Urzúa-Encina Constanza, Fernández-Sanhueza Bastián, Pavez-Muñoz Erika, Ramírez-Toloza Galia, Lujan-Tomazic Mariela, Rodríguez Anabel Elisa, Alegría-Morán Raúl
Departamento de Medicina Preventiva Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santa Rosa 11735, La Pintana, Santiago 8820808, Chile.
Laboratorio Centralizado de Investigación Veterinaria, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santa Rosa 11735, La Pintana, Santiago 8820808, Chile.
Animals (Basel). 2023 Jul 28;13(15):2444. doi: 10.3390/ani13152444.
Backyard production systems (BPS) are distributed worldwide, rearing animals recognized as reservoirs of and Shiga toxin-producing (STEC), both zoonotic pathogens. The aim of this study was to characterize isolates of both pathogens obtained from animals raised in BPS from two central Chile regions. The presence of pathogens was determined by bacterial culture and confirmatory PCR for each sampled BPS, calculating positivity rates. Multivariate logistic regression was used to determine risk factors. Additionally, phenotypic antimicrobial resistance was determined. A positivity rate of 2.88% for and 14.39% for STEC was determined for the complete study region (Valparaíso and Metropolitana regions). Risk factor analysis suggests that the presence of ruminants (OR = 1.03; 95% CI = 1.002-1.075) increases the risk of STEC-positive BPS, and the presence of ruminants (OR = 1.05; 95% CI = 1.002-1.075) and the animal handlers being exclusively women (OR = 3.54; 95% CI = 1.029-12.193) increase the risk for /STEC positivity. Eighty percent of isolates were multidrug resistant, and all STEC were resistant to Cephalexin. This study evidences the circulation of multidrug-resistant zoonotic bacterial strains in animals kept in BPS and the presence of factors that modify the risk of BPS positivity for both pathogens.
后院生产系统（BPS）遍布全球，饲养着被认为是人畜共患病原体——肠出血性大肠杆菌（EHEC）和产志贺毒素大肠杆菌（STEC）宿主的动物。本研究的目的是对从智利中部两个地区的BPS饲养动物中分离得到的这两种病原体进行特征描述。通过细菌培养和针对每个采样BPS的验证性PCR来确定病原体的存在，并计算阳性率。采用多变量逻辑回归来确定风险因素。此外，还测定了表型抗菌药物耐药性。在整个研究区域（瓦尔帕莱索和首都大区），EHEC的阳性率为2.88%，STEC的阳性率为14.39%。风险因素分析表明，反刍动物的存在（比值比[OR]=1.03；95%置信区间[CI]=1.002 - 1.075）会增加STEC阳性BPS的风险，而反刍动物的存在（OR = 1.05；95% CI = 1.002 - 1.075）以及动物饲养员全部为女性（OR = 3.54；95% CI = 1.029 - 1十二条193）会增加EHEC/STEC阳性的风险。80%的EHEC分离株具有多重耐药性，所有STEC对头孢氨苄耐药。本研究证明了在BPS饲养动物中存在多重耐药的人畜共患病细菌菌株，以及存在改变两种病原体BPS阳性风险的因素。
