Bacterial Meningitis Pathogens Research Articles

Development and validation of a novel multiplex digital PCR assay for identification of pathogens in cerebrospinal fluid of children with bacterial meningitis

Background and aimsIdentifying the pathogens of bacterial meningitis (BM) is crucial for its diagnosis and treatment. The aim of this study is to develop and validate a novel method for detecting pathogens in cerebrospinal fluid (CSF) of children with BM using a digital polymerase chain reaction (dPCR) assay.Materials and methods:A novel multiplex dPCR assay method has been developed and validated. The diagnostic performance of the dPCR assay was compared with that of synchronous CSF culture, and the factors affecting its performance were analyzed.Results:A total of 69 children with BM were enrolled prospectively. The sensitivity of the dPCR assay was 94.44 %, specificity was 100 %, coincidence rate was 98.55 %, Kappa value was 0.959, and net reclassification improvement was 61.11 %. Compared with the CSF culture assay, the dPCR assay had higher sensitivity in different bacterial groups. Multiple factors affected its performance, including previous use of antibiotics, sampling time, BM complications, and levels of inflammatory biomarkers in CSF and blood (all P < 0.05). Patients who required intensive care and died had a higher bacterial DNA loads identified by dPCR assay (both P < 0.05).Conclusion:This novel assay has better pathogen detection ability than CSF culture. Its performance was influenced by sampling time, previous use of antibiotics, and disease severity.

The Clinical and Genetic Characteristics of Streptococcus agalactiae Meningitis in Neonates.

Streptococcus agalactiae (Group B Streptococcus, GBS) is an important pathogen of bacterial meningitis in neonates. We aimed to investigate the clinical and genetic characteristics of neonatal GBS meningitis. All neonates with GBS meningitis at a tertiary level medical center in Taiwan between 2003 and 2020 were analyzed. Capsule serotyping, multilocus sequence typing, antimicrobial resistance, and whole-genome sequencing (WGS) were performed on the GBS isolates. We identified 48 neonates with GBS meningitis and 140 neonates with GBS sepsis. Neonates with GBS meningitis had significantly more severe clinical symptoms; thirty-seven neonates (77.8%) had neurological complications; seven (14.6%) neonates died; and 17 (41.5%) survivors had neurological sequelae at discharge. The most common serotypes that caused meningitis in neonates were type III (68.8%), Ia (20.8%), and Ib (8.3%). Sequence type (ST) is highly correlated with serotypes, and ST17/III GBS accounted for more than half of GBS meningitis cases (56.3%, n = 27), followed by ST19/Ia, ST23/Ia, and ST12/Ib. All GBS isolates were sensitive to ampicillin, but a high resistance rates of 72.3% and 70.7% to erythromycin and clindamycin, respectively, were noted in the cohort. The virulence and pilus genes varied greatly between different GBS serotypes. WGS analyses showed that the presence of PezT; BspC; and ICESag37 was likely associated with the occurrence of meningitis and was documented in 60.4%, 77.1%, and 52.1% of the GBS isolates that caused neonatal meningitis. We concluded that GBS meningitis can cause serious morbidity in neonates. Further experimental models are warranted to investigate the clinical and genetic relevance of GBS meningitis. Specific GBS strains that likely cause meningitis requires further investigation and clinical attention.

Development a prediction model for identifying bacterial meningitis in young infants aged 29–90 days: a retrospective analysis

