Search

Acute bacterial meningitis is a medical emergency, and delays in initiating effective antimicrobial therapy result in increased morbidity and mortality. Culture-based methods, thus far considered the "gold standard" for identifying bacterial microorganisms, require 24 to 48 h to provide a diagnosis. In addition, antimicrobial therapy is often started prior to clinical sample collection, thereby decreasing the probability of confirming the bacterial pathogen by culture-based methods. To enable a fast and accurate detection of the most important bacterial pathogens causing meningitis, namely, Streptococcus pneumoniae , Haemophilus influenzae , Neisseria meningitidis , Streptococcus agalactiae , and Listeria monocytogenes , we evaluated a commercially available multiplex LightMix real-time PCR (RT-PCR) in 220 cerebrospinal fluid (CSF) specimens. The majority of CSF samples were collected by lumbar puncture, but we also included some CSF samples from patients with symptoms of meningitis from the neurology department that were recovered from shunts. CSF samples were analyzed by multiplex RT-PCR enabling a first diagnosis within a few hours after sample arrival at our institute. In contrast, bacterial identification took between 24 and 48 h by culture. Overall, a high agreement of bacterial identification between culture and multiplex RT-PCR was observed (99%). Moreover, multiplex RT-PCR enabled the detection of pathogens, S. pneumoniae ( n = 2), S. agalactiae ( n = 1), and N. meningitidis ( n = 1), in four culture-negative samples. As a complement to classical bacteriological CSF culture, the LightMix RT-PCR assay proved to be valuable by improving the rapidity and accuracy of the diagnosis of bacterial meningitis., (Copyright © 2018 Wagner et al.)

Accurate diagnosis of bacterial meningitis (BM) relies on cerebrospinal fluid (CSF) Gram staining and bacterial culture, which often present high false-negative rates because of antibiotic abuse. Thus, a novel and reliable diagnostic biomarker is required. Procalcitonin (PCT) has been well demonstrated to be specifically produced from peripheral tissues by bacterial infection, which makes it a potential diagnostic biomarker candidate. Here, we performed a prospective clinical study comprising a total of 143 patients to investigate the diagnostic value of CSF PCT, serum PCT, and other conventional biomarkers for BM. Patients were assigned to the BM ( n = 49), tuberculous meningitis (TBM) ( n = 25), viral meningitis/encephalitis (VM/E) ( n = 34), autoimmune encephalitis (AIE) ( n = 15), or noninflammatory nervous system diseases (NINSD) group ( n = 20). Empirical antibiotic pretreatment was not an exclusion criterion. Our results show that the CSF PCT level was significantly ( P < 0.01) higher in patients with BM (median, 0.22 ng/ml; range, 0.13 to 0.54 ng/ml) than in those with TBM (median, 0.12 ng/ml; range, 0.07 to 0.16 ng/ml), VM/E (median, 0.09 ng/ml; range, 0.07 to 0.11 ng/ml), AIE (median, 0.06 ng/ml; range, 0.05 to 0.10 ng/ml), or NINSD (median, 0.07 ng/ml; range, 0.06 to 0.08 ng/ml). Among the assessed biomarkers, CSF PCT exhibited the largest area under the receiver operating characteristic curve (0.881; 95% confidence interval, 0.810 to 0.932; cutoff value, 0.15 ng/ml; sensitivity, 69.39%; specificity, 91.49%). Our study sheds light upon the diagnostic dilemma of BM due to antibiotic abuse. (This study has been registered at ClinicalTrials.gov under registration no. NCT02278016.)., (Copyright © 2017 American Society for Microbiology.)

Microbiological tests on cerebrospinal fluid (CSF) utilize a common urgent-care procedure that does not take into account the chemical and cytological characteristics of the CSF, resulting sometimes in an unnecessary use of human and diagnostic resources. The aim of this study was to retrospectively validate a simple scoring system (bacterial meningitis-Careggi score [BM-CASCO]) based on blood and CSF sample chemical/cytological parameters for evaluating the probability of acute bacterial meningitis (ABM) in adults. BM-CASCO (range, 0 to 6) was defined by the following parameters: CSF cell count, CSF protein levels, CSF lactate levels, CSF glucose-to-serum glucose ratio, and peripheral neutrophil count. BM-CASCO was retrospectively calculated for 784 cases of suspected ABM in adult subjects observed during a four-and-a-half-year-period (2010 to 2014) at the emergency department (ED) of a large tertiary-care teaching hospital in Italy. Among the 28 confirmed ABM cases (3.5%), Streptococcus pneumoniae was the most frequent cause (16 cases). All ABM cases showed a BM-CASCO value of ≥3. Most negative cases (591/756) exhibited a BM-CASCO value of ≤1, which was adopted in our laboratory as a cutoff to not proceed with urgent microbiological analysis of CSF in cases of suspected ABM in adults. During a subsequent 1-year follow-up, the introduction of the BM-CASCO in the diagnostic workflow of ABM in adults resulted in a significant decrease in unnecessary microbiological analysis, with no false negatives. In conclusion, BM-CASCO appears to be an accurate and simple scoring system for optimization of the microbiological diagnostic workflow of ABM in adults., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)

