Molecular epidemiology, antifungal susceptibility and virulence factors of Candida glabrata complex strains in Kayseri/Turkey.

BACKGROUND: Candida nivariensis and Candida bracarensis are included in Candida glabrata complex, which are usually misidentified as C. glabrata based on phenotypic identification methods. It was aimed to identify C. glabrata complex isolated from various clinical samples in Kayseri/Turkey to the species level and to determine antifungal susceptibilities, virulence factors, and molecular epidemiology. METHODS: Eighty three C. glabrata complex strains were studied in this study. Strains were phenotypically and molecularly identified. Phylogenetic analysis was done by the neighbor-joining method. Proteinase, phospholipase, esterase enzyme activity, and biofilm formation of strains were determined phenotypically. Antifungal susceptibility of strains were determined according to M60-Ed2 recommendations. RESULTS: All the 83 strains identified as C. glabrata complex by phenotypic tests were confirmed as C. glabrata sensu stricto (C. glabrata) by PCR amplification and sequence analysis, but other complex members C. nivariensis and C. bracarensis were not detected. Phylogenetic analysis results revealed 19 different genotypes. No clonal relationship was detected among the strains. Biofilm formation in 75.9% of strains and esterase activity in 7.2% were found positive. Antifungal resistance rates of strains were determined as 9.2% for fluconazole and 45.8% for itraconazole; 43.4% of the strains for voriconazole were determined as non-wild type. CONCLUSION: It was determined that biofilm and esterase activity might play an active role in the virulence of C. glabrata. In addition, high resistance rates to azoles in C. glabrata strains isolated in our hospital at Kayseri/Turkey emphasized the significance of epidemiological studies.

[Distribution of Yeast Species Isolated from Blood Cultures for a Six Year Period in Turkey: a Multicentre Study]. / Türkiye'de Alti Yillik Zaman Dilimi Içerisinde Kan Kültürlerinden Soyutlanan Maya Mantarlarinin Tür Dagilimi: Çok Merkezli Bir Çalisma.

Bloodstream infections due to yeast species especially Candida spp. have been reported to be important healthcare associated infections with high mortality and morbidity rates. Candidemia causes prolonged hospital stays as well as increased cost. In order to prevent or treat these life-threatening bloodstream infections successfully, nationwide epidemiological data should be available about the etiological agents of these infections. Multi-centre national epidemiological data on yeast bloodstream infections in Turkey is lacking. A retrospective study was designed and data from six different centres in Turkey between 2011 and 2016 years were gathered and analysed for the distribution and frequency of yeast species in order to assist clinicians in their choice of early and appropriate antifungal therapy. All laboratories used automated blood culture systems for the isolation of blood strains. All the participating centres performed the identification of their own isolates by conventional methods using germ tube test, morphology on corn meal agar with tween 80 and chromogenic media and the identification was confirmed by API 20C AUX, API ID 32C or matrix-assisted laser desorption/ionization time of flight mass spectrophotometry (MALDI-TOF MS) systems. The analysis of the results was performed on the basis of intensive care units (ICUs), other inpatient clinics (OICs) and totally all clinics (ACs). Totally 2547 yeast isolates were determined from six participating centres during six years. According to the total ACs results, Candida albicans was the most prevalent species (43.1%), followed by Candida parapsilosis complex (29.1%), Candida glabrata (10.1%), Candida tropicalis (7.5%), Candida krusei (2.4%) and Candida kefyr (1.6%) and the remaining (6.2%) of them consisted of other yeast species. The distribution of the Candida species did not show statistically significant difference between the years, however the increase of C.parapsilosis complex in 2016 was statistically significant, (p= 0.02). During the study period, totally 1054 yeast isolates were obtained from the ICUs of the centres. C.albicans predominated with 476 (45.2%) isolates and C.parapsilosis complex (28.7%), C.glabrata (10.7%) and C.tropicalis (7.3%) were the other leading species in ICUs. Among 1493 isolates of the OICs of six centres participated in the study, C.albicans was the most prevalent species with 622 (41.7%) isolates. The other frequent species of OICs were C.parapsilosis complex (29.5%), C.glabrata (9.6%) and C.tropicalis (7.6%) resembling ICU results. It can be concluded that C.albicans is still the leading cause of bloodstream infections in the six different centres located in various geographical areas of Turkey.

Identification and molecular epidemiology of dermatophyte isolates by repetitive-sequence-PCR-based DNA fingerprinting using the DiversiLab system in Turkey.

