Molecular epidemiology of Campylobacter fetus subsp. fetus on bovine artificial insemination stations using pulsed field gel electrophoresis.

The presence of Campylobacter fetus subspecies fetus (Cff) on bovine artificial insemination (AI)-stations can have major economical consequences. More knowledge on the epidemiology of C. fetus is needed to control Cff infections at AI-stations. We assessed the epidemiology of Cff on AI-stations and the molecular relationship between Cff strains isolated from outbreaks on AI-stations. Thirteen Cff strains (two Cff strains per outbreak and one sporadic case) isolated from bulls housed on different AI-stations were selected and compared with ten unrelated bovine and ovine Cff isolates from different geographical regions. Molecular typing by pulsed field gel electrophoresis (PFGE) with the restriction enzymes SmaI, SalI and KpnI, yielded unique profiles for most unrelated strains but indistinguishable profiles for all isolates from the same outbreak. Computer aided analysis using a composite data set of SmaI, SalI and KpnI restriction profiles revealed separate clusters for outbreak strains. Thus, PFGE profiling of Cff strains is a valuable tool to discriminate between strains derived from separate outbreaks and to identify routes of infection.

Microbiological Conditions and Keeping Quality of Veal Tongues as Affected by Lactic Acid Decontamination and Vacuum Packaging.

The effect of a lactic acid decontamination treatment on the microbiological condition and keeping quality of veal calf tongues was assessed. Thirty tongues were collected 45 min post mortem. Ten were washed with tap water in a centrifuge, 10 were treated with 2.0% (v/v) L-lactic acid instead of water, and 10 tongues received no treatment and served as control samples. Immediately following these treatments all tongues were vacuum-packaged, chilled 2 h in ice-water and stored at 3±1 °C and 85±5 % ERH. At 0, 14, and 28 d postmortem samples were taken for bacteriological, histobacterioscopic and sensory examination. The histobacterioscopic examination showed that the initial microflora appeared to be predominantly located under and between the papillae of the tongue surface. Centrifugation with water only did not significantly affect the bacteriological condition of tongues, although the overall appearance improved. Decontamination with lactic acid decreased mesophilic aerobic colony counts from 5.6 to 2.7 log10 CFU/cm2. After 14 d of storage the so-called "delayed" effect of lactic acid was still observed. At that time aerobic colony counts and Enterobacteriaceae counts of controls were 6.5 and 2.8 log10 CFU/cm2, while these counts of the lactic acid treated group were 4.0 and <1.3, respectively. Results of the bacteriological examinations were substantiated by the histobacterioscopic findings. Centrifugation with lactic acid detached superficial cells from the stratified squamous epithelium. Decontamination of tongues by centrifugation with lactic acid before vacuum packaging will increase storage life and safeguard public health.