Additive effect of the probiotics Lactobacillus exopolysaccharides and the Satureja calamintha extracts on enteropathogenic Escherichia coli adhesion

Abstract This study assessed the inhibitory potential of the probiotics Lactobacillus (LB) exopolysaccharides (EPS) with or without extracts of Satureja calamintha on enteropathogenic Escherichia coli (EPEc) responsible for gastroenteritis. Methanolic and hydromethanolic extracts were prepared by cold maceration and subjected to phytochemical screening. The compounds of the extracts were determined with the colorimetric assays and identified using high-performance liquid chromatography coupled with diode array detector (HPLC-DAD). Antioxidant activities of the extracts were also evaluated by using 2,2-diphenyl-1-picrylhydrazil (DPPH) radical scavenging. Antibacterial effect on EPEc was evaluated by using both agar disc diffusion and microdilution methods. The in vitro test of auto-aggregation was investigated. Microbiological analysis showed that 63% of the isolated LB were producing EPS, with the amount ranging from 8.21 to 43.13 mg/L. Chemical analysis of the extracts revealed the presence of polyphenols and flavonoids, more abundant in the hydromethanolic extract, which presented the highest content with 2.11 mg EGA/g of polyphenol and 1.64 mg EC/g of flavonoids and 1.71 mg EGA/g of polyphenol and 1.15 mg EC/g of flavonoids in the methanolic extract. Hydromethanolic extracts and EPS exhibited a more important activity than did the methanolic extract against EPEc. The combined action of EPS and extracts reduced the aggregation ability of EPEc and decreased the rate of their adhesion.

Detection of the mcr-1 gene in Enteropathogenic Escherichia coli (EPEC) and Shigatoxigenic E. coli (STEC) strains isolated from broilers / Detecção do gene mcr-1 em estirpes de Escherichia coli Enteropatogênicas (EPEC) e Shigatoxigênicas (STEC) isoladas de frangos de corte

Enteropathogenic Escherichia coli (EPEC) and Shigatoxigenic E. coli (STEC) strains are among the major pathotypes found in poultry and their products, which are capable of causing human enteric infections. Colistin has been claimed the drug of choice against diseases caused by multidrug-resistant Gram-negative bacteria (MDRGN) in humans. The mcr-1 gene was the first plasmidial gene that has been described to be responsible for colistin resistance and has also been detected in birds and poultry products. Our study aimed to detect the mcr-1 gene in enteropathogenic strains of E. coli in order to evaluate the resistance to colistin in broilers. The material was obtained from 240 cloacal samples and 60 broiler carcasses. The strains were isolated by the conventional bacteriological method and by the virulence genes, which characterize the enteropathogenic strains and resistance, and the samples were detected by polymerase chain reaction (PCR). Of the 213 isolated strains of E. coli, 57 (26.76%) were characterized as atypical EPEC and 35 (16.43%) as STEC. The mcr-1 gene was found in 3.5% (2/57) of the EPEC strains and 5.7% (2/35) of the STEC strains. In this study, it was possible to confirm that the mcr-1 resistance gene is already circulating in the broiler flocks studied and may be associated with the pathogenic strains.(AU)

Escherichia coli Enteropatogênica (EPEC) e Shigatoxigênica (STEC) estão entres os principais patotipos encontrados em aves e produtos avícolas que são capazes de causar doença entérica no homem. A colistina tem sido preconizada como droga de escolha para o tratamento de doenças causadas por bactérias Gram-negativas multirresistentes em humanos. O gene mcr-1 foi o primeiro gene plasmidial a ser descrito como responsável pela resistência a colistina e tem sido descrito em aves e produtos avícolas. Este estudo tem como objetivo a detecção do gene mcr-1 em estirpes de E. coli enteropatogênicas a fim de avaliar a resistência a colistina em frangos de corte. O material foi obtido a partir de 240 amostras cloacais e 60 carcaças de frango de corte. As estirpes foram isoladas pelo método bacteriológico convencional e os genes de virulência, que caracterizam as estirpes enteropatogênicas, e resistência foram detectados pela reação em cadeia pela polimerase (PCR). Das 213 estirpes de E. coli isoladas, 57 (26,76%) foram caracterizadas como EPEC atípica e 35 (16,43%) como STEC. O gene mcr-1 foi encontrado em 3,5% (2/57) das estirpes EPEC e 5,7% (2/35) das estirpes STEC. Neste estudo foi possível confirmar que o gene de resistência mcr-1 já está em circulação nos lotes de frango de corte estudados e pode estar associado às estirpes patogênicas.(AU)

