Changing epidemiology of adult bacterial meningitis in southern taiwan: a hospital-based study

First Report of Klebsiella pneumoniae subsp. ozaenae Meningitis in Japan

Although the frequency of community-acquired infections caused by Klebsiella pneumoniae subsp. ozaenae (K. ozaenae) is low, they are often detected in sputum specimens. In addition, lung abscesses, necrotizing pneumonia, and urinary tract infections caused by K. ozaenae have also been reported. We herein report the first detection of K. ozaenae as an etiological agent of bacterial meningitis in Japan. Cases of K. ozaenae meningitis complicated by diabetes mellitus and sinusitis have been reported elsewhere. When Klebsiella pneumoniae is detected in such cases, it is important to use other detection methods in addition to mass spectrometry for correct identification.

The clinical characteristics and therapeutic outcomes of adult patients with community-acquired spontaneous bacterial meningitis with a fulminant clinical course in Taiwan

PURPOSE

To examine the clinical characteristics of adult patients with community-acquired spontaneous bacterial meningitis (CASBM) with a fulminant clinical course.

MATERIALS AND METHODS

The clinical features and therapeutic outcomes of 127 adult CASBM patients were analyzed. The patients were divided into two groups as those with and without a fulminant clinical course. Fulminant clinical course was defined as meningitis presenting initially with marked consciousness disturbance (Glasgow Coma Scale score < 8) or a rapid deterioration in consciousness level within 48 h of hospitalization.

RESULTS

Among the 127 enrolled patients, 69 had a fulminant clinical course (47 men and 22 women) and 58 did not. The patients with a fulminant clinical course had a significantly higher incidence of end-stage renal disease (ESRD), severe clinical manifestations and higher mortality rate, and the survivors had significantly worse therapeutic outcomes. Klebsiella (K.) pneumoniae (50 strains) was the most important pathogen for the development of a fulminant clinical course, and all strains were susceptible to ceftriaxone and ceftazidime. With treatment, 50.7% (35/69) of the patients with a fulminant clinical course died, and the presence of K. pneumoniae infection was significant prognostic factor.

CONCLUSIONS

The presence of ESRD, initial presentation of altered consciousness, septic shock, seizures and CSF total protein level and K. pneumoniae infection were significantly associated with a fulminant clinical course of adult CASBM, and patients with this specific infectious syndrome had high mortality and morbidity rates. The presence of K. pneumoniae infection is a significant prognostic factor.

Klebsiella pneumoniae sepsis complicated with central nervous system involvement: A case series

Central nervous system (CNS) infection with Klebsiella pneumoniae can be a complication of invasive liver abscess syndrome; however, CNS infections due to K. pneumoniae without liver abscesses are rare. We report three fatal cases of CNS infection due to K. pneumoniae that lacked liver abscesses during the initial investigation.

Use of the FilmArray® Meningitis/Encephalitis panel to detect pathogenic microorganisms in cerebrospinal fluid specimens: a single-center retrospective study

OBJECTIVE

Meningitis and encephalitis are neurological emergencies requiring rapid diagnosis and treatment. The performance of the FilmArray® Meningitis/Encephalitis (ME) panel, a multiplex polymerase chain reaction test, and conventional methods for diagnosing meningitis and encephalitis was compared.

METHODS

This retrospective study assessed 20 patients diagnosed with meningitis or encephalitis according to clinical symptoms and laboratory examination findings between January 2018 and December 2019. The results of the FilmArray® ME panel were compared with those of conventional methods.

RESULTS

Pathogens were identified in 11 (55%) patients using the FilmArray® ME panel and in nine (45%) patients using conventional methods. The test identified herpes simplex virus type 1 in two patients, herpes simplex virus type 2 in one, varicella-zoster virus in four, Streptococcus pneumoniae in three, and Cryptococcus neoformans in one. Furthermore, additional pathogens were detected (n = 1, S. pneumoniae and n = 1, varicella-zoster virus). The median times to pathogen identification were 2 hours using the FilmArray® ME panel and 96 hours with conventional methods.

CONCLUSIONS

The sensitivity of the FilmArray® ME panel for rapidly detecting the most common pathogens was similar to that of conventional methods. Hence, this method could decrease the time to definitive diagnosis and treatment initiation.

Sex-based differences in bacterial meningitis in adults: Epidemiology, clinical features, and therapeutic outcomes

BACKGROUND

To investigate the sex-based differences in clinical features, causative pathogens, and outcomes of hospital-based culture-proven adult bacterial meningitis.

OBJECTIVE

This retrospective study enrolled 621 patients at a tertiary medical center. To compare changes over time, the presentation of disease among the enrolled patients was divided into two equal time periods: the first study period (1986-2002) and the second study period (2003-2019).

RESULTS

Of the 621 patients enrolled in this study, 396 were males and 225 were females. The overall case fatality rate was 30.4% with 30.1% and 31.1% in males and females, respectively. Regarding the causative pathogens, there was a rising incidence of coagulase-negative staphylococcal infections and a decreasing incidence of Klebsiella pneumoniae infection in both male and female in the second study period. The prevalence of patients with nosocomial infection in a postneurosurgical state were 41.9% (68/162) in the first study period and 58.1% (94/162) in the second study period in male group, and 34.8% (32/92) in the first study period and 65.2% (60/92) in the second study period in female group, respectively. Significant factors between the sexes difference included age (P = 0.004), traumatic brain injury (P = 0.01), alcoholism (P < 0.001), brain tumor (P < 0.001), systemic lupus erythematosus (SLE) (P = 0.004), presence of diabetic ketoacidosis/hyperglycemic hyperosmolar state (P = 0.033), brain abscess (P = 0.042), and total protein (P = 0.002) and white blood cell count (P = 0.036) of cerebrospinal fluid data.

CONCLUSION

Our study revealed an increase in the number of patients with nosocomial infection with a postneurosurgical state in both male and female in the second study period. Males were younger and frequently presented with a history of head trauma and alcoholism with concomitant brain abscesses while females presented with SLE and brain tumor. The therapeutic outcome did not show differences between the sexes.

Convergence of carbapenem-resistance and hypervirulence leads to high mortality in patients with postoperative Klebsiella pneumoniae meningitis

OBJECTIVE

To investigate the characteristics of Klebsiella pneumoniae meningitis and impact of convergence of carbapenem-resistance and hypervirulence on mortality.

METHODS

Drug-resistance and virulence-related genes were investigated in 25 K. pneumoniae strains causing meningitis. The clinical data of 25 patients (February 2009 to February 2019) were evaluated. Multilocus sequence typing, serotyping, mobile genetic element, and pulsed-field gel electrophoresis analysis were applied to generate the data. GraphPad Prism 8 was used for statistical analysis.

