Brain abscess of odontogenic origin: A case report and literature review.

BACKGROUND: The objective of this study is to investigate and understand the characteristics of odontogenic brain abscess. METHODS: A case of brain abscess suspected to be caused by odontogenic infection was documented, and a comprehensive analysis and summary of odontogenic brain abscess cases reported in various countries over the past 20 years was conducted. RESULTS: Based on the analysis and synthesis of both the present and previous reports, we have examined and consolidated the distinctive features of odontogenic brain abscess, the potential transmission pathway of pathogenic bacteria, diagnostic assertions, verification techniques, and crucial considerations during treatment. CONCLUSION: This investigation contributes to an enhanced comprehension and improved clinical identification of odontogenic brain abscess.

Brain abscess caused by Porphyromonas gingivalis and Eubacterium nodatum mimicking acute stroke.

We described a case of a 65-year-old man with a brain abscess caused by Porphyromonas gingivalis and Eubacterium nodatum. The patient presented right central facial nerve palsy, mutism and right hemiparesis at the examination. The patient underwent a left frontal craniotomy with evacuation of the brain abscess. Specimens were collected for microbiological analysis and intravenous treatment was started with levetiracetam, dexamethasone, meropenem (1 g/8 h) and linezolid (600 mg/12 h). After identification of anaerobic bacteria the antibiotic treatment was changed to piperacillin/tazobactam (4 g/0,5 g/8 h), fulfilling 8 weeks of antibiotic with good clinical and radiological evolution.

Identification of bacterial pathogens in brain abscesses by metagenomic approach using nanopore 16S amplicon sequencing.

Brain abscess is medically challenging. In this study, we applied nanopore sequencing for 16S rRNA analysis and investigated its efficacy and diagnostic value for patients with brain abscesses. Genomic DNA was extracted from the pus samples (n = 27) of brain abscess, and 16S rRNA genes were amplified by PCR. Sequencing libraries were generated using a rapid barcoding kit, and the generated reads were analyzed using the EPI2ME16S workflow. A conventional culture study was performed. More sensitive identification of pathogens was made by 16S sequencing, faster than the culture study. The proportion of anaerobic bacteria identified by 16S sequencing was higher (75%) than that obtained by culturing (32%). Polymicrobial infections were identified in 10 cases (40%) by 16S sequencing, while the culture study identified multiple bacteria in only 2 cases (8%). 16S sequencing was useful for identifying the composition of polymicrobial infections, including rare pathogens, and for the initial diagnosis of space-occupying lesions.

Pleural Empyema Caused by Streptococcus intermedius and Fusobacterium nucleatum: A Distinct Entity of Pleural Infections.

BACKGROUND: Many community-acquired pleural infections are caused by facultative and anaerobic bacteria from the human oral microbiota. The epidemiology, clinical characteristics, pathogenesis, and etiology of such infections are little studied. The aim of the present prospective multicenter cohort study was to provide a thorough microbiological and clinical characterization of such oral-type pleural infections and to improve our understanding of the underlying etiology and associated risk factors. METHODS: Over a 2-year period, we included 77 patients with community-acquired pleural infection, whereof 63 (82%) represented oral-type pleural infections. Clinical and anamnestic data were systematically collected, and patients were offered a dental assessment by an oral surgeon. Microbial characterizations were done using next-generation sequencing. Obtained bacterial profiles were compared with microbiology data from previous investigations on odontogenic infections, bacteremia after extraction of infected teeth, and community-acquired brain abscesses. RESULTS: From the oral-type pleural infections, we made 267 bacterial identifications representing 89 different species. Streptococcus intermedius and/or Fusobacterium nucleatum were identified as a dominant component in all infections. We found a high prevalence of dental infections among patients with oral-type pleural infection and demonstrate substantial similarities between the microbiology of such pleural infections and that of odontogenic infections, odontogenic bacteremia, and community-acquired brain abscesses. CONCLUSIONS: Oral-type pleural infection is the most common type of community-acquired pleural infection. Current evidence supports hematogenous seeding of bacteria from a dental focus as the most important underlying etiology. Streptococcus intermedius and Fusobacterium nucleatum most likely represent key pathogens necessary for establishing the infection.

First case of Rhinocladiella mackenziei brain abscess in Turkey: Case report and review of the literature.

