Extended-spectrum beta-lactamase (ESBL) production and biofilm formation are mechanisms employed by Escherichia coli to resist beta-lactam antibiotics. Thus, we aimed to examine antibiotic resistance associated with ESBL production and biofilm formation in E. coli isolates from swine farms in Southern Thailand. In total, 159 E. coli isolates were obtained, with 44 isolates identified as ESBL producers, originating from feces (18.87%) and wastewater (8.80%) samples. All ESBL-producing strains exhibited resistance to ampicillin (100%), followed by the cephalosporin group (97.73%) and tetracycline (84.09%). Multidrug resistance was observed in 17 isolates (38.63%). Among the isolates from feces samples, the bla_GES gene was the most prevalent, detected in 90% of the samples, followed by bla_CTX-M9 (86.67%) and bla_CTX-M1 (66.67%), respectively. In the bacteria isolated from wastewater, both bla_GES and bla_CTX-M9 genes were the predominant resistance genes, detected in 100% of the isolates, followed by bla_CTX-M1 (64.29%) and bla_TEM (50%), respectively. Strong biofilm formation was observed in 11 isolates (36.67%) from feces and 4 isolates (25.57%) from wastewater samples. Notably, nearly 100% of ESBL-producing strains isolated from feces tested positive for both pgaA and pgaC genes, which play a role in intracellular adhesion and biofilm production. These findings contribute to the understanding and potential control of ESBL-producing E. coli, and the dissemination of antibiotic resistance and biofilm-related genes in swine farms.

超广谱 β-内酰胺酶 (ESBL) 产生和生物膜形成是大肠杆菌抵抗 β-内酰胺抗生素的机制。因此，我们的目的是检查泰国南部养猪场大肠杆菌分离物中与 ESBL 产生和生物膜形成相关的抗生素耐药性。总共获得了 159 株大肠杆菌分离株，其中 44 株被确定为 ESBL 产生者，源自粪便（18.87%）和废水（8.80%）样品。所有产ESBL菌株均对氨苄西林耐药（100%），其次是头孢菌素组（97.73%）和四环素组（84.09%）。17株（38.63%）出现多重耐药。在粪便样本中分离的菌株中，bla _GES基因最为普遍，在 90% 的样本中检测到，其次是bla _CTX-M9 (86.67%) 和bla _CTX-M1 (66.67%)。在从废水中分离的细菌中，bla _GES和bla _CTX-M9基因都是主要的抗性基因，在 100% 的分离株中检测到，其次是bla _CTX-M1 (64.29%) 和bla _TEM (50%)。在粪便样品中的 11 株分离株 (36.67%) 和废水样品中的 4 株分离株 (25.57%) 中观察到强烈的生物膜形成。值得注意的是，从粪便中分离出的产 ESBL 菌株几乎 100% 的pgaA和pgaC基因检测呈阳性，这两个基因在细胞内粘附和生物膜产生中发挥作用。这些发现有助于了解和潜在控制产 ESBL大肠杆菌，以及抗生素抗性和生物膜相关基因在养猪场中的传播。