Efectos del medio de cultivo y de la metodología aplicada sobre la formación de biopelículas de 2 cepas de Escherichia coli diarreagénicas / Effects of the culture medium and the methodology applied on the biofilm formation of 2 diarrheagenic Escherichia coli strains

La capacidad de formar biopelículas de los microorganismos patógenos en gran variedad de ambientes, superficies y condiciones trae consigo un importante riesgo, tanto para la industria alimentaria como para la salud pública. Este trabajo tuvo como objetivo evaluar y comparar los efectos de la metodología empleada y de los medios de cultivo utilizados, sobre la capacidad de una cepa de Escherichia coli verotoxigénica no O157 y una enteropatogénica de formar biopelículas sobre una superficie de poliestireno. Se ensayaron 2 variantes metodológicas en cultivo estático y se utilizaron medios de cultivo con diferente composición. Los resultados mostraron que ambas cepas formaron una mayor cantidad de biopelícula en cultivo en LB suplementado con glucosa, con recambio del medio a las 24 h y la cuantificación de la biopelícula realizada a las 48 h de incubación. Dichas condiciones podrían ser utilizadas en futuros estudios sobre formación de biopelícula.

The ability to form biofilms of pathogenic microorganisms in a wide variety of environments, surfaces and conditions constitute an important risk, both for the food industry and for public health. The aim of this work was to evaluate and to compare the effects of the methodology applied and the culture medium used on the ability of a non-O157 verotoxigenic Escherichia coli strain and an enteropathogenic strain to form biofilm on polystyrene surface. Two methodological variants were tested in static culture and culture mediums with different composition were used. The results showed that both strains were able to form a greater biofilm under culture in LB supplemented with glucose, with medium replacement at 24 h and the quantification of the biofilm carried out at 48 h of incubation. These conditions could be used in future studies on biofilm formation.

Adaptação cruzada de Escherichia coli enteropatogênica ao cinamaldeído e citral / Cross adaptation of enteropatogenic Escherichia coli tocinnamaldehyde and citral

O objetivo do trabalho foi verificar a capacidade de adaptação cruzada de EPEC CDC O55 aos compostos majoritários citral e cinamaldeído. Para isso, foi determinada a Concentração Mínima Bactericida (CMB) do citral e em seguida,as células de EPEC foram expostas a concentração subletal de cinamaldeído (CMB/16). Posteriormente testadas frente a diferentes concentrações do composto citral (CMB/2; CMB; 1,2CMB; 1,4CMB; 1,6CMB; 1,8CMB e 2CMB), estas foram incubadas e plaqueadas em TSA (Ágar Triptona de Soja) empregando-se a técnica de microgotas. As células de EPEC foram classificadas como capazes de se adaptarem, quando cresceram em placas após cultivo em presença do composto em concentração igual ou maior que a CMB. A CMB do citral foi de 1,0% (v/v). As células de EPEC não apresentaram a capacidade de adaptação cruzada. Os resultados demonstram que os compostos majoritários são alternativas eficazes no controle de EPEC.

Resistência antimicrobiana e caracterização molecular do grupo filogenético de STEC e EPEC típicas e atípicas isoladas de queijos Minas Frescal clandestinos / Antimicrobial resistance and molecular characterization of the phylogenetic group of STEC and EPEC typical and atypical isolated from clandestines Minas Frescal cheeses

Esse estudo avaliou a resistência antimicrobiana e o grupo filogenético de Escherichia coli enteropatogênicas (EPEC) e produtoras de toxina shiga-like (STEC) em 10 amostras de queijos Minas Frescal clandestinos. A média da contagem de E. coli foi de 1,1 x 105 UFC/g. Duas (1,8%) das 111 cepas foram identificadas como EPEC (gene eaeA) sendo uma EPEC típica (gene bfpA) e outra atípica. Outras três (2,7%) foram identificadas como STEC (gene stx2). A t-EPEC foi resistente à estreptomicina e a a-EPEC à cefoxitina e ampicilina. Uma STEC foi considerada multirresistente (ampicilina, estreptomicina e tetraciclina), outra resistente à tetraciclina e outra sensível. A presença de t-EPEC, juntamente com o predomínio de cepas do grupo filogenético A (60%), confirmam a possível origem fecal humana dos isolados de E. coli nos queijos clandestinos.

Shigatoxigenic and atypical enteropathogenic Escherichia coli in fish for human consumption

ABSTRACT Shigatoxigenic and enteropathogenic Escherichia coli with virulence and multidrug resistance profile were isolated from Nile tilapia. This study finding is of great importance to public health because they help understand this pathogen epidemiology in fish and demonstrate how these animals can transmit E. coli related diseases to humans.

