Staphylococcus aureus
| Other names | Staph aureus, S. aureus |
| Specialty | Infectious disease |
| Types | Methicillin-susceptible Staphylococcus a ... |
| Causes | Staphylococcus aureus bacteria |
How long does it take staph infection to heal?
Staph skin infections have similar duration, while invasive staph infections have varying duration. Staph skin infections such as, boil, impetigo, and skin abscess usually take around 10 days to recover once treatment begins on an immediate basis. The rashes and blisters caused due to staphylococcal scalded skin syndrome may go away after 5-7 days if treatment is administered immediately.
How dangerous is staph infection?
Staphylococcus aureus (staph) is a germ found on people’s skin. Staph can cause serious infections if it gets into the blood and can lead to sepsis or death. Staph is either methicillin-resistant staph (MRSA) or methicillin-susceptible staph (MSSA). Staph can spread in and between hospitals and other healthcare facilities, and in communities.
What are the early signs of staph infection?
The most common visible signs of MRSA and Staph are:
- Bumps, pimple-like lumps, or blisters on the skin, either singly or more than one. ...
- Swelling, reddening, and tenderness of the skin often surround the lumps or bumps.
- White or yellow pus filled heads are often found at the center of lumps, which often drain on their own.
When does a staph infection become serious?
When does a staph infection become serious? Staph infections must be treated right away. If left untreated the bacteria can spread into the bloodstream and travel to organs inside the body. Once this happens in the infection can take over and cause serious health problems.
What is staph in the nose?
Staphylococcus aureus [staf I lō-kok is aw ree us] (staph), is a type of germ that about 30% of people carry in their noses. Most of the time, staph does not cause any harm; however, sometimes staph causes infections. In healthcare settings, these staph infections can be serious or fatal, including: 1 Bacteremia or sepsis when bacteria spread to the bloodstream. 2 Pneumonia, which most often affects people with underlying lung disease including those on mechanical ventilators. 3 Endocarditis (infection of the heart valves), which can lead to heart failure or stroke. 4 Osteomyelitis (bone infection), which can be caused by staph bacteria traveling in the bloodstream or put there by direct contact such as following trauma (puncture wound of foot or intravenous (IV) drug abuse).
What is the condition that can lead to heart failure?
Endocarditis (infection of the heart valves), which can lead to heart failure or stroke.
Is MRSA a staph?
methicillin-resistant Staphylococcus aureus (MRSA) methicillin-susceptible Staphylococcus aureus (MSSA) vancomycin-intermediate Staphylococcus aureus (VISA) vancomycin-resistant Staphylococcus aureus (VRSA) Although MRSA is often better known, any staph infection can be dangerous even if it is not resistant to antibiotics.
Is staph infection more serious in ICUs?
In healthcare, the risk of more serious staph infection is higher for patients in intensive care units (ICUs), patients who have undergone certain types of surgeries and patients with medical devices inserted in their bodies. Top of Page.
Can anyone get staph?
Populations at risk for Staphylococcus aureus infection. Anyone can develop a staph infection, although certain groups of people are at greater risk, including people with chronic conditions such as diabetes, cancer, vascular disease, eczema, lung disease, and people who inject drugs. In healthcare facilities, the risk of more serious staph ...
Can staph infection be fatal?
In healthcare settings, these staph infections can be serious or fatal, including: Bacteremia or sepsis when bacteria spread to the bloodstream. Pneumonia, which most often affects people with underlying lung disease including those on mechanical ventilators.
What is the highest prevalence of Staphylococcus aureus?
The highest prevalence of Staphylococcus aureus is witnessed in patients with diabetes mellitus, cardiovascular patients, an d patients with granulocytic and immune deficiency. Sta phylococcus pneumonia is considered as an. important disease due to its high mortality (up to 50%).
How many specimens were tested for staph aureus?
The coagulase (coa) gene PCR was preformed, which confirmed 288 specimens as S. aureus and 51 specimens as coagulase negative staphylococci (CONS). All the specimens were subjected to slide coagulase test, Slidex Staph plus test and tube coagulase test. Sensitivity, specificity, positive predictive value and negative predictive values of were calculated using coa gene PCR as gold standard for the detection ofS. aureus. The tube coagulase test showed very good sensitivity (98.7%), specificity (98.1%), PPV (99.5%) and NPV (94.4%) than other methods. Slidex Staph plus test showed fairly good sensitivity and specificity. Slide coagulase test has good specificity but poor sensitivity. Therefore we recommend that tube coagulase test be done routinely for the detection ofS. aureus in microbiology laboratory.
