Department of Veterinary Microbiology, West Bengal University of Animal and Fishery Sciences, 37, K.B. Sarani, Belgachia, Kolkata, 700037, West Bengal, India.
Department of Microbiology, School of Life Science and Biotechnology, Adamas University, Kolkata, 700126, West Bengal, India.
Microb Pathog. 2022 Sep;170:105700. doi: 10.1016/j.micpath.2022.105700. Epub 2022 Aug 4.
The generation of antimicrobial-resistant bacteria largely depends on the use of antimicrobials not only in humans but also in pet animals and livestock. The present study was conducted to detect the occurrence of beta-lactamase and biofilm-producing- E.coli in healthy pet and backyard livestock. The study also intended on molecular docking experiments to confirm the nature of the catalytic mechanism in β-lactamase enzymes, encoded by the various bla genotypes and phylogenetic analysis to reveal clonal relationship of the animal origin E. coli isolates with human clinical strains. The rectal swabs were collected from healthy dogs (n = 254), cats (n = 108), sheep (n = 119) and goats (n = 143) in India. In total 247 (76.47%) E. coli strains were identified as ESBL producers. The possession of ESBL-producers was significantly more (p < 0.05) in pets than in the backyard livestock. Most of the strains possessed bla like clones. E. coli strains possessing bla, bla, bla and bla like clones, isolated from pets were not reported earlier. The study detected 56.65% of E. coli strains as moderate or strong biofilm producers possessing biofilm-associated genes (csgA, rcsA, rpoS, sdiA). ESBL-producing E. coli showed phenotypical resistance to tetracycline (93.1%), azithromycin (89.8%), ampicillin (84.2%), cefotaxime (80.9%), doxycycline (82.5%), co-trimoxazole (80.9%), ampicillin/cloxacillin (76.9%). The CTX-M variants obtained in this study were modelled by the SWISS-MODEL and verified. Ligand having minimum binding energy, show the highest affinity of β-lactamases for cefotaxime and cefpodoxime. The Gibbs free energy release for all 14 different complex ranges between -6.9 (CTX-M-15.2+cefpodoxime) to -5.3 (CTX-M-218+cefpodoxime) Kcal/mol. Phylogenetic analysis of the animal origin ESBL-E. coli strains revealed a partial clonal relationship with the clinical isolates of local human patients. The present study described the significant presence of biofilm and β-lactamase producing, multi-drug resistant E. coli in pet animals having public health importance.
耐抗生素细菌的产生在很大程度上取决于抗生素的使用，不仅在人类中，而且在宠物动物和牲畜中也是如此。本研究旨在检测健康宠物和后院牲畜中β-内酰胺酶和产生物膜大肠杆菌的发生情况。该研究还旨在进行分子对接实验，以确认不同 bla 基因型编码的β-内酰胺酶的催化机制的性质，并进行系统发育分析，以揭示动物源性大肠杆菌分离株与人类临床株之间的克隆关系。从印度的健康狗（n=254）、猫（n=108）、绵羊（n=119）和山羊（n=143）中采集直肠拭子。总共鉴定出 247（76.47%）株大肠杆菌为 ESBL 产生菌。宠物中 ESBL 产生菌的携带率明显更高（p<0.05）。大多数菌株携带 bla 样克隆。从宠物中分离出的携带 bla、bla、bla 和 bla 样克隆的大肠杆菌菌株以前没有报道过。该研究检测到 56.65%的大肠杆菌菌株为中度或强生物膜产生菌，具有生物膜相关基因（csgA、rcsA、rpoS、sdiA）。产 ESBL 的大肠杆菌对四环素（93.1%）、阿奇霉素（89.8%）、氨苄西林（84.2%）、头孢噻肟（80.9%）、强力霉素（82.5%）、复方新诺明（80.9%）和氨苄西林/氯唑西林（76.9%）表现出表型耐药性。本研究获得的 CTX-M 变体通过 SWISS-MODEL 进行建模并验证。具有最低结合能的配体显示β-内酰胺酶对头孢噻肟和头孢泊肟的亲和力最高。所有 14 种不同复合物的吉布斯自由能释放范围在-6.9（CTX-M-15.2+头孢泊肟）至-5.3（CTX-M-218+头孢泊肟）Kcal/mol。动物源性 ESBL-大肠杆菌菌株的系统发育分析显示与当地人类患者的临床分离株具有部分克隆关系。本研究描述了在具有公共卫生重要性的宠物动物中存在大量产生物膜和β-内酰胺酶、多药耐药的大肠杆菌。
