Chronic recurrent vulvovaginitis is not only due to Candida

BackgroundRecurrent vulvovaginitis is a growing problem that affects millions of women worldwide. In many cases it is treated as vulvovaginal candidiasis, but there is not always microbiological confirmation.AimsTo determine the etiology of vulvovaginitis in a group of patients.MethodsThis is a cross-sectional study in which the data from the medical records of 316 adult patients who consulted for vulvovaginitis were analyzed. Eighty nine percent of the cases had already suffered previous episodes.ResultsThe median age was 34 (265 patients were between 16 and 45 years old). Yeasts were isolated in culture from 211 (66.8%) patients, although pseudo-hyphae and yeasts were observed in only 166 samples (52.5%) in the direct microscopic examination. Multiple predisposing factors were found, among which the use of contraceptives or previous antibiotics stand out. Most of the patients (almost 90%) had been treated with antifungals, with or without microbiological confirmation. Candida albicans was isolated in 187 (88.6%) patients, followed by Candida glabrata in 6 (2.8%) patients. Association with bacterial vaginosis was found in 35.1% and with intermediate bacterial microbiota in 33.2% of the cases. A remarkably high proportion of C. albicans isolates resistant to fluconazole (80.1%) and itraconazole (58.8%) was found.ConclusionsA microbiological analysis is essential to confirm the diagnosis of vulvovaginal candidiasis, whether simple, complicated, or recurrent. Identifying the isolated yeast species and determining its susceptibility to antifungal agents are particularly important.     

The emergence of non-albicans Candida species as causes of invasive candidiasis and candidemia

The last three decades have seen an expanding pool of high-risk patients susceptible to the opportunistic pathogen Candida. Accordingly, a dramatic increase in nosocomial blood stream infections (BSIs) due to Candida spp has been reported throughout the world, starting in tertiary care centers and spreading to community hospitals. This absolute increase in Candida BSIs was accompanied by both an absolute and then a proportional increase in invasive infection caused by reduced fluconazole-susceptible non-albicans Candida spp. Currently, the incidence trend of BSI has stabilized, and Candida albicans remains the most common species causing fungal BSI. Clinicians must be aware of the importance and implications of non-albicans Candida spp when selecting antifungal drugs, although most studies have not shown significant outcome differences with use of the various antifungal classes.     

复发性外阴阴道假丝酵母菌病菌种分型及药敏

目的对RVVC、VVC患者阴道分泌物进行培养、菌种分型及药物敏感试验,探讨RVVC发生的原因。方法用沙保弱琼脂培养基培养阴道分泌物,分离纯化菌株;VITEK 2全自动微生物分析仪鉴定菌种;同时进行药物敏感试验。结果共分离出101株假丝酵母菌,其中RVVC组45株,VVC组51株,健康组5株。101株中白色假丝酵母菌86株,占85.1%(86/101),RVVC组45株中35株为白色假丝酵母菌,占77.8%(35/45);VVC组51株中47株为白色假丝酵母菌,占92.2%(47/51),健康组5株中4株为白色假丝酵母菌,占80%(4/5)。RV-VC组非白色假丝酵母菌比例高,与VVC组比较差异有显著性(P<0.05)。RVVC组假丝酵母菌对唑类药物敏感性低于VVC组。结论VVC、RVVC的主要致病菌仍是白色假丝酵母菌,RVVC组非白色假丝酵母菌比例高于VVC组。RVVC组假丝酵母菌对氟康唑的敏感率明显低于VVC组。     

Action mechanisms of probiotics on Candida spp. and candidiasis prevention: an update

Due to the high incidence of fungal infections caused by Candida species and their increasing resistance to antimicrobial treatments, alternative therapies such as probiotics have been studied. It has been show that several species of the genus Lactobacillus have anti-Candida activity, probably by direct inhibition, through competition for adhesion sites or production of secondary metabolites, and by indirect inhibition, through stimulation of the immune system of their host. However, the mechanisms of inhibition of these probiotics on Candida species have not yet been fully elucidated since this effect is related to more than one inhibition pathway. In the literature, several in vitro and in vivo studies have been developed seeking to elucidate the probiotics mechanisms of action. These studies have been focused on C. albicans inhibition assays, including analysis of antimicrobial activity, adherence capacity, biofilms formation, filamentation and interference on virulence genes, as well as assays of experimental candidiasis in invertebrate and vertebrate models. In this context, the purpose of this review was to gather different studies focused on the action mechanism of probiotic strains on Candida sp. and to discuss their impact on the candidiasis prevention.     

