某蛋鸡养殖场沙门氏菌病的诊断及致病菌耐药元件的检测

Diagnosis of Salmonellosis from a Layer Farm and Detection of Drug-Resistant Elements in the Isolates

摘要: 目的：分析某养殖场蛋鸡死亡的原因，为疾病防控提供借鉴。方法：剖检病死鸡，结合病理变化和临床特征作出疑似诊断；从内脏组织分离致病菌，并对分离株的耐药元件进行PCR检测，为治疗提供借鉴。结果：病鸡呈现副伤寒样病变，如肝肿大出血，有坏死灶；肾肿大；心和肠黏膜有出血点；卵泡充血、变形、萎缩等；从病变组织中分离鉴定出4株肠炎沙门氏菌；分离株携带多种耐药基因(blaTEM、tetA、tetB等)与可移动遗传元件。结论：该场蛋鸡死亡的原因可能是因感染多重耐药性肠炎沙门氏菌引起的；致病菌携带多种耐药基因，可合理使用多粘菌素类药物进行疾病治疗；此外分离株携带多种可移动元件，易发生耐药性传播，应引起重视。

Abstract: Aim: The reasons for the death of laying hens in a farm were analyzed to provide information for disease prevention and control. Methods: The sick and dead chickens were necropsied, and the suspected diagnosis was made based on the pathological changes and clinical features. Pathogenic bacteria were isolated from the visceral tissues. Then, the drug resistance elements of the isolated strains were detected by PCR to provide support for the treatment. Results: In this case, the sick chickens showed paratyphoid like lesions, such as hepatomegaly, hemorrhage and necrosis; nephromegaly; bleeding spots in heart and intestinal mucosa; follicular congestion, deformation and atrophy; 4 suspected pathogenic bacteria were isolated from different internal organs and identified as Salmonella enteritidis. The isolates carried a variety of drug resistance genes (blaTEM, tetA, tetB, etc.) and mobile genetic elements. Conclusion: The death of this case was caused by the infection of multiple drug-resistant Salmonella enteritidis. Since the bacteria carry multiple drug- resistant genes, polymyxins can be used rationally for disease treatment. In addition, we should be paid attention to resistance transmission, because of the isolates carrying a variety of mobile genetic elements with high transmission properties.