Anti-Candida Activity of Essential Oils from Lamiaceae Plants from the Mediterranean Area and the Middle East

Extensive documentation is available on plant essential oils as a potential source of antimicrobials, including natural drugs against Candida spp. Yeasts of the genus Candida are responsible for various clinical manifestations, from mucocutaneous overgrowth to bloodstream infections, whose incidence and mortality rates are increasing because of the expanding population of immunocompromised patients. In the last decade, although C. albicans is still regarded as the most common species, epidemiological data reveal that the global distribution of Candida spp. has changed, and non-albicans species of Candida are being increasingly isolated worldwide. The present study aimed to review the anti-Candida activity of essential oils collected from 100 species of the Lamiaceae family growing in the Mediterranean area and the Middle East. An overview is given on the most promising essential oils and constituents inhibiting Candida spp. growth, with a particular focus for those natural products able to reduce the expression of virulence factors, such as yeast-hyphal transition and biofilm formation. Based on current knowledge on members of the Lamiaceae family, future recommendations to strengthen the value of these essential oils as antimicrobial agents include pathogen selection, with an extension towards the new emerging Candida spp. and toxicological screening, as it cannot be taken for granted that plant-derived products are void of potential toxic and/or carcinogenic properties.

Vaginal pH and microbiota during fluconazole maintenance treatment for recurrent vulvovaginal candidosis (RVVC)

BACKGROUND

It is commonly stated that Candida in the vagina prefers a low pH to develop infection. However, mixed infections of Candida with bacterial vaginosis (BV) and aerobic vaginitis (AV) are rather common and may challenge the rule that Candida should only be looked for in low vaginal pH settings. In this study we tested whether the vaginal pH in acute vaginal candidosis is lower than in women successfully treated to prevent Candida recurrences.

METHODS

Vaginal pH and microscopy findings of vaginal microbiota were recorded during 12 visits over 1.5 years in 117 patients medically monitored during a degressive fluconazole maintenance regimen for proven recurrent vulvovaginal candidosis (ReCiDiF trial). The fluctuation of the mean pH of and microscopic findings of the vaginal smears were studied before, during and after the treatment.

RESULTS

The mean vaginal pH of women with acute infection before or after ending maintenance treatment was (4.7±0.8 and 4.8 ±1.0, respectively, p>0.05). During maintenance treatment with fluconazole, the pH dropped significantly to 4.5±0.8 (p=0.01). Depression of Lactobacilli spp. (increased lactobacillary grades) was more frequent during the acute, pre-treatment period (30.0%) than during the treatment period (23.1%, p=0.03). Aerobic vaginitis type flora was also more prevalent pre-treatment than during treatment (30.0% vs 22.2%, OR=0.7 (95%CI 0.5-0.9), p=0.01).

DISCUSSION

In women with RVVC, acute vaginal Candida infection is associated with an increased pH, and disturbed vaginal bacterial microbiota. During fluconazole maintenance treatment, the pH drops to normal levels and the lactobacillary grade improves.

CONDENSATION

Acute Candida vulvovaginitis can be associated with a disturbance of the vaginal microbiota. In patients with recurrent vulvovaginal candidosis, decrease of pH, and increase of Lactobacilli spp. were observed during fluconazole maintenance treatment. This pH drop was seen in all response groups. This contradicts the common belief that active vaginal Candida infection is related to low pH.

Candida albicans and non-albicans Isolates from Bloodstream Have Different Capacities to Induce Neutrophil Extracellular Traps

Neutrophils activated with pathogens or their products induce formation of extracellular traps (NETs), but if this constitutes a general response against all pathogenic species in a single genus or intrageneric differences exist remains unknown, yet this is of great importance for the establishment of effective treatments. To determine this, we analyzed neutrophil extracellular traps formation after the stimulation with bloodstream isolates from different Candida species (Candida albicans, C. tropicalis, C. parapsilosis, and C. glabrata), and found that each species has a different capacity to induce DNA extrusion, which is independent of their morphology (yeast or hyphae). We observed that phospholipase producer's strains and their secretion products were able to induce NETs, a property not observed with phospholipase deficient strains, with exception of some Candida glabrata sensu stricto isolates, which showed no NETs induction although they did show phospholipase production. To further analyze this, we extended our study to include Candida glabrata cryptic species (C. bracarensis and C. nivariensis) and no extracellular traps formation was observed. Here, we contribute to the understanding of how neutrophils initiate NETs, and we found that certain strains may have a differential capacity to trigger these structures, which may explain the high mortality of some isolates.

