Mycobacterium avium complex (MAC) infection causes disseminated disease in immunocompromised hosts, such as human immunodeficiency virus (HIV)-positive patients, and pulmonary disease in persons without systemic immunosuppression, which has been increasing in many countries. In Japan, the incidence of pulmonary MAC disease caused by M. avium is about 7 times higher than that caused by M. intracellulare. To explore the bacterial factors that affect the pathological state of MAC disease caused by M. avium, we determined the complete genome sequence of the previously unreported M. avium subsp. hominissuis strain TH135 isolated from a HIV-negative patient with pulmonary MAC disease and compared it with the known genomic sequence of M. avium strain 104 derived from an acquired immunodeficiency syndrome patient with MAC disease. The genome of strain TH135 consists of a 4,951,217-bp circular chromosome with 4,636 coding sequences. Comparative analysis revealed that 4,012 genes are shared between the two strains, and strains TH135 and 104 have 624 and 1,108 unique genes, respectively. Many strain-specific regions including virulence-associated genes were found in genomes of both strains, and except for some regions, the G+C content in the specific regions was low compared with the mean G+C content of the corresponding chromosome. Screening of clinical isolates for genes located in the strain-specific regions revealed that the detection rates of strain TH135-specific genes were relatively high in specimens isolated from pulmonary MAC disease patients, while, those of strain 104-specific genes were relatively high in those from HIV-positive patients. Collectively, M. avium strains that cause pulmonary and disseminated disease possess genetically distinct features, and it suggests that the acquisition of specific genes during strain evolution has played an important role in the pathological manifestations of MAC disease.
Substituted phenylazo and phenylazoxy compounds were systematically prepared and their anti-androgenic activity was measured in terms of (1) the growth-inhibiting effect on an androgen-dependent cell line, SC-3, and (2) the binding affinity to nuclear androgen receptor. Generally, azo/azoxy compounds showed cell toxicity, and the growth-inhibiting effects on SC-3 cells correlated with the toxicity. However, some compounds, including 4,4'-dinitroazobenzene (25), 4,4'-dimethoxyazobenzene (33), and 2,2'-dichloroazoxybenzene (47), possessed potent anti-androgenic activity without apparent cell toxicity.
Mycobacterium avium complex (MAC) causes mainly two types of disease. The first is disseminated disease in immunocompromised hosts, such as individuals infected by human immunodeficiency virus (HIV). The second is pulmonary disease in individuals without systemic immunosuppression, and the incidence of this type is increasing worldwide. M. avium subsp. hominissuis, a component of MAC, causes infection in pigs as well as in humans. Many aspects of the different modes of M. avium infection and its host specificity remain unclear. Here, we report the characteristics and complete sequence of a novel plasmid, designated pMAH135, derived from M. avium strain TH135 in an HIV-negative patient with pulmonary MAC disease. The pMAH135 plasmid consists of 194,711 nucleotides with an average G + C content of 66.5% and encodes 164 coding sequences (CDSs). This plasmid was unique in terms of its homology to other mycobacterial plasmids. Interestingly, it contains CDSs with sequence homology to mycobactin biosynthesis proteins and type VII secretion system-related proteins, which are involved in the pathogenicity of mycobacteria. It also contains putative conserved domains of the multidrug efflux transporter. Screening of isolates from humans and pigs for genes located on pMAH135 revealed that the detection rate of these genes was higher in clinical isolates from pulmonary MAC disease patients than in those from HIV-positive patients, whereas the genes were almost entirely absent in isolates from pigs. Moreover, variable number tandem repeats typing analysis showed that isolates carrying pMAH135 genes are grouped in a specific cluster. Collectively, the pMAH135 plasmid contains genes associated with M. avium’s pathogenicity and resistance to antimicrobial agents. The results of this study suggest that pMAH135 influence not only the pathological manifestations of MAC disease, but also the host specificity of MAC infection.
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