Comparison between the Vitek Immunodiagnostic Assay System and PCR for the Detection of Pathogenic Microorganisms in an Experimental Dry Sausage during Its Curing Process

2009 ◽  
Vol 72 (9) ◽  
pp. 1977-1981 ◽  
Author(s):  
R. PRIEGO ◽  
L. M. MEDINA ◽  
R. JORDANO

The comparison between the Vitek Immunodiagnostic Assay System (VIDAS) and PCR methods for the detection of the pathogenic microorganisms Salmonella Typhimurium, Listeria monocytogenes, Escherichia coli O157:H7, Clostridium perfringens, and Staphylococcus aureus in salchichón (a type of Spanish fermented dry sausage) was studied. The automated mini-VIDAS method and the PCR method were used to detect the presence of these microorganisms in 90 samples grouped into six batches (one control batch, and five batches inoculated with Salmonella Typhimurium, L. monocytogenes, E. coli O157:H7, S. aureus, and C. perfringens, respectively). The determinations were carried out on fresh sausage, semicured (14 days), and finished product (28 days of curing). The concordance between both methods was 100%. For salchichón-type sausage samples, both the VIDAS method and PCR (in comparison to traditional methods) permit a significant reduction in the time required for the detection of the pathogens assayed. The absence of Salmonella Typhimurium, E. coli O157:H7, L. monocytogenes, S. aureus, their enterotoxins, and C. perfringens were verified in the control batch. Conversely, for batches inoculated with these pathogens, the results were positive in the fresh sausage up to 14 days of curing and in the finished product; this demonstrated the null or scant influence of the curing conditions and the constitutive lactic acid biota on the pathogens investigated.

1979 ◽  
Vol 42 (6) ◽  
pp. 464-469 ◽  
Author(s):  
M. E. STILES ◽  
L.-K. NG

Ham and chopped ham from two manufacturers were contaminated with five enteropathogens: Bacillus cereus, Clostridium perfringens, Escherichia coli, Salmonella typhimurium and Staphylococcus aureus, at time of slicing and vacuum-packaging, to simulate contamination by manufacturer. Subsequent treatment of the samples, representing sound and undesirable retail handling and consumer use conditions, indicated marked differences in the fate of the pathogens between these products and within product type between the two manufacturers. Greatest differences were observed between the chopped ham products. All pathogens, except C. perfringens, grew actively in fresh ham and chopped ham with abusive holding at 30 and 21 C. After storage at 4 or 10 C for 30 days, B. cereus and C. perfringens were no longer detected, even after subsequent holding at 30 or 21 C for 24 h. E. coli survival and growth was variable, S. typhimurium survived well and grew under some conditions and S. aureus was generally inhibited at high levels of competition.


2021 ◽  
Vol 11 (3) ◽  
pp. 20-21
Author(s):  
Andrew Martusevich ◽  
Ivan Bocharin ◽  
Maxim Guryanov ◽  
Alexey Kochkurov ◽  
Elena Kochkurova ◽  
...  

The aim of the study was to clarify the character of the initiatory activity of pathogenic and nonpathogenic microorganisms in regard to salt solutions. We selected colonies of two microorganisms: Escherichia coli (E. coli) and Staphylococcus aureus (St. aureus) [106 , 108 , 1010, 1012, 1014, 1016, 1018 and 1020 CFU/ml of solution]. A 10% solution of sodium chloride was used as the initiated substance, which made it possible to perform a tezigraphic test. On the basis of model experiments with colonies of some pathogenic and non-pathogenic microorganisms, a new phenomenon was confirmed — microbial initiation of crystal formation (the phenomenon of microorganismassociated crystallogenesis). This phenomenon is universal for microagents, but it also has specific features imposed by the species of the microorganism and its current functional state.


2011 ◽  
Vol 74 (10) ◽  
pp. 1670-1675 ◽  
Author(s):  
GARRY MENZ ◽  
PETER ALDRED ◽  
FRANK VRIESEKOOP

This work aimed to assess the growth and survival of four foodborne pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus) in beer. The effects of ethanol, pH, and storage temperature were investigated for the gram-negative pathogens (E. coli O157:H7 and Salmonella Typhimurium), whereas the presence of hops ensured that the gram-positive pathogens (L. monocytogenes and S. aureus) were rapidly inactivated in alcohol-free beer. The pathogens E. coli O157:H7 and Salmonella Typhimurium could not grow in the mid-strength or full-strength beers, although they could survive for more than 30 days in the mid-strength beer when held at 4°C. These pathogens grew rapidly in the alcohol-free beer; however, growth was prevented when the pH of the alcohol-free beer was lowered from the “as received” value of 4.3 to 4.0. Pathogen survival in all beers was prolonged at lowered storage temperatures.


