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Öğe Bacteriophage Applications to Control Listeria monocytogenes in Foods(Nova Science Publishers, Inc., 2022) Ayaz, Naim Deniz; Cufaoglu, Gizem; Erol, IrfanFoods are playing a significant role in human infections and intoxications because they are frequent vehicles of some human pathogens. Animals are primary reservoir of many zoonotic diseases and can transmit pathogens via foods particularly with cross contamination during production and processing entire food chain. Due to lack of hygienic precautions during stable to table, contaminations of food and food products with Listeria monocytogenes can cause foodborne listeriosis. Bacteriophages were first described as bacteria-eating viruses. Compared to other antibacterial agents such as antibiotics and antiseptics, bacteriophages have a different and functional antimicrobial activity. Bacteriophages can be applied to living tissues without causing any harm due to their highly selective toxicity. This is the most important advantage when they compared with antibiotics and antiseptics. Rapidly growing bacterial resistance to antibiotics and urgent need for development of alternative methods, increasing interest in using bacteriophages in treatment, and prophylaxes or as biocontrol agents in foods nowadays. In addition to the systems like HACCP and GMP for food safety from farm to table, the use of specific virulent bacteriophages for Listeria monocytogenes in order to reduce the bacterial load in foods of animal origin emerges as promising method. It is reported that the use of specific virulent bacteriophages to Listeria monocytogenes as a biocontrol and decontamination agent in foods, don’t cause any side effects in humans. Although there are many advantages of bacteriophages such as specificity, effectiveness and showing no toxicity to humans, they have some disadvantages that limit their usage as a decontamination agent. Therefore, further studies should focus on improving the efficiency of lytic activity of bacteriophages to increase the reduction level of pathogens in different food models. Being not cost effective and easy to isolate from different sources make bacteriophages appropriate to be used in various forms such as mixing in food, spraying, attaching to food packaging material or dipping food in phage water alone and/or together with other inhibitors. The phages can prolong the shelf life of foods significantly. In addition to these, they can also be used for the decontamination of the surfaces of food processing plants, treatment of wastewater, and also phage therapy in human and animal diseases including listeriosis, since the world is entering most likely to a post antibiotic era because of rapid increase in antibiotic resistance of pathogens due to imprudent use of antimicrobials. © 2022 by Nova Science Publishers, Inc.Öğe Biocontrol of Shiga Toxigenic Escherichia coli O157:H7 in Turkish Raw Meatball by Bacteriophage(Wiley, 2016) Gencay, Yilmaz Emre; Ayaz, Naim Deniz; Copuroglu, Gizem; Erol, IrfanWith an Escherichia coli O157:H7 virulent bacteriophage, M8AEC16, biocontrol efficiency of phages on a highly risky, ready-to-eat, traditional delicacy food called raw meatball under different storage conditions was investigated. Phage, belonging to the Myoviridae family, was isolated from the wastewater of a local slaughterhouse and showed a broad lytic activity toward many E.coli O157:H7 strains with high efficiency of plating and O157 specificity. Our experimental study provided favorable results, with 0.69-2.09 log colony-forming unit (cfu)/g E.coli O157:H7 reductions in the first 5h of the replica trials. Major reductions of viable E.coli O157:H7 counts were observed in the beginning of the storage period, reaching up to 1.85 log cfu/g. Although a significant reduction in E.coli O157:H7 was observed with increased phage concentration, storage conditions had minor effect on efficiency of phage biocontrol. This is the first study in Turkey that investigates applicability of phage biocontrol for a traditional food model. Practical ApplicationsPhage addition in preparation stage of a very complex food model, ready-to-eat Turkish raw meatball, is a promising application in decontamination of Escherichia coli O157:H7. Although investigation of its genomic characteristics along with its stability to different food matrices must be completed for further use of the model phage M8AEC16, findings of this work were encouraging, as phages are valuable in biocontrol of important foodborne in this ready-to-eat Turkish delicacy.