EnvironmentalEscherichia coli: ecology and public health implications-a review

Abstract

Summary Escherichia coli is classified as a rod‐shaped, Gram‐negative bacterium in the family Enterobacteriaceae. The bacterium mainly inhabits the lower intestinal tract of warm‐blooded animals, including humans, and is often discharged into the environment through faeces or wastewater effluent. The presence of E. coli in environmental waters has long been considered as an indicator of recent faecal pollution. However, numerous recent studies have reported that some specific strains of E. coli can survive for long periods of time, and potentially reproduce, in extraintestinal environments. This indicates that E. coli can be integrated into indigenous microbial communities in the environment. This naturalization phenomenon calls into question the reliability of E. coli as a faecal indicator bacterium (FIB). Recently, many studies reported that E. coli populations in the environment are affected by ambient environmental conditions affecting their long‐term survival. Large‐scale studies of population genetics revealed the diversity and complexity of E. coli strains in various environments, which are affected by multiple environmental factors. This review examines the current knowledge on the ecology of E. coli strains in various environments with regard to its role as a FIB and as a naturalized member of indigenous microbial communities. Special emphasis is given on the growth of pathogenic E. coli in the environment, and the population genetics of environmental members of the genus Escherichia. The impact of environmental E. coli on water quality and public health is also discussed.

Prevalence of Multidrug-ResistantEscherichia coliIsolated from Drinking Water Sources

“…The sample collection period spanned over the two seasons in Ghana, that is, the dry and rainy seasons. All water sampling and preservation procedures were performed according to Standard Methods for the examination of water and wastewater [16, 17] and WHO guidelines for drinking water quality [14, 15]. Sampling for bacteriological analysis was done aseptically with care, ensuring no external contamination of samples.…”

“…Although there are several studies assessing multidrug resistance (MDR) in E. coli populations of animal origin, not much work has been done on the ecology of MDR [13, 14]. The spread of MDR into environments where antibiotics are not used is a possibility that has not yet been well researched, although it has been postulated that water could disseminate antimicrobial resistance [15]. The objectives of this study are to determine the antibiotic sensitivity pattern and the multiple antibiotic resistance index of E. coli strains isolated from six drinking water sources during bacteriological monitoring over a year.…”

Bacterium, Fungus, and Virus Microorganisms for Energy Storage and Conversion

“…The common conditions for the growth of E. coli bacterium are stable temperature (>30 °C), relatively low pH, high humidity, and sufficient nutrients of carbon, nitrogen, and phosphorus . Generally, E. coli bacterium is cultured overnight in Luria–Bertani medium under soft shaking.…”

Fecal pollution: new trends and challenges in microbial source tracking using next‐generation sequencing

“…Additionally, many FIB do not meet one of the central tenets of the concept: that they should mimic the fate of enteric pathogens in waterways. A number of studies have reported the persistence of FIB in extraintestinmal environments (Byappanahalli et al, 2012;Jang et al, 2017). Nevertheless, quantification of FIB is still applied to monitor the microbiological quality of recreational water worldwide.…”

“…Due to their widespread occurrence and presumed relation to fecal pollution, E. coli and Enterococcus strains were initially thought to be good candidates for MST methods (Scott et al, 2002;Simpson et al, 2002). However, this has not proven to be the case, since their ubiquitous presence in feces and environmental persistence of these FIB rarely mimic that of pathogens (Byappanahalli et al, 2012;Jang et al, 2017;Staley et al, 2014). The primary idea underlying all MST approaches is that a specific trait of a bacterial group (e.g.…”