BackgroundThe early diagnosis and treatment of bacterial meningitis (BM) in young infants was very critical. But, it was difficult to make a definite diagnosis in the early stage due to nonspecific clinical symptoms. Our objectives were to find the risk factors associated with BM and develop a prediction model of BM especially for young infants.MethodsWe retrospectively reviewed the clinical data of young infants with meningitis between January 2011 and December 2020 in Children’s Hospital of Soochow University. The independent risk factors of young infants with BM were screened using univariate and multivariate logistic regression analyses. The independent risk factors were used to construct a new scoring model and compared with Bacterial Meningitis Score (BMS) and Meningitis Score for Emergencies (MSE) models.ResultsAmong the 102 young infants included, there were 44 cases of BM and 58 of aseptic meningitis. Group B Streptococcus (22, 50.0%) and Escherichia coli (14, 31.8%) were the main pathogens of BM in the young infants. Multivariate logistic regression analysis identified procalcitonin (PCT), cerebrospinal fluid (CSF) glucose, CSF protein as independent risk factors for young infants with BM. We assigned one point for CSF glucose ≤ 1.86 mmol/L, two points were assigned for PCT ≥ 3.80 ng/ml and CSF protein ≥ 1269 mg/L. Using the not low risk criterion (score ≥ 1) with our new prediction model, we identified the young infantile BM with 100% (95% CI 91.9%-100%) sensitivity and 60.3% (95% CI 46.4%-72.9%) specificity. Compared with BMS and MSE model, our prediction model had larger area under receiver operating characteristic curve and higher specificity, the differences were statistically significant.ConclusionOur new scoring model for young infants can facilitate early identification of BM and has a better performance than BMS and MSE models.

Salmonella typhimurium : A Rare Pathogen of Bacterial Meningitis in Infants, Not Associated With Household Contacts?

Salmonella typhimurium : A Rare Pathogen of Bacterial Meningitis in Infants, Not Associated With Household Contacts?

Characteristics and risk factors of bacterial meningitis caused by Streptococcus agalactiae, Streptococcus pneumoniae or Escherichia coli in Guangzhou China from 2015 to 2022.

Bacterial meningitis (BM) is an infectious disease with high morbidity and mortality rates in children. Although vaccination has improved prevention of BM, this severe disease continues to cause considerable harm to children across the globe. Several risk factors have been identified for BM, including immune status, age, and sex. However, additional patient and disease information is required in order to better understand the local characteristics, epidemiology and risk factors of BM. Here, we collected information from 252 children with BM in the Guangzhou Women and Children Medical Centre medical record database infected with Streptococcus agalactiae, Streptococcus pneumoniae, or Escherichia coli between May 2015 and May 2022. The three pathogen infected BM cased showed distinct trends during the period, and distribution of three BM pathogens across age groups varied significantly. We reviewed the antimicrobial resistance patterns for each of the pathogens which may direct drug use in BM. Finally, we found blood WBC was a protective factor, while glucose levels in the CFS was risk factor, for the length of hospitalization. Collectively, this study provides multi-parameter characteristics of BM, and potentially guide the drug use.

Brain abscess with Ureaplasma parvum in a patient with granulomatosis with polyangiitis

PurposeUreaplasma species are associated with urogenital infections, infertility and adverse pregnancy outcomes as well as neonatal infections. Involvement of the central nervous system in adults is extremely rare. We report an unusual case of a brain abscess secondary to otitis media with Ureaplasma parvum in a patient with granulomatosis with polyangiitis (GPA).MethodsImaging and laboratory findings, treatment decisions, and outcome of this case are explicated.ResultsA young adult with GPA presented with progredient earache after ambulant diagnosis of otitis media. Despite different courses of broad-spectrum antibiotic therapy, she developed meningoencephalitis due to mastoiditis following temporal abscess formation. Mastoidectomy and neurosurgical abscess removal were performed. Standard cultures of cerebrospinal fluid, blood and intracranial abscess material, as well as polymerase chain reaction (PCR) for common bacterial and viral meningitis pathogens remained negative. Only eubacterial PCR of intracranial abscess material returned positive for Ureaplasma parvum. The patient finally improved under antibiotic therapy with moxifloxacin and doxycycline.ConclusionUreaplasma species are rare causative pathogens in immunocompromised patients. They should be considered in patients with humoral immunodeficiencies with culture-negative infections failing standard therapy. Eubacterial PCR should be performed in early states of infection in these patients for immediate diagnosis and initiation of appropriate treatment to prevent adverse outcomes.

