Dolunay Gülmez

Distribution, virulence attributes and antifungal susceptibility patterns of Candida parapsilosis complex strains isolated from clinical samples

It was recently proposed that Candida parapsilosis represents a complex composed of three closely related species, i.e., C. parapsilosis sensu stricto, C. orthopsilosis, and C. metapsilosis. The aim of this study was to describe the distribution of C. parapsilosis complex isolates among clinical samples. We also evaluated antifungal susceptibility profiles, in vitro presence of lipase and secreted aspartyl proteinase, as well as their ability to grow in total parenteral nutrition (TPN) solution, and biofilm production. A total of 413 non-C. albicans Candida isolates were obtained from various clinical samples between 2010 and 2011 in a Turkish Tertiary Care Hospital. Of them, 42 were identified as members of the C. parapsilosis complex. Among these, 38 (90.5%) were C. parapsilosis sensu stricto, 3 (7.1%) C. metapsilosis, and 1 (2.4%) C. orthopsilosis. All isolates recovered from blood were found to be C. parapsilosis sensu stricto and C. metapsilosis. In phenotypic tests, all 42 isolates grew in TPN solution and, although 26.2% of C. parapsilosis sensu stricto-isolates were capable of forming biofilms in vitro, neither C. orthopsilosis nor C. metapsilosis isolates were able to do so. Acid proteinase activity was detected in 31% of isolates and lipase activity in 33%. All isolates were sensitive to voriconazole, caspofungin, and anidulafungin, with only a single C. parapsilosis sensu stricto isolate showing dose-dependent susceptible to fluconazole. While the number of C. metapsilosis and C. orthopsilosis isolates remained low, there were no significant differences in antifungal MIC as compared to C. parapsilosis sensu stricto.

Epidemiology of candidaemia in a tertiary care university hospital: 10-year experience with 381 candidaemia episodes between 2001 and 2010

Defining the epidemiology of and risk factors for candidaemia is necessary to guide empirical treatment. The objectives of this study were to determine the ranking of Candida among positive blood cultures, to define the epidemiology of candidaemia and to investigate patient characteristics and their relationship with C. albicans vs. non‐albicans Candida (NAC) candidaemia. Candidaemia episodes between January 2001 and December 2010 were evaluated retrospectively. Patient characteristics were compared across Candida species. Candida ranked as the fifth most frequently isolated pathogen. Among 381 candidaemia episodes, 58.3% were due to C. albicans, followed by C. parapsilosis (15.2%), C. tropicalis (13.4%) and C. glabrata (6.8%). No statistically significant difference was observed in the distribution of C. albicans vs. NAC (P = 0.432). Patients with NAC had significantly higher rates of haematological disorders (P < 0.001) and neutropenia (P = 0.003), and were older (P = 0.024) than patients with C. albicans, whereas patients with urinary catheters had higher rates of C. albicans (P = 0.007). On species basis, C. tropicalis was more frequently isolated from patients with haematological disorders (P < 0.001) and neutropenia (P = 0.008). Patients with urinary catheters were less likely to have C. parapsilosis (P = 0.043). C. glabrata was most prevalent among patients with solid organ tumours (P = 0.038), but not evident in patients with haematological disorders. Local epidemiological features and risk factors may have important implications for the management of candidaemia.

The growth of bacteria in infusion drugs: propofol 2% supports growth when remifentanil and pantoprazole do not

BACKGROUND AND OBJECTIVES Contamination risks of propofol 2%, remifentanil, and pantoprazole; and in vitro effects of these drugs on the growth of common infective agents in intensive care units were evaluated. METHODS For detection of contamination risk, drugs were prepared ready to use under intensive care unit conditions, were tested. Effects of these three drugs on bacterial growth were also investigated. Drugs were prepared at the concentrations used in the intensive care unit and inoculated with common pathogens after which they were incubated at 4°C, 22°C and 36°C. Subcultures were made at 0, 2, 4 and 8h and colony counts were evaluated. Minimum inhibitory concentration values were determined for all drugs at 4°C, 22°C and 36°C. RESULTS No growth was observed in the drugs prepared in the intensive care unit. Propofol tended to support while remifentanil inhibited bacterial growth. Effect of pantoprozole differed according to the bacteria tested. None of the drugs showed antibacterial activity at the maximum concentrations which may be achieved in blood of the patients. CONCLUSION Propofol strongly supports the growth of the microorganisms tested, although remifentanil and pantoprazole do not. Therefore, it is important to follow the strict aseptic techniques for the preparation of propofol.

Container type and bactericidal activity of human milk during refrigerated storage.

