PCR test for Microsporum canis identification.

Microsporum canis, for which the natural hosts are cats and dogs, is the most prevalent zoophilic agent causing tinea capitis and tinea corporis in humans. We present here a diagnostic PCR test for M. canis, since its detection and species identification is relevant to the choice of treatment and to the understanding of a probable source of infection. An M. canis-specific PCR was evaluated using 130 clinical isolates of dermatophytes (including M. canis [n = 15] and 13 other species), 10 yeast or mold isolates, 12 hair and skin samples from animals with or without experimental M. canis infection, and 35 patient specimens, including seven specimens positive for M. canis and 15 dermatophyte negative samples. All pure cultures, animal specimens and clinical samples with M. canis were detected by the PCR test, whereas none of the other fungal isolates or samples without M. canis was negative. This study indicates that the PCR test for M. canis identification applied directly to patient specimens or animal hair, as well as to clinical isolates had 100% specificity and sensitivity.

The prevalence and clinical significance of intestinal parasites in HIV-infected patients in Denmark.

To investigate the prevalence and clinical significance of intestinal parasites in human immunodeficiency virus (HIV)-infected patients, faecal specimens from 96 HIV-infected patients were submitted to microbiological analyses, including microscopy and polymerase chain reaction for protozoa and enteropathogenic bacteria. Results of microbiological analyses were compared with self-reported gastrointestinal complaints collected using a validated questionnaire. Thirty-two (33%) patients were positive for parasites. However, opportunistic parasites (Isospora and Cryptosporidium) were detected in only 2 instances. Entamoeba dispar was detected in 10 cases, 9 of which represented men who have sex with men (MSM). Despite generally low HIV RNA loads and high CD4+ T-cell counts, 42% of the 76 patients reporting symptoms complained of diarrhoea, 31% of whom were parasite-positive. The presence of diarrhoea was not associated with the presence or absence of parasites; neither was it associated with receiving highly active anti-retroviral therapy (HAART) in general, or protease inhibitors (PI) in particular. A CD4+ T-cell count <200 cells/mm³ was not associated with parasitic infection or with diarrhoea. The data show that diarrhoea is a common symptom among HIV-infected patients in Denmark, but do not indicate that the diarrhoea is due to intestinal parasites.

Optimized 5-hour multiplex PCR test for the detection of tinea unguium: performance in a routine PCR laboratory.

We recently reported the development of a 5-hour multiplex PCR test for the detection of tinea unguium and the optimization of this test by the inclusion of an inhibition control. Here we report the performance of this procedure as used in a routine clinical laboratory as compared to conventional microscopy and culture-based techniques performed in a mycology reference laboratory. We found in processing 109 samples that 22 (20.2%) yielded fungi in culture while the suspected etiologic agents were noted microscopically in 15 (13.8%) that were negative in culture. Fungi were detected by PCR in 37 (33.9%) samples, of which only three were positive in culture. Since the majority of PCR positive but culture negative samples were positive in microscopic examinations, the increased sensitivity was not due to contamination. PCR inhibitors were present in 5% of the samples, but this was overcome by re-running the samples with a 50% reduction of sample DNA. In conclusion, the PCR test performance in the routine setting was excellent and provided a markedly reduced time to diagnosis with a higher sensitivity.