RESULTS

A mortality rate of 30.0% was found in the patients with K. pneumoniae meningitis. Significant differences were observed between the non-survivor and survivor groups in terms of mechanical ventilation, peripheral deep vein catheter insertion, ICU stay, and GCS and not in sex, age, and meningeal integrity destruction. Multi-drug resistance was found in 21 strains. Different detection rates were observed for each virulence gene, ranging from 8.0% in wzy-K1 to 100.0% in entB. Detection rates of carbapenem-resistant K. pneumoniae (CRKP), hypervirulent K. pneumoniae (HvKP), and hypervirulent carbapenem-resistant K. pneumoniae (Hv-CRKP) were 68.0%, 68.0%, and 48.0%, respectively. Totally 16 clusters and 19 clones were identified among the 25 strains. Mortality rates were significantly different between the non-Hv-CRKP (1/11) and Hv-CRKP groups (5/9), but comparable among the carbapenem-susceptible K. pneumoniae (CSKP)/CRKP groups and classical K. pneumoniae (cKP)/HvKP groups.

CONCLUSIONS

K. pneumoniae meningitis is associated with high mortality. K. pneumoniae-induced meningitis has highly divergent origins. Convergence of carbapenem-resistance and hypervirulence leads to high mortality in patients with K. pneumoniae meningitis, which is of great clinical concern.

A hospital-based study on etiology and prognosis of bacterial meningitis in adults

Bacterial meningitis is a neurological emergency with high morbidity and mortality. We herein investigated clinical features, etiology, antimicrobial susceptibility profiles, and prognosis of bacterial meningitis in adults from a single tertiary center. We retrospectively reviewed medical records of patients with laboratory-confirmed bacterial meningitis from 2007 to 2016. Patients with recent neurosurgery, head trauma, or indwelling neurosurgical devices were classified as having healthcare-related meningitis. Causative microorganisms were identified by analyzing cerebrospinal fluid (CSF) and blood cultures, and antimicrobial susceptibility profiles were evaluated. We performed multiple logistic regression analysis to identify factors associated with unfavorable outcomes. We identified 161 cases (age, 55.9 ± 15.5 years; male, 50.9%), of which 43 had community-acquired and 118 had healthcare-related meningitis. CSF and blood culture positivity rates were 91.3% and 30.4%, respectively. In community-acquired meningitis patients, Klebsiella pneumoniae (25.6%) was the most common isolate, followed by Streptococcus pneumoniae (18.6%) and Listeria monocytogenes (11.6%). The susceptibility rates of K. pneumoniae to ceftriaxone, cefepime, and meropenem were 85.7%, 81.3%, and 100%, respectively. Among healthcare-related meningitis patients, the most common bacterial isolates were coagulase-negative staphylococci (28.0%), followed by Staphylococcus aureus (16.1%) and Enterobacter spp. (13.6%). Neurological complications occurred in 39.1% of the patients and the 3-month mortality rate was 14.8%. After adjusting for covariates, unfavorable outcome was significantly associated with old age (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.00–1.06), neurological complications (OR 4.53, 95% CI 1.57–13.05), and initial Glasgow coma scale ≤ 8 (OR 19.71, 95% CI 4.35–89.40). Understanding bacterial pathogens and their antibiotic susceptibility may help optimize antimicrobial therapy in adult bacterial meningitis.

Development and validation of a multiplex-PCR based assay for the detection of 18 pathogens in the cerebrospinal fluid of hospitalized children with viral encephalitis

BACKGROUND

The Applied Biosystems 3500 Genetic Analyzer (ABI3500) allows for automated capillary electrophoresis on multiple targets. So far, the application of this method for detecting cerebrospinal fluid pathogens has hardly been reported.

METHODS

To assess the performance of multiplex-PCR assay for 18 pathogens detection, 127 CSF samples from hospitalized children with suspected viral encephalitis were prospectively collected from April to November 2018. The Sanger sequencing was applied to verify this assay.

RESULTS

All of the 18 target pathogens can be identified by multiplex-PCR assay at 10⁴ copies (or CFU/mL) of each virus, bacterium and fungus. In contrast, 10 control microorganisms failed to be amplified. Approximately 68.5 % of the cases tested had positive results, the enterovirus accounted for the majority of the positive cases (63.8 %). Agreement between multiplex-PCR and sequencing was 91.49 %.

CONCLUSIONS

Our findings suggest that the ABI3500-based multiplex-PCR detection kit could be a valuable diagnostic tool for pathogen detection in CSF of children with suspected viral encephalitis.

High incidence of severe neurological manifestations and high mortality rate for adult Listeria monocytogenes meningitis in Taiwan

The clinical characteristics and therapeutic outcomes of adult Listeria monocytogenes meningitis are not commonly examined in isolation in the literature. During a study period of 19 years (2000-2018), 366 patients with culture-proven adult bacterial meningitis (ABM) were identified in the author's hospital (264 patients in 2000-2010 and 102 patients in 2011-2018). Of the 366 ABM patients, 330 had monomicrobial infections while the other 36 had mixed infections. L. monocytogenes infection was identified in 11 of the 330 patients with monomicrobial ABM (3 in 2000-2010 and 8 in 2011-2018). These 11 patients included 5 males and 6 females, aged 47 to 76 years (median age = 61.7). None of the 11 patients had a postneurosurgical state as the underlying cause, but 3 of them contracted the infection nosocomially. Common underlying conditions included liver cirrhosis (4), systemic malignancy (3), diabetes mellitus (3), and renal disease (2). The most common clinical manifestations were fever (11), altered consciousness (8), seizure (8), bacteremia (7) and hydrocephalus (5). The therapeutic result revealed a mortality rate of 72.7% (8/11), but no significant prognostic factors were identified. The clinical features of 8 additional Taiwanese L. monocytogenes ABM patients reported in the literature, were also included for analysis. The present study revealed an increase in L. monocytogenes ABM in recent years and most patients presented with severe neurological manifestations. The current study is a preliminary overview of L. monocytogenes meningitis in adults and a further large-scale study is needed for improved delineation of this specific infectious syndrome.

