The influence of external factors on bacteriophages—review

The ability of bacteriophages to survive under unfavorable conditions is highly diversified. We summarize the influence of different external physical and chemical factors, such as temperature, acidity, and ions, on phage persistence. The relationships between a phage’s morphology and its survival abilities suggested by some authors are also discussed. A better understanding of the complex problem of phage sensitivity to external factors may be useful not only for those interested in pharmaceutical and agricultural applications of bacteriophages, but also for others working with phages

Relationship between lentin, insulin resistance, insulin-like growth factor-1 and insulin-like growth factor binding protein-3 in patients with chronic kidney disease

This study examined the relationship between leptin, insulin-like growth factor-1 (IGF-1), IGF binding protein-3 (IGFBP-3) and insulin resistance in patients with chronic kidney disease (CKD). Levels of leptin, insulin, IGF-1, IGFBP-3 and common routine parameters were measured in 45 patients (23 males and 22 females) with CKD and 45 healthy controls matched for age, gender and body mass index. IGF-1 and IGFBP-3 levels were measured using a two-site immunoradiometric assay. Leptin levels were measured using an enzyme-linked immunosorbent assay. A homeostasis model assessment computer-solved model was used to assess insulin resistance (HOMA-IR). Levels of serum leptin, insulin, IGF-1, IGFBP-3 and HOMA-IR were significantly increased in patients with CKD compared with healthy subjects, whereas fasting blood glucose was not significantly different between the two groups. In patients with CKD, the serum leptin level was significantly correlated with IGF-1, IGFBP-3 and HOMA-IR. In conclusion, this study suggests that there is an interaction between leptin, IGF-1, IGFBP-3 and insulin resistance in patients with CKD

Relationship between Leptin, Insulin Resistance, Insulin-like Growth Factor-1 and Insulin-like Growth Factor Binding Protein-3 in Patients with Chronic Kidney Disease

This study examined the relationship between leptin, insulin-like growth factor-1 (IGF-1), IGF binding protein-3 (IGFBP-3) and insulin resistance in patients with chronic kidney disease (CKD). Levels of leptin, insulin, IGF-1, IGFBP-3 and common routine parameters were measured in 45 patients (23 males and 22 females) with CKD and 45 healthy controls matched for age, gender and body mass index. IGF-1 and IGFBP-3 levels were measured using a two-site immunoradiometric assay. Leptin levels were measured using an enzyme-linked immunosorbent assay. A homeostasis model assessment computer-solved model was used to assess insulin resistance (HOMA-IR). Levels of serum leptin, insulin, IGF-1, IGFBP-3 and HOMA-IR were significantly increased in patients with CKD compared with healthy subjects, whereas fasting blood glucose was not significantly different between the two groups. In patients with CKD, the serum leptin level was significantly correlated with IGF-1, IGFBP-3 and HOMA-IR. In conclusion, this study suggests that there is an interaction between leptin, IGF-1, IGFBP-3 and insulin resistance in patients with CKD

Identification of the Receptor-Binding Protein in Lytic Leuconostoc pseudomesenteroides Bacteriophages

Two phages, P793 and ΦLN04, sharing 80.1% nucleotide sequence identity but having different strains of Leuconostoc pseudomesenteroides as hosts, were selected for identification of the host determinant gene. Construction of chimeric phages leading to the expected switch in host range identified the host determinant genes as ORF21(P793)/ORF23(ΦLN04). The genes are located in the tail structural module and have low sequence similarity at the distal end

Investigation of the Relationship between Lactococcal Host Cell Wall Polysaccharide Genotype and 936 Phage Receptor Binding Protein Phylogeny

Comparative genomics of 11 lactococcal 936-type phages combined with host range analysis allowed subgrouping of these phage genomes, particularly with respect to their encoded receptor binding proteins. The so-called pellicle or cell wall polysaccharide of Lactococcus lactis, which has been implicated as a host receptor of (certain) 936-type phages, is specified by a large gene cluster, which, among different lactococcal strains, contains highly conserved regions as well as regions of diversity. The regions of diversity within this cluster on the genomes of lactococcal strains MG1363, SK11, IL1403, KF147, CV56, and UC509.9 were used for the development of a multiplex PCR system to identify the pellicle genotype of lactococcal strains used in this study. The resulting comparative analysis revealed an apparent correlation between the pellicle genotype of a given host strain and the host range of tested 936-type phages. Such a correlation would allow prediction of the intrinsic 936-type phage sensitivity of a particular lactococcal strain and substantiates the notion that the lactococcal pellicle polysaccharide represents the receptor for (certain) 936-type phages while also partially explaining the molecular reasons behind the observed narrow host range of such phages