Oral candidiasis is frequently associated with Candida biofilms. Biofilms are microbial communities related to persistent, recalcitrant and difficult to-treat infections. Conventional treatments are ...not sufficient to overcome biofilm-associated candidiasis; thus, the search of new antifungal compounds is necessary. In the current study, we have evaluated the effect of three phytocompounds, carvacrol, cinnamaldehyde and thymol, against Candida planktonic and sessile cells. Reduction in biofilm biomass and metabolic activity was assessed during adhesion and mature biofilm phases. Candida albicans was the most biofilm-producing Candida species. All phytocompounds tested were fungicidal against Candida planktonic cells. Cinnamaldehyde was the most active in inhibiting biofilm adhesion, but carvacrol and thymol significantly reduced both mature biofilm biomass and metabolic activity. These results highlight the role of cinnamaldehyde, carvacrol and thymol as promising alternatives for the treatment of candidiasis due to their antibiofilm capacities, and stress the necessity to continue studies on their safety, toxicity and pharmacodynamics and pharmacokinetics.
•Phytocompounds are promising alternatives against Candida biofilms.•Carvacrol, cinnamaldehyde & thymol are fungicidal against Candida planktonic cells.•High activity of cinnamaldehyde in inhibiting biofilm adhesion.•Carvacrol and thymol reduce both biomass and metabolic activity of mature biofilms.
Summary
Background
Candida parapsilosis is the second or third most frequently isolated Candida species related to nosocomial infections, even overtaking Candida albicans in some hospitals. ...C. parapsilosis constitutes a complex of closely related species: Candida parapsilosis sensu stricto, Candida orthopsilosis and Candida metapsilosis. Accurate detection of these species is of importance, as the incidence of C. orthopsilosis has been reported to surpass that of Candida krusei.
Objective
To evaluate the diagnostic utility of two PCR‐RFLP methods targeting the SADH and FKS1 genes and to determine the prevalence of cryptic species in 96 bloodstream isolates of C. parapsilosis from 93 patients.
Methods
Restriction patterns of the SADH and FKS1 genes were analysed, and sequencing of the D1/D2 regions of the ribosomal RNA was used to evaluate the reliability of both PCR‐RFLP methods.
Results
In our study, 77 C. parapsilosis sensu stricto, 13 C. orthopsilosis and five C. metapsilosis were identified by sequencing. Both PCR‐RFLP methods demonstrated strong agreement with D1/D2 sequencing in the identification of C. parapsilosis and C. orthopsilosis, while both methods were unable to identify the C. metapsilosis isolates. Moreover, unexpected restriction patterns were observed for two isolates on SADH PCR‐RFLP and for four isolates on FKS1 PCR‐RFLP. Mixed bloodstream infections of C. parapsilosis sensu stricto and C. orthopsilosis were detected for three patients, for which differential growth characteristics were observed.
Conclusion
The molecular method chosen for identification could have an impact on determination of the real prevalence of C. metapsilosis in candidaemia, and mixed fungaemias can remain undetected.
Candidiasis caused by species of the
complex (
and
) and closely related species,
and
are increasing. These species often show reduced susceptibility to antifungal drugs, such as azoles and ...amphotericin B or, less frequently, echinocandins. However, conventional phenotypic identification methods are unable to accurately differentiate these species and, therefore, their prevalence may have been underestimated. In this study, 150 isolates that were probably misidentified were reanalyzed using two novel PCR approaches. We found that one isolate previously identified in 1996 as
was
, being one of the oldest isolates of this species described to date. We also found that this isolate had reduced susceptibility to fluconazole, itraconazole, and amphotericin B.
Abstract Since the coronavirus pandemic set in in Spain in March 2020, a noteworthy increase in the incidence of acute limb ischemia (ALI) has been observed. It has been recently discovered that ...SARS-CoV 2 may lead to ALI secondary to arterial thrombosis. Elevation of D-dimer (DD) in patients with coronavirus infection (COVID-19) indicates that a hypercoagulable state causes acute arterial thrombosis. A remarkably high DD elevation has been reported to be a poor prognosis factor in COVID-19. The ways in which SARS-CoV 2 results in arterial thrombosis may be multiple. On the other hand, surgical revascularization for ALI is associated with poor outcomes in COVID-19 patients, probably in relation to hypercoagulability. Here, we describe two ALI cases in patients who required urgent surgical treatment for limb salvage and were positive for the novel coronavirus infection (COVID 19).