Dermatophyte species, isolation and identification in clinical samples are still difficult and take a long time. The identification and molecular epidemiology of dermatophytes commonly isolated in a clinical laboratory in Turkey by repetitive sequence-based PCR (rep-PCR) were assessed by comparing the results with those of reference identification. A total of 44 dermatophytes isolated from various clinical specimens of 20 patients with superficial mycoses in Kayseri and 24 patients in Hatay were studied. The identification of dermatophyte isolates was based on the reference identification and rep-PCR using the DiversiLab System (BioMerieux). The genotyping of dermatophyte isolates from different patients was determined by rep-PCR. In the identification of dermatophyte isolates, agreement between rep-PCR and conventional methods was 87.8 % ( 36 of 41). The dermatophyte strains belonged to four clones (A -D) which were determined by the use of rep-PCR. The dermatophyte strains in Clone B, D showed identical patterns with respect to the region. In conclusion, rep-PCR appears to be useful for evaluation of the identification and clonal relationships between Trichophyton rubrum species complex and Trichophyton mentagrophytes species complex isolates. The similarity and diversity of these isolates may be assessed according to different regions by rep-PCR.

Assessing the risk of false positive serum galactomannan among patients receiving piperacillin/tazobactam for febrile neutropenia.

Galactomannan (GM) assay is commonly used as an early diagnostic tool for invasive fungal infection (IFI) in high-risk hematology patients. False positivity is frequently observed in GM with the use of piperacillin/tazobactam. The usage of generic drugs over the original brand has a significant cost advantage. The aim of this study was to assess the performance of GM test among patients receiving original and generic piperacillin/tazobactam formulations. The study included 85 adult patients; 62.4% were male with hematological malignancy currently receiving piperacillin/tazobactam. The study group was divided into two groups: patients receiving original and generic piperacillin/tazobactam. Serum GM index was positive in one of 35 patients receiving original piperacillin/tazobactam, whereas it was positive in 46 out of 50 patients receiving generic piperacillin/tazobactam (P < .001). However, the patients receiving generic piperacillin/tazobactam underwent computed tomography (CT) scans more frequently than those receiving original piperacillin/tazobactam (P = .047). In addition, in vitro analysis of GM was performed in two generics and one original piperacillin/tazobactam vials. One generic piperacillin/tazobactam vial included high GM level. False positivity of serum GM with generic formulations of piperacillin/tazobactam is still an ongoing issue in hematology patients. A high rate of serum GM index false positivity may unexpectedly lead to a higher rate of CT scan. Selected piperacillin/tazobactam vials in each batch should be checked for GM to identify a false positivity of GM before purchase.

Molecular epidemiology and antifungal susceptibility of Saprochaete capitata (Blastoschizomyces capitatus) isolates causing nosocomial infection in Kayseri/Turkey.

BACKGROUND: Saprochaete capitata isolates have emerged as important nosocomial pathogens, among immunosuppressed or neutropenic patients, and a rare cause of nosocomial infection in the hematology-bone marrow unit (HBMU) and the intensive care unit (ICU). The purpose of this study was to molecular epidemiology and antifungal susceptibility of S. capitata (Blastoschizomyces capitatus) isolates causing nosocomial infection at Kayseri in Turkey. METHODS: During a period from 2012 to 2015, a total of 20 S. capitata strains were obtained from patients hospitalized at Erciyes University Hospital. The identification of S. capitata was performed by phenotypic and biochemical methods; this was confirmed by molecular methods by DNA sequencing analysis. Genotyping of S.capitata isolates from different patients was determined to by the repetitive sequence PCR (repPCR) using the DiversiLab System (BioMerieux). RESULTS: More than half of the patients with S. capitata infections were hospitalized in the hematology-oncology unit (60%). The patients mainly included those using intravascular devices (90%), and receiving parenteral antibiotics (85%); the mortality rate was 55%. The microbiological investigation failed to identify S. capitata in the hospital environment. All isolates were resistant to caspofungin (>32). However, the MIC90 values for voriconazole, amphotericin B, and fluconazole against all of the isolates were 0.125, 0.25, and 1µg/ml, respectively. The S. capitata strains belonged to five clones (A-E) which were determined by the use of rep-PCR and Clone C was found to be predominant. CONCLUSIONS: S. capitata isolates are an important cause of nosocomial infection in the HBMU and ICUs.

Interdigital foot infections: Corynebacterium minutissimum and agents of superficial mycoses.

