Whole genome characterization of Trichophyton indotineae isolated in Singapore.

Complete genome sequences from two Trichophyton indotineae isolates were obtained from a 23-year-old male presenting with tinea cruris after an overseas recreational water exposure and from a 53-year-old female patient with unknown travel history. Analysis of the squalene epoxidase gene and the cyp51 gene family showed an absence of mutations, correlating with phenotypic drug susceptibility. The Single Nucleotide Polymorphisms (SNPs) distance between both isolates was 92. Within the T. indotineae cluster, SNPs ranged from 7 to 182, suggesting a high genetic relatedness with other South Asian isolates. This study suggests that the prevalence of T. indotineae is under-reported and more widespread than previously thought.

Trichophyton indotineae, is a fungus causing difficult to treat ringworm infections. Two isolates were sequenced and their relationship and to other isolates was characterized. We also studied the genes responsible for first-line antifungal treatment.

Predominance of clarithromycin-susceptible Mycobacterium massiliense subspecies: Characterization of the Mycobacterium abscessus complex at a tertiary acute care hospital.

To characterize members of the Mycobacterium abscessus complex, with an emphasis on the correlation between species identification and clarithromycin associated genetic polymorphisms that contribute to inducible and constitutive macrolide resistance. PCR and sequencing analysis was used to elucidate the subspecies, erm(41) genotypes and the presence of rrl mutations. M. abscessus subsp. massiliense was the dominant subspecies (70.2 %), followed by M. abscessus subsp. abscessus (23.8 %) and M. abscessus subsp. bolletii (5.9 %). The majority of M. abscessus and M. bolletii isolates possessed T28 erm(41) sequevar and were inducibly resistant to clarithromycin. All M. massiliense carried the truncated erm(41) and were largely clarithromycin-susceptible (98.3 %). Constitutive resistance involving rrl mutations was rare and seen in only 2 isolates (2.2 %). Subspecies identification was insufficient to predict clarithromycin susceptibility and required the genetic resistance to be determined via sequencing. In our context, rrl mutations were uncommon and may not be an essential test.

A Novel Mycobacterium cosmeticum-Like Bacterium Isolated from the Ear Swab of a Patient with Otitis Externa.

We describe the identification and characterization of a novel nontuberculous mycobacterium (NTM), isolated from an ear swab of an adult male patient with chronic otitis externa. Genetically, the bacterium is most closely related to Mycobacterium cosmeticum; however, growth and biochemical features indicate that it is distinctly different. Here, we highlight for the first time an unusual NTM that is a probable cause of ear infection.

Clinical utility of RD1, RD9 and hsp65 based PCR assay for the identification of BCG in vaccinated children.

BACKGROUND: Mycobacterium bovis Bacille Calmette-Guérin (BCG) vaccine is widely administered to prevent tuberculosis. Vaccine complications are rare. However, when BCG-related adverse reactions arise there is a need to rapidly and reliably identify BCG from other members of the Mycobacterium tuberculosis complex (TBC). PCR assays based on the detection of the regions of difference (RD), in particular RD1 and RD9, have been invaluable in the identification of BCG. Prior to this study, specimens were identified through HPLC analysis at a local reference laboratory taking up to 2 weeks for a result. We sought to expedite the identification process by validating a RD1, RD9 and hsp65 PCR assay for the identification and differentiation of BCG from TBC. FINDINGS: In last past 3 years, we validated the RD1, RD9 and hsp65 PCR assay for 16 mycobacterial isolates obtained from children who had experienced adverse reactions to BCG vaccination. In these cases, the clinician required a definitive identification of the isolate. The RD1 and RD9 PCR profiles indicated that all 16 isolates were BCG whilst amplification of the hsp65 target functioned as a PCR positive control. When tested against clinical M. tuberculosis (MTB), reference and non-tuberculous mycobacteria the PCR assay demonstrated 100% sensitivity and specificity. CONCLUSIONS: The RD1, RD9 and hsp65 PCR assay is a useful tool for the rapid and reliable identification of BCG. Its ease of use has allowed it to be implemented in our clinical microbiology laboratory.