Multidrug-Resistant Trichosporon asahii Infection of Nongranulocytopenic Patients in Three Intensive Care Units

Abstract

Trichosporon asahii (Trichosporon beigelii) infections are rare but have been associated with a wide spectrum of clinical manifestations, ranging from superficial involvement in immunocompetent individuals to severe systemic disease in immunocompromised patients. We report on the recent recovery of T. asahii isolates with reduced susceptibility in vitro to amphotericin B (AMB), flucytosine, and azoles from six nongranulocytopenic patients who exhibited risk factors and who developed either superficial infections (four individuals) or invasive infections (two individuals) while in intensive care units. The latter two patients responded clinically and microbiologically to AMB treatment. All six isolates were closely related according to random amplified polymorphic DNA studies and showed 71% similarity by amplified fragment length polymorphism analysis, suggesting a common nosocomial origin. We also review the literature pertaining to T. asahii infections and discuss the salient characteristics of this fungus and recent taxonomic proposals for the genus.Trichosporon infections are associated with a wide spectrum of clinical manifestations, ranging from superficial cutaneous involvement in immunocompetent individuals to severe systemic disease in immunocompromised patients (9, 44). Trichosporon asahii (Trichosporon beigelii) has increasingly been described as an opportunistic pathogen involved in disseminated infections in patients with profound granulocytopenia (9,11,26). Less commonly reported risk factors associated with infections caused by this agent include treatment with immunosuppressive drugs, transplantation, AIDS, extensive burns, and the presence of implanted prosthetic devices (9,11,14,20,24,27,29).Trichosporon species were the most common non-Candida cause of fungemia at a national cancer institute (23). Disseminated Trichosporon infections in immunocompromised patients are frequently fatal, despite therapy with amphotericin B (AMB) (9,44,46). This antifungal agent has been shown to have a limited in vitro effect against Trichosporon species. In contrast, azoles have been demonstrated to have in vitro activity against members of this genus and their use has been associated with favorable responses in animal models (2,3,9,27,31,32,45,46).We report on the recent recovery of T. asahii isolates resistant in vitro to AMB and azoles from six nongranulocytopenic patients who developed either invasive or superficial infections while hospitalized in different intensive care units (ICUs). We describe the demographic and major clinical characteristics of these patients and review the literature pertaining to T. asahii infections. Results from molecular biology-based studies based on random amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) analyses suggest that the isolates recovered from specimens of these six patients were closely related. In addition, we discuss the salient characteristics of this fungus and recent taxonomic proposals for the genus. MATERIALS AND METHODSCase re...

Trichosporon asahii causing nosocomial urinary tract infections in intensive care unit patients: genotypes, virulence factors and antifungal susceptibility testing

“…Breakout in patients receiving echinocandin prophylaxis has been reported (Bayramoglu et al, 2008;Fera et al, 2009). On the whole, consistent with a previous report (Wolf et al, 2001), the triazole antifungal agents exhibited greater in vitro activities against planktonic T. asahii. Furthermore, due to the poor physiological condition of severely ill patients in ICUs, a potent agent with a much broader antifungal activity spectrum, such as voriconazole, may be recommended.…”

Comparision of matrix-assisted laser desorption ionization-time of flight (MALDI-TOF MS) with API ID 32C and VITEK 2 for the identification of Trichosporon species

“…Trichosporon asahii Türkiye dâhil birçok ülkede en sık izole edilen Trichosporon türüdür (20)(21)(22)(23) . Bu türün birçok antifungale karşı yüksek MİK değerlerine sahip olması özellikle daha sık izole edildiği immunsupresif ve yenidoğan hasta grubunda sorun oluşturmaktadır (20) .…”

“…Ülkemizde yapılan bir çalışmada, bu türün amfoterisin B, flukonazol ve 5-flusitozine düşük duyarlı olduğu ve vorikonazolün en aktif antifungal olduğu belirtilmiştir (23) . Mantar tedavisinde sıklıkla kullanılan bu antifungallere karşı duyarlılığının düşük olması, bu türün hızlı ve doğru olarak tanımlanmasının tedaviyi yönlendirmede önem taşıdığını göstermektedir (21)(22)(23) . …”

Genetic diversity and antifungal susceptibility testing of Trichosporon asahii isolated of Intensive Care Units patients

“…This yeast is found in the normal skin, nails and mouth of healthy individuals (28,35,58), as well as, in Brazil, T. asahii was also recovered from rice and cassava used in fermented beverages (45).…”

“…Trichosporon infections are rare but have been associated with a wide spectrum of clinical manifestations, ranging from superficial involvement in immunocompetent individuals such as white piedra (40,47) to severe systemic disease in immunocompromised patients with a pattern similar to candidiasis (6,19,29,30,43,58). Rodrigues et al (43) described twenty-two cases of nosocomial infection caused by T. asahii, detected during a period of six years (1999)(2000)(2001)(2002)(2003)(2004)(2005) in a Brazil hospital.…”