Peptidase profiles from non-albicans Candida spp. isolated from the blood of a patient with chronic myeloid leukemia and another with sickle cell disease

Candida lipolytica and Candida rugosa were isolated from blood samples from a patient with chronic myeloid leukemia (31 years old) and a patient with sickle cell disease (1-year-old), respectively. Isolates were grown for 48 h at 37 degrees C in either Sabouraud or tryptone soy broth (TSB). Peptidases were tested for using substrate sodium dodecyl sulfate-polyacrylamide gels with gelatin, casein, bovine serum albumin (BSA) or hemoglobin. Enzymography analyses were made on the following substrates: human albumin, IgG and human fibrinogen, which had been incubated with the concentrated supernatants. For C. lipolytica, a approximately 60-kDa gelatin-degrading serine proteolytic activity was found in the TSB supernantant as well as a metallopeptidase activity capable of hydrolysing human albumin, IgG and human fibrinogen. With C. rugosa, albumin, IgG and human fibrinogen substrates were degraded by an aspartyl-like peptidase activity. Supernatants from C. rugosa also showed three serine proteolytic activities towards gelatin (approximately 50 kDa, TSB), casein ( approximately 94 kDa, TSB) and BSA ( approximately 120-kDa, Sabouraud), in addition to a metallopeptidase capable of degrading casein ( approximately 110 kDa, Sabouraud). Little is known about peptidases of C. rugosa and C. lipolytica and this preliminary data may prove useful for future work on host-parasite relationship and antifungal agents.     

Sensitivity of Candida strains to polyenic antibiotics in the treatment of oral candidiasis

Sensitivity of 146 clinical strains of Candida albicans to nystatin, levorin and amphoglucamine was studied on solid media with the replica method. The strains were isolated from 79 patients with candidiasis of the oral mucosa. It was found that sensitivity of the fungi to the polyenic antibiotics was different which should be considered in treatment of candidiasis. On the basis of the mean MICs for the clinical strains and their distribution by the MICs it was shown that the activity level of levorin and amphoglucamine was higher than that of nystatin. During the treatment resistance of the Candida strains to the polyenic antibiotics increased and cross resistance developed which required application of other treatment means.     

Cross-reacting Candida albicans antigens in the pathogenesis of candidiasis]

Organ- and tissue-specific antigens with affinity to C. albicans have been detected in some organs and tissues of the body. The occurrence of C. albicans colonization of different organs correlates with the presence of cross-reacting antigens in these organs.     

Characterization of agglutinin-like sequence genes from non-albicans Candida and phylogenetic analysis of the ALS family

The ALS (agglutinin-like sequence) gene family of Candida albicans encodes cell-surface glycoproteins implicated in adhesion of the organism to host surfaces. Southern blot analysis with ALS-specific probes suggested the presence of ALS gene families in C. dubliniensis and C. tropicalis; three partial ALS genes were isolated from each organism. Northern blot analysis demonstrated that mechanisms governing expression of ALS genes in C. albicans and C. dubliniensis are different. Western blots with an anti-Als serum showed that cross-reactive proteins are linked by beta 1,6-glucan in the cell wall of each non-albicans Candida, suggesting similar cell wall architecture and conserved processing of Als proteins in these organisms. Although an ALS family is present in each organism, phylogenetic analysis of the C. albicans, C. dubliniensis, and C. tropicalis ALS genes indicated that, within each species, sequence diversification is extensive and unique ALS sequences have arisen. Phylogenetic analysis of the ALS and SAP (secreted aspartyl proteinase) families show that the ALS family is younger than the SAP family. ALS genes in C. albicans, C. dubliniensis, and C. tropicalis tend to be located on chromosomes that also encode genes from the SAP family, yet the two families have unexpectedly different evolutionary histories. Homologous recombination between the tandem repeat sequences present in ALS genes could explain the different histories for co-localized genes in a predominantly clonal organism like C. albicans.     

