Conidiophores arising from submerged hyphae 4–6 μm in length, occasionally forming loose synnemata up to 2 mm high; stalks with roughened thick walls 3–4 μm wide consisting of verticillate branches with whorls of two to four phialides. Phialides 6–9 × 2.5–3 μm, having a swollen basal portion tapering into a short distinct neck about 1 μm wide. Conidia in divergent chains,

ellipsoidal to fusiform, smooth-walled to slightly roughened, hyaline, purple en masse, 2–3 × 2–4 μm. Conidial structures formed near the agar atypical: phialides solitary or in verticils, 2–4, variable in length (Fig. 3g and h); shaped like typical Purpureocillium lilacinum phialides, or very long (up to 30 μm) and Acremonium-like. Cylindrical, occasionally slightly curved conidia formed in ‘slimy heads’ on these Acremonium-like structures, conidia on these structures variable Dabrafenib datasheet in size, measuring 2.0–14 × CH5424802 manufacturer 1.5–2.5 μm

(Fig. 3i). This conidiogenesis was also observed by Okada et al. (1995) for P. nostocoides (=Purpureocillium lilacinum). Chlamydospores absent. Species previously assigned to Paecilomyces causing human mycoses include Paecilomyces farinosus, Paecilomyces javanicus, P. lilacinus, P. marquandii, Paecilomyces taitungiacus (=anamorph of Thermoascus taitungiacus), P. variotii and Paecilomyces viridis. Of these, P. variotii is retained in the genus Paecilomyces (as it is the type), P. javanicus and P. farinosus CHIR-99021 have been returned to

the genus Isaria in the Hypocreales (Luangsa-ard et al., 2004), P. viridis has been transferred to Chamaeleomyces (Sigler et al., 2010) and P. lilacinus is accommodated here in the genus Purpureocillium. P. marquandii is currently maintained in Paecilomyces; however, this species is unrelated to P. variotii and should to be transferred to a new genus. Paranomuraea was suggested for P. marquandii and Paecilomyces carneus (Domsch et al., 2007), but this genus has yet not been published validly. Samson (1974) considered P. lilacinus and P. marquandii to be very close to each other, based on overall morphology and spore color. Paecilomyces marquandii differs from Purpureocillium lilacinum by its hyaline conidiophores and the typical yellow reverse. Although both species have a similar morphology, phylogenies show them to be separated in two families of the Hypocreales (Sung et al., 2007). Some clinical isolates have been identified as P. marquandii (Castro et al., 1990; Naldi et al., 2000). These isolates need to be re-examined using sequence-based methods to determine whether P. marquandii genuinely has the potential for human pathogenicity or whether this is merely a misidentification of Purpureocillium lilacinum. Correct identification is crucial because Purpureocillium lilacinum is significantly more resistant to amphotericin B than P. marquandii (Aguilar et al., 1998).