Growth of Escherichia coli in a pulp and cardboard mill

1987 ◽  
Vol 33 (6) ◽  
pp. 541-545 ◽  
Author(s):  
R. Maarit Niemi ◽  
Seppo Niemelä ◽  
Juha Mentu ◽  
Anja Siitonen
Keyword(s):  
Escherichia Coli ◽  
Ammonium Sulphate ◽  
Maximum Growth ◽  
Raw Material ◽  
Biochemical Characteristics ◽  
Total Coliforms ◽  
E Coli

The coliform flora of a pulp and cardboard mill that uses birch as the raw material and ammonium sulphate as the process chemical was studied. Escherichia coli was observed to multiply in the mill. It persisted as the dominant thermotolerant coliform in the effluent. Klebsiellae were encountered among total coliforms only. The E. coli strains isolated had the biochemical characteristics and maximum growth temperatures typical to the species. However, serotyping and hemolysin test differentiated these strains from pathogenic and fecal E. coli.

scholarly journals Evaluation of the Sanitary Conditions of Head Meat, Esophagus, Diaphragm Meat, and Boning Scrap Processing

2017 ◽  
Vol 2017 ◽  
pp. 1-4 ◽  
Author(s):  
Elis Caroline Celestina dos Santos ◽  
Adelino Cunha Neto ◽  
Vinicius Silva Castro ◽  
Ricardo Cesar Tavares Carvalho ◽  
Eduardo Eustáquio de Souza Figueiredo
Keyword(s):  
Escherichia Coli ◽  
European Union ◽  
Raw Material ◽  
Microbiological Contamination ◽  
Total Coliforms ◽  
E Coli ◽  
End Products ◽  
Sanitary Conditions ◽  
Hygienic Conditions

Enterobacteriaceae, coliforms, and Escherichia coli counts are important hygiene indicators and may be pathogenic. Thus, the aim of the present study was to determine microbiological contamination in head meat, the esophagus, diaphragm, and boning scraps and evaluate the hygienic conditions of the processing of these products. The Petrifilm® (3M) method for determining Enterobacteriaceae, total coliforms, and E. coli was applied for 104 samples. APHA, European Union, PAHO/WHO, and Brazil/MAPA recommendations were followed. Bleeding and skinning knives were contaminated with E. coli (61.5%). Regarding the meat cuts, 30.76% samples from head meat, the esophagus and the boning flap showed the presence of E. coli in counts up to 2 log CFU/g, while 15.3% of the diaphragm samples showed up to 1.85 log CFU/g. The analyzed comminuted meat was, therefore, shown to be contaminated with E. coli during processing, indicating that end-products from this raw material can offer biological risks.

Bacteriophages reduce Escherichia coli O157:H7 levels in experimentally inoculated sheep

2009 ◽  
Vol 89 (2) ◽  
pp. 285-293 ◽  
Author(s):  
S J Bach ◽  
R P Johnson ◽  
K. Stanford ◽  
T A McAllister
Keyword(s):  
Escherichia Coli ◽  
Oral Administration ◽  
Coliform Bacteria ◽  
Escherichia Coli O157 ◽  
Fecal Shedding ◽  
Total Coliforms ◽  
E Coli ◽  
Oral Inoculation ◽  
Experimental Treatments ◽  
And Control

