scholarly journals Effect of Long-Term Starvation on the Survival, Recovery, and Carbon Utilization Profiles of a Bovine Escherichia coli O157:H7 Isolate from New Zealand

2014 ◽  
Vol 80 (14) ◽  
pp. 4383-4390 ◽  
Author(s):  
Ron N. Xavier ◽  
Hugh W. Morgan ◽  
Ian R. McDonald ◽  
Helen Withers
Keyword(s):  
Escherichia Coli ◽  
New Zealand ◽  
Membrane Integrity ◽  
Nutrient Level ◽  
Carbon Utilization ◽  
Content Type ◽  
E Coli ◽  
Significant Difference ◽  
Carbon Utilization Profiles ◽  
Phosphate Buffered Saline

ABSTRACTThe ability to maintain a dual lifestyle of colonizing the ruminant gut and surviving in nonhost environments once shed is key to the success ofEscherichia coliO157:H7 as a zoonotic pathogen. Both physical and biological conditions encountered by the bacteria are likely to change during the transition between host and nonhost environments. In this study, carbon starvation at suboptimal temperatures in nonhost environments was simulated by starving a New Zealand bovineE. coliO157:H7 isolate in phosphate-buffered saline at 4 and 15°C for 84 days. Recovery of starved cells on media with different nutrient availabilities was monitored under aerobic and anaerobic conditions. We found that the New Zealand bovineE. coliO157:H7 isolate was able to maintain membrane integrity and viability over 84 days and that the level of recovery depended on the nutrient level of the recovery medium as well as the starvation temperature. In addition, a significant difference in carbon utilization was observed between starved and nonstarved cells.

Factors Influencing Attachment of Escherichia coli O157:H7 to Beef Tissues and Removal Using Selected Sanitizing Rinses‡

1996 ◽  
Vol 59 (5) ◽  
pp. 453-459 ◽  
Author(s):  
PINA M. FRATAMICO ◽  
FRANKIE J. SCHULTZ ◽  
ROBERT C. BENEDICT ◽  
ROBERT L. BUCHANAN ◽  
PETER H. COOKE
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Surface Structures ◽  
Escherichia Coli O157 ◽  
Adipose Tissues ◽  
E Coli ◽  
Factors Influencing ◽  
Significant Difference ◽  
Phosphate Buffered Saline ◽  
Scanning Electron

Attachment of E. coli O157:H7 and E. coli K12 to beef tenderloin filet, chuck, and adipose tissues was studied. Most attachment occurred within 1 min of incubation; the number of attached organisms depended on the concentration of bacteria in the liquid inoculum. Similar levels of E. coli bound to the three types of beef tissues tested. E. coli O157:H7 was heavily piliated; however, there was no significant difference between levels of bound E. coli O157:H7 and E. coli K12, indicating that these surface structures apparently are not involved in attachment. Scanning electron photomicrographs of meat tissue and of purified collagen suggested that bacteria attached primarily to collagen fibers. Rinsing solutions consisting of 10% trisodium phosphate (TSP), 2% acetic acid (HAc), phosphate-buffered saline (PBS) and combinations of each were tested for effectiveness in reducing the number of attached E. coli. The level of bacteria removed from tenderloin tissue following TSP, HAc, or PBS rinses did not differ considerably. When beef tissues were stored at 4°C for 18 h after the various rinse combinations, TSP rinse treatments reduced the levels of E. coli K12 and O157:H7 attached to adipose tissue up to 3.4 and 2.7 log units, respectively, compared to PBS rinse treatments. Therefore, TSP may be effective for reducing populations of E. coli O157:H7 on beef carcass tissue.

scholarly journals Genome Sequence of a Podovirus (AAPEc6) Isolated from Wastewater in New Zealand That Infects Escherichia coli O45:H10

2017 ◽  
Vol 5 (31) ◽  
Author(s):  
Judith Nonis ◽  
Aruni Premaratne ◽  
Craig Billington ◽  
Arvind Varsani
Keyword(s):  
Escherichia Coli ◽  
New Zealand ◽  
Genome Sequence ◽  
Foodborne Pathogens ◽  
Content Type ◽  
E Coli