Up-regulation of NHE8 by somatostatin ameliorates the diarrhea symptom in infectious colitis mice model

Na⁺/H⁺ exchangers (NHEs) have been shown to be involved in regulating cell volume and maintaining fluid and electrolyte homeostasis. Pooled evidences have suggested that loss of Na⁺/H⁺ exchanger isoform 8 (NHE8) impairs intestinal mucosa. Whether NHE8 participates in the pathology of infectious colitis is still unknown. Our previous study demonstrated that somatostatin (SST) could stimulate the expression of intestinal NHE8 so as to facilitate Na⁺ absorption under normal condition. This study further explored whether NHE8 participates in the pathological processes of infectious colitis and the effects of SST on intestinal NHE8 expression in the setting of infectious colitis. Our data showed that NHE8 expression was reduced in Citrobacter rodentium (CR) infected mice. Up-regulation of NHE8 improved diarrhea symptom and mucosal damage induced by CR. In vitro, a similar observation was also seen in Enteropathogenic E. coli (EPEC) infected Caco-2 cells. Seglitide, a SST receptor (SSTR) 2 agonist, partly reversed the inhibiting action of EPEC on NHE8 expression, but SSTR5 agonist (L-817,818) had no effect on the expression of NHE8. Moreover, SST blocked the phosphorylation of p38 in EPEC-infected Caco-2 cells. Taken together, these results suggest that enhancement of intestinal NHE8 expression by SST could ameliorate the symptoms of mice with infectious colitis.

Intestinal cell migration damage induced by enteropathogenic Escherichia coli strains

Epithelial cell migration is an essential response to enteric pathogens such as enteropathogenic Escherichia coli (EPEC). This study aimed to investigate the effects of EPEC infection on intestinal epithelial cell migration in vitro, as well as the involvement of type III secretion system (T3SS) and Rho GTPases. Crypt intestinal epithelial cells (IEC-6) were infected with EPEC strains (E2348/69, ΔescF, and the LDI001 strain isolated from a malnourished Brazilian child) and commensal E. coli HS. Wound migration and cell death assays were performed at different time-points. Transcription and expression of Rho GTPases were evaluated using real-time PCR and western blotting. Overall, EPEC E2348/69 reduced migration and increased apoptosis and necrosis levels compared to EPEC LDI001 and E. coli HS strains. Moreover, EPEC LDI001 impaired cell migration at a higher level than E. coli HS and increased necrosis after 24 hours compared to the control group. The different profiles of virulence genes between the two wild-type EPEC strains, characterized by the absence of espL and nleE genes in the LDI001, might explain the phenotypic results, playing significant roles on cell migration impairment and cell death-related events. Moreover, the type III secretion system is determinant for the inhibition of intestinal epithelial cell migration by EPEC 2348/69, as its deletion prevented the effect. Active Rac1 concentrations were increased in E2348/69 and LDI001-infected cells, while the T3SS-deficient strain did not demonstrate this activation. This study contributes with valuable insight to characterize the mechanisms involved in the impairment of intestinal cell migration induced by EPEC.

Captive wild birds as reservoirs of enteropathogenic E. coli (EPEC) and Shiga-toxin producing E. coli (STEC)

ABSTRACT Psittacine birds have been identified as reservoirs of diarrheagenic Escherichia coli, a subset of pathogens associated with mortality of children in tropical countries. The role of other orders of birds as source of infection is unclear. The aim of this study was to perform the molecular diagnosis of infection with diarrheagenic E. coli in 10 different orders of captive wild birds in the state of São Paulo, Brazil. Fecal samples were analyzed from 516 birds belonging to 10 orders: Accipitriformes, Anseriformes, Columbiformes, Falconiformes, Galliformes, Passeriformes, Pelecaniformes, Piciformes, Psittaciformes and Strigiformes. After isolation, 401 E. coli strains were subjected to multiplex PCR system with amplification of genes eae and bfp (EPEC), stx1 and stx2 for STEC. The results of these tests revealed 23/401 (5.74%) positive strains for eae gene, 16/401 positive strains for the bfp gene (3.99%) and 3/401 positive for stx2 gene (0.75%) distributed among the orders of Psittaciformes, Strigiformes and Columbiformes. None of strains were positive for stx1 gene. These data reveal the infection by STEC, typical and atypical EPEC in captive birds. The frequency of these pathotypes is low and restricted to few orders, but the data suggest the potential public health risk that these birds represent as reservoirs of diarrheagenic E. coli.

