J.B. Kurtz

Interaction of L. pneumophilia and a free living amoeba (Acanthamoeba palestinensis).

Co-cultivation of Legionella pneumophila serogroup I and Acanthamoeba palestinensis in Neffs medium at 35 degrees C resulted in the intracellular multiplication of the bacteria as demonstrated by electron microscopy and immunofluorescence. In the closed experimental system used, the number of legionellae rose from 10(7) colony forming units (c.f.u.)/ml initially to a maximum of 10(10) c.f.u./ml on day 5. Legionellae were seen in expelled phagosomes, in some amoebae filling the cytoplasm and in others in which the process of encystment appeared to have commenced. At 20 degrees C the acanthamoebae phagocytosed and digested the legionellae. The bacteria disappeared from the co-cultivation flask by day 2 but reappeared in low numbers (10(2) c.f.u./ml) by day 6 suggesting that even at this temperature some intra-amoebal multiplication occurred.

HTLV-III INFECTION AND AIDS IN A ZAMBIAN NURSE RESIDENT IN BRITAIN

This letter presents the case of a 27-year old Zambian nurse resident in the UK for 3 years who had clinical features of acquired immunodeficiency syndrome (AIDS) and died of fulminating cerebral toxoplasmosis. She presented with a 3-month history of fatigue night sweats and weight loss as well as generalized lymphadenopathy. She did not use drugs and reported no recent sexual contact. 6 months later the patient had headaches nausea weakness in the left arm weight loss and a more severe lymphadenopathy. She was treated for possible toxoplasmosis with no improvement. 10 weeks later she had increased headache diarrhea vomiting and left-sided weakness. A brian scan revealed a mass deep in the right parietal lobe with surrounding edema. Necroscopy confirmed an intense subacute encephalitis with numerous intracerebral toxoplasma cysts. Subsequent serologic examination confirmed significant seropositivity for human T-lymphotropic virus type III (HTLV-III). The patient lived in the UK for 3 years before AIDS developed; if the HTLV-III infection was acquired in Zambia the incubation period for AIDS can be assumed to be long in Africans. This case illustrates the difficulties of diagnosing and treating central nervous system toxoplasmosis in the context of AIDS. The patient had full 6-week course of therapy for toxoplasmosis 3 months before her death of overwhelming infection. This emphasizes the need when treating suspected cerebral toxoplasmosis in AIDS cases to continue therapy for a long time.