Differences in proteolytic activity and gene profiles of fungal strains isolated from the total parenteral nutrition patients

Fungal infections constitute a serious clinical problem in the group of patients receiving total parenteral nutrition. The majority of species isolated from infections of the total parenteral nutrition patients belong to Candida genus. The most important factors of Candida spp. virulence are the phenomenon of “phenotypic switching,” adhesins, dimorphism of fungal cells and the secretion of hydrolytic enzymes such as proteinases and lipases, including aspartyl proteinases. We determined the proteolytic activity of yeast-like fungal strains cultured from the clinical materials of patients receiving total parenteral nutrition and detected genes encoding aspartyl proteinases in predominant species Candida glabrata—YPS2, YPS4, and YPS6, and Candida albicans—SAP1–3, SAP4, SAP5, and SAP6. C. albicans released proteinases on the various activity levels. All C. glabrata strains obtained from the clinical materials of examined and control groups exhibited secretion of the proteinases. All 13 isolates of C. albicans possessed genes SAP1–3. Gene SAP4 was detected in genome of 11 C. albicans strains, SAP5 in 6, and SAP6 in 11. Twenty-six among 31 of C. glabrata isolates contained YPS2 gene, 21 the YPS4 gene, and 28 the YPS6 gene. We observed that clinical isolates of C. albicans and C. glabrata differed in SAPs and YPSs gene profiles, respectively, and displayed differentiated proteolytic activity. We suppose that different sets of aspartyl proteinases genes as well as various proteinase-activity levels would have the influence on strains virulence

Candida glabrata : a review of its features and resistance

Candida species belong to the normal microbiota of the oral cavity and gastrointestinal and vaginal tracts, and are responsible for several clinical manifestations, from mucocutaneous overgrowth to bloodstream infections. Once believed to be non-pathogenic, Candida glabrata was rapidly blamable for many human diseases. Year after year, these pathological circumstances are more recurrent and problematic to treat, especially when patients reveal any level of immunosuppression. These difficulties arise from the capacity of C. glabrata to form biofilms and also from its high resistance to traditional antifungal therapies. Thus, this review intends to present an excerpt of the biology, epidemiology, and pathology of C. glabrata, and detail an approach to its resistance mechanisms based on studies carried out up to the present.The authors are grateful to strategic project PTDC/SAU-MIC/119069/2010 for the financial support to the research center and for Celia F. Rodrigues' grant

Clinical characteristics of Turkish women with Candida krusei vaginitis and antifungal susceptibility of the C. krusei isolates

PubMedID: 24396265Objective. Candida krusei causes approximately 1% of vulvovaginal candidiasis (VVC) cases and is naturally resistant to fluconazole. Antifungal testing may be required if C. krusei vaginitis fails to respond to non-fluconazole therapy, particularly in patients with recurrent infections. Design. We investigated the clinical characteristics and antifungal susceptibility profile of vaginal C. krusei isolates. Between 2009 and 2012, we identified 560 unrelated Candida spp.-positive vaginal cultures, of which 28 (5.0%) were C. krusei. These isolates were analyzed according to host factors and the clinical forms of VVC, and their in vitro susceptibility to 10 antifungal agents was tested using a reference microdilution method. Results. We observed that perineal laceration and increased age (>50 years) were significant predictors of C. krusei in vaginal samples (P<0.05). All isolates were susceptible to amphotericin B, caspofungin, ketoconazole, and miconazole. Additionally, susceptible dose-dependent and resistant rates were found for fluconazole as 42.9% and 57.1%, respectively. Remarkably, only 42.9% and 67.9% of the isolates were susceptible to itraconazole and voriconazole, respectively. Conclusions. Understanding local susceptibility patterns, especially those of non-C. albicans Candida species, can significantly aid in the selection of an effective antifungal agent. The in vivo response of C. krusei vaginitis to various antifungal therapeutics remains unknown and requires further research. © 2013 Ahmet Bariş Güzel et al

Candida hellenica Candidemia occurred after esophagus surgery [Özofagus cerrahisi sonrası gelişen candida hellenica kandidemisi]

