Can Staphylococcus aureus live without oxygen?
However, it can result in infection when given the chance. Staphylococcus aureus grows best in an aerobic (oxygen-rich) environment but it can also live in anaerobic conditions (without oxygen). The bacterium has a diameter of about 0.8 µm, 60 times smaller than a hair’s breadth.
Is Staphylococcus aureus aerobic or anaerobic?
Staphylococcus aureus grows best in an aerobic (oxygen-rich) environment but it can also live in anaerobic conditions (without oxygen). The bacterium has a diameter of about 0.8 µm, 60 times smaller than a hair’s breadth. S. aureus is termed an opportunistic pathogen.
Is Staphylococcus aureus dangerous?
Staphylococcus aureus grows best in an aerobic (oxygen-rich) environment but it can also live in anaerobic conditions (without oxygen). The bacterium has a diameter of about 0.8 µm, 60 times smaller than a hair’s breadth. S. aureus is termed an opportunistic pathogen. It is not dangerous under normal conditions.
What is Staphylococcus aureus in healthcare settings?
Staphylococcus aureus in Healthcare Settings. General Information about Staphylococcus aureus. 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.
Is Staphylococcus aureus anaerobic or aerobic?
facultative anaerobic bacteriumAlthough S. aureus is a facultative anaerobic bacterium, the growth rate was drastically reduced after the shift from aerobic to anaerobic growth conditions.
What does Staphylococcus aureus need to grow?
aureus can grow at a temperature range between 15° to 45°C and at NaCl concentrations up to 15%. However, extended exposures above 42°C or below 10°C are not recommended. Plates should not be stored for longer than one week at 4°C.
What is the oxygen requirement of staphylococci?
Staphylococcus epidermidis ATCC 12228NamesStaphylococcus epidermidis ATCC 12228Flagellar presenceNoNumber of membranes1Oxygen requirementsFacultativeOptimal temperature30.032 more rows
What is the energy source for Staphylococcus aureus?
As for other pathogens, the synthesis and acquisition of certain nutrients are critical to support the infection capacity of S. aureus, glucose being one of the preferred carbon sources of this bacterium.
What kills Staphylococcus aureus?
Hydrogen peroxide kills Staphylococcus aureus by reacting with staphylococcal iron to form hydroxyl radical. J Biol Chem.
Where does Staphylococcus aureus grow?
Staphylococcus aureus or “staph” is a type of bacteria found on human skin, in the nose, armpit, groin, and other areas.
Can staph be anaerobic?
The only known staphylococcus that can behave as an anaerobe is Staphylococcus saccharolyticus (14).
Is Staph an anaerobic bacteria?
Staphylococcus aureus grows best in an aerobic (oxygen-rich) environment but it can also live in anaerobic conditions (without oxygen). The bacterium has a diameter of about 0.8 µm, 60 times smaller than a hair's breadth. S. aureus is termed an opportunistic pathogen.
What are the 3 types of oxygen requirements in bacteria?
SummaryClassificationCharacteristicsFacultative anaerobesWill respire aerobically until oxygen is depleted and then ferment or respire anaerobicallyObligate anaerobesLack superoxide dismutase Generally lack catalase Are fermenters Can not use oxygen as terminal electron acceptor2 more rows•May 5, 2022
Does Staphylococcus aureus use glucose?
Glucose serves as an important carbohydrate for the growth of Staphylococcus aureus. Carbohydrates support the growth of S. aureus under anaerobic conditions and high nitric oxide stress (Richardson et al., 2008; Vitko et al., 2015).
Does Staphylococcus aureus ferment glucose?
aureus, which favors the fermentation of glucose over other carbohydrates (Vitko et al., 2016). Our previous study has revealed that fermentation of glucose contributes to aggregation of S. aureus (Luo et al., 2019). These data indicate that glucose is essential for the growth of S.
Why is S. aureus resistant to penicillin?
Staphylococcal resistance to penicillin is mediated by blaZ, the gene that encodes β-lactamase (Figure 2a). This predominantly extracellular enzyme, synthesized when staphylococci are exposed to β-lactam antibiotics, hydrolyzes the β-lactam ring, rendering the β-lactam inactive.
What media does Staphylococcus aureus grow on?
Staph. aureus will grow on general culture media such as Blood Agar and chocolated Blood Agar and therefore can be isolated from direct plating of clinical specimens. More specialised media, such as Staph/Strep Selective Medium contain antimicrobials.