Rhinocladiella mackenziei is a highly neurotropic fungus, mainly reported from the Middle East. However, in recent years, there have been some cases from outside this region. We described an additional fatal case of R. mackenziei cerebral infection for the first time from Turkey and made a literature review of all previously reported cases. During 34 years (1988-2022), there have been 42 R. mackenziei brain abscess cases. Most patients have been reported from Saudi Arabia (n = 14, 33.3%). It is noteworthy that 40.5% of patients, including our case, were immunocompetent at initial diagnosis and mostly presented with a single lesion (n = 10, 23.8%). The most frequent comorbidities were solid organ transplant (n = 9, 21.4%), diabetes mellitus (n = 6, 14.3%), malignancy (n = 6, 14.3%) and prior surgery (n = 3, 7.1%). The most commonly used initial antifungal regimen were amphotericin B together with itraconazole (n = 9, 21.4%), combinations of lipid preparations of amphotericin B, voriconazole and/or posaconazole (n = 9, 21.4%) and amphotericin B alone (n = 8, 19%). Although both surgical procedures and antifungal medication in the majority of patients were performed, mortality rates remained high (90.4%). The area at risk of R. mackenziei cerebral abscess cases extends to other countries. Clinicians should be aware of this emerging disease and take a detailed travel history in patients with atypical and undocumented brain abscesses. Our case confirms the hypothesis that this fungus might spread more widely than previously predicted regions.

Culture-Negative Fusobacterium nucleatum Brain Abscess and Pleural Empyema Cases Revealed by 16S rRNA Sequencing.

BACKGROUND: We reported two Fusobacterium nucleatum cases each of brain abscesses and pleural empyema, using 16S rRNA sequencing technology. METHODS: We reviewed clinical records and microbiological findings in four patients with F. nucleatum infection. RESULTS: All conventional culture results from peripheral blood, cerebrospinal fluid, and pleural fluid samples were found to be negative for this pathogen. Three patients were treated with antimicrobial agents for more than a week before specimen sampling. All patients recovered from their fusobacterial infections and were discharged. CONCLUSIONS: Molecular identification methods such as 16S rRNA sequencing should accompany conventional culture to detect obligate anaerobic bacteria in deep-seated sites and organs.

Nodulisporium Fungal Brain Abscess In Early Post-Renal Transplant: A Rare, Unexpected, Mysterious Pathogen.

BACKGROUND Central nervous system fungal infections are rarely encountered in current medicine, with fungal abscesses even less commonly seen. Clinical entities and their development largely depend on the interplay between the host's immune system and fungal virulence factors. Due to the large size of fungal organisms, they are prevented from entering the meningeal circulation. Hence, they cause focal diseases like cerebritis, abscesses, vasculitis of larger vessels, vascular occlusion, cerebral infarcts, and aneurysms. CASE REPORT A 34-year-old male patient of Indian descent diagnosed with stage 5 chronic kidney disease, bilaterally small kidneys, and hypertension underwent cadaveric renal transplantation and subsequent immunosuppression. Three months later, he returned with complaints of high-grade fever with chills and rigor, along with massive headaches. Plain brain computed tomography showed an intra-axial heterogeneously hypodense area with a hyperdense rim in the right temporal lobe. MRI revealed a well-defined enhancing lesion with irregular crenated margins and satellite lesions. Abscess wall biopsy showed fragments of hyaline septate filamentous fungal hyphae. Craniotomy with excision and drainage of the abscess was done and sent for histopathological examination along with culture. The results showed the growth of Nodulisporium fungus. The patient was then managed on amphotericin B and voriconazole for completion of treatment. CONCLUSIONS This is the first case reported of a Nodulisporium species fungal abscess developing in the brain after cadaveric kidney transplantation. Urgent evaluation via imaging and biopsy is crucial in determining the exact causal organism of brain abscesses, which can lead to better patient outcomes.

Dermacoccus nishinomiyaensis brain abscesses as the first manifestation of chronic granulomatous disease. / Abscesos cerebrales por Dermacoccus nishinomiyaensis como primera manifestación de enfermedad granulomatosa crónica.

