Campylobacter anatolicus sp. nov., a novel member of the genus Campylobacter isolated from feces of Anatolian Ground Squirrel (Spermophilus xanthoprymnus) in Turkey.

Seventy-four Gram-negative, motile, slightly curved rod-shaped, microaerophilic, oxidase-positive and catalase-negative isolates, recovered from fecal samples of the Anatolian ground squirrel (Spermophilus xanthoprymnus) in Kayseri, Turkey, were subjected to a polyphasic taxonomic study. Results of a genus-specific PCR indicated that all isolates belonged to the genus Campylobacter. 16S rRNA gene sequence analyses revealed the closest match as Campylobacter curvus DSM 6644T with identity levels of 96.41-96.70%. Based on the 16S rRNA gene phylogeny of the 74 isolates, six isolates (faydin-G24, faydin-G52, faydin-G105, faydin-G114, faydin-G129 and faydin-G140T) were chosen as representatives for further characterization. The overall genome relatedness indices for the strain faydin-G140T, compared to the most closely related type strain C. curvus ATCC 35224T, were calculated as 15.2%, 72.5%, and 83.7% for digital DNA-DNA hybridization (dDDH), and average nucleotide identity (ANIb and ANIm), respectively. The G+C content and genome size of the strains ranged between 35.2-35.4 mol% and 1.7-1.8 Mb, respectively. Based on data obtained from the polyphasic taxonomy approach, including phenotypic characterization as well as genomic and chemotaxonomic analyses, these strains are concluded to represent a novel species, for which the name Campylobacter anatolicus sp. nov. is proposed with faydin-G140T as the type strain (=DSM 112311T = LMG 32238T).

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.

The 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 µg/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.

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

Swab 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.

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.