Microbiological spectrum of brain abscess at a tertiary care hospital in South India: 24-year data and review

Pertinence of Streptococcus anginosus group in intracerebral abscesses in the era of extended antibiotic resistance

AIMS

• To study the incidence of Streptococcus anginosus group (SAG) in pyogenic or community acquired intra cerebral abscess. • To understand the risk factors for the same. • To analyze the specific radiological features and clinical outcome after surgery and antibiotic therapy.

METHODS

This is a retrospective observational study of case series over a period of one year. Patients diagnosed with intracerebral abscess were included in the study. Pus collected from were received in the laboratory and processed according to the standard protocols. Data regarding the clinical findings and demographics were collected from medical records.

FINDINGS

A total of 202 samples were studied. 103 were found to be pyogenic. SAG were isolated from 21 samples (20.38%) and all the isolates were sensitive to Penicillin. Age of the patients ranged from 18months to 68years. Male preponderance was noted with male to female ratio of 4:1. Otogenic infections were the most common predisposing factors and focus of infection could not be ascertained in 5 patients. All patients were treated with surgical intervention and antibiotics (Vancomycin, Amikacin and Metronidazole) for 6 weeks and recovery was remarkable. One patient succumbed to the illness.

CONCLUSION

SAG can be an aggressive pathogen with propensity for abscess formation. Chronic Suppurative Otitis Media (CSOM) is still a major cause of intracerebral abscess in developing country like India which is a benign and curable disease and should not be neglected. Injudicious use of antibiotics and negligence regarding the dose and duration of therapy from both patients and health care providers is the major cause for common infections to become more difficult to treat and succumbing to complications.

An Eight Year Clinico-Microbiological Retrospective Study on Brain Abscesses in India

Background:

Intracranial abscesses have been a diagnostic and therapeutic challenge since time immemorial for both the microbiologists and the neurosurgeons. There is paucity of detailed studies documenting the infecting organism causing brain abscesses in South India.

Aims:

The study aimed at identifying and assessing the prevalence of aerobic, anaerobic bacteria and fungi associated with brain abscesses at a tertiary care hospital in South India.

Methods and Material:

Eight years data was collected from the records of culture reports from 2007 to 2010 and 2013 to 2018. The corresponding clinical case records were retrieved for the assessment of risk factors. Risk factors of brain abscess development were assessed based on clinical cases records.

Results:

Data from 140 brain abscess cases obtained over a period of 8 years were analyzed. Out of the 140 samples, 66 (47.14%) were culture positive in which 33 (50%) had single aerobic/facultative anaerobic bacteria, 20 (30.3%) had mixture of more than one aerobic/facultative anaerobic bacteria, 12 (18.18%) had single obligate anaerobic bacteria and 1(1.5%) sample had Mycobacterium tuberculosis isolated. Among the total 92 isolates, Pseudomonas aeruginosa (21/92, 23%) and Staphylococcus aureus (20/92, 22%) predominated. Bacteroides fragilis group was the most common obligate anaerobe isolated. There were no fungal isolates. As there were various isolates isolated, hence there is heterogeneity of isolates detected Neuroanatomically, parietal lobe (45/140, 32%) was the most common location. Otogenic infection was the major risk factor for parietal and temporal lobe abscess (P value < .05).

Conclusions:

It has become essential for the microbiologists to be aware of unusual isolates from brain abscess and its complex nature. Obscurity and difficulty in their microbiological diagnosis calls for more such detailed studies.

Brain Abscess in the Current Decade (2010–2019) in India—A Review

Brain abscess outcomes have improved in recent years due to advancements in cranial imaging, microbiological techniques, minimally invasive neurosurgical procedures, and effective antibiotic treatments. However, the incidence of brain abscess remains unchanged in developing countries. We searched PubMed and Google Scholar for references using the key words “brain abscess” and “India” and reviewed both retrospective and prospective studies published in peer-reviewed journals in the current decade to understand the present status. The review shows that the patients’ ages, the predominance of male patients, the symptoms and locations of brain abscesses, and the types of bacteria associated with them have remained unchanged over the past decade. The most common predisposing condition in recent years has been chronic suppurative otitis media with a mortality rate of 7 to 10%. Middle ear infection is often neglected and not treated aggressively in Asian countries. It requires multidisciplinary treatment strategies to address the primary source of infection and better health awareness to prevent the development of brain abscess.

