Socioeconomic Disparities Affecting the Presentation and Outcomes in Pediatric Subdural Empyema Patients.

BACKGROUND AND OBJECTIVES: Pediatric subdural empyemas (SDE) carry significant morbidity and mortality, and prompt diagnosis and treatment are essential to ensure optimal outcomes. Nonclinical factors affect presentation, time to diagnosis, and outcomes in several neurosurgical conditions and are potential causes of delay in presentation and treatment for patients with SDE. To evaluate whether socioeconomic status, race, and insurance status affect presentation, time to diagnosis, and outcomes for children with subdural empyema. METHODS: We conducted a retrospective cohort study with patients diagnosed with SDE between 2005 and 2020 at our institution. Information regarding demographics (age, sex, zip code, insurance status, race/ethnicity) and presentation (symptoms, number of prior visits, duration of symptoms) was collected. Outcome measures included mortality, postoperative complications, length of stay, and discharge disposition. RESULTS: 42 patients were diagnosed with SDE with a mean age of 9.5 years. Most (85.7%) (n = 36) were male ( P = .0004), and a majority, 28/42 (66.7%), were African American ( P < .0001). There was no significant difference in socioeconomic status based on zip codes, although a significantly higher number of patients were on public insurance ( P = .015). African American patients had a significantly longer duration of symptoms than their Caucasian counterparts (8.4 days vs 1.8 days P = .0316). In total, 41/42 underwent surgery for the SDE, most within 24 hours of initial neurosurgical evaluation. There were no significant differences in the average length of stay. The average length of antibiotic duration was 57.2 days and was similar for all patients. There were no significant differences in discharge disposition based on any of the factors identified with most of the patients (52.4%) being discharged to home. There was 1 mortality (2.4%). CONCLUSION: Although there were no differences in outcomes based on nonclinical factors, African American men on public insurance bear a disproportionately high burden of SDE. Further investigation into the causes of this is warranted.

Empiema subdural y su relación con hematomas subdurales: experiencia local y revisión de la literatura / Subdural empyema and its relationship to subdural hematomas: local experience and literature review

RESUMEN: Los empiemas subdurales, tanto los de aparición espontánea o como complicación en la evolución de un hematoma subdural (HSD), son infrecuentes y de los cuales existen pocas publicaciones en la literatura(1). En este trabajo se revisa una serie de 15 casos operados en el Hospital de Urgencia Asistencia Pública (HUAP) en un período de 15 años. Se observó que en general tienen buena evolución con el tratamiento instaurado en forma oportuna y que son larvados en su presentación, pudiendo llegar a ser diagnosticados incluso en el intraoperatorio. No se observó diferencia en su evolución cuando se operaron a través de una craniectomía o de una craneotomía (plaqueta)(2). No se encontró tampoco diferencia cuando se trataron con o sin drenaje. Como consenso general, deben ser tratados con antibioticoterapia prolongada de al menos 3-4 semanas para controlar el foco infeccioso(2). Ninguno de los casos revisados requirió de reintervención.

ABSTRACT Subdural empyemas, both spontaneous or as a complication in the evolution of subdural hematomas, are an uncommon fact of which there are few publications in literature. In this review we analyze a retrospective serie of 15 cases operated in HUAP in a period of 15 years. In general we don't observed differences in the outcome using different surgical techniques, both in those treated by craniectomy as those treated by craniotomy. Also we don't observed differences in those treated with or without drainage. In the same way is clear that the optimal period of antibiotic treatment must be 3-4 weeks to fully cover them. None of the cases treated, needed reintervention.

Postoperative empyema following chronic subdural hematoma surgery: Clinically based medicine.