ABSTRACT Bacteriophages are ideal candidates for pathogen biocontrol to mitigate outbreaks of prevalent foodborne pathogens, such as Escherichia coli. We identified a bacteriophage (AAPEc6) from wastewater that infects E. coli O45:H10. The AAPEc6 genome sequence shares 93% identity (with 92% coverage) to enterobacterial phage K1E (Sp6likevirus) in the Autographivirinae subfamily (Podoviridae).

scholarly journals Antimicrobial Resistance in Fecal Escherichia coli Isolates from Healthy Urban Children of Two Age Groups in Relation to Their Antibiotic Therapy

2011 ◽  
Vol 55 (6) ◽  
pp. 3005-3007 ◽  
Author(s):  
Ivan Literak ◽  
Radim Petro ◽  
Monika Dolejska ◽  
Erika Gruberova ◽  
Hana Dobiasova ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Czech Republic ◽  
Antimicrobial Resistance ◽  
Age Groups ◽  
Antibiotic Resistant ◽  
The Czech Republic ◽  
Content Type ◽  
E Coli ◽  
Significant Difference ◽  
Two Age Groups

ABSTRACTThe study was performed in the Czech Republic during 2007 to 2009. OfEscherichia coliisolates from 275 children aged 6 weeks, 36% (n= 177) were resistant to 1 to 7 antibiotics. Of isolates from 253 children aged 6 to 17 years, 24% (n= 205) were resistant to 1 to 5 antibiotics. There was no significant difference in the prevalences of antibiotic-resistantE. coliisolates between these groups of children, even though the consumptions of antibiotics were quite different.

scholarly journals CsgA Production by Escherichia coli O157:H7 Alters Attachment to Abiotic Surfaces in Some Growth Environments

2011 ◽  
Vol 77 (20) ◽  
pp. 7339-7344 ◽  
Author(s):  
R. M. Goulter-Thorsen ◽  
E. Taran ◽  
I. R. Gentle ◽  
K. S. Gobius ◽  
G. A. Dykes
Keyword(s):  
Escherichia Coli ◽  
Growth Medium ◽  
Epifluorescence Microscopy ◽  
Clear Correlation ◽  
Bacterial Cells ◽  
Content Type ◽  
E Coli ◽  
Abiotic Surfaces ◽  
Significant Difference ◽  
Force Mapping

ABSTRACTThe role of curli expression in attachment ofEscherichia coliO157:H7 to glass, Teflon, and stainless steel (SS) was investigated through the creation ofcsgAknockout mutants in two isolates ofE. coliO157:H7. Attachment assays using epifluorescence microscopy and measurements of the force of adhesion of bacterial cells to the substrates using atomic force microscopy (AFM) force mapping were used to determine differences in attachment between wild-type (wt) andcsgA-negative (ΔcsgA) strains following growth in four different media. The hydrophobicity of the cells was determined using contact angle measurements (CAM) and bacterial adhesion to hydrocarbons (BATH). The attachment assay results indicated that ΔcsgAstrains attached to glass, Teflon, and SS surfaces in significantly different numbers than their wt counterparts in a growth medium-dependent fashion (P< 0.05). However, no clear correlation was seen between attachment numbers, surface type, or growth medium. No correlation was seen between BATH and CAM results (R2< 0.70). Hydrophobicity differed between the wt and ΔcsgAin some cases in a growth medium- and method-dependent fashion (P< 0.05). AFM force mapping revealed no significant difference in the forces of adhesion to glass and SS surfaces between wt and ΔcsgAstrains (P> 0.05) but a significantly greater force of adhesion to Teflon for one of the two wt strains than for its ΔcsgAcounterpart (P< 0.05). This study shows that CsgA production byE. coliO157:H7 may alter attachment behavior in some environments; however, further investigation is required in order to determine the exact relationship between CsgA production and attachment to abiotic surfaces.

scholarly journals Assessment of Adhesins as an Indicator of Pathovar-Associated Virulence Factors in Bovine Escherichia coli

2014 ◽  
Vol 80 (23) ◽  
pp. 7230-7234 ◽  
Author(s):  
Charlotte Valat ◽  
Karine Forest ◽  
Frédéric Auvray ◽  
Véronique Métayer ◽  
Thomas Méheut ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Beta Lactamase ◽  
Esbl Production ◽  
Content Type ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Heat Stable ◽  
Significant Difference ◽  
Fimbrial Adhesins ◽  
The Relationship

