ABSTRACT
Previous studies have shown the sugarcane microbiome harbors diverse plant growth promoting microorganisms, including nitrogen-fixing bacteria (diazotrophs), which can serve as biofertilizers. The genomes of 22 diazotrophs from Colombian sugarcane fields were sequenced to investigate potential biofertilizers. A genome-enabled computational phenotyping approach was developed to prioritize sugarcane associated diazotrophs according to their potential as biofertilizers. This method selects isolates that have potential for nitrogen fixation and other plant growth promoting (PGP) phenotypes while showing low risk for virulence and antibiotic resistance. Intact nitrogenase (nif) genes and operons were found in 18 of the isolates. Isolates also encode phosphate solubilization and siderophore production operons, and other PGP genes. The majority of sugarcane isolates showed uniformly low predicted virulence and antibiotic resistance compared to clinical isolates. Six strains with the highest overall genotype scores were experimentally evaluated for nitrogen fixation, phosphate solubilization, and the production of siderophores, gibberellic acid, and indole acetic acid. Results from the biochemical assays were consistent and validated computational phenotype predictions. A genotypic and phenotypic threshold was observed that separated strains by their potential for PGP versus predicted pathogenicity. Our results indicate that computational phenotyping is a promising tool for the assessment of bacteria detected in agricultural ecosystems.
Subject(s)
Bacterial Proteins/genetics , Genome, Bacterial , Nitrogen-Fixing Bacteria/physiology , Saccharum/microbiology , Agriculture , Drug Resistance, Bacterial/drug effects , Drug Resistance, Bacterial/genetics , Genomics/methods , Klebsiella/genetics , Klebsiella/isolation & purification , Nitrogen-Fixing Bacteria/drug effects , Nitrogen-Fixing Bacteria/genetics , Nitrogen-Fixing Bacteria/isolation & purification , Oxidoreductases/genetics , Rhizosphere , Soil Microbiology , Virulence Factors/geneticsABSTRACT
Laboratories play critical roles in bacterial meningitis disease surveillance in the African meningitis belt, where the highest global burden of meningitis exists. Reinforcement of laboratory capacity ensures rapid detection of meningitis cases and outbreaks and a public health response that is timely, specific, and appropriate. Since 2008, joint efforts to strengthen laboratory capacity by multiple partners, including MenAfriNet, beginning in 2014, have been made in countries within and beyond the meningitis belt. Over the course of 10 years, national reference laboratories were supported in 5 strategically targeted areas: specimen transport systems, laboratory procurement systems, laboratory diagnosis, quality management, and laboratory workforce with substantial gains made in each of these areas. To support the initiative to eliminate meningitis by 2030, continued efforts are needed to strengthen laboratory systems.
Subject(s)
Clinical Laboratory Techniques , Laboratories , Meningitis, Bacterial/epidemiology , Africa South of the Sahara/epidemiology , Clinical Laboratory Techniques/methods , Clinical Laboratory Techniques/standards , Disease Outbreaks , Health Workforce , History, 21st Century , Humans , Laboratories/organization & administration , Laboratories/supply & distribution , Meningitis, Bacterial/diagnosis , Meningitis, Bacterial/history , Meningitis, Bacterial/microbiology , Population Surveillance , Quality of Health CareABSTRACT
Improved methods for the detection and characterization of carried Neisseria meningitidis isolates are needed. We evaluated a multiplex PCR algorithm for the detection of a variety of carriage strains in the meningitis belt. To further improve the sensitivity and specificity of the existing PCR assays, primers for gel-based PCR assays (sodC, H, Z) and primers/probe for real-time quantitative PCR (qPCR) assays (porA, cnl, sodC, H, E, Z) were modified or created using Primer Express software. Optimized multiplex PCR assays were tested on 247 well-characterised carriage isolates from six countries of the African meningitis belt. The PCR algorithm developed enabled the detection of N. meningitidis species using gel-based and real-time multiplex PCR targeting porA, sodC, cnl and characterization of capsule genes through sequential multiplex PCR assays for genogroups (A, W, X, then B, C, Y and finally H, E and Z). Targeting both porA and sodC genes together allowed the detection of meningococci with a sensitivity of 96% and 89% and a specificity of 78% and 67%, for qPCR and gel-based PCR respectively. The sensitivity and specificity ranges for capsular genogrouping of N. meningitidis are 67% - 100% and 98%-100% respectively for gel-based PCR and 90%-100% and 99%-100% for qPCR. We developed a PCR algorithm that allows simple, rapid and systematic detection and characterisation of most major and minor N. meningitidis capsular groups, including uncommon capsular groups (H, E, Z).
