scholarly journals First detection of Shiga toxin producing Escherichia coli O157:H7 (HlyA gene) and enumeration of most probable number (MPN) of fecal coliforms and Escherichia coli in cage cultured oysters (Crassostrea iredalei) and water from southern Malaysia

Author(s):  
Hong, T. K. ◽  
Bobby, G. ◽  
Norizan, N. ◽  
Ariff, N. ◽  
Addis, S. N. K. ◽  
...  
2019 ◽  
Vol 2 (2) ◽  
pp. a13-19
Author(s):  
ELEXSON NILLIAN ◽  
AMIZA NUR ◽  
DIYANA NUR ◽  
AMIRAH ZAKIRAH ◽  
GRACE BEBEY

Contamination of drinks with E. coli O157:H7 served in food premises such as restaurants can cause haemorrhagic colitis and haemolytic uremic syndrome to humans. The presence or absence of faecal pathogen was demonstrated using coliform group as indicator microorganisms. Therefore, this study was conducted to detect the presence of E. coli O157:H7 in drinking water from food restaurant premise in Kota Samarahan and Kuching to ensure safe and potable drinking water is served to the consumer. A total of thirty (n=30) drink samples including six types of each of the samples are cold plain water, iced tea, iced milo, syrup and iced milk tea. Most Probable Number (MPN) procedure was used in this study to enumerate the MPN values of coliform bacteria in each drink collected. A total of 53.33% (16/30) of the drink samples showed positive E. coli detection. Then, the PCR assay showed 6.25% (one out of 16 isolates) samples were positive and carried stx1 gene produced by E. coli O157:H7 in iced milo sample types. This study showed the drinks collected from food premises was contaminated with faecal contamination, which was not safe to drink by the consumer. Therefore, preventive actions should be taken to prevent foodborne illness outbreak in future


1997 ◽  
Vol 60 (8) ◽  
pp. 883-890 ◽  
Author(s):  
PHYLLIS ENTIS ◽  
IRINA LERNER

Two 24-hour presumptive enumeration methods for Escherichia coli O157:H7 organisms based on the hydrophobic grid membrane filter (ISO-GRID) and using SD-39 agar, a new selective and differential culture medium, were developed and compared to a 3-tube MPN (most probable number) method using modified tryptone soy broth enrichment. The comparative study comprised 22 combinations of storage conditions and food products, including a variety of raw and cooked meats and several dairy products. The ISO-GRID direct filtration method produced counts which were equivalent to or significantly higher than the 3-tube MPN method for all food-storage combinations except for frozen pasteurized whole egg. The ISO-GRID resuscitation method produced counts equivalent to the 3-tube MPN method for the frozen egg.


2005 ◽  
Vol 68 (3) ◽  
pp. 451-457 ◽  
Author(s):  
NARELLE FEGAN ◽  
GLEN HIGGS ◽  
PAUL VANDERLINDE ◽  
PATRICIA DESMARCHELIER

The extent of contamination with Escherichia coli O157 was determined for 100 cattle during slaughter. Samples from 25 consecutively slaughtered cattle from four unrelated groups were collected from the oral cavity, hide, rumen, feces after evisceration, and pre- and postchill carcass. Ten random fecal samples were collected from the pen where each group of animals was held at the abattoir. E. coli O157 was detected using automated immunomagnetic separation (AIMS), and cell counts were determined using a combination of most probable number (MPN) and AIMS. E. coli O157 was isolated from 87 (14%) of the 606 samples collected, including 24% of 99 oral cavity samples, 44% of 100 hides, 10% of 68 fecal samples collected postevisceration, 6% of 100 prechill carcass swabs, and 15% of 40 fecal samples collected from holding pens. E. coli O157 was not isolated from rumen or postchill carcass samples. E. coli O157 was isolated from at least one sample from each group of cattle tested, and the prevalence in different groups ranged from less than 1 to 41%. The numbers of E. coli O157 differed among the animals groups. The group which contained the highest fecal (7.5 × 105 MPN/g) and hide (22 MPN/cm2) counts in any individual animal was the only group in which E. coli O157 was isolated from carcasses, suggesting a link between the numbers of E. coli O157 present and the risk of carcass contamination. Processing practices at this abattoir were adequate for minimizing contamination of carcasses, even when animals were heavily contaminated with E. coli O157.


1995 ◽  
Vol 58 (11) ◽  
pp. 1197-1200 ◽  
Author(s):  
GUADALUPE R. GARCIA ◽  
ROBERT E. HAYMOND ◽  
DIANE M. SPRAGUE ◽  
EMMA R. SINGLETON ◽  
JAMES T. PEELER ◽  
...  

