Virulence Factors and Antifungal Susceptibility in Candida Species Isolated from Dermatomycosis Patients

Mycopathologia - Dermatomycoses caused by Candida spp. are increasingly common, however there are few reports in the literature regarding their epidemiology, pathogenesis and antifungal...     

Recipient-Related Risk Factors for Graft Failure and Death in Elderly Kidney Transplant Recipients

Background

Elderly patients with end-stage renal disease have become the fastest growing population of kidney transplant candidates in recent years. However, the risk factors associated with long-term outcomes in these patients remain unclear.

Methods

We retrospectively analyzed 166 recipients aged 60 years or older who underwent primary deceased kidney transplantation between 2002 and 2013 in our center. The main outcomes included 1-, 3- and 5-year patient survival as well as overall and death-censored graft survival. The independent risk factors affecting graft and patient survival were analyzed using Cox regression analysis.

Results

The 1-, 3-, 5-year death-censored graft survival rates were 93.6%, 89.4% and 83.6%, respectively. Based on the Cox multivariate analysis, panel reactive antibody (PRA)>5% [hazard ratio (HR) 4.295, 95% confidence interval (CI) 1.321–13.97], delayed graft function (HR 4.744, 95% CI 1.611–13.973) and acute rejection (HR 4.971, 95% CI 1.516–16.301) were independent risk factors for graft failure. The 1-, 3-, 5-year patient survival rates were 84.8%, 82.1% and 77.1%, respectively. Longer dialysis time (HR 1.011 for 1-month increase, 95% CI 1.002–1.020), graft loss (HR 3.501, 95% CI 1.559–7.865) and low-dose ganciclovir prophylaxis (1.5 g/d for 3 months) (HR 3.173, 95% CI 1.063–9.473) were risk factors associated with patient death.

Conclusions

The five-year results show an excellent graft and patient survival in elderly kidney transplant recipients aged ≥60 years. PRA>5%, delayed graft function, and acute rejection are risk factors for graft failure, while longer duration of dialysis, graft loss and low-dose ganciclovir prophylaxis are risk factors for mortality in elderly recipients. These factors represent potential targets for interventions aimed at improving graft and patient survival in elderly recipients.     

Distribution of Virulence Factors in Escherichia coli Isolated from Urine of Cystitis Patients

The distribution of 7 urovirulence factors, such as type 1 pilus (pil), pilus associated with pyelonephritis (pap), S fimbriae (sfa), afimbrial adhesin I (afaI), hemolysin (hly), aerobactin (aer) and cytotoxic necrotizing factor 1 (cnf1) was examined by a DNA colony hybridization test among 194 Escherichia coli strains isolated from the urine of cystitis patients and in 80 strains isolated from the stool specimens of healthy adults. All virulence factors examined, except pil, were significantly more frequently detected among the cystitis isolates than among the fecal isolates. When individual virulence factors were analyzed against the others, an association was discernible which was not apparent when all 7 virulence factors were considered collectively. There was an apparent correlation between the genotypes and serotypes of the E. coli strains from the cystitis patients. From the data presented, it was proposed that genetic detection of virulence factors would be useful for rapid diagnosis of cystitis, especially in patients without severe pyuria or bacteriuria.     

海南岛4市县人群口腔假丝酵母菌分布情况的初步调查

目的：调查海南岛海口、三亚市、五指山市和保亭县四市县人群口腔假丝酵母菌的分布情况,为口腔假丝酵母菌分子生物学和遗传学特点研究提供基础资料。方法：分离出的假丝酵母菌经过菌落特征、制片乳酸酚棉蓝染色、芽管形成试验、厚膜孢子形成试验等初步鉴定,并用科玛嘉显色培养基培养确定。结果：海口、三亚市、五指山市和保亭县人群口腔假丝酵母菌总分离率为25．23％．其中白假丝酵母菌占54．48％,光滑假丝酵母菌占14．04％,热带假丝酵母菌占11．06％,克柔假丝酵母菌占9．36％。住院病人和健康人口腔假丝酵母菌的分离率分别为39．95％和11．61％,差异有统计学意义（P〈0．01）,结论：海南地区人群口腔假丝酵母菌的总分离率高于国内其它省份,分离出的假丝酵母菌以白假丝酵母菌为首位,病人口腔假丝酵母菌分离率明显高于健康人。     

