scholarly journals Transfer of Persistent Listeria monocytogenes Contamination between Food-Processing Plants Associated with a Dicing Machine

2002 ◽  
Vol 65 (7) ◽  
pp. 1129-1133 ◽  
Author(s):  
JANNE M. LUNDÉN ◽  
TIINA J. AUTIO ◽  
HANNU J. KORKEALA
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Sodium Hypochlorite ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Compound ◽  
Pfge Type ◽  
Ammonium Compound ◽  
Type I ◽  
Minimal Inhibitory Concentrations ◽  
Steel Surfaces

The possibility of the transfer of persistent Listeria monocytogenes contamination from one plant to another with a dicing machine was evaluated, and possible reasons for persistent contamination were analyzed. A dicing machine that diced cooked meat products was transferred from plant A to plant B and then to plant C. After the transfer of the dicing machine, L. monocytogenes PFGE type I, originally found in plant A, was soon also found in plants B and C. This L. monocytogenes PFGE type I caused persistent contamination of the dicing lines in plants B and C. The persistent L. monocytogenes strain and three nonpersistent L. monocytogenes strains found in the dicing line of plant C were tested for adherence to stainless steel surfaces and minimal inhibitory concentrations of a quaternary ammonium compound and sodium hypochlorite, disinfectants widely used in the dicing lines. The persistent strain showed significantly higher adherence to stainless steel surfaces than did the nonpersistent strains. The minimal inhibitory concentrations of sodium hypochlorite were similar for all strains, and the minimal inhibitory concentrations of the quaternary ammonium compound for three of the L. monocytogenes PFGE types, including the persistent PFGE type, were high. All persistent L. monocytogenes PFGE type I isolates were found in an area with high hygienic standards, with the dicing machine being the first point of contamination. These observations show that the dicing machine sustained the contamination and suggest that the dicing machine transferred the persistent L. monocytogenes PFGE type from one plant to another.

scholarly journals Comparison of three neutralizing broths for environmental sampling of low levels of Listeria monocytogenes desiccated on stainless steel surfaces and exposed to quaternary ammonium compounds

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Fengmin Li ◽  
Zhihan Xian ◽  
Hee Jin Kwon ◽  
Jiyoon Yoo ◽  
Laurel Burall ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Quaternary Ammonium ◽  
Storage Conditions ◽  
Ammonium Compound ◽  
Environmental Sampling ◽  
High Concentration ◽  
Environmental Test ◽  
Steel Surfaces ◽  
Low Levels

Abstract Background An effective environmental sampling method involves the use of a transport/neutralizing broth with the ability to neutralize sanitizer residues that are collected during sampling and to maintain viability of stressed Listeria monocytogenes (Lm) cells. Results We applied Lm onto stainless steel surfaces and then subjected Lm to desiccation stress for 16–18 h at room temperature (RT, 21–24 °C). This was followed by the subsequent application of Whisper™ V, a quaternary ammonium compound (QAC)-based sanitizer, diluted to 400 ppm and 8000 ppm of active quat, for 6 h. We then sampled Lm with sponges pre-moistened in three transport broths, Dey/Engley (D/E) broth, Letheen broth and HiCap™ broth, to generate environmental samples that contained sanitizer residues and low levels of stressed Lm, which were subsequently analyzed by an enrichment-based method. This scheme conformed with validation guidelines of AOAC International by using 20 environmental test portions per broth that contained low levels of Lm such that not all test portions were positive (i.e., fractional positive). We showed that D/E broth, Letheen broth and HiCap™ broth performed similarly when no quat or 400 ppm of quat was applied to the Lm contaminating stainless steel surfaces. However, when 8000 ppm of quat was applied, Letheen broth did not effectively neutralize the QAC in the samples. These comparisons were performed on samples stored under three conditions after collection to replicate scenarios of sample transport, RT for 2 h, 4 °C for 24 h and 4 °C for 72 h. Comparisons under the three different scenarios generally reached the same conclusions. In addition, we further demonstrated that storing Letheen and HiCap™ broths at RT for two months before sampling did not reduce their capacity to neutralize sanitizers. Conclusions We developed a scheme to evaluate the ability of transport broths to neutralize QAC sanitizers. The three transport broths performed similarly with a commonly used concentration of quat, but Letheen broth could not effectively neutralize a very high concentration of QAC. The performance of transport broths was not significantly affected under the assessed pre-sampling and post-sampling storage conditions.

