EHEC O111:H8 strain and norovirus GII.4 Sydney [P16] causing an outbreak in a daycare center, Brazil, 2019

Abstract

Background This study describes the investigation of an outbreak of diarrhea, hemorrhagic colitis (HC), and hemolytic uremic syndrome (HUS) at a daycare center in southeastern Brazil, involving fourteen children, six staff members, six family members, and one nurse. All bacterial and viral pathogens detected were genetically characterized. Results Two isolates of a strain of enterohemorrhagic Escherichia coli (EHEC) serotype O111:H8 were recovered, one implicated in a case of HUS and the other in a case of uncomplicated diarrhea. These isolates had a clonal relationship of 94% and carried the stx2a and eae virulence genes and the OI-122 pathogenicity island. The EHEC strain was determined to be a single-locus variant of sequence type (ST) 327. EHEC isolates were resistant to ofloxacin, doxycycline, tetracycline, ampicillin, and trimethoprim-sulfamethoxazole and intermediately resistant to levofloxacin and ciprofloxacin. Rotavirus was not detected in any samples, and norovirus was detected in 46.7% (14/30) of the stool samples, three of which were from asymptomatic staff members. The noroviruses were classified as the recombinant GII.4 Sydney [P16] by gene sequencing. Conclusion In this outbreak, it was possible to identify an uncommon stx2a + EHEC O111:H8 strain, and the most recent pandemic norovirus strain GII.4 Sydney [P16]. Our findings reinforce the need for surveillance and diagnosis of multiple enteric pathogens by public health authorities, especially during outbreaks.

Genotyping Based on CRISPR Loci Diversity and Pathogenic Potential of Diarrheagenic Escherichia coli

“…The strains with eae + and bfp + were marked as typical EPEC (tEPEC), and the strains with eae + , bfp – , stx1 – , and stx2 – were recorded as atypical EPEC (aEPEC) ( Spano et al, 2021 ). Among the EPEC ( n = 105) downloaded in this study, atypical EPEC covered a relatively high proportion (75.24%), which was similar to the results of other studies ( Afset et al, 2004 ).…”

“…Strains can be identified according to the characteristic virulence genes of different DEC categories: stx1 , stx2 , and eae in STEC; aggR and astA in EAEC; invE and ipaH in EIEC; est and elt in ETEC. Furthermore, typical ( eae + , bfp + ) EPEC and atypical ( eae + , bfp – , stx1 – , stx2 – ) EPEC can be distinguished ( Fujioka et al, 2013 ; Rodrigues et al, 2016 ; Spano et al, 2021 ). Some studies have shown the association between EPEC and diarrhea.…”

“…For example, O157:H7 caused severe disease harming to patients. In addition, some studies have shown that O26:H11, O45:H2, O103:H2, O111:H8(NM), O121:H19, and O145:NM are also the main serotypes of major foodborne diseases ( Karmali, 2018 ; Spano et al, 2021 ). Consequently, O:H serotyping plays an important role in bacterial classification, epidemiological monitoring, epidemic detection, and other aspects, and it can also provide information directly related to antigen response ( Joensen et al, 2015 ).…”

Changing Predominance of Norovirus Recombinant Strains GII.2[P16] to GII.4[P16] and GII.4[P31] in Thailand, 2017 to 2018

“…In Thailand, GII.2[P16] has been demonstrated not only as the cause of acute gastroenteritis but also detected in oysters that could be a potential source for foodborne transmission to humans ( 28 ). The outbreaks were also attributable to the emergence of GII.4[P16] and GII.4[P31] ( 29 , 30 ). This study aimed to investigate the prevalence of norovirus and to identify the dynamics of norovirus recombinant strains circulating in children hospitalized with acute gastroenteritis in Chiang Mai, Thailand from 2017 to 2018.…”