OBJECTIVETo determine the contamination condition of Salmonella in broiler breeding and slaughter processing in China and to investigate the distribution of antimicrobial resistance profiles.

METHODSFive large-scale broiler holdings and fourteen slaughterhouses were chosen to detect Salmonella in Henan, Jiangsu, Sichuan and Shandong provinces in 2010. A total of 835 anal swabs and 744 chicken carcasses were sampled to compare the difference of Salmonella contamination rate.Salmonella isolates were identified by serotyping according to Kauffmann-White scheme.The antimicrobial susceptibilities of Salmonella isolates were determined by broth microdilution method and sixteen antimicrobial agents were chosen and examined.

RESULTSIn total, Salmonella isolates were recovered in 56 (6.7%) specimens among 835 collected anal swabs and 122 (16.4%) specimens among 744 broiler carcasses. Positive rate of Salmonella in broiler carcasses was higher than anal swabs (χ(2) = 36.94, P < 0.05). The dominant Salmonella serovars isolated from broiler anal swabs were S.enterica serovar Indiana and S.enterica serovar Enteritidis, accounting for 58.9% (33/56) and 32.1% (18/56) respectively. The prevalent serovars in broiler carcasses were also the two serovars and occupied 29.8% (37/124), 32.2% (40/124) respectively. Nearly 95.0% (171/180) Salmonella isolates were resistant to at least one antimicrobial, 78.3% (141/180) Salmonella strains were multi-drug resistant isolates and 20 (11.1%) Salmonella isolates were resistant to 14 antimicrobials.

CONCLUSIONOur findings indicated that Salmonella contamination was common and serious in commercial broiler production and processing course in China. Salmonella contamination rate in broiler slaughter processing performance was higher than broiler flocks. Additionally, antibiotic resistance of Salmonella was in serious situation.

Animals ; Chickens ; microbiology ; China ; Drug Resistance, Multiple, Bacterial ; Food Contamination ; Meat-Packing Industry ; Salmonella ; classification ; drug effects ; isolation & purification ; Serotyping

OBJECTIVETo investigate the pollution level and development trend of lead in the preserved egg in our country.

METHODSBy the national food contamination monitoring system and under the strict analysis quality control, the content of lead in the preserved eggs was analyzed according to the national standard method (GB/T 5009.12-2003) in fourteen provinces from 2000 to 2006.

RESULTSAll 1358 data on contents of lead in the preserved eggs were obtained during seven years, the total average was 1.782 mg/kg, the maximum was 334.0 mg/kg, P90 was 3.50 mg/kg, P95 was 7.397 mg/kg and P97.5 was 12.01 mg/kg, all exceeded 2 mg/kg of the national limit standard, and the rate of violated samples exceeded 10.0%. Analyzing from time, contents of lead in the preserved eggs were depressive from 2.994 mg/kg to 1.138 mg/kg year after year.

CONCLUSIONThe lead contamination in preserved eggs was serious in whole country. It shows that the continuous work of monitoring and forewarning should be carried out to make the contamination of lead in preserved eggs to reduce year by year.

China ; Eggs ; analysis ; Food Contamination ; analysis ; Food Handling ; methods ; Food Inspection ; methods ; Lead ; analysis

OBJECTIVETo improve the mini-modified semi solid rappaport vassiliadis most probable number (mini-MSRV MPN) method for Salmonella detection.

METHODSBased on the mini-MSRV MPN method,Buffered Peptone Water (BPW) was modified as one step enrichment medium and Modified Semi Solid Rappaport Vassiliadis (MSRV) medium was ameliorated as modified MSRV for Salmonella detection under standard Salmonella addition recovery. A total of 154 raw chicken samples, 48 swabs of pheasantry and 48 poultry dung samples were collected to compare the detection results of Salmonella by using improved mini-MSRV MPN, mini-MSRV MPN and regular most probable number (MPN) method.

RESULTSSalmonella recovery was < 2.7 MPN/g when the standard Salmonella addition was at the concentration of 0.9 CFU/g when the mini-MSRV MPN method was employed. If the standard Salmonella addition were at 9.0 and 90.0 CFU/g, the recoveries of bacteria were 10.1 and 94.0 MPN/g, and the average recovery rate was 112% and 104%, respectively. Salmonella detection rate of modified mini-MSRV MPN, mini-MSRV MPN and regular MPN method was 18.4% (46/250), 5.2% (13/250) and 6.0% (15/250), respectively. The detection rate was higher for modified mini-MSRV MPN method than of the other two methods (χ(2) values were 19.68 and 17.82, respectively, all P values < 0.05). The detection quantity of Salmonella (medians were 21.0, < 2.7 and < 3.0 MPN/g, respectively). The quantity detected by modified mini-MSRV MPN method was higher than that of the other two methods (both Z values were 5.71, both P values < 0.05).

