title: In vitro growth versus inhibition of growth of Malassezia pachydermatis in the presence of the antibacterial drug gentamicin.
abstract: Malassezia pachydermatis is part of the normal cutaneous microbiota of most warm-blooded vertebrates and is associated with otitis externa and seborrhoeic dermatitis in dogs and cats. In this study, we evaluated the growth capacity of nine M. pachydermatis strains on Sabouraud medium in the presence of a high concentration of gentamicin. Strains of M. pachydermatis cultured on Sabouraud medium in the presence of 50 and 100 µg gentamicin ml(-1) displayed different growth patterns such as growth or lack of growth. We hypothesized that this difference in growth of M. pachydermatis strains was correlated with the different genotypes of the strains. Random amplification of polymorphic DNA (RAPD) was applied for genetic typing of M. pachydermatis isolates, derived from the external ears of house pet cats suffering from otitis externa. The M. pachydermatis strains were cultured on commercial or home-made Sabouraud medium supplemented or not with gentamicin. RAPD analysis demonstrated a genetic heterogeneity between each strain. In particular, five out of nine strains tested were able to form colonies in the presence of gentamicin. However, a correlation between M. pachydermatis genotype and growth capacity in the presence of gentamicin was not widely demonstrated.
authors: Department of Experimental Medicine, Second University of Naples, Naples, Italy.
authors: Elisabetta
authors: E
authors: Buommino
authors: Department of Dermatology and Venereology, Second University of Naples, Naples, Italy.
authors: Adone
authors: A
authors: Baroni
authors: Department of Experimental Medicine, Second University of Naples, Naples, Italy.
authors: Annamaria
authors: A
authors: Parisi
authors: Department of Experimental Medicine, Second University of Naples, Naples, Italy.
authors: Flavia Elena
authors: FE
authors: Borriello
authors: Department of Experimental Medicine, Second University of Naples, Naples, Italy.
authors: Pina
authors: P
authors: Caputo
authors: Department of Experimental Medicine, Second University of Naples, Naples, Italy giovanna.donnarumma@unina2.it.
authors: Giovanna
authors: G
authors: Donnarumma
authors: Department of Veterinary Medicine and Animal Production, University of Naples 'Federico II', Naples, Italy.
authors: Sandra
authors: S
authors: Nizza
authors: Department of Veterinary Medicine and Animal Production, University of Naples 'Federico II', Naples, Italy.
authors: Francesca Paola
authors: FP
authors: Nocera
authors: Department of Veterinary Medicine and Animal Production, University of Naples 'Federico II', Naples, Italy.
authors: Filomena
authors: F
authors: Fiorito
authors: Department of Veterinary Medicine and Animal Production, University of Naples 'Federico II', Naples, Italy.
authors: Luisa
authors: L
authors: De Martino
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D002371:Cat Diseases / Q000382:microbiology; D002415:Cats; D003470:Culture Media / Q000737:chemistry; D014644:Genetic Variation; D005838:Genotype; D005839:Gentamicins / Q000378:metabolism*; D008290:Malassezia / Q000145:classification / Q000187:drug effects* / Q000254:growth & development* / Q000302:isolation & purification; D058889:Molecular Typing; D016533:Mycological Typing Techniques; D010032:Otitis Externa / Q000382:microbiology / Q000662:veterinary; D057805:Pets; D019105:Random Amplified Polymorphic DNA Technique
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D005839:Gentamicins