Pasteurization profiles of cured meats products with respect to safety

A total of 162 heat penetration sets were collected during commercial pasteurization of 9 types of cured meats. Calculated FP7a-values (with z=10°C) ranged from 45 to 391 min. For L. monocytogenes (D70 =0.27 min) such FP70 represented at least 167 to 1448 decimal reductions (DR) to the initial population of the pathogen. Lack of healing uniformity in lots of the same product and samples in the same chamber was detected. Maximum core temperatures and FP70 values could vary by up to 6.4°C and up to 345 min respectively. Observed FP70 may affect product nutritional value, yield decrease and energy waste. In hundreds of samples of cooked in casing product no Salmonella spp, L.monocytogenes and E.coli were detected immediately after processing. During 2003-5 no Salmonella spp was detected in 404 in retail samples of sliced or pealed meats produced by 8 companies. L.monocytogenes incidence was 7.9%. Incidence per company for sliced and pealed products ranged from 2.5-40% and 0-20% respectively. Incidence decreased with age since production day. Commercial thermal processing of meat products is more than sufficient to assure safety from non-sporoforming pathogens. Cross contaminations lead to isolations of pathogens from cooked and later sliced and repackaged products

Elimination of cross reactions during detection of Salmonella spp., with commercial ELISA kits

In this paper we first speculated and later on have proved that the increased number of Salmonella positive results, using the Salmonella Tek-Eiisa method as compared to the standard technique, was due to false positive results of the former method. We found out that the higher sensitivity of the former method was due to P.stuartii E. cloacae and E.coli bacteria (CRBs), which cross-reacted with the monoclonal antibodies of the method, giving rise to a higher number of Salmonella false positive results. The purpose of the present study was to identify the source of the higher sensitivity of the Elisa Tek technique and propose corrective steps

Prevalence of L.monocytogenes and Listeria spp., in the environment and raw meat products during pig slaughtering, deboning and meat cutting operations.

From 9/2001 –6/2002 we estimated the prevalence of Listeria monocytogenes and Listeria spp., in the environment, and raw pork products of a meat plant. Of 41environmental samples taken before and after initiation of slaughtering, in 2 visits, 10.7% and 7.7% of the samples respectively harbored L. monocytogenes. In each of 2 additional visits we collected 45 samples each time from carcass surfaces. L. monocytogenes was present 2.2% and 2.2% of the samples respectively. Of 109 environmental surface samples from the deboning room before and 104 taken 2-3 h after the beginning of the operation 3.7% and 5.8% harbored L. monocytogenes. Of 132 environmental surfaces samples taken before and 125 after the initiation of work in a special working area handling the cutting and packaging of modified atmosphere (MAP) consumer size meat cuts 3% and 5.6% harbored L. monocytogenes. Of 35 wholesale meat cuts from imported meat collected in the central deboning and cutting room 34.3% harbored L. monocytogenes. Finally of 201 consumer size MAP products prepared from the company`s own pig carcasses, 6% harbored L. monocytogenes. The results indicated the low prevalence of L.monocytogenes on local origin carcasses and MAP cuts prepared from such carcasses under strict sanitary conditions. Cross contaminations of equipment and worker’s hands from imported meats may result in excessive contamination of meat cuts whether the meat is imported or local

Seroprevalence and antibiotic sensitivity of Salmonella enterica serotypes in Greek swine herds

Blood samples were taken from 50 pigs in each of 59 farrow-to-finish herds and from 40 gilts in each of 4/5 registered multiplying herds. Samples of feed and faeces were collected from 17 of the production herds and from the multiplying herds. The sera were tested for antibodies by the Danish-mix-ELISA (positive cut-off OD\u3e10 or OD\u3e40 %), and the organisms were isolated, serotyped and sensitivity tested by standard techniques. The average within herd seroprevalence was 15.6 or 3.4% and at least one pig tested seropositive in 52/59 or 21159 production herds at the low and the high cut-off values, respectively. All the multiplying herds had seroreactors at the low but only a single seroreactor was detected at the high cut-off. The salmonellae isolated were S. tennessee, S. typhimurium. S. bredeney, S. london and an untypable strain. The S. typhimurium and S. london had low sensitivity to streptomycin, kanamycin and neomycin. the former had low sensitivity also to amoxicillin, ticarcillin, piperacillin, cefalotin and cefoperazone. The other isolates were sensitive to the antimicrobial agents tested

Post harvest epidemioilogy of Salmonella enterica in pork: Prevalence in the environment, carcasses and by-products in two slaughterhouses in Greece (1996-1998)

