Where is the mecA gene located?
Penicillin binding protein (PBP) 2′ is the most important mechanism of the resistance to beta-lactams in methicillin-resistant Staphylococcus aureus (MRSA). And the mecA gene is the coding gene of PBP2′, and located in the SmaI fragment G of the chromosome map by Pattle P.A.,.
What is the role of mecA in MRSA?
mecA is a gene found in bacterial cells which allows them to be resistant to antibiotics such as methicillin, penicillin and other penicillin-like antibiotics. The bacteria strain most commonly known to carry mecA is methicillin-resistant Staphylococcus aureus (MRSA).
What resistance is mediated by the mecA gene?
Methicillin resistance results from the production of an alternative penicillin-binding protein, PBP2A (or PBP2′), encoded by the mecA gene on the staphylococcal cassette chromosome mec (SCCmec), a mobile genetic element, supposedly acquired through horizontal gene transfer from CoNS (Table 176-4).
Does the presence of the mecA gene confirm MRSA?
MRSA is resistant to all β-lactams because of the presence of mecA, a gene that produces a pencillin binding protein (PBP2a) with low affinity for β-lactam antibiotics.
What gene causes MRSA?
Genetic studies for MRSA identified structural genes responsible for methicillin resistance and it is known as mecA genes, also referred to as the staphylococcal chromosomal cassette gene SCCmec. There are three common types of SCCmecA, type I (34 kb), type II (52 kb), and type III (66 kb).
What bacteria does linezolid cover?
Linezolid is active against most Gram-positive bacteria that cause disease, including streptococci, vancomycin-resistant enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA).
Is oxacillin a penicillin?
Oxacillin is a penicillin antibiotic that fights bacteria in the body. Oxacillin is used to treat many different types of infections caused by staphylococcus (also called “staph” infection). Oxacillin may also be used for purposes not listed in this medication guide.
Is methicillin still used?
Methicillin was the first semisynthetic penicillinase-resistant penicillin. It has been withdrawn from the market in the United States because of the high incidence of interstitial nephritis associated with its use.
What is cassette chromosome?
Staphylococcal Cassette Chromosome mec Types. SCCmec is a mobile genetic element that carries mecA (methicillin-resistant gene) and other functional genes. Zong et al. (9) stated that SCCmec contains the following two essential components: the mec gene complex and the ccr gene complex.
How does mecA gene confer resistance?
The mecA determinant encodes an extra penicillin-binding protein (PBP2a). The expression of resistance is achieved by a slow rate of acylation of PBP2a as well as a low affinity of the enzyme for β-lactams [6].
Is MRSA inherited?
Scientists have found that genetic mutations in MRSA allow it to evolve and become more resistant to antibiotics such as penicillin. Scientists from the University of Sheffield have found that genetic mutations in MRSA allow it to evolve and become more resistant to antibiotics such as penicillin.
What is a chromosomal cassette?
A gene cassette is a type of mobile genetic element that contains a gene and a recombination site. Each cassette usually contains a single gene and tends to be very small; on the order of 500–1000 base pairs. They may exist incorporated into an integron or freely as circular DNA.