Epidemiology and genetic screening of diarrheagenic Escherichia coli among symptomatic and asymptomatic children.

PURPOSE: Enteropathogens are frequently associated with diarrheal disease. Knowledge of their etiology and epidemiology is essential for the prevention and control of the sickness. This study describes the microbiological and epidemiological features of diarrheal disease in 197 symptomatic and 223 asymptomatic under-five-year-old children from southeastern Brazil, between January 2015 and September 2016. METHODS: Isolation of Escherichia coli, Salmonella, Shigella and Campylobacter was realized by culture. E. coli strains were screened by multiplex PCR, PFGE and O:H serotyping. Antimicrobial susceptibility testing was also performed. RESULTS: Most of the 127 enteropathogens isolated were diarrheagenic E. coli (96.1 %), with predominance of several serotypes of enteropathogenic E. coli (EPEC) and enteroaggregative E. coli (EAEC). Age, sex, rotavirus vaccination, recent use of antibiotics and previous contact with pets, were factors that revealed no significant effects on the probability of infection by the predominant pathogens. Even so, higher incomes could be related to a lesser chance of testing positive for EPEC. Evidence of possible EAEC clonal spread was detected, as well as genetic similarity among strains from both symptomatic and asymptomatic children. Resistance to antimicrobial agents was more pronounced among EAEC than EPEC. CONCLUSION: The occurrence of genetically similar diarrheagenic E. coli in both groups of children, likewise resistant to these agents, underscores the importance of establishing strategies for the prevention of outbreaks, especially among low-income households.

Frequência laboratorial e resistência antimicrobiana de enteropatógenos bacterianso isolados em crianças na primeira infância na região do ABC Paulista, 2015 - 2016 / Laboratory frequency and antimicrobial resistance of the enteropathogens bacteria isolated from infants at early childhood in the region of ABC Paulista, 2015 - 2016

O objetivo deste estudo foi avaliar o perfil dos enteropatógenos bacterianos isolados em crianças menores de 5 anos durante casos de diarreia em instituições de 4 municípios do Estado de São Paulo, durante 2015 e 2016. A coleta das fezes foi realizada em 107 crianças, 78 (72,9%) crianças com diarreia e 29 (27,1%) crianças sem diarreia. A metodologia foi coprocultura, identificação bacteriana e teste de sensibilidade aos antimicrobianos. Quarenta e seis das 107 (43%) amostras clínicas apresentaram crescimento de enteropatógenos. Amostras de Escherichia coli enteropatogênicas (EPEC), Escherichia coli enteroagregativas (EAEC) e Salmonella enterica subsp houtenae foram as mais frequentemente isoladas entre as crianças. Do total de crianças estudadas, três delas apresentaram co-infecção por 2 agentes etiológicos diferentes: EPEC/EAEC e Salmonella enterica subsp houtenae/EAEC. A maior ocorrência entre os 49 agentes etiológicos isolados foi EPEC (24/49, 49%), seguido de EAEC (14/49, 28,6%). Duas amostras de EPEC pertencentes ao sorotipo O109:H21 foram sensíveis aos antimicrobianos testados, enquanto outras duas pertencentes ao sorotipo O156:H1 foram resistentes a gentamicina e a amicacina e estreptomicina, respectivamente. Duas amostras de EAEC pertencentes ao mesmo sorotipo O80:H10 e duas EAEC O15:H2 apresentaram multirresistência, pelo menos, ao ácido nalidíxico, sulfametoxazol e tetraciclina. Podemos sugerir que crianças frequentadoras de três instituições diferentes, que apresentaram agregados de casos de diarreia sugestivo de surto, eram portadoras de clones bacterianos de amostras de EPEC ou EAEC, por pertencerem ao mesmo sorotipo e com semelhante perfil de sensibilidade. Nossos resultados são preocupantes e mostram que a vigilância epidemiológica antimicrobiana constante deve ser garantida para o monitoramento do surgimento de clones resistentes e para estabelecer estratégias para a prevenção e c ontrole de surtos e epidemias

This study aimed at evaluating the profile of enteropathogens isolated from children under 5 years of age, during the occurrence of cases of diarrhe a in the institutions of four municipalities in the State of São Paulo in 2015 and 2016. Feces samples were collected from 107 children, 78 (72.9%) with diarrhea and 29 (27.1%) without. The employed methodologies were copro-culture, bacterial identification and antimicrobial susceptibility testing. Forty-six (46%) of 107 clinical samples presented growth of enteropathogens. Enteropathogenic Escherichia coli (EPEC), enteroaggregative Escherichia coli (EAEC) and Salmonella enterica subsp houtenae were the mostly frequent isolated from children. Of the total number of the studied children, three of them presented co-infection with two etiological agents: EPEC/EAEC and Salmonella enterica subsp houtenae/EAEC. The highest occurrence among the isolated etiologic agents was EPEC (24/49, 49%), followed by EAEC (14/49, 28.6%). Two EPEC strains belonged to the O109:H21 serotype were sensitive to the tested antimicrobials, whereas two belonging to the O156:H1 serotype were resistant to gentamicin and amicacin and streptomycin, respectively. Two EAEC strains of the same serotype O80:H10 and two EAEC O15:H2 presented multi-resistance at least to nalidixic acid, sulfamethoxazole and tetracycline. It may suggest that the children attending three different institutions, who had clusters of cases of diarrhoea carried the bacterial clones of EPEC or EAEC strains, because they belonged to the same serotype and show a similar sensitivity profile. The results found in the present study are worrying and they show that the constant antimicrobial epidemiological surveillance should be ensured for monitoring the emergence of resistant clones, and for establishing strategies for preventing and controlling the outbreaks and epidemics.