A direct elevated temperature plate count method utilizing modified fecal coliform agar with rosolic acid (ETPC/mFC) was compared to 5-tube and 3-tube most probable number (MPN) procedures for its accuracy in enumerating fecal coliforms and Escherichia coli in naturally and artificially contaminated soft-shell clams (Mya arenaria). The results indicated that the extent of overall recovery of fecal coliforms was similar in the two methods tested. Therefore, the ETPC/mFC method may be considered as a rapid procedure for fecal coliform screening during depuration of soft-shell clams.


1998 ◽  
Vol 61 (3) ◽  
pp. 280-284 ◽  
Author(s):  
MICKEY E. PARISH

A salmonellosis outbreak occurred during the summer of 1995 among individuals who consumed nonpasteurized orange juice from a Florida citrus-processing facility. Clinical isolates were identified by the Centers for Disease Control as Salmonella serovars Hartford, Gaminara, and Rubislaw. At the processing facility, 70 samples (equipment swabs, fruit surface swabs, juice, and miscellaneous environmental samples) were collected before, during, and after processing runs on two different dates. Bottled juice samples from eight previous extraction dates were also collected. Total plate counts, fecal coliforms, and Escherichia coli were enumerated for each sample. Analyses for Salmonella cells were conducted on all juice samples, fruit surface swabs, environmental samples, and selected equipment swabs using direct enrichment and pre-enrichment techniques. Salmonella serovars Hartford, Rubislaw, Saintpaul, and Newport were detected from either juice, unwashed fruit surfaces, or amphibians (Hyla cinerea and Bufo terrestris) captured outside the processing building. Salmonella cells in juice were associated with population levels of fecal coliforms and E. coli above the upper most probable number (MPN) limits of detection (>110/ml).


2015 ◽  
Vol 78 (9) ◽  
pp. 1733-1737 ◽  
Author(s):  
ALEXANDER GILL ◽  
DENISE OUDIT

In this article, we discuss the enumerative analysis for Escherichia coli O157 in two raw milk Gouda cheese products (A and B), implicated in an outbreak of 29 cases of E. coli O157:H7 illness that occurred across Canada in 2013. Samples were enumerated for E. coli O157 by most probable number (MPN) over a period of 30 to 60 days after the end of the outbreak. Samples (55.55 g) of product A (n = 14) were analyzed at 146 to 180 days postproduction. E. coli O157 was isolated from six samples at 19.9 to 44.6 MPN/kg. The E. coli O157 concentration of product A estimated from the results of all 14 samples was 9.5 MPN/kg. Samples (55.55 g) of product B (n = 20) were analyzed at 133 to 149 days postproduction. E. coli O157 was isolated from four samples at 19.9 MPN/kg. The E. coli O157 concentration of product B estimated from the results of all 20 samples was 3.7 MPN/kg. Analysis of a 305-g sample of product A (n = 1) stored at 4°C until 306 days postproduction revealed that the E. coli O157 concentration had declined to 3.6 MPN/kg. E. coli O157 could not be isolated from 555-g samples of product B (n = 5) after 280 days postproduction. The physicochemical parameters (pH, water activity, percent moisture, and percent salt) of both cheese products were found to be in the normal range for this type of product. The results of this study demonstrate that E. coli O157 could not replicate during storage at 4°C in the products tested but was capable of survival following aging and prolonged storage. This indicates that, if contaminated, the minimum 60-day aging period, which is required for raw milk Gouda cheeses, is not sufficient in all cases to ensure that the product does not contain viable cells of E. coli O157. The results also indicate that samples sizes greater than 100 g may be required to reliably detect E. coli O157 in cheese products associated with outbreaks.


2015 ◽  
Vol 78 (8) ◽  
pp. 1547-1553 ◽  
Author(s):  
GORDON R. DAVIDSON ◽  
JOHN C. FRELKA ◽  
MAI YANG ◽  
THOMAS M. JONES ◽  
LINDA J. HARRIS

Inshell walnuts collected from California walnut handlers over four harvests were evaluated for the presence of Escherichia coli O157:H7 and Salmonella. E. coli O157:H7 was not detected in any of 2,903 375-g samples evaluated in 2011, 2012, and 2013 (<0.034% prevalence; 95% confidence interval [CI], 0 to 0.13%). Salmonella was not isolated from any of the 935 samples in 2010 (100 g evaluated; <0.11% prevalence; 95% CI, 0 to 0.41%) but was isolated from 2 of 905 (375 g; 0.22% prevalence; 95% CI, 0.061 to 0.80%), 1 of 998 (375 g; 0.10% prevalence; 95% CI, 0.018 to 0.56%), and 1 of 1,000 (375 g; 0.10% prevalence; 95% CI, 0.018 to 0.56%) samples in 2011, 2012, and 2013, respectively, for an average annual prevalence of 0.14% (375 g; 95% CI, 0.054 to 0.35%). The levels of Salmonella in positive samples determined by a modified most-probable-number (MPN) method were estimated to be 0.32 to 0.42 MPN/100 g (95% CI, 0.045 to 3.6 MPN/100 g).