Neutralization Serotyping of BK Polyomavirus Infection in Kidney Transplant Recipients

BK polyomavirus (BKV or BKPyV) associated nephropathy affects up to 10% of kidney transplant recipients (KTRs). BKV isolates are categorized into four genotypes. It is currently unclear whether the four genotypes are also serotypes. To address this issue, we developed high-throughput serological assays based on antibody-mediated neutralization of BKV genotype I and IV reporter vectors (pseudoviruses). Neutralization-based testing of sera from mice immunized with BKV-I or BKV-IV virus-like particles (VLPs) or sera from naturally infected human subjects revealed that BKV-I specific serum antibodies are poorly neutralizing against BKV-IV and vice versa. The fact that BKV-I and BKV-IV are distinct serotypes was less evident in traditional VLP-based ELISAs. BKV-I and BKV-IV neutralization assays were used to examine BKV type-specific neutralizing antibody responses in KTRs at various time points after transplantation. At study entry, sera from 5% and 49% of KTRs showed no detectable neutralizing activity for BKV-I or BKV-IV neutralization, respectively. By one year after transplantation, all KTRs were neutralization seropositive for BKV-I, and 43% of the initially BKV-IV seronegative subjects showed evidence of acute seroconversion for BKV-IV neutralization. The results suggest a model in which BKV-IV-specific seroconversion reflects a de novo BKV-IV infection in KTRs who initially lack protective antibody responses capable of neutralizing genotype IV BKVs. If this model is correct, it suggests that pre-vaccinating prospective KTRs with a multivalent VLP-based vaccine against all BKV serotypes, or administration of BKV-neutralizing antibodies, might offer protection against graft loss or dysfunction due to BKV associated nephropathy.     

In Vitro Susceptibility of Candida Isolates from Organ Transplant Recipients to Newer Antifungals

Organ transplant recipients (OTR) are at higher risk of developing life-threatening infections. In this study, we tested 527 Candida isolates obtained from the oral and genital mucosa from OTR and healthy controls in order to monitor antifungal susceptibility patterns in this particular risk group. Testing was carried out in parallel for already marketed azoles and anidulafungin. Minimal inhibitory concentrations (MICs) were determined using the E-test^® for azoles and CLSI broth microdilution for anidulafungin. Overall, there was no difference in the distribution of Candida spp. for both groups, C. albicans being the most frequently isolated Candida sp. followed by C. glabrata. Also, there were only minor differences in the susceptibility patterns to all antifungal agents. All C. albicans isolates were fully susceptible to fluconazole and voriconazole. In C. glabrata, 2.2 % (n = 1) were resistant to fluconazole, and 82.6 % (n = 38) to itraconazole, and in C. krusei, 66.7 % (n = 2) were resistant in itraconazole. All strains were susceptible to voriconazole. Only fluconazole showed a higher rate of resistant C. glabrata isolates for OTR (3.7 %), whereas the control group showed only intermediate susceptible and no resistant isolates. As there are no breakpoints established for posaconazole by CLSI, breakpoints determined by EUCAST were used. A total of 87.9 % of C. albicans, 81.3 % of C. parapsilosis and 66.7 % of C. tropicalis were considered susceptible. C. glabrata and C. krusei showed higher MIC values and thus lesser susceptibility than the other Candida species. There were no differences observed between OTR and control groups. For anidulafungin, 99.8 % of C. albicans isolates were susceptible, 0.2 % were intermediate, whereas for C. glabrata, only 95.3 % were susceptible, 0.2 % were resistant and 4.5 % were interpreted as intermediate. Interestingly, the two resistant isolates were found in the control group. Also, the controls showed a marginally higher percentage of intermediate strains compared to the transplant patients. All in all, resistant isolates were only observed for C. glabrata of the control group.     

Species Distribution and Antifungal Susceptibility Profile of Oral Candida Isolates from HIV-infected Patients in the Antiretroviral Therapy Era

In this study, we investigated the yeasts colonization of genus Candida, including C. dubliniensis, isolated of HIV-infected patients oral cavities and we accessed in vitro susceptibility pattern of the Candida isolates to four antifungal agents. Out of 99 patients investigated, 62 (62.6%) were colonized with yeasts. C. albicans was the prevailing species (50%). C. dubliniensis isolates were not recovered in our study. We verified that 8.1% of the yeasts isolated were resistant to fluconazole, 8.1% to itraconazole and 3.2% to voriconazole. The isolates demonstrated very low voriconazole MICs, in which 79% (49/62) presented values of 0.015 μg/ml. All Candida isolates were susceptible to amphotericin B. The results reported here showed that although C. albicans continues to be present in one-half of oral Candida carriage of HIV-infected patients, Candida non-albicans species are increasing among these patients. Besides, the findings of resistant isolates endorse the role of antifungal susceptibility testing whenever antifungal treatment with azoles is planned.     