1994 ◽  
Vol 57 (3) ◽  
pp. 253-255 ◽  
Author(s):  
DEREK A. BOWEN ◽  
DAVID R. HENNING

Fifty commercial retail samples of natural cheeses (American and non-American-type) were examined for coliform bacteria, Escherichia coli, E. coli O157:H7, and thermonuclease-positive S. aureus. Nine cheese samples had coliform group bacteria ranging from 10 to 1.1 × 103 CFU/ml by the violet red bile agar procedure. Twenty-four or 48% of the cheeses were positive for coliform group bacteria when a 25-g sample was used in an enrichment broth. One sample had a confirmed E. coli by both the violet red bile agar and enrichment methods. No E. coli O157:H7 were found in the retail natural cheeses examined. Also, no thermonuclease-positive S. aureus were isolated. The levels of potentially pathogenic microorganisms in cheeses were lower in this study than reported in a 1974 to 1976 Canadian study.


2010 ◽  
Vol 73 (7) ◽  
pp. 1247-1256 ◽  
Author(s):  
STACEY COLLIGNON ◽  
LISE KORSTEN

The ability of the foodborne pathogens Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica subsp. enterica serovar Typhimurium, and Staphylococcus aureus to attach, colonize, and survive on stone fruit surfaces was investigated. Fifty microliters of bacterial suspension was spot inoculated onto the sterile intact fructoplane of whole peaches and plums. Minimum time required for initial adhesion and attachment was recorded for different surface contact times. Surface colonization patterns of the four pathogens and survival under simulated commercial export conditions also were evaluated. L. monocytogenes and Salmonella Typhimurium attached immediately to stone fruit surfaces. E. coli O157:H7 and S. aureus were visibly attached after 30 s and 1 h, respectively, of direct exposure. Holding freshly harvested stone fruit at 0.5°C to simulate cold storage conditions significantly lowered the titer of E. coli O157:H7 on plums and the titers of L. monocytogenes and Salmonella Typhimurium on stone fruit. E. coli O157:H7 and L. monocytogenes at a low inoculum level and S. aureus and Salmonella Typhimurium at high and low levels did not survive the simulated export chain conditions at titers that exceeded the minimum infectious dose. However, E. coli O157:H7 and L. monocytogenes were able to survive on stone fruit surfaces when inoculated at an artificially high level. In this case, the final titer at the end of the supply chain was higher than the infectious dose. In this laboratory experiment, E. coli O157:H7, L. monocytogenes, Salmonella Typhimurium, and S. aureus at potential natural contamination levels were unable to survive simulated export conditions.


2020 ◽  
Vol 23 ◽  
Author(s):  
Márcio Moura-Alves ◽  
Carolina Machado ◽  
Cristina Saraiva ◽  
José A. Silva

Abstract Eggs, often used in pastry products, are one of the major transmission vehicles of Salmonella. The main purpose of this study was to evaluate Salmonella Typhimurium thermal resistance, by D and z values determination, in a traditional Portuguese egg-based pastry and its microbial and physical-chemical characterization. Salmonella Typhimurium ATCC 14028 (OXOID C6000L) (Ca. 1.33×108 cfu g-1) was inoculated in a liquid batter consisting of 8 whole eggs, 7 egg yolks, 280 g of wheat flour and 250 g of sugar. D and z values determinations were performed after applying a water bath to vacuum-packed samples of liquid batter (5 g), following thermal treatments: 52 °C (45, 90, 135, 180 and 225 min); 55 °C (15, 30, 45, 60, 70 and 80 min); 58 °C (5, 10, 15, 20, 25 and 30 min) and 61 °C (1, 2, 3, 4 and 5 min). Physico-chemical (aw, pH, moisture, sugar, ashes, protein and free fat) and microbiological determinations (mesophilic microorganisms, psychrotrophic, molds and yeasts, Enterobacteriacea, E. coli; Salmonella spp., Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus) were also conducted in raw liquid batter. It was possible to investigate different combinations of time and temperature for Salmonella Typhimurium inactivation, compared to other studies on egg-based batter, often used to make pastry products. Liquid batter aw before inoculation was 0.94 and pH 7.26. The D values were obtained 53.19 min, 20.45 min, 6.95 min and 1.60 min, at 52 °C, 55 °C, 58 °C e 61 °C, respectively. From the calculated D values, the corresponding z value was 5.96 °C.


Author(s):  
М. S. Saypullaev ◽  
А. U. Koychuev ◽  
Т. B. Mirzoeva

The successful conduct of disinfection measures largely depends on the availability of veterinary practice a highly efficient, environmentally safe disinfectants. In this regard, finding new highly efficient disinfectant remains relevant. Studies found that the "Polied" (OOO "Razvitie XXI Vek, Russia) can be attributed to the highly efficient and environmentally friendly means. Solutions "Polied" have a high disinfectant activity against smooth and rough surfaces in the laboratory against gram-positive, gram-negative bacteria, mycobacteria and spores of microorganisms. Studies have established that solutions should be "Polied" obezzarajivatmi E. coli (EA 1257) concentrations of 0.1% on smooth surfaces and Staphylococcus aureus concentration of 0.05% in 1 hour from the calculation of 0.25-0.3 litres/m2. Disinfection of rough test surfaces against Escherichia coli and Staphylococcus aureus occurred after treatment with 0,3% solution of 3-hour exposure, at a rate of 0.5 l/m2. It was also found that 1.0% solution "Polied" fully obezzarazhivatel test the surface of mycobacteria (PCs-5) and at double the 0.6% concentration for 24 hours. Disinfection of rough test surfaces contaminated with spores of B. cereus (PCs 96) was achieved with a 4.0% solution at twice the irrigation rate of 0.5 l/m2 at an exposure of 24 hours. Toxicity solutions of the drug "Polied" refer to "moderate" threat (hazard class 3) and low-hazard substances (4 hazard class) when applied to the skin, mucous membranes of the eyes, and inhalation exposure on the respiratory system.