Placental and colostral transfer of antibodies reactive with enteropathogenic Escherichia coli intimins α, ß, or γ / Transferência placentária e colostral de anticorpos reativos a Escherichia coli enteropatogênica com expressão das intiminas α, ß, or γ

Abstract Objective: Intimins are protein adhesins of enteropathogenic Escherichia coli and enterohemorrhagic E. coli capable of inducing attachment and effacement lesions in enterocytes. Anti-intimin antibodies are important for the protection from enteropathogenic E. coli and enterohemorrhagic E. coli infections because these antibodies inhibit bacterial adhesion and impair the initial step of the pathogenesis. We studied the transfer of maternal anti-intimin antibodies from healthy Brazilian mothers to their newborns through the placenta and colostrum. Methods: Serum immunoglobulin G and secretory immunoglobulin A antibodies against conserved and variable regions of intimins α, β, and γ were analyzed using an enzyme linked-immunosorbent assay in the blood and colostrum from 45 healthy women as well as cord blood serum samples from their newborns. Results: The concentrations of antibodies reactive with α intimin were significantly lower than those of anti-γ and anti-conserved intimin antibodies in the colostrum samples. IgG serum antibodies reactive with all the subtypes of intimins were transferred to the newborns, but the concentrations of anti-conserved intimin serum antibodies were significantly higher in mothers and newborns than concentrations of antibodies against variable regions. The patterns of IgG transfer from mothers to newborns were similar for all anti-intimin antibodies. These values are similar to the percentage transference of total IgG. Conclusions: Anti-intimin antibodies are transferred from mothers to newborns through the placenta, and reinforce the protection provided by breastfeeding against diarrheagenic E. coli infections.

Resumo Objetivo: As intiminas são adesinas proteicas de Escherichia coli enteropatogênicas (EPEC) e enterro-hemorrágicas (EHEC) capazes de induzir as lesões attaching and effacing nos enterócitos. Anticorpos anti-intiminas são importantes para a proteção contra infecções por EPEC e EHEC porque esses anticorpos inibem a adesão bacteriana e impedem o passo inicial do mecanismo patogênico dessas bactérias. Nós estudamos a transferência de anticorpos maternos anti-intiminas de mães brasileiras saudáveis para os seus recém-nascidos através da placenta e do colostro. Métodos: Anticorpos séricos da classe IgG e secretórios da classe IgA (SIgA) reativos com as porções conservada (cons) e variáveis das intiminas α (vα), β (vβ) e γ (vγ) foram analisados pelo teste de ELISA no sangue e no colostro de 45 parturientes saudáveis e no sangue de cordão umbilical dos seus respectivos recém-nascidos. Resultados: As concentrações de anticorpos reativos com intimina vα foram significativamente mais baixas que as dos anticorpos anti-vγ e anti-cons nas amostras de colostro. Anticorpos IgG séricos reativos com todas as intiminas foram transferidos para os recém-nascidos, mas as concentrações de anti-cons foram significativamente mais altas tanto nas mães como nos recém-nascidos do que os anticorpos reativos com as regiões variáveis das intiminas. O padrão de transferência de IgG das mães para os recém-nascidos foi muito semelhante para todos os anticorpos anti-intiminas. Os valores de porcentagem de transferência foram semelhantes à transferência de IgG total. Conclusões: Anticorpos anti-intimina são transferidos das mães para os recém-nascidos pela placenta e corroboram a proteção contra infecções por Escherichia coli diarreiogênicas (DEC) conferida pelo aleitamento materno.

Community-acquired Escherichia coli Enteritis in Korean Children: The Clinical Application of a Stool Polymerase Chain Reaction Assay

