Seventy-one different Lactococcus lactis subsp. cremoris strains were isolated from seven mesophilic mixed starters used in the manufacture of aged Cheddar cheese in Canada. Based on plasmid profiles and growth in milk (with or without glucose, Casamino Acids or both), two mixed starters were highly heterogeneous, containing at least 18 to 24 distinct L. lactis strains. Three mixed starters were comprised of seven to nine strains, whereas two starters were relatively homogeneous, containing two or three strains. Many strains with similar plasmid profiles behaved differently during growth in milk, indicating variability in the phenotypes. Only 20% of the strains could grow in plain milk, whereas 30% could not grow in milk supplemented with glucose and Casamino Acids. Twenty-five lactococcal bacteriophages were also isolated from whey samples with single strains as hosts. Eighteen phages belonged to the 936 species and seven to the c2 species. Thirteen strains were insensitive to all 25 phages. Almost all sensitive strains were phage species-specific. The 936-like phages had a broader host range.

Objectives: To determine the association between risk of rheumatoid arthritis (RA) and alcohol consumption in combination with smoking and HLA-DRB1 shared epitope (SE). Methods: Data from two independent case-control studies of RA, the Swedish EIRA (1204 cases and 871 controls) and the Danish CACORA (444 cases and 533 controls), were used to estimate ORs of developing RA for different amounts of alcohol consumed. Results: Alcohol consumption was significantly more common in controls (p,0.05) and dose-dependently associated with reduced risk of RA (p for trend ,0.001) in both studies. Among alcohol consumers, the quarter with the highest consumption had a decreased risk of RA of the order of 40-50% compared with the half with the lowest consumption (EIRA, OR = 0.5 (95% CI 0.4 to 0.6); CACORA, OR = 0.6 (95% CI 0.4 to 0.9)). For the subset of RA that is seropositive for antibodies to citrullinated peptide antigens, alcohol consumption reduced the risk most in smokers carrying HLA-DRB1 SE alleles. Conclusions: The observed inverse association between alcohol intake and risk of RA and the recent demonstration of a preventive effect of alcohol in experimental arthritis indicate that alcohol may protect against RA. This highlights the potential role of lifestyle in determining the risk of developing RA, and emphasises the advice to stop smoking, but not necessarily to abstain from alcohol in order to diminish risk of RA. The evidence of potential RA prevention should prompt additional studies on how this can be achieved.Rheumatoid arthritis (RA) is a common, complex disease which seems to develop as a result of an interplay between inducing and protective environmental and genetic factors. [1][2][3][4][5] Recently, evidence for a possible interaction between lifestyle factors and genetic factors was provided by studies showing how smoking interacts with the shared epitope (SE) alleles of the HLA-DRB1 gene in providing a very high risk of developing RA. Furthermore, the effect of both these risk factors was confined to one subset of RA, characterised by the presence of antibodies to citrullinated peptide antigens (ACPAs).2-4 6 These findings are of interest not only for public health, but also from a biological perspective, as they provide leads to a possible aetiology of RA.2 In a more general sense, they illustrate how investigations of lifestyle factors can benefit from being performed in the context of genetics, after appropriate subdivision of the disease into subsets.Our interest in the role of alcohol consumption was triggered by several reports suggesting that alcohol influences inflammation in general and arthritis in particular; alcohol has been shown to diminish the response to immunogens in animals as well as in humans.7-10 Alcohol can downregulate the production of proinflammatory molecules through its influence on innate immunity. 11Notably, addition of alcohol to the drinking water of mice was recently shown to reduce clinical signs of arthritis as well as joint destruction.12 An indication that ...

The virulent cos-type Streptococcus thermophilus phage DT1 was previously isolated from a mozzarella whey sample, and its complete genomic sequence is available. The putative ori of phage DT1 is characterized by three inverted and two direct repeats located in a noncoding region between orf36 and orf37. As the replication ability of the putative ori and flanking genes could not be established, its ability to confer phage resistance was tested. When ori is cloned on a high-copy-number plasmid, it provides protection to S. thermophilus strains against phage infection during milk fermentation. This protection is phage specific and strain dependent. Then, a detailed transcriptional map was established for the region located between the cro-like gene (orf29) and the ori. The results of the Northern blots indicated that the transcription of this region started 5 min after the onset of phage infection. Comparative analysis of the expression of the cro-ori region in the three S. thermophilus cos-type phages DT1, Sfi19 (virulent), and Sfi21 (temperate) reveals significant differences in the number and size of transcripts. The promoter upstream of orf29 was further investigated by primer extension analysis, and its activity was confirmed by a chloramphenicol acetyltransferase assay, which showed that the phage promoter is more efficient than the constitutive bacterial promoter of the S. thermophilus operon encoding the general proteins of the phosphoenolpyruvate:sugar phosphotransferase system. However, the phage promoter is less efficient than the pts promoter in Lactococcus lactis and in Escherichia coli.Thermophilic lactic acid bacteria, such as Streptococcus thermophilus, are widely used as starter cultures in many yogurtand cheese-manufacturing processes. Bacteriophage infection of these lactic acid bacteria is the main factor impairing lactic acid fermentations, which ultimately decreases the efficiency of the production process and the value of the final product.S. thermophilus phages are currently classified into two general groups based on their mode of DNA packaging and their major structural proteins (27). The first group includes phages with cohesive genome extremities (cos type), and the second group contains phages with a DNA packaging scheme that proceeds via a headful mechanism (pac type) (27). To date, the complete nucleotide sequence of six S. thermophilus phage genomes is available through public databases: four cos-type phages, Sfi21 (temperate) (6), DT1 (virulent) (52), Sfi19 (virulent) (33), and 7201 (virulent) (49), and two pac-type phages, O1205 (temperate) (48) and Sfi11 (virulent) (31). Comparative analysis indicated a close genetic relationship between temperate and virulent S. thermophilus phages. It was even proposed that virulent S. thermophilus phages were derived from temperate phages by a combination of rearrangements and deletion events within the lysogeny module (4, 33). Despite these genetic modifications in the lysogeny module, a gene coding for a cro-like repressor is still found amon...