Our investigations identified sprouts as the most likely outbreak vehicle, underlining the need to take into account food items that may be overlooked during subjects' recall of consumption.

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.

Numerous outbreak investigations and case-control studies for campylobacteriosis have provided evidence that handling Campylobacter-contaminated chicken products is a risk factor for infection and illness. There is currently extremely limited quantitative data on the levels of Campylobacter cross-contamination in the kitchen, hindering risk assessments for the pathogen commodity combination of Campylobacter and chicken meat. An exposure assessment needs to quantify the transfer of the bacteria from chicken to hands and the kitchen environment and from there onto ready-to-eat foods. We simulated some typical situations in kitchens and quantified the Campylobacter transfer from naturally contaminated chicken parts most commonly used in Germany. One scenario simulated the seasoning of five chicken legs and the reuse of the same plate for cooked meat. In another, five chicken breast filets were cut into small slices on a wooden board where, without intermediate cleaning, a cucumber was sliced. We also investigated the transfer of the pathogen from chicken via hands to a bread roll. The numbers of Campylobacter present on the surfaces of the chicken parts, hands, utensils, and ready-to-eat foods were detected by using Preston enrichment and colony counting after surface plating on Karmali agar. The mean transfer rates from legs and filets to hands were 2.9 and 3.8%. The transfer from legs to the plate (0.3%) was significantly smaller (P < 0.01) than the percentage transferred from filets to the cutting board and knife (1.1%). Average transfer rates from hands or kitchen utensils to ready-to-eat foods ranged from 2.9 to 27.5%.Most of the case-control studies and outbreak investigations for infections with the zoonotic bacteria Campylobacter jejuni and C. coli have identified consumption and handling of raw chicken as an important risk factor for human illness (1, 2, 8, 10, 13). Consumers' exposure to Campylobacter takes place either through consumption of undercooked, internally contaminated chicken meat or via cross-contamination to readyto-eat food during the preparation of externally contaminated chicken parts and carcasses. There are currently limited quantitative data on Campylobacter cross-contamination available in the literature. Quantification of the transfer of Campylobacter from chicken via hands and the kitchen environment to ready-to-eat foods during handling of contaminated products is a central part of all risk assessments for this pathogen commodity combination. Using naturally contaminated fresh chicken parts purchased in retail stores, experiments were performed that simulated some of the typical situations and handling procedures that are common in German kitchens and presumably in many other countries as well. MATERIALS AND METHODSSampling and quantification of Campylobacter on chicken parts. From June to November 2004 we bought random, independent packages containing several fresh chicken legs (drumstick plus thigh) or fresh, skinless and boneless chicken breast filets at various supermarkets in B...

No abstract

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.