Genotypes and population genetics of cryptococcus neoformans and cryptococcus gattii species complexes in Europe and the mediterranean area.

A total of 476 European isolates (310 Cryptococcus neoformans var. grubii, 150 C. neoformans var. neoformans, and 16 C. gattii species complex) from both clinical and environmental sources were analyzed by multi-locus sequence typing. Phylogenetic and population genetic analyses were performed. Sequence analysis identified 74 sequence types among C. neoformans var. neoformans (VNIV), 65 among C. neoformans var. grubii (56 VNI, 8 VNII, 1 VNB), and 5 among the C. gattii species complex (4 VGI and 1 VGIV) isolates. ST23 was the most frequent genotype (22%) among VNI isolates which were mostly grouped in a large clonal cluster including 50% of isolates. Among VNIV isolates, a predominant genotype was not identified. A high percentage of autochthonous STs were identified in both VNI (71%) and VNIV (96%) group of isolates. The 16 European C. gattii species complex isolates analyzed in the present study originated all from the environment and all belonged to a large cluster endemic in the Mediterranean area. Population genetic analysis confirmed that VNI group of isolates were characterized by low variability and clonal expansion while VNIV by a higher variability and a number of recombination events. However, when VNI and VNIV environmental isolates were compared, they showed a similar population structure with a high percentage of shared mutations and the absence of fixed mutations. Also linkage disequilibrium analysis reveals differences between clinical and environmental isolates showing a key role of PLB1 allele combinations in host infection as well as the key role of LAC1 allele combinations for survival of the fungus in the environment. The present study shows that genetic comparison of clinical and environmental isolates represents a first step to understand the genetic characteristics that cause the shift of some genotypes from a saprophytic to a parasitic life style.

Fundamental niche prediction of the pathogenic yeasts Cryptococcus neoformans and Cryptococcus gattii in Europe.

Fundamental niche prediction of Cryptococcus neoformans and Cryptococcus gattii in Europe is an important tool to understand where these pathogenic yeasts have a high probability to survive in the environment and therefore to identify the areas with high risk of infection. In this study, occurrence data for C. neoformans and C. gattii were compared by MaxEnt software with several bioclimatic conditions as well as with soil characteristics and land use. The results showed that C. gattii distribution can be predicted with high probability along the Mediterranean coast. The analysis of variables showed that its distribution is limited by low temperatures during the coldest season, and by heavy precipitations in the driest season. C. neoformans var. grubii is able to colonize the same areas of C. gattii but is more tolerant to cold winter temperatures and summer precipitations. In contrast, the C. neoformans var. neoformans map was completely different. The best conditions for its survival were displayed in sub-continental areas and not along the Mediterranean coasts. In conclusion, we produced for the first time detailed prediction maps of the species and varieties of the C. neoformans and C. gattii species complex in Europe and Mediterranean area.

Environmental distribution of Cryptococcus neoformans and C. gattii around the Mediterranean basin.

In order to elucidate the distribution of Cryptococcus neoformans and C. gattii in the Mediterranean basin, an extensive environmental survey was carried out during 2012-2015. A total of 302 sites located in 12 countries were sampled, 6436 samples from 3765 trees were collected and 5% of trees were found to be colonized by cryptococcal yeasts. Cryptococcus neoformans was isolated from 177 trees and C. gattii from 13. Cryptococcus neoformans colonized 27% of Ceratonia, 10% of Olea, Platanus and Prunus trees and a lower percentage of other tree genera. The 13 C. gattii isolates were collected from five Eucalyptus, four Ceratonia, two Pinus and two Olea trees. Cryptococcus neoformans was distributed all around the Mediterranean basin, whereas C. gattii was isolated in Greece, Southern Italy and Spain, in agreement with previous findings from both clinical and environmental sources. Among C. neoformans isolates, VNI was the prevalent molecular type but VNII, VNIV and VNIII hybrid strains were also isolated. With the exception of a single VGIV isolate, all C. gattii isolates were VGI. The results confirmed the presence of both Cryptococcus species in the Mediterranean environment, and showed that both carob and olive trees represent an important niche for these yeasts.

Multilocus sequence typing analysis reveals that Cryptococcus neoformans var. neoformans is a recombinant population.

