Intestinal enterococci
Enterococcus spp.
Intestinal enterococci are a group of Gram-positive, cocci-shaped bacteria primarily residing in the intestines of humans and warm-blooded animals. In aquatic ecology, they are utilized as microbiological indicators to assess the hygienic quality of recreational and drinking waters. They are more resilient to environmental stressors such as UV radiation and high salinity compared to Escherichia coli. Their presence in the environment indicates fecal contamination and the associated risk of co-occurring pathogenic microorganisms.
Details
Identification
Gram-positive cocci, usually arranged in pairs or short chains; catalase-negative; capable of growth at 44.5 °C and in media containing 6.5% NaCl.
Social behavior
Ability to form biofilms on surfaces; exist as individual cells or colonies.
Diet
Chemoorganotrophic; energy acquisition through fermentation of carbohydrates to lactic acid.
Overwintering
Persistence in aquatic sediments or as part of the intestinal flora of vertebrates.
Ecology
Ecological role
Important component of the intestinal microbiome; in water bodies, they serve as an indicator of anthropogenic impacts.
Natural predators
Bacteriophage viruses and bacterivorous protozoa (e.g., flagellates and ciliates).
Competitor species
Other intestinal bacteria such as Escherichia coli, Bacteroides species, and lactobacilli.
Ecosystem service
Contribution to the decomposition of organic matter and nutrient recycling in the gut and sediment.
Threats
Disinfectants (chlorine), strong UV radiation, and antibiotics.
Scientific profile
Profile
Habitat
Primarily the gastrointestinal tract of warm-blooded animals; secondary in soil, surface water, and on plants following fecal input.
Ecological role
Important commensals of the intestinal flora; ecologically serve as key indicators for fecal contamination and anthropogenic impacts in ecosystems.