Kelly Mari Pires de Oliveira

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

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 distribution 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 identified using classical methodologies. Antifungal susceptibility tests to amphotericin B and fluconazole 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 identified: 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 fluconazole, 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 confirms the importance of species-level identification for implementing appropriate antifungal therapies.

Genotype, antifungal susceptibility, and biofilm formation of Trichosporon asahii isolated from the urine of hospitalized patients

In this study, the culture analysis of urine samples from patients hospitalized in the Central-West region of Brazil was performed, and the isolated microorganisms were phylogenetically identified as Trichosporon asahii. Maximum parsimony analysis of the IGS1 sequences revealed three novel genotypes that have not been described. The minimum inhibitory concentrations of the nine isolates identified were in the range of 0.06-1 μg/ml for amphotericin B, 0.25-4 μg/ml for fluconazole, and 0.03-0.06 μg/ml for itraconazole. Approximately 6/9 of the T. asahii isolates could form biofilms on the surface of polystyrene microplates. This study reports that the microorganisms isolated here as T. asahii are agents of nosocomial urinary tract infections. Furthermore, the IGS1 region can be considered a new epidemiological tool for genotyping T. asahii isolates. The least common genotypes reported in this study can be related to local epidemiological trends.

The influence of industrial and agricultural waste on water quality in the Água Boa stream (Dourados, Mato Grosso do Sul, Brazil)

Water quality monitoring is used to determine the impact of human activities on the environment. We evaluated water quality in the Água Boa stream, located within the municipality of Dourados, State of Mato Grosso do Sul, Brazil, by analyzing physico-chemical, chemical, and microbiological parameters, as well as chlorophyll concentrations. Five sets of water samples were collected between December 2012 and November 2013 from three locations within the stream. The results showed the presence of Escherichia coli and antibiotic-resistant Pseudomonas spp. strains and high concentrations of organic matter (total dissolved solids), inorganic species (Mg, Ca, and Fe), and agrochemical residues (thiamethoxam). The main stream water contaminants are derived from urban, industrial, and agricultural activities within the watershed. Given the presence of contaminants, it is important that such findings are disseminated in order to highlight the risks that contact with this water may pose to human health. To preserve the environment and improve site conditions, people would need to participate by demanding that normative national and international standards be respected and that the situation be supervised by the competent governmental agencies; this would make it possible to reverse or minimize contamination problems within the Água Boa stream.

Identification of class 1 and 2 integrons from clinical and environmental Salmonella isolates

INTRODUCTION The indiscriminate use of antimicrobials has selected for the emergence of resistant strains. Many mechanisms contribute to the spread of antimicrobial-resistant genes, and integrons play a key role in this process. The aim of this study was to describe the serotypes and resistance profiles, and to characterize the presence of integrons in Salmonella strains isolated from Dourados, Mato Grosso do Sul, Brazil. METHODOLOGY Thirty-six isolates from different sources were used. To evaluate the resistance profiles, the determination of minimum inhibitory concentrations together with polymerase chain reaction were used to screen for the presence of class 1 and class 2 integrons. RESULTS The Infantis serotype of Salmonella was the most frequently isolated serotype. Minimum inhibitory concentrations showed that out of the 36 isolates, 11 (30.5%) were resistant to all the antimicrobials tested. These resistant isolates were separated into three groups: 4 clinical isolates (36.4%), 3 food isolates (36.4%), and 4 water isolates (27.2%). Class 1 integrons occurred in 31 (86.1%) isolates and were found in all 11 resistant isolates (35.5 %) and in 20 (64.5%) of the non-resistant isolates. Class 2 integrons were found in 3 (8.3%) isolates, which were all non-resistant. CONCLUSION The presence of an integron did not necessarily confer resistance. Future studies will seek to identify the mechanism behind integron-mediated antimicrobial resistance.

Novel point mutations in the ERG11 gene in clinical isolates of azole resistant Candida species

The azoles are the class of medications most commonly used to fight infections caused by Candida sp. Typically, resistance can be attributed to mutations in ERG11 gene (CYP51) which encodes the cytochrome P450 14α-demethylase, the primary target for the activity of azoles. The objective of this study was to identify mutations in the coding region of theERG11 gene in clinical isolates of Candidaspecies known to be resistant to azoles. We identified three new synonymous mutations in the ERG11 gene in the isolates of Candida glabrata (C108G, C423T and A1581G) and two new nonsynonymous mutations in the isolates of Candida krusei - A497C (Y166S) and G1570A (G524R). The functional consequence of these nonsynonymous mutations was predicted using evolutionary conservation scores. The G524R mutation did not have effect on 14α-demethylase functionality, while the Y166S mutation was found to affect the enzyme. This observation suggests a possible link between the mutation and dose-dependent sensitivity to voriconazole in the clinical isolate of C. krusei. Although the presence of the Y166S in phenotype of reduced azole sensitivity observed in isolate C. kruseidemands investigation, it might contribute to the search of new therapeutic agents against resistant Candida isolates.

