Survival of Shiga Toxin–Producing Escherichia coli in Various Wild Animal Feces That May Contaminate Produce

2020 ◽  
Vol 83 (8) ◽  
pp. 1420-1429
Author(s):  
ZEYNAL TOPALCENGIZ ◽  
SAHARUETAI JEAMSRIPONG ◽  
PATRICK M. SPANNINGER ◽  
ANIL K. PERSAD ◽  
FEI WANG ◽  
...  

ABSTRACT Domestic and wild animal intrusions are identified as a food safety risk during fresh produce production. The purpose of this study was to evaluate the survival of Shiga toxin–producing Escherichia coli (STEC) in cattle, feral pig, waterfowl, deer, and raccoon feces from sources in California, Delaware, Florida, and Ohio. Fecal samples were inoculated with a cocktail of rifampin-resistant STEC serotypes (O103, O104, O111, O145, and O157) (104 to 106 CFU/g of feces). Inoculated feces were held at ambient temperature. Populations of surviving cells were monitored throughout 1 year (364 days), with viable populations being enumerated by spread plating and enrichment when the bacteria were no longer detected by plating. Representative colonies were collected at various time intervals based on availability from different locations to determine the persistence of surviving STEC serotypes. Over the 364-day storage period, similar survival trends were observed for each type of animal feces from all states except for cattle and deer feces from Ohio. STEC populations remained the highest in cattle and deer feces from all states between days 28 and 364, except for those from Ohio. Feral pig, waterfowl, and raccoon feces had populations of STEC of <1.0 log CFU/g starting from day 112 in feces from all states. E. coli O103 and O104 were the predominant serotypes throughout the entire storage period in feces from all animals and from all states. The survival of both O157 and non-O157 STEC strains in domesticated and wild animal feces indicates a potential risk of contamination from animal intrusion. HIGHLIGHTS

2014 ◽  
Vol 77 (6) ◽  
pp. 872-879 ◽  
Author(s):  
MARILYN C. ERICKSON ◽  
CATHY C. WEBB ◽  
LINDSEY E. DAVEY ◽  
ALISON S. PAYTON ◽  
IAN D. FLITCROFT ◽  
...  

Preharvest internalization of Escherichia coli O157:H7 into the roots of leafy greens is a food safety risk because the pathogen may be systemically transported to edible portions of the plant. In this study, both abiotic (degree of soil moisture) and biotic (E. coli O157:H7 exposure, presence of Shiga toxin genes, and type of leafy green) factors were examined to determine their potential effects on pathogen internalization into roots of leafy greens. Using field soil that should have an active indigenous microbial community, internalized populations in lettuce roots were 0.8 to 1.6 log CFU/g after exposure to soil containing E. coli O157:H7 at 5.6 to 6.1 log CFU/g. Internalization of E. coli O157:H7 into leafy green plant roots was higher when E. coli O157:H7 populations in soil were increased to 7 or 8 log CFU/g or when the soil was saturated with water. No differences were noted in the extent to which internalization of E. coli O157:H7 occurred in spinach, lettuce, or parsley roots; however, in saturated soil, maximum levels in parsley occurred later than did those in spinach or lettuce. Translocation of E. coli O157:H7 from roots to leaves was rare; therefore, decreases observed in root populations over time were likely the result of inactivation within the plant tissue. Shiga toxin–negative (nontoxigenic) E. coli O157:H7 isolates were more stable than were virulent isolates in soil, but the degree of internalization of E. coli O157:H7 into roots did not differ between isolate type. Therefore, these nontoxigenic isolates could be used as surrogates for virulent isolates in field trials involving internalization.


2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Selene Marozzi ◽  
Paola De Santis ◽  
Sarah Lovari ◽  
Roberto Condoleo ◽  
Stefano Bilei ◽  
...  

In recent years, the incidence of foodborne diseases caused by shiga toxin-producing <em>Escherichia coli</em> (STEC) has increased globally. For this reason, within the specific regional control plan for the detection of STEC in food products in Italy, the presence of STEC in unpasteurized milk cheeses was investigated. In total 203 samples obtained from March 2011 to December 2013 were analysed, with two standard methods (ISO 16654:2001 and ISO 13136:2012). Two strains of <em>E. coli</em> O157 were isolated (2/161, 1.2%) but did not carry any virulence-associated genes and 22 <em>stx</em>-positive samples (22/146, 15.1%) were detected in enrichment cultures, mostly from ovine cheeses. Only two strains isolated from different ovine cheeses carried <em>stx</em> gene and none of these was <em>eae</em>-positive. This study confirms the presence of <em>stx</em>-positive <em>E. coli</em> and suggests that this type of food cannot be excluded as a potential vehicle of STEC.


