Prolonged cold stress response of Escherichia coli O157 and the role of rpoS

Vidović, Sinisa; Mangalappalli-Illathu, Anil K.; Korber, Darren R.

doi:10.1016/j.ijfoodmicro.2011.02.018

Cited by 39 publications

(12 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…There was no difference between the profile distribution of phylogenetic groups in cows and calves. (Vidovic et al, 2011). In the present study, an extremely high number of STECcarrying animals (45.4%) was detected.…”

Section: Resultssupporting

confidence: 52%

Distribution of the stx1 and stx2 genes in Escherichia coli isolated from milk cattle according to season, age, and production scale in southwestern region of Goiás, Brazil

Ferreira

Stella

Filho

et al. 2018

Arq. Bras. Med. Vet. Zootec.

View full text Add to dashboard Cite

This study determined the distribution of stx1 and stx2 genes in Escherichia coli isolated from dairy herds with regard to animal age, season, and farm production-scale, and analyzed the phylogenetic distribution of the groups A, B1, B2, and D of 276 isolates of bovine feces Shiga toxin-producing E. coli (STEC). The stx1 profile was the most common, detected in 20.4% (202/990) of the isolates, followed by stx2 (4.54%, 45/990) and stx1+stx2 (2.92%, 29/990). The stx1 gene was detected more frequently in calves than in adult animals. In the dry season (winter), the presence of stx1+stx2 profile in cattle feces was higher than in the rainy season (summer), while no significant changes were observed between seasons for the stx1 and stx2 profiles. The most predominant phylogenetic groups in adult animals were B1, A, and D, while groups A and B1 prevailed in calves. Our data highlight the importance of identifying STEC reservoirs, since 7.5% of the tested isolates were positive for stx2, the main profile responsible for the hemolytic-uremic syndrome (HUS). Moreover, these microorganisms are adapted to survive even in hostile environments and can contaminate the food production chain, posing a significant risk to consumers of animal products.

show abstract

Section: Resultssupporting

confidence: 52%

Distribution of the stx1 and stx2 genes in Escherichia coli isolated from milk cattle according to season, age, and production scale in southwestern region of Goiás, Brazil

Ferreira

Stella

Filho

et al. 2018

Arq. Bras. Med. Vet. Zootec.

View full text Add to dashboard Cite

show abstract

“…This is in complete agreement with gene expression studies with rpoS mutants of E. coli O157 showing that these cells have impaired expression regarding fatty acid oxidation (Dong & Schellhorn, ) and that these bacteria have decreased abilities to oxidize propionic acid, α‐ketobutyric acid and α‐hydroxybutyric acid but an increased ability to oxidize l ‐threonine (Dong et al ., ). Recently it was shown that expression of the rpoS gene in E. coli O157 cells in sterile soil was 2.68‐fold higher when compared with cells cultured in broth (Duffitt et al ., ) and that RpoS plays a significant role in the cold stress response of E. coli O157 (Vidovic et al ., ). Phenotypically, 10/11 short surviving strains with rpoS mutations showed growth on succinate minimal medium (demonstrating increased nutritional capability).…”

Section: Resultsmentioning

confidence: 97%

The role ofrpoSinEscherichia coliO157 manure-amended soil survival and distribution of allelic variations among bovine, food and clinical isolates

Hoek

Aarts

Bouw

et al. 2012

FEMS Microbiol Lett

View full text Add to dashboard Cite

Although it is known that Escherichia coli O157 is capable of long-term soil survival, little is known about the mechanisms involved. This study investigated the role of the general stress response system RpoS in E. coli soil survival. The results showed that E. coli O157 isolates capable of long-term survival (longer than 200 days) in manure-amended soil were characterized by the absence of mutations in their rpoS gene. In contrast, the strains not capable of long-term survival all possessed mutations in their rpoS gene. In addition, the long-term surviving strains showed significantly higher levels of acid resistance in simulated gastric fluid (pH 2.5). Sequencing of the rpoS gene of bovine, food and clinical isolates revealed a skewed distribution of rpoS wild-type and mutant strains among the different sources. Bovine and food isolates had low numbers of mutants (< 1.4 and 6.9%, respectively), while a relatively high number of mutants was observed among human isolates (32.9%). The results indicate that a fully functional RpoS system is an advantage for survival in the manure-amended soil environment. Further deletion and complementation studies should provide more evidence on the role of RpoS in the long-term survival of E. coli O157 in diverse environments.

