Twelve-hour PCR-based method for detection of Salmonella spp. in food.
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A PCR-based method for the detection of Salmonella spp. in food was developed. The method, set up on typical salami from the Italian region of Marche, is sensitive and specific and shows excellent correlation with the conventional method of reference when naturally contaminated foods are analyzed. Moreover, it can be easily performed within a maximum of 12 h from food sampling, thus allowing prompt detection of Salmonella spp. in the food stocks analyzed. (+info)
Sporadic Campylobacter jejuni infections in Hawaii: associations with prior antibiotic use and commercially prepared chicken.
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Campylobacter is the most common cause of bacterial foodborne illness in the United States, and Hawaii has the highest rate of Campylobacter jejuni infections in the nation. A case-control study was conducted to determine indigenous exposures that contribute to the high incidence of sporadic C. jejuni infection in Hawaii. A total of 211 case patients with diarrhea and confirmed Campylobacter infection was enrolled, along with 1 age- and telephone exchange-matched control subject for each patient. Participants were interviewed about illness, medicines, food consumption, food-handling practices, and exposure to animals. In matched logistic regression analyses, eating chicken prepared by a commercial food establishment in the 7 days before case illness onset (adjusted odds ratio [AOR], 1.8; P=.03) and consuming antibiotics during the 28 days before illness onset (AOR, 3.3; P=.03) were significant independent predictors of illness. Further study of the association of Campylobacter illness with commercially prepared chicken and prior antibiotic use is needed. (+info)
Surprising findings following a Belgian food contamination with polychlorobiphenyls and dioxins.
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We found that 12.1% of Belgian export meat samples from chicken or pork, unrelated to the PCB/dioxin crisis from 1999, contained more than 50 ng polychlorinated biphenyls (PCBs)/g fat and that 6.5% of samples contain more than 20 ng/g fat for the sum of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its metabolites. Part of this background contamination stems from imported animal feed ingredients (fish flour and grains), sometimes contaminated by recent use of DDT, as can be deduced from the ratio between DDT and its main metabolite, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE). However, after comparing PCB concentrations in fish flour and grains with those found in meat, we suggest that the high concentrations stem from recycled fat. This is the first paper describing background concentrations of PCBs in animal meat from Belgium. (+info)
Purification and characterization of an X-prolyl-dipeptidyl peptidase from Lactobacillus sakei.
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An X-prolyl-dipeptidyl peptidase has been purified from Lactobacillus sakei by ammonium sulfate fractionation and five chromatographic steps, which included hydrophobic interaction, anion-exchange chromatography, and gel filtration chromatography. This procedure resulted in a recovery yield of 7% and an increase in specificity of 737-fold. The enzyme appeared to be a dimer with a subunit molecular mass of approximately 88 kDa. Optimal activity was shown at pH 7.5 and 55 degrees C. The enzyme was inhibited by serine proteinase inhibitors and several divalent cations (Cu(2+), Hg(2+), and Zn(2+)). The enzyme almost exclusively hydrolyzed X-Pro from the N terminus of each peptide as well as fluorescent and colorimetric substrates; it also hydrolyzed X-Ala at the N terminus, albeit at lower rates. K(m) s for Gly-Pro- and Lys-Ala-7-amido-4-methylcoumarin were 29 and 88 microM, respectively; those for Gly-Pro- and Ala-Pro-p-nitroanilide were 192 and 50 microM, respectively. Among peptides, beta-casomorphin 1-3 was hydrolyzed at the highest rates, while the relative hydrolysis of the other tested peptides was only 1 to 12%. The potential role of the purified enzyme in the proteolytic pathway by catalyzing the hydrolysis of peptide bonds involving proline is discussed. (+info)
Method for the analysis of thyreostats in meat tissue using gas chromatography with nitrogen phosphorus detection and tandem mass spectrometric confirmation.