Chronic granulomatous disease is a rare primary immunodeficiency characterized by defects in one of the subunits of the nicotinamide adenine dinucleotide phosphate oxidase enzyme complex, which causes a deficiency in the capacity of phagocytes to generate superoxide anion. Within this group, the X-linked form is the most frequent. Here we report the case of a 2-year-old female patient with autosomal recessive chronic granulomatous disease, with a mutation in the CYBA gene, whose initial manifestation was brain abscesses caused by an opportunistic microorganism (Dermacoccus nishinomiyaensis). The infection led to an early diagnostic suspicion, so treatment and prophylaxis were administered in a timely manner. Currently, she is infectionfree, awaiting hematopoietic progenitor cell transplantation. .

La enfermedad granulomatosa crónica es una inmunodeficiencia primaria poco frecuente, que secaracteriza por defectos en alguna de las subunidades del complejo enzimático nicotinamida adeninadinucleótido fosfato oxidasa, que ocasiona un déficit en la generación de anión superóxido por los fagocitos. Dentro de este grupo, la forma ligada al X es la más frecuente. Se reporta el caso de una paciente de sexo femenino de 2 años con enfermedad granulomatosa crónica autosómica recesiva, con mutación en gen CYBA, quien presentó manifestación inicial de la enfermedad con abscesos cerebrales ocasionados por un germen oportunista (Dermacoccus nishinomiyaensis). Esta infección permitió la sospecha diagnóstica temprana, por lo que recibió el tratamiento y la profilaxis en forma oportuna. Actualmente, se encuentra libre de infecciones, a la espera del trasplante de células progenitoras hematopoyéticas.

Oral microbes and the formation of cerebral abscesses: A single-centre retrospective study.

OBJECTIVE: Intracranial abscesses are relatively uncommon, but can result in significant mortality and morbidity. Whilst many potential causes of brain abscesses are recognised, in many cases the origin of infection remains clinically unidentified. Our objective was to investigate the role of bacteria found in the oral cavity in the development of brain abscesses. METHODS: A retrospective analysis was performed using data from 87 patients admitted to a single UK neurosurgical unit with brain abscesses over a 16-year period. Using microbiological data obtained from abscess sampling and peripheral cultures, species of bacteria were categorised in patients where no primary source of infection was identified (NSI) for their brain abscess (n = 52), or where an infective source (ISI) was identified. The microbiological data was then screened to identify common oral bacteria in each group. RESULTS: Brain abscesses from the ISI group (n = 35) demonstrated a significantly lower preponderance of oral bacteria (n = 8), than the NSI group (n = 29) (p < 0.05). Brain abscesses from the NSI group also had significantly higher counts of Streptococcus anginosus compared to ISI (p < 0.05), with brain abscesses being most common in the frontal and parietal lobes for both ISI and NSI. CONCLUSIONS: These findings suggest that the oral cavity could be considered as a source of occult infection in cases of brain abscess where no clear cause has been identified. Future studies should include oral screening and microbiome analysis to better understand the mechanisms involved and develop approaches for prevention. CLINICAL SIGNIFICANCE STATEMENT: Oral bacteria may be an under-recognised cause of brain abscesses. Careful review of oral health in brain abscess patients may help establish causation, particularly in patients with no cause for their abscess identified. Good levels of oral health may help prevent the development of brain abscesses in some individuals.

Diabetic ketoacidosis and coronavirus disease 2019-associated mucormycosis: a case report.

