Enterococcus
Enterococcus
By Richard Guilford
Enterococcus
Enterococcus, or more appropriately enterococci, are a family of bacteria in the division firmicutes (meaning strong skin and referring to the cell wall) and the class bacilli (which refers to its rod like shape). They look just like streptococcus bacteria from physical characteristics alone. In fact, members of the genus Enterococcus were classified as Group D Streptococcus until 1984 when genomic DNA analysis showed that a separate genus classification would be appropriate. Enterococci are part of the normal intestinal flora (good bacteria) of humans and animals but are also important pathogens responsible for serious infections. They are considered gram-positive, meaning they stain dark blue or violet. They also mostly occur in pairs or short chains. Enterococci are facultative anaerobic organisms, meaning they can thrive in both oxygen rich and oxygen poor environments. They do not form spores as many bacteria do, meaning they do not have a reproductive structure that is adapted for dispersal and survival for extended periods of time in unfavorable conditions. Nevertheless, they are tolerant of a wide range of environmental conditions: such as extreme temperature (10-45°C), pH (4.5-10.0) and high sodium chloride concentration. In bodies of water, the acceptable level of contamination is very low, for example in the state of Hawaii, with among the strictest tolerances in the United States, the limit for water off its beaches is 7 colony-forming units per 100 ml of water. Anything above that, the state may post warnings to stay out of the ocean. In 2004, Enterococcus spp. took the place of fecal coliform as the new federal standard for water quality at public beaches. It is believed to provide a higher correlation than fecal coliform with many of the human pathogens often found in city sewage (eww right?).
There are many strains of enterococcus. Important clinical infections caused by Enterococcus include
By Richard Guilford
Enterococcus
Enterococcus, or more appropriately enterococci, are a family of bacteria in the division firmicutes (meaning strong skin and referring to the cell wall) and the class bacilli (which refers to its rod like shape). They look just like streptococcus bacteria from physical characteristics alone. In fact, members of the genus Enterococcus were classified as Group D Streptococcus until 1984 when genomic DNA analysis showed that a separate genus classification would be appropriate. Enterococci are part of the normal intestinal flora (good bacteria) of humans and animals but are also important pathogens responsible for serious infections. They are considered gram-positive, meaning they stain dark blue or violet. They also mostly occur in pairs or short chains. Enterococci are facultative anaerobic organisms, meaning they can thrive in both oxygen rich and oxygen poor environments. They do not form spores as many bacteria do, meaning they do not have a reproductive structure that is adapted for dispersal and survival for extended periods of time in unfavorable conditions. Nevertheless, they are tolerant of a wide range of environmental conditions: such as extreme temperature (10-45°C), pH (4.5-10.0) and high sodium chloride concentration. In bodies of water, the acceptable level of contamination is very low, for example in the state of Hawaii, with among the strictest tolerances in the United States, the limit for water off its beaches is 7 colony-forming units per 100 ml of water. Anything above that, the state may post warnings to stay out of the ocean. In 2004, Enterococcus spp. took the place of fecal coliform as the new federal standard for water quality at public beaches. It is believed to provide a higher correlation than fecal coliform with many of the human pathogens often found in city sewage (eww right?).
There are many strains of enterococcus. Important clinical infections caused by Enterococcus include