Changes in pathogens of neonatal bacterial meningitis over the past 12 years: a single-center retrospective study.

Bacterial meningitis is a serious central nervous system infection associated with high morbidity and mortality during the neonatal period, while the pathogen distribution was rarely reported on a large scale in China. This study aimed to investigate the distribution and change trends of neonatal bacterial meningitis pathogens in Children's Hospital of Fudan University over the past 12 years. This retrospective study included all cases diagnosed with neonatal bacterial meningitis and admitted to our hospital from 2009 to 2020. Totally 231 cases were enrolled, including 128 (55.4%) for male, 72 (31.2%) for premature infants, 48 (20.8%) for early-onset meningitis. The most common pathogens were Escherichia coli (E. coli) (39.0%) and Group B Streptococcus (GBS) (22.1%). Gram-negative bacteria were more common in preterm infants than in full-term infants (P=0.005). GBS was more common in term infants (P=0.000); Klebsiella pneumoniae (P=0.000) and Enterobacter cloacae (P=0.034) were more common in preterm infants. Gram-positive bacteria were more frequent in early-onset meningitis than in late-onset meningitis (P=0.002). Both E. coli (46.3% vs. 30.9%, P=0.017) and GBS (29.8% vs. 13.6%, P=0.003) increased, and Enterococcus (3.3% vs. 12.7%, P=0.008) decreased significantly in the epoch from 2015 to 2020 compared with the epoch from 2009 to 2014. GBS and E. coli are the most common pathogens of neonatal bacterial meningitis in our hospital, and both have shown an upward trend over the past 12 years.

Pneumococcal meningitis and COVID-19: dangerous coexistence. A case report

BackgroundSARS-CoV-2 is the major cause of infections in humans since December 2019 and is top of the global health concern currently. Streptococcus pneumoniae is one of the leading pathogens of invasive bacterial diseases, including pneumonia, sepsis, and meningitis. Moreover, this bacteria is mostly responsible for secondary infections subsequent to post-viral respiratory disease. Co-infections with bacterial and viral pathogens are associated with severe course of the disease and are a major cause of mortality. In this report, we describe a rare case of COVID-19 patient with pneumococcal sepsis and meningitis of unsuccessful course.Case presentationA 89-year-old man, not vaccinated against SARS-CoV-2 infection, was diagnosed with COVID-19 pneumonia. Patient required oxygen therapy due to respiratory failure. The initial treatment of viral infection with tocilizumab and dexamethasone allowed for the stabilization of the patient’s condition and improvement of laboratory parameters. On the 9th day of hospitalization the patient’s condition deteriorated. Consciousness disorders and acute respiratory disorders requiring intubation and mechanical ventilation were observed. Brain computed tomography excluded intracranial bleeding. The Streptococcus pneumoniae sepsis with concomitant pneumoniae and meningitis was diagnosed based on microbiological culture of blood, bronchial wash, and cerebrospinal fluid examination. Despite targeted antibiotic therapy with ceftriaxone and multidisciplinary treatment, symptoms of multiple organ failure increased. On the 13th day of hospitalization, the patient died.ConclusionsCo-infections with bacterial pathogens appear to be not common among COVID-19 patients, but may cause a sudden deterioration of the general condition. Not only vascular neurological complications, but also meningitis should be always considered in patients with sudden disturbances of consciousness. Anti-inflammatory treatment with the combination of corticosteroids and tocilizumab (or tocilizumab alone) pose a severe risk for secondary lethal bacterial or fungal infections. Thus, treating a high-risk population (i.e. elderly and old patients) with these anti-inflammatory agents, require daily clinical assessment, regular monitoring of C-reactive protein and procalcitonin, as well as standard culture of blood, urine and sputum in order to detect concomitant infections, as rapidly as possible.

Short information: Bacterial meningitis in very low birthweight infants in Korea from 2013-2016.

