Comparative analysis of Shigella boydii 18 foodborne outbreak isolate and related enteric bacteria: role of rpoS and adiA in acid stress response

Shigella boydii CDPH (Chicago Department of Public Health) serotype 18 was implicated in an outbreak of foodborne illness in 1998. The suspected food vehicles were parsley and cilantro imported from Mexico used to prepare bean salad. Previous studies revealed that S. boydii CDPH serotype 18 can survive in bean salad, which contains organic acids and whose pH decreases over time. Acid challenge assays in acidified tryptic soy broth at pH 4.5, acidified Luria-Bertani broth at pH 4.5, and acidified M9 minimal salts medium at pH 2.5 containing amino acids, arginine, or glutamic acid were performed using S. boydii CDPH, S. boydii ATCC 35966, S. flexneri 3136, Escherichia coli O157:H7 dd8872, and E. coli O157:H7 dd642 to compare differences in acid tolerance. Differences in survival of exponential-phase cells were detected in acidified tryptic soy broth and Luria-Bertani broth at pH 4.5. In acidified minimal medium containing arginine, S. boydii strains were able to survive at pH 2.5. The arginine decarboxylase gene (adiA) present in S. boydii is involved in survival at extremely low pH. The discovery of adiA expression in S. boydii serotype 18 by use of an acidified minimal medium challenge and arginine decarboxylase biochemical assay is significant because arginine decarboxylase activity was thought to be unique to E. coli. Sequencing of the rpoS gene from the S. boydii outbreak strain indicates that it is 99% conserved compared with the E. coli K-12 rpoS gene and plays a vital role in survival under acidic conditions.     

Influence of acid adaptation on the tolerance of Escherichia coli O157:H7 to some subsequent stresses

Three stains of Escherichia coli O157:H7, including ATCC 43889, ATCC 43895, and 933, were first subjected to acid adaptation at a pH of 5.0 for 4 h. Thermal tolerance at 52 degrees C and survival of the acid-adapted as well as the nonadapted cells of E. coli O157:H7 in the presence of 10% sodium chloride, 0.85% bile salt, or 15.0% ethanol were investigated. Results showed that the effect of acid adaptation on the survival of E. coli O157:H7 varied with the strains and types of subsequent stress. Acid adaptation caused an increase in the thermal tolerance of E. coli O157:H7 ATCC 43889 and ATCC 43895, but no significant difference in the thermal tolerance was noted between acid-adapted and nonadapted cells of E. coli O157:H7 933. Although the magnitude of increase varied with strains of test organisms, acid adaptation generally led to an increase in the tolerance of E. coli O157:H7 to sodium chloride. On the other hand, the susceptibility of acid-adapted cells of the three strains of E. coli O157:H7 tested did not show a significant difference from that of their nonadapted counterparts when stressed with bile salt. The acid-adapted cells of E. coli O157:H7 ATCC 43889 and ATCC 43895 were less tolerant than the nonadapted cells to ethanol, whereas the tolerance of adapted and nonadapted cells of E. coli O157:H7 933 showed no significant differences.     

Studies to select appropriate nonpathogenic surrogate Escherichia coli strains for potential use in place of Escherichia coli O157:H7 and salmonella in pilot plant studiest

The response of a potential nonpathogenic surrogate organism to a particular treatment should closely mimic the response of the target pathogenic organism. In this study, growth characteristics (generation time, lag phase duration, and maximum population), pH at stationary phase, and survival characteristics (level of attachment and survival on apple surfaces, resistance to hydrogen peroxide decontamination treatments, and thermal resistance at 60 degrees C) of 15 nonpathogenic generic Escherichia coli strains and one nonpathogenic E. coli O157:H43 strain were compared with those of two E. coli O157:H7 strains and two Salmonella strains. Few differences in growth characteristics or pH at stationary phase were evident between nonpathogenic and pathogenic strains tested. However, considerably more separation among strains was seen following investigation of survival characteristics. E. coli ECRC 97.0152, which does not contain genes encoding for known virulence factors associated with E. coli O157:H7, appears to be a good surrogate candidate, with growth and survival characteristics similar to those of E. coli O157:H7 strains. The less heat-resistant surrogate strains E. coli NRRL B-766 and NRRL B-3054 and E. coli ATCC 11775, ATCC 25253, and ATCC 25922 may be used when attempting to model the heat resistance of Salmonella Montevideo G4639 and Salmonella Poona RM 2350, respectively. These surrogate strains may be useful for evaluating the efficacy of intervention steps in reducing populations of selected strains of E. coli O157:H7 and Salmonella in processing environments where these pathogens cannot be introduced.     

