Gertrudes Corção

Antibiotic-resistant Pseudomonas aeruginosa from hospital wastewater and superficial water: Are they genetically related?

Many studies have reported the presence of antibiotic-resistant Pseudomonas aeruginosa in environmental samples such as hospital wastewater and surface water. The present study evaluated the contribution of untreated hospital wastewater to the dissemination of resistant P. aeruginosa strains in aquatic environments, through the analysis of their antibiotic susceptibility profile and genetic similarity. Wastewater samples were collected from two hospitals located in Rio Grande do Sul, RS, Brazil. Superficial water samples were collected from water bodies that received this wastewater discharge. The antibiotic susceptibility profiles of the strains were determined using the disk-diffusion technique and their genotyping was done by amplification of the Enterobacterial Repetitive Intergenic Consensus sequences (ERIC-PCR). The antibiotic resistance was higher among the hospital wastewater strains and the multiresistant phenotype was also observed only among these strains. The ERIC-PCR profiles did not reveal any genetic similarity among the P. aeruginosa strains from the wastewater and superficial water samples. On the contrary, they showed that genetically distinct populations were established in these different environments and probably that some other contamination source could be contributing to the presence of resistant strains in these water bodies.

Pseudomonas aeruginosa: disseminação de resistência antimicrobiana em efluente hospitalar e água superficial

The aim of this study was to compare sewage samples from Hospital Sao Vicente de Paulo with water samples from the Passo Fundo river, with regard to the susceptibility profile of Pseudomonas aeruginosa isolates, in order to make inferences about the presence of strains of hospital origin in surface water samples. The statistical significance between the susceptibility profiles of the samples was tested using analysis of variance, and the samples were compared by means of contrasts of interest. One hundred and ninety-eight isolates of Pseudomonas aeruginosa were recovered from the samples analyzed. No phenotype for multiresistance was found in the samples from the Passo Fundo river, although some carbapenem-resistant isolates were identified, thereby indicating the presence of contamination with bacteria derived from an environment under strong selection pressure. Significant differences between the water and hospital effluent samples were observed, based on the analysis of variance by means of contrasts of interest. Key-words: Pseudomonas aeruginosa. Bacterial resistance. Surface water. Hospital sewage. nao metabolizadas por pacientes 3 . A ocorrencia de ambientes

Microbiological quality of minimally processed vegetables sold in Porto Alegre, Brazil

Minimally processed vegetables go through various steps during their preparation, with many modifications to their natural structure. However, they must maintain the same quality as the fresh produce. The aim of the present study was to quantify mesophilic and psychrotrophic microorganisms and total and faecal coliforms, and to assess the presence of Escherichia coli, parasites, and dirt material in ready-to-eat minimally processed vegetables. Fifty-six samples of minimally processed vegetables were analysed for the presence of mesophilic and psychrotrophic microorganisms by the plate-count method. Monthly means ranged from 4.7x10 5 to 1.6x10 8 CFU/g and from 7.9x10 6 to 2.7x10 8 CFU/g, respectively for mesophilic and psychrotrophic microorganisms. Coliforms were analysed by the multiple-tube method; total coliforms ranged from <3 to ≥ 2.4x10 4 MPN/g and faecal coliforms from <3 to 1.1x10 4 MPN/g. Escherichia coli was detected in eight samples. Out of 52 samples, eight (15.3%) contained oocysts of Eimeria spp.. Dirt matter, such as insect body parts and young mites, was also found. Contamination of faecal origin was observed in these samples, suggesting that either the sanitisation of the product was unsuccessful, or soil or irrigation water could be the source of these microorganisms.

Presence of OXA-23-Producing Isolates of Acinetobacter baumannii in Wastewater from Hospitals in Southern Brazil

The aim of the study was to evaluate the dissemination of multiresistant isolates of Acinetobacter baumannii carrying resistance genes, by samples of wastewater from hospitals in Porto Alegre, Rio Grande do Sul, Brazil. We obtained 303 bacterial isolates from the wastewater of three hospitals in Porto Alegre, Rio Grande do Sul. For each isolate, we determined the profile of susceptibility to antimicrobials and the presence of the genes bla(OXA-23), bla(OXA-24), bla(OXA-51), bla(OXA-58), bla(SPM-1), bla(IMP), and bla(VIM.) The bla(OXA-51) gene was found in 56% of the isolates, indicating the presence of A. baumannii in this environment. Of these, three multiresistant isolates were positive for the bla(OXA-23) gene, in wastewater from two of the hospitals. The results obtained in this study indicate that isolates of A. baumannii which are multiresistant and carry resistance genes such as bla(OXA-51) and bla(OXA-23) are being released into the environment in the wastewater from the hospitals analyzed. Multiresistant Acinetobacter junii, the newly emerging pathogen, were also found among the multiresistant isolates. Hospital wastewater may be crucial to the development and dispersal of multiresistant bacteria, making waterbodies reservoirs of bacterial resistance.