Interdigital foot infections are mostly caused initially by dermatophytes, yeasts and less frequently by bacteria. Erythrasma caused by Corynebacterium minutissimum can be confused with superficial mycoses. The aim of the study was to determine the prevalence of the etiologic agents of superficial mycoses and the frequency of Corynebacterium minutissimum in interdigital foot infections. All the samples obtained from the 121 patients with interdigital foot infections were examined directly with the use of 20% potassium hydroxide mounts and Gram stain under the microscope and cultured on Sabouraud's dextrose agar plates. In identification of superficial mycoses, the rate was found to be 14% with the cultural method and 14% with direct microscopic examination. Using a combination of direct microscopic examination and culture, a 33.8% ratio was achieved. In the culture of these samples, the most isolated factor was Trichophyton rubrum (33.7%). In 24 of the patients (19.8%) Corynebacterium minutissimum was detected by Gram staining, in 6 of these patients Trichophyton rubrum was found, Trichophyton mentagrophytes was found in 2 and Trichosporon spp. was found in 1. The examination of interdigital foot lesions in the laboratory, the coexistence of erythrasma with dermatophytes and yeast should be considered.

[Investigation of Pneumocystis jirovecii in clinical specimens by different methods]. / Klinik Örneklerde Çesitli Yöntemlerle Pneumocystis jirovecii Arastirilmasi

Pneumocystis jirovecii causes pneumonia in premature, newborn or malnourished children, as well as in immunocompromised subjects such as chemotherapy receiving, transplant and AIDS patients. Since the mortality and morbidity rates of Pneumocystis pneumonia (PCP) in these patients were high, rapid and accurate diagnosis is important. The aim of this study was to evaluate the diagnostic value of Giemsa staining (GS), direct fluorescent antibody (DFA) assay, (1→3)-ß-D-Glucan (BDG) test and real-time polymerase chain reaction (PCR) for the detection of P.jirovecii in clinical specimens. A total of 100 PCP-suspected patients with underlying diseases who were followed-up in outpatient and inpatient clinics of our hospital between December 2008-July 2010 were included in the study. All the patients (66 male, 34 female; mean age: 42.04 years) were under long-term immunosuppressive drug therapy due to their hematological malignancies, kidney transplantation, neutropenia or chronic diseases. Respiratory samples [86 bronchoalveolar lavage (BAL), 8 endotracheal aspirate, 1 nasotracheal aspirate, 3 pleural, 2 lung biopsy samples] obtained from the patients have been studied with GS (Merck, Germany), DFA (Pneumo Cel, Cellabs, Australia) and PCR (primers targeting MSG gene, LightCycler, Roche, USA), while serum samples (n= 100) with BDG (Fungitell, ACC Inc, USA) and PCR methods. In BAL samples two were found positive by GS, DFA and PCR, and six were positive only by PCR, yielding a total positivity in 8 (8%) samples. All of the sera were negative with PCR, however 29 of them were positive (> 80 pg/ml), five were equivocal (61-79 pg/ml) and 66 were negative (< 60 pg/ml) with BDG test. Eight patients with positive results in BAL-PCR were also positive with BDG test. Although the agreement between GS and DFA was high (κ= 1), it was observed as low between PCR and DFA (κ= 0.38), DFA and BDG (κ= 0.07), BAL-PCR and BDG (κ= 0.28). DFA taken as the gold standard, the sensitivity and specificity values of GS, PCR and BDG methods were calculated as 100% and 100%; 100% and 93%; 100% and 67%, respectively. In the ROC analysis performed for BDG test, with DFA and BAL-PCR taken as the gold standards, the sensitivity, specificity and cut-off values of BDG were estimated as 100%, 93.9% and 494 pg/ml, and 100%, 72.8% and 62 pg/ml, respectively. Our data indicated that, overall specificity was high (100%) when using GS and DFA tests together, while the sensitivity has been elevated to 93% with the additional use of PCR and BDG tests, in the diagnosis of PCP-suspected patients. In conclusion, combination of all these tests should be performed for the laboratory diagnosis of P.jirovecii.

[Three cases of fungemia caused by Blastoschizomyces capitatus]. / Blastoschizomyces capitatus'un Neden Oldugu Üç Fungemi Olgusu.