Subject(s)
Algorithms , Meningitis, Meningococcal , Multiplex Polymerase Chain Reaction/methods , Neisseria meningitidis/genetics , Porins/genetics , Superoxide Dismutase/genetics , Female , Humans , Male , Mali/epidemiology , Meningitis, Meningococcal/diagnosis , Meningitis, Meningococcal/epidemiology , Meningitis, Meningococcal/genetics , Neisseria meningitidis/isolation & purification , Sensitivity and SpecificityABSTRACT
Members of the Klebsiella genus promote plant growth. We report here draft whole-genome sequences for 15 Klebsiella sp. isolates from sugarcane fields in the Cauca Valley of Colombia. The genomes of these isolates were characterized as part of a broader effort to evaluate their utility as endemic plant growth-promoting biofertilizers.
ABSTRACT
Bivalent rLP2086 (Trumenba), a vaccine for prevention of Neisseria meningitidis serogroup B (NmB) disease, was licensed for use in adolescents and young adults after it was demonstrated that it elicits antibodies that initiate complement-mediated killing of invasive NmB isolates in a serum bactericidal assay with human complement (hSBA). The vaccine consists of two factor H binding proteins (fHBPs) representing divergent subfamilies to ensure broad coverage. Although it is the surrogate of efficacy, an hSBA is not suitable for testing large numbers of strains in local laboratories. Previously, an association between the in vitro fHBP surface expression level and the susceptibility of NmB isolates to killing was observed. Therefore, a flow cytometric meningococcal antigen surface expression (MEASURE) assay was developed and validated by using an antibody that binds to all fHBP variants from both fHBP subfamilies and accurately quantitates the level of fHBP expressed on the cell surface of NmB isolates with mean fluorescence intensity as the readout. Two collections of invasive NmB isolates (n = 1,814, n = 109) were evaluated in the assay, with the smaller set also tested in hSBAs using individual and pooled human serum samples from young adults vaccinated with bivalent rLP2086. From these data, an analysis based on fHBP variant prevalence in the larger 1,814-isolate set showed that >91% of all meningococcal serogroup B isolates expressed sufficient levels of fHBP to be susceptible to bactericidal killing by vaccine-induced antibodies.IMPORTANCE Bivalent rLP2086 (Trumenba) vaccine, composed of two factor H binding proteins (fHBPs), was recently licensed for the prevention of N. meningitidis serogroup B (NmB) disease in individuals 10 to 25 years old in the United States. This study evaluated a large collection of NmB isolates from the United States and Europe by using a flow cytometric MEASURE assay to quantitate the surface expression of the vaccine antigen fHBP. We find that expression levels and the proportion of strains above the level associated with susceptibility in an hSBA are generally consistent across these geographic regions. Thus, the assay can be used to predict which NmB isolates are susceptible to killing in the hSBA and therefore is able to demonstrate an fHBP vaccine-induced bactericidal response. This work significantly advances our understanding of the potential for bivalent rLP2086 to provide broad coverage against diverse invasive-disease-causing NmB isolates.
Subject(s)
Anti-Bacterial Agents/pharmacology , Antibodies, Bacterial/pharmacology , Antigens, Bacterial/analysis , Bacterial Proteins/analysis , Meningococcal Vaccines/immunology , Microbial Viability/drug effects , Neisseria meningitidis, Serogroup B/drug effects , Neisseria meningitidis, Serogroup B/physiology , Blood Bactericidal Activity , Flow Cytometry/methods , Humans , Neisseria meningitidis, Serogroup B/chemistry , Neisseria meningitidis, Serogroup B/isolation & purificationABSTRACT
In 2009, in the Active Bacterial Core surveillance sites, penicillin was not commonly used to treat meningococcal disease. This is likely because of inconsistent availability of antimicrobial susceptibility testing and ease of use of third-generation cephalosporins. Consideration of current practices may inform future meningococcal disease management guidelines.