Survival of enterohemorrhagic Escherichia coli O157:H7 in retail mustard

Escherichia coli O157:H7 survival in acid foods such as unpasteurized apple cider and fermented sausage is well documented. Researchers have determined that E. coli O157:H7 can survive in refrigerated acid foods for weeks. The potential of acid foods to serve as a vector of E. coli O157:H7 foodborne illness prompted this study to determine the fate of this organism in retail mustard containing acetic acid when stored at room and refrigerated temperatures. Various retail brands of dijon, yellow, and deli style mustard, pH ranging from 3.17 to 3.63, were inoculated individually with three test strains of E. coli O157:H7. Samples were inoculated with approximately 1.0 x 10(6) CFU/g, incubated at room (25+/-2.5 degrees C) and refrigerated (5+/-3 degrees C) temperatures, and assayed for surviving test strains at predetermined time intervals. An aliquot was appropriately diluted and plated using sorbitol MacConkey agar (SMAC). When the test strain was not recoverable by direct plating, the sample was assayed by enrichment in modified tryptic soy broth and recovered using SMAC. Growth of E. coli O157:H7 test strains was inhibited in all retail mustard styles. E. coli O157:H7 was not detected in dijon style mustard beyond 3 h at room and 2 days at refrigerated temperatures. Survival in yellow and deli style mustard was not detected beyond 1 h. Overall, test strain survival was greater at refrigerated than room temperature. Retail mustard demonstrated the ability to eliminate effectively any chance contamination by this organism within hours to days, suggesting that these products are not a likely factor in E. coli O157:H7 foodborne illness.     

Acid adaptation and temperature effect on the survival of E. coli O157:H7 in acidic fruit juice and lactic fermented milk product.

In this study, two strains of Escherichia coli O157:H7, (ATCC 43889 and ATCC 43895) were acid adapted at pH 5.0 in tryptic soy broth (TSB) for 4 h. Commercial products of mango juice (pH 3.2), asparagus juice (pH 3.6), Yakult--a diluted milk fermented drink (pH 3.6), and low-fat yoghurt (pH 3.9) were inoculated with acid-adapted or nonadapted cells of E. coli O157:H7. Survival of the inoculated E. coli O157:H7 in these commercial food products during storage at 25 or 7 degrees C was examined. It was found that although survival of the acid-adapted and nonadapted E. coli O157:H7 ATCC 43895 in asparagus juice during storage at 7 degrees C did not show marked difference, in general, acid adaptation and low temperature enhanced the survival of E. coli O157:H7 in both the commercial fruit juices tested. On the contrary, acid adaptation reduced the survival of both the strains of the test organism in Yakult and low-fat yoghurt stored at 7 degrees C. Besides, E. coli O157:H7 ATCC 43895 survived longer than ATCC 43889 in all the products examined, regardless of the storage temperature and acid adaptation.     

乳酸菌对肠出血性大肠杆菌O157:H7抑制作用的研究

为探讨乳酸菌对肠出血性大肠杆菌O157：H7 ATCC43895(E．Coli O157：H7)的抑制作用，在培养基上进行了研究。将E．Coli O157：H7与干酪乳杆菌干酪亚种、植物乳杆菌、发酵乳杆菌、乳酸乳球菌和瑞士乳杆菌同时接种在培养基中，E．Coli O157：H7的活性不受影响；将E．Coli O157：H7接种到培养了24h的乳酸茵培养液中，E．Coli O157：H7活性显下降。以乳酸调整的低pH值对E．Coli O157：H7有一定的杀灭作用。本研究表明：乳酸菌的代谢产物乳酸对E．Coli O157：H7有杀灭作用。     

Interactions of high hydrostatic pressure, pressurization temperature and pH on death and injury of pressure-resistant and pressure-sensitive strains of foodborne pathogens