Öğe Comparison Of Prevalence And Genetic Diversity Of Escherichia Coli O157:H7 In Cattle And Sheep(Slovak Univ Agriculture Nitra, 2016) Erol, Irfan; Goncuoglu, Muammer; Ayaz, Naim Deniz; Ormanci, Fatma Seda BilirIn this study the prevalence of Escherichia coli O157: H7 was detected by immunomagnetic separation (IMS) based cultivation technique and polymerase chain reaction (PCR) in feces and/or colon tissue of cattle (n= 282) and sheep (n= 218) at slaughterhouse. The major virulence genes, intimin variants, Shiga toxin variants and antibiotic resistance genes of the isolates were examined by PCR and genomic diversity of the cattle and sheep E. coli O157: H7 isolates were assessed using pulsed field gel electrophoresis (PFGE). In the present study the prevalence of E. coli O157: H7 was found higher in sheep (6.4 %) than in cattle (3.9 %). All the E. coli O157: H7 isolates were detected as positive for at least one stx gene and positive for other virulence genes. Twelve (29.3 %) and one (2.4 %) of the cattle isolates carried stx2 and stx1 gene, respectively. However 11 (17.7 %) of the sheep E. coli O157: H7 isolates carried stx2 and five (8.1 %) of the isolates harbored stx1 gene only. At least one antibiotic resistance gene was detected from 35 isolates. E. coli O157: H7 isolates from four sheep and three cattle harbored tetB gene. From three cattle and one sheep samples strA carrying E. coli O157: H7 were isolated. Among them, isolates from 2 cattle and one sheep samples were carried both tetB and strA. Isolates were grouped into six different clusters. From a cattle and a sheep, two different E. coli O157: H7 which have different PFGE patterns, were isolated. It can be concluded that sheep pose a risk as cattle for STEC O157: H7 contamination in Turkey.Öğe Food Safety Awareness, Changes in Food Purchasing Behaviour and Attitudes towards Food Waste during COVID-19 in Türkiye(Mdpi, 2023) Erol, Irfan; Mutus, Begum; Ayaz, Naim Deniz; Stowell, Julian D.; Siriken, Belgin(1) Background: The COVID-19 pandemic brought the key issues of food security, food safety, and food waste into sharp focus. Turkiye is in the enviable position of being among the top ten agricultural economies worldwide, with a wide diversity of food production. This survey was undertaken in order to gain insights into consumer behaviour and attitudes in Turkiye with respect to these issues. The objective was to highlight strengths and weaknesses, identify areas for improvement, and present strategies for the future. (2) Methods: This survey was carried out between April and May 2022 in 12 provinces throughout Turkiye. Face-to-face interviews were performed with 2400 participants representing a cross-section of ages, educational attainment, and socio-economic categories. The findings were evaluated statistically. (3) Results: The results provide an insight into attitudes and behaviours, both pre-COVID-19 and during the pandemic. In several ways, the pandemic enhanced knowledge and improved behaviour, leading to improvements in diet and reductions in food waste. However, worrying concerns about food safety persist. Specific attention has been given to understanding patterns of bread consumption, particularly in consideration of waste. (4) Conclusions: It is hoped that the results of this survey will increase dialogue between the components of the food sector, encourage education initiatives, and contribute to improving food safety and security and reducing food waste in Turkiye and beyond.Öğe Phenotypic and genotypic antibiotic resistance profiles of Escherichia coli O157 from cattle and slaughterhouse wastewater isolates(Springer, 2015) Ayaz, Naim Deniz; Gencay, Yilmaz Emre; Erol, IrfanThe aims of this study were to determine the minimal inhibition concentration of 20 different antibiotics on cattle and slaughterhouse wastewater Escherichia coli O157, including both Shiga toxigenic E. coli O157 (STEC O157) and non-Shiga toxigenic strains (non-STEC O157) by the Epsilometer test, and to determine the antibiotic resistance gene profiles of the isolates by PCR. A total of 102 cattle and slaughterhouse wastewater E. coli O157 isolates including 96 E. coli O157:H7(+) (81 non-sorbitol fermenting [NSF] STEC O157:H7, 12 NSF non-STEC O157:H7, and three sorbitol fermenting [SF] non-STEC O157:H7) and six non-STEC O157:H7(-) isolated from 744 cattle and slaughterhouse wastewater samples collected within a 2-year period were assessed. Of 93 NSF E. coli O157:H7 isolates, 19 were resistant to tetracycline and sulfamethoxazole, 14 to trimethoprim, 13 to cefoxitin, 11 to streptomycin, 10 to ampicillin, eight to chloramphenicol, six to cephalothin, four to cefaclor, four to aztreonam, and four to nalidixic acid. In six of the E. coli O157:H7(-) isolates, tetracycline resistance was detected while five of them