BACKGROUND: Mucormycosis is a rare, life-threatening fungal infection that affects immunocompromised hosts. Diabetes mellitus is a common predisposing condition and most often presents with rhino-orbital-cerebral infection. Association with coronavirus disease 2019 infection was revealed following a resurgence in cases of mucormycosis during the second wave of the pandemic wherein poorly controlled diabetes mellitus was the most significant risk factor in the affected population. Rhino-orbital-cerebral mucormycosis has a high mortality rate, and cerebral involvement is a poor prognostic factor. Herein, we report a case of newly diagnosed diabetes mellitus with concurrent coronavirus disease 2019 infection complicated by diabetic ketoacidosis and rhinocerebral mucormycosis at presentation, describe the diagnostic and therapeutic challenges, and discuss the interventions that ultimately resulted in a favorable clinical response. CASE PRESENTATION: We describe the case of a previously healthy 13-year-old African American female patient with newly diagnosed diabetes mellitus and concurrent severe acute respiratory syndrome coronavirus 2 infection whose disease course was complicated by rhinocerebral mucormycosis. She presented with fever, altered mental status, and Kussmaul respirations and was diagnosed with diabetic ketoacidosis with concern for cerebral edema. Concern for infectious cerebritis arose due to recurring fevers and persistently altered mental status despite correction of her metabolic derangements. This raised concern for infectious cerebritis and prompted evaluation with serial head imaging, lumbar puncture, and initiation of broad empiric antimicrobial regimen. Head imaging revealed an evolving cerebral abscess, and fungal deoxyribonucleic acid was identified on blood metagenomics testing, which ultimately confirmed the diagnosis of rhinocerebral mucormycosis. Treatment was challenging as she required surgical debridement of the frontal lobe and aggressive antifungal therapy complicated by electrolyte derangements and electrocardiogram changes that necessitated modification of the antimicrobial regimen. Despite these challenges and high mortality rate, the patient was discharged from the hospital in stable condition to inpatient rehabilitation service for reconditioning after prolonged hospitalization. CONCLUSION: Rhinocerebral mucormycosis mortality is associated with delays in therapeutic interventions, thus a high index of suspicion and early recognition were essential for timely initiation of antifungal therapy and surgical debridement.

Pediatric Brain Abscesses, Epidural Empyemas, and Subdural Empyemas Associated with Streptococcus Species - United States, January 2016-August 2022.

In May 2022, CDC learned of three children in California hospitalized concurrently for brain abscess, epidural empyema, or subdural empyema caused by Streptococcus intermedius. Discussions with clinicians in multiple states raised concerns about a possible increase in pediatric intracranial infections, particularly those caused by Streptococcus bacteria, during the past year and the possible contributing role of SARS-CoV-2 infection (1). Pediatric bacterial brain abscesses, epidural empyemas, and subdural empyemas, rare complications of respiratory infections and sinusitis, are often caused by Streptococcus species but might also be polymicrobial or caused by other genera, such as Staphylococcus. On June 9, CDC asked clinicians and health departments to report possible cases of these conditions and to submit clinical specimens for laboratory testing. Through collaboration with the Children's Hospital Association (CHA), CDC analyzed nationally representative pediatric hospitalizations for brain abscess and empyema. Hospitalizations declined after the onset of the COVID-19 pandemic in March 2020, increased during summer 2021 to a peak in March 2022, and then declined to baseline levels. After the increase in summer 2021, no evidence of higher levels of intensive care unit (ICU) admission, mortality, genetic relatedness of isolates from different patients, or increased antimicrobial resistance of isolates was observed. The peak in cases in March 2022 was consistent with historical seasonal fluctuations observed since 2016. Based on these findings, initial reports from clinicians (1) are consistent with seasonal fluctuations and a redistribution of cases over time during the COVID-19 pandemic. CDC will continue to work with investigation partners to monitor ongoing trends in pediatric brain abscesses and empyemas.

Brain abscesses caused by anaerobic bacteria.

OBJECTIVES: The objective of this study was to review the characteristics, causative bacteria, treatment and outcomes of brain abscesses due to anaerobes in our health setting. METHODS: A retrospective analysis of all brain abscesses caused by anaerobic bacteria over the period 2005-2021 was performed. RESULTS: Out of 300 brain abscesses identified during the study period, 31 were produced by anaerobic pathogens, either alone (monomicrobial infection) or together with aerobic and/or anaerobic bacteria (polymicrobial infection). The mean age of the 31 patients was 53 years, and 61.2% were male; 51.6% of infections were polymicrobial, with only four (12.9%) caused by anaerobic bacteria alone. Forty-three anaerobic bacteria were isolated: Cutibacterium acnes in thirteen (41.9%), Parvimonas micra in eight (25.8%), and Prevotella spp. in seven (22.5%). The most frequent etiologies were local neurosurgery (13/41.9%) and contiguous otogenic, oral, or sinus foci of infection (8/28.8%). Cancer was present in eight patients (28.8%), headaches in seventeen (54.8%), and fever in nine (28.8%). All patients received both surgery and antimicrobial therapy. The abscess was in the frontal region in 12 patients (38.7%) and in the parietal region in 11 (35.4%). A good outcome was obtained in all patients. CONCLUSIONS: Anaerobes were isolated in 10.3% of patients with brain abscesses in our health setting, similar to other reports. C. acnes was the most frequently detected anaerobe, especially in neurosurgical patients.

