scholarly journals Adaptation of Escherichia coli ATCC 8739 to 11% NaCl

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Jian Ann How ◽  
Joshua Z. R. Lim ◽  
Desmond J. W. Goh ◽  
Wei Chuan Ng ◽  
Jack S. H. Oon ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Microbial Growth ◽  
Food Additive ◽  
Human Diet ◽  
Genetic Changes ◽  
E Coli ◽  
Gram Staining ◽  
Pcr Rflp ◽  
Dna Profiles ◽  
Kinetics Of

Escherichia coli (E. coli) is a nonhalophilic microbe and used to indicate faecal contamination. Salt (sodium chloride, NaCl) is a common food additive and is used in preservatives to encounter microbial growth. The effect of how E. coli interacts with the salt present in the human diet is unclear. Thus, it is important to investigate this relationship. In order to adapt and survive the changes in the environment, E. coli may undergo halophilization. In this study, we observed the genetic changes and growth kinetics of E. coli ATCC 8739 under 3%–11% NaCl over 80 passages. Our results suggest that E. coli adapted to 1% increase in NaCl every month with a successful adaptation to 11% NaCl. Gram staining and PCR/RFLP showed that the cultures are Gram negative and the DNA profiles of all 4 replicates to be similar, suggesting that the cultures had not been contaminated.

Inactivation of Escherichia coli by Ultrasound Combined with Nisin

2018 ◽  
Vol 81 (6) ◽  
pp. 993-1000 ◽  
Author(s):  
ZUWEN WANG ◽  
XIUFANG BI ◽  
RUI XIANG ◽  
LIYI CHEN ◽  
XIAOPING FENG ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Synergistic Effect ◽  
Linear Models ◽  
Treatment Time ◽  
Nutrient Broth ◽  
Inactivation Kinetics ◽  
Growth Phases ◽  
E Coli ◽  
Kinetics Of ◽  
Inactivation Effect

ABSTRACT The aim of this study was to investigate the inactivation of nonpathogenic Escherichia coli in nutrient broth and milk through the use of either ultrasound (US) alone or US combined with nisin (US + nisin) treatments. The E. coli cells were treated at 0 to 55°C, 242.04 to 968.16 W/cm2 for 0 to 15 min. The results showed that the inactivation of E. coli by US and US + nisin increased when the temperature, US power density, and treatment time were increased. The inactivation kinetics of E. coli in nutrient broth by US and US + nisin both conformed to linear models. The largest reductions of 2.89 and 2.93 log cycles by US and US + nisin, respectively, were achieved at 968.16 W/cm2 and at 25°C for 15 min. The suspension media of the E. coli cells influenced the inactivation effect of US, while the growth phases of E. coli cells did not affect their resistance to US. Under all experiment conditions of this study, the differences between US and US + nisin in their respective inactivation effects on E. coli were not obvious. The results suggested that nisin had either no effect at all or a weak synergistic effect with US and that the E. coli cells were inactivated mainly by US, thus indicating that the inactivation of E. coli by US is an “all or nothing” event.

scholarly journals Origin of Contamination and Genetic Diversity of Escherichia coli in Beef Cattle

2003 ◽  
Vol 69 (5) ◽  
pp. 2794-2799 ◽  
Author(s):  
Mueen Aslam ◽  
Frances Nattress ◽  
Gordon Greer ◽  
Chris Yost ◽  
Colin Gill ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genetic Diversity ◽  
Beef Cattle ◽  
Ground Beef ◽  
Rflp Analysis ◽  
E Coli ◽  
Cattle Feces ◽  
Genetic Subtypes ◽  
Random Amplification ◽  
Pcr Rflp

