Elife Berk

Investigation of the relationship between virulence factors and genotype of Candida spp. isolated from blood cultures.

INTRODUCTION The aim of study was to investigate the virulence factors of phospholipase, proteinase, esterase production and biofilm formation in Candida species isolated from patients with candidemia, and to assess their relationship with Candida genotypes derived after repetitive sequence-based polymerase chain reaction (rep-PCR) fingerprinting. METHODOLOGY Fifty-two strains were identified to species level according to conventional methods and sequencing. The DiversiLab system was used for the genotyping. Enzyme activities and biofilm formation were evaluated using microbiological methods. RESULTS The 52 strains were identified as follows: 29 C. parapsilosis, 19 C. albicans, 2 C. glabrata, and 2 C. tropicalis. Phospholipase and proteinase activities were observed to have statistically significant differences between C. albicans and non-albicans Candida (NAC) strains (p < 0.05), with C. albicans strains showing higher virulence. Rep-PCR revealed eight major genotypes (A-H).The 19 C. albicans and the 33 non-albicans Candida isolates yielded seven (A-G) and four (A, B, C, H) genotypes, respectively. C. albicans strains were not shown to have a predominant genotype and showed higher phospholipase and proteinase activitiy than did NAC, regardless of genotype. Genotype H (52%) was the predominant genotype for the NAC including 27 C. parapsilosis strains, but the majority of strains showed low virulence. CONCLUSIONS NAC species were the most common causative agent for candidemia. Genotyping showed low transmission of C. albicans strains, but transmission of C. parapsilosis was high. In candidemia, several Candida virulence factors may be responsible at the same time. However, different genotypes of Candida strains showed different virulence activity.

Is surveillance for colonization of carbapenem-resistant gram-negative bacteria important in adult bone marrow transplantation units?

HIGHLIGHTSThe colonization rate with carbapenem‐resistant gram‐negative bacteria (CRGNB) is 11.4% in hematopoietic stem cell transplantation patients.Regimens including busulfan and fludarabine and transfer history increase the risk of colonization of CRGNB.Bacteremia with the same strain was detected in 23.8% of CRGNB‐colonized patients (5/21).Colonization with CRGNB did not change the empirical antimicrobial treatment preference for febrile neutropenia.Colonization with CRGNB did not change the mortality rate. Background: The aim of this study was to investigate the rate of carbapenem‐resistant gram‐negative bacilli (CRGNB) colonization and to analyze the risk factors associated with CRGNB colonization. Methods: This prospective study was conducted in adult patients hospitalized in hematopoietic stem cell transplantation (HSCT) units over a period of 8 months. Rectal swab samples were obtained from each participant every Monday, and patients CRGNB positive on admission were excluded. Results: Of 185 participants, the median age was 47 years, and 59.5% were men. CRGNB colonization was detected in 21 (11.4%) patients. The most commonly isolated CRGNB were Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Multivariate analysis revealed that busulfan use (11.9 times), fludarabine use (6.4 times), transfer from another hospital (7.8 times), transfer between units (9.3 times), and central venous catheterization (5.1 times) were risk factors for CRGNB colonization. During the study period, febrile neutropenia (FN) developed in 9 (56.2%) of the 21 colonized patients, and 1 patient died. Conclusions: Screening of patients for CRGNB colonization may have a role in preventing the spread of CRGNB. However, the empirical antimicrobial treatment for FN in patients with CRGNB colonization did not change, and their mortality rates were similar.

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.

