# Mycoplasma hominis Intracranial Abscess Diagnosed by Characteristic Colonies Obtained Through Extended Culture: Case Report and Literature Review

## TL;DR

A rare case of intracranial abscess caused by Mycoplasma hominis was diagnosed through extended culture after initial tests failed to detect the bacteria.

## Contribution

This case highlights the importance of extended culture for diagnosing M. hominis intracranial abscess when Gram staining is negative.

## Key findings

- M. hominis was identified through 16S rRNA gene sequencing of colonies observed on day 19 of culture.
- Antibiotic treatment with levofloxacin and clindamycin resolved the abscesses over 52 days.
- No recurrence was observed after treatment completion.

## Abstract

Mycoplasma hominis (M. hominis) causes genitourinary infections and pregnancy-related complications. Reports of intracranial abscesses due to M. hominis infection are rare. Here, we report a M. hominis intracranial abscess case following a traffic accident who was admitted to our hospital (day 0). The patient, a man in his 70s, underwent cystourethrography, and a urethral catheter was inserted. On day three, the patient underwent intracerebral hematoma evacuation, and on day seven, intravenous ceftazidime and vancomycin were administered after the patient developed a fever. On day 10, the antibiotics were switched to meropenem and vancomycin due to persistent fever. On day 17, magnetic resonance imaging revealed brain and epidural abscesses, and abscess drainage was performed. Gram staining of the abscess specimen showed numerous polymorphonuclear leukocytes, but no visible microorganisms. On day 19, two days after inoculating the culture, tiny pinpoint colonies were observed on the blood agar. Sequencing of the 16S rRNA gene from these colonies revealed the presence of M. hominis. On day 27, the treatment was changed to levofloxacin and clindamycin for treatment of the intracranial abscesses caused by M. hominis. Antibiotic therapy was continued for an additional 52 days until the abscesses disappeared. No recurrences were observed. When bacteria are suspected to be the cause of an intracranial abscess with a risk of M. hominis infection, and Gram staining does not show any microorganisms, considering M. hominis as one of the causative pathogens, conducting extended culture is important.