scholarly journals Nanotextile membranes for bacteria Escherichia coli capturing

2010 ◽  
Vol 58 (5) ◽  
pp. 239-246
Author(s):  
Jaroslav Lev ◽  
Libor Kalhotka ◽  
Michal Černý
Keyword(s):  
Escherichia Coli ◽  
Experimental Study ◽  
Microbial Contamination ◽  
Model Simulation ◽  
Water Filtration ◽  
Contaminated Water ◽  
Air Filtration ◽  
E Coli ◽  
Before And After ◽  
Input Side

The article describes an experimental study dealing with the possibility of nanotextile materials usa­ge for microbiologically contaminated water filtration. The aim of the study is to verify filtration ability of different nanotextile materials and evaluate the possibilities of practical usage. Good detention ability of these materials in the air filtration is the presumption for nanotextile to be used for bacteria filtration from a liquid. High nanotextile porosity with the nanotextile pores dimensions smaller than a bacteria size predicates the possibility of a successful usage of these materials. For the experiment were used materials made from electrospinning nanofibres under the label PA612, PUR1, PUR2 s PUR3 on the supporting unwoven textiles (viscose and PP). As a model simulation of the microbial contamination, bacteria Escherichia coli was chosen. Contaminated water was filtered during the overpressure activity of 105Pa on the input side of the filter from the mentioned material. After three-day incubation on the nutrient medium, cultures found in the samples before and after filtration were compared. In the filtrated water, bacteria E. coli were indicated, which did not verify the theoretical presumptions about an absolut bacteria detention. However, used materials caught at least 94% of bacteria in case of material PUR1 and up to 99,996% in case of material PUR2. These results predict the possibility of producing effective nanotextile filters for microbiologically contaminated water filtration.Recommendation: For the production of materials with better filtrating qualities, experiments need to be done, enabling better understanding of the bacteria detention mechanisms on the nanotextile material, and parameters of the used materials that influence the filtrating abilities need to be verified.

A Comparison of the Survival in Feces and Water of Escherichia coli O157:H7 Grown under Laboratory Conditions or Obtained from Cattle Feces

2006 ◽  
Vol 69 (1) ◽  
pp. 6-11 ◽  
Author(s):  
L. SCOTT ◽  
P. McGEE ◽  
J. J. SHERIDAN ◽  
B. EARLEY ◽  
N. LEONARD
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogen ◽  
Hemorrhagic Colitis ◽  
Contaminated Water ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Cattle Feces ◽  
Oral Inoculation ◽  
Before And After ◽  
Uremic Syndrome

Escherichia coli O157:H7 is an important foodborne pathogen that can cause hemorrhagic colitis and hemolytic uremic syndrome. Cattle feces and fecally contaminated water are important in the transmission of this organism on the farm. In this study, the survival of E. coli O157:H7 in feces and water was compared following passage through the animal digestive tract or preparation in the laboratory. Feces were collected from steers before and after oral inoculation with a marked strain of E. coli O157:H7. Fecal samples collected before cattle inoculation were subsequently inoculated with the marked strain of E. coli O157:H7 prepared in the laboratory. Subsamples were taken from both animal and laboratory-inoculated feces to inoculate 5-liter volumes of water. E. coli O157:H7 in feces survived up to 97 days, and survival was not affected by the method used to prepare the inoculating strain. E. coli O157:H7 survived up to 109 days in water, and the bacteria collected from inoculated cattle were detected up to 10 weeks longer than the laboratory-prepared culture. This study suggests that pathogen survival in low-nutrient conditions may be enhanced by passage through the gastrointestinal tract.

