Comparison of recto-anal mucosal swab and faecal culture for the detection ofEscherichia coliO157 and identification of super-shedding in a mob of Merino sheep

2015 ◽  
Vol 143 (13) ◽  
pp. 2733-2742 ◽  
Author(s):  
A. S. McPHERSON ◽  
O. P. DHUNGYEL ◽  
M. P. WARD
Keyword(s):  
Enrichment Culture ◽  
Kappa Statistic ◽  
Immunomagnetic Separation ◽  
Sampling Point ◽  
Merino Sheep ◽  
E Coli ◽  
Faecal Culture ◽  
Significant Difference ◽  
Sampling Points ◽  
Culture Positive

SUMMARYWe compared the use of recto-anal mucosal swab (RAMS) culture and faecal culture for the detection ofE. coliO157 in a mob of Merino sheep. Fifty Merino wethers and maiden ewes housed in indoor pens were sampled on five occasions. We detectedE coliO157 in 32% (16/50) of sheep, with weekly prevalence ranging from 4% (2/50) to 16% (8/50). Overall, 12·5% (2/16) were detected by RAMS culture only, and 37·5% (6/16) were detected by faecal culture only. The level of agreement between the two sampling methods was moderate [kappa statistic = 0·583, 95% confidence interval (CI) 0·460–0·707]. The relative sensitivities of RAMS and faecal culture were 67% (95% CI 41–86) and 57% (95% CI 34–77), respectively. We identified four super-shedding sheep using direct faecal culture. Although the majority of culture-positive sheep were detected at one sampling point only, 3/4 super-shedding sheep were culture-positive at two sampling points, and 1/4 was culture-positive at four sampling points. Persistent culture positivity may indicate sheep that could be considered ‘super-shedders' at some point. The use of immunomagnetic separation further improved the rate of detection ofE. coliO157, which was isolated from 1/34 animals that were previously negative by enrichment culture alone. A significant difference between sampling weeks was detected for both faecal (P= 0·021) and RAMS (P= 0·006), with the prevalence at the mid-point of sampling (week 4) significantly (P< 0·05) higher than at the beginning or end of the study. Study conditions (penned sheep) might have been responsible for the high prevalence and the epidemic pattern of infection observed, and could serve as a future model for studies ofE. coliO157 transmission, shedding and super-shedding in sheep.

scholarly journals A one year study of Escherichia coli O157 in raw beef and lamb products

2000 ◽  
Vol 124 (2) ◽  
pp. 207-213 ◽  
Author(s):  
P. A. CHAPMAN ◽  
C. A. SIDDONS ◽  
A. T. CERDAN MALO ◽  
M. A. HARKIN
Keyword(s):  
Magnetic Beads ◽  
Enrichment Culture ◽  
Immunomagnetic Separation ◽  
Plasmid Profile ◽  
Early Summer ◽  
Phage Typing ◽  
E Coli ◽  
Genes Encoding ◽  
Beef Products ◽  
Peptone Water

Between April 1996 and March 1997 we examined 5093 samples of raw beef and lamb products for the presence of E. coli O157. Samples were purchased from 81 small butchers' shops in south Yorkshire. In March 1997 we also examined five samples of dried mint for the presence of E. coli O157.Strains of E. coli O157 were isolated by enrichment culture in modified buffered peptone water followed by immunomagnetic separation and culture of magnetic beads onto cefixime tellurite sorbitol MacConkey agar. Strains were characterized by phage typing, toxin genotyping and plasmid analysis.Strains of E. coli O157 were isolated from 72 (1·4%) of 5093 samples; it was isolated from 36 (1·1%) of 3216 samples of beef products and from 29 (2·9%) samples of lamb products. The highest prevalence was found in lamb sausages and lamb burgers where E. coli O157 was isolated from 3 (4·1%) of 73 and 18 (3·7%) of 484 samples respectively. Strains of E. coli O157 were isolated most frequently during early summer. Strains of E. coli O157 were also isolated from 2 of 5 samples of dried mint although we did not determine how the mint had become contaminated.All isolates of E. coli O157 were Verocytotoxin-producing as determined by both Vero cell assay and DNA hybridization for the genes encoding Verocytotoxin and all were positive for the eaeA gene. A combination of phage typing, toxin genotyping and plasmid profile subdivided the 72 strains of E. coli isolated into 20 different subtypes, of which 18 were indistinguishable from strains isolated previously from cattle and sheep; of these 18 strains, 8 were indistinguishable from strains isolated from human cases of infection during the study period.

