Spondylodiscitis due to Parvimonas micra diagnosed by the melting temperature mapping method: a case report

Yoshitsugu Higashi,Tomohiro Ueno,Isao Kitajima,Ippei Sakamaki,Shigeki Nakamura,Kaoru Matsumoto,Hideki Niimi,Yoshihiro Yamamoto,Koyomi Kawago

doi:10.1186/s12879-017-2690-4

Abstract

BackgroundIt has been suggested that more than 100 bacterial species can be identified using only seven universal bacterial primer sets in the melting temperature (Tm) mapping method and that these findings can be obtained within 3 h of sterile site collection.Case presentationA 67-year-old Japanese man with type 2 diabetes visited our hospital complaining of progressive lower back pain for 2 months. The patient was suspected to have spondylodiscitis on magnetic resonance imaging of the spine. Blood culture and transcutaneous vertebral biopsy were subsequently performed. Using the Tm mapping method, Parvimonas micra was detected from a transcutaneous vertebral biopsy specimen in 3 h. Gram-positive cocci were also detected by Gram staining and P. micra was identified directly from the anaerobic blood culture by matrix-assisted laser desorption ionization-time of flight mass spectrometry. Four days after admission, the biopsy specimen culture isolate was identified as P. micra.ConclusionsThe Tm mapping method may be useful for the diagnosis of bacterial infections where diagnosis is challenging because of the difficulty of culturing.

Highlights

It has been suggested that more than 100 bacterial species can be identified using only seven universal bacterial primer sets in the melting temperature (Tm) mapping method and that these findings can be obtained within 3 h of sterile site collection.Case presentation: A 67-year-old Japanese man with type 2 diabetes visited our hospital complaining of progressive lower back pain for 2 months
The Tm mapping method may be useful for the diagnosis of bacterial infections where diagnosis is challenging because of the difficulty of culturing
P. micra has been increasingly isolated or detected, and recognized as the pathogen, in various invasive human infections owing to the widespread use of diagnostic technology such as matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and 16S rRNA

Summary

Background

Parvimonas micra (P. micra) is an anaerobic Grampositive coccus normally found in the oral cavity, respiratory systems, and gastrointestinal and female genitourinary tracts. Case presentation A 67-year-old Japanese man with type 2 diabetes visited our hospital with complaints of progressive lower back pain for 2 months. He had sensory impairment in the Higashi et al BMC Infectious Diseases (2017) 17:584 right leg. The patient was suspected to have spondylodiscitis, and blood culture and transcutaneous vertebral biopsy were performed. On day 4 of admission, the biopsy specimen culture revealed the presence of P. micra. Prior to the onset of lower back pain, the patient had refused dental extraction for periodontitis As this could have been the source of infection, the patient underwent tooth extraction on day 7 of admission. The patient’s condition improved postoperatively, and we discontinued ampicillin administration on day 72 of admission

Discussion and conclusions

Findings

Method for definitive diagnosis