Elucidating the aetiology of human Campylobacter coli infections

Peer reviewedPublisher PD

The use of measured genotype information in the analysis of quantitative phenotypes in man

Improved laboratory methods allow one to investigate the contribution of measured allelic variability at a locus physiologically involved in determining the expression of a quantitative trait. We present statistical methods that incorporate measured genotype information into the analysis of a quantitative phenotype that allows one simultaneously to detect and estimate the effects of a measured single locus and residual polygenic effects. Likelihoods are presented for the joint distribution of the quantitative phenotype and a measured genotype that are appropriate when the data are collected as a sample of unrelated individuals or as a sample of nuclear families. Application of this method to the analysis of serum cholesterol levels and the concentration of the group specific component (Gc) are presented. The analysis of the contribution of the common Gc polymorphism to the determination of quantitative variability in Gc using smaples of related and unrelated individuals presents, for the first time, the simultaneous estimation of the frequencies and the effects of the genotypes at a measured locus, and the contribution of residual unmeasured polygenes to phenotypic variability.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65935/1/j.1469-1809.1986.tb01037.x.pd

A Longitudinal 6-Year Study of the Molecular Epidemiology of Clinical Campylobacter Isolates in Oxfordshire, United Kingdom

Temporal and seasonal trends in Campylobacter genotypes causing human gastroenteritis were investigated in a 6-year study of 3,300 recent isolates from Oxfordshire, United Kingdom. Genotypes (sequence types [ST]) were defined using multilocus sequence typing and assigned to a clonal complex (a cluster of related strains that share four or more identical alleles with a previously defined central genotype). A previously undescribed clonal complex (ST-464) was identified which, together with ST-42, ST-45, and ST-52 complexes, showed increasing incidence. Concurrently, the incidence of ST-574, ST-607, and ST-658 complexes declined. The relative frequencies of three clonal complexes (ST-45, ST-283, and ST-42) peaked during summer and those of two (ST-353 and ST-403) peaked during winter. Nine clonal complexes (ST-22, ST-45, ST-48, ST-61, ST-257, ST-283, ST-403, ST-658, and ST-677) were significantly associated with ciprofloxacin sensitivity (P < 0.05). Seven clonal complexes (ST-49, ST-206, ST-354, ST-446, ST-460, ST-464, and ST-607) were associated with ciprofloxacin resistance (P < 0.05). Clonal complexes exhibited changing incidence and differences in seasonality and antibiotic resistance phenotype. These data also demonstrated that detailed surveillance at a single site captures information which reflects that observed nationally

Neonatal E. coli pericarditis

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