ABSTRACT
Haemophilus haemolyticus has been recently discovered to have the potential to cause invasive disease. It is closely related to nontypeable Haemophilus influenzae (NT H. influenzae). NT H. influenzae and H. haemolyticus are often misidentified because none of the existing tests targeting the known phenotypes of H. haemolyticus are able to specifically identify H. haemolyticus Through comparative genomic analysis of H. haemolyticus and NT H. influenzae, we identified genes unique to H. haemolyticus that can be used as targets for the identification of H. haemolyticus A real-time PCR targeting purT (encoding phosphoribosylglycinamide formyltransferase 2 in the purine synthesis pathway) was developed and evaluated. The lower limit of detection was 40 genomes/PCR; the sensitivity and specificity in detecting H. haemolyticus were 98.9% and 97%, respectively. To improve the discrimination of H. haemolyticus and NT H. influenzae, a testing scheme combining two targets (H. haemolyticus purT and H. influenzae hpd, encoding protein D lipoprotein) was also evaluated and showed 96.7% sensitivity and 98.2% specificity for the identification of H. haemolyticus and 92.8% sensitivity and 100% specificity for the identification of H. influenzae, respectively. The dual-target testing scheme can be used for the diagnosis and surveillance of infection and disease caused by H. haemolyticus and NT H. influenzae.
Subject(s)
Comparative Genomic Hybridization/methods , Haemophilus Infections/diagnosis , Haemophilus influenzae/classification , Haemophilus influenzae/genetics , Lipoproteins/genetics , Phosphoribosylglycinamide Formyltransferase/genetics , Base Sequence , DNA, Bacterial/genetics , Genome, Bacterial/genetics , Haemophilus Infections/microbiology , Haemophilus influenzae/isolation & purification , Humans , Limit of Detection , Real-Time Polymerase Chain Reaction/methods , Sensitivity and Specificity , Sequence Analysis, DNAABSTRACT
Neisseria meningitidis is an important cause of meningococcal disease globally. Sequence type (ST)-11 clonal complex (cc11) is a hypervirulent meningococcal lineage historically associated with serogroup C capsule and is believed to have acquired the W capsule through a C to W capsular switching event. We studied the sequence of capsule gene cluster (cps) and adjoining genomic regions of 524 invasive W cc11 strains isolated globally. We identified recombination breakpoints corresponding to two distinct recombination events within W cc11: A 8.4-kb recombinant region likely acquired from W cc22 including the sialic acid/glycosyl-transferase gene, csw resulted in a CâW change in capsular phenotype and a 13.7-kb recombinant segment likely acquired from Y cc23 lineage includes 4.5 kb of cps genes and 8.2 kb downstream of the cps cluster resulting in allelic changes in capsule translocation genes. A vast majority of W cc11 strains (497/524, 94.8%) retain both recombination events as evidenced by sharing identical or very closely related capsular allelic profiles. These data suggest that the W cc11 capsular switch involved two separate recombination events and that current global W cc11 meningococcal disease is caused by strains bearing this mosaic capsular switch.