The clinical characteristics of spontaneous Gram-negative bacterial meningitis in adults: A hospital-based study

The epidemiologic trend of acute bacterial meningitis can change more dramatically than any other bacterial disease, and a decrease in spontaneous adult bacterial meningitis (ABM) has been noted in serial studies of the epidemiologic trend of ABM in Taiwan. The purpose of this study was to analyze the clinical characteristics, laboratory data and therapeutic outcomes of 149 patients with spontaneous Gram-negative (G(-)) ABM collected during a study period of 31 years (1986-2016). The 149 patients included 107 men and 42 women, aged 18-86 years. The common underlying conditions were diabetes mellitus, liver cirrhosis and alcoholism, and the leading clinical presentations were fever, altered consciousness and septic shock. Compared the clinical characteristics of the patients identified in the study period of 2001-2106 to the patients identified in the study period of 1986-2000, the former group of patients had a significantly higher incidence of systemic malignance. In the recent 16 years (2001-2016), Klebsiella pneumoniae, Pseudomonas spp. and Escherichia coli were the leading three implicated bacterial pathogens of spontaneous G(-) ABM, accounting for 61.3% (38/62), 11.3% (7/62) and 11.3% (7/62%) of all cases, respectively. The overall mortality rate from spontaneous G(-) ABM was high (47.0%, 70/149) and the presence of septic shock and lower cerebrospinal fluid glucose level were significant prognostic factors. Because of the decreasing incidence of spontaneous ABM in Taiwan, close examination of this specific infectious syndrome is important in order to monitor the epidemiologic trend and improve the therapeutic strategy.

High prevalence of KPC-2-producing hypervirulent Klebsiella pneumoniae causing meningitis in Eastern China

BACKGROUND

Klebsiella pneumoniae has been the leading causative pathogen for adult bacterial meningitis in several Asian countries. The clinical and microbiological characteristics of K. pneumoniae meningitis in mainland China are still unknown.

MATERIALS AND METHODS

The clinical data of patients with K. pneumoniae meningitis from January 2011 to July 2017 in a tertiary hospital were retrospectively evaluated. The isolates were tested for antibiotic-resistance genes, virulence-associated genes, and molecular subtypes. Hyper-virulent K. pneumoniae (hvKP) was defined as the presence of pLVPK-like virulence plasmid.

RESULTS

During the study period, a total of 48 patients with meningitis caused by K. pneumoniae were identified, accounting for 21.2% (48/226) of Gram-negative bacilli meningitis. Of the 44 available isolates, 65.9% (29/44) were carbapenem resistant, and all except one har-bored bla KPC-2. K64 was the most common serotype (n=13), followed by K47 (n=11) and K1 (n=5). The pLVPK-related genetic loci were found in about half of isolates (iutA: 56.8%, iucA: 56.8%, rmpA2:50.0%, rmpA: 43.2%, and iroN: 40.9%). Twenty-two strains carrying pLVPK-derived virulence plasmid were defined as hvKP. Notably, the coexistence of bla KPC-2-encoding plasmid and the pLVPK-derived virulence plasmid was detected in 15 strains (34.1%, 15/44), suggesting K. pneumoniae carbapenemase-2 (KPC-2)-producing hvKP. The proportion of KPC-2-producing hvKP by year increased remarkably from 0% (2011) to 71.4% (2017). Of the 15 KPC-2-producing hvKP strains, 80.0% (12/15) were assigned to sequence type 11 and 2 strains (13.3%) belonged to clonal complex 23. Most of the patients infected with KPC-2-producing hvKP had preceding postneurosurgical state (93.3%, 14/15) and severe pneumonia (73.3%, 11/15). All the cases (100%, 15/15) had fatal outcome.

CONCLUSION

The high prevalence and mortality of K. pneumoniae, especially KPC-2-producing hvKP meningitis, in China should be of concern. The implementation of epidemiological surveillance and identification of an effective clinical treatment are paramount.

Outcomes of adjunctive steroid therapy in adult patients with bacterial meningitis in Taiwan: A nationwide population-based epidemiologic study

BACKGROUND

Although corticosteroids are an effective anti-inflammatory adjuvant therapy, the role of adjunctive steroid therapy in treating adult bacterial meningitis in Taiwan remains controversial.

METHODS

Cases of acute bacterial meningitis were identified from the annual hospitalization discharge claims of the National Health Insurance Research Database using International Classification of Diseases, Ninth Revision codes from January 2000 to December 2013. Patients were classified into two groups: (1) steroid group (adjunctive steroids and empirical antibiotics) and (2) placebo group (empirical antibiotics only).

RESULTS

There were 15,037 patients enrolled in this study; of these, 57% (7175/15,037) and 52% (7862/15,037) were placed in the placebo and steroid groups, respectively. The case-fatality rates were 11.5% (826/7175) in the placebo group and 19.9% (1562/7862) in the steroid groups during hospitalization (P = 0.77). Further, the hazard ratio (relative to placebo group) of in-hospital and one-year case fatality rate were 0.923 (95% confidence interval [CI]: 0.846-1.007, P = 0.073) and 1.514 (95% CI: 1.425-1.608, P < 0.0001) according to the multivariate Cox model after adjustment for age and sex.

CONCLUSION

On the basis of these results, steroid group had a more fulminant clinical course (e.g., acute respiratory failure and pneumonia, etc.), and unfavorable outcomes than placebo group. Therefore, more prospective, randomized, double-blind trials are warranted to evaluate the efficacy of adjunctive steroid therapy in treating adult bacterial meningitis in Taiwan.

Community acquired Klebsiella pneumoniae meningitis: a case report

Introduction

Klebsiella pneumoniae meningitis is most commonly seen as a nosocomial infection and in post-neurosurgical patients. Reports of community acquired Klebsiella pneumoniae meningitis cases are rare in the United States. The objective of this case report is to discuss an uncommon pathogen causing meningitis, Klebsiella pneumoniae, its risk and prognostic factors and to emphasize the importance of early recognition and appropriate antibiotic treatment.

Case report

We report a clinical case of adult community acquired Klebsiella pneumoniae meningitis with recovery. A 54-year-old diabetic male presented with two-week history of intermittent fevers, acute bilateral ear pain, headache and unsteady gait. Broad spectrum antibiotics were initiated. Klebsiella pneumoniae was isolated in the cerebrospinal fluid cultures. The patient recovered with only mild hearing loss in his left ear.

Conclusion

Our case highlights the importance of suspecting Klebsiella pneumoniae in community acquired meningitis.

A chinese case of prevotella intermedia and streptococcus constellatus intracranial mixed infection

Streptococcal Species is increasingly recognized as a potentially preventable emerging infection in human's brain with high prevalence around the world. Streptococcus constellatus is one of the most common pathogens. Meanwhile, anaerobic bacteria are the rare causes for intracranial infection. To date, intracranial mixed infection caused by Prevotella intermedia and Streptococcus constellatus has not been reported. We reported a Chinese case to raise the global awareness of severity of the intracranial mixed infection. Here, we illustrated the epidemiological risk factors, clinical manifestations and outcomes of the patient. For patients who suffer from exacerbated brain infection with fetid cerebrospinal fluid, early repeated imaging is urgently needed and empiric antibiotic therapy should consider anaerobic and aerobic bacteria in these situations.