New perspectives in the endoscopic treatment of brain purulent collections: targets, techniques, results in a case series, and overview of the literature

BACKGROUND

Purulent intracranial infections are threatening conditions. Different surgical approaches have been described, respecting the rationale of evacuating the fluid component of the purulent collection. Emerging evidence supports the use of the endoscope for the treatment of cerebral abscesses and subdural empyemas; especially the peculiarities of flexible endoscopes could potentially offer a more effective and conclusive management as compared with the drainage through catheters. We describe our experience in the treatment of intracranial purulent collections with flexible endoscopy, comparing it with the most recent literature.

METHODS

Ten patients affected by intracranial suppuration were treated with endoscopy at our institution. The neurosurgical technique is thoroughly described. The related literature is reviewed, providing a comprehensive overview on the endoscopic treatment of intracranial suppuration so far.

RESULTS

All the patients had a good clinical outcome, with no peri-operative complications. The postoperative scans showed significant radiological improvement, with important reduction of the pus volume. In all cases, the microbiological cultures showed positivity.

CONCLUSIONS

In our experience, the use of the flexible scope proved feasible and effective in the treatment of intracranial purulent collections. Visual awareness of the internal capsule is not limited to a direct inspection of the fluid pus; it rather allows an active removal of the more solid (and perhaps more microbiologically significant) fibrinoid component, and also assists in final bleeding control and in assessing the extent of the evacuation. The steering capabilities of the fiberscope are particularly suitable for such purposes, allowing sampling the solid internal layer of the pyogenic membrane, and potentially shedding light on the actual clinical significance of this component of the abscess.

Intracranial abscess due to Prevotella bivia: First case report from India

The association of Prevotella bivia (P. bivia), a Gram negative obligate anaerobic bacillus with brain abscess has been rarely reported. We hereby, report a case of brain abscess in a 50-year-old man, who suffered a head trauma followed by decompression surgery 10 months ago. Aspirated pus sample grew Methicillin resistant Staphylococcus aureus (MRSA) and P. bivia sensitive to metronidazole. The patient recovered well after a brain abscess evacuation surgery and post-operative metronidazole therapy, confirming the pathogenic role of P. bivia in this case.

A rare case of brain abscess caused by Actinomyces meyeri

Background

Brain abscesses are the rare and most severe form of actinomycosis, which usually manifests as abscesses of the occipital or parietal lobe due to direct expansion from an adjacent area, the oral cavity. In the medical literature, there are only a few reported cases of brain abscess caused by Actinomyces meyeri. In this report, we present a 35-year-old male patient who experienced an insidious headache and left-sided weakness and was diagnosed with an Actinomyces meyeri brain abscess.

Case presentation

A 35-year-old Nepalese man came to our institute with the primary complaint of insidious onset of headache and left-sided weakness. His physical examination was remarkable for the left-sided weakness with power 2/5 on both upper and lower limbs, hypertonia, hyperreflexia and positive Babinski sign, with intact sensory function. Cardiac examination revealed systolic murmur with regular S1 and S2, and lung examination was normal. The patient had poor dental hygiene. Biochemistry and haematology panel were normal. Urinalysis, chest X-ray and electrocardiogram revealed no abnormality. A transthoracic echocardiogram revealed mitral regurgitation. However, there was no evidence of valvular vegetation. A magnetic resonance imaging (MRI) of the brain was performed, which showed a bi-lobed rim enhancing lesion with a conglomeration of two adjoining round lesions in the right parietal parasagittal region. Perilesional oedema resulting in mass effect over the right lateral ventricle and mid-right uncal herniation with midline shift was noted. Craniotomy was performed, and the lesion was excised. Gram staining of the extracted sample revealed gram variable filamentous rods. Creamy white, moist, confluent colonies were observed after performing anaerobic culture in chocolate agar. On the gram staining, they showed gram-positive filamentous rods. Actinomyces meyeri was identified based on matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) technology. Based on the susceptibilities, he was successfully treated with ampicillin-sulbactam.

