Reaction of Surrogate Escherichia coli Serotype O157:H7 and Non-O157 Strains to Nutrient Starvation: Variation in Phenotype and Transcription of Stress Response Genes and Behavior on Lettuce Plants in the Field

ABSTRACT Preharvest contamination with bacteria borne by irrigation water may result in leafy vegetables serving as vehicles for transmission of Shiga toxin–producing Escherichia coli (STEC) to humans. The influence of starvation-associated stress on the behavior of non–toxin-producing strains of E. coli serotype O157:H7 and serotypes O26, O103, O111, and O145 was examined subsequent to their introduction to the phyllosphere of field-grown romaine lettuce as inocula simulating starved (96 h in sterile deionized water) and nutrient-depleted (24 h broth culture) cells. As with E. coli O157:H7, leaf populations of the non-O157 strains declined rapidly during the first 72 h postinoculation, displaying the biphasic decay curve typical of serotype O157:H7 isolates. Preinoculation treatment appeared not to influence decay rates greatly (P > 0.5), but strain-specific differences (persistence period and attachment proficiency) indicated that serotype O103:H2 strain PARC445 was a better survivor. Also assessed was the impact of preinoculation treatment on phenotypes key to leaf colonization and survival and the expression of starvation stress–associated genes. The 96-h starvation period enhanced biofilm formation in one strain but reduced motility and autoinducer 2 formation in all five study strains relative to those characteristics in stationary-phase cells. Transcription of rpoS, dps, uspA, and gapA was reduced significantly (P < 0.05) in starvation-stressed cells relative to that for exponential- and stationary-phase cultures. Strain-specific differences were observed; serotype O103:H2 PARC445 had greater downturns than did serotype O157:H7 and other non-O157 strains. Within this particular cohort, the behavior of the representative serotype O157:H7 strain, PARC443 (ATCC 700728), was not predictive of behavior of non-O157 members of this STEC group.

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The Protein Interactome of Glycolysis in Escherichia coli

Proteomes ◽

10.3390/proteomes9020016 ◽

2021 ◽

Vol 9 (2) ◽

pp. 16

Author(s):

Shomeek Chowdhury ◽

Stephen Hepper ◽

Mudassir K. Lodi ◽

Milton H. Saier ◽

Peter Uetz

Keyword(s):

Escherichia Coli ◽

Protein Interactions ◽

Allosteric Regulation ◽

Glycolytic Enzymes ◽

Protein Protein Interactions ◽

Post Translational Modification ◽

Interacting Protein ◽

E Coli ◽

Protein Interactome ◽

The Impact

Glycolysis is regulated by numerous mechanisms including allosteric regulation, post-translational modification or protein-protein interactions (PPI). While glycolytic enzymes have been found to interact with hundreds of proteins, the impact of only some of these PPIs on glycolysis is well understood. Here we investigate which of these interactions may affect glycolysis in E. coli and possibly across numerous other bacteria, based on the stoichiometry of interacting protein pairs (from proteomic studies) and their conservation across bacteria. We present a list of 339 protein-protein interactions involving glycolytic enzymes but predict that ~70% of glycolytic interactors are not present in adequate amounts to have a significant impact on glycolysis. Finally, we identify a conserved but uncharacterized subset of interactions that are likely to affect glycolysis and deserve further study.

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Solubility assessment of single-chain antibody fragment against epithelial cell adhesion molecule extracellular domain in four Escherichia coli strains

Journal of Genetic Engineering and Biotechnology ◽

10.1186/s43141-021-00126-1 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Fatemeh Sadat Javadian ◽

Majid Basafa ◽

Aidin Behravan ◽

Atieh Hashemi

Keyword(s):

