Molecular identification and antifungal susceptibility testing of Candida species isolated from dental plaques.

OBJECTIVE: The aim of the present study was to provide insight into the prevalence and susceptibility profiles of Candida species isolated from the dental plaque of Iranian immunocompetent patients. As a biofilm, Candida species are responsible for several disorders common to the oral cavity including gingivitis, dental caries, periodontitis, and the less common severe systemic infections specifically in immunosuppressed individuals. METHOD: PCR-RFLP was performed to identify yeasts isolated from the dental plaques of 40 immunocompetent patients. Moreover, antifungal susceptibility testing was performed in according to CLSI guidelines (M27-A3). RESULTS: Among 40 yeasts isolated from the dental plaques of immunocompetent patients, Candida albicans was the most common species (92.5%), followed by P. kudriavzevii (7.5%). It is the first isolation of P. kudriavzevii from dental plaques and the first evaluation of antifungal effect of the new imidazole, luliconazole and echinocandins against these samples worldwide. Luliconazole, voriconazole, amphotericin B and anidulafungin showed the best activity with the lowest geometric mean (GM) 0.03, 0.06, 0.08 and 0.09µg/ml, respectively, followed by miconazole (0.14µg/mL), caspofungin (0.24µg/mL) fluconazole (0.38µg/mL) and itraconazole (0.5µg/mL). CONCLUSION: The current study demonstrated luliconazole and echinocandins displayed excellent activity against all Candida isolates from dental plaques, presenting promising and potent alternative for all oral Candidiasis.

Consistent high prevalence of Exophiala dermatitidis, a neurotropic opportunist, on railway sleepers.

Environmental isolation of black yeasts potentially causing human disorders is essential for understanding ecology and routes of infection. Several Exophiala species show prevalence for man-made environments rich in monoaromatic compounds, such as creosote-treated or petroleum-stained railway sleepers. Ambient climatic conditions play a role in species composition in suitable habitats. Therefore, the aim of the present study was to establish the composition of Exophiala species in railway stations as a potential source of human infections in a subtropical region with evaluation of their antifungal susceptibility profiles. We examined 150 railway samples using cotton swabs moistened with sterile physiological saline. Black yeasts and relatives were selected on theirs colony morphology and identified based on ITS rDNA sequencing. Overall, 36 (24%) of samples were positive for black yeast-like fungi, i.e., Exophiala dermatitidis (n=20, 55.6%) was predominant, followed by E. phaeomuriformis (n=9, 25%), E. heteromorpha (n=5, 13.9%), and E. xenobiotica (n=2, 5.6%). Massive contaminations of E. dermatitidis were seen on railway sleepers on creosoted oak wood at the region close to the sea level, while in cold climates were primarily contaminated with clinically insignificant or rare human opportunists (E. crusticola). It seems that, high temperature and humidity are significant effect on species diversity. Moreover, the MIC results for all E. dermatitidis and E. phaeomuriformis strains revealed the widest range and the highest MICs to caspofungin (range 1-16mg/L, Geometric mean 4.912mg/L), and the lowest MIC for posaconazole (0.016-0.031mg/L, G mean 0.061mg/L). However, their clinical effectiveness in the treatment of Exophiala infections remains to be determined.

In vitro activities of five antifungal agents against 199 clinical and environmental isolates of Aspergillus flavus, an opportunistic fungal pathogen.

Aspergillus flavus is the second leading cause of invasive and non-invasive aspergillosis, as well as the most common cause of fungal sinusitis, cutaneous infections, and endophthalmitis in tropical countries. Since resistance to antifungal agents has been observed in patients, susceptibility testing is helpful in defining the activity spectrum of antifungals and determining the appropriate drug for treatment. A collection of 199 clinical and environmental strains of Aspergillus flavus consisted of clinical (n=171) and environmental (n=28) were verified by DNA sequencing of the partial b-tubulin gene. MICs of amphotericin B, itraconazole, voriconazole, posaconazole, and MEC of caspofungin were determined in accordance with the Clinical and Laboratory Standards Institute M38-A2 document. Caspofungin, followed by posaconazole, exhibited the lowest minimum inhibitory concentrations (MIC). All isolates had caspofungin MEC90 (0.063µg/ml) lower than the epidemiologic cutoff values, and 3.5% of the isolates had amphotericin B MIC higher than the epidemiologic cutoff values. However, their clinical effectiveness in the treatment of A. flavus infection remains to be determined.

Hyphal wall protein 1 gene: A potential marker for the identification of different Candida species and phylogenetic analysis.

BACKGROUND AND PURPOSE: Hyphal wall protein 1 (HWP1) is an important adhesin which usually is expressed on the germ tube and hyphal surface produced by different Candida species. The hyphal wall protein-coding gene (HWP1) was evaluated as a novel identification and phylogenetic marker in Candida tropicalis, C. orthopsilosis, C. parapsilosis and C. glabrata. MATERIALS AND METHODS: Initially, four specific primer pairs were designed, and the target was amplified and finally sequenced. A total of 77 Candida isolates from four different species were included in the study. Consensus sequences were used for the evaluation of phylogenetic tree using the CLC Genome Workbench, GENEIOUS, and MEGA softwares and the levels of nucleotide and amino acid polymorphism were assessed. RESULTS: According to the results, the specific amplified fragments of HWP1 gene were useful for the differentiation of four species. Intra-species variation was observed only in C. tropicalis with two DNA types. The phylogenetic tree of Candida species based on the HWP1 gene showed consistency in topology with those inferred from other gene sequences. CONCLUSION: We found that HWP1 gene was an excellent marker for the identification of non-albicansCandida species as well as the phylogenetic analysis of the most clinically significant Candida species.

