Efficacy of Spray Application of Chlorinated Water in Killing Pathogenic Bacteria on Raw Apples, Tomatoes, and Lettuce

1998 ◽  
Vol 61 (10) ◽  
pp. 1305-1311 ◽  
Author(s):  
L. R. BEUCHAT ◽  
B. V. NAIL ◽  
B. B. ADLER ◽  
M. R. S. CLAVERO
Keyword(s):  
Pathogenic Bacteria ◽  
Food Service ◽  
Microbial Populations ◽  
Control Treatment ◽  
Escherichia Coli O157 ◽  
Pathogenic Microorganisms ◽  
Sterile Water ◽  
Spray Application ◽  
Water Control ◽  
Yeasts And Molds

Washing whole and cut produce by dipping or submerging in chlorinated water has a sanitizing effect, although reduction in microbial populations is minimal and is usually less than 100-fold. A study was undertaken to evaluate the efficacy of a spray application of chlorine in killing Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, yeasts and molds, and total aerobic mesophilic microorganisms on whole apples, tomatoes, and lettuce leaves. Inoculated produce was treated (sprayed and then soaked) with water (control) or Solutions containing 200 or 2,000 ppm of chlorine for 0, 1,3, 5, or 10 min, rinsed with sterile water, and analyzed for populations (CFU/cm2) of target microorganisms. Compared to the control treatment, further reductions in numbers of pathogens of 0.35 to 2.30 log CFU/cm2 were achieved by treatment with chlorine. Chlorine was generally more effective at 2,000 ppm than at 200 ppm. Inactivation of microorganisms occurred essentially within 1 min after application of chlorine. These reductions are significant relative to populations of pathogenic microorganisms that may be present on produce. Spray application of chlorine to raw produce at food Service or household levels may be a suitable, and more convenient, alternative to treatment by dipping or submersion.

MICROBIAL POPULATIONS OF RESTAURANT COUNTER CLOTHS1

1972 ◽  
Vol 35 (2) ◽  
pp. 115-116
Author(s):  
F. Eugene Nelson ◽  
Lee Halle
Keyword(s):  
Food Service ◽  
Coliform Bacteria ◽  
Microbial Populations ◽  
General Level ◽  
Psychrotrophic Bacteria ◽  
Yeasts And Molds

Of 18 counter cloths in use at food service establishments, 6 gave “total” counts exceeding 1,000,000/4 inehes2, and only 5 had counts less than 10,000/4 inches2, Yeasts and molds were encountered in appreciable numbers from nearly all samples. Typical colonies of psychrotrophic bacteria, coliform bacteria, staphylococci, and enterococci were obtained from many samples, Microbiological condition of counter cloths did not correlate with inspection ratings or general level of housekeeping.

Bacterial Contamination of Keyboards: Efficacy and Functional Impact of Disinfectants

2006 ◽  
Vol 27 (4) ◽  
pp. 372-377 ◽  
Author(s):  
William A. Rutala ◽  
Matthew S. White ◽  
Maria F. Gergen ◽  
David J. Weber
Keyword(s):  
Bacterial Contamination ◽  
Microbial Contamination ◽  
Healthcare Setting ◽  
Pathogenic Microorganisms ◽  
Sterile Water ◽  
Water Control ◽  
Coagulase Negative Staphylococci ◽  
Test Organisms ◽  
Vancomycin Resistant ◽  
Potentially Pathogenic Microorganisms

Background.Computers are ubiquitous in the healthcare setting and have been shown to be contaminated with potentially pathogenic microorganisms. This study was performed to determine the degree of microbial contamination, the efficacy of different disinfectants, and the cosmetic and functional effects of the disinfectants on the computer keyboards.Methods.We assessed the effectiveness of 6 different disinfectants (1 each containing chlorine, alcohol, or phenol and 3 containing quaternary ammonium) against 3 test organisms (oxacillin-resistant Staphylococcus aureus [ORSA], Pseudomonas aeruginosa, and vancomycin-resistant Enterococcus species) inoculated onto study computer keyboards. We also assessed the computer keyboards for functional and cosmetic damage after disinfectant use.Results.Potential pathogens cultured from more than 50% of the computers included coagulase-negative staphylococci (100% of keyboards), diphtheroids (80%), Micrococcus species (72%), and Bacillus species (64%). Other pathogens cultured included ORSA (4% of keyboards), OSSA (4%), vancomycin-susceptible Enterococcus species (12%), and nonfermentative gram-negative rods (36%). All disinfectants, as well as the sterile water control, were effective at removing or inactivating more than 95% of the test bacteria. No functional or cosmetic damage to the computer keyboards was observed after 300 disinfection cycles.Conclusions.Our data suggest that microbial contamination of keyboards is prevalent and that keyboards may be successfully decontaminated with disinfectants. Keyboards should be disinfected daily or when visibly soiled or if they become contaminated with blood.

