Severe prosthetic joint infection in an immunocompetent male patient due to a therapy refractory Pseudallescheria apiosperma.

Prosthetic joint infections (PJI) are rarely due to fungal agents and if so they are mainly caused by Candida strains. This case represents a PJI caused by a multi-drug resistant Pseudallescheria apiosperma, with poor in vivo response to itraconazole and voriconazole. This case differs also by the way of infection, since the joint infection did not follow a penetrating trauma. In the majority of cases, Scedosporium extremity infections remain local in immunocompetent individuals. We report a persistent joint infection with multiple therapeutic failures, and subsequent amputation of the left leg. Detailed clinical data, patient history, treatment regime and outcome of a very long-lasting (>4 years) P. apiosperma prosthetic knee infection in an immunocompetent, 61-year-old male patient are presented with this case. The patient was finally cured by the combination of multiple and extensive surgical interventions and prolonged antifungal combination therapy with voriconazole and terbinafine.

Decolonization of methicillin-resistant Staphylococcus aureus using oral vancomycin and topical mupirocin.

The objective of this study was to assess the efficacy and safety of a short course of oral vancomycin and intranasal mupirocin ointment in the eradication of methicillin-resistant Staphylococcus aureus (MRSA) colonization. During an outbreak of MRSA, the colonized subjects received oral vancomycin and topical mupirocin. They were screened for MRSA 1, 3, 6 and 12 months after decolonization. A questionnaire was developed to evaluate the side-effects of oral vancomycin. Thirty-five subjects were treated. Clearance was achieved in all cases, in 24 (69%) subjects after one course of therapy. Twenty-eight (80%) subjects experienced some side-effects, including six (17%) who did not tolerate oral vancomycin. Although oral vancomycin, in combination with topical mupirocin, is effective in the elimination of MRSA colonization, there is a need for further studies to confirm our results and to evaluate the safety of oral vancomycin.

The cost-effectiveness of ESBL detection: towards molecular detection methods?

Correct detection of extended-spectrum beta-lactamases (ESBLs) is crucial for infection control and antibiotic choice. We performed a study to determine the cost-effectiveness of phenotypical testing, which can be inaccurate, and genotypical tests, which are considered to be more reliable but also more expensive. All patients that had been in isolation in the Amphia hospital because of the detection of ESBL according to the ESBL Etest were included in the survey. All strains were retested using the double disk confirmation test (DDCT) and a genotypical method. This was a commercially available microarray (Check-Points). Discordant results were confirmed by PCR and sequencing. In total 174 patients were included. In 24 of 174 (14%) patients, ESBL carriage could not be confirmed with the microarray. This was verified with PCR and sequencing. The mean duration of isolation was 15 days, adding up to a total number of isolation days of 2571. False-positive results according to the microarray resulted in a total of 279 days of unnecessary isolation for the Etest and 151 days for the DDCT. Using Etest to detect the presence of ESBL results in a false-positive outcome in 14% of the cases. This results in unnecessary isolation of patients, which can be omitted by using a genotypic method.

Evaluation of a single-tube real-time PCR for detection and identification of 11 dermatophyte species in clinical material.

We developed a dermatophyte-specific single-tube real-time PCR assay based on internal transcribed sequences. This assay allows the rapid detection and identification of 11 clinically relevant species within the three dermatophyte genera Trichophyton, Microsporum and Epidermophyton in nail, skin and hair samples within a few hours. Analysis of 145 clinical samples (107 nail, 36 skin scale, and two hair) by both real-time PCR and a PCR-reverse line blot (PCR-RLB) assay described earlier revealed that 133 of the 145 samples had concordant real-time PCR and PCR-RLB detection results (83 positive, 49 negative, and one inhibited). Six samples were positive by real-time PCR and negative by PCR-RLB, and two were negative by real-time PCR and positive by PCR-RLB. Four samples demonstrated inhibition in one of the two PCR assays. Only one of 83 positive samples had discordant identification results between both assays (Trichophyton verrucosum and Trichophyton erinacei by real-time PCR and Trichophyton erinacei by PCR-RLB). Dermatophytes present in seven positive samples that were incompletely identified as Trichophyton sp. by PCR-RLB were identified to the species level by real-time PCR as Trichophyton interdigitale and Trichophyton rubrum in six cases and one case, respectively. One hundred and twenty of 145 samples were also analysed by conventional dermatophyte culture and by direct microscopy. Our single-tube real-time PCR assay proved to be suitable for direct detection and identification of dermatophytes in nail, skin and hair samples with minimal total assay time (4 h after overnight lysis) and hands-on time, without the need for post-PCR analysis, and with good sensitivity and specificity.

Validation of PCR-reverse line blot, a method for rapid detection and identification of nine dermatophyte species in nail, skin and hair samples.

A dermatophyte-specific PCR-reverse line blot (PCR-RLB) assay based on internal transcribed sequences was developed. This assay allows the rapid detection and identification of nine clinically relevant species within the three dermatophyte genera Trichophyton, Microsporum and Epidermophyton in nail, skin and hair samples within 1 day. Analysis of 819 clinical samples (596 nail, 203 skin and 20 hair) revealed a positive PCR-RLB result in 93.6% of 172 culture-positive and microscopy-positive samples. PCR-RLB was superior to culture and direct microscopy, in both detection and species identification. Comparison of identification results of 208 PCR-positive and culture-positive clinical samples showed five discrepancies (2.4%) between PCR-RLB identification and classical microscopic/biochemical identification of isolates. Comparison of PCR-RLB identification and classical identification of 98 other isolates (dermatophytes and non-dermatophytes) revealed 13 discrepancies (13.3%) and five incomplete identifications of Trichophyton spp. Sequence analysis of ITS1 regions of 23 samples with discrepant or incomplete identification results (four Centraalbureau voor Schimmelcultures dermatophyte strains, four clinical samples and 15 clinical isolates) confirmed identification results of PCR-RLB in 21 of the 23 analyzed samples. PCR-RLB proved to be extremely suitable for routine detection and identification of dermatophytes directly in nail, skin and hair samples because it is rapid, sensitive, specific and accurate.