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An analytical method not requiring a mercury column cleanup step is described for the isolation and detection of four thyreostatic agents in meat tissue. The use of these growth promotants in livestock has been banned by regulatory agencies. The meat tissue is homogenized with acetonitrile-water, centrifuged, and the supernatant is partitioned with petroleum ether. The acetonitrile-water is concentrated and then passed through a silica-gel column. The solvent is then removed and the residue derivatized with N-methyl-N-(trimethylsilyl)-trifluoroacetamide. The total amount of organic solvent used for the analysis is merely 35 mL. The derivatized thyreostats are detected and quantitated by gas chromatography (GC) equipped with a nitrogen-phosphorus detector. Percent recoveries from fortified meat tissue (n = 6) at the 0.1-microg/g (parts per million) level are 93.5 +/- 2.9 for 2-thiouracil, 90.3 +/- 3.0 for tapazole, 87.5 +/- 2.9 for 6-methyl-2-thiouracil, and 85.1 +/- 5.8 for 6-n-propyl-2-thiouracil. For the confirmation of analyte identities, GC-tandem mass spectrometry with an ion-trap instrument is used. The estimated minimum level for a reliable measurement is 0.050 microg/g in meat tissue. (+info)
Systematic review of the prospective cohort studies on meat consumption and colorectal cancer risk: a meta-analytical approach.
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The relation between meat consumption and colorectal cancer risk remains controversial. In this report, we quantitatively reviewed the prospective observational studies that have analyzed the relation between meat consumption and colorectal cancer. We conducted electronic searches of MEDLINE, EMBASE, and CANCERLIT databases through to the end of June 1999 and manual searches of references from retrieved articles. We used both fixed and random-effects meta-analytical techniques to estimate the overall association and to investigate possible sources of heterogeneity among studies. Thirteen studies were eligible for inclusion in the meta-analysis. Pooled results indicate that a daily increase of 100 g of all meat or red meat is associated with a significant 12-17% increased risk of colorectal cancer. The marginally significant between-study heterogeneity for all meat and red meat was explained by a number of study-level covariates. A significant 49% increased risk was found for a daily increase of 25 g of processed meat. The individual study estimates for processed meat showed no detectable heterogeneity. On the basis of this quantitative review of prospective studies, the overall association between meat consumption and risk of colorectal cancer appears to be positive, with marginal heterogeneity between studies. The finding for processed meat and data from experimental studies suggests that it may also be an important predictor of colorectal cancer risk. However, because only a few of the studies reviewed here attempted to examine the independent effect of meat intake on colorectal cancer risk, the possibility that the overall association may be confounded or modified by other factors cannot be excluded. (+info)
Occurrence of vancomycin-resistant enterococci in pork and poultry products from a cattle-rearing area of France.
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Meat products were collected from public retail outlets and tested for the presence of vancomycin-resistant enterococci (VRE) in an area with a high prevalence of VRE reported in human fecal samples. VRE were detected in 66% of the samples, and a predominance of VanC strains was found, which is also true for human fecal samples. (+info)
A one-year study of foodborne illnesses in the municipality of Uppsala, Sweden.
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Surveillance was enhanced and a retrospective interview study performed in 1998-99 to determine incidence, causes, and costs of foodborne illnesses in Uppsala, Sweden. Sixty-eight percent of the detected foodborne illness incidents were single cases, and 32% were outbreaks. Most (85%) of the incidents came to the attention of the municipal authorities through telephone calls from affected persons. Calicivirus, Campylobacter spp., and Staphyloccocus aureus were the most common etiological agents; meat, meat products, and mixed dishes were the most implicated food categories. The incidence of foodborne illness was estimated to be 38 cases per 1,000 inhabitants per year. The estimated average costs per illness were 2,164 Swedish Krona (SEK) ($246) to society and 500 SEK ($57) to the patient. The annual cost of foodborne illnesses in Sweden was estimated to be 1,082 million SEK ($123 million). (+info)