Pavez-Muñoz Erika, González Camilo, Fernández-Sanhueza Bastián, Sánchez Fernando, Escobar Beatriz, Ramos Romina, Fuenzalida Verónica, Galarce Nicolás, Arriagada Gabriel, Neira Víctor, Muñoz-Aguayo Jeannette, Flores-Figueroa Cristian, Johnson Timothy J, Alegría-Morán Raúl
Departamento de Medicina Preventiva Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile.
Instituto de Ciencias Agroalimentarias, Animales y Ambientales-ICA3, Universidad de O'Higgins, Rancagua, Chile.
Front Vet Sci. 2021 Jan 15;7:595149. doi: 10.3389/fvets.2020.595149. eCollection 2020.
Shiga toxin-producing (STEC) is a zoonotic pathogen and important cause of foodborne disease worldwide. Many animal species in backyard production systems (BPS) harbor STEC, systems characterized by low biosecurity and technification. No information is reported on STEC circulation, antimicrobial resistance (AMR) and potential drivers of antimicrobial usage in Chilean BPS, increasing the risk of maintenance and transmission of zoonotic pathogens and AMR generation. Thus, the aim of this study was to characterize phenotypic and genotypic AMR and to study the epidemiology of STEC isolated in BPS from Metropolitana region, Chile. A total of 85 BPS were sampled. Minimal inhibitory concentration and whole genome sequencing was assessed in 10 STEC strain isolated from BPS. All strains were cephalexin-resistant (100%, = 10), and five strains were resistant to chloramphenicol (50%). The most frequent serotype was O113:H21 (40%), followed by O76:H19 (40%), O91:H14 (10%), and O130:H11 (10%). The 1 type was detected in all isolated strains, while 2 was only detected in two strains. The Stx subtype most frequently detected was 1c (80%), followed by 1a (20%), 2b (10%), and 2d (10%). All strains harbored chromosomal . Principal component analysis shows that BPS size, number of cattle, pet and horse, and elevation act as driver of antimicrobial usage. Logistic multivariable regression shows that recognition of diseases in animals ( = 0.038; OR = 9.382; 95% CI: 1.138-77.345), neighboring poultry and/or swine BPS ( = 0.006; OR = 10.564; 95% CI: 1.996-55.894), visit of Veterinary Officials ( = 0.010; OR = 76.178; 95% CI: 2.860-2029.315) and close contact between animal species in the BPS ( = 0.021; OR = 9.030; 95% CI: 1.385-58.888) increase significantly the risk of antimicrobial use in BPS. This is the first evidence of STEC strains circulating in BPS in Chile, exhibiting phenotypic AMR, representing a threat for animal and public health. Additionally, we identified factors acting as drivers for antimicrobial usage in BPS, highlighting the importance of integration of these populations into surveillance and education programs to tackle the potential development of antimicrobial resistance and therefore the risk for ecosystemic health.
产志贺毒素大肠杆菌（STEC）是一种人畜共患病原体，也是全球食源性疾病的重要病因。后院养殖系统（BPS）中的许多动物物种都携带STEC，该系统的特点是生物安全性和技术化程度低。目前尚无关于智利BPS中STEC传播、抗菌药物耐药性（AMR）以及抗菌药物使用潜在驱动因素的报道，这增加了人畜共患病原体维持和传播以及AMR产生的风险。因此，本研究的目的是对AMR的表型和基因型进行特征分析，并研究从智利首都大区BPS分离出的STEC的流行病学。总共对85个BPS进行了采样。对从BPS分离出的10株STEC菌株进行了最低抑菌浓度和全基因组测序评估。所有菌株均对头孢氨苄耐药（100%，n = 10），5株对氯霉素耐药（50%）。最常见的血清型是O113:H21（40%），其次是O76:H19（40%）、O91:H14（10%）和O130:H11（10%）。在所有分离菌株中均检测到1型，而2型仅在两株菌株中检测到。最常检测到的Stx亚型是1c（80%），其次是1a（20%）、2b（10%）和2d（10%）。所有菌株都携带染色体……主成分分析表明，BPS规模、牛、宠物和马的数量以及海拔是抗菌药物使用的驱动因素。逻辑多变量回归表明，动物疾病的识别（P = 0.038；OR = 9.382；95% CI：1.138 - 77.345）、邻近的家禽和/或猪BPS（P = 0.006；OR = 10.564；95% CI：1.996 - 55.894）、兽医官员的来访（P = 0.010；OR = 76.178；95% CI：2.860 - 2029.315）以及BPS中动物物种之间的密切接触（P = 0.021；OR = 9.030；95% CI：1.385 - 58.888）会显著增加BPS中抗菌药物使用的风险。这是智利BPS中存在STEC菌株传播的首个证据，这些菌株表现出表型AMR，对动物和公众健康构成威胁。此外，我们确定了BPS中抗菌药物使用的驱动因素，强调了将这些群体纳入监测和教育计划以应对抗菌药物耐药性潜在发展从而降低生态系统健康风险的重要性。
