The mycobacterial species distribution in acquired immunodeficiency syndrome patients in Guangzhou

Abstract

Objective To investigate the characteristics of mycobacteria species distribution in human immunodeficiency virus (HIV)-positive patients co-infected with mycobacteria in Guangzhou. Methods A total of 133 mycobacteria strains isolated from HIV-positive patients and 150 strains isolated from HIV-negative patients were included in this study. After DNA extraction of mycobacteria, mycobacteria species identification was performed by sequencing of multiple genes. Differences in the identified species were compared between patients with and without HIV infection and the correlation between CD4+ T cells level and the mycobacterial species distribution was analyzed. Chi-square test was used for statistical analysis. Results Of the 133 mycobacteria strains isolated from HIV-positive patients, 82 were identified as Mycobacterium tuberculosis complex (MTC). Fifty-one were identified as nontuberculous mycobacteria (NTM), of which the main species was Mycobacterium avium complex (MAC, 31/51). Of the 150 mycobacteria strains isolated from HIV-negative patients, 126 were identified as MTC and 24 as NTM, of which the main species was Mycobacterium abscessus (9/24). In patients with CD4+ T cell counts ≤100/μL, the positive rate of mycobacteria was 75.94%(101/133), 93.55%(29/31) of MAC and 85.00%(17/20) of other NTM. When the CD4+ T cell counts >100/μL, the positive rate for mycobacteria were all obviously decreased. Conclusions The proportion of NTM infection is higher in HIV-positive patients than HIV-negative patients in Guangzhou. Among HIV-positive patients, the most prevalent NTM species is MAC, while Mycobacterium abscessus is the most common species in HIV-negative patients. Mycobacterial infection in acquired immunodeficiency syndrome patients is closely associated with low CD4+ cells level. Key words: Acquired immunodeficiency syndrome; Mycobacterium tuberculosis complex; Nontuberculous mycobacteria