| detection of verotoxin-producing escherichia coli o157:h7 by multiplex polymerase chain reaction. | we constructed primers for multiplex polymerase chain reaction (pcr) to detect verotoxin-producing escherichia coli (vtec) o157:h7. the multiplex pcr primers were designed from the sequence of the flagellin structural gene of escherichia coli flagellar type h7 (genbank under accession number l07388), and from the sequence of the rfbe gene of escherichia coli o157:h7 (genbank under accession number s83460). in addition to these primers, we used a primer pair reported by karch and meyer (j. clin. ... | 1998 | 9654369 |
| topics in microbial risk assessment: dynamic flow tree process. | microbial risk assessment is emerging as a new discipline in risk assessment. a systematic approach to microbial risk assessment is presented that employs data analysis for developing parsimonious models and accounts formally for the variability and uncertainty of model inputs using analysis of variance and monte carlo simulation. the purpose of the paper is to raise and examine issues in conducting microbial risk assessments. the enteric pathogen escherichia coli o157:h7 was selected as an exam ... | 1998 | 9664727 |
| development of a colony lift immunoassay to facilitate rapid detection and quantification of escherichia coli o157:h7 from agar plates and filter monitor membranes. | e. coli o157:h7 is a food-borne adulterant that can cause hemorrhagic ulcerative colitis and hemolytic uremic syndrome. faced with an increasing risk of foods contaminated with e. coli o157:h7, food safety officials are seeking improved methods to detect and isolate e. coli o157:h7 in hazard analysis and critical control point systems in meat- and poultry-processing plants. a colony lift immunoassay was developed to facilitate the positive identification and quantification of e. coli o157:h7 by ... | 1998 | 9665968 |
| identification of a rough strain of escherichia coli o157:h7 that produces no detectable o157 antigen. | ma6, an o157:h7-like strain, did not react with most anti-o157 kits examined; however, it had the rfbe gene that is essential for o157 expression and carried o157:h7 virulence factors. lipopolysaccharide analysis showed that ma6 is a rough strain that does not produce the o157 antigen, but genetically, it belongs in the o157:h7 clonal group. | 1998 | 9666018 |
| quantitative analysis of polymerase chain reaction using anisotropy ratio and relative hydrodynamic volume of fluorescence polarization method. | the method based on the combination of polymerase chain reaction (pcr) and fluorescence polarization is presented. a targeted dna was amplified with a 5'-fluorescein labeled primer, using a 256 bp dna fragment of stx2 gene in escherichia coli o157:h7 (188-443 bp) as a template. the fluorescence anisotropy of the 5'-fluorescein labeled primer increased upon the polymerization through taq polymerase. the conversion of primer to pcr product was quantitatively monitored by anisotropy ratio and relat ... | 1998 | 9671828 |
| molecular evolution of a pathogenicity island from enterohemorrhagic escherichia coli o157:h7. | we report the complete 43,359-bp sequence of the locus of enterocyte effacement (lee) from edl933, an enterohemorrhagic escherichia coli o157:h7 serovar originally isolated from contaminated hamburger implicated in an outbreak of hemorrhagic colitis. the locus was isolated from the edl933 chromosome with a homologous-recombination-driven targeting vector. recent completion of the lee sequence from enteropathogenic e. coli (epec) e2348/69 afforded the opportunity for a comparative analysis of the ... | 1998 | 9673266 |
| effect of oxygen concentration and redox potential on recovery of sublethally heat-damaged cells of escherichia coli o157:h7, salmonella enteritidis and listeria monocytogenes. | the measured heat resistance of cells of escherichia coli o157:h7, salmonella enteritidis and listeria monocytogenes was up to eightfold greater when they were grown, heated and recovered anaerobically rather than aerobically. measured heat resistance was highest when anaerobic gas mixtures were used (time at 59 degrees c for a 6-decimal (6-d) reduction of e. coli o157:h7, 19-24 min); moderate when low concentrations of oxygen (0.5-1%) were included (time for a 6-d reduction, 5-17 min); and lowe ... | 1998 | 9674145 |
| immunomagnetic separation and flow cytometry for rapid detection of escherichia coli o157:h7. | a rapid method for detecting escherichia coli o157:h7 combining immunomagnetic beads (imb) and flow cytometry was developed. labeling antigens separated by imb with fluorescent antibody enabled the detection of < 10(3) cfu bacteria per ml in pure culture. the optimum concentration of magnetic beads for flow cytometry was lower (ca. 10(5) particles per ml) than that reported for conventional imb assay (more than 6 x 10(6) to 8 x 10(6) particles per ml). immunomagnetic separation and flow cytometr ... | 1998 | 9678161 |
| attachment of escherichia coli o157:h7 in ground beef to meat grinders and survival after sanitation with chlorine and peroxyacetic acid. | the potential for transfer of escherichia coli o157:h7 from contaminated ground beef to grinding equipment and the inactivation of attached cells during cleaning and sanitizing was examined. chub-packed ground beef with lean:fat ratios of 75:25, 80:20 or 90:10 was inoculated with 6 log cfu/g or 2 log cfu/g e. coli o157:h7 strain frik 910. samples were consecutively ground in a hobart meat grinder with stainless steel (ss) chips (1 cm2) glued to the auger housing. chips were harvested after grind ... | 1998 | 9678162 |
| comparison of water wash, trimming, and combined hot water and lactic acid treatments for reducing bacteria of fecal origin on beef carcasses. | cleaning treatments, such as high-pressure water wash at 35 degrees c or trim, alone and combined with sanitizing treatments, such as hot water (95 degrees c at the source), warm (55 degrees c) 2% lactic acid spray, and combinations of these two sanitizing methods, were compared for their effectiveness in reducing inoculated numbers (5.0 to 6.0 log cfu/cm2) of salmonella typhimurium, escherichia coli o157:h7, aerobic plate counts, enterobacteriaceae, total coliforms, thermotolerant coliforms, an ... | 1998 | 9678163 |
| development of a magnetic microplate chemifluorimmunoassay for rapid detection of bacteria and toxin in blood. | a magnetic microplate chemifluorimmunoassay (mmcia) is described using an immunomagnetic separation and a fluorescent microplate technique for rapid detection of low-level escherichia coli o157:h7, bacillus subtilis var. niger spores, and staphylococcal enterotoxin type b from whole blood. in general, the mmcia has at least several-fold more sensitivity than the conventional enzyme-linked immunosorbent assay. in addition, the assay sensitivities using direct fluorochrome label as the reporter, o ... | 1998 | 9683505 |
| induction of protection against oral infection with cytotoxin-producing escherichia coli o157:h7 in mice by shiga-like toxin-liposome conjugate. | we have previously reported that purified shiga-like toxins (slt), slt-i and slt-ii coupled with liposomes induced a substantial amount of anti-slt-i and anti-slt-ii igg antibody production, respectively, in mice. the levels of anti-slt antibody in the sera of slt-liposome-immune mice correlated well with the protection against subsequent challenge with slt. in this study, mice were immunized intraperitoneally with the mixture of slt-i-liposome and slt-ii-liposome and protection against oral inf ... | 1998 | 9693282 |