INTRODUCTION: Subdural empyema (SDE) is a rare complication of chronic subdural hematoma (CSDH) surgery. We introduced antibiotic prophylaxis (AP) for this procedure in 2014 following a morbidity-mortality conference (MMC) in our department. We report the results of retrospective data analysis to assess the effect of systematic AP and to identify risk factors for SDE. MATERIAL AND METHODS: Two hundred eight patients were recruited between January 2013 and December 2015; 5 were excluded for incomplete data: 107 without and 96 with AP (n=203). SDE was confirmed by clinical examination, imaging and bacteriological analysis. Comparisons between AP-(no cefuroxime) and AP+ (cefuroxime) groups were made with Chi2 test and Student's t-test. RESULTS: One empyema was found in each group, indicating that AP had no effect (P=1). The only criterion associated with SDE for these two patients was a greater number of reoperations for CSDH recurrence (P=0.013). DISCUSSION: The incidence of postoperative empyema was 1%, similar to the range of 0.2%-2.1% reported in the literature. This rare incidence explains why we found no significant effect of AP. The medical decision taken at the MMC did not help to reduce the rate of postoperative SDE. MMCs can help to define factors associated with adverse surgical events and identify opportunities for improvement. CONCLUSION: AP, introduced after an MMC, did not impact SDE rates. In practice, AP should be required only in case of reoperation for CSDH recurrence. However, we still continue to use AP following the MMC considering different parameters discussed in the manuscript.

Risk Factors and Outcomes of Cutibacterium acnes Postoperative Central Nervous System Infection: A Case-Control Study.

OBJECTIVE: Cutibacterium acnes has emerged as a significant cause of postoperative central nervous system infections (PCNSIs). We sought to determine risk factors and outcomes associated with C. acnes PCNSI. METHODS: This was a single-center 1:1 case-control study of patients with monobacterial C. acnes-associated PCNSI (cases) and unmatched controls with PCNSI caused by aerobic organisms. Patient and procedure-related characteristics were compared between groups. The main outcome was cure at 90 days after diagnosis. Mortality and neurologic disability were secondary outcomes. RESULTS: We identified 13 patients with C. acnes PCNSI and 13 controls. All patients had postoperative intracranial abscess. Onset of infection was significantly later for cases versus controls (median and range, 22 [19-116] days and 15 [1-27] days, respectively; P = 0.002). Prolonged anaerobic incubation was required for C. acnes isolation (median, 8 days vs. 2 days for aerobic pathogens; P < 0.0001). The use of sealant and implants, fever at presentation, and white blood cell and C-reactive protein levels were similar between the 2 groups. All patients underwent surgical drainage. Patients received a median of 4 antibiotic drugs and 85 antibiotic days of treatment, with no significant between-group differences. Cure at 90 days was achieved for 10 patients (76.9%) with C. acnes PCNSI and 11 (84.6%) controls (P = 1.0). CONCLUSIONS: C. acnes PCNSI presents later than infection with aerobic bacteria but is associated with similar risk factors and clinical outcomes. These results underscore the importance of prolonged anaerobic incubation to optimize the recovery of C. acnes in the laboratory.

Successful surgical management of an Escherichia coli epidural-subdural abscess secondary to sino-rhinotomy.

OBJECTIVE: To describe a case of successful management of epidural-subdural abscess and severe meningitis with secondary brain herniation in a dog. CASE SUMMARY: A rhino-sinusotomy was performed in a 3-year-old mixed-breed dog for management of refractory sinonasal aspergillosis. Initial recovery was good, but the dog became acutely stuporous 36 hours after surgery. Evidence of increased intracranial pressure with brain herniation and midline shift secondary to an epidural abscess was observed on magnetic resonance imaging. Decompressive craniectomy and drainage of the abscess was performed. Intensive nursing care and physiologic support was performed with consciousness returning 7 days after initial stupor. The dog was discharged 14 days after craniectomy and was ambulatory with support. NEW/UNIQUE INFORMATION PROVIDED: Intracranial abscesses are rarely described in dogs and few had a successful outcome reported. All previous reports have been of brain abscesses or empyema, rather than a combination of epidural and subdural abscessation. Additionally, the process of sino-rhinotomy for management of aspergillosis has not been previously linked to intracranial abscess formation. To the authors' knowledge, this is the first report of successful management of an epidural-subdural abscess and suggests that even with cases with low modified Glasgow Coma Scale scores outcome may be positive.

[A Case of Subdural Empyema with Cerebral Arteritis and Brain Ischemia in the Middle Cerebral Artery Distribution, Secondary to Odontogenic Maxillary Sinusitis].

