A survival study of Escherichia coli in a south African river using membrane diffusion chambers

1995 ◽  
Vol 31 (5-6) ◽  
pp. 185-188 ◽  
Author(s):  
C. M. E. de Wet ◽  
S. N. Venter ◽  
N. Rodda ◽  
R. Kfir ◽  
M. C. Steynberg ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
South African ◽  
The Other ◽  
Membrane Diffusion ◽  
Diffusion Chambers ◽  
E Coli ◽  
Significant Difference ◽  
Survival Pattern ◽  
The One ◽  
Different Parts

Studies to describe the survival of Escherichia coli were performed at two sites in a river. The one site was dominated by domestic discharge and the other by industrial inputs. E coli suspensions within membrane diffusion chambers were immersed in the river at the selected sites. An identical chamber was submerged in river water in the laboratory as a comparison. Two test runs were performed, one during winter (July) and one during summer (December). Samples to determine the survival of E coli was taken on a scheduled basis. Results obtained showed no significant difference between the survival pattern of E coli as determined during the summer and winter periods or in the different parts of the river. The same survival pattern was observed for the studies performed in the laboratory.

Fate of Escherichia coli O157:H7 in Ground Apples Used in Cider Production

1998 ◽  
Vol 61 (10) ◽  
pp. 1372-1374 ◽  
Author(s):  
TOMEKA L. FISHER ◽  
DAVID A. GOLDEN
Keyword(s):  
Escherichia Coli ◽  
Statistical Difference ◽  
The Other ◽  
Escherichia Coli O157 ◽  
Apple Cultivar ◽  
Mold Growth ◽  
E Coli ◽  
Significant Difference ◽  
Golden Delicious ◽  
Pathogen Populations

Survival of Escherichia coli O157:H7 in ground Golden Delicious, Red Delicious, Rome, and Winesap apples stored at 4, 10, and 25°C was determined. E. coli O157:H7 populations were monitored for up to 18 days (4°C), 12 days (10°C), and 5 days (25°C), when mold contamination became visible. At 25°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 not statistically different (P > 0.05). Winesap apples were the least favorable (P < 0.05) for survival of E. coli O157:H7 at 25°C. E. coli O157:H7 was recovered at similar rates from Golden Delicious and Red Delicious apples, (P > 0.05), but pathogen populations increased in both cultivars (P < 0.05) during storage at 25°C. At 10°C, survival of E. coli O157:H7 was poorest (P < 0.05) in ground Red Delicious apples, while there was no significant difference in survival of E. coli O157:H7 among ground Golden Delicious, Rome, or Winesap cultivars (P > 0.05). When stored at 4°C, Golden Delicious and Rome apples were not statistically different in supporting survival of the pathogen (P > 0.05) and there was no statistical difference in the recovery of E. coli O157:H7 from ground Red Delicious, Rome, and Winesap apples (P > 0.05). In general, apple pH increased during storage and was associated with mold growth. Results of this investigation indicate that there is no trend toward a particular apple cultivar supporting survival of E. coli O157:H7. However, variation in apple pH during storage can negatively or positively influence E. coli O157:H7 survival at 25 °C.

Influence of Acid Adaptation on the Tolerance of Escherichia coli O157:H7 to Some Subsequent Stresses

2002 ◽  
Vol 65 (2) ◽  
pp. 260-265 ◽  
Author(s):  
HSIN-YI CHENG ◽  
HSIN-YI YANG ◽  
CHENG-CHUN CHOU
Keyword(s):  
Escherichia Coli ◽  
Sodium Chloride ◽  
Bile Salt ◽  
Thermal Tolerance ◽  
The Other ◽  
Escherichia Coli O157 ◽  
Acid Adaptation ◽  
E Coli ◽  
Significant Difference ◽  
Test Organisms

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°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.

scholarly journals A comparison of swab and maceration methods for bacterial sampling of pig carcasses

1985 ◽  
Vol 95 (2) ◽  
pp. 383-390 ◽  
Author(s):  
I. R. Morgan ◽  
F. Krautil ◽  
J. A. Craven
Keyword(s):  
Escherichia Coli ◽  
Sampling Methods ◽  
The Other ◽  
E Coli ◽  
Significant Difference ◽  
Pig Carcasses

SUMMARYA swabbing technique was compared with an excision and maceration technique for bacteriological sampling of pig carcass skin surfaces. Total viable counts at 37 °C obtained by swabbing were 46% of those obtained by maceration. At 21 °C, swabbing gave total viable counts which were 54% of the counts obtained from excision samples.Escherichia colicounts showed wide variation with both sampling methods. Neither method was more efficient than the other in recoveringE. coli, although excision sampling gave generally higher counts. Both methods were equally effective at recovering salmonellac from carcass surfaces. There was no significant difference between the methods in recovering particularSalmonellaserotypes.