CONCLUSIONModified mini-MSRV MPN method is an accurate method for foodborne Salmonella detection.

Animals ; Chickens ; microbiology ; Culture Media ; Food Contamination ; analysis ; Food Inspection ; methods ; Salmonella ; isolation & purification

OBJECTIVEThe loop-mediated isothermal amplification (LAMP) detection method was applied to detect Listeria monocytogenes in food. The specificity and sensitivity of this method were evaluated through comparing it with Real-time PCR and conventional detection method.

METHODSThe LAMP primers were designed based on hly gene of Listeria monocytogenes. The LAMP method was applied to detect 88 Listeria monocytogenes, 1 reference strain ATCC 15313 of Listeria monocytogenes and 33 non-targets bacteria strains; base-material addition test and practical food samples detection were also conducted. Both of Real-time PCR and ISO 11290-1 methods were used as parallel detection method in addition to LAMP. The three kinds of methods were compared by specificity, sensitivity, detection limit and the detection result of practical food samples.

RESULTSBoth detection results of LAMP and Real-time PCR for 89 Listeria monocytogenes were positive (100%, 89/89), 33 non-targets bacteria strains were negative (100%, 33/33). The sensitivity of LAMP was 2 × 10² CFU/ml, which was consistent with Real-time PCR method (2 × 10² CFU/ml) and better than ISO 11290-1 method (2 × 10² CFU/ml). Base-material addition test result showed that the detection limit of the three kinds of methods were 3 CFU/25 g samples. And the result of practical food samples displayed the same detection rate of 4% in the three methods (2/45).

CONCLUSIONThe LAMP method of Listeria monocytogenes established in this study has good specificity and sensitivity, which can be applied to the rapid detection of Listeria monocytogenes.

Food Contamination ; analysis ; Food Inspection ; methods ; Food Microbiology ; Listeria monocytogenes ; genetics ; isolation & purification ; Nucleic Acid Amplification Techniques ; methods

In recent years, China has become an increasingly important and the largest chestnut producer in the world. This study aimed to evaluate the nutritional value and microbiological quality of the roasted freeze-dried Chinese chestnut (Castanea mollissima) (RFDC) coated with dark chocolate (DCC) and milk chocolate (MCC) for industrial use and commercial consumption. Chocolate coating significantly improved the nutritional value of chestnut. RFDC had high levels of starch (66.23%) and fibers (3.85%) while DCC and MCC contained significantly high amounts of sucrose, protein, fat and minerals. Furthermore, the protein content doubled in MCC rather than in DCC. This could be attributed to the different formulations in the two products. Milk powder and whey protein constituted the source of protein in MCC while cocoa powder added to MCC formulation constituted an additional source of minerals. The amino acid profile showed differences in amino acid composition related to the sample's protein content, indicating their good nutritional quality. The moisture contents in all RFDC, DCC and MCC were suitable for industrial processing. These results provide information about the additional nutrients of chocolate-coated chestnut and confirm that the product is an interesting nutritional food. The combination of freeze-drying and chocolate-coating generally results in greater reductions on microbiological loads, extending shelf life of harvested chestnut for commercial application. This is an alternative strategy to add value to chestnut, minimizing the significant losses in harvested fruits and providing a wider range of choices of new products to the consumer disposal.
Cacao ; chemistry ; microbiology ; China ; Fagaceae ; chemistry ; microbiology ; Food Analysis ; Food Handling ; methods ; Food Microbiology ; Food Packaging ; methods ; Fruit ; chemistry ; microbiology ; Nutritive Value

OBJECTIVETo investigate Benzo (a) pyrene (BaP) residue in retail food of Xiamen.

METHODSBaP residue in 121 retail food samples collected from Xiamen were determined by a rapid BaP detector based on derivative constant-energy synchronous fluorescence technique.

