Work

Detection of EPEC and STEC strains isolated from children with diarrhea in Argentina

Year: 2024

Type: article

Abstract: • Stool samples from 122 children diagnosed with acute diarrhea were recollected for detection of STEC and EPEC pathotypes. • E. coli were detected in 68% of the stool samples, of which 18.8% were STEC or EPEC. • STEC O145 and EPEC O130, O113 and O157 were the serotypes detected. • DEC are not routinely tested in clinical laboratories and proper surveillance is necessary. Rectal swabs (122) from pediatric patients were analyzed by polymerase chain reaction (PCR) for the detection of EPEC and STEC. STEC isolates were tested for the presence of stx1 , stx2 , eae , saa and ehxA . All eae -positive samples were tested for the presence of bfpA , and antigen O was determined using the agglutination test. Int1 and Int2 were detected to identify the presence of integrons class 1 and 2, respectively. Escherichia coli was detected in 68% of the samples, of which 18.8% were STEC (2.45%) and EPEC (16.3%). Serogroups STEC O145 and EPEC O130, O113 and O157 were observed, while three strains were non-typable. None of the EPEC strains carrying t bfpA and class 1 and 2 integrons was detected in any of the samples. The results obtained are important considering the virulence profiles found in the isolated EPEC and STEC strains and the serogroups associated with disease in humans. Se analizaron hisopados rectales (n = 122) de pacientes pediátricos mediante reacción en cadena de la polimerasa (PCR) para detectar cepas de E. coli enteropatógenas (EPEC) y productoras de toxina Shiga (STEC). En los aislamientos de STEC, se investigó la presencia de los genes stx1 , stx2 , eae , saa y ehxA . En todas las muestras positivas para eae se evaluó la presencia de bfpA y el antígeno O se investigó mediante aglutinación. Además, se analizó la presencia de Int1 e Int2 para identificar integrones de clase 1 y 2, respectivamente. Se detectó E. coli en el 68% de las muestras, de las cuales el 18,8% fueron STEC (2,45%) o EPEC (16,3%). Se detectaron los serogrupos STEC O145 y EPEC O130, O113 y O157, mientras que tres cepas no fueron tipables. No se detectó ninguna cepa de EPEC que portara t bfpA o integrones de clase 1 y 2 en ninguna de las muestras. Los resultados son importantes considerando los perfiles de virulencia encontrados en cepas aisladas de EPEC y STEC y los serogrupos asociados con enfermedades en humanos.

Source: Revista Argentina de Microbiología

DOI: 10.1016/j.ram.2024.07.003