IMMUNOLOGICAL REACTIVITY OF INSULIN IN HUMAN SERUM

1966 ◽  
Vol 53 (4) ◽  
pp. 673-680 ◽  
Author(s):  
Torsten Deckert ◽  
Kai R. Jorgensen
Keyword(s):  
Normal Subjects ◽  
The Other ◽  
Human Pancreas ◽  
Porcine Pancreas ◽  
Crystalline Insulin ◽  
Endogenous Insulin ◽  
Significant Difference ◽  
Human Sera ◽  
Normal Human ◽  
The One

ABSTRACT The purpose of this study was to investigate whether a difference could be demonstrated between crystalline insulin extracted from normal human pancreas, and crystalline insulin extracted from bovine and porcine pancreas. Using Hales & Randle's (1963) immunoassay no immunological differences could be demonstrated between human and pig insulin. On the other hand, a significant difference was found, between pig and ox insulin. An attempt was also made to determine whether an immunological difference could be demonstrated between crystalline pig insulin and crystalline human insulin from non diabetic subjects on the one hand and endogenous, circulating insulin from normal subjects, obese subjects and diabetic subjects on the other. No such difference was found. From these experiments it is concluded that endogenous insulin in normal, obese and diabetic human sera is immunologically identical with human, crystalline insulin from non diabetic subjects and crystalline pig insulin.

scholarly journals Escherichia coli O157:H7 SURVIVAL IN TRADITIONAL AND LOW LACTOSE YOGURT DURING FERMENTATION AND COOLING PERIODS

2017 ◽  
Vol 18 (0) ◽  
Author(s):  
Camila Sampaio Cutrim ◽  
Raphael Ferreira de Barros ◽  
Robson Maia Franco ◽  
Marco Antonio Sloboda Cortez
Keyword(s):  
Escherichia Coli ◽  
The Other ◽  
Lactose Hydrolysis ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Gas Formation ◽  
Whole Milk ◽  
Milk Contamination ◽  
Different Types ◽  
Fermentation Period

Abstract The purpose of this study was to evaluate the behavior of E. coli O157:H7 during lactose hydrolysis and fermentation of traditional and low lactose yogurt. It also aimed to verify E. coli O157:H7 survival after 12 h of storage at 4 ºC ±1 ºC. Two different types of yogurts were prepared, two with whole milk and two with pre-hydrolyzed whole milk; in both groups one yogurt was inoculated with E. coli O157:H7 and the other one was not inoculated. The survival of E. coli and pH of yogurt were determined during fermentation and after 12-h refrigeration. The results showed that E. coli O157:H7 was able to grow during the fermentation period (from 4.34 log CFU.mL-1 to 6.13 log CFU.mL-1 in traditional yogurt and 4.34 log CFU.mL-1 to 6.16 log CFU.mL-1 in low lactose yogurt). The samples with E. coli O157:H7 showed gas formation and syneresis. Thus, E. coli O157:H7 was able to survive and grow during fermentation of traditional and low lactose yogurts affecting the manufacture technology. Moreover, milk contamination by E. coli before LAB addition reduces the growth of L. bulgaricus and S. thermophilus especially when associated with reduction of lactose content.

scholarly journals Distribution of Sulfonamide Resistance Genes in Escherichia coli and Salmonella Isolates from Swine and Chickens at Abattoirs in Ontario and Québec, Canada

2009 ◽  
Vol 75 (18) ◽  
pp. 5999-6001 ◽  
Author(s):  
Gosia K. Kozak ◽  
David L. Pearl ◽  
Julia Parkman ◽  
Richard J. Reid-Smith ◽  
Anne Deckert ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Genes ◽  
E Coli ◽  
Significant Difference ◽  
Sulfonamide Resistance ◽  
Sulfonamide Resistance Genes

ABSTRACT Sulfonamide-resistant Escherichia coli and Salmonella isolates from pigs and chickens in Ontario and Québec were screened for sul1, sul2, and sul3 by PCR. Each sul gene was distributed differently across populations, with a significant difference between distribution in commensal E. coli and Salmonella isolates and sul3 restricted mainly to porcine E. coli isolates.

