Maciel Jonas Fernandes, Matter Letícia Beatriz, Trindade Michele Martins, Camillo Giovana, Lovato Maristela, de Ávila Botton Sônia, Castagna de Vargas Agueda
Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria (UFSM), Prédio 44, Sala 5125, 97105-900, Av. Roraima, 1000, Santa Maria, Rio Grande do Sul, Brazil.
Departamento de Medicina Veterinária Preventiva, Centro de Ciências Rurais, Universidade Federal de Santa Maria (UFSM), Prédio 44, Sala 5125, 97105-900, Av. Roraima, 1000, Santa Maria, Rio Grande do Sul, Brazil; Departamento de Ciências da Saúde, Curso de Farmácia, Universidade Regional Integrada do Alto Uruguai e das Missões, campus Santo Ângelo, 98802-470, Rua Universidade das Missões, 464, Santo Ângelo, Rio Grande do Sul, Brazil.
Microb Pathog. 2017 Feb;103:119-122. doi: 10.1016/j.micpath.2016.12.020. Epub 2016 Dec 21.
In this study an avian colisepticemia outbreak was investigated. Two isolates from a chicken with colisepticemia were characterized for antimicrobial susceptibility and virulence factors profile. For this purpose 7 antimicrobial and 29 genes (fimH, hrlA/hek, iha, papC, sfa/focCD, tsh, mat, tia, gimB, ibeA, chuA, fyuA, ireA, iroN, irp2, iucD, sitD. chr., sitD. ep., iss, neuC, ompA, traT, astA, hlyA, sat, vat, pic, malX, cvi/cva) were tested. The outbreak happened in a hick chicken breeding located in the northwestern region of Rio Grande do Sul state in South of Brazil and caused 28.3% (102 deads of a total of 360 chickens) of mortality rate. Escherichia coli isolates obtained from the avian spleen and liver belong to the same phylogenetic group A and present resistance to all antimicrobials tested (ampicillin, tetracycline, gentamicin, neomycin, sulfa + trimethoprim, enrofloxacin, and norfloxacin). Both isolates harbor virulence factors related to adhesion (fimH, papC, mat), invasion (tia), iron acquisition system (iroN) and serum resistance (iss, ompA, traT), showing that these groups are important for Avian Pathogenic E. coli (APEC). However, they present different virulence profiles for some genes, whereas liver-isolate carries more hrlA/hek (adhesin), gimB (invasin), sitD ep. (iron acquisition system), sat (toxin) and hylA (toxin) genes, the spleen-isolate harbors fyuA (iron acquisition system) gene. Here, we highlight a coinfection by different strains of APEC in the same animal with colisepticemia, the great antimicrobial resistance of these bacterial isolates and the genetic traits that modulate the virulence for high mortality rate of chickens for human consumption.
在本研究中，对一场禽大肠杆菌败血症疫情进行了调查。从一只患有大肠杆菌败血症的鸡身上分离出两株菌株，对其进行了抗菌药敏性和毒力因子分析。为此，检测了7种抗菌药物和29个基因（fimH、hrlA/hek、iha、papC、sfa/focCD、tsh、mat、tia、gimB、ibeA、chuA、fyuA、ireA、iroN、irp2、iucD、sitD.chr.、sitD.ep.、iss、neuC、ompA、traT、astA、hlyA、sat、vat、pic、malX、cvi/cva）。该疫情发生在巴西南部南里奥格兰德州西北部的一个山鸡养殖场，死亡率为28.3%（360只鸡中死亡102只）。从禽脾脏和肝脏分离得到的大肠杆菌菌株属于同一系统发育群A，对所有检测的抗菌药物（氨苄青霉素、四环素、庆大霉素、新霉素、磺胺+甲氧苄啶、恩诺沙星和诺氟沙星）均具有抗性。两株分离株都含有与黏附（fimH、papC、mat）、侵袭（tia）、铁获取系统（iroN）和血清抗性（iss、ompA、traT）相关的毒力因子，表明这些菌群对禽致病性大肠杆菌（APEC）很重要。然而，它们在一些基因上呈现出不同的毒力谱，肝脏分离株携带更多的hrlA/hek（黏附素）、gimB（侵袭素）、sitD ep.（铁获取系统）、sat（毒素）和hylA（毒素）基因，脾脏分离株则含有fyuA（铁获取系统）基因。在此，我们强调了同一患有大肠杆菌败血症的动物体内存在不同菌株的APEC共感染情况、这些细菌分离株的高度抗菌耐药性以及调节毒力导致供人类食用鸡高死亡率的遗传特征。
