ABSTRACT. Methicillin-ResistantStaphylococcus aureus is an important pathogen that causes severe infections in humans and animals. The aim of this study was to determine the prevalence and the antimicrobial profile of methicillin-resistant S. aureus (MRSA) in cow bulk tank milk and dairy products in the region of Balikesir in Turkey. Of 175 milk and dairy products' samples, 26 were found to be positive for coagulase-positive staphylococci and 3 (2 samples from cow bulk tank milk and 1 sample from tulum cheese) were MRSA phenotypically being resistant against both oxacillin and cefoxitin. Among these, 17 were confirmed as S. aureus by the detection of nuc gene and one as MRSA carrying the mecA gene. All MRSA isolates were found to be also resistant against ampicillin, penicillin and sulfamethoxazole-trimethoprim. Consequently, even though the prevalence of MRSA in cow bulk tank milk and dairy products was relatively low (1.70%), it may pose serious risks in terms of food safety and public health. In order to prevent the prevalence of MRSA in dairy products, hygienic measures, especially in terms of personal hygiene and disinfection of equipment in all stages of dairy production, should be taken, and HACCP and GMP regulations should be implemented.

The objective of this research was to determine the presence of virulence genes (asa1, gelE, cylA, ace, esp, hyl and efaA), and vancomycin resistance genes (vanA, vanB, vanC2/C3) and the resistance to some antibiotics of Enterococcus spp. isolates previously identified from different stages of ripened white cheese production. In addition, gelatinase, β-hemolytic and DNase activity, and biofilm formations were examined phenotypically. In this study, efaA in 95.9%, asa1 in 89%, ace in 68.5%, esp in 52.1%, gelE in 78.1%, cylA in 16.4% and hyl in 23.3% of isolates were detected. Also, vanA in 31.5%, vanB in 8.2%, and in vanC2/C3 23.3% resistance genes were determined. β-hemolytic and DNase activity were detected in 23.2% and 16.4% of the isolates, while gelatinase activity and biofilm formation could not be detected phenotypically. Moreover, streptomycin and erythromycin resistances were found in 73.9% and in %43.8 of isolates. As a result, it was concluded that Enterococcus spp. may pose a risk for public health and food safety in terms of their virulence factors and antibiotic resistance. For this reason, it was suggested that the strains to be selected as starter cultures should be used after evaluating their virulence factors and resistance to antibiotics.

Bu çalışmada laboratuvar ortamında üretilen yoğurt örneklerine üretimin farklı aşamalarında (mayalamadan önce ve sonra) uygulanan ultrason işleminin yoğurtların su tutma kapasitesi, homojenizasyon ve raf ömrü üzerine etkilerinin değerlendirilmesi amaçlanmıştır. Bu amaca yönelik olarak yoğurt gruplarına 2-4 °C soğuk soğukta muhafazanın 1., 7. ve 15. günlerinde mikrobiyolojik ve fizikokimyasal analizler yapılmıştır. L. delbrueckii subsp. bulgaricus sayısında her grupta 7. günde yaklaşık 0,5 log artışın olduğu belirlenmiştir. İnokulasyon sonrası ultrason (İ+U) grubunda 7. gün sonuçlarına göre S. thermophilus sayısında 1 log azalma olduğu saptanmıştır. En yüksek maya sayısı yine bu grupta 15. gün örneklerinde 5,02 log kob/g düzeyinde saptanmıştır. Kontrol, ultrason sonrası inokülasyon (U+İ) ve İ+U gruplarında su tutma kapasitesi 1. gün analizlerinde ortalama

In this study, milk samples from Saanen goats were tested in terms of somatic cell count (SCC), electrical conductivity (EI), total aerobic mesophilic bacteria (TAMB) count and some physico-chemical parameters. It was aimed to investigate their usability in the diagnosis of subclinical mastitis by comparing the results with two different international criteria (EC, 1992; FDA, 2017) and the results of a study (Persson and Olofsson, 2011, p.1-5). In the study, milk samples were taken from a total of 313 Saanen goats that milked by hand 190 (60.7%) and 123 (39.3%) machine. Then, milk samples were analyzed in terms of SCC, dry matter, fat, protein, lactose, EI, pH and TAMB count. It was observed that milk samples gave more consistent results with the criteria of the European Union Authority. Thus, a statistical difference was found between milk samples below and above the European Union Authority SCC threshold value in terms of pH, protein, lactose and TAMB count (p<0.05). According to EC Authority; in milk samples with SCC below the threshold value; pH, protein and lactose ratio and TAMB count were 6.72%, 4.47%, 4.60% and 3.92 cfu/mL; above the threshold value; 6.76, 3.46%, 4.46%, and 4.98 cfu/mL, arespectively. It was observed that milk samples gave more consistent results with the criteria of the European Union Authority in the diagnosis of subclinical mastitis.

Shiga toxin–producing Escherichia coli (STEC) has emerged as important enteric foodborne zoonotic pathogens of considerable public health significance worldwide. The aim of this study was to determine the prevalence of the top seven STEC serotypes and to identify these serotypes in samples of animal source foods and vegetables. A total of 294 samples including 84 meat samples, 135 milk and dairy product samples and 75 green leafy vegetable samples were tested. The samples were harvested in mTSB-broth pre-enriched with novobiocin and then were tested by amplifying 16S shiga toxin ( stx1/2), and eae genes using multiplex polymerase chain reaction (m-PCR) assay. A total of 260 (88.4%) samples were positive for E. coli and 29 (11.1%) of them were positive for shiga toxin, and eae genes. The positive samples were cultivated on CHROMAgar STEC and the colonies were evaluated for top seven STEC by m-PCR. The top seven STEC serotypes were detected in 27 (93.1%) of the samples: the STEC O111 serotype in 11 (40.7%) beef samples, STEC O45 in 3 (11.1%) chicken, STEC O145 in 6 (22.2%) parsley, 3 (11.1%) lettuce, 1 (3.7%) spinach, and 1 (3.7%) cheese, and STEC O103 in 2 (7.4%) lettuce samples. None of the samples was found positive for STEC O26, O121, and O157 serotypes. This study highlights the fact that the top seven STEC group poses a great risk in terms of food safety and public health in both animal source foods and vegetables.

The most important goal of the production of quality dairy products is to extend the storage period of the product within the scope of food safety and security while maintainig the sensory quality criteria such as taste and aroma. There are many factors that determine the shelf life of milk and dairy products and the development of their taste and aroma. Among these factors, those associated with milk; milk composition are raw milk quality parameters such as total viable bacteria and somatic cell count. In this context, the effects of different barn floor types and manure disposal systems on raw milk quality parameters were examined in this study. Average sometic cell count of the concrete floor / grid system, rubber bed floor / scraper system and concrete floor / scraper system were determined as respectively 720.10 3 cells/ml; 397.10 3 cells/ml; 376.10 3 cells/ml, and total viable bacteria numbers were determined as respectively 135. 10 3 cfu / ml; 80.10 3 cfu / ml and 88.10 3 cfu / ml. The average dry matter values of the concrete floor / grid system, rubber bed floor / scraper system and concrete floor / scraper system were determined as