Staphylococcus aureus

Staphylococcus aureus
Staphylococcus aureus (/ˌstæfɪləˈkɒkəs ˈɔːriəs, -loʊ-/, Greek σταφυλόκοκκος 'grape-cluster berry', Latin aureus, 'golden') is a facultative anaerobic, Gram-positive coccal (round) bacterium also known as "golden staph" and "oro staphira". S. aureus is nonmotile and does not form spores.[18] In medical literature, the bacterium is often referred to as S. aureus, Staph aureus or Staph a.. S. aureus appears as staphylococci (grape-like clusters) when viewed through a microscope, and has large, round, golden-yellow colonies, often with hemolysis, when grown on blood agar plates. S. aureus reproduces asexually by binary fission. Complete separation of the daughter cells is mediated by S. aureus autolysin, and in its absence or targeted inhibition, the daughter cells remain attached and appear as clusters.

Staphylococcus aureus is catalase-positive (meaning it can produce the enzyme catalase). Catalase converts hydrogen peroxide (H
2O2) to water and oxygen. Catalase-activity tests are sometimes used to distinguish staphylococci from enterococci and streptococci. Previously, S. aureus was differentiated from other staphylococci by the coagulase test. However, not all S. aureus strains are coagulase-positive and incorrect species identification can impact effective treatment and control measures.

Natural genetic transformation is a reproductive process involving DNA transfer from one bacterium to another through the intervening medium, and the integration of the donor sequence into the recipient genome by homologous recombination. S. aureus was found to be capable of natural genetic transformation, but only at low frequency under the experimental conditions employed. Further studies suggested that the development of competence for natural genetic transformation may be substantially higher under appropriate conditions, yet to be discovered.

Role in health
In humans, S. aureus can be present in the upper respiratory tract, gut mucosa, and skin as a member of the normal microbiota. However, because S. aureus can cause disease under certain host and environmental conditions, it is characterized as a pathobiont.

In the United States, MRSA infections alone are estimated to cost the healthcare system over $3.2 billion annually. These infections account for nearly 20,000 deaths each year in the U.S., exceeding those caused by HIV/AIDS, Parkinson's disease, and homicide. Annually, over 119,000 bloodstream infections in the U.S. are attributed to S. aureus. S. aureus infections are ranked as one of the costliest healthcare-associated infections (HAIs), with each case averaging $23,000 to $46,000 in treatment and hospital resource utilization.

On average, patients with MRSA infections experience a lengthened hospital stay of approximately 6 to 11 days, which drives up inpatient care costs. The burden extends beyond direct healthcare expenses. Indirect costs, such as lost wages, reduced productivity, and long-term disability, can significantly amplify the overall economic toll. Severe S. aureus infections, including bacteremia, endocarditis, and osteomyelitis, often require prolonged recovery and rehabilitation, affecting patients' ability to return to work or perform daily activities.

Hospitals also invest heavily in infection control protocols to limit the spread of S. aureus, especially drug-resistant strains. These measures include routine screening, isolation practices, use of personal protective equipment, and antibiotic stewardship programs, which collectively contribute to rising operational costs. These necessary preventative measures can raise hospital costs by tens of thousands of dollars.
https://en.wikipedia.org/wiki/Staphylococcus_aureus

https://en.wikipedia.org/wiki/Staphylococcus_aureus

Staphylococcus aureus

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