Caracterização de Escherichia coli diarreiogênica isolada de água subterrânea para consumo humano em um assentamento rural / Characterization of diarrheagenic Escherichia coli isolated from underground water for human consumption in a rural settlement

Escherichia coli diarreiogênica (DEC) é um importante agente de infecções gastrointestinais transmitidas pela água. O trabalho teve como objetivo avaliar a qualidade microbiológica e físicoquímica de 58 amostras de água subterrânea in natura para consumo de um assentamento rural e caracterizar os isolados de E. coli, genotipicamente dentro dos patotipos de DEC, pela técnica da PCR, e fenotipicamente. Todas as amostras apresentaram contaminação por coliformes totais e 36 (62,1%) por E. coli. Em células HEp-2, dos 170 isolados de E. coli, 106 (62,36%) apresentaram AA, 15 (8,82%) AD, 17 (10%) adesão não caracterizado e 32 (18,82%) foram não aderentes. Quanto à formação de biofilme, 126 (74,12%) cepas são formadoras, e 44 (25,88%) não formaram biofilme. Foram identificadas DEC em 6,89% das amostras de água: três (5,17%) ETEC e uma (1,72%) EAEC. EAEC apresentou AA e as três cepas de ETEC apresentaram AD, AA e não definida. Todas as DEC foram formadoras de biofilme. Dois isolados de ETEC apresentaram resistência à ampicilina e tetraciclina, uma ETEC à aminoglicosídeos, e EAEC foi sensível a todos os antibióticos testados. As ETEC foram classificadas no filogrupo B1 e a EAEC no E. Os sorotipos encontrados foram: O24:H21, OR:H21, O17:H46 e O6:H12. Todas as amostras estavam dentro dos parâmetros normais de flúor e 13 (22,4%) apresentaram resultados acima do padrão permitido de turbidez. A presença de E. coli e DEC nas amostras de água indica a necessidade de adoção de medidas que evitem a contaminação da água fornecida à população, evitando, assim, a transmissão de doenças.(AU)

Diarrheogenic Escherichia coli (DEC) is an important agent of waterborne gastrointestinal infections. The objective of this work was to evaluate the microbiological and physico-chemical quality of 58 freshwater groundwater samples for the consumption of a rural settlement and to characterize the E. coli isolates, genotyped within the DEC pathophyses, by the PCR technique, and phenotypically. All water samples presented contamination with total coliforms, and 36 (62.1%) with E. coli. In HEp-2 cells, of 170 E. coli isolates, 106 (62.36%) showed AA, 15 (8.82%) AD, 17 (10%) noncharacterized adhesion and 32 (18.82%) were non-adherent. As for biofilm formation, 126 (74.12%) strains are forming, and 44 (25.88%) did not form biofilm. DEC was identified in 6.89% of the water samples with E. coli: three (5.17%) with enterotoxigenic E. coli (ETEC), and one (1.72%) with enteroaggregative E. coli (EAEC). EAEC showed aggregative adherence, whereas various ETEC strains presented diffuse, aggregative, and non-defined adherence. All DEC strains were biofilm forming. Two isolates of ETEC showed resistance to ampicillin and tetracycline, and one isolate showed resistance to aminoglycosides. The EAEC isolate was sensitive to all antibiotics tested. All ETECs were classified into phylogenetic B1 and EAEC in E. The serotypes identified in our study were: O24:H21, ONT:H21, O17:H46, and O6:H12. All water samples were within normal fluorine parameters; however, measured turbidity was above the permitted standard in 13 (22.4%) samples. The presence of E. coli and DEC in water samples indicates the need to take action to prevent contamination of water resources accessed by people to prevent the transmission of diseases.(AU)

Antibacterial Activity of Sophorolipids from Candida bombicola Against Human Pathogens

Abstract Sophorolipids are glycolipids that have natural antimicrobial properties and present great potential in the pharmaceutical field. The present study aimed to produce sophorolipids from Candida bombicola using a chicken fat-based medium and evaluate the antimicrobial activity against Gram-negative (Proteus mirabilis, Escherichia coli, Salmonella enterica subsp. enterica) and Gram-positive bacteria (Enterococcus faecium, Staphylococcus aureus and Streptococcus mutans). The production of sophorolipids reached 27.86 g L-1. Based on the structural characterization, 73.55% of the sophorolipids present a mixture of acidic monoacetylated C18:2 and lactonic diacetylated C16:0, and 26.45% were present in the diacetylated C18:1 lactonic form. Bacteria submitted to sophorolipid exposure showed a reduction in viability at doses of 500 μg mL-1 and 2,000 μg mL-1 against Gram-positive and Gram-negative bacteria, respectively. These results suggest that sophorolipids produced in chicken fat medium may be used as antimicrobial agents to prevent or eliminate contamination by different pathogens.