We present a rare case of subdural empyema with cerebral arteritis and brain ischemia in the middle cerebral artery distribution secondary to odontogenic maxillary sinusitis. A 32-year-old man was admitted to our hospital because of high fever and generalized convulsions. Computed tomography(CT)and magnetic resonance imaging(MRI)showed subdural empyema at the left convexity, with a small amount of air. An interruption of the right maxillary sinus floor corresponding to the alveolar process was evident on coronal CT. He was diagnosed as having subdural empyema caused by odontogenic maxillary sinusitis. MR angiography showed stenosis of the left middle cerebral artery(MCA). Despite antibiotic administration, he became drowsy and developed aphasia with right hemiparesis. Repeat MRI showed enlargement of the encapsulated subdural empyema with increased midline shift to the right. We performed prompt surgical evacuation with craniotomy, endoscopic drainage of the sinusitis, and tooth extraction. A hyperintense lesion was observed on subsequent diffusion-weighted imaging in the left MCA distribution. After repeat drainage of the re-enlarged subdural empyema, he was discharged without apparent neurological deficits. This case indicates that subdural empyema from odontogenic sinusitis requires a suitable imaging study of the brain, head, and neck region, and a multidisciplinary approach involving a neurosurgeon, otolaryngologist, and oral surgeon. Prompt initiation of appropriate antibiotic therapy with surgical intervention is recommended for treatment of subdural empyema from odontogenic sinusitis.

Bacterial Infections of the Central Nervous System.

Bacterial infections of the central nervous system (CNS) continue to be an important cause of morbidity and mortality in children. The spectrum of bacterial infection of CNS includes; focal or multifocal infections like brain abscesses or subdural empyema; or more generalized or diffuse infections like pyogenic meningitis or ventriculitis. Focal and generalized infections may co-exist in an individual patient. Prompt and adequate antibiotic therapy and occasionally neurosurgical interventions are the cornerstone of effective management. The recent emergence of several multidrug-resistant bacteria poses a threat to the effective management of bacterial CNS infections. Several adjunctive anti-inflammatory and neuroprotective therapies are being tried, however; none has made a remarkable impact on the outcome. Consequently, bacterial CNS infections in children still remain a challenge to manage. In this review, authors discuss the current updates on the diagnostic and therapeutic aspects of bacterial infections of the CNS in children (post-neonatal age group).

Subdural empyema case report of a rare disease with a high mortality.

Subdural empyema is a rare purulent intracranial infection. Outcome is dependent on the preoperative level of consciousness, therefore an early diagnosis and urgent neurosurgical intervention are necessary. Mortality of subdural empyema remains high, ranging from 6% to 15%. The case report presents a patient with subdural empyema which resulted from sinusitis. The integral and first part of therapy was an urgent neurosurgical drainage of subdural empyema, followed by functional endoscopic sinus surgery performed by ENT surgeon. Conservative treatment consisted of systemic antibiotics and antiedematous therapy. Later the patient developed post-infectious hydrocephalus, which was solved by implantation of a ventriculo-peritoneal shunt. Consequently, cranioplasty was performed. Despite acute onset of the disease and severe neurologic deficit prior to the first neurosurgical intervention, the clinical condition of the patient is favorable after multiple surgeries. The patient is able to live independently without any significant limitations in everyday activities. The presenting symptoms of subdural empyema are reflective of increased intracranial pressure, meningeal irritation, and cerebritis. Radiographic imaging (contrast CT, DWI-MRI, contrast MRI) is an essential diagnostic tool. The integral part of therapy is a neurosurgical evacuation of subdural empyema combined with intravenous antibiotic therapy. Subdural empyema is a rare, rapidly progressing disease which is underestimated by the physicians in many cases. Diagnosis is often delayed and therefore, despite recent progress in treatment, the mortality rate remains high. Key words: empyema - subdural - sinusitis - diagnostic imaging - surgical method.

Pyogenic brain abscess and subdural empyema: presentation, management, and factors predicting outcome.

