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Sample records for meningoencefalitis por neisseria

  1. Crystallographic analysis of Neisseria meningitidis PorB extracellular loops potentially implicated in TLR2 recognition

    PubMed Central

    Kattner, Christof; Toussi, Deana; Zaucha, Jan; Wetzler, Lee M.; Rüppel, Nadine; Zachariae, Ulrich; Massari, Paola; Tanabe, Mikio

    2014-01-01

    Among all Neisseriae species, N. meningitidis and N. gonorrhoeae are the only human pathogens, causative agents of bacterial meningitis and gonorrhoea, respectively. PorB, a pan-Neisseriae trimeric porin that mediates diffusive transport of essential molecules across the bacterial outer membrane, is also known to activate host innate immunity via Toll-like receptor 2 (TLR2)-mediated signaling. The molecular mechanism of PorB binding to TLR2 is not known, but it has been hypothesized that electrostatic interactions contribute to ligand/receptor binding. Strain-specific sequence variability in the surface-exposed loops of PorB which are potentially implicated in TLR2 binding, may explain the difference in TLR2-mediated cell activation in vitro by PorB homologs from the commensal N. lactamica and the pathogen N. meningitidis. Here, we report a comparative structural analysis of PorB from N. meningitidis serogroup B strain 8765 (63% sequence homology with PorB from N. meningitidis serogroup W135) and a mutant in which amino acid substitutions in the extracellular loop 7 lead to significantly reduced TLR2-dependent activity in vitro. We observe that this mutation both alters the loop conformation and causes dramatic changes of electrostatic surface charge, both of which may affect TLR2 recognition and signalling. PMID:24361688

  2. Variation in the Neisseria lactamica porin, and its relationship to meningococcal PorB.

    PubMed

    Bennett, Julia S; Callaghan, Martin J; Derrick, Jeremy P; Maiden, Martin C J

    2008-05-01

    One potential vaccine strategy in the fight against meningococcal disease involves the exploitation of outer-membrane components of Neisseria lactamica, a commensal bacterium closely related to the meningococcus, Neisseria meningitidis. Although N. lactamica shares many surface structures with the meningococcus, little is known about the antigenic diversity of this commensal bacterium or the antigenic relationships between N. lactamica and N. meningitidis. Here, the N. lactamica porin protein (Por) was examined and compared to the related PorB antigens of N. meningitidis, to investigate potential involvement in anti-meningococcal immunity. Relationships among porin sequences were determined using distance-based methods and F(ST), and maximum-likelihood analyses were used to compare the selection pressures acting on the encoded proteins. These analyses demonstrated that the N. lactamica porin was less diverse than meningococcal PorB and although it was subject to positive selection, this was not as strong as the positive selection pressures acting on the meningococcal porin. In addition, the N. lactamica porin gene sequences and the protein sequences of the loop regions predicted to be exposed to the human immune system were dissimilar to the corresponding sequences in the meningococcus. This suggests that N. lactamica Por, contrary to previous suggestions, may have limited involvement in the development of natural immunity to meningococcal disease and might not be effective as a meningococcal vaccine component.

  3. In silico studies of outer membrane of Neisseria meningitidis por a: its expression and immunogenic properties.

    PubMed

    Behrouzi, Ava; Bouzari, Saeid; Siadat, Seyed Davar; Irani, Shiva

    2014-01-01

    Neisseria meningitidis is a major causative agent of bacterial septicemia and meningitis in humans. Currently, there are no vaccines to prevent disease caused by strains of N.meningitidis serogroup B. The Class 1 Outer Membrane Protein (OMP) has been named porA which is a cation selective transmembrane protein of 45 KDa that forms trimeric pore in the meningococcal outer membrane. PorA from serogroup B N. meningitidis was cloned into prokaryotic expression vector pBAD-gIIIA. Recombinant protein was expressed with arabinose and affinity purified by Ni-NTA agarose, SDS-PAGE and western blotting were performed for protein determination and verification. BALB/c mice were immunized subcutaneously with purified rPorA together with alum adjuvant. Serum antibody responses to serogroups B N.meningitidis were determined by ELISA. Serum IgG response significantly increased in the group immunized with rPorA together with alum adjuvant in comparison with control groups. These results suggest that rPorA can be a potential vaccine candidate for serogroup B N.meningitidis.

  4. In Silico Studies of Outer Membrane of Neisseria Meningitidis Por A: Its Expression and Immunogenic Properties

    PubMed Central

    Behrouzi, Ava; Bouzari, Saeid; Siadat, Seyed Davar; Irani, Shiva

    2014-01-01

    Neisseria meningitidis is a major causative agent of bacterial septicemia and meningitis in humans. Currently, there are no vaccines to prevent disease caused by strains of N.meningitidis serogroup B. The Class 1 Outer Membrane Protein (OMP) has been named porA which is a cation selective transmembrane protein of 45 KDa that forms trimeric pore in the meningococcal outer membrane. PorA from serogroup B N. meningitidis was cloned into prokaryotic expression vector pBAD-gIIIA. Recombinant protein was expressed with arabinose and affinity purified by Ni-NTA agarose, SDS-PAGE and western blotting were performed for protein determination and verification. BALB/c mice were immunized subcutaneously with purified rPorA together with alum adjuvant. Serum antibody responses to serogroups B N.meningitidis were determined by ELISA. Serum IgG response significantly increased in the group immunized with rPorA together with alum adjuvant in comparison with control groups. These results suggest that rPorA can be a potential vaccine candidate for serogroup B N.meningitidis. PMID:25317403

  5. Characterization of invasive Neisseria meningitidis from Atlantic Canada, 2009 to 2013: With special reference to the nonpolysaccharide vaccine targets (PorA, factor H binding protein, Neisseria heparin-binding antigen and Neisseria adhesin A)

    PubMed Central

    Tsang, Raymond SW; Law, Dennis KS; Gad, Rita R; Mailman, Tim; German, Gregory; Needle, Robert

    2015-01-01

    BACKGROUND: Serogroup B Neisseria meningitidis (MenB) has always been a major cause of invasive meningococcal disease (IMD) in Canada. With the successful implementation of a meningitis C conjugate vaccine, the majority of IMD in Canada is now caused by MenB. OBJECTIVE: To investigate IMD case isolates in Atlantic Canada from 2009 to 2013. Data were analyzed to determine the potential coverage of the newly licensed MenB vaccine. METHODS: Serogroup, serotype and serosubtype antigens were determined from IMD case isolates. Clonal analysis was performed using multilocus sequence typing. The protein-based vaccine antigen genes were sequenced and the predicted peptides were investigated. RESULTS: The majority of the IMD isolates were MenB (82.5%, 33 of 40) and, in particular, sequence type (ST)-154 B:4:P1.4 was responsible for 47.5% (19 of 40) of all IMD case isolates in Atlantic Canada. Isolates of this clone expressed the PorA antigen P1.4 and possessed the nhba genes encoding for Neisseria heparin-binding antigen peptide 2, which together matched exactly with two of the four components of the new four-component meningococcal B vaccine. Nineteen MenB isolates had two antigenic matches, another five MenB and one meningitis Y isolate had one antigenic match. This provided 75.8% (25 of 33) potential coverage for MenB, or a 62.5% (25 of 40) overall potential coverage for IMD. CONCLUSION: From 2009 to 2013, IMD in Atlantic Canada was mainly caused by MenB and, in particular, the B:4:P1.4 ST-154 clone, which accounted for 47.5% of all IMD case isolates. The new four-component meningococcal B vaccine appeared to offer adequate coverage against MenB in Atlantic Canada. PMID:26744586

  6. A Fast Real-Time Polymerase Chain Reaction Method for Sensitive and Specific Detection of the Neisseria gonorrhoeae porA Pseudogene

    PubMed Central

    Hjelmevoll, Stig Ove; Olsen, Merethe Elise; Sollid, Johanna U. Ericson; Haaheim, Håkon; Unemo, Magnus; Skogen, Vegard

    2006-01-01

    Ever since the advent of molecular methods, the diagnostics of Neisseria gonorrhoeae has been troubled by false negative and false positive results compared with culture. Commensal Neisseria species and Neisseria meningitidis are closely related to N. gonorrhoeae and may cross-react when using molecular tests comprising too-low specificity. We have devised a real-time polymerase chain reaction (PCR), including an internal amplification control, that targets the N. gonorrhoeae porA pseudogene. DNA was automatically isolated on a BioRobot M48. Our subsequent PCR method amplified all of the different N. gonorrhoeae international reference strains (n = 34) and N. gonorrhoeae clinical isolates (n = 176) but not isolates of the 13 different nongonococcal Neisseria species (n = 68) that we tested. Furthermore, a panel of gram-negative bacterial (n = 18), gram-positive bacterial (n = 23), fungal (n = 1), and viral (n = 4) as well as human DNA did not amplify. The limit of detection was determined to be less than 7.5 genome equivalents/PCR reaction. In conclusion, the N. gonorrhoeae porA pseudogene real-time PCR developed in the present study is highly sensitive, specific, robust, rapid and reproducible, making it suitable for diagnosis of N. gonorrhoeae infection. PMID:17065426

  7. The PorB porin from commensal Neisseria lactamica induces Th1 and Th2 immune responses to ovalbumin in mice and is a potential immune adjuvant.

    PubMed

    Liu, Xiuping; Wetzler, Lee M; Massari, Paola

    2008-02-06

    Porins from pathogenic Neisseriae are among several bacterial products with immune adjuvant activity. Neisseria meningitidis (Nme) PorB, has been shown to induce immune cells activation in a TLR2-dependent manner and acts as a vaccine immune adjuvant. The PorB porin from Neisseria lactamica (Nlac), a common nasopharyngeal commensal, shares significant structural and functional similarities with Nme PorB. In this work we ask whether the immune adjuvant ability of porins from pathogenic Neisserial strains is a characteristic shared with porins from non-pathogenic Neisserial species or whether it is unique for bacterial products derived from microorganisms capable of inducing inflammation and disease. We evaluated the potential immune adjuvant effect of Nlac PorB in mice using ovalbumin (OVA) as a prototype antigen. Immunization with Nlac PorB/OVA induced high OVA-specific IgG and IgM titers compared to OVA alone, similar to other adjuvants such as Nme PorB and alum. High titers of IgG1 and IgG2b were detected as well as production of IL-4, IL-10, IL-12 and INF-gamma in response to Nlac PorB, consistent with induction of both a Th1-type and a Th2-type immune response. OVA-specific proliferation was also determined in splenocytes from Nlac PorB/OVA-immunized mice. In addition, B cell activation in vitro and cytokine production in response to Nlac PorB was found to be mediated by TLR2, in a similar manner to Nme PorB.

  8. Oral administration of recombinant Neisseria meningitidis PorA genetically fused to H. pylori HpaA antigen increases antibody levels in mouse serum, suggesting that PorA behaves as a putative adjuvant

    PubMed Central

    Vasquez, Abel E; Manzo, Ricardo A; Soto, Daniel A; Barrientos, Magaly J; Maldonado, Aurora E; Mosqueira, Macarena; Avila, Anastasia; Touma, Jorge; Bruce, Elsa; Harris, Paul R; Venegas, Alejandro

    2015-01-01

    The Neisseria meningitidis outer membrane protein PorA from a Chilean strain was purified as a recombinant protein. PorA mixed with AbISCO induced bactericidal antibodies against N. meningitidis in mice. When PorA was fused to the Helicobacter pylori HpaA antigen gene, the specific response against H. pylori protein increased. Splenocytes from PorA-immunized mice were stimulated with PorA, and an increase in the secretion of IL-4 was observed compared with that of IFN-γ. Moreover, in an immunoglobulin sub-typing analysis, a substantially higher IgG1 level was found compared with IgG2a levels, suggesting a Th2-type immune response. This study revealed a peculiar behavior of the purified recombinant PorA protein per se in the absence of AbISCO as an adjuvant. Therefore, the resistance of PorA to proteolytic enzymes, such as those in the gastrointestinal tract, was analyzed, because this is an important feature for an oral protein adjuvant. Finally, we found that PorA fused to the H. pylori HpaA antigen, when expressed in Lactococcus lactis and administered orally, could enhance the antibody response against the HpaA antigen approximately 3 fold. These observations strongly suggest that PorA behaves as an effective oral adjuvant. PMID:25750999

  9. The amino acid sequence of Neisseria lactamica PorB surface-exposed loops influences Toll-like receptor 2-dependent cell activation.

    PubMed

    Toussi, Deana N; Carraway, Margaretha; Wetzler, Lee M; Lewis, Lisa A; Liu, Xiuping; Massari, Paola

    2012-10-01

    Toll-like receptors (TLRs) play a major role in host mucosal and systemic defense mechanisms by recognizing a diverse array of conserved pathogen-associated molecular patterns (PAMPs). TLR2, with TLR1 and TLR6, recognizes structurally diverse bacterial products such as lipidated factors (lipoproteins and peptidoglycans) and nonlipidated proteins, i.e., bacterial porins. PorB is a pan-neisserial porin expressed regardless of organisms' pathogenicity. However, commensal Neisseria lactamica organisms and purified N. lactamica PorB (published elsewhere as Nlac PorB) induce TLR2-dependent proinflammatory responses of lower magnitude than N. meningitidis organisms and N. meningitidis PorB (published elsewhere as Nme PorB). Both PorB types bind to TLR2 in vitro but with different apparent specificities. The structural and molecular details of PorB-TLR2 interaction are only beginning to be unraveled and may be due to electrostatic attraction. PorB molecules have significant strain-specific sequence variability within surface-exposed regions (loops) putatively involved in TLR2 interaction. By constructing chimeric recombinant PorB loop mutants in which surface-exposed loop residues have been switched between N. lactamica PorB and N. meningitidis PorB, we identified residues in loop 5 and loop 7 that influence TLR2-dependent cell activation using HEK cells and BEAS-2B cells. These loops are not uniquely responsible for PorB interaction with TLR2, but NF-κB and MAP kinases signaling downstream of TLR2 recognition are likely influenced by a hypothetical "TLR2-binding signature" within the sequence of PorB surface-exposed loops. Consistent with the effect of purified PorB in vitro, a chimeric N. meningitidis strain expressing N. lactamica PorB induces lower levels of interleukin 8 (IL-8) secretion than wild-type N. meningitidis, suggesting a role for PorB in induction of host cell activation by whole bacteria.

  10. Adjuvant effects elicited by novel oligosaccharide variants of detoxified meningococcal lipopolysaccharides on Neisseria meningitidis recombinant PorA protein: a comparison in mice.

    PubMed

    Mehta, Ojas H; Norheim, Gunnstein; Hoe, J Claire; Rollier, Christine S; Nagaputra, Jerry C; Makepeace, Katherine; Saleem, Muhammad; Chan, Hannah; Ferguson, David J P; Jones, Claire; Sadarangani, Manish; Hood, Derek W; Feavers, Ian; Derrick, Jeremy P; Pollard, Andrew J; Moxon, E Richard

    2014-01-01

    Neisseria meningitidis lipopolysaccharide (LPS) has adjuvant properties that can be exploited to assist vaccine immunogenicity. The modified penta-acylated LPS retains the adjuvant properties of hexa-acylated LPS but has a reduced toxicity profile. In this study we investigated whether two modified glycoform structures (LgtE and IcsB) of detoxified penta-acylated LPS exhibited differential adjuvant properties when formulated as native outer membrane vesicles (nOMVs) as compared to the previously described LgtB variant. Detoxified penta-acylated LPS was obtained by disruption of the lpxL1 gene (LpxL1 LPS), and three different glycoforms were obtained by disruption of the lgtB, lgtE or icsB genes respectively. Mice (mus musculus) were immunized with a recombinant PorA P1.7-2,4 (rPorA) protein co-administered with different nOMVs (containing a different PorA serosubtype P1.7,16), each of which expressed one of the three penta-acylated LPS glycoforms. All nOMVs induced IgG responses against the rPorA, but the nOMVs containing the penta-acylated LgtB-LpxL1 LPS glycoform induced significantly greater bactericidal activity compared to the other nOMVs or when the adjuvant was Alhydrogel. Compared to LgtE or IcsB LPS glycoforms, these data support the use of nOMVs containing detoxified, modified LgtB-LpxL1 LPS as a potential adjuvant for future meningococcal protein vaccines.

  11. One-step purification and porin transport activity of the major outer membrane proteins P2 from Haemophilus influenzae, FomA from Fusobacterium nucleatum and PorB from Neisseria meningitidis.

    PubMed

    Kattner, Christof; Pfennig, Sabrina; Massari, Paola; Tanabe, Mikio

    2015-03-01

    Bacterial porins are major outer membrane proteins that function as essential solute transporters between the bacteria and the extracellular environment. Structural features of porins are also recognized by eukaryotic cell receptors involved in innate and adaptive immunity. To better investigate the function of porins, proper refolding is necessary following purification from inclusion bodies [1, 2]. Using a single-step size exclusion chromatographic method, we have purified three major porins from pathogenic bacteria, the OmpP2 (P2) from Haemophilus influenzae, FomA from Fusobacterium nucleatum and PorB from Neisseria meningitidis, at high yield and report their unique solute transport activity with size exclusion limit. Furthermore, we have optimized their purification method and achieved improvement of their thermostability for facilitating functional and structural analyses.

  12. Plasmid diversity in neisseriae.

    PubMed

    van Passel, Mark W J; van der Ende, Arie; Bart, Aldert

    2006-08-01

    Horizontal gene transfer constitutes an important force in prokaryotic genome evolution, and it is well-known that plasmids are vehicles for DNA transfer. Chromosomal DNA is frequently exchanged between pathogenic and commensal neisseriae, but relatively little is known about plasmid diversity and prevalence among these nasopharyngeal inhabitants. We investigated the plasmid contents of 18 Neisseria lactamica isolates and 20 nasopharyngeal Neisseria meningitidis isolates. Of 18 N. lactamica strains, 9 harbored one or more plasmids, whereas only one N. meningitidis isolate contained a plasmid. Twelve plasmids were completely sequenced, while five plasmid sequences from the public databases were also included in the analyses. On the basis of nucleic acid sequences, mobilization, and replicase protein alignments, we distinguish six different plasmid groups (I to VI). Three plasmids from N. lactamica appeared to be highly similar on the nucleotide level to the meningococcal plasmids pJS-A (>99%) and pJS-B (>75%). The genetic organizations of two plasmids show a striking resemblance with that of the recently identified meningococcal disease-associated (MDA) phage, while four putative proteins encoded by these plasmids show 25% to 39% protein identity to those encoded by the MDA phage. The putative promoter of the gene encoding the replicase on these plasmids contains a polycytidine tract, suggesting that replication is subjected to phase variation. In conclusion, extensive plasmid diversity is encountered among commensal neisseriae. Members of three plasmid groups are found in both pathogenic and commensal neisseriae, indicating plasmid exchange between these species. Resemblance between plasmids and MDA phage may be indicative of dissemination of phage-related sequences among pathogenic and commensal neisseriae.

  13. [Factors affecting Neisseria meningitidis and Neisseria lactamica carrier state].

    PubMed

    Krízová, P; Vlcková, J

    1998-12-01

    Invasive meningococcal diseases have become in the Czech Republic since 1993 a serious epidemiological and clinical problem due to a clonus which was not present previously: Neisseria meningitidis C:2a:P1.2,P1.5, ET-15/37. In 1996 a trial was conducted focused on the problem how this altered epidemiological and clinical situation is reflected in carriership of Neisseria meningitidis and Neisseria lactamica in the healthy population. Two age groups were followed up which were most severely affected by the new clonus of the meningococcus: 15-19 years (410 subjects) and 1-4 years (116 subjects). The trial was implemented in Olomouc where in 1993 the new epidemiological situation of the incidence of the invasive meningococcal disease was so serious that targeted vaccination was introduced. Of 116 children in the age group from 1-4 years in none Neisseria meningitidis was detected, in 9 Neisseria lactamica was found (7.7%). On repeated examination of children with a positive cultivation of Neisseria lactamica after two weeks in none Neisseria meningitidis nor Neisseria lactamica were found. Of 410 subjects in the age group from 15-19 years in none Neisseria lactamica was detected and in 35 Neisseria meningitidis (8.5%). Examinations were repeated after two weeks in 33 carriers: in 31 Neisseria meningitidis was again cultivated. Analysis of factors influencing carriership revealed in Neisseria lactamica two factors in young children which significantly promote this carriership: cold and close contact/kissing. A risk factor at the limit of significance are frequent respiratory diseases. In the carriership of Neisseria meningitidis in 15-19 year-old subjects six factors were revealed which promote carriership. A significant risk factor is close contact/kissing, the existence of partnership, participation in activities of the "disco" type, living in a town, flats in the centre of the town. Effort is a risk factor at the limit of significance.