RESULTSBaP was detected in 84.3% samples and the concentration were ranged from 0.17 to 59.0 microg/kg. There were 49.6% samples exceeding 5.00 microg/kg, and most of them were roasting food (1.44 - 54.10 microg/kg), processed meat products (0.17 - 59.00 microg/kg) and aquatic products (2.79 - 36.80 microg/kg). The BaP concentration in 34 samples collected from roadside stands were 1.78 - 49.60 microg/kg, of which the rate of the samples exceeding 5.00 microg/kg was 88.2%.

CONCLUSIONThe BaP contamination in retail food samples from Xiamen is serious.

Benzo(a)pyrene ; analysis ; China ; Food Contamination ; analysis ; Food Inspection ; methods ; Meat Products ; analysis

OBJECTIVETo investigate the lead and cadmium pollution in edible mushrooms sold in Beijing.

METHODS146 samples of 14 species were collected form 25 markets during the period of Mar. through May, 2007 in Beijing. The pollution of lead and cadmium were analyzed respectively according to the standard of GB/T5009. 12-2003 and GB 7096-2003.

RESULTSThe content of lead and cadmium in edible mushrooms was ND--1.592 mg/kg, ND--0.550 mg/kg, respectively, both lower than the allowable content prescribed by The National Ministry of Health.

CONCLUSIONThe contents of lead and cadmium in the mushrooms marketed in Beijing are in safe ranges. It is worthy of mentioning the variation coefficients of heavy metal concentrations existing in edible mushrooms.

Agaricales ; Cadmium ; analysis ; China ; Food Contamination ; statistics & numerical data ; Food Inspection ; Lead ; analysis

OBJECTIVETo study main risk factors that cause foodborne diseases in food catering business.

METHODSData from references and investigations conducted in food catering units were used to establish models which based on @Risk 4.5 with Monte Carlo method referring to food handling practice model (FHPM) to make risk assessment on factors of food contamination in food catering units. The Beta-Poisson models on dose-response relationship to Salmonella (developed by WHO/FAO and United States Department of Agriculture) and Vibrio parahaemolyticus (developed by US FDA) were used in this article to analyze the dose-response relationship of pathogens.

RESULTSThe average probability of food poisoning by consuming Salmonella contaminated cooked meat under refrigeration was 1.96 × 10(-4) which was 1/2800 of the food under non-refrigeration (the average probability of food poisoning was 0.35 at room temperature 25°C). The average probability by consuming 6 hours stored meat under room temperature was 0.11 which was 16 times of 2 hours storage (6.79 × 10(-3)). The average probability by consuming contaminated meat without fully cooking was 1.71 × 10(-4) which was 100 times of consuming fully cooked meat (1.88 × 10(-6)). The probability growth of food poisoning by consuming Vibrio parahaemolyticus contaminated fresh seafood was proportional with contamination level and prevalence.

CONCLUSIONThe primary contamination level, storage temperature and time, cooking process and cross contamination are important factors of catering food safety.

Disease Outbreaks ; prevention & control ; Food Handling ; methods ; Food Microbiology ; Food Services ; organization & administration ; Foodborne Diseases ; epidemiology ; prevention & control ; Models, Theoretical ; Risk Assessment ; Risk Factors ; Software

OBJECTIVETo introduce green fluorescence protein (GFP) into E. coli O157:H7 and improve the detection methods for this bacteria, and to study the kinetics of E. coli O157:H7.

METHODSThe plasmid pGFP was transferred into E. coli O157:H7. The characteristic of the new built O157:H7-pGFP strain was evaluated. Some food samples were inoculated with the recombinant strain under certain temperature to imitate different storage circumstances. The contaminated E. coli O157:H7 were counted after certain time.

RESULTSThe pGFP was stable in E. coli O157:H7. The E. coli O157:H7-pGFP inoculated in ground poultry meat and pasteurized milk were enriched to 35 000 approximately 200 000 times in 12 h under higher storage temperature (37 degrees C), whereas the quantity decreased slowly under lower temperature (4 degrees C).

CONCLUSIONThe recombinant strain with the characters of ampicillin resistance and green fluorescence under UV 365 nm was a useful tool in detection methods improvement and bacteria survival studies.

Colony Count, Microbial ; Escherichia coli O157 ; isolation & purification ; Food Contamination ; Food Handling ; methods ; Food Microbiology ; Green Fluorescent Proteins ; Meat Products ; microbiology

China ; Consumer Product Safety ; standards ; Food Contamination ; prevention & control ; Food Inspection ; standards ; Food Microbiology ; Foodborne Diseases ; prevention & control ; Humans