More sensitive immune complex transfer enzyme immunoassay for antibody IgG to p17 of HIV-1 with shorter incubation time for immunoreactions and larger volumes of serum samples

In the previous immune complex transfer enzyme immunoassay for antibody IgG to p17 of HIV-1, the immune complex comprising 2,4-dinitrophenyl-bovine serum albumin-recombinant p17 conjugate, anti-p17 IgG, and recombinant p17-β-D-galactosidase conjugate was trapped onto polystyrene beads coated with (anti-2,4-dinitrophenyl group) IgG by overnight incubation and was transferred to polystyrene beads coated with (antihuman IgG γ-chain) IgG by 3 hr incubation in the presence of excess of ϵN-2,4-dinitrophenyl-L -lysine. These processes were made efficient by incubation with shaking and by using solid phases with larger surface areas. In addition, the volume of serum samples used was increased from 10 μl to 100 μl. As a result, the sensitivity was improved 20–30-fold and was ˜100,000-fold higher than that of Western blotting for p17 band, even when both trapping and transferring of the immune complex were performed for only 30 min. Furthermore, testing many samples became easily possible with higher sensitivity using microplates and a fluororeader. J. Clin. Lab. Anal. 11:244–250, 1997. © 1997 Wiley-Liss, Inc. No abstract.     

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

BackgroundIn 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.MethodsHIV-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.ResultsWe 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%).ConclusionsThese 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.