Virulence markers, adhesion and biofilm formation of Escherichia coli strains isolated from drinking water supplies of north Paraná State, Brazil.

Waterborne diseases are a major public health problem responsible for a high number of deaths worldwide, of which Escherichia coli is a major agent of contamination. This study investigates the occurrence of different diarrheagenic E. coli (DEC) pathotypes and its relationship with adherence patterns and biofilm formation. Between 2012 and 2014, a total of 1,780 drinking water samples were collected from different rural communities and urban water systems of north Paraná State. A total of 14% were positive for E. coli and 250 non-duplicate E. coli isolates were obtained. Between the E. coli isolates, 28 (11.2%) harbored DEC-associated genes, 10.7% being classified as Shiga toxin-producing E. coli (STEC), 64.3% enteroaggregative E. coli (EAEC) and 25% atypical enteropathogenic E. coli (aEPEC). The aggregative adherence (AA) was the predominant adherence pattern (84%), significantly associated with biofilm formation (p < 0.0001). On the other hand, the AA pattern and biofilm formation were not significantly associated to DEC pathotypes (p > 0.05). Therefore, we proposed that the AA pattern and biofilm formation in E. coli isolated from drinking water supplies could be associated with adherence and colonization of abiotic surfaces, such as pipes, leading to persistence and resistance to treatment or disinfection.

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)

Molecular and phenotypic characterization of diarrheagenic Escherichia coli isolated from groundwater in rural areas in southern Brazil.

Water-borne diseases like diarrheagenic Escherichia coli (DEC)-induced gastroenteritis are major public health problems in developing countries. In this study, the microbiological quality of water from mines and shallow wells was analyzed for human consumption. Genotypic and phenotypic characterization of DEC strains was performed. A total of 210 water samples was analyzed, of which 153 (72.9%) contained total coliforms and 96 (45.7%) E. coli. Of the E. coli isolates, 27 (28.1%) contained DEC genes. The DEC isolates included 48.1% Shiga toxin-producing E. coli (STEC), 29.6% enteroaggregative E. coli (EAEC), 14.9% enteropathogenic E. coli (EPEC), 3.7% enterotoxigenic E. coli (ETEC), and 3.7% enteroinvasive E. coli (EIEC). All the STECs had cytotoxic effects on Vero cells and 14.8% of the DEC isolates were resistant to at least one of the antibiotics tested. All DEC formed biofilms and 92.6% adhered to HEp-2 cells with a prevalence of aggregative adhesion (74%). We identified 25 different serotypes. One EPEC isolate was serotype O44037:H7, reported for the first time in Brazil. Phylogenetically, 63% of the strains belonged to group B1. The analyzed waters were potential reservoirs for DEC and could act as a source for infection of humans. Preventive measures are needed to avoid such contamination.

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.

New approach for detection of Escherichia coli invasion to HeLa cells.

To establish a successful infection, microorganisms have developed strategies to invade host cells. One of the most important human pathogens and the greatest cause of urinary tract infections, Escherichia coli, still do not have its invasion mechanisms fully understood. This work aims to present a new approach for detecting bacterial invasion of lineage cells, based on an enzymatic-fluorogenic method. The focus of this technique is the detection of E. coli invasion of HeLa cells, exploring ß-glucuronidase, a specific constitutive enzyme of this bacterium. This enzyme hydrolyses the key substrate of this work, 4-methylumbelliferyl-ß-d-glucuronide (MUG), resulting in a fluorogenic molecule, 4-methylumbelliferone. The fluorescence curve created by this method, analyzed by Tukey statistical test, demonstrated that this detection can be efficiently performed after 5 h incubation with MUG. When testing uropathogenic E. coli and E. coli isolated from human gastrointestinal microbiota, the proposed method presented similar results to those exhibited by plate counting invasion detection. Data examination by Duncan statistical test allowed the creation of an intensity range of bacterial invasion, which is part of the process of results interpretation. Detection by this enzymatic-fluorogenic method, compared to other existing bacterial invasion detection techniques, is less burdensome, more sensitive and allows fast achievement of reliable results.

Diversity of Shiga toxin-producing Escherichia coli in sheep flocks of Paraná State, southern Brazil.

