title: Utilization of the Etest assay for comparative antibiotic susceptibility profiles of citrus variegated Chlorosis and Pierce's disease strains of Xylella fastidiosa.
abstract: Xylella fastidiosa has a wide host range. Isolates of this bacterium that cause diseases in citrus (CVC) and grapes (PD) share 98% genome homology, and 95.7% amino acid identity. Drug resistance genes show a higher level of divergence and may be involved in the X. fastidiosa-host interaction. Antibiotic susceptibility of CVC and PD strains were compared utilizing the Etest strip method (AB Biodisk). Etest is applicable for fastidious slow-growing organisms due to its reproducibility. Results showed that the CVC strain was resistant to bacitracin, cefotaxime, and trimethoprim, and susceptible to chloramphenicol, erythromycin, gentamicin, kanamycin, streptomycin, and tetracycline. The PD strain was susceptible to all tested antibiotics, except kanamycin and trimethoprim. Both isolates produced a class C beta-lactamase. These data support previous antibiotic studies and gene discrepancies found in the sequencing data of PD and CVC strains. These results demonstrate the efficacy of utilizing Etest assays for X. fastidiosa strains.
authors.affiliation: Laboratório de Biologia Celular e Molecular, CENA/USP, CP96 13416-000, Piracicaba, SP, Brazil.
authors.forename: Milena
authors.initials: M
authors.lastname: de P M A Ribeiro
authors.forename: Marina
authors.initials: M
authors.lastname: de T F Dellias
authors.forename: Siu M
authors.initials: SM
authors.lastname: Tsai
authors.forename: Anne
authors.initials: A
authors.lastname: Bolmströn
authors.forename: Lyndel W
authors.initials: LW
authors.lastname: Meinhardt
authors.forename: Cláudia
authors.initials: C
authors.lastname: de M Bellato
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001681:Biological Assay; D002734:Chlorophyll; D002957:Citrus / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D044167:Xylella / Q000187:drug effects* / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D002734:Chlorophyll