The clinical characteristics of adult bacterial meningitis caused by non-Pseudomonas (Ps.) aeruginosa Pseudomonas species: A clinical comparison with Ps. aeruginosa meningitis

Adult bacterial meningitis (ABM) caused by non-Pseudomonas (Ps.) aeruginosa Pseudomonas (NPAP) species infection has rarely been reported. The clinical characteristics of 52 cases of Pseudomonas ABM (11 NPAP- and 41 Ps. aeruginosa-related meningitis) collected during a 30-year study period (1986-2015) were included. Eleven cases of NPAP ABM were identified in the literature, and their clinical data were also collected. Therefore, a total of 22 NPAP ABM cases were enrolled. The clinical characteristics of the NPAP ABM and Ps. aeruginosa ABM groups were compared. Of the implicated NPAP strains, Ps. putida and Ps. stutzeri were the most common (7 cases each), followed by Ps. mendocina in 4, Ps. fluorescens in 1, Ps. fulva in 1, Ps. alcaligenes in 1, and Ps. mosselii in 1. Of the 22 cases, 50% (11/22) had an underlying postneurosurgical state. Fever (77.3%, 17/22) and altered consciousness (45.5%, 10/22) were the most common clinical presentations. Antibiotic non-susceptibility was found in 3 strains of Ps. putida and 1 Ps. mosselii strain. Compared to the patients with Ps. aeruginosa ABM, those with NPAP ABM had a higher incidence of spontaneous infections and a better survival rate. In conclusion, although Ps. putida, Ps. stutzeri and Ps. mendocina were the major implicated strains of NPAP ABM, the clinical characteristics of this specific group of ABM demonstrated marked heterogeneity. Even though the cases with NPAP ABM had better therapeutic results than those with Ps. aeruginosa ABM, further large-scale studies are needed to better delineate this specific group of ABM.

Klebsiella pneumoniae Isolates from Meningitis: Epidemiology, Virulence and Antibiotic Resistance

Klebsiella pneumoniae (KP) resistance to broad-spectrum cephalosporin (BSC) in meningitis is important because of limited therapeutic options. To investigate the antibiotic resistance, virulence and epidemiology of KP in meningitis, we conducted a retrospective study for 33 non-metastatic isolates, including primary meningitis (n = 20) and post-craniotomy meningitis (n = 13) collected from 1999 to 2013. BSC resistance was found in 9 (27.3%) isolates, all from post-craniotomy meningitis, harboring bla _SHV-5 (n = 6), bla _CMY-2 (n = 2), bla _DHA-1 (n = 2), and bla _TEM-1B (n = 1). Positive virulence factors were hypermucoviscosity (n = 22), larger bacterial size (n = 24), virulent capsule serotypes (n = 24, K2, 11; K1, 5; K57, 3; K5, 2; K20, 2 and K54, 1), rmpA (n = 23), rmpA ₂ (n = 20), aerobactin gene (n = 22) and high-grade serum resistance (n = 23, 69.7%). Higher mouse lethality (LD₅₀ < 10⁶) was found in 16 isolates (48.5%). Post-craniotomy isolates were significantly less virulent than primary meningitis isolates, except for similar serum resistance capability. The pulsotype and sequence typing (ST) results were diverse. A minor cluster with pulsotype C and ST23 (n = 5) was identified in primary meningitis isolates. In conclusion, virulence factors and BSC resistance corresponded to about 70% and 30% of KP meningitis isolates respectively. BSC remains appropriate for treating primary meningitis, whereas meropenem is indicated for post-craniotomy meningitis empirically.

Acute Bacterial Meningitis in Qatar: A Hospital-Based Study from 2009 to 2013

Background and Objectives

Bacterial meningitis is a common medical condition in Qatar. The aim of this study was to describe the clinical characteristics of bacterial meningitis, the frequency of each pathogen, and its sensitivity to antibiotics and risk factors for death.

Patients and Methods

This retrospective study was conducted at Hamad General Hospital between January 1, 2009, and December 31, 2013.

Results

We identified 117 episodes of acute bacterial meningitis in 110 patients. Their mean age was 26.4 ± 22.3 years (range: 2–74) and 81 (69.2%) of them were male patients. Fifty-nine episodes (50.4%) were community-acquired infection and fever was the most frequent symptom (94%), whereas neurosurgery is the most common underlying condition. Coagulase-negative staphylococci were the most common causative agent, of which 95% were oxacillin-resistant, while 63.3% of Acinetobacter spp. showed resistance to meropenem. The in-hospital mortality was 14 (12%). Only the presence of underlying diseases, hypotension, and inappropriate treatment were found to be independent predictors of mortality.

Conclusion

Acute bacterial meningitis predominantly affected adults and coagulase-negative staphylococci species were the common causative agent in Qatar with majority of infections occurring nosocomially. More than 90% of all implicated coagulase-negative staphylococci strains were oxacillin-resistant.

Colibactin Contributes to the Hypervirulence of pks+ K1 CC23 Klebsiella pneumoniae in Mouse Meningitis Infections

Klebsiella pneumoniae is the most common pathogen of community-acquired meningitis in Taiwan. However, the lack of a physiologically relevant meningitis model for K. pneumoniae has impeded research into its pathogenesis mechanism. Based on the core genome MLST analyses, the hypervirulent K1 K. pneumoniae strains, which are etiologically implicated in adult meningitis, mostly belong to a single clonal complex, CC23. Some K1 CC23 K. pneumoniae strains carry a gene cluster responsible for colibactin production. Colibactin is a small genotoxic molecule biosynthesized by an NRPS-PKS complex, which is encoded by genes located on the pks island. Compared to other hypervirulent K. pneumoniae which primarily infect the liver, the colibactin-producing (pks⁺) K1 CC23 strains had significant tropism toward the brain of BALB/c mice. We aimed in this study to develop a physiologically relevant meningitis model with the use of pks⁺ K1 CC23 K. pneumoniae. Acute meningitis was successfully induced in adult BALB/c male mice through orogastric, intranasal, and intravenous inoculation of pks⁺ K1 CC23 K. pneumoniae. Besides the typical symptoms of bacterial meningitis, severe DNA damages, and caspase 3-independent cell death were elicited by the colibactin-producing K1 CC23 K. pneumoniae strain. The deletion of clbA, which abolished the production of colibactin, substantially hindered K. pneumoniae hypervirulence in the key pathogenic steps toward the development of meningitis. Our findings collectively demonstrated that colibactin was necessary but not sufficient for the meningeal tropism of pks⁺ K1 CC23 K. pneumoniae, and the mouse model established in this study can be applied to identify other virulence factors participating in the development of this life-threatening disease.

