ABSTRACT
The yeasts Malassezia (M.) pachydermatis and Candida (C.) parapsilosis are often co-isolated in case of canine seborrhea dermatitis (SD) and also are emerging as opportunistic pathogens of immunocompromised human beings. Increased information about how their relationship results in biofilm production and an antifungal response would be useful to inform treatment and control. This study was designed to investigate biofilm production derived from co-culture of M. pachydermatis and C. parapsilosis from dog skin and to determine their in vitro antifungal susceptibility. We demonstrated that regardless of yeast strain or origin all single and dual cultures produced biofilms within 24 hours, and the greatest amount was present after 72 hours. Biofilm production from mixed cultures was greater than for single strains (P < .05). All sessile forms of the single and dual cultures were resistant to the tested antifungals itraconazole and ketoconazole, whereas planktonic forms were susceptible. The study suggests that dual cultures produce stronger biofilms that are likely to enhance persistence in skin lesions in dogs and result in greater resistance to antifungal treatment.
Subject(s)
Antifungal Agents/pharmacology , Biofilms/drug effects , Biofilms/growth & development , Candida/drug effects , Dermatitis, Seborrheic/veterinary , Dog Diseases/microbiology , Malassezia/drug effects , Animals , Candida/isolation & purification , Candida/physiology , Dermatitis, Seborrheic/microbiology , Dogs , Itraconazole/pharmacology , Ketoconazole/pharmacology , Malassezia/isolation & purification , Malassezia/physiology , Microbial Sensitivity Tests , Microscopy, Electron, ScanningABSTRACT
Eighty-one fresh isolates of Pseudomonas pseudomallei from melioidosis patients were subjected to the analysis for the fatty acid composition by gas-liquid chromatography (GLC) and pH-dependent pattern of nonspecific phosphatase activity. All the test strains were identical in the GLC profile showing the three peaks of characteristic hydroxy acids (3-OH 14:0, 2-OH 16:0, 3-OH 16:0) and the two prominent peaks of cyclopropane acids (17:0 delta, 19:0 delta). They had also basically the same pH-dependent curves of the enzymatic activity with paranitrophenyl phosphate as substrate, showing two to three peaks or shoulders only in the acidic side of the curve. These two biochemical characteristics could differentiate P. pseudomallei distinctly from P. aeruginosa, but not from P. cepacia.
