Evaluation of the virulence of Mycobacteria intracellular in a guinea pig infection model
10.3969/j.issn.1002-2694.2024.00.182
- VernacularTitle:豚鼠感染模型评价胞内分枝杆菌毒力的研究
- Author:
Guang LI
1
;
Xing HE
;
Da XU
;
Zhen LI
;
Kun-peng LU
;
Ping WANG
;
Yu-zhen YUAN
;
Ma-chao LI
;
Hai-can LIU
;
Kang-lin WAN
Author Information
1. 岳阳职业技术学院,岳阳 414000;岳阳新华达制药有限公司,岳阳 414000
- Publication Type:Journal Article
- Keywords:
Mycobacteria intracellular;
guinea pig infection model;
virulence evaluation
- From:
Chinese Journal of Zoonoses
2024;40(12):1128-1133,1139
- CountryChina
- Language:Chinese
-
Abstract:
Mycobacterium intracellular CHPC 1.5701 strain was isolated from the sputum specimen of the patient.This study attempted to establish a guinea pig infection model to evaluate its virulence,so as to provide basic scientific basis for the prevention and treatment of Mycobacterium intracellular infection.Mycobacterium intracellular CHPC 1.5701 was cultured in 7H10 medium.The morphology of the colony changed from colorless to light yellow smooth colony,and the acid-fast staining was positive.Mycobacterium intracellular suspension was diluted with 0.9％sodium chloride solution to 1 × 1010 CFU/mL,1×109 CFU/mL,1 × 108 CFU/mL,1 × 107 CFU/mL and 1 × 106 CFU/mL,respectively.Healthy Hartly guinea pigs with negative skin test of pure protein derivatives of tuberculin were selected and randomly divided into 6 groups with 10 guinea pigs in each group,half male and half female.Guinea pigs in the ex-perimental group were divided into 5 groups,which were intra-peritoneally injected with 5 different concentrations of 1.0 mL suspension/guinea pig,and those in the control group were in-traperitoneally injected with 0.9％sodium chloride solution 1.0 mL suspension/guinea pig.The guinea pigs was then observed,weighed every week,dissected 5 weeks later,lung,spleen and liver tissues were taken,and the tissue lesions were analyzed by hematoxylin-eosin(HE)staining,and the bacteria load was detected by tissue homogenate culture in 7H10 medium.The results showed that Mycobacterium intracellular challenge test had no significant effect on body weight of male guinea pigs(P＞0.05),but could reduce body weight of female guinea pigs(P＜0.01).No pathological changes of organ tissues were ob-served in guinea pigs in the control group,while HE staining of lung,spleen and liver tissues of guinea pigs in challenge experi-mental groups showed alveolar wall alveolar epithelial hyperplasia,monocyte infiltration in liver and spleen,granulomatous in-flammation and other pathological changes,and the degree of pathological changes was related to the injection dose of Mycobac-terium intracellular.Mycobacteria intracellular could be isolated from tissue culture of some organs,among which the spleen had a large amount of bacteria.Intrabitoneal injection of Mycobacteria intracellular CHPC 1.5701 can affect the body weight of female guinea pigs and cause lung,liver and spleen infection of guinea pigs,but no caseous necrosis of guinea pigs was ob-served.Compared with the reported data of Mycobacterium tuberculosis virulence test,it is concluded that Mycobacterium in-tracellular has certain virulence to guinea pigs and belongs to low virulence and low pathogenicity bacteria...
