Antimicrobial activities of thiolactomycin against gram-negative anaerobes associated with periodontal disease. f1.

Thiolactomycin (TLM), (4R)-(2E,5E)-2,4,6-trimethyl-3-hydroxy-2,5, 7-octatriene-4-thiolide, purified from a culture filtrate of a strain of the Nocardia species, was examined for antimicrobial activities against more than 100 strains of oral and periodontally associated bacteria. Nine other commonly used antibiotics were also included for the test. We found that TLM exhibited strong and selective antimicrobial activities against Bacteroides gingivalis and other oral black-pigmented Bacteroides species that may be etiologically associated with adult periodontitis. TLM also inhibited the growth of Actinobacillus actinomycetemcomitans, but did not affect the growth of oral streptococcal species and Eubacterium species. Strains of Eikenella corrodens were moderately susceptible to TLM, while Actinomyces viscosus strains were only slightly susceptible to it. Other antibiotics used for comparison showed a broad spectrum of antimicrobial activities in general. In conclusion, TLM exhibited highly selective antimicrobial activities to black-pigmented Bacteroides species and A. actinomycetemcomitans, both of which are implicated in the pathogenesis of human periodontal disease.

Semisynthetic beta-lactam antibiotics. III. Effect on antibacterial activity and comt-susceptibility of chlorine-introduction into the catechol nucleus of 6-[(R)-2-[3-(3,4-dihydroxybenzoyl)-3-(3-hydroxypropyl)-1-ureido]-2- phenylacetamido]penicillanic acid.

The resistance of 6-[(R)-2-[3-(3,4-dihydroxybenzoyl)-3-(3-hydroxypropyl)-1-ureido]-2- phenylacetamido]penicillanic acid (1a) to metabolism by catechol-O-methyl-transferase (COMT) was increased by introduction of the chlorine atom into the catechol moiety. Penicillins (1b-1d) having one or two chlorine atoms at the positions adjacent to the hydroxyl group were found to have greater stability to COMT. This resulted in greater efficiency in vivo in experimental Pseudomonas aeruginosa and Escherichia coli infections. In vitro activities were essentially unchanged.

Semisynthetic beta-lactam antibiotics. II. Effect on antibacterial activity of ureido N-substituents in the 6-[(R)-2-[3-(3,4-dihydroxybenzoyl)-1- ureido]-2-phenylacetamido]penicillanic acids.

The synthesis and the relationship between in vitro and in vivo activities of 6-[(R)-2-[3-(3,4-dihydroxybenzoyl)-3-R1-1-ureido]-2- phenylacetamido]penicillanic acids having C2 approximately 8 alkyl or substituted alkyl groups as the substituents (R1) are described. In this series, 6-[(R)-2-[3-(3,4-dihydroxybenzoyl)-3-(3-hydroxypropyl)-1-ureido] -2-phenylacetamido]penicillanic acid (1b, AO-1100) showed the most potent protective effect on mice in experimental Pseudomonas aeruginosa infections, although it did not have the strongest in vitro activity among the penicillins we synthesized.

Semisynthetic beta-lactam antibiotics. I. Synthesis and antibacterial activity of new ureidopenicillin derivatives having catechol moieties.

The synthesis and antibacterial activity of new ureidopenicillin derivatives having catechol moieties in the 6-acyl side chain are described. These compounds showed remarkably strong activities against Pseudomonas aeruginosa. Especially, 6-[(R)-2-[3-(3,4-dihydroxybenzoyl)-3-methyl-1-ureido]-2- phenylacetamido]penicillanic acid (7a) had the most potent activity in vitro against Gram-negative bacteria, its activity being 30 approximately 60-fold greater than that of piperacillin against most strains of P. aeruginosa.

Ceftezole, a new cephalosporin C derivative I. In vitro and in vivo antimicrobial activity.

