Comparison of Sodium Hypochlorite–Based Foam and Peroxyacetic Acid–Based Fog Sanitizing Procedures in a Salmon Smokehouse: Survival of the General Microflora and Listeria monocytogenes†

2003 ◽  
Vol 66 (4) ◽  
pp. 592-598 ◽  
Author(s):  
DORTHE BAGGE-RAVN ◽  
KELNA GARDSHODN ◽  
LONE GRAM ◽  
BIRTE FONNESBECH VOGEL
Keyword(s):  
Listeria Monocytogenes ◽  
Sodium Hypochlorite ◽  
Random Amplified Polymorphic Dna ◽  
Plate Count ◽  
Peroxyacetic Acid ◽  
Bacterial Strains ◽  
Biochemical Tests ◽  
Gram Positive Bacteria ◽  
Bacillus Spp ◽  
Aerobic Plate Count

The effects of fog sanitization with peroxyacetic acid (hydrogen peroxide, peracetic acid, and acetic acid in combination) on general hygiene (aerobic plate count) and on Listeria monocytogenes were assessed in a slicing area at a salmon smokehouse and compared with the effects of foam sanitization with sodium hypochlorite (routinely performed at the smokehouse). Two hundred twenty-three environmental samples were collected with sponges and swabs after each of the sanitization procedures, and 68 samples were collected during production. The total culturable aerobic plate count was determined for each sample, and a total of 288 bacterial strains were randomly isolated and tentatively identified to genus level by physiological and biochemical tests. The microflora was dominated by Neisseriaceae, Enterobacteriaceae, and lactic acid bacteria during production. Foam sanitization caused a change in the composition of the flora, with Pseudomonas spp. and Alcaligenes spp. being the dominant gram-negative bacteria and Kurthia spp. and Bacillus spp. being the surviving gram-positive bacteria. Bacteria were very sensitive to fog sanitization, and yeasts accounted for almost half of the surviving flora. By a selective isolation method, strains of L. monocytogenes were isolated and subsequently characterized by random amplified polymorphic DNA (RAPD) typing. Following foam sanitization, 14 to 42% of the samples contained <10 CFU per site, whereas 29 to 78% of the samples collected after fog sanitization contained this level of bacteria. The prevalence of L. monocytogeneswas unchanged, but L. monocytogenes was found only in poorly cleaned areas such as drains. The RAPD types for all positive samples were identical to the type that had persisted in the smokehouse since 1995, indicating the importance of drains as a niche.

scholarly journals Microbial Ecology Evaluation of an Iberian Pig Processing Plant through Implementing SCH Sensors and the Influence of the Resident Microbiota on Listeria monocytogenes

2019 ◽  
Vol 9 (21) ◽  
pp. 4611 ◽  
Author(s):  
Anne-Sophie Hascoët ◽  
Carolina Ripolles-Avila ◽  
Alfons Eduard Guerrero-Navarro ◽  
José Juan Rodríguez-Jerez
Keyword(s):  
Listeria Monocytogenes ◽  
Foodborne Pathogens ◽  
Food Industry ◽  
Control Strategies ◽  
Plate Count ◽  
Processing Plant ◽  
Biochemical Tests ◽  
Bacillus Spp ◽  
Iberian Pig ◽  
Cleaning And Disinfection

There is a whole community of microorganisms capable of surviving the cleaning and disinfection processes in the food industry. These persistent microorganisms can enhance or inhibit biofilm formation and the proliferation of foodborne pathogens. Cleaning and disinfection protocols will never reduce the contamination load to 0; however, it is crucial to know which resident species are present and the risk they represent to pathogens, such as Listeria monocytogenes, as they can be further used as a complementary control strategy. The aim of this study was to evaluate the resident surface microbiota in an Iberian pig processing plant after carrying out the cleaning and disinfection processes. To do so, surface sensors were implemented, sampled, and evaluated by culture plate count. Further, isolated microorganisms were identified through biochemical tests. The results show that the surfaces are dominated by Bacillus spp., Pseudomonas spp., different enterobacteria, Mannheimia haemolytica, Rhizobium radiobacter, Staphylococcus spp., Aeromonas spp., lactic acid bacteria, and yeasts and molds. Moreover, their probable relationship with the presence of L. monocytogenes in three areas of the plant is also explained. Further studies of the resident microbiota and their interaction with pathogens such as L. monocytogenes are required. New control strategies that promote the most advantageous profile of microorganisms in the resident microbiota could be a possible alternative for pathogen control in the food industry. To this end, the understanding of the resident microbiota on the surfaces of the food industry and its relation with pathogen presence is crucial.