| viability of escherichia coli o157:h7 in ground and formed beef jerky prepared at levels of 5 and 20% fat and dried at 52, 57, 63 or 68 degrees c in a home-style dehydrator. | beef jerky batter was prepared to fat contents of about 5 and 20% and inoculated with about 10(8) cfu g(-1) of a five-strain inoculum of escherichia coli o157:h7. pathogen numbers were determined in the raw batter and in the strips formed from it after drying at 52, 57, 63, and 68 degrees c for times that ranged from 2 to 20 h. for both the high and low fat products, pathogen numbers were reduced by about 5 log10 cfu g(-1) within 4 h drying at 68 degrees c and within 8 h drying at 63 degrees c. ... | 1998 | 9706789 |
| survival of escherichia coli o157:h7 in ground beef jerky assessed on two plating media. | recent outbreaks of food-borne illness due to salmonella spp. in beef jerky and escherichia coli o157:h7 in venison jerky, coupled with the fact that a variety of preparation methods and dying procedures abound, raise concern over the safety of processed meat products made in the home. the potential of injured bacterial cells to regain the ability to cause illness is a particular threat with pathogens such as e. coli o157:h7, which is believed to have a low infectious dose. this study examined t ... | 1998 | 9708245 |
| use of hot water for beef carcass decontamination. | hot water treatment of beef carcass surfaces for reduction of escherichia coli o157:h7, salmonella typhimurium, and various indicator organisms was studied using a model carcass spray cabinet. paired hot carcass surface regions with different external fat characteristics (inside round, outside round, brisket, flank, and clod) were removed from carcasses immediately after the slaughter and dressing process. all cuts were inoculated with bovine feces containing 10(6)/g each of rifampicin-resistant ... | 1998 | 9708247 |
| bacterial growth in ground beef patties made with meat from animals fed diets without or with supplemental vitamin e. | a study was designed to determine populations of aerobic bacteria, coliforms, sorbitol-negative bacteria, and listeria monocytogenes during display at 4 and 12 degrees c of ground beef patties made with meat from animals fed diets supplemented daily (for 100 days) with 0, 1,000, or 2,000 iu of vitamin e. the patties (113.5 g) were either left uninoculated or were inoculated with escherichia coli o157:h7 or l. monocytogenes and were tray-overwrapped and stored (at 4 or 12 degrees c for 8 to 10 or ... | 1998 | 9708250 |
| comparison of the difco ez coil rapid detection system and petrifilm test kit-hec for detection of escherichia coli o157:h7 in fresh and frozen ground beef. | the difco ez coli rapid detection system was compared to the 3m petrifilm method for detection of escherichia coli o157:h7 in raw ground beef. raw meatballs (25 g) were inoculated with 10 to 15 cells of escherichia coli o157:h7, stored for various times and at different temperatures, and then stomached for 2 min in 225 ml of ez coli enrichment broth, which was then incubated at 42 degrees c for 18 to 24 h. a 1-ml sample of the enrichment broth was loaded into the top of the detector tips and the ... | 1998 | 9708263 |
| survival of escherichia coli o157:h7 during the manufacture of pepperoni. | this study investigated the growth and survival of escherichia coli o157:h7 during the manufacture of pepperoni to determine whether a 5-log10-unit decline in numbers, as recommended by the u.s. food safety and inspection service (fsis), could be achieved. a range of pepperoni formulations with variations in salt (2.5 to 4.8%) and sodium nitrite (100 to 400 ppm) levels, and with ph (4.4 to 5.6) adjusted by manipulation of dextrose concentrations were prepared. the batters produced were inoculate ... | 1998 | 9708271 |
| destruction of escherichia coli o157:h7 and salmonella typhimurium in lebanon bologna by interaction of fermentation ph, heating temperature, and time. | fermented meats have caused food-borne illness due to enterohemorrhagic escherichia coli. consumption of lebanon bologna was epidemiologically associated wit a recent outbreak of salmonellosis. the present study was conducted to determine the effect of ph (after the fermentation step), final heating temperature, and time on destruction of e. coli o157:h7 and salmonella typhimurium in lebanon bologna. raw lebanon bologna mix was inoculate with either of the pathogens (ca.10(8) cfr/g and fermented ... | 1998 | 9708272 |
| acid tolerance and acid shock response of escherichia coli o157:h7 and non-o157:h7 isolates provide cross protection to sodium lactate and sodium chloride. | the survival of escherichia coli o157:h7 and non-o157:h7 due to an enhanced acid tolerance response (atr), and enhanced acid shock response (asr), or the stationary phase protective system when exposed to lactic acid and the resulting cross protection against increased concentration of sodium chloride and sodium lactate was studied. escherichia coli o157:h7 isolates (1932 and 009) and a non-o157:h7 strain (atcc 23716) were grown to stationary phase at 32 degrees c and o157:h7 to one of two treat ... | 1998 | 9708273 |
| a representative microbial sampling method for large commercial containers of raw beef based on purge. | the purge from beef combos ( a boxed collection of beef trimmings) was tested as a means of representatively sampling the microbial content of this raw product. in the first experiment, purge was sampled from model beef combos that had been inoculated with bovine feces.. data from this experiment indicated a strong correlation (r = 0.94) between the total aerobic bacteria counts derived from the purge samples of a model beef combo and the total aerobic bacteria present in a rinse sample of the e ... | 1998 | 9708274 |
| antagonistic action of cells of lactobacillus lactis toward escherichia coli o157:h7 on refrigerated raw chicken meat. | cells of a strain of lactobacillus lactis selected for ability to produce hydrogen peroxide were added to trypticase soy broth (tsb) containing escherichia coli o157:h7 to determine if l. lactis was antagonistic towards the e. coli during storage at 7 degrees c for 7 days. e. coli was enumerated on violet red bile agar. three strains of e. coli o157:h7 (43894, 43890, and 35150) were evaluated. control samples containing no l. lactis did not show significant declines in numbers of e. coli during ... | 1998 | 9708275 |
| thermal inactivation of escherichia coli o157:h7, salmonella senftenberg, and enzymes with potential as time-temperature indicators in ground turkey thigh meat. | the usda food safety and inspection service has proposed to amend cooking regulations to require that any thermal process used for poultry products be sufficient to cause a 7 d reduction in salmonellae. several enzymes have been suggested as potential indicators of heat processing in poultry, yet no relationship between the inactivation rates of these enzymes and salmonellae had been determine. the thermal inactivation kinetics of endogenous muscle proteins. escherichia coli o157:h7 and salmonel ... | 1998 | 9708276 |
| indicative and pathogenic microbiological quality of aquacultured finfish grown in different production systems. | the nature and number of indicator and pathogenic microbes in fish reared using recirculating and nonrecirculating water systems were compared. for each system, 20 samples of rainbow trout (oncorhynchus mykiss), tilapia (oreochromis spp.), hybrid striped bass (morone saxatilis x m. chrysops), and pacu (piaractus mesopotamicus) were randomly selected and gutted, and microbial analyses were performed using aoac procedures. five fish were subsampled and analyzed for indicative microbial quality wit ... | 1998 | 9708283 |