Fate of Escherichia coli O157:H7 and Other Coliforms in Commercial Mayonnaise and Refrigerated Salad Dressing

1995 ◽  
Vol 58 (1) ◽  
pp. 13-18 ◽  
Author(s):  
ERROL V. RAGHUBEER ◽  
JIM S. KE ◽  
MICHAEL L. CAMPBELL ◽  
RICHARD S. MEYER
Keyword(s):  
Escherichia Coli ◽  
Storage Temperature ◽  
Enterobacter Aerogenes ◽  
Antimicrobial Effect ◽  
Coliform Bacteria ◽  
Escherichia Coli O157 ◽  
Salad Dressing ◽  
E Coli ◽  
Survival Pattern ◽  
High Level

Commercial mayonnaise and refrigerated ranch salad dressing were inoculated at two levels with two strains of Escherichia coli O157:H7, a non-pathogenic E. coli, and the non-fecal coliform Enterobacter aerogenes. Results showed that at the high inoculation level (>106 colony forming units [CFU]/g) in mayonnaise stored at room temperature (ca. 22°C) both strains of O157:H7 were undetected at 96 h. At the high inoculation level, all strains of coliform bacteria tested survived longer in salad dressing stored at 4°C than in mayonnaise stored at 22°C. The O157:H7 strains were still present at low levels after 17 days. The survival time in the low-level inoculum (104CFU/g) study decreased, but the survival pattern in the two products was similar to that observed in the high-level inoculum study. Slight differences in survival among strains were observed. The greater antimicrobial effect of mayonnaise may be attributable to differences in pH, water activity (aw), nutrients, storage temperature, and the presence of lysozyme in the whole eggs used in the production of commercial mayonnaise. Coliform bacteria survived longer in refrigerated salad dressing than in mayonnaise particularly at the high-level inoculum. Both mayonnaise (pH 3.91) and salad dressing (pH 4.51) did not support the growth of any of the microorganisms even though survival was observed.

A Tug of War Between Heritage Conservation and Property Rights: Some Success at Last for Heritage Conservation—City of Cape Town v. Oudekraal Estates (Pty) Ltd. [2007] JOL 20887 (C)

2009 ◽  
Vol 16 (1) ◽  
pp. 67-83 ◽  
Author(s):  
Margaret Beukes
Keyword(s):  
Property Rights ◽  
South African ◽  
Cape Town ◽  
The Other ◽  
Heritage Conservation ◽  
South African Context ◽  
Sensitive Issue ◽  
African Context ◽  
The One ◽  
The Right

When the idea of heritage conservation arises, one specific facet of the ensuing reflection is bound to emerge at some stage: the (inevitable) tension between property rights, on the one hand, and the right to culture (of which heritage conservation is an aspect), on the other. This tension intensifies when the cultural material to be conserved concerns a traditionally sensitive issue—that of the burial places of the ancestors of people designated in the South African context as previously disadvantaged.

scholarly journals Fasciola hepatica findings in cattle of Jablanica region

2007 ◽  
Vol 61 (1-2) ◽  
pp. 89-97
Author(s):  
Valentina Milanovic ◽  
Aleksandar Nitovski ◽  
Zoran Kulisic ◽  
Milorad Mirilovic ◽  
Boban Popovic ◽  
...  
Keyword(s):  
Liver Fluke ◽  
Fasciola Hepatica ◽  
The Other ◽  
Infected Cattle ◽  
Significant Difference ◽  
The One

In the period from January 2001 to December 2005, a total of 6,904 slaughtered cattle originating from the territory of the region of Jablanica were examined at the Mesokombinat AD abattoir. The Trematoda Fasciola hepatica was found in 429 cattle (6.21%). A total of 2,150 kg livers were condemned due to the presence of the liver fluke. A comparison of cattle with bovine fasciolosis according to the years yielded a very significant difference (p<0.01) between the year 2003 (10.02) and the year 2002 (9.97), on the one side, in comparison with the years 2001 (5.14), 2004 (3.37), and 2005 (5.08), on the other side. A significant difference (p<0.05) was also established in the year 2004 (3.37) in comparison with the years 2001 (5.14) and 2005 (5.08). After analyzing the significance of the differences between the infected cattle according to the seasons, a very significant difference (p<0.01) was established between the summer (7.23) and the winter (4.74) periods. A significant difference (p<0.05) was also established between the autumn (6.49) and the winter periods. The amount of precipitation was directly proportionate to the percentage of cattle infected with fasciolosis.

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