Activity of moxifloxacin, administered once a day, against Streptococcus pneumoniae in an in vitro pharmacodynamic model of infection.

The antibacterial effect of moxifloxacin was studied by using an in vitro pharmacodynamic model of infection with dosing simulations of 400 mg every 24 h for 48 h. Streptococcus pneumoniae was tested by using four wild-type strains for which the moxifloxacin MICs were 0. 008, 0.

Difficulties in the assay of liposomal amikacin (MiKasome) in serum.

Antibiotic-free human serum was spiked with known concentrations of liposomal amikacin and assayed on the Abbott TDx System, using polarization fluoroimmuno assay (PFIA) kits from Abbott Laboratories, Oxis and Sigma. Although all three kits gave a linear response, the Abbott and Oxis kits showed very low recovery (<21%) with only the Sigma kit giving near 100% recovery. Heating samples at 56 degrees C for 30 min improved recovery with the Abbott and Oxis kits (75-80% of target value), but decreased recovery with the Sigma kit (85% of target value).

Ultrastructural studies demonstrate that epithelial polarity is established in cultured mouse pre-Sertoli cells by extracellular matrix components.

The effect of three different substrates, laminin, fibronectin and reconstituted basement membrane, on isolated mouse pre-Sertoli cells maintained in vitro has been investigated. Cultures were monitored on a daily basis by phase contrast microscopy, and processed for light and electron microscopy at the end of the culture period. Extra-cellular matrix components have been found to influence Sertoli cell differentiation: both fibronectin and laminin promoted cell adhesion and differentiation, though laminin cultures showed poor viability.

The antibacterial efficacy of levofloxacin and ciprofloxacin against Pseudomonas aeruginosa assessed by combining antibiotic exposure and bacterial susceptibility.

Ciprofloxacin has a four-fold greater in-vitro activity than levofloxacin against Pseudomonas aeruginosa, but levofloxacin has a four-fold higher area under the serum concentration-time curve (AUC) for an equivalent dose. It has been proposed that the AUC/MIC ratio is a general predictor of antibacterial efficacy for quinolones. Using an in-vitro kill curve technique, performed in quadruplicate, with nine antibiotic concentrations and three strains of P.

A comparative study of the rifampicin binding and elution characteristics for collagen- and albumin-sealed vascular grafts.

Objectives: To assess the rifampicin binding and elution characteristics for three protein-sealed vascular grafts.

Design: In vitro study.

Materials: Cardial and Hemashield collagen-sealed and the DeBakey/Vasculour albumin-sealed vascular grafts.

Continuous infusion of beta-lactam antibiotics.

There are considerable laboratory data and information from animal and continuous culture in vitro models to support continuous infusion therapy for penicillins and cephalosporins, but, as yet, the only existing clinical data relate to cephalosporins. Penicillins do not exert concentration-dependent killing in the therapeutic range but have a post-antibiotic effect (PAE) against Gram-positive cocci but not Gram-negative rods. Animal models indicate the time (T) during which the serum concentrations exceed the minimum inhibitory concentration (MIC) of the pathogen [T > MIC] determines outcomes.

Sequential antimicrobial therapy: pharmacokinetic and pharmacodynamic considerations in sequential therapy.

The pharmacodynamic factors important in sequential therapy are largely unknown. This is because most pharmacodynamic investigations concentrate on how bacterial populations respond to first antimicrobial exposures. However, it is likely that for B lactams T>MIC and for quinolones the antimicrobial AUC/MIC ratio will be important.

Comparative pharmacodynamics of meropenem using an in-vitro model to simulate once, twice and three times daily dosing in humans.

An in-vitro pharmacokinetic model was used to study the antibacterial activity of meropenem. Strains of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were exposed to meropenem concentrations likely to be produced in an adult by rapid iv infusion of 3 g once a day (q24h regimen), 1.5 g twice a day (ql2h regimen) or 1 g three times a day (q8h regimen).

