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    Decontamination effect of zinc oxide nanoparticles, rosmarinic acid and anatolian propolis on foodborne bacteria
    (Turkish Science and Technology Publishing (TURSTEP), 2022) Kevenk, Tahsin Onur; Aras, Zeki
    Zinc oxide (ZnO) has been used in the pharmaceutical, cosmetic, paint, textile, and food industries to coat surfaces and absorb UV rays. As a result of its antimicrobial properties in nanoscale, it may be a promising chemical for decontamination. Zinc oxide nanoparticles (ZnO-NPs) are generally considered safe (GRAS) for their stability under challenging processing conditions. Our study investigated the antimicrobial activities of rosmarinic acid and propolis, prepared at different concentrations together with ZnO-NPs. For this purpose, six leading foodborne pathogens and a starter culture were chosen. The invitro decontamination effects of ZnO-NPs, rosmarinic acid, and propolis combinations on selected bacteria in the first 24 hours were demonstrated by bacterial counts at regular intervals. According to our results, propolis and ZnO-NPs showed remarkable results together. In addition, rosmarinic acid’s lower concentrations were also found to induce the decontamination effect of ZnO-NPs. Although the antimicrobial effect of ZnO-NPs, when used alone, was less than when used in combination, it was still found to be sufficient.
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    Detection of Clostridium perfringens and determination of enterotoxin genes (cpa and cpe) in traditional Turkish chicken Doner Kebab
    (Chartered Inst. of Building Services Engineers, 2022) Kevenk, Tahsin Onur; Uyanık, Tolga; Kanat, Sibel; Çadırcı, Özgür; Gücükoğlu, Ali
    The demand for the fast-food industry in the world is increasing day by day. In this sense, chicken doner kebab becomes frequently preferred food source in daily life. At the same time, chicken doner kebab is both a good animal origin protein source and a cheaper option. Therefore, it is prepared and consumed in high amounts in Turkey. In this study, it was aimed to determine the presence of Clostridium perfringens and its toxin genes in traditional Turkish chicken doner kebabs purchased from restaurants and modified atmosphere packaged (MAP) samples collected from markets. For this purpose, 100 ready-to-cook and 100 ready-to-eat, totally 200 doner samples have been used as material. As a result, the prevalence of C. perfringens has been found 29%, 6% in readyto-cook and ready-to-eat samples, respectively. The cpa gene was detected in all isolates. However, both cpa and cpe gene was found only in 4% of isolates.
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    Determination of Carbapenem-Resistant Enterobacteriaceae from Chicken Meat by Advanced Modified ISO 21528-1:2017 Method
    (University of Agricultural Sciences and Veterinary, 2022) Kevenk, Tahsin Onur; Aras, Zeki
    Antibiotic resistance is critical today, and carbapenem-resistant Enterobacteriaceae (CRE) are the current reflection of this threat in terms of public health. Our study aimed to investigate the effectiveness of a known ISO method used to detect of CREs in chicken meat sold in the Aksaray Region. A total of 150 chicken samples (50 drumsticks, 50 breasts, and 50 wings) were analyzed in terms of CRE by modifying the ISO 21528-1:2017 method. For this purpose, meropenem and ertapenem powders were added into buffered peptone water and Violet Red Bile Glucose Agar at the resistance levels determined in EUCAST. At the same time, target DNA extraction was performed from all samples with a tissue isolation kit (Hybrigen) and stored for PCR to support and strengthen our results to compare the cultural method's results. According to the results of the cultural procedure, the existing flora of chicken meats was suppressed by antibiotic supplements, and no suspicious colonies were detected. Likewise, CRE was not detected in DNA samples obtained from 150 chicken meat samples. Carbapenem resistance, described as the last fortress, is today's significant public health problem. According to our results, CRE was not isolated in 150 chicken meat samples offered for sale in our region.