Phylogenetic identification of marine bacteria isolated from deep-sea sediments of the eastern South Atlantic Ocean

The deep-sea environments of the South Atlantic Ocean are less studied in comparison to the North Atlantic and Pacific Oceans. With the aim of identifying the deep-sea bacteria in this less known ocean, 70 strains were isolated from eight sediment samples (depth range between 1905 to 5560 m) collected in the eastern part of the South Atlantic, from the equatorial region to the Cape Abyssal Plain, using three different culture media. The strains were classified into three phylogenetic groups, Gammaproteobacteria, Firmicutes and Actinobacteria, by the analysis of 16s rRNA gene sequences. Gammaproteobacteria and Firmicutes were the most frequently identified groups, with Halomonas the most frequent genus among the strains. Microorganisms belonging to Firmicutes were the only ones observed in all samples. Sixteen of the 41 identified operational taxonomic units probably represent new species. The presence of potentially new species reinforces the need for new studies in the deep-sea environments of the South Atlantic.

Evaluation of antimicrobial activity in Paenibacillus spp. strains isolated from natural environment

Aims:  Paenibacillus isolates were selected to test antimicrobial activity against bacteria, filamentous fungi and yeasts isolates, with the purpose of finding new bacterium species for microbiological control.

Characterization of enterocins produced by Enterococcus mundtii isolated from humans feces

The aim of this study was to characterize bacterioc ins produced by 70 strains of Enterococcus mundtii.Four strains exhibited antibiotic activity towards Listeria inno cua , L. monocytogenes , Lactobacillus plantarum , and Salmonella Enteritidis. They remained active under temperature s of up to 121 o C for 20 min, and under pH treatments that varied from 2.0 to 10.0. Antimicrobial activity was maintained during the storage test for 60 days und er freezing. The kinetics of production revealed the peak activi ty of 1600 AU /mL during the logarithmic growth pha se and the molecular weight found was approximately 3.0 kDa. Tion of the products with antimicrob ial activity indicated their proteic nature, presenting a typica l kinetics of primary metabolite and a molecular we ight similar to many purified enterocins.

Spread of Metallo-β-lactamases: screening reveals the presence of a BLA SPM-1 gene in hospital sewage in southern Brazil

Of 396 Pseudomonas aeruginosa strains isolated from hospital sewage, the blaSPM-1 gene was confirmed in nine. This is the first report of environmental P. aeruginosa strains carrying the blaSPM-1 gene in Brazil. The carbapenem resistance, already disseminated among clinical isolates, has been detected among environmental isolates.

Beta-lactams resistance and presence of class 1 integron in Pseudomonas spp. isolated from untreated hospital effluents in Brazil

The aim of the present study was to investigate the resistance profile, to detect the presence of beta-lactam resistance genes, phenotypic expression of efflux pump systems and class 1 integrons in Pseudomonas spp. strains obtained from untreated hospital effluents. Effluent samples were collected from four hospitals in Porto Alegre, RS, Brazil. Pseudomonas were isolated on MacConkey agar plates and the identification was confirmed by 16S rRNA PCR and biochemical tests. Susceptibility testing was determined by disk-diffusion method using 11 different beta-lactams and MIC assays were performed on isolates resistant to imipenem and ceftazidime. The beta-lactamase genes blaIMP, blaVIM, blaSPM-1, blaOXA-23-like, blaOXA-24-like, blaOXA-51-like and the intl1 gene from class 1 integron were analysed by PCR. One hundred and twenty-four isolates were recovered and the most common species was Pseudomonas pseudoalcaligenes. The resistance found among the isolates was considered high, 62 (50%) isolates were multiresistant. No isolate carrying the beta-lactamase genes tested was found among the strains. Seven isolates showed reduction of MIC for imipenem and ceftazidime in the presence of cyanide m-chlorophenylhydrazone, indicating the hyper expression of efflux pumps. From the 124 isolates, 52 (41.9%) were identified as carrying the class 1 integron gene, intI1. Untreated hospital effluents could be a source of environmental contamination due to discharge of antimicrobial resistant bacteria which can carry integron class 1 and act as a reservoir of resistance genes and have efflux pump systems.

Ocorrência de cepas de Pseudomonas aeruginosa multirresistentes produtoras de metalo-β-lactamase blaSPM-1 em amostras clínicas

This study analyzed the occurrence of metallo-beta-lactamase genes in clinical samples of Pseudomonas aeruginosa from the Hospital São Vicente de Paulo, RS. The genes were analysed by PCR and the susceptibility profiles were studied by diffusion-disk. Forty six strains were analyzed and five strains were positive for blaSPM-1 gene.