Antimicrobial susceptibility and genetic characterization of Escherichia coli recovered from frozen game meat.

The increasing number of antimicrobial resistant Enterobacteriaceae both in veterinary and human medicine, the dissemination of these bacteria in several environments and their possible repercussions on human health is causing concern. Game meat is usually seen as free of antimicrobial resistant bacteria. The objective of this study was to evaluate the current antimicrobial susceptibility status in generic Escherichia coli isolated from packed frozen game meat from a game handling establishment in Germany. A total of 229 E. coli isolates were obtained from cuts of red deer, roe deer and wild boar. The susceptibility to 12 antimicrobial agents was evaluated by a broth microdilution method according to ISO 20776-1:2006. Minimal Inhibitory Concentration (MIC) values were compared to breakpoints and cut-off values published by the EUCAST. Isolates showing MICs above the reference values were further studied for associated resistance determinants and phylogrouping by PCR. Overall, 16 E. coli isolates (7.0%) showed resistance (microbiological or clinical) to at least one antimicrobial agent tested. Clinical resistance was recorded to ampicillin (5/229) and chloramphenicol (4/229), whereas the MIC of 9 isolates exceeded the epidemiological cut-off value for doxycycline. One of the ampicillin-resistant isolates showed resistance to the ß-lactam antibiotic derivatives tested, cephalosporines and aztreonam. Three of 9 non-wild-type isolates for doxycycline were positive for tet (B) genes. The ß-lactam-resistant isolate was found to harbour blaCTX-M-1 gene. These data show a low prevalence of resistant E. coli in packed game meat compared to studies on conventional meat. Although isolates obtained in this study may also be originating from the processing environment and not necessarily from animals, based on our results, it is important to monitor the development of antimicrobial resistance in game animals and products in order to identify future threats for the consumers.

Extended-spectrum ß-lactamase- and AmpC-producing enterobacteria in healthy broiler chickens, Germany.

During 2010, we evaluated the presence of extended-spectrum ß-lactamase- and AmpC-producing enterobacteria in broiler chickens at slaughter. Samples (70 carcasses and 51 ceca) from 4 flocks were analyzed by direct plating and after enrichment. Extended-spectrum ß-lactamase producers were found in 88.6% and 72.5% of carcasses and ceca, respectively; AmpC producers were found in 52.9% and 56.9% of carcasses and ceca, respectively. Most isolates were identified as Escherichia coli; Enterobacter cloacae (cecum) and Proteus mirabilis (carcass) were found in 2 samples each. Molecular characterization revealed the domination of CTX-M genes; plasmidic AmpC was CIT-like. Phylogenetic grouping of E. coli showed types A (31.5%), B1 (20.2%), B2 (13.5%), and D (34.8%). These findings provide evidence that healthy broilers in Germany are a source for the dissemination of transmissible resistance mechanisms in enterobacteria brought from the rearing environment into the food chain during slaughtering.

The effects of Campylobacter numbers in caeca on the contamination of broiler carcasses with Campylobacter.

For the presence and number of Campylobacter, 18 broiler flocks were sampled over a period of 18 months. A total of 70% of the flocks were positive for Campylobacter, with higher prevalence found in summer and autumn, compared to winter and spring. Positive flocks showed contamination rates above 90%, in negative flocks this was lower, mostly below 50%. The enumeration showed a decrease in Campylobacter during processing of positive flocks. The numbers were highest in carcasses after scalding/defeathering (mean 5.9 log10 cfu/carcass) and dropped by 0.7 log10 cfu/carcass after chilling. A positive correlation was observed between the number of Campylobacter present in the caeca and the number of bacteria present on carcasses and cut products. When a negative flock was slaughtered after Campylobacter positive flocks, the number of positive samples was higher compared to the case when a negative flock had been slaughtered previously. C. jejuni was isolated from 73.6% of the poultry samples.

Microbiological quality of sushi from sushi bars and retailers.

Sushi is a traditional Japanese food, mostly consisting of rice and raw fish. Fish is considered a healthy food, but as with other animal products, consumption of raw muscle incurs potential health risks such as ingestion of pathogenic bacteria or parasites. In this study, 250 sushi samples were analyzed for their microbiological status and the prevalence of pathogenic bacteria. A comparison was made between frozen sushi from supermarkets and fresh sushi from sushi bars. Aerobic mesophilic bacteria counts differed for sushi from these two sources, with means of 2.7 log CFU/g for frozen sushi and 6.3 log CFU/g for fresh sushi. The prevalence of Escherichia coli and Staphylococcus aureus was higher in the fresh samples. Salmonella was found in four (1.6%) of the sushi samples, and Listeria monocytogenes was found in three (1.2%) of the samples. These results indicate that the microbiological quality of industrially processed sushi is higher than that of freshly prepared sushi. The quality of freshly prepared sushi strongly depends on the skills and habits of the preparation cooks, which may vary.

Incidence of Arcobacter spp. in poultry: quantitative and qualitative analysis and PCR differentiation.

