ABSTRACT
Yersinia enterocolitica is an enteric pathogen frequently implicated in a variety of diseases from diarrhea to hepatosplenic abscesses and septicemia. Deoxyribonucleic acid (DNA) and oligonucleotide probes have long been developed for the identification of Y. enterocolitica. Molecular probes have enabled scientists and clinicians to make important observations on the biology of hepatitis B virus (HBV) and pathogenesis of HBV infection that are helpful in patient management. Restriction endonuclease analysis of extrachromosomal circular DNA molecules containing ribosomal RNA genes as well as clusters of tandemly reiterated sequences identified two types of sequences and displayed specificity to pathogenic and nonpathogenic Entamoeba histolytica. Polymerase chain reaction studies established that repetitive sequences characteristic of pathogenic E. histolytica are also present in low copy numbers in a nonpathogenic strain. A cDNA library has been constructed on the basis of RNA isolated from an axenically grown strain of E. histolytica expressing a pathogenic isoenzyme pattern.