A Comparison of Hand Washing Techniques To Remove Escherichia coli and Caliciviruses under Natural or Artificial Fingernails

2003 ◽  
Vol 66 (12) ◽  
pp. 2296-2301 ◽  
Author(s):  
CHIA-MIN LIN ◽  
FONE-MAO WU ◽  
HOI-KYUNG KIM ◽  
MICHAEL P. DOYLE ◽  
BARRY S. MICHAELS ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Tap Water ◽  
Hand Washing ◽  
Microbial Populations ◽  
Liquid Soap ◽  
E Coli ◽  
Hand Sanitizer ◽  
Before And After ◽  
Escherichia Coli Jm109 ◽  
Viral Indicators

Compared with other parts of the hand, the area beneath fingernails harbors the most microorganisms and is most difficult to clean. Artificial fingernails, which are usually long and polished, reportedly harbor higher microbial populations than natural nails. Hence, the efficacy of different hand washing methods for removing microbes from natural and artificial fingernails was evaluated. Strains of nonpathogenic Escherichia coli JM109 and feline calicivirus (FCV) strain F9 were used as bacterial and viral indicators, respectively. Volunteers with artificial or natural nails were artificially contaminated with ground beef containing E. coli JM109 or artificial feces containing FCV. Volunteers washed their hands with tap water, regular liquid soap, antibacterial liquid soap, alcohol-based hand sanitizer gel, regular liquid soap followed by alcohol gel, or regular liquid soap plus a nailbrush. The greatest reduction of inoculated microbial populations was obtained by washing with liquid soap plus a nailbrush, and the least reduction was obtained by rubbing hands with alcohol gel. Lower but not significantly different (P > 0.05) reductions of E. coli and FCV counts were obtained from beneath artificial than from natural fingernails. However, significantly (P ≤ 0.05) higher E. coli and FCV counts were recovered from hands with artificial nails than from natural nails before and after hand washing. In addition, microbial cell numbers were correlated with fingernail length, with greater numbers beneath fingernails with longer nails. These results indicate that best practices for fingernail sanitation of food handlers are to maintain short fingernails and scrub fingernails with soap and a nailbrush when washing hands.

Multiplex Quantitative PCR Assays for the Detection and Quantification of the Six Major Non-O157 Escherichia coli Serogroups in Cattle Feces†

2016 ◽  
Vol 79 (1) ◽  
pp. 66-74 ◽  
Author(s):  
P. B. SHRIDHAR ◽  
L. W. NOLL ◽  
X. SHI ◽  
B. AN ◽  
N. CERNICCHIARO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Quantitative Pcr ◽  
Foodborne Pathogens ◽  
Virulence Genes ◽  
Target Genes ◽  
Culture Methods ◽  
Fecal Samples ◽  
E Coli ◽  
Cattle Feces ◽  
Before And After

ABSTRACT Shiga toxin–producing Escherichia coli (STEC) serogroups O26, O45, O103, O111, O121, and O145, called non-O157 STEC, are important foodborne pathogens. Cattle, a major reservoir, harbor the organisms in the hindgut and shed them in the feces. Although limited data exist on fecal shedding, concentrations of non-O157 STEC in feces have not been reported. The objectives of our study were (i) to develop and validate two multiplex quantitative PCR (mqPCR) assays, targeting O-antigen genes of O26, O103, and O111 (mqPCR-1) and O45, O121, and O145 (mqPCR-2); (ii) to utilize the two assays, together with a previously developed four-plex qPCR assay (mqPCR-3) targeting the O157 antigen and three virulence genes (stx1, stx2, and eae), to quantify seven serogroups and three virulence genes in cattle feces; and (iii) to compare the three mqPCR assays to a 10-plex conventional PCR (cPCR) targeting seven serogroups and three virulence genes and culture methods to detect seven E. coli serogroups in cattle feces. The two mqPCR assays (1 and 2) were shown to be specific to the target genes, and the detection limits were 4 and 2 log CFU/g of pure culture–spiked fecal samples, before and after enrichment, respectively. A total of 576 fecal samples collected from a feedlot were enriched in E. coli broth and were subjected to quantification (before enrichment) and detection (after enrichment). Of the 576 fecal samples subjected, before enrichment, to three mqPCR assays for quantification, 175 (30.4%) were quantifiable (≥4 log CFU/g) for at least one of the seven serogroups, with O157 being the most common serogroup. The three mqPCR assays detected higher proportions of postenriched fecal samples (P < 0.01) as positive for one or more serogroups compared with cPCR and culture methods. This is the first study to assess the applicability of qPCR assays to detect and quantify six non-O157 serogroups in cattle feces and to generate data on fecal concentration of the six serogroups.

