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

INTRODUCTION

() is a common colonizer in the microflora of the genitourinary tract of many sexually active adolescent females.can be found in the cervical or vaginal secretions of up to 50% of healthy women[1]. At present, it has been demonstrated that pathogenicis mainly distributed in the oropharynx and urogenital tract[2].is associated with certain diseases of parturient women, their fetuses and newborns, but it is rare forto cause central nervous system infections in adults. Becausehas no cell wall, it cannot be observed by Gram staining. Moreover, the difficulty of culturingincreases the challenge of clinical detection and often delays treatment. Here, we report a case ofinfection secondary to craniocerebral surgery detected by next-generation metagenomic sequencing (mNGS). We also reviewed relevant literature to analyze the clinical features, diagnosis and treatment methods of central nervous system infections caused byto deepen the understanding of this type of infection among clinicians and improve the diagnosis and treatment options.

CASE PRESENTATION

Chief complaints

A 44-year-old man presented to our hospital complaining of worsening dizziness.

History of present illness

July 25, 2021

History of past illness

从思路对比中可看出，十年后所设想的更注重学生动手操作实践的经验积累，充分利用图例“两次”来直观理解“2倍”，并建立“2倍”模型，同时延伸至简单乘除法的解决问题；再从“2倍”过渡到“多倍”，通过变式加深理解“标准量”的重要性；最后由“一题”拓展到“一类”强化理解倍的本质——两个量的比较关系，使知识结构化；再延伸至“倍数与因数”，使知识关联化，解题策略模型化。

没过几分钟，斯坦利和妻子都面色发青，瘫倒在地。亲属们吓坏了，立即叫来了救护车。但悲剧再次重演，斯坦利夫妇均告不治。

Physical examination

Single blind

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Healthy, with no specific diseases.

Laboratory examinations

On admission, the patient's examination results were completely normal, including leukocyte count, hypersensitive C-reactive protein, procalcitonin, electrolytes, liver and kidney function tests and coagulation function tests. On the third postoperative day, the leukocyte count was 14.8 × 10/L (reference range: 4-10 × 10/L), and the neutrophil count (NEUT%) was 89.5% (reference range: 40%-75%). The cerebrospinal fluid (CSF) examination showed 62.9 × 10white blood cell (WBC)/μL, with a protein level of 8036 mg/L, glucose level of 3.8 mmol/L and chloride ion concentration of 139 mmol/L.

Imaging examinations

The brain magnetic resonance imaging (MRI) examination revealed a massive mass outside the right anterior and middle cranial base. The main body of the lesion was in the middle cranial base with an irregular shape and a size of approximately 7.0 cm ×6.0 cm × 6.1 cm. The right ventricle and cerebral peduncle were compressed, and the midline was shifted to the left (Figure 1). On postoperative day 10, we reviewed the brain MRI and excluded a brain abscess (Figure 2).

超厚宽幅水泥稳定碎石基层有效避免了上下基层黏结紧密的问题，提高路面结构层整体性，提升路面承载能力、抗变形能力。本项目在K21+300及K21+350标段处各结构层埋设应力—应变传感器，每个横断面分三层布设，用于监测试验车辆荷载作用下各结构层应力及应变状况。测点1位于沥青面层与超厚基层之间，测点2位于超厚基层中部偏下位置，该位置为传统分层施工基层的上下基层结合处，测点3位于底基层与基层交接处，图1为应力及应变测试结果曲线。

FINAL DIAGNOSIS

The initial diagnosis on admission was intracranial space-occupying meningioma.Meningioma,meningitis and pulmonary infection were diagnosed postoperatively.

TREATMENT

Grade D (Fair): 0

OUTCOME AND FOLLOW-UP

At follow-up 1 year later, the muscle strength of the patient's left limb had returned tonormal, and the patient could work normally.