Ceftezole, a new cephalosporin antibiotic similar to cefazolin, has the following chemical structure: (6R,7R)-8-oxo-7[2-(1H-tetrazol-1-yl)acetamido]-3-[(1,3,4-thiadiazol-2-ylthio)methyl]-5-thia-1-azabicyclo[4.2.0]oct-2-ene-carboxylic acid. Ceftezole was found to be a broad-spectrum antibiotic, active in vitro against many species of gram-positive and gram-negative bacteria except Pseudomonas aeruginosa, Serratia marcescens and Proteus vulgaris. The activity of ceftezole against clinical isolates of Escherichia coli and Klebsiella spp. appeared to be nearly equal to that of cefazolin and higher than those of cephaloridine and cephalothin. Cross-resistance was observed between ampicillin and cephaloridine, but not between ampicillin and ceftezole, in susceptibility tests on clinical isolates of P. mirabilis. The in vitro activity was little affected by the inoculum size, the presence of human serum or the test medium. Ceftezole exhibited apparent bactericidal activity at the concentrations above the minimum inhibitory concentration (MIC) against both S. aureus and E. coli. The development in vitro of resistance by S. aureus 209p and E. coli NIHJ to ceftezole after 16 transfers was similar to or somewhat slower than that to other drugs tested. Ceftezole was relatively stable in nutrient broth and minimally degraded in the serum or tissue homogenates of rats. Ceftezole, in a single subcutaneous administration, exhibited somewhat less efficacy in mice against intraperitoneal infections with Streptococcus pyogenes, S. pneumoniae, E. coli, K. pneumoniae or P. mirabilis than either cephaloridine or cefazolin. However, ceftezole exhibited efficacy similar to that of cephaloridine or cefazolin when administered in three doses. Furthermore, ceftezole was as effective as cefazolin in the treatment of experimental abscesses in mice caused by subcutaneous inoculation with S. aureus.

Ceftezole, a new cephalosporin C derivative II. Distribution and excretion in parenteral administration.

The distribution of ceftezole in blood and tissues and its excretion after intramuscular or intravenous administration of single doses of 10 and 20 mg/kg were compared with those of cefazolin, cephaloridine and cephalothin. Blood levels of ceftezole in rats and rabbits were lower than those of cefazolin, and higher than those of cephaloridine and cephalothin. Retention time of ceftezole in the blood was somewhat shorter than that of cefazolin. However, blood levels of ceftezole in dogs were nearly the same as those of cefazolin and cephaloridine. The rate of urinary excretion of ceftezole in 24-hour urine after administration in rats and rabbits was found to be higher than those of the other antibiotics tested. In dogs, however, the rate of urinary excretion of ceftezole was nearly the same as that of cefazolin and higher than those of cephaloridine and cephalothin. The biliary excretion of ceftezole in rats and dogs was much higher than those of cephaloridine and cephalothin, but lower than that of cefazolin. Tissue distribution of ceftezole in rats was compared with that of the other antibiotics by intramuscular and intravenous administration. The initial level of ceftezole in the kidneys was found to be substantially higher than those of the other antibiotics. The initial level of ceftezole in the liver and lungs was also slightly higher than those of the other drugs when administered intramuscularly. Tissue levels of ceftezole were somewhat lower than those of cefazolin in rabbits after intravenous administration. Ceftezole attained a higher maximum level in rat lymph by intramuscular administration than the other antibiotics tested. The maximum concentration of ceftezole present in the exudate in the rat inflammatory pouch was higher than that of cefazolin. In rabbits with cerebrospinal meningitis induced by infection of Streptococcus pyogenes, the level of ceftezole in the cerebrospinal fluid was several times higher than that in normal rabbits. The serum level and urinary excretion of ceftezole was examined in 6 healthy male volunteers after intramuscular administration of a single dose of 500 mg. Ceftezole attained a mean maximum serum level of 22.9 mug/ml 30 minutes after administration and disappeared from the blood in about 6 hours. It was excreted rapidly in the urine. The concentration in 1-hour urine was the highest (mean level: 2,667 mug/ml) and the total excretion rate was 92.6%. No metabolites with antimicrobial activity were observed in the urine. No changes in the pattern of plasma level and urinary excretion and no accumulation in the tissues were observed after repeated intramuscular administration of 20 mg/kg of ceftezole in rabbits, 26 times, for 14 days.

Antimicrobial properties of mannopeptins.

Mannopeptins show in vitro antimicrobial activity against gram-positive and some gram-negative bacteria. The antimicrobial activity is unaffected by the addition of serum, and potentiated by alkaline pH or decrease in inoculum size. The antibiotics exert bectericidal effect at doses twice as high as the minimum inhibitory concentration. When the antibiotics were injected into mice through either intravenous, intraperitoneal, intramuscular or subcutaneous routes, the antimicrobial activity appeared within 15 minutes in the serum of mice and was slowly excreted in the urine. However, the antibiotics were poorly absorbed by the oral route. The antibiotics were capable of protecting mice from lethal infection produced by the intravenous injection of Staphylococcus aureus, Streptococcus pyogenes and the intraperitoneal injection of Shigella sp. and Escherichia coli, but ineffective against Salmonella typhosa.