Evaluation of UVC Radiation and a UVC-Ozone Combination as Fresh Beef Interventions against Shiga Toxin–Producing Escherichia coli, Salmonella, and Listeria monocytogenes and Their Effects on Beef Quality

2020 ◽  
Vol 83 (9) ◽  
pp. 1520-1529
Author(s):  
NORASAK KALCHAYANAND ◽  
JOSEPH M. BOSILEVAC ◽  
DAVID A. KING ◽  
TOMMY L. WHEELER

ABSTRACT This research study was conducted to evaluate treatments with UVC light and a combination of UVC and ozone that have recently received attention from the beef processing industry as antimicrobial interventions that leave no chemical residues on products. The effectiveness of UVC and UVC plus gaseous ozone treatments was evaluated for inactivation of pathogenic bacteria on fresh beef and for any impact on fresh beef quality. Fresh beef tissues were inoculated with cocktails of Shiga toxin–producing Escherichia coli (STEC) strains (serotypes O26, O45, O103, O111, O121, O145, and O157:H7), Salmonella, and Listeria monocytogenes. Inoculated fresh beef tissues were subjected to UVC or UVC-ozone treatments at 106 to 590 mJ/cm2. UVC treatment alone or in combination with ozone reduced populations of STEC, Salmonella, L. monocytogenes, and aerobic bacteria from 0.86 to 1.49, 0.76 to 1.33, 0.5 to 1.14, and 0.64 to 1.23 log CFU, respectively. Gaseous ozone alone reduced populations of E. coli O157:H7, Salmonella, and L. monocytogenes by 0.65, 0.70, and 0.33 log CFU, respectively. Decimal reduction times (D-values) for STEC serotypes, Salmonella, and L. monocytogenes on surfaces of fresh beef indicated that the UVC-ozone treatment was more effective (P ≤ 0.05) than UVC light alone for reducing pathogens on the surface of fresh beef. Exposure to UVC or UVC plus gaseous ozone did not have a deleterious effect on fresh meat color and did not accelerate the formation of oxidative rancidity. These findings suggest that UVC and UVC in combination with gaseous ozone can be useful for enhancing the microbial safety of fresh beef without impairing fresh beef quality. HIGHLIGHTS

2006 ◽  
Vol 69 (5) ◽  
pp. 1080-1086 ◽  
Author(s):  
T. OSAILI ◽  
C. L. GRIFFIS ◽  
E. M. MARTIN ◽  
B. L. BEARD ◽  
A. KEENER ◽  
...  

Thermal inactivation studies were used to determine the D- and z-values of Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes in ready-to-eat chicken-fried beef patties. Inoculated meat was packaged in sterile bags, which were immersed in a circulated water bath and held at 55, 57.5, 60, 62.5, 65, 67.5, and 70°C for different lengths of time. D- and z-values were determined with a linear regression model. Average D-values at temperatures 55 to 70°C were 27.62 to 0.04 min for E. coli O157:H7, 67.68 to 0.22 min for Salmonella, and 81.37 to 0.31 min for L. monocytogenes. The z-values were 5.2°C for E. coli O157:H7, 6.0°C for Salmonella, and 6.1°C for L. monocytogenes. The results of this study can be used by food processors to validate their processes and help eliminate pathogenic bacteria associated with chicken-fried beef products.


2014 ◽  
Vol 77 (10) ◽  
pp. 1768-1772 ◽  
Author(s):  
ANA CAROLINA B. REZENDE ◽  
MARIA CRYSTINA IGARASHI ◽  
MARIA TERESA DESTRO ◽  
BERNADETTE D. G. M. FRANCO ◽  
MARIZA LANDGRAF

This study evaluated the effects of irradiation on the reduction of Shiga toxin–producing Escherichia coli (STEC), Salmonella strains, and Listeria monocytogenes, as well as on the sensory characteristics of minimally processed spinach. Spinach samples were inoculated with a cocktail of three strains each of STEC, Salmonella strains, and L. monocytogenes, separately, and were exposed to gamma radiation doses of 0, 0.2, 0.4, 0.6, 0.8, and 1.0 kGy. Samples that were exposed to 0.0, 1.0, and 1.5 kGy and kept under refrigeration (4°C) for 12 days were submitted to sensory analysis. D10-values ranged from 0.19 to 0.20 kGy for Salmonella and from 0.20 to 0.21 for L. monocytogenes; for STEC, the value was 0.17 kGy. Spinach showed good acceptability, even after exposure to 1.5 kGy. Because gamma radiation reduced the selected pathogens without causing significant changes in the quality of spinach leaves, it may be a useful method to improve safety in the fresh produce industry.


Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1423
Author(s):  
Nicola Mangieri ◽  
Roberto Foschino ◽  
Claudia Picozzi

Shiga toxin-producing Escherichia coli are pathogenic bacteria able to form biofilms both on abiotic surfaces and on food, thus increasing risks for food consumers. Moreover, biofilms are difficult to remove and more resistant to antimicrobial agents compared to planktonic cells. Bacteriophages, natural predators of bacteria, can be used as an alternative to prevent biofilm formation or to remove pre-formed biofilm. In this work, four STEC able to produce biofilm were selected among 31 different strains and tested against single bacteriophages and two-phage cocktails. Results showed that our phages were able to reduce biofilm formation by 43.46% both when used as single phage preparation and as a cocktail formulation. Since one of the two cocktails had a slightly better performance, it was used to remove pre-existing biofilms. In this case, the phages were unable to destroy the biofilms and reduce the number of bacterial cells. Our data confirm that preventing biofilm formation in a food plant is better than trying to remove a preformed biofilm and the continuous presence of bacteriophages in the process environment could reduce the number of bacteria able to form biofilms and therefore improve the food safety.


2021 ◽  
Vol 10 (12) ◽  
pp. e596101220735
Author(s):  
Iara Nunes de Siqueira ◽  
Aline Antas Cordeiro Cavalcanti ◽  
Joyce Galvão de Souza ◽  
Filipe Jordão Pereira de Medeiros ◽  
João Carlos Taveira ◽  
...  

The sanitary evaluation of equipment and hands is fundamental to investigate the presence of pathogens in the dairy industry. Then, this study aims to evaluate the sanitization of equipment, workers’ hands, raw and pasteurized milk in goat milk dairies in the Cariri region, state of Paraíba.  Collected 32 samples of four dairies represented by letters A, B, C, and D. The followings contents were analyzed: mesophiles, total and thermotolerant coliforms, Escherichia coli, Staphylococcus aureus, Samonella spp. and Listeria monocytogenes in the reception tank, pasteurization tank, packing machine, package, wall, workers’ hand, and each dairy’s raw and pasteurized milk. After isolation, 84 colonies were confirmed by MALDI TOF. The indicator microorganisms presented variations for the workers’ hands, while A and B stayed within the patterns. For the equipment, only dairy B was within limits. They were out of the standard for mesophiles, total coliforms, and thermotolerant regarding raw and pasteurized milk. The microorganisms, the Enterobacteriaceae family presented a higher frequency, with 77.38%, and within this family, Escherichia coli, Klebsiella spp., and Enterobacter spp. were the most prevalent. Gram-positive corresponded to 22.62%, Bacillus spp., Staphylococcus spp., Enterococcus spp., and Macrococcus caseolyticus. Listeria monocytogenes and Salmonella spp. were not isolated. These demonstrate failures in goat milk processing with pathogenic bacteria in several dairy plants, indicating the need to adjust the product’s quality control.


2018 ◽  
Vol 7 (2) ◽  
pp. 125-139
Author(s):  
Thais Nogueira Gonzaga ◽  
Dora Inés Kozusny-Andreani

Nesta pesquisa objetivou-se avaliar a viabilidade técnica da aplicação de ozônio como bactericida e fungicida em amostras de resíduos de serviços de saúde potencialmente infectantes. Foram determinados os     micro-organismos presentes nos resíduos gerados em um hospital particular. Para realização das análises microbiológicas e o tratamento com ozônio o material foi particulado e homogeneizado. As análises microbiológicas foram realizadas antes e após a ozonização.Para os testes de desinfecção foram retirados 10,0g de amostra que foi submetida à ozonização por 5, 10, 15, 20 e 25 minutos com doses de 140,0; 280,0; 420,0; 560,0 e 700,0mg L-1 de ozônio, respectivamente. Verificou-se presença de mesófilos totais, coliformes totais e termotolerantes, Escherichia coli, Pseudomonas aeruginosa, Proteus spp., Staphylococcus aureus, Staphylococcus spp, Candida albicans e Rhizopus spp. O ozônio foi eficiente para eliminação de todos os micro-organismos em 20 minutos; nos primeiros cinco minutos de exposição ao gás verificou-se redução superior a 98%.Palavras-chave: Bactérias patogênicas. Fungos. Ozonização. USING OZONE GAS FOR DISINFECTION OF SOLID WASTE FROM HEALTH CARE SERVICES ABSTRACT: The aim of this research was to evaluate the technical viability of the application of ozone as bactericide and fungicide in samples of potentially infectious health services residues. The microorganisms present in the waste generated in a private hospital were determined. The material was particulated and homogenized to perform the microbiological analysis and to undergo ozone treatment. Microbiological analysis was performed before and after ozonization. For the disinfection tests, 10.0g of sample were removed and submitted to ozonization for 5, 10, 15, 20 and 25 minutes with 140,0; 280,0; 420,0; 560,0 and 700,0mg doses of L-1 of ozone, respectively. It was verified the presence of total mesophiles, total and thermotolerant coliforms, Escherichia coli, Pseudomonas aeruginosa, Proteus spp., Staphylococcus aureus, Staphylococcus spp, Candida albicans and Rhizopus spp. Ozone was efficient while eliminating all microorganisms in 20 minutes; in the first five minutes of gas exposure, the reduction was greater than 98%.Keywords: Pathogenic bacteria. Fungi. Ozonization.


Meat Science ◽  
2014 ◽  
Vol 96 (1) ◽  
pp. 484-485 ◽  
Author(s):  
A.M. King ◽  
R.P. McMinn ◽  
J.J. Sindelar ◽  
K.A. Glass ◽  
A.L. Milkowski ◽  
...  

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