Neisseria cinerea is a human commensal. The first known case of meningitis and bacteremia due to Neisseria cinerea following percutaneous glycerol instillation of the trigeminal ganglion is reported. Conventional phenotypic methods and complete 16S RNA gene sequencing accurately identified the pathogen. Difficulties in differentiation from pathogenic neisseriae are discussed., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Pasteurella multocida is a rare cause of neonatal bacterial meningitis. We describe such a case and verify two household cats as the source of infection using repetitive-element PCR (rep-PCR) molecular fingering., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Children with temporary external ventricular drains (EVD) are prone to nosocomial infections. Diagnosis of bacterial meningitis and ventriculitis in these children is challenging due to frequent blood contamination of cerebrospinal fluid (CSF) and the presence of chemical ventriculitis. The aim of this study was to compare diagnostic accuracy of presepsin (sCD14-ST), a novel biomarker of bacterial infection in CSF, to predict bacterial infection in comparison to the accuracy of established biomarkers like those demonstrated in biochemical analysis of CSF. We conducted a prospective study with 18 children with suspected bacterial meningitis or ventriculitis who had 66 episodes of disease. CSF samples were taken from external ventricular drainage. We measured presepsin in CSF, as well as CSF leukocyte count, glucose, and proteins. CSF was also taken to prove bacterial infection with culture methods or with 16S rRNA gene broad-range PCR (SepsiTest; Molzym, Germany). Infection was clinically confirmed in 57 (86%) episodes of suspected meningitis or ventriculitis. Chemical ventriculitis was diagnosed in 9 (14%) episodes of suspected meningitis or ventriculitis. Diagnostic accuracies presented as area under the curve (AUC) for sCD14-ST, leukocytes, and proteins measured in CSF were 0.877 (95% confidence interval [CI], 0.793 to 0.961), 0.798 (95% CI, 0.677 to 0.920), and 0.857 (95% CI, 0.749 to 0.964), respectively. With CSF culture, we detected bacteria in 17 samples, compared to 37 detected with broad-range PCR. It was found that presepsin was present at a significantly higher level in children with clinically proven ventriculitis than in those without meningitis or ventriculitis. Diagnostic accuracies of presepsin were superior to those of leukocytes or proteins in CSF. Presepsin-guided 16S rRNA gene PCR could be used in everyday clinical practice to improve etiological diagnosis of meningitis and ventriculitis and to prescribe more appropriate antibiotics., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Sphingomonas koreensis is an aerobic Gram-negative rod originally described in 2001 following isolation from natural mineral water in Korea. Here, we report a case study with Sphingomonas koreensis as the causative agent of meningitis. To our knowledge, this is the first documented case of Sphingomonas koreensis as a human pathogen., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Anaerobic bacteria are often difficult to detect, especially after the initiation of antibiotics. We describe the application of PCR-electrospray ionization mass spectrometry (PCR/ESI-MS) using a sample of cerebrospinal fluid to identify an anaerobic Gram-negative bacillus, Fusobacterium nucleatum, in a patient with "culture-negative" meningitis and cerebral abscesses., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

We report the first case of postneurosurgical meningitis due to Psychrobacter sanguinis, identified only by 16S rRNA analysis. Psychrobacter spp. usually live in deep sea environments and cold habitats. Despite a strict questioning of the patient and the medical staff, we did not find the source of this bacterium., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

