Some potential sources for transmission of Campylobacter jejuni to broiler chickens.

AIMS: The aim of the study was to determine Campylobacter jejuni contamination and prevalence on fomites moving between broiler farms and the processing plant in the period after cleaning and before departure to harvest chickens. In addition, changes in the proportion of contaminated fomites in the course of a day were assessed. METHODS AND RESULTS: Pooled swab samples were obtained from pallets, crates, wheels of trucks, tractors and forklifts, truck beds, and from drivers' and catchers' boots. After enrichment in Bolton's broth Campylobacter were recovered on modified blood-free Campylobacter selective agar (mCCDA). Isolates were identified using tests for phenotypic and biochemical characteristics. Of the 209 samples collected, 53% were positive for C. jejuni, with all fomites positive except tractor wheels. Pallets had the highest contamination rate at 75%. More than 50% of catchers' boots, drivers' boots, crates and truck wheels were positive. Forty-seven per cent and 31% of truck beds and forklift wheels, respectively, were contaminated. The proportion of contaminated fomites did not change significantly during the day. CONCLUSIONS: This study has identified trucks, forklifts, pallets, crates, drivers' and catchers' boots as potential sources of C. jejuni for broilers. SIGNIFICANCE AND IMPACT OF THE STUDY: Campylobacter jejuni contamination of broiler processing plant fomites was found to be extensive ranging from 31% for truck beds to 75% for pallets. The proportion of contaminated fomites was observed to be similar throughout the day. The impact of contaminated fomites as sources of colonization of broilers with C. jejuni is discussed.

Prevalence and clonal diversity of Campylobacter jejuni from dairy farms and urban sources.

AIM: To investigate the role of free-living animals such as sparrows, rodents and flies as potential reservoirs of Campylobacter spp on a dairy farm, and to assess the genetic diversity among Campylobacter isolates from the farm and an urban source. METHODS: A total of 290 samples (bovine, passerine and rodent faeces, and whole flies) were collected from a large commercial dairy farm in the Manawatu district in New Zealand, and from faeces from urban sparrows in a nearby city. Other samples collected from the dairy farm included five from silage, two from aprons worn by workers during milking, two from workers' boots and two from water in troughs in a paddock. Isolates of thermophilic Campylobacter spp were identified morphologically and phenotypically and further characterised molecularly using pulsed-field gel electrophoresis (PFGE) and the restriction enzyme SmaI. RESULTS: Campylobacter jejuni was the only Campylobacter species isolated from all samples. The highest prevalence was found in faeces from dairy cows (54%), followed by faeces from sparrows from the urban area (40%) and the farm (38%), and from rodents (11%) and whole flies (9%). Other samples from the farm environment such as silage, trough water, and workers' aprons and boots were also positive for C. jejuni. Of the 22 restriction patterns obtained, seven were common to more than one source. CONCLUSIONS: Cattle, sparrows, rodents and flies are potential reservoirs of C. jejuni on dairy farms. Identical clones of C. jejuni carried by cattle, sparrows, flies and rodents probably indicate a common source of infection. The high level of asymptomatic carriage of C. jejuni by healthy dairy cows could be sufficient to maintain infections within the dairy farm surroundings via environmental contamination.

A comparison of bacterial adherence to bare hands and gloves following simulated contamination from a beef carcass.

One of the risks for contamination of edible product in the pre-inspection area of processing lines in meat plants is cross contamination. This can occur directly as a result of carcass-to-carcass contact or indirectly via knives or the hands of butchers. Standard procedures require that operators rinse their hands and knives to remove any visible contamination. In New Zealand, protective gloves are not allowed in the pre-inspection area because they are considered a potential risk for cross contamination until the carcasses have passed the final meat inspection. However, the risk of injury to the bare hands is as high in this area as in other parts of the plant, where such gloves are permitted. There is therefore a need to evaluate the risk of bacterial cross contamination via bare hands and via protective gloves. The present study compared bacterial adherence to bare hands and to gloves after rinsing for 5 s in a shower of water at 40 degrees C and after rinsing gloves in hotter water (60 degrees C) following simulated contact with the hide of a recently slaughtered animal. Under laboratory conditions there were no statistically significant differences between bacterial adherence to bare hands or to gloves rinsed in water at 40 degrees C or 60 degrees C.

Assessment of the humane aspects of electric lancing of whales by measurement of current densities in the brain and heart of dead animals.

The potential physiological effects of the electric lance are assessed, as used in Japanese whaling operations. Current densities are measured in the brains and hearts of six whales to which a controlled current of 5 A is applied by two electrodes inserted at various sites in the carcasses. The whales vary in size from 1.8 m (22 kg) to 16 m (40 t). The minimum current density in the brain necessary to cause depolarisation of neurones is estimated to be 10 mA cm-2 and to cause ventricular fibrillation is estimated to be 0.5 mA cm-2. No current densities exceeding 4.8 mA cm-2 are recorded in the brain. Very few recordings of current density from the heart are above 0.5 mA cm-2, and they occur only when electrodes are in optimal positions. When electrodes are placed as in whaling operations, no whale over 3 m in length would receive current densities in the heart or brain sufficient to cause permanent dysfunction. It is concluded that electric lancing is ineffective as a secondary method of killing whales and that the current densities recorded could cause pain and suffering to an already distressed animal.

The role of wild birds and the environment in the epidemiology of Yersiniae in New Zealand.