| thermal inactivation of escherichia coli o157:h7 isolated from ground beef and bovine feces, and suitability of media for enumeration. | rates of thermal inactivation of five strains of escherichia coli o157:h7 isolated from ground beef implicated in outbreaks of hemorrhagic colitis and five strains isolated from bovine feces were determined. ground beef (22% fat, 10 g), inoculated with individual test strains at populations ranging from 6.85 to 7.40 log10 cfu g-1 of beef, was formed into patties (0.3 cm thick and 8.0 cm in diameter) and sealed in polyethylene bags. for each strain and treatment temperature (54.4, 58.9, 62.8, 65. ... | 1998 | 9708297 |
| survival of bacterial pathogens in pasteurized process cheese slices stored at 30 degrees c. | six lots of commercial pasteurized process cheese slices were evaluated for the ability to support the growth of four foodborne pathogens, listeria monocytogenes, staphylococcus aureus, salmonella serotypes, and escherichia coli o157:h7, during 4 days of storage at 30 degrees c. individual cheese slices were inoculated separately with each pathogen to yield ca. 10(3) cfu/g. slices were packaged in sterile plastic sample bags and stored at 30 degrees c for up to 96 h. population of salmonella ser ... | 1998 | 9708298 |
| long-term effect of alkaline, organic acid, or hot water washes on the microbial profile of refrigerated beef contaminated with bacterial pathogens after washing. | the effect of 2% (vol/vol) lactic acid, 2% (vol/vol) acetic acid, 12% (wt/vol) trisodium phosphate, water at 72 degrees c and water at 32 degrees c washes on bacterial populations introduced onto beef carcass surfaces after treatment was determined for up to 21 days at 4 degrees c storage in vacuum packaging. beef carcass short plates were collected from cattle immediately after slaughter and subjected to the above treatments or left untreated (c). short plates were then inoculated with low leve ... | 1998 | 9708300 |
| viability of escherichia coli o157:h7 in salami following conditioning of batter, fermentation and drying of sticks, and storage of slices. | the fate of escherichia coli o157:h7 was monitored in salami during conditioning of batter, fermentation and drying of sticks, and storage of slices. the raw batter (75% pork: 25% beef, wt/wt, fat content about 20%) was inoculated with a pediococcal starter culture (about 10(8) cfu/g) and a five-strain cocktail of e. coli o157:h7 ( > or = 2 x 10(7) cfu/g) and stuffed into 104-mm diameter fibrous casings. after being refrigerated at 4 degrees c or being tempered at 13 degrees c, frozen at -20 deg ... | 1998 | 9709197 |
| survival of escherichia coli o157:h7 in full- and reduced-fat pepperoni after manufacture of sticks, storage of slices at 4 degrees c or 21 degrees c under air and vacuum, and baking of slices on frozen pizza at 135, 191 and 246 degrees c. | pepperoni batter was prepared with fat contents of about 15, 20, and 32% (wt/wt) and inoculated with a pediococcal starter culture and > or = 2.0 x 10(7) cfu/g of a five-strain inoculum of escherichia coli o157:h7. the batter was fermented at 96 degrees f (ca. 36 degrees c and 85% relative humidity (rh) to ph < or = 4.8 and then dried at 55 degrees f (ca. 13 degrees c) and 65% rh to a moisture/protein ratio of < or = 1.6:1. for storage, slices were packaged under air or vacuum and stored at 39 d ... | 1998 | 9709198 |
| prior storage conditions influence the destruction of escherichia coli o157:h7 during heating of apple cider and juice. | in apple beverage manufacture, cider and juice may be stored for a short time prior to pasteurization. storage time and temperature may affect the subsequent thermotolerance of bacteria in these beverages. this study examined whether prior storage in ph 3.4 apple cider or apple juice affected the thermotolerance of two escherichia coli o157:h7 strains in the same beverages at 61 degrees c. both strains exhibited biphasic survivor curves. strain atcc 43894 was consistently more thermotolerant tha ... | 1998 | 9709199 |
| influence of growth temperature on inactivation and injury of escherichia coli o157:h7 by heat, acid, and freezing. | the influence of growth temperature on heat-, lactic acid-, and freeze-induced inactivation and injury of escherichia coli o157:h7 in 0.1% peptone water was investigated. three strains of e. coli o157:h7 isolated respectively from salami, apple cider, and ground beef were evaluated. growth of strains at 10 degrees c compared with growth at 37 degrees c had a significant impact on reducing (p < 0.01) d values obtained for heating (dh value), acid exposure (da value), with the exception of the cid ... | 1998 | 9709200 |
| repeatability of the petrifilm hec test and agreement with a hydrophobic grid membrane filtration method for the enumeration of escherichia coli o157:h7 on beef carcasses. | the petrifilm hec test (3m canada inc., london, ontario), a quantitative microbiological test for escherichia coli o157:h7, was evaluated for its performance as a beef-carcass monitoring test. test repeatability and agreement and agreement with an e. coli o157:h7 detection method using a hydrophobic grid membrane filter (hgmf) overlaid onto cefixime-tellurite-sorbitol macconkey agar (ct-smac) followed by a latex agglutination test for the o157 antigen were determined by using pure cultures of e. ... | 1998 | 9709201 |
| interaction of hydrostatic pressure, time and temperature of pressurization and pediocin ach on inactivation of foodborne bacteria. | high hydrostatic pressure, because it can kill microorganisms, is being investigated for potential use as a nonthermal food preservation method. the objective of this study was to determine the hydrostatic pressurization parameters, pressure, time, and temperature, and a bacteriocin that in combination would destroy 7 to 8 log cycles of pathogenic and spoilage bacterial populations. we suspended cells of staphylococcus aureus, listeria monocytogenes, salmonella typhimurium, escherichia coli o157 ... | 1998 | 9709205 |
| the combined effect of high hydrostatic pressure and mild heat on inactivation of pathogens in milk and poultry. | the combined effects of high hydrostatic pressure and heat on the inactivation of escherichia coli o157:h7 nctc 12079 and staphylococcus aureus nctc 10652 in poultry meat and ultra-high-temperature-treated (uht) milk were investigated. the to have a significant effect on the survival of the pathogens during treatment. for e. coli o157:h7, a 15-min treatment of 400 mpa at 50 degrees c resulted in approximately a 6.0-log10 reduction in cfu/g in poultry meat and a 5.0-log10 reduction in uht milk; h ... | 1998 | 9709206 |
| evaluating survival of escherichia coli o157:h7 in frozen and thawed apple cider: potential use of a hydrophobic grid membrane filter-sd-39 agar method. | to determine the susceptibility of escherichia coli o157:h7 to freezing and thawing in apple cider, methods that recover injured cells are needed for accurate enumeration. this study compared the iso-grid hydrophobic grid membrane filter (hgmf) sd-39 agar method to two other methods: a reference most probable number (mpn) method, and plating on sorbitol macconkey agar (sma). to determine numbers of injured cells, sma spread plating was also compared to trypticase soy agar (tsa) spread plating. t ... | 1998 | 9709216 |