How many strains of Staphylococcus spp. were isolated from bovine mastitis?
A total of 180 strains of Staphylococcus spp. were isolated from bovine mastitis, dogs with otitis externa and chickens with various infections. The isolates were identified as S. aureus (29.4%), S. hyicus (16.7%), S. intermedius (3.9%), S. chromogenes (16.1%), S. lentus (13.3%), S. epidermidis (11.1%), S. simulans (7.8%) and S. haemolyticus (1.7%). The rate of positiveness for deoxyribonuclease (DNase) test, thermonuclease (TNase) test, presence of the capsule, slime and biofilm formation, hemolysis, and hemagglutination tests for CoPS strains were 42.2%, 43.3%, 53.3%, 77.8%, 74.4%, 58.9%, 46.7%, and for CoNS strains were 54.4%, 5.6%, 13.3%, 44.4%, 36.7%, 28.9% and 41.1%, respectively. The virulence factors which were investigated were determined CoNS and CoPS strains. Thus, it was thought that CoNS strains might be as dangerous as CoPS strains for both animals and humans.
What is the bacterium that causes scale skin syndrome?
The sudden appearance of local erythema around the mouth (redness and inflammation), which takes over the entire body over two days, is a characteristic of Scale skin syndrome. Bullous impetigo is the topical form of scale skin syndrome. In this syndrome, specific strains of Staphylococcus aureus generate toxins (such as phage type 71) as well as skin surface blisters. This disease is witnessed in young children and is highly contagious. Also toxic shock syndrome is produced by Staphylococcus aureus species that produce TSST-1 or enterotoxin B. Previously, TSST-1 was called enterotoxin B, pyrogenic exotoxin C, and enterotoxin F. (this toxin is similar to enterotoxin F). Folliculitis is the most cutaneous infection caused by Staphylococcus aureus. Folliculitis is a purulent infection of hair follicles that causes redness and swelling of the hair follicle. Furuncle is a developed folliculitis, and large painful protruded nodules appear that contain dead tissue (necrotic) in its lower region. As a consequence of the furuncles joining together and their extension into the deeper subcutaneous tissues, carbuncle may develop. Staphylococcus impetigo is commonly observed in children that are mainly produced on the face and organs, especially around the nose, and most likely spreads to other parts of the face through a running nose or at the time of nose blowing. Staphylococcus aureus is also the common agent for bacteremia. The highest prevalence of Staphylococcus aureus is witnessed in patients with diabetes mellitus, cardiovascular patients, and patients with granulocytic and immune deficiency. Staphylococcus pneumonia is considered as an important disease due to its high mortality (up to 50%). It may be observed in all age groups, but it is a rare disease with the exception of its association with the flu epidemic. Staphylococcus aureus is the cause of most cases of primary osteomyelitis. This disease is predominantly occurring in boys under the age of 12, and is often followed by the diffusion of a primary hemorrhage (ulcer or furuncle). To design appropriate empirical therapy, physicians should be knowledgeable about the disease caused by of Staphylococcus aureus in their communities. This article reviews the some important diseases caused by Staphylococcus aureus.
What is the infection in the hum population?
infections in the hum an population. Staphylococcus aureus is
What causes redness and swelling in hair follicles?
Folliculitis is a purulent infection of hair follicles that causes redness and swelling of the hair follicle. Furuncle is a developed
Which disease is the most common cause of osteomyelitis?
exception of its association with the flu epidemic. Staphylococcus aureus is the cause of most cases of primary osteomyelitis. This
What is Staphylococcus aureus?
Last Update: August 23, 2020. Continuing Education Activity. Staphylococcus aureus is a gram-positive bacteria that cause a wide variety of clinical diseases. Infections caused by this pathogen are common both in community-acquired and hospital-acquired settings. The treatment remains challenging due to the emergence of multi-drug resistant strains ...
