Phylogeny, Antifungal Susceptibility, and Point Mutations of SQLE Gene in Major Pathogenic Dermatophytes Isolated From Clinical Dermatophytosis.

Drug resistance is one of the major challenges to skin fungal infections, especially in tropical and subtropical infections caused by dermatophytes. This study aimed to determine the antifungal susceptibility of clinically dermatophytes and evaluate point mutations in terbinafine-resistant isolates. A total number of 123 clinical dermatophyte isolates in eight species were evaluated in terms of sensitivity to seven major antifungals. Furthermore, the point mutation in squalene epoxidase (SQLE) gene responsible for terbinafine resistance was studied. The dermatophytes species were identified by morphological characteristics and confirmed by the ITS sequencing. Also, the phylogenetic tree was drawn using the RAxML analyses for 123 dermatophytes isolates. A new XXIX genotype was also found in 4 Trichophyton mentagrophytes isolates. Based on the results obtained, terbinafine was the most effective antifungal drug followed by itraconazole and voriconazole. Trichophyton rubrum and Trichophyton tonsurans were the most susceptible species (MIC50 = 0.01, 0.09 µg/ml), and T. mentagrophytes was the most resistant species (MIC50 = 0.125 µg/ml) to terbinafine. Of the 123 dermatophytes isolates, six isolates showed reduced susceptibility to terbinafine, and only Trichophyton indotineae had a mutation in SQLE gene as a Phe397Leu substitution. Overall, the antifungal susceptibility test is necessary for managing dermatophytosis. These results help physicians to control the course of the disease and provide further insights to select effective drugs for patients with dermatophytosis, especially in tropical and subtropical regions of the world, where dermatophytosis is still a public health problem.

Circulation of imipenem-resistant Acinetobacter baumannii ST10, ST2 and ST3 in a university teaching hospital from Tehran, Iran.

PURPOSE: Multi-drug resistant (MDR) Acinetobacter baumannii has introduced a worldwide health crisis. The purposes of this study were to characterize the clonal relatedness among MDR clinical strains and to introduce a new two-locus typing method confirmed by multi-locus sequence typing (MLST). METHODOLOGY: In this study, we determined antimicrobial resistance, detected genes associated with carbapenem resistance and characterized clonal relatedness among 99 clinical isolates extracted from 82 hospitalized inpatients in a university hospital. RESULTS: Of the 99 A. baumannii isolates, 92.9% (92/99) were resistant to imipenem and 97.9% (97/99) had an MDR profile. We found that the high prevalence of blaVIM [94.9% (94/99)] and blaOXA-23-like [93.93% (93/99)] is the main mechanism of carbapenem resistance. This study proposes a new two-locus typing (blaOXA-51-like and ampC) method for the rapid identification of clonal complexes (CCs). The results of this method and confirmation by MLST show that clinical isolates carry blaOXA-68 as well as ampC-10 or ampC-20 genes belonging to CC10 (ST10); blaOXA-66 and ampC-2 belonging to CC2 (ST2); and blaOXA-71 and ampC-3 belonging to CC3 (ST3). One isolate had blaOXA-90 with an undetermined allele number of ampC belonging to ST513. CONCLUSION: The high prevalence of MDR strains and the circulation of four limited clones, including ST10 (45/99), ST2 (41/99), ST3 (12/99) and ST513 (1/99), in the clinical setting highlights the importance of a rigorous infection control programme. The two-locus typing method has more discrimination than the application of each method separately and it could be applied for the rapid determination of the CC without performing MLST.

Helicobacter pylori infection in oral lesions of patients with recurrent aphthous stomatitis.

BACKGROUND: Recurrent aphthous stomatitis (RAS) is a disorder distinguished by ulcers restricted to the oral mucosa. Because of the histological similarities between peptic ulcers and RAS and the identified role of Helicobacter pylori (H. pylori) in peptic ulcer, the possibility of bacterial involvement in the progression of aphthae has been suggested. Our aim was to find H. Pylori in brushed samples of oral aphthous ulcers by the polymerase chain reaction (PCR) method. MATERIAL/METHODS: The evaluated patients were referred to the laboratory with the diagnosis of RAS from the beginning of 2001 throughout 2002 in Rasht city. We collected oral aphthous specimens by toothbrush from these patients. PCR was used to isolate H. Pylori in the samples of RAS lesions and other parts of the oral cavity. Enzyme-linked immunosorbant assay (ELISA) was also done in all patients to determine IgG antibody RESULTS: We studied 50 patients with ages between 18 to 60 years (mean+/-SD: 32.38+/-11.30). Twenty-six patients (52%) had positive ELISA test and we obtained H. Pylori DNA in only one patient (2%). CONCLUSIONS: According to the results of this study, H. Pylori DNA could not be found in the aphthous ulcers of these patients, even in those with positive anti-H. Pylori antibody (IgG), and it is probable that these bacteria are not involved in recurrent oral aphthous ulcers.

Differentiation of old and new world leishmania species at complex and species levels by PCR.

The variable and conserved sequence boxes of kinetoplast DNA (kDNA) of 11 standard strains of 6 complexes of New and Old World Leishmania were amplified using PCR. Four strains from 2 complexes of Old World Leishmania - L. major (MRHO/IR/64/Nadim-1), with 2 bands at 850 and 620 bp, L. major (MHOM/SU/73/5-ASKH), with a band at 620 bp, L. donovani, with a band at 800 bp and L. infantum, with a band at 650 bp - could be differentiated from each other and from the New World strains, with the exception of L. infantum. Seven Leishmania strains from 4 complexes of New World Leishmania - L. mexicana and L. pifanoi, with a band at 730 bp, L. guyanensis, with 2 bands at 730 and 650 bp, L. peruviana, with a band at 710 bp and L. amazonensis, L. garnhami and L. braziliensis, each with a band at 650 bp - were identified. Of these strains, L. guyanensis and L. peruviana could be differentiated from each other and from the Old World strains. These results show that using PCR amplification of kDNA we could differentiate between New and Old World Leishmania at both complex and strain levels. The amplified kDNA PCR products, together with other techniques, could be useful as a diagnostic tool for the identification of Leishmania species.