scholarly journals Isolation and identification of halophilic and halotolerant bacteria from the sediments of the Qeshm Island mangrove forest

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Pegah Javid ◽  
Hassan Zadabbas Shahabadi ◽  
Homeyra Amirkhani ◽  
Narges Amrollahi ◽  
Mohammad Sharif Ranjbar
Keyword(s):  
Halophilic Bacteria ◽  
Mangrove Forests ◽  
Bacterial Strains ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
Qeshm Island ◽  
Gram Positive ◽  
Halotolerant Bacteria ◽  
Gram Positive Bacteria ◽  
Phylogenetic Taxonomy

Due to specific environmental and ecological conditions, mangrove forests are known as marine transitional zones between sea and land, and, as such, they host organisms with high ecological plasticity. The mangrove forests of Qeshm Island (Iran) are relatively pristine habitats and represent an ideal target for investigating patterns of either aquatic or benthic biodiversity. To provide insights on microbial diversity in this area, nineteen halophilic and halotolerant bacteria were isolated from the sediments in 2017 during low tide. The extracted bacterial strains were studied morphologically by streaking, initial observation of colonies and bacterial staining, and characterized using a battery of biochemical tests including KOH, MR, VP, urease, TSI, S/I/M, Mac, LIA, ODC, ADH, oxidase, catalase, and tryptophan deaminase. The optimum growth of halophilic bacteria was observed in salt concentrations from 5 to 20% NaCl, whereas the extreme halophilic Gram-positive strain grew in salt concentration of up to 30% NaCl. Molecular analyses were also carried out on four halophilic strains and one extreme halophilic gram-positive bacteria. Phylogenetic taxonomy analysis, after 16S rDNA gene Sanger sequencing, revealed that the halophilic bacteria were closely related to the strain types of the genus Bacillus including Bacillus licheniformis, Bacillus velezensis, Bacillus Paralicheniformis and Bacillus sp. with 99% bootstrap value. The extreme halophilic strain was associated to strains of Planococcus plakortidis with 100% bootstrap value.

Efficacy of Sodium Hypochlorite and Peroxyacetic Acid To Reduce Murine Norovirus 1, B40-8, Listeria monocytogenes, and Escherichia coli O157:H7 on Shredded Iceberg Lettuce and in Residual Wash Water

2009 ◽  
Vol 72 (5) ◽  
pp. 1047-1054 ◽  
Author(s):  
LEEN BAERT ◽  
ISABELLE VANDEKINDEREN ◽  
FRANK DEVLIEGHERE ◽  
ELS VAN COILLIE ◽  
JOHAN DEBEVERE ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Sodium Hypochlorite ◽  
Tap Water ◽  
Bacterial Pathogens ◽  
Wash Water ◽  
Escherichia Coli O157 ◽  
Murine Norovirus ◽  
Peroxyacetic Acid ◽  
Iceberg Lettuce

The efficiency of sodium hypochlorite (NaOCl) and peroxyacetic acid (PAA) to reduce murine norovirus 1 (MNV-1), a surrogate for human norovirus, and Bacteroides fragilis HSP40–infecting phage B40-8 on shredded iceberg lettuce was investigated. The levels of removal of viruses MNV-1 and B40-8 were compared with the reductions observed for bacterial pathogens Listeria monocytogenes and Escherichia coli O157:H7. Two inoculation levels, one with a high organic load and the other containing a 10-fold lower number of pathogens and organic matter, showed that the effectiveness of NaOClwas greatly influenced by the presence of organic material, which was not observed for PAA. Moreover, the present study showed that 200 mg/liter NaOCl or 250 mg/liter PAA is needed to obtain an additional reduction of 1 log (compared with tap water) of MNV-1 on shredded iceberg lettuce, whereas only 250 mg/liter PAA achieved this for bacterial pathogens. None of the treatments resulted in a supplementary 1-log PFU/g reduction of B40-8 compared with tap water. B40-8 could therefore be useful as an indicator of decontamination processes of shredded iceberg lettuce based on NaOCl or PAA. Neither MNV-1, B40-8, nor bacterial pathogens could be detected in residual wash water after shredded iceberg lettuce was treated with NaOCl and PAA, whereas considerable numbers of all these microorganisms were found in residual wash water consisting solely of tap water. This study illustrates the usefulness of PAA and NaOCl in preventing cross-contamination during the washing process rather than in causing a reduction of the number of pathogens present on lettuce.

