Faecal Escherichia coli isolates show potential to cause endogenous infection in patients admitted to the ICU in a tertiary care hospital

Abstract

Nosocomial infections are acquired during hospital treatment or in a hospital environment. One such infecting agent, Escherichia coli, harbours many virulence genes that enable it to become pathogenic, causing damage to the host. The mechanism of the E. coli virulence factors provenance to cause infection in host environments is not clearly elucidated. We investigated the virulence and pathogenicity of E. coli affected by the host environment. For this, blood (n = 78) and faecal (n = 83) E. coli isolates were collected from patients with and without sepsis, respectively, who had been admitted to the intensive care unit. The E. coli genomic DNA was isolated; the phylogenetic grouping was conducted by triplex PCR. The occurrence of nine virulence genes among the all the isolates was confirmed by gene-specific PCR. The prevalence of E. coli in blood isolates was more in phylogenetic groups B2 and D compared to groups A and B1. However, in faecal isolates, there was no significant difference. The prevalence of adhesin and toxin (papG, sfa, afa, cnf1, hlyA) genes was higher in blood compared to faecal E. coli isolates. However, the prevalence of aer, traT and PAI was similar as well as higher among both of these groups. These observations indicate a role of external environment (hospital setting) on host susceptibility (development of infection) in the faecal E. coli isolates, thereby making the patient prone to a sepsis condition.

Virulence Characteristics, Serotyping and Phylogenetic Typing of Clinical and Environmental Escherichia coli Isolates

“…The reverse scenario was observed for ExPEC PAIs combination, where dominant percentage was observed in environmental isolates ( Figure 2B). The unusual PAIs prevalence among environmental isolates may provide them with means for infection, reaching sepsis (35). With respect to median PAIs ( Figure 3A and B), there was very close convergence between clinical and environmental isolates.…”

“…Clinical isolates showed higher percentage for all VGs, except stx2 and hlyA, which were interestingly higher in environmental isolates. This can be interpreted as a result of poor hygiene for food handlers or environmental samples contamination by livestock manure, wastewaters, or by wildlife (35).…”

A COMPARATIVE STUDY OF SOME VIRULENCE FACTORS AND PHYLOGENETIC CHARACTRIZATION OF Escherichia.coli ISOLATES CAUSING URINARY TRACT INFECTION AND THE COMMENSAL GUT MICROBIOTA

“…The hlyA, and cnf1.genes were produced by the same percentage (12%) but it is more common in UPEC (table2,3). Table 2 (14). Hence , To develop a new strategies for the treatment of MDR isolates, it is essential to understand and characterize their factors essential for pathogenicity or virulence.it is also important to find.the distinction between the commensal that are not harmful to their hosts and the.pathogens that are aggressive.and harmful to their hosts.…”

Whole-Genome Shotgun Sequence of Escherichia coli Strain MN067 from India, a Commensal Bacterium with Potent Pathogenic Ability

“…Patients admitted to intensive care units (ICUs) are at a higher risk of developing bacteremia and septicemia due to invasive procedures such as peripheral cannulation, central venous catheter placement, tracheal incubation, and ventilation (1). The human gut microbiota has long been known to contribute to both health and disease (2).…”