Escherichia Coli ◽

Cell Adhesion ◽

Epithelial Cell ◽

Adhesion Molecule ◽

Cell Adhesion Molecule ◽

Extracellular Domain ◽

Epithelial Cell Adhesion Molecule ◽

Single Chain ◽

E Coli ◽

The Impact

Abstract Background Overexpression of the EpCAM (epithelial cell adhesion molecule) in malignancies makes it an attractive target for passive immunotherapy in a wide range of carcinomas. In comparison with full-length antibodies, due to the small size, the scFvs (single-chain variable fragments) are more suitable for recombinant expression in E. coli (Escherichia coli). However, the proteins expressed in large amounts in E. coli tend to form inclusion bodies that need to be refolded which may result in poor recovery of bioactive proteins. Various engineered strains were shown to be able to alleviate the insolubility problem. Here, we studied the impact of four E. coli strains on the soluble level of anti-EpEX-scFv (anti-EpCAM extracellular domain-scFv) protein. Results Although results showed that the amount of soluble anti-EpEX-scFv obtained in BL21TM (DE3) (114.22 ± 3.47 mg/L) was significantly higher to those produced in the same condition in E. coli RosettaTM (DE3) (71.39 ± 0.31 mg/L), and OrigamiTM T7 (58.99 ± 0.44 mg/L) strains, it was not significantly different from that produced by E. coli SHuffleTM T7 (108.87 ± 2.71 mg/L). Furthermore, the highest volumetric productivity of protein reached 318.29 ± 26.38 mg/L in BL21TM (DE3). Conclusions Although BL21TM (DE3) can be a suitable strain for high-level production of anti-EpEX-scFv protein, due to higher solubility yield (about 55%), E. coli SHuffleTM T7 seems to be better candidate for soluble production of scfv compared to BL21TM (DE3) (solubility yield of about 30%).

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degS Is Necessary for Virulence and Is among Extraintestinal Escherichia coli Genes Induced in Murine Peritonitis

Infection and Immunity ◽

10.1128/iai.71.6.3088-3096.2003 ◽

2003 ◽

Vol 71 (6) ◽

pp. 3088-3096 ◽

Cited By ~ 40

Author(s):

Peter Redford ◽

Paula L. Roesch ◽

Rodney A. Welch

Keyword(s):

Escherichia Coli ◽

Urinary Tract Infection ◽

Urinary Tract ◽

Tract Infection ◽

Luria Bertani ◽

Broth Culture ◽

Wild Type ◽

E Coli ◽

Virulence Attenuation

ABSTRACT Extraintestinal Escherichia coli strains cause meningitis, sepsis, urinary tract infection, and other infections outside the bowel. We examined here extraintestinal E. coli strain CFT073 by differential fluorescence induction. Pools of CFT073 clones carrying a CFT073 genomic fragment library in a promoterless gfp vector were inoculated intraperitoneally into mice; bacteria were recovered by lavage 6 h later and then subjected to fluorescence-activated cell sorting. Eleven promoters were found to be active in the mouse but not in Luria-Bertani (LB) broth culture. Three are linked to genes for enterobactin, aerobactin, and yersiniabactin. Three others are linked to the metabolic genes metA, gltB, and sucA, and another was linked to iha, a possible adhesin. Three lie before open reading frames of unknown function. One promoter is associated with degS, an inner membrane protease. Mutants of the in vivo-induced loci were tested in competition with the wild type in mouse peritonitis. Of the mutants tested, only CFT073 degS was found to be attenuated in peritoneal and in urinary tract infection, with virulence restored by complementation. CFT073 degS shows growth similar to that of the wild type at 37°C but is impaired at 43°C or in 3% ethanol LB broth at 37°C. Compared to the wild type, the mutant shows similar serum survival, motility, hemolysis, erythrocyte agglutination, and tolerance to oxidative stress. It also has the same lipopolysaccharide appearance on a silver-stained gel. The basis for the virulence attenuation is unclear, but because DegS is needed for σE activity, our findings implicate σE and its regulon in E. coli extraintestinal pathogenesis.

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Mannose-Binding Activity of Escherichia coli: a Determinant of Attachment and Ingestion of the Bacteria by Macrophages

Infection and Immunity ◽

10.1128/iai.29.2.417-424.1980 ◽

1980 ◽

Vol 29 (2) ◽

pp. 417-424

Author(s):

Zvi Bar-Shavit ◽

Rachel Goldman ◽

Itzhak Ofek ◽

Nathan Sharon ◽

David Mirelman

Keyword(s):

