Mycoplasma hominis meningitis after operative neurosurgery: A case report and review of literature

BACKGROUND

Mycoplasma hominis (M. hominis), which causes central nervous system infections in adults, is very rare. It is also relatively difficult to culture mycoplasma and culturing requires special media, resulting in a high rate of clinical underdiagnosis. Therefore, clinicians often treat patients based on their own experience before obtaining pathogenic results and may ignore infections with atypical pathogens, thus delaying the diagnosis and treatment of patients and increasing the length of hospital stay and costs.

CASE SUMMARY

A 44-year-old man presented to the hospital complaining of recurrent dizziness for 1 year, which had worsened in the last week. After admission, brain magnetic resonance imaging (MRI) revealed a 7.0 cm × 6.0 cm × 6.1 cm lesion at the skull base, which was irregular in shape and had a midline shift to the left. Based on imaging findings, meningioma was our primary consideration. After lesion resection, the patient had persistent fever and a diagnosis of suppurative meningitis based on cerebrospinal fluid (CSF) examination. The patient was treated with the highest level of antibiotics (meropenem and linezolid), but the response was ineffective. Finally, M. hominis was detected by next-generation metagenomic sequencing (mNGS) in the CSF. Therefore, we changed the antibiotics to moxifloxacin 0.4 g daily combined with doxycycline 0.1 g twice a day for 2 wk, and the patient had a normal temperature the next day.

CONCLUSION

Mycoplasma meningitis after neurosurgery is rare. We can use mNGS to detect M. hominis in the CSF and then provide targeted treatment.

Mycoplasmas-Host Interaction: Mechanisms of Inflammation and Association with Cellular Transformation

Mycoplasmas are the smallest and simplest self-replicating prokaryotes. Located everywhere in nature, they are widespread as parasites of humans, mammals, reptiles, fish, arthropods, and plants. They usually exhibiting organ and tissue specificity. Mycoplasmas belong to the class named Mollicutes (mollis = soft and cutis = skin, in Latin), and their small size and absence of a cell wall contribute to distinguish them from other bacteria. Mycoplasma species are found both outside the cells as membrane surface parasites and inside the cells, where they become intracellular residents as "silent parasites". In humans, some Mycoplasma species are found as commensal inhabitants, while others have a significant impact on the cellular metabolism and physiology. Mollicutes lack typical bacterial PAMPs (e.g., lipoteichoic acid, flagellin, and some lipopolysaccharides) and consequently the exact molecular mechanisms of Mycoplasmas' recognition by the cells of the immune system is the subjects of several researches for its pathogenic implications. It is well known that several strains of Mycoplasma suppress the transcriptional activity of p53, resulting in reduced apoptosis of damaged cells. In addition, some Mycoplasmas were reported to have oncogenic potential since they demonstrated not just accumulation of abnormalities but also phenotypic changes of the cells. Aim of this review is to provide an update of the current literature that implicates Mycoplasmas in triggering inflammation and altering critical cellular pathways, thus providing a better insight into potential mechanisms of cellular transformation.