| influence of incubation conditions on survival and acid tolerance response of escherichia coli o157:h7 and non-o157:h7 isolates exposed to acetic acid. | the increasing frequency of escherichia coli o157:h7 outbreaks, especially in acidic foods, raises the concern of an acid tolerance response (atr). organic acids can be present in processed and preserved foods: shifts in the acid levels of foods due to these acids may allow e. coli to adapt and later tolerate ph levels that would normally inactivate the organism. the effect of temperature and agitation on the atrs of three e. coli o157:h7 and two non-o157:h7 isolates were determined. triggered a ... | 1998 | 9709224 |
| decontaminating beef for escherichia coli o157:h7. | beef lean, fat, and connective tissues were inoculated with escherichia coli o157:h7 before and after a prewashing procedure to compare the efficacy of prewashing and no prewashing on bacterial adherence and, consequently, on the removal of bacteria from the inoculated surfaces. prewashing consisted of spraying tissues with tap water before inoculation. final washing with disinfectant solutions compared the efficacy of several chemicals for the removal or destruction of e. coli o157:h7. the resu ... | 1998 | 9709225 |
| chemical dehairing of bovine skin to reduce pathogenic bacteria and bacteria of fecal origin. | a chemical dehairing process was applied to artificially contaminated bovine hide to evaluate the effect on populations of escherichia coli o157:h7 and salmonella typhimurium, as well as other strains of e. coli, total coliforms, and aerobic plate counts (apc). pieces of hide (4 cm2) were contaminated with bovine feces inoculated with both rifampicin-resistant e. coli o157:h7 and s. typhimurium to yield a final count of each pathogen of ca. 5.0 log10 cfu/cm2, or with noninoculated feces which pr ... | 1998 | 9709238 |
| reduction of escherichia coli o157:h7 populations in soy sauce, a fermented seasoning. | we studied five escherichia coli o157:h7 strains in soy sauce which was incubated at 4, 18, or 30 degrees c after inoculation. the cell numbers of e. coli o157:h7 decreased to an undetectable level (<20 cfu/ml) within 9 days in all the soy sauce samples at 30 degrees c, but did not decrease in the 0.1 m phosphate-buffered saline (ph 7.0) control solution under the same conditions. soy sauce reduced the cell numbers of bacteria at 18 degrees c to a lesser extent than at 30 degrees c, but to a gre ... | 1998 | 9709244 |
| survival of enterohemorrhagic escherichia coli o157:h7 in water. | several recent escherichia coli o157:h7 outbreaks associated with both drinking and recreational water raise concerns about waterborne illness caused by this pathogen. the survival characteristics of a mixture of five nalidixic acid-resistant e. coli o157:h7 strains (10(3) cfu/ml) in filtered and autoclaved municipal water, in reservoir water, and in water from two recreational lakes were determined for a period of 91 days at 8, 15 or 25 degrees c. greatest survival was in filtered autoclaved mu ... | 1998 | 9709245 |
| gamma irradiation and ozone treatment for inactivation of escherichia coli o157:h7 in culture media. | a study was conducted to investigate the reduction and elimination of escherichia coli o157:h7 by the effects of gamma irradiation and ozone treatment. log phase cells were found to be more sensitive to gamma irradiation than stationary phase cells. e. coli o157:h7 was found to be considerably more resistant to irradiation at -18 degrees c than at 20 degrees c. the d values for this organism for treatment with ozone in tryptic soy agar were higher than those for treatment with ozone in phosphate ... | 1998 | 9709258 |
| survival of bioluminescent listeria monocytogenes and escherichia coli o157:h7 in soft cheeses. | pasteurized and raw milks that had been inoculated at 10(4) cfu/ml with bioluminescent strains of listeria monocytogenes and escherichia coli o157:h7 were used in the manufacture of camembert and feta cheeses with or without nisin-producing starter culture. survival of both organisms was determined during the manufacture and storage of camembert and feta cheeses at 2 +/- 1 degree c for 65 and 75 d, respectively. bacterial bioluminescence was used as an indicator to enumerate the colonies plated ... | 1998 | 9710748 |
| escherichia coli o157:h7 requires intimin for enteropathogenicity in calves. | enterohemorrhagic escherichia coli (ehec) strains require intimin to induce attaching and effacing (a/e) lesions in newborn piglets. infection of newborn calves with intimin-positive or intimin-negative ehec o157:h7 demonstrated that intimin is needed for colonization, a/e lesions, and disease in cattle. these results suggest that experiments to determine if intimin-based vaccines reduce o157:h7 levels in cattle are warranted. | 1998 | 9712821 |
| evaluation of an enzyme-linked immunosorbent assay, direct immunofluorescent filter technique, and multiplex polymerase chain reaction for detection of escherichia coli o157:h7 seeded in beef carcass wash water. | in commercial beef processing, carcasses are customarily washed with water to remove physical and microbial contamination. assaying the water that is shed from the carcasses after washing is a convenient method to determine whether the carcass is contaminated with escherichia coli o157:h7 or other bacterial pathogens. e. coli o157:h7 was inoculated into carcass wash water at various levels and the bacteria were then concentrated by filtration. after collection of bacteria in the filter units, th ... | 1998 | 9713750 |
| survival of escherichia coli o157:h7 in synthetic gastric fluid after cold and acid habituation in apple juice or trypticase soy broth acidified with hydrochloric acid or organic acids. | extreme acid tolerance of escherichia coli o157:h7 has raised doubts about the safety of acidic foods. this study examined whether prior storage in acidic and/or cold conditions enhanced survival of e. coli o157:h7 in synthetic gastric fluid (sgf). three e. coli o157:h7 strains were stored in trypticase soy broth (tsb; acidified with hcl, malic acid, citric acid, or lactic acid) or ph 3.5 and 6.5 (nonacidic control) apple juice at 4 and 21 degrees c for < or = 7 days and then were incubated in p ... | 1998 | 9713751 |
| survival and recovery of escherichia coli o157:h7 in inoculated bottled water. | a methodology used to isolate escherichia coli o157:h7 from water and survival of this pathogen in inoculated water is described. the methodology used in the isolation of e. coli o157:h7 included the use of selective plating on sorbitol macconkey agar (supplemented with potassium tellurite [2.5 mg/liter], cefixime [0.05 mg/liter], and cefsulodin [10 mg/liter], and modified hemorrhagic colitis agar (also supplemented with potassium tellurite [2.5 mg/liter]) and cefsulodin [10 mg/liter]). there we ... | 1998 | 9713752 |
| antibacterial action of vinegar against food-borne pathogenic bacteria including escherichia coli o157:h7. | the bacteriostatic and bactericidal actions of vinegar on food-borne pathogenic bacteria including enterohemorrhagic e. coli (ehec) o157:h7 were examined. the growth of all strains evaluated was inhibited with a 0.1% concentration of acetic acid in the vinegar. this inhibition was generally increased in the presence of sodium chloride or glucose. there was almost no difference in sensitivity to the bacteriostatic action of vinegar among the strains of pathogenic e. coli. vinegar had a bactericid ... | 1998 | 9713753 |
