ABSTRACT
OBJECTIVE: To compare genetic profiles of uropathogenic E.coli (UPEC) to strains isolated from freshwater, seawater and iguanas in Grenada. DESIGN AND METHODS: Eighty-five E. coli strains were isolated using double streak-plating on eosin methylene blue (EMB) and MacConkey agar from human urine, iguanas, fresh and marine water. Species identification was confirmed using API20E. Genomic DNA was extracted from individual pure cultures of E. coli and amplified using the oligonucleotide (GTG5) and BOX primers. The DNA fingerprints were separated by electrophoresis, normalized using reference American Test Culture collection (ATCC) E.coli and compared using DendroUPGMA, the FigTree, dominance and co-clustering analyses. RESULTS: Both DNA fingerprinting methods targeted extragenic DNA and demonstrated enormous intra-species diversity within the population of studied 85 E. coli isolated from four major eco-habitats. DNA fingerprinting based on BOX-PCR was less discriminating than the (GTG)5-PCR. The BOX analysis correlated better with the ecotype distribution. The combination of dominance and co-clustering analyses allowed us to trace the relatedness of strains among and between the four different ecotypes. CONCLUSIONS: The (GTG5) PCR based co-clustering analysis indicated that the clinical isolates had a closer relationship to iguana E. coli isolates than to fresh and marine water isolates. However, in accordance with the BOX analysis, clinical isolates were most similar to marine, followed by freshwater and iguanas.
Subject(s)
Genetic Variation , Escherichia coli/genetics , GrenadaABSTRACT
CD200R1 is a member of the immunoglobulin supergene family that is thought to play an inhibitory role in immunity. Previous studies have established the anti-arthritic effect of CD200Fc, an agonist of CD200R1. However, the physiological role played by CD200R1 in arthritis remains to be established. The aims of this study are to assess the contribution of endogenous CD200R1 in regulating the severity of arthritis and to determine its role in shaping the immune response to type II collagen within the context of collagen-induced arthritis, an animal model of rheumatoid arthritis. Arthritis was induced in DBA/1 mice by immunization with type II collagen and the kinetics of expression of CD200R1 and CD200 were monitored by quantitative reverse transcription-polymerase chain reaction. Next, a comparison was made between CD200R1(-/-) and wild-type mice in terms of the progression of collagen-induced arthritis, as well as the B and T cell responses to type II collagen. The expression of both CD200R1 and CD200 was increased after immunization and reached maximal levels at the height of the inflammatory response. In addition, the severity of arthritis was increased significantly in CD200R1(-/-) mice compared to wild-type mice. However, little or no differences were observed between CD200R1(-/-) and wild-type mice in terms of the T or B cell responses to type II collagen. It was concluded that the CD200R1/CD200 pathway is up-regulated in arthritis and plays a significant physiological role in regulating the severity of disease. In contrast, CD200R1 plays a minimal role in shaping the immune response to collagen in this model.
Subject(s)
Adaptive Immunity/immunology , Antigens, Surface/immunology , Arthritis, Experimental/immunology , Receptors, Cell Surface/immunology , Animals , Antigens, CD/genetics , Antigens, CD/immunology , Antigens, CD/metabolism , Antigens, Surface/genetics , Antigens, Surface/metabolism , Arthritis, Experimental/metabolism , Arthritis, Experimental/pathology , Cell Proliferation , Cells, Cultured , Cytokines/metabolism , Female , Flow Cytometry , Gene Expression Profiling , Kinetics , Male , Mice , Mice, Inbred C57BL , Mice, Inbred DBA , Mice, Knockout , Orexin Receptors , Receptors, Cell Surface/genetics , Receptors, Cell Surface/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Severity of Illness Index , Signal Transduction/immunology , T-Lymphocytes/cytology , T-Lymphocytes/immunology , T-Lymphocytes/metabolismABSTRACT
AIMS: To differentiate the subspecies of Lactobacillus delbrueckii, subsp. delbrueckii, subsp. lactis and subsp. bulgaricus. METHODS AND RESULTS: Amplified ribosomal DNA restriction analysis (ARDRA) and ribotyping were applied to over 30 strains. Both methods analyse the ribosomal genes which carry useful information about the evolutionary and taxonomic relationship among bacteria. The methods proved to be reliable and highly reproducible. ARDRA was applied to 16S rDNA, 23S rDNA and the IGS region, thus covering the whole rrn operon with eight restriction enzymes. Only EcoRI differentiated Lact. delbrueckii subsp. bulgaricus from Lact. delbrueckii subsp. delbrueckii/Lact. delbrueckii subsp. lactis, which confirmed the finding of other authors. Ribotyping with different enzymes under precisely optimized conditions revealed a high level of strain polymorphism. Only ribotyping with EcoRI allowed differentiation of the three subspecies on the basis of typical hybridization patterns. CONCLUSION: The successful differentiation of the three subspecies of Lact. delbrueckii by EcoRI ribotyping offers a new possibility for precise identification and differentiation of strains and new isolates. SIGNIFICANCE AND IMPACT OF THE STUDY: Both methods could be used for differentiation of Lact. delbrueckii subspecies.
