Clinical microbiology review: Gastrointestinal infections
- Stephen B Calderwood, MD
Stephen B Calderwood, MD
- Editor-in-Chief — Infectious Diseases
- Section Editor — Bacterial Infections
- Professor of Medicine (Microbiology and Immunobiology)
- Harvard Medical School
Although the Gram's stain is a first step in the examination of most specimens, only rarely can it be used to distinguish enteric pathogens from normal stool flora. Thus a variety of culture media, biochemical reactions, serological grouping, polymerase chain reaction (PCR) amplification, and other tests must be used to identify the bacteria that cause gastrointestinal infection (picture 1A-C).
Microscopic examination, on the other hand, is the principal method for diagnosing intestinal protozoal and helminthic infection (picture 2).