The heterogeneous expression of methicillin resistance in Staphylococcus aureus affects the efficiency of tests available to detect it. Not all laboratories have access to accurate molecular tests used for this purpose. This study compares the performances of four phenotypic tests used to detect methicillin resistant S. aureus (MRSA) with the mecA gene polymerase chain reaction. Two hundred thi...

We assessed the extent and mechanisms of antagonism of beta-lactam antibiotics by cefoxitin. In tests with 41 gram-negative isolates, cefoxitin antagonized cephalothin, cefamandole, cefsulodin, cefotaxime, moxalactam, ampicillin, carbenicillin, piperacillin, mezlocillin, and azlocillin, but not cephalexin, mecillinam, or N-formimidoyl thienamycin. The extent of antagonism varied with the beta-l...

To evaluate the effects of parenteral cefoxitin therapy on human fecal flora, we cultured fecal specimens obtained from six patients before, during, and after therapy and used standard methods to identify and quantify all microorganisms. The major changes (observed in at least three patients) included the acquisition or proliferation of group D Streptococcus species, coagulase-negative Staphylo...

Susceptibility testing with the use of surrogate agents is common among clinical microbiology laboratories. One such example is oxacillin and cefoxitin for β-lactams against methicillin-susceptible Staphylococcus aureus (MSSA). This study aimed to assess the surrogate predictive value (SPV) of oxacillin and cefoxitin for the susceptibility of commonly utilized parenteral β-lactams against MSSA ...

A rapid, specific, and reproducible high-pressure liquid chromatographic method was developed for the determination of cefoperazone concentration in serum and tissue. The assay uses a simple methanol extraction, with cefoxitin as the internal standard. The limits of detection are 1 to 150 micrograms/ml; the maximum coefficient of variation is 7.4%. Using the same chromatography column, muBondap...

We studied the prevalence of methicillin sensitive Staphylococcus aureus (MSSA) and methicillin resistant Staphylococcus aureus (MRSA) nasal colonization among healthy young Thai adults. MSSA nasal colonization was found in 30 of 200 subjects (15%). The prevalence of MRSAnasal carriage was 1% (2 of 200) detected by cefoxitin/oxacillin disk diffusion and oxacillin salt screening methods. These c...

Background: Staphylococcus aureus is commonly found in dairy cows and a source of contamination milk. S. aureus that are resistant to beta-lactam antibiotics (especially cefoxitin) referred as methicillin-resistant Staphylococcus (MRSA). The spread MRSA cannot be separated from sanitation mana...

The minimum inhibitory concentrations of penicillin and cephalothin necessary to inhibit growth of most anaerobic bacteria were reduced to a susceptible level by 1 to 5 mug of clavulanic acid per ml. In most cases, minimum inhibitory concentrations of cefoxitin were not affected.

Gas-Liquid chromatography (GLC) was used to detect the presence of isocaproic acid produced by Clostridium difficile from 54 stool samples grown in cycloserine-cefoxitin broth. Isocaproic acid was detected in 12 samples of which 5 were confirmed to be Clostridium difficile by culture and biochemical tests. The detection of isocaproic acid by GLC together with the presence of presumptive colonie...

Background: Methicillin resistant Staphylococcus aureus (MRSA) has been emerged as a nosocomial and community acquired pathogen worldwide. There are many challenges for laboratory detection of MRSA. The aim of this study was to compare different phenotypic methods with PCR based method as a gold standard for detection of mecA gene. <b...