Antibacterial activity of cefuroxime, a new cephalosporin antibiotic, compared with that of cephaloridine, cephalothin, and cefamandole. (33/313)

The in vitro activity of cefuroxime, a new cephalosporin derivative, was compared with that of cephaloridine, cephalothin, and cefamandole against strains of gram-positive and gram-negative bacteria recently isolated from clinical sources. Cefuroxime showed very similar activity to cefamandole against Staphylococcus aureus, Haemophilus influenzae, and most members of the Enterobacteriaceae. It was more active than cefamandole against gonococci, pneumococci, and most streptococci. Increasing the inoculum size appeared to have less effect on the minimum inhibitory concentrations of cefuroxime for gram-negative bacilli than has been found with the other cephalosporin derivatives, and minimum bactericidal concentrations of cefuroxime were only marginally greater than minimum inhibitory concentrations.  (+info)

Comparison of phlebitis produced by cephapirin and cephalothin. (34/313)

In a single-blinded study involving 120 patients neither the incidence nor severity of phlebitis observed with cephapirin and cephalothin was significantly different.  (+info)

Dependence of hydrolysis of beta-lactams with a zinc(II)-beta-lactamase produced from Serratia marcescens (IMP-1) on pH and concentration of zinc(II) ion: dissociation of Zn(II) from IMP-1 in acidic medium. (35/313)

The pH dependence for the hydrolysis of beta-lactam antibiotics by a metallo-beta-lactamase (IMP-1) produced from Serratia marcescens was investigated varying the concentration of Zn(II). The activity of IMP-1 for imipenem was decreased at pH less than pH 5.3 without external addition of Zn(II) ions but was recovered with addition of Zn(II). Varying the concentration of external Zn(II), the molar activity of the enzyme, k(obs), that was defined by the velocity of hydrolysis of imipenem/concentration of IMP-1 was expressed by k(obs)=v(init)/[E](T)=k(max)[Zn]/(K(d)+[Zn]) in which K(d) stands for the dissociation constant between Zn(II) and IMP-1. The dissociation constants, K(d), vary with pH; K(d)=840 x 10(-6) M at pH 4.3 and K(d)=0.19 x 10(-6) M at pH 6.0. The plot of -log K(d) against pH showed a straight line having a slope of 4.0 below pH 5.0, showing the existence of four functional groups which may be protonated upon dissociation of Zn(II) ion(s). The k(cat), K(m), and k(cat)/K(m) of hydrolysis of imipenem and cephalothin in the presence of sufficient concentration of Zn(NO(3))(2) for saturation of IMP-1 with Zn(II) showed similar dependency to each other on pH between pH 6.0 and 9.0.  (+info)

Beta-Lactamase activity in strains of Bacteroides melaninogenicus and Bacteroides oralis. (36/313)

beta-Lactamase from strains of Bacteroides melaninogenicus and Bacteroides oralis hydrolyzed penicillin more rapidly than ampicillin or carbenicillin. Cephalothin and a chromogenic cephalosporin (87/312) were also hydrolyzed by the enzyme. Activity was found only in beta-lactam-resistant strains, but there was considerable variation in activity among strains having the same minimal inhibitory concentrations of antibiotic. beta-Lactamase activity was cell bound and appeared to be tightly associated with the cell envelope since detergents were required to elute this activity.  (+info)

INDUCTION BY ANTIBIOTICS AND COMPARATIVE SENSITIVITY OF L-PHASE VARIANTS OF STAPHYLOCOCCUS AUREUS. (37/313)

Molander, C. W. (Cedars of Lebanon-Mount Sinai Hospitals, Los Angeles, Calif.), B. M. Kagan, H. J. Weinberger, E. M. Heimlich, and R. J. Busser. Induction by antibiotics and comparative sensitivity of L-phase variants of Staphylococcus aureus. J. Bacteriol. 88:591-594. 1964.-The penicillins, cephalothin, vancomycin, and bacitracin were found to be less inhibitory to the L-phase variants than to their respective parent bacteria. Those antibiotics not considered to be primarily inhibitors of cell-wall synthesis were, in general, somewhat more inhibitory to the L form than to their parent bacteria. Only the penicillins and cephalothin readily induced L-phase variation. Novobiocin induced pleomorphic growth resembling the earliest stages of L-phase transformation. Failure of observable induction by bacitracin and vancomycin suggests that these two antibiotics affect cell-wall synthesis in a manner different from the penicillins, or that L-phase transformation may require more than "penicillin-like" interference with cell-wall synthesis.  (+info)

MORPHOLOGICAL CHANGES IN GRAM-NEGATIVE BACILLI EXPOSED TO CEPHALOTHIN. (38/313)

Chang, Te-Wen (Tufts University School of Medicine, Boston, Mass.), and Louis Weinstein. Morphological changes in gram-negative bacilli exposed to cephalothin. J. Bacteriol. 88:1790-1797. 1964.-Exposure of gram-negative bacteria to cephalothin (7-[thiophene-2-acetamido]-cephalosporanic acid) revealed the formation of long filaments and large bodies, which were capable of reverting to normal cells when removed from contact with the drug. The degree of morphological change was found to be related to the concentration of antibiotic in which the organisms were suspended. The large bodies were altered by contact with solutions of varying osmolarity. Different species showed variation in the ability to develop large bodies. A relationship between antibiotic sensitivity and the capacity to resist morphological alteration was observed. Though most sensitive gram-negative bacilli were strikingly changed by exposure to cephalothin, naturally resistant ones were unaffected. Organisms made drug-resistant in vitro underwent changes in cellular form which were qualitatively the same but less intense than those which developed in parent strains originally sensitive to cephalothin.  (+info)

MICROBIOLOGICAL ACTIVITIES OF LYSOSTAPHIN AND PENICILLINS AGAINST BACTERIOPHAGE 80/81 STRAINS OF STAPHYLOCOCCUS AUREUS. (39/313)

Using 20 clinical isolates of S. aureus (all bacteriophage 80/81 type), we found that lysostaphin inhibits the growth of all cultures at concentrations significantly lower than those observed with any of eight penicillins, a penicillin-like compound (cephalothin), or fusidic acid (a steroid antibiotic). All test cultures were shown to be resistant to penicillin G, ampicillin, and propicillin. Of the remaining penicillins (all penicillinase-insensitive), oxacillin, nafcillin, cloxacillin, and cephalothin were approximately equal in antimicrobial activity. Ancillin was slightly less active, and methicillin was even lower in potency. Cultures varied more widely in susceptibility to fusidic acid. None of the clinical isolates tested was found to be resistant to lysostaphin.  (+info)

IN VITRO AND IN VIVO LABORATORY EVALUATION OF CEPHALOGLYCIN AND CEPHALORIDINE. (40/313)

Two new antibiotics, structurally related to cephalothin, have been given the generic names cephaloglycin and cephaloridine. Cephaloglycin is the dipolar ion of 7-(d-alpha-aminophenylacetamido)-cephalosporanic acid. Cephaloridine is 7-[alpha-(2-thiophene)acetamido]-3-(1-pyridylmethyl)-3-cephem-4-carboxylic acid betaine. These new compounds were evaluated simultaneously. The broad spectrum of activity observed in vitro and in vivo with both antibiotics, the good oral absorption obtained with cephaloglycin, and the stability of cephaloridine are emphasized. The data suggest that both antibiotics merit clinical trial in humans.  (+info)