Meningococcal meningitis: clinical and laboratorial characteristics, fatality rate and variables associated with in-hospital mortality

ABSTRACT Meningococcal meningitis is a public health problem. The aim of this study was to describe the clinical characteristics of patients with meningococcal meningitis, and to identify associated factors with mortality. This was a retrospective study, between 2006 and 2011, at a referral center in São Paulo, Brazil. Logistic regression analysis was used to identify factors associated with mortality. We included 316 patients. The median age was 16 years (IQR: 7–27) and 60% were male. The clinical triad: fever, headache and neck stiffness was observed in 89% of the patients. The cerebrospinal triad: pleocytosis, elevated protein levels and low glucose levels was present in 79% of patients. Factors associated with mortality in the multivariate model were age above 50 years, seizures, tachycardia, hypotension and neck stiffness. The classic clinical and laboratory triads of meningococcal meningitis were variable. The fatality rate was low. Age, seizures and shock signs were independently associated with mortality.

Multiplex polymerase chain reaction assay developed to diagnose adult bacterial meningitis in Taiwan

Acute bacterial meningitis causes high morbidity and mortality; the associated clinical symptoms often are insensitive or non-specific; and the pathogenic bacteria are geographically diverse. Clinical diagnosis requires a rapid and accurate methodology. This study aimed to develop a new multiplex polymerase chain reaction (mPCR) assay to detect simultaneously six major bacteria that cause adult bacterial meningitis in Taiwan: Klebsiella pneumoniae, Pseudomonas aeruginosa, Streptococcus pneumoniae, Staphylococcus aureus, Escherichia coli, and Acinetobacter baumannii. Species-specific primers for the six bacteria were developed using reference strains. The specificities of the mPCRs for these bacteria were validated, and the sensitivities were evaluated via serial dilutions. The mPCR assay specifically detected all of the six pathogens, particularly with sensitivities of 12 colony forming units (CFU)/mL, 90 CFU/mL, and 390 CFU/mL for E. coli, S. pneumoniae, and K. pneumoniae, respectively. This mPCR assay is a rapid and specific tool to detect the six major bacterial pathogens that cause acute adult meningitis in Taiwan, particularly sensitive for detecting E. coli, S. pneumoniae, and K. pneumoniae. The assay may facilitate early diagnosis and guidance for antimicrobial therapy for adult patients with this deadly disease in Taiwan.

Types, Risk Factors, Clinical symptoms and Diagnostic Tests of Acute Adult Meningitis in Northern Iran During 2006-2012

BACKGROUND

Acute bacterial meningitis is a medical emergency condition that requires prompt diagnosis and treatment and otherwise associated with serious morbidity and mortality.

AIM

The aim of this study was to assess types, risk factors, clinical symptoms and diagnostic tests of meningitis in hospitalized patients of Mazandaran University of medical sciences hospitals during 2006-2012.

MATHERIALS AND METHODS

This is a retrospective descriptive study. Following approval of the ethics committee of Mazandaran University of Medical Sciences, records of adult patients diagnosed with acute meningitis from 2006 to 2012 were extracted from Mazandaran Provincial Health Center and patients attending hospitals affiliated to Mazandaran University of Medical Sciences.

STATISTICAL ANALYSIS

Data were analyzed with SPSS-16 using descriptive statistics (frequency, mean, standard deviation, and median).

RESULTS

In this study, of the 137 patients with meningitis, 73 (53.9%) were viral, 61 (46%) bacterial, 1 (0.7%) fungal, and 2 (1.4%) unknown. The majority of risk factors in patients were head trauma, upper respiratory infection, and drug addiction. The most common clinical signs were headache, fever, nausea and vomiting, and stiff neck.

CONCLUSION

In this study, the incidence of meningitis was much lower than any other country. It could be due to geographic variation or incomplete recording of patient's data. It is recommended to perform a longitudinal study during the coming years on patients with meningitis.

Comparison of the clinical characteristics and outcomes of Klebsiella pneumoniae and Streptococcus pneumoniae meningitis

This multicenter, retrospective cohort study compared the clinical characteristics and outcomes of community-acquired Klebsiella pneumoniae meningitis (CA-KPM) with those of community-acquired Streptococcus pneumoniae meningitis (CA-SPM). Eighty-three adult patients, 27 with CA-KPM and 56 with CA-SPM, were included. Diabetes mellitus (48.1% versus 21.4%; P=0.01) and liver cirrhosis (22.2% versus 5.4%; P=0.05) were more commonly associated with CA-KPM. Comatose mental status (40.7% versus 12.5%; P=0.01), septic shock (44.4% versus 8.9%; P<0.001), and concomitant extrameningeal infections (40.7% versus 7.1%; P=0.001) were also more common in the CA-KPM group. The 28-day mortality (44.4% versus 10.7%; P<0.001) and inhospital mortality (51.9% versus 14.3%; P<0.001) were higher in the CA-KPM group. In conclusion, diabetes mellitus and liver cirrhosis are more common in the CA-KPM patients who were also more likely to present with severe manifestations and poor outcomes.

Intracranial malignant lesions correlate with the requirement for a long treatment course in postoperative central nervous system infection

AIM

Our aim was to study the clinical features of postoperative meningitis after neurosurgery and identify the factors affecting the duration of treatment.

METHODS

This retrospective study assessed 283 patients with postoperative bacterial meningitis in the Neurosurgery Department of Beijing Tiantan Hospital, Beijing, People's Republic of China, between January and December 2012. Patients' clinical data were reviewed, and multivariate logistic regression analysis was used to identify the factors associated with a prolonged treatment course.

RESULTS

The mortality rate was 0.4% in these patients, of whom 12.4% were found with pathogens in the cerebrospinal fluid. Among the three most common pathogens detected were methicillin-resistant Staphylococcus aureus, Acinetobacter baumannii, and Pseudomonas aeruginosa. The mean treatment course was 13.5±2.1 days. Interestingly, the treatment duration for postoperative meningitis was significantly longer in patients with intracranial malignant tumors than in those with benign lesions. Single-factor analysis showed that male sex (P=0.042) and malignant (rather than benign) lesions (P<0.001) were significantly associated with prolonged treatment duration. Multivariate analysis further confirmed that malignant intracranial lesions represented an independent risk factor for prolonged treatment duration (odds ratio: 2.5962; 95% confidence interval: 1.1092-6.6134).