Bacteriophage biocontrol has potential as a means of mitigating the prevalence of Escherichia coli O157:H7 in ruminants. The efficacy of oral administration of bacteriophages for reducing fecal shedding of E. coli O157:H7 by sheep was evaluated using 20 Canadian Arcott rams (50.0 ± 3.0) housed in four rooms (n = 5) in a contained facility. The rams had ad libitum access to drinking water and a pelleted barley-based total mixed ration, delivered once daily. Experimental treatments consisted of administration of E. coli O157:H7 (O157), E. coli O157:H7+bacteriophages (O157+phage), bacteriophages (phage), and control (CON). Oral inoculation of the rams with 109 CFU of a mixture of four nalidixic acid-resistant strains of E. coli O157:H7 was performed on day 0. A mixture of 1010 PFU of bacteriophages P5, P8 and P11 was administered on days -2, -1, 0, 6 and 7. Fecal samples collected on 14 occasions over 21 d were analyzed for E. coli O157:H7, total E. coli, total coliforms and bacteriophages. Sheep in treatment O157+phage shed fewer (P < 0.05) E. coli O157:H7 than did sheep in treatment O157. Populations of total coliforms and total E. coli were similar (P < 0.05) among treatments, implying that bacteriophage lysis of non-target E. coli and coliform bacteria in the gastrointestinal tract did not occur. Bacteriophage numbers declined rapidly over 21 d, which likely reduced the chance of collision between bacteria and bacteriophage. Oral administration of bacteriophages reduced shedding of E. coli O157:H7 by sheep, but a delivery system that would protect bacteriophages during passage through the intestine may increase the effectiveness of this strategy as well as allow phage to be administered in the feed.Key words: Escherichia coli O157:H7, bacteriophage, sheep, environment, coliforms

scholarly journals Metabolic engineering of Escherichia coli W for isobutanol production on chemically defined medium and cheese whey as alternative raw material

2020 ◽  
Vol 47 (12) ◽  
pp. 1117-1132
Author(s):  
Katharina Novak ◽  
Juliane Baar ◽  
Philipp Freitag ◽  
Stefan Pflügl
Keyword(s):  
Escherichia Coli ◽  
Cheese Whey ◽  
Strain Improvement ◽  
Defined Medium ◽  
Raw Material ◽  
Efficient Production ◽  
Substrate Uptake ◽  
Chemically Defined Medium ◽  
E Coli ◽  
Plasmid Library

AbstractThe aim of this study was to establish isobutanol production on chemically defined medium in Escherichia coli. By individually expressing each gene of the pathway, we constructed a plasmid library for isobutanol production. Strain screening on chemically defined medium showed successful production in the robust E. coli W strain, and expression vector IB 4 was selected as the most promising construct due to its high isobutanol yields and efficient substrate uptake. The investigation of different aeration strategies in combination with strain improvement and the implementation of a pulsed fed-batch were key for the development of an efficient production process. E. coli W ΔldhA ΔadhE Δpta ΔfrdA enabled aerobic isobutanol production at 38% of the theoretical maximum. Use of cheese whey as raw material resulted in longer process stability, which allowed production of 20 g l−1 isobutanol. Demonstrating isobutanol production on both chemically defined medium and a residual waste stream, this study provides valuable information for further development of industrially relevant isobutanol production processes.

scholarly journals Performance of three pilot-scale hybrid constructed wetlands for total coliforms and Escherichia coli removal from primary effluent – a 2-year study in a subtropical climate

2014 ◽  
Vol 13 (2) ◽  
pp. 446-458 ◽  
Author(s):  
Florentina Zurita ◽  
Alejandra Carreón-Álvarez
Keyword(s):  
Escherichia Coli ◽  
Constructed Wetlands ◽  
Pilot Scale ◽  
World Health ◽  
First Year ◽  
Subtropical Climate ◽  
Total Coliforms ◽  
E Coli ◽  
Stage System ◽  
Health Organization

Three pilot-scale two-stage hybrid constructed wetlands were evaluated in order to compare their efficiency for total coliforms (TCol) and Escherichia coli removal and to analyze their performances in two 1-year periods of experimentation. System I consisted of a horizontal flow (HF) constructed wetland (CW) followed by a stabilization pond. System II was also configured with a HF CW as a first stage which was then followed by a vertical flow (VF) CW as a second stage. System III was configured with a VF CW followed by a HF CW. In the first year of evaluation, the HF–VF system was the most effective for TCol removal (p &lt; 0.05) and achieved a reduction of 2.2 log units. With regard to E. coli removal, the HF–VF and VF–HF systems were the most effective (p &lt; 0.05) with average reductions of 3.2 and 3.8 log units, respectively. In the second year, the most effective were those with a VF component for both TCol and E. coli which underwent average reductions of 2.34–2.44 and 3.44–3.74 log units, respectively. The reduction achieved in E. coli densities, in both years, satisfy the World Health Organization guidelines that require a 3–4 log unit pathogen reduction in wastewater treatment systems.