Sheep constitute an important source of zoonotic pathogens as Shiga toxin-producing Escherichia coli (STEC). In this study, the prevalence, serotypes and virulence profiles of STEC were investigated among 130 healthy sheep from small and medium farms in southern Brazil. STEC was isolated from 65 (50%) of the tested animals and detected in all flocks. A total of 70 STEC isolates were characterized, and belonged to 23 different O:H serotypes, many of which associated with human disease, including hemolytic-uremic syndrome (HUS). Among the serotypes identified, O76:H19 and O65:H- were the most common, and O75:H14 and O169:H7 have not been previously reported in STEC strains. Most of the STEC isolates harbored only stx1, whereas the Stx2b subtype was the most common among those carrying stx2. Enterohemolysin (ehxA) and intimin (eae) genes were detected in 61 (87.1%) and four (5.7%) isolates, respectively. Genes encoding putative adhesins (saa, iha, lpfO113) and toxins (subAB and cdtV) were also observed. The majority of the isolates displayed virulence features related to pathogenesis of STEC, such as adherence to epithelial cells, high cytotoxicity and enterohemolytic activity. Ovine STEC isolates belonged mostly to phylogenetic group B1. PFGE revealed particular clones distributed in some farms, as well as variations in the degree of genetic similarity within serotypes examined. In conclusion, STEC are widely distributed in southern Brazilian sheep, and belonged mainly to serotypes that are not commonly reported in other regions, such as O76:H19 and O65:H-. A geographical variation in the distribution of STEC serotypes seems to occur in sheep.

Qualidade microbiológica da água do Lago Igapó de Londrina - PR e caracterização genotípica de fatores de virulência associados a Escherichiacoli enteropatogênica (EPEC) e E. coli produtora de toxina Shiga (STEC) / Microbiological water quality of Igapó Lake Londrina - PR and genotypic characterization of virulence factors associated with enteropathogenic Escherichia coli (EPEC) and Shiga toxin-producing E. coli (STEC)

Esse trabalho teve como objetivo a detecção e quantificação de coliformes totais e Escherichia coli, no Lago Igapó, com a finalidade de avaliar a qualidade destas águas como próprias ou impróprias para recreação, além da caracterização genotípica de fatores de virulência associados a EPEC e STEC pela técnica da PCR. A área de estudo foi o Lago Igapó I, II, III e IV. As coletas foram realizadas mensalmente entre março de 2011 a fevereiro de 2012. A técnica utilizada para detecção e quantificação de Coliformes Totais e E. coli foi a do substrato cromogênico Colilert. Na PCR os genes eae e bfp foram pesquisados para caracterizar o patotipo de EPEC típica; stx1, stx2, eae e hlyA o de STEC e as que apresentaram somente o gene eae foram caracterizadas como EPEC atípica. De acordo com a Resolução CONAMA 357/2005, foi observado que para a recreação de contato primário, apenas o Lago Igapó III foi classificado impróprio, já para recreação de contato secundário, todos os lagos apresentaram-se próprios. Além disso, pode ser observada uma forte relação entre o índice pluviométrico e os índices deE. coli no Lago Igapó, na qual em meses mais secos a sua quantidade decresce drasticamente, enquanto que em meses chuvosos se observava uma relação contrária. Das 97 cepas de E. coli isoladas, duas apresentaram o gene eae (EPEC atípica). Nenhum isolado apresentou os genes stx1, stx2, bfp e hlyA. Desse modo, esperamos conscientizar a população e os órgãos públicos da importância do monitoramento microbiológico das águas recreacionais para prevenção de surtos de infecções de veiculação hídrica.

This work aimed at the detection and quantification of total coliforms and Escherichia coli in IgapóLake, in order to evaluate the quality of these waters as proper or unfit for recreation, in addition to the genotypic characterization of virulence factors associated with EPEC and STEC by PCR. The study areawas the Igapó Lake I, II, III and IV. Samples were collected monthly from March 2011 to February 2012.The technique used for the detection and quantification of Total Coliforms and E. coli was the Colilert chromogenic substrate. In the technique of PCR, the eae and bfp genes were tested to characterize the typical EPEC pathotype; stx1, stx2, eae and hlyA the STEC pathotype and the samples that presented only the eae gene were characterized as atypical EPEC. According to CONAMA Resolution 357/2005, it has been observed that only Igapó Lake III was rated inappropriate for primary contact recreation, while for secondary contact recreation, all lakes were considered appropriate. Moreover, a strong relationship between rainfall and E. coli indices in Igapó Lake can be observed, which in dry months the quantity drastically decreases, while in rainy months the opposite relationship was observed. Of the 97 strains of E. coli isolated, two had the eae gene (atypical EPEC). None of the isolates contained genes stx1,stx2, bfp and hlyA. Thus, we hope to educate the population and public agencies of the importance of microbiological monitoring of recreational waters to prevent outbreaks of waterborne infections.