CONCLUSION

The nature of the intracranial lesion is an independent risk factor for the duration of treatment in postoperative meningitis after neurosurgery.

Non-cephalosporin-susceptible, glucose non-fermentative Gram-negative bacilli meningitis in post-neurosurgical adults: clinical characteristics and therapeutic outcome

OBJECTIVE

The clinical and laboratory characteristics of non-cephalosporin-susceptible (non-CS) glucose non-fermentative Gram-negative (G(-)) infections in adults with postneurosurgical meningitis are rarely examined solely in the literature.

METHODS

The data of 28 post-neurosurgical adults meningitis with glucose non-fermentative G(-) infections, collected during a study period of 5 years (2006-2010), were reviewed. The clinical and laboratory data between the non-cephalosporin-susceptible groups and the cephalosporin-susceptible groups were compared.

RESULTS

A total of 30 G(-) strains were collected from the 28 enrolled cases. Among the implicated glucose non-fermentative G(-) strains, 18 strains, belonging to 17 cases, were non-CS. Among the 18 non-cephalosporin-susceptible strains, Acinetobacter spp. (39%, 7/18) was the most common, followed by Pseudomonas spp. (22%, 4/18), Stenotrophomonas maltophilia (22%, 4/18) and Elizabethkingia meningoseptica (11%, 2/18). With a comparative analysis, there were no significant difference between the non-cephalosporin-susceptible and cephalosporin-susceptible glucose non-fermentative G(-) groups. The clinical and laboratory data were also of no statistical significance between the fatal (n=4) and non-fatal (n=13) non-cephalosporin-susceptible groups.

CONCLUSION

Sixty percent (18/30) of implicated glucose non-fermentative G(-) strains of post-NS meningitis in adults are non-cephalosporin-susceptible. Among the non-cephalosporin-susceptible glucose non-fermentative G(-) strains, Acinetobacter spp., Pseudomonas spp., S. maltophilia and E. meningoseptica are the commonly implicated pathogens, and their emergence in this specific group of meningitis has caused a therapeutic dilemma. The clinical manifestations of non-cephalosporin-susceptible glucose non-fermentative G(-) meningitis were not unique; therefore, only bacterial culture and antimicrobial susceptibility test are the methods for identification confirmation.

Prognostic indicators in bacterial meningitis: a case–control study

This was a case–control study to identify prognostic indicators of bacterial meningitis in a reference hospital in Pernambuco/Brazil. The data were collected from charts of 294 patients with bacterial meningitis between January 2000 and December 2004. Variables were grouped in biological, clinical, laboratory and etiologic agent/treatment. Variables selected in each step were grouped and adjusted for age. Two models were created: one containing clinical variables (clinical model) and other containing laboratory variables (laboratory model). In the clinical model the variables associated with death due to bacterial meningitis were dyspnea (p = 0.006), evidence of shock (p = 0.051), evidence of altered mental state (p = 0.000), absence of headache (p = 0.008), absence of vomiting (p = 0.052), and age ≥40 years old (p = 0.013). In the laboratory model, the variables associated with death due to bacterial meningitis were positive blood cultures (p = 0.073) and thrombocytopenia (p = 0.019). Identification of prognostic indicators soon after admission may allow early specific measures, like admission of patients with higher risk of death to Intensive Care Units.

Clinical characteristics of Stenotrophomonas maltophilia meningitis in adults: a high incidence in patients with a postneurosurgical state, long hospital staying and antibiotic use

OBJECTIVE

Stenotrophomonas (S.) maltophilia is an uncommon pathogen of adult bacterial meningitis (ABM).

METHODS

The clinical characteristics of six S. maltophilia ABM cases, collected during a study period of nine years (2001-2009) were included. In the related literature, 13 S. maltophilia ABM cases were reported, and their clinical data were also collected.

RESULTS

The 19 S. maltophilia ABM cases included 11 men and 8 women, aged 28-70 years. Of these 19 cases, 89.5% (17/19) had underlying neurosurgical (NS) conditions as the preceding event. Before the development of S. maltophilia ABM, 52.6% (10/19) of them had long stays in hospital and 63.2% (12/19) had undergone antibiotic treatment. Among the implicated S. maltophilia cases, three strains were found to have a resistance to sulfamethoxazole-trimethoprim (SMZ-TMP). Two of our five cases had resistant strains to levofloxacin. Among the antibiotics chosen for treatment, SMZ-TMP was the most common followed by quinolone (ciprofloxacin, levofloxacin, moxifloxacin). The therapeutic results showed 2 cases expired while the other 17 cases survived.

CONCLUSIONS

S. maltophilia ABM usually develops in patients with a preceding neurosurgical condition, a long hospital stay and antibiotic use. SMZ-TMP and quinolones, especially the ciprofloxacin, are the major antibiotic used. This study also shows the emergence of clinical S. maltophilia strains which are not susceptible to SMZ-TMP and quinolones and this development may pose a more serious threat in the near future because treatment options may become depleted and limited despite the mortality rate of this specific group of ABM not being high at this time.

Serratia marcescens meningitis: epidemiology, prognostic factors and treatment outcomes

BACKGROUND/PURPOSE

Serratia marcescens is a rare pathogen of central nervous system infections. This study was to investigate the epidemiology, prognostic factors, and treatment outcomes of S. marcescens meningitis.

METHODS

This retrospective analysis included 33 patients with culture-proven S. marcescens meningitis hospitalized between January 2000 and June 2011.

RESULTS

Of the 33 patients enrolled, only one did not receive neurosurgery before the onset of S. marcescens meningitis. Patients with S. marcescens meningitis had higher ratios of brain solid tumors (54.5%) and neurosurgery (97.0%) with a mortality rate of 15.2%. The mean interval between the first neurosurgical procedure and the diagnosis of meningitis was 17.1 days (range, 4-51 days). Only one third-generation cephalosporin-resistant S. marcescens isolate was recovered from the patients' cerebrospinal fluid (CSF) specimens. Compared with the favorable outcome group (n = 20), the unfavorable outcome group (n = 13) had a higher percentage of brain solid tumors, more intensive care unit stays, and higher Sequential Organ Failure Assessment score, CSF lactate and serum C-reactive protein concentrations at diagnosis of meningitis. Under the multiple regression analysis, CSF lactate concentration ≥2-fold the upper limit of normal (ULN) was independently associated with unfavorable outcomes (odds ratio, 7.20; 95% confidence interval, 1.08-47.96; p = 0.041).