In North America, the widespread use of vaccines targeting Haemophilus influenzae type b and Streptococcus pneumoniae have dramatically altered the epidemiology of bacterial meningitis, while the methodology for culturing cerebrospinal fluid (CSF) specimens has remained largely unchanged. The aims of this study were 2-fold: to document the current epidemiology of bacterial meningitis at a tertiary care medical center and to assess the clinical utility of routinely querying for anaerobes in CSF cultures. To that end, we assessed CSF cultures submitted over a 2-year period. A brucella blood agar (BBA) plate, incubated anaerobically for 5 days, was included in the culture procedure for all CSF specimens during the second year of evaluation. In the pre- and postimplementation years, 2,353 and 2,302 CSF specimens were cultured, with 49 and 99 patients having positive culture results, respectively. The clinical and laboratory data for patients with positive cultures were reviewed. Anaerobic bacteria were isolated in the CSF samples from 33 patients post-BBA compared to two patients pre-BBA (P = 0.01). The anaerobic isolates included Bacteroides thetaiotaomicron (n = 1), Propionibacterium species (n = 15), and Propionibacterium acnes (n = 19) isolates; all of these isolates were recovered on the BBA. Eight of the 35 patients from whom anaerobic organisms were isolated received antimicrobial therapy. Although six of these patients had central nervous system hardware, two patients did not have a history of a neurosurgical procedure and had community-acquired anaerobic bacterial meningitis. This study demonstrates that the simple addition of an anaerobically incubated BBA to the culture of CSF specimens enhances the recovery of clinically significant anaerobic pathogens., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

A universal PCR assay for bacteria and fungi detected meningitis pathogens in 65% of 20 cerebrospinal fluid (CSF) samples from patients with suspected central nervous system (CNS) infections compared to a 35% detection rate by culture and/or microscopy methods. Thus, the PCR assay can improve the diagnosis rate of infective meningitis when standard methods provide a negative result.

Eggerthella lenta bacteremia is uncommon and generally associated with abdominal sepsis. The organism and its clinical significance have not been well characterized due to historical difficulties with identification. We report a case of severe infection in a paraplegic man complicated by psoas abscess, osteomyelitis, and meningitis and discuss treatment challenges.

Propionibacterium acnes is a known cause of postneurosurgical meningitis; however, it is rarely implicated in de novo meningitis. Herein we report a case of a 49-year-old male with de novo meningitis caused by P. acnes with metastatic melanoma as the only identified risk factor for his infection.

We report Campylobacter fetus meningitis associated with endocarditis in a 75-year-old diabetic man after he consumed raw liver. C. fetus was isolated from blood samples and cerebrospinal fluid. Cure was obtained with combined intravenous imipenem-gentamicin for 4 weeks; no relapse occurred after 6 months of follow-up.

Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae are important causes of meningitis and other infections, and rapid, sensitive, and specific laboratory assays are critical for effective public health interventions. Singleplex real-time PCR assays have been developed to detect N. meningitidis ctrA, H. influenzae hpd, and S. pneumoniae lytA and serogroup-specific genes in the cap locus for N. meningitidis serogroups A, B, C, W135, X, and Y. However, the assay sensitivity for serogroups B, W135, and Y is low. We aimed to improve assay sensitivity and develop multiplex assays to reduce time and cost. New singleplex real-time PCR assays for serogroup B synD, W135 synG, and Y synF showed 100% specificity for detecting N. meningitidis species, with high sensitivity (serogroup B synD, 99% [75/76]; W135 synG, 97% [38/39]; and Y synF, 100% [66/66]). The lower limits of detection (LLD) were 9, 43, and 10 copies/reaction for serogroup B synD, W135 synG, and Y synF assays, respectively, a significant improvement compared to results for the previous singleplex assays. We developed three multiplex real-time PCR assays for detection of (i) N. meningitidis ctrA, H. influenzae hpd, and S. pneumoniae lytA (NHS assay); (ii) N. meningitidis serogroups A, W135, and X (AWX assay); and (iii) N. meningitidis serogroups B, C, and Y (BCY assay). Each multiplex assay was 100% specific for detecting its target organisms or serogroups, and the LLD was similar to that for the singleplex assay. Pairwise comparison of real-time PCR between multiplex and singleplex assays showed that cycle threshold values of the multiplex assay were similar to those for the singleplex assay. There were no substantial differences in sensitivity and specificity between these multiplex and singleplex real-time PCR assays.