Neonatal bacterial meningitis (BM) has an incidence of 0.2-0.4 per 1,000 births and a mortality rate of 20-25%. Data from the Korean Neonatal Network (KNN) were evaluated to study the incidence, mortality, and risk factors associated with BM in very-low-birthweight (VLBW; <1,500 g) infants. We analyzed KNN data from 2013-2016 collected from 70 neonatal units. The incidence of BM in VLBW infants was 40 out of 8,263 (0.5%). The 40 infants with BM had a mean gestational age of 27.1 ± 2.0 weeks and a mean birthweight of 1,036.8 ± 220.0 g. Mean age at diagnosis was 51.5 ± 38.3 days (range, 1-171). Infants with BM were divided into two groups: Group 1 (onset age ≤ 28 days) and Group 2 (onset age > 28 days). Coagulase-negative Staphylococcus (CONS) was the most common pathogen underlying meningitis in 11 of 40 cases (28%). BM co-occurred with bacteremia in 14 of 40) of cases (35%); bacteremia was significantly more common in Group 1 than Group 2 (P < 0.05). Seizure and intraventricular hemorrhage (≥grade 3) were significantly more prevalent in Group 2 than Group 1 (P < 0.05). The mortality rate of infants with BM was 4 out of 40 (10%), which was significantly lower than that of VLBW infants without BM (1,152/8,223, [14%]; P < 0.05). The incidence of BM in VLBW infants was high, but the mortality rate was low. CONS was the most common pathogen of BM in VLBW infants.

Antimicrobial Resistance Pattern of Bacterial Meningitis Among Patients in Quetta, Pakistan.

IntroductionBacterial meningitis (BM) is a lethal infectious disease that persists as a substantial cause of morbidity and mortality. The antimicrobial drug resistance in BM pathogens poses a major threat to the community while raising challenges for clinicians. For the first time, we elucidate the incidence rate of BM and its drug resistance among the population of Quetta, Balochistan.MethodsA cross-sectional study was conducted (from January 2018 to March 2021) among meningitis patients admitted to government hospitals in Quetta. The cerebrospinal fluid (CSF) specimen was collected and processed for microbiological and cytological analysis. Bacterial isolates were identified and confirmed using phylogenetic analysis of the 16S rRNA gene.ResultsWe found 35.9% (321/894) confirmed cases of BM among the population of Quetta, Balochistan. The identified bacterial isolates comprised Streptococcus pneumoniae 14.7% (130/894), Staphylococcus aureus 6.9% (61/894), Neisseria meningitidis 5.7% (51/894), Haemophilus influenzae 2.5% (22/894), Escherichia coli 4.5% (40/894), and Klebsiella pneumoniae 1.9% (17/894). A high percentage in male patients of 20.8% (186/894) was identified as compared to female patients of 15.1% (135/894). Extreme age groups such as infants (age range: 1 month to 1 year) and adults (age range: 61 years to 99 years) with low immunity were critically affected by BM. Clinical parameters such as abnormal CSF appearance, pH, and high WBCs in BM patients with endocarditis as the underlying disease were significantly at elevated risk of fatal outcome. 16S rRNA gene phylogenetic analysis confirmed the evolutionary similarity of isolated strains with prevailing pathogenic strains in Asia. Furthermore, age was identified as a significant risk factor for clinical outcomes.ConclusionThe majority of the identified BM patients belonged to rural areas with limited health-care facilities and paramedic staff. The high case fatality rate 11% demonstrates increased antibiotic resistance among BM isolates, thereby stimulating its devastation in underdeveloped regions. Timely detection and intensive treatment of BM may improve critical outcomes in patients.

Modeling Optimal Laboratory Testing Strategies for Bacterial Meningitis Surveillance in Africa.