| antibacterial activity of bovine lactoferrin and its peptides against enterohaemorrhagic escherichia coli o157:h7. | the antimicrobial activities of bovine lactoferrin (blf), its pepsin hydrolysate (blfh) and the active peptide lactoferricin b (lfcinb) against four clinical isolates of enterohaemorrhagic escherichia coli o157:h7 were studied. the mics against these isolates were 3 mg ml-1 for blf, 0.1-0.2 mg ml-1 for blfh and 8-10 micrograms ml-1 for lfcinb in 1% bactopeptone broth. lfcinb killed these bacteria within 3 h at concentrations above 10 micrograms ml-1. transmission electron microscopy findings sug ... | 1998 | 9717310 |
| combined use of bacteriophage typing and pulsed-field gel electrophoresis in the epidemiological analysis of japanese isolates of enterohemorrhagic escherichia coli o157:h7. | a total of 236 enterohemorrhagic escherichia coli (ehec) o157:h7 isolates in japan were investigated by bacteriophage typing, and the results were compared with those of pulsed-field gel electrophoresis (pfge). seven phage types (pts) were observed in 71 isolates which were derived from 22 outbreaks. all of the isolates from ten outbreaks in the kinki region (midwestern part of japan) in july-august 1996 were grouped into the same pfge type (iia) and pt 32, while among total isolates, there were ... | 1998 | 9719105 |
| the microbiological examination of butchery products and butchers' premises in the united kingdom. | in a study of 1400 manufacturing butchers' premises, 2330 raw prepared meats, 2192 cooked meats and 4635 environmental samples were examined. verocytotoxin-producing escherichia coli o157:h7 (o157 vtec) was isolated from five of 1400 (0.4%) premises. three raw meat products contained o157 vtec, and two raw meat preparation areas and two items of equipment used exclusively for cooked meats were contaminated with o157 vtec. salmonella spp. and campylobacter spp. were detected in 84 of 2330 (4%) an ... | 1998 | 9721668 |
| the complete dna sequence and analysis of the large virulence plasmid of escherichia coli o157:h7. | the complete dna sequence of po157, the large virulence plasmid of ehec strain o157:h7 edl 933, is presented. the 92 kb f-like plasmid is composed of segments of putative virulence genes in a framework of replication and maintenance regions, with seven insertion sequence elements, located mostly at the boundaries of the virulence segments. one hundred open reading frames (orfs) were identified, of which 19 were previously sequenced potential virulence genes. forty-two orfs were sufficiently simi ... | 1998 | 9722640 |
| analysis of escherichia coli o157:h7 survival in ovine or bovine manure and manure slurry. | farm animal manure or manure slurry may disseminate, transmit, or propagate escherichia coli o157:h7. in this study, the survival and growth of e. coli o157:h7 in ovine or bovine feces under various experimental and environmental conditions were determined. a manure pile collected from experimentally inoculated sheep was incubated outside under fluctuating environmental conditions. e. coli o157:h7 survived in the manure for 21 months, and the concentrations of bacteria recovered ranged from <10( ... | 1998 | 9726855 |
| pcr-based dna amplification and presumptive detection of escherichia coli o157:h7 with an internal fluorogenic probe and the 5' nuclease (taqman) assay. | presumptive identification of escherichia coli o157:h7 is possible in an individual, nonmultiplexed pcr if the reaction targets the enterohemorrhagic e. coli (ehec) eaea gene. in this report, we describe the development and evaluation of the sensitivity and specificity of a pcr-based 5' nuclease assay for presumptively detecting e. coli o157:h7 dna. the specificity of the eaea-based 5' nuclease assay system was sufficient to correctly identify all e. coli o157:h7 strains evaluated, mirroring the ... | 1998 | 9726887 |
| isolation of an escherichia coli o157:h7 strain producing shiga toxin 1 but not shiga toxin 2 from a patient with hemolytic uremic syndrome in korea. | escherichia coli strains isolated from patients with diarrhea or hemolytic uremic syndrome (hus) at pusan university hospital, south korea, between 1990 and 1996 were examined for traits of the o157:h7 serogroup. one strain isolated from a patient with hus belonged to the o157:h7 serotype, possessed a 60-mda plasmid, the eae gene, and ability to produce shiga toxin 1 but not shiga toxin 2. arbitrarily primed pcr analysis suggested that this strain is genetically very close to a o157:h7 strain is ... | 1998 | 9741083 |
| renal function in inuit survivors of epidemic hemolytic-uremic syndrome. | we undertook a case-control study to evaluate the renal health of survivors of hemolytic-uremic syndrome (hus) from the 1991 arctic epidemic of escherichia coli o157:h7 gastroenteritis 4 years after the epidemic. eighteen children who developed hus during the 1991 epidemic and 18 age- and sex-matched controls from the same community who had uncomplicated gastroenteritis were compared in 1995 for height, weight, blood pressure, urinalysis, and glomerular filtration rate (gfr), measured using cont ... | 1998 | 9745874 |
| oxygen sensitivity of heated cells of escherichia coli o157:h7. | following defined heat treatments (55 degrees c for 100 min, 50 degrees c for 5 min, 61 degrees c for l min), a 6 decimal (6-d) reduction was obtained when cells of escherichia coli o157:h7 were enumerated in aerobic growth medium. part of this reduction (3-d) was due to thermal inactivation (as determined when cells were enumerated in anaerobic growth medium), and part (3-d) was due to the inability of sub-lethally heat-injured cells of e. coli o157:h7 to grow in the presence of oxygen. when he ... | 1998 | 9750295 |
| direct inoculation into media containing bile salts and antibiotics is unsuitable for the detection of acid/salt stressed escherichia coli o157:h7. | the efficiency of selective enrichment broths for the recovery of low numbers of acid/salt stressed escherichia coli o157:h7 was determined. stressed cultures were diluted to low levels and recovered in tryptone soya broth with added bile salts, to make modified tryptone soya broth, and buffered peptone water with various combinations of antibiotic supplementation including novobiocin, acriflavine and a mixture of vancomycin, cefsulodin and cefixime (vcc) at 37 degrees c and 42 degrees c. signif ... | 1998 | 9750318 |
| characterization of a phage specific to hemorrhagic escherichia coli o157:h7 and disclosure of variations in host outer membrane protein ompc. | | 1998 | 9758911 |
| mathematical modeling to predict the bactericidal effect of processed vinegar on escherichia coli o157:h7. | the combined effects of acetic acid, temperature and sodium chloride on escherichia coli o157:h7 inactivation were examined in processed vinegar. to express their effects, quadratic polynomial models were applied. the logarithm transformation of sodium chloride concentration provided a better fit of the data than the use of a non-transformation value. on the basis of this finding, the polynomial models should be distinguished into two types, i.e. the non-sodium chloride model and the sodium chlo ... | 1998 | 9761348 |
| an improved direct plate method for the enumeration of stressed escherichia coli o157:h7 from food. | the use of sorbitol macconkey agar (smac) performed poorly in supporting growth of stressed escherichia coli o157:h7 cells. up to a 3-log difference was observed between counts on smac and tryptone soy agar (tsa). it is critical in the risk assessment of certain foods to be able to enumerate stressed and healthy e. coli o157:h7 in a background of potentially healthy competing bacteria. investigations carried out to overcome the inhibitory effect of smac included the reduction of the selective ag ... | 1998 | 9766057 |
