Peptostreptococcus anaerobius VPI 4330-1 was tested under various conditions for examination of the bactericidal effect of hydrogen peroxide. The cells were most rapidly killed by hydrogen peroxide when they were in the exponential-growth phase. Cooling or starving the cells decreased the bactericidal effect of hydrogen peroxide. The ionophore nigericin and the metal ion chelating agent 2,2'-bi...

The serum bactericidal test represents one of the few in vitro tests performed in the clinical microbiology laboratory that combines the interaction of the pathogen, the antimicrobial agent, and the patient. Although the use of such a test antedates the antimicrobial era, its performance, results, and interpretation have been subject to question and controversy. Much of the confusion concerning...

All extract of polymorphonuclear leucocytes of the rat, prepared by means of ultrasonic vibration, was found to be bactericidal against M. aureus. The bactericidal activity was primarily confined to the mitochondrial fraction of the leucocytes. The rat leucocyte mitochondrial extract was bactericidal against both Gram-positive (M. aureus, beta-Streptococci, Diplococcus pneumoniae, Corynebacteri...

The initial bactericidal activity of quinolones against Streptococcus pneumoniae at the concentration equivalent to their respective peak serum concentration (C(max)) and free drug fraction of C(max) (fC(max)) were investigated. The bactericidal activity of sitafloxacin (STFX), levofloxacin (LVFX), moxifloxacin (MFLX), and garenoxacin (GRNX) were compared by determining the actual killing of ba...

The Bordetella pertussis BrkA protein protects against the bactericidal activity of complement and antibody; however, some individuals mount an immune response that overcomes this bacterial defense. To further characterize this process, the bactericidal activities of sera from 13 adults with different modes of exposure to B. pertussis (infected as adults, occupational exposure, immunized with a...

The bactericidal effects of chloramphenicol and three beta-lactams (ampicillin, cefamandole, and penicillin G) were measured for 27 strains of Haemophilus influenzae type b isolated from the blood or cerebrospinal fluid of infected infants. Of the ampicillin-susceptible strains, 75% were killed by less than 2.0 micrograms of each antibiotic per ml; however, the concentration of the beta-lactam ...

In addition to Ag recognition, some Abs are capable of killing target organisms in the absence of phagocytes and complement. In this study, we report that an anti-Pseudomonas aeruginosa O6ad LPS IgG(1), tobacco-expressed human S20 IgG(1) (te-hS20), as well as its recombinant Fab and single-chain variable fragment (scFv) fragments have cellular- and complement-independent bactericidal activity. ...

In the preceding paper (1), it was reported that rat leucocyfic extracts prepared by ultrasonic disintegration of polymorphonuclear neutrophils (leucocytes) were bactericidal against both Gram-negative and Gram-positive organisms. The bactericidal activity of these extracts was confined primarily to the mitochondria. The purpose of this report is to characterize this bactericidal substance or s...

Of five parenteral cephalosporins tested against 43 lactobacilli, cephaloridine, cefazolin, and cefamandole were the most active inhibitory and bactericidal agents. Timed-kill analysis revealed a slow bactericidal effect, with significant declines in mean minimal bactericidal concentration values at 48 h versus 24 h.