Seroepidemiology of Helicobacter pylori infection in vegans and meat-eaters.

An enzyme-linked immunosorbent assay has been used to diagnose serologically the prevalence of Helicobacter pylori infection in Asian life-long vegans. There was no difference in the seropositivity between these individuals and a group of age- and sex-matched Asian meat-eaters, indicating the meat consumption is not a risk factor for H. pylori infection. However, both Asian groups had a higher prevalence of infection than age- and sex-matched Caucasian meat-eaters. Additionally, the Asian individuals had a wider range of specific IgG antibody concentrations than the Caucasians. This did not appear to be due to antigenic cross-reactivity between H. pylori and Campylobacter jejuni. The significance of these observations to the establishment of cut-off levels for the serodiagnosis of certain ethnic groups is discussed.

A comparison of the pharmacokinetics and tissue penetration of spiramycin and erythromycin.

The pharmacokinetics of two orally administered macrolides, spiramycin and erythromycin, were compared in six healthy male volunteers in a single dose cross-over study. Penetration of these antimicrobial agents into inflammatory fluid was studied. Spiramycin was administered in a 2 g dose and erythromycin in a 500 mg dose. Spiramycin (Tmax = 3.3 h) and erythromycin (Tmax = 1.2 h) were well absorbed reaching mean plasma Cmax of 3.1 mg/l and 2.1 mg/l, respectively. The relative bioavailability of erythromycin compared to spiramycin appeared to be three- to four-fold greater. The mean plasma elimination half-life was 3.8 h for spiramycin and 1.6 h for erythromycin. The percentage penetration of the antibiotics into inflammatory fluid was good, being 66% for spiramycin and 54% for erythromycin. Both antimicrobial agents attained inflammatory fluid Cmax of 0.7 mg/l by 4-4.8 h. Spiramycin persisted in the inflammatory fluid with a mean elimination half-life of 7.7 h compared to 2.2 h for erythromycin. Twenty-four hour urinary recovery of the administered dose of each antimicrobial agent was less than 5%.

The pharmacokinetics and tissue penetration of FCE 22101 following intravenous and oral administration.

One gram each of FCE 22101 and its acetoxymethyl ester (FCE 22891) were administered sequentially to six healthy volunteers. After intravenous administration Cmax was 167 mg/l, and the elimination half-life 0.8 h. Following oral administration Cmax was 6.9 mg/l and the elimination half-life 0.6 h. Penetration into inflammatory fluid was rapid, and the percentage penetration 86.1 and 60.9% following oral and intravenous dosing respectively. Urine recovery was greater after intravenous administration (31%) than after oral (11%).

The pharmacokinetics and tissue penetration of intravenously administered CGP 31608.

The pharmacokinetics of CGP 31608, a new injectable penem antibiotic, were studied following a 1 g intravenous infusion. Concentrations were determined in serum, urine and cantharidin-induced inflammatory fluid by a microbiological assay. Peak serum concentrations were achieved at, or before the end of, the 1 h infusion, with a mean of 24.9 mg/l occurring at 0.8 h. The mean serum elimination half-life was 0.5 h, with no detectable drug in serum after 3 h. Inflammatory fluid was penetrated rapidly with a mean peak level of 10.5 mg/l occurring at 1.3 h (i.e. 20 min after the end of the infusion). Urinary elimination of CGP 31608 accounted for 52.1% of the administered dose within an hour of finishing the infusion, and 57.1% by 12 h. This study suggests that therapeutic serum levels (greater than 8 mg/l) are present for about 1.5 h after starting a 1 h infusion, and in inflammatory fluid for about 2.5 h. Unless a dose in excess of 1 g is used, CGP 31608 will probably have to be given four or more times a day.

Commercially available fluorescein-conjugated monoclonal antibody for determining the in vitro activity of antimicrobial agents against Chlamydia trachomatis.

A simple, reproducible method for determining the antibiotic susceptibility of chlamydial isolates is described. Minimum inhibitory and lethal concentrations (MICs and MLCs) were determined for tetracycline and erythromycin titrated against a recent clinical isolate of Chlamydia trachomatis in McCoy cell cultures. A fluorescent antibody stain was found to be more sensitive than giemsa staining, generally giving two-fold higher values for both MICs and MLCs.

Pharmacokinetics and tissue penetration of orally administered pefloxacin.

The pharmacokinetics of the quinolone pefloxacin were determined following a 400 mg oral dose given to each of six male volunteers. Concentrations were determined in serum and urine by high-performance liquid chromatography, and in cantharidin-induced inflammatory fluid by a microbiological assay. The mean peak serum level of 6.6 micrograms/ml was attained rapidly 0.8 h after administration. The mean serum elimination half-life was 11.6 h. Inflammatory fluid was penetrated quickly with a mean peak level of 3.9 micrograms/ml occurring at 2.4 h. Pefloxacin was excreted in the urine as the parent compound and its two metabolites, norfloxacin and pefloxacin N-oxide (24 h urinary recovery being 8.0%, 12.0% and 13.1% respectively of the dose). This study suggests that a twice or possibly once daily dosage may be sufficient to treat systemic infections caused by susceptible pathogens. Once daily dosing should be sufficient for urinary tract infections.