Since 2010, the introduction of an effective serogroup A meningococcal conjugate vaccine has led to the near-elimination of invasive Neisseria meningitidis serogroup A disease in Africa’s meningitis belt. However, a significant burden of disease and epidemics due to other bacterial meningitis pathogens remain in the region. High-quality surveillance data with laboratory confirmation is important to monitor circulating bacterial meningitis pathogens and design appropriate interventions, but complete testing of all reported cases is often infeasible. Here, we use case-based surveillance data from 5 countries in the meningitis belt to determine how accurately estimates of the distribution of causative pathogens would represent the true distribution under different laboratory testing strategies. Detailed case-based surveillance data was collected by the MenAfriNet surveillance consortium in up to 3 seasons from participating districts in 5 countries. For each unique country-season pair, we simulated the accuracy of laboratory surveillance by repeatedly drawing subsets of tested cases and calculating the margin of error of the estimated proportion of cases caused by each pathogen (the greatest pathogen-specific absolute error in proportions between the subset and the full set of cases). Across the 12 country-season pairs analyzed, the 95% credible intervals around estimates of the proportion of cases caused by each pathogen had median widths of ±0.13, ±0.07, and ±0.05, respectively, when random samples of 25%, 50%, and 75% of cases were selected for testing. The level of geographic stratification in the sampling process did not meaningfully affect accuracy estimates. These findings can inform testing thresholds for laboratory surveillance programs in the meningitis belt.

Molecular diagnostic assays for the detection of common bacterial meningitis pathogens: A narrative review.

Bacterial meningitis is a major global cause of morbidity and mortality. Rapid identification of the aetiological agent of meningitis is essential for clinical and public health management and disease prevention given the wide range of pathogens that cause the clinical syndrome and the availability of vaccines that protect against some, but not all, of these. Since microbiological culture is complex, slow, and often impacted by prior antimicrobial treatment of the patient, molecular diagnostic assays have been developed for bacterial detection. Distinguishing between meningitis caused by Neisseria meningitidis (meningococcus), Streptococcus pneumoniae (pneumococcus), Haemophilus influenzae, and Streptococcus agalactiae and identifying their polysaccharide capsules is especially important. Here, we review methods used in the identification of these bacteria, providing an up-to-date account of available assays, allowing clinicians and diagnostic laboratories to make informed decisions about which assays to use.

The search for novel treatment strategies for Streptococcus pneumoniae infections.

ABSTRACTThis review provides an overview of the most important novel treatment strategies against Streptococcus pneumoniae infections published over the past 10 years. The pneumococcus causes the majority of community-acquired bacterial pneumonia cases, and it is one of the prime pathogens in bacterial meningitis. Over the last 10 years, extensive research has been conducted to prevent severe pneumococcal infections, with a major focus on (i) boosting the host immune system and (ii) discovering novel antibacterials. Boosting the immune system can be done in two ways, either by actively modulating host immunity, mostly through administration of selective antibodies, or by interfering with pneumococcal virulence factors, thereby supporting the host immune system to effectively overcome an infection. While several of such experimental therapies are promising, few have evolved to clinical trials. The discovery of novel antibacterials is hampered by the high research and development costs versus the relatively low revenues for the pharmaceutical industry. Nevertheless, novel enzymatic assays and target-based drug design, allow the identification of targets and the development of novel molecules to effectively treat this life-threatening pathogen.

A systematic literature review on the prevalence and etiology of meningitis among critically ill and hospitalized patients in India.