  14. Neisseria lactamica meningitis.

    PubMed

    Lauer, B A; Fisher, C E

    1976-02-01

    Neisseria lactamica was recovered from the blood and cerebrospinal fluid of a 7-month-old girl with acute purulent meningitis. The isolate was identified initially as N meningitidis. However, additional biochemical testing at the Center for Disease Control showed that the organism fermented lactose and produced beta-D-galactosidase, thereby confirming its identity as N lactamica.

  15. [Neisseria gonorrhoeae infections].

    PubMed

    Furuya, Ryusaburo; Tanaka, Masatoshi

    2009-01-01

    Neisseria gonorrhoeae infections are common bacterial sexually transmitted diseases. Men will usually experience lower urinary tract symptons attributed to urethritis, epididymitis, proctitis, or prostatitis, with associated mucopurulent urethral discharge. Many women are asymptomatic. But, occasionally, they have symptons of vaginal and pelvic discomfort of dysuria, and these infections can lead to pelvic inflammatory disease. Recentry, high prevalence of Neisseria gonorrhoeae isolates resistant to antimicrobial agents is a serious problem in the treatment of gonorrhea. For example, in Fukuoka city, Japan, the proportion of the isolates resistant to ciprofloxacin (CPFX) were 73.4% in 2006 and it was still so high. The proportion of the isolates resistant to tetracycline (TC) was 38.5% in 2006 and that of isolates resistant to penicillin G (PCG) was 17.5%. Owing to this high prevalence of antimicrobial-resistant Neisseria gonorrhoeae in Japan, the clinical efficacy rates of oral antimicrobial agents have become lower. So, as first-line therapy for gonococcal infections, only three parenteral regimens of single doses of ceftriaxone, cefodizime or spectinomycin are recommended by the Japanese Society for Sexually Transmitted Diseases. In the circumstances, we studied in vitro activity of combinations of oral agents such as, beta-lactam and azithromycin, fluoroquinolone and azithromycin, or beta-lactam and fluoroquinolone against Neisseria gonorrhoeae. The cefixime+azithromycin combination demonstrated greater synergy than other combinations.

  16. The Biology of Neisseria Adhesins

    PubMed Central

    Hung, Miao-Chiu; Christodoulides, Myron

    2013-01-01

    Members of the genus Neisseria include pathogens causing important human diseases such as meningitis, septicaemia, gonorrhoea and pelvic inflammatory disease syndrome. Neisseriae are found on the exposed epithelia of the upper respiratory tract and the urogenital tract. Colonisation of these exposed epithelia is dependent on a repertoire of diverse bacterial molecules, extending not only from the surface of the bacteria but also found within the outer membrane. During invasive disease, pathogenic Neisseriae also interact with immune effector cells, vascular endothelia and the meninges. Neisseria adhesion involves the interplay of these multiple surface factors and in this review we discuss the structure and function of these important molecules and the nature of the host cell receptors and mechanisms involved in their recognition. We also describe the current status for recently identified Neisseria adhesins. Understanding the biology of Neisseria adhesins has an impact not only on the development of new vaccines but also in revealing fundamental knowledge about human biology. PMID:24833056

  17. Septicemia due to Neisseria lactamica.

    PubMed

    Wilson, H D; Overman, T L

    1976-09-01

    Neisseria lactamica was isolated from the blood of a pediatric patient who had signs of septicemia and otitis media. Organisms morphologically resembling Neisseria, as well as gram-positive cocci, were seen on a Gram stain of fluid from the middle ear. It is hypothesized that the N. lactamica septicemia was secondary to infection of the middle ear by this organism.

  18. Analysis of Moraxella catarrhalis outer membrane antigens cross-reactive with Neisseria meningitidis and Neisseria lactamica.

    PubMed

    Troncoso, Gemma; Sánchez, Sandra; Criado, María Teresa; Ferreirós, Carlos

    2004-01-15

    Mouse sera against outer membrane proteins from Moraxella catarrhalis, Neisseria meningitidis and Neisseria lactamica, and human sera from both healthy individuals and patients convalescing from meningococcal meningitis were used to identify cross-reactive antigens. Mouse anti-N. meningitidis and anti-N. lactamica sera recognized 77, 62 and 32 kDa outer membrane antigens in M. catarrhalis strains; on the contrary, the meningococcal porin PorB (38-42 kDa) was recognized by one of the two anti-M. catarrhalis sera. Human sera from both healthy individuals and patients convalescing from meningococcal meningitis also showed cross-reactive antibodies against these proteins. The existence of cross-reactive antigens in M. catarrhalis and N. meningitidis (as well as in N. lactamica) could favor the development of natural immunization against both pathogens.

  19. Homology of cryptic plasmid of Neisseria gonorrhoeae with plasmids from Neisseria meningitidis and Neisseria lactamica.

    PubMed

    Ison, C A; Bellinger, C M; Walker, J

    1986-10-01

    DNA probe hybridisation was used to examine the relation between the cryptic plasmid from Neisseria gonorrhoeae and plasmids carried by pharyngeal isolates of Neisseria meningitidis and Neisseria lactamica. The complete gonococcal cryptic plasmid and HinfI derived digestion fragments subcloned into Escherichia coli were used to probe Southern blots of plasmid extracts. Homology was found to a plasmid of approximate molecular weight 4.5 kilobase pairs (Kb) but not to plasmids of less than 3.2 Kb or 6.5 Kb. Eleven of 16 strains of N meningitidis and two of six strains of N lactamica carried plasmids that showed strong hybridisation with the 4.2 Kb gonococcal plasmid. Hybridisation of plasmids from non-gonococcal species of neisseria with the gonococcal cryptic plasmid indicates that caution should be taken when using the cryptic plasmid as a diagnostic probe for gonorrhoea.

  20. Neisseria-Avoiding the Jump to Conclusions

    ERIC Educational Resources Information Center

    Spivey, Maria I.; Paschall, Robert T.; Ferrett, Rhonda; Alexander, Randell

    2011-01-01

    "Neisseria gonorrhoeae" infection in a prepubertal child is virtually diagnostic of sexual abuse, provided perinatal infection has been excluded. Therefore, it is imperative that "Neisseria gonorrhoeae" be correctly identified. We present two cases of false positive "Neisseria gonorrhoeae" meningitis encountered at two different children's…

  1. Neisseria Species Identification Assay for the Confirmation of Neisseria gonorrhoeae-Positive Results of the COBAS Amplicor PCR▿

    PubMed Central

    Mangold, Kathy A.; Regner, MaryAnn; Tajuddin, Mohammed; Tajuddin, Aamair M.; Jennings, Lawrence; Du, Hongyan; Kaul, Karen L.

    2007-01-01

    Screening assays for Neisseria gonorrhoeae exhibit low positive predictive values, particularly in low-prevalence populations. A new real-time PCR assay that detects and identifies individual Neisseria spp. using melt curve analysis was compared to two previously published supplementary assays. NsppID, a 16S rRNA real-time PCR/melt curve assay developed to distinguish N. gonorrhoeae from other Neisseria spp., was compared to real-time PCR assays targeting genes reportedly specific for N. gonorrhoeae, the cppB gene and the porA pseudogene. A total of 408 clinical specimens (324 female endocervical swabs and 84 male urine or urogenital swab specimens) were screened using the COBAS Amplicor assay for Chlamydia trachomatis and N. gonorrhoeae (CT/NG) (Roche Diagnostics, Indianapolis, IN) followed by confirmatory testing via real-time PCR. The NsppID assay detected Neisseria spp. in 150/181 COBAS-positive specimens (82%), including six dual infections, and identified N. gonorrhoeae in 102 (56%) specimens. Sixty-nine of 181 (38%) specimens were positive for N. gonorrhoeae by porA pseudogene, and 115/181 (64%) were positive for cppB. However, cppB was also positive in 15% of COBAS-negative specimens, more than either NsppID (4%) or porA pseudogene (2%) assays. The porA pseudogene assay had the highest specificity for both genders but the lowest sensitivity, especially in female specimens. NsppID had a slightly lower specificity but greater sensitivity and overall accuracy. The least desirable confirmatory assay was cppB, due to poor specificity. The NsppID assay is an accurate confirmatory assay for N. gonorrhoeae detection. In addition, the NsppID assay can identify the non-N. gonorrhoeae species responsible for the majority of false-positive results from the COBAS Amplicor CT/NG assay. PMID:17360838

  2. [Experience with Neisseria lactamica (author's transl)].

    PubMed

    Kuzemenská, P; Burian, V; Janovská, D; Mysková, M; Hausenblasová, M

    1976-12-01

    The authors have performed a detailed study of the presence of a new microbial species, Neisseria lactamica which even recently had still been classified among the nontypable Neisseria meningitidis strains. An examination of the spread of Neisseria strains among the healthy population of this country revealed 1.6% to be carriers of Neisseria lactamica as compared with 4.7% being carriers of Neisseria meningitidis. From the material examined, the highest number of Neisseria lactamica carriers was found among the 0-1 year age group (5.9%) whereas the maximum number of Neisseria meningitidis carriers was found in the 25-34 year age group (11.1%). The simultaneous identification of N. meningitidis and N. lactamica in exceptional cases means a new and important observation.

  3. Analysis of Neisseria lactamica antigens putatively implicated in acquisition of natural immunity to Neisseria meningitidis.

    PubMed

    Troncoso, G; Sánchez, S; Criado, M T; Ferreirós, C M

    2002-09-06

    Sera from healthy human volunteers, patients convalescent from meningococcal meningitis, and mice immunized with outer membrane proteins from Neisseria meningitidis and Neisseria lactamica strains were used to analyze and identify antigens cross-reactive to both neisserial species. All classes of meningococcal proteins except class 1 (PorA) and class 5 cross-reacted with N. lactamica proteins and two other proteins of 65 and 55 kDa (an iron-regulated protein). Results obtained with the mouse sera demonstrate that cross-reactive antibodies can be elicited by either N. meningitidis or N. lactamica. These results support the suggestion that N. lactamica contributes to the development of natural immunity against N. meningitidis during the first years of life. The use of vaccines containing proteins other than PorA could interfere in colonization of mucosal surfaces by N. lactamica, hampering the natural mechanisms of immunity acquisition in humans. Only convalescent sera reacted with the 55 and 65 kDa proteins, which suggests that they might be relevant for pathogenicity.

  4. A national quality assurance survey of Neisseria gonorrhoeae testing.

    PubMed

    Trembizki, Ella; Lahra, Monica; Stevens, Kerrie; Freeman, Kevin; Hogan, Tiffany; Hogg, Geoff; Lawrence, Andrew; Limnios, Athena; Pearson, Julie; Smith, Helen; Nissen, Michael; Sloots, Theo; Whiley, David

    2014-01-01

    The aims of this study were to (1) conduct a national survey of Neisseria gonorrhoeae identification by National Neisseria Network (NNN) reference laboratories contributing data to the Australian Gonococcal Surveillance Programme and (2) determine the prevalence in Australia of strains of N. gonorrhoeae lacking gene sequences commonly targeted by in-house PCR assays for confirmation of gonococcal nucleic acid amplification tests. Gonococcal clinical isolates referred to NNN laboratories for the first half of 2012 were screened using in-house real-time PCR assays targeting multicopy opa, porA pseudogene and cppB genes. There were 2455 clinical gonococcal isolates received in the study period; 98.6 % (2420/2455) of isolates harboured all three gene targets, 0.12 % (3/2455) were porA-negative, 0.04 % (1/2455) opa-negative and 1.14 % (28/2455) cppB-negative by PCR. Notably, no isolates were simultaneously negative for two targets. However, three isolates failed to be amplified by all three PCR methods, one isolate of which was shown to be a commensal Neisseria strain by 16S rRNA sequencing. Using PCR as the reference standard the results showed that (1) identification of N. gonorrhoeae isolates by NNN laboratories was highly specific (99.96 %) and (2) strains of N. gonorrhoeae lacking gene sequences commonly targeted by in-house PCR assays are present but not widespread throughout Australia at this point in time.

  5. Mobile DNA in the pathogenic Neisseria

    PubMed Central

    Obergfell, Kyle P.; Seifert, H. Steven

    2015-01-01

    The genus Neisseria contains two pathogenic species of notable public health concern: Neisseria gonorrhoeae and Neisseria meningitidis. These pathogens display a notable ability to undergo frequent programmed recombination events. The recombination mediated pathways of transformation and pilin antigenic variation in the Neisseria are well studied systems that are critical for pathogenesis. Here we will detail the conserved and unique aspects of transformation and antigenic variation in the Neisseria. Transformation will be followed from initial DNA binding through recombination into the genome with consideration to the factors necessary at each step. Additional focus is paid to the unique type IV secretion system that mediates donation of transforming DNA in the pathogenic Neisseria. The pilin antigenic variation system uses programed recombinations to alter a major surface determinant which allows immune avoidance and promotes infection. We discuss the trans- and cis- acting factors which facilitate pilin antigenic variation and present the current understanding of the mechanisms involved in the process. PMID:25866700

  6. Bioinformatic analysis of outer membrane proteome of Neisseria meningitidis and Neisseria lactamica.

    PubMed

    Abel, Ana; Sánchez, Sandra; Arenas, Jesús; Criado, María T; Ferreirós, Carlos M

    2007-03-01

    Two-dimensional electrophoresis (isoelectric focusing/SDS-PAGE) and Western-blotting techniques were used to analyze and compare common and/or specific outer-membrane proteins and antigens from Neisseria meningitidis and Neisseria lactamica. Bioinformatic image analyses of proteome and immunoproteome maps indicated the presence of numerous proteins and several antigens shared by N. meningitidis and N. lactamica, although the inter-strain variation in the maps was of similar magnitude to the inter-species variation, and digital comparison of the maps did not reveal proteins found to be identical by MALDI-TOF fingerprinting analysis. PorA and RmpM, two relevant outer-membrane antigens, manifested as various spots at several different positions. While some of these were common to all the strains analyzed, others were exclusive to N. meningitidis and their electrophoretic mobilities were different than expected. One such spot, with a molecular mass of 19 kDa, may be the C-terminal fragment of RmpM (RmpM-Cter). The results demonstrate that computer-driven analysis based exclusively on spot positions in the proteome or immunoproteome maps is not a reliable approach to predict the identity of proteins or antigens; rather, other identification techniques are necessary to obtain accurate comparisons.

  7. Environmental Survival of Neisseria meningitidis

    PubMed Central

    Tzeng, Y.-L.; Martin, L.E.; Stephens, D.S.

    2017-01-01

    Summary Neisseria meningitidis is transmitted through the inhalation of large human respiratory droplets, but the risk from contaminated environmental surfaces is controversial. Compared to Streptococcus pneumoniae and Acinetobacter baumanni, meningococcal viability after desiccation on plastic, glass or metal surfaces decreased rapidly; but viable meningococci were present for up to 72 hours. Encapsulation did not provide an advantage for meningococcal environmental survival on environmental surfaces. PMID:23574798

  8. Can Neisseria lactamica antigens provide an effective vaccine to prevent meningococcal disease?

    PubMed

    Gorringe, Andrew R

    2005-06-01

    Neisseria lactamica is a commensal organism that is closely related to Neisseria meningitidis, the causative agent of meningococcal disease. N. lactamica has many antigens in common with N. meningitidis, but it lacks a polysaccharide capsule and the serosubtyping antigen PorA. Carriage studies have demonstrated that N. lactamica is carried in the nasopharynx of young children at a time when meningococcal carriage is rare. However, natural immunity to meningococcal disease develops during this period and carriage of commensal Neisseria is implicated in the development of this immunity. Recent studies have characterized the antigens which may be responsible for inducing a crossreactive antibody response and have demonstrated that N. lactamica-based vaccines can protect in experimental models of meningococcal disease. The potential for these vaccines to be effective in preventing meningococcal disease is discussed.

  9. Proctitis associated with Neisseria cinerea misidentified as Neisseria gonorrhoeae in a child.

    PubMed

    Dossett, J H; Appelbaum, P C; Knapp, J S; Totten, P A

    1985-04-01

    An 8-year-old boy developed proctitis. Rectal swabs yielded a Neisseria sp. that was repeatedly identified by API (Analytab Products, Plainview, N.Y.), Minitek (BBL Microbiology Systems, Cockeysville, Md.), and Bactec (Johnston Laboratories, Towson, Md.) methods as Neisseria gonorrhoeae. Subsequent testing in a reference laboratory yielded an identification of Neisseria cinerea. It is suggested that identification of a Neisseria sp. isolated from genital or rectal sites in a child be confirmed by additional serological, growth, and antibiotic susceptibility tests and, if necessary, by a reference laboratory. The implications of such misidentifications are discussed.

  10. Neisseria lactamica meningitis following skull trauma.

    PubMed

    Denning, D W; Gill, S S

    1991-01-01

    A woman developed meningitis due to Neisseria lactamica in association with a cribriform plate fracture. Cerebrospinal fluid antigen tests for Neisseria meningitidis were negative. The patient recovered with intravenous penicillin therapy. N. lactamica can be rapidly distinguished from N. meningitidis by the hydrolysis of ONPG (o-nitrophenyl-beta-D-galactopyranoside). In contrast to N. meningitidis and Neisseria gonorrhoeae, N. lactamica lacks virulence properties. As 100% of N. lactamica strains are susceptible to penicillin and all three previously described patients with N. lactamica meningitis have recovered with penicillin treatment, the reason for distinguishing the organisms in this context is primarily to prevent unnecessary anxiety and prophylaxis among contacts.

  11. Genetic distribution of noncapsular meningococcal group B vaccine antigens in Neisseria lactamica.

    PubMed

    Lucidarme, Jay; Gilchrist, Stefanie; Newbold, Lynne S; Gray, Stephen J; Kaczmarski, Edward B; Richardson, Lynne; Bennett, Julia S; Maiden, Martin C J; Findlow, Jamie; Borrow, Ray

    2013-09-01

    The poor immunogenicity of the meningococcal serogroup B (MenB) capsule has led to the development of vaccines targeting subcapsular antigens, in particular the immunodominant and diverse outer membrane porin, PorA. These vaccines are largely strain specific; however, they offer limited protection against the diverse MenB-associated diseases observed in many industrialized nations. To broaden the scope of its protection, the multicomponent vaccine (4CMenB) incorporates a PorA-containing outer membrane vesicle (OMV) alongside relatively conserved recombinant protein components, including factor H-binding protein (fHbp), Neisseria adhesin A (NadA), and neisserial heparin-binding antigen (NHBA). The expression of PorA is unique to meningococci (Neisseria meningitidis); however, many subcapsular antigens are shared with nonpathogenic members of the genus Neisseria that also inhabit the nasopharynx. These organisms may elicit cross-protective immunity against meningococci and/or occupy a niche that might otherwise accommodate pathogens. The potential for 4CMenB responses to impact such species (and vice versa) was investigated by determining the genetic distribution of the primary 4CMenB antigens among diverse members of the common childhood commensal, Neisseria lactamica. All the isolates possessed nhba but were devoid of fhbp and nadA. The nhba alleles were mainly distinct from but closely related to those observed among a representative panel of invasive MenB isolates from the same broad geographic region. We made similar findings for the immunogenic typing antigen, FetA, which constitutes a major part of the 4CMenB OMV. Thus, 4CMenB vaccine responses may impact or be impacted by nasopharyngeal carriage of commensal neisseriae. This highlights an area for further research and surveillance should the vaccine be routinely implemented.

  12. Genetic Distribution of Noncapsular Meningococcal Group B Vaccine Antigens in Neisseria lactamica

    PubMed Central

    Gilchrist, Stefanie; Newbold, Lynne S.; Gray, Stephen J.; Kaczmarski, Edward B.; Richardson, Lynne; Bennett, Julia S.; Maiden, Martin C. J.; Findlow, Jamie; Borrow, Ray

    2013-01-01

    The poor immunogenicity of the meningococcal serogroup B (MenB) capsule has led to the development of vaccines targeting subcapsular antigens, in particular the immunodominant and diverse outer membrane porin, PorA. These vaccines are largely strain specific; however, they offer limited protection against the diverse MenB-associated diseases observed in many industrialized nations. To broaden the scope of its protection, the multicomponent vaccine (4CMenB) incorporates a PorA-containing outer membrane vesicle (OMV) alongside relatively conserved recombinant protein components, including factor H-binding protein (fHbp), Neisseria adhesin A (NadA), and neisserial heparin-binding antigen (NHBA). The expression of PorA is unique to meningococci (Neisseria meningitidis); however, many subcapsular antigens are shared with nonpathogenic members of the genus Neisseria that also inhabit the nasopharynx. These organisms may elicit cross-protective immunity against meningococci and/or occupy a niche that might otherwise accommodate pathogens. The potential for 4CMenB responses to impact such species (and vice versa) was investigated by determining the genetic distribution of the primary 4CMenB antigens among diverse members of the common childhood commensal, Neisseria lactamica. All the isolates possessed nhba but were devoid of fhbp and nadA. The nhba alleles were mainly distinct from but closely related to those observed among a representative panel of invasive MenB isolates from the same broad geographic region. We made similar findings for the immunogenic typing antigen, FetA, which constitutes a major part of the 4CMenB OMV. Thus, 4CMenB vaccine responses may impact or be impacted by nasopharyngeal carriage of commensal neisseriae. This highlights an area for further research and surveillance should the vaccine be routinely implemented. PMID:23803905

  13. Ophthalmia neonatorum caused by Neisseria cinerea.

    PubMed

    Bourbeau, P; Holla, V; Piemontese, S

    1990-07-01

    Neisseria cinerea is an organism that has only recently been implicated as a human pathogen. In this case, N. cinerea was identified as the cause of ophthalmia neonatorum (conjunctivitis) in a 2-day-old girl.