BACKGROUND: Although Escherichia coli is a common cause of bacterial enteritis in Korea, reports on community-acquired E. coli enteritis in Korean children are scarce. This study aimed to determine the clinical characteristics and pathotype distribution of community-acquired E. coli enteritis diagnosed by a multiplex polymerase chain reaction (PCR) assay in Korean children. MATERIALS AND METHODS: The medical records of children aged 18 years or less who were diagnosed with acute gastroenteritis by the attending physician between 2013 and 2016 were retrospectively reviewed. The clinical characteristics of children diagnosed with E. coli enteritis were investigated and compared with those diagnosed with Salmonella enteritis. E. coli and Salmonella infections were diagnosed by a stool PCR assay. RESULTS: Among 279 children, in whom PCR assays for E. coli and Salmonella spp. were performed, Salmonella enteritis and E. coli enteritis were diagnosed in 43 (15.4%) and 39 (14.0%) children, respectively. Among the 39 children with E. coli enteritis, enteropathogenic E. coli (n=21, 53.8%) and enteroaggregative E. coli (n=15, 38.4%) were the most common causative agents. Empirical antibiotics were administered to 33 (84.6%) children. A total of 31 (79.5%) children developed fever, and 25 (80.6%) of them had the fever for 3 days or less, which resolved a median of 1 day (range 0-3 days) after hospitalization. The most frequent gastrointestinal symptom was diarrhea (n=36, 92.3%). Significantly more children with E. coli enteritis were aged 2 years or less as compared with those with Salmonella enteritis (41.0% vs. 21.9%, P = 0.021). Children with Salmonella enteritis more frequently complained of fever (97.7% vs. 79.5%, P = 0.012), abdominal pain (90.7% vs. 64.1%, P = 0.004), and hematochezia (46.5% vs. 10.3%, P < 0.001) than those with E. coli enteritis. Erythrocyte sedimentation rate and C-reactive protein levels were significantly higher in children with Salmonella enteritis than those with E. coli enteritis (P < 0.001). CONCLUSION: Enteropathogenic E. coli was the most frequent pathotype in Korean children with E. coli enteritis that caused mild clinical symptoms. A stool PCR assay for E. coli may be useful for epidemiological purpose and for an early diagnosis of E. coli enteritis.

Identificación de Escherichia coli enteropatógena en niños con síndrome diarreico agudo del Estado Sucre, Venezuela / Identification of enteropathogenic Escherichia coli in children with acute diarrheic syndrome from Sucre State, Venezuela

Introducción. Escherichia coli es uno de los principales agentes causales del síndrome diarreico agudo. Objetivo. Identificar grupos clonales de E. coli enteropatógena en 485 casos de diarrea aguda en niños entre 0 y 10 años de edad atendidos en centros de salud de los municipios de Arismendi, Benítez y Sucre del estado Sucre, Venezuela, entre marzo y diciembre de 2011. Materiales y métodos. Previo consentimiento informado, se recolectaron muestras fecales y se identificó E. coli mediante coprocultivo estándar y serología con antisueros polivalentes y monovalentes. Se aisló el ADN y se amplificaron los genes eae (intimina) y bfpA (bundlina) mediante dos pruebas de reacción en cadena de la polimerasa (PCR) múltiples. Resultados. En 39,6 % de los coprocultivos se determinó la presencia de infección bacteriana. La prevalencia de E. coli fue de 54,7 %; 82,9 % de estas cepas fue positivo por serología para los serogrupos y el serotipo evaluados, principalmente en niños entre los 0 y los 2 años (37,9 %). El 48,6 % de las cepas de E. coli amplificaron para el gen eae y, de estas, 58,8 % se clasificó como cepas de E. coli enteropatógena típica (eae+ y bfp+). El ECEP II fue el serogrupo más frecuente (38,7 %), con predominio de bacterias E. coli enteropatógenas típicas (60 %). El alelo ß de la intimina fue el más identificado (74,5 %) en las cepas positivas para el gen eae. Solo se identificaron cuatro cepas con el serotipo O157:H7 utilizando antisueros, las cuales no amplificaron mediante PCR para los genes eae y bfpA. Conclusiones. Este estudio demostró la importancia de aplicar pruebas moleculares en la identificación de las cepas de E. coli causantes de diarrea de diversa gravedad.

Introduction: Diarrheagenic Escherichia coli is an important causative agent of acute diarrheic syndrome. Objective: To identify clonal groups of enteropathogenic E. coli (EPEC), in 485 children with acute diarrhea aged 0 to 10 years attending health care centers in Arismendi, Benítez and Sucre municipalities, Sucre state, Venezuela, from March to December, 2011. Materials and methods: After obtaining the informed consent, stool samples were collected. Escherichia coli was identified using standard coproculture methods and serology with polyvalent and monovalent antisera. DNA was isolated, and eae (intimin) and bfpA (bundlin) genes were amplified through two multiplex polymerase chain reactions (PCR). Results: The presence of bacterial infection was determined in 39.6% of coprocultures. The prevalence of E. coli was 54.7%; 82.9% of these isolates were positive by serology for the evaluated serogroups and serotypes, which were mostly identified in children between 0 and 2 years (37.9%); 48.6% of E. coli strains amplified the eae gene; of these, 58.8% were classified as typical EPEC (eae+ y bfp+). EPEC II was the most common serogroup (38.7%), with predominance of typical EPEC (60%). In positive strains for eae gene, the ß intimin allele was the most frequently identified (74.5%). Only four strains with O157:H7 serotype were identified, which showed no PCR amplification of the eae and bfpA genes. Conclusion: This study showed the importance of molecular tests to identify diarrheagenic E. coli strains causing clinical conditions of varying severity.

