Identification and isolation of Cryptosporidium parvum genes encoding microtubule and microfilament proteins

Microtubules and microfilaments are highly conserved cytoskeletal polymers hypothesized to play essential biomechanical roles in the unusual gliding motility of Apicomplexan zoites and in their invasion of, and development within, host epithelial cells. We have identified and isolated Cryptosporidium parvum genes encoding the microtubule proteins alpha- and beta-tubulin and the microfilament protein actin by screening a lambda gt11 C. parvum genomic DNA library with degenerate oligonucleotide and heterologous cDNA hybridization probes respectively. The alpha- and beta-tubulin genes have been partially sequenced and the deduced peptide sequences show greatest homology with the tubulins of the related parasites, T. gondii and P. falciparum. The complete nucleic acid sequence of the actin gene predicts a 376 amino acid, 42 kDa protein having 85% sequence identity with the P. falciparum actin I and the human gamma-actin proteins. Each of these cytoskeletal protein genes was demonstrated to be of cryptosporidial origin by Southern analyses of C. parvum chromosomes fractionated by pulsed field gel electrophoresis; the cloned alpha- and beta-tubulin genes hybridized with chromosomes of ca. 1,200 and 1,500 kb respectively and the cloned actin gene also hybridized with a 1,200 kb chromosome.

Foscarnet therapy for severe acyclovir-resistant herpes simplex virus type-2 infections in patients with the acquired immunodeficiency syndrome (AIDS). An uncontrolled trial

STUDY OBJECTIVE

To determine whether trisodium phosphonoformate (foscarnet) is efficacious in treating severe mucocutaneous disease due to acyclovir-resistant herpes simplex virus type-2 (HSV-2) infection in patients with the acquired immunodeficiency syndrome (AIDS).

DESIGN

Open-labeled drug administration to patients with AIDS and severe ulcerative disease due to acyclovir-resistant HSV-2 infection.

SETTING

Medical floors of acute care hospital.

PATIENTS

Four patients with AIDS who developed progressive ulcerative mucocutaneous lesions of the genitals, perineum, perianal region, or finger due to acyclovir-resistant, thymidine-kinase (TK)-negative strains of HSV-2.

INTERVENTION

Foscarnet, 60 mg/kg body weight intravenously every 8 hours (with reduced dosage for renal impairment), for 12 to 50 days.

MEASUREMENT AND MAIN RESULTS

All patients receiving foscarnet had dramatic improvement in their clinical findings with marked clearing of mucocutaneous lesions and eradication of HSV from mucosal surfaces.

CONCLUSION

Foscarnet may be an effective treatment for severe mucocutaneous disease due to acyclovir-resistant, TK-negative strains of HSV-2.