Usage of Enterococcus faecium as starter culture in white cheese production

Goncuoglu, Muammer/0000-0001-7245-1941WOS: 000273222800003The objectives of the present Study was to determine the function of Enterococcus faecium as a starter Culture in Turkish white cheese and to investigate the effects oil the ripening period and the texture defects. Two types (traditional - white cheese made with high temperature pasteurized milk) of white cheeses were produced. All groups were ripened in vacuum pack at 4 degrees C for 90 d. Cheese samples were assessed for microbiological and compositional properties, proteolysis, and sensory evaluation at different ripening stages. E. faecium FAIR-E 198 Survived to numbers 10(7) cfu/g in two type of cheeses until 90 d of ripening. Although lactic acid was not significantly different in two types, city matter, salt in dry matter, fiat in dry matter and total protein were significantly different between two types of cheeses. Treatment group of the traditional cheese had the highest sensory scores of all cheeses. Consequently, E. faecium FAIR-E 198 could be used as a functional starter for white cheese and be shorten ripening time

Comparison of hipO and ceuE Gene Based PCR Assays for the Detection of Campylobacter Jejuni

Campylobacter infections are one of the most prevalent zoonotic bacterial foodborne diseases of humans mostly caused by C. coli and C. jejuni. In the last decade, the prevalence of gastroenteritis caused by Campylobacter species were in an increasing trend [1]. In addition to enteritis, extraintestinal infections and sequelae may occur, including bacteremia, urinary tract infection, reactive arthritis and “Guillain–Barre´ syndrome” affecting the peripheral nervous system [2]. As C. jejuni has an ability to colonize and in some cases infect poultry intestine which makes poultry meat a significant reservoir and vehicle of foodborne campylobacteriosis [3]. In order to find out the prevalence of Campylobacter in poultry meat, routinely, conventional culturing technique is using in many food control laboratories [4]. Campylobacter species are known as fastidious microorganisms, so mostly it is hard to detect with conventional method and isolate by routine media [5]. In general, detection of Campylobacter species especially C. jejuni, is difficult and time consuming using conventional techniques. Therefore specific, sensitive and rapid methods are needed for the detection of Campylobacter spp. from food. To overcome these concerns many detection and molecular-based typing methods including PCR have been developed and used as an important and effective tool for the detection of Campylobacter spp. [6-10].</p

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

Goncuoglu, Muammer/0000-0001-7245-1941WOS: 000476250300001PubMed: 31314669The 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

COMPARISON OF PREVALENCE AND GENETIC DIVERSITY OF ESCHERICHIA COLI O157: H7 IN CATTLE AND SHEEP

Goncuoglu, Muammer/0000-0001-7245-1941;WOS: 000458341900012In 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.TUBITAK (The Scientific and Technological Research Council of Turkey)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [107T612]; Ankara University, Biotechnology Scientific Research Project (BIAP) [2001K120-240]This study was supported by TUBITAK (The Scientific and Technological Research Council of Turkey) grant no. 107T612 and Ankara University, Biotechnology Scientific Research Project (BIAP) grant no. 2001K120-240

Biocontrol of Escherichia coli O157:H7 in ready-to-eat salad using a lytic bacteriophage

Goncuoglu, Muammer/0000-0001-7245-1941; ONARAN, BAHAR/0000-0002-3515-7548;WOS: 000404398800007E. coli O157:H7 is a life threatening foodborne pathogen associated with thousands of infections. Controlling such bacterial pathogens in raw and ready-to-eat foods has gained urgency with each passing day. The use of specific virulent bacteriophages as a biocontrol agent on minimally processed foods is an effective, natural and non-destructive treatment. This study was aimed at determining the efficiency of a lytic bacteriophage against E. coli O157:H7 in ready-to-eat salads. For this purpose, E. coli O157:H7 NCTC 12900 (EC00) and nalidixic acid resistant E. coli O157:H7 ATCC 43895 (NA-EC95) were used as the model bacterium in decontamination trials of mayonnaise based ready-to-eat salads which are consumed without any heating process and include beans, carrots, potatoes, pickled cucumbers and salami. A previously described phage M8AEC16 which was classified in Myoviridae family was used as the biocontrol agent. The highest reductions were observed at 22 degrees C storage conditions. Reductions reaching up to 2.7 log cfu/g of viable E. coli O157:H7 counts were observed in the beginning of the storage period. The findings of the study showed that phage M8AEC16 can be used as a biocontrol agent in the decontamination of E. coli O157:H7 in such mayonnaise based ready-to-eat salads

