Methicillin-Resistant Staphyloccus Aureus
Molecular Characterization of Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal Colonization and Infection Isolates in a Veterans Affairs Hospital Staphylococcus aureus (S. aureus) belongs to the genus Staphylococcus. It is Gram-positive, cocci shaped anaerobic bacteria that forms clusters and produces catalase, which catalyzes hydrogen peroxide to water and oxygen. It contains a cell wall structure (including peptidoglycan and teichoic acid) and a low G + C content of DNA between 30-40 mol %. (Bauman, R., & Masuoka, E. (2015). Microbiology: With diseases by body system (4th ed.). San Francisco: Pearson Benjamin Cummings. According to Chang (2008), Staphylococcus includes 40 different species. Most are harmless and reside on the skin
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The objective was to compare molecular and phenotypic characteristics between colonization and clinical isolates according to population and individual levels, and markers that could be indicatory of livestock origin. Samples were collected from patients through routine nasal cultures; patient wound sites, and bodily fluids. During the time of screening, all patients were screened for MRSA upon hospital admission, unit transfer, and discharge. According to Kolendi (2010) mecA , a gene found in bacterial cells, allows bacteria to be resistant to certain antibiotics. The mecA gene does not allow the ring-like structure of penicillin-like antibiotics to bind to enzymes that help form the cell wall of bacterium (transpeptidases), so the bacteria continues to replicate normally. The gene encodes the protein known as PBP2A (penicillin-binding protein 2A). PBP2A has a low affinity for beta-lactam antibiotics, such as penicillin and methicillin. This action enables transpeptidase in the prescence of beta-lactams. It prevents inhibiting cell wall synthesis. MRSA is the greatest carrier of mecA gene, and therefore this isolate was given preference for testing. The samples obtained were collected on blood agar plates and then further tested for MRSA on polymerase chain reaction (PCR). MRSA samples were stored at -80 degrees at ICVAHCS until September 2013. All the samples that tested positive for the mecA gene, they were re-tested for confirmation. (Eko, K., Forshey, B., Carrel, M., Schweizer, M., Perencevich, E., & Smith, T. (2015). Molecular characterization of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization and infection isolates in a Veterans Affairs hospital. Antimicrob Resist Infect Antimicrobial Resistance and Infection Control. ) For molecular testing genomic DNA was
The objective was to compare molecular and phenotypic characteristics between colonization and clinical isolates according to population and individual levels, and markers that could be indicatory of livestock origin. Samples were collected from patients through routine nasal cultures; patient wound sites, and bodily fluids. During the time of screening, all patients were screened for MRSA upon hospital admission, unit transfer, and discharge. According to Kolendi (2010) mecA , a gene found in bacterial cells, allows bacteria to be resistant to certain antibiotics. The mecA gene does not allow the ring-like structure of penicillin-like antibiotics to bind to enzymes that help form the cell wall of bacterium (transpeptidases), so the bacteria continues to replicate normally. The gene encodes the protein known as PBP2A (penicillin-binding protein 2A). PBP2A has a low affinity for beta-lactam antibiotics, such as penicillin and methicillin. This action enables transpeptidase in the prescence of beta-lactams. It prevents inhibiting cell wall synthesis. MRSA is the greatest carrier of mecA gene, and therefore this isolate was given preference for testing. The samples obtained were collected on blood agar plates and then further tested for MRSA on polymerase chain reaction (PCR). MRSA samples were stored at -80 degrees at ICVAHCS until September 2013. All the samples that tested positive for the mecA gene, they were re-tested for confirmation. (Eko, K., Forshey, B., Carrel, M., Schweizer, M., Perencevich, E., & Smith, T. (2015). Molecular characterization of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization and infection isolates in a Veterans Affairs hospital. Antimicrob Resist Infect Antimicrobial Resistance and Infection Control. ) For molecular testing genomic DNA was