Streptococcus intermedius Acute Meningitis in an Immunocompetent Child.

Streptococcus intermedius is a commensal bacterium increasingly associated with brain abscesses. It can infect the brain through a direct extension of an inflammatory process or a hematogenous route. Meningitis due to this pathogen is sporadic and has not been described in children before. We report a case of an immunocompetent 6-year-old boy who developed bacterial meningitis due to S. intermedius .

Culture on Selective Media and Amplicon-Based Sequencing of 16S rRNA from Spontaneous Brain Abscess-the View from the Diagnostic Laboratory.

Forty-one stored samples from cases of spontaneous brain abscess were investigated to gain insight into the natural history, causative agents, and relevant laboratory diagnostics of a rare infection. Samples from a larger collection were selected based on retrospective analysis of patient records. All samples were subjected to amplicon sequencing of 16S rRNA gene fragments. Supplementary culture on selected media was performed as suggested by bioinformatics analysis. For three cases, no microorganism was disclosed, while Toxoplasma gondii, Aspergillus fumigatus, and various bacteria were the cause of 1, 2, and 35 cases, respectively. Bacterial infections were monomicrobial in 20 cases and polymicrobial in 15; the microorganisms of the latter cases were restricted to residents of cavum oris. Amplicon sequencing did not further enhance the importance of the Streptococcus anginosus group, which was involved in 17 cases, and the single primer set used may be suboptimal for amplification of Actinomyces and Nocardia. But, amplicon-based sequencing unquestionably expanded the number of polybacterial infections, with focus on the Fusobacterium nucleatum group, Parvimonas, and Porphyromonas. Culture on selective media confirmed the presence of F. nucleatum group bacteria, which attained a prominence in spontaneous brain abscess similar to the S. anginosus group. Metagenomics is a powerful tool to disclose the spectrum of agents in polymicrobial infections, but a reliable cutoff value for substantial detection is complex. Commercial media for isolation of F. nucleatum group bacteria from mixed infections are available, and these pathogens should be carefully characterized. Isolation of Parvimonas and Porphyromonas in polymicrobial infections has not been resolved. IMPORTANCE Polymicrobial brain abscess is a challenge to the clinical microbiology laboratory due to the aggregative nature of the dental and oral microbiota. Because polymicrobial infections may escape detection by conventional culture methods, directed therapy toward a single detected bacterium is problematic. Amplicon-based sequencing provides important clues to these infections, but only cultured microorganisms can be fully characterized, subjected to antimicrobial susceptibility testing, and formally named. By use of specific selective culture plates, we successfully isolated bacteria of the Fusobacterium nucleatum group, and these bacteria rose to the same prominence as the widely recognized pathogen, the Streptococcus anginosus group. Named and unnamed members of the Fusobacterium nucleatum group must be further investigated to gain insight into a rare but grave disease.

Observational study of the clinical utility of sulfamethoxazole serum level monitoring in the treatment of brain abscesses due to Nocardia species.

ABSTRACT: Although there is a lack of data in trimethoprim-sulfamethoxazole (TMP-SMX) serum monitoring utility for invasive nocardial infections, therapeutic drug monitoring is widely used to optimize dosing and avoid adverse reactions that may cause treatment interruption.We retrospectively reviewed all adults who received TMP-SMX to treat nocardial brain abscess and had SMX serum level testing from 2010 to 2020.Twenty-two patients received treatment with TMP-SMX for Nocardia species brain abscess and 16 (72.7%) had a reported SMX level, with a median patient age of 65.5 years (interquartile range, IQR 59.5-72.5). Compared to those who did not have a documented SMX serum level, patients with SMX levels had a shorter median course of TMP-SMX treatment (322 days [IQR 188-365] vs. 365 [IQR 224-365]; P = .31) and higher therapeutic induction dose (10 [62.5%] vs. 3 [50%]; P = .92). Similarly, they were more frequently on hemodialysis (3 [13.6%] vs. 1 [4.5%]; P = > .99). The median peak level was 158.5 (IQR 120-218) µg/mL, collected at 2 hours (75%) post-administration in the induction phase (81.3%). Patients with documented SMX levels had fewer reported drug toxicity (5 [31.3%] vs. 4 [66.7%]; P = .1) than those without SMX levels. Among the five patients who reported TMP-SMX-related toxicity, 4 (80%) had an SMX peak level >150 µg/mL. There was no difference in the cure, relapse, and death rates among the two groups.While SMX level was not associated with Nocardia species brain abscess cure rates and mortality, most patients with SMX peak >150 µg/mL experienced drug toxicity.