Arcobacter is part of the family Campylobacteraceae. As with the genus Campylobacter, Arcobacter is found responsible for human gastrointestinal infection, and it is assumed to originate from poultry meat sources. Samples from poultry slaughtering originating from a broiler slaughterhouse and a turkey slaughterhouse were analyzed for Arcobacter. Five broiler flocks and five turkey flocks were analyzed in the course of slaughtering and processing for the prevalence of Arcobacter. The prevalence in broilers was 43.0%, while turkey samples were contaminated with 18.2% of positive samples. The numbers of Arcobacter present on turkey skin samples ranged between 1.7 and 2.4 log CFU/cm2. The prevalence changes during processing showed an increase after chilling in broilers, whereas there was a constant decrease in turkey processing. Species identification showed that all three Arcobacter spp. of relevance in human infection could be isolated, with A. butzleri being found at higher prevalence, which was followed by A. skirrowii and A. cryaerophilus.

Prevalence of Campylobacter spp. in poultry and poultry products for sale on the Bulgarian retail market.

The aim of this study was to investigate the presence of Campylobacter spp. in poultry and poultry products available for the consumers at retail markets in Bulgaria. Samples (n = 210) of poultry carcasses and poultry products for sale at the retail market in Bulgaria were analysed for the presence of Campylobacter spp., of these 35 frozen whole carcasses, 135 chilled poultry cuts (45 wing cuts, 45 thigh cuts and 45 fillet) and 40 thermally treated (ready-to-eat) poultry products. The results obtained showed that 35.2% of the frozen poultry carcasses for sale in the markets were Campylobacter contaminated. In the chilled poultry cuts Campylobacter was isolated at the highest percentage in wing- and thigh cuts, 91.1% and 88.9%, respectively. The fillet samples were contaminated by Campylobacter in 48.9% of cases. In the chilled poultry products as well as in the frozen carcasses C. jejuni (74.8%/70.3%) was the most commonly isolated Campylobacter species, with the remainder being C. coli (25.2%/29.7%). Campylobacter spp. were not detected in the thermally treated poultry products.

Quantification of thermophilic Campylobacter spp. in broilers during meat processing.

Campylobacter spp. is a common cause of gastrointestinal illness. Since animal products, especially poultry meat, are an important source of human outbreaks of campylobacteriosis, tracing back to processing and initial production is of great interest. Samples were collected at a German poultry slaughterhouse for the estimation of the prevalence of Campylobacter at different processing steps. Quantification of Campylobacter in each of the samples was also performed. Out of 99 samples examined, 51 (51.5%) were positive for Campylobacter, with bacterial counts ranging from log(10) 6.5 cfu sample(-1) for carcasses to log 3.6 cfu ml(-1) for scalding water. The Campylobacter isolates (n = 51) were subtyped by pulsed-field gel electrophoresis using SmaI and KpnI restriction enzymes. Molecular typing showed a multitude of strains with different molecular patterns. Strains found in cloacal swabs before processing could also be isolated from carcasses at different processing steps.

Prevalence of Campylobacter spp. in turkey meat from a slaughterhouse and in turkey meat retail products.

One hundred and forty-four samples of chilled turkey meat from six flocks, taken directly from the slaughterhouse, and 100 samples of turkey meat retail products were examined. Over one-quarter (29.2%) of the tested samples from the slaughterhouse were Campylobacter positive, showing high variability in the flocks. The lowest percentage of Campylobacter-positive samples was found in flocks I and III (8.3%), whereas, in flock VI, 91.7% of the samples were Campylobacter positive. Turkey meat retail products showed a prevalence of 34% for Campylobacter. Heat-treated meat was negative for Campylobacter. Quantitative studies of the samples taken at the slaughterhouse revealed a mean log range of 1.9-2.5 CFU g(-1)Campylobacter spp. Results from the quantification of retail products gave a mean log value of 2.1 CFU g(-1).

Impact of different storage factors on the survivability of Campylobacter jejuni in turkey meat.

Campylobacter jejuni is often prevalent in turkey and poultry, but the effects of storage temperatures and storage periods and the interruption of the cooling chain on its survival have not been evaluated so far. In this study, 700 samples of turkey meat were artificially contaminated by inoculating their surface with 10(3) CFU of C. jejuni per sample, wrapped in airtight cellophane bags, and stored under different chilling and freezing conditions for various storage periods; this was followed by analysis of the cultures. Subsequent to incubation at 25 degrees C for 48 h, C. jejuni was reisolated in only 7% of the samples. When the samples were stored under refrigerator conditions at 4 degrees C, the organism was reisolated in 42% of the samples after 1 week, and in 28% of the samples after 2 weeks. The recovery rates in the samples that had been stored frozen at -20 degrees C without interruption of the cooling chain were 68% after 2 weeks and 24% after 4 weeks. Different storage conditions were simulated in order to examine the impact of an interruption of the cooling chain on the survival of Campylobacter.