Canadian invasive Haemophilus influenzae isolates from 1990 to 2006 were examined for antibiotic susceptibility: 42 strains (17.8%) were resistant to ampicillin by beta-lactamase production, 5.5% were beta-lactamase negative ampicillin intermediate, and 2.5% were intermediate to only the 2-microg ampicillin disk. An increase in beta-lactamase-negative ampicillin-intermediate strains has been fo...

The in vitro susceptibility of group D streptococci (enterococci) to ampicillin was studied comparing the results obtained in Mueller-Hinton broth (MHB) with those obtained in normal human serum (NHS). The rate of enterococcal killing was consistently faster in NHS than in MHB at equivalent ampicillin concentrations. Whereas an increasing media pH appeared to decrease the susceptibility of ente...

Seizure is a rare but documented adverse event associated with ampicillin, which one of the most commonly used antibiotics in pediatrics. We report case 4-month-old male infant Haemophilus influenzae type A meningitis that experienced recurrent tonic-clonic seizures, possibly secondary to ampicillin treatment. After administration was withdrawn and antiepileptic agents were administered, seizur...

Intravenous ampicillin-sulbactam is effective in the treatment of various infections in adults, but little is known about the pharmacokinetics (PK) of ampicillin-sulbactam in children. The objective of this study was to determine the PK of ampicillin and sulbactam in pediatric patients with intra-abdominal infection, skin and/or skin structure infection, or periorbital-preseptal and facial cell...

Since November 1982 at the Sainte-Justine Hospital in Montreal, ampicillin and cefotaxime were used in association as initial treatment (greater than or equal to 48 h) for childhood bacterial meningitis. In this report is described the in vitro interaction of the new regimen in comparison with that of the previous ampicillin-chloramphenicol combination against 284 Haemophilus isolates. Among th...

Ampicillin, a β-lactam antibiotic, dose-dependently protects neurons against ischemic brain injury. The present study was performed to investigate the neuroprotective mechanism of ampicillin in a mouse model of transient global forebrain ischemia. Male C57BL/6 mice were anesthetized with halothane and subjected to bilateral common carotid artery occlusion for 40 min. Before transient forebrain ...

A total of 1,102 clinical isolates of Gram-negative bacilli was obtained from four hospitals during 1967 and these cultures were tested for sensitivity to ampicillin. Approximately 80% of the strains of Escherichia coli and 90% of the strains of Proteus mirabilis, the two organisms most frequently isolated, were sensitive to ampicillin. Klebsiella-Enterobacter species and Pseudomonas aeruginosa...

Minimum inhibitory and bactericidal concentrations of four antibiotics and their combinations were determined for 38 strains of enterococci by a microtitration tube dilution technique. The drugs were ampicillin, vancomycin, gentamicin, and streptomycin; the combinations were ampicillin-gentamicin, ampicillin-streptomycin, vancomycin-gentamicin, and vancomycin-streptomycin. At achievable serum c...

Strains of Haemophilus influenzae type b sporadically isolated from clinical specimens are ampicillin resistant due to production of a beta-lactamase. This enzyme which inactivates ampicillin and penicillin G is not produced by ampicillin-susceptible strains. Various characteristics of beta-lactamase production and ampicillin resistance of three H. influenzae type b isolates were investigated. ...

The effects of free ampicillin, microencapsulated ampicillin anhydrate (MEAA) and antibiotic-free microspheres on the cell-mediated immune response in Balb/c mice were measured by lymphoproliferation assay, delayed-type hypersensitivity (DTH) and cytokine production. Injection into mice for seven consecutive days with equivalent subcutaneous doses of ampicillin, MEAA or placebo microspheres did...