CONCLUSION

S. marcescens meningitis is highly associated with neurosurgical procedures for brain solid tumors. CSF lactate concentration ≥2x ULN may predict an unfavorable outcome. Its mortality is not high and empiric treatment with parenteral third-generation cephalosporins may have a satisfactory clinical response.

Clinical characteristics, pathogens implicated and therapeutic outcomes of mixed infection in adult bacterial meningitis

We reviewed retrospectively the data for adult patients with bacterial meningitis over a period of 10.5 years in our hospital. The clinical characteristics and laboratory data of the 21 cases (52 strains) of mixed infection were analyzed. Two hundred and fifteen cases of single pathogen adult bacterial meningitis (ABM) were also included for comparison. Post-neurosurgical type of ABM was presented in 86% of the mixed infection group. Brain abscess was found in three patients. Fourteen patients survived and seven cases died. The analysis showed a statistical significance for the mixed infection group having a higher rate of nosocomially-acquired, post-neurosurgical condition, hydrocephalus, and lower level of cerebrospinal fluid white cell count, protein and lactate than the single pathogen group. Logistic regression analysis showed the independent factor of "hydrocephalus" (p = 0.002). Presence of hydrocephalus is a significant neuroimaging feature when compared with the single pathogen group. As compared with the previous study results of mixed infection in ABM, the present study showed a change of pathogens implicated of increasing Pseudomonas spp. and Acinetobacter spp. infections, and an emergence of anaerobic pathogens. All these changes deserve special attention because of the need for an appropriate choice of empirical antibiotics and choice of culture method.

Clinical characteristics and prognosis of acute bacterial meningitis in elderly patients over 65: a hospital-based study

Background

To examine the clinical characteristics of bacterial meningitis in elderly patients.

Methods

261 patients with adult bacterial meningitis (ABM), collected during a study period of 11 years (2000-2010), were included for study. Among them, 87 patients aged ≥ 65 years and were classified as the elderly group. The clinical and laboratory characteristics and prognostic factors were analyzed, and a clinical comparison with those of non-elderly ABM patients was also made.

Results

The 87 elderly ABM patients were composed of 53 males and 34 females, aged 65-87 years old (median = 71 years). Diabetes mellitus (DM) was the most common underlying condition (34%), followed by end stage renal disease (7%), alcoholism (4%) and malignancies (4%). Fever was the most common clinical manifestation (86%), followed by altered consciousness (62%), leukocytosis (53%), hydrocephalus (38%), seizure (30%), bacteremia (21%) and shock (11%). Thirty-nine of these 87 elderly ABM patients had spontaneous infection, while the other 48 had post-neurosurgical infection. Forty-four patients contracted ABM in a community-acquired state, while the other 43, a nosocomial state. The therapeutic results of the 87 elderly ABM patients were that 34 patients expired and 53 patients survived. The comparative results of the clinical and laboratory characteristics between the elderly and non-elderly ABM patients showed that only peripheral blood leukocytosis was significant. Presence of shock and seizure were significant prognostic factors of elderly ABM patients.

Conclusions

Elderly ABM patients accounted for 34.8% of the overall ABM cases, and this relatively high incidence rate may signify the future burden of ABM in the elderly population in Taiwan. The relative frequency of implicated pathogens of elderly ABM is similar to that of non-elderly ABM. Compared with non-elderly patients, the elderly ABM patients have a significantly lower incidence of peripheral blood leukocytosis. The mortality rate of elderly ABM remains high, and the presence of shock and seizures are important prognostic factors.

Spinal epidural abscess in adults caused by Staphylococcus aureus: clinical characteristics and prognostic factors

OBJECTIVE

Spinal epidural abscess (SEA) is a devastating infectious disease, which may result in neurologic sequelae. Staphylococcus (S.) aureus is a common pathogen of SEA. Here, we analyzed the clinical characteristics and laboratory data of adult patients with S. aureus SEA and compared the clinical characteristics of methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) infections.

METHODS

Between 2003 and 2008, we collected data regarding 29 adult cases of S. aureus SEA and analyzed the clinical presentations, magnetic resonance (MR) imaging features, therapeutic outcome, and prognostic factors. Antibiotic susceptibility test results of 11 implicated MRSA strains were also further analyzed.

RESULTS

We identified 17 MSSA strains and 12 MRSA strains. Lumbar and lumbosacral spine segments were the most commonly involved segments. All 29 patients had back pain. Other findings included sensory abnormalities (25), motor weakness (21), fever (16), bladder dysfunction (16), and altered consciousness (3). Disease onset at admission was acute in 6 cases and chronic in 23. The stages of disease severity were early stage in 9 and late stage in 20. After therapy, 21 patients had a good prognosis and 8 had a poor prognosis. Significant prognostic factors included older age (>70years), presence of diabetes mellitus, adrenal insufficiency, and MRSA infection. The prognosis alone was clinically different between patients with MSSA and MRSA infections.

CONCLUSIONS

Patients with localized back pain, particularly those with a fever and compromised immune system, should undergo MR imaging to ensure an early diagnosis and management.

Evaluation of the Seeplex® Meningitis ACE Detection kit for the detection of 12 common bacterial and viral pathogens of acute meningitis

BACKGROUND

Bacterial meningitis is an infectious disease with high rates of mortality and high frequency of severe sequelae. Early identification of causative bacterial and viral pathogens is important for prompt and proper treatment of meningitis and for prevention of life-threatening clinical outcomes. In the present study, we evaluated the value of the Seeplex Meningitis ACE Detection kit (Seegene Inc., Korea), a newly developed multiplex PCR kit employing dual priming oligonucleotide methods, for diagnosing acute meningitis.

METHODS

Analytical sensitivity of the kit was studied using reference strains for each pathogen targeted by the kit, while it's analytical specificity was studied using the human genome DNA and 58 clinically well-identified reference strains. For clinical validation experiment, we used 27 control cerebrospinal fluid (CSF) samples and 78 clinical CSF samples collected from patients at the time of diagnosis of acute meningitis.

RESULTS

The lower detection limits ranged from 10(1) copies/µL to 5×10(1) copies/µL for the 12 viral and bacterial pathogens targeted. No cross-reaction was observed. In the validation study, high detection rate of 56.4% was obtained. None of the control samples tested positive, i.e., false-positive results were absent.

CONCLUSIONS

The Seeplex Meningitis ACE Detection kit showed high sensitivity, specificity, and detection rate for the identification of pathogens in clinical CSF samples. This kit may be useful for rapid identification of important acute meningitis-causing pathogens.

Molecular epidemiology and the clinical significance of Acinetobacter baumannii complex isolated from cerebrospinal fluid in neurosurgical intensive care unit patients

OBJECTIVE

This study was intended to investigate the clinical significance and molecular epidemiology of Acinetobacter baumannii complex (ABC) isolated from cerebrospinal fluid (CSF) in neurosurgical intensive care unit (NSICU) patients, particularly comparing isolates from healthcare workers' (HCW) hands.