ABSTRACT The possible origin of beef contamination and genetic diversity of Escherichia coli populations in beef cattle, on carcasses and ground beef, was examined by using random amplification of polymorphic DNA (RAPD) and PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of the fliC gene. E. coli was recovered from the feces of 10 beef cattle during pasture grazing and feedlot finishing and from hides, carcasses, and ground beef after slaughter. The 1,403 E. coli isolates (855 fecal, 320 hide, 153 carcass, and 75 ground beef) were grouped into 121 genetic subtypes by using the RAPD method. Some of the genetic subtypes in cattle feces were also recovered from hides, prechilled carcasses, chilled carcasses, and ground beef. E. coli genetic subtypes were shared among cattle at all sample times, but a number of transient types were unique to individual animals. The genetic diversity of the E. coli population changed over time within individual animals grazing on pasture and in the feedlot. Isolates from one animal (59 fecal, 30 hide, 19 carcass, and 12 ground beef) were characterized by the PCR-RFLP analysis of the fliC gene and were grouped into eight genotypes. There was good agreement between the results obtained with the RAPD and PCR-RFLP techniques. In conclusion, the E. coli contaminating meat can originate from cattle feces, and the E. coli population in beef cattle was highly diverse. Also, genetic subtypes can be shared among animals or can be unique to an animal, and they are constantly changing.

Viability of Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes in Yellow Fat Spreads as Affected by Storage Temperature

2003 ◽  
Vol 66 (4) ◽  
pp. 549-558 ◽  
Author(s):  
SARAH L. HOLLIDAY ◽  
LARRY R. BEUCHAT
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Storage Temperature ◽  
Salt Content ◽  
Inactivation Kinetics ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Inhibition Of Growth ◽  
Time Required ◽  
Kinetics Of

A study was conducted to characterize the survival and inactivation kinetics of a five-serotype mixture of Salmonella (6.23 to 6.55 log10 CFU per 3.5-ml or 4-g sample), a five-strain mixture of Escherichia coli O157:H7 (5.36 to 6.14 log10 CFU per 3.5-ml or 4-g sample), and a six-strain mixture of Listeria monocytogenes (5.91 to 6.18 log10 CFU per 3.5-ml or 4-g sample) inoculated into seven yellow fat spreads (one margarine, one butter-margarine blend, and five dairy and nondairy spreads and toppings) after formulation and processing and stored at 4.4, 10, and 21°C for up to 94 days. Neither Salmonella nor E. coli O157:H7 grew in any of the test products. The time required for the elimination of each pathogen depended on the product and the storage temperature. Death was more rapid at 21°C than at 4.4 or 10°C. Depending on the product, the time required for the elimination of viable cells at 21°C ranged from 5 to 7 days to >94 days for Salmonella, from 3 to 5 days to 28 to 42 days for E. coli O157:H7, and from 10 to 14 days to >94 days for L. monocytogenes. Death was most rapid in a water-continuous spray product (pH 3.66, 4.12% salt) and least rapid in a butter-margarine blend (pH 6.66, 1.88% salt). E. coli O157:H7 died more rapidly than did Salmonella or L. monocytogenes regardless of storage temperature. Salmonella survived longer in high-fat (≥61%) products than in products with lower fat contents. The inhibition of growth is attributed to factors such as acidic pH, salt content, the presence of preservatives, emulsion characteristics, and nutrient deprivation. L. monocytogenes did not grow in six of the test products, but its population increased between 42 and 63 days in a butter-margarine blend stored at 10°C and between 3 and 7 days when the blend was stored at 21°C. On the basis of the experimental parameters examined in this study, traditional margarine and spreads not containing butter are not “potentially hazardous foods” in that they do not support the growth of Salmonella, E. coli O157:H7, or L. monocytogenes.

Determination of flagellar types by PCR-RFLP analysis of enteropathogenic Escherichia coli (EPEC) and Shiga toxin-producing E. coli (STEC) strains isolated from animals in São Paulo, Brazil

2012 ◽  
Vol 92 (1) ◽  
pp. 18-23 ◽  
Author(s):  
Claudia de Oliveira Ayala ◽  
Ana Carolina Ramos Moreno ◽  
Marina Baquerizo Martinez ◽  
Ylanna Kelner Burgos ◽  
Antonio Fernando Pestana de Castro ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Rflp Analysis ◽  
Sao Paulo ◽  
São Paulo ◽  
Enteropathogenic Escherichia Coli ◽  
E Coli ◽  
Pcr Rflp

Growth of Escherichia coli O157:H7 and Listeria monocytogenes in Packaged Fresh-Cut Romaine Mix at Fluctuating Temperatures during Commercial Transport, Retail Storage, and Display