Escherichia Coli ◽

Stationary Phase ◽

Pathogenic Bacteria ◽

Binding Activity ◽

Exponential Phase ◽

Restrictive Temperature ◽

Filamentous Bacteria ◽

Phagocytic Cells ◽

E Coli ◽

Mannose Binding

Recently, it was suggested that a mannose-specific lectin on the bacterial cell surface is responsible for the recognition by phagocytic cells of certain nonopsonized Escherichia coli strains. In this study we assessed the interaction of two strains of E. coli at different phases of growth with a monolayer of mouse peritoneal macrophages and developed a direct method with [ 14 C]mannan to quantitate the bacterial mannose-binding activity. Normal-sized bacteria were obtained from logarithmic and stationary phases of growth. Nonseptated filamentous cells were formed by growing the organisms in the presence of cephalexin or at a restrictive temperature. Attachment to macrophages of all bacterial forms was inhibited by methyl α- d -mannoside and mannan but not by other sugars tested. The attachment of stationary phase and filamentous bacteria to macrophages, as well as their mannose-binding activity, was similar, whereas in the exponential-phase bacteria they were markedly reduced. The results show a linear relation between the two parameters ( R = 0.98, P < 0.001). The internalization of the filamentous cells attached to macrophages during 45 min of incubation was much less efficient (20%) compared to that of exponential-phase, stationary-phase, or antibody-coated filamentous bacteria (90%). The results indicate that the mannose-binding activity of E. coli determines the recognition of the organisms by phagocytes. They further suggest that administration of β-lactam antibiotics may impair elimination of certain pathogenic bacteria by inducing the formation of filaments which are inefficiently internalized by the host's phagocytic cells.

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Impact of Vacuum Cooling on Escherichia coli O157:H7 Infiltration into Lettuce Tissue

Applied and Environmental Microbiology ◽

10.1128/aem.02811-07 ◽

2008 ◽

Vol 74 (10) ◽

pp. 3138-3142 ◽

Cited By ~ 57

Author(s):

Haiping Li ◽

Mehrdad Tajkarimi ◽

Bennie I. Osburn

Keyword(s):

Escherichia Coli ◽

Risk Assessment ◽

Reduction Rate ◽

Escherichia Coli O157 ◽

Surface Sterilization ◽

E Coli ◽

Green Industry ◽

Vacuum Cooling ◽

The Impact

ABSTRACT Vacuum cooling is a common practice in the California leafy green industry. This study addressed the impact of vacuum cooling on the infiltration of Escherichia coli O157:H7 into lettuce as part of the risk assessment responding to the E. coli O157:H7 outbreaks associated with leafy green produce from California. Vacuum cooling significantly increased the infiltration of E. coli O157:H7 into the lettuce tissue (2.65E+06 CFU/g) compared to the nonvacuumed condition (1.98E+05 CFU/g). A stringent surface sterilization and quadruple washing could not eliminate the internalized bacteria from lettuce. It appeared that vacuuming forcibly changed the structure of lettuce tissue such as the stomata, suggesting a possible mechanism of E. coli O157:H7 internalization. Vacuuming also caused a lower reduction rate of E. coli O157:H7 in stored lettuce leaves than that for the nonvacuumed condition.

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Impact of Extended-Spectrum β-Lactamase Production on Treatment Outcomes of Acute Pyelonephritis Caused by Escherichia coli in Patients without Health Care-Associated Risk Factors

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.04821-14 ◽

2015 ◽

Vol 59 (4) ◽

pp. 1962-1968 ◽

Cited By ~ 13

Author(s):

Sun Hee Park ◽

Su-Mi Choi ◽

Dong-Gun Lee ◽

Sung-Yeon Cho ◽

Hyo-Jin Lee ◽

...

Keyword(s):

Risk Factors ◽

Escherichia Coli ◽

Health Care ◽

Treatment Outcomes ◽

Acute Pyelonephritis ◽

Esbl Production ◽

Content Type ◽

E Coli ◽

Extended Spectrum ◽

The Impact

ABSTRACTExtended-spectrum β-lactamase-producingEscherichia coli(ESBL-EC) is increasingly identified as a cause of acute pyelonephritis (APN) among patients without recent health care contact, i.e., community-associated APN. This case-control study compared 75 cases of community-associated ESBL-EC APN (CA-ESBL) to 225 controls of community-associated non-ESBL-EC APN (CA-non-ESBL) to identify the risk factors for ESBL-EC acquisition and investigate the impact of ESBL on the treatment outcomes of community-associated APN (CA-APN) caused byE. coliat a Korean hospital during 2007 to 2013. The baseline characteristics were similar between the cases and controls; the risk factors for ESBL-EC were age (>55 years), antibiotic use within the previous year, and diabetes with recurrent APN. The severity of illness did not differ between CA-ESBL and CA-non-ESBL (Acute Physiology and Chronic Health Evaluation [APACHE] II scores [mean ± standard deviation], 7.7 ± 5.9 versus 6.4 ± 5.3;P= 0.071). The proportions of clinical (odds ratio [OR], 1.76; 95% confidence interval [CI], 0.57 to 5.38;P= 0.323) and microbiological (OR, 1.16; 95% CI, 0.51 to 2.65;P= 0.730) cures were similar, although the CA-ESBL APN patients were less likely to receive appropriate antibiotics within 48 h. A multivariable Cox proportional hazards analysis of the prognostic factors for CA-APN caused byE. colishowed that ESBL production was not a significant factor for clinical (hazard ratio [HR], 0.39; 95% CI, 0.12 to 1.30;P= 0.126) or microbiological (HR, 0.49; 95% CI, 0.21 to 1.12;P= 0.091) failure. The estimates did not change after incorporating weights calculated using propensity scores for acquiring ESBL-EC. Therefore, ESBL production did not negatively affect treatment outcomes among patients with community-associatedE. coliAPN.

