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1.
Extended spectrum β‐lactamase (ESBL) and plasmid‐mediated AmpC β‐lactamase (pAmpC) producing Escherichia coli have been shown to be present in humans and animals representing a significant problem worldwide. This study aimed to search the presence of ESBL and/or AmpC‐producing E. coli in retail meats (chicken and beef) in Turkey. A total of 88 β‐lactamase‐producing E. coli were isolated from chicken (n = 81/100) and beef meat (n = 7/100) samples and their susceptibility to several antimicrobials were tested using disc diffusion method. E. coli isolates were further characterized for their phylogenetic groups. β‐Lactamase encoding (blaTEM, blaSHV, blaOXA, blaCTX‐M, and blaAmpC) and quinolone resistance genes (qnrA, qnrB, qnrS, qepA, and acc(6′)‐Ib‐cr) were also secreened by polymerase chain reaction (PCR). However, in regard to β‐lactamase genes, 84 of 88 isolates were positive for blaCTX‐M‐1 (n = 39), blaCTX‐M‐3 (n = 5), blaCTX‐M‐15 (n = 4), blaTEM‐1b (n = 2), blaSHV‐12 (n = 1), blaCTX‐M‐1/blaTEM‐1b (n = 10), blaCTX‐M‐1/blaTEM‐1b/blaSHV‐5 (n = 1), blaCTX‐M‐1/blaCMY‐2 (n = 1) and blaTEM‐1b/blaCMY‐2 (n = 6), blaCTX‐M‐15/blaSHV‐12 (n = 1), blaCTX‐M‐15/blaTEM‐1b (n = 1), blaTEM‐1b/blaSHV‐12 (n = 1), and blaCMY‐2 (n = 12) genes. Resistance to cefuroxime (75.6% and 85.7%), nalidixic acid (89% and 85.7%), tetracycline (91.4% and 100%), streptomycin (40.2% and 100%), and trimethoprim‐sulfamethoxazole (36.6% and 85.7%) was observed among strains isolated from chicken and beef, respectively. However, all isolates were found to be susceptible to amikacin, imipenem, and cefepime. Resistance to ampicillin and cefoxitin was significantly linked to blaCMY‐2 gene, while there was a significant correlation between CTX‐M type ESBL and antimicrobial resistance to cefuroxime and streptomycin (P < 0.05). The results of this study suggest that raw chicken retail meats are highly contaminated with ESBL‐producing E. coli implementing a great risk to human health in Turkey.  相似文献   

2.
The aim of this work was to develop a molecular method using loop‐mediated isothermal amplification (LAMP) for detection of extended spectrum β‐lactamase (ESBL)‐producing Enterobacteriaceae from meat, and to compare it with different isolation agars and microarrays. LAMP assays were developed for CTX‐M groups 1, 2, and 9 and OXA‐10‐like genes. Chicken, lamb, beef, pork, and turkey samples were spiked with 10, 100, and 1,000 cfu/gram using 8 strains of ESBL‐producing Enterobacteriaceae (CTX‐M sequence types 1, 2, 3, 14, 15, OXA‐11, SHV‐2, TEM‐52) +/– a mix of competitor organisms. Samples were enriched overnight in buffered peptone water (BPW) +/– antibacterials before plating to CHROMagar CTX, OXOID ESBL Brilliance agar, and MacConkey agar with 1 mg/L cefotaxime. Selected BPW broths were also tested using LAMP assays, microarrays and using cefpodoxime discs on agar. For isolation/detection of ESBL producers from beef, pork, lamb, and turkey spiked with 10 or 100 cfu/gram ESBL (natural flora only), all agars and the LAMP assays showed 100% sensitivity and specificity for ESBL spike strains. For chicken samples, both LAMP and chromogenic agars showed improved sensitivity and specificity for isolation of ESBLs compared with MacConkey agar, particularly with competitor bacteria added. In comparison, the cefpodoxime disc method and microarray showed reduced sensitivity.  相似文献   