2014 ◽  
Vol 77 (2) ◽  
pp. 197-206 ◽  
Author(s):  
WENTING ZENG ◽  
KEITH VORST ◽  
WYATT BROWN ◽  
BRADLEY P. MARKS ◽  
SANGHYUP JEONG ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Large Scale ◽  
Microbial Growth ◽  
Escherichia Coli O157 ◽  
Temperature Profiles ◽  
E Coli ◽  
Leafy Greens ◽  
Retail Display ◽  
Fluctuating Temperatures

Temperature abuse during commercial transport and retail sale of leafy greens negatively impacts both microbial safety and product quality. Consequently, the effect of fluctuating temperatures on Escherichia coli O157:H7 and Listeria monocytogenes growth in commercially-bagged salad greens was assessed during transport, retail storage, and display. Over a 16-month period, a series of time-temperature profiles for bagged salads were obtained from five transportation routes covering four geographic regions (432 profiles), as well as during retail storage (4,867 profiles) and display (3,799 profiles). Five different time-temperature profiles collected during 2 to 3 days of transport, 1 and 3 days of retail storage, and 3 days of retail display were then duplicated in a programmable incubator to assess E. coli O157:H7 and L. monocytogenes growth in commercial bags of romaine lettuce mix. Microbial growth predictions using the Koseki-Isobe and McKellar-Delaquis models were validated by comparing the root mean square error (RMSE), bias, and the acceptable prediction zone between the laboratory growth data and model predictions. Monte Carlo simulations were performed to calculate the probability distribution of microbial growth from 8,122,127,472 scenarios during transport, cold room storage, and retail display. Using inoculated bags of retail salad, E. coli O157:H7 and L. monocytogenes populations increased a maximum of 3.1 and 3.0 log CFU/g at retail storage. Both models yielded acceptable RMSEs and biases within the acceptable prediction zone for E. coli O157:H7. Based on the simulation, both pathogens generally increased <2 log CFU/g during transport, storage, and display. However, retail storage duration can significantly impact pathogen growth. This large-scale U.S. study—the first using commercial time/temperature profiles to assess the microbial risk of leafy greens—should be useful in filling some of the data gaps in current risk assessments for leafy greens.

scholarly journals ISOLASI Escherichia coli DARI URINE PASIEN INFEKSI SALURAN KEMIH DI RUMAH SAKIT BHAYANGKARA KEDIRI

2018 ◽  
Vol 11 (2) ◽  
pp. 99-108
Author(s):  
Mastuti Widianingsih ◽  
Aldino Marcos De Jesus
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Urinary Tract Obstruction ◽  
Staining Technique ◽  
Urine Samples ◽  
E Coli ◽  
Gram Staining ◽  
Microbial Invasion ◽  
Lactose Fermentation ◽  
Klebsiella Spp

AbstrakInfeksi saluran kemih (ISK) terjadi akibat adanya invasi mikroorganisme (bakteri) pada saluran kemih. Peningkatan kejadian ISK dapat dipengaruhi oleh kondisi refluks vesikouretral (RVU), obstruksi saluran kemih, pemakaian instrumen uretral baru, dan septikimia. Angka kejadian ISK di Rumah Sakit Bhayangkara Kediri tahun 2016 berjumlah 346 kasus. Penelitian ini bertujuan untuk mengetahui ada tidaknya Escherichia coli pada urine pasien ISK di Rumah Sakit Bhayangkara Kediri. Besarnya persentase ISK yang disebabkan E. coli mendorong peneliti untuk melakukan isolasi bakteri tersebut dari urine pasien ISK di rumah sakit tersebut. Teknik sampling yang digunakan berupa Accidental sampling dengan sampel berupa urine porsi tengah (UPT) sebanyak 30. Sampel urine diinokulasikan pada media MCA, kemudian dilakukan pewarnaan Gram, dilanjutkan uji biokimia reaksi untuk membedakan golongan Enterobacter. Hasil penelitian menunjukkan bahwa 12 sampel positif mengandung E. coli, 3 sampel mengandung Klebsiella spp., dan 15 sampel tidak terdeteksi sama sekali. Hasil positif E. coli ditunjukkan dengan koloni bulat berukuran kecil, elevasi semi mucoid, dan fermentasi laktosa positif pada media MCA. Hal tersebut menunjukkan bahwa E. coli dapat ditemukan pada sampel urine pasien ISK di Rumah Sakit Bayangkara Kediri.Abstract Urinary tract infection (UTI) is caused by microbial invasion (bacteria) in the urinary tract. The increased of UTI can be affected by a condition of vesicouretral reflux (RVU), urinary tract obstruction, application of new urethral instruments, and septicemia. The incidence of UTI in Bhayangkara Kediri Hospital in 2016 was 346 cases. The objective of this research was to determine the presence of E. coli in UTI patients in the Bhayangkara Kediri Hospital. The large percentage of UTI caused by Escherichia coli encouraged researchers to isolate the bacteria from the urine of UTI patients in the hospital. Accidental sampling with 30 middle portion urine samples (UPT) was carried out. The samples were inoculated onto separate MCA media. Representative bacterial isolates were stained with Gram staining technique and followed by reaction biochemistry tests to distinguish Enterobacter groups. The results showed that 12 urine samples contained E. coli, 3 urine samples contained Klebsiella spp., while 15 urine samples were negative (not containing bacteria). The positive results of E. coli showed small rounded, elevation of semi mucoid colonies, and positive lactose fermentation on the MCA media. It showed that E. coli indeed exists in the urine samples of UTI patients in Bayangkara Kediri Hospital.

