Evaluation of Jones' Medium Culture versus Locke Egg Medium in Diagnosis of Blastocystis Hominis

Abstract

Background: Blastocystis is a widely distributed protozoa. Blastocystis hominis suspected to be possible cause of irritable bowel syndrome, and chronic diarrhea. It is transmitted via fecal-oral route through ingestion of cysts. Laboratory diagnosis of Blastocystis infection is usually via microscopic examination of freshly stained or chemically preserved stool samples but it lacking the sensitivity. The current study is concerned with evaluation of sensitivity and specificity of Jones' medium culture in comparison to Locke egg medium for diagnosis of Blastocystis hominis.

Subjects and Methods: Stool samples were collected from seventy two people, complaining of different gastrointestinal symptoms and attending to different Outpatient Clinics of Zagazig Hospitals. All samples were examined microscopically by wet mount, saline, iodine then preserved for staining by Modified Ziehl-Neelsen (MZN) and trichrome stain and were cultured on Boeck and Drbohlav Locke egg serum medium (LE) and Jones' medium , then examined by light microscope with objectives x10, x40 and x100.

Results: Blastocystis hominis infection was common in younger aged males (14-35years). Usual methods for diagnosis of Blastocystis e.g simple saline, iodine stained smears, MZN and trichrome stain  are simple, specific, non-invasive methods but with low sensitivity. Stool culture was more accurate and sensitive for detection of Blastocystis than direct microscopy. LE medium was more accurate and gave better result than Jones' medium culture.

Conclusions: LE medium culture offers better sensitivity than other ordinary methods and Jones’ medium culture for detecting B. hominis infection in stool samples. It is appropriate for use in large hospitals or public health laboratories.