beta-Lactam resistance in Serratia marcescens: comparison of action of benzylpenicillin, Apalcillin, Cefazolin, and ceftizoxime

Abstract

The intrinsic mechanisms of resistance to beta-lactam antibiotics in Serratia marcescens IFO 12648 were investigated, comparing the action of benzylpenicillin, apalcillin, cefazolin, and ceftizoxime. The minimal inhibitory concentrations for this strain were 1,600, 3.13, 6,400, and 0.05 microgram/ml, respectively. The addition of ethylenediaminetetraacetic acid markedly reduced the minimal inhibitory concentrations of benzylpenicillin and cefazolin, whereas those of apalcillin and ceftizoxime were not influenced. S. marcescens IFO 12648 produced only a low level of beta-lactamase activity constitutively, and the production was considerably increased by the addition of benzylpenicillin. Cefazolin was hydrolyzed rapidly by beta-lactamase activity, whereas benzylpenicillin, apalcillin, and ceftizoxime were poorly hydrolyzed. Peptidoglycan synthesis in ether-treated strain IFO 12646 cells was inhibited by a concentration of ceftizoxime markedly lower than that of cefazolin and by a concentration of apalcillin moderately lower than that of benzylpenicillin.

In vitro activity of apalcillin compared with those of piperacillin and carbenicillin against 6,797 bacterial isolates from four separate medical centers

“…Table 3 summarizes data with nonenteric gram-negative bacilli and streptococci. Apalcillin was significantly more active than piperacillin against P. aeruginosa (MIC90s, 8.0 versus 64 ,ug/ml; MIC50s, 2.0 versus 4.0 pLg/ml) and against Acinetobacter calcoaceticus subsp. anitratus (MIC90s, 8.0 versus 64 ,ug/ml; MIC50s, 2.0 versus 16 ,ug/ml).…”

“…Apalcillin was significantly more active than piperacillin against P. aeruginosa (MIC90s, 8.0 versus 64 ,ug/ml; MIC50s, 2.0 versus 4.0 pLg/ml) and against Acinetobacter calcoaceticus subsp. anitratus (MIC90s, 8.0 versus 64 ,ug/ml; MIC50s, 2.0 versus 16 ,ug/ml). Among the P. aeruginosa isolates, 11.5% were resistant to carbenicillin (MIC, >128 ,ug/ml), 5.3% were resistant to piperacillin (MIC, >64 ,ug/ml), and only 0.7% were resistant to apalcillin (MIC, >64 ,uglml).…”

“…It has a broad spectrum of antibacterial activity, including activity against Pseudomonas aeruginosa (1,(4)(5)(6)(7)(8). The present report compares apalcillin with piperacillin and carbenicillin against all bacterial isolates that were selected for antimicrobial susceptibility testing in four separate institutions over a 45-to 60-day period.…”

The In Vitro Activity, Human Pharmacology, and Clinical Effectiveness of New beta-Lactam Antibiotics

“…Ceftizoxime is slightly less active than cefotaxime against S. aureus, with an MIC90 of 6.3 lLg/ml compared to 3.1 lLg/ml. Ceftizoxime has been more active than cefotaxime against highly resistant Serratia marcesc ens, with MICs two-to eightfold lower (83). In contrast, there has been minimal or no difference in the activity of ceftizoxime and cefotaxime against the streptococcal species (79,(80)(81)(82)84).…”

Effects ofBacillusSerine Proteases on the Bacterial Biofilms

“…Examination of clinically isolated S. marcescens strains revealed that most of them possess fimbriae capable of adherence to the human uroepithelial cells and considered to be a colonization factor in the urinary tract infections [ 20 ]. S. marcescens is resistant to many antibiotics traditionally used to eradicate bacterial infections, including β -lactams and aminoglycosides [ 21 , 22 ]. Its motility and ability to form flagellated swarmer cells as well as the biofilm formation are important virulence/pathogenicity factors [ 23 ].…”