Acid Tolerance of Acid-Adapted and Nonadapted Escherichia coli O157:H7 following Habituation (10°C) in Fresh Beef Decontamination Runoff Fluids of Different pH Values

2004 ◽  
Vol 67 (4) ◽  
pp. 638-645 ◽  
Author(s):  
JOHN SAMELIS ◽  
PATRICIA KENDALL ◽  
GARY C. SMITH ◽  
JOHN N. SOFOS
Keyword(s):  
Escherichia Coli ◽  
Acid Tolerance ◽  
Growth Potential ◽  
Escherichia Coli O157 ◽  
Sterile Water ◽  
Water Control ◽  
Term Survival ◽  
Acid Adaptation ◽  
E Coli ◽  
Natural Flora

This study evaluated survival of Escherichia coli O157:H7 strain ATCC 43895 during exposure to pH 3.5 following its habituation for 2 or 7 days at 10°C in fresh beef decontamination waste runoff fluid mixtures (washings) containing 0, 0.02, or 0.2% of lactic or acetic acids. Meat washings and sterile water (control) were initially inoculated with approximately 5 log CFU/ml of acid- and nonadapted E. coli O157:H7 cells cultured (30°C, 24 h) in broth with and without 1% glucose, respectively. After 2 days, E. coli O157:H7 survivors from acetate washings (pH 3.7 to 4.7) survived at pH 3.5 better than E. coli O157:H7 survivors from lactate washings (pH 3.1 to 4.6), especially when the original inoculum was acid adapted. Also, although E. coli O157:H7 habituated in sterile water for 2 days survived well at pH 3.5, the corresponding survivors from nonacid water meat washings (pH 6.8) were rapidly killed at pH 3.5, irrespective of acid adaptation. After 7 days, E. coli O157:H7 survivors from acetate washings (pH 3.6 to 4.7) continued to resist pH 3.5, whereas those from lactate washings died off. This loss of acid tolerance by E. coli O157:H7 was due to either its low survival in 0.2% lactate washings (pH 3.1) or its acid sensitization in 0.02% lactate washings, in which a Pseudomonas-like natural flora showed extensive growth (>8 log CFU/ml) and the pH increased to 6.5 to 6.6. Acid-adapted E. coli O157:H7 populations habituated in water washings (pH 7.1 to 7.3) for 7 days continued to be acid sensitive, whereas nonadapted populations increased their acid tolerance, a response merely correlated with their slight (<1 log) growth at 10°C. These results indicate that the expression of high acid tolerance by acid-adapted E. coli O157:H7 can be maintained or enhanced in acid-diluted meat decontamination waste runoff fluids of pH levels that could permit long-term survival at 10°C. Previous acid adaptation, however, could reduce the growth potential of E. coli O157:H7 at 10°C in nonacid waste fluids of high pH and enriched in natural flora. These conditions might further induce an acid sensitization to stationary E. coli O157:H7 cells.

Calcinated Calcium Killing of Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes on the Surface of Tomatoes

2002 ◽  
Vol 65 (11) ◽  
pp. 1706-1711 ◽  
Author(s):  
M. L. BARI ◽  
Y. INATSU ◽  
S. KAWASAKI ◽  
E. NAZUKA ◽  
K. ISSHIKI
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Fresh Produce ◽  
Active Chlorine ◽  
Distilled Water ◽  
Escherichia Coli O157 ◽  
Pathogenic Microorganisms ◽  
Water Control ◽  
E Coli ◽  
Wash Solution

This study was conducted to evaluate the efficacy of calcinated calcium, 200 ppm chlorine water (1% active chlorine), and sterile distilled water in killing Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes on the surfaces of spot-inoculated tomatoes. Inoculated tomatoes were sprayed with calcinated calcium, chlorinated water, or sterile distilled water (control) and hand rubbed for 30 s. Populations of E. coli O157:H7, Salmonella, and L. monocytogenes in the rinse water and in the residual (0.1% peptone) wash solution were determined. Treatment with 200 ppm chlorine and calcinated calcium resulted in 3.40- and 7.85-log10 reductions of E. coli O157:H7, respectively, and 2.07- and 7.36-log10 reductions of Salmonella, respectively. Treatment with 200 ppm chlorine and calcinated calcium reduced L. monocytogenes numbers by 2.27 and 7.59 log10 CFU per tomato, respectively. The findings of this study suggest that calcinated calcium could be useful in controlling pathogenic microorganisms in fresh produce.