Blastoschizomyces capitatus is a rare fungal pathogen that may lead to severe and fatal systemic infections especially in immunosuppressive individuals. B.capitatus strains have also been reported as the cause of hospital-acquired infections and outbreaks. In this report, three fungemia cases caused by B.capitatus with hematologic malignancies have been presented. The first case was a 20-year-old female with acute lymphoblastic leukemia, the second was a 26-year-old female with B-cell malignant lymphoma and the third was a 7-year-old male with B-cell acute lymphoblastic leukemia. All of the patients have been receiving chemotherapy, and treated with antibacterial and antifungal agents due to neutropenia. The blood cultures obtained from the second and third patients yielded B.capitatus although they were under empirical caspofungin therapy. Those patients have been treated with voriconazole and amphotericin B after the identification of B.capitatus, and clinical improvement were noted during their follow-up. However the first patient who was also under caspofungin therapy had died just before the isolation of B.capitatus from her blood culture. Conventional mycological methods [macroscopic and microscopic morphology, germ tube test, urea hydrolysis, carbohydrate assimilation tests (API 20C AUX; BioMerieux, France), growth temperature, cycloheximide sensitivity] were used for the identification of the isolates. The strains were identified as B.capitatus with the characteristics of annelloconidia formation, urease negativity, carbohydrate utilization, growth at 45°C and resistance to cycloheximide. Antifungal susceptibilities of isolates were determined by using microdilution method (for amphotericin B, fluconazole, itraconazole, voriconazole, ketoconazole) and E-test (for caspofungin). Minimum inhibitory concentration (MIC) values of the three B.capitatus strains were detected as 0.25, 0.125, 0.032 µg/ml for amphotericin B; 2, 2, 16 µg/ml for fluconazole; 0.064, 0.032, 0.032 µg/ml for itraconazole and 0.125, 0.064, 0.064 µg/ml for ketoconazole, respectively, while MIC values of all strains were 0.032 µg/ml for voriconazole and > 32 µg/ml for caspofungin. Since B.capitatus strains were isolated from the cases within about 15 days -sequentially-, the genotypes of the isolates were determined by repetitive sequence-based PCR (DiversiLab System; BioMerieux, France) to investigate the similarity rates. The results of analysis indicated 97% similarity between two (case 1 and 2) strains and 94.9% similarity in one strain (case 3) of B.capitatus, however the transmission route could not be clarified due to the absence of environmental sampling. In conclusion, B.capitatus should also be considered as a cause of systemic fungal infections in immunocompromised patients. Determination of the in vitro antifungal susceptibilities of clinical B.capitatus strains may contribute to the therapeutic approaches and epidemiological data.

What should be the optimal cut-off of serum 1,3-ß-D-glucan for the detection of invasive pulmonary aspergillosis in patients with haematological malignancies?

BACKGROUND: The detection of 1,3-ß-d-glucan (BDG), a cell wall component of several medically important fungi, is a promising tool for the diagnosis of invasive pulmonary aspergillosis. The aim of this study was to evaluate the diagnostic accuracy of the BDG test in invasive pulmonary aspergillosis (IPA) by focusing on the optimal cut-off value. METHODS: The records of the Infection Control Committee were reviewed to identify patients with haematological malignancies and stem cell transplantation who had at least 1 BDG (Fungitell kit) measurement during the period January 2008 through April 2011. The European Organization for Research and Treatment of Cancer and the Mycoses Study Group (EORTC/MSG) criteria (independent of BDG results) were used to categorize the patients with IPA. Patients with possible IPA were not included in the study. RESULTS: A total of 128 patients (50 with proven or probable IPA) were included in the study. At the manufacturer's recommended cut-off value of 80 pg/ml, the sensitivity of BDG was 66% (95% CI 51.2-78.7), specificity 75.6% (95% CI 64.6-84.5), positive predictive value (PPV) 63.4%, and negative predictive value (NPV) 77.6%. A receiver operating characteristic (ROC) curve was constructed to define the optimum serum BDG cut-off for the diagnosis of IPA. At a cut-off value of 181 pg/ml, the sensitivity was 52% (95% CI 37.4-66.3), specificity 94.8% (95% CI 87.4-98.6), PPV 86.7%, and NPV 75.5%. CONCLUSIONS: Although higher cut-off levels increased the specificity of the BDG test, sensitivity decreased to an unacceptable level; the commercially recommended cut-off value appears to be appropriate for screening purposes.

Pleuritis caused by Acremonium strictum in a patient with colon adenocarcinoma.

Although Acremonium strictum is environmentally widespread as opportunistic mold, it may cause infection in patients who have immunodeficiency problems. In this study, Staphylococcus aureus and A. strictum were isolated from the pleural fluid of a patient with colon adenocarcinoma. The patient did not receive antifungal therapy because the patient died after the isolation of mold. The minimal inhibitory concentrations of amphotericin B, fluconazole, ketoconazole, itraconazole, voriconazole for the A. strictum strain isolated from pleural fluid were 0.125, 256, 2 and 1.5, 0.25 mug ml(-1) respectively. In conclusion, bacteria and fungus, especially opportunistic mold, should be taken into consideration in developing pleuritis in the patients with immune-deficiency.

