Evidence for Escherichia coli DcuD carrier dependent FOF1-ATPase activity during fermentation of glycerol

During fermentation Escherichia coli excrete succinate mainly via Dcu family carriers. Current work reveals the total and N,N’-dicyclohexylcarbodiimide (DCCD) inhibited ATPase activity at pH 7.5 and 5.5 in E. coli wild type and dcu mutants upon glycerol fermentation. The overall ATPase activity was highest at pH 7.5 in dcuABCD mutant. In wild type cells 50% of the activity came from the FOF1-ATPase but in dcuD mutant it reached ~80%. K+ (100 mM) stimulate total but not DCCD inhibited ATPase activity 40% and 20% in wild type and dcuD mutant, respectively. 90% of overall ATPase activity was inhibited by DCCD at pH 5.5 only in dcuABC mutant. At pH 7.5 the H+ fluxes in E. coli wild type, dcuD and dcuABCD mutants was similar but in dcuABC triple mutant the H+ flux decreased 1.4 fold reaching 1.15 mM/min when glycerol was supplemented. In succinate assays the H+ flux was higher in the strains where DcuD is absent. No significant differences were determined in wild type and mutants specific growth rate except dcuD strain. Taken together it is suggested that during glycerol fermentation DcuD has impact on H+ fluxes, FOF1-ATPase activity and depends on potassium ions

IL-11 Induces NLRP3 Inflammasome Activation in Monocytes and Inflammatory Cell Migration to the Central Nervous System

The objective of this study is to examine IL-11-induced mechanisms of inflammatory cell migration to the central nervous system (CNS). We report that IL-11 is produced at highest frequency by myeloid cells among the peripheral blood mononuclear cell (PBMC) subsets. Patients with relapsing-remitting multiple sclerosis (RRMS) have an increased frequency of IL-11+ monocytes, IL-11+ and IL-11R+ CD4+ lymphocytes, and IL-11R+ neutrophils in comparison to matched healthy controls. IL-11+ and granulocyte-macrophage colony-stimulating factor (GM-CSF)+ monocytes, CD4+ lymphocytes, and neutrophils accumulate in the cerebrospinal fluid (CSF). The effect of IL-11 in-vitro stimulation, examined using single-cell RNA sequencing, revealed the highest number of differentially expressed genes in classical monocytes, including up-regulated NFKB1, NLRP3, and IL1B. All CD4+ cell subsets had increased expression of S100A8/9 alarmin genes involved in NLRP3 inflammasome activation. In IL-11R+-sorted cells from the CSF, classical and intermediate monocytes significantly up-regulated the expression of multiple NLRP3 inflammasome-related genes, including complement, IL18, and migratory genes (VEGFA/B) in comparison to blood-derived cells. Therapeutic targeting of this pathway with αIL-11 mAb in mice with RR experimental autoimmune encephalomyelitis (EAE) decreased clinical scores, CNS inflammatory infiltrates, and demyelination. αIL-11 mAb treatment decreased the numbers of NFκBp65+, NLRP3+, and IL-1β+ monocytes in the CNS of mice with EAE. The results suggest that IL-11/IL-11R signaling in monocytes represents a therapeutic target in RRMS

Determination of Brucella spp. in raw milk and Turkish white cheese in Kirikkale

WOS: 000177745900006PubMed: 12161972In this study, a total of 105 samples including 35 raw milk, 35 cows' milk cheese, and 35 ewes' milk cheese samples were obtained from Kirikkale city and investigated for the presence and contamination level of Brucella species. For this reason, milk and cheese samples were collected in aseptic conditions and brought to the laboratory under cold conditions. The method suggested from FARREL was used for the isolation and identification of Brucella spp. In addition, Most Probable Number Technique was used to determine the contamination level in Brucella spp. positive samples. According to analysis findings, B. melitensis was isolated from 5 (14.2%) of 35 ewes' milk cheese samples at the level of 3.6x10(1) -9.3x10(3) MPN/g. Brucella spp. were not detected in any of raw milk and cows' milk cheese samples. In conclusion this study reinforced the previous reports that ewes' milk cheese is an important source of Brucella spp. and they have been risk for public health

Survival of Escherichia coli O157 : H7 in the processing and post-processing stages of acidophilus yogurt

WOS: 000221095700010In this study the survival of Escherichia coli O157:H7 in the production process of acidophilus yogurt was examined and compared with traditional yogurt. Milk was inoculated with different doses of E. coli O157:H7 (10(2), 10(4) and 10(6) CFU mL(-1)) and two kinds of yogurt were produced. Samples were taken for pH measurements and bacterial enumeration at 0, 3, 24, 48, and 72 h after inoculation. Escherichia coli O157:H7 was analysed by using a Most Probable Number technique and yogurt starter culture and Lactobacillus acidophilus were counted by using classical culture methods. Elimination times of E. coli O157:H7 were determined for 10(2) CFU mL(-1) as 3 h, and for 10(4) and 10(6) CFU mL(-1) as 48 h in acidophilus yogurt. Elimination times in traditional yogurt were 48 h for 10(2) and 10(4) CFU mL(-1) and 72 h for 10(6) CFU mL(-1) E. coli O157:H7. In conclusion, the elimination time of E. coli O157:H7 in acidophilus yogurt was shorter than in traditional yogurt during the processing and post-processing stages