1993 ◽  
Vol 27 (7-8) ◽  
pp. 287-294 ◽  
Author(s):  
S. Lerman ◽  
O. Lev ◽  
A. Adin ◽  
E. Katzenelson

The Israel Ministry of Health is now revising its regulations for the assurance of safe water quality in public swimming pools. Since it is not possible to monitor each of the pathogenic microorganisms, it is often recommended to monitor indicator bacteria which provide indirect information on the water quality in the swimming pool. Three indicator microorganisms are often recommended: coliform counts (total coliforms, fecal coliforms or E. Coli), staphylococcus aureus and pseudomonas aeruginosa. A four year survey of the water quality of swimming pools in the Jerusalem District was conducted in order to determine whether the monitoring of all three indicators is necessary to assure safe water quality or is it sufficient to monitor only a single microorganism. A statistical analysis, conducted by using several different statistical techniques, reveals that the populations of the three indicator organisms are significantly interdependent but the correlations between each pair of these indicators are not sufficient to base a prediction of any of the organisms based on the measurements of the others. Therefore, it is concluded that monitoring of all three indicators should be recommended in order to provide an adequate picture of the water quality in swimming pools.


2020 ◽  
Vol 10 (3) ◽  
pp. 316-329
Author(s):  
Fateme Mirzajani ◽  
Amin Hamidi

Introduction: In this project, the growth and volatile metabolites profiles of Escherichia coli (E. coli ) and Staphylococcus aureus were monitored under the influence of silver base chemical, nanoparticle and ultra-highly diluted compounds. Materials & Methods: The treatments were done for 12000 life cycles using silver nanoparticles (AgNPs) as well as ultra-highly diluted Argentum nitricum (Arg-n). Volatile organic metabolites analysis was performed using gas chromatography mass spectrometry (GC-MS). The results indicated that AgNPs treatment made the bacteria resistant and adapted to growth in the nanoparticle condition. The use of ultra-highly diluted Arg-n initially increased growth but it decreased later. Also, with the continuous usage of these materials, no more bacterial growth was observed. Results: The most important compounds produced by E. coli are Acetophenone, Octyl acetate, Styrene, 1,8-cineole, 4-t-butyl-2-(1-methyl-2-nitroethyl)cyclohexane, hexadecane and 2-Undecanol. The main compounds derived from S. aureus are Acetophenone,1,8-cineole, Benzaldehyde, 2-Hexan-1-ol, Tridecanol, Dimethyl Octenal and tetradecane. Acetophenone and 1,8-cineole were common and produced by both organisms. Conclusion: Based on the origin of the produced volatiles, main volatiles percentage of untreated sample is hydrocarbon (>50%), while bacteria treatments convert the ratio in to aldehydes, ketones and alcohols in the case of AgNPs, (>80%) and aldehydes, ketones and terpenes in the case of Arg-n (>70%).


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1786
Author(s):  
György Schneider ◽  
Bettina Schweitzer ◽  
Anita Steinbach ◽  
Botond Zsombor Pertics ◽  
Alysia Cox ◽  
...  

Contamination of meats and meat products with foodborne pathogenic bacteria raises serious safety issues in the food industry. The antibacterial activities of phosphorous-fluorine co-doped TiO2 nanoparticles (PF-TiO2) were investigated against seven foodborne pathogenic bacteria: Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus. PF-TiO2 NPs were synthesized hydrothermally at 250 °C for 1, 3, 6 or 12 h, and then tested at three different concentrations (500 μg/mL, 100 μg/mL, 20 μg/mL) for the inactivation of foodborne bacteria under UVA irradiation, daylight exposure or dark conditions. The antibacterial efficacies were compared after 30 min of exposure to light. Distinct differences in the antibacterial activities of the PF-TiO2 NPs, and the susceptibilities of tested foodborne pathogenic bacterium species were found. PF-TiO2/3 h and PF-TiO2/6 h showed the highest antibacterial activity by decreasing the living bacterial cell number from ~106 by ~5 log (L. monocytogenes), ~4 log (EHEC), ~3 log (Y. enterolcolitca, S. putrefaciens) and ~2.5 log (S. aureus), along with complete eradication of C. jejuni and S. Typhimurium. Efficacy of PF-TiO2/1 h and PF-TiO2/12 h NPs was lower, typically causing a ~2–4 log decrease in colony forming units depending on the tested bacterium while the effect of PF-TiO2/0 h was comparable to P25 TiO2, a commercial TiO2 with high photocatalytic activity. Our results show that PF-co-doping of TiO2 NPs enhanced the antibacterial action against foodborne pathogenic bacteria and are potential candidates for use in the food industry as active surface components, potentially contributing to the production of meats that are safe for consumption.


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