Species distribution and in vitro fluconazole susceptibility of clinical Candida isolates in a Brazilian tertiary-care hospital over a 3-year period

Introduction: Hospital infections caused by Candida spp. are a leading cause of morbidity and mortality in hospitalized patients, particularly those that are critically ill or immunocompromised. In this study, the distributio n of Candida species in isolates from the University Hospital of the Federal University at Grande Dourados and their in vitro susceptibility to antifungal drugs were analyzed. Methods: Yeasts were phenotypically identifi ed using classical methodologies. Antifungal susceptibility tests to amphotericin B and fl uconazole were performed using the broth microdilution technique. Results: A total of 50 Candida isolates were obtained from hospitalized patients during the study period. We analyzed yeast isolates from urine (n=31; 62%), blood (n=12; 24%), and tracheal secretions (n=7; 14%). The following Candida species were identifi ed: C. tropicalis (n=21; 42%), C. albicans (n=18; 36%), C. glabrata (n=10; 20%), and C. krusei (n=1; 2%). Antifungal susceptibility tests demonstrated that C. albicans was susceptible to both antifungal agents. However, 31.2% of the non-C. albicans Candida isolates displayed dose-dependent susceptibility to fl uconazole, and 3.1% were resistant to amphotericin B. Conclusions: In contrast to previous reports, our results indicated that C. tropicalis was the most commonly isolated yeast species among the hospital patients. The predominance of non-C. albicans Candida infections confi rms the importance of species-level identifi cation for implementing appropriate antifungal therapies.

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 96%

See 1 more Smart Citation

Antifungal susceptibility and distribution of Candida spp. isolates from the University Hospital in the municipality of Dourados, State of Mato Grosso do Sul, Brazil

Almeida

Shinobu-Mesquita

Svidzinski

et al. 2013

“…The most common causative agent is still C. albicans, but its incidence is declining and the frequencies of other species are increasing. Recently, Furlaneto et al 1 noted that non-albicans Candida was the predominant species in different clinical specimens, with the exception of urine samples, in a Brazilian tertiary-care hospital. Invasive candidiasis has a mortality rate that approaches 40% 2,3 .…”

mentioning

confidence: 99%

Glutathione levels in and total antioxidant capacity of Candida sp. cells exposed to oxidative stress caused by hydrogen peroxide

Abegg

Alabarse

Schüller

et al. 2012

Candida albicans, C. glabrata, C. tropicalis, and C. parapsilosis account for approximately 95% of identifiable Candida infections. Other species, including C. krusei, C. lusitaniae, and C. guilliermondii, account for less than 5% of cases of invasive candidiasis. The most common causative agent is still C. albicans, but its incidence is declining and the frequencies of other species are increasing. Recently, Furlaneto et al. 1 noted that non-albicans Candida was the predominant species in different clinical specimens, with the exception of urine samples, in a Brazilian tertiary-care hospital. Invasive candidiasis has a mortality rate that approaches 40% 2,3 . Although most people are colonized by Candida sp., the majority never develop invasive candidiasis. Alterations in host immunity, physiological features, or normal microflora, rather than the acquisition of novel or hypervirulent factors by Candida, are suggested to degenerate the commensal-host interaction and lead to an opportunistic infection 4 .During the course of a systemic infection, Candida cells are engulfed by host phagocytes, where they are exposed to reactive oxygen species (ROS) 5 . ROS contribute to the killing of C. albicans in both cultured cells and entire organisms [6][7][8][9] . Upon incubation with macrophages, C. albicans deoxyribonucleic acid (DNA) repair genes are transcriptionally induced, suggesting that DNA damage indeed occurs in the phagosome and that genotoxic hypersensitivity stress would be disadvantageous to the pathogen 10 . Recently, it was demonstrated that a large proportion of C. albicans cell surface antigens related to acute candidemia are involved in oxidative stress 4 . In C. albicans, hyphal cells ABSTRACT Introduction: The capacity to overcome the oxidative stress imposed by phagocytes seems to be critical for Candida species to cause invasive candidiasis. Methods: To better characterize the oxidative stress response (OSR) of 8 clinically relevant Candida sp., glutathione, a vital component of the intracellular redox balance, was measured using the 5,5'-dithiobis-(2-nitrobenzoic acid (DTNB)-glutathione disulfide (GSSG) reductase reconversion method; the total antioxidant capacity (TAC) was measured using a modified method based on the decolorization of the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic) acid radical cation (ABTS* + ). Both methods were used with cellular Candida sp. extracts treated or not with hydrogen peroxide (0.5 mM). Results: Oxidative stress induced by hydrogen peroxide clearly reduced intracellular glutathione levels. This depletion was stronger in Candida albicans and the levels of glutathione in untreated cells were also higher in this species. The TAC demonstrated intra-specific variation. Conclusions: Glutathione levels did not correlate with the measured TAC values, despite this being the most important non-enzymatic intracellular antioxidant molecule. The results indicate that the isolated measurement of TAC does not give a clear picture of the ability of a given Candida sp. to resp...

“…Candida glabrata shows less susceptibility than other Candida species, and the development of resistance to fl uconazole among the clinical strains of C. albicans, C. parapsilosis and Candida tropicalis, hampers the treatment of these infections 13 . The activity against C. neoformans is of particular importance, as this yeast is the major cause of meningitis in AIDS patients and has been identifi ed as the fourth most common cause of life-threatening infection in AIDS patients 14 .…”

Section: Candida Krusei Candida Parapsilosis Candida Tropicalis Cryptmentioning

confidence: 99%

In vitro antifungal activities of leaf extracts of Lippia alba (Verbenaceae) against clinically important yeast species

Oliveira

Ferreira

Rosa

et al. 2014

Introduction:There are few studies reporting the antifungal activities of Lippia alba extracts. Methods: A broth microdilution assay was used to evaluate the antifungal effects of Lippia alba extracts against seven yeast species of Candida and Cryptococcus. The butanol fraction was investigated by gas chromatography-mass spectrometry. Results: The butanol fraction showed the highest activity against Candida glabrata. The fraction also acted synergistically with itraconazole and fl uconazole against C. glabrata. The dominant compounds in the butanol fraction were 2,2,5-trimethyl-3,4-hexanedione, 3,5-dimethyl-4-octanone and hexadecane. Conclusions: The butanol fraction may be a good candidate in the search for new drugs from natural products with antifungal activity.