Mecanismos de virulencia de Escherichia coli enteropatógena / Virulence mechanisms of enteropathogenic Escherichia coli

Acute diarrheal disease (ADD) is a global public health problem, especially in developing countries and is one of the causes of mortality in children under five. ADD etiologic agents include viruses, bacteria and parasites in that order. Escherichia coli bacteria it is classified as a major diarrheagenic agent and transmitted by consuming contaminated water or undercooked foods. This review compiled updates on information virulence factors and pathogenic mechanisms involved in adhesion and colonization of seven pathotypes of E. coli called enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), shigatoxigenic E. coli (STEC), enteroaggregative E. coli (EAEC) and diffusely-adherent E. coli (DAEC). A final pathotype, adherent-invasive E. coli (AIEC) associated with Crohn's disease was also reviewed. The diarrheagenic pathotypes of E. coli affect different population groups and knowledge of the molecular mechanisms involved in the interaction with the human is important to guide research towards the development of vaccines and new tools for diagnosis and control.

La enfermedad diarreica aguda (EDA) es un problema de salud pública mundial, especialmente en los países en vía de desarrollo y es una de las causas de mortalidad en niños bajo cinco años de edad. Los agentes etiológicos de EDA incluyen virus, bacterias y parásitos, en ese orden. Dentro de las bacterias, Escherichia coli está clasificada como uno de los principales agentes diarreagénicos y se trasmite por el consumo de agua y alimentos contaminados o mal cocidos. Esta revisión recopiló información actualizada sobre los factores de virulencia y los mecanismos de patogenicidad implicados en la adhesión y colonización de siete patotipos de E. coli denominados, E. coli enteropatógena (ECEP), E. coli enterotoxigénica (ECET), E. coli enteroinvasora (ECEI), E. coli shigatoxigénica (ECST), E. coli enteroagregativa (ECEA) y E. coli de adherencia difusa (ECAD). Un último patotipo, E. coli adherente invasor (ECAI) asociado a la enfermedad de Crohn también fue revisado. Los patotipos diarreagénicos de E. coli afectan a diferentes grupos poblacionales y el conocimiento de los mecanismos moleculares implicados en la interacción con el humano es importante para orientar las investigaciones hacia el desarrollo de vacunas o nuevas herramientas para su diagnóstico y control.

Avaliação do transporte transmembrânico de glicose, glutamina e alanil-glutamina em íleo decamundongos nutridos e desnutridos infectados por Escherichia coli enteropatogênica

A Escherichia coli enteropatogênica (EPEC) e a desnutrição são uma das maiores causadorasde morbidade e mortalidade infantil em países subdesenvolvidos. Este estudo propõe avaliar otransporte de Na+-glicose, Na+-glutamina e H+-alanil-glutamina através da medida da correntede curto circuito (CCC) e da resistência transepitelial (Rt) no íleo de camundongos nutridos edesnutridos infectados com EPEC. Camundongos albinos de 28 a 35 dias de idade foramsubmetidos a uma dieta padrão ou a uma dieta multideficiente em proteínas, lipídeos eminerais, a DBR. Parte desses animais foi submetida à infecção aguda por 3 horas de contatodireto com a bactéria em alça ligada. Para comparações, o mesmo foi feito utilizando abactéria comensal Escherichia coli HS...

Enteropathogenic Escherichia coli (EPEC) and malnutrition are a major cause of morbidityand mortality in developing countries. The purpose of this study was to evaluate the transportof Na+-glucose, Na+-glutamine and H+-alanyl-glutamine by measurement of short circuitcurrent (Isc) and transepithelial resistance (TR) in the ileum of nourished and malnourishedmice infected with EPEC. Albino mice of approximately 35 days of age were subjected to astandard diet or a diet deficient in proteins, lipids and minerals, the Regional Basic Diet(RBD). Of these animals was submitted to acute infection for 3 hours of direct contact withbacteria in isolated intestinal loop. For comparison, the same was done using the commensalbacterium Escherichia coli HS...

