Sornplang Pairat, Aieamsaard Jareerat, Saksangawong Chuleeporn, Suayroop Naritsara
Division of Veterinary Public Health, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
Division of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
Vet World. 2022 Mar;15(3):543-550. doi: 10.14202/vetworld.2022.543-550. Epub 2022 Mar 9.
Human salmonellosis with non-typhoidal remains a global public health concern related to the consumption of contaminated eggs and egg-based products. This study aimed to examine the prevalence of , antimicrobial-resistant , and egg antibiotic residues concerning risk factors associated with contamination in eggs, the layer farming environment, and laying hens kept in battery-cage closed-housing systems.
This study used a repeated cross-sectional design to collect 488 samples from eggs, laying hens, and the farm environment on one laying farm for detection according to ISO 6579:2002/AMD 1:2007. -positive samples were further tested for serotype and antimicrobial susceptibility using the disk diffusion test. The layer farm contact person was interviewed at the sampling time to evaluate the risk factors associated with contamination using logistic regression analysis. For each month, 24 eggs (144 eggs in total) were also randomly sampled from the collection egg area at the farm for antibiotic residue detection using the European Four Plate Test.
The highest prevalence rates were in the samples from the layer pen floors, followed by the egg sizing machine (ESM) and eggshells at 65.5%, 52.5%, and 15%, respectively. serovar Corvallis was the dominant serovar (48.38%), followed by Mbandaka (37.76%), Braenderup (14.29%), and Typhimurium (4.08%). Rodent presence at the farm and the frequency of changing the disinfectant foot dip were significant factors related to contamination on the pen floors (odds ratio [OR]=22.5, 95% confidence interval [CI]=2.11-240.48, p=0.01; OR=24, 95% CI=2.78-206.96, p=0.004, respectively). Hand-washing before sorting and cleaning the ESM were the significant factors (OR=13, 95% CI=1.2-140.73, p=0.04). The most resistant isolates were resistant to oxytetracycline. One isolate of . Typhimurium was resistant to cefotaxime, enrofloxacin, and oxytetracycline. The antibiotic residues in the egg yolks were streptomycin, enrofloxacin, and tetracycline at prevalence rates of 36.11%, 11.81%, and 7.64%, respectively. Streptomycin was the most abundant residue in the albumen and yolk, followed by tetracycline.
prevalence in layer farming with a closed-housing system is related to effective biosecurity and hygiene issues, such as rodent control, clean farm equipment, and good worker hygiene. In addition, eggs' antibiotic residues may be related to treating antimicrobial-resistant isolates and medicated feed with inappropriate antibiotic withdrawal time.
非伤寒型人类沙门氏菌病仍是一个与食用受污染鸡蛋及蛋制品相关的全球公共卫生问题。本研究旨在检测鸡蛋、蛋鸡养殖环境以及层架式笼养封闭鸡舍系统中的蛋鸡体内沙门氏菌的流行情况、耐药性以及鸡蛋抗生素残留，并探究与鸡蛋污染相关的危险因素。
本研究采用重复横断面设计，根据ISO 6579:2002/AMD 1:2007标准，从一个蛋鸡养殖场的鸡蛋、蛋鸡和农场环境中采集488份样本进行沙门氏菌检测。沙门氏菌阳性样本进一步通过纸片扩散法检测血清型和药敏性。在采样时对蛋鸡养殖场联系人进行访谈，采用逻辑回归分析评估与沙门氏菌污染相关的危险因素。每月还从养殖场的集蛋区随机抽取24枚鸡蛋（共144枚），采用欧洲四板试验检测抗生素残留。
沙门氏菌检出率最高的样本来自层架式鸡舍地面，其次是鸡蛋分级机（ESM）和蛋壳，分别为65.5%、52.5%和15%。沙门氏菌血清型Corvallis是优势血清型（48.38%），其次是Mbandaka（37.76%）、Braenderup（14.29%）和鼠伤寒沙门氏菌（4.08%）。养殖场有啮齿动物以及更换消毒脚垫的频率是与鸡舍地面沙门氏菌污染相关的显著因素（比值比[OR]=22.5，95%置信区间[CI]=2.11 - 240.48，p = 0.01；OR = 24，95% CI = 2.78 - 206.96，p = 0.004）。在分拣和清洁ESM前洗手是显著因素（OR = 13，95% CI = 1.2 - 140.73，p = 0.04）。耐药性最强的沙门氏菌分离株对土霉素耐药。一株鼠伤寒沙门氏菌分离株对头孢噻肟、恩诺沙星和土霉素耐药。蛋黄中的抗生素残留为链霉素、恩诺沙星和四环素，检出率分别为36.11%、11.81%和7.64%。链霉素是蛋白和蛋黄中最常见的残留抗生素，其次是四环素。
封闭鸡舍系统的蛋鸡养殖中沙门氏菌的流行与有效的生物安全和卫生问题有关，如啮齿动物控制、清洁的农场设备和良好的工人卫生习惯。此外，鸡蛋中的抗生素残留可能与治疗耐药性沙门氏菌分离株以及使用停药期不当的药物饲料有关。