scholarly journals Monitoring antimicrobial resistance trends in commensal Escherichia coli from livestock, the Netherlands, 1998 to 2016

2019 ◽  
Vol 24 (25) ◽  
Author(s):  
Ayla Hesp ◽  
Kees Veldman ◽  
Jeanet van der Goot ◽  
Dik Mevius ◽  
Gerdien van Schaik
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Monitoring Data ◽  
Resistant Isolate ◽  
Similar Data ◽  
Explanatory Variables ◽  
E Coli ◽  
Veal Calves ◽  
Before And After ◽  
Using Data

Background Monitoring of antimicrobial resistance (AMR) in animals is essential for public health surveillance. To enhance interpretation of monitoring data, evaluation and optimisation of AMR trend analysis is needed. Aims To quantify and evaluate trends in AMR in commensal Escherichia coli, using data from the Dutch national AMR monitoring programme in livestock (1998–2016). Methods Faecal samples were collected at slaughter from broilers, pigs and veal calves. Minimum inhibitory concentration values were obtained by broth microdilution for E. coli for 15 antimicrobials of eight antimicrobial classes. A Poisson regression model was applied to resistant isolate counts, with explanatory variables representing time before and after 2009 (reference year); for veal calves, sampling changed from 2012 represented by an extra explanatory variable. Results Resistant counts increased significantly from 1998-2009 in broilers and pigs, except for tetracyclines and sulfamethoxazole in broilers and chloramphenicol and aminoglycosides in pigs. Since 2009, resistant counts decreased for all antimicrobials in broilers and for all but the phenicols in pigs. In veal calves, for most antimicrobials no significant decrease in resistant counts could be determined for 2009–16, except for sulfamethoxazole and nalidixic acid. Within animal species, antimicrobial-specific trends were similar. Conclusions Using Dutch monitoring data from 1998-2016, this study quantified AMR trends in broilers and slaughter pigs and showed significant trend changes in the reference year 2009. We showed that monitoring in commensal E. coli is useful to quantify trends and detect trend changes in AMR. This model is applicable to similar data from other European countries.

Use of the Systems Approach To Determine the Fate of Escherichia coli O157:H7 on Fresh Lettuce and Spinach

2009 ◽  
Vol 72 (7) ◽  
pp. 1560-1568 ◽  
Author(s):  
HELGA J. DOERING ◽  
MARK A. HARRISON ◽  
RUTH A. MORROW ◽  
WILLIAM C. HURST ◽  
WILLIAM L. KERR
Keyword(s):  
Escherichia Coli ◽  
Systems Approach ◽  
Storage Temperature ◽  
Storage Period ◽  
Categorical Variables ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Field Temperature ◽  
Before And After ◽  
Handling Practices

Lettuce and spinach inoculated with Escherichia coli O157:H7 were processed and handled in ways that might occur in commercial situations, including variations in holding times before and after product cooling, transportation conditions and temperatures, wash treatments, and product storage temperatures and times. Populations of background microflora and E. coli O157:H7 were enumerated after each step in the system. Data analysis was done to predict response variables with a combination of independent categorical variables. Field temperature, time before cooling, and wash treatment significantly affected E. coli O157:H7 populations on both products. The lowest populations of E. coli O157:H7 were encountered when precool time was minimal, lettuce was washed with chlorine, and storage temperature was 4°C. For lettuce, field and transportation temperature were not important once the storage period started, whereas after 2 days E. coli O157:H7 populations on packaged baby spinach were not affected by field temperature. On chopped iceberg lettuce and whole leaf spinach that was packaged and stored at 4°C, E. coli O157:H7 contamination could still be detected after typical handling practices, although populations decreased from initial levels in many cases by at least 1.5 log units. In abusive cases, where populations increased, the product quality quickly deteriorated. Although E. coli O157:H7 levels decreased on products handled and stored under recommended conditions, survivors persisted. This study highlights practices that may or may not affect the populations of E. coli O157:H7 on the final product.