ABSTRACTThe CS31A, F17, and F5 adhesins are usually targeted by serology-based methods to detect pathogenicEscherichia coliassociated with calf enteritis. However, the virulence traits of the selected isolates are still poorly described. Here, from a set of 349 diarrheagenicE. coliisolates from cattle, we demonstrated a 70.8% concordance rate (Cohen's kappa, 0.599) between serology- and PCR-based approaches for the detection of adhesins under field conditions. A 79% to 82.4% correspondence between the two methods was found for fimbrial adhesins, whereas major discrepancies (33%) were observed for CS31A-type antigens. Various F17A variants were found, such as F17Ac (20K) (50%), F17Aa (FY) (18.9%), F17Ab (8.1%), and F17Ad (111K) (5.4%), including a high proportion (17.6%) of new F17A internal combinations (F17Aab, F17Aac, and F17Abc) or untypeable variants. In addition, the highest proportion of pathovar-associated virulence factor (VF) genes was observed amongE. coliisolates that produced F5/F41 adhesins. A specific link between the heat-stable toxins related to the enterotoxigenicE. coli(ETEC) pathovar and adhesins was identified. STa was significantly linked to F5/F41 and EAST1 to CS31A adhesins (P< 0.001), respectively, whereas NTEC was associated with F17 adhesin (P= 0.001). Clustering between phylogroups according to the adhesin types was also observed. Also, few Shiga toxin-producingE. coli(STEC) or enteropathogenicE. coli(EPEC) pathovars were identified. Finally, no statistically significant difference was observed in the occurrence of extended-spectrum beta lactamase (ESBL) production according to the adhesins expressed by the isolates (P= 0.09). Altogether, this study gives new insights into the relationship between adhesins, VF, and antimicrobial resistance in calf enteritis and supports the need for further standardization of methodologies for such approaches.

scholarly journals Inoculum Effect on the Efficacies of Amoxicillin-Clavulanate, Piperacillin-Tazobactam, and Imipenem against Extended-Spectrum β-Lactamase (ESBL)-Producing and Non-ESBL-Producing Escherichia coli in an Experimental Murine Sepsis Model

2013 ◽  
Vol 57 (5) ◽  
pp. 2109-2113 ◽  
Author(s):  
F. Docobo-Pérez ◽  
L. López-Cerero ◽  
R. López-Rojas ◽  
P. Egea ◽  
J. Domínguez-Herrera ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Serum Drug Concentration ◽  
Esbl Producer ◽  
Inoculum Concentration ◽  
Content Type ◽  
E Coli ◽  
Sepsis Model ◽  
Extended Spectrum ◽  
Significant Difference ◽  
Amoxicillin Clavulanate

ABSTRACTEscherichia coliis commonly involved in infections with a heavy bacterial burden. Piperacillin-tazobactam and carbapenems are among the recommended empirical treatments for health care-associated complicated intra-abdominal infections. In contrast to amoxicillin-clavulanate, both have reducedin vitroactivity in the presence of high concentrations of extended-spectrum β-lactamase (ESBL)-producing and non-ESBL-producingE. colibacteria. Our goal was to compare the efficacy of these antimicrobials against different concentrations of two clinicalE. colistrains, one an ESBL-producer and the other a non-ESBL-producer, in a murine sepsis model. An experimental sepsis model {∼5.5 log10CFU/g [low inoculum concentration (LI)] or ∼7.5 log10CFU/g [high inoculum concentration (HI)]} usingE. colistrains ATCC 25922 (non-ESBL producer) and Ec1062 (CTX-M-14 producer), which are susceptible to the three antimicrobials, was used. Amoxicillin-clavulanate (50/12.5 mg/kg given intramuscularly [i.m.]), piperacillin-tazobactam (25/3.125 mg/kg given intraperitoneally [i.p.]), and imipenem (30 mg/kg i.m.) were used. Piperacillin-tazobactam and imipenem reduced spleen ATCC 25922 strain concentrations (−2.53 and −2.14 log10CFU/g [P< 0.05, respectively]) in the HI versus LI groups, while amoxicillin-clavulanate maintained its efficacy (−1.01 log10CFU/g [no statistically significant difference]). Regarding the Ec1062 strain, the antimicrobials showed lower efficacy in the HI than in the LI groups: −0.73, −1.89, and −1.62 log10CFU/g (P< 0.05, for piperacillin-tazobactam, imipenem, and amoxicillin-clavulanate, respectively, although imipenem and amoxicillin-clavulanate were more efficacious than piperacillin-tazobactam). An adapted imipenem treatment (based on the time for which the serum drug concentration remained above the MIC obtained with a HI of the ATCC 25922 strain) improved its efficacy to −1.67 log10CFU/g (P< 0.05). These results suggest that amoxicillin-clavulanate could be an alternative to imipenem treatment of infections caused by ESBL- and non-ESBL-producingE. colistrains in patients with therapeutic failure with piperacillin-tazobactam.