Comparison of microdilution method and E-test procedure in susceptibility testing of caspofungin against Candida non-albicans species

It is widely known that systemic and mucosal candidiasis caused by Candida non-albicans strains endangers the lives of hospitalised patients since these pathogens are extremely difficult to defeat by commonly used antifungal agents. The present study determined the in vitro activities of a novel antimicotic drug - caspofungin - against 76 Candida non-albicans isolates by means of the CLSI reference method for broth dilution antifungal susceptibility testing of yeasts and the E-test procedure for comparison. Caspofungin was efficacious against the majority of strains tested, with the average MICs90 evaluated by the microdilution method and E-tests amounting to 1 mg/l and 0.5 mg/l, respectively. Since the agreement between MICs within +/-2 dilutions obtained by these two techniques was 92% (Kappa coefficient of 0.92), the E-test procedure seems to be a reliable alternative to the broth microdilution method and may provide another choice for clinical laboratories.     

Interactions of Candida albicans with other Candida spp. and bacteria in the biofilms

AIMS: To study the interactions between Candida albicans and 12 other species of Candida and bacteria in biofilms. METHODS AND RESULTS: The number of cells within growing biofilms in a polystyrene tube model was measured after adding C. albicans to preformed biofilms of other micro-organisms and vice versa. It was also measured after simultaneous biofilm formation of C. albicans and other micro-organisms. The number of cells of C. albicans within the growing biofilms decreased significantly (P < 0.05) when the fungus was added to preformed biofilms of Candida spp. and bacteria except, with C. parapsilosis, Torulopsis glabrata and the glycocalyx producer Pseudomonas aeruginosa. When C. parapsilosis, Staphylococcus epidermidis (nonglycocalyx producer) or Serratia marcescens was added to preformed biofilms of C. albicans, the number of cells of these micro-organisms increased in the growing biofilms. CONCLUSIONS: Biofilms of C. albicans are capable of holding other micro-organisms and more likely to be heterogeneous with other bacteria and fungi in the environment and on medical devices. SIGNIFICANCE AND IMPACT OF THE STUDY: Recognition of the heterogeneity of biofilm-associated organisms can influence treatment decisions, particularly in patients who do not respond to initial appropriate therapy.     

Optimization of the conditions for RAPD-PCR of Candida spp. and Cryptococcus spp

In this study, we determined the optimal RAPD amplification conditions to obtain genetic molecular markers for the rapid and accurate identification of Cryptococcus spp. and Candida spp. The following parameters are modified: template DNA, DNA polymerase, magnesium cloride and primer concentration; denaturation, annealing and extension time, temperature of annealing and thermal cycles. After the optimization, reliable and reproducible RAPD patterns are obtained.     

Antibodies to Candida albicans germ tubes in two intensive care patients with invasive candidiasis

Two cases of invasive candidiasis in intensive care patients are presented to illustrate the usefulness of detection of antibodies to Candida albicans germ tubes in the diagnosis of invasive candidiasis and in monitoring the efficacy of the antifungal treatment.     

Antibodies to Candida albicans germ tubes in two intensive care patients with invasive candidiasis

Two cases of invasive candidiasis in intensive care patients are presented to illustrate the usefulness of detection of antibodies to Candida albicans germ tubes in the diagnosis of invasive candidiasis and in monitoring the efficacy of the antifungal treatment.     

