The Outliers of Enterococcus Family

Enterococci have been highly adapted members of the gastrointestinal flora in a wide range of hosts for a long time, including humans and other mammals, birds, reptiles, and insects. However, they became one of the main culprits in hospital-acquired infections that are resistant to multiple drugs.

The Enterococcaceae family includes the Enterococcus genus. Over the last ten years, the taxonomy of Enterococcus has undergone significant changes and the genus now contains over forty different species with diverse habitats, tropisms, and metabolic and behavioral traits. In many of these environments, antibiotic-resistant enterococcal strains have surfaced, and the frequency with which bacteria with novel resistance mechanisms are isolated is concerning.  The correlation between the non-therapeutic utilization of antibiotics and the prevalence of Enterococci in diverse non-human environments is therefore a subject of significant curiosity.

Their remarkable adaptability, which allows them to survive a wide range of pH, temperature, and hypotonic and hypertonic environments, is a major factor in their widespread dispersion in nature. All Enterococci have certain fundamental morphological and physiological characteristics. Enterococcus species that possess Group D antigen are gram-positive, non-motile, non-capsulated without spores ovoid cells that are arranged in pairs at angles or in chains. They are fermentative chemoorganotrophs and facultative anaerobes. Their usual growth range is 10 to 45°C, with 35°C being the ideal temperature. Usually grown in broth with 6.5% NaCl, they hydrolyze esculin when 40% bile salts are present.

Some strains of Enterococcus are employed as probiotics in various treatments and hold significant biotechnological value in the food sector. But it is important to remember that Enterococci have the potential to be pathogenic in high-risk patients, particularly in a hospital setting.

Among all the microorganisms, Enterococci are one of the most controversial groups. It is now essential to gain a thorough understanding of this pathogen that has made the transition from commensal to pathogen. It will be easier for us to comprehend and cure illnesses if we are aware of the diversity within this species.

References

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