zithromax and Amebiasis

Amoebic keratitis is a potentially blinding eye infection caused by ubiquitous, free-living, environmental acanthamoebae, which are known to harbor bacterial endosymbionts. A Chlamydia-like endosymbiont has previously enhanced Acanthamoeba virulence in vitro. We investigated the potential effect of Acanthamoeba-endosymbiont coinfection in a human corneal tissue model representing clinical amoebic keratitis infection.. Environmental and corneal Acanthamoeba isolates from the American Type Culture Collection were screened for endosymbionts by amplifying and sequencing bacterial 16S as well as Chlamydiales-specific DNA. Each Acanthamoeba isolate was used to infect EpiCorneal cells, a 3-dimensional human corneal tissue model. EpiCorneal cells were then treated with azithromycin, doxycycline, or control medium to determine whether antibiotics targeting common classes of bacterial endosymbionts attenuated Acanthamoeba virulence, as indicated by decreased observed cytopathic effect and inflammatory biomarker production.. A novel endosymbiont closely related to Mycobacterium spp. was identified in Acanthamoeba polyphaga 50495. Infection of EpiCorneal cells with Acanthamoeba castellanii 50493 and A. polyphaga 50372 led to increased production of inflammatory cytokines and cytopathic effects visible under microscopy. These increases were attenuated by azithromycin and doxycycline.. Our findings suggest that azithromycin and doxycycline may be effective adjuvants to standard antiacanthamoebal chemotherapy by potentially abrogating virulence-enhancing properties of bacterial endosymbionts.

Topics: Acanthamoeba; Amebiasis; Azithromycin; Biomarkers; Cells, Cultured; Chlamydiaceae; Cornea; Cytokines; Doxycycline; Humans; Keratitis; RNA, Ribosomal, 16S; Symbiosis; Virulence

Primary amoebic meningoencephalitis (PAM) is a rare and almost always fatal disease that is caused by Naegleria fowleri, a freshwater thermophilic amoeba. Our case involves an adolescent female who presented with fever of unknown origin. A lumbar puncture was performed, and the Wright-Giemsa and Gram stained cerebrospinal fluid (CSF) cytospin slides showed numerous organisms. Experienced medical technologists in the microbiology and hematology laboratories identified the organisms as morphologically consistent with Naegleria species. The laboratory made a rapid diagnosis and alerted emergency department care providers within 75 minutes. The patient was treated for PAM with amphotericin, rifampin, azithromycin, fluconazole and aggressive supportive therapy including dexamethasone. The Centers for Disease Control and Prevention (CDC) was contacted, and miltefosine, an investigational medication, was started. Additional treatment included an intraventricular shunt and controlled hypothermia in order to mitigate potential cerebral edema. Our patient is a rare success story, as she was diagnosed swiftly, successfully treated, and survived PAM.

Topics: Amebiasis; Amphotericin B; Antiprotozoal Agents; Azithromycin; Central Nervous System Protozoal Infections; Cerebrospinal Fluid; Cerebrospinal Fluid Shunts; Child; Early Diagnosis; Female; Fluconazole; Humans; Hypothermia, Induced; Meningoencephalitis; Naegleria fowleri; Phosphorylcholine; Rifampin

This case is reported with the intention of highlighting the presentation of primary amebic meningoencephalitis as acute meningitis, a rare differential diagnosis with presence of free living amoebas in the CSF.

Topics: Acute Disease; Adult; Amebiasis; Animals; Anti-Bacterial Agents; Azithromycin; Diagnosis, Differential; Humans; Male; Meningoencephalitis

Disseminated Acanthamoeba infections are almost invariably fatal, with no universally accepted standard for treatment. Reports of acanthamoebiasis in non-human-immunodeficiency-virus infected hosts are rare. We successfully treated a lung transplant patient who had disseminated acanthamoebiasis using a combination of pentamidine, 5-fluorocytosine, itraconazole, and topical chlorhexidine gluconate/ketoconazole cream.

Topics: Acanthamoeba; Adult; Amebiasis; Animals; Anti-Bacterial Agents; Antifungal Agents; Antiprotozoal Agents; Azithromycin; Drug Therapy, Combination; Female; Humans; Itraconazole; Lung Transplantation; Pentamidine