Evaluation of the antigen from chlamydospores of Candida albicans in the serodiagnosis of candidiasis

Antigens have been prepared from the chlamydospores and blastospores of Candida albicans and their precipitin patterns were analysed by two-dimensional immunoelectrophoresis using specific antisera.The two antigens were used in routine serological tests of patients suffering from candidiasis. On double-diffusion tests for the detection of circulating antibodies of Candida albicans, the antigen from chlamydospores displays precipitin lines that differ in number and intensity from those obtained with the antigen from blastospores. The results are briefly discussed in the framework of C. albicans antigen standardization.     

The study of cell-mediated immune response in recurrent vulvovaginal candidiasis

The aim of this work was to examine in vitro the ability of cells from patients with recurrent vulvovaginal candidiasis (RVVC) to cell-mediated immune response. Peripheral blood mononuclear cells (PBMC) and whole blood cells (WBC) of 37 RVVC patients in acute infection and 14 in remission were examined for the ability to proliferation and cytokines production (IFN, TNF, IL-6). As a control, a group of 25 healthy women were examined. The cells were stimulated with Candida antigen (HKCA), LPS and PHA. To indicate the level of cytokines, the following cell-lines were used: A549 for IFN, WEHI 164 for TNF and 7TD1 for IL-6. The proliferation/death of cells was determined by colorimetric test using MTT. Distinct suppression of cell-mediated immune response (CMI) was shown in all patients comparing to the control. Greatest suppression was found in the acute phase of the disease. The ability of cells to proliferate and produce IFN increases only in remission. The data seem to suggest that in this phase of disease, the ability of cell-mediated immune response is restored. It was also indicated that IFN may take part in protection against Candida infection.     

Diagnostic potential of IgA coated Candida cells in mucous membrane candidiasis

The significance of in vivo IgA coated yeast cells for the diagnosis of candidiasis of the oral and vaginal mucosal membranes was evaluated by direct immunofluorescence in 70 patients with or without clinical symptoms, shown to be positive for yeast growth in the cultural test. Most of the patients with clinically suspected candidiasis of the mucosal membranes gave positive results by serologic assays in contrast to the majority of symptomless patients. The diagnostic approach proved to be essentially consistent with the clinical signs, persistance of infection, response to antifungal therapy and quantitative cultural data.     

Copulatory function and development shape modular architecture of genitalia differently in males and females

Genitalia are multitasking structures whose development is mediated by numerous regulatory pathways. This multifactorial nature provides an avenue for multiple sources of selection. As a result, genitalia tend to evolve as modular systems comprising semi-independent subsets of structures, yet the processes that give rise to those patterns are still poorly understood. Here, we ask what are the relative roles of development and function in shaping modular patterns of genitalia within populations and across species of stink-bugs. We found that male genitalia are less integrated, more modular, and primarily shaped by functional demands. In contrast, females show higher integration, lower modularity, and a predominant role of developmental processes. Further, interactions among parts of each sex are more determinant to modularity than those between the sexes, and patterns of modularity are equivalent between and within species. Our results strongly indicate that genitalia have been subjected to sex-specific selection, although male and female genitalia are homologous and functionally associated. Moreover, modular patterns are seemingly constant in the evolutionary history of stink-bugs, suggesting a scenario of multivariate stabilizing selection within each sex. Our study demonstrates that interactions among genital parts of the same sex may be more fundamental to genital evolution than previously thought.     

Detection of Candida dubliniensis in patients with candidiasis in Caracas, Venezuela

Candida species are responsible for 80% of all nosocomial fungal infections. In 1995 a new yeast species was described, Candida dubliniensis which shares with Candida albicans characteristics. We have studied 109 yeast isolates identified as C. albicans to investigate the presence of C. dubliniensis by microbiological studies and PCR using DUBR/DUBF primers. Positive results using microbiological tools were between 90 and 98%. Two morphological and physiological of the 80 DNA examined samples (2.5%) showed a PCR product of 288 bp which allow the identification of C. dubliniensis. This is the first report in Venezuela of identification of this species using a PCR approach.