Wengenack, Nancy L.

ABSTRACTNeither breakpoints (BPs) nor epidemiological cutoff values (ECVs) have been established forCandidaspp. with anidulafungin, caspofungin, and micafungin when using the Sensititre YeastOne (SYO) broth dilution colorimetric method. In addition, reference caspofungin MICs have so far proven to be unreliable.Candidaspecies wild-type (WT) MIC distributions (for microorganisms in a species/drug combination with no detectable phenotypic resistance) were established for 6,007Candida albicans, 186C. dubliniensis, 3,188C. glabratacomplex, 119C. guilliermondii, 493C. krusei, 205C. lusitaniae, 3,136C. parapsilosiscomplex, and 1,016C. tropicalisisolates. SYO MIC data gathered from 38 laboratories in Australia, Canada, Europe, Mexico, New Zealand, South Africa, and the United States were pooled to statistically define SYO ECVs. ECVs for anidulafungin, caspofungin, and micafungin encompassing ≥97.5% of the statistically modeled population were, respectively, 0.12, 0.25, and 0.06 μg/ml forC. albicans, 0.12, 0.25, and 0.03 μg/ml forC. glabratacomplex, 4, 2, and 4 μg/ml forC. parapsilosiscomplex, 0.5, 0.25, and 0.06 μg/ml forC. tropicalis, 0.25, 1, and 0.25 μg/ml forC. krusei, 0.25, 1, and 0.12 μg/ml forC. lusitaniae, 4, 2, and 2 μg/ml forC. guilliermondii, and 0.25, 0.25, and 0.12 μg/ml forC. dubliniensis. Species-specific SYO ECVs for anidulafungin, caspofungin, and micafungin correctly classified 72 (88.9%), 74 (91.4%), 76 (93.8%), respectively, of 81Candidaisolates with identifiedfksmutations. SYO ECVs may aid in detecting non-WT isolates with reduced susceptibility to anidulafungin, micafungin, and especially caspofungin, since testing the susceptibilities ofCandidaspp. to caspofungin by reference methodologies is not recommended.

ABSTRACT We present a case of tenosynovitis caused by a novel, slowly growing, nonchromogenic, nontuberculous mycobacterium (NTM). Originally misidentified as Mycobacterium tuberculosis complex, the NTM cross-reacts with the M. tuberculosis complex nucleic acid hybridization probe, a M. tuberculosis gamma interferon release assay, and is closely related to M. tuberculosis by 16S rRNA gene sequencing.

SummaryAs invasive mucormycosis (IM) numbers rise, clinicians suspect prior voriconazole worsens IM incidence and severity, and believe combination anti‐fungal therapy improves IM survival. To compare the cumulative incidence (CI), severity and mortality of IM in eras immediately before and after the commercial availability of voriconazole all IM cases from 1995 to 2011 were analysed across four risk‐groups (hematologic/oncologic malignancy (H/O), stem cell transplantation (SCT), solid organ transplantation (SOT) and other), and two eras, E1 (1995–2003) and E2, (2004–2011). Of 101 IM cases, (79 proven, 22 probable): 30 were in E1 (3.3/year) and 71 in E2 (8.9/year). Between eras, the proportion with H/O or SCT rose from 47% to 73%, while ‘other’ dropped from 33% to 11% (P = 0.036). Between eras, the CI of IM did not significantly increase in SCT (P = 0.27) or SOT (P = 0.30), and patterns of anatomic location (P = 0.122) and surgical debridement (P = 0.200) were similar. Significantly more patients received amphotericin‐echinocandin combination therapy in E2 (31% vs. 5%, P = 0.01); however, 90‐day survival did not improve (54% vs. 59%, P = 0.67). Since 2003, the rise of IM reflects increasing numbers at risk, not prior use of voriconazole. Frequent combination of anti‐fungal therapy has not improved survival.

ABSTRACT We present a case of disseminated Neosartorya pseudofischeri infection in a bilateral lung transplant patient with cystic fibrosis. The organism was originally misidentified from respiratory specimens as Aspergillus fumigatus using colonial and microscopic morphology. DNA sequencing subsequently identified the organism correctly as N. pseudofischeri .

