Müge Demirbilek

Superficial fungal infections in 102 renal transplant recipients: a case-control study

BACKGROUND Renal transplant recipients are predisposed to superficial fungal infections caused by graft-preserving immunosuppressive therapy. Reports have documented a wide range of prevalence rates for superficial fungal infections in this patient group. OBJECTIVE The aim of this study was to determine the prevalence and clinical and mycological features of superficial fungal infections in renal transplant recipients at our center. METHODS One hundred two consecutively registered renal transplant recipients (34 women, 68 men) and 88 healthy age- and sex-matched persons acting as controls (30 women, 58 men) underwent screening for the presence of superficial fungal infection. Skin scrapings and swabs were obtained from the dorsum of the tongue, upper part of the back, toe webs, and any suspicious lesions. Nail clippings were also collected. All samples were examined by direct microscopy and were stained with calcofluor white. The samples were cultured in Sabouraud dextrose agar, mycobiotic agar, and dermatophyte test medium. Candida species were identified on the basis of germ-tube production, spore formation in cornmeal agar, and results of biochemical testing. Dermatophytes were identified on the basis of colonial and microscopic morphologic features in conjunction with results of physiologic evaluation (in vitro hair perforation test, urease activity, temperature tolerance test, and nutritional test). RESULTS Sixty-five (63.7%) of the 102 renal transplant recipients had cutaneous-oral candidiasis, dermatophytosis, or pityriasis versicolor, whereas only 27 (30.7%) of controls had fungal infection. Pityriasis versicolor was the most common fungal infection in the patient group (36.3%), followed by cutaneous-oral candidiasis (25.5%), onychomycosis (12.7%), and fungal toe-web infection (11.8%). Pityriasis versicolor and oral candidiasis were significantly more common among the renal transplant recipients, whereas the frequency of dermatophytosis in patients and controls was similar. Candida albicans was the main agent responsible for oral candidiasis, and Trichophyton rubrum was the most common dermatophyte isolated. Analysis showed that age, sex, and duration of immunosuppression did not significantly affect the prevalence of superficial fungal infection. Cyclosporine treatment and azathioprine therapy were identified as independent risk factors for superficial fungal disease. CONCLUSIONS The prevalence of opportunistic infections with Pityrosporum ovale and C albicans is increased among renal transplant recipients, probably owing to the immunosuppressed state of this patient population. However, renal transplant recipients are not at increased risk of dermatophytosis.

In vitro antifungal susceptibility patterns of dermatophyte strains causing tinea unguium.

Background.  Dermatophytes are the major responsible organisms in onychomycosis. Although recent antifungal agents have high success rates in treating this condition, lack of clinical response may occur in 20%. Antifungal drug resistance may be one of the causes of treatment failure. The need for in vitro antifungal drug resistance in daily practice is still under discussion.

Urease Activity and Urea Gene Sequencing of Coccoid Forms of H. pylori Induced by Different Factors

Helicobacter pylori exists in two morphologic forms: spiral shaped and coccoid. The nonculturable coccoid forms were believed to be the morphologic manifestations of cell death for a long time. However, recent studies indicate the viability of such forms. This form of H. pylori is now suspected to play a role in the transmission of the bacteria and is partly responsible for relapse of infection after antimicrobial treatment. Urease activity of H. pylori is an important maintenance factor. Determination of urease activity and possible mutations in the DNA sequences of coccoid bacteria will hence contribute to the understanding of pathogenesis of infections, which these forms might be responsible for. In this study, our aim was to analyze the urease activity and investigate the urease gene sequences of coccoid H. pylori forms induced by different factors with respect to the spiral form. For this purpose, the urease activities of H. pylori NCTC 11637 standard strain and two clinical isolates were examined before and after transformation of the cells to coccoid forms by different methods such as exposure to amoxicillin, aerobiosis, cold starvation, and aging. The effects of these conditions on the urease gene were examined by the amplification of 411-bp ureA gene and 115-bp ureB gene regions by PCR technique and sequencing of the ureA gene. The urease activities of coccoid cells were found to be lower than those of the spiral form. ureA and ureB gene regions were amplified in all coccoid cells by PCR. Inducing the change to coccoid form by different methods was found to have no effect on the nucleotide sequence of the ureA gene. These results show that the urease gene region of coccoid H. pylori is highly protected under various mild environmental conditions.

The Bactericidal and Morphological Effects of Peroxynitrite on Helicobacter pylori

Peroxynitrite (ONOO−) is correlated with the pathogenesis of Helicobacter pylori‐induced peptic ulcer diseases. We aimed to investigate the time‐ and concentration‐dependent bactericidal and morphological effects of ONOO− on H. pylori. Authentic ONOO− was synthesized as quenched‐flow method. A stock culture of H. pylori NCTC 11637 was exposed to different concentrations of ONOO− (0.1–40 µmol/L) or decomposed ONOO− or fresh medium. Samples were taken at 0, 15, 30, 60, and 120 minutes, for the evaluation of viable bacteria and bacterial morphology with gram strain and transmission electron microscopy. Decomposed ONOO− showed no bactericidal activity against H. pylori. ONOO− application caused a decrease in the number of viable bacteria within the first 15 minutes. The significant conversion of H. pylori from spiral form to coccoid form was determined with 10 µmol/L of ONOO−, and higher concentrations caused lysis of the cells. Separation of cell wall, bleb formation, vacuolization, decrease of secretory granules, and lysis of bacteria were the morphological effects of ONOO− on H. pylori. Because the morphology of the bacteria is one of the important factors in virulence; peroxynitrite‐related morphological effects might have an impact in the progress of the H. pylori‐induced peptic ulcer diseases.