Molecular detection of HpmA and HlyA hemolysin of uropathogenic Proteus mirabilis.

Urinary tract infection (UTI) is one of the bacterial infections frequently documented in humans. Proteus mirabilis is associated with UTI mainly in individuals with urinary tract abnormality or related with vesicular catheterism and it can be difficult to treat because of the formation of stones in the bladder and kidneys. These stones are formed due to the presence of urease synthesized by the bacteria. Another important factor is that P. mirabilis produces hemolysin HpmA, used by the bacteria to damage the kidney tissues. Proteus spp. samples can also express HlyA hemolysin, similar to that found in Escherichia coli. A total of 211 uropathogenic P. mirabilis isolates were analyzed to detect the presence of the hpmA and hpmB genes by the techniques of polymerase chain reaction (PCR) and dot blot and hlyA by PCR. The hpmA and hpmB genes were expressed by the RT-PCR technique and two P. mirabilis isolates were sequenced for the hpmA and hpmB genes. The presence of the hpmA and hpmB genes was confirmed by PCR in 205 (97.15 %) of the 211 isolates. The dot blot confirmed the presence of the hpmA and hpmB genes in the isolates that did not amplify in the PCR. None of the isolates studied presented the hlyA gene. The hpmA and hpmB genes that were sequenced presented 98 % identity with the same genes of the HI4320 P. mirabilis sample. This study showed that the PCR technique has good sensitivity for detecting the hpmA and hpmB genes of P. mirabilis.

Metallo-ß-lactamase-production in meropenem-susceptible Pseudomonas aeruginosa isolates: risk for silent spread.

The aim of this study was to characterize two metallo-ß-lactamases (MBLs)-producing Pseudomonas aeruginosa clinical isolates showing meropenem susceptibility. Antimicrobial susceptibility was assessed by automated testing and Clinical and Laboratory Standards Institute agar dilution method. MBL production was investigated by phenotypic tests. Molecular typing was determined by pulsed field gel electrophoresis (PFGE). MBL-encoding genes, as well as their genetic context, were identified by polymerase chain reaction (PCR) and sequencing. The location of blaIMP-16 was determined by plasmid electrophoresis, Southern blot and hybridization. Transcriptional levels of blaIMP-16, mexB, mexD, mexF, mexY, ampC and oprD were determined by semi-quantitative real time PCR. The P. aeruginosa isolates studied, Pa30 and Pa43, showed imipenem and meropenem susceptibility by automated testing. Agar dilution assays confirmed meropenem susceptibility whereas both isolates showed low level of imipenem resistance. Pa30 and Pa43 were phenotypically detected as MBL producers. PFGE revealed their clonal relatedness. blaIMP-16 was identified in both isolates, carried as a single cassette in a class 1 integron that was embedded in a plasmid of about 60-Kb. Pa30 and Pa43 overexpressed MexAB-OprM, MexCD-OprJ and MexXY-OprM efflux systems and showed basal transcriptional levels of ampC and oprD. MBL-producing P. aeruginosa that are not resistant to meropenem may represent a risk for therapeutic failure and act as silent reservoirs of MBL-encoding genes.

Metallo-β-lactamase-production in meropenem-susceptible Pseudomonas aeruginosa isolates: risk for silent spread

The aim of this study was to characterize two metallo-β-lactamases (MBLs)-producing Pseudomonas aeruginosa clinical isolates showing meropenem susceptibility. Antimicrobial susceptibility was assessed by automated testing and Clinical and Laboratory Standards Institute agar dilution method. MBL production was investigated by phenotypic tests. Molecular typing was determined by pulsed field gel electrophoresis (PFGE). MBL-encoding genes, as well as their genetic context, were identified by polymerase chain reaction (PCR) and sequencing. The location of blaIMP-16 was determined by plasmid electrophoresis, Southern blot and hybridization. Transcriptional levels of blaIMP-16, mexB, mexD, mexF, mexY, ampC and oprD were determined by semi-quantitative real time PCR. The P. aeruginosa isolates studied, Pa30 and Pa43, showed imipenem and meropenem susceptibility by automated testing. Agar dilution assays confirmed meropenem susceptibility whereas both isolates showed low level of imipenem resistance. Pa30 and Pa43 were phenotypically detected as MBL producers. PFGE revealed their clonal relatedness. blaIMP-16 was identified in both isolates, carried as a single cassette in a class 1 integron that was embedded in a plasmid of about 60-Kb. Pa30 and Pa43 overexpressed MexAB-OprM, MexCD-OprJ and MexXY-OprM efflux systems and showed basal transcriptional levels of ampC and oprD. MBL-producing P. aeruginosa that are not resistant to meropenem may represent a risk for therapeutic failure and act as silent reservoirs of MBL-encoding genes.