3.
The aim of this study was to investigate the presence of extended‐spectrum β‐lactamase (ESBL) and plasmid‐mediated quinolone resistance (PMQR) genes in Escherichia coli isolated from retail meat samples in Henan Province, China. E. coli isolates were detected in 179 of 645 (27.7%) retail meat samples. Resistance of these isolates to antimicrobials was commonly observed, with 78.2% of isolates resistant to streptomycin, 74.3% resistant to tetracycline and 54.2% resistant to trimethoprim/sulfamethoxazole. Of the 179 isolates, 30 (16.7%) expressed ESBL, with blaTEM‐1 (n = 17) and blaCTX‐M‐14 (n = 9) most commonly mediating the ESBL phenotype. PMQR genes were present in 14 isolates (7.8%), with qnr and aac(6′)‐Ib‐cr detected alone or in combination in nine (5.0%) and seven isolates (3.9%), respectively. The qnr genes detected included qnrS1 (n = 5), qnrA1 (n = 3), and qnrB4 (n = 1). The qepA gene was absent among these isolates. CTX‐M‐14 was the most prevalent ESBL type among the PMQR‐positive isolates. The qnr and aac(6′)‐Ib‐cr genes were found to co‐reside and be co‐transferred with blaCTX‐M‐14 or blaTEM‐1 in five isolates. Our data suggest that retail meat may act as a reservoir for multi‐resistant E. coli and may facilitate the dissemination of resistance genes.  相似文献   

4.
The objective of this study was to evaluate the effect of dietary olive leaves versus α‐tocopheryl acetate on lipid and protein oxidation of raw and cooked longissimus dorsi muscle from pigs fed diets supplemented with fish oil. Enrichment of pork with the very long chain n‐3 fatty acids increased ( 0.05) lipid oxidation in both raw and cooked chops during refrigerated storage, and decreased ( 0.05) the sensory attributes of the cooked chops, but had no effect (> 0.05) on protein oxidation of both raw and cooked chops. Dietary olive leaves or α‐tocopheryl acetate had no effect (> 0.05) on the fatty acid composition but decreased ( 0.05) lipid oxidation while exerting no effect (> 0.05) on protein oxidation in both raw and cooked chops during refrigerated storage. In addition, dietary olive leaves at 10 g kg?1 feed and α‐tocopheryl acetate at 200 mg kg?1 feed exerted ( 0.05) a beneficial effect on the sensory attributes of cooked n‐3‐enriched chops.  相似文献   

5.
This study investigated the presence of methicillin‐resistant Staphylococcus aureus (MRSA) in raw meat and fish and foods prepared from them for patient consumption in public hospitals in Salvador, Bahia, in northeastern Brazil. A total of 114 samples of raw meat and fish (chicken, n = 30; beef, n = 30; pork, n = 24; and fish, n = 30) and 63 samples of prepared foods (made with chicken, n = 15; beef, n = 15; pork, n = 15; and fish, n = 18) were collected from the kitchens of 10 different hospitals. Of the 114 investigated raw meat and fish samples, 28.1% were positive for MRSA, which comprised 23.3% beef, 23.3% chicken, 37.5% pork, and 30% fish samples. Of the prepared foods, 9.5% were positive for MRSA, which comprised 5.6% chicken products, 6.7% pork products, and 22.2% fish products. MRSA contamination was not detected in prepared beef dishes. A statistical analysis showed no association between the presence of MRSA and the type of raw food (P > 0.05). The high prevalence of MRSA among the raw foods tested and the presence of the microorganism in prepared foods emphasizes the necessity of enforcing hygienic practices within hospital kitchens.  相似文献   

6.
The aim of this study was to determine the possibility of 3‐D scanning method in chemical composition evaluation of pork meat. The sampling material comprised neck muscles (1000 g each) obtained from 20 pork carcasses. The volumetric estimation process of the elements was conducted on the basis of point cloud collected using 3‐D scanner. Knowing the weight of neck muscles, their density was calculated which was subsequently correlated with the content of basic chemical components of the pork meat (water, protein and fat content, determined by standard methods). The significant correlations (P ≤ 0.05) between meat density and water (r = 0.5213), protein (r = 0.5887), and fat (r = ?0.6601) content were obtained. Based on the obtained results it seems likely to employ the 3‐D scanning method to compute the meat chemical composition.  相似文献   

