scholarly journals IDENTIFICATION OF FOOD PATHOGENS AND DETERMINATION OF THEIR DISTRIBUTION LEVEL IN UKRAINIAN FOOD PRODUCTS OF ANIMAL AND PLANT ORIGIN BY PCR METHOD

2019 ◽  
Vol 13 (4) ◽  
Author(s):  
O. Berhilevych ◽  
L. Pylypenko ◽  
V. Kasianchuk ◽  
A. Ilyeva ◽  
P. Shubin

The foodborne pathogens cause serious public health problems in each country. In this regard, microbiological investigation is included in food safety management of the food chain. Molecular methods and mostly polymerase chain reaction (PCR) are considered highly sensitive, specific and rapid methods for pathogens detection from raw material and food. This study describes the using of specially designed and highly specific primers for PCR to identify 5 common and especially dangerous causeve agents of food poisoning and disease and to determine their level of distribution in food of animal and plant origin. The studies included the identification of methicillin-resistant Staphylococcus aureus (MRSA) and Cronobacter spp. (E. sakazakii) from raw milk, Shiga toxin-producing strains of Escherichia coli (STEC) from beef and swine carcasses, Bacillus cereus and Clostridium perfringens from various types of plant and animal raw materials and products of its processing - fruits, vegetables, berries, dried and preserved products, food concentrates, half-canned food. A total of 397 food samples were investigated to detect these pathogens using classical bacteriological methods and PCR. It was found that the distribution of foodborne pathogens in the studied products of animal and plant origin was as follows: Staphylococcus aureus (MRSA) and Cronobacterspp. (E. sakazakii) in raw cow milk in 6.5% and 19.4% of cases, respectively; shiga-toxin-producing Escherichia coli (STEC) from beef and pork carcasses in 8.1% and 5.7%; Bacillus cereus and Clostridium perfringens from different types of plant and animal raw materials and their processing products averages 27.5 % and 7.7 %, respectively. The advantages of molecular biological methods to which the PCR method relates, include their speed, as well as the specificity of identification of microorganisms by the features of genetic regions of genes that carry information about their pathogenicity factors. It has been found that the rate of detection of these pathogens when using the PCR method in comparison with classical methods increases at least 5-9 times. This data will be useful for assessing microbiological risk and will help authorities develop strategies to reduce consumer health risks.

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.


2020 ◽  
Vol 83 (8) ◽  
pp. 1302-1306
Author(s):  
EUN-SEON LEE ◽  
JONG-HUI KIM ◽  
MI-HWA OH

ABSTRACT In dairy plants, clean-in-place (CIP) equipment cannot be disassembled, making it difficult to clean the inner surface of pipes. In this study, the inhibitory effects of chemical agents on biofilms formed by three foodborne pathogens, Bacillus cereus, Escherichia coli, and Staphylococcus aureus, was evaluated in a dairy CIP system. The experiment was conducted on a laboratory scale. Each of the three bacteria (200 μL) was inoculated onto stainless steel (SS) chips (25 by 25 mm), and the effect of single cleaning agents was evaluated. Individual treatments with NaClO (30, 50, 100, and 200 ppm), NaOH (0.005, 0.01, 0.05, and 0.1%), citric acid (1, 3, 5, and 7%), and nisin (5, 10, 25, 50, 100, and 200 ppm) were used to clean the SS chip for 10 min. The most effective concentration of each solution was selected for further testing in a commercial plant. Simultaneous cleaning with 200 ppm of NaClO (10 min) and 7% citric acid (10 min) reduced the biofilms of B. cereus, E. coli, and S. aureus by 6.9, 7.0, and 8.0 log CFU/cm2, respectively. Both 7% citric acid and 0.1% NaOH were optimal treatments for E. coli. NaClO and citric acid are approved for use as food additives in the Republic of Korea. Our results revealed that a combined treatment with NaClO and citric acid is the most effective approach for reducing biofilms formed by common foodborne pathogens on CIP equipment. These findings can contribute to the production of safe dairy products. HIGHLIGHTS


1986 ◽  
Vol 49 (5) ◽  
pp. 369-377 ◽  
Author(s):  
EWEN C. D. TODD ◽  
R. SZABO ◽  
F. SPIRING