Pharmacodynamics, pharmacokinetics, and therapeutic drug monitoring of glycopeptides.

The glycopeptide antibacterial drugs, vancomycin and teicoplanin, are widely used in hospitals for therapy of severe or multiresistant infection that has a positive results on Gram's stain test. Although vancomycin resistance is common in some hospital-acquired Enterococcus sp and resistance to teicoplanin occurs among Staphylococci sp glycopeptides remain the cornerstone of therapy for infection due to methicillin-resistant Staphylococcus aureus (MRSA), coagulase-negative Staphylococcus organisms, and infection related to implanted devices. Therapeutic drug monitoring (TDM) of these agents remains controversial, but advances in our understanding of their pharmacodynamics and further clinical studies are helping clarify the situation.

Comparison of the modified Stokes' method of susceptibility testing with results obtained using MIC methods and British Society of Antimicrobial Chemotherapy breakpoints.

The majority of clinical microbiology laboratories in the UK use comparative disc diffusion methods based on the Stokes' method to determine antibiotic susceptibility. The technical validity of the results obtained from the modified Stokes' method of disc testing and how they relate to MIC data are not known. We studied susceptibility testing using a modified Stokes' disc diffusion method for a wide range of clinical isolates against which MICs had been determined by collaborators not involved with the disc testing evaluation.

Importance of air quality and related factors in the prevention of infection in orthopaedic implant surgery.

Small numbers of organisms can cause orthopaedic implant infections, which give rise to a considerable degree of morbidity and also mortality. The periprosthetic infection rates have been shown to correlate with the number of airborne bacteria within 30 cm of the wound. This is influenced by factors such as the number of operating theatre personnel, their clothing and the type of ventilation system used.

Venous allografts prepared from stripped long saphenous vein. Is there a need for antibiotic sterilisation?

Aim: Can useful lengths of vein be retrieved from varicose vein stripping procedures; is it necessary to sterilise this tissue prior to use as vein allografts?

Method: Stripped long saphenous vein was retrieved at operation. Vein samples were cultured using direct plate inoculation and enrichment culture. Further samples were immersed in two low concentration antibiotic solutions and recultured.

Nucleotide and amino acid sequences of the metallo-beta-lactamase, ImiS, from Aeromonas veronii bv. sobria.

The Aeromonas veronii bv. sobria metallo-beta-lactamase gene, imiS, was cloned. The imiS open reading frame extends for 762 bp and encodes a protein of 254 amino acids with a secreted modified protein of 227 amino acids and a predicted pI of 8.

In vitro activities of Y-688, a new 7-substituted fluoroquinolone, against anaerobic bacteria.

The in vitro activities of Y-688, a new 7-substituted fluoroquinolone derivative, against 317 nonduplicate anaerobic isolates were determined. Eighty-five percent of the Bacteroides fragilis group (n = 89) were inhibited by < or = 2 mg of Y-688 per liter, while 78, 100, 89, and 98% of gram-negative bacilli (n = 135), gram-positive cocci (n = 59), and non-spore-forming (n = 58) and spore-forming (n = 51) gram-positive bacilli, respectively, were inhibited by < or = 1 mg of Y-688 per liter.

Bay 12-8039, a new 8-methoxy-quinolone: comparative in-vitro activity with nine other antimicrobials against anaerobic bacteria.

The in-vitro activity of a new 8-methoxy-quinolone, Bay 12-8039, was assessed against 218 anaerobic bacteria. Ninety-eight per cent of strains belonging to the Bacteroides fragilis group (n = 65) were inhibited by < or = 2 mg/L of Bay 12-8039 whereas 97%, 94%, 94% and 100%, respectively, of Gram-negative bacilli (n = 93), non-sporing Gram-positive bacilli (n = 36), endospore-forming Gram-positive bacilli (n = 34) and Gram-positive cocci (n = 45) were also inhibited by < or = 2 mg/L. Eighty-three per cent of all anaerobes tested were inhibited by < or = 1 mg/L Bay 12-8039 and 99.