Tahsin Onur Kevenk - Academia.edu (original) (raw)

Papers by Tahsin Onur Kevenk

Research paper thumbnail of Detection of EnterotoxigenicStaphylococcus aureusin Raw Milk and Dairy Products by Multiplex PCR

Journal of Food Science, 2012

The aim of this study was to investigate the prevalence of enterotoxigenic Staphylococcus aureus ... more The aim of this study was to investigate the prevalence of enterotoxigenic Staphylococcus aureus in 122 samples, including 60 raw milk, 32 white cheese, 10 kashar cheese, 10 butter, and 10 ice cream samples obtained from Samsun province, Turkey. In this study, S. aureus was detected in 64 samples, including raw milk (45/60; 75%), white cheese (12/32; 37.5%), kashar cheese (3/10; 30%), butter (3/10; 30%), and ice cream (1/10; 10%) samples. A total of 81 isolates were identified as S. aureus by PCR with the presence of 16S rRNA and nuc genes. The presence of genes encoding the staphylococcal enterotoxins (SEs) SEA, SEB, SEC, and SED was detected by multiplex PCR. According to the analysis, seven isolates from the raw milk samples (7/51; 13.7%) were enterotoxigenic; five of them produced SEA (5/7; 71.4%), one produced SEB (1/7; 14.2%), and one produced SEA+SEB (1/7; 14.2%). Four isolates from the white cheese samples (4/21; 19%) produced the SEA (1/4; 25%), SEC (1/4; 25%), SED (1/4; 25%), and SEA+SED (1/4; 25%) toxins. Two isolates from the kashar cheese samples (2/4; 50%) were found to be enterotoxigenic; one produced SEA (1/2; 50%) and the other produced SED (1/2; 50%). One isolate from the butter samples (1/4; 25%) showed enterotoxigenic character (SEB, 1/1; 100%). The products were found to be potentially hazardous to public health because of the fact that levels of contamination were higher than 105-106 cfu/g ml in 39% (25/64, 17 raw milk, 7 white cheese, and 1 butter) of the analyzed samples.

Research paper thumbnail of Determination of Carbapenem-Resistant Enterobacteriaceae from Chicken Meat by Advanced Modified ISO 21528-1:2017 Method

Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Food Science and Technology

Antibiotic resistance is critical today, and carbapenem-resistant Enterobacteriaceae (CRE) are th... more 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. ...

Research paper thumbnail of ICNASE'16 Antibiotic Resistance Patterns of Salmonella isolates from Chicken Meat

Research paper thumbnail of Seasonal effect on L. monocytogenes prevalence in meat and dairy products assessed by VIDAS LMO2 and ISO 11290:1 methods

International Food Research Journal

In the present work, the seasonal distribution of L. monocytogenes in frequently consumed foods i... more 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...

Research paper thumbnail of Decontamination Effect of Zinc Oxide Nanoparticles, Rosmarinic Acid and Anatolian Propolis on Foodborne Bacteria

Turkish Journal of Agriculture - Food Science and Technology

Zinc oxide (ZnO) has been used in the pharmaceutical, cosmetic, paint, textile, and food industri... more 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 Zn...

Research paper thumbnail of Invitro Decontamination Effect of Zinc Oxide Nanoparticles (ZnO-NPs) on Important Foodborne Pathogens

Research paper thumbnail of Presence of Clostridium perfringens in Traditional Turkish Chicken Doner Kebabs and Determination of the cpa and cpe Genes by mPCR

Ankara Üniversitesi Veteriner Fakültesi Dergisi

Research paper thumbnail of Aflatoxin M1 Contamination of Anatolian Water Buffalo Milk

Etlik Veteriner Mikrobiyoloji Dergisi

Research paper thumbnail of The prevalence of Escherichia coli 0157 and O157:H7 in ground beef and raw meatball by immunomagnetic separation and the detection of virulence genes using multiplex PCR

Research paper thumbnail of Prevalence, Antimicrobial Resistance and Serotype Distribution of L isteria monocytogenes Isolated from Raw Milk and Dairy Products