Background:In India, owing to multiple factors, such as insufficient laboratory capacity, poor reporting systems due to limited access to healthcare facilities and limited disease surveillance programmes, the actual disease burden of meningitis is unknown and may be largely under-reported.Objective:A systematic literature review was performed to describe: (a) the prevalence of meningitis; and (b) its etiological pathogen across different regions, age groups and patients with comorbidities.Method:A systematic literature search was conducted between 1990 and 2020 using PubMed and Google Scholar databases to identify Indian studies reporting the prevalence rates and etiology of meningitis. A total of 51 studies were included in the final analysis.Results:A total of 38 studies reported prevalence of meningitis and 21 studies reported data on the etiology of meningitis in India. These studies included mixed patient populations: (a) pyogenic meningitis; (b) meningitis in sick or hospitalized patients with tuberculosis, acute febrile encephalopathy syndrome, septicaemia, invasive pneumococcal disease or respiratory compromise; and (c) meningitis patients with comorbidities. The prevalence of confirmed bacterial meningitis in the pediatric population (0–14 years) ranged between 0.5% and 61.8%. A total of seven studies reported the prevalence of meningitis in patients of all age groups (0–75 years), with prevalence ranging between 8.68% and 78.85%. Cryptococcal meningitis was predominant in patients with positive HIV/AIDS, with a prevalence ranging between 2.09% and 53.1%. Streptococcus pneumoniae was found to be the predominant pathogen causing meningitis across different regions of India, with a frequency ranging from 4% to 61.8% in patients of all age groups.Conclusion:This systematic literature review displayed the possible range of frequency of bacterial meningitis pathogens across a wide variety of age groups in different regions of India. Further studies are warranted to monitor meningitis cases, which may facilitate the development of prevention and treatment strategies in India.

Web-Based Genome Analysis of Bacterial Meningitis Pathogens for Public Health Applications Using the Bacterial Meningitis Genomic Analysis Platform (BMGAP).

Effective laboratory-based surveillance and public health response to bacterial meningitis depends on timely characterization of bacterial meningitis pathogens. Traditionally, characterizing bacterial meningitis pathogens such as Neisseria meningitidis (Nm) and Haemophilus influenzae (Hi) required several biochemical and molecular tests. Whole genome sequencing (WGS) has enabled the development of pipelines capable of characterizing the given pathogen with equivalent results to many of the traditional tests. Here, we present the Bacterial Meningitis Genomic Analysis Platform (BMGAP): a secure, web-accessible informatics platform that facilitates automated analysis of WGS data in public health laboratories. BMGAP is a pipeline comprised of several components, including both widely used, open-source third-party software and customized analysis modules for the specific target pathogens. BMGAP performs de novo draft genome assembly and identifies the bacterial species by whole-genome comparisons against a curated reference collection of 17 focal species including Nm, Hi, and other closely related species. Genomes identified as Nm or Hi undergo multi-locus sequence typing (MLST) and capsule characterization. Further typing information is captured from Nm genomes, such as peptides for the vaccine antigens FHbp, NadA, and NhbA. Assembled genomes are retained in the BMGAP database, serving as a repository for genomic comparisons. BMGAP’s species identification and capsule characterization modules were validated using PCR and slide agglutination from 446 bacterial invasive isolates (273 Nm from nine different serogroups, 150 Hi from seven different serotypes, and 23 from nine other species) collected from 2017 to 2019 through surveillance programs. Among the validation isolates, BMGAP correctly identified the species for all 440 isolates (100% sensitivity and specificity) and accurately characterized all Nm serogroups (99% sensitivity and 98% specificity) and Hi serotypes (100% sensitivity and specificity). BMGAP provides an automated, multi-species analysis pipeline that can be extended to include additional analysis modules as needed. This provides easy-to-interpret and validated Nm and Hi genome analysis capacity to public health laboratories and collaborators. As the BMGAP database accumulates more genomic data, it grows as a valuable resource for rapid comparative genomic analyses during outbreak investigations.

The global meningitis genome partnership

Genomic surveillance of bacterial meningitis pathogens is essential for effective disease control globally, enabling identification of emerging and expanding strains and consequent public health interventions. While there has been a rise in the use of whole genome sequencing, this has been driven predominately by a subset of countries with adequate capacity and resources. Global capacity to participate in surveillance needs to be expanded, particularly in low and middle-income countries with high disease burdens. In light of this, the WHO-led collaboration, Defeating Meningitis by 2030 Global Roadmap, has called for the establishment of a Global Meningitis Genome Partnership that links resources for: N. meningitidis (Nm), S. pneumoniae (Sp), H. influenzae (Hi) and S. agalactiae (Sa) to improve worldwide co-ordination of strain identification and tracking. Existing platforms containing relevant genomes include: PubMLST: Nm (31,622), Sp (15,132), Hi (1935), Sa (9026); The Wellcome Sanger Institute: Nm (13,711), Sp (>24,000), Sa (6200), Hi (1738); and BMGAP: Nm (8785), Hi (2030). A steering group is being established to coordinate the initiative and encourage high-quality data curation. Next steps include: developing guidelines on open-access sharing of genomic data; defining a core set of metadata; and facilitating development of user-friendly interfaces that represent publicly available data.