scholarly journals Dynamics of Microbial Shedding in Market Pigs during Fasting and the Influence of Alginate Hydrogel Bead Supplementation during Transportation

2021 ◽  
Vol 12 (4) ◽  
pp. 888-898
Author(s):  
Mariana Fernandez ◽  
Arlene Garcia ◽  
David A. Vargas ◽  
Alexandra Calle
Keyword(s):  
Pathogenic Bacteria ◽  
Animal Health ◽  
Control Group ◽  
Sampling Point ◽  
Fasting Period ◽  
Hydrogel Bead ◽  
Hydrogel Beads ◽  
Significant Difference ◽  
Sampling Points ◽  
And Control

The shedding of foodborne pathogenic bacteria by food-animals can be affected by multiple factors, such as animal health, diet, stress, and environmental conditions. The practices that come with transport involve fasting, handling, mixing with unfamiliar pigs, and fluctuating temperatures. These practices, especially fasting and transport, can increase the microbial load in the feces of animals. The use of alginate hydrogels is a novel delivery system that can be a potential food safety intervention during transport to induce satiety and provide electrolytes to the animal’s system. This study sought to observe microbial shedding as affected by fasting and hydrogel bead supplementation during transport. Sixty market pigs were subjected to a 12 h fasting period and an additional 4 h transport period, in which a treatment group was fed hydrogel beads and a control group was not. Sampling points were before fast (BF), before transport (BT), and after transport (AT). Fecal samples were collected from every animal at each sampling point. Results from this study showed a significant increase in the concentrations of both Enterobacteriaceae and Escherichia coli between the before fast (BF) and after transport (AT) sampling points. However, no difference (p > 0.05) was found between the treatment (hydrogel) and control (no hydrogel) during transport. Moreover, no significant difference was found in the prevalence of Salmonella and E. coli O157:H7 at the three different sampling points, or between the treatment and control groups.

scholarly journals Bacterial Composition of Biofilms of a Local Tigernut Drink Processing Unit in Yenagoa, Nigeria

2021 ◽  
Vol 4 (2) ◽  
pp. 59-70
Author(s):  
Juliana O.P. ◽  
Adenike B.A.
Keyword(s):  
Bacterial Load ◽  
Water Storage ◽  
Health Concern ◽  
Processing Unit ◽  
Open Market ◽  
Salmonella Spp ◽  
E Coli ◽  
Significant Difference ◽  
Sampling Points ◽  
Storage Containers

Microorganisms grow and form biofilms on surfaces of equipment employed in food processing. These biofilms are considered as the major sources of contamination in the food industry. The study determined the bacterial load and composition on surfaces of equipment and utensils employed in tigernut drink production, from a vendor with a production unit located in an open market in Yenagoa, Nigeria. Swabs were taken from different sampling points made of varying materials—the grinding machine (metal), the collection bowls, water storage containers (thick plastic) and retail bottles (light plastic). These were analysed for total heterotrophic bacterial counts (THBC) and bacterial diversity using standard procedures. The THBC of water used in the drink production was also determined. The THBC of the sampling points ranged from log 3.28±0.06 cfu/cm2 to log 5.18±0.05 cfu/cm2, and log 5.13±0.07 cfu/ml for the water sample. The grinder and water recorded higher bacterial load with a statistically significant difference (P<0.05). The retail bottles had the least bacterial count. Shigella spp. were the most isolated (27.451%), then Salmonella spp. (21.568%) and E. coli (15.686%). Streptococcus spp., Staphylococcus spp. and Vibrio spp. were the least isolated (11.765% each). Shigella and Salmonella species occurred at all sampling points but not on the retail bottles. E. coli was present in the water collection bowls and retail bottles while Streptococcus, Staphylococcus and Vibrio were found only in the retail bottles. On diversity, four bacterial genera (39.216%) were isolated from the retail bottles, three (25.490%) from the water storage containers and two (17.647%) from the grinder and collection bowls. The microorganisms possibly had preference for attachment to the surfaces based on the material makeup and nutrient availability. Their occurrence and high numbers reflect the low level of hygiene employed prior to drink production. This could be of public health concern.

scholarly journals Improvement of Immunomagnetic Separation for Escherichia coli O157:H7 Detection by the PickPen Magnetic Particle Separation Device†