Effectiveness of Electrolyzed Acidic Water in Killing Escherichia coli O157:H7, Salmonella Enteritidis, and Listeria monocytogenes on the Surfaces of Tomatoes

2003 ◽  
Vol 66 (4) ◽  
pp. 542-548 ◽  
Author(s):  
M. L. BARI ◽  
Y. SABINA ◽  
S. ISOBE ◽  
T. UEMURA ◽  
K. ISSHIKI
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Salmonella Enteritidis ◽  
Distilled Water ◽  
Escherichia Coli O157 ◽  
Pathogenic Microorganisms ◽  
Acidic Water ◽  
Water Control ◽  
E Coli ◽  
Chlorine Water

A study was conducted to evaluate the efficacy of electrolyzed acidic water, 200-ppm chlorine water, and sterile distilled water in killing Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes on the surfaces of spot-inoculatedtomatoes. Inoculated tomatoes were sprayed with electrolyzed acidic water, 200-ppm chlorine water, and sterile distilled water (control) and rubbed by hand for 40 s. Populations of E. coli O157:H7, Salmonella, and L. monocytogenes in the rinse water and in the peptone wash solution were determined. Treatment with 200-ppm chlorine water and electrolyzed acidic water resulted in 4.87- and 7.85-log10 reductions, respectively, in Escherichia coli O157:H7 counts and 4.69- and 7.46-log10 reductions, respectively, in Salmonella counts. Treatment with 200-ppm chlorine water and electrolyzed acidic water reduced the number of L. monocytogenes by 4.76 and 7.54 log10 CFU per tomato, respectively. This study's findings suggest that electrolyzed acidic water could be useful in controlling pathogenic microorganisms on fresh produce.

Essential Oils Reduce Escherichia coli O157:H7 and Salmonella on Spinach Leaves†

2012 ◽  
Vol 75 (3) ◽  
pp. 488-496 ◽  
Author(s):  
NADINE YOSSA ◽  
JITENDRA PATEL ◽  
PATRICIA MILLNER ◽  
Y. MARTIN LO
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Adverse Effects ◽  
Escherichia Coli O157 ◽  
Leaf Color ◽  
Water Control ◽  
E Coli ◽  
Psychrotrophic Bacteria ◽  
Yeasts And Molds ◽  
Spinach Leaves

The efficacy of cinnamaldehyde and Sporan for reducing Escherichia coli O157:H7 and Salmonella on spinach leaves was investigated. Spinach leaves were inoculated with a five-strain cocktail of Salmonella or E. coli O157:H7, air dried for ca. 30 min, and then immersed in a treatment solution containing 5 ppm of free chlorine, cinnamaldehyde, or Sporan (800 and 1,000 ppm) alone or in combination with 200 ppm of acetic acid (20%) for 1 min or with water (control). After spin drying, treated leaves were analyzed periodically during 14 days of storage at 4°C for Salmonella, E. coli O157:H7, total coliforms, mesophilic and psychrotrophic bacteria, and yeasts and molds. Treatment effects on color and texture of leaves also were determined. Sporan alone (1,000S), Sporan plus acetic acid (1,000SV), and cinnamaldehyde-Tween (800T) reduced E. coli O157:H7 by more than 3 log CFU/g (P < 0.05), and 1,000SV treatment reduced Salmonella by 2.5 log CFU/g on day 0. E. coli O157:H7 and Salmonella populations on treated spinach leaves declined during storage at 4°C. The 1,000SV treatment was superior to chlorine and other treatments for reducing E. coli O157:H7 during storage. Saprophytic microbiota on spinach leaves increased during storage at 4°C but remained lower on leaves treated with Sporan (800S) and Sporan plus acetic acid (1,000SV) than on control leaves. The color and texture of Sporan-treated leaves were not significantly different from those of the control leaves after 14 days. Sporan plus acetic acid (1,000SV) reduced E. coli O157:H7 and Salmonella on baby spinach leaves without adverse effects on leaf color and texture.

FOOD AND OTHER SOURCES OF PATHOGENIC MICROORGANISMS IN HOSPITALS. A REVIEW1

1974 ◽  
Vol 37 (10) ◽  
pp. 487-493 ◽  
Author(s):  
John H. Pasch
Keyword(s):  
Nosocomial Infections ◽  
Food Supply ◽  
Pathogenic Bacteria ◽  
Food Service ◽  
Pathogenic Microorganisms ◽  
Employee Education ◽  
Burn Victims ◽  
Potential Source ◽  
Hospital Equipment ◽  
Food Bacteria