Complicaciones intracraneales graves secundarias a infecciones por Streptococcus intermedius / Serious intracranial complications secondary to Streptococcus intermedius infections

Streptococcus intermedius es un microorganismo anaerobio, perteneciente al grupo de Streptococcus anginosus. Es una bacteria comensal habitual de la cavidad oral y nasofaringe, conocida por su potencial capacidad de formar abscesos cerebrales por contigüidad o por vía hematógena a partir de infecciones de la esfera otorrinolaringológica. Las infecciones del sistema nervioso central debidas a miembros de este grupo son potencialmente mortales y requieren de un manejo multidisciplinar. La obtención de imágenes mediante tomografía computarizada o resonancia magnética debe realizarse de forma precoz para evaluar las colecciones que requieren drenaje. La intervención quirúrgica y el inicio de terapia antibiótica empírica a tiempo son imprescindibles para asegurar una correcta evolución (AU)

treptococcus intermedius is an anaerobic bacterium and a member of the Streptococcus anginosus group. It is a commensal bacterium of the oral cavity and nasopharynx, which is known for its potential ability to form brain abscesses by contiguity or hematogenous dissemination from infections of the otorhinolaryngological sphere. Central nervous system infections due to members of this group are life-threatening and need multidisciplinary management. Imaging with computed tomography or magnetic resonance imaging should be performed as soon as possible to evaluate the collections requiring drainage. Timely initiation of surgical intervention and appropriate empirical antibiotic therapy are essential to ensure a correct evolution. (AU)

Klebsiella pneumoniae-related brain abscess and meningitis in adults: Case report.

INTRODUCTION: Klebsiella pneumoniae is once thought to be a less common cause of brain abscess in adults and is mainly hospital-acquired. Community-acquired CNS infection (brain abscess and meningitis) caused by K pneumoniae without other metastatic septic abscesses is exceedingly rare. Therefore, we present a rare adult patient with invasive cerebral abscess and meningitis without other invasive abscesses related to K pneumoniae. PATIENT CONCERNS: A 64-year-old woman experienced a sudden onset of severe continuous headache accompanied by intermittent nausea, vomiting, and fever. Meanwhile, she experienced tinnitus and had a feeling of swelling in the right ear. DIAGNOSIS: Cranial magnetic resonance imaging revealed abnormal hyperintensity signals in the left head of the caudate nucleus. The next generation sequencing of cerebral spinal fluid showed infection with K pneumoniae. The patient was diagnosed with K pneumoniae-related brain abscesses and meningitis. INTERVENTIONS: Antibacterial treatment was carried out for 2 months. OUTCOMES: The patient recovered well. CONCLUSION: Despite the progress of modern neurosurgical techniques, new antibiotics, and modern imaging techniques, brain abscesses are still a potentially fatal infection. Streptococci are common organisms that result in brain abscesses. Nevertheless, Klebsiella species, once thought to be a less common cause of brain abscess in adults, has become an increasingly important cause of brain abscess, especially in Asia.

Identification of microbial agents in culture-negative brain abscess samples by 16S/18S rRNA gene PCR and sequencing.

Despite clinical suspicion of an infection, brain abscess samples are often culture-negative in routine microbiological testing. Direct PCR of such samples enables the identification of microbes that may be fastidious, non-viable, or unculturable. Brain abscess samples (n = 217) from neurosurgical patients were subjected to broad range 16S rRNA gene PCR and sequencing for bacteria. All these samples and seven formalin-fixed paraffin-embedded tissue (FFPE) samples were subjected to species-specific 18S rRNA PCR for neurotropic free-living amoeba that harbour pathogenic bacteria. The concordance between smear and/or culture and PCR was 69%. One-third of the samples were smear- and culture-negative for bacterial agents. However, 88% of these culture-negative samples showed the presence of bacterial 16S rRNA by PCR. Sanger sequencing of 27 selected samples showed anaerobic/fastidious gram negative bacteria (GNB, 38%), facultative Streptococci (35%), and aerobic GNB (27%). Targeted metagenomics sequencing of three samples showed multiple bacterial species, including anaerobic and non-culturable bacteria. One FFPE tissue revealed the presence of Acanthamoeba 18S rRNA. None of the frozen brain abscess samples tested was positive for 18S rRNA of Acanthamoeba or Balamuthia mandrillaris. The microbial 16/18S rRNA PCR and sequencing outperformed culture in detecting anaerobes, facultative Streptococci and FLA in brain abscess samples. Genetic analyses of 16S/18S sequences, either through Sanger or metagenomic sequencing, will be an essential diagnostic technology to be included for diagnosing culture-negative brain abscess samples. Characterizing the microbiome of culture-negative brain abscess samples by molecular methods could enable detection and/or treatment of the source of infection.