Genotoxic and mutagenic effects of polluted surface water in the midwestern region of Brazil using animal and plant bioassays

Abstract This study aimed to evaluate DNA damage in animal and plant cells exposed to water from the Água Boa stream (Dourados, Mato Grosso do Sul, Brazil) by using bioassays, and to identify the chemical compounds in the water to determine the water quality in the area. Through the cytotoxicity bioassay with Allium cepa, using micronucleus test, and comet assay, using Astyanax altiparanae fish, the results indicated that biological samples were genetically altered. Micronuclei were observed in erythrocytes of A. altiparanae after exposure to water from locations close to industrial waste discharge. The highest DNA damage observed with the comet assay in fish occurred with the exposure to water from locations where the presence of metals (Cu, Pb, Cd, Ni) was high, indicating the possibility of genotoxic effects of these compounds. Thus, these results reinforce the importance of conducting genotoxicity tests for developing management plans to improve water quality, and indicate the need for waste management before domestic and industrial effluents are released into the rivers and streams.

Genotypic variability and antifungal susceptibility of Candida tropicalis isolated from patients with candiduria

BACKGROUND Candida tropicalis is an emerging major human pathogen in nosocomial infections, and it is considered the second or third species of Candida most isolated from urine cultures. AIMS The study aimed at characterizing genotypically C. tropicalis strains from patients with candiduria in a university hospital, and assessed the antifungal susceptibility profile. METHODS The study was conducted with hospitalized patients who developed urinary tract infection from C. tropicalis from June 2010 to June 2011 at the Grande Dourados University Hospital of the Federal University, Dourados, MS, Brazil. Susceptibility to the antifungal agents amphotericin B and fluconazole was determined by broth microdilution. The genotypic variability of isolates of C. tropicalis was analyzed by microsatellite markers and RAPD-PCR. RESULTS Only one isolate was resistant to amphotericin B (MIC→16μg/ml); the others were susceptible to fluconazole and amphotericin B. The genotypic variability by RAPD-PCR resulted in distinct profiles for RAPD markers. A total of 10 alleles were observed for the microsatellite loci, URA3 and CT14, which were grouped differently, and four associations were observed for locus URA3 and eight for locus CT14. CONCLUSIONS C. tropicalis isolates from urine were susceptible to the antifungal agents tested. The genotyping techniques make possible proving the similarity and genetic diversity among isolates of C. tropicalis involved in nosocomial infections. This knowledge is important for the control and prevention of nosocomial infections caused by this yeast species.

Profile susceptibility to fluconazole and voriconazole antifungals by species of Candida albicans isolated from urine culture

Background The term candiduria can be defined as the observation of yeasts on direct examination of urine through the presence of pseudo-hyphae and fungal growth in urine culture [1]. The yeast Candiduria can be detected in the urine in patients who have bladder colonization and in patients who have urinary tract infection [2]. Currently, there are few options in the medicine antifungal market for the treatment of urinary tract infections. And the most used are amphotericin B, ketoconazole, fluconazole and voriconazole. Therefore, the determination of the profile of antifungal susceptibility among isolates of C. albicans urine in patients, it is so important as epidemiological marker that serves to guide therapeutic procedures [3]. Thus, many methods have been tested as alternative to the antifungal susceptibility, as the method of agar disk diffusion M44-A12. So, this study aimed to evaluate the antifungal susceptibility profile of Candida albicans isolated from the urine of patients admitted at the university hospital in Dourados MS.

Evaluation of antibacterial and antifungal activity of ethanolic extract of Cochlospermum regium (Cochlospermaceae) leaf, a medicinal plant from the Cerrado of Brazil

Background Bioprospecting of medicinal plants is a promising activity on biotechnology researches and detection of new compounds with biological activities of interest in health. Studies on medicinal plants of the brazilian Cerrado, still limited across the wide biodiversity found in this biome, it is an important source for the treatment several diseases, including fungal and bacterial infections [5]. Cochlospermum regium (Cochlospermaceae), popularly known as “algodaozinho do cerrado” or “algodaozinho-do-campo”, is a plant used in brazilian folk medicine. Among the various medicinal properties attributed to the plant stands out its use to treat diseases of infectious etiology as well as inflammation [3]. The purpose of this study was to evaluate the antibacterial and antifungal activity of the leaf extract Cochlospermum regium against Gram-positive Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 51299, Gram-negative bacteria Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853, and against the yeast Candida albicans ATCC 90028, Candida tropicalis ATCC 750, Candida glabrata ATCC 2001, Candida krusei ATCC 6558.

Variability in the clinical distributions of Candida species and the emergence of azole-resistant non-Candida albicans species in public hospitals in the Midwest region of Brazil

INTRODUCTION Incidence and antifungal susceptibility of Candida spp. from two teaching public hospitals are described. METHODS The minimum inhibitory concentrations of fluconazole, voriconazole, itraconazole, and amphotericin B were determined using Clinical Laboratory Standard Institute broth microdilution and genomic differentiation using PCR. RESULTS Of 221 Candida isolates, 50.2% were obtained from intensive care unit patients; 71.5% were recovered from urine and 9.1% from bloodstream samples. Candida parapsilosis sensu stricto was the most common candidemia agent. CONCLUSIONS We observed variations in Candida species distribution in hospitals in the same geographic region and documented the emergence of non-C. albicans species resistant to azoles.