Comparative activity of mezlocillin, penicillin, ampicillin, carbenicillin, and ticarcillin against gram-positive bacteria and Haemophilus influenzae

The aim of this study was to determine the susceptibility patterns of 100 group B streptococcal strains isolated in our hospital and to ascertain tolerance to penicillin by determining quantitative killing curves. We found two strains with intermediate susceptibility to penicillin and eight strains to ampicillin. Seventeen isolates were tolerant to penicillin, with bacterial counts decreasing 2 to 3 log during the first 8 h but still above 10(2) CFU/ml after 24 h. The kinetic study shows that penicillin tolerance is not rare among group B streptococci isolated in our hospital.

supporting

confidence: 71%

Antibiotic resistance and penicillin tolerance in clinical isolates of group B streptococci

Betriú

Gómez

Sánchez

et al. 1994

“…Their greater activities against enterococci and some anaerobes (6,9,10,16,19,23) makes them more useful in treating certain mixed bacterial infections. Their lower sodium content is an advantage in treating patients who are adversely affected by large sodium loads.…”

Section: Discussionmentioning

confidence: 99%

Statistical comparison of the antibacterial activities of broad-spectrum penicillins against gram-negative bacilli

Fass¹

1983

Minimal inhibitory concentrations (MICs) or two a-carboxypenicillins (carbenicillin and ticarcillin) and three acylaminopenicillins (azlocillin, mezlociliin, and piperacillin) for 300 aerobic and facultative gram-negative bacilli were determined by-a microdilution method and compared by parametric statistical tests. Within each group of penicillins, MICs were highly interrelated; MICs of one antibiotic were readily predictable based on knowledge of MICs of another antibiotic. Ticarcillin was consistently more active than carbenicillin by approximately one dilution step, but the relative activities of the acylaminopenicillins varied by bacterial species. The acylaminopenicillins were generally more active than the acarboxypenicillins, particularly against a-carboxypenicillin-resistant organisms. There were exceptions, however, and antibiotic MICs in one group were not readily predictable on the basis of the knowledge of antibiotic MICs in the other group. The enhanced antibacterial potencies and spectra of the acylaminopenicillins against gram-negative bacilli make these antibiotics potentially useful therapeutic agents. It is not necessary for clinical laboratories to routinely perform susceptibility tests with all five antibiotics.

“…Two acylureidopenicillins (azlocillin and mezlocillin) have been tested in vitro and were found to be active against members of the family Enterobacteriaceae, Pseudomonas aeruginosa, Streptococcus pneumoniae, and Haemophilus influenzae (1, 3,8). Piperacillin, a piperazine derivative of ampicillin, and apalcillin, a napthyridino derivative of ampicillin, have also shown increased activity against the aforementioned organisms (2, 5, 6).…”

mentioning

confidence: 99%

“…Piperacillin, a piperazine derivative of ampicillin, and apalcillin, a napthyridino derivative of ampicillin, have also shown increased activity against the aforementioned organisms (2, 5, 6). When compared against ticarcillin or carbenicillin, the MICs for these new semisynthetic penicillins are generally reduced two to four times (1, 3,6,8 In this study, we chose P. aeruginosa as the organism to test the in vitro activity of three ureidopenicillins and a naphthyridino derivative of ampicillin compared with that of carbenicillin. All of these beta-lactam antibiotics showed more activity against P. aeruginosa, with carbenicillin MICs ranging from 4 to 32 times greater.…”

mentioning

confidence: 99%

Activity of apalcillin against Pseudomonas aeruginosa

Hollick¹,

Gundrum²,

Venezia³

1984

The in vitro activity of apalcillin was tested against 107 clinical isolates of Pseudomonas aeruginosa, and the results were compared to those for piperacillin, miezlocillin, azlocillin, and carbenicillin. MIC analysis showed that 97% of the isolates were susceptible to piperacillin, 97% were susceptible to apalcillin, 93% were susceptible to azlocilli , 87% were suseptible to mezlocillin, and 84% were susceptible to carbenicillin.Recently, a number of new penicillins with extended antibacterial spectra have been developed. Two acylureidopenicillins (azlocillin and mezlocillin) have been tested in vitro and were found to be active against members of the family Enterobacteriaceae, Pseudomonas aeruginosa, Streptococcus pneumoniae, and Haemophilus influenzae (1, 3,8). Piperacillin, a piperazine derivative of ampicillin, and apalcillin, a napthyridino derivative of ampicillin, have also shown increased activity against the aforementioned organisms (2, 5, 6). When compared against ticarcillin or carbenicillin, the MICs for these new semisynthetic penicillins are generally reduced two to four times (1, 3,6,8 In this study, we chose P. aeruginosa as the organism to test the in vitro activity of three ureidopenicillins and a naphthyridino derivative of ampicillin compared with that of carbenicillin. All of these beta-lactam antibiotics showed more activity against P. aeruginosa, with carbenicillin MICs ranging from 4 to 32 times greater. Our data indicate that the activity of these new antibiotics can be ordered as follows: apalcillin = piperacillin > azlocillin > mezlocillin. This relative order confirms previously reported studies (1, 3, 5, 7).It would be interesting to examine the effects that P. aeruginosa inoculum size may have on the MICs of these antibiotics and the contribution of other antibiotics in combination with these beta-lactams.