ABSTRACT We describe a case of chronic tenosynovitis in the hand of a 58-year-old cattle farmer. Surgical biopsy specimens grew Mycobacterium arupense . The patient responded to surgery and antimicrobial therapy based on in vitro susceptibility testing. The antimicrobial susceptibility profiles of the isolate from this patient and 39 additional clinical isolates are presented.

ABSTRACT A retrospective analysis of 386,706 specimens representing a variety of matrix types used in qualitative real-time PCR assays determined the overall inhibition rate to be 0.87% when the inhibition control was added preextraction to 5,613 specimens and 0.01% when the inhibition control was added postextraction but preamplification in 381,093 specimens. Inhibition rates of ≤1% were found for all specimen matrix types except urine and formalin-fixed, paraffin-embedded tissue.

ABSTRACT Diagnosis of yeast infection is typically accomplished by fungal smear and culture, histopathologic examination, and/or serologic studies. Newer assays based on mass spectrometry may be useful for yeast identification when histologic examination is inconclusive, fungal cultures are not ordered, or cultures fail to yield a causative agent. The purpose of this study was to evaluate the ability of the PLEX-ID broad fungal assay to accurately detect and identify yeasts in formalin-fixed paraffin-embedded (FFPE) tissues. Tissue samples from 78 FFPE specimens with both histopathology and corresponding culture results for a variety of yeasts were tested using the PLEX-ID broad fungal assay. A 40-μm FFPE tissue section from each specimen was digested with proteinase K followed by nucleic acid extraction and PCR using broad-range fungal primers. Yeast DNA in amplified products was identified using electrospray ionization mass spectrometry. Discordant results were resolved by D2 rRNA gene sequencing. PLEX-ID analysis detected yeast DNA in 78.2% (61/78) of the cases, of which 91.8% (56/61) were concordant with culture results. Of the 5 discordant positive results, 4 PLEX-ID results were considered to result from environmental contaminants, while 1 clinically important discrepancy was observed ( Blastomyces dermatitidis by culture and Cryptococcus neoformans by PLEX-ID). Sequencing of the discordant sample was unsuccessful. The majority of histopathology results (89.7% [70/78]) correlated with culture results. The PLEX-ID broad fungal assay identifies fungi directly from FFPE tissues and can be a useful adjunct to traditional culture and histopathology tests.

ABSTRACT PCR coupled with electrospray ionization mass spectrometry (PCR–ESI-MS) is a novel technology that has recently been used to identify pathogens from clinical specimens or after culture within about 6 h. We evaluated the MDR-TB (multidrug-resistant tuberculosis) assay, which uses PCR–ESI-MS for detection and identification of Mycobacterium spp. and Mycobacterium tuberculosis complex (MTBC) resistance determinants from solid and broth Middlebrook culture media. The performance of the MDR-TB assay was compared to identification using nucleic acid hybridization probes and 16S rRNA gene sequencing for 68 MTBC and 97 nontuberculous mycobacterial (NTM) isolates grown on agar and 107 cultures grown in Bactec MGIT broth. MTBC resistance profiles from the MDR-TB assay were compared to results with the agar proportion method. The PCR–ESI-MS system correctly identified all MTBC isolates and 97.9% and 95.8% of the NTM isolates from characterized agar cultures and MGIT broth cultures to the species level, respectively. In comparison to the agar proportion method, the sensitivity and specificity for the detection of drug resistance using the MDR-TB assay were 100% and 92.3% for rifampin, 100% and 93.8% for isoniazid, 91.6% and 94.4% for ethambutol, and 100% and 100% for fluoroquinolones, respectively. The MDR-TB assay appears to be a rapid and accurate method for the simultaneous detection and identification of mycobacterial species and resistance determinants of MTBC from culture.

ABSTRACT Gordonia species are ubiquitous aerobic actinomycetes that rarely cause infection in humans. We report the second known case of Gordonia otitidis catheter-related bacteremia in an immunocompromised patient and review four additional cases of Gordonia bacteremia seen at our institution over the past 14 years. In addition, the existing literature on Gordonia infections is reviewed.