Putative Virulence Genes and Biofilm Production Among Typical Enteroaggregative Escherichia coli Isolates from Diarrhoeic Children in Kashmir and Andhra Pradesh

Wani, S.A.; Hussain, I.; Rather, Mudasir Ali; Kabli, Z. A.; Nagamani, K.; Nishikawa, Yoshikazu; Qureshi, Sabia; Khan, İmran

doi:10.1007/s12088-012-0284-9

Cited by 8 publications

(6 citation statements)

References 25 publications

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“…Human-intestinal research shows that EAEC causes moderate to severe mucosal damage [9]. EAEC strains usually increase mucus production, trapping the bacteria in a bacterium-mucus biofilm [10]. A thick biofilm may be linked to its ability to cause chronic colonization and diarrhea [10].…”

Section: Introductionmentioning

confidence: 99%

Comparative analysis of virulence determinants, phylogroups, and antibiotic susceptibility patterns of typical versus atypical Enteroaggregative E. coli in India

et al. 2020

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Enteroaggregative Escherichia coli (EAEC) is an evolving enteric pathogen that causes acute and chronic diarrhea in developed and industrialized nations in children. EAEC epidemiology and the importance of atypical EAEC (aEAEC) isolation in childhood diarrhea are not well documented in the Indian setting. A comparative analysis was undertaken to evaluate virulence, phylogeny, and antibiotic sensitivity among typical tEAEC versus aEAEC. A total of 171 EAEC isolates were extracted from a broad surveillance sample of diarrheal (N = 1210) and healthy children (N = 550) across North India. Polymerase chain reaction (PCR) for the aggR gene (master regulator gene) was conducted to differentiate tEAEC and aEAEC. For 21 virulence genes, we used multiplex PCR to classify possible virulence factors among these strains. Phylogenetic classes were identified by a multiplex PCR for chuA, yjaA, and a cryptic DNA fragment, TspE4C2. Antibiotic susceptibility was conducted by the disc diffusion method as per CLSI guidelines. EAEC was associated with moderate to severe diarrhea in children. The prevalence of EAEC infection (11.4%) was higher than any other DEC group (p = 0.002). tEAEC occurrence in the diarrheal group was higher than in the control group (p = 0.0001). tEAEC strain harbored more virulence genes than aEAEC. astA, aap, and aggR genes were most frequently found in the EAEC from the diarrheal population. Within tEAEC, this gene combination was present in more than 50% of strains. Also, 75.8% of EAEC strains were multidrug-resistant (MDR). Phylogroup D (43.9%) and B1 (39.4%) were most prevalent in the diarrheal and control group, respectively. Genetic analysis revealed EAEC variability; the comparison of tEAEC and aEAEC allowed us to better understand the EAEC virulence repertoire. Further microbiological and epidemiological research is required to examine the pathogenicity of not only typical but also atypical EAEC.

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Section: Introductionmentioning

confidence: 99%

Comparative analysis of virulence determinants, phylogroups, and antibiotic susceptibility patterns of typical versus atypical Enteroaggregative E. coli in India

et al. 2020

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“…Hence, other simplified methods replaced the HEp-2 cell adherence assay to detect EAEC in epidemiological studies [13,28]. However, these simplified methods cannot detect cvd432 gene negative strains demonstrating aggregative adherence in vitro and therefore, despite of all these listed disadvantages, the HEp-2 cell adherence test remains the gold standard for identification of EAEC [16,20,29]. In the present study, the formalin treated HEp-2 cell adherence assay displayed an increased ease of detection of the EAEC which is in accordance with the earlier results [24].…”

Section: Discussionmentioning

confidence: 99%

“…Although, there are several studies that have been undertaken to unravel the biofilm formation mechanism of EAEC strains ('typical' or 'atypical'), however, the results obtained are yet conflicting [15,[18][19][20]. In India, though there are few reports of isolation of EAEC strains from humans and animals, their further characterization as 'typical' or 'atypical' EAEC strain, including the comparative biofilm formation ability between human and animal EAEC isolates are yet to be explored [21].…”