Journal of Food Safety, 2015

ABSTRACT

Research paper thumbnail of Sütlü Tatlılardan İzole Edilen Bacillus cereus Suşlarının Enterotoksijenik Gen Profillerinin Multipleks PCR ile Belirlenmesi

Kafkas Universitesi Veteriner Fakultesi Dergisi, 2013

ABSTRACT

Research paper thumbnail of Determination of Enterotoxigenic and Methicillin Resistant Staphylococcus aureus in Ice Cream

Journal of Food Science, 2013

The aim of this study was to determine the prevalence of enterotoxigenic and methicillin-resistan... more The aim of this study was to determine the prevalence of enterotoxigenic and methicillin-resistant Staphylococcus aureus in ice creams. After culture-based identification of isolates, the presence of 16S rRNA and nuc was confirmed by mPCR. S. aureus was identified in 18 of 56 fruity (32.1%), 4 of 32 vanilla (12.5%), and 1 of 12 chocolate (8.3%) ice creams. S. aureus was identified as 38 isolates in 23 ice cream samples by culture-based techniques, but only 35 isolates were confirmed by PCR as S. aureus. To determine the enterotoxigenic properties of PCR-confirmed S. aureus isolates, a toxin detection kit was used (SET RPLA®). Of the 12 enterotoxigenic S. aureus isolates, 9 SEB (75%), 1 SED (8.3%), 1 SEB+SED (8.3%), and 1 SEA+SEB+SED (8.3%) expressing isolates were found. The presence of enterotoxin genes (sea, seb, sed) was identified in 13 (37.1%) out of 35 isolates by the mPCR technique. In the ice cream isolates, the sea, seb, and sed genes were detected: 1 sea (7.6%), 9 seb (69.2%), 1 sed (7.6%), 1 seb+sed (7.6%), and 1 sea+seb+sed (7.6%), respectively. The sec gene was not detected in any of these isolates. One of the 35 (2.8%) S. aureus strain was mecA positive.

Research paper thumbnail of Molecular typing and cdt genes prevalence of Campylobacter jejuni isolates from various sources

Tropical Animal Health and Production

The genetic diversity of 168 Campylobacter jejuni isolates originating from human (n=30), cattle ... more The genetic diversity of 168 Campylobacter jejuni isolates originating from human (n=30), cattle (n=36), sheep (n=44), dog (n=35), and poultry (n=21) and cdt genes prevalence of the isolates were investigated. To determine the genetic diversity of these strains, random amplified polymorphic DNA-polymerase chain reaction (PCR) using a random primer (M13) was performed. The numbers of genotypes determined in human, cattle, sheep, dog, and poultry isolates were 19, 18, 17, 18, and 6, respectively. To find out the prevalence of cdt genes in C. jejuni isolates simultaneously, a multiplex PCR was performed. The prevalence of the separate cdt genes was found to vary from 69% to 100% for cdtA, 92% to 100% for cdtB, and 39% to 98% for cdtC. These rates without host discriminating were 95%, 98%, and 93% for cdtA, cdtB, and cdtC, respectively. The prevalence of all three cdt genes in strains originating from human, cattle, sheep, dog, and poultry were 87%, 67%, 84%, 89%, and 39%, respectively....

Research paper thumbnail of Laktik Asit ve Kitosanın Soğukta Muhafaza Edilen Midyelerdeki Kalite Değişiklikleri Üzerine Etkileri