2018 ◽  
Vol 9 ◽  
Author(s):  
Rosely Martins Gioia-Di Chiacchio ◽  
Marcos Paulo Vieira Cunha ◽  
Lilian Rose Marques de Sá ◽  
Yamê Minieiro Davies ◽  
Camila Bueno Pacheco Pereira ◽  
...  

2014 ◽  
Vol 77 (7) ◽  
pp. 1212-1218 ◽  
Author(s):  
BURTON BLAIS ◽  
MYLÈNE DESCHÊNES ◽  
GEORGE HUSZCZYNSKI ◽  
MARTINE GAUTHIER

A simple immunoenzymatic enterohemorrhagic Escherichia coli (EHEC) colony check (ECC) assay was developed for the presumptive identification of priority EHEC colonies isolated on plating media from enrichment broth cultures of foods. With this approach, lipopolysaccharide extracted from a colony is spotted on the grid of a polymyxin-coated polyester cloth strip, and bound E. coli serogroup O26, O45, O103, O111, O121, O145, and O157 antigens are subsequently detected by sequential reactions with a pool of commercially available peroxidase-conjugated goat antibodies and tetramethylbenzidine substrate solution. Each strip can accommodate up to 15 colonies, and test results are available within 30 min. Assay performance was verified using colonies from a total of 73 target EHEC isolates covering the range of designated priority serogroups (all of which were reactive), 41 nontarget E. coli isolates including several nontarget Shiga toxin–producing E. coli serogroups (all unreactive), and 33 non–E. coli strains (all unreactive except two bacterial strains possessing O-antigenic structures in common with those of the priority EHEC). The ECC assay was reactive with target colonies grown on several types of selective and nonselective plating media designed for their cultivation. These results support the use of the ECC assay for high-throughput screening of colonies isolated on plating media for detecting priority EHEC strains in foods.


2020 ◽  
Vol 8 (11) ◽  
pp. 1662
Author(s):  
Zachary R. Stromberg ◽  
Rick E. Masonbrink ◽  
Melha Mellata

Foodborne pathogens are a public health threat globally. Shiga toxin-producing Escherichia coli (STEC), particularly O26, O111, and O157 STEC, are often associated with foodborne illness in humans. To create effective preharvest interventions, it is critical to understand which factors STEC strains use to colonize the gastrointestinal tract of cattle, which serves as the reservoir for these pathogens. Several colonization factors are known, but little is understood about initial STEC colonization factors. Our objective was to identify these factors via contrasting gene expression between nonpathogenic E. coli and STEC. Colonic explants were inoculated with nonpathogenic E. coli strain MG1655 or STEC strains (O26, O111, or O157), bacterial colonization levels were determined, and RNA was isolated and sequenced. STEC strains adhered to colonic explants at numerically but not significantly higher levels compared to MG1655. After incubation with colonic explants, flagellin (fliC) was upregulated (log2 fold-change = 4.0, p < 0.0001) in O157 STEC, and collectively, Lon protease (lon) was upregulated (log2 fold-change = 3.6, p = 0.0009) in STEC strains compared to MG1655. These results demonstrate that H7 flagellum and Lon protease may play roles in early colonization and could be potential targets to reduce colonization in cattle.


2004 ◽  
Vol 67 (3) ◽  
pp. 591-595 ◽  
Author(s):  
LARRY R. BEUCHAT ◽  
ALAN J. SCOUTEN

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


2016 ◽  
Vol 14 (1) ◽  
pp. 63-68 ◽  
Author(s):  
MM Akter ◽  
S Majumder ◽  
KH MNH Nazir ◽  
M Rahman