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EVALUATION OF THE IMPACT OF PLASMID CURING ON ANTIBIOTIC RESISTANCE ON SOME CLINICAL ISOLATES OF ESCHERICHIA COLI

FUDMA Journal of Sciences ◽

10.33003/fjs-2020-0403-335 ◽

2020 ◽

Vol 4 (3) ◽

pp. 323-327

Author(s):

Mamunu Abdulkadir SULAIMAN ◽

H.S Muhammad ◽

Aliyu Muhammad Sani ◽

Aminu Ibrahim ◽

Ibrahim Muhammad Hussain ◽

...

Keyword(s):

Escherichia Coli ◽

Antibiotic Resistance ◽

Clinical Isolates ◽

Diffusion Method ◽

Plasmid Curing ◽

Sensitivity Testing ◽

E Coli ◽

Risk Of Death ◽

Mar Index ◽

The Impact

Multidrug resistance (MDR) exhibited by some strains of Escherichia coli may be due to acquiring mobile genetic element (R-plasmid) by the bacteria, or intrinsically induced by inappropriate use of antibiotics by the hosts. Infection by such strains may result to prolonged illness and greater risk of death. The study evaluated the impact of curing on antibiotic resistance on selected clinical isolates of E. coli. Twenty clinical isolates of E. coli from our previous studies were re-characterized using conventional microbiological techniques. Antibiotic sensitivity testing was determined by disk diffusion method, MDR selected based on resistance to ≥ 2 classes of antibiotics. Multiple antibiotic resistance (MAR) index was determined as ratio of the number of antibiotic resisted to the total number of antibiotics tested and considered significant if ≥. 0.2. The isolates that showed significant MAR index were subjected to plasmid curing using acridine orange, thereafter, profiled for plasmid and the cured ones were re-tested against the antibiotics they initially resisted. Out of the 20 isolates, 19 (95%) were confirmed as E. coli, all (100%) of which were MDRs, which was highest against augmentin (78.9%) followed by amoxacillin (52.6%). However, after the plasmid curing only 6 (31.6%) out of the 19 isolates cured retained significant MAR index and the level of the significance had reduced drastically in 16 (84.2%) isolates. Conclusively, curing assay can completely eliminate R-plasmid acquired resistance. More studied on plasmid curing agents for possible augmentation of the agents into antibiotics may see the rise of successful antibiotic era again.

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The Effect Ultrasound and Surfactants on Nanobubbles Efficacy against Listeria innocua and Escherichia coli O157:H7, in Cell Suspension and on Fresh Produce Surfaces

Foods ◽

10.3390/foods10092154 ◽

2021 ◽

Vol 10 (9) ◽

pp. 2154

Author(s):

Shamil Rafeeq ◽

Reza Ovissipour

Keyword(s):

Escherichia Coli ◽

Cell Suspension ◽

Sodium Dodecyl ◽

Listeria Innocua ◽

Wash Water ◽

Tween 20 ◽

Escherichia Coli O157 ◽

E Coli ◽

Bacterial Removal ◽

The Impact

Removing foodborne pathogens from food surfaces and inactivating them in wash water are critical steps for reducing the number of foodborne illnesses. In this study we evaluated the impact of surfactants on enhancing nanobubbles’ efficacy on Escherichia coli O157:H7, and Listeria innocua removal from spinach leaves. We evaluated the synergistic impact of nanobubbles and ultrasound on these two pathogens inactivation in the cell suspension. The results indicated that nanobubbles or ultrasound alone could not significantly reduce bacteria in cell suspension after 15 min. However, a combination of nanobubbles and ultrasonication caused more than 6 log cfu/mL reduction after 15 min, and 7 log cfu/mL reduction after 10 min of L. innocua and E. coli, respectively. Nanobubbles also enhanced bacterial removal from spinach surface in combination with ultrasonication. Nanobubbles with ultrasound removed more than 2 and 4 log cfu/cm2 of L. innocua and E. coli, respectively, while ultrasound alone caused 0.5 and 1 log cfu/cm2 of L. innocua and E. coli reduction, respectively. No reduction was observed in the solutions with PBS and nanobubbles. Adding food-grade surfactants (0.1% Sodium dodecyl sulfate-SDS, and 0.1% Tween 20), did not significantly enhance nanobubbles efficacy on bacterial removal from spinach surface.