PURPOSE: To describe the presentation and management of bacterial brain abscess and subdural empyema in adults treated at two tertiary centers. In addition, to identify factors that may predict a poor clinical outcome. METHODS: A retrospective analysis of data obtained from clinical records was performed, followed by multivariate regression analysis of patient and treatment-related factors. RESULTS: 113 patients were included with a median age of 53 years and a male preponderance. At presentation symptoms were variable, 28% had a focal neurological deficit, and 39% had a reduced Glasgow coma scale (GCS). Brain abscesses most frequently affected the frontal, temporal, and parietal lobes while 36% had a subdural empyema. An underlying cause was identified in 76%; a contiguous ear or sinus infection (43%), recent surgery or trauma (18%) and haematogenous spread (15%). A microbiological diagnosis was confirmed in 86%, with streptococci, staphylococci, and anaerobes most frequently isolated. Treatment involved complex, prolonged antibiotic therapy (> 6 weeks in 84%) combined with neurosurgical drainage (91%) and source control surgery (34%). Mortality was 5% with 31% suffering long-term disability and 64% achieving a good clinical outcome. A reduced GCS, focal neurological deficit, and seizures at presentation were independently associated with an unfavorable clinical outcome (death or disability). CONCLUSIONS: Complex surgical and antimicrobial treatment achieves a good outcome in the majority of patients with bacterial brain abscess and subdural empyema. Factors present at diagnosis can help to predict those likely to suffer adverse outcomes. Research to determine optimal surgical and antibiotic management would be valuable.

Treatment and reconstruction of a complicated infected scalp squamous cell carcinoma with CNS invasion.

A 60-year-old male patient with a large infected cranial apex lesion was admitted with lethargy and mental status changes. The patient underwent evaluation with imaging studies, a skin biopsy, cultures with microscopy and a diagnostic burr hole. MRI and positron emission tomography/CT scan revealed a squamous cell carcinoma with ingrowth in the midline of the brain and subdural empyema infected with Streptococcus anginosus and Staphylococcus aureusHigh dose intravenous antibiotic treatment was initiated and the patient subsequently underwent a surgical resection of the carcinoma with a 1 cm margin of surrounding skin and skull. The defect was reconstructed using a titanium plate and a free microvascular lattisimus dorsi muscle flap then covered with a split skin graft.The patient received 37 radiation therapy sessions (66 GY) as adjuvant therapy.Intensive neurorehabilitation slowly improved an initial paraparesis. The 7-month follow-up revealed a satisfactory cosmetic result and residual gait impairment secondary to central nervous system invasion.

Simultaneous treatment of intracranial complications of paranasal sinusitis.

PURPOSE: The objective of this study was to analyse 51 patients with intracranial complications of sinusitis treated in the Department of Otolaryngology and Laryngeal Oncology at Poznan University of Medical Sciences from 1964 to 2016. MATERIALS AND METHODS: Males made up a significant portion of study participants at 70.5%. Treatment included simultaneous removal of inflammatory focal points in the paranasal sinuses and drainage of cerebral and epidural abscesses and subdural empyemas under the control of neuronavigation preceded by the implementation of broad-spectrum antibiotics continuously for 4 weeks. Seventy-three intracranial complications were found among 51 patients. Of the 51 patients, 25 had frontal lobe abscesses (including multiple abscesses). Other complications included the following: 16 epidural abscesses, 9 subdural empyemas, 15 meningitis cases, 3 intracerebral abscesses, 3 sinus thrombosis cases and 2 patients with cerebritis. Co-occurrence of these complications worsened the state of the patient and increased the duration of treatment. Patients with frontal lobe abscesses had a better prognosis and less pronounced neurological symptoms in recent years versus earlier treatment approaches. CONCLUSIONS: Simultaneous treatment of intracranial complications of sinusitis is an effective treatment method that has minimal burden for the patient. From 1964 to 1978, three deaths (17%) were reported among patients with these complications. Since 1978, no deaths were reported in the clinic.

Treatment of a subdural empyema complicated by intracerebral abscess due to Brucella infection.

A 55-year-old male presented with fever, stupor, aphasia, and left hemiparesis. A history of head trauma 3 months before was also reported. Cranial magnetic resonance imaging revealed slight contrast enhancement of lesions under the right frontal skull plate and right frontal lobe. Because of deterioration in nutritional status and intracranial hypertension, the patient was prepared for burr hole surgery. A subdural empyema (SDE) recurred after simple drainage. After detection of Brucella species in SDE, craniotomy combined with antibiotic treatment was undertaken. The patient received antibiotic therapy for 6 months (two doses of 2 g ceftriaxone, two doses of 100 mg doxycycline, and 700 mg rifapentine for 6 months) that resulted in complete cure of the infection. Thus, it was speculated that the preexisting subdural hematoma was formed after head trauma, which was followed by a hematogenous infection caused by Brucella species.