show abstract

“…Food-related bacteria have developed strategies to overcome a wide variety of unfavorable environmental conditions encountered during food processing or storage: extremely low or high temperatures (Vidovic et al, 2011 , 2012 ), acid pH and a high amount of salts (McMahon et al, 2007 ), pulsed electric fields (PEF; Sagarzazu et al, 2013 ), high hydrostatic pressure (HHP; Hauben et al, 1997 ), and chemical preservatives (Patrignani et al, 2008 ; Dubois-Brissonnet et al, 2011 ). These strategies can lead to an increase in bacterial resistance to the homologous stress agent (direct resistance) as well as to heterologous environmental stresses (cross-resistance; Hengge-Aronis, 2011 ).…”

Section: Introductionmentioning

confidence: 99%

Emergence of Hyper-Resistant Escherichia coli MG1655 Derivative Strains after Applying Sub-Inhibitory Doses of Individual Constituents of Essential Oils

et al. 2016

View full text Add to dashboard Cite

The improvement of food preservation by using essential oils (EOs) and their individual constituents (ICs) is attracting enormous interest worldwide. Until now, researchers considered that treatments with such antimicrobial compounds did not induce bacterial resistance via a phenotypic (i.e., transient) response. Nevertheless, the emergence of genotypic (i.e., stable) resistance after treatment with these compounds had not been previously tested. Our results confirm that growth of Escherichia coli MG1655 in presence of sub-inhibitory concentrations of the ICs carvacrol, citral, and (+)-limonene oxide do not increase resistance to further treatments with either the same IC (direct resistance) or with other preservation treatments (cross-resistance) such as heat or pulsed electric fields (PEF). Bacterial mutation frequency was likewise lower when those IC's were applied; however, after 10 days of re-culturing cells in presence of sub-inhibitory concentrations of the ICs, we were able to isolate several derivative strains (i.e., mutants) displaying an increased minimum inhibitory concentration to those ICs. Furthermore, when compared to the wild type (WT) strain, they also displayed direct resistance and cross-resistance. Derivative strains selected with carvacrol and citral also displayed morphological changes involving filamentation along with cell counts at late-stationary growth phase that were lower than the WT strain. In addition, co-cultures of each derivative strain with the WT strain resulted in a predominance of the original strain in absence of ICs, indicating that mutants would not out-compete WT cells under optimal growth conditions. Nevertheless, growth in the presence of ICs facilitated the selection of these resistant mutants. Thus, as a result, subsequent food preservation treatments of these bacterial cultures might be less effective than expected for WT cultures. In conclusion, this study recommends that treatment with ICs at sub-inhibitory concentrations should be generally avoided, since it could favor the emergence of hyper-resistant strains. To ascertain the true value of EOs and their ICs in the field of food preservation, further research thus needs to be conducted on the induction of increased transient and stable bacterial resistance via such antimicrobial compounds, as revealed in this study.

show abstract

Prolonged cold stress response of Escherichia coli O157 and the role of rpoS

Cited by 39 publications

References 25 publications

Distribution of the stx1 and stx2 genes in Escherichia coli isolated from milk cattle according to season, age, and production scale in southwestern region of Goiás, Brazil

Distribution of the stx1 and stx2 genes in Escherichia coli isolated from milk cattle according to season, age, and production scale in southwestern region of Goiás, Brazil

The role ofrpoSinEscherichia coliO157 manure-amended soil survival and distribution of allelic variations among bovine, food and clinical isolates

Emergence of Hyper-Resistant Escherichia coli MG1655 Derivative Strains after Applying Sub-Inhibitory Doses of Individual Constituents of Essential Oils

Contact Info

Product

Resources

About