Destruction of Listeria monocytogenes by Sodium Hypochlorite and Quaternary Ammonium Sanitizers

1989 ◽  
Vol 52 (5) ◽  
pp. 306-311 ◽  
Author(s):  
A. MUSTAPHA ◽  
M. B. LIEWEN
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Sodium Hypochlorite ◽  
Quaternary Ammonium ◽  
Ammonium Compound ◽  
Electron Microscopic ◽  
Acidic Polysaccharide ◽  
Scanning Electron Microscopic ◽  
Dairy Plant

The antimicrobial effects of two commonly used dairy plant sanitizers on Listeria monocytogenes ATCC 7644 were studied. The two sanitizers used were commercial sodium hypochlorite and quaternary ammonium compound (QAC). The effects were studied on L. monocytogenes in vitro and on stainless steel chips inoculated with the organism. Cells were exposed to concentrations of 0, 50, 100, 200, 400, and 800 ppm chlorine and QAC for 1, 2, and 5 minutes, and neutralized with tryptic soy broth. Decreases in cell numbers ranged from 3-logs to >4-logs in vitro, whereas with the stainless steel, it ranged from 1-log to >4-logs. Scanning electron microscopic (SEM) studies were done to evaluate the attachment characteristics of L. monocytogenes as compared to those of Escherichia coli on stainless steel. L. monocytogenes was found to produce a fibrous-like material similar in appearance to acidic polysaccharide fibrils produced by Pseudomonas sp., which appeared to be removed by the sanitizer solutions.

Inactivation of Listeria monocytogenes by Disinfectants and Bacteriophages in Suspension and Stainless Steel Carrier Tests

2014 ◽  
Vol 77 (12) ◽  
pp. 2012-2020 ◽  
Author(s):  
N. CHAITIEMWONG ◽  
W. C. HAZELEGER ◽  
R. R. BEUMER
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Quaternary Ammonium ◽  
Antimicrobial Effect ◽  
Quaternary Ammonium Compound ◽  
Steel Plates ◽  
Ammonium Compound ◽  
Standard Requirement ◽  
Sodium Dichloroisocyanurate ◽  
Food Residues

To simulate food contact surfaces with pits or cracks, stainless steel plates with grooves (depths between 0.2 and 5 mm) were constructed. These plates were artificially contaminated with Listeria monocytogenes in clean conditions, with organic soiling, or after 14 days of biofilm formation after which inactivation of the pathogen by Suma Tab D4 (sodium dichloroisocyanurate, 240 and 300 mg/liter), Suma Bac D10 (quaternary ammonium compound, 740 mg/liter), and bacteriophage suspension (Listex P100) was determined. Both chemical disinfectants performed well in suspension tests and in clean carrier tests according to the European standard with a reduction of more than 5 and 4 log units, respectively, of Listeria cells after 5 min of contact time. However, for the plates with grooves, the reduction could not meet the standard requirement, although a higher reduction of L. monocytogenes was observed in the shallow grooves compared with the deeper grooves. Furthermore, presence of food residues and biofilm reduced the effect of the disinfectants especially in the deep grooves, which was dependent on type of food substrate. Bacteriophages showed the best antimicrobial effect compared with the chemical disinfectants (sodium dichloroisocyanurate and quaternary ammonium compound) in most cases in the shallow grooves, but not in the deep grooves. The chlorine based disinfectants were usually less effective than quaternary ammonium compound. The results clearly demonstrate that surfaces with grooves influenced the antimicrobial effect of the chemical disinfectants and bacteriophages because the pathogen is protected in the deep grooves. The use of bacteriophages to inactivate pathogens on surfaces could be helpful in limited cases; however, use of large quantities in practice may be costly and phage-resistant strains may develop.

