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    Antimicrobial Resistance of Enterococcus Species Isolated from Chicken in Turkey
    (Korean Soc Food Science Animal Resources, 2018) Sanlibaba, Pinar; Tezel, Basar Uymaz; Senturk, Esra
    The aim of the present work was to provide information about Enterococcus strains isolated from pre-packaged chicken samples in Ankara (Turkey), focusing on their prevalence, phenotypic and genotypic characteristics, and antibiotic resistance. We report the first study on the occurrence of antibiotic resistant enterococci in pre-packaged chicken samples in Ankara. A total of 97 suspicious enterococcal isolates were identified from 122 chicken samples. All isolates were identified to species level by phenotypic and molecular methods. In the 16S rDNA sequence analysis, Enterococcus faecium (61.85%) and Enterococcus faecalis (38.15%) were found to be the most frequently detected Enterococcus spp. Of the 97 isolates tested for hemolytic activity, 12.37% enterococcal strains were beta-hemolytic. beta-Hemolysin was most prevalent among E. faecium (58.33%) compared to E. faecalis (41.66%). Disk diffusion method was used for determining of antibiotic resistance. The analysis of the antimicrobial resistance of the 97 Enterococcus isolates revealed that the resistance to kanamycin (98.96%), rifampicin (80.41%) and ampicillin (60.82%) was most frequent. Furthermore, resistance to erythromycin (38.14%) and ciprofloxacin (34.02%) was also observed. The frequencies of resistance to tetracycline (9.27%), penicillin G (8.24%), and chloramphenicol (3.09%), gentamicin (2.06%) and streptomycin (1.03%) were low. None of the isolates was resistant to vancomycin. Multi-drug resistance was found in 97.93% of Enterococcus strains. E. faecium strains showed a more resistant phenotype than E. faecalis strains according to the antibiotic resistance levels. The results of this study indicated that chicken meat is a potential reservoir for the transmission of antibiotic resistance from animals to humans.
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    Effects of sub-MIC antibiotic concentrations on biofilm production of Salmonella Infantis
    (Taylor & Francis Ltd, 2016) Tezel, Basar Uymaz; Akcelik, Nefise; Yuksel, Fatma Neslihan; Karatug, Neslihan Taskale; Akcelik, Mustafa
    In the present study, 13 Salmonella Infantis strains, which have been originated from Turkey, were selected due to their clinical and industrial relevance, sufficient biofilm producing capability and multidrug resistance. Although all tested strains were built up of thin pellicle, optimum pellicle formation has occurred at 28 degrees C. All S. Infantis biofilms were categorized as bdar' morphotype following the incubation at both 20 and 28 degrees C, while they were categorized as saw' morphotype at 37 degrees C. Under a certain incubation temperature (28 degrees C), 84.62% of strains have formed strong biofilm structures. By using the disk diffusion method, high levels of resistance have been observed among tested bacteria against nalidixic acid (100%), spectinomycin (100%), streptomycin (92.3%), tetracycline (92.3%), kanamycin (76.9%) and neomycin (76.9%). Further studies were performed with S. Infantis DMC 12 strain, due to its capability to produce biofilm and multidrug resistance phenotype. Gentamycin (>64 mu g/mL, 2x MIC) and tetracycline (>128 mu g/mL, 4x MIC) were determined as the most effective antibiotics against biofilm formation. The biofilm forms have showed increased antimicrobial resistance when it was compared to the planktonic bacteria. The highest resistance rates of the biofilm bacteria were observed to neomycin (12x MIC) followed by spectinomycin (10x MIC) and streptomycin (10x MIC). Biofilm structure was induced as a result of nalidixic acid, spectinomycin, tetracycline and neomycin treatment at sub-MIC concentrations of tested antibiotics.