Subject(s)
Meningococcal Infections/genetics , Neisseria meningitidis/genetics , Phylogeny , Recombination, Genetic , Genome, Bacterial , Genomics , Humans , Meningococcal Infections/microbiology , Multigene Family , Neisseria meningitidis/pathogenicity , SerogroupABSTRACT
Neisseria meningitidis (Nm), Haemophilus influenzae (Hi), and Streptococcus pneumoniae (Sp) are the lead causes of bacterial meningitis. Detection of these pathogens from clinical specimens using traditional real-time PCR (rt-PCR) requires DNA extraction to remove the PCR inhibitors prior to testing, which is time consuming and labor intensive. In this study, five species-specific (Nm-sodC and -ctrA, Hi-hpd#1 and -hpd#3 and Sp-lytA) and six serogroup-specific rt-PCR tests (A, B, C, W, X, Y) targeting Nm capsular genes were evaluated in the two direct rt-PCR methods using PerfeCTa and 5x Omni that do not require DNA extraction. The sensitivity and specify of the two direct rt-PCR methods were compared to TaqMan traditional rt-PCR, the current standard rt-PCR method for the detection of meningitis pathogens. The LLD for all 11 rt-PCR tests ranged from 6,227 to 272,229 CFU/ml for TaqMan, 1,824-135,982 for 5x Omni, and 168-6,836 CFU/ml for PerfeCTa. The diagnostic sensitivity using TaqMan ranged from 89.2%-99.6%, except for NmB-csb, which was 69.7%. For 5x Omni, the sensitivity varied from 67.1% to 99.8%, with three tests below 90%. The sensitivity of these tests using PerfeCTa varied from 89.4% to 99.8%. The specificity ranges of the 11 tests were 98.0-99.9%, 97.5-99.9%, and 92.9-99.9% for TaqMan, 5x Omni, and PerfeCTa, respectively. PerfeCTa direct rt-PCR demonstrated similar or better sensitivity compared to 5x Omni direct rt-PCR or TaqMan traditional rt-PCR. Since the direct rt-PCR method does not require DNA extraction, it reduces the time and cost for processing CSF specimens, increases testing throughput, decreases the risk of cross-contamination, and conserves precious CSF. The direct rt-PCR method will be beneficial to laboratories with high testing volume.
Subject(s)
DNA, Bacterial/isolation & purification , Meningitis, Bacterial/diagnosis , Real-Time Polymerase Chain Reaction/methods , Humans , Limit of Detection , Meningitis, Bacterial/cerebrospinal fluid , Sensitivity and SpecificityABSTRACT
Neisseria meningitidis serogroup B (MnB) is a leading cause of bacterial meningitis; however, MnB is most commonly associated with asymptomatic carriage in the nasopharyngeal cavity, as opposed to the disease state. Two vaccines are now licensed for the prevention of MnB disease; a possible additional benefit of these vaccines could be to protect against disease indirectly by disrupting nasopharyngeal carriage (e.g., herd protection). To investigate this possibility, accurate diagnostic approaches to characterize MnB carriage isolates are required. In contrast to invasive meningococcal disease (IMD) isolates, which can be readily serogrouped, carriage isolates often lack capsule expression, making standard phenotypic assays unsuitable for strain characterization. Several antibody-based methods were evaluated for their abilities to serogroup isolates and were compared with two genotyping methods (real-time PCR [rt-PCR] and whole-genome sequencing [WGS]) to identify which approach would most accurately ascertain the polysaccharide groups associated with carriage isolates. WGS and rt-PCR were in agreement for 99% of IMD isolates, including those with coding sequences for MnB, MnC, MnW, and MnY, and the phenotypic methods correctly identified serogroups for 69 to 98% of IMD isolates. In contrast, only 47% of carriage isolates were groupable by genotypic methods, due to mutations within the capsule operon; of the isolates identified by genotypic methods, ≤43% were serogroupable with any of the phenotypic methods tested. These observations highlight the difficulties in the serogrouping and capsular genogrouping of meningococcal carriage isolates. Based on our findings, WGS is the most suitable approach for the characterization of meningococcal carriage isolates.