  14. Isolation of Bacteriophages Active Against Neisseria meningitidis

    PubMed Central

    Cary, Sylvia G.; Hunter, Donald H.

    1967-01-01

    Five distinct bacteriophages have been isolated from strains of Neisseria meningitidis. Filtrates with titers of 10−4 to 10−6 were produced with a modified Swanstrom and Adams semisolid agar procedure, employing Eugonbroth with added agar and an incubation temperature of 30 C. Of 49 strains of N. meningitidis (groups B and C), 25 were lysed by one or more of the phages, but there was no lysis of other Neisseria and Mima polymorpha strains. Images PMID:4990042

  15. Conjugative Plasmids of Neisseria gonorrhoeae

    PubMed Central

    Pachulec, Emilia; van der Does, Chris

    2010-01-01

    Many clinical isolates of the human pathogen Neisseria gonorrhoeae contain conjugative plasmids. The host range of these plasmids is limited to Neisseria species, but presence of a tetracycline (tetM) determinant inserted in several of these plasmids is an important cause of the rapid spread of tetracycline resistance. Previously plasmids with different backbones (Dutch and American type backbones) and with and without different tetM determinants (Dutch and American type tetM determinants) have been identified. Within the isolates tested, all plasmids with American or Dutch type tetM determinants contained a Dutch type plasmid backbone. This demonstrated that tetM determinants should not be used to differentiate between conjugal plasmid backbones. The nucleotide sequences of conjugative plasmids with Dutch type plasmid backbones either not containing the tetM determinant (pEP5233) or containing Dutch (pEP5289) or American (pEP5050) type tetM determinants were determined. Analysis of the backbone sequences showed that they belong to a novel IncP1 subfamily divergent from the IncP1α, β, γ, δ and ε subfamilies. The tetM determinants were inserted in a genetic load region found in all these plasmids. Insertion was accompanied by the insertion of a gene with an unknown function, and rearrangement of a toxin/antitoxin gene cluster. The genetic load region contains two toxin/antitoxins of the Zeta/Epsilon toxin/antitoxin family previously only found in Gram positive organisms and the virulence associated protein D of the VapD/VapX toxin/antitoxin family. Remarkably, presence of VapX of pJD1, a small cryptic neisserial plasmid, in the acceptor strain strongly increased the conjugation efficiency, suggesting that it functions as an antitoxin for the conjugative plasmid. The presence of the toxin and antitoxin on different plasmids might explain why the host range of this IncP1 plasmid is limited to Neisseria species. The isolated plasmids conjugated efficiently between

  16. Septicaemia due to Neisseria lactamica--initial confusion with Neisseria meningitidis.

    PubMed

    Brown, N M; Ragge, N K; Speller, D C

    1987-11-01

    Neisseria lactamica, isolated from a baby with septicaemia, was at first thought to be Neisseria meningitidis, possibly acquired in hospital. Extensive investigation of contacts was made until the O-nitrophenyl-D-galactopyranoside reaction proved positive. Distinction between the two species, easily made in this way, is important both in individual patients and in population surveys.

  17. Prosthetic Valve Endocarditis Due to Neisseria skkuensis, a Novel Neisseria Species

    PubMed Central

    Park, So Yeon; Kang, Seung Ji; Joo, Eun-Jeong; Ha, Young Eun; Baek, Jin Yang; Wi, Yu Mi; Kang, Cheol-In; Chung, Doo Ryeon; Lee, Nam Young; Song, Jae-Hoon

    2012-01-01

    We describe the first reported case of endocarditis due to Neisseria skkuensis. The organism from the blood cultures taken on admission day was identified initially as unidentified Gram-negative cocci by Vitek2. Finally, it was identified as Neisseria skkuensis by 16 rRNA gene sequence analysis. PMID:22675133

  18. NeisseriaBase: a specialised Neisseria genomic resource and analysis platform.

    PubMed

    Zheng, Wenning; Mutha, Naresh V R; Heydari, Hamed; Dutta, Avirup; Siow, Cheuk Chuen; Jakubovics, Nicholas S; Wee, Wei Yee; Tan, Shi Yang; Ang, Mia Yang; Wong, Guat Jah; Choo, Siew Woh

    2016-01-01

    Background. The gram-negative Neisseria is associated with two of the most potent human epidemic diseases: meningococcal meningitis and gonorrhoea. In both cases, disease is caused by bacteria colonizing human mucosal membrane surfaces. Overall, the genus shows great diversity and genetic variation mainly due to its ability to acquire and incorporate genetic material from a diverse range of sources through horizontal gene transfer. Although a number of databases exist for the Neisseria genomes, they are mostly focused on the pathogenic species. In this present study we present the freely available NeisseriaBase, a database dedicated to the genus Neisseria encompassing the complete and draft genomes of 15 pathogenic and commensal Neisseria species. Methods. The genomic data were retrieved from National Center for Biotechnology Information (NCBI) and annotated using the RAST server which were then stored into the MySQL database. The protein-coding genes were further analyzed to obtain information such as calculation of GC content (%), predicted hydrophobicity and molecular weight (Da) using in-house Perl scripts. The web application was developed following the secure four-tier web application architecture: (1) client workstation, (2) web server, (3) application server, and (4) database server. The web interface was constructed using PHP, JavaScript, jQuery, AJAX and CSS, utilizing the model-view-controller (MVC) framework. The in-house developed bioinformatics tools implemented in NeisseraBase were developed using Python, Perl, BioPerl and R languages. Results. Currently, NeisseriaBase houses 603,500 Coding Sequences (CDSs), 16,071 RNAs and 13,119 tRNA genes from 227 Neisseria genomes. The database is equipped with interactive web interfaces. Incorporation of the JBrowse genome browser in the database enables fast and smooth browsing of Neisseria genomes. NeisseriaBase includes the standard BLAST program to facilitate homology searching, and for Virulence Factor

  19. NeisseriaBase: a specialised Neisseria genomic resource and analysis platform

    PubMed Central

    Zheng, Wenning; Mutha, Naresh V.R.; Heydari, Hamed; Dutta, Avirup; Siow, Cheuk Chuen; Jakubovics, Nicholas S.; Wee, Wei Yee; Tan, Shi Yang; Ang, Mia Yang; Wong, Guat Jah

    2016-01-01

    Background. The gram-negative Neisseria is associated with two of the most potent human epidemic diseases: meningococcal meningitis and gonorrhoea. In both cases, disease is caused by bacteria colonizing human mucosal membrane surfaces. Overall, the genus shows great diversity and genetic variation mainly due to its ability to acquire and incorporate genetic material from a diverse range of sources through horizontal gene transfer. Although a number of databases exist for the Neisseria genomes, they are mostly focused on the pathogenic species. In this present study we present the freely available NeisseriaBase, a database dedicated to the genus Neisseria encompassing the complete and draft genomes of 15 pathogenic and commensal Neisseria species. Methods. The genomic data were retrieved from National Center for Biotechnology Information (NCBI) and annotated using the RAST server which were then stored into the MySQL database. The protein-coding genes were further analyzed to obtain information such as calculation of GC content (%), predicted hydrophobicity and molecular weight (Da) using in-house Perl scripts. The web application was developed following the secure four-tier web application architecture: (1) client workstation, (2) web server, (3) application server, and (4) database server. The web interface was constructed using PHP, JavaScript, jQuery, AJAX and CSS, utilizing the model-view-controller (MVC) framework. The in-house developed bioinformatics tools implemented in NeisseraBase were developed using Python, Perl, BioPerl and R languages. Results. Currently, NeisseriaBase houses 603,500 Coding Sequences (CDSs), 16,071 RNAs and 13,119 tRNA genes from 227 Neisseria genomes. The database is equipped with interactive web interfaces. Incorporation of the JBrowse genome browser in the database enables fast and smooth browsing of Neisseria genomes. NeisseriaBase includes the standard BLAST program to facilitate homology searching, and for Virulence Factor

  20. Prevalence and persistence of Neisseria cinerea and other Neisseria spp. in adults.

    PubMed

    Knapp, J S; Hook, E W

    1988-05-01

    Neisseria cinerea is a commensal Neisseria sp. which was first described in 1906 but was subsequently misclassified as a subtype of Branhamella catarrhalis. N. cinerea resembles Neisseria gonorrhoeae in both cultural and biochemical characteristics and, thus, may also have been misidentified as N. gonorrhoeae. Of 202 patients whose oropharynges were colonized by Neisseria spp., N. cinerea was isolated in 57 (28.2%) patients, including 25 (30.1%) of 83 women, 22 (23.9%) of 92 heterosexual men, and 10 (37.0%) of 27 homosexual men in Seattle, Wash., in 1983 to 1984. N. cinerea was isolated from the urethra of only one (1.1%) patient. The oropharynges of many individuals were colonized persistently by strains of N. cinerea and other Neisseria spp.

  1. Carriage of Neisseria meningitidis and Neisseria lactamica in northern Greece.

    PubMed

    Kremastinou, Jenny; Tzanakaki, Georgina; Levidiotou, Stamatina; Markou, Fani; Themeli, Eleftheria; Voyiatzi, Aliki; Psoma, Eleni; Theodoridou, Maria; Blackwell, C Caroline

    2003-10-24

    In response to an increase in the number of cases of invasive meningococcal disease (IMD) in northern regions of Greece, a survey was carried out to determine if there was an increase in carriage of Neisseria meningitidis, particularly in areas where there have been increases in immigrant populations from neighbouring countries. The second objective was to determine if there was an increase in the serogroup C:2a:P1.5,2 a phenotype associated with recent outbreaks or changes in antibiotic sensitivities. As carriage of Neisseria lactamica is associated with development of natural immunity to IMD, the third objective was to determine the carriage rate of N. lactamica in this population. Among 3167 individuals tested, meningococci were isolated from 334 (10.5%). Compared with our previous studies, the proportion of meningococcal carriers was significantly increased among children in secondary education (11.3%) (chi2=9.67, P<0.005) and military recruits (37.4%) (chi2=21.11, P<0.000). Only 5/334 (1.5%) isolates expressed the phenotype associated with the increase in IMD in Greece. N. lactamica was isolated from 146/3167 (4.6%) participants. It was isolated from 71/987 (7.2%) children attending primary or nursery schools; however, the highest proportion of carriers (11.3%) was found in the boarding school for young Albanian men. In the 21-59-year age range, the majority of N. lactamica isolates (22/25, 88%) were from women, probably due to closer or more prolonged contact with children in the primary school age range. Smoking was significantly associated with isolation of meningococci from men but not from women. Penicillin-insensitive strains (25/334, 7.5%) were identified in all four regions examined; the majority (14/25, 56%) were obtained from military personnel. We conclude that there was a higher proportion of carriers in the population of northern Greece; however, the increase in carriage rate was not associated with the influx of immigrants from neighbouring

  2. Human airway epithelial cell responses to Neisseria lactamica and purified porin via Toll-like receptor 2-dependent signaling.

    PubMed

    Liu, Xiuping; Wetzler, Lee M; Nascimento, Laura Oliveira; Massari, Paola

    2010-12-01

    The human airway epithelium is constantly exposed to microbial products from colonizing organisms. Regulation of Toll-like receptor (TLR) expression and specific interactions with bacterial ligands is thought to mitigate exacerbation of inflammatory processes induced by the commensal flora in these cells. The genus Neisseria comprises pathogenic and commensal organisms that colonize the human nasopharynx. Neisseria lactamica is not associated with disease, but N. meningitidis occasionally invades the host, causing meningococcal disease and septicemia. Upon colonization of the airway epithelium, specific host cell receptors interact with numerous Neisseria components, including the PorB porin, at the immediate bacterial-host cell interface. This major outer membrane protein is expressed by all Neisseria strains, regardless of pathogenicity, but its amino acid sequence varies among strains, particularly in the surface-exposed regions. The interaction of Neisseria PorB with TLR2 is essential for driving TLR2/TLR1-dependent cellular responses and is thought to occur via the porin's surface-exposed loop regions. Our studies show that N. lactamica PorB is a TLR2 ligand but its binding specificity for TLR2 is different from that of meningococcal PorB. Furthermore, N. lactamica PorB is a poor inducer of proinflammatory mediators and of TLR2 expression in human airway epithelial cells. These effects are reproduced by whole N. lactamica organisms. Since the responsiveness of human airway epithelial cells to colonizing bacteria is in part regulated via TLR2 expression and signaling, commensal organisms such as N. lactamica would benefit from expressing a product that induces low TLR2-dependent local inflammation, likely delaying or avoiding clearance by the host.

  3. What about antibiotic resistance in Neisseria lactamica?

    PubMed

    Arreaza, L; Salcedo, C; Alcalá, B; Vázquez, J A

    2002-03-01

    The in vitro activity of penicillin, ampicillin, cefotaxime, ceftriaxone, rifampicin and ciprofloxacin against 286 Neisseria lactamica isolates was determined by agar dilution and the category of susceptibility was analysed in accordance with the criteria used for Neisseria meningitidis. All isolates were considered to have intermediate susceptibility to penicillin. A total of 1.7% of the isolates were resistant to ampicillin but all were susceptible to cefotaxime and ceftriaxone. Rifampicin MICs ranged between 0.12 and 2 mg/L. Six isolates (2.1%) showed decreased susceptibility to ciprofloxacin.

  4. Production of UC-labeled gas in BACTEC Neisseria Differentiation kits by Neisseria cinerea

    SciTech Connect

    Boyce, J.M.; Mitchell, E.B. Jr.; Knapp, J.S.; Buttke, T.M.

    1985-09-01

    Six strains of Neisseria cinerea were tested in BACTEC Neisseria Differentiation kits (Johnston Laboratories, Inc., Towson, Md.), and all yielded positive glucose growth indices and negative maltose and fructose growth indices. These results were similar to those achieved with Neisseria gonorrhoeae. However, most of the N. cinerea isolates tested yielded 3-h glucose growth indices that were lower than those obtained with gonococci. UC-labeled gas was produced significantly faster by N. gonorrhoeae than by N. cinerea. Additional studies suggested that the UC-labeled gas produced by N. cinerea was carbon dioxide. N. cinerea strains were similar to Branhamella catarrhalis strains because both species failed to produce detectable acid from glucose, maltose, sucrose, fructose, and lactose in cysteine-tryptic agar media. However, in contrast to N. cinerea strains, B. catarrhalis strains did not metabolize glucose in BACTEC Neisseria Differentiation kits.

  5. Production of 14C-labeled gas in BACTEC Neisseria Differentiation kits by Neisseria cinerea.

    PubMed

    Boyce, J M; Mitchell, E B; Knapp, J S; Buttke, T M

    1985-09-01

    Six strains of Neisseria cinerea were tested in BACTEC Neisseria Differentiation kits (Johnston Laboratories, Inc., Towson, Md.), and all yielded positive glucose growth indices and negative maltose and fructose growth indices. These results were similar to those achieved with Neisseria gonorrhoeae. However, most of the N. cinerea isolates tested yielded 3-h glucose growth indices that were lower than those obtained with gonococci. 14C-labeled gas was produced significantly faster (P less than 0.02) by N. gonorrhoeae than by N. cinerea. Additional studies suggested that the 14C-labeled gas produced by N. cinerea was carbon dioxide. N. cinerea strains were similar to Branhamella catarrhalis strains because both species failed to produce detectable acid from glucose, maltose, sucrose, fructose, and lactose in cysteine-tryptic agar media. However, in contrast to N. cinerea strains, B. catarrhalis strains did not metabolize glucose in BACTEC Neisseria Differentiation kits.

  6. Conjugation of plasmids of Neisseria gonorrhoeae to other Neisseria species: potential reservoirs for the beta-lactamase plasmid.

    PubMed

    Genco, C A; Knapp, J S; Clark, V L

    1984-09-01

    The discovery that penicillinase production in Neisseria gonorrhoeae was plasmid mediated and the spread of the beta-lactamase encoding plasmids in gonococcal isolates since 1976, raise the possibility that a nonpathogenic indigenous bacterium could serve as a reservoir for these plasmids. We initiated studies to define the ability of commensal Neisseria species and Branhamella catarrhalis strains, as well as strains of the pathogen Neisseria meningitidis, to serve as recipients in conjugation with Neisseria gonorrhoeae. We found that with N. gonorrhoeae as the donor, 3 of 5 Neisseria cinerea, 2 of 5 Neisseria flava, 0 of 1 Neisseria flavescens, 1 of 3 Neisseria subflava, 0 of 6 B. catarrhalis, 0 of 7 Neisseria lactamica, 1 of 5 Neisseria mucosa, 1 of 7 Neisseria perflava/sicca, and 0 of 13 N. meningitidis strains gave detectable conjugation frequencies (greater than 10(-8). N. cinerea was the only species found to maintain the gonococcal conjugal plasmid (pLE2451). A N. cinerea transconjugant containing pLE2451 was observed to transfer both the beta-lactamase plasmid and pLE2451 to N. gonorrhoeae at high frequency.

  7. New complementation constructs for inducible and constitutive gene expression in Neisseria gonorrhoeae and Neisseria meningitidis.

    PubMed

    Ramsey, Meghan E; Hackett, Kathleen T; Kotha, Chaitra; Dillard, Joseph P

    2012-05-01

    We have created new complementation constructs for use in Neisseria gonorrhoeae and Neisseria meningitidis. The constructs contain regions of homology with the chromosome and direct the insertion of a gene of interest into the intergenic region between the genes iga and trpB. In order to increase the available options for gene expression in Neisseria, we designed the constructs to contain one of three different promoters. One of the constructs contains the isopropyl-β-d-thiogalactopyranoside-inducible lac promoter, which has been widely used in Neisseria. We also designed a construct that contains the strong, constitutive promoter from the gonococcal opaB gene. The third construct contains a tetracycline-inducible promoter, a novel use of this promoter in Neisseria. We demonstrate that anhydrotetracycline can be used to induce gene expression in the pathogenic Neisseria at very low concentrations and without negatively affecting the growth of the organisms. We use these constructs to complement an arginine auxotrophy in N. gonorrhoeae as well as to express a translational fusion of alkaline phosphatase with TraW. TraW is a component of the gonococcal type IV secretion system, and we demonstrate that TraW localizes to the periplasm.

  8. Cervical spondylitis due to Neisseria meningitidis.

    PubMed

    Mendes, Stéphanie; Bémer, Pascale; Corvec, Stéphane; Faure, Alexis; Redon, Hervé; Drugeon, Henri B

    2006-05-01

    The diverse clinical spectrum of meningococcal infections includes frequent clinical forms, such as meningitis or septicemia, and uncommon manifestations, such as septic arthritis. Neisseria meningitidis is not generally considered to be a causative agent of osteoarticular infections. We report the first case of acute primary cervical spondylitis in a 48-year-old man.

  9. Identification of acquired DNA in Neisseria lactamica.

    PubMed

    van Passel, Mark W J; Bart, Aldert; Luyf, Angela C M; van Kampen, Antoine H C; van der Ende, Arie

    2006-09-01

    Anomalous DNA (aDNA) in prokaryotic genomes, identified by its aberrant nucleotide composition, generally represents horizontally acquired DNA. Previous studies showed that frequent DNA transfer occurs between commensal Neisseriae and Neisseria meningitidis. Currently, it is unknown whether aDNA regions are also transferred between these species. The genome of Neisseria lactamica strain 892586 was assessed by a strategy that enables the selective isolation of aDNA, using endonucleases with recognition sites that are overrepresented in aDNA. Of eight regions with aDNA, five displayed similarity to virulence-associated meningococcal sequences. Of three aDNA fragments with limited or no similarity to neisserial sequences, one encodes a novel putative autotransporter/adhesin. The remaining two fragments are adjacent in the N. lactamica genome, and encode a novel putative ATPase/subtilisin-like protease operon. A similar operon is present in the genomes of different respiratory tract pathogens. The identification of aDNA from N. lactamica with similarity to meningococcal aDNA shows that genetic exchange between the Neisseriae is not limited to the neisserial core genome. The discovery of aDNA in N. lactamica similar to a locus in other pathogens substantially expands the neisserial gene pool.

