Purification and characterization of galactose- and N-acetylgalactosamine-specific adhesin lectin of Entamoeba histolytica

The host, an obligate participant in all host–pathogen interactions, is a necessary component of microbial adhesion and thus is explicitly or implicitly included in studies of adhesion. It is the host component of microbial adhesion and specifically its epidemiological aspects (i.e., characteristics of human or microbial populations related to disease causation by adhering microorganisms) that this chapter addresses. The chapter discusses principles of study design and analysis fundamental to sound epidemiological investigation. Examples are drawn primarily from the literature regarding adhesins of uropathogenic Escherichia coli, but the underlying principles apply equally well to other organisms and other clinical settings. Epidemiological considerations regarding study design, data collection and analysis, and interpretation of results are fundamental to studies of microbial adhesion, if relevance to the pathogenesis of clinical infection is a goal. Pitfalls to be avoided include type II statistical errors, inattention to confounding variables, and post hoc hypotheses; absence of internal controls; nonuniform evaluation of subjects; failure to characterize subjects adequately or to stratify analyses according to important clinical characteristics; and inattention to the in vivo relevance of the adhesin or receptor studied, or of the assay system used. Attention to these principles enhances the scientific quality and clinical relevance of studies of microbial adhesion.