Cryptococcus neoformans var. neoformans (serotype D) represents about 30% of the clinical isolates in Europe and is present less frequently in the other continents. It is the prevalent etiological agent in primary cutaneous cryptococcosis as well as in cryptococcal skin lesions of disseminated cryptococcosis. Very little is known about the genotypic diversity of this Cryptococcus subtype. The aim of this study was to investigate the genotypic diversity among a set of clinical and environmental C. neoformans var. neoformans isolates and to evaluate the relationship between genotypes, geographical origin and clinical manifestations. A total of 83 globally collected C. neoformans var. neoformans isolates from Italy, Germany, France, Belgium, Denmark, Greece, Turkey, Thailand, Japan, Colombia, and the USA, recovered from different sources (primary and secondary cutaneous cryptococcosis, disseminated cryptococcosis, the environment, and animals), were included in the study. All isolates were confirmed to belong to genotype VNIV by molecular typing and they were further investigated by MLST analysis. Maximum likelihood phylogenetic as well as network analysis strongly suggested the existence of a recombinant rather than a clonal population structure. Geographical origin and source of isolation were not correlated with a specific MLST genotype. The comparison with a set of outgroup C. neoformans var. grubii isolates provided clear evidence that the two varieties have different population structures.

An investigation of Candida species isolated from blood cultures during 17 years in a university hospital.

Candidemia is the most frequent manifestation observed with invasive candidiasis. The aim of this study was to analyse the trends of candidemia in a large tertiary-care hospital to determine the overall incidence during January 1996-December 2012, as well as to determine the susceptibility of 453 isolates according to the revised Clinical and Laboratory Standards Institute (CLSI) breakpoints. Candidemia episodes in adult and paediatric patients were retrospectively analysed from the laboratory data of Uludag University Healthcare and Research Hospital. The 17-year period studied was divided into three periods (1996-2001, 2002-2007 and 2008-2012) for better comparison, and candidemia incidence was determined by the ratio of total number of patients with candidemia per 1000 patients admitted to the hospital and per 10 000 patient days in these three periods. Redefined CLSI M27-A3 breakpoints were used for interpretation of antifungal susceptibility results. Candidemia incidence was determined as 2.2, 1.7 and 1.5 per 1000 admitted patients during 1996-2001, 2002-2007 and 2008-2012 respectively. A significantly decreased candidemia incidence was obtained in the third period. C. albicans (43.8%) was the most common candidemia agent, followed by C.parapsilosis (26.5%) in all three periods. According to the revised CLSI breakpoints, there was fluconazole resistance in C. albicans, C.parapsilosis, C.tropicalis and C.glabrata species (1.4%, 18.2%, 2.6% and 14.3% respectively). Almost all Candida species were found susceptible to voriconazole except one C.glabrata (7.1%) isolate. Candidemia is an important health problem. Local epidemiological data are determinative in the choice of appropriate antifungal treatment agents.

Effects of Malassezia yeasts on serum Th1 and Th2 cytokines in patients with guttate psoriasis.

BACKGROUND: Systemic and focal infections caused by microorganisms have been known to induce or exacerbate psoriasis. Although the role of yeast species of the genus Malassezia in the pathogenesis of psoriasis is not fully understood, it is thought that these lipophilic yeasts may represent a triggering factor in the exacerbation of psoriatic lesions. OBJECTIVES: This study investigated the effects of Malassezia yeasts on serum Th1 and Th2 cytokines in patients with guttate psoriasis (GP) in order to define their role in the pathogenesis of psoriasis. METHODS: Fifty patients with GP and 29 clinically healthy individuals were included in the study. All samples consisted of scales and scrapings taken from the scalps, trunks, and upper limbs of both psoriasis patients and healthy subjects. Psoriasis patients and healthy subjects were grouped according to their positivity or negativity for Malassezia yeasts as ascertained by direct microscopy and/or culture. An enzyme-linked immunosorbent assay (ELISA) was used to measure serum levels of Th1 and Th2 cytokines in these groups. RESULTS: No significant differences in positivity for Malassezia yeasts were found between psoriatic skin and healthy skin in samples taken from different body sites. Serum interleukin-13 (IL-13) levels were significantly lower in the psoriasis group compared with the control group (P = 0.04). Levels of other cytokines did not differ significantly between the psoriasis and control groups. Mean levels of Th2 cytokines (IL-4, IL-10, IL-13), but not of Th1 cytokines (IL-2 and IFN-γ), were significantly lower in psoriasis patients positive for Malassezia yeasts compared with those negative for Malassezia yeasts and control subjects (P = 0.04, P < 0.001 and P = 0.01, respectively). CONCLUSIONS: The isolation of Malassezia yeasts from GP lesions does not necessarily mean that these species are pathogenic, but their downregulating effects on anti-inflammatory Th2 cytokines may contribute to the occurrence of GP.

A comparative study of dermatophyte infections in Bursa, Turkey.

A total of 555 specimens from 372 patients with symptoms compatible with superficial mycosis were included in this study. Those from patients clinically diagnosed as having dermatomycosis were thoroughly investigated by mycological examinations in the laboratory, including microscopic studies of KOH mounts and cultivation of the samples in culture. The results of this study and a previous study in our hospital conducted in 1980 were compared with respect to clinical presentation and etiological agents. Onychomycosis was the most common clinical form of dermatomycoses, and Trichophyton rubrum was the most common pathogen in this study.