scholarly journals Microbial Assessment of Selected, Locally- Fermented and Ready-to-eat Cassava Products Sold in Lokoja, Nigeria

2019 ◽  
pp. 1-9
Author(s):  
O. N. Akoma ◽  
C. M. Ononugbo ◽  
C. C. Eze ◽  
K. I. Chukwudozie ◽  
J. O. Ogwu
Keyword(s):  
Plate Count ◽  
Economic Disadvantage ◽  
Salmonella Spp ◽  
Coliform Count ◽  
Food Borne ◽  
Bacillus Spp ◽  
Microbial Analysis ◽  
Aerobic Plate Count ◽  
And Storage ◽  
Penicillium Spp

This study was conducted to assess the microbiological safety of locally-fermented, ready-to-eat cassava products, namely garri and ‘fufu’, in Lokoja. A total of sixty samples comprising; twenty white garri, twenty yellow garri and twenty fufu were subjected to microbial analysis. The samples were serially diluted to 10-4 and appropriate dilutions inoculated by spread plate method into Nutrient agar, MacConkey agar and Potato Dextrose agar plates which were used for total aerobic plate count (TAPC), coliform count (CC) and fungal count respectively. The TAPC for white garri ranged from 0.78 to 3.83 log cfu/g, the coliform count ranged from no growth (NG) to 3.80 log cfu/g, while the mean fungal count ranged from 1.96 to 3.39 log cfu/g. The TAPC for yellow garri ranged from 2.04 to 3.95 log cfu/g, the coliform count ranged from NG to 3.62 log cfu/g and the fungal count ranged from 2.08 to 3.44 log cfu/g. The TAPC of fufu was within the range of 1.07 to 3.70 log cfu/g, the coliform count ranged from NG to 3.48 log cfu/g and the fungal count ranged from 1.94 to 2.78 log cfu/g. The bacteria isolated include Bacillus spp., Enterobacter spp., Pseudomonas spp., Staphylococcus aureus, Salmonella spp., Escherichia coli and Klebsiella spp. The fungi isolated from the study samples include Aspergillus niger, Cladosporium spp., Fusarium spp., Rhizopus spp., Alternaria spp., Montospora spp., and Penicillium spp. The pH of the samples ranged from 4.02 to 4.96 in white garri, 4.02 to 4.99 in yellow garri, and 5.02 to 6.44 in fufu. Findings showed that these widely consumed fermented (ready-to-eat) cassava products presents (may represent) a serious risk and route for transmission of food borne pathogens to consumers and generally huge economic disadvantage to food handlers. Improving manufacturing, packaging and storage practices in garri production and for public health purposes are strongly encouraged.

Microbiological Quality of Foodservice Menu Items Produced and Stored by Cook/Chill, Cook/Freeze, Cook/Hot-Hold and Heat/Serve Methods1

1984 ◽  
Vol 47 (11) ◽  
pp. 876-885 ◽  
Author(s):  
P. O. SNYDER ◽  
M. E. MATTHEWS
Keyword(s):  
Fast Food ◽  
Microbiological Quality ◽  
Fecal Coliforms ◽  
Plate Count ◽  
Clostridium Sporogenes ◽  
Bacillus Spp ◽  
Health Significance ◽  
Aerobic Plate Count ◽  
Initial Heating

Microbiological quality of menu items prepared by cook/chill, cook/freeze, cook/hot-hold and heat/serve methods for producing and storing menu items in foodservice systems is reviewed. Of the 40 studies, 21 focused on the cook/chill method and two on the heat/serve. Nine studies on the microbiological quality of delicatessen and fast food were also reviewed. Microbiological evaluation included total plate count, mesophilic aerobic plate count, psychrotrophic aerobic plate count, streptococcal count, staphylococcal count, clostridial count, coliforms, fecal coliforms, yeast and mold, Clostridium perfringens, Staphylococcus aureus, Escherichia coli, Clostridium sporogenes, Streptococcus faecium, Staphylococcus epidermidis, Bacillus cereus, Bacillus spp., coagulase-positive staphylococci, fecal streptococci and Salmonella. In 29 of the studies, heat was applied to menu items at one or more process steps - initial heating, hot-holding and/or final heating. Initial heating temperatures for entrees ranged from 45 to 90°C, while final heating temperatures ranged from 23 to 98°C. Times ranged from 15 to 90 min for initial heating and 0.33 to 35 min for final heating. Continued research is needed to provide data on effects of time and temperature on the microbiological quality of menu items. Such data will provide foodservice practitioners with adequate assurance that chosen thermal processing methods destroy microorganisms of public health significance.

