Streptomyces rubellomurinus produces an antibiotic possessing Gram-negative antibacterial ac-tivity1) with the chemical structure given in Fig. 1-A. FR-31564, a synthetic analog with the structure shown in Fig. 1-B, is superior in antibacterial activity to its parent compound2). This paper presents a laboratory assessment of the antimicrobial activities, in vitro and in vivo, of FR-31564. Materials and Methods Organism S. aureus 209P JC-1 S. epidermidis 1 B. subtilis ATCC 6633 M. luteus PCI-1001 S. pyogenes S-23a) S. faecalis 6783a) N. gonorrhoeae Okab) E. coli NIHJ JC-2 E. coli 18 K. pneumoniae NCTC-418 C. freundii 3 E. aerogenes 10 E. cloacae 4 S. ntarcescens 4 P. mirabilis 75 P. vulgaris IAM
The effect of antibiotics on phagocytosis and killing of Pseudomonas aeruginosa by rabbit polymorphonuclear leukocytes was studied. Carbenicillin and sulbenicillin, when added to an incubation medium at a concentration as low as 1/16 MIC, increased phagocytosis and killing of P. aeruginosa by PMN. Meanwhile, gentamicin and 3’,4’-dideoxykanamycin B gave no influence on the PMN activity, and polymyxin B and colistin enhanced the activity only at MIC. The PMN activity was not facilitated even when the cells of P. aeruginosa had been pretreated with antibiotics. The bactericidal activity of PMN decreased after sonification, but was restored following addition of carbenicillin.
Nocardicin A is a new monocyclic B-lactam antibiotic which provides a potent therapeutic effect in mice experimentally infected with gram-negative bacilli. When given subcutaneously
The polymorphonuclear leukocyte (PMN) inhibitor isolated from a strain of Pseudomonas aeruginosa which is resistant to the phagocytic and killing activities of rabbit PMN inhibited migration of PMN and engulfment of latex particles by PMN. In studies of the bactericidal metabolism of PMN, the PMN inhibitor did not inhibit the intracellular activity and extracellular release of lysosomal enzymes. However, the PMN inhibitor caused a decrease of Nitro Blue Tetrazolium reduction. The PMN inhibitor had a cytotoxic effect on PMN and inhibited [14C]tyrosine uptake in intact PMN inhibitor had no inhibitory effect on protein synthesis in cell extracts.
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