Isolation of Candida spp. from denture-related stomatitis in Pará, Brazil

The aim of this study was to isolate and identify Candida species from the oral cavity of denture wearers with denture-related stomatitis who were attended at the University Federal of Pará (Belém City, Pará State, Brazil). A total of 36 denture wearers with denture-related stomatitis were included, and type I (50%), type II (33%) and type III (17%) stomatitis were observed. Candida spp. were isolated from 89% of the cases and included five different Candida species. C. albicans was the most frequently recovered species (78% of the cases), followed by C. famata and C. tropicalis. We observed a significant association between Candida species isolation and unsatisfactory denture condition (p = 0.0017). Our results demonstrated the highly frequency of Candida species isolation in denture wearers with denture-related stomatitis and showed the relationship between these species and poor denture maintenance.

Antifungal activity of extracts and isolated compounds from Buchenavia tomentosa on Candida albicans and non-albicans

AIM

This study aimed to evaluate the antifungal activity of Buchenavia tomentosa extract and bioactive compounds on six Candida species.

MATERIALS & METHODS

The antimicrobial activity of extract was evaluated using standard strains and clinical isolates. Cytotoxicity was tested in order to evaluate cell damage caused by the extract. Extract was chemically characterized and the antifungal activity of its compounds was evaluated.

RESULTS

Extract showed antifungal activity on Candida species. Candida non-albicans were more susceptible than Candida albicans. Low cytotoxicity for extract was observed. The isolated compounds presented antifungal activity at least against one Candida spp. and all compounds presented antifungal effect on Candida glabrata.

CONCLUSION

Extracts from Buchenavia tomentosa showed promising antifungal activity on Candida species with low cytotoxicity. Gallic acid, corilagin and ellagic acid showed promising inhibitory activity on Candida glabrata.

A case of pediatric acute lymphoblastic leukemia with invasive candidiasis: short review

Mortality rate associated with invasive fungal infections is very high. Early suspicion for fungal infections is important during intensive chemotherapy for acute leukemia. Empirical treatment with antifungals amphotericin B or caspofungin should be started if patient is not responding to broad spectrum antibiotics and if expected duration of neutropenia is prolonged. We are reporting a 3 years old girl child with diagnosis of pre-B acute lymphoblastic leukemia who developed invasive candidiasis with typical clinical and radiological findings during induction chemotherapy. Candida non-albicans was isolated and she was treated with amphotericin B followed by caspofungin. Patient deteriorated after initial response and succumbed to death. Species identification and sensitivity pattern of fungus can help in selecting appropriate antifungal drug.

A case of Candida glabrata severe urinary sepsis successfully treated with micafungin

Candida glabrata is frequently resistant to fluconazole, and in advanced renal failure the safe use of this and other recommended drugs is limited. We report a case of a 56 years-old diabetic woman with renal failure and severe urinary sepsis from C. glabrata successfully treated with micafungin.

Rapid and reliable MALDI-TOF mass spectrometry identification of Candida non-albicans isolates from bloodstream infections

Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) fingerprinting has recently become an effective instrument for rapid microbiological diagnostics and in particular for identification of micro-organisms directly in a positive blood culture. The aim of the study was to evaluate a collection of 82 stored yeast isolates from bloodstream infection, by MALDI-TOF MS; 21 isolates were identified also directly from positive blood cultures and in the presence of other co-infecting micro-organisms. Of the 82 isolates grown on plates, 64 (76%) were correctly identified by the Vitek II system and 82 (100%) by MALDI-TOF MS; when the two methods gave different results, the isolate was identified by PCR. MALDI-TOF MS was unreliable in identifying two isolates (Candida glabrata and Candida parapsilosis) directly from blood culture; however, direct analysis from positive blood culture samples was fast and effective for the identification of yeast, which is of great importance for early and adequate treatment.