7.
The objective of this study was to predict the total viable counts (TVC) and total volatile basic nitrogen (TVB‐N) in pork using an electronic nose (E‐nose), and to assess the freshness of chilled pork during storage using different packaging methods, including pallet packaging (PP), vacuum packaging (VP), and modified atmosphere packaging (MAP, 40% O2/40% CO2/20% N2). Principal component analysis (PCA) was used to analyze the E‐nose signals, and the results showed that the relationships between the freshness of chilled pork and E‐nose signals could be distinguished in the loadings plots, and the freshness of chilled pork could be distributed along 2 first principal components. Multiple linear regression (MLR) was used to correlate TVC and TVB‐N to E‐nose signals. High F and R2 values were obtained in the MLR output of TVB‐N (F = 32.1, 21.6, and 24.2 for PP [R2 = 0.93], VP [R2 = 0.94], and MAP [R2 = 0.95], respectively) and TVC (F = 34.2, 46.4, and 7.8 for PP [R2 = 0.98], VP [R2 = 0.89], and MAP [R2 = 0.85], respectively). The results of this study suggest that it is possible to use the E‐nose technology to predict TVB‐N and TVC for assessing the freshness of chilled pork during storage.  相似文献   

8.
This study aimed to investigate the effect of the fast cooling process on the microbiological community in chilled fresh pork during storage. We established a culture‐independent method to study viable microbes in raw pork. Tray‐packaged fresh pork and chilled fresh pork were completely spoiled after 18 and 49 d in aseptic bags at 4 °C, respectively. 16S/18S ribosomal RNAs were reverse transcribed to cDNA to characterize the activity of viable bacteria/fungi in the 2 types of pork. Both cDNA and total DNA were analyzed by high‐throughput sequencing, which revealed that viable Bacteroides sp. were the most active genus in rotten pork, although viable Myroides sp. and Pseudomonas sp. were also active. Moreover, viable fungi were only detected in chilled fresh pork. The sequencing results revealed that the fast cooling process could suppress the growth of microbes present initially in the raw meat to extend its shelf life. Our results also suggested that fungi associated with pork spoilage could not grow well in aseptic tray‐packaged conditions.  相似文献   

9.
Changes were measured in TBARS, color, and volatiles of irradiated (4.5 kGy) pork patties with antioxidants (sesamol, quercetin, rutin, BHT, and rosemary oleoresin) during 7 days storage at 4°C. Irradiation accelerated lipid oxidation of raw pork during storage. However, irradiation before cooking did not influence lipid oxidation of cooked pork during storage. Sesamol, quercetin, and BHT were effective in both irradiated raw and cooked pork during 7-days storage. Rosemary oleoresin and rutin were effective only in irradiated raw pork for 3 days. Hexanal, propanal and higher boiling components were well correlated (P < 0.01) with TBARS in cooked pork. Generation of volatiles was reduced by sesamol and quercetin, but the effects of antioxidants on color changes of raw pork patties were minor and inconsistent.  相似文献   

10.
The individual and combined effects of muscle vitamin E level, cooking conditions (duration, temperature and rate) and packaging on lipid oxidation in refrigerated cooked pork were examined. Oxidative stability following cooking was higher in pork with a higher vitamin E level (p<0.01), cooked at a lower cooking temperature (p<0.01), cooked for a shorter time (p<0.01), cooked at a faster cooking rate (p<0.05) or stored in vacuum packs (p<0.01). Significant two-way and three-way interactions were observed between the effects of muscle vitamin E level, cooking conditions and packaging on lipid oxidation. Adopting more than one of these approaches to minimize lipid oxidation was more effective than adopting a single approach.  相似文献   