Streptococcus gallolyticus subsp. pasteurianus, previously known as Streptococcus bovis biotype II.2, is known to cause multiple infectious complications, including bacterial meningitis, in adults. Only sporadic individual case reports have identified this pathogen as a cause of meningitis in infants. This study is the first to longitudinally document S. gallolyticus subsp. pasteurianus as a cause of meningitis in four epidemiologically unrelated infants less than 2 weeks of age. The 16S rRNA gene sequences of all 4 isolates were identical, and further were identical to 3 central nervous system (CNS) strains (two adults and one child) reported in existing literature. S. gallolyticus subsp. pasteurianus is an increasingly recognized cause of meningitis and bacteremia in the newborn period, and it merits further study with respect to etiology of infection.

In this report, we present a case of postneurosurgical meningitis due to Providencia stuartii, which was treated successfully with meropenem therapy lasting 21 days.

We report a case of meningitis due to Lactobacillus rhamnosus in a child undergoing allogeneic hematopoietic stem cell transplantation for acute leukemia. Four episodes of bacteremia involving strains with pulsotypes identical to that of the cerebrospinal fluid isolate preceded meningitis. After several courses of clindamycin, no relapse occurred during the patient follow-up.

We report a case of Streptococcus bovis (Streptococcus gallolyticus subsp. pasteurianus) meningitis, a rare cause of central nervous system (CNS) infection in an adult, and comment on the importance of investigation of the lower gastrointestinal tract to identify a portal of entry in cases of systemic Streptococcus bovis infection.

We report the first case of adult meningitis confirmed to be due to Streptococcus gallolyticus subsp. pasteurianus. Phenotypically reported as Streptococcus bovis biotype II/2, 16S rRNA sequencing revealed S. gallolyticus subsp. pasteurianus. Because of taxonomic uncertainties, S. gallolyticus subsp. pasteurianus may be an underrecognized agent of systemic infections.

Globicatella sanguinis is a rare cause of acute meningitis. We demonstrated human carriage of Globicatella by identifying cefotaxime-resistant strains in groin and rectal specimens 9 months after invasive infection. The pathogenic strain isolated from the cerebrospinal fluid and the carriage strains were accurately identified by sodA gene sequence analysis.

We describe the case of an adult male with nasopharyngeal carcinoma who had meningitis caused by Citrobacter farmeri. The isolate was confirmed as C. farmeri by two commercial identification systems and 16S rRNA gene analysis. The patient developed multiorgan failure and died despite antibiotic treatment with in vitro active agents (ceftriaxone and meropenem).

We report the first case of human infection due to Pseudomonas fulva. P. fulva caused acute meningitis following the placement of a drainage system in a 2-year-old female. Additionally, the isolate displayed a VIM-2 carbapenemase in a class 1 integron context.

We report the case of a teenager with chronic lymphocytic meningitis for whom Tropheryma whipplei 16S rRNA PCR results were positive in two cerebrospinal fluid samples and one duodenal biopsy specimen. PCR targeting another specific sequence of Tropheryma whipplei and sequencing of the initially amplified 16S rRNA fragment did not confirm the results.

We present the first documented case of Salmonella enterica serotype Agona meningitis in a 6-day-old baby. S. enterica serotype Agona was isolated concurrently from infant cerebrospinal fluid and parental fecal samples, and Salmonella was isolated from breast milk. The role of breast milk in transmission of Salmonella enterica is discussed.

We report the second human case of infection caused by an organism identified as the proposed Bartonella species, "B. washoensis." The organism was isolated from a blood sample from a patient presenting with meningitis and early sepsis. Oropsylla montana fleas were implicated as the vector for disease transmission in this case.

We here report on the development of a novel multiplex PCR with product detection in a Luminex 100 suspension array system. The assay covers the nine most important bacterial and viral pathogens found in Danish meningitis patients. The microorganisms include Neisseria meningitidis, Streptococcus pneumoniae, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Streptococcus agalactiae, herpes simplex virus types 1 and 2, and varicella-zoster virus. The study was based on 1,187 samples, of which 55 were found to be positive by PCR. The assay was found to have an excellent sensitivity and an excellent specificity compared to the results of a "gold standard," defined by routine laboratory tests, for the two most important pathogens, S. pneumoniae (95 and 99.1%, respectively) and N. meningitidis (100 and 99.7%, respectively). The method provides a valuable supplement to the traditional microscopy and culture of cerebrospinal fluid (CSF) samples in a routine diagnostic setting, and results can be available within 1 workday. The method is suitable for use for the initial screening and identification of nine important microorganisms in CSF samples from patients with suspected meningitis. Compared to microscopy and culture of CSF, this rapid and sensitive method will support physicians with the selection of the appropriate antimicrobial agents and the initiation of timely treatment in the absence of live microorganisms in the CSF.

