中国畜牧兽医 ›› 2026, Vol. 53 ›› Issue (1): 499-508.doi: 10.16431/j.cnki.1671-7236.2026.01.045

• 基础兽医 • 上一篇    下一篇

云南地区血清7型猪胸膜肺炎放线杆菌的分离鉴定及生物学特性分析

李富祥(), 宋建领, 李占鸿   

  1. 云南省畜牧兽医科学院,云南省热带亚热带动物病毒病重点实验室,昆明 650224
  • 收稿日期:2025-06-09 出版日期:2026-01-05 发布日期:2025-12-26
  • 通讯作者: 李富祥 E-mail:lfxkmkm@163.com
  • 基金资助:
    云南省创新引导与科技型企业培育计划(202304BI090001)

Isolation, Identification and Biological Characterization of Actinobacillus pleuropneumoniae Serotype 7 from Pigs in Yunnan

LI Fuxiang(), SONG Jianling, LI Zhanhong   

  1. Yunnan Tropical and Subtropical Animal Virus Diseases Laboratory,Yunnan Animal Science and Veterinary Institute,Kunming 650224,China
  • Received:2025-06-09 Online:2026-01-05 Published:2025-12-26
  • Contact: LI Fuxiang E-mail:lfxkmkm@163.com

摘要:

目的 研究云南地区猪源胸膜肺炎放线杆菌的生物学特性。 方法 从云南红河州某猪场患呼吸道疾病猪肺脏中分离细菌,采用生化试验、16S rDNA序列分析和PCR扩增鉴定分离菌,并分析分离菌的血清型、致病性、药物敏感性和耐药基因等生物学特性。 结果 从病猪肺脏样品中分离到1株革兰阴性小球杆菌,将其编号为YN240724。生化鉴定结果显示,分离菌分解葡萄糖、果糖、蔗糖、木糖和甘露醇产酸,氧化酶、尿素酶及硝酸盐还原试验呈阳性,其生化特性与胸膜肺炎放线杆菌(Actinobacillus pleuropneumoniae)参考株相同。16S rDNA基因序列分析结果显示,分离菌与胸膜肺炎放线杆菌模式菌株ATCC 27088T和其他胸膜肺炎放线杆菌参考株间的16S rDNA序列相似性分别为100%和99.6%~100%;分离菌株与全部胸膜肺炎放线杆菌参考株形成同一个进化分支;基于上述特征分离菌YN24074被鉴定为胸膜肺炎放线杆菌。血清型鉴定结果显示,该分离菌为胸膜肺炎放线杆菌血清7型。耐药基因检测结果显示,分离菌携带β-内酰胺内耐药基因blaCITblaTEM以及四环素类耐药基因tetM。药敏试验结果显示,分离菌对氨基糖苷类(庆大霉素和阿米卡星)、喹诺酮类(氧氟沙星)、酰胺醇类(氟苯尼考)、四环素类(四环素)、磺胺类(磺胺甲噁唑)以及头孢类(头孢噻肟和头孢呋辛)敏感,对青霉素类(青霉素、氨苄西林和哌拉西林)以及糖肽类(万古霉素)耐药。致病性试验结果显示,分离菌对小鼠的半数致死量(LD50)为7.5×104 CFU,致病性较强。 结论 本研究从云南地区分离获得1株猪源血清7型胸膜肺炎放线杆菌,其携带耐药基因blaCITblaTEMtetM,对多种抗菌药物表现耐药,致病性较强。试验结果可为云南地区猪场猪传染性胸膜肺炎的治疗和免疫防控提供重要参考。

关键词: 猪; 胸膜肺炎放线杆菌; 分离鉴定; 血清型; 致病性

Abstract:

Objective This experiment aimed to study the biological characteristics of Actinobacillus pleuropneumoniae from pigs in Yunnan. Method The bacteria was isolated from the lung of pigs suffering from respiratory diseases in a pig farm located at Honghe, Yunnan. The bacterial isolate was identified through biochemical tests, 16S rDNA sequence analysis and PCR amplification. The biological characteristics of the isolate, including serotypes, pathogenicity, drug sensitivity and resistance genes, were analyzed. Result A Gram-negative coccobacillus was isolated from the lung samples of the diseased pig and was numbered YN240724. The biochemical identification results showed that the isolate decomposed glucose, fructose, sucrose, xylose and mannitol to produce acid, and the oxidase, urease and nitrate reduction tests were positive. These biochemical characteristics were the same as those of the reference strain of Actinobacillus pleuropneumoniae. The results of the 16S rDNA gene sequence analysis showed that the 16S rDNA sequence similarity between the isolate and the type strain ATCC 27088T of Actinobacillus pleuropneumoniae and other reference strains of Actinobacilluspleuropneumoniae was 100% and 99.6%-100%, respectively. The isolate formed the same evolutionary branch with all the reference strains of Actinobacillus pleuropneumoniae. Based on these characteristics, the isolate YN24074 was identified as Actinobacillus pleuropneumoniae. The serotype identification results showed that the isolate was Actinobacillus pleuropneumoniae serotype 7. The results of the drug resistance gene detection showed that the isolate carried the β-lactam resistance genes blaCIT and blaTEM, as well as the tetracycline resistance gene tetM. The results of the antimicrobial susceptibility test showed that the isolate was sensitive to aminoglycosides (gentamicin and amikacin), quinolones (ofloxacin), chloramphenicols (florfenicol), tetracyclines (tetracycline), sulfonamides (sulfamethoxazole), and cephalosporins (cefotaxime and cefuroxime), but resistant to penicillins (penicillin, ampicillin and piperacillin) and glycopeptides (vancomycin). The pathogenicity test results showed that the median lethal dose (LD50) of the isolate for mice was 7.5×104 CFU, indicating a relatively strong pathogenicity. Conclusion In this study, a strain of porcine Actinobacillus pleuropneumoniae serotype 7 from Yunnan was isolated. This strain carried the resistance genes blaCITblaTEM and tetM, and showed resistance to various antibacterial agents, with strong pathogenicity. This test results could provide important references for the treatment and immunization prevention and control of porcine contagious pleuropneumonia in pig farms of Yunnan.

Key words: pigs; Actinobacillus pleuropneumoniae; isolation and identification; serotype; pathogenicity

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