scholarly journals Fitness, Stress Resistance, and Extraintestinal Virulence in Escherichia coli

2013 ◽  
Vol 81 (8) ◽  
pp. 2733-2742 ◽  
Author(s):  
Alexandre Bleibtreu ◽  
Pierre-Alexis Gros ◽  
Cédric Laouénan ◽  
Olivier Clermont ◽  
Hervé Le Nagard ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Stress Response ◽  
Mouse Model ◽  
Stress Resistance ◽  
Maximum Growth ◽  
Competitive Fitness ◽  
Content Type ◽  
General Stress Response ◽  
E Coli

ABSTRACTThe extraintestinal virulence ofEscherichia coliis dependent on numerous virulence genes. However, there is growing evidence for a role of the metabolic properties and stress responses of strains in pathogenesis. We assessed the respective roles of these factors in strain virulence by developing phenotypic assays for measuringin vitroindividual and competitive fitness and the general stress response, which we applied to 82 commensal and extraintestinal pathogenicE. colistrains previously tested in a mouse model of sepsis. Individual fitness properties, in terms of maximum growth rates in various media (Luria-Bertani broth with and without iron chelator, minimal medium supplemented with gluconate, and human urine) and competitive fitness properties, estimated as the mean relative growth rate per generation in mixed cultures with a reference fluorescentE. colistrain, were highly diverse between strains. The activity of the main general stress response regulator, RpoS, as determined by iodine staining of the colonies, H2O2resistance, andrpoSsequencing, was also highly variable. No correlation between strain fitness and stress resistance and virulence in the mouse model was found, except that the maximum growth rate in urine was higher for virulent strains. Multivariate analysis showed that the number of virulence factors was the only independent factor explaining the virulence in mice. At the species level, growth capacity and stress resistance are heterogeneous properties that do not contribute significantly to the intrinsic virulence of the strains.

scholarly journals Isolation of Shiga toxin-producing strains of Escherichia coli from beef and swine carcasses and the characterization of their genes

2018 ◽  
Vol 9 (2) ◽  
pp. 275-780 ◽  
Author(s):  
O. М. Berhilevych ◽  
V. V. Kasianchuk ◽  
O. M. Deriabin ◽  
M. D. Kukhtyn
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Raw Material ◽  
Animal Origin ◽  
E Coli ◽  
Food Of Animal Origin ◽  
Beef Carcasses ◽  
Positive Isolate ◽  
Stx1 Gene ◽  
Beef Carcass

Escherichia coli is part of the normal microflora of the intestinal tract of humans and warm-blooded animals, but its presence in raw material and food of animal origin is considered as fecal contamination and can be very dangerous for consumers. The determination of the number of E. coli in raw material and food is important because among them can be pathogenic strains. The most dangerous strains are considered enterohemorrhagic E. coli as a causative agent of severe bloody diarrhea and hemorrhagic uremic syndrome in humans through the production of Shiga-toxin, which is the main virulence factor, responsible for disease. The aim of this study was to identify the prevalence of Shiga toxin-producing strains of E. coli (STEC) from swabs of beef and swine carcass in slaughterhouses in Ukraine and characterize their genes, which are responsible for pathogenic properties. A total of 230 samples of swabs from beef (130) and swine (100) carcasses were obtained from 5 slaughterhouses in Ukraine between 2012 and 2015. Samples of swabs from carcasses were randomly selected at the final point of the process after the final washing of the carcass from the following areas: distal hind limb, abdomen (lateral and medial) from swine carcasses, brisket, flank and flank groin areas from beef carcasses. All samples were examined by culture-dependent method, after that each positive isolate of STEC was analyzed by multiplex PCR to detect the stx1, stx2, and eae genes. Out of 230 collected samples, seven (7.2%) were contaminated with STEC. The highest prevalence of STEC was found in swabs from beef carcasses (8.1%) in comparison to swabs from swine carcasses (5.7%). The stx1 gene was the predominant gene detected in all STEC positive samples. The eae gene was found in one of the examined isolates from beef carcass. Three isolates from swabs of beef carcass carried both stx1 and stx2 genes, one isolate showed association between stx1 and eae genes, one isolate was positive for stx1 gene only. In swabs from swine carcasses (2 isolates) stx1 and stx2 genes were presented simultaneously. The results of this study suggested that fresh raw meat could be a potential vehicle for transmission of the Shiga toxin-producing strain of E. coli to humans. This is the first report of STEC prevalence in beef and swine carcasses in Ukraine and these data will be valuable for microbiological risk assessment and help the appropriate services to develop strategies to mitigate health risk.