The objective of this study is to determine the interactions between high hydrostatic pressure, pressurization temperature, time and pH during pressurization on death and injury of pressure-resistant and pressure-sensitive strains of four foodborne pathogens: Staphylococcus aureus 485 and 765, Listeria ,monocytogenes CA and OH2, Escherichia coli O157:H7 933 and 931, Salmonella enteritidis FDA and Salmonella typhimurium E21274. Among these strains S. aureus 485, L. monocytogenes CA, E. coli O157:H7 933 and S. enteritidis FDA were reported to be more pressure-resistant than the respective strain of the same species (Alpas et al., 1999). In general, viability loss of all pathogens was enhanced significantly as the level of pressure and temperature were increased (P < 0.05). All the strains except S. aureus 485 demonstrated more than 8 log cycle reduction when pressurized at 345 MPa at 50 degrees C for 5 min. This strain seemed to be the most pressure-resistant strain within the conditions of the study. Pressurization in the presence of either citric or lactic acid increased the viability loss by an additional 1.2-3.9 log cycles at pH 4.5 for both acids at 345 MPa. This study has indicated that high hydrostatic pressure applied in conjunction with mild heat and acidity can be an effective method for inactivating pressure-resistant and pressure-sensitive strains of four foodborne pathogens in organic acid solutions. This combination treatment indicates possible pressure pasteurization applications to liquid foods that have low pH. reserved.     

Acid stress, starvation, and cold stress affect poststress behavior of Escherichia coli O157:H7 and nonpathogenic Escherichia coli.

The effects of acid shock, acid adaptation, starvation, and cold stress of Escherichia coli O157:H7 (ATCC 43895), an rpoS mutant (FRIK 816-3), and nonpathogenic E. coli (ATCC 25922) on poststress heat resistance and freeze-thaw resistance were investigated. Following stress, heat tolerance at 56 degrees C and freeze-thaw resistance at -20 to 21 degrees C were determined. Heat and freeze-thaw resistance of E. coli O157:H7 and nonpathogenic E. coli was enhanced after acid adaptation and starvation. Following cold stress, heat resistance of E. coli O157:H7 and nonpathogenic E. coli was decreased, while freeze-thaw resistance was increased. Heat and freeze-thaw resistance of the rpoS mutant was enhanced only after acid adaptation. Increased or decreased tolerance of acid-adapted, starved, or cold-stressed E. coli O157:H7 cells to heat or freeze-thaw processes should be considered when processing minimally processed or extended shelf-life foods.     

Growth and survival of foodborne pathogens in beer

This work aimed to assess the growth and survival of four foodborne pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus) in beer. The effects of ethanol, pH, and storage temperature were investigated for the gram-negative pathogens (E. coli O157:H7 and Salmonella Typhimurium), whereas the presence of hops ensured that the gram-positive pathogens (L. monocytogenes and S. aureus) were rapidly inactivated in alcohol-free beer. The pathogens E. coli O157:H7 and Salmonella Typhimurium could not grow in the mid-strength or full-strength beers, although they could survive for more than 30 days in the mid-strength beer when held at 4°C. These pathogens grew rapidly in the alcohol-free beer; however, growth was prevented when the pH of the alcohol-free beer was lowered from the "as received" value of 4.3 to 4.0. Pathogen survival in all beers was prolonged at lowered storage temperatures.     

Acid tolerance and survival of Escherichia coli O157:H7 inoculated in fruit pulps stored under refrigeration.

The adaptation of Escherichia coli O157:H7 cells to acid conditions has been reported. This study showed the behavior of three strains of E. coli O157:H7 in two different physiological stages (acid shocked and control cells), inoculated in five fruit pulps stored at 4 degrees C for up to 30 days. The three strains of E. coli O157:H7 inoculated in grape pulp could be recovered up to day 30. E. coli O157:H7 strains survived for 4 days in all fruit pulps tested with different pH values (2.51 to 3.26), with the exception of acid-shocked cells of E. coli O157:H7 strain 933, which did not survive in "cajá" (Spodias lutea L.) pulp. The results clearly indicated that acid resistance can persist for long periods during storage at 4 degrees C. The protection conferred by acid adaptation suggests that acid-resistant organisms will be better equipped to outlast these acid challenges. The survival of E. coli O157:H7 in fruit pulps with a low pH, stored under refrigeration, is of extreme importance due to the high virulence of this microorganism. The viability of microorganisms was dependent on the viscosity index of fruit pulps. Less viscous pulps supported the bacteria survival longer than more viscous fruit pulps.     

Effect of stress induced by suboptimal growth factors on survival of Escherichia coli O157:H7.