Evaluation of the level of microbial contamination and prevalence of gram-negative non-fermentative rods in dental unit waterlines

Introduction: The cross infection control in dental office has received great attention from professionals and one of the critical points is the bacteriological control of water used in dental unit. Objective: To perform a microbiological evaluation of the water used in dental units, the identification of Gram-negative non-fermentative rods (GNNR) and their ability to adhere to polystyrene, and the antimicrobial activity of disinfectants on the identified strains. Material and methods: The heterotrophic bacteria count and GNNR identification were performed on water samples collected from 25 dental units (air/water syringe and reservoir). The GNNR were assessed on their capability to adhere to polystyrene and on their antimicrobial activity to the following disinfectants: sodium hypochlorite (0.06%, 0.12%, 0.25%, and0.5%) and chlorhexidine (0.03%, 0.06%, and 0.12%). Results: 88% of the air/water syringe collected samples and 68% of the reservoir collected samples were out of the potability standards. The quantity of isolated bacteria from the reservoir was lower than from the air/water syringe in 88% of the dental units. Methylobacterium spp. was found in highest percentage (19.7%) during GNNR genus isolation. There was a weak adherence to polystyrene in 85.04% of the samples. Sodium hypochlorite at 0.25%, inactivated 100% of the GNNRs in 10 minutes, while the highest tested concentration of chlorhexidine (0.12%), inactivated 98.5% of the GNNRs. Conclusion: These results provide information on the contamination problem of dental unit waterlines (DUWL) and indicate a need for treatment of the water used in dental units. The disinfection of DUWL can be performed with sodium hypochlorite at 0.25% (half the concentration recommended in the literature). However, further studies are necessary regarding DUWL frequency disinfection.

Análise microbiológica de pontas de cateteres venosos centrais provenientes de pacientes internados no Hospital Universitário da Universidade Estadual de Londrina / Microbiological analysis of the central venous catheter tips from hospitalized patients at Hospital Universitário of Universidade Estadual de Londrina

Cateteres venosos centrais (CVC) são utilizados na terapia intravenosa com a finalidade de facilitar o diagnóstico e o tratamento do paciente, pois permitem a administração de edicamentos, nutrição parenteral, além de serem usados como acesso vascular para hemodiálise. Entretanto, o uso desses cateteres oferece riscos de infecção local e sistêmica, incluindo endocardite e bacteremia. O presente estudo teve por objetivo isolar microrganismos de CVC, utilizando a técnica de cultura semi-quantitativa,e identificar os mesmos, mediante provas bioquímicas convencionais e por sistema automatizado. Neste estudo, 198 pontas de CVC foram avaliadas e 105 (53%) foram consideradas positivas, ou seja, apresentaram crescimento microbiano ³ 15 UFC. Os microrganismos encontrados foram os seguintes:63,8% de bactérias Gram-positivas; 30,5% de bactérias Gram-negativas e 5,7% de leveduras. Os microrganismos predominantes foram: Staphylococci coagulase-negativa (35,2%), Staphylococcus aureus (25,7%), Klebsiella pneumoniae (8,5%), Pseudomonas aeruginosa (7,6%), Acinetobacter baumannii (7,6%) e Candida albicans (4,7%). O aumento da incidência de infecção relacionada a cateter tem sido observado mundialmente, e decorre do aumento de procedimentos médicos invasivos, utilizados para o tratamento de pacientes. Este estudo possibilitou identificar os microrganismos predominantes em pontas de CVC, em um hospital escola da região de Londrina-PR. A identificação destes microrganismos é de extrema importância para otimizar o tratamento da infecção e estabelecer medidas preventivas.

Resistance profile to antimicrobials of Salmonella spp. isolated from human infections

O objetivo deste estudo foi analisar o perfil de resistência à antimicrobianos, de Salmonella isoladas de 21 amostras provenientes de pacientes com sintomatologia de gastroenterite. Verificou-se que S. enteritidis foi o sorotipo com maior prevalência. Estas cepas mostraram-se sensíveis à maioria dos antimicrobianos testados, no entanto, as cepas S. typhimurium e S. enterica subsp. enterica sorotipo 4,5,12:i:-, mostraram-se resistentes à vários antimicrobianos. Vigilância e um monitoramento eficiente, para diminuir a resistência antimicrobiana em microrganismos que causam infecções veiculadas por alimentos, devem ser prioridade para a saúde pública.