  10. Two unique restriction endonucleases from Neisseria lactamica.

    PubMed

    Qiang, B Q; Schildkraut, I

    1986-03-11

    Two new site-specific endonucleases, N1a III and N1a IV, have been isolated from Neisseria lactamica. N1a III recognizes the sequence, CATG, and cleaves 3' of the sequence to produce a four base 3' extension. N1a IV recognizes the sequence, GGNNCC, and cleaves between the two N's to produce blunt ended fragments.

  11. Neisseria lactamica septicemia in an immunocompromised patient.

    PubMed

    Schifman, R B; Ryan, K J

    1983-05-01

    Neisseria lactamica was isolated from the blood of a 7-year-old girl who was immunosuppressed from chemotherapy for acute lymphocytic leukemia. She was receiving trimethoprim-sulfamethoxazole prophylactically. The isolate was resistant to trimethoprim-sulfamethoxazole and sensitive to penicillin. The patient responded to intravenous penicillin therapy. The organism did not produce immunoglobulin A1 protease.

  12. Nucleotide sequence composition and method for detection of neisseria gonorrhoeae

    SciTech Connect

    Lo, A.; Yang, H.L.

    1990-02-13

    This patent describes a composition of matter that is specific for {ital Neisseria gonorrhoeae}. It comprises: at least one nucleotide sequence for which the ratio of the amount of the sequence which hybridizes to chromosomal DNA of {ital Neisseria gonorrhoeae} to the amount of the sequence which hybridizes to chromosomal DNA of {ital Neisseria meningitidis} is greater than about five. The ratio being obtained by a method described.

  13. Difficulties in differentiating Neisseria cinerea from Neisseria gonorrhoeae in rapid systems used for identifying pathogenic Neisseria species.

    PubMed

    Boyce, J M; Mitchell, E B

    1985-11-01

    Neisseria cinerea and Neisseria gonorrhoeae may occur at the same body sites and may have similar colony morphologies. Ideally, systems used for rapid identification of N. gonorrhoeae should be able to differentiate N. cinerea from gonococci. We tested seven N. cinerea strains using the Gonochek II (Du Pont Diagnostics), Minitek (BBL Microbiology Systems), RapID-NH (Innovative Diagnostics, Inc.), RIM-N (American Microscan), and Phadebact (Pharmacia Diagnostics) systems. We found that the reactions produced by N. cinerea in Gonochek II, Minitek, and RapID-NH kits could be confused with the results produced by some strains of N. gonorrhoeae. The susceptibility of N. cinerea to colistin, its ability to grow on tryptic soy or Mueller-Hinton agar, and its inability to grow on modified Thayer-Martin medium help differentiate it from gonococci.

  14. [Frequency and characterization of "Neisseria lactamica" among the population of Milan Italy (author's transl)].

    PubMed

    Gelosa, L

    1981-01-01

    In 1979, 4,941 asymptomatic subjects, ranging from children to adolescents and working-age adults living in the Milan area, were examined for the presence of neisseriae in rhinopharyngeal exudate. 382 carriers of neisseriae were identified (7.7%); of these, 265 (5.3%) presented Neisseria meningitidis and 117 (2.4%) Neisseria lactamica. Carriers of Neisseria lactamica were found more frequently among children and adolescents than among adults of working age. The strains of Neisseria lactamica isolated showed the same degree of sensitivity and resistance to chemoantibiotics as Neisseria meningitidis strains. Difficulty was found in serotyping the strains of Neisseria lactamica isolated, due to tendency to polyagglutinability. The Author stresses the need to include the lactose test in the identification of neisseria, in order to differentiate between Neisseria lactamica and Neisseria meningitidis.

  15. Genome sequence analyses show that Neisseria oralis is the same species as ‘Neisseria mucosa var. heidelbergensis’

    PubMed Central

    Jolley, Keith A.; Maiden, Martin C. J.

    2013-01-01

    Phylogenies generated from whole genome sequence (WGS) data provide definitive means of bacterial isolate characterization for typing and taxonomy. The species status of strains recently defined with conventional taxonomic approaches as representing Neisseria oralis was examined by the analysis of sequences derived from WGS data, specifically: (i) 53 Neisseria ribosomal protein subunit (rps) genes (ribosomal multi-locus sequence typing, rMLST); and (ii) 246 Neisseria core genes (core genome MLST, cgMLST). These data were compared with phylogenies derived from 16S and 23S rRNA gene sequences, demonstrating that the N. oralis strains were monophyletic with strains described previously as representing ‘Neisseria mucosa var. heidelbergensis’ and that this group was of equivalent taxonomic status to other well-described species of the genus Neisseria. Phylogenetic analyses also indicated that Neisseria sicca and Neisseria macacae should be considered the same species as Neisseria mucosa and that Neisseria flavescens should be considered the same species as Neisseria subflava. Analyses using rMLST showed that some strains currently defined as belonging to the genus Neisseria were more closely related to species belonging to other genera within the family; however, whole genome analysis of a more comprehensive selection of strains from within the family Neisseriaceae would be necessary to confirm this. We suggest that strains previously identified as representing ‘N. mucosa var. heidelbergensis’ and deposited in culture collections should be renamed N. oralis. Finally, one of the strains of N. oralis was able to ferment lactose, due to the presence of β-galactosidase and lactose permease genes, a characteristic previously thought to be unique to Neisseria lactamica, which therefore cannot be thought of as diagnostic for this species; however, the rMLST and cgMLST analyses confirm that N. oralis is most closely related to N. mucosa. PMID:24097834

  16. Cross-linking analysis of antigenic outer membrane protein complexes of Neisseria meningitidis.

    PubMed

    Sánchez, Sandra; Abel, Ana; Arenas, Jesús; Criado, María Teresa; Ferreirós, Carlos M

    2006-03-01

    Polysaccharide-based approaches have not enabled the development of effective vaccines against meningococci of serogroup B, and the most promising current research is focused on the use of outer membrane vesicles. Due to the toxicity of the outer membrane oligosaccharides, new vaccines based on purified proteins are being sought, but despite the application of advanced techniques, they remain elusive, perhaps due to the fact that standard techniques for analysis of antigens overlook conformational epitopes located in membrane complexes. Membrane complex antigens have been analyzed in Neisseria gonorrhoeae, and a study published on Neisseria meningitidis has reported the in vitro formation of 800-kD complexes by deposition of a purified protein (MSP63) onto synthetic lipid layers; however, no studies to date have attempted to identify membrane complexes present in vivo in N. meningitidis. In the present study, cross-linking with formaldehyde was used to identify outer membrane protein associations in various N. meningitidis and Neisseria lactamica strains. In N. meningitides, complexes of about 450 kD (also present in N. lactamica), 165 and 95 kD were detected and shown to be made up of the proteins MSP63, PorA/PorB/RmpM/FetA, and PorA/PorB/RmpM, respectively. In western blots, the 450-kD complex was identified by mouse antibodies raised against outer membrane vesicles, but not by antibodies raised against the purified complex, demonstrating the importance of conformational epitopes, and thus suggesting that the analysis of antigens in their native conformation may be useful or even essential for the design of effective vaccines against meningococci.

  17. The epidemiology of infections due to Neisseria meningitidis and Neisseria lactamica in a northern Nigerian community.

    PubMed

    Blakebrough, I S; Greenwood, B M; Whittle, H C; Bradley, A K; Gilles, H M

    1982-11-01

    The epidemiology of infection due to Neisseria meningitidis and Neisseria lactamica was studied in a northern Nigerian community. A low meningococcal carriage rate was observed throughout the two-year survey. Initially, most meningococci isolated from nasopharyngeal carriers belonged to serogroup C or to serogroup Y. Following an outbreak of group A meningococcal disease, more group A meningococcal carriers were detected. Antibody studies indicated that infection with group A meningococci had been more widespread in the community than was suggested by regular carrier surveys. Carriage of meningococci was detected most frequently in children one to nine years of age. Children were identified as the first carriers in households more frequently than adults. The half-life of carriage was three months. The meningococcal carriage rate did not increase during the hot dry season when epidemics of meningococcal disease occur most frequently in Nigeria. Neisseria lactamica was isolated from the nasopharynx of children more frequently than were meningococci.

  18. Tricuspid valve endocarditis due to Neisseria cinerea.

    PubMed

    Benes, J; Dzupova, O; Krizova, P; Rozsypal, H

    2003-02-01

    Reported here is a case of infective endocarditis caused by the saprophytic species Neisseria cinerea. To the best of our knowledge, this etiology has not been documented in the medical literature previously. The patient was an intravenous drug addict who developed tricuspid endocarditis with lung embolism. The disease was cured after treatment with ampicillin/clavulanate that was changed to ceftriaxone after an embolic event.

  19. Nucleic Acid Amplification Testing for Neisseria gonorrhoeae

    PubMed Central

    Whiley, David M.; Tapsall, John W.; Sloots, Theo P.

    2006-01-01

    Nucleic acid amplification tests (NAATs) for the detection of Neisseria gonorrhoeae became available in the early 1990s. Although offering several advantages over traditional detection methods, N. gonorrhoeae NAATs do have some limitations. These include cost, risk of carryover contamination, inhibition, and inability to provide antibiotic resistance data. In addition, there are sequence-related limitations that are unique to N. gonorrhoeae NAATs. In particular, false-positive results are a major consideration. These primarily stem from the frequent horizontal genetic exchange occurring within the Neisseria genus, leading to commensal Neisseria species acquiring N. gonorrhoeae genes. Furthermore, some N. gonorrhoeae subtypes may lack specific sequences targeted by a particular NAAT. Therefore, NAAT false-negative results because of sequence variation may occur in some gonococcal populations. Overall, the N. gonorrhoeae species continues to present a considerable challenge for molecular diagnostics. The need to evaluate N. gonorrhoeae NAATs before their use in any new patient population and to educate physicians on the limitations of these tests is emphasized in this review. PMID:16436629

  20. Draft Genome Assembly of Neisseria lactamica Type Strain A7515.

    PubMed

    Minogue, T D; Daligault, H A; Davenport, K W; Bishop-Lilly, K A; Bruce, D C; Chain, P S; Chertkov, O; Coyne, S R; Freitas, T; Frey, K G; Jaissle, J; Koroleva, G I; Ladner, J T; Palacios, G F; Redden, C L; Xu, Y; Johnson, S L

    2014-09-25

    We present the scaffolded genome assembly of Neisseria lactamica type strain A7515 (ATCC 23970) as submitted to NCBI under accession no. JOVI00000000. This type strain of the lactose-fermenting Neisseria species is often used in quality control testing and intra-genus phylogenetic analyses. The assembly includes four contigs placed into a single scaffold.

  1. A novel mimetic antigen eliciting protective antibody to Neisseria meningitidis.

    PubMed

    Granoff, D M; Moe, G R; Giuliani, M M; Adu-Bobie, J; Santini, L; Brunelli, B; Piccinetti, F; Zuno-Mitchell, P; Lee, S S; Neri, P; Bracci, L; Lozzi, L; Rappuoli, R

    2001-12-01

    Molecular mimetic Ags are of considerable interest as vaccine candidates. Yet there are few examples of mimetic Ags that elicit protective Ab against a pathogen, and the functional activity of anti-mimetic Abs has not been studied in detail. As part of the Neisseria meningitidis serogroup B genome sequencing project, a large number of novel proteins were identified. Herein, we provide evidence that genome-derived Ag 33 (GNA33), a lipoprotein with homology to Escherichia coli murein transglycosylase, elicits protective Ab to meningococci as a result of mimicking an epitope on loop 4 of porin A (PorA) in strains with serosubtype P1.2. Epitope mapping of a bactericidal anti-GNA33 mAb using overlapping peptides shows that the mAb recognizes peptides from GNA33 and PorA that share a QTP sequence that is necessary but not sufficient for binding. By flow cytometry, mouse antisera prepared against rGNA33 and the anti-GNA33 mAb bind as well as an anti-PorA P1.2 mAb to the surface of eight of nine N. meningitidis serogroup B strains tested with the P1.2 serosubtype. Anti-GNA33 Abs also are bactericidal for most P1.2 strains and, for susceptible strains, the activity of an anti-GNA33 mAb is similar to that of an anticapsular mAb but less active than an anti-P1.2 mAb. Anti-GNA Abs also confer passive protection against bacteremia in infant rats challenged with P1.2 strains. Thus, GNA33 represents one of the most effective immunogenic mimetics yet described. These results demonstrate that molecular mimetics have potential as meningococcal vaccine candidates.

  2. Amylosucrase from Neisseria polysaccharea: novel catalytic properties.

    PubMed

    Potocki de Montalk, G; Remaud-Simeon, M; Willemot, R M; Sarçabal, P; Planchot, V; Monsan, P

    2000-04-14

    Amylosucrase is a glucosyltransferase that synthesises an insoluble alpha-glucan from sucrose. The catalytic properties of the highly purified amylosucrase from Neisseria polysaccharea were characterised. Contrary to previously published results, it was demonstrated that in the presence of sucrose alone, several reactions are catalysed, in addition to polymer synthesis: sucrose hydrolysis, maltose and maltotriose synthesis by successive transfers of the glucosyl moiety of sucrose onto the released glucose, and finally turanose and trehalulose synthesis - these two sucrose isomers being obtained by glucosyl transfer onto fructose. The effect of initial sucrose concentration on initial activity demonstrated a non-Michaelian profile never previously described.

  3. Sucrose-mediated giant cell formation in the genus Neisseria.

    PubMed

    Johnson, K G; McDonald, I J

    1976-03-01

    Growth of Neisseria perflava, Neisseria cinerea, and Neisseria sicca strain Kirkland in media supplemented with sucrose (0.5 to 5.0% w/v) resulted in the formation of giant cells. Response to sucrose was specific in that a variety of other carbohydrates did not mediate giant cell formation. Giant cells appeared only under growth conditions and did not lyse upon transfer to medium lacking sucrose or upon resuspension in hypotonic media. Reversion of giant to normal cells occurred when giant cells were used as inocula and allowed to multiply in media lacking sucrose.

  4. Neisseria gonorrhoeae : Detection and Typing by Probe Hybridization, LCR, and PCR.

    PubMed

    Gaydos, C A; Quinn, T C

    1999-01-01

    Neisseria gonorrhoeae, first described by Neisser in 1879, is a Gram-negative, nonmotile, nonspore-forming diplococcus, belonging to the family Neisseriaceae. It is the etiologic agent of gonorrhea. The other pathogenic species is Neisseria meningitidis, to which N. gonorrhoeae is genetically closely related. Although N. meningitidis is not usually considered to be a sexually transmitted disease, it may infect the mucous membranes of the anogenital area of homosexual men (1). The other members of the genus, which include Neisseria lactamic a, Neisseriapolysaccharea, Neisseria cinerea, and Neisseria flavescens, which are related to Neisseria gonorrhoeae, and saccharolytic strains, such as Neisseria subflava, Neisseria sicca, and Neisseria mucosa, which are less genetically related to the aforementioned, are considered to be nonpathogenic, being normal flora of the nasopharyngeal mucous membranes (2).

  5. Neisseria prophage repressor implicated in gonococcal pathogenesis.

    PubMed

    Daou, Nadine; Yu, Chunxiao; McClure, Ryan; Gudino, Cynthia; Reed, George W; Genco, Caroline A

    2013-10-01

    Neisseria gonorrhoeae, the causative agent of the sexually transmitted disease gonorrhea, can infect and colonize multiple mucosal sites in both men and women. The ability to cope with different environmental conditions requires tight regulation of gene expression. In this study, we identified and characterized a gonococcal transcriptional regulatory protein (Neisseria phage repressor [Npr]) that was previously annotated as a putative gonococcal phage repressor protein. Npr was found to repress transcription of NGNG_00460 to NGNG_00463 (NGNG_00460-00463), an operon present within the phage locus NgoΦ4. Npr binding sites within the NGNG_00460-00463 promoter region were found to overlap the -10 and -35 promoter motifs. A gonococcal npr mutant demonstrated increased adherence to and invasion of human endocervical epithelial cells compared to a wild-type gonococcal strain. Likewise, the gonococcal npr mutant exhibited enhanced colonization in a gonococcal mouse model of mucosal infection. Analysis of the gonococcal npr mutant using RNA sequence (RNA-seq) analysis demonstrated that the Npr regulon is limited to the operon present within the phage locus. Collectively, our studies have defined a new gonococcal phage repressor protein that controls the transcription of genes implicated in gonococcal pathogenesis.

  6. Neisseria Prophage Repressor Implicated in Gonococcal Pathogenesis

    PubMed Central

    Daou, Nadine; Yu, Chunxiao; Mcclure, Ryan; Gudino, Cynthia; Reed, George W.

    2013-01-01

    Neisseria gonorrhoeae, the causative agent of the sexually transmitted disease gonorrhea, can infect and colonize multiple mucosal sites in both men and women. The ability to cope with different environmental conditions requires tight regulation of gene expression. In this study, we identified and characterized a gonococcal transcriptional regulatory protein (Neisseria phage repressor [Npr]) that was previously annotated as a putative gonococcal phage repressor protein. Npr was found to repress transcription of NGNG_00460 to NGNG_00463 (NGNG_00460-00463), an operon present within the phage locus NgoΦ4. Npr binding sites within the NGNG_00460-00463 promoter region were found to overlap the −10 and −35 promoter motifs. A gonococcal npr mutant demonstrated increased adherence to and invasion of human endocervical epithelial cells compared to a wild-type gonococcal strain. Likewise, the gonococcal npr mutant exhibited enhanced colonization in a gonococcal mouse model of mucosal infection. Analysis of the gonococcal npr mutant using RNA sequence (RNA-seq) analysis demonstrated that the Npr regulon is limited to the operon present within the phage locus. Collectively, our studies have defined a new gonococcal phage repressor protein that controls the transcription of genes implicated in gonococcal pathogenesis. PMID:23876804

  7. The use of monoclonal antibodies to Neisseria lactamica in an antigen selection to Neisseria meningitides B vaccine.

    PubMed

    De Gaspari, Elizabeth N

    2008-10-01

    Abstract Neisseria lactamica, a commensal bacterium that is non-pathogenic to humans and is usually found in the upper respiratory tract of children, is closely related to the pathogenic species Neisseria meningitidis. Colonization by Neisseria lactamica can be responsible for the development of natural immunity to meningococcal infection in childhood, when rates of meningococcal carriers are low. These features suggest that N. lactamica components can be key elements in the production of a new vaccine for N. meningitidis. The production of monoclonal antibodies for N. lactamica is an important tool in the selection of new antigens for the preparation of a vaccine for N. meningitidis B.

  8. Neisseria meningitidis serogroup A capsular polysaccharide acetyltransferase, methods and compositions

    DOEpatents

    Stephens, David S [Stone Mountain, GA; Gudlavalleti, Seshu K [Kensington, MD; Tzeng, Yih-Ling [Atlanta, GA; Datta, Anup K [San Diego, CA; Carlson, Russell W [Athens, GA

    2011-02-08

    Provided are methods for recombinant production of an O-acetyltransferase and methods for acetylating capsular polysaccharides, especially those of a Serogroup A Neisseria meningitidis using the recombinant O-acetyltransferase, and immunogenic compositions comprising the acetylated capsular polysaccharide.

  9. Population genomics: diversity and virulence in the Neisseria.

    PubMed

    Maiden, Martin Cj

    2008-10-01

    Advances in high-throughput nucleotide sequencing and bioinformatics make the study of genomes at the population level feasible. Preliminary population genomic studies have explored the relationships among three closely related bacteria, Neisseria meningitidis, Neisseria gonorrhoeae and Neisseria lactamica, which exhibit very different phenotypes with respect to human colonisation. The data obtained have been especially valuable in the establishing of the role of horizontal genetic exchange in bacterial speciation and shaping population structure. In the meningococcus, they have been used to define invasive genetic types, search for virulence factors and potential vaccine components and investigate the effects of vaccines on population structure. These are generic approaches and their application to the Neisseria provides a foretaste for their application to the wider bacterial world.