Herbominerals and Antibacterial Activities of Allium sativum L Extracts on Pathogenic Bacteria Causing Meningitis in Sub-Saharan Africa, Zaria, Kaduna State, Nigeria

Bacterial Meningitis (BM) is the most common serious infection of the central nervous system (brain and spinal cord). This research aims to determine the mineral composition and to evaluate the in vitro antibacterial activity of the Juice Extract of Allium Sativum, Ethanolic Extract of Allium Sativum and Aqueous Extract of Allium sativum (JEAS, EEAS and AEAS). The collected bulbs of A. sativum (600 g) were washed and air dried under shade for 2 hours and the dry scaly outer covering was peeled-off to obtain the fresh garlic cloves which were then divided into three parts of 200 g each. These three portions were crushed separately for cold extraction. The first portion was homogenized and poured into a muslin cloth to squeeze out the juice, while second and third portions were homogenized and submerged into 500 ml of 96% ethanol and 500 ml of distilled water respectively for 24 hours and both filtered after thorough shaking. The antibacterial activity of bulbs of A. sativum juice, ethanolic and aqueous (JEAS, EEAS and AEAS) extracts as folkloric medicine against clinical isolates were determined using Agar well diffusion and broth dilution method. Distilled water, concentrated nitric acid (HNO3) and hydrochloric acid (HCl) were used to digest the extract, which was then heated in water bath at 90ºC and filtered to obtain the filtrate for the analytical studies for A. sativum nutritional composition and zeolite herbominerals. The micro-herbominerals with their proximate values observed pharmacologic of Silver, Manganese, Zinc, Iron and Selenium; which has biocidal properties as well as immune system to cushioning the challenges of the BM pathogens. The minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and phytochemical screening of the extracts were evaluated. The results obtained showed that the juice and ethanolic extracts were potent, inhibiting the growth of clinical isolates with zone of inhibition ranging from 14-36 mm. The extracts inhibited bacterial isolates in concentration dependant manner with MICs ranging 0.02-15 mg/ml and MBCs 0.04-5 mg/ml. Phytochemical screening of the extracts revealed the presence of alkaloids, flavonoids, anthraquinone, carbohydrates, fats and oils, steroidal ring, saponins and terpenoids. This experimental investigation has provided the scientific validation basis for the ethnomedical use of A. sativum as a remedy to treat bacterial meningitis locally as anti-infectious agent.

Implementation of Case-Based Surveillance and Real-time Polymerase Chain Reaction to Monitor Bacterial Meningitis Pathogens in Chad.