Sensitivity of Listeria monocytogenes to Sanitizers after Exposure to a Chemical Shock

1996 ◽  
Vol 59 (4) ◽  
pp. 374-378 ◽  
Author(s):  
EUREKA L. PICKETT ◽  
ELSA A. MURANO
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Inhibitory Concentration ◽  
Quaternary Ammonium Compound ◽  
Ammonium Compound ◽  
Ph Adjustment ◽  
Lethal Level ◽  
Significant Difference ◽  
Subsequent Exposure ◽  
Steel Surfaces

We tested the hypothesis that exposure of Listeria monocytogenes to sublethal levels of sanitizers (chemical shock) could affect survival to a subsequent exposure to lethal levels and the ability of the cells to attach to stainless steel surfaces. L. monocytogenes was exposed to an acidic anionic sanitizer, a chlorine-based sanitizer, an iodophor, and a quaternary ammonium compound, as well as to citric, lactic, and propionic acids. The cells were exposed to sublethal levels of each sanitizer for up to 60 min (chemical shock), followed by exposure to either the minimum inhibitory concentration (MIC) for 48 h, to the lethal level for 48 h, or to the MIC for 40 min followed by the lethal level for 48 h. No significant difference in survival was observed with most of the sanitizers used. However, exposure to a chemical shock with the acid anionic sanitizer for at least 10 min resulted in survival of the cells in the MIC of this sanitizer, as well as in the lethal level, but only when the cells were first exposed to the MIC for 40 min. Deliberate dissociation of citric acid by pH adjustment also resulted in survival of chemically shocked cells to lethal levels of this acid, suggesting that exposure to the dissociated form somehow enabled cells to survive exposure to lethal levels of the acid. Chemical shock did not affect attachment of the cells to stainless-steel chips.

scholarly journals Prevalence and Detection of qac Genes from Disinfectant-Resistant Staphylococcus aureus Isolated from Salon Tools in Ishaka Town, Bushenyi District of Uganda

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Solange Gahongayire ◽  
Adamu Almustapha Aliero ◽  
Charles Drago Kato ◽  
Alice Namatovu
Keyword(s):  
Sodium Hypochlorite ◽  
Quaternary Ammonium ◽  
Bacterial Infections ◽  
Healthcare Providers ◽  
Quaternary Ammonium Compound ◽  
Diffusion Method ◽  
Ammonium Compound ◽  
Bacterial Strains ◽  
Microbiological Methods ◽  
Phenotypic Methods

Bacterial infections are on a rise with causal-resistant strains increasing the economic burden to both patients and healthcare providers. Salons are recently reported as one of the sources for transmission of such resistant bacterial strains. The current study aimed at the identification of the prevalent bacteria and characterization of quaternary ammonium compound (qac) genes from disinfectant-resistant S. aureus isolated from salon tools in Ishaka town, Bushenyi District of Uganda. A total of 125 swabs were collected from different salon tools (combs, brushes, scissors, clippers, and shaving machines), and prevalent bacteria were isolated using standard microbiological methods. Identification of isolated bacteria was done using standard phenotypic methods including analytical profile index (API). Susceptibility patterns of the isolated bacteria to disinfectant were determined using the agar well diffusion method. Quaternary ammonium compound (qac) genes (qacA/B and qacC) associated with disinfectant resistances were detected from disinfectant-resistant S. aureus using multiplex polymerase chain reaction (PCR) and Sanger sequencing methods. Of the 125 swab samples collected from salons, 78 (62.4%) were contaminated with different bacteria species. Among the salon tools, clippers had the highest contamination of 20 (80.0%), while shaving machines had the lowest contamination of 11 (44.0%). The most prevalent bacteria identified were Staphylococcus epidermidis (28.1%) followed by S. aureus (26.5%). Of all the disinfectants tested, the highest resistance was shown with sodium hypochlorite 1%. Out of the eight (8) disinfectant-resistant S. aureus analysed for qac genes, 2 (25%) isolates (STP6 and STP9) were found to be qacA/B positive, while 2 (25%) isolates (STP8 and STP9) were found to be qacC gene positive. This study has shown that bacterial contamination of salon tools is common, coupled with resistance to disinfectants with sodium hypochlorite resistance being more common. Furthermore, observed resistance was attributed to the presence of qac genes among S. aureus isolates. A search for qac genes for disinfectant resistance from other bacteria species is recommended.