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    Invitro decontamination effect of zinc oxide nanoparticles (ZnO-NPs) on important foodborne pathogens
    (Veteriner Kontrol Merkez Araştırma Enstitüsü, 2021) Kevenk, Tahsin Onur; Koluman, Ahmet
    Zinc oxide (ZnO) has been used for many years in the pharmaceutical, cosmetic, paint, textile, and food industries for coating surfaces, absorbing UV rays and due to its antimicrobial properties in nanoscale, it has been identified as an important chemical for decontamination. Zinc can be found in many foods as well and its allowed daily intake for adults has been reported as 8-11 mg. Zinc Oxide Nanoparticles (ZnO-NPs) are generally regarded as safe (GRAS) for it being stable under hard processing conditions. Compared to organic acids, ZnO-NPs have better durability, selectivity, and heat resistance. In the present study, it was aimed to understand the decontamination effect of ZnO-NPs on S. enteritidis, S. typhimurium, S. aureus, L. monocytogenes, and E. coli O157 to develop novel, safe decontamination agents for the food industry. For this purpose, <50 µ ZnO-NPs were added into Tryptic Soy Broth in 20 mMolar final concentration for the understanding of the antimicrobial effect. After inoculation of the pathogens, a counting procedure was performed using the Tryptic Soy Agar by the pour on plate method at 0, 1st, 2nd, 4th, 6th, 8th, 12th, and 24th hours. As a result, S. enteritidis and S. aureus 3 Log CFU/mL, S. typhimurium and E. coli O157 4 Log CFU/mL, L. monocytogenes 2 Log CFU/mL decreased in 24 hours.
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    METHOD VALIDATION AND PREVALENCE OF L. Monocytogenes CONTAMINATION IN GROUND BEEF WITH VIDAS: AS AN ALTERNATIVE METHOD COMPARED WITH ISO 11290
    (Parlar Scientific Publications, 2022) Kevenk, Tahsin Onur; Koluman, Ahmet
    L. monocytogenes, which is recognized among the leading foodborne pathogen has been identified as the causative agent of listeriosis, which causes important symptoms such as abortion, septicemia, and meningitis. In the first stage of our study, the effectiveness of VIDAS LMO2 and ISO 11290:1 methods, which are frequently used today in the diagnosis of this pathogen, were compared in artificially contaminated samples. In the second stage, the presence of L. monocytogenes in ground beef samples sold in the market was revealed by both methods. According to the data achieved in the study, the relative sensitivity, specificity, accuracy, false positive, and false negative of the VIDAS LMO2 method against ISO 11290-1:2017 was found 99.236%, 73,684%, 90%, 0.263%, and 0.007% in ground beef, respectively. Although no significant difference was detected between the two methods, VIDAS LMO2 was found to be superior in terms of analysis time. Since it is known that rapid and reliable diagnosis is very important in food poisoning, the VIDAS method can be preferred more desirable due to this superiority.
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    Salmonella detection in different types of packed raw poultry meat by culture elisa and pcr methods
    (Parlar Scientific Publications, 2022) Aras, Zeki; Sanioğlu Gölen, Gökçenur; Kevenk, Tahsin Onur
    Chicken meat is one of the most widely consumed nutrients worldwide. This study aimed to investigate the presence of Salmonella spp. in raw chicken meats by culture, ELISA, and PCR methods. A total of 200 raw chicken meat samples (80 whole chicken carcasses, 60 drumsticks, and 60 wings) were randomly collected from the butchers, supermarkets, and restaurants. The samples were analyzed by culture technique, ELISA, and PCR methods. Salmonella spp. was isolated from 34 of 200 (17 %) chicken meat samples, and 83 % were found negative. Salmonella spp. was isolated from the whole chicken carcass, drumstick, and wing samples as 15 %, 20 %, and 16.6 %, respectively. All samples were also investigated by ELISA and PCR at the same time. According to these results, Salmonella spp. was detected 13% and 16%, respectively. The high prevalence of Salmonella contamination of raw chicken meats may constitute a potential public health risk. To reduce contamination of Salmonella spp., it was stated that good manufacturing practices, good hygiene practices, and HACCP-based quality assurance systems should be applied.
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    Seasonal effect on L. monocytogenes prevalence in meat and dairy products assessed by VIDAS LMO2 and ISO 11290:1 methods
    (Universiti Putra Malaysia, 2022) Kevenk, Tahsin Onur; Koluman, A.
    In the present work, the seasonal distribution of L. monocytogenes in frequently consumed foods in the Aksaray region, an important transition point, was investigated by cultural and automated methods (ISO 11290 and VIDAS LMO2). For this purpose, a total of 800 food samples (100 samples of each white, kashar, cream, and Tulum cheeses, and beef, lamb, chicken, and turkey meats) were analysed. Listeria spp. were detected in 64 (8%) samples, and 177 suspected Listeria colonies were isolated. Of the 177 suspected colonies, 71 were identified as L. monocytogenes by the ISO 11290 and VIDAS LMO2 methods. The pathogen was detected from samples purchased during winter, spring, summer, and autumn at the rates of 3.7, 3, 26, and 3.6%, respectively; the highest isolation rate was found in summer, while the lowest isolation rate found in spring. Although the contamination of L. monocytogenes was found at the highest rate in summer, it has been revealed that there was a risk of listeriosis, which was not low, throughout the entire year.