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Stable phenotypic resistance of Candida species to amphotericin B conferred by preexposure to subinhibitory levels of azoles.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Vazquez, Jose Alberto Arganoza, M. Teresa Boikov, Dina A. Yoon, Seitetsu Sobel, Jack D. Akins, Robert A. |
| Copyright Year | 1998 |
| Abstract | The fungicidal activity of amphotericin B (AmB) was quantitated for several Candida species. Candida albicans and C. tropicalis were consistently susceptible to AmB, with less than 1% survivors after 6 h of exposure to AmB. C. parapsilosis and variants of C. lusitaniae and C. guilliermondii were the most resistant, demonstrating 50 to 90% survivors in this time period and as high as 1% survival after a 24-h exposure time. All Candida species were killed (<1% survivors) after 24 h of exposure to AmB. In contrast, overnight exposure to either fluconazole or itraconazole resulted in pronounced increases in resistance to subsequent exposures to AmB. Most dramatically, C. albicans was able to grow in AmB cultures after azole preexposure. Several other Candida species did not grow in AmB but showed little or no reduction in viability after up to 24 h in AmB. Depending on the growth conditions, Candida cells preexposed to azoles may retain AmB resistance for days after the azoles have been removed. If this in vitro antagonism applies to the clinical setting, treatment of patients with certain antifungal combinations may not be beneficial. The ability of some Candida isolates to survive transient exposures to AmB was not reflected in the in vitro susceptibility changes as measured by standard MIC assays. This finding should be considered in studies attempting to correlate patient outcome with in vitro susceptibilities of clinical fungal isolates. Patients who fail to respond to AmB may be infected with isolates that are classified as susceptible by standard in vitro assays but that may be resistant to transient antifungal exposures which may be more relevant in the clinical setting. |
| Starting Page | 2S |
| Ending Page | 7S |
| Page Count | 6 |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://jcm.asm.org/content/36/9/2690.full.pdf |
| PubMed reference number | 9705415v1 |
| Volume Number | 36 |
| Issue Number | 9 |
| Journal | Journal of clinical microbiology |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Amphotericin B Antifungal Agents Azoles Candida (fungus) Candida albicans reaction wheal^1D post 50 ug Candida albicans ID:Diam:Pt:Skin:Qn Candida parapsilosis Candida tropicalis Classification Clavispora lusitaniae Disease susceptibility Fluconazole Itraconazole Patients Pichia guilliermondii Survivors X-Ray Exposure Time negative regulation of reactive oxygen species biosynthetic process |
| Content Type | Text |
| Resource Type | Article |