Effectiveness of Sanitation with Quaternary Ammonium Compound or Chlorine on Stainless Steel and Other Domestic Food-Preparation Surfaces

1997 ◽  
Vol 60 (1) ◽  
pp. 43-47 ◽  
Author(s):  
JOSEPH F. FRANK ◽  
REVIS A. N. CHMIELEWSKI
Keyword(s):  
Stainless Steel ◽  
Quaternary Ammonium ◽  
Test Procedure ◽  
Food Service ◽  
Quaternary Ammonium Compound ◽  
Ammonium Compound ◽  
Relative Ability ◽  
Polished Stainless Steel ◽  
Materials Used ◽  
Type 304

The relative ability of various materials used for domestic and/or food-service sinks and countertops to be sanitized was determined. Both smooth (unused) and abraded surfaces were tested by exposure to 200 mg of quaternary ammonium compound per liter or 200 mg of sodium hypochlorite per liter. Surface materials tested included mechanically polished (type 304, #4 finish) and electropolished stainless steel, polycarbonate, and mineral resin. Surfaces were prepared for testing by allowing attachment of a Staphylococcus aureus culture for 4 h to achieve an initial attached population of 104 to 105 CFU/cm2. The test procedure involved immersion of the surface in sanitizer solution followed by wiping with a sanitizer-saturated cloth. Residual staphylococci were detected by overlaying agar directly on the treated surface. Results indicated that the stainless steels and the smooth polycarbonate, which had 0.5 log CFU/cm2 or fewer of residual staphylococci, were more readily sanitized by quaternary ammonium compound than were either the mineral resin surfaces, which had nearly 2.0 log CFU/cm2 of residual staphylococci, or the abraded polycarbonate which had nearly 1.0 log CFU/cm2 of residual staphylococci. Chlorine was most effective on the mechanically polished stainless steel, the unabraded electropolished stainless steel, and the polycarbonate surfaces, reducing cell populations to less than 1.0 log CFU/cm2. Chlorine was less effective on abraded electropolished stainless steel and mineral resin surfaces, where populations remained greater than 1.0 log CFU/cm2. Sanitation with quaternary ammonium compound or chlorine reduced S. aureus populations more than 1,000-fold on all surfaces except unabraded mineral resin.

The Effect of Blood on the Antiviral Activity of Sodium Hypochlorite, a Phenolic, and a Quaternary Ammonium Compound

1999 ◽  
Vol 20 (12) ◽  
pp. 821-827 ◽  
Author(s):  
David J. Weber ◽  
Susan L. Barbee ◽  
Mark D. Sobsey ◽  
William A Rutala
Keyword(s):  
Sodium Hypochlorite ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Compound ◽  
Final Concentration ◽  
Ammonium Compound ◽  
Complete Inactivation ◽  
Test Organisms ◽  
Viral Survival ◽  
Simplex Virus

AbstractObjective:To assess the virucidal activity of three disinfectants (sodium hypochlorite, a phenolic, and a quaternary ammonium compound) in the presence and absence of blood.Methods:Disinfectants at varying concentrations (hypochlorite: 5,000, 500, or 50 ppm; phenolic: 1:10 or 1:128 dilution; quaternary ammonium compound: 1:10 or 1:128 dilution) were added to either saline or whole blood (final concentration, 80% or 20% blood) and mixed. Test organisms included an attenuated vaccine strain of poliovirus type 1 (prototype for relatively resistant hydrophilic viruses) and herpes simplex virus (HSV) type 1 (prototype for relatively susceptible lipophilic viruses). Virus was added to create a viral-blood suspension. Viral survival was tested at room temperature at the following times: 0, 15 seconds, 30 seconds, 1 minute, 2 minutes, 5 minutes, and 10 minutes. A neutralizer stopped the reaction, and virus was assayed using a plaque technique.Results:In the absence of blood, complete inactivation of HSV was achieved within 30 seconds with 5,000 (1:10 dilution of bleach) and 500 (1:100 dilution of bleach) ppm chlorine, 1:10 and 1:128 diluted phenolic (use dilution), and 1:10 and 1:128 diluted quaternary ammonium compound (use dilution). In the presence of 80% blood, only 5,000 ppm hypochlorite, 1:10 phenolic, and 1:10 or 1:128 quaternary ammonium compound were effective. In the absence of blood, complete inactivation of polio was achieved within 30 seconds by 5,000 and 500 ppm chlorine and 1:10 quaternary ammonium compound. In the presence of 80% blood, no solution tested was capable of completely inactivating poliovirus within 10 minutes.Conclusions:Our data suggest that, in the absence of visible blood, environmental surfaces may be disinfected with a diluted hypochlorite solution (1:10 or 1:100), a phenolic, or a quaternary ammonium compound. Based on our studies using HSV, which has similar susceptibilities to disinfectants as human immunodeficiency virus (HIV), phenolics at their use dilution and 1:100 diluted hypochlorite are unlikely to inactivate HIV or hepatitis B virus reliably in the presence of blood. Hypochlorite at a final concentration of 5,000 ppm (1:10 dilution) should be used to decontaminate blood spills, but, even after decontamination, care should be used to avoid sharps injuries.