This study investigated the growth and survival of E. coli O157:H7 exposed to a combination of suboptimal factors (22 degrees C, 7 degrees C, -18 degrees C/0.5% NaCl, 5.0% NaCl/pH 7.0, pH 5.4, pH 4.5/addition of lactic acid) in a simulation medium for red meat (beef gravy). Prolonged survival was noted as the imposed stress was more severe, and as multiple growth factors became suboptimal. At a defined temperature (7 degrees C or -18 degrees C), survival was prolonged at the more acid, more suboptimal pH (pH 4.5 > pH 5.4 > pH 7.0) while at a defined pH (pH 4.5), better survival was observed at 7 degrees C than at 22 degrees C. This suggests that application of the hurdle concept for preservation of food may inhibit outgrowth but induce prolonged survival of E. coli O157:H7 in minimal processed foods. At both 22 degrees C and 7 degrees C, the addition of lactic acid instead of HCl to reduce pH (to pH 4.5) resulted in a more rapid decrease of E. coli O157:H7. High survival was observed in beef gravy, pH 5.4 at -18 degrees C (simulation of frozen meat)-reduction of log 3.0 to log 1.9 after 43 days--and in beef gravy, pH 4.5 and 5% NaCl at 7 degrees C (simulation of a fermented dried meat product kept in refrigeration)--less than 1 log reduction in 43 days. In these circumstances, however, a high degree of sublethal damage of the bacterial cells was noted. The degree of sublethal damage can be estimated from the difference in recovery of the pathogen on the non-selective TSA medium and the selective SMAC medium.     

Sodium chloride decreases the bacteriocidal effect of acid pH on Escherichia coli O157:H45

To reduce the risk of foodborne illness, many fermented and minimally processed foods rely on the "hurdle effect", i.e. a combination of two or more inhibitory agents being more inhibitory than any of the agents alone. However, we have observed that such a combination of agents is not always more inhibitory to foodborne pathogens than one alone. In this paper, we show that a combination of NaCl and acid pH is less effective than acid pH alone in reducing the numbers of Escherichia coli O157:H45. The presence of sodium chloride reduces the bacteriocidal effect of lactic acid on logarithmically growing cells of E. coli O157:H45. with approximately 10(3)-fold more survivors at pH(o) 4.2 when 4% NaCl was added to the medium. A similar protective effect was also seen with other organic acidulants and E. coli strains. The cytoplasmic pH (pH(i)) of cells in medium at pH 4.2 containing added salt was 5.8 which was 0.56 units higher than that of cells in the same medium without added salt. When the pH(i) of cells in medium without added salt was adjusted to the same value (5.8) by adding KOH, the rate of survival was also considerably greater than that of cells in medium without added salt. These data suggest that E. coli can use NaCl to counteract acidification of its cytoplasm by organic acids, and in addition, that combinations of antimicrobial agents cannot always be relied upon to achieve additive antimicrobial effects.     

Determination of 5-log reduction times for food pathogens in acidified cucumbers during storage at 10 and 25 degrees C

Outbreaks of acid-resistant foodborne pathogens in acid foods with pH values below 4.0, including apple cider and orange juice, have raised concerns about the safety of acidified vegetable products. For acidified vegetable products with pH values between 3.3 and 4.6, previous research has demonstrated that thermal treatments are needed to achieve a 5-log reduction in the numbers of Escherichia coli O157:H7, Listeria monocytogenes, or Salmonella enterica. For some acidified vegetable products with a pH of 3.3 or below, heat processing can result in unacceptable product quality. The purpose of this study was to determine the holding times needed to achieve a 5-log reduction in E. coli O157:H7, L. monocytogenes, and S. enterica strains in acidified vegetable products with acetic acid as the primary acidulant, a pH of 3.3 or below, and a minimum equilibrated temperature of 10 degrees C. We found E. coli O157:H7 to be the most acid-resistant microorganism for the conditions tested, with a predicted time to achieve a 5-log reduction in cell numbers at 10 degrees C of 5.7 days, compared with 2.1 days (51 h) for Salmonella or 0.5 days (11.2 h) for Listeria. At 25 degrees C, the E. coli O157:H7 population achieved a 5-log reduction in 1.4 days (34.3 h).     