METHODS

We retrospectively reviewed the medical records of 30 patients with CSF cultures positive for ABC seen at our NSICU from the date it first opened, January 2007, to September 2010. Pulsed-field gel electrophoresis (PFGE) typing was performed on 68 strains isolated from 32 patients' CSF and 36 HCWs' hands.

RESULTS

ABC isolates were considered to be clinically significant in 21 (70.0%) patients but insignificant in the other nine (30.0%) patients. The prolonged (>7 days) use of cephalosporins was more common in patients with clinically significant ABC isolates (p = 0.049). Multiple drug resistance (MDR) was observed in 12 (57.1%) clinically significant isolates. Empirical antimicrobial therapies were not appropriate for nine of these 21 patients (42.8%). Mortality was significantly higher in the clinically significant group than in the clinically insignificant group (18/21 vs. 3/9; p = 0.008). Fifty-three isolates (77.9%) were grouped into 15 clusters, three of which contained possibly related isolates from patients' CSF and staff members' hands.

CONCLUSIONS

The fact that ABC isolates grown from CSF cultures do not always exhibit infection and have high multiple antibiotic resistance, including to carbapenems, should be borne in mind when planning treatment for these patients. In addition, HCWs' hands may play a significant role in transmission to patients, and compliance with infection control procedures, especially hand washing, must be enhanced in order to avoid ABC infections.

Fatal Klebsiella pneumoniae meningitis and concomitant disseminated intravascular coagulation in a patient with diabetes mellitus

Bacterial meningitis remains a major cause of death and long-term neurologic sequelae worldwide. We present a case of fatal Klebsiella pneumoniae meningitis and concomitant disseminated intravascular coagulation (DIC) in a 72-year-old woman with diabetes mellitus (DM). Both blood and cerebrospinal fluid cultures grew Klebsiella pneumoniae. Due to advanced age, newly recognized DM, K. pneumoniae bacteremia, and DIC, the prognosis of our patient was poor. Eight hours after arrival to the emergency department, cardiopulmonary resuscitation was necessary in this patient, but she died despite an early diagnosis and appropriate antibiotic therapy.

Meningococcal disease in Asia: an under-recognized public health burden

A literature search traced existing information on meningococcal disease in Asia. Reviewed data describing the epidemiology of meningococcal disease in Asia are incomplete, due in part to absence of surveillance in many countries, poor bacterial detection methods and social and healthcare barriers to disease reporting. This suggests that meningococcal disease in some Asian countries may be under-recognized, with a need to introduce/improve existing surveillance and case identification systems. Nevertheless, in some developing Asian countries, the disease burden may be significant. Serogroup A meningococcal epidemics are responsible for high morbidity and mortality in some countries and continue to be an ongoing threat, particularly in developing countries. There is an increasing role played by serogroups C, Y, and W-135 in invasive disease, indicating evolving meningococcal disease epidemiology in some countries. Multivalent meningococcal conjugate vaccines offer new opportunities in the region for reducing the meningococcal disease burden.

Clinical characteristics and therapeutic outcomes of nosocomial super-infection in adult bacterial meningitis

BACKGROUND

Super-infection in adult bacterial meningitis (ABM) is a condition wherein the cerebrospinal fluid (CSF) grows new pathogen(s) during the therapeutic course of meningitis. It is an uncommon but clinically important condition rarely examined in literature.

METHODS

Twenty-seven episodes of super-infection states in 21 ABM patients collected in a 9.5-year study period (January 2001 to June 2010) were evaluated. The clinical characteristics, implicated pathogens, results of antimicrobial susceptibility tests, and therapeutic outcomes were analyzed.

RESULTS

Twenty-one patients (13 men, 8 women) aged 25-73 years (median, 45 years) had post-neurosurgical state as the preceding event and nosocomial infection. The post-neurosurgical states included spontaneous intracranial hemorrhage (ICH) with craniectomy or craniotomy with extra-ventricular drainage (EVD) or ventriculo-peritoneal shunt (VPS) in 10 patients, traumatic ICH with craniectomy or craniotomy with EVD or VPS in 6 patients, hydrocephalus s/p VPS in 2 patients, and one patient each with cerebral infarct s/p craniectomy with EVD, meningeal metastasis s/p Omaya implant, and head injury. All 21 patients had EVD and/or VP shunt and/or Omaya implant during the whole course of ABM. Recurrent fever was the most common presentation and the implicated bacterial pathogens were protean, many of which were antibiotic resistant. Most patients required adjustment of antibiotics after the pathogens were identified but even with antimicrobial therapy, 33.3% (7/21) died. Morbidity was also high among survivors.

CONCLUSIONS

Super-infection in ABM is usually seen in patients with preceding neurosurgical event, especially insertion of an external drainage device. Repeat CSF culture is mandatory for diagnostic confirmation because most of the implicated bacterial strains are non-susceptible to common antibiotics used. Unusual pathogens like anaerobic bacteria and fungi may also appear. Despite antimicrobial therapy, prognosis remains poor.

Changing etiology of community-acquired bacterial meningitis in adults: a nationwide multicenter study in Korea

Epidemiologic data on the etiologic organisms is important for appropriate empirical antibiotic treatment of bacterial meningitis. We identified the etiologies of community-acquired bacterial meningitis in Korean adults and the associated epidemiological factors. A retrospective, multicenter nationwide study was carried out. Patients 18 years of age or older with community-acquired bacterial meningitis with a confirmed pathogen were enrolled. Demographic, clinical, and microbiological data were collected. One hundred and ninety-five cases were collected. Streptococcus pneumoniae was the most common pathogen (50.8%), followed by Staphylococcus aureus (10.3%), Klebsiella pneumoniae (7.7%), Listeria monocytogenes (6.7%), and group B Streptococcus (3.1%). The penicillin resistance rate of the S. pneumoniae was 60.3%; 40.0% of the organisms were not susceptible to third-generation cephalosporins. The combination of third-generation cephalosporin with vancomycin was used in 76.3% of cases. Steroids were given before or with the first dose of antibiotics in 37.4% of patients. The 30-day mortality rate was 20.5% and neurological sequelae developed in 15.6% of cases. S. pneumoniae was the most common organism identified in community-acquired bacterial meningitis among Korean adults. S. aureus, K. pneumoniae, L. monocytogenes, and group B Streptococcus were also common. S. pneumoniae had high rates of resistance to penicillin and third-generation cephalosporins.