Persons entering a hospital are often more susceptible to infection than normal persons because of their debilitated condition. The hospital food supply is a potential source of infectious pathogenic microorganisms. Three infectious bacteria are of particular concern because of their ubiquitous nature and heartiness. They are Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. Transfer of microorganisms to patients via hospital food supplies can occur in three ways. First, pathogenic bacteria can be brought in on food itself. If food is not cooked, as is true of many fruits and some vegetables, bacteria can be transferred from the food to the patient. Second, food service personnel may be carriers of pathogenic organisms that can contaminate food and then be transferred to the patient via the food supply. Third, mishandling of food by improper or insufficient heating, refrigeration, or storage can result in foodborne illness. Beside food, bacteria that cause nosocomial infections can come from such sources as hospital personnel (nurses, doctors, etc.), general hospital equipment, and burn victims. Proper food handling together with adequate employee education are probably the most practical means to control the problem of nosocomial infections resulting from hospital food.

Changes in the Population Density of Pathogenic Microorganisms in Response to the Allelopathic Effect of Thypha Latifolia

2014 ◽  
Vol 1 (1) ◽  
pp. 31-36 ◽  
Author(s):  
O. Zhukorskiy ◽  
O. Gulay ◽  
V. Gulay ◽  
N. Tkachuk
Keyword(s):  
Cell Density ◽  
Allelopathic Effect ◽  
Pathogenic Microorganisms ◽  
Sterile Water ◽  
Erysipelothrix Rhusiopathiae ◽  
Pathogenic Leptospira ◽  
Favorable Conditions ◽  
And Control ◽  
The Impact ◽  
Control Samples

Aim. To determine the response of the populations of Erysipelothrix rhusiopathiae and Leptospira interrogans pathogenic microorganisms to the impact of broadleaf cattail (Thypha latifolia) root diffusates. Methods. Aqueous solutions of T. latifolia root diffusates were sterilized by vacuum fi ltration through the fi lters with 0.2-micron pore diameter. The experimental samples contained cattail secretions, sterile water, and cultures of E. rhusiopathiae or L. interrogans. The same amount of sterile water, as in the experimental samples, was used for the purpose of control, and the same quantity of microbial cultures was added in it. After exposure, the density of cells in the experimental and control samples was determined. Results. Root diffusates of T. latifolia caused an increase in cell density in the populations of E. rhusiopathiae throughout the whole range of the studied dilutions (1:10–1:10000). In the populations of the 6 studied serological variants of L. interrogans spirochetes (pomona, grippotyphosa, copenhageni, kabura, tarassovi, canicola), the action of broadleaf cattail root diffusates caused the decrease in cell density. A stimulatory effect was marked in the experimental samples of the pollonica serological variant of leptospira. Conclusions. The populations of E. rhusiopathiae and L. interrogans pathogenic microorganisms respond to the allelopathic effect of Thypha latifolia by changing the cell density. The obtained results provide the background to assume that broadleaf cattail thickets create favorable conditions for the existence of E. rhusiopathiae pathogen bacteria. The reduced cell density of L. interrogans in the experimental samples compared to the control samples observed under the infl uence of T. latifolia root diffusates suggests that reservoirs with broadleaf cattail thickets are marked by the unfavorable conditions for the existence of pathogenic leptospira (except L. pollonica).

Isolation of Epigallocatechin Gallate from Green Tea and its Effects on Probiotics and Pathogenic Bacteria

2017 ◽  
Vol 17 (1) ◽  
pp. 69-77
Author(s):  
Tu Lijun ◽  
Sun Hanju ◽  
He Shudong ◽  
Zhu Yongsheng ◽  
Yu Ming ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Escherichia Coli ◽  
Green Tea ◽  
Lactobacillus Acidophilus ◽  
Pathogenic Bacteria ◽  
Epigallocatechin Gallate ◽  
Microbial Populations ◽  
Medium Ph ◽  
Bioactive Substance ◽  
Tea Extract

The aim of this study was to investigate epigallocatechin gallate (EGCG) prebiotics activities systematically which was reported as a bioactive substance. Therefore, EGCG was separated by water extraction, resin purification and prep-HPLC. Then the production of EGCG was confirmed by HPLC and mass spectrometry (MS) analysis and its purify was 97.23%. EGCG extractive and green tea extract (GTE) were further incubated with Bifidobacterium infantis, B. adolescentis, B. bifidum and Lactobacillus acidophilus to study its effect on microbial populations and medium pH. Finally, Escherichia coli, Salmonella, Staphylococcus aureus and Candida albicans were employed as pathogenic bacteria to explore the antimicrobial activity of EGCG and GTE. The results demonstrated that EGCG extractive could be beneficial for the proliferation of Bifidobacterium and L. acidophilus and also inhibit some pathogenic bacteria. In conclusion, both EGCG extractive and GTE had prebiotics activities and the effects of EGCG extractive were superior to those of GTE.

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