Effects of various analgesics on the level of prostaglandin E2 during orthodontic tooth movement

AIM The aim of this double-blind, randomized, placebo-controlled clinical study was to evaluate the analgesic effects of preoperative/postoperative ibuprofen and acetaminophen use after bonding and to find a relation between the pain level and the amount of prostaglandin released. MATERIALS AND METHODS Forty-eight patients were included and randomly divided to three equal groups that received either ibuprofen, acetaminophen or placebo for pain relief. The pain levels were measured before bonding, after bonding, at first, second, third, and seventh days on a 100 mm visual analogue scale (VAS) and gingival crevicular fluid (GCF) samples were collected at the same time intervals to measure the amount of prostaglandin E2 (PGE2) released. PGE2 levels were determined with ELISA test. The results were evaluated with Wilcoxon and Kruskal–Wallis tests with Bonferroni correction. RESULTS Acetaminophen and placebo groups showed similar pain levels during the first 2 days, whereas ibuprofen group showed lower pain levels during the first day after bonding. PGE2 levels did not show statistically significant difference in time within the analgesic groups. No significant relation between the pain perceived and PGE2 released was found. LIMITATIONS The biggest limitation of this study is the subjective nature of pain and its method of evaluation. CONCLUSIONS The perception of pain by patients taking ibuprofen and acetaminophen at pre/post appliance placement was not different from patients taking placebo. No time-related differences in PGE2 level were found between the groups and no significant correlation was found between the perception of pain and PGE2 levels.

Biofilm-forming capacity of blood–borne Candida albicans strains and effects of antifungal agents

Infections related to Candida albicans biofilms and subsequent antifungal resistance have become more common with the increased use of indwelling medical devices. Regimens for preventing fungal biofilm formation are needed, particularly in high-risk patients. In this study, we investigated the biofilm formation rate of multiple strains of Candida albicans (n=162 clinical isolates), their antifungal susceptibility patterns, and the efficacy of certain antifungals for preventing biofilm formation. Biofilm formation was graded using a modified Christensens 96-well plate method. We further analyzed 30 randomly chosen intense biofilm-forming isolates using the XTT method. Minimum biofilm inhibition concentrations (MBIC) of caspofungin, micafungin, anidulafungin, fluconazole, voriconazole, posaconazole, itraconazole, and amphotericin B were determined using the modified Calgary biofilm method. In addition, the inhibitory effects of antifungal agents on biofilm formation were investigated. Our study showed weak, moderate, and extensive biofilm formation in 29% (n=47), 38% (n=61), and 23% (n=37) of the isolates, respectively. We found that echinocandins had the lowest MBIC values and that itraconazole inhibited biofilm formation in more isolates (26/32; 81.3%) than other tested agents. In conclusion, echinocandins were most effective against formed biofilms, while itraconazole was most effective for preventing biofilm formation. Standardized methods are needed for biofilm antifungal sensitivity tests when determining the treatment and prophylaxis of C. albicans infections.

Efficacy of multipurpose contact lens solutions against ESBL-positive Escherichia coli, MRSA, and Candida albicans clinical isolates.

Objectives: The antimicrobial effects of multipurpose contact lens solutions (MPSs) have been evaluated according to ISO 14729 standards. The aim of this study was to assess the efficacy of commercially available MPSs against extended-spectrum beta lactamases (ESBL)-producing Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans clinical isolates. Methods: Three commercially available contact lens solutions (Opti-Free Expresss, ReNu MultiPlus, and Solo Care Aqua) were tested against 18 ESBL-positive E. coli clinical strains, 20 MRSA clinical strains, and 20 C. albicans clinical strains. The stand-alone assays for bacteria and fungi were performed according to ISO 14729 criteria, and all samples were evaluated after 2, 4, and 24 hours of incubation. The numbers of viable microorganisms were evaluated by the plate-counting method. Results: All MPSs demonstrated at least 3 log reduction in colony-forming units (CFU) for all bacterial isolates and 1 log reduction in CFU for all yeast isolates, which meets ISO 14729 standards. Although no statistically significant differences were obtained among MPSs for bacterial isolates, variable responses were observed against clinical isolates: 5% povidone–iodine was more effective compared with Solo Care Aqua for C. albicans clinical strains (P<0.05); and all solutions were effective after an incubation time of only 2 hrs. The MPSs showed good activity against S. aureus, E. coli, and C. albicans. Conclusions: Although effective log reductions were provided with all MPSs, the reduction was variable depending on the strains tested. Multipurpose contact lens solutions should be tested under ISO 14729 standards for both standard and clinical strains.