Shiga toxin-producing Escherichia coli (STEC) are zoonotically important pathogen which causes hemorrhagic colitis, diarrhea, and hemolytic uremic syndrome in animals and humans. The present study was designed to isolate and identify the STEC from fecal samples of diarrheic cattle. A total of 35 diarrheic fecal samples were collected from Bangladesh Agricultural University (BAU) Veterinary Teaching Hospital. The samples were primarily examined for the detection of E. coli by cultural, morphological and biochemical characteristics, followed by confirmation of the isolates by Polymerase Chain Reaction (PCR) using gene specific primers. Later, the STEC were identified among the isolated E. coli through detection of Stx-1 and Stx-2 genes using duplex PCR. Out of 35 samples, 25 (71.43%) isolates were confirmed to be associated with E. coli, of which only 7 (28%) isolates were shiga toxin producers, and all of them were positive for Stx-1. However, no Stx-2 positive isolate could be detected. From this study, it may be concluded that cattle can act as a reservoir of STEC which may transmit to human or other animals.J. Bangladesh Agril. Univ. 14(1): 63-68, June 2016


2020 ◽  
Author(s):  
Ivan Nastasijevic ◽  
John W. Schmidt ◽  
Marija Boskovic ◽  
Milica Glisic ◽  
Norasak Kalchayanand ◽  
...  

ABSTRACTShiga toxin (stx) -producing Escherichia coli (STEC) are foodborne pathogens that have a significant impact on public health, with those possessing the attachment factor intimin (eae) referred to as enterohemorrhagic E. coli (EHEC) associated with life threatening illnesses. Cattle and beef are considered typical sources of STEC, but their presence in pork products is a growing concern. Therefore, carcasses (n=1536) at two U.S. pork processors were sampled once per season at three stages of harvest (post-stunning skins; post-scald carcasses; chilled carcasses) then examined using PCR for stx and eae, aerobic plate count (APC) and Enterobacteriaceae counts (EBC). Skins, post-scald, and chilled carcasses had prevalence of stx (85.3, 17.5, and 5.4%, respectively), with 82.3, 7.8, and 1.7% respectively, having stx and eae present. All stx positive samples were subjected to culture isolation that resulted in 368 STEC and 46 EHEC isolates. The most frequently identified STEC were serogroup O121, O8, and O91(63, 6.7, and 6.0% of total STEC, respectively). The most frequently isolated EHEC was serotype O157:H7 (63% of total EHEC). Results showed that scalding significantly reduced (P < 0.05) carcass APC and EBC by 3.00 and 2.50 log10 CFU/100 cm2 respectively. A seasonal effect was observed with STEC prevalence lower (P < 0.05) in winter. The data from this study shows significant (P < 0.05) reduction in the incidence of STEC (stx) from 85.3% to 5.4% and of EHEC (stx+eae) from 82.3% to 1.7% within slaughter-to-chilling continuum, respectively, and that potential EHEC can be confirmed present throughout using culture isolation.IMPORTANCESeven serogroups of Shiga toxin-producing Escherichia coli (STEC) are responsible for most (>75%) cases of severe illnesses caused by STEC and are considered adulterants of beef. However, some STEC outbreaks have been attributed to pork products although the same E. coli are not considered adulterants in pork because little is known of their prevalence along the pork chain. The significance of the work presented here is that it identifies disease causing STEC, enterohemorrhagic E. coli (EHEC), demonstrating that these same organisms are a food safety hazard in pork as well as beef. The results show that most STEC isolated from pork are not likely to cause severe disease in humans and that processes used in pork harvest, such as scalding, offer a significant control point to reduce contamination. The results will assist the pork processing industry and regulatory agencies to optimize interventions to improve the safety of pork products.


2011 ◽  
Vol 16 (31) ◽  
Author(s):  
A M Hauri ◽  
U Götsch ◽  
I Strotmann ◽  
J Krahn ◽  
G Bettge-Weller ◽  
...  

During the recent outbreak of Shiga toxin-producing Escherichia coli (STEC) O104:H4 in Germany most cases notified in the State of Hesse (6 million inhabitants) were linked to satellite clusters or had travelled to the outbreak area in northern Germany. Intensified surveillance was introduced to rapidly identify cases not linked to known clusters or cases and thus to obtain timely information on possible further contaminated vehicles distributed in Hesse, as well to describe the risk of secondary transmission among known cases. As of 2 August 2011*, 56 cases of haemolytic uraemic syndrome (HUS) including two fatal cases, and 124 cases of STEC gastroenteritis meeting the national case definitions have been reported in Hesse. Among the 55 HUS and 81 STEC gastroenteritis cases that met the outbreak case definition, one HUS case and eight STEC gastroenteritis cases may have acquired their infection through secondary transmission. They include six possible transmissions within the family, two possible nosocomial and one possible laboratory transmission. Our results do not suggest an increased transmissibility of the outbreak strain compared to what is already known about E. coli O157 and other STEC serotypes.


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