A survey was carried out to determine the prevalence of Yersiniae in wild passerines in the lower half of the North island of New Zealand over a period of 12 months. Samples of soil, water and foliage were also collected. Out of a total of 1370 avian samples, only two strains of Y. pseudotuberculosis were isolated and a total of 98 strains of environmental yersiniae were identified, including Y. enterocolitica biotype 1a, Y. frederiksenii, Y. kristensenii and Y. intermedia. No strains of Y. pseudotuberculosis were isolated from 1032 non-avian samples collected, which included 100 samples taken from wild mammals. From the non-avian samples, 51 strains of environmental Yersiniae were identified, of which the relative prevalence of Yersinia enterocolitica, biotype 1a, Y. frederiksenii, Y. kristensenii and Y. intermedia was similar to that in the rural passerines. The prevalence of Yersiniae in soil samples was greater in rural areas than in urban areas of the survey region. In both rural and urban passerine populations, the prevalence of Yersiniae was greater in the winter and early summer than at other times of the year.

The use of a shotgun for the emergency slaughter or euthanasia of large mature pigs.

The isolated heads of a Friesian bull and three large, Large White pigs were shot from various aspects with a 12-gauge shotgun using both a single 28 g solid lead projectile and buckshot, the latter consisting of nine individual lead pellets with a combined mass of 28 g. The sites of impact to the skull included the conventional frontal region, an occipital site and immediately behind the ear. A live mature Large White sow was shot with buckshot in the depression just caudal to the right ear, resulting in immediate insensibility and death. The damage caused to the isolated heads indicated that similar effects could be expected if the heads had been part of intact living animals. It is suggested that buckshot (nine lead pellets with a combined mass of 28 g) fired from a 12-gauge shotgun may be suitable for the emergency slaughter or euthanasia of a wide variety of domestic livestock and other species of animal.

The use of a shotgun for euthanasia of stranded cetaceans.

A 12-gauge shotgun, loaded with either a solid 28 g lead slug or buckshot consisting of nine individual lead pellets with a total mass of 28 g, was used to shoot the heads of one dead common dolphin (Delphinus delphis) and five dead long-finned pilot whales (Globicephala melaena) varying in length from 2.5 m to 5 m. The dolphin and the smallest pilot whale were shot with both projectiles from the dorsal surface of the head. The projectiles penetrated the head and dorsal surface of the skull, but not the base of the cranium. This site using buckshot was not effective in the larger animals. Two whales between 3 and 4 m in length were shot with buckshot through the lateral side of the head caudal to and above the eye, without penetration of the contralateral side of the head. It is concluded that shooting smaller cetaceans with a shotgun can be effective and safe. Further work is required to develop more suitable projectiles for cetaceans up to the size of mature pilot whales.

The isolation of Yersinia species from retailed sausages containing venison.

Thirteen isolates of Yersinia spp., regarded as environmental strains, were recovered from 70 sausages containing venison which were presented for sale through retail outlets. It is not possible to incriminate venison as the source of these strains because the sausages contained other food ingredients. The pathogenic potential of such environmental strains remains unclear.

Duration of carriage and transmission of Yersinia enterocolitica biotype 4, serotype 0:3 in dogs.

Human infections with pathogenic strains of Yersinia enterocolitica have been linked to contact with dogs excreting these microorganisms. This study examines the carriage and transmission of Y. enterocolitica biotype 4, serotype 03 in dogs. Fourteen 6-month-old cross-bred dogs were separated into 5 groups, 2 containing 4 dogs (I and II) and the others 2 dogs (III-V). Each of the 4 dogs in Group I and 2 of the dogs in Group II were inoculated orally with the test strain. Bacteriological examination of faecal samples showed that dogs can be readily infected and can carry the organism for up to 23 days. The two in-contact dogs in Group II started to shed the test organism after 5 days. Subsequent transfer of these dogs to Group III and those in Group III to Group IV showed that Y. enterocolitica biotype 4, serotype 03 can be readily transmitted between dogs. At no time did any of the dogs show clinical signs of infection. Group V served as a negative control for the trial. These findings suggest that dogs can carry Y. enterocolitica biotype 4, serotype 03 asymptomatically and hence might act as a potential source of infection for people.

Lesions in the carcasses and viscera of very young slaughter calves condemned at post-mortem meat inspection.

The carcasses of 370 very young slaughter calves condemned for various diseases and defects at routine post-mortem meat inspection were subjected to further and more detailed macroscopic examination as well as histopathological examination of some tissues. Of the carcasses examined, 138 were condemned for navel ill, and in the majority of these cases the lesions extended beyond the umbilicus, particularly involving the umbilical vein and the urachus. Enzootic pneumonia was the most common cause of pleuritic lesions in the carcass, and 75 carcasses were condemned for this lesion. Arthritis, whether localised or involving a number of joints, was the primary lesion in 32 carcasses. Focal interstitial nephritis was observed in the kidneys of 36 carcasses, while 23 carcasses were condemned for wounds and bruising. A number of other miscellaneous diseases and defects, including generalised peritonitis, jaundice, hepatic abscesses and fever, were observed at low rates in condemned carcasses. Resolution or localisation of lesions had occurred at the time of slaughter on average in 35% of the condemned carcasses and the judgment of total condemnation was difficult to justify on a scientific basis and would not have been applied to other classes of slaughtered livestock. In the case of wounds and bruising, 95.6% of the carcasses could have been trimmed. There was also considerable variation in the likely pathogenesis and systemic effects of the diseases and defects observed. A need for clear and specific judgment criteria to be applied to the carcasses of very young slaughter calves at post-mortem meat inspection was identified.

Organisation of veterinary public health in the western Pacific region.

Information on veterinary public health organisation and activities was obtained from government sources in countries located in the Western Pacific region. This region has a wide range of geographical features, population densities, farming practices, social structures and disease prevalences. In spite of this variation, there is common agreement on the importance of veterinary public health both for the provision of safe food and for the control of zoonotic diseases. Not all countries, however, are able to put all the resources they would wish into these activities; financial, social and personnel constraints are recognised.