Gemella haemolysans is a rare pathogen in cases of bacterial meningitis. We present a case of meningitis due to G. haemolysans in a 17-month-old boy. This is the first reported case of Gemella meningitis in a child. The patient completely recovered following intravenous therapy with linezolid and chloramphenicol.

Real-time PCR and fluorescence in situ hybridization (FISH) were evaluated as rapid methods for the diagnosis of bacterial meningitis and compared to standard diagnostic procedures. For PCR, a LightCycler approach was chosen, implementing eubacterial and specific PCR assays for the most relevant bacteria. For FISH, a similar probe set containing eubacterial and specific probes was composed of published and newly designed probes. Both methods were evaluated by use of cerebrospinal fluid (CSF) samples from patients with suspected bacterial meningitis. For all microscopy- and culture-positive samples (n = 28), the eubacterial PCR was positive. In addition, all identifiable pathogens were detected with specific PCR assays, according to an algorithm based on the Gram stain. The FISH method detected the pathogen in 13 of 18 positive samples. While the FISH method remained negative for all microscopy- and culture-negative samples (n = 113), the eubacterial PCR was positive for five of these samples. Sequencing of the amplicon revealed the presence of Neisseria meningitidis, Streptococcus agalactiae, and Haemophilus influenzae in three of these five samples. In addition, samples with discordant results by culture and microscopy were successfully investigated by PCR (10 samples) and FISH (5 samples). In conclusion, PCR is a highly sensitive tool for rapid diagnosis of bacterial meningitis. FISH is less sensitive but is useful for the identification of CSF samples showing bacteria in the Gram stain. Based on our results, an approach for laboratory diagnosis of meningitis including PCR and FISH is discussed.

Thirty-seven Haemophilus influenzae strains from nasopharyngeal swabs (NP) and 44 H. influenzae strains from cerebrospinal fluid (CSF) were investigated. Of the 37 H. influenzae isolates from NP, the serotypes of 30 isolates were nontypeable, 4 were type b, 2 were type c, and 1 was type a, whereas all of the 44 isolates from CSF were type b. The MICs of 16 antibiotics for the H. influenzae isolates from NP and CSF were similar, and no beta-lactamase-negative ampicillin-resistant strain was found. Molecular typing by pulsed-field gel electrophoresis (PFGE) showed that the 37 H. influenzae strains from NP had 22 PFGE patterns, with none predominating, and the 44 H. influenzae strains from CSF had 9 PFGE patterns, with patterns alpha (22 isolates) and beta (12 isolates) predominating. Our results indicate that two predominant types of H. influenzae type b strains have the potential to spread among children with meningitis in Hanoi, Vietnam.

We have evaluated the use of a broad-range PCR aimed at the 16S rRNA gene in detecting bacterial meningitis in a clinical setting. To achieve a uniform DNA extraction procedure for both gram-positive and gram-negative organisms, a combination of physical disruption (bead beating) and a silica-guanidiniumthiocyanate procedure was used for nucleic acid preparation. To diminish the risk of contamination as much as possible, we chose to amplify almost the entire 16S rRNA gene. The analytical sensitivity of the assay was approximately 1 x 10(2) to 2 x 10(2) CFU/ml of cerebrospinal fluid (CSF) for both gram-negative and gram-positive bacteria. In a prospective study of 227 CSF samples, broad-range PCR proved to be superior to conventional methods in detecting bacterial meningitis when antimicrobial therapy had already started. Overall, our assay showed a sensitivity of 86%, a specificity of 97%, a positive predictive value of 80%, and a negative predictive value of 98% compared to culture. We are currently adapting the standard procedures in our laboratory for detecting bacterial meningitis; broad-range 16S ribosomal DNA PCR detection is indicated when antimicrobial therapy has already started at time of lumbar puncture or when cultures remain negative, although the suspicion of bacterial meningitis remains.

Human and bovine Streptococcus bovis strains had the same 16S ribosomal DNA restriction fragment length polymorphism and often had the same patterns of starch, mannitol, lactose, and raffinose utilization. PCRs of BOX sequences differed, but numerical analyses indicated that some human strains clustered with bovine strains. However, human and bovine strains had distinctly different sensitivities to lysozyme and 2-deoxyglucose.