Conclusions

In conclusion, Actinomyces should be considered in the differential diagnosis of brain abscess in patients with poor dental hygiene, and early diagnosis and appropriate treatment can lead to better results.

Brain abscess in patients with chronic kidney disease: A case-based approach to management in resource-limited settings

The management of patients with brain abscess poses a significant challenge to clinicians in patients with chronic kidney disease. Obtaining a biopsy sample from the affected area is the mainstay in the diagnosis, but it is often unavailable. In most cases, therapy is guided by clinical findings and imaging alone. We discuss three cases of brain abscess- each with a different scenario and discuss the issues faced in management. The first case was a 32-year-old post-renal transplant male patient with a brain abscess due to dematiaceous fungi and was treated with amphotericin. The second case was a 42-year-old female patient with stage 5 chronic kidney disease on maintenance hemodialysis who presented with a brain abscess due to suspected fungal infection based on imaging findings and was managed with antibiotics and voriconazole. The third case was a 42-year-old post-renal transplant male patient who presented with a brain abscess due to nocardiosis and was managed with cotrimoxazole, meropenem and linezolid. We also summarize the approach to the management of brain abscess in resource-limited settings.

Anaerobic bacteriological profile of brain abscess in a tertiary care center in southern India

Brain abscess accounts for 8% of all intracranial insults in developing countries. Anaerobic infections are missed in most cases due to difficult isolation techniques. This study was done to determine the anaerobic bacteriological profile of brain abscess, their distribution according to sociodemographic variables, anatomical location, management and the outcome during the subjects' stay in a neurosciences' speciality hospital. We included 190 cases of confirmed anaerobic brain abscess from the year 1998-2017. The median age was 22 years with more males (73% of 190 cases) than females. The Bacteroides spp. were the most common (64%) anaerobic organisms isolated followed by Gram positive anaerobic cocci (51%). While 67% of the samples showed purely anaerobic bacteria on culture, remaining were mixed. Chronic suppurative otitis media (CSOM) was the most common predisposing factor.

A Clinical Report of Two Cases of Cryptogenic Brain Abscess and a Relevant Literature Review

Brain abscess, a severe intracranial infectious disease, refers to the parenchyma abscess caused by local infection or remote spread. Recently, advancements in modern medicine, especially the wide application of antimicrobial drugs, have contributed to the gradual decrease in the prevalence of this disease. However, cases of cryptogenic brain abscess that feature an unknown origin and atypical symptoms are rising. In this retrospective study, we report and analyze two cases of cryptogenic brain abscess. The first patient was a 30-year-old healthy man who was admitted to our hospital due to 1 week of headache and 3 days of headache aggravation, accompanied by nausea and vomiting. Head MRI shows a circular space-occupying as well as apparently enhanced DWI signals were observed in the right parietal lobe, and the ring wall manifested an apparent increase in signal intensity after enhancement. The patient was diagnosed as a brain abscess before operation and given craniotomy. The postoperative pathology confirmed brain abscess and recovered well after surgery. The second patient was a 45-year-old healthy woman who was hospitalized in a local hospital due to symptoms of headache and right limb weakness for 1 week. Head MRI shows a circular space-occupying lesion in the left basal ganglia, and the ring wall manifested an apparent increase in signal intensity after enhancement. The patient was suspected of glioma at the local hospital and was transferred to our hospital. Twelve hours after hospitalization, the patient was suspected of developing cerebral palsy and thus underwent emergency surgery including lesion resection in the left basal ganglia, resection of the polus temporalis, and a decompressive craniotomy. Postoperative pathology confirmed brain abscess. The patient was eventually conscious, but left the right limb hemiplegia. Hence, when a patient develops the classical triad of fever, headache, and focal neurologic deficits, the possibility of brain abscess should be investigated. Early diagnosis and treatment are crucial to minimize various complications and the number of deaths.