were also resistant to ampicillin, sulfamethoxazole, and trimethoprim. In PCR analysis, 26.0 % (25/96) of the NSF E. coli O157:H7(+) and all of the E. coli O157:H7(-) isolates harbored one or more antibiotic resistance genes. While tetA, tetB, tetC, strA, strB, and sulI genes were detected from a number of the isolates, tetD, tetE, tetG, cmlA, floR, sulII, aadA, and ampC genes were not detected in any of the isolates. Results suggest a high antibiotic resistance in E. coli O157:H7(+)/H7(-) cattle and wastewater isolates. The majority of our resistant isolates, antibacterial resistance genes did not correlate with observed phenotypic resistance. Other resistance traits and regulatory factors that mediate antibiotic resistance should be included in further antimicrobial resistance investigations.Öğe Plasmid-Mediated Colistin Resistance in Escherichia coli O157:H7 Cattle and Sheep Isolates and Whole-Genome Sequence of a Colistin-Resistant Sorbitol Fermentative Escherichia coli O157:H7(Mary Ann Liebert, Inc, 2019) Ayaz, Naim Deniz; Cufaoglu, Gizem; Yonsul, Yesim; Goncuoglu, Muammer; Erol, IrfanThe aims of this study were to investigate the plasmid-mediated colistin resistance genes (mcr-1, mcr-2, mcr-3, mcr-4, and mcr-5), phenotypic colistin resistance in Escherichia coli O157:H7(+)/H7(-) strains isolated from cattle and sheep, and whole-genome sequence (WGS) analysis of colistin-resistant sorbitol fermentative E. coli O157:H7. According to the results, 5 of the 49 isolates were found to harbor mcr-2 and/or mcr-3 genes. Three isolates, including a sorbitol fermentative E. coli O157:H7, were found phenotypically resistant to colistin with a minimum inhibitory concentration value of 128 mu g/mL. The genome of sorbitol fermentative E. coli O157:H7 did not show 100% similarity to any of the other genome sequences found in the universal genome database. It has also been determined that this isolate carried 62 different antimicrobial resistance genes. This is the first report of plasmid-mediated mcr-2 and mcr-3 genes carrying E. coli O157:H7 from cattle and sheep isolates and WGS of a colistin-resistant sorbitol fermentative E. coli O157:H7. Findings of this study indicate that cattle and sheep can be an important source of colistin resistance in E. coli O157:H7, and slaughterhouse wastewater might be a significant route for dissemination of the plasmid-mediated colistin genes. Therefore, the use of colistin in veterinary medicine should be restricted to reduce the development of resistance. Also it may be necessary to review the non-sorbitol fermentation-based isolation protocol for not missing the sorbitol fermentative E. coli O157:H7 in epidemiological studies.Öğe Prevalence and Characterization of Listeria monocytogenes Isolated from Beef and Sheep Carcasses in Turkey with Characterization of Locally Isolated Listeriophages as a Control Measure(Int Assoc Food Protection, 2018) Ayaz, Naim Deniz; Onaran, Bahar; Cufaoglu, Gizem; Goncuoglu, Muammer; Ormanci, Fatma Seda; Erol, IrfanSwab samples from cattle and sheep carcasses (120 of each) were tested for Listeria monocytogenes, and 120 slaughterhouse wastewater samples were tested for listeriophages over 12 months (10 samples per month) to note the seasonal distribution. L. monocytogenes and bacteriophage isolates were characterized, and the biocontrol of L. monocytogenes was investigated in meatballs with a phage cocktail. L. monocytogenes was found in 3.4 and 2.5% of cattle and sheep carcasses, respectively. All the isolates were found to harbor hlyA, actA, inlA, inlB, inlC, inlJ, plcA, plcB, fbpA, and fri genes with varied mRNA expression levels by real-time reverse transcriptase PCR analysis. Five isolates did not harbor the vip gene. According to enterobacterial repetitive intergenic consensus PCR, L. monocytogenes isolates were classified into four different groups based on their DNA patterns. The L. monocytogenes isolates were characterized for antibiotic susceptibility; one strain was found to be resistant to five different antibiotic classes. Of 11 lytic listeriophages, two were selected for the cocktail based on their DNA restriction profiles, efficiency of plating, transmission electron microscopy, and in vitro and in vivo analyses. In the biocontrol study, we used a food model that consisted of a novel bacteriophage cocktail in raw meatballs. The highest reduction of L. monocytogenes was recorded as 2.2 log CFU/g at a multiplicity of cellular infection of 4.7 at the end of 1 h. In conclusion, the new bacteriophage cocktail in this study can be considered an efficient biocontrol agent of L. monocytogenes in meatballs.