Survival of Escherichia coli on Lettuce under Field Conditions Encountered in the Northeastern United States

2017 ◽  
Vol 80 (7) ◽  
pp. 1214-1221 ◽  
Author(s):  
Daniel L. Weller ◽  
Jasna Kovac ◽  
Sherry Roof ◽  
David J. Kent ◽  
Jeffrey I. Tokman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Microbial Contamination ◽  
Field Conditions ◽  
Risk Assessments ◽  
Most Probable Number ◽  
Northeastern United States ◽  
Probable Number ◽  
E Coli ◽  
The Relationship ◽  
Sample Time

ABSTRACT Although wildlife intrusion and untreated manure have been associated with microbial contamination of produce, relatively few studies have examined the survival of Escherichia coli on produce under field conditions following contamination (e.g., via splash from wildlife feces). This experimental study was performed to estimate the die-off rate of E. coli on preharvest lettuce following contamination with a fecal slurry. During August 2015, field-grown lettuce was inoculated via pipette with a fecal slurry that was spiked with a three-strain cocktail of rifampin-resistant nonpathogenic E. coli. Ten lettuce heads were harvested at each of 13 time points following inoculation (0, 2.5, 5, and 24 h after inoculation and every 24 h thereafter until day 10). The most probable number (MPN) of E. coli on each lettuce head was determined, and die-off rates were estimated. The relationship between sample time and the log MPN of E. coli per head was modeled using a segmented linear model. This model had a breakpoint at 106 h (95% confidence interval = 69, 142 h) after inoculation, with a daily decrease of 0.70 and 0.19 log MPN for 0 to 106 h and 106 to 240 h following inoculation, respectively. These findings are consistent with die-off rates obtained in similar studies that assessed E. coli survival on produce following irrigation. Overall, these findings provide die-off rates for E. coli on lettuce that can be used in future quantitative risk assessments.

Microbiological Effects of Hand Washing at a Beef Carcass–Breaking Facility†

2003 ◽  
Vol 66 (3) ◽  
pp. 493-496 ◽  
Author(s):  
C. O. GILL ◽  
J. C. McGINNIS
Keyword(s):  
Escherichia Coli ◽  
Hand Washing ◽  
E Coli ◽  
Before And After ◽  
Disinfectant Solution ◽  
The Mean ◽  
Beef Carcass

The hands of workers in the carcass-breaking facility at a beef packing plant were sampled by rinsing. Total aerobes, coliforms, and Escherichia coli were enumerated for each sample. The numbers of bacteria recovered from duplicate groups of 25 hand samples collected before and after hands were washed with an antibacterial gel, rinsed in a disinfectant solution, washed with the gel and rinsed with the disinfectant, or washed in the disinfectant for 20 s were similar for samples collected before work began after breaks. The numbers of bacteria recovered from samples collected before and after hands were washed with the antibacterial gel and rinsed in the disinfectant solution were similar for samples collected after work as well. However, the mean numbers of aerobes recovered from the four groups of hand samples after work were all >6.5 log CFU per hand, while 9 of the 10 corresponding values for groups of hand samples collected before work were <6.5 log CFU per hand; the total numbers of coliforms recovered from three groups of hand samples collected after work were >4 log CFU/25 hands, while 9 of the corresponding values for groups of hand samples collected before work were <4 log CFU/25 hands. The total numbers of E. coli recovered from all groups of hand samples collected after work were >3.5 log CFU/25 hands, while 9 of the corresponding values for groups of hand samples collected before work were <3 log CFU/25 hands. Thus, although washing and/or rinsing apparently did not reduce the numbers of bacteria on hands, fewer bacteria were recovered from hands before than after work.

