A Rare Case of Keratitis Caused by Graphium basitruncatum in China

Graphium basitruncatum (G. basitruncatum) has been rarely reported in human infections. In this study, a rare fungal keratitis case caused by G. basitruncatum in China was reported. Its microbiological and molecular characteristics were described. The strain was isolated from corneal of a 35-year-old male farm worker. Routine biochemical and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) methods failed to identify the pathogenic strain. Internal transcribed space (ITS) second-generation sequencing was performed. ITS sequence of the isolate showed 99.77% similarity with Graphium basitruncatum JCM 9300,which identified the strain as G. basitruncatum . The strain had physiological characteristics including strong adaptability (able to grow on various cultured medias) and thermal tolerance (able to grow at 42°C), which may prompt its environmental adaptability and potential for opportunistic human infection. The patient had a favorable outcome after receiving treatment. In conclusion, this case indicates that G. basitruncatum should be recognized as an emerging opportunistic pathogen that can cause human infections.