Subject(s)
Bacterial Capsules/classification , Carrier State/microbiology , Genotyping Techniques/methods , Neisseria meningitidis/classification , Neisseriaceae Infections/microbiology , Serotyping/methods , Adolescent , Adult , Bacterial Capsules/genetics , Bacterial Capsules/immunology , Epidemiologic Studies , Female , Humans , Male , Neisseria meningitidis/genetics , Neisseria meningitidis/immunology , Young AdultABSTRACT
In this study, a multicenter evaluation of the Life Technologies TaqMan(®) Array Card (TAC) with 21 custom viral and bacterial respiratory assays was performed on the Applied Biosystems ViiA™ 7 Real-Time PCR System. The goal of the study was to demonstrate the analytical performance of this platform when compared to identical individual pathogen specific laboratory developed tests (LDTs) designed at the Centers for Disease Control and Prevention (CDC), equivalent LDTs provided by state public health laboratories, or to three different commercial multi-respiratory panels. CDC and Association of Public Health Laboratories (APHL) LDTs had similar analytical sensitivities for viral pathogens, while several of the bacterial pathogen APHL LDTs demonstrated sensitivities one log higher than the corresponding CDC LDT. When compared to CDC LDTs, TAC assays were generally one to two logs less sensitive depending on the site performing the analysis. Finally, TAC assays were generally more sensitive than their counterparts in three different commercial multi-respiratory panels. TAC technology allows users to spot customized assays and design TAC layout, simplify assay setup, conserve specimen, dramatically reduce contamination potential, and as demonstrated in this study, analyze multiple samples in parallel with good reproducibility between instruments and operators.
Subject(s)
Oligonucleotide Array Sequence Analysis/standards , Real-Time Polymerase Chain Reaction/methods , Real-Time Polymerase Chain Reaction/standards , Bacteria/genetics , Bacteria/isolation & purification , Centers for Disease Control and Prevention, U.S. , Humans , Microfluidics/methods , Microfluidics/standards , Real-Time Polymerase Chain Reaction/instrumentation , Reproducibility of Results , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/microbiology , Respiratory Tract Infections/virology , Sensitivity and Specificity , United States , Viruses/genetics , Viruses/isolation & purificationABSTRACT
Neisseria meningitidis is a leading bacterial cause of sepsis and meningitis globally with dynamic strain distribution over time. Beginning with an epidemic among Hajj pilgrims in 2000, serogroup W (W) sequence type (ST) 11 emerged as a leading cause of epidemic meningitis in the African 'meningitis belt' and endemic cases in South America, Europe, Middle East and China. Previous genotyping studies were unable to reliably discriminate sporadic W ST-11 strains in circulation since 1970 from the Hajj outbreak strain (Hajj clone). It is also unclear what proportion of more recent W ST-11 disease clusters are caused by direct descendants of the Hajj clone. Whole genome sequences of 270 meningococcal strains isolated from patients with invasive meningococcal disease globally from 1970 to 2013 were compared using whole genome phylogenetic and major antigen-encoding gene sequence analyses. We found that all W ST-11 strains were descendants of an ancestral strain that had undergone unique capsular switching events. The Hajj clone and its descendants were distinct from other W ST-11 strains in that they shared a common antigen gene profile and had undergone recombination involving virulence genes encoding factor H binding protein, nitric oxide reductase, and nitrite reductase. These data demonstrate that recent acquisition of a distinct antigen-encoding gene profile and variations in meningococcal virulence genes was associated with the emergence of the Hajj clone. Importantly, W ST-11 strains unrelated to the Hajj outbreak contribute a significant proportion of W ST-11 cases globally. This study helps illuminate genomic factors associated with meningococcal strain emergence and evolution.
Subject(s)
Genome, Viral , Genomics , Meningitis, Meningococcal/epidemiology , Meningitis, Meningococcal/microbiology , Neisseria meningitidis/genetics , Neisseria meningitidis/pathogenicity , Antigens, Bacterial/genetics , Computational Biology/methods , Disease Outbreaks , Genes, Bacterial , Genotype , High-Throughput Nucleotide Sequencing , Humans , Molecular Sequence Annotation , Neisseria meningitidis/classification , Neisseria meningitidis/isolation & purification , Open Reading Frames , Phylogeny , Polymorphism, Single Nucleotide , Serogroup , Virulence/geneticsABSTRACT
BACKGROUND: During the first introduction of a group A meningococcal vaccine (PsA-TT) in 2010-2011 and its rollout from 2011 to 2013, >150 million eligible people, representing 12 hyperendemic meningitis countries, have been vaccinated. METHODS: The new vaccine effectiveness evaluation framework was established by the World Health Organization and partners. Meningitis case-based surveillance was strengthened in PsA-TT first-introducer countries, and several evaluation studies were conducted to estimate the vaccination coverage and to measure the impact of vaccine introduction on meningococcal carriage and disease incidence. RESULTS: PsA-TT implementation achieved high vaccination coverage, and results from studies conducted showed significant decrease of disease incidence as well as significant reduction of oropharyngeal carriage of group A meningococci in vaccinated and unvaccinated individuals, demonstrating the vaccine's ability to generate herd protection and prevent group A epidemics. CONCLUSIONS: Lessons learned from this experience provide useful insights in how to guide and better prepare for future new vaccine introductions in resource-limited settings.