What are the most common infections caused by S. aureus?
aureusare one the most common bacterial infections in humans and are the causative agents of multiple human infections, including bacteremia, infective endocarditis, skin and soft tissue infections (e.g., impetigo, folliculitis, furuncles, carbuncles, cellulitis, scalded skin syndrome, and others), osteomyelitis, septic arthritis, prosthetic device infections, pulmonary infections (e.g., pneumonia and empyema), gastroenteritis, meningitis, toxic shock syndrome, and urinary tract infections.[6] Depending on the strains involved and the site of infection, these bacteria can cause invasive infections and/or toxin-mediated diseases. [6][7] The pathophysiology varies greatly depending on the type of S. aureusinfection.[6] Mechanisms for evasion of the host immune response include the production of an antiphagocytic capsule, sequestering of host antibodies or antigen masking by Protein A, biofilm formation, intracellular survival, and blocking chemotaxis of leukocytes. [8][7] Binding of the bacteria to extracellular matrix proteins and fibronectin in infectious endocarditis is mediated by bacterial cell wall-associated proteins such as fibrinogen-binding proteins, clumping factors, and teichoic acids.[7] Also, Staphylococcal superantigens (TSST-1 or toxic shock syndrome toxin 1) are important virulence factors in infectious endocarditis, sepsis, as well as toxic shock syndrome. [9][10] Pneumonia infections are associated with the bacterial production of PVL (Panton-Valentine leukocidin), Protein A, and alpha-hemolysin, and infections are more common following influenza virus infection as well as a diagnosis of Cystic Fibrosis. Prosthetic device infections are often mediated by the ability of S. aureusstrains to form biofilms as well as communicate using quorum sensing in a bacterial cell density-dependent manner. [11]
What is the color of a staph?
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.” On media, these organisms can grow in up to 10% salt, and colonies are often golden or yellow (aureus means golden or yellow). These organisms can grow aerobically or anaerobically (facultative) and at temperatures between 18 C and 40 C. Typical biochemical identification tests include catalase positive (all pathogenic Staphylococcusspecies), coagulase positive (to distinguish Staphylococcus aureusfrom other Staphylococcusspecies), novobiocin sensitive (to distinguish from Staphylococcus saprophyticus), and mannitol fermentation positive (to distinguish from Staphylococcus epidermidis). [4][1] MRSA strains carry a mecgene on the bacterial chromosome, which is a component of the larger Staphylococcal chromosomal cassette mec(SCCmec) region, conferring resistance to multiple antibiotics depending on the SCCmectype.[2] The mecgene encodes the protein PBP-2a (penicillin-binding protein 2a). PBP-2a is a penicillin-binding protein (PBP), or essential bacterial cell wall enzyme that catalyzes the production of the peptidoglycan in the bacterial cell wall. PBP-2A has a lower affinity to bind to beta-lactams (and other penicillin-derived antibiotics) when compared to other PBPs, so PBP-2A continues to catalyze the synthesis of the bacterial cell wall even in the presence of many antibiotics. As a result, S. aureusstrains that synthesize PBP-2A can grow in the presence of many antibiotics, and these MRSA strains are resistant to many antibiotics. MRSA strains tend to be resistant to methicillin, nafcillin, oxacillin, and cephalosporins. [2][4]
How to prevent S. aureus infection?
Prevention of S. aureusinfections remains challenging. Despite many efforts, a routine vaccination for S. aureusinfections has remained elusive. As a result, efforts have relied on infection control methods such as hospital decontamination procedures, handwashing techniques, and MRSA transmission prevention guidelines. Topical antimicrobials such as mupirocin can be used to eliminate nasal colonization in some nasal carriers. However, usage is controversial.
How long does it take to treat S. aureus?
When prescribing antibiotics, one should limit the duration to no more than 7 to 10 days for most infections. The reason is that the empirical prescription of antibiotics has led to the development of resistant strains. Pharmacists should coordinate with the clinician to target antimicrobial therapy, and nursing can chart the progress so modification to the regimen can be made if treatment is ineffective. This kind of interprofessional coordination is necessary to treat such infections with precision.
How to diagnose S. aureus?
In many cases, routine cultures will reveal the diagnosis (i.e.,blood, sputum); however, RT-PCR (real-time PCR) for 16S rRNA genes may be necessary in some cases. Drug susceptibility testing often is required to guide treatment. If patient samples are collected for pathogen identification in the microbiology laboratory, caution must be exercised as the presence of S. aureusin the skin or mucous membrane does not necessarily indicate infection because these organisms are frequently members of the normal flora. [4]
What is the mecgene of a bacterial cell?