Viability of acid-adapted Escherichia coli O157:H7 in ground beef treated with acidic calcium sulfate

The effects of lactic acid, acetic acid, and acidic calcium sulfate (ACS) on viability and subsequent acid tolerance of three strains of Escherichia coli O157:H7 were determined. Differences in tolerance to acidic environments were observed among strains, but the level of tolerance was not affected by the acidulant to which cells had been exposed. Cells of E. coli O157:H7 adapted to grow on tryptic soy agar acidified to pH 4.5 with ACS were compared to cells grown at pH 7.2 in the absence of ACS for their ability to survive after inoculation into ground beef treated with ACS, as well as untreated beef. The number of ACS-adapted cells recovered from ACS-treated beef was significantly (alpha = 0.05) higher than the number of control cells recovered from ACS-treated beef during the first 3 days of a 10-day storage period at 4 degrees C, suggesting that ACS-adapted cells might be initially more tolerant than unadapted cells to reduced pH in ACS-treated beef. Regardless of treatment of ground beef with ACS or adaptation of E. coli O157:H7 to ACS before inoculating ground beef, the pathogen survived in high numbers.     

Stationary-phase acid resistance and injury of recent bovine Escherichia coli O157 and non-O157 biotype I Escherichia coli isolatest

Stationary-phase acid resistance and the induction of acid resistance were assessed for recent bovine carcass isolates of Escherichia coli, including 39 serotype O157 strains and 20 non-O157 strains. When grown to stationary phase in the absence of glucose and without prior acid exposure, there was a range of responses to a pH challenge of 6 h at pH 2.5. However, populations of 53 of the 59 E. coli isolates examined were reduced by less than 2.00 log CFU/ml, and populations of 24 of these isolates were reduced by less than 1.00 log CFU/ml. In contrast, there was little variation in population reductions when the E. coli were grown with glucose and preadapted to acidic conditions. With few exceptions, acid adaptation improved survival to the acid challenge, with 57 of the 59 isolates exhibiting a log reduction of less than 0.50. Differences in acid resistance or the ability to adapt to acidic conditions between E. coli O157:H7 and non-O157 commensal E. coli were not observed. However, we did find that the E. coli O157 were disposed to greater acid injury after the low pH challenge than the non-O157 E. coli, both for cells that were and were not adapted to acidic conditions before the challenge. The enhancement of low pH survival after acid adaptation that was seen among these recent natural isolates of E. coli O157 further supports the idea that the previous environment of this pathogen should be a consideration when designing microbial safety strategies for foods preserved by low pH and acid.     

Aqueous extracts of yerba mate (Ilex paraguariensis) as a natural antimicrobial against Escherichia coli O157:H7 in a microbiological medium and pH 6.0 apple juice

Ilex paraguariensis is popularly used in the preparation of a tea infusion (yerba mate), most commonly produced and consumed in the South American countries of Uruguay, Paraguay, Argentina, and Brazil. In this study, aqueous extracts of commercial tea, derived from the holly plant species I. paraguariensis were evaluated for their ability to inhibit or inactivate Escherichia coli O157:H7 in a microbiological medium and modified apple juice. Dialyzed, lyophilized aqueous extracts were screened for antimicrobial activity against E. coli O157:H7 strains ATCC 43894 and 'Cider' in tryptic soy broth (TSB) and apple juice (adjusted to pH 6.0 to allow for growth of the bacterium). A mixture of the two strains was used as the inoculum when apple juice was used as the medium. MBCs were determined to be ca. 5 and 10 mg/ml for ATCC 43894 and 'Cider', respectively, in TSB. Higher concentrations of the extract were required to inactivate E. coli O157:H7 in pH-adjusted apple juice. An approximate 4.5-log reduction was observed for E. coli O157:H7 treated with 40 mg/ml extract. It was concluded that aqueous extracts from commercial yerba mate have potential to be used as antimicrobials in foods and beverages against pathogenic E. coli O157:H7.     

Microbiological safety of mayonnaise, salad dressings, and sauces produced in the United States: a review

The literature on the death and survival of foodborne pathogens in commercial mayonnaise, dressing, and sauces was reviewed and statistically analyzed with emphasis on Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes. The absence of reports of foodborne illness associated directly with the consumption of commercially prepared acidic dressings and sauces is evidence of their safety. Salmonella, E. coli O157:H7, E. coli, L. monocytogenes, Staphylococcus aureus, and Yersinia enterocolitica die when inoculated into mayonnaise and dressings. Historically, mayonnaise and dressings have been exempt from the acidified food regulations and have justly deserved this status due primarily to the toxic effect of acetic and to a lesser extent lactic and citric acids. These organic acids are inimical to pathogenic bacteria and are effective natural preservatives with acetic being the most effective in killing pathogenic bacteria at the pH values encountered in these products. Statistical analysis on data reported in the literature shows that the most important and significant factor in destroying pathogenic bacteria is pH as adjusted with acetic acid followed by the concentration of acetic acid in the water phase. The reported highest manufacturing target pH for dressings and sauces is 4.4, which is below the 4.75 pKa of acetic acid and below the reported inhibitory pH of 4.5 for foodborne pathogens in the presence of acetic acid. The overall conclusion is that these products are very safe. They should remain exempt from the acidified food regulations providing adequate research has been done to validate their safety, and the predominant acid is acetic and reasonable manufacturing precautions are taken.     