11.
The effect of the modified wheat gluten (MWG) extender, prepared by alcalase‐based hydrolysis and transglutaminase cross‐linking, on meatballs was analyzed in this study. Here, we studied the effect of MWG addition on the boiling resistance capacity of pork meatballs (MB‐MWG) at high temperature (100 °C) and increasing cooking time; meatballs with added soy protein isolates (MB‐SPI) and raw wheat gluten (MB‐WG) were used as references. The cooking loss, water‐holding capacity (WHC), and textural properties of meatballs were investigated. The results revealed that MB‐MWG showed lower cooking loss, which decreased by 49.16% compared to meatballs without added extenders when treated for 30 min. The WHC of MB‐MWG significantly increased from 80.68% to 95.42%. The hardness, springiness, and chewiness (textural properties) of MB‐MWG were also significantly increased by 97.05%, 6.68%, and 121.96%, respectively. The addition of MWG increased the cross‐linking in meatballs during the cooking process, as indicated by the higher G′. SDS‐PAGE indicated an obvious decrease in myosin heavy chain in MB‐MWG cooked for 30 min at 100 °C, which was attributed to the interaction of myofibrillar proteins in pork meat with MWG. The nuclear magnetic resonance T2 relaxation time patterns indicated that MWG addition caused an increase in the bound water content, and decrease in the free water content, of meatballs. An analysis of the microstructures revealed that the MB‐MWG formed the most regular and compact network. Therefore, MWG could be used as an ingredient to facilitate the processing of meat products.  相似文献   

12.
Raw-meat patties were prepared from three pork muscles, irradiated in different packaging environments, and stored for 0 or 3 days before cooking. Lipid oxidation by-products were formed in the raw meat during storage and the baseline lipid oxidation data of raw meat was used to measure the progression of lipid oxidation after cooking. Thiobarbituric acid-reactive substances (TBARS) and volatiles data indicated that preventing oxygen exposure after cooking was more important for cooked meat quality than packaging, irradiation, or storage conditions of raw meat. Propanal, pentanal, hexanal, 1 -pentanol, and total volatiles correlated highly (P < 0.01) with TBARS values of cooked meat. Hexanal and total volatiles represented the lipid oxidation status better than any other individual volatile components.  相似文献   

13.
Four hybridoma cell lines secreting monoclonal antibodies (MAbs) specific to porcine thermal-stable muscle proteins (TSMPs) were developed. The MAbs reacted with three protein bands (20.5, 22 and 24 kD) from raw pork extract; the protein band (24 kD) which was also present in cooked pork was identified as porcine-specific TSMP. Epitope analysis indicated four MAbs recognized same or closely located antigenic sites on the pork TSMP. The developed MAb-based indirect enzyme-linked immunosorbent assay (ELISA) enabled the detection of pork in raw and cooked heterogeneous meat mixtures as low as 10 g/kg. The curvilinear relations of second-degree polynomial (r2 > 0.995) between pork concentrations and ELISA responses enabled quantifying degree of adulteration of pork in meat products.  相似文献   

14.
Heterocyclic amines (HCAs) are mutagenic and carcinogenic compounds found in cooked meat and fish. Although HCAs are known to form adducts with protein after metabolic activation, adduct formation during cooking has not been elucidated. In this study, we showed that 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) is released from high molecular weight compounds by acid or enzymatic hydrolysis of cooked foods. Formation of free and protein adduct forms of PhIP was dependent on cooking temperature and time, and PhIP–protein adducts were estimated to form after formation of free PhIP. We also demonstrated that PhIP–protein adduct is formed by heating of PhIP and albumin as a model protein. A new adduct peak including [M+H]+ (m/z=225) of PhIP as a fragment ion was detected in the high molecular weight fraction of heat‐treated protein by LC–MS analysis. From model experiments by heating of PhIP and amino acids, the adduct was estimated to be produced by condensation of the amino group of PhIP and the carboxyl group of protein. PhIP–protein adducts were detected in several cooked meat and fish at ng/g food level as PhIP content. These results suggest that food‐borne protein adducts of HCAs may influence human HCA exposure and carcinogenic risk.  相似文献   

