Fusun Can

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.

Risk factors for candidemia with non-albicans Candida spp. in intensive care unit patients with end-stage renal disease on chronic hemodialysis

BACKGROUND/PURPOSE The objective of this study was to describe factors associated with bloodstream infections (BSIs) with non-albicans Candida species (NAC), compared with Candida albicans BSIs, and antifungal susceptibility patterns in adult intensive care unit (ICU) patients with chronic renal failure undergoing hemodialysis. To the best of our knowledge, this is the first study to report the potential factors for NAC candidemia in ICU patients with end-stage renal disease on chronic hemodialysis. METHODS This prospective, observational, multicenter study was conducted in the two centers of Baskent University between January 2007 and July 2010. All adult patients excluding patients with neutropenia, malignancy, glucocorticoid treatment or AIDS, were included. RESULTS Sixty cases (58.8%) of candidemia were due to C. albicans and 42 (41.2%) to NAC. Multivariate regression analysis revealed that the presence of a central venous catheter was the only risk factor independently associated with BSI due to NAC (p=0.046, odds ratio: 5.90, 95% confidence interval: 1.032-33.717). Mortality was more frequent in those with NAC than C. albicans BSIs (64.3% vs. 55%), but the difference was not significant (p=0.067). Except for two Candida glabrata strains, which were dose-dependently fluconazole susceptible, all Candida species were susceptible to fluconazole, caspofungin, voriconazole and amphotericin B. CONCLUSION Central venous catheterization was the only factor significantly associated with BSI due to NAC in ICU patients with end-stage renal disease.

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.

Effect of manual bowel decompression (milking) in the obstructed small bowel

BACKGROUND Mechanical intestinal obstruction is a frequently encountered problem in general surgery. One of the frequently used techniques for surgical decompression, so-called milking, is to caress the intestinal contents cephalad into the stomach or caudally into the colon. The aim of our study was to examine the functional, morphologic, and microbiologic effects of manual bowel decompression (milking) in the obstructed small bowel. METHODS Six rats in the milking (M) group (obstructed and decompressed manually), 6 in the control (C) group (obstructed only), and 5 rats in the sham (S) group (laparotomy and evisceration) underwent surgery. Muscle contractility, gastrointestinal dye transmission, histopathologic changes of ileum, and bacterial translocation were analyzed. RESULTS The contractile response of intestinal segments to acetylcholine was significantly less in group M compared with those of groups C and S (P < .05). The maximal contractile response to acetylcholine also was significantly lower in group M (P < .05). There was no statistically significant difference between the groups regarding the sensitivity of cholinergic receptors. Frequency of peristaltic movements, progression of Evans blue dye, histopathologic variables, and the quantitative evaluation (colony-forming units/gram of tissue) of isolated bacteria were not different among the groups. However, Escherichia coli in group M and Klebsiella spp in group S were the main isolated bacteria. CONCLUSIONS Although it reduces muscle contractility, a milking procedure in an intestinal obstruction model does not cause peristaltic deterioration, histopathologic or inflammatory changes, or alterations in the degree of bacterial translocation.

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