Update on methods used for mycological testing: wide diversity and opportunities for improvement persist

Abstract

Past analysis of laboratory methods used for mycology specimens revealed significant variation in practices, many of which fell short of recommended procedures. In 2016 these findings led to a set of recommendations for laboratories to consider modification of their methods where appropriate, to analyse current laboratory methods used by participants in the Royal College of Pathologists of Australasia Quality Assurance Programs (RCPAQAP) Mycology module, and to compare these to the 2016 recommendations.

Seven test items, with 105–107 participants each, were analysed. Several laboratories (7–12%) did not handle specimens as recommended in an appropriate biological safety cabinet. Direct microscopy was not performed on tissue specimens 23–25% of the time. The most used staining method was potassium hydroxide with an optical brightener for fluorescent microscopy (49%) followed by Gram stain (33%). While 17–25% of laboratories used three or more media, use of four or more was uncommon (<3%). Between 9–13% of participants used only a single non-inhibitory medium for cultures. Urine specimens were incubated longer than recommended with 57% of laboratories incubating for >7days and 24% >21 days. Duration of incubation was shorter than recommended for several specimen types with 36% of skin specimens and 37–48% of tissue specimens being kept ≤21 days. For cultures kept >7 days, 13% were inspected daily, but for those incubating >14 days only 3%.

The methods of several laboratories remain outside recommended practice. An updated set of recommendations are made.