2006 ◽  
Vol 69 (12) ◽  
pp. 2870-2874 ◽  
Author(s):  
XIANGWU NOU ◽  
TERRANCE M. ARTHUR ◽  
JOSEPH M. BOSILEVAC ◽  
DAYNA M. BRICHTA-HARHAY ◽  
MICHAEL N. GUERINI ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pathogen Detection ◽  
Magnetic Particles ◽  
Magnetic Particle ◽  
Ground Beef ◽  
Immunomagnetic Separation ◽  
Escherichia Coli O157 ◽  
High Background ◽  
E Coli ◽  
Significant Difference

Conventional immunomagnetic separation (IMS) procedures, which use an external magnetic source to capture magnetic particles against the side of a test tube, are labor-intensive and can have poor sensitivity for the target organism because of high background microflora that is not effectively washed away during the IMS process. This report compares the conventional IMS procedure to a new IMS procedure with an intrasolution magnetic particle transfer device, the PickPen. The IMS target for the majority of these studies is Escherichia coli O157:H7 in various types of samples, including cattle feces, hides, carcasses, and ground beef. Comparison of the two IMS methods showed a significant difference (P &lt; 0.05) in the efficiency of detecting E. coli O157:H7 from cattle carcass surface, cattle hide, and cattle fecal samples. No significant improvement (P &gt; 0.05) in E. coli O157:H7 detection was observed when the PickPen IMS procedure was used to isolate this pathogen from ground beef samples. Use of the PickPen IMS greatly increases the throughput of the IMS procedure and may be more compatible with various emerging technologies for pathogen detection. In addition, the efficacy of sequential IMS for multiple pathogens is reported herein.

scholarly journals A 1-year study of Escherichia coli O157 in cattle, sheep, pigs and poultry

1997 ◽  
Vol 119 (2) ◽  
pp. 245-250 ◽  
Author(s):  
P. A. CHAPMAN ◽  
C. A. SIDDONS ◽  
A. T. CERDAN MALO ◽  
M. A. HARKIN
Keyword(s):  
Escherichia Coli ◽  
Magnetic Particles ◽  
Enrichment Culture ◽  
Late Summer ◽  
Immunomagnetic Separation ◽  
E Coli ◽  
Source Of Infection ◽  
The Status ◽  
Peptone Water ◽  
Dairy Animals

Samples of rectal faeces were collected immediately after slaughter from 400 cattle each month for a 1-year period and from 1000 each of sheep, pigs and poultry over the same period. Samples were examined for Escherichia coli O157 by enrichment culture in buffered peptone water with vancomycin, cefixime and cefsulodin followed by immunomagnetic separation and culture of magnetic particles onto cefixime tellurite sorbitol MacConkey agar. E. coli O157 was isolated from 752 (15·7%) of 4800 cattle, 22 (2·2%) of 1000 sheep and from 4 (0·4%) of 1000 pigs, but not from any of 1000 chickens. Of the cattle sampled, 1840 (38·4%) were prime beef animals, 1661 (34·6%) were dairy animals being culled and the status could not be determined for the other 1299 (27%) animals. E. coli O157 was found in 246 (13·4%) of the 1840 beef cattle and 268 (16·1%) of the 1661 dairy cattle. The monthly prevalence of E. coli O157 in cattle was 4·8–36·8% and was at its highest in spring and late summer. Seventeen of the 22 isolates from sheep were also made over the summer period. All E. coli O157 isolates from sheep and 749 (99·6%) of the 752 E. coli O157 isolates from cattle were verocytotoxigenic as determined by Vero cell assay and DNA hybridization, eaeA gene positive, contained a 92 kb plasmid and were thus typical of strains causing infections in man. In contrast isolates from pigs were non-toxigenic, eaeA gene negative and did not contain a 92 kb plasmid and would, therefore, be unlikely to be a source of infection for man.

scholarly journals Infection with verocytotoxin-producing Escherichia coli O157 during a visit to an inner city open farm

2000 ◽  
Vol 125 (3) ◽  
pp. 531-536 ◽  
Author(s):  
P. A. CHAPMAN ◽  
J. CORNELL ◽  
C. GREEN
Keyword(s):  
Escherichia Coli ◽  
Inner City ◽  
Magnetic Beads ◽  
Profile Analysis ◽  
Enrichment Culture ◽  
Phage Type ◽  
Immunomagnetic Separation ◽  
E Coli ◽  
Zoonotic Infections ◽  
Faecal Samples