In this study our objective was to estimate the prevalence of Salmonella enterica in the environment, on the pork carcasses and on several by-products in 2 industrial slaughterhouses over a 2-year period. In the period from 1/7/96 until 1/8/98, 1874 samples were obtained from the slaughterhouse environment (from the floor, the worker\u27s hands and their knives), product samples (from pork carcasses) and by products (livers and plucks). The prevalence of infection in pigs slaughtered at the sampling dates was estimated by testing samples from mesenteric lymph nodes and caecal content. Environmental samples were collected before the onset of slaughter. After the onset of slaughter and for every 50 pigs, a round of samplings of all sources mentioned above was repeated. Salmonella isolation and identification was carried out by standard cultural method. In total, based on the isolation method, 178/1874 (9.5%) samples were positive. The mean prevalence on floors, workers\u27 hands. workers\u27 knives, pork carcasses and by-products were 19.6% (range: 0%-100%), 5.2% (0%-50%), 3.1% (0%-37.5%), .3% (0%-88.9), 6.6% (0%-90%), respectively. The average prevalence of infection in pigs slaughtered at the sampling dates was 20.7% based on mesenteric lymph nodes and 15.2% based on caecal contents. Before the onset of slaughter, 37.5%, 6.3% and 8.7% of samples obtained from floors, worker hands and knives harbored Salmonella. This may reflect an inadequate plant hygiene. The frequent presence of Salmonella in the caecal contents and the lymph nodes may contribute to significant environmental contamination, including inspectors hands, eventually leading to final product contamination. The isolated salmonellae belonged to 22 serotypes. Among those, S. Derby and S. London were the most frequent representing 25.8% and 15.2% respectively. In conclusion, the frequent presence of Salmonella spp. in the lymph nodes, may indicate infection in the herd. Furthermore, the moderate prevalence of Salmonella on carcasses and by-products calls for further identification and institution of postharvest control options

Antibiotic sensitivity profile of Salmonella isolated from two slaughterhouses and human clinical cases

The antibiotic sensitivity of Salmonella strains isolated during the period 1996-98 from two industrial slaughterhouses of Northern Greece was detennined and compared with that of salmonellae isolated from human hospital cases during the period 1995-1997. For antibiotic sensitivity the disc agar diffusion method was used. Of 1874 samples obtained from the slaughterhouse environment (floors, worker\u27s hands and their knives), pork carcasses, by-products (livers and plucks) as well as lymph nodes and caecal contents 178 (9.5%) were positive for Salmonella spp. The salmonellae belonged to 22 serotypes. S. derby, S. london and S. typhimurium represented 25.8%, 15.2%, and 10.7% of the serotypes respectively. Of the salmonellae 59%, and 4.5%, were resistant and 33%, and 4.5% were intermediate sensitive to Tetracyclin, and Streptomycin, respectively and 26.4%, 14.6%, 5.1%, 1.7% and 1% were resistant to Ampicillin, Sulfamethoxa\u3eole I Trimethoprim, Chloramphenicol, Gentamicin, and Tobramycin respectively. Of the S. typhimurium strains 47% were resistant to Ampicillin and 41.2% to Chloramphenicol. Seven of the 19 strains were DT I 04, isolated for the first time in Greece, and multiple drug resistant. Of all isolates 5.1% were resistant to Chloramphenicol, the use of which is prohibited in food animal veterinary practice. Of the 422 salmonellae isolated at the Hospital of Infectious Diseases in Thessaloniki during the period 1996-98 77.4% were S. enteritidis and 17.7% S. typhimurium. Of the salmonellae isolated during 1995-1997, 76-79 % were resistant to Ampicillin and 1.2-1.5% to Chloramphenicol. Many of S. typhimurium strains isolated from the slaughterhouses and human cases exhibited the same antibiotic sensitivity profile a fact indicative of a potential transfer of animal strains to humans. Salmonellae of the same serotype exhibited different antibiotic resistance profiles, an indication of the presence of different clones within the same serotype. No S. enteritidis was isolated in slaughterhouses

A farm-level study of risk factors associated with the colonization of broiler flocks with Campylobacter spp. in Iceland, 2001 – 2004

<p>Abstract</p> <p>Background</p> <p>Following increased rates of human campylobacteriosis in the late 1990's, and their apparent association with increased consumption of fresh chicken meat, a longitudinal study was conducted in Iceland to identify the means to decrease the frequency of broiler flock colonization with <it>Campylobacter</it>. Our objective in this study was to identify risk factors for flock colonization acting at the broiler farm level.</p> <p>Methods</p> <p>Between May 2001 and September 2004, pooled caecal samples were obtained from 1,425 flocks at slaughter and cultured for <it>Campylobacter</it>. Due to the strong seasonal variation in flock prevalence, analyses were restricted to a subset of 792 flocks raised during the four summer seasons. Flock results were collapsed to the farm level, such that the number of positive flocks and the total number of flocks raised were summed for each farm. Logistic regression models were fitted to the data using automated and manual selection methods. Variables of interest included manure management, water source and treatment, other poultry/livestock on farm, and farm size and management.</p> <p>Results</p> <p>The 792 flocks raised during the summer seasons originated from 83 houses on 33 farms, and of these, 217 (27.4%) tested positive. The median number of flocks per farm was 14, and the median number of positive flocks per farm was three. Three farms did not have any positive flocks. In general, factors associated with an increased risk of <it>Campylobacter </it>were increasing median flock size on the farm (p ≤ 0.001), spreading manure on the farm (p = 0.004 to 0.035), and increasing the number of broiler houses on the farm (p = 0.008 to 0.038). Protective factors included the use of official (municipal) (p = 0.004 to 0.051) or official treated (p = 0.006 to 0.032) water compared to the use of non-official untreated water, storing manure on the farm (p = 0.025 to 0.029), and the presence of other domestic livestock on the farm (p = 0.004 to 0.028).</p> <p>Conclusion</p> <p>Limiting the average flock size, and limiting the number of houses built on new farms, are interventions that require investigation. Water may play a role in the transmission of <it>Campylobacter</it>, therefore the use of official water, and potentially, treating non-official water may reduce the risk of colonization. Manure management practices deserve further attention.</p