Staphylococcus aureus, which has emerged as a major pathogen in the past decades [1], can infect the skin and soft tissues, bones, joints, lungs, endocardium, bloodstream, and other organs [2]. Normally, this bacterium colonizes about 30% of humans [3]. Epidemiology reports note that in addition to community-associated infections, this pathogen is also responsible for many health-care associated infections related to medical devices [2]. S. aureus is transmitted by contact with an infected person or contaminated objects, and inhalation of droplets. Risk factors for this infection are chronic lung diseases, diabetes mellitus, chronic skin diseases, influenza infection, malignancies, surgeries, immunosuppressant use, intravenous drug use, and HIV infection.

Clinical manifestations

S. aureus infection consists of diseases that range from benign to life-threatening [2] and their manifestations are described below.

Skin and soft tissue infections (SSTIs) include impetigo, cellulitis, and abscesses such as folliculitis, furuncles, and carbuncles. Very importantly, SSTIs can disseminate via the bloodstream and cause septicemia [4] and spread to muscles [5] and other organs [6].

Osteomyelitis and septic arthritis are two of the most serious S.aureus infections. Some of the features of osteomyelitis are fever, bone pain, and limping while septic arthritis features include fever and warm, erythematous, and painful joints with restricted motion [2].

Staphylococcal pneumonia is characterized by fever, respiratory distress, cyanosis, and gastrointestinal symptoms and primarily occurs in infants, children, and disabled individuals.

Symptoms of infective endocarditis (IE), which can affect heart valves and the endocardium, are fever, malaise, chills, and sweating. Moreover, patients may exhibit new onset of murmur or the worsening of a preexisting one, Osler nodes, Janeway lesions, Roths spots, subungual hemorrhages, and others.

One of the most ominous S.aureus infections is known as toxic shock syndrome (TSS). The CDC criteria for the diagnosis of TSS are 1) fever, 2) shock that is refractory to resuscitation, 3) diffuse macular rash, and 4) involvement of at least 3 organ systems [7]. Patients are likely to exhibit an altered mental status, vaginal hyperemia, skin manifestations, etc.

• Recurrent Infection

  Active duty beneficiaries were at a five-fold higher risk for S. aureus SSTIs (63% MRSA). 2 Patients with S. aureus SSTIs have a 50% risk of having a recurrent infection within six months. 3 Household contacts of patients with MRSA SSTIs have been reported [novadigm.net]

  Follow-up Advise the patient to return if infection persists or recurs. Patients with recurrent infections or persistent colonisation should maintain sensible precautions to prevent transmission (see below). [patient.info]

  […] with good response to I&D ± antibiotics, although recurrent infections can occur. in some. [hopkinsguides.com]

  Infective endocarditis was present in 17.1%, septic emboli or arthritis in 4.8%, and abscesses in 5.7% ( 51 ). Recurrent infections within 12 wk were seen in 12.9% of the patients ( 51 ). [cjasn.asnjournals.org]

• Furunculosis

  Recurrent skin infections include boils (furunculosis), carbuncles, folliculitis and cellulitis. Cutaneous lesions can be more than 5 cm in size, and may be associated with necrosis. [patient.info]

When evaluating a suspected S. aureus infection, the clinician should elicit the individual's personal history and risk factors, and perform a thorough physical exam and the appropriate studies.

Diagnostic tests

With regards to skin infections, inspection is usually sufficient to confirm the diagnosis although some cases will warrant aspiration and culture of the purulent material [8]. Also, ultrasonography may help in the diagnosis of soft tissue infections [9].

Osteomyelitis is typically associated with peripheral leukocytosis and increased levels of erythrocyte sedimentation rate (ESR) and serum C-reactive protein (CRP) [2]. Additionally, patients may have positive blood cultures, but if not, bone biopsy and culture should be performed [10]. Very importantly, imaging studies such as radiography, magnetic resonance imaging (MRI), and/or other modalities are obtained.

Septic arthritis is diagnosed based on elevated leukocytes in synovial fluid [11]. Moreover, the aspirated fluid is also sent for a culture and a Gram stain and radiography and/or other imaging tools are used in the workup.

To assess for S. aureus pneumonia, blood cultures are not reliable and therefore, a sample from the respiratory tract should be obtained. Additionally, chest radiography findings vary depending on whether the staphylococcal pneumonia is a primary or secondary infection. For example, primary infection demonstrates unilateral consolidation whereas secondary reveals bilateral involvement. Note that chest X-rays will reveal disease progression, which usually occurs rapidly.

Diseases such as IE and TSS are complicated and require an extensive workup. For example, patients diagnosed with IE should meet modified Duke criteria that consist of history and physical findings as well as blood culture and echocardiography results [12]. Finally, TSS requires a careful assessment of the history, physical exam, and the appropriate studies.