Because of concerns that meat in donairs could allow growth of pathogens during cooking and overnight cooling of leftovers, 34 donairs from eleven establishments had temperatures taken and were examined microbiologically. Temperatures varied depending on depth of measurement and stage from the raw product to reheated leftovers. These were frequently >4 or <60°C and could be considered at temperatures favorable for growth of pathogens. Although aerobic colony counts were high (mean of 105 to 107 CFU/g), counts tended to decrease the longer the donair remained cooking on the spit. Staphylococcus aureus, Bacillus cereus, Clostridium perfringens and Escherichia coli were never more than 104/g despite some abusive practices, such as leaving donairs on the spit with the heat source turned off because the demand was low. Salmonella was found only in raw chicken slices to be used in donairs. It is recommended that good hygienic practices be encouraged at donair establishments and temperature measurements of donairs taken to verify these. Only if meat is <50°C at 1 cm below the surface during cooking or >5°C for the raw product or cooled leftovers, should samples be considered for microbiological analysis unless abusive practices have been observed. Because temperatures may vary over a short period of time during cooking, at least five measurements are recommended for each stage of the donair life (raw product, cooking donair, cooled leftovers and reheating donairs).


2013 ◽  
Vol 62 (4) ◽  
pp. 439-443
Author(s):  
BEATA ROZWADOWSKA ◽  
MARTA ALBERTYŃSKA ◽  
GRZEGORZ HUDZIK ◽  
HUBERT OKŁA ◽  
KRZYSZTOF P. JASIK ◽  
...  

The diagnostic assessment of water sanitary state is based mainly on the cultivation of bacteria retained on membrane filters. However classical microbiology methods have a lot of disadvantages. More and more frequently, rapid detection and identification of pathogens present in water is based on molecular biology techniques. The aim of this study was to determine the effectiveness and usefulness of a real-time PCR method, when compared to the recommended bacteria culture method, in diagnostics of pathogens in water samples. The research concerned the detection and identification of main sanitary indicators of water such as: Salmonella spp., Escherichia coli, Staphylococcus aureus and Clostridium perfringens. The analyses were conducted in water samples contaminated with the reference material (the aforementioned bacteria) and real environmental samples, which were examined for the presence of nucleic acid of: Salmonella spp., E. coli, S. aureus and C. perfringens using a real-time PCR method.


2015 ◽  
Vol 35 (03) ◽  
pp. 300
Author(s):  
Reny Mailia ◽  
Bara Yudhistira ◽  
Yudi Pranoto ◽  
Saiful Rochdyanto ◽  
Endang Sutriswati Rahayu

