title: In vitro anticryptosporidial activity of ranalexin alone and in combination with other peptides and with hydrophobic antibiotics.
abstract: The in vitro activity of ranalexin alone and in combination with other cationic peptides, macrolides, rifampin, and rifabutin was investigated against a clinical isolate of Cryptosporidium parvum. Susceptibility tests were performed by inoculation of the isolate onto cell monolayers and determining the parasite count after 48 h of incubation at 37 degrees C. Antibiotic-free cultures were used as controls in the study. Ranalexin showed low anticryptosporidial activity: it suppressed the growth of parasites by > or = 40% at 50 microM. Ranalexin showed enhanced activity when it was combined with noninhibitory concentrations of other compounds: a 74.4-94.1% reduction in the number of parasites was observed when ranalexin 50 microM was combined with magainin II 50 microM, indolicidin 50 microM, clarithromycin 8 mg/l, azithromycin 8 mg/l, rifampin 8 mg/l, and rifabutin 8 mg/l. The results suggest that ranalexin may be effective in inhibiting Cryptosporidium parvum growth in vitro upon combination with other peptides and hydrophobic antibiotics.
authors.affiliation: Institute of Infectious Diseases and Public Health, University of Ancona, Italy. cmalinf@popcsi.unian.it
authors.forename: A
authors.initials: A
authors.lastname: Giacometti
authors.forename: O
authors.initials: O
authors.lastname: Cirioni
authors.forename: F
authors.initials: F
authors.lastname: Barchiesi
authors.forename: M
authors.initials: M
authors.lastname: Fortuna
authors.forename: G
authors.initials: G
authors.lastname: Scalise
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D016785:Cryptosporidium parvum / Q000187:drug effects* / Q000302:isolation & purification; D004353:Drug Evaluation, Preclinical; D004357:Drug Synergism; D006801:Humans; D054806:Magainins; D010455:Peptides / Q000494:pharmacology*; D010456:Peptides, Cyclic / Q000494:pharmacology*; D029867:Xenopus Proteins
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D000981:Antiprotozoal Agents; D054806:Magainins; D010455:Peptides; D010456:Peptides, Cyclic; D029867:Xenopus Proteins; C073143:indolicidin; C053301:magainin 2 peptide, Xenopus; C086618:ranalexin