The Authors' Reply to "Additional Bacteriological Examinations Might be Required for the Correct Identification of Staphylococcus warneri".

The Authors Reply We thank Dr. Fukuchi and Dr. Sugawara for their interests in our article (1). They raised a very important question about the pathogen of our case, as Staphylococcus pasteuri is phenotypically similar to S. warneri and is, therefore, frequently misidentified as S. warneri when examined with biochemical procedures (2).

In our case, however, we utilized matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify the pathogenic bacteria and detected S. warneri as the causative pathogen of this case of native valve endocarditis. MALDI-TOF MS is a rapid, accurate and cost-effective method for microbial identification in clinical laboratories (3). It also allows for the accurate identification of most Gram-positive and Gram-negative bacterial strains at the species level (3). While 16S rRNA sequencing is useful for the identification and taxonomic classification of bacterial species, MALDI-TOF MS reportedly distinguishes S. warneri and S. pasteuri (4,5).

Therefore, we concluded that S. warneri was the pathogen of our case and that the asymptomatic and chronic clinical course is a feature of infective endocarditis due to S. warneri. The accumulation of more case reports will help clarify the clinical features of S. warneri infectious diseases.

The authors state that they have no Conflict of Interest (COI).