Isolation of atypical enteropathogenic and shiga toxin encoding Escherichia coli strains from poultry in Tehran, Iran

Aim: The purpose of this study was to investigate the prevalence of enteropathogenic Escherichia coli [EPEC] and shiga toxin producing E. coli [STEC] strains in healthy broilers in Iran

Background: STEC and EPEC strains as diarrheagenic E. coli are among the most prevalent causative agents in acute diarrhea. Domestic animals, mainly cattle and sheep, have been implicated as the principal reservoirs of these pathotypes; however their prevalence among the broilers is varied among different countries

Patients and methods: A total of 500 cloacal swab samples from broilers of five different poultry houses [A-E] were collected to investigate the presence of stx1, stx2, hly, eae, and bfp virulence genes among the E. coli isolates by polymerase chain reaction. The shiga toxin encoding strains were evaluated serologically to detect their interaction with a commercial antiserum against O157 antigen

Results: Out of the 500 collected samples, 444 E. coli strains were isolated. Three strains [0.67%] presented at least one of the studied virulence genes [stx2, hly and eae], two strains were identified as STEC [stx2+, O157:nonH7] and one as an atypical EPEC strains [eae[+]bfp[-]]

Conclusion: The study established the presence of STEC and atypical EPEC in healthy broilers in Iran. Poultry might serve as vectors for transmission of pathogenic E. coli to human populations

A survey on gram-negative bacteria in saffron finches (Sicalis flaveola) from illegal wildlife tradein Brazil / Pesquisa de bactérias gram-negativas em canários-da-terra (Sicalis flaveola) resgatados do tráfico ilegal de aves no Brasil

Passerines such as canaries or finches are the most unlawfully captured species that are sent to wildlife centers in São Paulo, Brazil. Captured birds may have infection by opportunistic bacteria in stressful situations. This fact becomes relevant when seized passerine are reintroduced. The aim of this study was to evaluate the health state of finches from illegal wildlife trade using microbiological approaches. Microbiological samples were collected by cloacal and tracheal swabs of 100 birds, captured during 2012 and 2013. The results indicate high frequency of gram-negative bacteria in feces and oropharynx, especially from the Enterobacteriaceae family (97.5%). The most frequent genera were Escherichia coli (46.5%) and Klebsiella pneumoniae (10.4%). Enterobacter cloacae, Serratia liquefaciens, Serratia spp. Klebsiella oxytoca and Citrobacter freundii were isolated with lower frequency from asymptomatic birds. The presence of enteropathogenic Escherichia coli (EPEC) and Shiga toxinproducing strain (STEC) confirm the zoonotic risks and public health concern.(AU)

No Estado de São Paulo, Brasil, os pássaros como os canários-da-terra têm sido uma das espécies mais frequentemente resgatadas do tráfico ilegal e enviadas aos centros de vida selvagem. Em situações de estresse estas aves podem ser acometidas por infecções causadas por bactérias oportunistas. Este fato é de grande importância quando é planejada da reintrodução das aves na natureza. O presente trabalho foi delineado para avaliar o estado de saúde de canários-da-terra resgatados do tráfico ilegal. Foram colhidas soabes da traqueia e da cloaca de 100 aves resgatadas durante os anos de 2012 e 2013. Os resultados obtidos revelaram alta frequência de bactérias gram-negativas nas fezes e no orofaringe dos animais, com maior frequência para os membros da família Enterobacteriaceae (97,5%). Os gêneros mais frequentes foram Escherichia coli (46,55) e Klebsiella pneumoniae (10,4%). Outros microorganismos incluindo Enterobacter cloacae, Serratia liquefaciens, Serratia spp, Klebsiella oxytoca e Citrobacter freundii também foram isolados em menor frequencia de aves assintomáticas. A presença de estirpes de Escherichia coli enteropagênicas (EPEC) e as produtoras da toxina de Shiga confirmam o risco de zoonose e a importância para saúde pública deste tipo de ave.(AU)

Histomorphologic effects of Bacillus clausii spores in enteropathogenic E. coli O127:H21-infected mice: A pilot study

OBJECTIVE: The study aimed to determine the basic histomorphologic effects of Bacillus clausii (B. clausii) spores in enteropathogenic Escherichia coli (E. coli) O127:H21-infected mice by evaluating the spleen, mesenteric lymph nodes, and intestinal mucosa. METHODS: The study involved 46 apparently healthy Balb/c mice (Mus musculus) which were acclimatized for 19 days prior to any intervention. Sixteen mice were used to determine the sublethal dose of E. coli, which was performed by administering serially-diluted solutions and subsequent generation of a standard curve. From the remaining 30 mice, ten served as normal controls while the remaining 20 were randomized to receive either B. clausii or placebo of sterile water for a week. All mice were then challenged with E. coli for another week and euthanized, and the spleen, mesenteric lymph nodes, and small intestine harvested and examined microscopically. All study personnel were blinded of the treatment assignments. RESULTS: Histologic evaluation of the small intestine in E. coli only-fed mice exhibited prominent attachment effacement lesions, with severely denuded mucosa, lymphocytic infiltration, and debris in the intestinal lumen. However, mice given B. clausii prior to E. coli infection displayed only minimal mucosal damage with less sloughing of villus tips, plus increased mucus-secreting goblet cells. In the spleen, E. coli only-fed mice showed moderate to severe lymphoid hyperplasia with blurred boundaries between red and white pulp. In contrast, mice which received B. clausii prior to E. coli infection had only mild degrees of lymphoid hyperplasia. Similar findings were seen in the mesenteric lymph nodes where E. coli only-fed mice showed moderate to severe lymphoid hyperplasia while those given B. clausii prior to E. coli infection merely had mild lymphoid hyperplasia. CONCLUSION: B. clausii exerts a potential protective and immunomodulatory action in E. coli O127:H21-infected mice based on histomorphologic effects. However, additional studies are needed to fully characterize these mechanisms.mice based on histomorphologic effects. 