scholarly journals Despite Predominance of Uropathogenic/Extraintestinal Pathotypes Among Travel-acquired Extended-spectrum β-Lactamase–producing Escherichia coli, the Most Commonly Associated Clinical Manifestation Is Travelers’ Diarrhea

2019 ◽  
Vol 70 (2) ◽  
pp. 210-218 ◽  
Author(s):  
Anu Kantele ◽  
Tinja Lääveri ◽  
Sointu Mero ◽  
Inka M K Häkkinen ◽  
Juha Kirveskari ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Chain Reaction ◽  
Symptomatic Infection ◽  
E Coli ◽  
Extended Spectrum ◽  
Before And After ◽  
Clinical Consequences ◽  
Polymerase Chain ◽  
Enterobacteriaceae Infections ◽  
The Tropics

AbstractBackgroundOne-third of the 100 million travelers to the tropics annually acquire extended-spectrum β-lactamase (ESBL)–producing Enterobacteriaceae (ESBL-PE), with undefined clinical consequences.MethodsSymptoms suggesting Enterobacteriaceae infections were recorded prospectively among 430 Finnish travelers, 90 (21%) of whom acquired ESBL-PE abroad. ESBL-PE isolates underwent polymerase chain reaction–based detection of diarrheagenic Escherichia coli (DEC) pathotypes (enteroaggregative E. coli [EAEC], enteropathogenic E. coli [EPEC], enterotoxigenic E. coli [ETEC], enteroinvasive E. coli, and Shiga toxin–producing E. coli), and extraintestinal pathogenic/uropathogenic E. coli (ExPEC/UPEC). Laboratory-confirmed ESBL-PE infections were surveyed 5 years before and after travel.ResultsAmong the 90 ESBL-PE carriers, manifestations of Enterobacteriaceae infection included travelers’ diarrhea (TD) (75/90 subjects) and urinary tract infection (UTI) (3/90). The carriers had 96 ESBL-producing E. coli isolates, 51% exhibiting a molecular pathotype: 13 (14%) were DEC (10 EAEC, 2 EPEC, 1 ETEC) (12 associated with TD) and 39 (41%) ExPEC/UPEC (none associated with UTI). Of ESBL-PE, 3 (3%) were ExPEC/UPEC-EAEC hybrids (2 associated with diarrhea, none with UTI). Potential ESBL-PE infections were detected in 15 of 90 subjects (17%). The 10-year medical record survey identified 4 laboratory-confirmed ESBL-PE infections among the 430 travelers, all in subjects who screened ESBL-PE negative after returning home from their index journeys but had traveled abroad before their infection episodes.ConclusionsHalf of all travel-acquired ESBL-producing E. coli strains qualified molecularly as pathogens. Extraintestinal and uropathogenic pathotypes outnumbered enteric pathotypes (41% vs 14%), yet the latter correlated more closely with symptomatic infection (0% vs 92%). Despite more ESBL-PE strains qualifying as ExPEC/UPEC than DEC, travel-acquired ESBL-PE are more often associated with TD than UTI.

Impact of Transportation of Feedlot Cattle to the Harvest Facility on the Prevalence of Escherichia coli O157:H7, Salmonella, and Total Aerobic Microorganisms on Hides

2007 ◽  
Vol 70 (1) ◽  
pp. 17-21 ◽  
Author(s):  
A. L. REICKS ◽  
M. M. BRASHEARS ◽  
K. D. ADAMS ◽  
J. C. BROOKS ◽  
J. R. BLANTON ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Feedlot Cattle ◽  
Lower Percentage ◽  
Escherichia Coli O157 ◽  
Sample Collection ◽  
Treatment Groups ◽  
E Coli ◽  
Sampling Locations ◽  
Before And After