Background: Refrigeration of human milk has been recommended for its short-term storage. It has been shown that some nutritional, immunological, and bioactive properties and bactericidal activity of human milk can be altered during refrigeration. Pyrex bottles and polyethylene bags are 2 commonly used containers for human milk storage. Objective: The aim of this study was to compare the association between storage container type on the bactericidal activity of human milk for different durations of refrigeration (fresh, and at 24 and 48 hours). Methods: Forty-four samples of human milk were collected from 22 lactating mothers. Two samples of breast milk (approximately 10 mL each) were obtained by manual expression from each mother. One was collected directly into sterile Pyrex bottles and the other into polyethylene bags. One mL of human milk from each container was processed immediately after arrival to the laboratory. The remaining human milk was kept in the Pyrex and polyethylene containers at 4°C until analysis at 24 and 48 hours. The bactericidal activity of each sample was studied. A strain of Escherichia coli ATCC 25922 was used to determine the bactericidal effect of human milk. Results: Bactericidal activity was significantly reduced in milk samples stored in polyethylene bags compared to those stored in Pyrex bottles when milk samples were stored at 4°C for 24 and 48 hours (P < .05). Conclusion: Short-term storage of human milk in Pyrex bottles is more appropriate than polyethylene bags for preserving its bactericidal activity against E coli.

Predominance of hospital-associated MRSA among cystic fibrosis patients in a Turkish reference cystic fibrosis centre

Abstract Methicillin-resistant Staphylococcus aureus (MRSA) strains are the major causative agents of numerous hospital- and community-acquired infections. Increasing prevalence of MRSA in cystic fibrosis (CF) populations is reported all over the world. Although there are papers reporting the prevalence and genetic backgrounds of MRSA isolates from different settings in Turkey, there is no information regarding the situation in the CF community. This study was conducted to characterize the MRSA strains recovered from CF patients followed-up at a Turkish reference CF centre. Microbiological testing of isolates was performed via conventional microbiological techniques. Molecular characterization of MRSA isolates was carried out by SCCmec typing by multiplex PCR and PVL gene determination. Among a total of 604 CF patients included in the study, 325 patients were found to harbour S. aureus (53·8%). Of those 325 patients, 24 were positive for MRSA during their follow-up (7·4%). Thirty-two MRSA isolates from these patients were chosen for further assessment of molecular characteristics. Twenty-six MRSA isolates exhibited a pattern like SCCmec type III (81·2%) and six consecutive MRSA isolates of a single patient revealed SCCmec type IV (18·7%). Our findings definitely support the need for further surveillance studies for CF-MRSA strains and highlight the need for infection control measures in the setting of CF centres.

In vitro activities of antifungal drugs against environmental Exophiala isolates and review of the literature

Exophiala is a genus of black fungi isolated worldwide from environmental and clinical specimens. Data on antifungal susceptibility of Exophiala isolates are limited and the methodology on susceptibility testing is not yet standardised. In this study, we investigated in vitro antifungal susceptibilities of environmental Exophiala isolates. A total of 87 Exophiala isolated from dishwashers or railway ties were included. A CLSI M38‐A2 microdilution method with modifications was used to determine antifungal susceptibility for fluconazole, voriconazole, posaconazole, itraconazole, amphotericin B and terbinafine. Minimum inhibitory concentration (MIC) values were determined visually at 48 hours, 72 hours and 96 hours. MIC‐0 endpoint (complete inhibition of growth) was used for amphotericin B and azoles, except fluconazole, for which MIC‐2 endpoint (~50% inhibition compared to growth control) was used. Both MIC‐0 and MIC‐1 (~80% inhibition compared to growth control) results were analysed for terbinafine to enable comparison with previous studies. Fungal growth was sufficient for determination of MICs at 48 hours for all isolates except two Exophiala dermatitidis strains. At 72 hours, most active antifungal agents according to GM MIC were voriconazole and terbinafine, followed by posaconazole, itraconazole and amphotericin B in rank order of decreasing activity. While amphotericin B displayed adequate in vitro activity despite relatively high MICs, fluconazole showed no meaningful antifungal activity against Exophiala.

1406 Effect of Storage Container on Bactericidal Activity of Human Milk

Aim Storage of human milk in refrigerator has been recommended for short term storage. It has been shown that some nutritional, immunological, bioactive properties and bactericidal activity of human milk can alter by refrigeration. Pyrex bottles and polyethylene bags are the two common containers in the setting of storage of human milk. The aim of this study is to compare the effect of the type of storage container on bactericidal activity of human milk at different duration of refrigeration. Methods Forty four samples of human milk were collected from 22 lactating mother. Two samples of human milk were obtained by manual expression from each mother. One was collected directly into sterile pyrex bottles and the other into polyethylene bags. Each sample was divided into three aliquots, one was processed immediately and remaining two were kept at 4°C for 24 and 48 hours. Bactericidal activity of each sample was studied. A strain of E.coli ATCC 25922 was used to determine the bacteridal effect of human milk. Results Bactericidal activity was significantly reduced in milk samples kept in polyethylene bags compared to the samples kept in pyrex bottles when milk samples stored at 4°C for 24 and 48 hours (p<0.05). Conclusion Short term storage of human milk in pyrex bottles is more appropriate than polyethylene bags for prevention of decrease in bactericidal activity.