Martínez-Álvarez Sandra, Sanz Susana, Olarte Carmen, Hidalgo-Sanz Raquel, Carvalho Isabel, Fernández-Fernández Rosa, Campaña-Burguet Allelen, Latorre-Fernández Javier, Zarazaga Myriam, Torres Carmen
Department of Agriculture and Food, University of La Rioja, 26006 Logroño, Spain.
Department of Veterinary Sciences, University of Trás-os-Montes-and Alto Douro, 5000-801 Vila Real, Portugal.
Antibiotics (Basel). 2022 Mar 25;11(4):444. doi: 10.3390/antibiotics11040444.
Antimicrobial resistance is an important One Health challenge that encompasses the human, animal, and environmental fields. A total of 111 Escherichia coli isolates previously recovered from manure (n = 57) and indoor air (n = 54) samples from a broiler farm were analyzed to determine their phenotypes and genotypes of antimicrobial resistance and integron characterization; in addition, plasmid replicon analysis and molecular typing were performed in extended-spectrum-beta-lactamase (ESBL) producer isolates. A multidrug-resistance phenotype was detected in 46.8% of the isolates, and the highest rates of resistance were found for ampicillin, trimethoprim−sulfamethoxazole, and tetracycline (>40%); moreover, 15 isolates (13.5%) showed susceptibility to all tested antibiotics. None of the isolates showed imipenem and/or cefoxitin resistance. Twenty-three of the one hundred and eleven E. coli isolates (20.7%) were ESBL producers and carried the blaSHV-12 gene; one of these isolates was recovered from the air, and the remaining 22 were from manure samples. Most of ESBL-positive isolates carried the cmlA (n = 23), tet(A) (n = 19), and aac(6′)-Ib-cr (n = 11) genes. The following genetic lineages were identified among the ESBL-producing isolates (sequence type-phylogroup-clonotype): ST770-E-CH116−552 (n = 12), ST117-B2-CH45−97 (n = 4), ST68-E-CH26−382/49 (n = 3), ST68-E-CH26−49 (n = 1), and ST10992-A/B1-CH11−23/41/580 (n = 4); the latter two were detected for the first time in the poultry sector. At least two plasmid replicon types were detected in the ESBL-producing E. coli isolates, with IncF, IncF1B, IncK, and IncHI1 being the most frequently found. The following antimicrobial resistance genes were identified among the non-ESBL-producing isolates (number of isolates): blaTEM (58), aac(6′)-Ib-cr (6), qnrS (2), aac(3)-II (2), cmlA (6), tet(A)/tet(B) (22), and sul1/2/3 (51). Four different gene-cassette arrays were detected in the variable region of class 1 (dfrA1-aadA1, dfrA12-aadA2, and dfrA12-orf-aadA2-cmlA) and class 2 integrons (sat2-aadA1-orfX). This work reveals the worrying presence of antimicrobial-resistant E. coli in the broiler farm environment, with ESBL-producing isolates of SHV-12 type being extensively disseminated.
抗菌药物耐药性是一项重要的“同一健康”挑战，涉及人类、动物和环境领域。对先前从一个肉鸡场的粪便（n = 57）和室内空气（n = 54）样本中分离出的111株大肠杆菌进行分析，以确定其抗菌药物耐药性的表型和基因型以及整合子特征；此外，对产超广谱β-内酰胺酶（ESBL）的分离株进行了质粒复制子分析和分子分型。在46.8%的分离株中检测到多重耐药表型，氨苄西林、甲氧苄啶-磺胺甲恶唑和四环素的耐药率最高（>40%）；此外，15株分离株（13.5%）对所有测试抗生素敏感。没有分离株显示对亚胺培南和/或头孢西丁耐药。111株大肠杆菌分离株中有23株（20.7%）是ESBL产生菌，携带blaSHV-12基因；其中1株分离自空气，其余22株来自粪便样本。大多数ESBL阳性分离株携带cmlA（n = 23）、tet(A)（n = 19）和aac(6′)-Ib-cr（n = 11）基因。在产ESBL的分离株中鉴定出以下遗传谱系（序列型-系统发育群-克隆型）：ST770-E-CH116−552（n = 12）、ST117-B2-CH45−97（n = 4）、ST68-E-CH26−382/49（n = 3）、ST68-E-CH26−49（n = 1）和ST10992-A/B1-CH11−23/41/580（n = 4）；后两种是在家禽领域首次检测到。在产ESBL的大肠杆菌分离株中检测到至少两种质粒复制子类型，其中IncF、IncF1B、IncK和IncHI1最为常见。在非产ESBL的分离株中鉴定出以下抗菌药物耐药基因（分离株数量）：blaTEM（58）、aac(6′)-Ib-cr（6）、qnrS（2）、aac(3)-II（2）、cmlA（6）、tet(A)/tet(B)（22）和sul1/2/3（51）。在1类（dfrA1-aadA1、dfrA12-aadA2和dfrA12-orf-aadA2-cmlA）和2类整合子（sat2-aadA1-orfX）的可变区检测到四种不同的基因盒阵列。这项工作揭示了肉鸡场环境中存在令人担忧的抗菌药物耐药大肠杆菌，其中产SHV-12型ESBL的分离株广泛传播。