Kafkas Universitesi Veteriner Fakultesi Dergisi, 2013

The objective of this study was to determine the effects of different pretreatment agents such as... more The objective of this study was to determine the effects of different pretreatment agents such as chitosan (0.5% (w/v), pH 2.9-3.2) and lactic acid (0.5% (v/v), pH 2.5-2.7) on the chemical and sensory qualities of mussels stored at 4ºC. Mussels were dipped in 100 mL of 0.5% solution of lactic acid (v/v) and chitosan (w/v) at room temperature (22ºC) for 15 min. Mussels from the control group were dipped in 100 mL of sterile distiled water (2% NaCl) without chitosan and lactic acid. Treatment of mussels with lactic acid and chitosan at the beginning of the experiment (day 0) for 15 min reduced bacterial counts of total aerobic mesophilic bacteria (0.53-1.07 log) psychrotrophic bacteria (0.11-0.13 log), Lactobacillus spp. (0.46-1.30 log), enterobacteriaceae (0.43-0.48 log) and coliform bacteria (0.52-0.66 log). Total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA), trimethylamine nitrogen (TMA-N) and histamine values of control group mussels were increased from (day 0) 13.1 mg N 100 g-1 , 1.37 mg MA kg-1 , 1.97 mg N 100 g-1 and 4 ppm to 39.9 mg N 100 g-1 , 3.02 mg MA kg-1 , 4.86 mg N 100 g-1 and 7.75 ppm at the end of the storage period (day 11), respectively (P<0.05). The results indicated that shelf-life of mussels stored at 4ºC were limited to 4 days in the control group. However, mussels pretreated with lactic acid and chitosan were stored for 6-7 days and the shelf-life of mussels was extended for ca. 2-3 days, as compared with the control group (P<0.05).

Research paper thumbnail of The prevalence of Escherichia coli O157 and O157: H7 in ground beef and raw meatball by immunomagnetic separation and the detection of virulence genes using …

Meat science, 2010

The present study was conducted to investigate the presence of Escherichia coli O157 and O157:H7 ... more The present study was conducted to investigate the presence of Escherichia coli O157 and O157:H7 strains and to detect the presence of the stx1, stx2, and eaeA genes in isolates derived from 200 samples (100 samples from fresh ground beef and 100 samples from raw meatball). The samples were purchased from the Samsun Province in Turkey, over a period of 1 year. Enrichment-based immunomagnetic separation and multiplex polymerase chain reaction were applied for these analyses. E. coli O157 was detected in five of the 200 (2.5%) samples tested (one isolated from ground beef and four from meatball samples), whereas E. coli O157: H7 was not detected in any sample. During the analysis, eight strains of E. coli O157 were obtained. The genes stx1, stx2, and eaeA were detected in two E. coli O157 isolates obtained from two meatball samples, whereas only the eaeA and the stx2 genes were detected in four E. coli O157 strains that were isolated from one meatball sample. None of the stx1, stx2, and eaeA was detected in the E. coli O157 isolates obtained from the ground beef and the one meatball samples.

Research paper thumbnail of Detection of EnterotoxigenicStaphylococcus aureusin Raw Milk and Dairy Products by Multiplex PCR

Journal of Food Science, 2012

The aim of this study was to investigate the prevalence of enterotoxigenic Staphylococcus aureus ... more The aim of this study was to investigate the prevalence of enterotoxigenic Staphylococcus aureus in 122 samples, including 60 raw milk, 32 white cheese, 10 kashar cheese, 10 butter, and 10 ice cream samples obtained from Samsun province, Turkey. In this study, S. aureus was detected in 64 samples, including raw milk (45/60; 75%), white cheese (12/32; 37.5%), kashar cheese (3/10; 30%), butter (3/10; 30%), and ice cream (1/10; 10%) samples. A total of 81 isolates were identified as S. aureus by PCR with the presence of 16S rRNA and nuc genes. The presence of genes encoding the staphylococcal enterotoxins (SEs) SEA, SEB, SEC, and SED was detected by multiplex PCR. According to the analysis, seven isolates from the raw milk samples (7/51; 13.7%) were enterotoxigenic; five of them produced SEA (5/7; 71.4%), one produced SEB (1/7; 14.2%), and one produced SEA+SEB (1/7; 14.2%). Four isolates from the white cheese samples (4/21; 19%) produced the SEA (1/4; 25%), SEC (1/4; 25%), SED (1/4; 25%), and SEA+SED (1/4; 25%) toxins. Two isolates from the kashar cheese samples (2/4; 50%) were found to be enterotoxigenic; one produced SEA (1/2; 50%) and the other produced SED (1/2; 50%). One isolate from the butter samples (1/4; 25%) showed enterotoxigenic character (SEB, 1/1; 100%). The products were found to be potentially hazardous to public health because of the fact that levels of contamination were higher than 105-106 cfu/g ml in 39% (25/64, 17 raw milk, 7 white cheese, and 1 butter) of the analyzed samples.