Is human Dectin-1 Y238X gene polymorphism related to susceptibility to recurrent vulvovaginal candidiasis?

BACKGROUND AND PURPOSE: Vulvovaginal candidiasis is a frequent disease affecting approximately more than %75 of all childbearing women at least once in their lifetime by overgrowth of opportunistic Candida species. Recurrent vulvovaginal candidiasis (RVVC) is common in otherwise healthy individuals. Several risk factors were reported to contribute to RVVC susceptibility. A polymorphism in Dectin-1 (Y238X, rs16910526 ) was identified in patients with RVVC and hypothesized that genetic factors play an important role in susceptibility to RVVC. Herein, we aimed to survey the polymorphisms in the Dectin-1 gene, linked to susceptibility to RVVC. MATERIALS AND METHODS: In the current study, blood samples were obtained from 25 patients who had frequent vulvovaginal candidiasis relapses and were diagnosed as RVVC. In addition, blood cultures were obtained from control group comprising of healthy individuals (n=25) with no history of RVVC, vaginal discharge, or itching on the day of examination. Dectin-1 Y238X gene polymorphism was investigated using Bi-PASA and DNA sequencing. RESULTS: The analysis revealed that all of the patients were wild-type homozygous for Dectin-1 Y238X polymorphisms. None of the individuals showed heterozygous or mutant homozygous Dectin-1 polymorphism. CONCLUSION: No significant correlations were observed between the susceptibility to RVVC and Dectin-1 Y238X polymorphism in the Iranian population, which was not previously studied.

Optimizing technology for the management of colon and rectal diseases.

Surgery is one of the most dynamic sciences and the discipline of colorectal surgery continues to progress forward utilizing a combination of new technologies and innovative operative techniques to enhance patients care and improve outcomes.

First fatal cerebral phaeohyphomycosis due to Rhinocladiella mackenziei in Iran, based on ITS rDNA.

Black yeast-like fungi and relatives as agents of cerebral phaeohyphomycosis are often encountered in human fatal brain abscesses and lead to almost 100% mortality despite the application of antifungal and surgical therapy. We report to our knowledge the first case of brain infection due to Rhinocladiella mackenziei in a 54-year-old immunocompetent male in Iran where R. mackenziei has not been reported previously. The initial diagnosis was brain fungal infection because of pigmented, irregular, branched, septated hyphae based on histopathological staining. The patient was treated with intravenous amphotericin B deoxycholate (0.5mg/kg/day) combined with oral itraconazole (200mg twice daily), nevertheless, his neurological function deteriorated rapidly and ultimately the patient died due to respiratory failure later two weeks. R. mackenziei was identified based on the sequencing of internal transcribed spacer (ITS rDNA region) (KJ140287). Therefore, considerable attention for this life-threatening infection is highly recommended.

Portal venous versus systemic venous drainage of pancreas grafts: impact on long-term results.

Portal venous (PV) and systemic venous (SV) drainage methods are used in pancreas transplantation. The impact of the reconstruction technique on long-term outcome remains unclear. We compared the efficacy and side effects of both methods in 192 recipients who received synchronous pancreas kidney transplants between November 1995 and November 2007. SV and PV drainage were used in 147 and 45 cases, respectively. Pancreas function was determined by hemoglobin A1c levels and annual oral glucose tolerance test. Serum creatinine assessed kidney function. Serum lipid (low-density lipoprotein, high-density lipoprotein and cholesterol) levels and body mass index were measured annually. Patient and graft survival were calculated by log-rank analysis. Pancreas survival for SV versus PV patients was similar after 5 years (81.8% vs. 75.5%) and 10 years (65.1% vs. 60%; p = NS). Similarly, no difference was detected between the groups regarding kidney survival after 5 years (92.9% vs. 84.4%) and 10 years (81.6% vs. 75.5%; p = NS). Patient survival did not differ at 5 years (94.3% vs. 88.8%) and 10 years (85.1% vs. 84.4%; p = NS). Pancreas and kidney function and the lipid profiles were similar in both groups. SV and PV drainage of pancreas grafts offer similar long-term graft survival and function and choice of method should remain the preference of the surgeon.

Does mesh offer an advantage over tissue in the open repair of umbilical hernias? A systematic review and meta-analysis.

PURPOSE: To determine the best surgical approach for the open repair of primary umbilical hernias. METHODS: Studies were identified through searching MEDLINE, EMBASE, and the Cochrane database, as well as hand-searching references. Randomized controlled trials (RCTs) and observational studies comparing mesh to suture repair for primary umbilical hernias published between January 1965 and October 2009 were included. Data regarding the recurrence rate, complications, number of subjects, length of follow-up, size of hernia, and type of mesh were extracted. Log odds ratios were calculated and weighed by the Mantel-Haenszel method to obtain a pooled estimate with 95% confidence interval (CI). A fixed effects model was used. RESULTS: Three RCTs and ten observational studies were identified. The pooled odds ratio (OR) for RCTs was 0.09 in favor of mesh (95% CI 0.02-0.39). The pooled OR for observational studies was 0.40 in favor of mesh (95% CI 0.21-0.75). There was no difference in complication rates between mesh and tissue repair in RCTs or observational studies. CONCLUSIONS: The use of mesh in umbilical hernia repair results in decreased recurrence and similar wound complications rates compared to tissue repair for primary umbilical hernias.