The mecgene encodes the protein PBP-2a (penicillin-binding protein 2a). PBP-2a is a penicillin-binding protein (PBP), or essential bacterial cell wall enzyme that catalyzes the production of the peptidoglycan in the bacterial cell wall.
What are the causes of S. aureus?
S. aureus causes numerous infections at various sites of the body. Some of these include: 1 Skin infections – S. aureus causes boils, furuncles, styes, impetigo and other superficial skin infections in humans 2 Infections of surgical and trauma wounds – Those with chronic illness, diabetes, traumatic injury, burns or immunosuppression are susceptible to more severe skin, deeper tissue infections and deep abscesses 3 Urinary tract infections 4 Food poisoning and gastrointestinal tract infections may be caused by consuming food contaminated with S. aureus. 5 Infections of organs include pneumonia (lung infection), osteomyelitis (bone infection), endocarditis (heart infection), phlebitis (infection of veins and blood vessels), mastitis (infection of breast and formation of abscesses) and meningitis (brain infections). These infections are more common in hospitalized patients rather than healthy individuals in the community. 6 Infections from and on indwelling medical devices. These include infection of joint prostheses, cardiovascular devices and artificial heart valves. 7 Generalized life threatening blood infections or Toxic shock syndrome (TSS), bacteremia and septicaemia
Why is S. aureus a good bacteria?
The bacteria have a fibrinogen/fibrin binding protein that help it to attach to blood clots and traumatized tissue. This is the reason why S. aureus is capable of producing wound infections and post-surgery infections. S. aureus also has numerous factors that help it to evade the host defence mechanisms. For example, many of the strains carry ...
What are the factors that help S. aureus to evade the host defence mechanisms?
S. aureus also has numerous factors that help it to evade the host defence mechanisms. For example, many of the strains carry a polysaccharide on their surface which may help them to resist phagocytosis by macrophages. Protein A is a surface protein of S aureus which binds immunoglobulin G molecules by the Fc region.
What causes food poisoning?
Food poisoning and gastrointestinal tract infections may be caused by consuming food contaminated with S. aureus. Infections of organs include pneumonia (lung infection), osteomyelitis (bone infection), endocarditis (heart infection), phlebitis (infection of veins and blood vessels), mastitis (infection of breast and formation of abscesses) ...
What are the diseases that can be caused by indwelling medical devices?
Infections from and on indwelling medical devices. These include infection of joint prostheses, cardiovascular devices and artificial heart valves. Generalized life threatening blood infections or Toxic shock syndrome (TSS), bacteremia and septicaemia.
Does S. aureus cause phagocytosis?
This disrupts opsonization and phagocytosis. S. aureus can cause severe damage to the host. It makes several types of protein toxins which are probably responsible for symptoms during infections. These toxins damage the membrane of the red blood cells and lead to their breakdown.
Is S. aureus virulent?
S. aureus expresses quite a few extracellular proteins that are virulent to the host. For the majority of diseases caused by this organism, pathogenesis is multifactorial.
Why is S. aureus a common cause of IE?
aureus is now the most common cause of IE in the industrialized world ( 125 ). Due to its propensity to cause severe disease and its frequent antibiotic resistance, S. aureus is a dreaded cause of IE. Although our ability to rigorously study IE was previously limited by its relative infrequency at any single institution, large multinational collaborations such as the International Collaboration on Endocarditis Prospective Cohort Study (ICE-PCS) ( 126) and robust population-level studies ( 127, – 129) have provided critical insights into the epidemiology and prognosis of IE in general and S. aureus IE in particular.
What are the clinical manifestations of S. aureus?
The clinical manifestations of S. aureus IE are now well understood through the ICE-PCS cohort ( 125) as well as national cohorts ( 170) and long-term single-center studies ( 146, 171, 172 ). Patient characteristics associated with S. aureus IE include injection drug use, health care-associated infections, a shorter duration of symptoms prior to diagnosis, persistent bacteremia, the presence of a presumed intravascular device source, stroke, and diabetes mellitus ( 125, 171 ).
How does S. aureus gain access to the joint?