BackgroundMeningococcal serogroup A conjugate vaccine (MACV) was introduced in Chad during 2011–2012. Meningitis surveillance has been conducted nationwide since 2003, with case-based surveillance (CBS) in select districts from 2012. In 2016, the MenAfriNet consortium supported Chad to implement CBS in 4 additional districts and real-time polymerase chain reaction (rt-PCR) at the national reference laboratory (NRL) to improve pathogen detection. We describe analysis of bacterial meningitis cases during 3 periods: pre-MACV (2010–2012), pre-MenAfriNet (2013–2015), and post-MenAfriNet (2016–2018).MethodsNational surveillance targeted meningitis cases caused by Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae. Cerebrospinal fluid specimens, inoculated trans-isolate media, and/or isolates from suspected meningitis cases were tested via culture, latex, and/or rt-PCR; confirmed bacterial meningitis was defined by a positive result on any test. We calculated proportion of suspected cases with a specimen received by period, and proportion of specimens with a bacterial meningitis pathogen identified, by period, pathogen, and test.ResultsThe NRL received specimens for 6.8% (876/12813), 46.4% (316/681), and 79.1% (787/995) of suspected meningitis cases in 2010–2012, 2013–2015, and 2016–2018, respectively, with a bacterial meningitis pathogen detected in 33.6% (294/876), 27.8% (88/316), and 33.2% (261/787) of tested specimens. The number of N. meningitidis serogroup A (NmA) among confirmed bacterial meningitis cases decreased from 254 (86.4%) during 2010–2012 to 2 (2.3%) during 2013–2015, with zero NmA cases detected after 2014. In contrast, proportional and absolute increases were seen between 2010–2012, 2013–2015, and 2016–2018 in cases caused by S. pneumoniae (5.1% [15/294], 65.9% [58/88], and 52.1% [136/261]), NmX (0.7% [2/294], 1.1% [1/88], and 22.2% [58/261]), and Hib (0.3% [1/294], 11.4% [10/88], and 14.9% [39/261]). Of specimens received at the NRL, proportions tested during the 3 periods were 47.7% (418), 53.2% (168), and 9.0% (71) by latex; 81.4% (713), 98.4% (311), and 93.9% (739) by culture; and 0.0% (0), 0.0% (0), and 90.5% (712) by rt-PCR, respectively. During the post-MenAfriNet period (2016–2018), 86.1% (678) of confirmed cases were tested by both culture and rt-PCR, with 12.5% (85) and 32.4% (220) positive by culture and rt-PCR, respectively.ConclusionsCBS implementation was associated with increased specimen referral. Increased detection of non-NmA cases could reflect changes in incidence or increased sensitivity of case detection with rt-PCR. Continued surveillance with the use of rt-PCR to monitor changing epidemiology could inform the development of effective vaccination strategies.

A New Sequence Type of Neisseria meningitidis Serogroup C Associated With a 2016 Meningitis Outbreak in Mali.

In 2016, Mali reported a bacterial meningitis outbreak consisting of 39 suspected cases between epidemiologic weeks 9 and 17 with 15% case fatality ratio in the health district of Ouéléssebougou, 80 kilometers from the capital Bamako. Cerebrospinal fluid specimens from 29 cases were tested by culture and real-time polymerase chain reaction; 22 (76%) were positive for bacterial meningitis pathogens, 16 (73%) of which were Neisseria meningitidis (Nm). Of the Nm-positive specimens, 14 (88%) were N meningitidis serogroup C (NmC), 1 was NmW, and 1 was nongroupable. Eight NmC isolates recovered by culture from the outbreak were characterized using whole genome sequencing. Genomics analysis revealed that all 8 isolates belonged to a new sequence type (ST) 12446 of clonal complex 10217 that formed a distinct clade genetically similar to ST-10217, a NmC strain that recently caused large epidemics of meningitis in Niger and Nigeria. The emergence of a new ST of NmC associated with an outbreak in the African meningitis belt further highlights the need for continued molecular surveillance in the region.

Toward a Global Genomic Epidemiology of Meningococcal Disease.

Whole-genome sequencing (WGS) is invaluable for studying the epidemiology of meningococcal disease. Here we provide a perspective on the use of WGS for meningococcal molecular surveillance and outbreak investigation, where it helps to characterize pathogens, predict pathogen traits, identify emerging pathogens, and investigate pathogen transmission during outbreaks. Standardization of WGS workflows has facilitated their implementation by clinical and public health laboratories (PHLs), but further development is required for metagenomic shotgun sequencing and targeted sequencing to be widely available for culture-free characterization of bacterial meningitis pathogens. Internet-accessible servers are being established to support bioinformatics analysis, data management, and data sharing among PHLs. However, establishing WGS capacity requires investments in laboratory infrastructure and technical knowledge, which is particularly challenging in resource-limited regions, including the African meningitis belt. Strategic WGS implementation is necessary to monitor the molecular epidemiology of meningococcal disease in these regions and construct a global view of meningococcal disease epidemiology.