  10. In vitro induction of memory-driven responses against Neisseria meningitidis by priming with Neisseria lactamica.

    PubMed

    Sánchez, S; Troncoso, G; Criado, M T; Ferreirós, C

    2002-07-26

    Natural immunity against Neisseria meningitidis is acquired during childhood and youth through successive colonizations by commensal Neisseria, carrier N. meningitidis, and other bacterial genera sharing cross-reactive antigens with the meningococci. We have analyzed in mice the ability of Neisseria lactamica strains to induce immunological memory so that, upon a later contact with N. meningitidis, quickly raise protective responses against antigens that show cross-reactivity with meningococcal surface proteins. Sera obtained from mice immunized with N. lactamica and boosted with N. meningitidis were able to kill meningococci, with bactericidal activities variable depending on the immunizing strains used in the assays. Different mixtures of those sera resulted in higher killing activities, which agrees with the idea that successive colonizations by N. lactamica enhance the anti-meningococcal response. The existence of such outer membrane cross-reactive antigens has to be kept in mind when using outer membrane vesicle (OMV)-based anti-meningococcal vaccines because their use can affect colonization by N. lactamica and other species, hampering the natural mechanisms of acquisition of immunity to the meningococci, and leaving its ecological niche free for colonization by undesirable microorganisms.

  11. Role of outer-membrane proteins and lipopolysaccharide in conjugation between Neisseria gonorrhoeae and Neisseria cinerea.

    PubMed

    Genco, C A; Clark, V L

    1988-12-01

    Little is known concerning the mechanism involved in cell contact between the donor and recipient during conjugation in Neisseria gonorrhoeae. The formation of stable mating pairs during conjugation in Escherichia coli appears to require a specific protein as well as LPS in the outer membrane of the recipient cell. To attempt to identify the cell surface components necessary for conjugation in the neisseriae, we began a comparison of the outer membrane of Neisseria cinerea strains that can (Con+) and cannot (Con-) serve as recipients in conjugation with N. gonorrhoeae. There were no differences in outer-membrane protein profiles on SDS-polyacrylamide gel electrophoresis between Con+ and Con- strains that could be correlated with the ability to conjugate. However, whole outer membrane isolated from Con+ strains specifically inhibited conjugation while those from Con- strains did not. Proteolytic cleavage of outer-membrane proteins by trypsin, pronase or alpha-chymotrypsin abolished the inhibitory effect of Con+ outer membranes, suggesting that these outer membranes contained a protease-sensitive protein(s) involved in conjugation. Although periodate oxidation of Con+ outer-membrane carbohydrates did not abolish the inhibitory action of these membranes, purified LPS from both Con+ and Con- strains inhibited conjugation when added at low concentrations. These results suggest that conjugation requires the presence of a specific conjugal receptor that consists of both LPS and one or more outer-membrane proteins. Both Con+ and Con- strains contain the necessary LPS, but only Con+ strains contain the required protein(s).

  12. Neisseria lactamica and Neisseria polysaccharea as possible sources of meningococcal beta-lactam resistance by genetic transformation.

    PubMed Central

    Saez-Nieto, J A; Lujan, R; Martinez-Suarez, J V; Berron, S; Vazquez, J A; Viñas, M; Campos, J

    1990-01-01

    We studied the susceptibilities of relatively penicillin G-resistant and -susceptible strains of Neisseria meningitidis, as well as Neisseria lactamica and Neisseria polysaccharea, to penicillin, ampicillin, and several cephalosporins. The MICs of penicillin, ampicillin, cephalothin, and cefuroxime for moderately resistant meningococci have increased two- to sixfold in relation to MICs for susceptible strains. For these strains of meningococci, N. lactamica, and N. polysaccharea, penicillin, ampicillin, cephalothin, and cefuroxime MICs for 50 and 90% of strains were similar. By genetic transformation of a penicillin-susceptible strain of N. meningitidis to low-level penicillin resistance with DNA from penicillin-resistant strains of N. meningitidis, N. lactamica, N. polysaccharea, and N. gonorrhoeae, isogenic strains with the same pattern of resistance to beta-lactams were obtained, suggesting that these commensal Neisseria spp. could be the source of meningococcal resistance genes. PMID:2127349

  13. Neisseria lactamica and Neisseria polysaccharea as possible sources of meningococcal beta-lactam resistance by genetic transformation.

    PubMed

    Saez-Nieto, J A; Lujan, R; Martinez-Suarez, J V; Berron, S; Vazquez, J A; Viñas, M; Campos, J

    1990-11-01

    We studied the susceptibilities of relatively penicillin G-resistant and -susceptible strains of Neisseria meningitidis, as well as Neisseria lactamica and Neisseria polysaccharea, to penicillin, ampicillin, and several cephalosporins. The MICs of penicillin, ampicillin, cephalothin, and cefuroxime for moderately resistant meningococci have increased two- to sixfold in relation to MICs for susceptible strains. For these strains of meningococci, N. lactamica, and N. polysaccharea, penicillin, ampicillin, cephalothin, and cefuroxime MICs for 50 and 90% of strains were similar. By genetic transformation of a penicillin-susceptible strain of N. meningitidis to low-level penicillin resistance with DNA from penicillin-resistant strains of N. meningitidis, N. lactamica, N. polysaccharea, and N. gonorrhoeae, isogenic strains with the same pattern of resistance to beta-lactams were obtained, suggesting that these commensal Neisseria spp. could be the source of meningococcal resistance genes.

  14. Drug-resistant Neisseria gonorrhoeae: latest developments.

    PubMed

    Suay-García, B; Pérez-Gracia, M T

    2017-02-16

    Gonorrhea is the second most frequently reported notifiable disease in the United States and is becoming increasingly common in Europe. The purpose of this review was to assess the current state of drug-resistant Neisseria gonorrhoeae in order to evaluate future prospects for its treatment. An exhaustive literature search was conducted to include the latest research regarding drug resistance and treatment guidelines for gonorrhea. Gonococci have acquired all known resistance mechanisms to all antimicrobials used for treatment. Currently, the European Union, the United States, and the United Kingdom have established surveillance programs to assess, on a yearly basis, the development of gonococcal resistance. Current treatment guidelines are being threatened by the increasing number of ceftriaxone-, cefixime-, and azithromycin-resistant N. gonorrhoeae strains being detected worldwide. This has led the scientific community to develop new treatment options with new molecules in order to persevere in the battle against this "superbug".

  15. Neisseria lactamica protects against experimental meningococcal infection.

    PubMed

    Oliver, Kerry J; Reddin, Karen M; Bracegirdle, Philippa; Hudson, Michael J; Borrow, Ray; Feavers, Ian M; Robinson, Andrew; Cartwright, Keith; Gorringe, Andrew R

    2002-07-01

    Immunological and epidemiological evidence suggests that the development of natural immunity to meningococcal disease results from colonization of the nasopharynx by commensal Neisseria spp., particularly with N. lactamica. We report here that immunization with N. lactamica killed whole cells, outer membrane vesicles, or outer membrane protein (OMP) pools and protected mice against lethal challenge by a number of diverse serogroup B and C meningococcal isolates in a model of bacteremic infection. Sera raised to N. lactamica killed whole cells, OMPs, or protein pools were found to cross-react with meningococcal isolates of a diverse range of genotypes and phenotypes. The results confirm the potential of N. lactamica to form the basis of a vaccine against meningococcal disease.

  16. Meningitis and Bacteremia Due to Neisseria cinerea following a Percutaneous Rhizotomy of the Trigeminal Ganglion.

    PubMed

    von Kietzell, M; Richter, H; Bruderer, T; Goldenberger, D; Emonet, S; Strahm, C

    2016-01-01

    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.

  17. Meningitis and Bacteremia Due to Neisseria cinerea following a Percutaneous Rhizotomy of the Trigeminal Ganglion

    PubMed Central

    Richter, H.; Bruderer, T.; Goldenberger, D.; Emonet, S.; Strahm, C.

    2015-01-01

    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. PMID:26511743

  18. Neisseria lactamica selectively induces mitogenic proliferation of the naive B cell pool via cell surface Ig.

    PubMed

    Vaughan, Andrew T; Brackenbury, Louise S; Massari, Paola; Davenport, Victoria; Gorringe, Andrew; Heyderman, Robert S; Williams, Neil A

    2010-09-15

    Neisseria lactamica is a commensal bacteria that colonizes the human upper respiratory tract mucosa during early childhood. In contrast to the closely related opportunistic pathogen Neisseria meningitidis, there is an absence of adaptive cell-mediated immunity to N. lactamica during the peak age of carriage. Instead, outer membrane vesicles derived from N. lactamica mediate a B cell-dependent proliferative response in mucosal mononuclear cells that is associated with the production of polyclonal IgM. We demonstrate in this study that this is a mitogenic human B cell response that occurs independently of T cell help and any other accessory cell population. The ability to drive B cell proliferation is a highly conserved property and is present in N. lactamica strains derived from diverse clonal complexes. CFSE staining of purified human tonsillar B cells demonstrated that naive IgD(+) and CD27(-) B cells are selectively induced to proliferate by outer membrane vesicles, including the innate CD5(+) subset. Neither purified lipooligosaccharide nor PorB from N. lactamica is likely to be responsible for this activity. Prior treatment of B cells with pronase to remove cell-surface Ig or treatment with BCR-specific Abs abrogated the proliferative response to N. lactamica outer membrane vesicles, suggesting that this mitogenic response is dependent upon the BCR.

  19. Molecular characterization of a collection of Neisseria meningitidis isolates from Croatia, June 2009 to January 2014.

    PubMed

    Bukovski, Suzana; Vacca, Paola; Anselmo, Anna; Knezovic, Ivica; Fazio, Cecilia; Neri, Arianna; Ciammaruconi, Andrea; Fortunato, Antonella; Palozzi, Anna Maria; Fillo, Silvia; Lista, Florigio; Stefanelli, Paola

    2016-09-01

    In the last decade, the incidence of invasive meningococcal disease (IMD) in Croatia remained stable at approximately 1 case per 100 000 inhabitants, affecting mainly children aged ≤5 years. We report the molecular characterization of meningococci causing IMD occurring from June 2009 to January 2014 in Croatia. Genomic DNA from 50 clinical isolates was analysed for serogroup, multilocus sequence typing and allele type of the two outer membrane protein genes, porA and the iron-regulated fetA. Furthermore, 22 of them were characterized by using whole-genome sequencing to define the meningococcal vaccine four-component meningococcal serogroup B (4CMenB) antigen genes factor H-binding protein (fHbp), Neisseria heparin-binding antigen (nhba) and Neisseria adhesin A (nadA) and the antimicrobial target resistance genes for penicillin (penicillin binding protein 2, penA), ciprofloxacin (DNA gyrase subunit A, gyrA) and rifampicin (β-subunit of RNA polymerase, rpoB). The Etest was used to phenotypically determine the antimicrobial susceptibility of isolated meningococci. The main serogroup/clonal complex combinations were MenB cc41/44, MenC/cc11, MenW/cc174 and MenY/cc23. PorA P1.7-2, FetA F5-5 and F1-5 were the most represented through the serogroups. Meningococci with decreased susceptibility to penicillin (38.9 %) and one strain resistant to ciprofloxacin were identified. Forty-two percent of MenB showed the presence of at least one of the 4CMenB vaccine antigens (fHbp, NHBA, NadA and PorA). Our findings highlight the genetic variability of meningococci causing IMD in Croatia, especially for the serogroup B. Molecular-based characterization of meningococci is crucial to enhance IMD surveillance and to better plan national immunization programmes.

  20. Carriage of Neisseria meningitidis and Neisseria lactamica in infants and children.

    PubMed

    Gold, R; Goldschneider, I; Lepow, M L; Draper, T F; Randolph, M

    1978-02-01

    Asymptomatic carriage of Neisseria meningitidis and Neisseria lactamica was studied in a total of 2,969 healthy infants and children in Danbury, Conn., between October 1971 and June 1975. The prevalence of N. meningitidis averaged 0.71% during the first four years of life and increased to 5.4% by 14--17 years. Rates of carriage of N. lactamica increased from 3.8% in three-month-old infants to a peak of 21.0% at 18 months and then declined to 1.8% by 14--17 years of age. Of the children who acquired N. lactamica, 66% developed fourfold or greater rises in titers of IgG antibody to groups A, B, and/or C meningococci as determined by immunofluorescence compared with only 5% of control children. Of new carriers of N. lactamica, 40% developed increased titers of bactericidal antibody to groups A, B, and/or C meningococci as compared with 7% of noncarriers. Carriage of N. lactamica may assist in the development of natural immunity to N. meningitidis by induction of cross-reactive antibodies.

  1. How clonal are Neisseria species? The epidemic clonality model revisited.

    PubMed

    Tibayrenc, Michel; Ayala, Francisco J

    2015-07-21

    The three species Neisseria meningitidis, Neisseria gonorrheae, and Neisseria lactamica are often regarded as highly recombining bacteria. N. meningitidis has been considered a paradigmatic case of the "semiclonal model" or of "epidemic clonality," demonstrating occasional bouts of clonal propagation in an otherwise recombining species. In this model, occasional clonality generates linkage disequilibrium in the short term. In the long run, however, the effects of clonality are countered by recombination. We show that many data are at odds with this proposal and that N. meningitidis fits the criteria that we have proposed for predominant clonal evolution (PCE). We point out that (i) the proposed way to distinguish epidemic clonality from PCE may be faulty and (ii) the evidence of deep phylogenies by microarrays and whole-genome sequencing is at odds with the predictions of the semiclonal model. Last, we revisit the species status of N. meningitidis, N. gonorrheae, and N. lactamica in the light of the PCE model.

  2. Neisseria meningitidis: Biology, Microbiology, and Epidemiology

    PubMed Central

    Rouphael, Nadine G.; Stephens, David S.

    2015-01-01

    Neisseria meningitidis (the meningococcus) causes significant morbidity and mortality in children and young adults worldwide through epidemic or sporadic meningitis and/or septicemia. In this review, we describe the biology, microbiology, and epidemiology of this exclusive human pathogen. N. meningitidis is a fastidious, encapsulated, aerobic gram-negative diplococcus. Colonies are positive by the oxidase test and most strains utilize maltose. The phenotypic classification of meningococci, based on structural differences in capsular polysaccharide, lipooligosaccharide (LOS) and outer membrane proteins, is now complemented by genome sequence typing (ST). The epidemiological profile of N. meningitidis is variable in different populations and over time and virulence of the meningococcus is based on a transformable/plastic genome and expression of certain capsular polysaccharides (serogroups A, B, C, W-135, Y and X) and non-capsular antigens. N. meningitidis colonizes mucosal surfaces using a multifactorial process involving pili, twitching motility, LOS, opacity associated, and other surface proteins. Certain clonal groups have an increased capacity to gain access to the blood, evade innate immune responses, multiply, and cause systemic disease. Although new vaccines hold great promise, meningococcal infection continues to be reported in both developed and developing countries, where universal vaccine coverage is absent and antibiotic resistance increasingly more common. PMID:21993636

  3. Neisseria cuniculi in ruminants: epidemiological aspects.

    PubMed Central

    Elad, D.; Shlomovitz, S.; Bernstein, M.; Bassan, J.

    1990-01-01

    Neisseria cuniculi was isolated, between March 1987 and March 1989, from 38 cases of respiratory disease in small and large ruminants. In all but five cases N. cuniculi was cultured together with other potential respiratory pathogens. A survey was conducted to assess the prevalence of N. cuniculi in the pharyngeal region of Merino and Awassi purebred sheep, Awassi/East-Friesian and Merino/Romanov crossbred sheep and one exotic cross breed (goat/ibex). N. cuniculi was isolated from 80-88% of the animals under 1 month of age. Among older animals, the microorganism was isolated from 20.5% of the pure bred animals and 79.3% of the crossbred ones. This difference was significant (P less than 0.001) by the chi 2 test. The prevalence of N. cuniculi in the second age group coincides with the susceptibility of the breeds to respiratory pathology. This, we believe, is the first report of N. cuniculi involved in multiple cases of respiratory pathology and of a survey assessing the prevalence of this microorganism in small ruminants. PMID:2249720

  4. Superoxol and aminopeptidase tests for identification of pathogenic Neisseria species and Moraxella (Branhamella) catarrhalis.

    PubMed

    Pérez, J L; Pulido, A; Gómez, E; Sauca, G; Martín, R

    1990-06-01

    The superoxol test, and prolyl aminopeptidase and gammaglutamyl aminopeptidase tests were evaluated for the detection of pathogenic Neisseria spp. using 317 strains of Neisseria-ceae. The superoxol test was positive for all 116 gonococci and 62 Moraxella (Branhamella) catarrhalis strains, but also for three strains of Neisseria meningitidis, one strain of Neisseria lactamica and eight saprophytic neisseriae. When using strains grown on Thayer-Martin medium, the positive and negative predictive values of the superoxol test for the identification of Neisseria gonorrhoeae were 96.7% and 100% respectively. Meningococci were the only neisseriae growing on Thayer-Martin medium that showed gamma-glutamyl aminopeptidase activity. The prolyl aminopeptidase test showed low specificity.

  5. Conservation of Meningococcal Antigens in the Genus Neisseria

    PubMed Central

    Muzzi, Alessandro; Mora, Marirosa; Pizza, Mariagrazia; Rappuoli, Rino; Donati, Claudio

    2013-01-01

    ABSTRACT Neisseria meningitidis, one of the major causes of bacterial meningitis and sepsis, is a member of the genus Neisseria, which includes species that colonize the mucosae of many animals. Three meningococcal proteins, factor H-binding protein (fHbp), neisserial heparin-binding antigen (NHBA), and N. meningitidis adhesin A (NadA), have been described as antigens protective against N. meningitidis of serogroup B, and they have been employed as vaccine components in preclinical and clinical studies. In the vaccine formulation, fHbp and NHBA were fused to the GNA2091 and GNA1030 proteins, respectively, to enhance protein stability and immunogenicity. To determine the possible impact of vaccination on commensal neisseriae, we determined the presence, distribution, and conservation of these antigens in the available genome sequences of the genus Neisseria, finding that fHbp, NHBA, and NadA were conserved only in species colonizing humans, while GNA1030 and GNA2091 were conserved in many human and nonhuman neisseriae. Sequence analysis showed that homologous recombination contributed to shape the evolution and distribution of both NHBA and fHbp, three major variants of which have been defined. fHbp variant 3 was probably the ancestral form of meningococcal fHbp, while fHbp variant 1 from N. cinerea was introduced into N. meningitidis by a recombination event. fHbp variant 2 was the result of a recombination event inserting a stretch of 483 bp from variant 1 into the variant 3 background. These data indicate that a high rate of exchange of genetic material between neisseriae that colonize the human upper respiratory tract exists. PMID:23760461

  6. Epidemiological characterization of Neisseria gonorrhoeae by lectins.

    PubMed Central

    Schalla, W O; Whittington, W L; Rice, R J; Larsen, S A

    1985-01-01

    A total of 101 isolates of penicillinase-producing and non-penicillinase-producing Neisseria gonorrhoeae with known nutritional requirements, plasmid content, and serovars, were examined for lectin agglutination patterns. These isolates were from outbreaks in Georgia, California, Hawaii, and Pennsylvania. Cell suspensions made from 16- to 18-h cultures were mixed with 14 different lectins, and the resultant agglutination patterns were classified as agglutination groups. Among the 101 isolates tested, 24 different agglutination groups were demonstrated. Of the organisms tested, 55% were located in 3 of the 24 groups, and 86% of the isolates reacted with the lectins Trichosanthes kinlowii, Griffonia simplicifolia I, peanut agglutinin, soybean agglutinin, potato agglutinin, and wheat germ agglutinin. One isolate did not react with peanut or potato agglutinin, five isolates lacked reactivity with potato agglutinin, and six isolates did not react with wheat germ agglutinin. Of the wheat germ-negative isolates, four were from Pennsylvania and were identical with regard to auxotype, plasmid content, serovar, and lectin group. The other two wheat germ-negative isolates were from California and were unrelated by the same criteria to the four Pennsylvania isolates and to each other. Among the isolates tested, there were no differences in lectin groups with regard to the sex of the patient. In the Georgia collection, agglutination with one lectin group was confined to isolates of serogroup IA. This association was not observed for the other geographic areas. Some isolates showing identical auxotype, plasmid content, and serovars could be differentiated based on lectin agglutination patterns, whereas other isolates were identical by all testing criteria. PMID:3930560

  7. Expression of phosphofructokinase in Neisseria meningitidis

    PubMed Central

    Baart, Gino J. E.; Langenhof, Marc; van de Waterbeemd, Bas; Hamstra, Hendrik-Jan; Zomer, Bert; van der Pol, Leo A.; Beuvery, E. C.; Tramper, Johannes; Martens, Dirk E.