Guidelines for Antibiotic Prescription in Intensive Care Unit

How to cite this article: Khilnani GC, Zirpe K, Hadda V, Mehta Y, Madan K, Kulkarni A, Mohan A, Dixit S, Guleria R, Bhattacharya P. Guidelines for Antibiotic Prescription in Intensive Care Unit. Indian Journal of Critical Care Medicine 2019;23 (Suppl 1):1-63.

Management of brain abscesses: where are we now?

INTRODUCTION

Brain abscesses affect all age groups and are not peculiar to a particular country, race, or geographical location. It is a disease that, in the past, carried a high morbidity and mortality. With improvements in medical technology and expertise, outcomes have improved tremendously. The causative organisms vary vastly and have evolved with time. Treatment of brain abscesses is primarily with antimicrobial therapy but surgery plays a vital role in achieving better outcomes.

CONTENT

In this article, we review the literature to find out how the epidemiology of this disease has changed through the years and re-visit the basic pathological process of abscess evolution and highlight the new research in the biochemical pathways that initiate and regulate this process. We also highlight how magnetic resonance imaging and its various modalities have improved diagnostic accuracy. Finally, we discuss the pros and cons of traditional open surgery versus newer minimally invasive methods.

Good Outcomes with the Intraventricular Vancomycin Therapy in a Patient with Ruptured Brain Abscesses

Brain abscesses are associated with high morbidity and mortality rates. In particular, patients with intraventricular rupture of brain abscess (IVROBA) exhibit mortality rates up to 85%. Treatment options are lacking for IVROBA, once patients become refractory to intravenous antibiotics and surgical drainage. Limited data exist regarding the risks and benefits of intraventricular therapy in such a scenario. We report a patient with IVROBA, who deteriorated while on systemic antibiotics; once intraventricular vancomycin was employed, the patient demonstrated remarkable improvement without perceivable side effects. This case suggests that intraventricular vancomycin may be a safe, effective, and viable option for the treatment of IVROBA, especially for patients becoming refractory to systemic antibiotics.

Subdural empyema caused by Peptostreptococcus sp.: a complication of acute pharyngitis

Subdural Empyema (ESD) is the collection of purulent fluid that develops between the exterior "dura mater" layer and the middle "arachnoid mater" layer that covers the brain. ESD can be caused by a primary infection located in the paranasal sinuses. In many aerobic and/or anaerobic bacterial cases, hearing or traumatic processes serve as the causative agent. This report presents pharyngitis in a young girl which later developed into a subdural empyema caused by the bacteria Peptostreptococcus sp. The report emphasizes the correct clinical valuation of pharyngitis as a risk factor for developing subdural empyema in children.

An active principle of Nigella sativa L., thymoquinone, showing significant antimicrobial activity against anaerobic bacteria

Aim/Background:

Thymoquinone (TQ) is the major active principle of Nigella sativa seed (black seed) and is known to control many fungi, bacteria, and some viruses. However, the activity of TQ against anaerobic bacteria is not well demonstrated. Anaerobic bacteria can cause severe infections, including diarrhea, aspiration pneumonia, and brain abscess, particularly in immunodeficient individuals. The present study aimed to investigate the in vitro antimicrobial activity of TQ against some anaerobic pathogens in comparison to metronidazole.