Öğe Prevalence and molecular characterization of sorbitol fermenting and non-fermenting Escherichia coli O157:H7+/H7– isolated from cattle at slaughterhouse and slaughterhouse wastewater(Elsevier, 2014) Ayaz, Naim Deniz; Gencay, Yilmaz Emre; Erol, IrfanThe prevalence and seasonal distribution of E. colt 0157:H7(+)/H7(-) in an array of aged cattle at slaughter and its dissemination with slaughterhouse wastewater over a two year period in Turkey were investigated. For this purpose, a total of 720 samples (240 rectoanal mucosal swap [RAMS], 240 carcass sponge and 240 bile samples) of 240 cattle categorized according to age, gender, breed and sampling site were collected along with additional 24 wastewater samples and were subjected to immunomagnetic separation based cultivation technique to efficiently isolate E. coli 0157 from the background flora. Identification (rfbE(0157),fliC(h7)), detection of major virulence factors (sbc7, sU2, eaeA, hly, lpfA1-3 and espA), intimin variants (eae-alpha 1, eae-alpha 2, eae-beta 3, eae-beta 1, eae-beta 2, eae-gamma l and eae-gamma 2/0) and shiga toxin variants (stx70 stx(1d), stx(2c), stx(2d), stx(2e), stx(2f)and stx(2g)) of all the isolates were assessed by PCR. From 10(42%) of RAMS and 11(4.6%) of carcass sponge samples and 5 (20.8%) of slaughterhouse wastewater samples, a total of 102 colonies (99 sorbitol negative and 3 sorbitol positive) were isolated. Overall, 17 (7.1%) and 15 (6.3%) of 240 sampled cattle were shown to harbor E. coli 0157 and E. colt 0157:H7, respectively either in their RAMS or carcass sponge samples analyzed. Statistically significant differences between categories; season, age, gender and breed of cattle were not observed (p > 0.05). None of the isolated E. coli 0157:H7+/H7- strains harbored any of the investigated intimin types other than eaeyi or shiga toxin variants stx(1d), StX(2e), six(2f) or StX(2g) while all were lpfA1-3+ except 5 E. coli 0157:H7- strains. Intimin variant eaey, and shiga toxin 1 variant stx/c were detected from all of the eaeA+ (97/102, 95.1%) and stxt (32/102,313%) strains, respectively while from sbd" (80/102, 78.4%) isolates, both stx(2c) (68/80, 85.0%) and 5tx(2d) (12/80, 15.0%) variants were determined. In the last decade, prevalence of E. coli 0157:H7 has an increasing trend in cattle. Slaughterhouses are the significant sources of environmental contamination with E. coli 0157:H7. Isolation and molecular characterization of sorbitol fermenting E. coli 0157:H7 are a novel finding and may lead to a revision of reference isolation procedure of E. coli 0157:H7 in future. (C) 2014 Elsevier B.V. All rights reserved.Öğe Significance of Listeria monocytogenes as a Food-Borne Bacterial Pathogen(Nova Science Publishers, Inc., 2022) Ayaz, Naim Deniz; Cufaoglu, Gizem; Erol, IrfanListeria monoytogenes is an intracellular, zoonotic foodborne bacterium which causes listeriosis in humans. Due to widespread tolerance in natural conditions, growth at refrigerator temperature and broad pH spectrum provides difficulty in controlling bacterial growth and storage. Among 13 serotypes, 1/2a, 1/2b, 1/2c and 4b are the main serotypes causing infections in humans. It was stated that the serotype 4b is responsible for 30-50% of sporadic listeriosis cases in humans worldwide. However, in most countries serotype 1/2a is more frequently isolated from foods. Listeria monocytogenes is the only pathogen species of Listeria for humans which causes mild flu-like symptoms to meningitis, meningoencephalitis, septicemia, conjunctivitis and pneumonia. Although salmonellosis and campylobacteriosis are more common foodborne bacterial diseases worldwide, listeriosis is distinguished with high mortality rate up to 20-30%. Epidemiologic studies have revealed that a significant proportion of cases of listeriosis caused by contaminated foods. The growth potential of Listeria monocytogenes in meat and meat products particularly in poultry meat, depends on the type of product, the pH, the number and type of microorganisms found in microflora. There are many studies indicating that chicken and turkey meat are significant sources of Listeria monocytogenes. Regarding to foodborne Listeria monocytogenes infections, ready-to-eat (RTE) foods, unpasteurized milk and dairy products, raw meat and meat products and salads take place as the main risk groups of foods. The slaughtered animals may carry Listeria monocytogenes both symptomatically or asymptomatically, or the meat can be contaminated during or after the slaughtering process. On the other hand, it has been reported that sea products including shellfish (especially fresh and frozen mussels) and raw, salted or cold smoked fish are considered as high-risk foods for foodborne listeriosis. © 2022 by Nova Science Publishers, Inc.