Resumo Desde que a pandemia pelo novo coronavírus se estabeleceu na Espanha, em março de 2020, um aumento notável da incidência de isquemia aguda de membros foi observado. Recentemente, descobriu-se que o coronavírus 2 causador da síndrome respiratória aguda grave (SARS-CoV-2) pode ocasionar isquemia aguda de membros secundária à trombose arterial. A elevação do D-dímero em pacientes acometidos pela doença do novo coronavírus (COVID-19) indica o estado de hipercoagulabilidade como causa da trombose arterial aguda. Vale destacar que a alta elevação do D-dímero foi relatada como um fator de prognóstico reservado na COVID-19. Há diversas maneiras pelas quais o SARS-CoV-2 pode resultar em trombose arterial. Em pacientes com COVID-19, a revascularização cirúrgica para isquemia aguda de membros está associada a desfechos desfavoráveis, provavelmente relacionados a hipercoagulabilidade. Descrevemos dois casos de isquemia aguda de membros de pacientes que necessitaram de tratamento cirúrgico de urgência para salvamento de membro e que haviam testado positivo para COVID-19.
Summary
Candida albicans is one of the most frequent pathogens of the oral cavity, as a major cause of opportunistic disease. Moreover, Candida could be a cofactor of common oral diseases, such as ...dental caries. The aim of this study was to analyse the oral yeast colonisation in adults with dental caries and to evaluate its relationship with this clinical entity. We studied 190 patients distributed into controls (58 patients) and patients with caries (132 patients). Oral samples were collected by oral rinse and cultured in a chromogenic agar. C. albicans was the most prevalent species isolated from oral specimens in both groups. Patients with caries had a greater Candida colonisation (74 patients, 56.1%), than persons without caries (18 patients, 31%, P < 0.01). Patients with caries were significantly more colonised by non‐C. albicans species than individuals without caries (P = 0.006). Moreover, the diversity of Candida species was richer in patients suffering from caries. The odds ratio of the colonisation of patients with caries was 3.144 (95% CI 1.525–5.478). There is a significant clinical correlation between dental caries and oral Candida colonisation in adults.
The ability of Candida to develop biofilms on inert surfaces or living tissues favors recalcitrant and chronic candidiasis associated, in many instances, with resistance to current antifungal ...therapy.
The aim of this study was to evaluate the antifungal activity of citral, a phytocompound present in lemongrass essential oil, in monotherapy and combined with fluconazole against azole-resistant Candida planktonic cells and biofilms. The effect of citral combined with fluconazole was also analysed with regard to the expression of fluconazole resistance-associated genes in Candida albicans and the effectiveness of the combination therapy in a Caenorhabditis elegans model of candidiasis.
Citral reduced biofilm formation at initial stages and the metabolic activity of the mature biofilm. The combination of citral with fluconazole was synergistic, with a significant increase in the survival of C. elegans infected with Candida. RNA analysis revealed a reduction of the expression of the efflux pump encoded by MDR1, leading to a greater effect of fluconazole.
Citral in monotherapy and in combination with fluconazole could represent an interesting therapy to treat recalcitrant Candida infections associated to biofilms.
Candidiasis is a major cause of human morbidity and mortality. Human uterine cervical stem cells conditioned medium (hUCESC-CM) is obtained from stromal stem cells of the cervical transformation ...zone, which are in permanent contact with a wide array of potential vaginal pathogens. In previous reports we have found that hUCESC-CM has antitumor and antibacterial potential. Since
is the most prevalent yeast in the human vagina, it seems plausible that hUCESC-CM might also show activity against it.