Prevalence and Characterization of Listeria monocytogenes Isolated from Beef and Sheep Carcasses in Turkey with Characterization of Locally Isolated Listeriophages as a Control Measure

Goncuoglu, Muammer/0000-0001-7245-1941; ONARAN, BAHAR/0000-0002-3515-7548WOS: 000451442400019PubMed: 30485766Swab 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.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114R104]This work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK, grant no. 114R104). We thank Prof. Dr. Zekiye Suludere for her technical assistance in obtaining TEM micrographs. Also, we are grateful to Assoc. Prof. Serkan Erat for kindly helping with the statistical analyses

Serotype Distribution of Salmonella Isolates from Turkey Ground Meat and Meat Parts

The aim of the study was to find out the serotype distribution of 169 Salmonella colonies recovered from 112 Salmonella positive ground turkey (115 colonies) and 52 turkey meat parts (54 colonies). Out of 15 Salmonella serotypes: S. Corvallis, S. Kentucky, S. Bredeney, S. Virchow, S. Saintpaul and S. Agona were identified as the predominant serovars at the rates of 27%, 13%, 12%, 12%, 11%, and 10%, respectively. Other serotypes were below 6% of the total isolates. All S. Kentucky and S. Virchow and most of the S. Corvallis (39/46) and S. Heidelberg (9/9) serotypes were recovered from ground turkey. The results indicate that turkey ground meat and meat parts were contaminated with quite distinct Salmonella serotypes. This is the first study reporting Salmonella serotype distribution in turkey meat and S. Corvallis as predominant serotype in poultry meat in Turkey

Base study for the establishment of national Salmonella control program in hatching farms and table eggs in Turkey

WOS: 000523562000023Foodborne infections due to Salmonella are still a major concern worldwide. Particularly contaminated egg and egg related products are the primary sources for human salmonellosis. It is necessary to determine the risk factors associated with Salmonella contamination of eggs within the scope of farm to table and environment. The objective of this study was to develop the "National Salmonella Control Program in Laying Hens" and report the prevalence and serotype distribution findings of Salmonella in laying hens and eggs in Turkey. A total of 2122 samples were collected and analysed according to ISO 6579:2002 after the isolation and identification procedures. All Salmonella isolates were serotyped including 726 eggs and 1396 farm specimens from 241 epidemiological units (EpUs) that were located in 9 different provinces between 2015 and 2017. Salmonella contamination was detected in 14.9% of 241 EpUs. The results indicated that almost half of the flocks have multiple contamination sources. The highest contamination rate was obtained from environmental (11%) followed by faeces (7.5%) and the lowest was from water samples (1.6%). The overall contamination rate was detected as 7.46% for farms and 3.3% for eggs. As S. Enteritidis and S. Typhimurium are the most frequently seen serotypes all over the world, in Turkey S. Typhimurium was not detected and S. Enteritidis was the 5th most common isolated serotype. According to our results it can be concluded that differences in various countries, particularly geographical and egg hatching systems, may affect the contamination rate and serotype distribution of Salmonella.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [113R036, 113R037]The part of this study was supported by a grant of The Scientific and Technological Research Council of Turkey (TUBITAK-project numbers as; 113R036 and 113R037)