Section: Introductionmentioning

confidence: 99%

Characterization and biofilm forming ability of diarrhoeagenic enteroaggregative Escherichia coli isolates recovered from human infants and young animals

Vijay¹,

Dhaka²,

Vergis³

et al. 2015

Comparative Immunology, Microbiology and Infectious Diseases

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“…Other studies suggest that the Shf protein-encoding gene (shf) is required for strong biofilm formation of EAEC serotype O42, and that transcription of the shf gene is dependent on AggR (Fujiyama et al, 2008). There is considerable heterogeneity in putative virulence genes of EAEC isolates from diarrhoeic children in India and biofilm formation appears to be associated with multiple genes (Wani et al, 2012). When subjected to low iron conditions, an EAEC O42 strain showed a decrease in biofilm formation.…”

Section: Biofilm Formation By Eaec 46mentioning

confidence: 99%

Public health risks associated with Enteroaggregative Escherichia coli (EAEC) as a food‐borne pathogen

2015

EFS2

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Enteroaggregative Escherichia coli (EAEC) adhere to tissue culture cells in a stacked-brick pattern mediated by aggregative adherence fimbriae (AAF). EAEC strains often produce the heat-stable toxin EAST1, the Shigella enterotoxin (ShET1) and Haemolysin E. EAEC have been associated with cases of diarrhoea in travellers, children and immunocompromised patients and with urinary tract infections. Shiga toxin (Stx)-producing EAEC have been associated with Haemolytic Uraemic Syndrome and Haemorrhagic Colitis. EAEC are considered to be adapted to humans. In low-income countries animals may become exposed to EAEC from human waste. Food-related outbreaks of EAEC are frequently suggestive of cross-contamination by asympomatic food handlers. EAEC form biofilms, which has been linked to the severity of disease. The adhesion assay remains the most sensitive option for confirming isolates as EAEC. PCR provides accurate identification of EAEC and diagnosis of EAEC infections, but there is no consensus on a standard assay for the examination of foods. The protocol of the European Union Reference Laboratory for E. coli including Verocytotoxin-producing E. coli (EU RL VTEC) is considered a good candidate for the molecular detection of EAEC in food matrices by EU MSs. Whole genome sequencing (WGS) can provide data on the population structure of EAEC. Foodborne outbreaks of EAEC exhibiting antimicrobial resistance (AMR) have been reported but the origin of the resistance genes has not been fully established. Research needs include: (i) the development and validation of PCR-based methods for detection and quantification of EAEC in foods, and (ii) a standardised and validated multiplex approach to the identification of causal agents of diarrhoeal illnesses involving multiple pathogens. Surveillance needs include: (i) quantification of the possible involvement of EAEC strains in foods originating from low-income countries where sanitation is poor, and (ii) increased surveillance of foods associated with mixed pathogen outbreaks. When investigating foodborne outbreaks, testing for EAEC should be included as routine. Finally, WGS-based approaches for EAEC should be further explored.

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Putative Virulence Genes and Biofilm Production Among Typical Enteroaggregative Escherichia coli Isolates from Diarrhoeic Children in Kashmir and Andhra Pradesh

Cited by 8 publications

References 25 publications

Comparative analysis of virulence determinants, phylogroups, and antibiotic susceptibility patterns of typical versus atypical Enteroaggregative E. coli in India

Comparative analysis of virulence determinants, phylogroups, and antibiotic susceptibility patterns of typical versus atypical Enteroaggregative E. coli in India

Characterization and biofilm forming ability of diarrhoeagenic enteroaggregative Escherichia coli isolates recovered from human infants and young animals

Public health risks associated with Enteroaggregative Escherichia coli (EAEC) as a food‐borne pathogen

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