What does Staphylococcus aureus feed?
"Staph" bacteria feed on blood. They need the iron that's hidden away inside red blood cells to grow and cause infections.
What pH does Staphylococcus grow best?
6–7Growth of S. aureus occurs over the pH range of 4.0–10.0, with an optimum of 6–7 (ICMSF 1996; Stewart 2003). S. aureus is uniquely resistant to adverse conditions such as low aw, high salt content and osmotic stress.
What is the natural habitat of Staphylococcus aureus?
Their natural habitat includes humans and animals. They are part of the natural skin flora, specifically colonizing external mucous membranes. However, these bacteria are often found in the environment (untreated water, soil and contaminated objects).
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 ...
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.
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]
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]
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]
Is Staphylococcus aureus transmitted?
Transmission is typically from direct contact. However, some infections involve other transmission methods.[4] Staphylococcus aureus is a major bacterial human pathogen that causes a wide variety of clinical manifestations.[1] . Infections are common both in community-acquired as well as hospital-acquired settings and treatment remains challenging ...
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).
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 ...
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 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.
Where is Staphylococcus aureus found?
Staphylococcus aureus is found in our airways and on our skin. This bacterium does not cause illness under normal circumstances. However, it can result in infection when given the chance.
Is S. aureus a pathogen?
S. aureus is termed an opportunistic pathogen. It is not dangerous under normal conditions. However, if given the chance, for example when the skin or mucous membrane is damaged, it can take advantage of the opportunity and cause an infection, sometimes with serious results. S. aureus can also cause food poisoning.
Can you wash your hands with S. aureus?
Fortunately, we can take precautions against S. aureus. It is sensible to wash your hands regularly, especially after sneezing and before cooking. Too much soap, though, is not advisable. Soap reduces the acidity of your hands, making it easier for S. aureus to survive than its more benign relation Staphylococcus epidermidis.
Is Staphylococcus aureus an opportunistic pathogen?
The bacterium has a diameter of about 0.8 µm, 60 times smaller than a hair’s breadth. S. aureus is termed an opportunistic pathogen. It is not dangerous under normal conditions. However, if given the chance, for example when the skin or mucous membrane is damaged, it can take advantage of the opportunity and cause an infection, sometimes with serious results. S. aureus can also cause food poisoning.
What is Staphylococcus aureus?
Staphylococcus aureus is, in limited populations, a commensal bacterium that neither harms nor helps the body. When colonies grow, the bacteria can cause skin, blood, lung, heart valve, brain, and bone infections. Many strains are resistant to treatment with common antibiotics. Bunches of cocci.
What are the risk factors for Staphylococcus aureus?
Tattoo shops, hospitals, body piercing shops, and injected home medications such as insulin are all risk factors. A Staphylococcus aureus infection of the skin can enter the bloodstream and colonize in other areas; skin symptoms must be promptly treated.
What is the chance of S. aureus bacteriuria?
When S. aureus bacteriuria is diagnosed, the chance is high that this is the result of staphylococcal bacteremia. If the bacteria are found in the urine, it is more than probable that the blood is infected and immediate treatment is required.
How can S. aureus be passed on?
Bacteria can be passed on through direct contact with infected people or when in contact with medical staff that unconsciously transmit S. aureus bacteria from instruments and patients to new hosts (cross-infection). Typical signs of an S. aureus skin infection are even possible when the skin is punctured by a fine needle.
Which type of bacteremia is most likely to cause death?
Septicemia (blood poisoning) is also the result of the toxins produced by all types of bacteria, but S. aureus bacteremia is the most likely to cause death. Bacteremia describes the presence of bacteria in the bloodstream. The toxins they release makes the blood vessel walls leak; this means that the circulatory system becomes much less efficient.
Is S. aureus a bacterial colony?
If conditions suit staphylococci and do not suit the other types of commensal bacteria, S. aureus will colonize the area. In this case, it is an opportunistic bacterial ...
Does S. aureus die in higher temperatures?
This allows the bacteria to grow and increases areas of tissue necrosis (death). Other factors help S. aureus to successfully multiply – the bacteria are often resistant to antibiotics, they can live in the presence of oxygen (aerobic) or without (anaerobic), and they do not die in higher temperatures.
What is the cause of Staphylococcus aureus?
