Microbiology Tech Info

  Overview Vancomycin-resistant enterococcus (VRE) refers to strains of enterococcal bacteria that have developed resistance to the antibiotic vancomycin. Enterococci are bacteria that are commonly found in the human gastrointestinal tract and are also found in the environment. While most enterococcal infections can be treated with antibiotics, some strains have become resistant to multiple drugs, including vancomycin. Vancomycin is an antibiotic that is often used to treat serious infections, particularly those caused by Gram-positive bacteria. When enterococci become resistant to vancomycin, it limits the treatment options for infections caused by these bacteria, making them more challenging to manage. Types of VRE: There are two main species of enterococci that are commonly associated with vancomycin resistance: Enterococcus faecium: This species is more commonly associated with vancomycin resistance than Enterococcus faecalis. Vancomycin-resistant Enterococcus faecium

  Principle Urease is an enzyme possessed by many Mycobacterium species that can hydrolyze urea to form ammonia and carbon dioxide. The ammonia reacts in solution to form ammonium carbonate, resulting in alkalinisation and an increase in the pH of the medium. Specimen Type of Specimen Mature colony of the unknown Mycobacterium species recovered from clinical material, grown on a Lowenstein–Jensen slant. Materials Equipment Biologic safety hood   37°C incubator Medium Urea Broth Preparation Add 10 g of Difco (Detroit, MI) Bacto urea agar base concentrate to 90 mL of sterile deionized water. Mix well to dissolve. Aseptically aliquot 3.0 mL portions into sterile screw-capped test tubes. Store at 2°C–8°C; shelf life is 1 month.   Quality Control Positive control: M. kansasii American Type Culture Collection (ATCC) 12478 Negative control: M. avium/M. intracellulare ATCC 13950 Procedure Inoculate each substrate tube with a loopful of growth from an acti

  Purpose: Screening and confirmation of the mecA gene are essential steps in the detection of methicillin-resistant Staphylococcus aureus (MRSA), a bacterium that is resistant to many commonly used antibiotics, including methicillin. The mecA gene is involved in resistance to beta-lactamases by methicillin-resistance in Staphylococcus aureus. Principle:   The mecA gene is a gene found in bacterial cells. The most commonly known carrier of the mecA gene is the bacterium known as MRSA. The mecA gene allows a bacterium to be resistant to antibiotics such as Methicillin, Penicillin and other penicillin-like antibiotics. The mecA gene does not allow the ring like structure of penicillin-like antibiotics to attack the enzymes that help form the cell wall of the bacterium (transpeptidases), and hence the bacteria is allowed to replicate as normal. The mecA gene encodes the protein PBP2A (Penicillin binding protein 2A). PBP2A has a low affinity for beta-lactams such as Methicillin, Penic