Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciencesgrid.454840.9, Key Laboratory of Veterinary Biological Engineering and Technology, Ministry of Agriculture and Rural Affairs, Nanjing, China.
College of Agriculture, Engineering & Science, University of KwaZulu-Natalgrid.16463.36, Durban, South Africa.
Microbiol Spectr. 2022 Jun 29;10(3):e0249321. doi: 10.1128/spectrum.02493-21. Epub 2022 Apr 21.
Mycoplasma hyorhinis is a widespread pathogen in pig farms worldwide. Although the majority of -colonized pigs have no apparent clinical disease, the pathogen can induce diseases such as polyserositis, arthritis, and eustachitis in some cases. To explore the mechanisms for the occurrence of these diseases, we challenged 4 groups of Bama miniature pigs with isolated from pigs without clinical symptoms (non-clinical origin [NCO] strain) or with typical clinical symptoms (clinical origin [CO] strain) and investigated the impacts of different strains and inoculation routes (intranasal [IN], intravenous [IV] + intraperitoneal [IP], and IV+IP+IN) on disease induction. Another group of pigs was set as a negative control. Pigs inoculated with the CO strain through a combined intravenous and intraperitoneal (IV+IP) route showed a significant decrease in average daily weight gain (ADWG), serious joint swelling, and lameness compared with the pigs in the negative-control group. Furthermore, this group developed moderate-to-severe pericarditis, pleuritis, peritonitis, and arthritis, as well as high levels of IgG and IgM antibodies. Pigs inoculated IV+IP with the NCO strain developed less marked clinical, pathological changes and a weaker specific antibody response compared with the pigs inoculated with the CO strain. The challenging results of the NCO strain via different routes (IV+IP, IV+IP+IN, and IN) indicated that the combined route (IV+IP) induced the most serious disease compared to the other inoculation routes. Intranasal inoculation induced a smaller decrease in ADWG without obvious polyserositis or arthritis. These data suggest that differences in both strain virulence and inoculation route affect the consequences of infection. Mycoplasma hyorhinis is a widespread pathogen in pig farms worldwide. The mechanisms or conditions that lead to the occurrence of disease in -infected pigs are still unknown. The objective of this study was to evaluate the impact of differences in the virulence of strain and the inoculation route on the consequences of infection.
猪鼻支原体广泛存在于世界各地的养猪场。尽管大多数定植猪没有明显的临床疾病，但该病原体在某些情况下可引起多发性浆膜炎、关节炎和中耳炎等疾病。为了探讨这些疾病发生的机制，我们用从无临床症状（非临床起源[NCO]株）或有典型临床症状（临床起源[CO]株）的猪中分离的支原体对 4 组巴马小型猪进行了攻毒，并研究了不同菌株和接种途径（鼻内[IN]、静脉内[IV]+腹腔内[IP]和 IV+IP+IN）对疾病诱导的影响。另一组猪作为阴性对照。通过静脉内和腹腔内联合（IV+IP）途径接种 CO 株的猪与阴性对照组相比，平均日增重（ADWG）显著下降，关节严重肿胀和跛行。此外，该组出现了中等至重度的心包炎、胸膜炎、腹膜炎和关节炎，以及高水平的 IgG 和 IgM 抗体。与接种 CO 株的猪相比，接种 NCO 株通过 IV+IP 途径的猪临床和病理变化不那么明显，特异性抗体反应也较弱。通过不同途径（IV+IP、IV+IP+IN 和 IN）对 NCO 株进行攻毒的结果表明，与其他接种途径相比，联合途径（IV+IP）引起的疾病最为严重。鼻内接种导致 ADWG 下降较小，无明显多发性浆膜炎或关节炎。这些数据表明，菌株毒力和接种途径的差异影响了支原体感染的后果。猪鼻支原体是世界各地养猪场广泛存在的病原体。感染猪发生疾病的机制或条件尚不清楚。本研究的目的是评估菌株毒力和接种途径的差异对支原体感染后果的影响。