A 12-year-old child developed meningitis 6 days after a third ventriculostomy by endoscopy. A coagulase-negative Staphylococcus sp. was isolated in pure culture from the cerebrospinal fluid and was definitely identified as Staphylococcus lugdunensis after the 16S ribosomal DNA gene and rpoB gene were sequenced. This report describes the first case of S. lugdunensis meningitis.

A single-tube 5' nuclease multiplex PCR assay was developed on the ABI 7700 Sequence Detection System (TaqMan) for the detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae from clinical samples of cerebrospinal fluid (CSF), plasma, serum, and whole blood. Capsular transport (ctrA), capsulation (bexA), and pneumolysin (ply) gene targets specific for N. meningitidis, H. influenzae, and S. pneumoniae, respectively, were selected. Using sequence-specific fluorescent-dye-labeled probes and continuous real-time monitoring, accumulation of amplified product was measured. Sensitivity was assessed using clinical samples (CSF, serum, plasma, and whole blood) from culture-confirmed cases for the three organisms. The respective sensitivities (as percentages) for N. meningitidis, H. influenzae, and S. pneumoniae were 88.4, 100, and 91.8. The primer sets were 100% specific for the selected culture isolates. The ctrA primers amplified meningococcal serogroups A, B, C, 29E, W135, X, Y, and Z; the ply primers amplified pneumococcal serotypes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10A, 11A, 12, 14, 15B, 17F, 18C, 19, 20, 22, 23, 24, 31, and 33; and the bexA primers amplified H. influenzae types b and c. Coamplification of two target genes without a loss of sensitivity was demonstrated. The multiplex assay was then used to test a large number (n = 4,113) of culture-negative samples for the three pathogens. Cases of meningococcal, H. influenzae, and pneumococcal disease that had not previously been confirmed by culture were identified with this assay. The ctrA primer set used in the multiplex PCR was found to be more sensitive (P < 0.0001) than the ctrA primers that had been used for meningococcal PCR testing at that time.

We report a case of Pasteurella multocida meningitis in a 1-month-old baby exposed to close contact with two dogs and a cat but without any known history of injury by these animals. 16S rRNA gene sequencing of the isolate from the baby allowed identification at the subspecies level and pointed to the cat as a possible source of infection. Molecular typing of Pasteurella isolates from the animals, from the baby, and from unrelated animals clearly confirmed that the cat harbored the same P. multocida subsp. septica strain on its tonsils as the one isolated from the cerebrospinal fluid of the baby. This case stresses the necessity of informing susceptible hosts at risk of contracting zoonotic agents about some basic hygiene rules when keeping pets. In addition, this study illustrates the usefulness of molecular methods for identification and epidemiological tracing of Pasteurella isolates.

Streptococcus bovis is a nonenterococcal, group D streptococcus which has been identified as a causative agent for serious human infections, including endocarditis, bacteremia, and septic arthritis. Several cases of adult S. bovis meningitis have been reported, usually in association with underlying disease. In the neonatal period, it is an uncommon agent of meningitis. We report, to our knowledge, the third documented case of neonatal S. bovis meningitis in the English language literature. As in the previous cases, this neonate showed no anatomical or congenital immunologic lesion which might be expected to predispose the patient to meningitis. Sequencing of the 16S ribosomal DNA gene was performed and a new PCR test was used to secure a more reliable identification of the strain.

We reviewed the results of microscopic Gram stain examination and routine culture for 2,635 cerebrospinal fluid (CSF) samples processed in an adult hospital microbiology laboratory during 55 months. There were 56 instances of bacterial or fungal meningitis (16 associated with central nervous system [CNS] shunt infection), four infections adjacent to the subarachnoid space, four cases of sepsis without meningitis, and an additional 220 CSF specimens with positive cultures in which the organism isolated was judged to be a contaminant. Because 121 of these contaminants were isolated in broth only, elimination of the broth culture would decrease unnecessary work. However, 25% of the meningitis associated with CNS shunts would have been missed by this practice. The most common cause of meningitis was Cryptococcus neoformans, followed by Streptococcus pneumoniae and Neisseria meningitidis. In 48 of 56 (88%) of cases, examination of the Gram-stained specimen revealed the causative organism. If patients who had received effective antimicrobial therapy prior to lumbar puncture are excluded, the CSF Gram stain is 92% sensitive. Microscopic examination incorrectly suggested the presence of organisms in only 3 of 2,635 (0.1%) CSF examinations. Thus, microscopic examination of Gram-stained, concentrated CSF is highly sensitive and specific in early diagnosis of bacterial or fungal meningitis.