Comparison between corneal cross-linking, topical antibiotic and combined therapy in experimental bacterial keratitis model.

Purpose This study was conducted to investigate the effects of an experimental bacterial keratitis model on the corneal collagen cross-linking treatment (CXL), and also to compare topical antibiotic treatment with the combined treatment. Methods The study involved 40 young adult female Sprague Dawley rats, which had a 2 mm scraped defect of the central corneal epithelium in both eyes. The rats were divided into two equal groups. The first group was inoculated in both eyes with standard Pseudomonas Aeruginosa (PA) from a strain suspension prepared from 0.05 ml (Group 1), and the second group was inoculated with standard Methicillin Resistance Staphylococcus Aureus (MRSA) strains from a suspension prepared from 0.05 ml (Group 2). Group 1 was divided into four sub-groups: Group 1A was treated by collagen cross-linking (CXL), Group 1C was treated with topical tobramycin drops CXL and also treated by collagen cross-linking (CXL), Group 1D was treated with topical tobramycin drops, and Group 1B was left untreated in order to create a control group. Similarly, Group 2 was also divided into four sub-groups: Group 2A was treated by CXL, Group 2C was treated with topical 5% fortified vancomycin drops CXL and also treated by CXL, Group 2D was treated with topical 5% fortified vancomycin drops, and Group 2B was left untreated in order to create a control group. CXL was performed on the third day following the inoculation and topical drop therapy. Biomicroscopy and microbiologic assessments were performed on the third and seventh days following the inoculation of microorganisms. Results In the treatment, which compared baselines in all groups before treatment, the diameter of keratitis infiltrations, corneal clouding, and corneal swab samples were obtained from the reduction in reproduction. The results were statistically significant (p < 0.01). Keratitis infiltration groups were conducted on the seventh day for Groups 1C and 1D according to Group 1B, whilst Groups 2A, 2C and 2D were conducted according to Group 2B, which showed a significant statistical reduction (p < 0.01). On the seventh day, focal groups were conducted in corneal clouding Group 1D according to Group 1B and in Groups 2A, 2C and 2D according to Group 2B, which revealed a significant statistical reduction (p < 0.01). On the seventh day, reproduction in culture was obtained from corneal swab samples in Groups 1C and 1D according to Group 1B; in Groups 1C and 1D according to Group 1A; in Groups 2A, 2C and 2D according to Group 2B; and in Group 2C according to Group 2A, where a significant statistical reduction was observed (p < 0.01). Conclusions The clinical and microbiological efficacy of the CXL treatment is evaluated in our study. In accordance with the conclusion reached an effective reduction in the density and severity of (infection), occurred as a result of CXL treatment, CXL treatment combined with topical antibiotic treatment and topical antibiotic treatment of Pseudomonas Aeruginosa (PA) and Metisilin Rezistant Staphylococcus Aureus (MRSA) keratitis infections. From these results, it is shown that topical antibiotics and CXL potentiate each other’s effects in the treatment of resistant bacterial keratitis.

Değişik içeriklere sahip Castellani solüsyonunun farklı mikroorganizmalar üzerine in vitro etkinliği

Objective: As the external auditory canal is a moisture area, it facilitates the growth of bacteria and fungi. Infections and inflammation due to Staphylococcus aureus, Pseudomonas aeruginosa, Aspergillus spp. and Candida albicans can develop in this area. Classical Castellani solution including boric acid, fenol, fucsin, resorcinol, acetone, and alcohol is used for external ear tract infections due to fungi and bacteria, and also for the superficial der matophytoses, and eczematous dermatitis of the external ear tract infections. The purpose of this study is to investigate of the in vitro effectiveness of classical Castellani solution and its different formulations with different dilutions against the standard yeast and bacteria strains.

Micrococcus luteus, Prevotella ve Trikomonas Birlikteliğinin Neden Olduğu Ampiyem: Bir Olgu Sunumu ve Literatürün Gözden Geçirilmesi

230 rikomonaslar, flagellası ile hareketli birer protozoondurlar. İnsanları enfekte ettiği bilinen dört tipi vardır: Trichomonas tenax oral kavitede, Trichomonas vaginalis genitoüriner sistemde, Pentatrichomonas hominis ve Dientamoeba fragilis bağırsak florasında bulunur.1 Plevral boşlukta pürülan sıvı birikmesine plevral ampiyem denir ve sıklıklada pnömoni sonrası gelişen bir komplikasyondur. Trikomonaslara bağlı bildirilmiş plevral ampiyem nadirdir ve etiyolojide en sık sorumlu tutulan etken T. tenax’tır.2,3 Burada aerob-anaerob bakteriler ile trikomonasların neden olduğu plevral ampiyem tanısı alan ve takibinde göğüs duvarında nekrotizan yumuşak doku enfeksiyonu gelişen bir olgu sunulmuş ve ilgili literatür gözden geçirilmiştir. Micrococcus luteus, Prevotella ve Trikomonas Birlikteliğinin Neden Olduğu Ampiyem: Bir Olgu Sunumu ve Literatürün Gözden Geçirilmesi