Antibacterial activity and beta-lactamase stability of temocillin

Abstract

Temocillin, a 6-a-methoxy penicillin, inhibited 90% of strains of Escherichia coli, Klebsiella pneumoniae, Citrobacter, Proteus, Providencia, Salmonella, and Shigella at a concentration of <16 ,ug/ml. Haemophilus influenzae and Neisseria gonorrhoeae were inhibited by s1 pug/ml. Changing the medium or pH of the cultures did not alter the minimal inhibitory concentrations, which were similar in broth and human serum, as were the minimal bactericidal concentrations. An increase in inoculum size from 105 to 107 colony-forming units increased concentration required for inhibition. Temocillin inhibited strains resistant to ampicillin, ticarcillin, cefazolin, cefamandole, and cefoxitin. Most Pseudomonas aeruginosa strains and other Pseudomonas spp. and Acinetobacter spp. were resistant, as were gram-positive organisms. Temocillin was not hydrolyzed by the common plasmid and chromosomal P-lactamases but inhibited them. The resistance of certain gram-negative bacilli to temocillin seemed to be a result of failure of the molecule to enter through the cell wall, since combination of temocillin with EDTA made Pseudomonas, Acinetobacter, and Enterobacter strains susceptible to low concentrations of the compound.

Effect of temocillin in combination with other beta-lactam antibiotics

“…(3,7,8). Temocillin is protected against ,-lactamases by a 6-a-methoxy group in the nucleus and inhibits strains resistant to ampicil-* Corresponding author.…”

Ventriculitis Associated with Extended Spectrum Beta-Lactamase Producing Klebsiella pneumoniae after Acupuncture

“…The major drawbacks of Temocillin is its lack of activity against Gram-positive organisms, anaerobes, and Pseudomonas aeruginosa [82,83].…”

Validation of a HPLC-MS/MS assay for the determination of total and unbound concentration of temocillin in human serum

“…Temocillin is a β-lactam antibiotic active against gram-negative bacteria, including β-lactamase producers [1,2]. It is currently indicated for the treatment of septicemia, urinary tract infections, and lower respiratory tract infections [3].…”