Two cases of Escherichia coli O157 infection occurred in children after visiting an inner city open farm. Subsequently faecal samples collected from animal pens and samples of composted mixed animal manure and vegetable waste were examined for E. coli O157 by enrichment culture, immunomagnetic separation and culture of magnetic beads to cefixime tellurite sorbitol MacConkey agar. Strains of E. coli O157 were characterized by hybridization with DNA probes for VT1, VT2 and eaeA, plasmid profile analysis, phage typing and pulsed field gel electrophoresis (PFGE). Verocytotoxin-producing E. coli O157 strains were isolated from faecal samples from a cow, a horse, 3 breeds of pigs, 2 breeds of sheep and 2 breeds of goats and from 2 samples of compost which had been processed for 3 months. All strains were phage type 21, hybridized with probes for VT2 and eaeA but not with one for VT1, harboured 92 and 2 kb plasmids and gave indistinguishable banding patterns with PFGE. Although only two culture-confirmed cases of infection had been identified, the farm had over 100 000 visitors per year and so it was closed as a precaution both to allow a thorough investigation and to prevent further cases. The investigation identified many factors which may have contributed to transmission of E. coli O157 infection. Most of these were readily resolved by appropriate corrective measures and as there were no further cases associated with the farm during the ensuing 4 weeks it then re-opened. These cases highlight the risk, especially to young children, of acquiring zoonotic infections during visits to open farms and emphasize the need for adequate guidance and supervision before and during such visits.

Risk factors forEscherichia coliO157 shedding and super-shedding by dairy heifers at pasture

2014 ◽  
Vol 143 (5) ◽  
pp. 1004-1015 ◽  
Author(s):  
K. J. WILLIAMS ◽  
M. P. WARD ◽  
O. P. DHUNGYEL ◽  
E. J. S. HALL
Keyword(s):  
Risk Factors ◽  
Immunomagnetic Separation ◽  
E Coli ◽  
Dairy Heifers ◽  
Solar Exposure ◽  
Faecal Culture ◽  
Faecal Consistency ◽  
Negative Effect ◽  
Higher Temperature ◽  
Positive Effect

SUMMARYWe undertook a longitudinal study within a cohort of 52 dairy heifers maintained under constant management systems and sampled weekly to investigate a comprehensive range of risk factors which may influence shedding or super-shedding ofE. coliO157 (detected by direct faecal culture and immunomagnetic separation).E. coliO157 was detected from 416/933 (44·6%) samples (faeces and recto-anal mucosal swabs) and 32 (3·4%) samples enumerated at >10000 c.f.u./g. Weekly point prevalence ranged from 9·4% to 94·3%. Higher temperature (P < 0·001), rainfall (P = 0·02), relative humidity (P < 0·001), pasture growth (P = 0·013) and body score (P = 0·029) were positively associated with increased shedding. Higher rainfall (P < 0·001), hide contamination (P = 0·002) and increased faecal consistency (P = 0·023) were positively associated with super-shedding. Increased solar exposure had a negative effect on both shedding and super-shedding within bivariate analyses but in the final multivariate model for shedding demonstrated a positive effect (P = 0·017). Results suggest that environmental factors are important inE. coliO157 shedding in cattle.

Isolation and Characterization of Escherichia coli O157:H7 from Retail Meats in Argentina

2001 ◽  
Vol 64 (9) ◽  
pp. 1346-1351 ◽  
Author(s):  
ISABEL CHINEN ◽  
JOSÉ DANIEL TANARO ◽  
ELIZABETH MILIWEBSKY ◽  
LILIANA HAYDEÉ LOUND ◽  
GERMÁN CHILLEMI ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Enrichment Culture ◽  
Culture Method ◽  
Immunomagnetic Separation ◽  
Phage Typing ◽  
Escherichia Coli O157 ◽  
Potassium Tellurite ◽  
E Coli ◽  
Isolation And Characterization ◽  
Retail Meats

