Staphylococci correspond to a group of gram-positive bacteria that have a round shape, are found grouped in clusters, similar to a bunch of grapes and the genus is called Staphylococcus .
These bacteria are naturally present in people without any sign of illness. However, when the immune system is poorly developed, as in the case of newborns, or is weakened, due to chemotherapy treatment or old age, for example, Staphylococcus bacteria can enter the body and cause disease.
Main species
Staphylococci are small, immobile bacteria arranged in clusters and can be found naturally in people, especially on the skin and mucous membranes, not causing any type of disease. Most staph species are facultative anaerobic, that is, they are able to grow in an environment with or without oxygen.
Staphylococcus species can be classified into two groups according to the presence or absence of the coagulase enzyme. Thus, species that have the enzyme are called positive coagulase, with Staphylococcus aureus being the only species in this group, and species that do not have these are called coagulase negative staphylococci, whose main species are Staphylococcus epidermidis and Staphylococcus saprophyticus .
1. Staphylococcus aureus
Staphylococcus aureus , or S. aureus , is a species of staphylococcus normally found on people's skin and mucous membranes, especially in their mouth and nose, causing no disease. However, when the immune system is weakened, S. aureus can enter the body and cause infections that can be mild, such as folliculitis, or severe, such as sepsis, for example, which can put a person's life at risk. Find out what diseases are caused by S. aureus .
This bacterium can also be easily found in a hospital environment, and can cause serious infections that are difficult to treat due to the acquired resistance of the microorganism to various antibiotics.
Staphylococcus aureus can enter the body through injuries or needles, especially in the case of hospitalized people, who use injectable drugs or who need to take penicillin injections regularly, for example, but it can also be transmitted from person to person through the direct contact or through air droplets present from coughing and sneezing.
Staphylococcus aureus infection is identified through microbiological tests that can be performed on any material, that is, wound secretion, urine, saliva or blood. In addition, the identification of S. aureus can be done through coagulase, since it is the only species of Staphylococcus that has this enzyme, and is therefore called positive coagulase.
Main symptoms: The symptoms of S. aureus infection vary according to the type of infection, form of infection and condition of the person. Thus, there may be pain, redness and swelling in the skin, when the bacteria proliferates on the skin, or high fever, muscle pain, headache and general malaise, which is usually indicative that the bacteria is present in the blood.
How the treatment is done: The treatment of Staphylococcus aureus infection varies according to your sensitivity profile to antimicrobials, which may vary according to the person and the hospital you are in, if this is the case. In addition, the doctor takes into account the patient's health status and the symptoms presented by the patient, in addition to other infections that may exist. Usually the doctor recommends using Methicillin, Vancomycin or Oxacillin for 7 to 10 days.
2. Staphylococcus epidermidis
Staphylococcus epidermidis or S. epidermidis , like S. aureus , is normally present on the skin, not causing any type of infection. However, S. epidermidis can be considered opportunistic, since it is capable of causing disease when the immune system is weakened or underdeveloped, as in the case of newborns, for example.
S. epidermidis is one of the main microorganisms isolated in hospitalized patients, since it is naturally present in the skin, and its isolation is often considered as contamination of the sample. However, S. epidermidis has been linked to a large number of infections in the hospital environment due to its ability to colonize intravascular devices, large wounds, prostheses and heart valves, and can be associated with sepsis and endocarditis, for example.
The ability to colonize medical equipment makes this microorganism resistant to several antibiotics, which can make the treatment of the infection more complicated and put the person's life at risk.
Confirmation of infection by S. epidermidis occurs when two or more blood cultures are positive for this microorganism. In addition, it is possible to differentiate S. aureus from S. epidermidis through the coagulase test, in which Staphylococcus epidermidis does not have the enzyme, being called negative coagulase. Understand how Staphylococcus epidermidis is identified .
Main symptoms: Symptoms of Staphylococcus epidermidis infection usually only appear when the bacteria is in the bloodstream, with a high fever, headache, malaise, shortness of breath or difficulty in breathing and low blood pressure, for example.. Here's how to identify symptoms of blood infection.
How the treatment is done: The treatment of infection by S. epidermidis varies according to the type of infection and characteristics of the isolated microorganism. In case the infection is related to the colonization of medical devices, for example, the replacement of the devices is indicated, thus eliminating the bacteria.
When the infection is confirmed, the doctor may also indicate the use of antibiotics, such as Vancomycin and Rifampicin, for example.
3. Staphylococcus saprophyticus
Staphylococcus saprophyticus , or S. saprophyticus , as well as S. epidermidis , is considered a coagulase negative staphylococcus, requiring further tests to differentiate these two species, such as the novobiocin test, which is an antibiotic that S. saprophyticus is normally resistant and S. epidermidis is sensitive.
This bacteria can be found naturally on the skin and genital area, causing no symptoms. However, when there is an imbalance in the genital microbiota, S. saprophyticus can cause urinary tract infection, especially in women, since this bacterium is able to adhere to the cells of the urinary system of women of reproductive age.
Main symptoms: The symptoms of S. saprophyticus infection are the same as those of a urinary tract infection, with pain and difficulty in urinating, cloudy urine, feeling of not being able to empty the bladder and persistent low fever, for example. Learn how to recognize the symptoms of urinary tract infection.
How the treatment is done: The treatment of infection by S. saprophyticus is done with the use of antibiotics, such as Trimethoprim. However, treatment with antibiotics should only be indicated by the doctor in the presence of symptoms, otherwise it may favor the emergence of resistant bacteria.