Subject(s)
Carrier State/epidemiology , Carrier State/prevention & control , Disease Transmission, Infectious/prevention & control , Meningococcal Infections/epidemiology , Meningococcal Infections/prevention & control , Meningococcal Vaccines/administration & dosage , Meningococcal Vaccines/immunology , Adolescent , Adult , Africa/epidemiology , Child , Child, Preschool , Female , Humans , Incidence , Infant , Male , Treatment Outcome , Young AdultABSTRACT
Background. Antimicrobial treatment and chemoprophylaxis of patients and their close contacts is critical to reduce the morbidity and mortality and prevent secondary cases of meningococcal disease. Through the 1990's, the prevalence of antimicrobial resistance to commonly used antimicrobials among Neisseria meningitidis was low in the United States. Susceptibility testing was performed to ascertain whether the proportions of isolates with reduced susceptibility to antimicrobials commonly used for N meningitidis have increased since 2004 in the United States. Methods. Antimicrobial susceptibility testing was performed by broth microdilution on 466 isolates of N meningitidis collected in 2004, 2008, 2010, and 2011 from an active, population-based surveillance system for susceptibility to ceftriaxone, ciprofloxacin, penicillin G, rifampin, and azithromycin. The molecular mechanism of reduced susceptibility was investigated for isolates with intermediate or resistant phenotypes. Results. All isolates were susceptible to ceftriaxone and azithromycin, 10.3% were penicillin G intermediate (range, 8% in 2008-16.7% in 2010), and <1% were ciprofloxacin, rifampin, or penicillin G resistant. Of the penicillin G intermediate or resistant isolates, 63% contained mutations in the penA gene associated with reduced susceptibility to penicillin G. All ciprofloxacin-resistant isolates contained mutations in the gyrA gene associated with reduced susceptibility. Conclusions. Resistance of N meningitidis to antimicrobials used for empirical treatment of meningitis in the United States has not been detected, and resistance to penicillin G and chemoprophylaxis agents remains uncommon. Therapeutic agent recommendations remain valid. Although periodic surveillance is warranted to monitor trends in susceptibility, routine clinical testing may be of little use.
ABSTRACT
BACKGROUND: Surveillance for acute flaccid paralysis with laboratory confirmation has been a key strategy in the global polio eradication initiative, and the laboratory platform established for polio testing has been expanded in many countries to include surveillance for cases of febrile rash illness to identify measles and rubella cases. Vaccine-preventable disease surveillance is essential to detect outbreaks, define disease burden, guide vaccination strategies and assess immunization impact. Vaccines now exist to prevent Japanese encephalitis (JE) and some etiologies of bacterial meningitis. METHODS: We evaluated the feasibility of expanding polio-measles surveillance and laboratory networks to detect bacterial meningitis and JE, using surveillance for acute meningitis-encephalitis syndrome in Bangladesh and China and acute encephalitis syndrome in India. We developed nine syndromic surveillance performance indicators based on international surveillance guidelines and calculated scores using supervisory visit reports, annual reports, and case-based surveillance data. RESULTS: Scores, variable by country and targeted disease, were highest for the presence of national guidelines, sustainability, training, availability of JE laboratory resources, and effectiveness of using polio-measles networks for JE surveillance. Scores for effectiveness of building on polio-measles networks for bacterial meningitis surveillance and specimen referral were the lowest, because of differences in specimens and techniques. CONCLUSIONS: Polio-measles surveillance and laboratory networks provided useful infrastructure for establishing syndromic surveillance and building capacity for JE diagnosis, but were less applicable for bacterial meningitis. Laboratory-supported surveillance for vaccine-preventable bacterial diseases will require substantial technical and financial support to enhance local diagnostic capacity.