Effect of Statins on the Progression of Coronary Calcification in Kidney Transplant Recipients

BackgroundCoronary calcification (CAC) is highly prevalent in kidney transplant recipients (KTRs) and has been associated with cardiovascular morbidity and mortality. Some studies have shown a reduction in CAC progression with statin therapy in the general and chronic kidney disease (CKD) populations.ResultsAt baseline, CAC was observed in 30% and 21% of patients in the statin and control groups, respectively (p = 0.39). The calcium score at baseline and its absolute and relative changes over 12 months of follow up were similar among the groups. In the statin group, total cholesterol (p < 0.001), low density lipoprotein cholesterol (p < 0.001) and triglycerides (p = 0.005) decreased, and the estimated glomerular function rate increased (p<0.001) significantly. CRP levels remained stable (p = 0.52) in the statin group but increased in the control group (p = 0.01). In the multivariate model, there was no difference in CAC progression between the groups (group effect p = 0.034; time-effect p = 0.23; interaction p = 0.74). Similar results were obtained when only patients with ≥ 10AU calcium score (calcified) were analyzed (group effect p = 0.051; time-effect p = 0.58; interaction p = 0.99).ConclusionAlthough statins reduce the levels of cholesterol, triglycerides, inflammation and improve graft function, the dose adopted in the current study did not delay CAC progression within 12 months of follow up.

Trial Registration

Brazilian Clinical Trials Registry RBR-32RFMB     

Characterization of Prototheca wickerhamii Isolated from Disseminated Algaemia of Kidney Transplant Patient from Malaysia

Prototheca wickerhamii isolated from blood of 61-year-old kidney transplant patient was described. Although it is classified as an alga (genus Chlorella), the disease, protothecosis, is included under mycoses because of its clinical pathological presentations. Colony characteristics of P. wickerhamii are indistinguishable from other yeast-like organisms like Cryptococcus and Candida. Fortunately, commercial identification system for yeast can be used to identify this organism to the species level. Electron microscopy demonstrated "morula" or daisy-like appearance of its endosporulating sporangia. The organism was sensitive to amphotericin B by E test method. Even though human protothecosis is uncommon, it cannot be ignored because it is emerging as an opportunistic infection in immunosuppressed individuals. To our knowledge, this is the first reported case of disseminated algaemia due to P. wickerhamii in Malaysia.     

Vitamin K Intake and Plasma Desphospho-Uncarboxylated Matrix Gla-Protein Levels in Kidney Transplant Recipients

Vitamin K is essential for activation of γ-carboxyglutamate (Gla)-proteins including the vascular calcification inhibitor matrix Gla-protein (MGP). Insufficient vitamin K intake leads to production of uncarboxylated, mostly inactive proteins and contributes to an increased cardiovascular risk. In kidney transplant recipients, cardiovascular risk is high but vitamin K intake and status have not been defined. We investigated dietary vitamin K intake, vascular vitamin K status and its determinants in kidney transplant recipients. We estimated vitamin K intake in a cohort of kidney transplant recipients (n = 60) with stable renal function (creatinine clearance 61 [42–77] (median [interquartile range]) ml/min), who were 75 [35–188] months after transplantation, using three-day food records and food frequency questionnaires. Vascular vitamin K status was assessed by measuring plasma desphospho-uncarboxylated MGP (dp-ucMGP). Total vitamin K intake was below the recommended level in 50% of patients. Lower vitamin K intake was associated with less consumption of green vegetables (33 vs 40 g/d, p = 0.06) and increased dp-ucMGP levels (621 vs 852 pmol/L, p<0.05). Accordingly, dp-ucMGP levels were elevated (>500 pmol/L) in 80% of patients. Multivariate regression identified creatinine clearance, coumarin use, body mass index, high sensitivity-CRP and sodium excretion as independent determinants of dp-ucMGP levels. In a considerable part of the kidney transplant population, vitamin K intake is too low for maximal carboxylation of vascular MGP. The high dp-ucMGP levels may result in an increased risk for arterial calcification. Whether increasing vitamin K intake may have health benefits for kidney transplant recipients should be addressed by future studies.     