Research paper thumbnail of Determination of Carbapenem-Resistant Enterobacteriaceae from Chicken Meat by Advanced Modified ISO 21528-1:2017 Method

Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Food Science and Technology

Antibiotic resistance is critical today, and carbapenem-resistant Enterobacteriaceae (CRE) are th... more 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. ...

Research paper thumbnail of ICNASE'16 Antibiotic Resistance Patterns of Salmonella isolates from Chicken Meat

Research paper thumbnail of Seasonal effect on L. monocytogenes prevalence in meat and dairy products assessed by VIDAS LMO2 and ISO 11290:1 methods

International Food Research Journal

In the present work, the seasonal distribution of L. monocytogenes in frequently consumed foods i... more 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...

Research paper thumbnail of Decontamination Effect of Zinc Oxide Nanoparticles, Rosmarinic Acid and Anatolian Propolis on Foodborne Bacteria

Turkish Journal of Agriculture - Food Science and Technology

Zinc oxide (ZnO) has been used in the pharmaceutical, cosmetic, paint, textile, and food industri... more 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 Zn...

Research paper thumbnail of Invitro Decontamination Effect of Zinc Oxide Nanoparticles (ZnO-NPs) on Important Foodborne Pathogens

Research paper thumbnail of Presence of Clostridium perfringens in Traditional Turkish Chicken Doner Kebabs and Determination of the cpa and cpe Genes by mPCR

Ankara Üniversitesi Veteriner Fakültesi Dergisi

Research paper thumbnail of Aflatoxin M1 Contamination of Anatolian Water Buffalo Milk

Etlik Veteriner Mikrobiyoloji Dergisi

Research paper thumbnail of The prevalence of Escherichia coli 0157 and O157:H7 in ground beef and raw meatball by immunomagnetic separation and the detection of virulence genes using multiplex PCR

Research paper thumbnail of Prevalence, Antimicrobial Resistance and Serotype Distribution of L isteria monocytogenes Isolated from Raw Milk and Dairy Products

Journal of Food Safety, 2015

ABSTRACT

Research paper thumbnail of Sütlü Tatlılardan İzole Edilen Bacillus cereus Suşlarının Enterotoksijenik Gen Profillerinin Multipleks PCR ile Belirlenmesi

Kafkas Universitesi Veteriner Fakultesi Dergisi, 2013

ABSTRACT

Research paper thumbnail of Determination of Enterotoxigenic and Methicillin Resistant Staphylococcus aureus in Ice Cream

Journal of Food Science, 2013

The aim of this study was to determine the prevalence of enterotoxigenic and methicillin-resistan... more The aim of this study was to determine the prevalence of enterotoxigenic and methicillin-resistant Staphylococcus aureus in ice creams. After culture-based identification of isolates, the presence of 16S rRNA and nuc was confirmed by mPCR. S. aureus was identified in 18 of 56 fruity (32.1%), 4 of 32 vanilla (12.5%), and 1 of 12 chocolate (8.3%) ice creams. S. aureus was identified as 38 isolates in 23 ice cream samples by culture-based techniques, but only 35 isolates were confirmed by PCR as S. aureus. To determine the enterotoxigenic properties of PCR-confirmed S. aureus isolates, a toxin detection kit was used (SET RPLA®). Of the 12 enterotoxigenic S. aureus isolates, 9 SEB (75%), 1 SED (8.3%), 1 SEB+SED (8.3%), and 1 SEA+SEB+SED (8.3%) expressing isolates were found. The presence of enterotoxin genes (sea, seb, sed) was identified in 13 (37.1%) out of 35 isolates by the mPCR technique. In the ice cream isolates, the sea, seb, and sed genes were detected: 1 sea (7.6%), 9 seb (69.2%), 1 sed (7.6%), 1 seb+sed (7.6%), and 1 sea+seb+sed (7.6%), respectively. The sec gene was not detected in any of these isolates. One of the 35 (2.8%) S. aureus strain was mecA positive.