15.
目的:分析成都市各地区生鲜猪肉样品中耐甲氧西林金黄色葡萄球菌(Methicillin-resistant Staphylococcus aureus,MRSA)的流行特征。方法:对鉴定出的MRSA菌株进行SCCmec分型、spa分型以及多位点序列(MLST)分型分析,同时运用PCR技术对MRSA菌株携带的多种毒力基因、生物被膜形成相关基因、耐消毒剂基因以及耐药基因进行检测,并采用K-B纸片扩散法调查MRSA菌株的耐药表型。结果:本研究从297株猪肉源金黄色葡萄球菌中筛选出24株MRSA菌株,分离率为8.08%。MRSA菌株主要以ST88-IVa-t1376、ST59-IVa-t437和ST9-IVb-t3433型为主,携带耐药基因3~7个;所有菌株均表现出对氨苄西林和青霉素G耐药,并且存在多重耐药情况;分离菌株携带多种肠毒素基因,其中MRSA8和MRSA13菌株携带了完整的egc基因簇;MRSA分离菌株均携带clfB、eno、icaBC和sasG等生物被膜形成相关基因;携带耐消毒剂基因(qacA/B、qacC和qacG)的菌株占比为62.5%,其中以qacG为主要携带基因类型。另外,79.17%的MRSA菌株携带溶血素基因(hla、hlb),所有菌株中杀白细胞素基因(pvl)均未检出。结论:成都市猪肉源MRSA的流行可能存在一定的交叉污染,应加强动物源食品携带MRSA菌株的监测。  相似文献   

16.
Low‐fat ground pork patties (<10% total fat) made with carrageenan added at either 0.25, 0.50 or 0.75% final concentration were processed and the compositional and sensory characteristics compared with control patties which contained 20% fat. The moisture content of raw and cooked low‐fat patties was significantly (P < 0.05) higher than control patties because of greater amounts of water added during formulation. Cooking yield, fat and moisture retention also improved significantly (P < 0.05) in low‐fat patties that had carrageenan incorporated when compared to a control product. The dimensions of the low‐fat patties were maintained better than those of the control product during cooking. The sensory attributes of low‐fat patties with 0.5% carrageenan were similar to those of the high‐fat control. The lipid profile revealed as much as a 47.7 or 44.1% decrease in total lipids and cholesterol content respectively, compared with the controls. The calorie content was reduced by 31.1% in low‐fat cooked patties compared with the controls. The texture profile of low‐fat patties that had been made with 0.5% carrageenan were similar to control patties with only a slight increase in hardness and gumminess in the low‐fat product. The low‐fat ground pork patties made in the present study remained stable without any appreciable loss of physico‐chemical, microbiological and organoleptic quality during refrigerated storage (4 ± 1 °C) for 21 and 35 days in aerobic and vacuum packaging respectively.  相似文献   

17.
水浴复热时间对猪肉糜制品挥发性风味的影响   总被引:1,自引:0,他引:1  
利用动态顶空-气相色谱-质谱联用结合嗅闻技术对不同水浴复热时间(0、5、20、35、65?min)处理猪肉糜制品挥发性风味物质含量进行分析。结果表明,不同复热时间样品共鉴定出54?种风味物质,共有物质36?种;复热前期(5~20?min)以醛类物质为主,复热后期(35~65?min)酸类物质含量大幅升高;戊醛、己醛、辛醛、(E,E)-2,4-癸二烯醛含量随复热时间延长呈先升后降趋势,1-辛烯-3-醇和2-戊基呋喃受复热时间影响不显著(P>0.05);基于风味活性值分析和主成分分析,复热显著改变猪肉糜制品风味;以戊醛、己醛、辛醛和(E,E)-2,4-癸二烯醛为过熟味(warmed-off flavor,WOF)评价指标,随复热时间延长,WOF对猪肉糜制品总体复热风味的贡献略降。因此,脂质氧化是猪肉糜制品复热风味形成的主要途径,较短时间复热更易促进WOF产生。  相似文献   

