scholarly journals Restriction fragment length polymorphisms among the flagellar genes of the Lior heat-labile serogroup reference strains and field strains ofCampylobacter jejuniandC. coli

1995 ◽  
Vol 114 (3) ◽  
pp. 423-431 ◽  
Author(s):  
A. P. Burnens ◽  
J. Wagner ◽  
H. Lior ◽  
J. Nicolet ◽  
J. Frey
Keyword(s):  
Restriction Fragment ◽  
Fragment Length ◽  
Restriction Fragment Length Polymorphisms ◽  
Clinical Isolates ◽  
Pcr Product ◽  
Length Polymorphisms ◽  
Typing Methods ◽  
Reference Strains ◽  
Flagellar Genes ◽  
Restriction Fragment Length

SUMMARYSeveral typing systems have been described forCampylobacter jejuniandC. coli, to assess the complex epidemiology of these important enteric pathogens. In the present study two typing methods, slide agglutination according to the Lior scheme, and the demonstration of restriction-fragment length polymorphisms (RFLP) of flagellar genes, have been used in parallel on a set of 194 strains. This set comprised 118 sero-reference strains ofC. jejuniandC. coliof the Lior scheme, as well as 76 clinical isolates. All isolates were serotyped and subjected to PCR for amplification of flagellar genes, and the PCR product was restricted withAluI. Flagellar genes could be amplified in 152 strains. Among 85 seroreference strains, 74 different RFLP patterns were observed, and among 67 clinical isolates, there were 36 patterns. There was only limited correlation between flagellar RFLP and the Lior serogroup, and the variability of patterns in serogroups HL2 and HL4 were as marked as the variability between serogroups. Flagellar gene RFLP patterns are shown to be stable, highly discriminatory epidemiologic markers.

scholarly journals The application of genotyping techniques to the epidemiological analysis ofCampylobacter jejuni

1996 ◽  
Vol 117 (2) ◽  
pp. 233-244 ◽  
Author(s):  
C. J. Jackson ◽  
A. J. Fox ◽  
D. R. A. Wareing ◽  
D. N. Hutchinson ◽  
D. M. Jones
Keyword(s):  
Restriction Fragment ◽  
Fragment Length ◽  
Restriction Fragment Length Polymorphisms ◽  
Rrna Gene ◽  
Epidemiological Typing ◽  
Length Polymorphisms ◽  
Genotypic Analysis ◽  
Ofcampylobacter Jejuni ◽  
Reference Strains ◽  
Restriction Fragment Length

SummaryCampylobacter jejuniserogroup reference strains and collections of sporadic and outbreak- associated isolates were examined for restriction fragment length polymorphisms (RFLPs), usingC. jejunirandom chromosomal and 16S rRNA gene probes. A collection of 48 Penner (HS) and 14 Lior (HL) serogroup reference strains, plus 10 clinical isolates, generated 35 RFLP and 26 ribotype patterns. In combination the two loci generated 48 distinct genotypes. Both probes were able to differentiate between certain random isolates of the same HS/HL serogroups but greater discrimination was obtained with RFLP than with ribotyping. Genotyping distinguished accurately between related and unrelated strains when applied to several outbreaks. Genotypic analysis ofC. jejuniby restriction fragment length polymorphisms is a valuable technique for epidemiological typing. Chromosomal variation detected by the two unlinked probe loci provides some information about the genetic relationship between isolates.

scholarly journals A genetic linkage map for the domesticated silkworm, Bombyx mori, based on restriction fragment length polymorphisms

1995 ◽  
Vol 66 (2) ◽  
pp. 109-126 ◽  
Author(s):  
Jinrui Shi ◽  
David G. Heckel ◽  
Marian R. Goldsmith
Keyword(s):  
Linkage Map ◽  
Bombyx Mori ◽  
Restriction Fragment ◽  
Fragment Length ◽  
Restriction Fragment Length Polymorphisms ◽  
Genetic Maps ◽  
Crossing Over ◽  
Linkage Groups ◽  
Length Polymorphisms ◽  
Restriction Fragment Length

SummaryWe present data for the initial construction of a molecular linkage map for the domesticated silkworm, Bombyx mori, based on 52 progeny from an F2 cross from a pair mating of inbred strains p50 and C108, using restriction fragment length polymorphisms (RFLPs). The map contains 15 characterized single copy sequences, 36 anonymous sequences derived from a follicular cDNA library, and 10 loci corresponding to a low copy number retrotransposon, mag. The 15 linkage groups and 8 ungrouped loci account for 23 of the 28 chromosomes and span a total recombination length of 413 cM; 10 linkage groups were correlated with established classic genetic maps. Scoring data from Southern blots were analysed using two Pascal programs written specifically to analyse linkage data in Lepidoptera, where females are the heterogametic sex and have achiasmatic meiosis (no crossing-over). These first examine evidence for linkage by calculating the maximum lod score under the hypothesis that the two loci are linked over the likelihood under the hypothesis that the two loci assort independently, and then determine multilocus linkage maps for groups of putatively syntenic loci by calculating the maximum likelihood estimate of the recombination fractions and the log likelihood using the EM algorithm for a specified order of loci along the chromosome. In addition, the possibility of spurious linkage was exhaustively tested by searching for genotypes forbidden by the absence of crossing-over in one sex.

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