Nocardiosis in renal transplant patients.

Renal transplant patients are immunosuppressed and are at increased risk of opportunistic infections, including Nocardia infection. In renal transplant patients, information on the incidence and risk factors associated with nocardiosis is limited. To address the incidence and risk factors associated with nocardiosis in a large renal transplant population, we used the US Renal Data System (USRDS). Sequelae of allograft failure or rejection after infection were also examined. Demographics, clinical risk factors, Nocardia diagnosis, and allograft failure following Nocardia infection were queried in USRDS renal transplant patients using International Classification of Diseases, Ninth Revision (ICD-9) codes in billing claims and Centers for Medicare and Medicaid Services Form 2728. Generalized linear models were used to determine the risk factors associated with nocardiosis, and Cox proportional hazards models were used to examine the association of risk factors with graft failure among patients with Nocardia infection. Of 203,233 renal transplant recipients identified from 2001 to 2011, 657 (0.32%) were diagnosed with Nocardia infection. Pneumonia was the most frequent presentation (15.2%), followed by brain abscess (8.4%). Numerous factors associated with increased Nocardia infection included age >65 years (OR=2.10, 95% CI 1.71 to 2.59), history of transplant failure (OR=1.28, CI 1.02 to 1.60) or history of rejection (OR=4.83, CI 4.08 to 5.72), receipt of a deceased donor transplant (OR=1.23, CI 1.03 to 1.46), and treatment with basiliximab (OR=1.25, CI 1.00 to 1.55), cyclosporine (OR=1.30, CI 1.03 to 1.65), tacrolimus (OR=2.45, CI 2.00 to 3.00), or thymoglobulin (OR=1.89, CI 1.59 to 2.25). In patients with nocardiosis administration of antithymocyte globulin (HR=2.76), chronic obstructive pulmonary disease (HR=2.47), and presentation of Nocardia infection with brain abscess (HR=1.85) were associated with an increased risk of graft failure. This study provides new information to enhance early recognition and targeted treatment of nocardiosis in renal transplant patients.

Multiple brain abscesses due to Listeria monocytogenes infection in a patient with systemic lupus erythematosus: A case report and literature review.

AIM: To review the clinical features of systemic lupus erythematosus (SLE) complicated by central nervous system (CNS) infection due to Listeria monocytogenes. METHOD: A patient with SLE receiving high-dose glucocorticoids combined with cyclophosphamide who developed multiple brain abscesses due to Listeria infection is described. The case is compared with known cases in a literature review. RESULTS: A review of the literature showed that CNS infections are rare bacterial complications of SLE, but they can be a significant cause of mortality, especially those due to L. monocytogenes. The most significant risk factor for listerial meningitis is a prior history of receiving immunosuppressive therapy. At-risk patients should avoid unpasteurized milk and soft cheeses along with deli-style, ready-to-eat prepared meats, particularly poultry products. The case we report is the fifth SLE patient with multiple brain abscesses due to L. monocytogenes, and the first to be discharged with no sequelae. Timely and accurate identification and treatment of CNS infections and neuropsychiatric lupus are very important for favorable disease prognosis. CONCLUSION: Repeated blood culture is helpful for early diagnosis, and empirical anti-infective treatment that covers L. monocytogenes is recommended for SLE patients with risk factors when CNS infection occurs. A comprehensive assessment might be helpful to distinguish CNS infections from neuropsychiatric SLE. For severe infection, the dosage of steroids does not need to be reduced immediately but can be gradually adjusted based on the results of a comprehensive evaluation of the disease.