title: In vitro susceptibility of Prototheca zopfii genotypes 1 and 2.
abstract: Prototheca zopfii causes bovine mastitis that leads to reduced milk production. Since P. zopfii isolates from mastitis have been assigned P. zopfii genotype 2, it suggests that this genotype is the etiologic agent of the infection. However, isolates of P. zopfii have not been investigated with regard to their in vitro drug susceptibility. In this study, we examine the susceptibility of genotype 2 strains from bovine mastitis and genotype 1 isolates recovered from cow-barn surroundings. The in vitro susceptibility of ten isolates and the type strain (SAG2063(T)) of P. zopfii genotype 1, and equal number of genotype 2 isolates and the type strain (SAG2021(T)) were assessed by E-test against amphotericin B (AMB), gentamicin (GM), kanamycin (KM) and itraconazole (ITZ). Results showed that P. zopfii genotype 1 isolates are more susceptible in vitro to AMB, GM and KM than those of genotype 2. Moreover, genotype 2 isolates and seven isolates of genotype 1, including the type strain, are not susceptible to ITZ (>10 μg/ml). Thus, drug susceptibility of P. zopfii differs between these two genotypes.
authors.affiliation: Department of Pathobiology, Nihon University School of Veterinary Medicine, Kanagawa, Japan.
authors.forename: Hideto
authors.initials: H
authors.lastname: Sobukawa
authors.forename: Rui
authors.initials: R
authors.lastname: Kano
authors.forename: Takaaki
authors.initials: T
authors.lastname: Ito
authors.forename: Masanobu
authors.initials: M
authors.lastname: Onozaki
authors.forename: Koichi
authors.initials: K
authors.lastname: Makimura
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Hasegawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kamata
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002417:Cattle; D005838:Genotype; D008414:Mastitis, Bovine / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D011525:Prototheca / Q000145:classification* / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification
chemical_list: D000890:Anti-Infective Agents