    2010-01-01

    Neisseria meningitidis serogroup B is a pathogen that can infect diverse sites within the human host. According to the N. meningitidis genomic information and experimental observations, glucose can be completely catabolized through the Entner–Doudoroff pathway and the pentose phosphate pathway. The Embden–Meyerhof–Parnas pathway is not functional, because the gene for phosphofructokinase (PFK) is not present. The phylogenetic distribution of PFK indicates that in most obligate aerobic organisms, PFK is lacking. We conclude that this is because of the limited contribution of PFK to the energy supply in aerobically grown organisms in comparison with the energy generated through oxidative phosphorylation. Under anaerobic or microaerobic conditions, the available energy is limiting, and PFK provides an advantage, which explains the presence of PFK in many (facultatively) anaerobic organisms. In accordance with this, in silico flux balance analysis predicted an increase of biomass yield as a result of PFK expression. However, analysis of a genetically engineered N. meningitidis strain that expressed a heterologous PFK showed that the yield of biomass on substrate decreased in comparison with a pfkA-deficient control strain, which was associated mainly with an increase in CO2 production, whereas production of by-products was similar in the two strains. This might explain why the pfkA gene has not been obtained by horizontal gene transfer, since it is initially unfavourable for biomass yield. No large effects related to heterologous expression of pfkA were observed in the transcriptome. Although our results suggest that introduction of PFK does not contribute to a more efficient strain in terms of biomass yield, achievement of a robust, optimal metabolic network that enables a higher growth rate or a higher biomass yield might be possible after adaptive evolution of the strain, which remains to be investigated. PMID:19797358

  8. Cationic Antimicrobial Peptide Resistance in Neisseria meningitidis

    PubMed Central

    Tzeng, Yih-Ling; Ambrose, Karita D.; Zughaier, Susu; Zhou, Xiaoliu; Miller, Yoon K.; Shafer, William M.; Stephens, David S.

    2005-01-01

    Cationic antimicrobial peptides (CAMPs) are important components of the innate host defense system against microbial infections and microbial products. However, the human pathogen Neisseria meningitidis is intrinsically highly resistant to CAMPs, such as polymyxin B (PxB) (MIC ≥ 512 μg/ml). To ascertain the mechanisms by which meningococci resist PxB, mutants that displayed increased sensitivity (≥4-fold) to PxB were identified from a library of mariner transposon mutants generated in a meningococcal strain, NMB. Surprisingly, more than half of the initial PxB-sensitive mutants had insertions within the mtrCDE operon, which encodes proteins forming a multidrug efflux pump. Additional PxB-sensitive mariner mutants were identified from a second round of transposon mutagenesis performed in an mtr efflux pump-deficient background. Further, a mutation in lptA, the phosphoethanolamine (PEA) transferase responsible for modification of the lipid A head groups, was identified to cause the highest sensitivity to PxB. Mutations within the mtrD or lptA genes also increased meningococcal susceptibility to two structurally unrelated CAMPs, human LL-37 and protegrin-1. Consistently, PxB neutralized inflammatory responses elicited by the lptA mutant lipooligosaccharide more efficiently than those induced by wild-type lipooligosaccharide. mariner mutants with increased resistance to PxB were also identified in NMB background and found to contain insertions within the pilMNOPQ operon involved in pilin biogenesis. Taken together, these data indicated that meningococci utilize multiple mechanisms including the action of the MtrC-MtrD-MtrE efflux pump and lipid A modification as well as the type IV pilin secretion system to modulate levels of CAMP resistance. The modification of meningococcal lipid A head groups with PEA also prevents neutralization of the biological effects of endotoxin by CAMP. PMID:16030233

  9. Neisseria meningitis GNA1030 is a ubiquinone-8 binding protein.

    PubMed

    Donnarumma, Danilo; Golfieri, Giacomo; Brier, Sébastien; Castagnini, Marta; Veggi, Daniele; Bottomley, Matthew James; Delany, Isabel; Norais, Nathalie

    2015-06-01

    Bexsero, a new vaccine against Neisseria meningitidis serogroup B (MenB), is composed of 3 main recombinant proteins and an outer membrane vesicle component. One of the main bactericidal antigens, neisseria heparin binding antigen (NHBA), is present as a fusion protein with the accessory protein genome-derived neisserial antigen (GNA) 1030 to further increase its immunogenicity. The gene encoding for GNA1030 is present and highly conserved in all Neisseria strains, and although orthologs are present in numerous species, its biologic function is unknown. Native mass spectrometry was used to demonstrate that GNA1030 forms a homodimer associated with 2 molecules of ubiquinone-8 (Ub8), a cofactor mainly involved in the electron transport chain and with antioxidant properties. Disc diffusion assays on the wild-type and knockout mutant of GNA1030, in the presence of various compounds, suggested that GNA1030 is not involved in oxidative stress or electron chain transport per se, although it contributes to constitutive refilling of the inner membrane with Ub8. These studies shed light on an accessory protein present in Bexsero and reveal functional insights into the family of related proteins. On the basis of our findings, we propose to name the protein neisseria ubiquinone binding protein (NUbp).

  10. Transcriptional and functional analysis of the Neisseria gonorrhoeae fur regulon

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To ensure survival in the host, bacteria have evolved strategies to acquire the essential element iron. In Neisseria gonorrhoeae, the ferric uptake regulator senses intracellular iron stores and acting as a repressor, directly regulates transcription of iron-responsive genes by binding to a conserve...

  11. Bacteremia due to Neisseria cinerea: report of two cases.

    PubMed

    Southern, P M; Kutscher, A E

    1987-06-01

    We report two cases of bacteremia due to Neisseria cinerea. One was a 2.5-yr-old boy with otitis media and pneumonia, who responded to treatment with amoxicillin. The other was a 47-yr-old man with underlying ethanol abuse who developed severe polymicrobial sepsis due to apparent intraabdominal disease. This man died despite extensive antimicrobial therapy.

  12. Association of Neisseria cinerea with ocular infections in paediatric patients.

    PubMed

    Dolter, J; Wong, J; Janda, J M

    1998-01-01

    Twenty-two strains of Neisseria cinerea were recovered from paediatric patients over a 7-year period and forwarded to the Microbial Diseases Laboratory for biochemical identification and/or confirmation. Eighteen of these 22 strains (82%) were recovered from the eyes of very young children (< or = 1 year), > 50% occurring during the neonatal period. The majority of eye isolates were involved in a variety of ocular infections including orbital cellulitis, conjunctivitis, and eye discharge (most common); in four of the 13 instances (31%) where laboratory data was available, Neisseria cinerea was recovered in pure culture. Neisseria cinerea isolates were often submitted to the Microbial Diseases Laboratory as possible 'N. gonorrhoeae' or 'Neisseria species' due to problems resulting from the use of commercial assays or unfamiliarity with the organism. These observations indicate that N. cinerea can produce eye infections in very young children, who presumably acquire this organism vertically from the mother during birth. Accurate identification of N. cinerea in such infants can preclude the social trauma and possible legal ramifications which can initially result from its misidentification as N. gonorrhoeae.

  13. Modeling Neisseria meningitidis B metabolism at different specific growth rates.

    PubMed

    Baart, Gino J E; Willemsen, Marieke; Khatami, Elnaz; de Haan, Alex; Zomer, Bert; Beuvery, E Coen; Tramper, Johannes; Martens, Dirk E

    2008-12-01

    Neisseria meningitidis is a human pathogen that can infect diverse sites within the human host. The major diseases caused by N. meningitidis are responsible for death and disability, especially in young infants. At the Netherlands Vaccine Institute (NVI) a vaccine against serogroup B organisms is currently being developed. This study describes the influence of the growth rate of N. meningitidis on its macro-molecular composition and its metabolic activity and was determined in chemostat cultures. In the applied range of growth rates, no significant changes in RNA content and protein content with growth rate were observed in N. meningitidis. The DNA content in N. meningitidis was somewhat higher at the highest applied growth rate. The phospholipid and lipopolysaccharide content in N. meningitidis changed with growth rate but no specific trends were observed. The cellular fatty acid composition and the amino acid composition did not change significantly with growth rate. Additionally, it was found that the PorA content in outer membrane vesicles was significantly lower at the highest growth rate. The metabolic fluxes at various growth rates were calculated using flux balance analysis. Errors in fluxes were calculated using Monte Carlo Simulation and the reliability of the calculated flux distribution could be indicated, which has not been reported for this type of analysis. The yield of biomass on substrate (Y(x/s)) and the maintenance coefficient (m(s)) were determined as 0.44 (+/-0.04) g g(-1) and 0.04 (+/-0.02) g g(-1) h(-1), respectively. The growth associated energy requirement (Y(x/ATP)) and the non-growth associated ATP requirement for maintenance (m(ATP)) were estimated as 0.13 (+/-0.04) mol mol(-1) and 0.43 (+/-0.14) mol mol(-1) h(-1), respectively. It was found that the split ratio between the Entner-Doudoroff and the pentose phosphate pathway, the sole glucose utilizing pathways in N. meningitidis, had a minor effect on ATP formation rate but a major

  14. First Draft Genome Sequences of Neisseria sp. Strain 83E34 and Neisseria sp. Strain 74A18, Previously Identified as CDC Eugonic Fermenter 4b Species

    PubMed Central

    Greninger, Alexander L.; Streithorst, Jessica

    2016-01-01

    We report the first draft genome sequences of two isolates previously classified as CDC EF-4b species, Neisseria sp. 83E34 and Neisseria sp. 74A18. Both strains were isolated from patients with animal bites and likely constitute novel genomospecies with average nucleotide identities of <95% to other sequenced strains. PMID:27834718

  15. Neisseria lactamica and Neisseria meningitidis share lipooligosaccharide epitopes but lack common capsular and class 1, 2, and 3 protein epitopes.

    PubMed

    Kim, J J; Mandrell, R E; Griffiss, J M

    1989-02-01

    Neisseria lactamica, a common human pharyngeal commensal, contributes to acquired immunity to Neisseria meningitidis. To define the surface antigens shared between these two species, we used monoclonal antibodies (MAbs) to study 35 N. lactamica strains isolated in various parts of the world for cross-reactivity with meningococcal capsules, outer membrane proteins, and lipooligosaccharides (LOS). No N. lactamica strain reacted significantly with MAbs specific for capsular group A, B, C, Y, or W, and we were unable to extract capsular polysaccharide from them. Only 2 of 33 strains reacted weakly with MAbs against class 2 serotype proteins P2b and P2c. None reacted with MAbs specific for meningococcal class 1 protein P1.2 or P1.16 or class 2/3 serotype protein P2a or P15. Most N. lactamica strains (30 of 35) bound one or more of seven LOS-specific MAbs. Two LOS epitopes, defined by MAbs O6B4 and 3F11, that are commonly found on pathogenic Neisseria species were found on 25 of 35 N. lactamica. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting showed that the LOS of N. lactamica are composed of multiple components that are physically and antigenically similar to the LOS of pathogenic Neisseria species. Among four other commensal neisserial species, only Neisseria cinerea shared LOS epitopes defined by MAbs O6B4 and 3F11. Previous studies have shown that pharyngeal colonization with N. lactamica induces bactericidal antibodies against the meningococcus. We postulate that shared N. lactamica and meningococcal LOS epitopes may play an important role in the development of natural immunity to the meningococcus.

  16. Evaluation of Six Commercial Nucleic Acid Amplification Tests for Detection of Neisseria gonorrhoeae and Other Neisseria Species▿

    PubMed Central

    Tabrizi, Sepehr N.; Unemo, Magnus; Limnios, Athena E.; Hogan, Tiffany R.; Hjelmevoll, Stig-Ove; Garland, Susanne M.; Tapsall, John

    2011-01-01

    Molecular detection of Neisseria gonorrhoeae in extragenital samples may result in false-positive results due to cross-reaction with commensal Neisseria species or Neisseria meningitidis. This study examined 450 characterized clinical culture isolates, comprising 216 N. gonorrhoeae isolates and 234 isolates of nongonococcal Neisseria species (n = 218) and 16 isolates of other closely related bacteria, with six commercial nucleic acid amplification tests (NAATs). The six NAATs tested were Gen-Probe APTIMA COMBO 2 and APTIMA GC, Roche COBAS Amplicor CT/NG and COBAS 4800 CT/NG tests, BD ProbeTec GC Qx amplified DNA assay, and Abbott RealTime CT/NG test. All assays except COBAS Amplicor CT/NG test where four (1.9%) isolates were not detected showed a positive result with all N. gonorrhoeae isolates (n = 216). Among the 234 nongonococcal isolates examined, initial results from all assays displayed some false-positive results due to cross-reactions. Specifically, the COBAS Amplicor and ProbeTec tests showed the highest number of false-positive results, detecting 33 (14.1%) and 26 (11%) nongonococcal Neisseria isolates, respectively. On the first testing, APTIMA COMBO 2, APTIMA GC, Abbott RealTime, and Roche COBAS 4800 showed lower level of cross-reactions with five (2.1%), four (1.7%), two (1%), and two (1%) of the isolates showing low-level positivity, respectively. Upon retesting of these nine nongonococcal isolates using freshly cultured colonies, none were positive by the APTIMA COMBO 2, Abbott RealTime, or COBAS 4800 test. In conclusion, the COBAS Amplicor and ProbeTec tests displayed high number of false-positive results, while the remaining NAATs showed only sporadic low-level false-positive results. Supplementary testing for confirmation of N. gonorrhoeae NAATs remains recommended with all samples tested, in particular those from extragenital sites. PMID:21813721

  17. Biochemical and genomic analysis of the denitrification pathway within the genus Neisseria

    PubMed Central

    Barth, Kenneth R.; Isabella, Vincent M.; Clark, Virginia L.

    2009-01-01

    Since Neisseria gonorrhoeae and Neisseria meningitidis are obligate human pathogens, a comparison with commensal species of the same genus could reveal differences important in pathogenesis. The recent completion of commensal Neisseria genome draft assemblies allowed us to perform a comparison of the genes involved in the catalysis, assembly and regulation of the denitrification pathway, which has been implicated in the virulence of several bacteria. All species contained a highly conserved nitric oxide reductase (NorB) and a nitrite reductase (AniA or NirK) that was highly conserved in the catalytic but divergent in the N-terminal lipid modification and C-terminal glycosylation domains. Only Neisseria mucosa contained a nitrate reductase (Nar), and only Neisseria lactamica, Neisseria cinerea, Neisseria subflava, Neisseria flavescens and Neisseria sicca contained a nitrous oxide reductase (Nos) complex. The regulators of the denitrification genes, FNR, NarQP and NsrR, were highly conserved, except for the GAF domain of NarQ. Biochemical examination of laboratory strains revealed that all of the neisserial species tested except N. mucosa had a two- to fourfold lower nitrite reductase activity than N. gonorrhoeae, while N. meningitidis and most of the commensal Neisseria species had a two- to fourfold higher nitric oxide (NO) reductase activity. For N. meningitidis and most of the commensal Neisseria, there was a greater than fourfold reduction in the NO steady-state level in the presence of nitrite as compared with N. gonorrhoeae. All of the species tested generated an NO steady-state level in the presence of an NO donor that was similar to that of N. gonorrhoeae. The greatest difference between the Neisseria species was the lack of a functional Nos system in the pathogenic species N. gonorrhoeae and N. meningitidis. PMID:19762442

  18. Biochemical and genomic analysis of the denitrification pathway within the genus Neisseria.

    PubMed

    Barth, Kenneth R; Isabella, Vincent M; Clark, Virginia L

    2009-12-01

    Since Neisseria gonorrhoeae and Neisseria meningitidis are obligate human pathogens, a comparison with commensal species of the same genus could reveal differences important in pathogenesis. The recent completion of commensal Neisseria genome draft assemblies allowed us to perform a comparison of the genes involved in the catalysis, assembly and regulation of the denitrification pathway, which has been implicated in the virulence of several bacteria. All species contained a highly conserved nitric oxide reductase (NorB) and a nitrite reductase (AniA or NirK) that was highly conserved in the catalytic but divergent in the N-terminal lipid modification and C-terminal glycosylation domains. Only Neisseria mucosa contained a nitrate reductase (Nar), and only Neisseria lactamica, Neisseria cinerea, Neisseria subflava, Neisseria flavescens and Neisseria sicca contained a nitrous oxide reductase (Nos) complex. The regulators of the denitrification genes, FNR, NarQP and NsrR, were highly conserved, except for the GAF domain of NarQ. Biochemical examination of laboratory strains revealed that all of the neisserial species tested except N. mucosa had a two- to fourfold lower nitrite reductase activity than N. gonorrhoeae, while N. meningitidis and most of the commensal Neisseria species had a two- to fourfold higher nitric oxide (NO) reductase activity. For N. meningitidis and most of the commensal Neisseria, there was a greater than fourfold reduction in the NO steady-state level in the presence of nitrite as compared with N. gonorrhoeae. All of the species tested generated an NO steady-state level in the presence of an NO donor that was similar to that of N. gonorrhoeae. The greatest difference between the Neisseria species was the lack of a functional Nos system in the pathogenic species N. gonorrhoeae and N. meningitidis.

  19. Functional diversity of three different DsbA proteins from Neisseria meningitidis.

    PubMed

    Sinha, Sunita; Langford, Paul R; Kroll, J Simon

    2004-09-01

    The genome of Neisseria meningitidis serogroup B strain MC58 contains three genes - nmb0278, nmb0294 and nmb0407 - encoding putative homologues of DsbA, a periplasmic thiol disulphide oxidoreductase protein-folding catalyst of the Dsb protein family. DsbA assists the folding of periplasmic and membrane proteins in diverse organisms. While all three cloned genes complemented the DTT sensitivity of dsbA-null Escherichia coli, they showed different activities in folding specific target proteins in this background. NMB0278 protein was the most active in complementing defects in motility and alkaline phosphatase activity, while NMB0294 was the most active in folding periplasmic MalF. NMB0407 showed the weakest activity in all assays. It is extremely unusual for organisms to contain more than one chromosomal dsbA. Among the members of the genus Neisseria, only the meningococcus carries all three of these genes. Strains of Neisseria gonorrhoeae, Neisseria lactamica, Neisseria cinerea and Neisseria polysaccharea contained only homologues of nmb0278 and nmb0407, while Neisseria flava, Neisseria subflava and Neisseria flavescens carried only nmb0294. It is speculated that the versatility of the meningococcus in surviving in different colonizing and invasive disease settings may be derived in part from an enhanced potential to deploy outer-membrane proteins, a consequence of carrying an extended repertoire of protein-folding catalysts.

  20. Molecular Assay for Detection of Genetic Markers Associated with Decreased Susceptibility to Cephalosporins in Neisseria gonorrhoeae

    PubMed Central

    Peterson, S. W.; Martin, I.; Demczuk, W.; Bharat, A.; Hoang, L.; Wylie, J.; Allen, V.; Lefebvre, B.; Tyrrell, G.; Horsman, G.; Haldane, D.; Garceau, R.; Wong, T.

    2015-01-01

    The incidence of antimicrobial-resistant Neisseria gonorrhoeae continues to rise in Canada; however, antimicrobial resistance data are lacking for approximately 70% of gonorrhea infections that are diagnosed directly from clinical specimens by nucleic acid amplification tests (NAATs). We developed a molecular assay for surveillance use to detect mutations in genes associated with decreased susceptibility to cephalosporins that can be applied to both culture isolates and clinical samples. Real-time PCR assays were developed to detect single nucleotide polymorphisms (SNPs) in ponA, mtrR, penA, porB, and one N. gonorrhoeae-specific marker (porA). We tested the real-time PCR assay with 252 gonococcal isolates, 50 nongonococcal isolates, 24 N. gonorrhoeae-negative NAAT specimens, and 34 N. gonorrhoeae-positive NAAT specimens. Twenty-four of the N. gonorrhoeae-positive NAAT specimens had matched culture isolates. Assay results were confirmed by comparison with whole-genome sequencing data. For 252 N. gonorrhoeae strains, the agreement between the DNA sequence and real-time PCR was 100% for porA, ponA, and penA, 99.6% for mtrR, and 95.2% for porB. The presence of ≥2 SNPs correlated with decreased susceptibility to ceftriaxone (sensitivities of >98%) and cefixime (sensitivities of >96%). Of 24 NAAT specimens with matched cultures, the agreement between the DNA sequence and real-time PCR was 100% for porB, 95.8% for ponA and mtrR, and 91.7% for penA. We demonstrated the utility of a real-time PCR assay for sensitive detection of known markers for the decreased susceptibility to cephalosporins in N. gonorrhoeae. Preliminary results with clinical NAAT specimens were also promising, as they correlated well with bacterial culture results. PMID:25878350

  1. Secretor status and humoral immune responses to Neisseria lactamica and Neisseria meningitidis.

    PubMed

    Zorgani, A A; Stewart, J; Blackwell, C C; Elton, R A; Weir, D M

    1992-12-01

    Non-secretors of ABO blood group antigens are over-represented among patients with meningococcal diseases. Lower levels of secretory IgA reported for non-secretors have been suggested to compromise mucosal defences. Total serum and salivary IgG, IgA and IgM and levels of these isotypes specific for Neisseria lactamica and five isolates of meningococci were determined by ELISA for 357 pupils and staff of a secondary school in which an outbreak of meningitis occurred. There were no differences in total or specific levels of serum IgG, IgA or IgM or salivary IgG or IgA of secretors compared with non-secretors. Non-secretors had significantly lower levels of salivary IgM (P = 0.022). A similar pattern was observed for levels of IgM specific for N. lactamica and five meningococcal isolates. The significance of these results is discussed with reference to the role of secretory IgM in protection of mucosal surfaces in infants.