Between February and May 2000, 279 meat samples were collected from 136 retail stores in Gualeguaychú City, Argentina. Samples were assayed for Escherichia coli O157:H7 by selective enrichment in modified EC broth containing novobiocin, followed by immunomagnetic separation (IMS) and plating onto both sorbitol MacConkey agar supplemented with cefixime and potassium tellurite and a chromogenic medium. Eleven E. coli O157:H7 isolates were detected in 6 (3.8%) of 160 ground beef samples, in 4 (4.8%) of 83 fresh sausages, and in 1 (3.3%) of 30 dry sausages. E. coli O157:H7 was not isolated from five hamburger patties or one barbecue-type fresh sausage assayed. The isolates were tested for virulence-related genes. Ten additional Shiga toxin-producing E. coli (STEC) O157:H7 isolates of food origin, recovered from different locations in Argentina, were included for comparison purposes. All 21 isolates harbored both eae and EHEC-hlyA genes, and 12 (57.1%) encoded stx2/stx2vh-a. The isolates were of phage types 87 (seven strains), 14 (four strains), 4 (three strains), and 26 (one strain). Six strains were nontypable by phage typing. Pulsed-field gel electrophoresis (PFGE) revealed 19 XbaI-PFGE profiles. Fifteen (71%) strains were grouped in four clusters, which shared more than 80% of DNA restriction fragments. The enrichment culture method with IMS was a sensitive procedure to detect E. coli O157:H7 strains in retail meats. Some of the isolates from different stores presented a high clonal relatedness, as determined by XbaI-PFGE and phage typing, and harbored the virulence factors associated with human illness.

Daily variations inEscherichia coliO157 shedding patterns in a cohort of dairy heifers at pasture

2014 ◽  
Vol 143 (7) ◽  
pp. 1388-1397 ◽  
Author(s):  
K. J. WILLIAMS ◽  
M. P. WARD ◽  
O. P. DHUNGYEL
Keyword(s):  
Direct Contact ◽  
Immunomagnetic Separation ◽  
Intervention Strategies ◽  
Common Mechanism ◽  
Human Pathogen ◽  
E Coli ◽  
Dairy Heifers ◽  
Faecal Culture ◽  
Extreme Variation ◽  
Daily Sampling

SUMMARYEscherichia coliO157 is a human pathogen carried asymptomatically by cattle and shed in their faeces. Infection can occur from the consumption of contaminated beef or by direct contact. Large variations ofE. coliO157 shedding in cattle exist and vary in the number of cattle positive forE. coliO157 and the amount of bacteria (c.f.u./g faeces) shed by positive animals. To investigateE. coliO157 shedding and super-shedding (>104 c.f.u./g) we used daily sampling over two 8-day periods; in January 2013 (n = 12) and February 2013 (n = 21). Samples were tested by direct faecal culture for enumeration and by immunomagnetic separation to detect lower levels of shedding. We identified three patterns of shedding, similar to previously observed descriptions: intermittent, transient and consistent. The most commonly observed pattern was intermittent shedding and variation in the level of shedding could be large. This extreme variation is demonstrated by a heifer from whichE. coliO157 could be not detected one day, was super-sheddingE. coliO157 the next and was detected as shedding >100 c.f.u./g the following day. Recto-anal mucosal swab testing did not predict super-shedding in this cohort of heifers. The variable individual patterns of shedding suggest that a common mechanism of infection may not operate within such a herd when considering previously described patterns and the inferred mechanisms. The sporadic and intermittent nature of shedding is a challenge to identifying risk factors and potential intervention strategies.

scholarly journals Isolation ofEscherichia coli0157:H7 Strain from Fecal Samples of Zoo Animal

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Aseel Mohammed Hamzah ◽  
Aseel Mohammed Hussein ◽  
Jenan Mahmoud Khalef
Keyword(s):  
Enrichment Culture ◽  
Fecal Samples ◽  
Selective Enrichment ◽  
E Coli ◽  
Zoological Society ◽  
Isolation And Characterization ◽  
Single Animal ◽  
Zoo Animals ◽  
Culture Positive

The isolation and characterization ofEscherichia coliO157:H7 strains from 22 out of 174 fecal samples from petting zoo animals representing twenty-two different species (camel, lion, goats, zebra, bear, baboon monkey, Siberian monkey, deer, elk, llama, pony, horses, fox, kangaroo, wolf, porcupine, chickens, tiger, ostrich, hyena, dogs, and wildcats) were investigated. One petting Al-Zawraa zoological society of Baghdad was investigated forE. coliO157:H7 over a 16-month period that spanned two summer and two autumn seasons. Variation in the occurrence ofE. coliO157:H7-positive petting zoo animals was observed, with animals being culture positive only in the summer months but not in the spring, autumn, or winter.E. coliO157:H7 isolates were distinguished by agglutination withE. coliO157:H7 latex reagent (Oxoid), identified among the isolates, which showed that multipleE. colistrains were isolated from one petting zoo animal, in which a single animal simultaneously shed multipleE. colistrains;E. coliO157:H7 was isolated only by selective enrichment culture of 2 g of petting zoo animal feces. In contrast, strains other than O157:H7 were cultured from feces of petting zoo animals without enrichment.

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