S. aureus most commonly gains access to a joint space via bacteremic seeding of the vascular synovial lining of the joint , accounting for up to 70% of cases. Direct implantation, either through trauma or an iatrogenic event (e.g., following an intra-articular steroid injection), accounts for most of the remainder. Rarely, septic arthritis can occur following arthroscopy, the reported incidence of which is 0.01 to 0.23% ( 462 ).
How common are osteoarticular infections in children?
The incidence of osteoarticular infections in children ranges from 7 to 22 per 100,000 person-years based on studies from Europe ( 493, – 495 ). These infections are more common in males than in females (with incidences in French children of 24 per 100,000 person-years for boys and 19 per 100,000 person-years for girls) and in toddlers than in other age groups ( 494, 495 ). Some ethnic groups may be at higher risk, with Maori and Pacific Islander populations being overrepresented in a study involving 813 cases of acute OM in New Zealand ( 496 ). In the United States, CA-MRSA has become considerably more prominent as a cause of acute osteoarticular infections since 2000. In a study of 158 cases in Tennessee, the proportion of osteoarticular infections due to CA-MRSA rose from 4% to 40% from 2000 to 2004 ( 497 ). Similarly, the proportion of cases of acute OM due to CA-MRSA was 6% in 1999 to 2001 compared to 31% in 2001 to 2003 in Dallas, TX ( 498 ). In Houston, TX, between 2001 and 2010, 195 of 376 (52%) cases of S. aureus OM were due to MRSA ( 499 ).
How much of the human population is contaminated with S. aureus?
Approximately 30% of the human population is colonized with S. aureus ( 1 ). Simultaneously, it is a leading cause of bacteremia and infective endocarditis (IE) as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device-related infections.
What causes a nidus to form?
The formation of a nidus for bacterial colonization and infection begins with damage to the cardiac endothelium, either by direct trauma (e.g., intravascular catheters and electrodes, injected particulate matter from injection drug use, or turbulent blood flow resulting from valvular abnormalities) or inflammation (e.g., secondary to rheumatic heart disease or degenerative valvular disease). The exposure of subendothelial cells elicits the production of extracellular matrix proteins and tissue factor and the deposition of fibrin and platelets to form sterile vegetations. If these thrombotic vegetations become colonized by bacteria, IE can result ( 155 ).
Is S. aureus bacteremia a disease?
Bacteremia is perhaps the best-described manifestation of S. aureus infection. Multiple studies have now documented the prevalence, prognosis, and outcome of S. aureus bacteremia (SAB) in industrialized regions of the world. However, many basic questions about the epidemiology of SAB, particularly in the world's nonindustrialized regions, remain unanswered. Furthermore, there continues to be a paucity of high-quality evidence to guide the management of SAB.
What is the name of the disease that occurs when staph bacteria enters the bloodstream?
Also known as a bloodstream infection, bacteremia occurs when staph bacteria enter a person's bloodstream. A fever and low blood pressure are signs of bacteremia. The bacteria can travel to locations deep within your body, to produce infections affecting:
What is the most common type of staph infection?
Skin infections caused by staph bacteria include: Boils. The most common type of staph infection is the boil, a pocket of pus that develops in a hair follicle or oil gland. The skin over the infected area usually becomes red and swollen. If a boil breaks open, it will probably drain pus.
What causes staph on nose?
Staph infections are caused by staphylococcus bacteria, types of germs commonly found on the skin or in the nose of even healthy individuals. Most of the time, these bacteria cause no problems or result in relatively minor skin infections.
How does staph spread?
Contact sports. Staph bacteria can spread easily through cuts, abrasions and skin-to-skin contact. Staph infections may also spread in the locker room through shared razors, towels, uniforms or equipment.
What is the treatment for staph infection?
Treatment usually involves antibiotics and drainage of the infected area. However, some staph infections no longer respond to common antibiotics.
How long does it take for a staph infection to go away?
Symptoms come on quickly, usually within hours of eating a contaminated food. Symptoms usually disappear quickly, too, often lasting just half a day. A staph infection in food usually doesn't cause a fever.
How do you know if you have MRSA?
Symptoms. MRSA infections start out as small red bumps that can quickly turn into deep, painful abscesses. Staph infections can range from minor skin problems to endocarditis, a life-threatening infection of the inner lining of your heart (endocardium).
