To investigate the contribution of LamB in Klebsiella pneumoniae antimicrobial resistance, we determined the MICs of various antibiotics and the frequency of mutation to increased cefoxitin or meropenem resistance of the strains CSUB10S (expressing only OmpK36), CSUB10R (lacking OmpK35 and OmpK36), and their derived isogenic insertion-duplication mutants deficient in LamB. Expression of LamB wa...

The recovery of Clostridium difficile on a medium containing cefoxitin, cycloserine, fructose, and egg yolk was compared with that on media containing one of three preparations of sodium taurocholate. In aerobic environments contaminated with C. difficile, media containing either crude taurocholate from Mann Research Laboratories, New York, N.Y., or pure taurocholate from Sigma Chemical Co., St...

The in vitro activity of cefmetazole versus that of other antimicrobial drugs was assessed against 374 clinical isolates of Bacteroides spp., Clostridium spp., and anaerobic gram-positive cocci. Compared with cefoxitin, cefmetazole showed good activity against Bacteroides fragilis, other Bacteroides species, and anaerobic cocci. It was somewhat less active than cefoxitin against Bacteroides the...

Minimum inhibitory concentrations of ceftizoxime for seven clinical isolates of Bacteroides fragilis were found to be markedly affected by inoculum size; the very low minimum inhibitory concentration values (less than or equal to 0.25 microgram/ml) obtained in tests with most strains were not sustained when the inoculum was raised 100-fold. Benzylpenicillin and cephalothin were also affected by...

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 ...

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...

Three consecutive doses of 75 mg of cefoxitin per kg were given intravenously every 6 h (225 mg/kg), in addition to penicillin or ampicillin, to 24 patients on days 4 and 5 and 9 and 10 of therapy for meningitis. Haemophilus influenzae b was isolated from cerebrospinal fluid (CSF) of 21 patients, Streptococcus pneumoniae from 2 patients, and Neisseria meningitidis from 1 patient. The median min...

BACKGROUND AND OBJECTIVES Methicillin-resistant Staphylococcus aureus (MRSA) is a well-known pathogen with a worldwide distribution. Given the increasing rate of MRSA infections, implementing of reliable, accurate and rapid testing for diagnosis of MRSA is necessary. The aim of this study was to compare four diagnostic methods for detection of MRSA isolates. MATERIALS AND METHODS From Decembe...

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...