2007 ◽  
Vol 53 (6) ◽  
pp. 798-801 ◽  
Author(s):  
Tamara Garcia-Armisen ◽  
Josué Prats ◽  
Pierre Servais

Fecal coliforms (FC) counts were compared with Escherichia coli counts in differently contaminated freshwater samples (n = 166). FC were enumerated by plate count on triphenyl 2,3,5-tetrazolium chloride Tergitol medium. Escherichia coli were enumerated by the most probable number microplate method based on the detection of glucuronidase activity. FC and E. coli counts were highly correlated; an average E. coli/FC ratio equal to 0.77 was found, meaning that on average, 77% of FC were E. coli. Knowing the E. coli/FC ratio allows us to convert the historical microbiological quality data expressed in FC counts into E. coli abundance and thus to compare with present and future monitoring data that are (or will be) based on E. coli enumeration.


2000 ◽  
Vol 63 (8) ◽  
pp. 1038-1042 ◽  
Author(s):  
ROBIN C. ANDERSON ◽  
SANDRA A. BUCKLEY ◽  
LEON F. KUBENA ◽  
LARRY H. STANKER ◽  
ROGER B. HARVEY ◽  
...  

Escherichia coli O157:H7 and Salmonella Typhimurium DT104 are important foodborne pathogens affecting the beef and dairy industries and strategies are sought to rid these organisms from cattle at slaughter. Both pathogens possess respiratory nitrate reductase that also reduces chlorate to the lethal chlorite ion. Because most anaerobes lack respiratory nitrate reductase, we hypothesized that chlorate may selectively kill E. coli O157:H7 and Salmonella Typhimurium DT104 but not potentially beneficial anaerobes. In support of this hypothesis, we found that concentrations of E. coli O157:H7 and Salmonella Typhimurium DT104 were reduced from approximately 1,000,000 colony forming units (CFU) to below our level of detection (≤10 CFU) following in vitro incubation (24 h) in buffered ruminal contents (pH 6.8) containing 5 mM added chlorate. In contrast, chlorate had little effect on the most probable number (mean ± SD) of total culturable anaerobes (ranging from 9.9 ± 0.72 to 10.7 ± 0.01 log10 cells/ml). Thus, chlorate was bactericidal to E. coli O157:H7 and Salmonella Typhimurium DT104 but not to potentially beneficial bacteria. The bactericidal effect of chlorate was concentration dependent (less at 1.25 mM) and markedly affected by pH (more bactericidal at pH 6.8 than pH 5.6).


2008 ◽  
Vol 71 (10) ◽  
pp. 2078-2081 ◽  
Author(s):  
M. F. MILLER ◽  
G. H. LONERAGAN ◽  
D. D. HARRIS ◽  
K. D. ADAMS ◽  
J. C. BROOKS ◽  
...  

A study was conducted to determine the impact of exposure to dust in the cattle load-out area in feedyards on pathogen contamination of cattle hides. A total of 250 cattle hides were sampled during summer and fall months, which are associated with elevated prevalence of Escherichia coli O157 in West Texas. Animals were removed from their home pens and restrained in a chute and sampled prior to exposure to dust generated as a result of a simulated loading exercise. The cattle hides were sampled again after exposure to the loading dust to determine total numbers of pathogens on cattle hides on leaving their home pen (before loading) and on cattle hides after exposure to the dust in the loading area. Air and dirt samples from the home pens and the cattle load-out area were also collected. The presence of E. coli O157 and Salmonella was determined in all the samples, and when a positive sample was identified, the total numbers of these bacteria present were enumerated. The total numbers of pathogens increased after dust exposure; Salmonella counts increased from 1.09 log most probable number (MPN)/cm2 to 1.74 log MPN/cm2 after exposure, and E. coli O157 counts increased from 0.80 to 2.35 log MPN/cm2 after sampling. E. coli O157 and Salmonella were recovered from the air samples during dust generation at 6.66 and 11.1%, respectively. Salmonella and E. coli O157 prevalence was not changed and was not associated with the exposure to the dust. Results indicate airborne dust generated as a result of cattle movement and loading could be an important determining factor in total numbers of pathogens recovered on cattle hides.


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