scholarly journals Genetic Subtyping, Biofilm-Forming Ability and Biocide Susceptibility of Listeria monocytogenes Strains Isolated from a Ready-to-Eat Food Industry

Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 416
Author(s):  
Joana Catarina Andrade ◽  
António Lopes João ◽  
Carlos de Sousa Alonso ◽  
António Salvador Barreto ◽  
Ana Rita Henriques
Keyword(s):  
Listeria Monocytogenes ◽  
Quaternary Ammonium ◽  
Benzalkonium Chloride ◽  
Food Industry ◽  
Raw Materials ◽  
Foodborne Pathogen ◽  
Positive Association ◽  
Quaternary Ammonium Compound ◽  
Ammonium Compound ◽  
Food Grade

Listeria monocytogenes is a foodborne pathogen of special concern for ready-to-eat food producers. The control of its presence is a critical step in which food-grade sanitizers play an essential role. L. monocytogenes is believed to persist in food processing environments in biofilms, exhibiting less susceptibility to sanitizers than planktonic cells. This study aimed to test the susceptibility of L. monocytogenes in planktonic culture and biofilm to three commercial food-grade sanitizers and to benzalkonium chloride; together with the genetic subtyping of the isolates. L. monocytogenes isolates were collected from raw materials, final products and food-contact surfaces during a 6-year period from a ready-to-eat meat-producing food industry and genetically characterized. Serogrouping and pulsed-field gel electrophoresis (PFGE) revealed genetic variability and differentiated L. monocytogenes isolates in three clusters. The biofilm-forming ability assay revealed that the isolates were weak biofilm producers. L. monocytogenes strains were susceptible both in the planktonic and biofilm form to oxidizing and ethanol-based compounds and to benzalkonium chloride, but not to quaternary ammonium compound. A positive association of biofilm-forming ability and LD90 values for quaternary ammonium compound and benzalkonium chloride was found. This study highlights the need for preventive measures improvement and for a conscious selection and use of sanitizers in food-related environments to control Listeria monocytogenes.

Virucidal Efficacy of Four New Disinfectants

2002 ◽  
Vol 38 (3) ◽  
pp. 231-234 ◽  
Author(s):  
Nasser Z. Eleraky ◽  
Leon N.D. Potgieter ◽  
Melissa A. Kennedy
Keyword(s):  
Sodium Hypochlorite ◽  
Chlorine Dioxide ◽  
Quaternary Ammonium ◽  
Tap Water ◽  
Quaternary Ammonium Compound ◽  
Feline Calicivirus ◽  
Ammonium Compound ◽  
Feline Parvovirus ◽  
Virucidal Efficacy ◽  
Potassium Peroxymonosulfate

Virucidal efficacy was evaluated for four recently available disinfectants: chlorine dioxide, potassium peroxymonosulfate, a quaternary ammonium compound, and citricidal (grapefruit extract). Sodium hypochlorite (3%) and tap water were used as positive and negative controls respectively. Feline herpesvirus, feline calicivirus, and feline parvovirus were exposed to the manufacturers’ recommended dilutions of the evaluated disinfectants. Both chlorine dioxide and potassium peroxymonosulfate completely inactivated the three viruses used in this study. These disinfectants can aid in controlling nosocomial transmission of viruses with less of the deleterious effects of sodium hypochlorite. The quaternary ammonium compound evaluated in this study and citricidal were not effective against feline calicivirus and feline parvovirus.

Sign in / Sign up

Export Citation Format

Share Document