scholarly journals Are Antimicrobial Interventions Associated with Heat-Resistant Escherichia coli on Meat?

2020 ◽  
Vol 86 (13) ◽  
Author(s):  
Peipei Zhang ◽  
Frances Tran ◽  
Kim Stanford ◽  
Xianqin Yang
Keyword(s):  
Escherichia Coli ◽  
Heat Resistance ◽  
Ecological Niches ◽  
Beef Production ◽  
Production Chain ◽  
Content Type ◽  
E Coli ◽  
Heat Resistant ◽  
Significant Difference ◽  
Antimicrobial Interventions

ABSTRACT Decontamination practices, which often involve thermal treatments, are routinely performed in beef packing plants and have generally improved the safety of meat in North America. We investigated whether Escherichia coli in the beef production chain is becoming more heat resistant due to those treatments. Cattle isolates (n = 750) included seven serogroups (O157, O103, O111, O121, O145, O26, and O45) which were collected between 2002 and 2017. Beef plant isolates (n = 700) from carcasses, fabrication equipment, and beef products were included. Heat resistance was determined in Luria-Bertani broth at 60°C and by PCR screening for the locus of heat resistance (LHR). The decimal reduction for E. coli at 60°C (D60ºC values) ranged from 0 to 7.54 min, with 97.2% of the values being <2 min. The prevalence of E. coli with D60ºC values of >2 min was not significantly different (P > 0.05) among cattle and meat plant isolates. E. coli from equipment before sanitation (median, 1.03 min) was more heat resistant than that after sanitation (median, 0.9 min). No significant difference in D60ºC values was observed among E. coli isolates from different years, from carcasses before and after antimicrobial interventions, or from before and during carcass chilling. Of all isolates, 1.97% harbored LHR, and the LHR-positive isolates had greater median D60ºC values than the LHR-negative isolates (3.25 versus 0.96 min). No increase in heat resistance in E. coli was observed along the beef production chain or with time. IMPORTANCE The implementation of multiple hurdles in the beef production chain has resulted in substantial improvement in the microbial safety of beef in Canada. In this study, we characterized a large number of Escherichia coli isolates (n = 1,450) from various sources/stages of beef processing to determine whether the commonly used antimicrobial interventions would give rise to heat-resistant E. coli on meat, which in turn may require alternatives to the current control of pathogens and/or modifications to the current cooking recommendations for meat. The findings show that the degree and rate of heat resistance in E. coli did not increase along the production chain or with time. This furthers our understanding of man-made ecological niches that are required for the development of heat resistance in E. coli.

scholarly journals Draft Whole-Genome Sequences of Three Diarrheagenic Escherichia coli Strains Isolated from Farmed Deer in New Zealand

2018 ◽  
Vol 6 (16) ◽  
pp. e00300-18
Author(s):  
A. Springer Browne ◽  
Patrick J. Biggs ◽  
Alice Elliott ◽  
Patricia Jaros ◽  
Nigel P. French ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
New Zealand ◽  
Cervus Elaphus ◽  
Red Deer ◽  
Draft Genome ◽  
Whole Genome ◽  
Genome Sequences ◽  
Content Type ◽  
E Coli ◽  
Diarrheagenic Escherichia Coli

ABSTRACT Escherichia coli bacteria commonly colonize the gastrointestinal tracts of farmed ruminants. Cattle are a well-recognized reservoir of zoonotic E. coli; we report here, however, the draft genome sequences of three diarrheagenic E. coli strains isolated from farmed red deer (Cervus elaphus) in the Manawatu region of New Zealand.