Staphylococcus aureus is a bacterium that causes staphylococcal food poisoning, a form of gastroenteritis with rapid onset of symptoms. S. aureus is commonly found in the environment (soil, water and air) and is also found in the nose and on the skin of humans.
What are the factors that affect the growth of S. aureus?
The growth and survival of S. aureus is dependent on a number of environmental factors such as temperature, water activity (aw), pH, the presence of oxygen and composition of the food (refer to Table 1). These physical growth parameters vary for different S. aureus strains (Stewart 2003).
Is S. aureus a Gram positive bacterium?
S. aureus is a Gram-positive, non-spore forming spherical bacterium that belongs to the Staphylococcus genus. The Staphylococcus genus is subdivided into 32 species and subspecies. S. aureus produces staphylococcal enterotoxin (SE) and is responsible for almost all staphylococcal food poisoning (Montville and Matthews 2008; FDA 2012).
Is staphylococcus spp. a food poisoning?
All people are believed to be susceptible to staphylococcal food poisoning. However, the severity of symptoms may vary depending on the amount of SE consumed in the food and the general health of individuals. The young and elderly are more likely to develop more serious symptoms (FDA 2012).
What is the most pathogenic organism in the genus Staphylococcus?
Bacteria in the genus Staphylococcus are pathogens of man and other mammals. Traditionally they were divided into two groups on the basis of their ability to clot blood plasma (the coagulase reaction). The coagulase-positive staphylococci constitute the most pathogenic species S aureus.
Which is the most pathogenic species?
The coagulase-positive staphylococci constitute the most pathogenic species S aureus. The coagulase-negative staphylococci (CNS) are now known to comprise over 30 other species. The CNS are common commensals of skin, although some species can cause infections.
Is coagulase a virulence factor?
Coagulase is a marker for S aureus but there is no direct evidence that it is a virulence factor. Also, some natural isolates of S aureus are defective in coagulase. Nevertheless, the term is still in widespread use among clinical microbiologists.
Overview
Staphylococcus aureus is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive for catalase and nitrate reduction and is a facultative anaerobe that can grow without the need for oxygen. Although S. aureus usually acts as a commensal o…
History
In 1880, Alexander Ogston, a Scottish surgeon, discovered that Staphylococcus can cause wound infections after noticing groups of bacteria in pus from a surgical abscess during a procedure he was performing. He named it Staphylococcus after its clustered appearance evident under a microscope. Then, in 1884, German scientist Friedrich Julius Rosenbach identified Staphylococcus aureus, discriminating and separating it from Staphylococcus albus, a related bacterium. In the e…
Microbiology
S. aureus (/ˌstæfɪləˈkɒkəs ˈɔːriəs, -loʊ-/, Greek σταφυλόκοκκος, "grape-cluster berry", Latin aureus, "golden") is a facultative aerobic, Gram-positive coccal (round) bacterium also known as "golden staph" and "oro staphira". S. aureus is nonmotile and does not form spores. In medical literature, the bacterium is often referred to as S. aureus, Staph aureus or Staph a.. S. aureus appears as staphy…
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".
Role in disease
While S. aureus usually acts as a commensal bacterium, asymptomatically colonizing about 30% of the human population, it can sometimes cause disease. In particular, S. aureus is one of the most common causes of bacteremia and infective endocarditis. Additionally, it can cause various skin and soft-tissue infections, particularly when skin or mucosal barriers have been breached.
Virulence factors
S. aureus produces various enzymes such as coagulase (bound and free coagulases) which facilitates the conversion of fibrinogen to fibrin to cause clots which is important in skin infections. Hyaluronidase (also known as spreading factor) breaks down hyaluronic acid and helps in spreading it. Deoxyribonuclease, which breaks down the DNA, protects S. aureus from neutr…
Classical diagnosis
Depending upon the type of infection present, an appropriate specimen is obtained accordingly and sent to the laboratory for definitive identification by using biochemical or enzyme-based tests. A Gram stain is first performed to guide the way, which should show typical Gram-positive bacteria, cocci, in clusters. Second, the isolate is cultured on mannitol salt agar, which is a select…
Treatment
For susceptible strains, the treatment of choice for S. aureus infection is penicillin. An antibiotic derived from some Penicillium fungal species, penicillin inhibits the formation of peptidoglycan cross-linkages that provide the rigidity and strength in a bacterial cell wall. The four-membered β-lactam ring of penicillin is bound to enzyme DD-transpeptidase, an enzyme that when functio…