| effectiveness of salt, ph, and diacetyl as inhibitors for escherichia coli o157:h7 in dairy foods stored at refrigeration temperatures. | the behavior of escherichia coli o157:h7 inoculated in 10% rehydrated nonfat dry milk adjusted to ph levels between 3.8 and 5.4 with lactic acid, salt levels of 0 to 6%, and diacetyl levels of 0, 5, and 10 micrograms/g was determined at 4 and 12 degrees c. cell populations were determined by surface plating on tryptic soy agar after 7 and 35 days of incubation. survival was also determined using retail cultured diary products. e. coli o157:h7 did not survive in skim milk at ph 3.8 and was reduce ... | 1998 | 9766058 |
| bacterial cross-contamination of meat during liquid nitrogen immersion freezing. | prerigor beef carcass surface tissue (bct) was used to simulate lamb carcasses on a processing line with a 15-min liquid nitrogen (ln) immersion freezing step, and the potential for the dissemination of bacteria during freezing was examined. streptomycin-resistant strains of listeria innocua and escherichia coli o157:h7 spiked into a fecal slurry were inoculated onto bct pieces that were introduced into the freezing process to represent contaminated carcasses. following this introduction, subseq ... | 1998 | 9766059 |
| bacterial profile of ground beef made from carcass tissue experimentally contaminated with pathogenic and spoilage bacteria before being washed with hot water, alkaline solution, or organic acid and then stored at 4 or 12 degrees c. | the long-term effectiveness of several beef-carcass surface-tissue (bct) wash interventions on the microbiology of ground beef produced from this tissue was determined. bct was inoculated with bovine feces containing one of two different levels (ca. 4 or 6 log cfu/ml) of escherichia coli o157:h7, listeria innocua, salmonella typhimurium, and clostridium sporogenes. the bct was then subjected to one of several treatment washes: 2% (vol/vol) dl-lactic acid (la), 2% (vol/vol) acetic acid (aa), 12% ... | 1998 | 9766060 |
| survival of escherichia coli o157:h7 after freezing and thawing in ground beef patties. | survival of escherichia coli o157:h7 strains qa 326, and atcc 43889, 43894, and 43895 after freezing (-20 degrees c, 24 h) and thawing (4 degrees c for 12 h, 23 degrees c for 3 h, or microwave heating of 700 w for 120 s) in ground beef patties was determined by reference most probable number (mpn), hydrophobic grid membrane filter sd-39 agar, and sorbitol macconkey agar (sma) spread-plating methods. populations decreased from 0.62 to 2.52 log10 cfu/g, with the extent varying significantly by str ... | 1998 | 9766072 |
| thermotolerance of escherichia coli o157:h7 atcc 43,894, escherichia coli b, and an rpos-deficient mutant of escherichia coli o157:h7 atcc 43,895 following exposure to 1.5% acetic acid. | on a beef carcass, escherichia coli may sequentially encounter acid- and heat-intervention steps. this study tested whether acid stress (1.5% [vol/vol] acetic acid, ph 4.0, 37 degrees c, 15 min) would enhance subsequent heat resistance of e. coli. initially, cells (e. coli o157:h7 atcc 43894, nonpathogenic e. coli b [strain frik-124], and rpos-deficient mutant 813-6 [derived from e. coli o157:h7 atcc 43895]) were acid stressed and transferred to 54 degrees c trypticase soy broth (tsb), and survi ... | 1998 | 9766073 |
| identification of listeria monocytogenes from unpasteurized apple juice using rapid test kits. | a microbiological survey of 50 retail juices was conducted in the fall of 1996. these juices were analyzed for listeria monocytogenes, escherichia coli o157:h7, salmonella, coliforms, fecal coliforms, and ph. two unpasteurized juices were positive for l. monocytogenes: an apple juice and an apple raspberry blend with a ph of 3.78 and 3.75, respectively. three l. monocytogenes isolates were characterized. the colonies were typical for listeria sp. on oxford and lithium chloride-phenylethanol-moxa ... | 1998 | 9766077 |
| foodborne illness in the elderly. | the elderly (> or = 65 years of age) are more susceptible to morbidity and mortality from foodborne-induced gastroenteritis than younger individuals. several factors contribute to the increased susceptibility to foodborne infections as well as other infections in elderly populations. these include an age-associated decrease in humoral and cellular immunity, age-related changes in the gastrointestinal tract (decreased production of gastric acid and decreased intestinal motility), malnutrition, la ... | 1998 | 9766083 |
| incidence of foodborne illnesses--foodnet, 1997. | each year, millions of persons become ill from foodborne diseases, though many cases are not reported. the foodborne diseases active surveillance network (food-net), the primary foodborne diseases component of cdc's emerging infections program, was developed to better characterize, understand, and respond to foodborne illnesses in the united states. this report describes foodnet surveillance data from 1997, the second year of surveillance, and compares findings with data from 1996. the findings ... | 1998 | 9769137 |
| escherichia coli o157:h7. | escherichia coli o157 was first identified as a human pathogen in 1982. one of several shiga toxin-producing serotypes known to cause human illness, the organism probably evolved through horizontal acquisition of genes for shiga toxins and other virulence factors. e. coli o157 is found regularly in the faeces of healthy cattle, and is transmitted to humans through contaminated food, water, and direct contact with infected people or animals. human infection is associated with a wide range of clin ... | 1998 | 9777854 |
| hemolytic-uremic syndrome caused by escherichia coli o157:h7 after perforated appendix. | | 1998 | 9779779 |
| identification of the perosamine synthetase gene of brucella melitensis 16m and involvement of lipopolysaccharide o side chain in brucella survival in mice and in macrophages. | brucella organisms are facultative intracellular bacteria that may infect many species of animals as well as humans. the smooth lipopolysaccharide (s-lps) has been reported to be an important virulence factor of these organisms, but the genetic basis of expression of the s-lps o antigen has not yet been described. likewise, the role of the o side chain of s-lps in the survival of brucella has not been clearly defined. a mini-tn5 transposon mutant library of brucella melitensis 16m was screened b ... | 1998 | 9784561 |
| [hemorrhagic colitis and hemolytic uremic syndrome caused by escherichia coli o157:h7]. | we report the case of an escherichia coli o157:h7 infection in a patient with hemorrhagic colitis. initial diagnosis was ischemic colitis because of the age of the patient and clinical presentation. after one week, a hemolytic-uremic syndrome occurred and serologic antibodies to the lipopolysaccharide o157 of escherichia coli o157:h7 were positive, leading to the diagnosis of hemorrhagic colitis caused by this bacteria. escherichia coli o157:h7 colonic infection is not well known, specially in f ... | 1998 | 9791563 |
