Diagnostic microbiology and infectious disease
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Diagn. Microbiol. Infect. Dis. · Aug 2019
Comparative StudyDetection of Mycobacterium tuberculosis in paucibacillary sputum: performances of the Xpert MTB/RIF ultra compared to the Xpert MTB/RIF, and IS6110 PCR.
The Xpert MTB/RIF Ultra assay has recently been launched to improve the detection of smear negative disease. This retrospective study compares the sensitivity of Xpert MTB/RIF Ultra with that of Xpert MTB/RIF tests and IS6110 real-time PCR in sputum. Diagnostic performance of three molecular tests was evaluated using 48 culture-positive clinical respiratory specimens diluted to obtain paucibacillary sputum specimens. ⋯ All "very low" or "low" positive specimens using Xpert MTB/RIF Ultra were tested positive using IS6110-PCR, but 35.4% were found negative using Xpert MTB/RIF. Xpert MTB/RIF Ultra is more sensitive than the two other tests for sputum with a low bacterial load. Adding detection of IS6110 and IS1081 to rpoB, is a key evolution of the assay and improves the detection of Mycobacterium tuberculosis' DNA in paucibacillary sputum.
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Diagn. Microbiol. Infect. Dis. · Feb 2019
Drug susceptibility patterns of Mycobacterium abscessus and Mycobacterium massiliense isolated from respiratory specimens.
In this study, we aimed to retrospectively investigate and compare the drug susceptibility patterns of two major Mycobacterium abscessus complex (MABC) species; M. abscessus and M. massiliense. A total of 546 MABC respiratory isolates (277 M. abscessus and 269 M. massiliense) from 2011 to 2016 were analyzed in this study. We estimated minimum inhibitory concentrations (MICs) using the broth microdilution method, and we calculated MIC50 and MIC90 values from the MIC distribution. ⋯ A total of 92.6% of the M. massiliense remained susceptible at day 14. The resistance rate of M. abscessus to moxifloxacin (90.3%) was significantly higher than that of M. massiliense (83.3%; p = 0.016). These susceptibility differences may explain the divergent treatment outcomes between patients with pulmonary disease caused by these two species.
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Diagn. Microbiol. Infect. Dis. · Feb 2019
Staphylococcus aureus versus Staphylococcus epidermidis in periprosthetic joint infection-Outcome analysis of methicillin-resistant versus methicillin-susceptible strains.
Periprosthetic joint infections (PJIs) are a major complication in total joint arthroplasty. Staphylococcus aureus and coagulase-negative staphylococci are known to cause the majority of all PJIs. This study aimed to analyze the eradication rates of S. aureus and S. epidermidis with methicillin susceptibility and methicillin resistance in a 2-stage therapy algorithm. ⋯ After a minimal follow-up of 2 years, n = 56 patients (75.7%) were definitively free of infection. The analysis revealed significant differences between the groups, with eradication rates as follows: MSSA (92.6%), MSSE (95.2%), MRSA (80%), and MRSE (54.2%). MRSE showed a significantly lower rate of patients graded as "definitively free of infection" as compared to patients with infections caused by MSSA, MSSE, and MRSA.
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Diagn. Microbiol. Infect. Dis. · Jan 2019
Case ReportsDiagnosing candidemia with the T2Candida panel: an instructive case of septic shock in which blood cultures were negative.
T2Candida that was positive for C. albicans/C. tropicalis supported antifungal treatment of a patient with hematogenously disseminated candidiasis and septic shock in whom blood cultures were negative. T2Candida, used and interpreted as a Bayesian biomarker, can identify patients with candidemia who are missed by blood cultures, including those receiving antifungal treatment.