scholarly journals Microbiological quality of shellfish and evaluation of compact dry EC for detecting total coliforms and Escherichia coli

2020 ◽  
Vol 49 (1) ◽  
pp. 32-39 ◽  
Author(s):  
A. Vásquez García ◽  
S.H. Gomes de Sá ◽  
G. de Sousa Silva ◽  
J.E. Mejia Ballesteros ◽  
E. Barbieri ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Conventional Method ◽  
Microbiological Quality ◽  
Correlation Coefficients ◽  
Mean Values ◽  
Total Coliforms ◽  
E Coli ◽  
The Mean

The objective of this study was to evaluate the microbiological quality of oysters and mussels grown in Cananéia, Brazil, by analysing mesophiles, psychrothophic bacteria, moulds and yeasts, Staphylococcus aureus, and Salmonella spp., and to compare the efficiency of Compact Dry EC method and the conventional method for counting of total coliforms and Escherichia coli. The microbial analysis showed that the mean values of mesophilic counts were 3.14±0.81 log CFU g−1 for oysters and 3.92±0.90 for mussels; the mean values of psychrophilic counts were 2.78±0.75 log CFU g−1 for oysters and 3.22±0.75 log CFU g−1 for mussels; the mean values of mould and yeast counts were 3.70±0.58 log CFU g−1 for oysters and 3.33±0.81 log CFU g−1 for mussels. Salmonella spp. did not present positive results, and the maximal count of Staphylococcus aureus was 1.7 log CFU g−1, therefore, within the limits established in the legislation. The correlation coefficients between the Compact Dry EC method and conventional method were >0.87 for total coliform and E. coli counts for both types of shellfish. The data in this study show that the Compact Dry EC method is an acceptable alternative to conventional methods for enumeration of total coliforms and E. coli in shellfish.

scholarly journals Assessment of a Photoreactor with Immobilized Nanoparticle TiO2 Films for the Purification of Rainwater

2021 ◽  
Vol 8 (2) ◽  
pp. 81-85
Author(s):  
Jean Poll Alva-Araujo ◽  
María de los Ángeles García-Hernández ◽  
Asunción Guadalupe Morales Mendoza ◽  
Refugio Rodríguez-Vázquez
Keyword(s):  
Escherichia Coli ◽  
Uv Light ◽  
Combined Treatment ◽  
Heterogeneous Photocatalysis ◽  
Pathogen Removal ◽  
Total Coliforms ◽  
E Coli ◽  
Disinfection Process ◽  
Reducing Costs ◽  
Escherichia Coli Bacteria

The heterogeneous photocatalysis consists of the generation of reactive oxygen species (•OH, •-O2) from a catalyst, UV light, and oxygen; these reactive species can degrade contaminants and eliminate microorganisms. The purpose of this research was to evaluate a heterogeneous photocatalysis system and an UV light disinfection system for the elimination of total coliforms and Escherichia coli bacteria present in rainwater stored in five cisterns in Mexico City. The elimination of total coliforms (MPN/100 mL) and Escherichia coli (CFU/100 mL) were evaluated both in the rainwater treated with TiO2/UV and UV (in time periods of 30 and 60 minutes), according to the treatments established in the statistical model 22. The results show that although complete elimination of initial total coliforms (9.3 x 104 MPN/100 mL) and E. coli bacterium (1.5 x 103 CFU/mL) was achieved in one of the samples of rainwater using only UV light at 254 nm for 30 minutes, the use of 8 films coated with Degussa P-25 titanium dioxide, UV light at 254 nm and 1.5 vvm air in a reactor, achieves a total pathogen removal in a shorter time of 15 minutes. Thus, we anticipate that the combined treatment could be an alternative disinfection process for rainwater stored in cisterns, reducing costs and making the treatment viable for a larger-scale application.