[The prevalence of Pediculus capitis in students of eight primary schools in the rural area of the Kayseri province]. / Kayseri ili kirsalindaki sekiz ilkögretim okulunda Pediculus capitis prevalansi.

This study was performed, from May-June 2005, on 648 (51.4%) males and 613 (48.6%) females making total of 1261 students from eight primary schools in following towns, Yemliha, Mahzemin, Gesi, Günesli, Cirgalan, and Agirnas, in the rural area of the Kayseri Province. Either the adult or egg forms of Pediculus humanus var. capitis were found in 16 (2.1%) male students and 101 (16.4%), female making a total of 117 (9.1%) students. The prevalence of infestation was significantly higher in girls than in boys, the difference was found statistically significant (chi2=71.77, p < 0.05). In these eight primary schools the prevalence rate of infestation was also found statistically significant (chi 2= 95.7, p < 0.05). In conclusion, Pediculus capitis is still a public health problem. For an effective fight against this disease, students, teachers and parents must be acquainted with this subject and also surveillance must be increased.

Vulvovaginal candidiasis in children and adolescents with type 1 diabetes mellitus.

In this prospective study we investigated the frequency of vulvovaginal candidiasis, the results of yeast cultures and detection of ketoconazole resistance in female children and adolescents with type 1 diabetes mellitus (DM1). The study consisted of 35 patients with DM1 (age 1.7-20 years) and 22 controls (age 1.5-18 years). Age, duration of DM1 and evidence of genital symptoms were recorded initially. After a pelvic examination, two separate swabs and samples for blood glucose and hemoglobin A1c (HbA1c) were taken. One of the swabs was used for direct examination and the second was placed on Sabouraud's dextrose agar and incubated. In vitro susceptibility of Candida species to ketoconazole was established by using Etest (AB B1ODISC). Candida species were isolated in 32 of 61 (52.5%) swabs of patients with DM1 and five of 22 (18.2%) of the control group. The predominant Candida species isolated from patients with DM1 were C. albicans (72.7%), C. glabrata (22.7%), C. tropicalis (2.3%), and C. parapsilosis (2.3%). The mean HbA1c in diabetic patients from whom Candida species were isolated was significantly higher than that of patients without Candida infection (p = 0.002). Most of the C. glabrata isolates were significantly resistant to ketoconazole. During the follow-up of patients with DM1, genital candidiasis is generally overlooked. It should not be forgotten that species other than C. albicans might cause genital candidiasis.

In vitro susceptibility testing of dermatophytes: comparison of disk diffusion and reference broth dilution methods.

A total of 56 strains belonging to 4 species of dermatophytes were tested against 10 antifungal drugs by using a modification of the NCCLS (M38-P) standard for filamentous fungi. The minimum inhibitory concentration (MIC) values obtained using the dilution method were compared with the diameters of growth inhibition zones using the disk diffusion method. The antifungals used were itraconazole, fluconazole, ketoconazole, miconazole, sulconazole, oxiconazole, bifonazole, griseofulvin, ciclopiroxolamine, and terbinafine. Relative to the other agents tested, terbinafine possessed the highest antifungal activity against all of the dermatophytes. In contrast, fluconazole was the least active drug. An increase of MIC values was accompanied by a decrease of growth inhibition zone diameter. The disk diffusion method of fungal susceptibility assessment yields data consistent with results obtained from the dilution method. The study suggests the potential value of the disk diffusion method as a convenient alternative method for testing the susceptibilities of dermatophytes.

A case of pulmonary Microsporidiasis in an acute myeloblastic leukemia (AML) - M3 patient.

Reported here is a case of microsporidiasis that occurred in an acute myeloblastic leukemia (AML)-M3 patient who underwent chemotherapy. Fever, cough, expectorate and dyspnea were observed during the therapy. Since this case was considered as adult respiratory distress syndrome due to the chest X-ray and arterial blood gas findings, the male patient was bounded to a mechanical ventilator. As coagulation tests showed compatible findings with disseminate intravascular coagulation (DIC), it was thought to be a case of sepsis originating from the lungs and DIC. Pseudomonas aeruginosa and Staphylococcus aureus were found in the sputum of the patient. Although he was given combined antibiotic therapy, there was no reduction in the fever. A bronchoalveolar lavage (BAL) sample was taken and Microsporidia sp. was found upon staining with Giemsa. The patient died due to sepsis and DIC just before receiving therapy for microsporidiasis. Pulmonary infection with Microsporidia, although classically occurring in patients with HIV infection, may occur rarely in leukemia patients, especially if previously treated with systemic immune suppression. This case reinforces the need to consider Microsporidia as a possible pathogen in immunocompromised patients with pulmonary infections.