Subject(s)
Encephalitis/epidemiology , Epidemiological Monitoring , Meningitis/epidemiology , Sentinel Surveillance , Bangladesh/epidemiology , China/epidemiology , Health Services Research , Humans , India/epidemiologyABSTRACT
BACKGROUND: The incidence of meningococcal disease is currently at historic lows in the United States; however, incidence remains highest among infants aged <1 year. With routine use of Haemophilus influenzae type b and pneumococcal vaccines in infants and children in the United States, Neisseria meningitidis remains an important cause of bacterial meningitis in young children. METHODS: Data were collected from active, population- and laboratory-based surveillance for N meningitidis conducted through Active Bacterial Core surveillance during 2006 through 2012. Expanded data collection forms were completed for infant cases identified in the surveillance area during 2006 through 2010. RESULTS: An estimated 113 cases of culture-confirmed meningococcal disease occurred annually among infants aged <1 year in the United States from 2006 through 2012, for an overall incidence of 2.74 per 100,000 infants. Among these cases, an estimated 6 deaths occurred. Serogroup B was responsible for 64%, serogroup C for 12%, and serogroup Y for 16% of infant cases. Based on the expanded data collection forms, a high proportion of infant cases (36/58, 62%) had a smoker in the household and the socioeconomic status of the census tracts where infant meningococcal cases resided was lower compared with the other Active Bacterial Core surveillance areas and the United States as a whole. CONCLUSIONS: The burden of meningococcal disease remains highest in young infants and serogroup B predominates. Vaccines that provide long-term protection early in life have the potential to reduce the burden of meningococcal disease, especially if they provide protection against serogroup B meningococcal disease.
Subject(s)
Meningitis, Meningococcal/epidemiology , Female , Humans , Incidence , Infant , Male , Meningitis, Meningococcal/microbiology , Meningitis, Meningococcal/prevention & control , Meningococcal Vaccines/administration & dosage , Neisseria meningitidis, Serogroup B/pathogenicity , Neisseria meningitidis, Serogroup Y/pathogenicity , Population Surveillance , Survival Rate , United States , VirulenceABSTRACT
BACKGROUND: Meningococcal conjugate vaccines against serogroups A, C, W, and Y (MenACWY) are recommended for routine use in adolescents aged 11-18 years. The impact of these vaccines on the meningococcal population structure in the United States have yet to be evaluated. METHODS: Meningococcal isolates recovered during 2006-2010 (ie, after introduction of MenACWY) collected through Active Bacterial Core surveillance (ABCs) were characterized; serogroup distribution and molecular features of these isolates were compared to previously published data on ABCs isolates recovered from 2000 to 2005 (ie, before introduction of MenACWY). P values were generated using χ(2) statistics and exact methods. RESULTS: There was a significant change (P < .05) in serogroup distribution among all age groups between the 2 periods. A small proportion of isolates showed evidence of capsular switching in both periods. Between the 2 periods, significant changes were observed in the distribution of porin A, ferric enterobactin transport, and strain genotypes among vaccine and nonvaccine serogroups. CONCLUSIONS: The population structure of US meningococcal isolates is dynamic; some changes occurred over time, but the basic structure remained. Vaccine-induced serogroup replacement was not observed, although a small proportion of isolates had undergone capsule switching, possibly driven by non-vaccine-mediated selection. Changes in the distribution of molecular features are likely due to horizontal gene transfer and changes in serogroup distribution.
