Routes for Campylobacter contamination of poultry meat: epidemiological study from hatchery to slaughterhouse.

From April 1998 to March 2000, 18 broiler flocks were followed from the hatchery to the slaughterhouse. Campylobacter was not found in the hatchery, 1-day-old chicks or in the rearing house before the arrival of the chicks. The infection of broiler flocks increased continuously during the rearing time, with a total of seven positive flocks at the end of rearing. Farms with Campylobacter-positive broilers were characterized by the circulation of Campylobacter in the environment (puddles, dung hill) and on the footwear of the farmer. The administration of antibiotics did not significantly reduce Campylobacter shedding. With the exception of one flock during rearing and a few flocks in the slaughterhouse with a mixed Campylobacter coli-Campylobacter jejuni infection, C. jejuni exclusively was found both during rearing and on the carcasses. A significant correlation exits between the contamination of the broilers during rearing and the carcasses after processing. No slaughterhouse was able to avoid contamination of carcasses when status-positive animals were delivered. Moreover, six negatively delivered flocks yielded positive carcasses, the result of a supplementary contamination, which occurred during transport and slaughtering.

Routes for salmonella contamination of poultry meat: epidemiological study from hatchery to slaughterhouse.

Data were collected on the prevalence of salmonella at different stages during the life cycle of 18 broiler flocks on different farms as well as during slaughter in different poultry slaughterhouses. For the isolation of salmonella, the highest sensitivity (93.9%) was obtained by enrichment in the semi-solid agar Diasalm. The 'overshoe method' utilizing several pairs of overshoes provided the highest sensitivity for determining the salmonella status of the broilers during rearing. A clear decrease of the relative importance of the first production stages was demonstrated for the salmonella contamination of the end product, whereas horizontal transmission of salmonella to broilers during rearing and to broiler carcasses in the slaughterhouse was shown to be the main determinative factor. Ten of the 18 flocks received a salmonella positive status with the highest shedding occurring during the first 2 weeks of rearing. The shedding of the animals was significantly negatively influenced by the use of subtherapeutic or therapeutic doses of antibiotics. The intake of portable material in the broiler house was identified as the most important risk factor for horizontal transmission. Significant associations were found between the contamination level of a flock and hygiene of the broiler house, feed and water in the broiler house and both animal and non-animal material sampled in the environment. No correlation was found between contamination during the rearing period and contamination found after slaughtering. The presence of faecal material in the transport crates and predominantly the identity of the slaughterhouse seemed to be the determining factors for carcass quality. Improved hygiene management during transport of broilers and in some slaughterhouses could significantly reduce the risk of salmonella contamination of poultry meat.

A numerical taxonomic study of the Pseudomonas flora isolated from poultry meat.

Pseudomonas strains were isolated from both fresh and cold-stored broiler skin. Phenotypically-based numerical taxonomic techniques were used to characterize the isolates and 36 reference strains. For this purpose, Biolog GN Microplates, API 20NE and a number of other biochemical tests were used. Jaccard clustering revealed the predominance of four major Pseudomonas groups: Ps. fragi, Ps. lundensis, strains belonging to Ps. fluorescens biovars and an unidentified group of strains displaying a high degree of similarity to Ps. fluorescens biovars. Within Ps. fluorescens, biovar A was best represented. The marked proteolytic character of members of Ps. fluorescens biovars A, B and C, as well as of members of the unidentified cluster, supports their possible role in the origin of organoleptic defects. In the Ps. lundensis cluster, a distinct group of Ps. lundensis-like species was found. Further genotypic studies should be carried out to clarify the taxonomic status of the Ps. lundensis-like strains and that of the unidentified group resembling Ps. fluorescens biovars A and B.

Identities of the Pseudomonas spp. in flora from chilled chicken.

Nine broilers from each of two different broiler farms were collected at the slaughterhouse. Microbiological samples were collected from broiler chicken carcasses which were stored aerobically at 3+/-0.5 degrees C for 0, 3 or 8 days. By characterizing 40 colonies per broiler it was possible to evaluate the shift in psychrotrophic bacteria on the skin during cold storage. Most of these bacteria belong to the pseudomonads. The Shewan scheme was used in order to distinguish between four groups of pseudomonads. On fresh poultry group II pseudomonads were most abundantly represented, followed by group IV; group I and III strains were present in lower amounts. Non-fluorescing group II pseudomonads always predominated as spoilage became obvious (day 8). By including 36 reference strains, numerical analysis based on the simple matching coefficient was performed on 180 representatively selected strains. This revealed that Pseudomonas species indeed predominated when spoilage was obvious. Non-fluorescing species were identified mainly as P. fragi, but also as other strains belonging to P. fluorescens biovars A, B, C and F, P. lundensis and cluster 7 strains (unidentified). Microorganisms already substantially present on the fresh poultry were found in the highest numbers at the time of spoilage.

Influence of the inoculum concentration on the recovery of Listeria from meat by L-Palcamy enrichment.

Concentration of the inoculum in L-Palcamy broth enrichment had a marked influence on the recovery of Listeria from meat samples. A 1/100 dilution of ground meat yielded twice as many positive samples as the usually recommended tenfold dilution, whereas no such effect was observed with cheese or vegetables.