Methods for Detection of Antimicrobial-Induced Changes in the Normal Human Oropharyngeal and Colon Microflora

Abstract

The normal oropharyngeal and gastrointestinal microflora are stable ecosystems. Within a given person the microflora remains relatively constant over time. This ecosystem may however be disrupted. Irradiation of the head and neck causes changes in the oropharyngeal microflora and subsequently also in the gastrointestinal flora. Gastric surgery or pathologic conditions may affect normal peristalsis and can thus cause changes in the intestinal microflora. Hospitalization may also induce minor ecological changes. Ingestion of large bacterial inoculum may overhelm the resistance to new colonization and host defences (Nord et al. 1984). The most common and significant cause of disturbances in the oropharyngeal and gastrointestinal microflora is the administration of antimicrobial agents (Nord et al. 1984). The effect of antimicrobial agents on the patient’s normal micro flora can be separated into four general categories.