Microbiological characterization of cig kofte sold at retail in Ankara, Turkey, and evaluation of selected antimicrobials as ingredients to control foodborne pathogens in cig kofte during refrigerated storage

Goncuoglu, Muammer/0000-0001-7245-1941WOS: 000415769700018We monitored the occurrence and fate of Shiga toxin-producing Escherichia coli, E. coli O157, Listeria monocytogenes, and/or Salmonella spp. in cig kofte (translated as "raw meatball") purchased from establishments in Turkey or prepared and inoculated in our laboratory. Of the 24 beef and 144 vegetarian samples of cig kofte purchased, Salmonella were recovered from the vegetarian samples (1 of 24 samples), but not from the samples containing beef (<= 2.3 log CFU/g detection limit). L. monocytogenes were recovered from 2 of 24 beef (8.3%) and 2 of 144 vegetarian (1.4%) samples of cig kofte, whereas E. colt O157 were recovered from 5 of 24 meat (20.8%) and 21 of 144 vegetarian (14.6%) samples of cig kofte tested. Levels of total aerobic bacteria ranged from 3.7 to 9.0 log CFU/g, whereas levels of Enterobacteriaceae and coliforms ranged from 2.3 to 7.3 log CFU/g. In our laboratory, finely-ground beef (93:7%, lean:fat) was separately inoculated (ca. 4.0 log CFU/g) with multi-strain cocktails of STEC, Salmonella spp., or L. monocytogenes and then mixed with either bulgur wheat alone or with bulgur wheat along with tomato sauce, vegetables, and various spices. Next, aliquots of buffered vinegar (BV) or distilled white vinegar (DV; 5% acidity) were added as antimicrobials to the inoculated batter to deliver 0, 2.5, or 5.0% (vol/wt) of the antimicrobial. The resultant batter was shaped into ca. 15 g balls by hand and stored at 4 or 15 degrees C. When cig kofte was formulated with or without spices and with or without antimicrobials, pathogen numbers remained relatively unchanged after 3 days of storage at 4 degrees C. In contrast, when cig kofte was formulated without spices and without antimicrobials, pathogen levels increased by ca. 0.2 to 0.9 log CFU/g, respectively, after 3 days at 15 degrees C. When product was formulated with spices, in the absence of antimicrobials, STEC and L. monocytogenes levels decreased by ca. 03 and 0.7 log CFU/g, respectively, whereas Salmonella spp. increased by ca. 0.3 log CFU/g after 3 days at 15 degrees C. Thus, the formulation of cig kofte used in this study did not support growth (<= 1.0 log CFU/g) of either STEC, Salmonella spp., or L. monocytogenes. Our data also confirm that pathogens can be recovered on occasion from cig kofte sold at restaurants and at retail in Turkey, as well as highlight the importance of proper formulation, handling, and storage practices to ensure its safety. (C) 2017 Published by Elsevier Ltd.Agriculture and Food Research Initiative from the USDA National Institute of Food and Agriculture, Prevention, Detection and Control of Shiga Toxin-Producing Escherichia coli (STEC) [2012-68003-30155, A4101]We extend our sincere appreciation to Manuela Osoria (USDA/ARS/ERRC; Wyndmoor, PA) and Nicole Arnold (North Carolina State University; Raleigh, NC) for their assistance on this project. A special note of thanks to Dr. Bryan Vinyard (USDA/ARS/BARC, Beltsville, MD) for statistically analyzing these data. In addition, we are extremely grateful to Ben Chapman (NCSU) and Amy K. Tarlo and Cheryle K. Radcliff (Souderton Area High School; Souderton, PA) for their assistance with the recruitment and/or mentoring of students. This project is supported by Agriculture and Food Research Initiative Grant No. 2012-68003-30155 from the USDA National Institute of Food and Agriculture, Prevention, Detection and Control of Shiga Toxin-Producing Escherichia coli (STEC) from Pre-Harvest Through Consumption of Beef Products Program - A4101