scholarly journals Environmental inactivation and irrigation-mediated regrowth of Escherichia coli O157:H7 on romaine lettuce when inoculated in a fecal slurry matrix

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6591 ◽  
Author(s):  
Jennifer A. Chase ◽  
Melissa L. Partyka ◽  
Ronald F. Bond ◽  
Edward R. Atwill
Keyword(s):  
Escherichia Coli ◽  
Field Trials ◽  
Inactivation Rate ◽  
Bacterial Inactivation ◽  
Romaine Lettuce ◽  
E Coli ◽  
Log Reduction ◽  
Salinas Valley ◽  
Kinetics Of ◽  
Insight Into

Field trials were conducted in July–August and October 2012 to quantify the inactivation rate of Escherichia coli O157:H7 when mixed with fecal slurry and applied to romaine lettuce leaves. Lettuce was grown under commercial conditions in Salinas Valley, California. One-half milliliter of rabbit, chicken, or pig fecal slurry, containing an average of 4.05 × 107 CFU E. coli O157:H7 (C0), was inoculated onto the upper (adaxial) surface of a lower leaf on 288 heads of lettuce per trial immediately following a 2.5 h irrigation event. To estimate the bacterial inactivation rate as a function of time, fecal matrix, irrigation and seasonal climate effects, sets of lettuce heads (n = 28) were sampled each day over 10 days and the concentration of E. coli O157:H7 (Ct) determined. E. coli O157:H7 was detected on 100% of heads during the 10-day duration, with concentrations ranging from ≤340 MPN/head (∼5-log reduction) to >3.45 × 1012 MPN/head (∼5-log growth). Relative to C0, on day 10 (Ct = 12) we observed an overall 2.6-log and 3.2-log mean reduction of E. coli O157:H7 in July and October, respectively. However, we observed relative maximum concentrations due to bacterial growth on day 6 (maximum Ct = 8) apparently stimulated by foliar irrigation on day 5. From this maximum there was a mean 5.3-log and 5.1-log reduction by day 10 (Ct = 12) for the July and October trials, respectively. This study provides insight into the inactivation and growth kinetics of E. coli O157:H7 on romaine lettuce leaves under natural field conditions. This study provides evidence that harvesting within 24 h post irrigation has the potential to increase the concentration of E. coli O157:H7 contamination, if present on heads of romaine lettuce; foliar irrigation can temporarily stimulate substantial regrowth of E. coli O157:H7.

scholarly journals Bioaktivitas Turunan Metil Sinamat Terhadap Pertumbuhan Bakteri Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aureugenosa dan Jamur Candida albicans

2016 ◽  
pp. 60-64
Author(s):  
Teni Ernawati ◽  
Andri Budiana ◽  
Teni Ernawati
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Bacillus Subtilis ◽  
Candida Albicans ◽  
Cinnamic Acid ◽  
Microbial Growth ◽  
Test Results ◽  
Methyl Cinnamate ◽  
E Coli ◽  
The Family

