Virulence of Mycobacterium intracellulare clinical strains in a mouse model of lung infection - role of neutrophilic inflammation in disease severity.
BMC Microbiol
; 23(1): 94, 2023 04 03.
Article
em En
| MEDLINE
| ID: mdl-37009882
ABSTRACT
BACKGROUND:
Mycobacterium intracellulare is a major etiological agent of Mycobacterium avium-intracellulare pulmonary disease (MAC-PD). However, the characteristics of the virulence of M. intracellulare and the in vivo chemotherapeutic efficacy remain unclear. In this study, we examined the virulence of nine M. intracellulare strains with different clinical phenotypes and genotypes in C57BL/6 mice.RESULTS:
We classified three types of virulence phenotypes (high, intermediate, and low) based on the kinetics of the bacterial load, histological lung inflammation, and neutrophilic infiltration. High virulence strains showed more severe neutrophilic infiltration in the lungs than intermediate and low virulence strains, with 6.27-fold and 11.0-fold differences of the average percentage of neutrophils in bronchoalveolar lavage fluid, respectively. In particular, the high virulence strain M.i.198 showed the highest mortality in mice, which corresponded to the rapid progression of clinical disease. In mice infected with the drug-sensitive high virulence strain M019, clarithromycin-containing chemotherapy showed the highest efficacy. Monotherapy with rifampicin exacerbated lung inflammation with increased lymphocytic and neutrophilic infiltration into the lungs.CONCLUSIONS:
The virulence phenotypes of clinical strains of M. intracellulare were diverse, with high virulence strains being associated with neutrophilic infiltration and disease progression in infected mice. These high virulence strains were proposed as a useful subject for in vivo chemotherapeutic experiments.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pneumonia
/
Infecção por Mycobacterium avium-intracellulare
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article