Treatment of a subdural empyema complicated by intracerebral abscess due to Brucella infection

A 55-year-old male presented with fever, stupor, aphasia, and left hemiparesis. A history of head trauma 3 months before was also reported. Cranial magnetic resonance imaging revealed slight contrast enhancement of lesions under the right frontal skull plate and right frontal lobe. Because of deterioration in nutritional status and intracranial hypertension, the patient was prepared for burr hole surgery. A subdural empyema (SDE) recurred after simple drainage. After detection of Brucella species in SDE, craniotomy combined with antibiotic treatment was undertaken. The patient received antibiotic therapy for 6 months (two doses of 2 g ceftriaxone, two doses of 100 mg doxycycline, and 700 mg rifapentine for 6 months) that resulted in complete cure of the infection. Thus, it was speculated that the preexisting subdural hematoma was formed after head trauma, which was followed by a hematogenous infection caused by Brucella species.

Escherichia coli positive infratentorial subdural empyema secondary to mastoiditis and underlying cholesteatoma.

Infratentorial subdural empyema is a neurosurgical emergency that is associated with an alarmingly high morbidity and mortality if appropriate management is delayed. It is an important differential to consider when confronted with a patient with a reduced Glasgow Coma Scale, focal neurology and symptoms of raised intracranial pressure in the presence of a head and neck infection. It is also important that the primary team managing these patients is aware of the many pathogens that may be involved, including Escherichia coli. Early recognition, prompt diagnosis, timely involvement of the appropriate multidisciplinary teams, including neurosurgery, otorhinolaryngology, radiology and microbiology should be sought, and urgent intervention are imperative in avoiding a fatal outcome. This article presents a case of E coli-positive infratentorial subdural empyema secondary to mastoiditis due to underlying cholesteatoma, and a review of the pertinent literature.

The pediatric headache that would not go away.

We describe the clinical presentation, radiographic findings, management, and outcome of a subdural empyema in a 14-year-old male with history of recent partially treated acute sinusitis. Subdural empyema is a rare but life threatening complication, usually following paranasal sinusitis, otitis media, mastoiditis, cranial surgery, a skull fracture, or from distant spread from sites such as a pulmonary infection. The initial evaluation should include a thorough history and physical examination, complete blood count, electrolytes, C-reactive protein, erythrocyte sedimentation rate, chest x-ray, urinalysis, and neuroimaging of the brain with intravenous contrast. If a subdural empyema is identified, then intravenous antibiotics should be initiated, and immediate neurosurgical consultation should be obtained to consider operative drainage.

Hollow screws: a diagnostic tool for intracranial empyema.

BACKGROUND: Subdural (SDE) and epidural empyema (EDE) are life-threatening intracranial infections. They require immediate diagnosis and treatment. However, in some cases, magnet resonance imaging (MRI) is not able to contribute to diagnosis; therefore, surgical exploration is indicated. Hollow screws used for decompression of chronic subdural haematoma (cSDH) are valuable tools for minimally invasive biopsy in awake patients when SDE and EDE are suspected. METHODS: Between 2006 and 2010, eight patients in our department underwent biopsy of a suspected SDE or EDE using hollow screws. In these cases, MRI or computed tomography (CT) were not able to provide sufficient diagnostic security to indicate primary craniotomy. Diagnostic and therapeutic efficacy was evaluated on preoperative and postoperative imaging. The focus was on qualitative parameters, such as contrast enhancement or impaired diffusion on diffusion-weighted images (DWI). RESULTS: The application of the hollow screw under local anaesthesia permitted an exact diagnosis in all cases. In one case, the suspected diagnosis of cSDH could be refuted by diagnostic puncture. In four cases of uncertain diagnosis, the application of the hollow screw revealed a cSDH. Seven of eight patients previously received neurosurgical treatment; three of those cases were SDE or EDE and four were cSDH. Cases of SDE and EDE needed further craniotomy after diagnostic puncture, whereas patients with cSDH were sufficiently treated by hollow screws. CONCLUSIONS: Given their comparably wide diameter, hollow screws allow a sufficient sample size and, therefore, lead to precise diagnosis of SDE and EDE without significant operative risks or strains for the patient.

Pediatric focal intracranial suppuration: a UK single-center experience.