Subject(s)
Meningococcal Infections/epidemiology , Meningococcal Infections/microbiology , Meningococcal Vaccines/administration & dosage , Neisseria meningitidis/classification , Neisseria meningitidis/isolation & purification , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Genotype , Humans , Infant , Infant, Newborn , Male , Meningococcal Infections/prevention & control , Middle Aged , Neisseria meningitidis/genetics , Neisseria meningitidis/immunology , Serogroup , United States , Vaccines, Conjugate/administration & dosage , Young AdultABSTRACT
BACKGROUND: Meningococcal disease incidence in the United States is at an all-time low. In a previous study of Georgia high school students, meningococcal carriage prevalence was 7%. The purpose of this study was to measure the impact of a meningococcal conjugate vaccine on serogroup Y meningococcal carriage and to define the dynamics of carriage in high school students. METHODS: This was a prospective cohort study at 8 high schools, 4 each in Maryland and Georgia, during a school year. Students at participating schools received quadrivalent meningococcal conjugate vaccine that uses diphtheria toxoid as the protein carrier (MCV4-DT). In each state, 2 high schools were randomly assigned for MCV4-DT receipt by students at the beginning of the study, and 2 were randomly assigned for MCV4-DT receipt at the end. Oropharyngeal swab cultures for meningococcal carriage were performed 3 times during the school year. RESULTS: Among 3311 students, the prevalence of meningococcal carriage was 3.21%-4.01%. Phenotypically nongroupable strains accounted for 88% of carriage isolates. There were only 5 observed acquisitions of serogroup Y strains during the study; therefore, the impact of MCV4-DT on meningococcal carriage could not be determined. CONCLUSIONS: Meningococcal carriage rates in US high school students were lower than expected, and the vast majority of strains did not express capsule. These findings may help explain the historically low incidence of meningococcal disease in the United States.
Subject(s)
Carrier State/epidemiology , Carrier State/microbiology , Meningococcal Infections/epidemiology , Meningococcal Infections/microbiology , Neisseria meningitidis/immunology , Students/statistics & numerical data , Adolescent , Adult , Carrier State/immunology , Carrier State/prevention & control , Female , Georgia/epidemiology , Humans , Male , Maryland/epidemiology , Meningococcal Infections/immunology , Meningococcal Infections/prevention & control , Meningococcal Vaccines/immunology , Neisseria meningitidis/classification , Prospective Studies , Risk Factors , Young AdultABSTRACT
Polymerase chain reaction-based surveillance for bacterial meningitis including 841 children revealed 246 with bacterial DNA in cerebrospinal fluid samples of which 53% were Streptococcus pneumoniae, 19% Neisseria meningitidis, and 16% Haemophilus influenzae type b. The most common S. pneumoniae serotypes/serogroups were 1, 19F, 6A/6B, 23F, 5, 14, 18 and 19A. Among 47 meningococci, 86% were serogroup B, 6% serogroup C, 3% serogroup A, 3% serogroup X and 3% serogroup W.
Subject(s)
Cerebrospinal Fluid/microbiology , Epidemiological Monitoring , Meningitis, Bacterial/diagnosis , Meningitis, Bacterial/epidemiology , Molecular Diagnostic Techniques/methods , Polymerase Chain Reaction/methods , Adolescent , Bacteria/classification , Bacteria/isolation & purification , Child , Child, Preschool , Female , Humans , Infant , Male , Meningitis, Bacterial/microbiology , Prevalence , Prospective Studies , Serotyping , Turkey/epidemiologyABSTRACT
Occupationally acquired meningococcal disease is rare. Adherence to recommendations for safe handling of Neisseria meningitidis in the laboratory greatly reduces the risk for transmission to laboratory workers. A California microbiologist developed fatal serogroup B meningococcal disease after working with N. meningitidis patient isolates in a research laboratory (laboratory A). The California Department of Public Health (CDPH), the local health department, the California Division of Occupational Safety and Health (CalOSHA), and the federal Occupational Safety and Health Administration (OSHA) collaborated on an investigation of laboratory A, which revealed several breaches in recommended laboratory practice for safe handling of N. meningitidis, including manipulating cultures on the bench top. Additionally, laboratory workers had not been offered meningococcal vaccine in accordance with Advisory Committee on Immunization Practices (ACIP) recommendations and CalOSHA Aerosol Transmissible Diseases Standard requirements. In accordance with OSHA and CalOSHA regulations, laboratory staff members must receive laboratory biosafety training and use appropriate personal protective equipment, and those who routinely work with N. meningitidis isolates should receive meningococcal vaccine.