Dataset Information

Quantitative analysis and virulence phenotypes of atypical enteropathogenic Escherichia coli (EPEC) acquired from diarrheal stool samples from a Midwest US hospital.

ABSTRACT: Infectious diarrhea causes approximately 179 million illnesses annually in the US. Multiplex PCR assays for enteric pathogens detect enteropathogenic Escherichia coli (EPEC) in 12-29% of diarrheal stool samples from all age groups in developed nations. The aim of this study was to isolate and characterize EPEC from diarrhea samples identified as EPEC positive by BioFire Gastrointestinal Panel (GIP). EPEC is the second most common GIP-detected pathogen, equally present in sole and mixed infections peaking during summer months. EPEC bacterial load is higher in samples with additional pathogens. EPEC-GIP-positive stool samples were cultured on MacConkey II agar and analyzed by colony PCR for eaeA and bfpA to identify and classify EPEC isolates as typical (tEPEC) or atypical (aEPEC). EPEC were not recovered from the majority of stool samples with only 61 isolates obtained from 277 samples; most were aEPEC from adults. bfpA-mRNA was severely diminished in 3 of 4 bfpA-positive isolates. HeLa and SKCO-15 epithelial cells were infected with EPEC isolates and virulence-associated phenotypes, including adherence pattern, attachment level, pedestal formation, and tight junction disruption, were assessed. All aEPEC adherence patterns were represented with diffuse adherence predominating. Attachment rates of isolates adhering with defined adherence patterns were higher than tEPEC lacking bfpA (ΔbfpA). The majority of isolates formpedestals. All but one isolate initially increases but ultimately decreases transepithelial electrical resistance of SKCO-15 monolayers, similar to ΔbfpA. Most isolates severely disrupt occludin; ZO-1 disruption is variable. Most aEPEC isolates induce more robust virulence-phenotypes in vitro than ΔbfpA, but less than tEPEC-E2348/69.

SUBMITTER: Carlino MJ

PROVIDER: S-EPMC7644165 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:BackgroundEnterohaemorrhagic E. coli (EHEC) can cause severe disease such as bloody diarrhoea and haemolytic uraemic syndrome in humans. Besides production of Shiga toxins, the presence of LEE (eae-gene) and non-LEE (nle) encoded effector genes harboured on O-islands OI-122, OI-71 and OI-57 is associated with EHEC virulence and their frequency in outbreaks. Genes encoded by the EHEC-plasmid are putative virulence markers of EHEC. EHEC-plasmids, LEE and non-LEE effector genes have also been detected in some strains of enteropathogenic E. coli (EPEC). The objective of this study was to analyze the relationship between EHEC and EPEC for virulence genes encoded by genomic O-islands and by the EHEC-plasmids.ResultsNle genes ent/espL2, nleB and nleE (OI-122), nleA, nleF and nleH1-2 (OI-71), nleG5-2 and nleG6-2 (OI-57), espK (CP-933N) and the EHEC-plasmid encoded genes ehxA, espP, etpD and katP were searched in 73 typical and in 235 atypical enteropathogenic E. coli (EPEC) strains. Typical and atypical EPEC each fall into two clusters. Cluster 1 typical (n = 46) and atypical (n = 129) EPEC strains were characterized by the presence of OI-122 encoded genes and grouped together with 64 investigated EHEC strains. Cluster 2 typical (n = 27) and atypical (n = 106) strains grouped together with 52 LEE-negative, Shiga toxin-producing E. coli (STEC) and with 21 apathogenic E. coli strains. Typical EPEC Cluster 1 strains belonged to serotypes frequently involved in severe illness and outbreaks in children (O111:H2, O114:H2, O55:H6, O127:H6 and O142:H6). Atypical EPEC Cluster 1 strains were characterized by serotypes related to EHEC (O26:H11, O55:H7, O145:H28, O103:H2 and O103:H25).ConclusionThe OI-122 encoded nleB gene was found to be most closely associated with Cluster 1 strains and may serve as a diagnostic tool for the identification of virulent EHEC and EPEC seropathotypes. OI-71 encoded genes nleA, nleF and nleH1-2 are less associated with Cluster 1 strains. EHEC-plasmid, OI-57 and CP-933 associated genes showed only weak similarities with virulent Cluster 1 EHEC and EPEC strains.

Project description:Atypical enteropathogenic Escherichia coli (aEPEC) strains are emerging enteropathogens that have been detected worldwide. A collection of 228 aEPEC strains (121 from diarrheal patients, 27 from healthy carriers, 47 from animals and 33 from raw meats) were investigated for serotypes, virulence gene profiles and phylogenetic relationships. Sixty-six O serogroups were identified. Serogroup O51 was the most prevalent, followed by O119, O26 and O76. For the 20 virulence genes detected, statistically significant differences were observed in the overall prevalence of efa1 (lifA), nleB, nleE, set/ent, paa, and ehxA genes among strains from diarrheal patients, healthy carriers, animals and raw meats, respectively. Strains from diarrheal patients had significantly higher levels of efa1 (lifA) (29.8 vs. 0%, P = 0.0002), nleB (41.3 vs. 7.4%, P = 0.0004), nleE (43.8 vs. 7.4%, P = 0.0002) and set/ent (41.3 vs. 7.4%, P = 0.0004) genes than strains obtained from healthy carriers. The paa gene was identified more often in isolates from raw meats (63.6 vs. 14.8%, P < 0.0001), animals (42.6 vs. 14.8%, P < 0.0122), and diarrheal patients (36.4 vs. 14.8%, P < 0.0225) than in strains obtained from healthy carriers. The ehxA gene was detected more frequently in strains from raw meats than in strains from diarrheal patients (27.3 vs. 2.5%, P = 0.0000) and healthy carriers (27.3 vs. 7.4%, P = 0.0474). The phylogenetic marker, yjaA, was more frequently observed in strains among healthy carriers than in diarrheal patient strains. Among the 228 aEPEC strains, 79 sequence types (STs) were identified. The prominent STs, which comprised strains carrying the four OI-122 genes and lpfA, were ST40, ST328, and ST29. Overall, the results indicate that aEPEC strains isolated in China are highly heterogeneous. aEPEC strains that are potentially more pathogenic appear to be related to specific STs or clonal complexes and serotypes. The high prevalence of diarrhea-associated genes in animal or raw meat strains suggests a zoonotic transmission pathway for potentially human pathogenic aEPEC.

Dataset Information

Quantitative analysis and virulence phenotypes of atypical enteropathogenic Escherichia coli (EPEC) acquired from diarrheal stool samples from a Midwest US hospital.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets