Responses of the Human Gut Escherichia coli Population to Pathogen and Antibiotic Disturbances

Abstract

Research on human-associated E. coli tends to focus on pathogens, such as enterotoxigenic E. coli (ETEC) strains, which are a leading cause of diarrhea in developing countries. However, the severity of disease caused by these pathogens is thought to be influenced by the microbiome. The nonpathogenic E. coli community that resides in the human gastrointestinal tract may play a role in pathogen colonization and disease severity and may become a reservoir for virulence and antibiotic resistance genes. Our study used whole-genome sequencing of E. coli before, during, and after challenge with an archetype ETEC isolate, H10407, and antibiotic treatment to explore the diversity and resiliency of the resident E. coli population in response to the ecological disturbances caused by pathogen invasion and antibiotic treatment.

Mycobacterium tuberculosis, antimicrobials, immunity, and lung–gut microbiota crosstalk: current updates and emerging advances

“…Mtb ’s nondysbiotic effect is contrary to what was observed with pathogens, such as H. hepaticus and diarrhea‐causing enterotoxigenic E. coli (Fig. ) …”

“…1). 45,63 Using macaques to study Mtb's effect on the lower airway (lung) microbiota, Cadena et al compared Mtb-infected macaques with uninfected controls and studied them prospectively for 4 months without administering antimicrobials. 15 They observed an initial increase in the lung microbial diversity 1-month postinfection, which returned to normal after 5 months.…”

Temporal Variability of Escherichia coli Diversity in the Gastrointestinal Tracts of Tanzanian Children with and without Exposure to Antibiotics

“…The converse is also possible, in that E. coli strains may not contain traditional virulence factors, but be obtained from a diarrheal sample, as has been highlighted in the recent GEMS studies ( 41 , 42 ). While diarrheagenic E. coli is often the dominant strain when causing diarrhea ( 43 ), the fact that these pathogenic strains may have been missed due to undersampling in the diarrhea samples cannot be discounted. There are many potential explanations for these observations which include the following: (i) the subjects have been previously exposed to these bacteria, and thus, have an established immunity; (ii) the organisms are not pathogenic in the context of other host factors, including the host microbiota; (iii) additional necessary virulence factors are absent in these isolates; or (iv) the virulence factors are present but not expressed by the bacterium.…”

Factors Obscuring the Role of E. coli from Domestic Animals in the Global Antimicrobial Resistance Crisis: An Evidence-Based Review

“…Numerically dominant and resident lineages may disseminate more between different hosts. The constant competition between new arrivals with colonizing strains in the intestine is likely responsible for the rapid turnover of dominant E. coli strains observed in the intestines of humans [63]. Although a minority among E. coli lineages, pathogenic strains of E. coli (such as ST131 genotype) are an important category that contains virulence genes and are associated with invasive infections.…”