Genotypic and phenotypic characterization of attaching and effacing Escherichia coli (AEEC) isolated from children with and without diarrhoea in Londrina, Brazil.

Attaching and effacing Escherichia coli (AEEC) have been implicated in diarrhoea in humans in several countries. A total of 919 E. coli strains, isolated from 125 children with diarrhoea and 98 without diarrhoea, was investigated by PCR for the presence of the EAF, bfp, eae and stx genes. Thirty-four of these isolates were found to carry the eae gene; they were isolated from 27 (79.4 %) children with diarrhoea and seven (20.6 %) controls, in the city of Londrina, Brazil. These strains were investigated for their genotypic and phenotypic characteristics. Different genetic profiles were observed; strains containing the eae gene alone were most common (47.1 %). The characteristic genetic profile of typical enteropathogenic E. coli (EPEC), eae, bfp and EAF, was only found in isolates from children with diarrhoea. The stx gene was not detected in any of the 34 strains studied. Ten (29.4 %) strains were negative in the fluorescent actin-staining test. Localized adhesion (LA) was the most common pattern of adhesion (44.1 %), followed by the aggregative adhesion (AA) (23.5 %) and localized adhesion-like (LAL) (14.7 %) patterns. The results showed a strong association between strains presenting the LA pattern and diarrhoea. Forty-seven per cent of the strains studied belonged to classical O-serogroups of EPEC. The most common serotype found was O119 : H6; these isolates all showed the LA pattern, were positive for fluorescent actin-staining and were associated with diarrhoea. Intimin beta was detected in seven strains, four of which belonged to serotype O119 : H6 and three to serotype ONT : H7; all were associated with diarrhoea. On the other hand, intimin epsilon was detected in two strains of serotype O111 : H38 and one of serotype ONT : H19, isolated from children without diarrhoea. To our knowledge, this is the first report of the occurrence of intimin epsilon in strains of E. coli isolated from humans in Brazil.

Detecçäo de resíduos antimicrobianos no leite cru e pasteurizado tipo C, comercializado na regiäo de Londrina, Paraná, Brasil / Detection of antimicrobial residues in raw and pasteurized milk type C, commercially in Londrina, Parana, Brasil

No período compreendido entre março de 1986 a março de 1987, foram estudadas 130 amostras de leite bovino de uma usina de leite na regiäo de Londrina, Pr., Brasil, sendo 78 de leite cru, utilizadas no processamento do leite pasteurizado tipo C, 26 coletadas na saída do pasteurizador, e 26 de leite pasteurizado tipo C, comercializado nesta cidade. A técnica utilizada foi a proposta por VILELA & SANTOS (1981). Essa técnica baseia-se na difusäo do antimicrobiano em ágar, tendo como microorganismo teste a forma esporulada do Bacillus stearothermophilus var. calidolactis. Destas amostras, 4 (51,1%) de leite cru e 1 (3,85%) de leite pasteurizado adquirido no comércio apresentam resíduos antimicrobianos, näo se detectando nas amostras coletadas diretamente do pasteurizador

Isolamento de yersinia pseudotuberculosis de bezerros, na regiäo de Londrina, Paraná, Brasil / Isolation of yersinia psudotuberculosis from calves, in Londrina, Paraná, Brazil

Säo relatados o isolamento, características bioquímicas e sensibilidade a drogas antimicrobianas de 3 cepas de Yersinia pseudotuberculosis pertencentes ao grupo O-III. As cepas foram isoladas de bezerros com diarréia, na regiäo de Londrina, Paraná, Brazil

Sorotipos de Salmonella isolados de produtos cárneos em Londrina - Paraná / Serotypes of Salmonella isolated from meat products in Londrina - Paraná

A partir de 194 amostras de produtos cárneos, sendo 101 de carne moída de segunda qualidade e 93 de quibe cru, coletadas em 4 açougues, considerados de bom nível na regiäo de Londrina, foram isolados 12 cepas de Salmonella pertencentes a 3 diferentes sorotipos: S. give (1), S. london (2), S. infantis (9). Essas bactérias foram estudadas quanto a sua sensibilidade ou resistência a 8 drogas: Gentamicina (Gn), Trimexazol (Tri), Cloranfenicol (Cl), Ampicilina (Ap), Tetraciclina (Tt), Sulfanilamida (Su), Estreptomicina (Et), Cefalotina (Ce). As cepas isoladas apresentaram baixa resistência a drogas, com exceçäo da Sulfanilamida frente a qual, a resistência foi de 100%