Incidence of Virulence Factors and Antibiotic Resistance among Enterococci Isolated from Food

The incidence of virulence factors among 48 Enterococcus faecium and 47 Enterococcus faecalis strains from foods and their antibiotic susceptibility were investigated. No strain was resistant to all antibiotics, and for some strains, multiple resistances were observed. Of E. faecium strains, 10.4% were positive for one or more virulence determinants, compared to 78.7% of E. faecalis strains. Strains exhibiting virulence traits were not necessarily positive for all traits; thus, the incidence of virulence factors may be considered to be strain specific.     

Phosphatase Activity Among Candida Species and Other Yeasts Isolated from Clinical Material

A group of 277 yeasts isolated from burned children and 14 reference strains were tested for phosphatase activity by using phenolphthalein phosphate substrates. Phosphatase activity was widely distributed among various species and strains representing seven genera. Candida albicans, which was the most common yeast isolated from clinical material, was notably absent in producing the enzyme, whereas Candida tropicalis was the most consistent, strong, and rapidly active phosphatase-producing organism. The characteristic enzyme activity of a selected isolate of C. tropicalis was demonstrated in the presence of concentrations of inorganic phosphate which inhibited enzyme activity of other species. The greater enzyme activity of C. tropicalis was not related to more rapid or greater cell growth or decrease in the pH of culture media. Extracellular constitutive heat-labile acid phosphatase was found in broth filtrates of C. tropicalis, C. krusei, and a strain of Staphylococcus aureus.     

Species distribution and antifungal susceptibility profile of Candida spp. bloodstream isolates from Latin American hospitals

From March 1999 to March 2000, we conducted a prospective multicenter study of candidemia involving five tertiary care hospitals from four countries in Latin America. Yeast isolates were identified by classical methods and the antifungal susceptibility profile was determined according to the National Committee for Clinical Laboratory Standards microbroth assay method. During a 12 month-period we were able to collect a total of 103 bloodstream isolates of Candida spp. C. albicans was the most frequently isolated species accounting for 42% of all isolates. Non-albicans Candida species strains accounted for 58% of all episodes of candidemia and were mostly represented by C. tropicalis (24.2%) and C. parapsilosis (21.3%). It is noteworthy that we were able to identify two cases of C. lusitaniae from different institutions. In our casuistic, non-albicans Candida species isolates related to candidemic episodes were susceptible to fluconazole. Continuously surveillance programs are needed in order to identify possible changes in the species distribution and antifungal susceptibility patterns of yeasts that may occurs after increasing the use of azoles in Latin American hospitals.     

Antifungal Activity of Essential Oils Against Candida Species Isolated from Clinical Samples

Mycopathologia - We evaluated the in vitro antifungal activity of essential oils obtained from the aromatic plants Laurus nobilis, Thymus vulgaris, Mentha piperita, Cymbopogon citratus and Lippia...     

Expression Levels of Obesity-Related Genes Are Associated with Weight Change in Kidney Transplant Recipients

Background

The aim of this study was to investigate the association of gene expression profiles in subcutaneous adipose tissue with weight change in kidney transplant recipients and to gain insights into the underlying mechanisms of weight gain.

Methodology/Principal Findings

A secondary data analysis was done on a subgroup (n = 26) of existing clinical and gene expression data from a larger prospective longitudinal study examining factors contributing to weight gain in transplant recipients. Measurements taken included adipose tissue gene expression profiles at time of transplant, baseline and six-month weight, and demographic data. Using multivariate linear regression analysis controlled for race and gender, expression levels of 1553 genes were significantly (p<0.05) associated with weight change. Functional analysis using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes classifications identified metabolic pathways that were enriched in this dataset. Furthermore, GeneIndexer literature mining analysis identified a subset of genes that are highly associated with obesity in the literature and Ingenuity pathway analysis revealed several significant gene networks associated with metabolism and endocrine function. Polymorphisms in several of these genes have previously been linked to obesity.

Conclusions/Significance

We have successfully identified a set of molecular pathways that taken together may provide insights into the mechanisms of weight gain in kidney transplant recipients. Future work will be done to determine how these pathways may contribute to weight gain.