Bacterial antigen testing (BAT) of cerebrospinal fluid (CSF) by latex agglutination is a low-yield procedure in patients whose CSF specimens have normal laboratory parameters. Between August 1992 and August 1994, we evaluated 287 bacterial antigen (BA) test requests to determine whether yields could be improved and whether patient costs could be reduced by cancelling BAT for those patients with normal CSF parameters (cell count, protein, glucose) after consultation with physicians. A total of 171 (68%) BA tests were canceled by this approach. None of these CSF specimens was culture positive for an organism detectable by BAT. Of the remaining 116 CSF specimens tested, only 3 were positive by BAT, one each for Neisseria meningitidis, Streptococcus pneumoniae, and group B streptococcus. Only 43 of the CSF specimens tested had at least two abnormal parameters; the 3 positive CSF specimens were included in this group. In light of the low rate of positivity, the number of BA tests can be further reduced by establishing criteria that must be met before a CSF specimen is accepted for BAT. After review of our data and the literature concerning this topic, we concluded that only specimens with leukocyte counts of > or = 50 cells per mm3 should be tested. Of 287 specimens evaluated in our study, only 36 met this criterion, including the 3 BA-positive specimens. Enacting such a restriction would have reduced the total number of BA tests by 251 (87%) without compromising patient care. A laboratory cost savings of $6,500 per year would have been realized, with a substantial reduction in the cost per positive test. Patient charges would have been reduced by $12,500 per year.

Primers specific to conserved and variable regions in the 16S rRNA sequence were selected from the partially sequenced 16S rRNA genes of Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, S. agalactiae, and Staphylococcus epidermidis. The PCR assay was divided into two DNA amplifications. The first resulted in a general bacterial amplicon, and the second resulted in a species-specific amplicon. The high specificity of the PCR assay was documented after testing bacteria of 28 different species (133 strains). A total of 304 clinical cerebrospinal fluid samples, including 125 samples from patients with bacterial meningitis, were assayed to investigate the diagnostic sensitivity and specificity for bacterial meningitis. The assay showed high sensitivity (0.94) and specificity (0.96) with the clinical samples, although some false results were obtained, the reasons for which are discussed. With agarose gel electrophoresis for detection of the PCR products, the detection limit for meningococci in cerebrospinal fluid was 3 x 10(2) CFU/ml.

A set of broad-range PCR primers for the 16S rRNA gene in bacteria were tested, along with three series of oligonucleotide probes to detect the PCR product. The first series of probes is broad in range and consists of a universal bacterial probe, a gram-positive probe, a Bacteroides-Flavobacterium probe, and two probes for other gram-negative species. The second series was designed to detect PCR products from seven major bacterial species or groups frequently causing meningitis: Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, S. agalactiae, Escherichia coli and other enteric bacteria, Listeria monocytogenes, and Staphylococcus aureus. The third series was designed for the detection of DNA from species or genera commonly considered potential contaminants of clinical samples, including cerebrospinal fluid (CSF): Bacillus, Corynebacterium, Propionibacterium, and coagulase-negative Staphylococcus spp. The primers amplified DNA from all 124 different species of bacteria tested. Southern hybridization testing of the broad-range probes with washes containing 3 M tetramethylammonium chloride indicated that this set of probes correctly identified all but two of the 102 bacterial species tested, the exceptions being Deinococcus radiopugnans and Gardnerella vaginalis. The gram-negative and gram-positive probes hybridized to isolates of two newly characterized bacteria, Alloiococcus otitis and Rochalimaea henselii, as predicted by Gram stain characteristics. The CSF pathogen and contaminant probe sequences were compared with available sequence information and with sequencing data for 32 different species. Testing of the CSF pathogen and contaminant probes against DNA from over 60 different strains indicated that, with the exception of the coagulase-negative Staphylococcus probes, these probes provided the correct identification of bacterial species known to be found in CSF.

Psychrobacter immobilis was isolated from the cerebrospinal fluid (CSF) and blood of a 2-day-old infant who appeared well except for a fever and a full anterior fontanelle. The infant was treated with antibiotics intravenously. After 48 h, he became afebrile and CSF and blood cultures were negative; he was then discharged. After 96 h of incubation, CSF and blood cultures yielded a gram-negative organism, P. immobilis. The child was readmitted to the hospital, and the same organism was again isolated from his blood and CSF.