DISCUSSION

Intracranial infection is a common complication after neurosurgery with a reported incidence of less than 10% and a high incidence at 3 to 7 d postoperatively. Infection is mainly caused by Gram-positive bacteria, which can manifest as subdural empyema,brain abscess, ventriculitis, or meningoencephalitis[3,4]. In recent years, the epidemiology of pathogenic bacteria causing intracranial infections after neurosurgery has changed. Gram-negative bacteria exhibit an obvious increasing trend, and multidrug-resistant or extensively drug-resistantalso exhibits a gradually increasing trend[5]. Intracranial infection withis common in neonates but rare in adults after craniocerebral surgery. Current studies have found that cerebrospinal fluid leakage, ventricular drainage, multiple operations, surgical incision infection, and long operation time (greater than 4 h) are independent risk factors for intracranial infection after craniocerebral surgery[6]. There are three main sources of intracranial infection with mycoplasma: direct contamination during trauma, direct contamination during surgery, or bacteremia caused by urogenital tract manipulation secondary to brain site infection. Mycoplasma contains surface proteins that promote cell adhesion and can spread to other sites, leading to infection when the mucosa is damaged, such as with instrument manipulation, surgery, and trauma[1].Although the results of urine culture were negative many times in this patient, the urinary catheter was continuously indwelling after surgery. Because the urinary tract is a common site of mycoplasma, the possibility of intracranial infection caused by the urinary tract could not be excluded in this patient. Earlier, Kupila[7] reported a case of brain abscess withsecondary to cystoscopy and an indwelling catheter. In this case, the risk of secondary intracranial infection after surgery was significantly increased due to the large tumor volume, long operation time, greater volume of intraoperative bleeding, and presence of a postoperative extradural drainage tube. The patient developed fever on postoperative day 3, andwas detected in blood cultures. Early empirical coverage of Gram-positive bacteria was performed, but the treatment was ineffective. During treatment, we reviewed the relevant domestic and international literature. There have been a few reports oninfection in adults after craniocerebral surgery. In addition, we lacked clinical experience, so the treatment forwas delayed. Fortunately, the patient was finally cured and discharged.

At present, mycoplasma culture is the main method for detection of mycoplasma in domestic medical institutions, and this process mainly uses liquid medium for direct culture with simultaneous drug sensitivity tests. Mycoplasma releases ammonia gas by decomposing arginine, resulting in pH changes in the liquid medium and thus a change in the color of the indicator to infer the culture result. Because cholesterol is an important component of the cell membrane of mycoplasma and mycoplasma itself does not have the ability to synthesize it, animal serum must be added to the culture mediumto provide cholesterol components. Therefore, the liquid medium must contain arginine and cholesterol. If the solid culture method is adopted, the specimen is cultured in a COenvironment for 24-48 h after inoculation and characteristic "fried egg-like" colonies can be observed under the microscope. Due to the uncertainty of the factors leading to pH changes in liquid media, false-positive results may occur. Therefore, the liquid culture method can be combined with the solid culture method in clinical practice to improve the mycoplasma detection rate. The possibility of mycoplasma infection was not considered during the culture of the CSF specimen of this patient, and no special medium was used. Thus, the results of repeated culture were negative. After the mNGS test results suggested, we cultured the CSF again using special medium, and the results confirmed the intracranial infection caused by. Most of the cases we reviewed were diagnosed by mNGS, which not only directly sequences the genomes of samples but also identifies a variety of unknown pathogens in the samples. Compared with traditional culture methods, mNGS requires less time and is more efficient[8]. Long[9] showed that, compared with blood cultures, mNGS had a higher sensitivity and pathogen detection rate (30.77%12.82%). Currently, the conserved region of 16S rRNA is the main gene sequence used for the construction of primers. Studies have found that the application of 16S rRNA by real-time reverse transcription PCR (qRTPCR) can further improve the positive rate of specimen detection and eliminate falsepositives[10].

Because mycoplasmas lack a cell wall, they are resistant to β-lactam and glycopeptide antibiotics that act on the cell wall. Tetracyclines that interfere with protein synthesis are commonly used to treat mycoplasmas, which are also sensitive to quinolones that inhibit DNA replication.is typically resistant to macrolides and aminoglycosides. In the cases reviewed, 9 patients were switched to tetracycline antibiotics after the pathogen was confirmed as, and all the patients were cured. In patients with meningitis caused by, if doxycycline treatment fails,clindamycin or fluoroquinolones may be used instead[11]. In the treatment of this patient, levofloxacin was used in the early stages, but the treatment effect was not ideal. After the combined application of moxifloxacin and doxycycline, the patient's body temperature and infection indices gradually improved.was most sensitive to doxycycline and minocycline but more resistant to erythromycin,norfloxacin and clarithromycin[12]. Although some studies have shown that the drug resistance rate of levofloxacin to mycoplasma has exhibited a declining trend in recent years, the drug resistance rate ofis approximately 23.08%[13]. However,Zhang[14] used PCR to amplify drug-resistant genes and found that the drug resistance rate ofto levofloxacin reached 87.9% due toandgene variation. Therefore, doxycycline remains the drug of choice for the treatment of.

CONCLUSION

infection after craniocerebral surgery in adults is rare, but it can be clearly diagnosed by special culture or mNGS. The clinical prognosis is generally good when treated with targeted anti-infection therapy.