| rrna stability in heat-killed and uv-irradiated enterotoxigenic staphylococcus aureus and escherichia coli o157:h7. | differentiation of viable cells from nonviable cells is of considerable importance in the development of methods to detect foodborne pathogens. to study the suitability of 16s rrna as an indicator of cell viability in nucleic acid-based detection assays, we examined rrna stability in two representative foodborne pathogens, escherichia coli o157:h7 and enterotoxigenic staphylococcus aureus, which were inactivated by extreme heat, moderate heat, and uv irradiation. cell death under all conditions ... | 1998 | 9797275 |
| comparison of the bax for screening/e. coli o157:h7 method with conventional methods for detection of extremely low levels of escherichia coli o157:h7 in ground beef. | escherichia coli o157:h7 is an important food-borne pathogen. often e. coli o157:h7 is difficult to detect, because it is present sporadically at very low levels together with very high levels of competitor organisms which can be difficult to distinguish phenotypically. cultural methods are time-consuming and give variable results in the detection of e. coli o157:h7. this study examined the performance of bax for screening/e. coli o157:h7, a new rapid method for the detection of e. coli o157:h7, ... | 1998 | 9797296 |
| inactivation of escherichia coli o157:h7 in apple juice by irradiation. | three strains (932, ent-c9490, and sea13b88) of escherichia coli o157:h7 were used to determine the effectiveness of low-dose gamma irradiation for eliminating e. coli o157:h7 from apple juice or cider and to characterize the effect of inducing ph-dependent, stationary-phase acid resistance on radiation resistance. the strains were grown in tryptic soy broth with or without 1% dextrose for 18 h to produce cells that were or were not induced to ph-dependent stationary-phase acid resistance. the b ... | 1998 | 9797319 |
| the use of serodiagnosis in the retrospective investigation of a nursery outbreak associated with escherichia coli o157:h7. | to use serology to investigate an outbreak of verocytotoxin (vt) producing escherichia coli o157 in a hospital nursery, following the detection of faecal e coli o157 (phage type 49) producing vt type 2. | 1998 | 9797724 |
| a unique strain of escherichia coli o157:h7 that produces low verocytotoxin levels not detected by use of a commercial enzyme immunoassay kit. | | 1998 | 9798058 |
| removal of escherichia coli o157:h7 from surface tissues of beef carcasses inoculated with wet and dry manure. | beef tissues were contaminated with wet and dry manure. the manure was previously inoculated with escherichia coli o157:h7 gfp, genetically modified with a plasmid encoding a protein that fluoresces green when exposed to long-wave ultraviolet light. after incubation at 37 degrees c for 5 days, the wet manure was spread on the surface of beef tissues at an average e. coli o157:h7 gfp level of 6.62 log cfu/cm2. dry manure was obtained by subjecting wet manure to natural drying (simulating dry manu ... | 1998 | 9798139 |
| the effect of reuterin on listeria monocytogenes and escherichia coli o157:h7 in milk and cottage cheese. | a broad-spectrum reuterin produced during anaerobic fermentation of glycerol by lactobacillus reuteri strain 12002 was found to be inhibitory and bactericidal for listeria monocytogenes and escherichia coli o157:h7. lyophilized reuterin was prepared by a two-step fermentation process. a batch fermentation in a 15-liter fermentor was applied to produce a maximum biomass of l. reuteri using a modified mrs broth at ph 4.3. further, harvested cells were used to ferment glycerol (250 mm) under anaero ... | 1998 | 9798141 |
| efficacy of spray application of chlorinated water in killing pathogenic bacteria on raw apples, tomatoes, and lettuce. | washing whole and cut produce by dipping or submerging in chlorinated water has a sanitizing effect, although reduction in microbial populations is minimal and is usually less than 100-fold. a study was undertaken to evaluate the efficacy of a spray application of chlorine in killing salmonella, escherichia coli o157:h7, listeria monocytogenes, yeasts and molds, and total aerobic mesophilic microorganisms on whole apples, tomatoes, and lettuce leaves. inoculated produce was treated (sprayed and ... | 1998 | 9798146 |
| fate of escherichia coli o157:h7 in ground apples used in cider production. | survival of escherichia coli o157:h7 in ground golden delicious, red delicious, rome, and winesap apples stored at 4, 10, and 25 degrees c was determined. e. coli o157:h7 populations were monitored for up to 18 days (4 degrees c), 12 days (10 degrees c), and 5 days (25 degrees c), when mold contamination became visible. at 25 degrees c, red delicious apples supported survival of e. coli o157:h7 better (p < 0.05) than the other cultivars, followed by golden delicious and rome apples, which were n ... | 1998 | 9798157 |
| inflammatory mediators in escherichia coli o157:h7 hemorrhagic colitis and hemolytic-uremic syndrome. | recent experimental data suggest that the inflammatory response of the host to verotoxin and/or lipopolysaccharides of escherichia coli is involved in the pathophysiology of verotoxin-producing e. coli (vtec) infections. | 1998 | 9802632 |
| comparative studies of magnetic particle-based solid phase fluorogenic and electrochemiluminescent immunoassay. | two solid phase immunoassays, an electrochemiluminescent immunoassay (eclia) and a magnetic particle fluorogenic immunoassay (mpfia) were evaluated and compared for bacterial detection. briefly, the eclia is based on a redox reaction between ruthenium (ii)-trisbipyridyl ru[(bpy)3]2+ labeled antibody and the excess of tripropylamine, which generates photons. the entire reaction is carried on the near surface area between the spherical magnetic beads and an anode electrode. the detectable bacteria ... | 1998 | 9819118 |
| comparison of methods for determining the presence of escherichia coli o157:h7 in apple juice. | six methods were compared for detection of three strains of escherichia coli o157:h7 in enrichments of inoculated apple juice. juice was inoculated at levels varying from 0.1 to 100 cfu/ml and centrifuged after overnight storage at 4 degrees c, and pellets were incubated at 37 degrees c in nonselective enrichment broth. at hourly intervals between 5 and 10 h and at 24 h, the enrichments were tested for e. coli o157:h7 by direct fluorescent antibody (dfa), antibody-direct epifluorescent filter te ... | 1998 | 9829180 |
| antibiotic resistance of escherichia coli o157:h7 and o157:nm isolated from animals, food, and humans. | antibiotic resistance was determined for 118 e. coli o157:h7 and 7 o157:nm isolates from animals, foods, and humans. among the 125 isolates, 30 (24%) were resistant to at least one antibiotic and 24 (19%) were resistant to three or more antibiotics. cattle isolates had the highest rate (34%) of antibiotic resistance. the seven resistant food isolates were all from ground beef. the most frequent resistance type overall was streptomycin-sulfisoxazole-tetracycline, which accounted for over 70% of t ... | 1998 | 9829195 |
| simulation modeling for microbial risk assessment. | quantitative microbial risk assessment implies an estimation of the probability and impact of adverse health outcomes due to microbial hazards. in the case of food safety, the probability of human illness is a complex function of the variability of many parameters that influence the microbial environment, from the production to the consumption of a food. the analytical integration required to estimate the probability of foodborne illness is intractable in all but the simplest of models. monte ca ... | 1998 | 9829204 |