Tigecycline for the treatment of Clostridium difficile infection refractory to metronidazole in haematopoietic stem cell transplant recipients

Tigecycline for the treatment of Clostridium difficile infection refractory to metronidazole in haematopoietic stem cell transplant recipients Gökhan Metan, Zeynep Türe, Leylagül Kaynar, Elife Berk, Şebnem Gürsoy, Emine Alp, Hüseyin Kılıç, Mustafa Çetin Department of Infectious Diseases, Faculty of Medicine, Erciyes University, Kayseri, Turkey, Department of Hematology, Faculty of Medicine, Erciyes University, Kayseri, Turkey, Department of Clinical Microbiology, Faculty of Medicine, Erciyes University, Kayseri, Turkey, Department of Gastroenterology, Faculty of Medicine, Erciyes University, Kayseri, Turkey, Infection Control Committee, Faculty of Medicine, Erciyes University, Kayseri, Turkey

Antifungal Activity of Propolis Against Yeasts Isolated From Blood Culture: In Vitro Evaluation

Background: Due to the failure of available antifungal agents in the treatment of candidemia and the toxic activities of these drugs, a lot of researches are being conducted to develop new nontoxic and effective antifungal agents for optimal control of fungal pathogens. The aim of this study is to evaluate the in vitro antifungal activity of propolis against yeasts isolated from the blood cultures of intensive care unit patients.

Is rapid antibacterial susceptibility testing medium reliable for routine laboratory practices

Objective: Early detection of antibiotic susceptibility profile of the isolates has critical importance in terms of immediate beginning of the appropriate treatment and increasing of treatment success, such as meningitis, bacteriemia and sepsis. In the present study, it was aimed to compare the antibiotic susceptibility results of Quicolor (Salubris Inc., Massachusetts, USA) and standard disk diffusion method. Methods: One hundred twenty three isolates were included in this study (80 Enterobacteriaceae, 15 Staphylococci and 28 nonfermentative Gram-negative bacteria). Antibiotic susceptibility in clinical isolates was evaluated using Mueller-Hinton (MH) agar and Quicolor (ES and NF) agar plates. Results: For Enterobacteriaceae, frequency of total concordance, major error, and minor error between the tests were found as 96.8%, 0.8%, and 2.4%, respectively. For Staphylococci, frequency of total concordance, major error, and minor error among the tests were found as 95.7%, 3.5%, and 0.8%, respectively. For non fermentative bacteria, frequency of total concordance, major error, and minor error among the tests were found as 83.9%, 9.6%, and 6.4%, respectively. Conclusions: Quicolor media provided reliable susceptibility results in enteric bacteria and Staphylococci. However, further studies including higher number of nonfermentative bacteria are required to determine whether the chromogenic media are appropriate for this group of bacteria.

Evaluation of the Abbott Real Time HCV genotype II assay for Hepatitis C virus genotyping.

Objective: The determination of HCV genotypes and subtypes is very important for the selection of antiviral therapy and epidemiological studies. The aim of this study was to evaluate the performance of Abbott Real Time HCV Genotype II assay in HCV genotyping of HCV infected patients in Kayseri, Turkey. Methods: One hundred patients with chronic hepatitis C admitted to our hospital were evaluated between June 2012 and December 2012, HCV RNA levels were determined by the COBAS® AmpliPrep/COBAS® TaqMan® 48 HCV test. HCV genotyping was investigated by the Abbott Real Time HCV Genotype II assay. With the exception of genotype 1, subtypes of HCV genotypes could not be determined by Abbott assay. Sequencing analysis was used as the reference method. Results: Genotypes 1, 2, 3 and 4 were observed in 70, 4, 2 and 24 of the 100 patients, respectively, by two methods. The concordance between the two systems to determine HCV major genotypes was 100%. Of 70 patients with genotype 1, 66 showed infection with subtype 1b and 4 with subtype 1a by Abbott Real Time HCV Genotype II assay. Using sequence analysis, 61 showed infection with subtype 1b and 9 with subtype 1a. In determining of HCV genotype 1 subtypes, the difference between the two methods was not statistically significant (P>0.05). HCV genotype 4 and 3 samples were found to be subtype 4d and 3a, respectively, by sequence analysis. There were four patients with genotype 2. Sequence analysis revealed that two of these patients had type 2a and the other two had type 2b. Conclusion: The Abbott Real Time HCV Genotype II assay yielded results consistent with sequence analysis. However, further optimization of the Abbott Real Time HCV Genotype II assay for subtype identification of HCV is required.