Methyl cinnamic is a compound isolated from Alpinia malaccensis included in the family Zingiberaceae. A. malaccensis in Indonesia known as galangal forest. Some studies inform that ginger has anti-bacterial and pharmacologically galangal act as an antifungal. In this study the bioactivity of the compound methyl cinnamate and methyl cinnamic derivative which results cinnamic methyl esterification compound on the growth of Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aureugenosa and fungus Candida albicans. Methyl cinnamic derivative compounds tested are; cinnamic acid, cinnamic ethyl, butyl and 2-butyl cinnamic cinnamic. Anti-microbial test results showed that of the samples tested, cinnamic acid is able to inhibit microbial growth of S. aureus, B. subtilis, E. coli and P. aureugenosa and fungi C.albicans.DOI :http://dx.doi.org/10.15408/jkv.v0i0.3176 

scholarly journals Escherichia coli Survival in, and Release from, White-Tailed Deer Feces

2014 ◽  
Vol 81 (3) ◽  
pp. 1168-1176 ◽  
Author(s):  
Andrey K. Guber ◽  
Jessica Fry ◽  
Rebecca L. Ives ◽  
Joan B. Rose
Keyword(s):  
Escherichia Coli ◽  
Fate And Transport ◽  
Exponential Model ◽  
Temperature Correction ◽  
Content Type ◽  
E Coli ◽  
Naturally Occurring ◽  
Different Temperatures ◽  
Kinetics Of ◽  
Source Materials

ABSTRACTWhite-tailed deer are an important reservoir for pathogens that can contribute a large portion of microbial pollution in fragmented agricultural and forest landscapes. The scarcity of experimental data on survival of microorganisms in and release from deer feces makes prediction of their fate and transport less reliable and development of efficient strategies for environment protection more difficult. The goal of this study was to estimate parameters for modelingEscherichia colisurvival in and release from deer (Odocoileus virginianus) feces. Our objectives were as follows: (i) to measure survival ofE. coliin deer pellets at different temperatures, (ii) to measure kinetics ofE. colirelease from deer pellets at different rainfall intensities, and (iii) to estimate parameters of models describing survival and release of microorganisms from deer feces. Laboratory experiments were conducted to studyE. colisurvival in deer pellets at three temperatures and to estimate parameters of Chick's exponential model with temperature correction based on the Arrhenius equation. Kinetics ofE. colirelease from deer pellets were measured at two rainfall intensities and used to derive the parameters of Bradford-Schijven model of bacterial release. The results showed that parameters of the survival and release models obtained forE. coliin this study substantially differed from those obtained by using other source materials, e.g., feces of domestic animals and manures. This emphasizes the necessity of comprehensive studies of survival of naturally occurring populations of microorganisms in and release from wildlife animal feces in order to achieve better predictions of microbial fate and transport in fragmented agricultural and forest landscapes.

scholarly journals Identification of new flagellin-encoding fliC genes in Escherichia coli isolated from domestic animals using RFLP-PCR and sequencing methods

2013 ◽  
Vol 33 (4) ◽  
pp. 417-422 ◽  
Author(s):  
Cláudia de Moura ◽  
Monique Ribeiro Tiba ◽  
Marcio José da Silva ◽  
Domingos da Silva Leite
Keyword(s):  
Escherichia Coli ◽  
Fragment Length Polymorphism ◽  
Domestic Animals ◽  
Flic Gene ◽  
E Coli ◽  
New Genes ◽  
Pcr Rflp ◽  
Specific Antisera ◽  
Flagellar Antigen ◽  
Restriction Fragment Length

Identification of Escherichia coli requires knowledge regarding the prevalent serotypes and virulence factors profiles allows the classification in pathogenic/non-pathogenic. However, some of these bacteria do not express flagellar antigen invitro. In this case the PCR-restriction fragment length polymorphism (RFLP-PCR) and sequencing of the fliC may be suitable for the identification of antigens by replacing the traditional serology. We studied 17 samples of E. coli isolated from animals and presenting antigen H nontypeable (HNT). The H antigens were characterized by PCR-RFLP and sequencing of fliC gene. Three new flagellin genes were identified, for which specific antisera were obtained. The PCR-RFLP was shown to be faster than the serotyping H antigen in E. coli, provided information on some characteristics of these antigens and indicated the presence of new genes fliC.

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