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Abstract In a survey conducted in 1999–2001, the carriage of thermotolerant Campylobacters in cattle was investigated, and the genetic diversity of C. jejuni within one herd was examined and compared with human isolates. C. jejuni, C. coli and other thermotolerant Campylobacter spp. were isolated from intestinal contents from 26%, 3% and 2% of 804 cattle, respectively. The carriage rate was higher in calves (46%) than in adults (29%). Twenty-nine C. jejuni isolates from one herd and 31 human isolates from the study area were genotyped with amplified-fragment length polymorphism (AFLP). Eighty-three % of the bovine isolates fell into three distinct clusters with 95–100% similarity, persistent in the herd for 5–10 months. Among human isolates, 58% showed >90% similarity with bovine isolates. The results show that cattle are a significant and stable reservoir for C. jejuni in the study area. Transmission between individuals within the herd may be sufficient to maintain a steady C. jejuni population independent of environmental influx. The results of this study have provided new information on C. jejuni and C. coli transmission, and also on the carriage in cattle, genotypes stability and similarity between bovine and human isolates.

A procedure used by the Norwegian Food Safety Authority for surveillance of contaminants from plastic food contact materials (polyolefin drinking bottles, water boilers, polyamide cooking utensils and plastic multi-layer materials) is described. It is based on gas chromatographic-mass spectrometric (GC/MS) analysis of food simulants exposed to plastic materials. Most migrants were substances not-intentionally added to the plastic (degradation products, impurities) or originated from non-plastic components, such as printing inks, adhesives, not-listed additives, solvents and coatings. Hence, the majority of the identified migrants were regulated by the general statements in the EU Framework Regulation, which neither specify limits nor requirements regarding risk assessment, rather than by specific migration controls. Risk assessment has been carried out for selected non-authorized substances. The analysis and the management of these substances and materials with respect to safety represents a challenge to the food authorities.

The objective of this work was investigation of volatile organic compounds (VOC) in natural biofilm inside polyethylene (HDPE) pipelines at continuously flowing water. VOC in biofilm may contribute to off-flavour episodes in drinking water. The pipelines were supplied with raw lake water and treated water from the distribution network. Biofilm was established at test sites located at two different drinking water distribution networks and their raw water sources. A whole range of volatile compounds were identified in the biofilm, including compounds frequently associated with cyanobacteria and algae, such as ectocarpene, dictyopterene A and C', geosmin, beta-ionone and 6-methyl-5-hepten-2-one. In addition, volatile amines, dimethyldisulphide and 2-nonanone, presumably originating from microorganisms growing in the biofilm, were identified. C8-compounds such as 1-octen-3-one and 3-octanone were believed to be products from microfungi in the biofilm. Degradation products from antioxidants such as Irgafos 168, Irganox 1010 and Irganox 1076 used in HDPE pipes, corresponding to 2,4-di-tert-butylphenol and 2,6-di-tert-butylbenzoquinone, were present in the biofilm.

In 1999-2000, a prospective case-control study of sporadic, domestically acquired campylobacteriosis was conducted in three counties in Norway to identify preventable risk factors and potentially protective factors. A total of 212 cases and 422 population controls matched by age, sex, and geographic area were enrolled. In conditional logistic regression analysis, the following factors were found to be independently associated with an increased risk of Campylobacter infection: drinking undisinfected water, eating at barbecues, eating poultry bought raw, having occupational exposure to animals, and eating undercooked pork. The following factors were independently related to a decreased risk: eating mutton, eating raw fruits or berries, and swimming. Results indicated that infection is more likely to occur as a result of cross-contamination from raw poultry products than because of poultry consumption per se. Drinking undisinfected water, reported by 53% of cases, was a leading risk factor in this study. Drinking water may constitute the common reservoir linking infection in humans and animals, including poultry and wild birds. Insight into the ecology of Campylobacter in freshwater ecosystems may be required to understand the epidemiology of campylobacteriosis. The possibility that certain foods confer protection against campylobacteriosis deserves exploration.

High-density polyethylene pipes (HDPE), crossbonded polyethylene pipes (PEX) and polyvinyl chloride (PVC) pipes for drinking water were tested with respect to migration of volatile organic components (VOC) to water. The odour of water in contact with plastic pipes was assessed according to the quantitative threshold odour number (TON) concept. A major migrating component from HDPE pipes was 2,4-di-tert-butyl-phenol (2,4-DTBP) which is a known degradation product from antioxidants such as Irgafos 168(R). In addition, a range of esters, aldehydes, ketones, aromatic hydrocarbons and terpenoids were identified as migration products from HDPE pipes. Water in contact with HDPE pipes was assessed with respect to TON, and values > or =4 were determined for five out of seven brands of HDPE pipes. The total amount of VOC released to water during three successive test periods were fairly constant for the HDPE pipes. Corresponding migration tests carried out for PEX pipes showed that VOC migrated in significant amounts into the test water, and TON >/=5 of the test water were observed in all tests. Several of the migrated VOC were not identified. Oxygenates predominated the identified VOC in the test water from PEX pipes. Migration tests of PVC pipes revealed few volatile migrants in the test samples and no significant odour of the test water.

Solid phase analytical derivatization with trifluoroacetic anhydride has been introduced as sample preparation for the determination of primary aromatic amines in water by gas chromatography coupled with mass spectrometry. Water was used as a food simulant for testing migration from laminated flexible food packaging materials. The method was evaluated for 8 primary aromatic amines in 200 ml water samples, which resulted in detection limits in the 0.1-0.4 microg/l range, relative standard deviations in the 4-17% range and acceptable linearity (R2 = 0.997-1.000). Detectable levels of 2,4-diaminotoluene, 2,6-diaminotoluene and 4,4'-methylenedianiline were found in water food simulant from some of the investigated food packaging materials.

We conducted a national survey of antimicrobial resistance in human clinical isolates of Salmonella between July 1, 1994, and June 30, 1995. Every tenth nontyphoidal Salmonella isolate received at state public health laboratories in the United States during this period was tested for resistance to 12 antimicrobial agents, including two quinolones, nalidixic acid, and ciprofloxacin. Emerging quinolone resistance was detected; of 4,008 isolates tested, 21 (0.5%) were resistant to nalidixic acid, and one (0.02%) was resistant to ciprofloxacin. Continued surveillance for quinolone-resistant Salmonella is necessary, particularly after the recent approval of a fluoroquinolone for use in animals intended for food in the United States.

Bacillus subtilis has only seldom been associated with pathological conditions in mammals. As the organism is considered to be ubiquitous in the environment, care has to be taken not to put too much emphasis on the pathogenicity of the organism, even in cases where it is isolated in pure culture. Bacillus subtilis was isolated from 17 cases of bovine mastitis in which it was considered to be the etiological factor.