtained from drinking water sources in northern Tanzania: a cross-sectional study

“…AMR reduces the effectiveness of antibiotic treatment and thus leads to increased morbidity, mortality, and healthcare expenditures [8]. Commensal E. coli found in people and animals is considered a potential reservoir for AMR genes [9] and these genetic traits can be transferred to E. coli or to other bacteria found in people, animals, and in the environment [10]. Presumably, water sources contaminated with AMR bacteria is one contributing factor for the higher prevalence of antibiotic resistant bacteria from people living in low-income countries [11].…”

Antimicrobial resistance profile and prevalence of tetracycline resistance genes in Escherichia coli isolates from broiler chickens, northwestern Iran

“…Frequencies of tet(A) and tet(B) among E. coli isolates were 66% and 42%, respectively. A study conducted on E. coli isolated from healthy layer flocks in India showed that 88% of isolates were resistant to tetracycline and tet(A) was found in 29% of isolates (Balasubramaniam et al, 2014).…”

“…Previous studies have documented the presence of the tetracycline resistance genes tet(A) and tet(B) in tetracyclineresistant E. coli isolated from broiler and layer chickens (Zhang et al, 2012;Balasubramaniam et al, 2014). In Iran, poultry meat is the most widely produced and consumed meat protein source.…”