The extension of the shelf-life of sardine which were packaged in a vacuum stored under refrigeration, and treated by delta-irradiation

WOS: 000183522600005Sardines (Sardina pichardus) were vacuum packaged in polyethylene bags, and irradiated at 1, 2 and 3 kGy doses in a Co-60 delta-irradiator. The unirradiated and irradiated samples were stored at 2 +/- 1 degreesC. Microbiological analyses were done for total aerobic mesophiles, micrococci and staphylococci, coagulase positive staphylococci, Enterobacteriaceae, coliform. bacteria, Escherichia coli, and psychrophilic bacteria. Trimethylamine-nitrogen (TMA-N), thiobarbituric acid (TBA) and pH values were determined. Sensory attributes were also evaluated. In the unirradiated samples, TMA-N and pH values showed good correlations with sensory scores. There were no differences in TBA values between the irradiated samples. Based on microbiological criteria, the shelf-life increased two to threefold compared with the control samples. These experiments demonstrate that irradiation extends the storage life of pre-packaged sardines and that, for practical purposes, the different treatments make very little difference to the extension of shelf-life of acceptable product

Investigation and prevention of blown pack spoilage of vacuum-packed traditional kashar cheese

WOS: 000187404700004A study was conducted to determine the cause of blown pack spoilage of vacuum-packed traditional kashar cheese. A total of 138 samples consisting of unscalded curds, scalded curds, vacuum-packed kashar cheese ready for consumption and kashar cheese with blown packs were analysed. The samples were analysed for aerobic mesophilic count, micrococci-staphylococci, coagulase-positive staphylococci, Enterobacteriaceae, coliform bacteria, Escherichia coli, enterococci, Clostridium spp., yeasts and moulds. Gas-forming microorganisms including Enterobacteriaceae, coliform bacteria and yeasts were observed at respective counts of log 7.52, 5.49 and 5.12 cfu/g in unscalded curd; log 6.70, 4.66 and 4.30 cfu/g in scalded curd (72degreesC); log 3.86, 3.11 and 4.98 cfu/cm(2) on the surface of vacuum-packed kashar cheese ready for consumption; and log 7.98, 7.28 and 5.20 cfu/g in kashar cheese with blown packs. These results indicate that gas-blowing spoilage was caused by Enterobacteriaceae, coliform bacteria and yeasts, and their primary source is unscalcled curd produced from raw milk. The secondary source of gas-producing micro-organisms was post-scalding contamination. The problem of gas blowing may be prevented by immersing the kashar cheese into hot water at 85degreesC after vacuum-packaging for sufficient time to heat the cheese to at least 85degreesC for 1 min

Probiotic white cheese with Lactobacillus acidophilus

Goncuoglu, Muammer/0000-0001-7245-1941WOS: 000224317100006The objective of the present study was to determine the effects of Lactobacillus acidophilus on the sensory attributes, ripening time, and composition of Turkish white cheese and to investigate the survival of L. acidophilus during ripening of the cheese stored in vacuum or in brine. Two types of white cheeses, traditional cheese (control, made with Lactococcus lactis ssp. lactis and Lactococcus lactis ssp. cremoris) and probiotic cheese (made with Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris and L. acidophilus 593 N), were produced and ripened in vacuum pack or in brine at 4degreesC for 90 days. Cheese samples were assessed for microbiological and compositional properties, proteolysis, and sensory evaluation at different ripening stages. On ripening in vacuum pack, L. acidophilus survived to numbers > 10(7) cfu g(-1), Which is necessary for positive effects on health. Protein, dry matter, salt content, and percentage of lactic acid in the vacuum-packed and brine-salted probiotic cheeses were significantly different. Also, the lactic acid content of probiotic cheeses was slightly higher than that of the controls for both vacuum- and brine-packed cheeses. Vacuumpacked probiotic cheese had the highest levels of proteolysis and the highest sensory scores of all cheeses. Consequently, L. acidophihis could be used for the manufacturing of probiotic white cheese to shorten ripening time and vacuum packaging is the preferred storage format. (C) 2004 Elsevier Ltd. All rights reserved

Isolation and identification of motile Aeromonas spp. in ground beef

Sarimehmetoglu, Belgin/0000-0002-0007-235XWOS: 000088815700013In this study, a total of 100 ground beef samples purchased at different butchers' shops and supermarkets in Ankara including 50 samples obtained from butchers' shops and 50 samples obtained from supermarkets, were analysed for the presence of motile Aeromonas species. According to the analysis, motile Aeromonas spp. were found in 73 % (73/100) of ground beef samples. Aeromonas spp. were isolated from 33 samples (66 %) obtained from butchers' shops, and 40 samples (8D %) obtained From supermarkets. A. hydrophila was the most prevalent species, followed by A. sobria and A. caviae from all of the samples. In conclusion, it was determined that ground beef samples were contaminated with motile Aeromonas species and also A. hydrophila and A. caviae as, potential pathogens, were frequently identified species. Thus, it was suggested that hygienic precautions be applied and especially ground beef should be consumed after a short storage period in a refrigerator, in homes and markets