Methods:

Standard, ATCC, strains of four anaerobic bacteria (Clostridium difficile, Clostridium perfringens, Bacteroides fragilis, and Bacteroides thetaiotaomicron), were initially isolated on special Brucella agar base (with hemin and vitamin K). Then, minimum inhibitory concentrations (MICs) of TQ and metronidazole were determined against these anaerobes when grown in Brucella agar, using serial agar dilution method according to the recommended guidelines for anaerobic organisms instructed by the Clinical and Laboratory Standards Institute.

Results:

TQ showed a significant antimicrobial activity against anaerobic bacteria although much weaker than metronidazole. MICs of TQ and metronidazole against various anaerobic human pathogens tested were found to be between 10-160 mg/L and 0.19-6.25 mg/L, respectively.

Conclusions:

TQ controlled the anaerobic human pathogenic bacteria, which supports the use of N. sativa in the treatment of diarrhea in folk medicine. Further investigations are in need for determination of the synergistic effect of TQ in combination with metronidazole and the activity of derivatives of TQ against anaerobic infections.

Anaerobic brain abscess

BACKGROUND AND OBJECTIVES

Brain abscess remains a potentially fatal central nervous system (CNS) disease, especially in developing countries. Anaerobic abscess is difficult to diagnose because of cumbersome procedures associated with the isolation of anaerobes.

MATERIALS AND METHODS

This is a hospital-based retrospective microbiological analysis of 430 brain abscess materials (purulent aspirates and/or tissue), for anaerobic organisms, that were received between 1987-2014, by the Microbiology Laboratory in our Institute.

RESULTS

Culture showed growth of bacteria 116/430 (27%) of the cases of which anaerobes were isolated in 48/116 (41.1%) of the cases. Peptostreptococcus (51.4 %), was the predominant organism isolated in four cases followed by Bacteroides and Peptococcus species.

CONCLUSION

Early diagnosis and detection of these organisms would help in the appropriate management of these patients.

Brain abscess caused by Nocardia cyriacigeorgica in two patients with multiple myeloma: novel agents, new spectrum of infections

OBJECTIVE AND IMPORTANCE

Introduction of high-dose chemotherapy and the novel agents including bortezomib, Lenalidomide, and Thalidomide has provided a significant progress in the treatment of multiple myeloma (MM) with an increase in median overall survival up to 6-8 years. However, the advances in myeloma treatment comes at a price with new spectrum of treatment-related infectious complications which should be taken into consideration while treating these patients.

CLINICAL PRESENTATION

We report here two patients with Ig G λ MM presenting with intracerebral mass lesions in the abscence of constitutional symptoms that would suggest an infectious etiology. Both patients had severe hypogammaglobulinemia and lymphopenia, which was attributed to treatment regimens including bortezomib. Intervention The surgical intervention-revealed abscess in both cases caused by Nocardia cyriacigeorgica, a relatively new pathogen which rarely causes infections in humans and also an unexpected pathogen in myeloma patients.

CONCLUSION

Although every aspect of immune system is known to be affected in MM, humoral immune deficiency is the hallmark of the inherent immune defect in this disease. Introduction of the novel agents, bortezomib in particular seems to have changed the characteristics of the immune dysfunction and the spectrum of the opportunistic infections by causing qualitative and quantitative changes in cellular immunity. The new spectrum of infectious agents might not be limited to hepatitis B and herpes zoster. Monitoring lymphopenia and administration of prophylactic antimicrobial agents accordingly could be considered in patients treated with bortezomib.

Brain abscess: Current management

Brain abscess (BA) is defined as a focal infection within the brain parenchyma, which starts as a localized area of cerebritis, which is subsequently converted into a collection of pus within a well-vascularized capsule. BA must be differentiated from parameningeal infections, including epidural abscess and subdural empyema. The BA is a challenge for the neurosurgeon because it is needed good clinical, pharmacological, and surgical skills for providing good clinical outcomes and prognosis to BA patients. Considered an infrequent brain infection, BA could be a devastator entity that easily left the patient into dead. The aim of this work is to review the current concepts regarding epidemiology, pathophysiology, etiology, clinical presentation, diagnosis, and management of BA.