Impact of Mannanase-Producing Bacillus spp. on the Accuracy of the 3M Petrifilm Aerobic Count Method

2017 ◽  
Vol 80 (7) ◽  
pp. 1117-1122
Author(s):  
Guoping Feng ◽  
Amanda Hew ◽  
Ramesh Manoharan ◽  
Siva Subramanian
Keyword(s):  
Guar Gum ◽  
Negative Impact ◽  
Gelling Agent ◽  
Plate Count ◽  
Root Cause ◽  
Bacillus Spp ◽  
Aerobic Plate Count ◽  
Relationship Of ◽  
Diffusion Assay

ABSTRACTConsistent deviations of the 3M Petrifilm aerobic counts (AC) from the standard pour plate aerobic plate count (APC) were observed with dehydrated onion and garlic products. A large study was designed to determine the relationship of these two methods and the root cause for the deviations. A total of 3,800 dehydrated onion and garlic samples were analyzed by both the Petrifilm AC and the standard pour plate APC method. Large spreader-like liquefied areas were observed on numerous Petrifilm plates. These liquefied areas made enumeration inaccurate. “Liquefier” microorganisms from Petrifilm plates were isolated and identified to species level by 16S rRNA and gyrB gene sequencing. Enzyme diffusion assay was performed to determine potential enzymatic degradation of guar gum, the gelling agent used in Petrifilm plates. The results indicated that the correlation between Petrifilm AC and standard APC is relatively low. Paired t test results suggested that the Petrifilm AC method produced significantly different results compared with standard APC. The discrepancies were attributable at least partly to a liquefier organism that hydrolyzed guar gum, leading to liquefaction. Liquefaction of Petrifilm plates seems to have two effects on accuracy: (i) liquefied areas may allow motile organisms to move and multiply in the liquefied area during the incubation period, yielding more than one colony from one cell and, as a result, leading to overestimation of the microbial load and (ii) the blurred areas obscure other colonies, leading to potential underestimation. The liquefier organism was identified as Bacillus amyloliquefaciens, a potent mannanase producer and heat-resistant spore former. Enzyme diffusion assay confirmed that mannanase contained in the cell-free supernatant of B. amyloliquefaciens can hydrolyze the 1,4-β-mannopyranosyl bond, the backbone of guar gum. This is the first report of the role of B. amyloliquefaciens in the liquefaction of Petrifilm plates and its negative impact on accuracy.

Controlling Attachment and Growth of Listeria monocytogenes in Polyvinyl Chloride Model Floor Drains Using a Peroxide Chemical, Chitosan-Arginine, or Heat†

2014 ◽  
Vol 77 (12) ◽  
pp. 2129-2132 ◽  
Author(s):  
MARK E. BERRANG ◽  
CHARLES L. HOFACRE ◽  
JOSEPH F. FRANK
Keyword(s):  
Listeria Monocytogenes ◽  
Polyvinyl Chloride ◽  
Hot Water ◽  
Plate Count ◽  
Processing Plant ◽  
Peroxyacetic Acid ◽  
Planktonic Cells ◽  
Log Reduction ◽  
Before And After ◽  
Poultry Processing

Listeria monocytogenes can colonize a poultry processing plant as a resident in floor drains. Limiting growth and attachment to drain surfaces may help lessen the potential for cross-contamination of product. The objective of this study was to compare a hydrogen peroxide-peroxyacetic acid–based chemical to chitosan-arginine or heat to prevent attachment of or destroy existing L. monocytogenes on the inner surface of model floor drains. L. monocytogenes was introduced to result in about 109 planktonic and attached cells within untreated polyvinyl chloride model drain pipes. Treatments (0.13% peroxide-based sanitizer, 0.1% chitosan-arginine, or 15 s of hot water at 95 to 100°C) were applied immediately after inoculation or after 24 h of incubation. Following treatment, all pipes were incubated for an additional 24 h; planktonic and attached cells were enumerated by plate count. All treatments significantly (P < 0.05) lowered numbers of planktonic and attached cells recovered. Chitosan-arginine resulted in approximately a 6-log reduction in planktonic cells when applied prior to incubation and a 3-log reduction after the inoculum had a chance to grow. Both heat and peroxide significantly outperformed chitosan-arginine (8- to 9-log reduction) and were equally effective before and after incubation. Heat was the only treatment that eliminated planktonic L. monocytogenes. All treatments were less effective against attached cells. Chitosan-arginine provided about a 4.5-log decrease in attached cells when applied before incubation and no significant decrease when applied after growth. Like with planktonic cells, peroxide–peroxyacetic acid and heat were equally effective before or after incubation, causing decreases ranging from 7 to 8.5 log for attached L. monocytogenes. Applied at the most efficacious time, any of these techniques may lessen the potential for L. monocytogenes to remain as a long-term resident in processing plant floor drains.