| susceptibility of three strains of conventional adult mice to intestinal colonization by an isolate of escherichia coli o157:h7. | three mouse strains were assessed for their susceptibility to intestinal colonization by a strain of the enteric bacterial pathogen escherichia coli o157:h7. following intragastric inoculation of e. coli o157:h7, the intestines of young adult female cd1, balb/c, and c57bl/6 mice became colonized, as evidenced by faecal shedding of the pathogen for periods of up to 5 weeks. none of the three mouse strains examined developed overt disease in response to colonization by the organism. following clea ... | 1998 | 9830109 |
| effects of starvation on physiological activity and chlorine disinfection resistance in escherichia coli o157:h7. | escherichia coli o157:h7 can persist for days to weeks in microcosms simulating natural conditions. in this study, we used a suite of fluorescent, in situ stains and probes to assess the influence of starvation on physiological activity based on membrane potential (rhodamine 123 assay), membrane integrity (live/dead baclight kit), respiratory activity (5-cyano-2,3-di-4-tolyl-tetrazolium chloride assay), intracellular esterase activity (scanrdi assay), and 16s rrna content. growth-dependent assay ... | 1998 | 9835545 |
| gastroenteritis in children: principles of diagnosis and treatment. | gastroenteritis in children is a common reason for visits to family physicians. most cases of gastroenteritis have a viral etiology and are self-limited. however, more severe or prolonged cases of gastroenteritis can result in dehydration with significant morbidity and mortality. this is often the scenario in third-world countries, where gastroenteritis results in 3 million deaths annually. a proper clinical evaluation will allow the physician to estimate the percentage of dehydration and determ ... | 1998 | 9835852 |
| characterisation of escherichia coli o157:h7 (h-) derived from cattle using random amplification of polymorphic dna analysis. | one hundred and two isolates of escherichia coli o157:h7 derived from cattle were characterised by random amplification of polymorphic dna (rapd). four different rapd profiles were observed. based on the combined results of rapd typing and toxin genotyping, the isolates could be divided into six distinct groups. | 1998 | 9839900 |
| changes in pulsed-field gel electrophoresis patterns in clinical isolates of enterohemorrhagic escherichia coli o157:h7 associated with loss of shiga toxin genes. | pulsed-field gel electrophoresis (pfge) of xbai-digested dna fragments of enterohemorrhagic escherichia coli (ehec) o157:h7 strains showed disappearance of a 70- or 80-kb fragment in their patterns associated with loss of shiga toxin genes during maintenance or subcultivation. hybridization experiments with a dna probe complementary to shiga toxin sequences revealed that the shiga toxin genes in the parental strain were located on fragments the same size as the lost fragments from the toxin-nega ... | 1999 | 9841782 |
| rapid detection of escherichia coli o157:h7 using immuno-magnetic flow cytometry in ground beef, apple juice, and milk. | a rapid method combining flow cytometry and immunomagnetic bead separation (imfc) was effective for detecting low populations of escherichia coli o157:h7 inoculated into ground beef, apple juice, and raw milk samples. modified buffered peptone was most effective for enrichment of e. coli o157:h7 in ground beef. using imfc in combination with a 6-h enrichment, as few as four e. coli o157:h7 cells/g of ground beef were detected in as little as a 7-h total analysis time. our results demonstrate the ... | 1998 | 9849789 |
| irradiation as a method for decontaminating food. a review. | despite substantial efforts in avoidance of contamination, an upward trend in the number of outbreaks of foodborne illnesses caused by nonsporeforming pathogenic bacteria are reported in many countries. good hygienic practices can reduce the level of contamination but the most important pathogens cannot presently be eliminated from most farms nor is it possible to eliminate them by primary processing, particularly from those foods which are sold raw. several decontamination methods exist but the ... | 1998 | 9851599 |
| new perspectives on the role of escherichia coli o157:h7 and other enterohaemorrhagic e. coli serotypes in human disease. | this review compares the rates of detection of non-o157:h7 enterohaemorrhagic escherichia coli (ehec) with ehec o157:h7 in outbreaks and sporadic cases of human disease by analysing australian data and the world literature. numerous outbreaks of disease have been attributed to ehec o157:h7. in many studies, isolation rates of this organism have been low and attempts to seek other ehec have not been made. ease of isolation and identification of the o157:h7 serotype may have given the impression t ... | 1998 | 9856639 |
| surveillance for waterborne-disease outbreaks--united states, 1995-1996. | since 1971, cdc and the u.s. environmental protection agency have maintained a collaborative surveillance system for collecting and periodically reporting data that relate to occurrences and causes of waterborne-disease outbreaks (wbdos). | 1998 | 9859954 |
| escherichia coli o157:h7 outbreaks in the united states, 1982-1996. | | 1998 | 9861961 |
| mutators and long-term molecular evolution of pathogenic escherichia coli o157:h7. | it has been proposed that an increased mutation rate (indicated by the frequency of hypermutable isolates) has facilitated the emergence of escherichia coli o157:h7. analysis of the divergence of 12 genes shows no evidence that the pathogen has undergone an unusually high rate of mutation and molecular evolution. | 1998 | 9866737 |
| a possible role of prop, prou and cait in osmoprotection of escherichia coli by carnitine. | exogenously provided carnitine (beta-hydroxy-l-tau-n-trimethyl aminobutyrate) was found to stimulate aerobic growth of enterohaemorrhagic escherichia coli o157:h7 in a medium of inhibitory osmotic strength. its osmoprotective ability is comparable with that of betaine. as carnitine is an important compound in mammalian tissues, it is suggested that it might play a role in the growth of the pathogen on low water activity (aw) meat products. using specific uptake mutants of e. coli k-12, it was es ... | 1998 | 9871325 |
| redox potential affects the measured heat resistance of escherichia coli o157:h7 independently of oxygen concentration. | cells of escherichia coli o157:h7 were heat-treated at 59 degrees c and enumerated in (i) anaerobic medium with a low redox potential, (ii) anaerobic media with the oxidizing agents potassium ferricyanide or 2,6-dichloroindophenol (dpip) added to raise the redox potential, (iii) aerobic medium with a high redox potential and (iv) aerobic medium with the reducing agent dithiothreitol added to lower the redox potential. the measured heat-resistance was greatest when the enumeration medium was high ... | 1998 | 9871347 |
| fate of escherichia coli o157:h7 on fresh-cut apple tissue and its potential for transmission by fruit flies. | pathogenic escherichia coli o157:h7, as well as nonpathogenic strains atcc 11775 and atcc 23716, grew exponentially in wounds on golden delicious apple fruit. the exponential growth occurred over a longer time period on fruit inoculated with a lower concentration of the bacterium than on fruit inoculated with a higher concentration. the bacterium reached the maximum population supported in the wounds regardless of the initial inoculum concentrations. populations of e. coli o157:h7 in various con ... | 1999 | 9872751 |