  2. Neisseria meningitidis, Neisseria lactamica and Moraxella catarrhalis share cross-reactive carbohydrate antigens.

    PubMed

    Braun, Jan M; Beuth, Josef; Blackwell, C Caroline; Giersen, Sonja; Higgins, Paul G; Tzanakaki, Georgina; Unverhau, Heike; Weir, Donald M

    2004-02-17

    Carriage of commensal bacteria species is associated with the development of natural immunity to meningococcal disease, with lipo-oligosaccharides (LOS) of meningococci being one of the main virulence factors associated with severity of meningococcal disease. Meningococcal reference strains and isolates from the commensal species Neisseria lactamica and Moraxella catarrhalis were assessed for the presence of cross-reactive glycoconjugate antigens. Binding of human blood group antibodies of the P and Ii system to meningococcal immunotype reference strains were in accordance with the presence of known LOS carbohydrate structures. Binding studies with meningococcal immunotyping antibodies and blood group phenotyping antibodies to N. lactamica strains from different European countries showed, that a greater number of isolates obtained from native Greek and Scottish adults and children bound anti-meningococcal L(3, 7, 9) immunotyping (P < 0.001), pK (P = 0.035) and paragloboside (P < 0.001) blood group typing antibodies compared to isolates obtained from children of Russian immigrants in Greece. A greater number of M. catarrhalis strains isolated from children in Scotland bound anti-L(3, 7, 9) antibodies (38.2%) compared to strains isolated from adults (22.2%) (P = 0.017). These findings provide evidence that blood group like glycoconjugate antigens found on the commensal species N. lactamica and M. catarrhalis might be involved in the development of natural immunity to meningococcal endotoxins during childhood, and might be exploited as anti-meningococcal vaccine candidates.

  3. [Ciprofloxacin resistance of Neisseria gonorrhoeae according to sexual habits].

    PubMed

    García, Susana; Casco, Ricardo; Perazzi, Beatriz; De Mier, Carmen; Vay, Carlos; Famiglietti, Angela

    2008-01-01

    The first isolates of Neisseria gonorrhoeae resistant to fluoroquinolones in Argentina were reported in 2000. Since January 2005 to June 2007 Neisseria gonorrhoeae was studied in 595 men who have sex with men (MSM) and 571 heterosexual men. The gonorrhea prevalence in MSM and heterosexual men was 0.091(91/1000) and the Neisseria gonorrhoeae ciprofloxacin resistant (CRNG) was 20% in MSM and 3.8% in heterosexual men (p: 0.0416). Thirteen out of 106 isolates from 11 MSM and 2 heterosexual men were CRNG. Six out of eleven MSM had urethritis, one also carried Neisseria gonorrhoeae in rectum and 5 patients were asymptomatic carriers (rectum 2, pharynx 2, urethra 1). No epidemiological relation was found among the patients. Two heterosexual men had urethritis. The 8 symptomatic men were treated with ciprofloxacin but treatment failed in all of them. These patients and the asymptomatic ones were treated with ceftriaxone, 500 mg IM. The post treatment microbiological controls were negative. The CRNG isolates had ciprofloxacin MIC between 2 and 32 (microg/ml), all were negative to penicillinase, 4 out of 13 were chromosomally resistant to penicillin (MIC: 1 microg/ml). The MICs (microg/ml) ranges for several antimicrobial agents were: penicillin: 0.016-1; tetracycline: 0.125-2; ceftriaxone: 0.004-0.008; erythromycin: 0.032-2; azithromycin: 0.032-0.5; spectinomycin: 8-32. Due to the high level of ciprofloxacin-resistant N. gonorrhoeae isolated from MSM in our hospital, another antimicrobial agent for empirical therapy should be used in these patients.

  4. Superoxide dismutase and oxygen toxicity defenses in the genus Neisseria.

    PubMed Central

    Archibald, F S; Duong, M N

    1986-01-01

    Among aerotolerant cells, Neisseria gonorrhoeae is very unusual because despite its obligately aerobic lifestyle and frequent isolation from purulent exudates containing polymorphonuclear leukocytes vigorously evolving O2- and H2O2, it contains no superoxide dismutase (SOD). Strains (14) of N. gonorrhoeae were compared with each other and with strains of Neisseria meningitidis, Neisseria mucosa, and Neisseria subflava under identical growth conditions for their contents of the oxy-protective enzymes catalase, peroxidase, and SOD, as well as respiratory chain proteins and activity. The absence of SOD from N. gonorrhoeae strains was demonstrated under a variety of oxygen-stress conditions. The neisserial species showed very different SOD, catalase, and peroxidase profiles. These profiles correlated well with the tolerance of the species to various intra- and extracellular oxygen insults. The high tolerance of N. gonorrhoeae for extracellular O2- and H2O2 appeared to be due to very high constitutive levels of peroxidase and catalase activity combined with a cell envelope impervious to O2-. Nevertheless, N. gonorrhoeae 19424 was much more sensitive to an intracellular flux of O2- than were the other (SOD-containing) neisserial species. The responses of N. gonorrhoeae and N. meningitidis respiratory and oxy-protective enzymes to growth under high and low oxygen tensions were followed, and a novel response, the apparent repression of the respiratory chain intermediates, respiration, and SOD, peroxidase, and catalase activity, was observed. The gonococcal catalase was partially purified and characterized. The results suggest that the very active terminal oxidase, low pO2 natural habitat, O2-stable catalase, and possibly the high glutathione content of the organism explain its aerobic survival in the absence of SOD. PMID:3943903

  5. Conjunctivitis due to Neisseria sicca: a case report.

    PubMed

    Eser, Ilker; Akcali, Alper; Tatman-Otkun, Muserref; Taskiran-Comez, Arzu

    2014-03-01

    We report the first case, in Medline-based literature, of conjunctivitis caused by gram negative diplococcus, Neisseria sicca. Although it is not widely accepted as such, isolation from cultures of repeated eye swab samples suggests that N. sicca may be a pathogen in conjunctival infections. Positive culture for this organism should not be readily dismissed. Such conjunctivitis responded favorably to treatment with netilmicin eye drops.

  6. Conjunctivitis due to Neisseria sicca: A case report

    PubMed Central

    Eser, Ilker; Akcali, Alper; Tatman-Otkun, Muserref; Taskiran-Comez, Arzu

    2014-01-01

    We report the first case, in Medline-based literature, of conjunctivitis caused by gram negative diplococcus, Neisseria sicca. Although it is not widely accepted as such, isolation from cultures of repeated eye swab samples suggests that N. sicca may be a pathogen in conjunctival infections. Positive culture for this organism should not be readily dismissed. Such conjunctivitis responded favorably to treatment with netilmicin eye drops. PMID:23552355

  7. Structural basis for iron piracy by pathogenic Neisseria

    PubMed Central

    Noinaj, N.; Easley, N.C.; Oke, M.; Mizuno, N.; Gumbart, J.; Boura, E.; Steere, A.N.; Zak, O.; Aisen, P.; Tajkhorshid, E.; Evans, R.W.; Gorringe, A.R.; Mason, A.B.; Steven, A.C.; Buchanan, S.K.

    2012-01-01

    SUMMARY Neisseria are obligate human pathogens causing bacterial meningitis, septicemia, and gonorrhea. Neisseria require iron for survival and can extract it directly from human transferrin for transport across the outer membrane. The transport system consists of TbpA, an integral outer membrane protein, and TbpB, a co-receptor attached to the cell surface; both proteins are potentially important vaccine and therapeutic targets. Two key questions driving Neisseria research are: 1) how human transferrin is specifically targeted, and 2) how the bacteria liberate iron from transferrin at neutral pH. To address them, we solved crystal structures of the TbpA-transferrin complex and of the corresponding co-receptor TbpB. We characterized the TbpB-transferrin complex by small angle X-ray scattering and the TbpA-TbpB-transferrin complex by electron microscopy. Collectively, our studies provide a rational basis for the specificity of TbpA for human transferrin, show how TbpA promotes iron release from transferrin, and elucidate how TbpB facilitates this process. PMID:22327295

  8. Inhibition of Neisseria gonorrhoeae by a Bacteriocin from Pseudomonas aeruginosa

    PubMed Central

    Morse, Stephen A.; Vaughan, Patrick; Johnson, Deanne; Iglewski, Barbara H.

    1976-01-01

    Supernatants from broth-grown cultures of Pseudomonas aeruginosa PA 103 exhibited bactericidal activity against Neisseria gonorrhoeae. The concentration of the bactericidal substance increased significantly after induction by mitomycin C. Purification was effected by salt fractionation, chromatography on diethylaminoethyl-cellulose, and sedimentation by centrifugation at 100,000 × g for 90 min. Electron microscopy of this purified preparation revealed structures resembling R-type pyocins in both the contracted and uncontracted state. Pyocins in the contracted state were observed in association with the gonococcal cell surface. No loss of bactericidal activity was observed after treatment with proteolytic enzymes. Standard pyocin typing procedures identified the pyocin pattern as 611 131. The bactericidal activity of this pyocin was examined on various species of Neisseria. Out of 56 strains of N. gonorrhoeae from disseminated and nondisseminated infections, all were susceptible to pyocin 611 131. However, only 3 of 20 strains of N. meningitidis and 5 of 16 strains of N. lactamica were susceptible. The bactericidal activity that pyocin 611 131 has for N. gonorrhoeae and other species of Neisseria is significant because it departs from the expected specificity that heretofore has distinguished bacteriocins from most “classical” antibiotics. Images PMID:825024

  9. Structural basis for iron piracy by pathogenic Neisseria.

    PubMed

    Noinaj, Nicholas; Easley, Nicole C; Oke, Muse; Mizuno, Naoko; Gumbart, James; Boura, Evzen; Steere, Ashley N; Zak, Olga; Aisen, Philip; Tajkhorshid, Emad; Evans, Robert W; Gorringe, Andrew R; Mason, Anne B; Steven, Alasdair C; Buchanan, Susan K

    2012-02-12

    Neisseria are obligate human pathogens causing bacterial meningitis, septicaemia and gonorrhoea. Neisseria require iron for survival and can extract it directly from human transferrin for transport across the outer membrane. The transport system consists of TbpA, an integral outer membrane protein, and TbpB, a co-receptor attached to the cell surface; both proteins are potentially important vaccine and therapeutic targets. Two key questions driving Neisseria research are how human transferrin is specifically targeted, and how the bacteria liberate iron from transferrin at neutral pH. To address these questions, we solved crystal structures of the TbpA-transferrin complex and of the corresponding co-receptor TbpB. We characterized the TbpB-transferrin complex by small-angle X-ray scattering and the TbpA-TbpB-transferrin complex by electron microscopy. Our studies provide a rational basis for the specificity of TbpA for human transferrin, show how TbpA promotes iron release from transferrin, and elucidate how TbpB facilitates this process.

  10. How clonal are Neisseria species? The epidemic clonality model revisited

    PubMed Central

    Tibayrenc, Michel; Ayala, Francisco J.

    2015-01-01

    The three species Neisseria meningitidis, Neisseria gonorrheae, and Neisseria lactamica are often regarded as highly recombining bacteria. N. meningitidis has been considered a paradigmatic case of the “semiclonal model” or of “epidemic clonality,” demonstrating occasional bouts of clonal propagation in an otherwise recombining species. In this model, occasional clonality generates linkage disequilibrium in the short term. In the long run, however, the effects of clonality are countered by recombination. We show that many data are at odds with this proposal and that N. meningitidis fits the criteria that we have proposed for predominant clonal evolution (PCE). We point out that (i) the proposed way to distinguish epidemic clonality from PCE may be faulty and (ii) the evidence of deep phylogenies by microarrays and whole-genome sequencing is at odds with the predictions of the semiclonal model. Last, we revisit the species status of N. meningitidis, N. gonorrheae, and N. lactamica in the light of the PCE model. PMID:26195766

  11. A New Family of Secreted Toxins in Pathogenic Neisseria Species

    PubMed Central

    Jamet, Anne; Jousset, Agnès B.; Euphrasie, Daniel; Mukorako, Paulette; Boucharlat, Alix; Ducousso, Alexia; Charbit, Alain; Nassif, Xavier

    2015-01-01

    The genus Neisseria includes both commensal and pathogenic species which are genetically closely related. However, only meningococcus and gonococcus are important human pathogens. Very few toxins are known to be secreted by pathogenic Neisseria species. Recently, toxins secreted via type V secretion system and belonging to the widespread family of contact-dependent inhibition (CDI) toxins have been described in numerous species including meningococcus. In this study, we analyzed loci containing the maf genes in N. meningitidis and N. gonorrhoeae and proposed a novel uniform nomenclature for maf genomic islands (MGIs). We demonstrated that mafB genes encode secreted polymorphic toxins and that genes immediately downstream of mafB encode a specific immunity protein (MafI). We focused on a MafB toxin found in meningococcal strain NEM8013 and characterized its EndoU ribonuclease activity. maf genes represent 2% of the genome of pathogenic Neisseria, and are virtually absent from non-pathogenic species, thus arguing for an important biological role. Indeed, we showed that overexpression of one of the four MafB toxins of strain NEM8013 provides an advantage in competition assays, suggesting a role of maf loci in niche adaptation. PMID:25569427

  12. Functional comparison of the binding of factor H short consensus repeat 6 (SCR 6) to factor H binding protein from Neisseria meningitidis and the binding of factor H SCR 18 to 20 to Neisseria gonorrhoeae porin.

    PubMed

    Shaughnessy, Jutamas; Lewis, Lisa A; Jarva, Hanna; Ram, Sanjay

    2009-05-01

    Both Neisseria meningitidis and Neisseria gonorrhoeae recruit the alternative pathway complement inhibitory protein factor H (fH) to their surfaces to evade complement-dependent killing. Meningococci bind fH via fH binding protein (fHbp), a surface-exposed lipoprotein that is subdivided into three variant families based on one classification scheme. Chimeric proteins that comprise contiguous domains of fH fused to murine Fc were used to localize the binding site for all three fHbp variants on fH to short consensus repeat 6 (SCR 6). As expected, fH-like protein 1 (FHL-1), which contains fH SCR 6, also bound to fHbp-expressing meningococci. Using site-directed mutagenesis, we identified histidine 337 and histidine 371 in SCR 6 as important for binding to fHbp. These findings may provide the molecular basis for recent observations that demonstrated human-specific fH binding to meningococci. Differences in the interactions of fHbp variants with SCR 6 were evident. Gonococci bind fH via their porin (Por) molecules (PorB.1A or PorB.1B); sialylation of lipooligosaccharide enhances fH binding. Both sialylated PorB.1B- and (unsialylated) PorB.1A-bearing gonococci bind fH through SCR 18 to 20; PorB.1A can also bind SCR 6, but only weakly, as evidenced by a low level of binding of FHL-1 relative to that of fH. Using isogenic strains expressing either meningococcal fHbp or gonococcal PorB.1B, we discovered that strains expressing gonococcal PorB.1B in the presence of sialylated lipooligosaccharide bound more fH, more effectively limited C3 deposition, and were more serum resistant than their isogenic counterparts expressing fHbp. Differences in fH binding to these two related pathogens may be important for modulating their individual responses to host immune attack.

  13. Evaluation of molecular typing methods for identification of outbreak-associated Neisseria meningitidis isolates.

    PubMed

    Törös, Bianca; Hedberg, Sara T; Jacobsson, Susanne; Fredlund, Hans; Olcén, Per; Mölling, Paula

    2013-06-01

    It is essential in an outbreak investigation that strain characterization of Neisseria meningitidis is performed in a rapid and accurate manner. This study evaluated two new molecular typing methods, multiple-locus variable number tandem repeat analysis (MLVA) and repetitive sequence-based PCR (rep-PCR) (DiversiLab; bioMérieux) and compared them with current recommended methodologies. This retrospective study included 36 invasive N. meningitidis serogroup C isolates collected in Sweden 2001 through 2009 and previously subjected to outbreak investigation. All strains were typed with highly variable-MLVA (HV-MLVA) and rep-PCR. The isolates were further characterized by multilocus sequence typing (MLST) and sequencing of the fetA, fHbp, penA, porA and porB genes. The results showed that HV-MLVA had the highest index of diversity (0.99) and rep-PCR had the highest congruence (40%) with the currently recommended typing methods. The HV-MLVA correlated best to the spatiotemporal connections and had the overall highest Adjusted Wallace coefficients, suggesting that HV-MLVA can predict the results of the other typing methods in the study. We therefore suggest that after initial confirmation of species, serogroup and genosubtype, HV-MLVA should be used as the most discriminatory method for first hand investigation of N. meningitidis serogroup C isolates.

  14. Influence of conserved and hypervariable genetic markers on genotyping circulating strains of Neisseria gonorrhoeae.

    PubMed

    Vidovic, Sinisa; Horsman, Greg B; Liao, Mingmin; Dillon, Jo-Anne R

    2011-01-01

    Presently there is no vaccine against Neisseria gonorrhoeae and therefore accurate information on gonococcal transmission plays a crucial role for interventions designed to limit the spread of infections caused by this microorganism. We evaluated the impact of two different categories of genetic markers, (i) concatenated sequences of 10 housekeeping genes and (ii) hypervariable porB DNA sequences, on the genetic relatedness and subsequently on genotyping analysis of this human pathogen. Eighty gonococcal isolates from Canada, China, the US, Argentina, Venezuela and Chile, collected over different times, were analyzed. Our results show that the choice of genetic marker had a profound effect on the interpretation of genotyping results associated with N. gonorrhoeae. The concatenated sequences of the housekeeping genes preserved the genetic relatedness of closely related isolates, enabling detection of the predominant strains circulating within a community (Saskatchewan, Canada) over an extended period of time. In contrast, a genetic marker based on antigen gene, porB, may lead to a failure to detect these predominant circulating strains. Based on the analysis of the DNA sequences of the 10 housekeeping genes, we identified two major clonal complexes, CC33 and CC22, which comprised STs from China, and Argentina as well as two STs from Canada. Several minor clonal complexes were observed among isolates from Saskatchewan. eBURST analysis suggested that the majority of the tested gonococcal isolates from Saskatchewan, Canada were endemic, with only a couple of genotypes introduced.

  15. Sequence Type 4821 Clonal Complex Serogroup B Neisseria meningitidis in China, 1978–2013

    PubMed Central

    Zhu, Bingqing; Xu, Zheng; Du, Pengcheng; Xu, Li; Sun, Xiaofang; Gao, Yuan

    2015-01-01

    Serogroup B Neisseria meningitidis strains belonging to sequence type 4821 clonal complex (CC4821), a hyperinvasive lineage first identified for serogroup C in 2003, have been increasingly isolated in China. We characterized the outer membrane protein genes of 48 serogroup B and 214 serogroup C strains belonging to CC4821 and analyzed the genomic sequences of 22 strains. Four serogroup B strains had porin A (i.e., PorA), PorB, and ferric enterobactin transport (i.e., FetA) genotypes identical to those for serogroup C. Phylogenetic analysis of the genomic sequences showed that the 22 CC4821 strains from patients and healthy carriers were unevenly clustered into 2 closely related groups; each group contained serogroup B and C strains. Serogroup B strains appeared variable at the capsule locus, and several recombination events had occurred at uncertain breakpoints. These findings suggest that CC4821 serogroup C N. meningitidis is the probable origin of highly pathogenic CC4821 serogroup B strains. PMID:25989189

  16. Oropharyngeal Colonization With Neisseria lactamica, Other Nonpathogenic Neisseria Species and Moraxella catarrhalis Among Young Healthy Children in Ahvaz, Iran

    PubMed Central

    Sheikhi, Raheleh; Amin, Mansour; Rostami, Soodabeh; Shoja, Saeed; Ebrahimi, Nasim

    2015-01-01

    Background: Neisseria lactamica as one of the main commensal in oropharynx during the childhood is related to the induction of a natural immunity against meningococcal meningitis. Also Moraxella catarrhalis in oropharynx of children is a predisposing factor for otitis media infection. Objectives: The current study aimed to investigate the frequency of the N. lactamica, other nonpathogenic Neisseria spp. and M. catarrhalis in the oropharynx of young healthy children in Ahvaz, Iran by the two phenotypic tests and Polymerase Chain Reaction (PCR). Materials and Methods: A total of 192 oropharyngeal swab samples of the young healthy children were studied during four months. Swabs were plated onto enriched selective media and non-selective media. Gram-negative and oxidase-positive diplococci were identified by several conventional biochemical tests. The PCR and sequencing were used to confirm the accuracy of laboratory diagnosis to identify N. lactamica and M. catarrhalis. Results: Among 192 young healthy children with the mean age of 5.93 ± 2.5903 years, authors identified: N. lactamica (21.9%) in the age group of one to nine years; N. mucosa (6.3%); N. sicca (7.8%); N. cinerea (1.6%); N. subflava (biovar subflava) (4.2%); N. subflava (biovar perflava) (28.1%); N. subflava (biovar flava) (7.3%) and M. catarrhalis (42.7%). Conclusions: The young healthy children screening by colonization of N. lactamica and other nonpathogenic Neisseria spp. in oropharynx was the first report in Ahvaz, Iran. The study results demonstrated the high frequency of colonization of M. catarrhalis in the studied young healthy children other than Neisseria spp. PMID:25964847

  17. Gene expression profile in Neisseria meningitidis and Neisseria lactamica upon host-cell contact: from basic research to vaccine development.