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    Identification and Antibiotic Resistance of Lactobacillus and Bifidobacterium Species From Manufactured Probiotic Dairy Products
    (Wiley, 2024) Seyirt, Seda; Tezel, Basar Uymaz; Sanlibaba, Pinar
    The objective of this study was to enumerate and identify Lactobacillus spp. and Bifidobacterium spp. from 70 samples of commercial dairy probiotic products and assess the antibiotic resistance profile of these probiotic cultures. Viable Lactobacillus spp. and Bifidobacterium spp. were not detected in 13 of 70 probiotic dairy products. Fifty-six products with specific claims of viable bacteria met or exceeded their label claim. Only one of the tested products had a lower number of viable bacteria than stated on the label. Based on the label claims, 11 samples explicitly indicated the presence of monoculture Bifidobacterium spp. strains. Meanwhile, 36 samples were labelled as containing a combination of Lactobacillus spp. and Bifidobacterium spp. species. However, 23 samples did not provide detailed information about the specific probiotic species present. The disc diffusion method was used for determining antibiotic resistance. High levels of resistance to methicillin (100%), vancomycin (95.3%), and cefoxitin (90.7%) were observed in Lactobacillus spp. strains. Bifidobacterium spp. strains were determined to have high frequencies of resistance to cefoxitin (100%), vancomycin (100%), and methicillin (95.6%). Finally, MDR rates were found to be 100% in Bifidobacterium and 95.3% in Lactobacillus species. Antibiotic resistance should be regarded as a significant part of the safety assessment of probiotics. Novel approaches will be essential for addressing MDR bacteria.
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    Preliminary In Vitro Evaluation of the Probiotic Potential of the Bacteriocinogenic Strain Enterococcus lactis PMD74 Isolated from Ezine Cheese
    (Wiley-Hindawi, 2019) Tezel, Basar Uymaz
    Ezine cheese is a nonstarter and long-ripened cheese produced in the Mount of Ida region of Canakkale, Turkey, with a protected designation of origin (PDO) status. The nonstarter fermented foods serve as sources for the isolation of novel strains. The present study aimed to report the novelty of the bacteriocinogenic Enterococcus lactis PMD74 strain and the in vitro assessment of its potential as a probiotic candidate. Additionally, the present study aimed to describe the technological and safety-related properties of the aforementioned strain. The strain exhibited high viability at pH 3.0, in the presence of pepsin, pancreatin, and bile salts (0.3% and 0.5%), and considerable survival passage through the stimulated digestion tests. The strain PMD74 exhibited substantial autoaggregative (41%) and coaggregative properties, which increased as a function of time. The highest coaggregation percentage was obtained with Salmonella enterica serotype Typhimurium SL1344 (23%), followed by Staphylococcus aureus ATCC 6538 (10.3%) and Escherichia coli ATCC 26922 (7.4%), respectively. The strain PMD74 was able to inhibit the growth of a number of Gram-positive bacteria, including Listeria monocytogenes, Lactobacillus sake, Staphylococcus aureus, and E. faecalis. The antimicrobial activity of the proteinaceous compound was calculated as 6400AU mL( -1) by the critical dilution method against E. faecalis ATTC 29212. -Hemolytic PMD74 was observed to be sensitive to vancomycin, ampicillin, penicillin, gentamicin, tetracycline, chloramphenicol, and tylosin. Among the four genes tested, E. lactis PMD74 was observed to be positive for three virulence determinants, ace, sprE, and gelE, and negative for esp. The amino acid decarboxylase activities were detected negative for histidine, tyrosine, and ornithine. E. lactis PMD74 was classified as a low acidifier, which suggested its possible role as an adjunct culture. E. lactis PMD74 exhibited considerable survival ability (8.86logCFU mL( -1)) in the acidic condition of fermented milk for a four-week-long storage period.
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    THE ROLE OF PROBIOTICS ON SLOWING DOWN br THE AGING PROCESS
    (Poznan Univ Life Sciences, 2022) Sanlibaba, Pinar; Toprak, Zehra Tugce; Tezel, Basar Uymaz
    The gastrointestinal (GI) microbiota is one of the most complex ecosystems in nature that are mainly comprised of bacteria and other microbes like fungi, protozoa, and viruses. More than 1000 bacterial species have been reported in the gut microbiome, of which most of these species belong to Firmicutes (31.1%), Proteobacteria (29.5%), Actinobacteria (25.9%), or Bacteroidetes (7.1%) phylum. A symbiotic relationship, which plays a critical role in host health, exists between intestinal microflora and its host. With aging, the intestinal microbiota profile changes are observed, generally characterized by the decrease in biodiversity, carriage of commensals, and enrichment of opportunistic pathogens. The dysbiosis associated with aging in the gut microbiota increases the risk of several diseases. Probiotics are defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host and play crucial functions in improving gut health and disease in all age groups, particularly the elderly induvial. This review focuses on the promising effects of probiotics on slowing down the aging process, treating age-related diseases, and improving the quality of life in light of the current clinical studies.