Microbial growth and attachment of Salmonella and enterohemorrhagic and enteroaggregative Escherichia coli strains on cress microgreens grown in peat soil system

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sahin Namli ◽  
Hilal Samut ◽  
Yesim Soyer
Keyword(s):  
Escherichia Coli ◽  
Irrigation Water ◽  
Biofilm Formation ◽  
Peat Soil ◽  
Fresh Produce ◽  
Bacterial Load ◽  
Soil System ◽  
Content Type ◽  
E Coli ◽  
Significant Difference

PurposeThis study aimed to investigate how enteric pathogens and their biofilm populations on fresh produce survive according to time that contamination has occurred on leaves and contamination route: seed irrigation water.Design/methodology/approachCress was contaminated in two different ways: contamination of seeds and irrigation water with 8-log MPN/mL bacterial load, Salmonella Newport, Escherichia coli O157:H7, O104:H4 or O78:H2. While contaminated seeds were cultivated for seed contamination, contaminated irrigation was applied at the end of each week to separate groups of samples obtained from cultivated surface-sterile seeds to understand how long these pathogens could survive until harvest.FindingsThe results indicated these pathogens survived until harvest, and formed biofilms on cress leaves grown using both contaminated seeds and irrigation water. No significant difference was observed among populations of Salmonella and E. coli groups in terms of survival (∼4.5–6.0 log MPN/g) and biofilm formation (∼4.4–5.7 log MPN/g) for contamination by seed. Also, SEM images revealed biofilm-like structures, the proofs of the attachment of these pathogens on leaf surfaces.Originality/valueFrom our knowledge this is the first study focusing on the survival and biofilm formation of one Salmonella serotype (Newport) and three E. coli serotypes (O157:H7, O104:H4, and O78:H2), representing enterohemorrhagic and enteroaggregative E. coli pathogenic subgroups, under the same irrigation and growth schemes. Furthermore, this study mimics the contamination of seeds and irrigation water with sewage or wastewater and may shed light on contamination of fresh produce grown using poor wastewater treatment.

scholarly journals pqiABC and yebST, Putative mce Operons of Escherichia coli, Encode Transport Pathways and Contribute to Membrane Integrity

2016 ◽  
Vol 199 (1) ◽  
Author(s):  
Takayuki Nakayama ◽  
Qiu-Mei Zhang-Akiyama
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Unknown Function ◽  
Membrane Integrity ◽  
Transport Pathway ◽  
Transport Pathways ◽  
Content Type ◽  
E Coli ◽  
Outer Leaflet ◽  
Mutant Strains

ABSTRACT The membranes of single-cell organisms are crucial as the first line of defense. The outer membrane of Gram-negative bacteria is an asymmetric bilayer in which lipopolysaccharides (LPSs) and phospholipids are localized in the outer and inner leaflet, respectively. This asymmetry is important for membrane integrity. In Escherichia coli, the Mla transport pathway maintains this asymmetry by removing phospholipids from the outer leaflet. The MlaD component of this system is a mammalian cell entry (MCE) domain protein, and E. coli has two other MCE domain proteins of unknown function (PqiB and YebT). Here, we show that these two proteins are components of novel transport pathways that contribute to membrane integrity. The pqiAB operon is regulated by SoxS and RpoS. The yebST operon contains pqiAB homologues. Here, we found a third member of the pqi operon, ymbA (pqiC). A PqiB-PqiC complex bridges the inner and the outer membrane, and in other bacteria, pqiBC genes are located in operons together with transporter proteins. We show here that simultaneous deletion of pqiABC and yebST operons in an Δmla background rendered cells more sensitive to SDS-EDTA, and the SDS-EDTA sensitivity of mla mutants was rescued by additional copies of pqiABC. We also found that the yebST operon was induced by a defect in LPS molecules. In conclusion, PqiABC and YebST are novel transport pathways related to the Mla transport pathway and important for membrane integrity. IMPORTANCE Membranes of bacteria are crucial for stress resistance. The composition of the E. coli outer membrane is asymmetric, with asymmetry maintained by the Mla ABC transport pathway. We propose that the stress-inducible pqiABC operon and homologous yebST operon, both of previously unknown function, encode transport pathway proteins related to the Mla transport pathway. Deletion of these operons rendered cells more sensitive to membrane stress, and additional copies of pqiABC suppressed the SDS-EDTA sensitivity of mla mutant strains. We found that yebS′-′lacZ fusion was activated in mutant strains with defective LPS molecules.

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