Research paper thumbnail of Molecular typing and cdt genes prevalence of Campylobacter jejuni isolates from various sources

Tropical Animal Health and Production

The genetic diversity of 168 Campylobacter jejuni isolates originating from human (n=30), cattle ... more The genetic diversity of 168 Campylobacter jejuni isolates originating from human (n=30), cattle (n=36), sheep (n=44), dog (n=35), and poultry (n=21) and cdt genes prevalence of the isolates were investigated. To determine the genetic diversity of these strains, random amplified polymorphic DNA-polymerase chain reaction (PCR) using a random primer (M13) was performed. The numbers of genotypes determined in human, cattle, sheep, dog, and poultry isolates were 19, 18, 17, 18, and 6, respectively. To find out the prevalence of cdt genes in C. jejuni isolates simultaneously, a multiplex PCR was performed. The prevalence of the separate cdt genes was found to vary from 69% to 100% for cdtA, 92% to 100% for cdtB, and 39% to 98% for cdtC. These rates without host discriminating were 95%, 98%, and 93% for cdtA, cdtB, and cdtC, respectively. The prevalence of all three cdt genes in strains originating from human, cattle, sheep, dog, and poultry were 87%, 67%, 84%, 89%, and 39%, respectively....

Research paper thumbnail of Laktik Asit ve Kitosanın Soğukta Muhafaza Edilen Midyelerdeki Kalite Değişiklikleri Üzerine Etkileri

Kafkas Universitesi Veteriner Fakultesi Dergisi, 2013

The objective of this study was to determine the effects of different pretreatment agents such as... more The objective of this study was to determine the effects of different pretreatment agents such as chitosan (0.5% (w/v), pH 2.9-3.2) and lactic acid (0.5% (v/v), pH 2.5-2.7) on the chemical and sensory qualities of mussels stored at 4ºC. Mussels were dipped in 100 mL of 0.5% solution of lactic acid (v/v) and chitosan (w/v) at room temperature (22ºC) for 15 min. Mussels from the control group were dipped in 100 mL of sterile distiled water (2% NaCl) without chitosan and lactic acid. Treatment of mussels with lactic acid and chitosan at the beginning of the experiment (day 0) for 15 min reduced bacterial counts of total aerobic mesophilic bacteria (0.53-1.07 log) psychrotrophic bacteria (0.11-0.13 log), Lactobacillus spp. (0.46-1.30 log), enterobacteriaceae (0.43-0.48 log) and coliform bacteria (0.52-0.66 log). Total volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA), trimethylamine nitrogen (TMA-N) and histamine values of control group mussels were increased from (day 0) 13.1 mg N 100 g-1 , 1.37 mg MA kg-1 , 1.97 mg N 100 g-1 and 4 ppm to 39.9 mg N 100 g-1 , 3.02 mg MA kg-1 , 4.86 mg N 100 g-1 and 7.75 ppm at the end of the storage period (day 11), respectively (P<0.05). The results indicated that shelf-life of mussels stored at 4ºC were limited to 4 days in the control group. However, mussels pretreated with lactic acid and chitosan were stored for 6-7 days and the shelf-life of mussels was extended for ca. 2-3 days, as compared with the control group (P<0.05).

Research paper thumbnail of The prevalence of Escherichia coli O157 and O157: H7 in ground beef and raw meatball by immunomagnetic separation and the detection of virulence genes using …

Meat science, 2010

The present study was conducted to investigate the presence of Escherichia coli O157 and O157:H7 ... more The present study was conducted to investigate the presence of Escherichia coli O157 and O157:H7 strains and to detect the presence of the stx1, stx2, and eaeA genes in isolates derived from 200 samples (100 samples from fresh ground beef and 100 samples from raw meatball). The samples were purchased from the Samsun Province in Turkey, over a period of 1 year. Enrichment-based immunomagnetic separation and multiplex polymerase chain reaction were applied for these analyses. E. coli O157 was detected in five of the 200 (2.5%) samples tested (one isolated from ground beef and four from meatball samples), whereas E. coli O157: H7 was not detected in any sample. During the analysis, eight strains of E. coli O157 were obtained. The genes stx1, stx2, and eaeA were detected in two E. coli O157 isolates obtained from two meatball samples, whereas only the eaeA and the stx2 genes were detected in four E. coli O157 strains that were isolated from one meatball sample. None of the stx1, stx2, and eaeA was detected in the E. coli O157 isolates obtained from the ground beef and the one meatball samples.