In a preliminary step, to evaluate if hUCESC-CM showed any activity at all on
growth,
activities of hUCESC-CM against fluconazole-susceptible reference strains of
, and
were studied with a microdilution method on RPMI 1640, using the BioScreen C microbiological incubator. Each measurement was repeated five times. The same methodology was used subsequently on fluconazole-susceptible and fluconazole-resistant
isolates from blood and vagina of those species corresponding to the reference strains of
against which activity had been detected in the previous study. Moreover, two fluconazole-resistant clinical isolates of
from blood and urine were also included.
inhibitory activity of hUCESC-CM ranged from 57.5 to 96.6% growth-reduction against fluconazole-susceptible reference strains of
, and
. hUCESC-CM also reduced the growth of all fluconazole-susceptible tested vaginal isolates by more than 50%. For fluconazole-resistant isolates, growth-reduction was higher than 67% for
, regardless of its origin (vagina or blood). The isolate of
from urine with a MIC > 128 μ/ml for fluconazole was also significantly inhibited. However, hUCESC-CM was almost inactive against any of the fluconazole-resistant blood isolates of
, and
tested.
This is the first report about the growth-inhibiting properties of conditioned medium from human stromal stem cells against different species of
. Antifungal activity of stromal stem cells depends on their site of origin, being most effective against
species most prevalent at that particular location. If confirmed in further studies, these findings might result in a completely new therapeutic approach against superficial and invasive candidiasis.
Summary
The aim of the present study was to characterise phospholipase and proteinase activities of oral Candida isolates from 100 denture wearers and to study the relationship of these activities ...with denture stomatitis. Of 100 patients studied, 44 suffered from denture stomatitis. Specimens were collected by swabbing the denture and underlying mucosa. Isolates were previously identified by conventional mycological and genotypic methods. The phospholipase and proteinase activities were evaluated by agar plate methods. A total of 152 isolates were recovered from denture and underlying mucosa, including 101 Candida albicans, 18 Candida tropicalis, 14 Candida glabrata, 11 Candida guilliermondii, four Candida parapsilosis, two Saccharomyces cerevisiae and one isolate each of Candida dubliniensis and Candida krusei. Most C. albicans (97%) showed phospholipase activity; furthermore, the unique C. dubliniensis isolate showed a moderate phospholipase activity. The isolation of C. albicans (chi‐square test, P = 0.0016) and phospholipase production by Candida spp. (chi‐square test, P = 0.0213) was found to be significantly associated with denture stomatitis. Proteinase production was observed in <30% of isolates, and it was not related to the presence of denture stomatitis (P = 0.7675). Candida albicans isolates may produce both virulence factors, although the proteinase production was only observed in <30% of the isolates. Phospholipase production was exclusive of C. albicans and C. dubliniensis.
Candidiasis is one of the most common opportunistic oral infections that presents different acute and chronic clinical presentations with diverse diagnostic and therapeutic approaches. The present ...study carries out a bibliographic review on the therapeutic tools available against oral candidiasis and their usefulness in each clinical situation.
Recent studies on treatment of oral candidiasis were retrieved from PubMed and Cochrane Library.
Nystatin and miconazole are the most commonly used topical antifungal drugs. Both antifungal drugs are very effective but need a long time of use to eradicate the infection. The pharmacological presentations of miconazole are more comfortable for patients but this drug may interact with other drugs and this fact should be assessed before use. Other topical alternatives for oral candidiasis, such as amphotericin B or clotrimazole, are not available in many countries. Oral fluconazole is effective in treating oral candidiasis that does not respond to topical treatment. Other systemic treatment alternatives, oral or intravenous, less used are itraconazole, voriconazole or posaconazole. Available novelties include echinocandins (anidulafungin, caspofungin) and isavuconazole. Echinocandins can only be used intravenously. Isavuconazole is available for oral and intravenous use. Other hopeful alternatives are new drugs, such as ibrexafungerp, or the use of antibodies, cytokines and antimicrobial peptides.
Nystatin, miconazole, and fluconazole are very effective for treating oral candidiasis. There are systemic alternatives for treating recalcitrant infections, such as the new triazoles, echinocandins, or lipidic presentations of amphotericin B.
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