Survival of Escherichia coli O157:H7 in Galotyri cheese stored at 4 and 12 degrees C

Post-process contamination of fresh acid-curd cheeses with Escherichia coli O157:H7 may pose a risk considering the low infectious dose and the ability of the pathogen to survive in acidic foods. To evaluate its survival in Galotyri, a traditional Greek acid-curd cheese, portions (0.5 kg) of two commercial fresh products, one artisan (pH 3.9+/-0.1) and the other industrial (pH 3.7+/-0.1), were inoculated with approximately 3.0 or 6.5 log cfu g(-1) of a five-strain cocktail of E. coli O157:H7, including rifampicin-resistant derivatives of the strains ATCC 43895 and ATCC 51657, and stored aerobically at 4 and 12 degrees C. Survival was monitored for 28 days by plating cheese samples on tryptic soy agar with 100 mg l(-1) rifampicin (TSA+Rif), SMAC and Fluorocult E. coli O157:H7 agar media. The pathogen declined much faster (P<0.05) in the industrial as compared to the artisan cheeses at both temperatures. Thus, while E. coli O157:H7 became undetectable by culture enrichment after 14 days at 4 degrees C in industrial samples, irrespective of the inoculation level, populations of 1.4-1.9 and 4.2-5.1 log cfu g(-1) survived after 28 days in the corresponding artisan cheeses with the low and high inocula, respectively. Survival was longer and greater (P<0.05) on TSA+Rif than on SMAC and Fluorocult, indicating the presence of acid-injured cells. Interestingly, survival of E. coli O157:H7 after 14-28 days in cheeses was better at 12 degrees C than at 4 degrees C, probably due to yeasts which grew on the surface of temperature-abused cheeses. The large difference in the pathogen's inactivation between the industrial and artisan cheeses at 4 degrees C could not be associated with major differences in pH or type/concentration of organic acids, suggesting another anti-E. coli O157:H7 activity by the industrial starter. The high survival of the pathogen in artisan Galotyri under conditions simulating commercial storage should be of concern.     

植物乳杆菌对食源性病原菌作用的研究

通过牛津杯法筛选得到几株高抑菌活性的植物乳杆菌,使用蛋白酶K和NaOH对这几株杆菌的发酵液上清进行处理,以大肠杆菌O157:H7和金黄色葡萄球菌为指示菌,发现有机酸为主要抑菌物质,但是调节pH值至6.5后的发酵上清液可以对大肠杆菌有较好的抑菌效果。其中植物乳杆菌QB3-3具有长达96 h的持续抑菌效果。电子显微镜观察显示,植物乳杆菌抗病原菌的主要机理为破坏细胞结构,导致病原菌菌体形态改变,内容物流出,致使细胞死亡。     

2007年温州地区食源性致病菌污染调查分析

目的了解2007年温州地区食品中沙门菌、单核细胞增生李斯特菌、大肠杆菌O157∶H7、空肠弯曲菌、金黄色葡萄球菌、副溶血性弧菌、香港海鸥菌的污染状况,提高温州地区食源性疾病检测、预警和控制能力,有效地预防、预测食源性疾病的暴发。方法依据国家食源性疾病监测网2007年度工作手册进行。结果检测生鸡肉、生猪肉、生牛肉、生羊肉、散装熟肉制品、海水鱼、淡水鱼、冷菜等八大类,共检出各类病原菌74株。其中以金黄色葡萄球菌的总检出率为最高,检出20株,检出率达15.04%;其次为副溶血性弧菌,检出39株,检出率为9.75%;单核细胞增生李斯特菌和沙门菌分别检出9株和6株,检出率分别为3.77%和2.51%,未检出大肠杆菌O157∶H7、空肠弯曲菌、香港海鸥菌。结论温州地区各类食品存在一定的食源性致病菌污染,其中冷菜、海水鱼、散装熟肉制品是主要污染品种。