Observational study of skin and soft-tissue Staphylococcus aureus infection in patients infected with HIV-1 and epidemics of Panton-Valentine leucocidin-positive community-acquired MRSA infection in Osaka, Japan.

BACKGROUND: In patients infected with human immunodeficiency virus (HIV)-1 at our hospital, we observed increases in skin and soft-tissue infections (SSTIs) by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Therefore, we analyzed factors related to CA-MRSA infection and performed a molecular epidemiological investigation. METHODS: HIV-1-infected patients were diagnosed with SSTIs related to S. aureus between 2007 and 2017, and MRSA was classified into community and hospital-acquired types according to published criteria. Information was collected retrospectively from clinical records, and multivariate analysis by logistic regression was performed concerning factors related to CA-MRSA infection. We evaluated the staphylococcal cassette chromosome mec (SCCmec) type, multilocus sequence type, and the presence of genes encoding Panton-Valentine leucocidin (PVL) in 27 MRSA samples isolated during and after 2015. RESULTS: We found 218 episodes of SSTIs in 169 patients, and among initial episodes of SSTIs, the MRSA ratio was higher from 2015 to 2017 relative to that from 2007 to 2014 (88% vs. 44%; p < 0.0001). Multivariate analysis showed that in men having sex with men [MSM; odds ratio (OR): 13] and exhibiting onset during and after 2015 (OR: 5.4), CD4+ cell count ≥200 cells/µL (OR: 5.6) and the presence of lesions in the lower abdomen or buttocks (OR: 9.5) were independent factors related to CA-MRSA infection. Additionally, PVL+/ST8/SCCmec type IV MRSA was the predominant pathogen (22 cases; 81%). CONCLUSIONS: These data describe an increased prevalence of SSTIs due to PVL-positive ST8-MRSA-IV, not previously considered epidemic in Japan, in MSM infected with HIV-1 in Osaka, Japan.

Pulmonary disease caused by rapidly growing mycobacteria: a retrospective study of 44 cases in Japan.

BACKGROUND: The features of pulmonary disease caused by rapidly growing mycobacteria (RGM) have not been sufficiently documented. OBJECTIVES: To establish these features, we retrospectively evaluated 44 patients. METHODS: We screened respiratory isolates at the National Toneyama Hospital (Osaka, Japan) between 2003 and 2007. Diagnosis was based on the latest guidelines of the American Thoracic Society. The patients were classified into 3 types according to their radiographic findings: fibrocavitary, nodular bronchiectatic and unclassified variant. RESULTS: We obtained 1,348 nontuberculous mycobacteria respiratory isolates from 1,187 patients, including 119 RGM isolates from 100 patients. Forty-four of these 100 patients were definitively diagnosed with respiratory disease due to RGM. The most common pathogen was Mycobacterium abscessus, which accounted for 65.9% of cases, followed by Mycobacterium fortuitum at 20.5%. There was a statistically significant difference in smoking history between patients infected with these 4 RGM species (excluding those with an unknown smoking history; p = 0.039). The overall evaluation of radiographic findings revealed 18.2% as fibrocavitary, 43.2% as nodular bronchiectatic and 38.6% as unclassified variants in these 44 patients. There was a significant difference in radiographic findings between the 4 RGM species (p = 0.002). There was also a significant difference in radiographic findings between M. abscessus and M. fortuitum infected patients (p = 0.022). CONCLUSIONS: Patients with M. abscessus seem to have less of a smoking history and more frequent nodular bronchiectatic radiographic patterns than patients with M. fortuitum. In contrast, fibrocavitary patterns might be more frequent with M. fortuitum infection.

Mycobacterium avium complex organisms predominantly colonize in the bathtub inlets of patients' bathrooms.

Medical treatment of pulmonary Mycobacterium avium complex (MAC) disease does not always provide curative effects and is frequently hampered by recurrence. This suggests the presence of a reservoir for MAC in the environment surrounding patients. We previously reported the recovery of MAC isolates from the residential bathrooms of outpatients. In the present study, to ascertain the colonizing sites and the possibility of an MAC reservoir in the bathrooms of patients, we tested the recovery and the genetic diversity of MAC isolates from 6 sites of specimens, including 2 additional sampling sites, inside the showerhead and the bathtub inlet, in the residential bathrooms of patients with pulmonary MAC disease. MAC isolates were recovered from 15 out of the 29 bathrooms (52%), including specimens from 14 bathtub inlets and 3 showerheads. Nearly half of these bathrooms (7/15) contained MAC strains that were identical or similar to their respective clinical isolates Additionally, in 5 out of 15 bathrooms, polyclonal colonization was revealed by pulsed-field gel electrophoresis. The results imply that colonization of MAC organisms in the bathrooms of MAC patients occurs predominantly in the bathtub inlets, and there is thus a risk of infection and/or reinfection for patients via use of the bathtub and other sites in the bathroom.

The recovery of Mycobacterium avium-intracellulare complex (MAC) from the residential bathrooms of patients with pulmonary MAC.

The distribution of Mycobacterium avium-intracellulare complex (MAC) in residences was examined. MAC was only recovered from bathrooms but not from other sites of residences. The appearance ratio in the bathrooms of patients with pulmonary MAC was significantly higher than that in healthy volunteers' bathrooms (P=.01). For 2 patients, the genotypes of environmental isolates were identical to their respective clinical isolates.