A Giemsa stain of a thin peripheral blood smear is prepared. Which of the following cannot be diagnosed?
Bartonella henselae
Coxiella burnettii
Toxoplasma gondii
Ehrlichia chaffeensis
Ans. (B) Coxiella burnettii(Ref: Jawetz's Medical Microbiology 27th Ed; Page No-347)A diagnosis of Coxiella burnettii cannot be done using a Giemsa stain of a thin peripheral smear.The diagnosis of Coxiella burnetii is done mainly by serology which shows a rise in the titer of specific antibodies to C. burnettii.Other Options:Toxoplasma gondii: It can invade any nucleated cell and replicate within cytoplasmic vacuoles by a process called endogony (internal budding). The trophozoites stain with Giemsa stain.Bartonella henselae: Invade macrophages and neutrophils which can be seen by Giemsa staining of a peripheral smear.Ehrlichia chaffeensis: They infect circulating leukocytes, erythrocytes and platelets, where they multiply within phagocytic vacuoles, forming clusters known as morulae. They can be seen on peripheral blood smear using Giemsa stain.
Bacteria