Avaliação da presença e quantificação de coliformes totais e Escherichia coli em amostras de água destinada ao consumo humano proveniente de poços artesianos / Evaluation of the presence and quantification of total coliforms and Escherichia coli in samples of water intended for human consumption from artesian wells

A água é indispensável à vida e a sua contaminação com microrganismos patogênicos oferece grande risco à saúde humana, podendo causar doenças que variam de gastroenterites brandas a doenças fatais. Dessa forma, a água para o consumo humano deve estar livre de microrganismos patogênicos e não deve conter bactérias indicadoras de contaminação fecal, sendo a Escherichia coli o principal representante desse grupo de bactérias. Tendo em vista a importância da potabilidade da água para a saúde, o presente trabalho teve por objetivo verificar a qualidade bacteriológica da água utilizada para o consumo humano proveniente de 200 poços artesianos localizados na cidade de Cambé/Paraná, no período de 2013 a 2017, utilizando-se para tanto a análise da presença de coliformes totais e de E. coli como indicador de contaminação fecal. A metodologia empregada para a pesquisa de coliformes totais e E. coli foi o método do substrato cromogênico Colilert®. Dentre as 200 amostras analisadas, 113 (56,5%) estavam contaminadas com coliformes totais e 35 (17,5%) com E. coli. As análises realizadas durante o período de cinco anos possibilitaram encontrar 14 (7%) amostras de água tratadas que apresentavam contaminação por bactérias do grupo coliforme. A partir dos resultados obtidos nesse trabalho, espera-se conscientizar tanto a população quanto os órgãos públicos sobre a importância do controle da qualidade da água para a prevenção de doenças transmitidas por esse meio (AU)

Water is essential for life and its contamination by pathogenic microorganisms offers great risk to human health and may cause illnesses ranging from mild gastroenteritis to life threatening diseases. Thus, water for human consumption should be free of pathogenic microorganisms and must not contain indicators of faecal contamination such as Escherichia coli presence. Given the importance of drinking water quality for health, this study aimed to verify the bacteriological quality of water used for human consumption from 200 artesian wells located in the city of Cambé - Paraná, from 2013 to 2017. The methodology used for the research of total coliforms and E. coli was the Colilert® chromogenic substrate method. Among the 200 analysed water samples, 113 (56.5%) were contaminated with total coliforms and 35 (17,5%) with E. coli. The analyses carried out during the five-year period allowed finding 14 (7%) treated water samples that showed contamination by bacteria of the coliform group. Based on the results obtained in this study, it is expected that both the population and the public agencies will be aware of the importance of water quality control for the prevention of diseases transmitted by this means (AU)

Detection of Diarrheagenic Escherichia coli in Bovine Meat in the Northern Region of Paraná State, Brazil

Abstract Ground bovine meat is commonly consumed by the population of Brazil. However, it constitutes an excellent medium for the multiplication of microorganisms due to available nutrients and handling practices prior to consumption. Here, we examined 100 samples of ground beef for the presence of diarrheagenic Escherichia coli (DEC) pathotypes by PCR, and characterized isolates by analyzing their adherence to HEp-2 cells, serotype, antimicrobial susceptibility, and phylogeny. Enteroaggregative E. coli was detected in five (5%) meat samples, Shiga toxin-producing E. coli in three (3%), and atypical enteropathogenic E. coli in two (2%). According to the phylogeny, six isolates (60%) were classified in group A, two (20%) in group B1, and two (20%) in group E. The detected serotypes were O3:H2, O93:H9, O93:H46, O105ab:H7, O152:H8, O156:H10, and O175:H7. The antimicrobial susceptibility testing showed that one sample (10%) was resistant to ampicillin, two (20%) to sulfamethoxazole-trimethoprim, and two (20%) to cephalothin. Based on these results, bovine ground meat for human consumption can serve as a reservoir of DEC, which emphasizes the importance of appropriate hygienic-sanitary conditions during handling at every stage from slaughter to table.

Análise estrutural e funcional da região LEE de Escherichia coli enteropatogênica atípica / Structural and functional analysis of LEE region of atypical enteropathogenic Escherichia coli

Escherichia coli enteropatogênica é capaz de causar uma lesão histopatológica no epitélio intestinal conhecida como attaching-effacing (A/E) induzida por proteínas codificadas pelo locus of enterocyte effacement (LEE). EPEC é atualmente classificada em típica e atípica (aEPEC), baseado na presença ou ausência do EPEC adherence plasmid, respectivamente...

Enterophatogenic Escherichia coli is capable of cause a histopathological lession on the intestinal epithelium called attaching-effacing (A/E), triggered by proteins encoded by the locus of enterocyte effacement (LEE).EPEC is currently classified as typical and atypical (aEPEC), based on the presence or absence of the EPEC adherence plasmid, respectively...