Characteristics of tofu with higher a (0.89 to 0.90) and protein levels of 8% or more, made tofu to be a suitable medium for bacterial growth. This leads to out to be very easy to damage due to bacterial contamination. Contamination of bacteria is commonly found in the tofu because of contamination in the process making of tofu. Source of contamination can come out from the raw material, during the process of making tofu and hygienic sanitation level during processing. Generally, this study aimed to determine the level of contamination of Escherichia coli, Staphylococcus aureus, Bacillus cereus and spore-forming bacteria in the process of making tofu and study the properties of heat resistance of eachisolate. Phases of of the study started with the isolation and identification and then quantitative analysis of Escherichiawcoli, Staphylococcus aureus, Bacillus cereus and spore-forming bacteria in the tofu process from raw materials to end product, tofu, comprised from water and soybean, slurry, soymilk cooking, curd, whey and tofu. Isolates originating from the cooking process and the coagulation process was for testing the heat resistance (D value and Z value). D and Z values were calculated using linear regression. Escherichia coli found in the water, soybeans, soybean slurry, curd and tofu, the number 10 =4,83 min and the value of Z = 22.73°C. Staphylococcus aureus found in soybeans and curd, showed the number of 101-102 CFU/g. Escherichia coli GMP isolate had D60°C CFU/g. The Staphylococcus aureus GMP4 isolate, had D60°C 1=2.72 min and the value of Z = 18.87°C. The Staphylococcus aureus GMP 6 isolate, had D=2.54min and the value of Z = 18.18°C. Bacillus cereus found in the water, soybean, soybean slurry, soymilk cooking, curdand tofu, showed the number 102-103CFU/g. Bacillus cereus vegetative cells SK 2 had D=5.43 min and the value of Z = 22.72°C. Bacillus cereus vegetative cells SK 4 had D60°C 60°C =5.95 min and the value of Z = 22.22°C. Spore-forming bacteria found in water, soybean, soybean slurry from the grinding process, the process cooking of soymilk, the process of clotting, whey and tofu, showed the number of 102CFU/g.Keywords: Tofu, Escherichia coli, Staphylococcue aureus, Bacillus cereus, a spore forming bacteria, heat resistance 60°C ABSTRAKKarakteristik tahu dengan a0,89-0,90 dan kadar protein 8% atau lebih, menjadikan tahu sebagai media yang cocok bagipertumbuhan bakteri. Hal ini menyebabkan tahu menjadi sangat mudah rusak karena cemaran bakteri. Penelitian ini bertujuan untuk mengetahui tingkat cemaran Escherichia coli, Staphylococcus aureus, Bacillus cereus dan Bakteri pembentuk spora pada proses pembuatan tahu dan mempelajari sifat ketahanan panas dari masing-masing cemaran. Tahapan penelitian dimulai dari pengamatan proses pembuatan tahu, isolasi dan identifikasi dan analisa kuantitatif cemaran Escherichia coli, Staphylococcus aureus, Bacillus cereus dan bakteri pembentuk spora pada proses pembuatantahu. Isolat yang berasal dari proses pemasakan dan proses penggumpalan digunakan untuk pengujian ketahanan panasdengan melihat nilai D dan Z menggunakan regresi linier. Escherichia coli ditemukan pada air, kedelai, bubur kedelai, gumpalan tahu dan tahu, dengan jumlah 10w1-10CFU/g. Isolat Escherichia coli dari proses penggumpalan (GMP), nilaiD60°C 2=4,83 menit dan nilai Z=22,73°C. Staphylococcus aureus ditemukan pada kedelai, gumpalan tahu dan tahu, dengan jumlah 10=2,72 menit dan nilai Z =18,87°C. Untuk isolat Staphylococcus aureus GMP 6, nilai D1CFU/g.  Isolat Staphylococcus aureus GMP 4, memiliki nilai D60°C60°C =2,54 menit dan nilai Z =18,18°C. Bacillus cereus ditemukan pada air,kedelai, bubur kedelai, sari kedelai masak, gumpalan tahu dan tahu, dengan jumlah 102-10CFU/g. Sel vegetatif Bacilluscereus yang berasal dari sari kedelai (SK) 2, memiliki nilai D60°C3=5,43 menit dan nilai Z =22,72°C. Untuk sel vegetatif Bacillus cereus SK 4, memiliki nilai D60°C=5,95 menit dan nilai Z =22,22°C. Bakteri pembentuk spora ditemukan pada air, kedelai, bubur kedelai pada proses penggilingan, sari kedelai masak, gumpalan tahu, kecutan dan tahu, dengan jumlah 10CFU/g.Kata kunci: Tahu, Escherichia coli, Staphylococcue aureus, Bacillus cereus, bakteri pembentuk spora, ketahananpanas2    


1978 ◽  
Vol 41 (9) ◽  
pp. 692-695 ◽  
Author(s):  
JOHN T. FRUIN ◽  
JAMES F. FOSTER ◽  
JAMES L. FOWLER

Bologna products most frequently are stored and consumed as refrigerated products. Thus bacteria that survive processing or those that contaminate the product subsequent to processing are not destroyed. Ten types of presliced, vacuum-packaged bologna products were purchased from a high-volume retail market and analyzed for total aerobic plate count (APC) and common foodborne pathogens. No Salmonella were isolated. Less than 1% of the 419 samples analyzed contained either Clostridium perfringens or Escherichia coli, Staphylococcus aureus was isolated from 4% of the samples, but only one sample contained more than 1000/g. Just over 5% of the samples contained coliform organisms. The manufacturer appeared to play an important role in bacterial quality of the finished items. An APC < 5 × 106/g is a realistic criterion for bologna products at the time of delivery to retail markets.