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The l-Isoaspartyl Protein Repair Methyltransferase Enhances Survival of Aging Escherichia coli Subjected to Secondary Environmental Stresses

Journal of Bacteriology ◽

10.1128/jb.180.10.2623-2629.1998 ◽

1998 ◽

Vol 180 (10) ◽

pp. 2623-2629 ◽

Cited By ~ 57

Author(s):

Jonathan E. Visick ◽

Hui Cai ◽

Steven Clarke

Keyword(s):

Escherichia Coli ◽

Stationary Phase ◽

Protein Denaturation ◽

Environmental Stresses ◽

Protein Repair ◽

Repeated Heating ◽

E Coli ◽

Competitive Disadvantage ◽

Biological World

ABSTRACT Like its homologs throughout the biological world, thel-isoaspartyl protein repair methyltransferase ofEscherichia coli, encoded by the pcm gene, can convert abnormal l-isoaspartyl residues in proteins (which form spontaneously from asparaginyl or aspartyl residues) to normal aspartyl residues. Mutations in pcm were reported to greatly reduce survival in stationary phase and when cells were subjected to heat or osmotic stresses (C. Li and S. Clarke, Proc. Natl. Acad. Sci. USA 89:9885–9889, 1992). However, we subsequently demonstrated that those strains had a secondary mutation inrpoS, which encodes a stationary-phase-specific sigma factor (J. E. Visick and S. Clarke, J. Bacteriol. 179:4158–4163, 1997). We now show that the rpoS mutation, resulting in a 90% decrease in HPII catalase activity, can account for the previously observed phenotypes. We further demonstrate that a new pcmmutant lacks these phenotypes. Interestingly, the newly constructedpcm mutant, when maintained in stationary phase for extended periods, is susceptible to environmental stresses, including exposure to methanol, oxygen radical generation by paraquat, high salt concentrations, and repeated heating to 42°C. The pcmmutation also results in a competitive disadvantage in stationary-phase cells. All of these phenotypes can be complemented by a functionalpcm gene integrated elsewhere in the chromosome. These data suggest that protein denaturation and isoaspartyl formation may act synergistically to the detriment of aging E. coli and that the repair methyltransferase can play a role in limiting the accumulation of the potentially disruptive isoaspartyl residues in vivo.

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Impact of UV and Peracetic Acid Disinfection on the Prevalence of Virulence and Antimicrobial Resistance Genes in Uropathogenic Escherichia coli in Wastewater Effluents

Applied and Environmental Microbiology ◽

10.1128/aem.00418-14 ◽

2014 ◽

Vol 80 (12) ◽

pp. 3656-3666 ◽

Cited By ~ 24

Author(s):

Basanta Kumar Biswal ◽

Ramzi Khairallah ◽

Kareem Bibi ◽

Alberto Mazza ◽

Ronald Gehr ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Resistance ◽

Resistance Genes ◽

Peracetic Acid ◽

Content Type ◽

E Coli ◽

Antimicrobial Resistance Genes ◽

Antimicrobial Resistance Gene ◽

Municipal Wastewaters ◽

The Impact

ABSTRACTWastewater discharges may increase the populations of pathogens, includingEscherichia coli, and of antimicrobial-resistant strains in receiving waters. This study investigated the impact of UV and peracetic acid (PAA) disinfection on the prevalence of virulence and antimicrobial resistance genes in uropathogenicEscherichia coli(UPEC), the most abundantE. colipathotype in municipal wastewaters. Laboratory disinfection experiments were conducted on wastewater treated by physicochemical, activated sludge, or biofiltration processes; 1,766E. coliisolates were obtained for the evaluation. The target disinfection level was 200 CFU/100 ml, resulting in UV and PAA doses of 7 to 30 mJ/cm2and 0.9 to 2.0 mg/liter, respectively. The proportions of UPECs were reduced in all samples after disinfection, with an average reduction by UV of 55% (range, 22% to 80%) and by PAA of 52% (range, 11% to 100%). Analysis of urovirulence genes revealed that the decline in the UPEC populations was not associated with any particular virulence factor. A positive association was found between the occurrence of urovirulence and antimicrobial resistance genes (ARGs). However, the changes in the prevalence of ARGs in potential UPECs were different following disinfection, i.e., UV appears to have had no effect, while PAA significantly reduced the ARG levels. Thus, this study showed that both UV and PAA disinfections reduced the proportion of UPECs and that PAA disinfection also reduced the proportion of antimicrobial resistance gene-carrying UPEC pathotypes in municipal wastewaters.

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