Microbiology
Summary
The genus Enterococcus contains two notable species, Enterococcus faecalis and Enterococcus faecium, species of gram-positive cocci that inhabit the human intestinal tract. While E. faecalis is more common, E. faecium can be more dangerous due to its increased resistance to antibiotics. Both enterococci species are capable of growing in mediums with up to 6.5% sodium chloride, and they are bile-resistant.
Enterococcus species are responsible for three main types of infections: urinary tract infections (UTIs), endocarditis, and infections of the biliary tree. Notably, certain strains of E. faecalis and E. faecium have demonstrated resistance to an extensive array of antibiotics, including vancomycin, earning the name vancomycin-resistant Enterococcus (VRE). To treat VRE, two potent antibiotics can be used: linezolid and tigecycline.
Lesson Outline
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FAQs
E. faecalis and E. faecium are two different species of Enterococcus bacteria. E. faecalis is more prevalent and is generally more susceptible to antibiotics. E. faecium is less common but is often more resistant to antibiotics, including vancomycin. Both species can cause nosocomial infections, including urinary tract infections and endocarditis, but E. faecium is more commonly associated with vancomycin-resistant Enterococcus (VRE) infections.
Enterococci are opportunistic pathogens that can cause nosocomial infections in vulnerable patients. They are commonly found in the human gastrointestinal tract and in the environment. Due to their ability to survive harsh conditions and form biofilms, they can colonize hospital surfaces, equipment, and healthcare workers' hands. This can lead to the spread of Enterococcus within hospital settings.
The treatment options for VRE infections are limited due to the resistance of these bacteria to vancomycin. Some alternative antibiotics that may be used to treat VRE infections include linezolid and tigecycline. The choice of treatment depends on the specific strain of the bacteria, the severity of the infection, and the patient's medical history. It is crucial to perform antimicrobial susceptibility testing to determine the most effective treatment options for each case.
Risk factors for developing Enterococcus infections include prolonged hospital stays, the use of invasive devices such as urinary catheters and central venous lines, exposure to antibiotics, especially broad-spectrum antibiotics, compromised immune systems, and underlying medical conditions like diabetes or kidney disease. Patients in critical care and surgical units are particularly at risk for nosocomial Enterococcus infections.
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