• Gram-Positive Bacteria

  Gram-positive bacteria acquire resistance to beta-lactam antibiotics through the production of a protein called PBP2a, which is able to avoid the inhibitory effects of the antibiotics. [bcm.edu]

  The effect of propionate on other Gram-positive bacteria was also investigated. Results Of the three SCFAs, propionate most potently inhibited the growth of MRSA USA300, inhibiting its growth in a dose-dependent manner. [s-space.snu.ac.kr]

  However, some infections involve other transmission methods.[4] Etiology Staphylococcus aureus is Gram-positive bacteria (stain purple by Gram stain) that are cocci-shaped and tend to be arranged in clusters that are described as “grape-like.” [ncbi.nlm.nih.gov]

  Telavancin versus standard therapy for treatment of complicated skin and skin structure infections caused by gram-positive bacteria: FAST 2 study. Antimicrob Agents Chemother 2006;50:862–867. [jkma.org]

  Vancomycin has a broad anti–Gram-positive spectrum of action ( 97 ). [cjasn.asnjournals.org]

• Gram-Positive Coccus

  Abstract Staphylococcus aureus is a Gram-positive coccus that interacts with human hosts on a spectrum from quiet commensal to deadly pathogen. [ncbi.nlm.nih.gov]

• Leukocytosis

  Osteomyelitis is typically associated with peripheral leukocytosis and increased levels of erythrocyte sedimentation rate (ESR) and serum C-reactive protein (CRP). [symptoma.com]

  The response to therapy is usually slow, and patients may continue to have bacteremia, fever, and leukocytosis for at least a week after therapy is initiated. Some authors recommend obtaining blood cultures after the end of therapy. [emedicine.medscape.com]

Initial treatment with oxacillin and gentamicin was ineffective. Vancomycin was added to the regimen as the patient worsened, but after the 30(th) day of vancomycin treatment S. aureus was isolated from the blood. [ncbi.nlm.nih.gov]

Therefore, we expect that by targeting on a high risk patient population, by repeating the treatment, by intensifying the treatment with skin disinfection, by starting treatment on the day of admission, we can reduce nosocomial S. aureus infection by [zonmw.nl]

Deterioration of liver function caused LOHF, and LOHF has a poor prognosis, particularly when it is complicated by infection. [ncbi.nlm.nih.gov]

Staph Infection Prognosis When mild and promptly treated with antibiotics, the prognosis for recovery from a Staph infection is excellent. However, a MRSA infection can have an entirely different outlook. [onhealth.com]

Prognosis Necrotising pneumonia has a high mortality rate if not diagnosed early and treated energetically. [patient.info]

[…] of diseases in human communities. 2. the field of medicine concerned with the determination of the specific causes of localized outbreaks of infection, such as hepatitis, of toxic disorders, such as lead poisoning, or any other disease of recognized etiology [vdh.virginia.gov]

AR/MDROs Home Data FAQs Reporting Resources Organisms, Causative Agent, or Etiologic Agent Email Questions Transmission Once S. aureus is tested in the lab and known to be resistant to certain antibiotics, we call it methicillin-resistant Staphylococcus [dshs.state.tx.us]

However, some infections involve other transmission methods.[4] Etiology Staphylococcus aureus is Gram-positive bacteria (stain purple by Gram stain) that are cocci-shaped and tend to be arranged in clusters that are described as “grape-like.” [ncbi.nlm.nih.gov]

Treatment with antibiotics is specific to the etiologic agent and its characteristics. For more information, see Endocarditis, Bacterial. [emedicine.medscape.com]

In the book «Opportunistic infections: pathogens and etiologic diagnosis». Manual of Medical Microbiology. Book III, Volume 1. Edited by A.S. Labinskaya, N.N. Kostyukova. M.: Bean, 2013: 31–87 (in Russian)] Rigby K.M., DeLeo F.R. [molmedjournal.ru]

Pygmies), combined with close contact with animals (e.g. livestock and domestic animals, and wildlife), makes the epidemiology of S. aureus on the African continent unique and fascinating. [ncbi.nlm.nih.gov]

Bulletin Archive Contact Us Laurie Forlano, DO, MPH, State Epidemiologist Director, Office of Epidemiology 109 Governor Street, 6th Floor East Richmond, VA 23219 Phone: (804) 864-8141 Fax: (804) 864-8139 Contact Us by Email [vdh.virginia.gov]

Hydrocephalus is thought to be associated with arachnoiditis caused by S aureus infection, which provides new insights into the pathophysiology of arachnoiditis. [ncbi.nlm.nih.gov]

Staphylococcus aureus infections: Epidemiology, pathophysiology, clinical manifestations, and management. Clin. Microbiol. Rev. 28, 603–661 (2015). 2. Thwaites, G. E. et al. Clinical management of Staphylococcus aureus bacteraemia. Lancet Infect. [scriptiebank.be]

This cytokine release mediates the TSS; the resultant pathophysiology mimics that of endotoxic shock. [emedicine.medscape.com]

Editorial: Spreading the Benefits of Infections Prevention in the NICU In a related editorial, Pablo J. [sciencedaily.com]

This showed that 50% of nosocomial bacteremia (the most serious infection) may be prevented by mupirocin treatment alone, which would be cost-effective. [zonmw.nl]

Prevention: Hand washing is the single most important way to prevent the spread of staph infections. [conditions.health.qld.gov.au]

CONCLUSIONS: CSA-90 can promote osteogenesis and be used for prevention of Staphylococcus aureus infection in preclinical models. [ncbi.nlm.nih.gov]

Centers for Disease Control and Prevention. Overview of Healthcare-associated MRSA. (Online information). Available online at http://www.cdc.gov/ncidod/dhqp/ar_mrsa.html. Accessed December 2007. Centers for Disease Control and Prevention. [labtestsonline.org]

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