Nguyen Lam Thanh, Thuan Nguyen Khanh, Tam Nguyen Thu, Huyen Trang Chau Thi, Khanh Nguyen Phuc, Bich Tran Ngoc, Taniguchi Takahide, Hayashidani Hideki, Lien Khai Ly Thi
Department of Veterinary Medicine, College of Agriculture, Can Tho University, Campus II, 3/2 Street, Ninh Kieu District, Can Tho, Vietnam.
Division of Animal Life Science, Institute of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-Cho, Fuchu-Shi, Tokyo 183-8509, Japan.
Vet Med Int. 2021 Nov 11;2021:6504648. doi: 10.1155/2021/6504648. eCollection 2021.
Avian pathogenic (APEC) is the main causative agent of avian colibacillosis, which is an important systemic disease of profound economic and clinical consequences for the poultry industry worldwide. In this study, 975 strains were isolated from 2,169 samples collected from cloacal swabs of chickens, in-farm wild animals (ants, geckos, flies, and rats), and environment. The highest proportion of isolation was obtained from chicken cloacal swabs with 71.05% (95% confidence interval (CI) 66.69-75.05%) followed by the proportions of 38.15% (95% CI 35.41-40.97%) and 38.11% (95% CI 34.15-42.24%) from wild animals or environment, respectively. Distribution of O-antigen serotypes of the isolates, including O1, O2, O18, and O78, was determined by PCR. The most predominant serotype was O18 (10.56%) followed by O2 (9.44%), O1 (7.79%), and O78 (6.56%). Of note, serotype O18 was more likely distributed in the examined wild animals, especially in geckos. Polymorphic DNA fingerprints, generated by ERIC-PCR, of representative strains of each serotype revealed genetic heterogeneity of the examined and O18 was more divergent with 63 clusters formed from 66 isolates. Furthermore, several strains from different sample sources shared high DNA fingerprint relatedness, suggesting that there exists complex transmission of from chickens to wild animals and environment and vice versa in poultry husbandry settings. Although pathotypes of the examined were not determined in this study, our results provided important findings of epidemiological and genetic characteristics of in the Mekong Delta and highlighted the prerequisite of stricter biocontainment to reduce the prevalence and consequences of APEC in poultry production.
禽致病性大肠杆菌（APEC）是禽大肠杆菌病的主要病原体，禽大肠杆菌病是一种重要的全身性疾病，对全球家禽业造成深远的经济和临床影响。在本研究中，从2169份样本中分离出975株菌株，这些样本采集自鸡的泄殖腔拭子、农场中的野生动物（蚂蚁、壁虎、苍蝇和老鼠）以及环境。分离比例最高的是鸡泄殖腔拭子，为71.05%（95%置信区间（CI）66.69 - 75.05%），其次是野生动物或环境，比例分别为38.15%（95% CI 35.41 - 40.97%）和38.11%（95% CI 34.15 - 42.24%）。通过PCR确定分离株的O抗原血清型分布，包括O1、O2、O18和O78。最主要的血清型是O18（10.56%），其次是O2（9.44%）、O1（7.79%）和O78（6.56%）。值得注意的是，血清型O18更可能分布在所检测的野生动物中，尤其是壁虎。通过ERIC-PCR产生的各血清型代表性菌株的多态性DNA指纹图谱显示所检测菌株存在遗传异质性，并且O18差异更大，66株分离株形成了63个簇。此外，来自不同样本来源的几株菌株具有高度相关的DNA指纹图谱，这表明在家禽养殖环境中，禽致病性大肠杆菌存在从鸡到野生动物和环境以及反之亦然的复杂传播。尽管本研究未确定所检测菌株的致病型，但我们的结果提供了湄公河三角洲地区禽致病性大肠杆菌流行病学和遗传特征的重要发现，并强调了更严格生物安全措施以降低APEC在家禽生产中的流行率和影响的必要性。