scholarly journals Sanitizing action of triple-strength vinegar against Escherichia coli on lettuce

2018 ◽  
Vol 36 (3) ◽  
pp. 414-418 ◽  
Author(s):  
Giovanna C Souza ◽  
Wilma A Spinosa ◽  
Tereza CRM Oliveira
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Low Cost ◽  
Titratable Acidity ◽  
Total Acidity ◽  
Total Coliforms ◽  
E Coli ◽  
Total Titratable Acidity ◽  
Carcinogenic Effects ◽  
Interesting Alternative

ABSTRACT Vegetable sanitization protocols recommend the use of chlorine, which has adverse effects on the environment and carcinogenic effects on humans. Acetic acid is an interesting alternative to chlorine because it possesses no risk to human health and is widely available in the form of vinegar. This study aimed to evaluate the sanitizing action of vinegar, 130 g L-1 total titratable acidity expressed as acetic acid, on lettuce. Vinegar was chosen because it is a low-cost product widely available in the Brazilian market. The minimum inhibitory concentration and minimum bactericidal concentration of vinegar against Escherichia coli were 2.5 and 15 g L-1 total acidity, respectively. Lettuce leaves artificially contaminated with E. coli or naturally contaminated with total coliforms were washed with water and immersed in vinegar solution (15 g L-1 total acidity) for 15 min. This period was sufficient to reduce E. coli counts in artificially contaminated samples and total coliforms in naturally contaminated samples. There were no visual changes in lettuce leaves, which indicates that vinegar at 15 g L-1 total acidity can be used to sanitize vegetables without affecting their appearance.

scholarly journals Expression of a Temperature-Sensitive Esterase in a Novel Chaperone-Based Escherichia coli Strain

2004 ◽  
Vol 70 (8) ◽  
pp. 4499-4504 ◽  
Author(s):  
Manuel Ferrer ◽  
Tatyana N. Chernikova ◽  
Kenneth N. Timmis ◽  
Peter N. Golyshin
Keyword(s):  
Escherichia Coli ◽  
Recombinant Proteins ◽  
Growth Temperature ◽  
Specific Activity ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Coli Strain ◽  
Temperature Sensitive ◽  
Psychrophilic Bacterium ◽  
E Coli

ABSTRACT A new principle for expression of heat-sensitive recombinant proteins in Escherichia coli at temperatures close to 4°C was experimentally evaluated. This principle was based on simultaneous expression of the target protein with chaperones (Cpn60 and Cpn10) from a psychrophilic bacterium, Oleispira antarctica RB8T, that allow E. coli to grow at high rates at 4°C (maximum growth rate, 0.28 h−1) (M. Ferrer, T. N. Chernikova, M. Yakimov, P. N. Golyshin, and K. N. Timmis, Nat. Biotechnol. 21:1266-1267, 2003). The expression of a temperature-sensitive esterase in this host at 4 to 10°C yielded enzyme specific activity that was 180-fold higher than the activity purified from the non-chaperonin-producing E. coli strain grown at 37°C (32,380 versus 190 μmol min−1 g−1). We present evidence that the increased specific activity was not due to the low growth temperature per se but was due to the fact that low temperature was beneficial to folding, with or without chaperones. This is the first report of successful use of a chaperone-based E. coli strain to express heat-labile recombinant proteins at temperatures below the theoretical minimum growth temperature of a common E. coli strain (7.5°C).

Sign in / Sign up

Export Citation Format

Share Document