Cardozo Marita Vedovelli, Liakopoulos Apostolos, Brouwer Michael, Kant Arie, Pizauro Lucas José Luduvério, Borzi Mariana Monezi, Mevius Dik, de Ávila Fernando Antonio
Department of Veterinary Pathology, Faculty of Agricultural and Veterinary Sciences, São Paulo State University (Unesp), Jaboticabal, Brazil.
Department of Bacteriology and Epidemiology, Wageningen Bioveterinary Research, Wageningen University and Research, Lelystad, Netherlands.
Front Microbiol. 2021 Jun 22;12:628738. doi: 10.3389/fmicb.2021.628738. eCollection 2021.
This study aimed to investigate the phylogenetic diversity and epidemiology of extended-spectrum beta-lactamase (ESBL)-producing and from chicken, chicken meat, and human clinical isolates in Sao Paolo, Brazil, and characterize their respective ESBL-encoding plasmids. Three hundred samples from chicken cloaca, chicken meat, and clinical isolates were phenotypically and genotypically assessed for ESBL resistance. Isolates were identified by MALDI TOF-MS and further characterized by MLST analysis and phylogenetic grouping. ESBL genes were characterized and their location was determined by I-Ceu-I-PFGE and Southern blot, conjugation, transformation, and PCR-based replicon typing experiments. Thirty-seven ESBL-producing isolates (28 and 9 ) that were positive for the or gene groups were obtained. Two isolates were negative in the transformation assay, and the chromosomal location of the genes was deduced by Southern blot. The genes identified were carried on plasmid replicon-types X1, HI2, N, FII-variants, I1 and R. The isolates belonged to nine sequence types, while the isolates belonged to four sequence types. The isolates belonged to phylotype classification groups A, B1, D, and F. This study demonstrated that isolates from cloacal swabs, chicken meat, and human feces had genetic diversity, with a high frequency of among chickens, chicken meat, and human feces. Thus, this reinforces the hypothesis that chickens, as well as their by-products, could be an important source of transmission for ESBL-producing pathogens to humans in South America.
本研究旨在调查巴西圣保罗鸡肉、鸡肉制品及人类临床分离株中产超广谱β-内酰胺酶（ESBL）细菌的系统发育多样性和流行病学特征，并对其各自的ESBL编码质粒进行表征。对来自鸡泄殖腔、鸡肉制品和临床分离株的300份样本进行了ESBL耐药性的表型和基因型评估。通过基质辅助激光解吸电离飞行时间质谱（MALDI TOF-MS）鉴定分离株，并通过多位点序列分型（MLST）分析和系统发育分组进一步表征。通过I-Ceu-I脉冲场凝胶电泳（PFGE）、Southern杂交、接合、转化和基于PCR的复制子分型实验对ESBL基因进行表征并确定其位置。获得了37株产ESBL的分离株（28株大肠杆菌和9株肺炎克雷伯菌），它们对blaCTX-M或blaSHV基因群呈阳性。有2株分离株在转化试验中呈阴性，通过Southern杂交推断基因的染色体位置。鉴定出的blaCTX-M基因携带在质粒复制子类型X1、HI2、N、FII变体、I1和R上。大肠杆菌分离株属于9种序列类型，而肺炎克雷伯菌分离株属于4种序列类型。大肠杆菌分离株属于系统发育分类组A、B1、D和F。本研究表明，来自泄殖腔拭子、鸡肉制品和人类粪便的分离株具有遗传多样性，在鸡、鸡肉制品和人类粪便中blaCTX-M的频率较高。因此，这强化了这样一种假设，即在南美洲，鸡及其副产品可能是产ESBL病原体传播给人类的重要来源。
