A standardized broth microdilution method was compared to the E test and an agar dilution method for the antimicrobial susceptibility testing of Campylobacter jejuni and C. coli isolates. A group of 47 human clinical isolates, 37 isolates from retail poultry, and 29 isolates from living turkeys (total, 113 isolates) was included in the study. These encompassed 92 C. jejuni and 21 C. coli strains. The MICs of six antimicrobial agents were determined by the broth microdilution and E test methods, and the strains of human origin were additionally tested by the agar dilution method. In general, broth microdilution MICs agreed within 1 log 2 MIC increment with 90.0% of E test results and 78.7% of agar dilution test results. The agar dilution method gave much lower gentamicin MICs than the broth microdilution method, but the data were significantly (P < 0.01) correlated and there was 100% agreement in the sensitivities and specificities in the comparison of the tests. The broth microdilution method had the highest sensitivity for analysis of the susceptibilities of Campylobacter to nalidixic acid and trimethoprim-sulfamethoxazole. The MICs of ciprofloxacin and erythromycin complied numerically by all three methods. The classification of the results and the correlation of the data demonstrated a high degree of agreement. All methods were equally suitable for the testing of the sensitivity of Campylobacter to tetracycline. Thus, the broth microdilution method appears to be an easy and reliable method for determination of the MICs of antibiotics for C. jejuni and C. coli, and it may offer an interesting alternative to MIC determination by the agar dilution technique or the E test.

The susceptibilities of 430 Campylobacter jejuni strains and 79 C. coli strains to six antimicrobial agents were tested and analyzed. The two sets of strains originated from retail market chicken and turkey samples and from humans, respectively, in Berlin, Germany. Two groups of isolates, one dating from 1991 and the other dating from 2001-2002, were tested. Of the Campylobacter sp. isolates recovered from humans in 2001-2002, 45.1% were resistant to ciprofloxacin, 37.8% were resistant to tetracycline, 12.8% were resistant to ampicillin, and 50.0% were resistant to trimethoprim-sulfamethoxazole. All isolates were susceptible to gentamicin, while the overall rate of resistance to erythromycin was 6.1%. During the 10 years between the two sampling times, the rates of resistance to ciprofloxacin (P < 0.001), ampicillin (P ‫؍‬ 0.035), and tetracycline (P ‫؍‬ 0.01) increased significantly among strains isolated from humans. Furthermore, among human C. coli strains the rate of resistance to erythromycin rose from 7.1% in 1991 to 29.4% in 2001-2002. In comparison, Campylobacter sp. isolates from poultry already had high rates of resistance in 1991. Different rates of resistance to tetracycline among isolates from chickens and turkeys suggested the development of resistance during antimicrobial treatment in food animals. Thus, discrepancies in the antimicrobial resistance rates among Campylobacter isolates originating from poultry and humans support the hypothesis that at least some of the resistant Campylobacter strains causing infection in humans come from sources other than poultry products.

A total of 980 episodes of clinically and bacteriologically proven septicemia were included in four prospective 1-year studies at a 1,300-bed university hospital in Berlin between 1979 and 1989. The incidence was 8.1 per 1,000 admissions. The percentage of patients with severe underlying diseases increased significantly from 67% to 95% over the decade. Septicemia due to gram-positive bacteria decreased from 47.3% in 1979 to 43.7% in 1986 and increased again to 51.2% in 1989. Septicemia due to gram-negative organisms decreased constantly from 45.0% in 1979 to 39.8% in 1989. The most frequently isolated species were Escherichia coli (26.4%), Staphylococcus aureus (18.9%), coagulase-negative staphylococci (10.2%), enterococci (7.7%), viridans streptococci (6.4%), Klebsiella species (5.5%), and pneumococci (5.0%). The overall mortality rate decreased significantly from 33.6% in 1979 to 20.8% in 1989. Mortality for episodes of septicemia due to gram-positive bacteria (25.5%) was higher than that for septicemia due to gram-negative bacteria (18.3%). Mortality rates associated with polymicrobic and fungal septicemia were higher than the overall mortality rate.