18.
Modified atmosphere packaging (MAP) is increasingly popular for meat, but raw, chilled pork in vacuum or anoxic environments has a purple color. The retail shelf‐life of pork chops dipped in 500 ppm ascorbic acid, 250 ppm citric acid, or no acid dip and stored at 1 °C before simulated retail display in MAP with gas exchange or air‐permeable packaging after vacuum pouch storage was determined. The 80% N2:20% CO2 in MAP was exchanged with 80% O2:20% CO2, and chops were removed from vacuum packages and overwrapped with permeable film (VP‐PVC) on the 7th day before simulated retail display at 4 °C. Shelf‐life traits were determined at 1, 7, 8, 10, 12, and 14 d postpackaging. The pH values changed with time, but returned to post‐dipped, prepackaged levels at the end of simulated retail storage. Weight loss of chops increased (P < 0.05) in VP‐PVC compared with MAP. The a* values increased (P < 0.05) and L* and b* values decreased during simulated retail display, with higher L*, a*, and b* color values for chops in MAP than VP‐PVC. Log numbers of psychrotrophic microorganisms were higher (P < 0.05) on VP‐PVC samples than for chops in MAP on days 12 and 14. Psychrotrophic counts on ascorbic acid‐treated samples were decreased compared with citric acid or no dipping on pork during simulated retail display. Pork chops in MAP with gas exchange had lighter and redder color, increased weight retention, decreased psychrotrophic counts, and increased lipid oxidation compared with conventional vacuum and overwrap packaging systems.  相似文献   

19.
Extended‐spectrum β‐lactamases (ESBLs)‐producing Salmonella is a tremendous hazard to food safety and public health. The objective of this study was to determine the prevalence of 30 virulence genes (avrA, sipA, sseC, marT, rhuM, siiE, pipA, pipD, envR, gogB, gtgA, sodC1, sseI, irsA, sopE2, spvC, rck, spvR, fhuA, msgA, pagK, srfj, stkc, fimA, lpfD, pefA, stcC, steB, stjB, and tcfA) in 156 ESBLs‐producing Salmonella isolates that belonged to 21 serotypes. These isolates were recovered from retail raw chicken samples collected from 5 provinces and 2 national cities in China between 2007 and 2012. The results indicated that 154 (98.7%) ESBLs‐producing Salmonella isolates carried at least 1 virulence gene, 138 (88.5%) simultaneously carried at least 5 virulence genes, 107 (68.6%) carried 10 or more, and 20 (12.8%) carried 15 or more virulence genes. The most frequently detected virulence genes were marT (n = 127, 81.4%), siiE (n = 126, 80.8%), msgA (n = 121, 77.6%), and sipA (n = 121, 77.6%). Significant difference was identified between detection percentages of virulence genes of rhuM, pipD, envR, sopE2, pagK, lpfD, steB, and stjB in S. Indiana, S. Thompson, S. Enteritidis, S. Typhimurium, S. Shubra, S. Edinburg, and S. Agona isolates. Distribution of virulence genes were significantly influenced by sampling districts (< 0.01), especially for sodC1 and pipD, and then were msgA and sopE2. The heatmap showed the frequencies of virulence genes in ESBLs‐producing isolates from retail chickens in southern, central, and northern regions of China were completely different from each other. Based on our findings, ESBLs‐producing Salmonella of retail chicken origin were common carriers of multiple virulence genes and were regionally distributed.  相似文献   

20.
ABSTRACT: Effects of pork collagen in emulsified and whole muscle products were evaluated. Eight frankfurter treatments (0%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, and 3.5% pork collagen) and 4 ham treatments (0%, 1%, 2%, and 3% pork collagen) were formulated. Frankfurters and hams were evaluated for cooked yields, purge, color, texture, and sensory characteristics. Incorporation of pork collagen at 1% and above significantly ( P < 0.05) increased cooked and chilled yields in frankfurters but did not have any effect in hams. Purge was significantly ( P < 0.05) reduced in both frankfurters and hams after 4 wk of storage. Sensory difference testing showed no significant difference up to 2% usage level of pork collagen in both frankfurters and hams ( P > 0.05).  相似文献   

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