Prevalences of Escherichia coli O157:H7, Salmonella, and total aerobic microorganisms were determined on the hides of beef feedlot cattle before and after transport from the feedyard to the harvest facility in clean and dirty trailers. Swab samples were taken from the midline and withers of 40 animals on each of 8 days before and after shipping. After samples were collected, animals were loaded in groups of 10 on upper and lower levels of clean and dirty trailers. Animals were unloaded at the harvest facility and kept in treatment groups for sample collection after exsanguination. Salmonella was found more often on hide swabs collected from the midline than on than samples collected from the withers from animals transported in both clean and dirty trailers. Salmonella was found on significantly more hide swabs collected at harvest from both sampling locations than on those collected at the feedyard, with no differences attributed to the type of trailer. At the feedyard, clean trucks had a lower percentage of Salmonella-positive samples than did dirty trucks before animals were loaded. However, after transport, both clean and dirty trucks had a similar prevalence of Salmonella. There were no differences in Salmonella prevalence on hides collected from animals transported on the top and bottom levels of clean and dirty trucks. E. coli O157:H7 was detected on less than 2% of the samples; therefore, no practical conclusions about prevalence could be drawn. Hides sampled at harvest had higher concentrations of aerobic microorganisms than did hides sampled at the feedyard, and concentrations were higher on the midline than on the withers. Although the prevalences of Salmonella and total aerobic microorganisms increased on hides after transport from the feedyard to the plant, this increase was not related to the cleanliness of the trailers or the location of the cattle in the trailers.

Microbiological Effects of a Routine Treatment for Decontaminating Hide-On Carcasses at a Large Beef Packing Plant

2015 ◽  
Vol 78 (2) ◽  
pp. 256-263 ◽  
Author(s):  
XIANQIN YANG ◽  
MADHU BADONI ◽  
FRANCES TRAN ◽  
COLIN O. GILL
Keyword(s):  
Escherichia Coli ◽  
Tandem Repeat ◽  
Variable Number Tandem Repeat ◽  
Variable Number ◽  
Routine Treatment ◽  
Multiple Locus ◽  
E Coli ◽  
Repeat Analysis ◽  
Before And After

To investigate the microbiological effects of a hide-on carcass decontaminating treatment recently implemented at a beef packing plant, carcasses undergoing routine processing at the plant were sampled during successive periods in January/February, April/May, and September/October. During each period, samples were collected from carcasses before and after the decontamination of hide-on carcasses, after skinning, before decontamination of the skinned carcasses, and at the end of the carcass dressing process. At each stage of processing during each period, samples were obtained by swabbing an area of 1,000 cm2 on each of 25 carcasses. Aerobes, coliforms, and Escherichia coli were enumerated. In most samples, coliforms were predominantly E. coli. In all three periods, the log mean numbers of aerobes and E. coli recovered from hides before decontamination were between 6.6 and 6.8 and between 5.3 and 5.9 log CFU/1,000 cm2, respectively. The log mean numbers of aerobes recovered from decontaminated hides were 6.6 log CFU/1,000 cm2 in January/February and April/May but 5.4 log CFU/1,000 cm2 in September/October. The log total numbers of E. coli recovered from decontaminated hides in January/February and April/May were 2.4 and 3.8 log CFU/25,000 cm2, respectively, but no E. coli was recovered from such carcasses in September/October. Log total numbers of aerobes and E. coli recovered from skinned or dressed carcasses were mostly >4 and between 1 and 2 log CFU/25,000 cm2, respectively. Typing of 480 E. coli isolates by multiple-locus variable-number tandem repeat analysis (MLVA) identified 218 MLVA types. Most isolates recovered from carcasses in different periods or at different stages of processing were of different MLVA types. However, small numbers of MLVA types were recovered in more than one period or from both hides before and after decontamination and skinned or dressed carcasses. The findings show that the hide-decontaminating treatment disrupted the usual transfer of E. coli from hides to meat surfaces during carcass skinning.

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