Aislamiento de Escherichia coli enteropatógeno 0157: H16 de un caso de diarrea infantil y sus contactos familiares en La Pampa, Argentina / Isolation of enteropathogenic Eschjerichia coli0157:H16 identified in a diarrhea case in a chil and his household contacts in La Pampa Province, Argentina

Escherichia coli enteropatógeno (EPEC) es uno de los principales agentes de diarrea infantil aguda en los países en desarrollo. Se clasifica en típico (tEPEC) y atípico (aEPEC) sobre la base de la presencia del factor bfp, asociado a la adherencia y codificado en el plásmido pEAF. Se describe el aislamiento de E. coli O157:H16, de la categoría aEPEC, en un caso de diarrea sanguinolenta infantil y en sus contactos familiares. De las muestras de materia fecal del niño, de la madre, del padre y de la hermana se aisló E. coli O157:H16 eae-??-positivo, sorbitol-positivo, ß-glucuronidasa-positivo, sensible a los antimicrobianos ensayados, y negativo para los factores stx1, stx2, ehxA y bfp. Por XbaI-PFGE, todos los aislamientos presentaron el patrón de macrorrestricción AREXHX01.1040, con 100% de similitud. Es importante la vigilancia epidemiológica de los casos de diarrea asociados a E. coli O157 y sus contactos familiares, y la incorporación de técnicas para detectar los distintos patotipos de E. coli

Enteropathogenic Escherichia coli (EPEC) is a major causative agent of acute diarrhea in children in developing countries. This pathotype is divided into typical EPEC (tEPEC) and atypical EPEC (aEPEC), based on the presence of the bfp virulence factor associated with adhesion, encoded in the pEAF plasmid. In the present study, the isolation of aEPEC O157:H16 from a bloody diarrhea case in a child and his household contacts (mother, father and sister) is described. The strain was characterized as E. coli O157:H16 eae-??-positive, sorbitol fermenter with ß-glucuronidase activity, susceptible to all antimicrobials tested, and negative for virulence factors stx1, stx2, ehxA and bfp. XbaI-PFGE performed on all isolates showed the AREXHX01.1040 macrorestriction pattern, with 100% similarity. These results highlight the importance of epidemiological surveillance of E. coli O157-associated diarrhea cases identified in children and their family contacts, as well as the incorporation of molecular techniques that allow the detection of the different E. coli pathotypes

Adherence and virulence genes of Escherichia coli from children diarrhoea in the Brazilian Amazon

The bacterial pathogen most commonly associated with endemic forms of childhood diarrhoea is Escherichia coli. Studies of epidemiological characteristics of HEp-2 cell-adherent E. coli in diarrhoeal disease are required, particularly in developing countries. The aim of this study was evaluate the presence and significance of adherent Escherichia coli from diarrhoeal disease in children. The prevalence of LA, AA, and DA adherence patterns were determined in HEp-2 cells, the presence of virulence genes and the presence of the O serogroups in samples obtained from 470 children with acute diarrhoea and 407 controls in Porto Velho, Rondônia, Brazil. E. coli isolates were identified by PCR specific for groups of adherent E. coli. Out of 1,156 isolates obtained, 128 (11.0%) were positive for eae genes corresponding to EPEC, however only 38 (29.6%) of these amplified bfpA gene. EAEC were isolated from 164 (14.1%) samples; of those 41(25%), 32 (19%) and 16 (9.7%) amplified eagg, aggA or aafA genes, respectively and aggA was significantly associated with diarrhoea (P = 0.00006). DAEC identified by their adhesion pattern and there were few isolates. In conclusion, EAEC was the main cause of diarrhoea in children, especially when the aggA gene was present, followed by EPEC and with a negligible presence of DAEC.