Genetic evaluation of von Hippel-Lindau disease for early diagnosis and improved prognosis.

von Hippel-Lindau disease (VHL) is a rare autosomal-dominant disorder in which affected individuals develop tumors in a number of locations. It occurs at a frequency of one per 36,000 population. Metastatic renal cell carcinoma (RCC) remains the leading cause of mortality in patients with clear cell RCC arising from mutations in the VHL tumor suppressor. RCC is the presenting feature in only 10% of VHL patients. VHL patients can present with a number of other renal lesions, such as hemangiomas and benign adenomas, in addition to simple cysts and RCC. We have investigated VHL gene mutations in familial RCC. The study cohort consisted of four patients with synchronous VHL and RCC and 31 kindreds. Analysis of the chromosomes was performed by the Moorehead method. Although none of the kindreds investigated had clinical evidence of VHL disease, 22 were found to have a VHL gene mutation consisting of deletions on the short arm of chromosomes 3, 17, and 19. Detailed clinical examination of the 22 kindreds with a VHL mutation revealed cerebellar hemangioblastoma (three kindreds), meningioma (two) and renal cell carcinoma (five). No VHL gene mutation was detected in nine kindreds. The prevalence of VHL gene mutations was 70.9% in the familial RCC kindreds. As a result of this study, the kindreds of patients with synchronous VHL and RCC have undergone molecular genetic testing and should be investigated for associated disorders.

[Malaria in Bursa]. / Bursa'da sitma.

In this investigation, the records of malaria cases detected by the Malaria Control Unit of the Infectious Disease Division of Bursa Health Directory, from January 1, 2003-October 30, 2006, were retrospectively examined. During this period, a total of 64,529 blood samples were examined and 55 malaria cases (ranging from 01-71 years of age) were reported. Of these, 56.3% were found to be imported cases coming to Bursa from other countries for various reasons. According to the records, the total slide positivity determined during the malaria surveillance was 0.08%. With the exception of three cases of Plasmodium falciparum of foreign origin, the cases were caused by Plasmodium vivax. Of the 55 positive cases, 19 (34.5%) were female and 36 (65.5%), male and the highest rate of cases occurred during September. The aim of this study was to aid the work being done in the control of malaria in our region.

[Evaluation of the distribution of intestinal parasites in the Uludag University Medical Faculty during a period of eight years.]. / Uludag Üniversitesi Tip Fakültesinde farkli yillarda bagirsak parazit dagilimlarinin degerlendirilmesi.

The purpose of the present study was to investigate retrospectively the distribution and prevalence of intestinal parasites in patients who presented at the routine parasitology laboratory of the Uludag University Medical Faculty, Bursa, during the 8 years from January 1993-December 2000. A total of 32,346 stool specimens were examined for intestinal parasites using native- Lugol and formol ethyl ether methods. Also, 10,897 cellophane- tape preparations were studied directly. Parasites were found in 8.14% of the samples. Of the patients, 46.32% were females and 53.68%, male. G. intestinalis (3.63%) and Enterobius vermicularis (3.41%) were the most prevalent parasites. The distribution of the parasites according the species was as follows: 115 (0.35%) Entamoeba histolytica and/or dispar, 73 (0.22%) Ascaris lumbricoides, 29 (0.089%) Taenia spp., 7 (%0.021) Dicrocoelium dentriticum, 6 (0.018%) Trichuris trichiura, 4 (0.012%) Hymenolepis nana, and 2 (0.006%) Strongyloides stercoralis. At least one parasite was seen in 96.47% of samples. Two parasites were found in 3.53% of the stool specimens,. The results of our study were similar to the rates of the Marmara Region. Our laboratory findings were found to be lower than previous laboratory findings.

Persistence of candiduria in ICU catheterized patients is not linked to adherence and proteolytic activities of Candida strains.

OBJECTIVE: In this study, the patients who developed asymptomatic candiduria in the intensive care unit were followed prospectively for the persistence of candiduria after the replacement of indwelling urethral catheter and the correlation between persistence and virulence factors (proteinase enzyme activity and epithelial adhesion) was assessed. DESIGN: Prospective study. SETTING: Intensive care unit and mycology laboratory at a university hospital. PATIENTS: Thirty-four patients with asymptomatic candiduria were included in the study. RESULTS: Candiduria persisted in 19 of 34 patients(56%; group 1) and cleared in 15 of 34 patients(44%; group 2) after urinary catheters were changed. When the virulence factors (epithelial adhesion and proteinase activity) and distribution of Candida spp. were compared between two groups, no statistically significant correlation was found. CONCLUSION: The host immune response might be more important than virulence factors of Candida spp. for persistence of candiduria.