2021 ◽  
Author(s):  
Davood Gheidari ◽  
Morteza Mehrdad ◽  
Saloomeh Maleki ◽  
Samanesadat Hosseini

Abstract With the increase of general knowledge and the advancement of science and technology, antibacterial substances were used more than antibiotics. In our current study, the antibacterial virtues of CFO/BiOI nanocomposite were investigated due to its high importance on Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus. MIC, MBC , Disk Diffusion and IC50 tests Cefalotin (CF), Amoxicillin (AMX), Gentamicin (GM), Trimethoprim-sulphamethoxazole (SXT) and Ceftriaxone (CRO) antibiotics in concentration 30W, 10i, 10t , 25h and 30 were used to find the antibacterial properties of the synthesized nanocomposite, respectively. For the synthesis of nanocomposites polyethylene glycol (PEG) and sulfonic acid was used as a solvent. It is noteworthy that the synthesis was performed by heat dissolution method without the presence of surfactant. Also, various techniques such as X-Ray Diffraction(XRD), Scanning Electron Microscope (SEM), High resolution mapping and Energy Dispersive X-ray spectroscopy (EDAX) have been used to determine the properties of produced nanocomposites. SEM test results showed that the formed nanoparticles were globular and their size was limited area of 22 to 34 nm. The results showed CFO / BiOI nanocomposite exhibits strong significant biological activity against Bacillus cereus. The results of MBC (Minimum Bactericidal Concentration) and MIC (Minimum Inhibition Concentration) tests for CFO/BiOI nanocomposites on bacteria were examined in the range of 0.12-0.48 mg/ml and 0.06 to 0.24 mg/ml respectively. According to the results, the minimum IC50 value was determined at a concentration of 0.061 mg/ml. On the other hand, the most resisting and susceptible bacteria in this method were Pseudomonas aeruginosa and Bacillus cereus, respectively. These findings are identical to those of a prior study on CoFe2O4 nanoparticles antibacterial properties. MBC of the nanocomposites, 50 µl from all the tubes that showed no obvious bacterial growth were distributed on BHI agar plates and incubated for 24 h at 37 ◦C. The MBC endpoint is defined as the lowest concentration which killed 98% of the bacterial population.


2020 ◽  
Author(s):  
Ivan Nastasijevic ◽  
John W. Schmidt ◽  
Marija Boskovic ◽  
Milica Glisic ◽  
Norasak Kalchayanand ◽  
...  

ABSTRACTShiga toxin (stx) -producing Escherichia coli (STEC) are foodborne pathogens that have a significant impact on public health, with those possessing the attachment factor intimin (eae) referred to as enterohemorrhagic E. coli (EHEC) associated with life threatening illnesses. Cattle and beef are considered typical sources of STEC, but their presence in pork products is a growing concern. Therefore, carcasses (n=1536) at two U.S. pork processors were sampled once per season at three stages of harvest (post-stunning skins; post-scald carcasses; chilled carcasses) then examined using PCR for stx and eae, aerobic plate count (APC) and Enterobacteriaceae counts (EBC). Skins, post-scald, and chilled carcasses had prevalence of stx (85.3, 17.5, and 5.4%, respectively), with 82.3, 7.8, and 1.7% respectively, having stx and eae present. All stx positive samples were subjected to culture isolation that resulted in 368 STEC and 46 EHEC isolates. The most frequently identified STEC were serogroup O121, O8, and O91(63, 6.7, and 6.0% of total STEC, respectively). The most frequently isolated EHEC was serotype O157:H7 (63% of total EHEC). Results showed that scalding significantly reduced (P < 0.05) carcass APC and EBC by 3.00 and 2.50 log10 CFU/100 cm2 respectively. A seasonal effect was observed with STEC prevalence lower (P < 0.05) in winter. The data from this study shows significant (P < 0.05) reduction in the incidence of STEC (stx) from 85.3% to 5.4% and of EHEC (stx+eae) from 82.3% to 1.7% within slaughter-to-chilling continuum, respectively, and that potential EHEC can be confirmed present throughout using culture isolation.IMPORTANCESeven serogroups of Shiga toxin-producing Escherichia coli (STEC) are responsible for most (>75%) cases of severe illnesses caused by STEC and are considered adulterants of beef. However, some STEC outbreaks have been attributed to pork products although the same E. coli are not considered adulterants in pork because little is known of their prevalence along the pork chain. The significance of the work presented here is that it identifies disease causing STEC, enterohemorrhagic E. coli (EHEC), demonstrating that these same organisms are a food safety hazard in pork as well as beef. The results show that most STEC isolated from pork are not likely to cause severe disease in humans and that processes used in pork harvest, such as scalding, offer a significant control point to reduce contamination. The results will assist the pork processing industry and regulatory agencies to optimize interventions to improve the safety of pork products.


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