Quantitative Comparison of Two Enrichment Methods for Isolating Listeria monocytogenes from Seafoods

1991 ◽  
Vol 54 (1) ◽  
pp. 7-11 ◽  
Author(s):  
JOSEPH LOVETT ◽  
DAVID W. FRANCIS ◽  
JAMES T. PEELER ◽  
ROBERT M. TWEDT
Keyword(s):  
Listeria Monocytogenes ◽  
Drug Administration ◽  
Clinical Sample ◽  
Quantitative Comparison ◽  
Plate Count ◽  
Department Of Agriculture ◽  
Standard Procedures ◽  
Aerobic Plate Count ◽  
The U.S ◽  
Enrichment Methods

Two enrichment methods that had been used as standard procedures by the U.S. Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA) were quantitatively compared for their ability to isolate Listeria monocytogenes from seafoods. Cultures of a clinical sample and a seafood isolate were inoculated into raw and cooked shrimp; cultures heated at 57.8°C for 5 min were added to surimi, cooked crabmeat, and cooked shrimp. With the FDA procedure, which used enrichment intervals of 24 h, 48 h, and 7 d, KOH culture treatment and enrichment for 24 h provided no advantage for Listeria recovery. The FDA procedure isolated heated L. monocytogenes from seafoods at a lower level than the USDA method; however, the two methods isolated unheated cells equally well. The greater selectivity of the USDA procedure may offer an advantage for isolating nonheat-stressed Listeria when the aerobic plate count of the product is high.

Effects of Tea Polyphenols, Lysozyme and Chitosan on Improving Preservation Quality of Pomfret Fillet

2013 ◽  
Vol 781-784 ◽  
pp. 1582-1588 ◽  
Author(s):  
Jian Bing Shi ◽  
Jing Xie ◽  
Zhi Li Gao ◽  
Liu Li ◽  
Qing Xiong ◽  
...  
Keyword(s):  
Shelf Life ◽  
Ph Value ◽  
Tea Polyphenols ◽  
Plate Count ◽  
Control Group ◽  
Treatment Groups ◽  
Gram Positive Bacteria ◽  
Aerobic Plate Count ◽  
The Impact

The purpose of this study was to evaluate the impact of different concentrations of tea polyphenols (A1: 0.1%(w/v), A2: 0.5%, A3: 1%), lysozyme (B1: 0.01%, B2: 0.05%, B3: 0.08%) and chitosan (C1: 0.5%, C2: 1%, C3: 2%, C4: 3%) on the quality of pomfret during the storage in order to improve the quality of pomfret fresh preservation. The sensory evaluation, aerobic plate count (APC), trimethylamine (TMA), total volatile basis nitrogen (TVB-N),Kvalue and pH value with different treatments were determined. The results showed that the shelf-life of the control group was 4 days under the cold storage, and the effect of fresh preservation was better with the increasing of the concentration of tea polyphenols, especially the APC could be significantly lower under the treatment groups of A2 and A3 than that under the control group from the 2nd day (P<0.05), the shelf-life was increased by 2 to 3 days. The treatments of B1 and B2 could restrain the increasing of gram-positive bacteria and reduced the contain of TVB-N, TMA-N andKvalue significantly (P<0.05), the shelf-life was increased by 1 to 2 days. The preservation effect of the treatment of C3 was better than those of control group and other groups with chitosan. The APC, TMA-N, TVB-N andKvalue could be significantly lower than those of the control group from the 2nd day, so the shelf-life was increased by 3 days. All of tea polyphenols and chitosan could improve the quality of aquaculture and prolong the shelf-life of pomfret by restraining the increasing of APC and the enzyme activity. The results will offer theory reference to the preservation of pomfrets and the application of bio-preservative.

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