In this study, a case of candidemia caused by Candida hellenica as the first report in our country was presented. Fluconazole and liposomal amphotericin B treatment was initiated in a 20-year-old male patient in October 2018 due to the diagnosis of candidemia following esophageal surgery. The patient had a history of multiple esophageal operations. The patient was discharged during the last 24 hours due to the lack of fever, improvement in general condition and lack of growth in blood cultures. Germination tube test of the Candida isolate grown in blood culture was negative and the colony morphology in corn meal tween 80 agar was not defining. It was identified as C.hellenica according to the profile obtained from the ID32C (R) (bioMerieux, France) method based on carbohydrate assimilation. The target ITS regions of the rRNA genes were amplified by polymerase chain reaction and sequenced using suitable primers for the confirmation of the identification on species level. The DNA sequences obtained were searched by using the ``National Center for Biotechnology Information (BLAST){''} (http://www.ncbi.nlm.nih.gov/BLAST/) database and the isolate was identified as C.hellenica with a 99\% homology with GenBank sequences. MALDI-TOF (Vitek MS, bioMerieux) could not identify the yeast isolate. The reference microdilution method was performed according to the recommendations of the Clinical and Laboratory Standards Institute in order to test the antifungal susceptibility. The minimal inhibitory concentrations for the isolate, determined after 24-hour incubation were 0.25 mu g/ml for amphotericin B, 8 mu g/ml for fluconazole, 0.25 mu g/ml for voriconazole, and 0.25 mu g/ml for itraconazole. As our case had a previous history of gastrointestinal tract surgery it was thought that gastrointestinal tract was the endogenous source of candidemia by leading to mucosal disruption and this mucosal disruption might facilitate the translocation of Candida. The carbohydrate assimilation test ID32C (R), was able identify the causative agent of candidaemia at the species level in this case. However, uncommon or previously unrecognized organisms may be misidentified by commercial systems. While the phenotypic definition is sufficient in routine laboratories, it is mandatory to confirm the microorganism species definition by DNA sequence analysis, as done in this case. We have presented a correctly identifed and successfully treated candidemia case. Although the candidemia was not mortal in our patient, the mortality rate of candidemia which is 50\%, should be remembered. A total of two C.hellenica infections have been reported in the literature, including one candidaemia and one respiratory tract colonization. Our successfully treated case was presented to draw attention to this rare infectious agent

Genotyping Reveals no Link Between Candida albicans Genotype and Vaginitis Severity in Turkish Women

PubMedID: 23546773Recent studies have clearly defined the vaginopathic Candidaalbicans strains that cause severe vulvovaginal candidiasis (VVC). Therefore, genotyping C. albicans isolates may predict the success of and assist in choosing the appropriate antifungal therapy. The purpose of this study was to compare the genotypes of C. albicans isolates causing VVC with those found in asymptomatic healthy pregnant and non-pregnant women in Adana, Turkey, as well as the antifungal susceptibility profiles of these isolates. A total of 216 independent C. albicans isolates were genotyped by allelic combination based on the microsatellite marker analysis of one such microsatellite, present in the promoter region of the elongation factor 3-encoding gene (CEF3) of C. albicans. The susceptibility testing profiles of all of the isolates against five antifungals and boric acid were obtained retrospectively from our laboratory records. We identified 20 genotypes on the basis of different allelic combinations at the CEF3 locus with a discriminatory power of 0. 85. Genotypes 136-144 and 126-135 were present in 50 % of the isolates. No differences existed in the genotypic profiles of fungal isolates between pregnant and non-pregnant women. Remarkably, we did not find a single vaginopathic genotype. All of the isolates were susceptible to amphotericin B and 5-fluorocytosine, and the fluconazole and ketoconazole resistance rates were 0. 9 and 3. 7 %, respectively. Therefore, we did not find any correlation between genotype, severity of VVC, and antifungal resistance (P > 0. 05). Even so, additional molecular data may provide new insights into the management of VVC. © 2013 Springer Science+Business Media Dordrecht

Candida vaginitis in non-pregnant patients: A study of antifungal susceptibility testing and virulence factors

PubMedID: 23654320Vulvovaginal candidosis (VVC) is a major problem for the female population worldwide, and considerably little is known about the difference between acute VVC (AVVC) and recurrent VVC (RVVC). We investigated the susceptibility to six antifungal agents and boric acid of Candida spp. isolated from vaginal cultures, as described in the CLSI document M27-A3, from 228 non-pregnant sexually active women (aged 18-49 years), and the virulence factors of these isolates. The isolates were derived from patients with AVVC (n = 64), those with RVVC (n = 125) and those without signs or symptoms (n = 39). In total, C. albicans was the most commonly isolated species (50%), followed by C. glabrata (35.5%) and other Candida spp. (14.5%). We observed slightly different minimum inhibitory concentration (MICs) for various antifungals among the species and study groups that could have potential therapeutic benefits for the treatment. Analysis of the virulence factors revealed that haemolytic activity is not involved in VVC pathogenesis but that germ-tube formation, adhesion to VECs, and proteinase and phospholipase production may be important in the pathogenesis of VVC. © 2013 Informa UK, Ltd