PURPOSE: Brain abscess (BA) and subdural empyema (SDE) are uncommon but clinically important conditions in childhood. Treatment involves surgery and prolonged courses of antibiotics. There is no consensus on the optimal approach. The objective was to review management and outcome of BA and SDE in a single UK center. METHODS: This retrospective case notes review of children with brain abscess or subdural empyema admitted to a tertiary pediatric infectious diseases and neurosurgical center from 2001 to 2009. RESULTS: Forty-two children were included in the study; 17 children were with BA, 23 with SDE, and two both with BA and SDE. The causative factors found in 88 % of the patients were most commonly sinusitis and meningitis with congenital heart disease and immunocompromise unusual. Streptococcus anginosus group organisms were most common; 10 % of the children had a resistant pathogen and 86 % had surgical intervention. Fifteen patients with BA underwent surgery; nine of these patients underwent burrhole aspiration, three had craniotomy, two had stereotactic surgery, and one had endoscopic aspiration. Remaining 19 patients with SDE underwent surgery: seven had burrhole aspiration, 11 underwent craniotomy, and one had aspiration via the anterior fontanel. The most common antibiotic regime was cefotaxime, metronidazole, and amoxicillin. Mean duration of treatment was 14.4 weeks. Mean time until normalization of C reactive protein was 23 days. Survival was 95 % and 20 % had ongoing neurological sequelae. CONCLUSIONS: BA and SDE remain important childhood infections in the UK. Antibiotics are essential in the management of these cases. Empiric antibiotic choices require knowledge of likely pathogens and local resistance. Selected infections can be treated without surgical intervention. Long courses of antibiotics were administered. Outcome is good, and neurological sequelae were less common than found in previous series.

Posterior fossa subdural empyema in children--management and outcome.

AIMS: The aims of this study were to analyze the clinical features, radiologic findings, bacteriologic spectrum, and management protocols and outcomes in posterior fossa subdural empyemas in children. MATERIALS AND METHODS: This study is a retrospective analysis of all children (age, <18 years) treated over a ten-year period (1994-2004) at NIMHANS, India. Clinical, bacteriologic, radiologic, and follow-up data were analyzed. RESULTS: Twenty-seven children with posterior fossa empyemas were treated during this period, making this the largest series to date dealing with this rare entity. Posterior fossa empyemas are seen more commonly in the summer months and in males. Of the patients, 74.1% were in altered sensorium. The clinical features included the triad of fever, headache, and vomiting, which is a nonspecific picture. Cerebellar signs were elicited only in 40%. The most common source was untreated middle ear infection. Pus usually accumulates over the cerebellar convexity and is associated with hydrocephalus in 74% of patients. Cultures of the empyema pus were positive in 74% of cases, and 18.5% had polymicrobial infections. Only 21% of the patients needed a permanent CSF diversion procedure. Craniectomy is the treatment of choice in these cases. CONCLUSIONS: The clinical features are nonspecific. Early surgery can salvage most patients and obviate the need for permanent CSF diversion procedures. Surgery (evacuation of empyema and mastoidectomy), antibiotics, and management of hydrocephalus are the mainstays of treatment.

[Case of subdural empyema caused by Porphyromonas and Fusobacterium identified by 16S ribosomal RNA gene sequence analysis].

A 24-year-old woman presented subdural empyema developing from sinusitis caused by Porphyromonas and Fusobacterium infection. She experienced fever and progressive headache with gradually worsening symptoms. Neurological examination revealed drowsiness and neck stiffness. A CSF examination detected pleocytosis and a low glucose level. Gadolinium-enhanced T1-weighted images from brain MRI showed thickening enhancement at the leptomeninges in the left frontal to temporal lobes and interhemispheric fissure with edema. Based on the diagnosis of bacterial meningoencephalitis and subdural empyema developing from sinusitis primary to odontogenic infection, she received antibacterial chemotherapy with meropenem hydrate and vancomycin hydrochloride, after which motor aphasia and consciousness disturbance occurred. No bacteria were isolated from a trans-sphenoidal biopsy specimen and CSF culture. Molecular typing also was performed by sequencing the 16S ribosomal RNA intergenic spacer region, and Porphyromonas and Fusobacterium were identified. She was given cephalosporin and metronidazol, after which her neurological symptoms and signs gradually lessened. Physicians need to be aware that patients may develop subdural empyema subsequent to sinusitis associated with Porphyromonas and Fusobacterium infection and that amplification and sequence analysis of partial bacterial 16S ribosomal RNA gene should be examined when no bacteria is identified by culture.