    PubMed

    Grifantini, R; Bartolini, E; Muzzi, A; Draghi, M; Frigimelica, E; Berger, J; Randazzo, F; Grandi, G

    2002-12-01

    Differential gene regulation in the human pathogen Neisseria meningitidis group B (MenB) and in Neisseria lactamica, a human commensal species, was studied by whole genome microarray after bacterial interaction with epithelial cells. Host-cell contact induced changes in the expression of 347 and 285 genes in MenB and N. lactamica, respectively. Of these, only 167 were common to MenB and N. lactamica, suggesting that a different subset of genes is activated by pathogens and commensals. Change in gene expression was stable over time in N. lactamica, but short-lived in MenB. A large part (greater than 30%) of the regulated genes encoded proteins with unknown function. Among the known genes, those coding for pili, capsule, protein synthesis, nucleotide synthesis, cell wall metabolism, ATP synthesis, and protein folding were down-regulated in MenB. Transporters for iron, chloride and sulfate, some known virulence factors, GAPDH and the entire pathway of selenocysteine biosynthesis were upregulated. Gene expression profiling indicates that approximately 40% of the regulated genes encode putative surface-associated proteins, suggesting that upon cell contact Neisseria undergoes substantial surface remodeling. This was confirmed by FACS analysis of adhering bacteria using mouse sera against a subset of recombinant proteins. Finally, a few surface-located, adhesion-activated antigens were capable of inducing bactericidal antibodies, indicating that microarray technology can be exploited for the identification of new vaccine candidates.

  18. Characterization of Neisseria cinerea, a nonpathogenic species isolated on Martin-Lewis medium selective for pathogenic Neisseria spp.

    PubMed

    Knapp, J S; Totten, P A; Mulks, M H; Minshew, B H

    1984-01-01

    An asaccharolytic, gram-negative, oxidase-positive diplococcus was isolated on Martin-Lewis medium from the cervix of a patient attending an arthritis clinic at Seattle Public Health Hospital, Seattle, Wash. This strain, NRL 32165, did not produce detectable acid from glucose, maltose, sucrose, fructose, mannitol, or lactose in either cystine Trypticase agar (BBL Microbiology Systems, Cockeysville, Md.) or modified oxidation-fermentation medium and was identified presumptively as a glucose-negative Neisseria gonorrhoeae strain, but was identified later as Neisseria cinerea on the basis of its biochemical reactions. Nitrate was not reduced, nitrite (0.001%, wt/vol) was reduced, and polysaccharide was not produced from sucrose. Proline, arginine, and cystine-cysteine were required for growth on defined medium. Strain NRL 32165 did not react with antigonococcal protein I monoclonal antibodies and did not produce immunoglobulin A protease. In DNA:DNA homology studies with N. gonorrhoeae NRL 8038 (F62) and N. cinerea type strain NRL 30003, strain NRL 32165 showed 95% homology relative to N. cinerea and 44% homology relative to N. gonorrhoeae. Thus, the identity of strain NRL 32165 was confirmed as N. cinerea (von Lingelsheim 1906) Murray 1939. Of all Neisseria spp., N. cinerea is most likely to be misidentified as a glucose-negative N. gonorrhoeae strain.

  19. Neisseria meningitidis Infecting a Prosthetic Knee Joint: A New Case of an Unusual Disease

    PubMed Central

    Becerril Carral, Berta; López Cárdenas, Salvador; Canueto Quintero, Jesús

    2017-01-01

    Primary meningococcal meningitis is an infrequent but known disease. However, the infection of a prosthetic joint with Neisseria meningitidis is rare. We hereby describe the second case of an arthroplasty infected with Neisseria meningitidis that responded favourably to prosthesis retention with surgical debridement, in combination with antibiotics treatment. PMID:28326209

  20. Isolation of Neisseria lactamica from the female genital tract. A case report.

    PubMed

    Telfer Brunton, W A; Young, H; Fraser, D R

    1980-10-01

    Neisseria lactamica was isolated from the genital tract of a young patient with a persistent vaginal discharge. Although infection with N lactamica occurs very rarely, the importance of complete biochemical identification of neisseriae is emphasised in view of the serious social and medicolegal consequences which could result from a misdiagnosis of gonorrhoea.

  1. 21 CFR 866.2410 - Culture medium for pathogenic Neisseria spp.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Culture medium for pathogenic Neisseria spp. 866.2410 Section 866.2410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Culture medium for pathogenic Neisseria spp. (a) Identification. A culture medium for pathogenic...

  2. 21 CFR 866.2410 - Culture medium for pathogenic Neisseria spp.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Culture medium for pathogenic Neisseria spp. 866.2410 Section 866.2410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Culture medium for pathogenic Neisseria spp. (a) Identification. A culture medium for pathogenic...

  3. 21 CFR 866.2410 - Culture medium for pathogenic Neisseria spp.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Culture medium for pathogenic Neisseria spp. 866.2410 Section 866.2410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Culture medium for pathogenic Neisseria spp. (a) Identification. A culture medium for pathogenic...

  4. 21 CFR 866.2410 - Culture medium for pathogenic Neisseria spp.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Culture medium for pathogenic Neisseria spp. 866.2410 Section 866.2410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Culture medium for pathogenic Neisseria spp. (a) Identification. A culture medium for pathogenic...

  5. 21 CFR 866.2410 - Culture medium for pathogenic Neisseria spp.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Culture medium for pathogenic Neisseria spp. 866.2410 Section 866.2410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Culture medium for pathogenic Neisseria spp. (a) Identification. A culture medium for pathogenic...

  6. A case of polymicrobial infective endocarditis involving Neisseria mucosa occurring in an intravenous drug abuser.

    PubMed

    Giles, M W; Andrew, J H; Tellus, M M

    1988-12-01

    The incidence of polymicrobial endocarditis has increased markedly in recent years, in association with the increasing level of abuse of intravenous drugs. Neisseria mucosa, an upper respiratory tract commensal, is a rare cause of infective endocarditis. We report the first case of polymicrobial infective endocarditis involving Neisseria mucosa occurring in an intravenous drug abuser.

  7. Endocarditis Due to Neisseria bacilliformis in a Patient with a Bicuspid Aortic Valve ▿

    PubMed Central

    Masliah-Planchon, Julien; Breton, Guillaume; Jarlier, Vincent; Simon, Anne; Benveniste, Olivier; Herson, Serge; Drieux, Laurence

    2009-01-01

    We report a case of endocarditis due to the rod-shaped Neisseria species Neisseria bacilliformis. The phenotypic characterization of this recently characterized bacteria is difficult, and the identification requires the sequencing of the 16S rRNA gene. The resolution of the disease was complete after appropriate antibiotic therapy, and surgery was not required. PMID:19386832

  8. Fatal bacteremia by neisseria cinerea in a woman with myelodysplastic syndrome: a case report

    PubMed Central

    Zhu, Xiaofei; Li, Min; Cao, Huiling; Yang, Xuewen

    2015-01-01

    Neisseria cinerea has been rarely found in blood cultures. In this study, we are reporting a case of a Myelodysplastic Syndrome (MDS) patient in whose blood Neisseria cinerea was found and led a fatal consequence. This case will call our attentions to the uncommon pathogens in the pathogenicity of end-stage patients. PMID:26131259

  9. Fatal bacteremia by neisseria cinerea in a woman with myelodysplastic syndrome: a case report.

    PubMed

    Zhu, Xiaofei; Li, Min; Cao, Huiling; Yang, Xuewen

    2015-01-01

    Neisseria cinerea has been rarely found in blood cultures. In this study, we are reporting a case of a Myelodysplastic Syndrome (MDS) patient in whose blood Neisseria cinerea was found and led a fatal consequence. This case will call our attentions to the uncommon pathogens in the pathogenicity of end-stage patients.

  10. Role of penA polymorphisms for penicillin susceptibility in Neisseria lactamica and Neisseria meningitidis.

    PubMed

    Karch, André; Vogel, Ulrich; Claus, Heike

    2015-10-01

    In meningococci, reduced penicillin susceptibility is associated with five specific mutations in the transpeptidase region of penicillin binding protein 2 (PBP2). We showed that the same set of mutations was present in 64 of 123 Neisseria lactamica strains obtained from a carriage study (MIC range: 0.125-2.0mg/L). The PBP2 encoding penA alleles in these strains were genetically similar to those found in intermediate resistant meningococci suggesting frequent interspecies genetic exchange. Fifty-six N. lactamica isolates with mostly lower penicillin MICs (range: 0.064-0.38mg/L) exhibited only three of the five mutations. The corresponding penA alleles were unique to N. lactamica and formed a distinct genetic clade. PenA alleles with no mutations on the other hand were unique to meningococci. Under penicillin selective pressure, genetic transformation of N. lactamica penA alleles in meningococci was only possible for alleles encoding five mutations, but not for those encoding three mutations; the transfer resulted in MICs comparable to those of meningococci harboring penA alleles that encoded PBP2 with five mutations, but considerably lower than those of the corresponding N. lactamica donor strains. Due to a transformation barrier the complete N. lactamica penA could not be transformed into N. meningitidis. In summary, penicillin MICs in N. lactamica were associated with the number of mutations in the transpeptidase region of PBP2. Evidence for interspecific genetic transfer was only observed for penA alleles associated with higher MICs, suggesting that alleles encoding only three mutations in the transpeptidase region are biologically not effective in N. meningitidis. Factors other than PBP2 seem to be responsible for the high levels of penicillin resistance in N. lactamica. A reduction of penicillin susceptibility in N. meningitidis by horizontal gene transfer from N. lactamica is unlikely to happen.

  11. Expression of Heterologous Antigens in Commensal Neisseria spp.: Preservation of Conformational Epitopes with Vaccine Potential

    PubMed Central

    O'Dwyer, Clíona A.; Reddin, Karen; Martin, Denis; Taylor, Stephen C.; Gorringe, Andrew R.; Hudson, Michael J.; Brodeur, Bernard R.; Langford, Paul R.; Kroll, J. Simon

    2004-01-01

    Commensal neisseriae share with Neisseria meningitidis (meningococcus) a tendency towards overproduction of the bacterial outer envelope, leading to the formation and release during growth of outer membrane vesicles (OMVs). OMVs from both meningococci and commensal neisseriae have shown promise as vaccines to protect against meningococcal disease. We report here the successful expression at high levels of heterologous proteins in commensal neisseriae and the display, in its native conformation, of one meningococcal outer membrane protein vaccine candidate, NspA, in OMVs prepared from such a recombinant Neisseria flavescens strain. These NspA-containing OMVs conferred protection against otherwise lethal intraperitoneal challenge of mice with N. meningitidis serogroup B, and sera raised against them mediated opsonophagocytosis of meningococcal strains expressing this antigen. This development promises to facilitate the design of novel vaccines containing membrane protein antigens that are otherwise difficult to present in native conformation that provide cross-protective efficacy in the prevention of meningococcal disease. PMID:15501782

  12. Genome sequencing reveals widespread virulence gene exchange among human Neisseria species.

    PubMed

    Marri, Pradeep Reddy; Paniscus, Mary; Weyand, Nathan J; Rendón, María A; Calton, Christine M; Hernández, Diana R; Higashi, Dustin L; Sodergren, Erica; Weinstock, George M; Rounsley, Steven D; So, Magdalene

    2010-07-28

    Commensal bacteria comprise a large part of the microbial world, playing important roles in human development, health and disease. However, little is known about the genomic content of commensals or how related they are to their pathogenic counterparts. The genus Neisseria, containing both commensal and pathogenic species, provides an excellent opportunity to study these issues. We undertook a comprehensive sequencing and analysis of human commensal and pathogenic Neisseria genomes. Commensals have an extensive repertoire of virulence alleles, a large fraction of which has been exchanged among Neisseria species. Commensals also have the genetic capacity to donate DNA to, and take up DNA from, other Neisseria. Our findings strongly suggest that commensal Neisseria serve as reservoirs of virulence alleles, and that they engage extensively in genetic exchange.

  13. Genome Sequencing Reveals Widespread Virulence Gene Exchange among Human Neisseria Species

    PubMed Central

    Marri, Pradeep Reddy; Paniscus, Mary; Hernández, Diana R.; Higashi, Dustin L.; Sodergren, Erica; Weinstock, George M.; Rounsley, Steven D.; So, Magdalene

    2010-01-01

    Commensal bacteria comprise a large part of the microbial world, playing important roles in human development, health and disease. However, little is known about the genomic content of commensals or how related they are to their pathogenic counterparts. The genus Neisseria, containing both commensal and pathogenic species, provides an excellent opportunity to study these issues. We undertook a comprehensive sequencing and analysis of human commensal and pathogenic Neisseria genomes. Commensals have an extensive repertoire of virulence alleles, a large fraction of which has been exchanged among Neisseria species. Commensals also have the genetic capacity to donate DNA to, and take up DNA from, other Neisseria. Our findings strongly suggest that commensal Neisseria serve as reservoirs of virulence alleles, and that they engage extensively in genetic exchange. PMID:20676376

  14. Neisseria infection of rhesus macaques as a model to study colonization, transmission, persistence, and horizontal gene transfer

    PubMed Central

    Weyand, Nathan J.; Wertheimer, Anne M.; Hobbs, Theodore R.; Sisko, Jennifer L.; Taku, Nyiawung A.; Gregston, Lindsay D.; Clary, Susan; Higashi, Dustin L.; Biais, Nicolas; Brown, Lewis M.; Planer, Shannon L.; Legasse, Alfred W.; Axthelm, Michael K.; Wong, Scott W.; So, Magdalene

    2013-01-01

    The strict tropism of many pathogens for man hampers the development of animal models that recapitulate important microbe–host interactions. We developed a rhesus macaque model for studying Neisseria–host interactions using Neisseria species indigenous to the animal. We report that Neisseria are common inhabitants of the rhesus macaque. Neisseria isolated from the rhesus macaque recolonize animals after laboratory passage, persist in the animals for at least 72 d, and are transmitted between animals. Neisseria are naturally competent and acquire genetic markers from each other in vivo, in the absence of selection, within 44 d after colonization. Neisseria macacae encodes orthologs of known or presumed virulence factors of human-adapted Neisseria, as well as current or candidate vaccine antigens. We conclude that the rhesus macaque model will allow studies of the molecular mechanisms of Neisseria colonization, transmission, persistence, and horizontal gene transfer. The model can potentially be developed further for preclinical testing of vaccine candidates. PMID:23382234

  15. Neisseria Adhesin A Variation and Revised Nomenclature Scheme

    PubMed Central

    Bambini, Stefania; De Chiara, Matteo; Muzzi, Alessandro; Mora, Marirosa; Lucidarme, Jay; Brehony, Carina; Borrow, Ray; Masignani, Vega; Comanducci, Maurizio; Maiden, Martin C. J.; Pizza, Mariagrazia; Jolley, Keith A.

    2014-01-01

    Neisseria adhesin A (NadA), involved in the adhesion and invasion of Neisseria meningitidis into host tissues, is one of the major components of Bexsero, a novel multicomponent vaccine licensed for protection against meningococcal serogroup B in Europe, Australia, and Canada. NadA has been identified in approximately 30% of clinical isolates and in a much lower proportion of carrier isolates. Three protein variants were originally identified in invasive meningococci and named NadA-1, NadA-2, and NadA-3, whereas most carrier isolates either lacked the gene or harbored a different variant, NadA-4. Further analysis of isolates belonging to the sequence type 213 (ST-213) clonal complex identified NadA-5, which was structurally similar to NadA-4, but more distantly related to NadA-1, -2, and -3. At the time of this writing, more than 89 distinct nadA allele sequences and 43 distinct peptides have been described. Here, we present a revised nomenclature system, taking into account the complete data set, which is compatible with previous classification schemes and is expandable. The main features of this new scheme include (i) the grouping of the previously named NadA-2 and NadA-3 variants into a single NadA-2/3 variant, (ii) the grouping of the previously assigned NadA-4 and NadA-5 variants into a single NadA-4/5 variant, (iii) the introduction of an additional variant (NadA-6), and (iv) the classification of the variants into two main groups, named groups I and II. To facilitate querying of the sequences and submission of new allele sequences, the nucleotide and amino acid sequences are available at http://pubmlst.org/neisseria/NadA/. PMID:24807056

  16. Comparative Proteomics Analysis of Two Strains of Neisseria meningitidis Serogroup B and Neisseria lactamica

    PubMed Central

    Sheikhi, Raheleh; Amin, Mansour; Hamidinia, Maryam; Assarehzadegan, Mohammad Ali; Rostami, Soodabeh; Mojtahedi, Zahra

    2015-01-01

    Background: Antigenic similarities between Neisseria lactamica as a commensal species and N. meningitidis serogroup B (NmB) as an important cause of meningitis infection have been considered for the development of an effective vaccine based on their common proteins to prevent life-threatening bacterial meningitis. Objectives: The main aims of this study were to determine whole proteome profiles of N. lactamica strains and to compare them with whole proteome profile of a reference strain of NmB for identification of some of common proteins between the two species. Materials and Methods: We compared the whole proteomic profiles of N. lactamica strains and a reference strain of NmB. Lysates from bacterial strains were resolved by two-dimensional gel electrophoresis (2-DE), followed by Coomassie Brilliant blue staining. Some of the protein spots were excised from the gel and subjected to matrix-assisted laser desorption/ionization-tandem time-of-flight mass spectrometry (MALDI-TOF/TOF MS) analysis. Results: The analysis of Coomassie-stained gels using ImageMaster 2D Platinum software identified approximately 800 reproducible protein spots in the range of pI 4.5 - 9.5 and Mr of 8 - 100 kDa for each 2-DE gel of the studied bacterial strains. By comparing proteome maps of 2-DE gels, more than 200 common protein spots were recognized between the two species. Forty-eight common protein spots between the studied bacterial strains were identified by MALDI-TOF/TOF-MS. The results indicated that among the protein spots identified by MOLDI-TOF/TOF mass spectrometry, the groups of proteins included cell surface, energy metabolism, amino acid transport and metabolism, coenzyme metabolism, defense, multifunctional cellular processes, DNA, RNA and protein synthesis, ribosomal structure, regulatory functions, replication, transcription, translation, unknown and hypothetical proteins with unknown function. We found that N. lactamica strains have a proteome profile somewhat similar to

  17. Detection of Neisseria gonorrhoeae Isolates from Tonsils and Posterior Oropharynx

    PubMed Central

    Whiley, D. M.; Lee, D. M.; Snow, A. F.; Fairley, C. K.; Peel, J.; Bradshaw, C. S.; Hocking, J. S.; Lahra, M. M.; Chen, M. Y.

    2015-01-01

    We examined the factors influencing gonorrhea detection at the pharynx. One hundred men infected with Neisseria gonorrhoeae were swabbed from the tonsils and posterior oropharynx. N. gonorrhoeae was reisolated from the tonsils and posterior oropharynx in 62% and 52%, respectively (P = 0.041). Culture positivity was greater with higher gonococcal DNA loads at the tonsils (P = 0.001) and oropharynx (P < 0.001). N. gonorrhoeae can be cultured from the tonsils and posterior oropharynx with greater isolation rates where gonococcal loads are higher. PMID:26292303

  18. In vitro antibiotic susceptibility of Neisseria gonorrhoeae in Jakarta, Indonesia.

    PubMed

    Lesmana, M; Lebron, C I; Taslim, D; Tjaniadi, P; Subekti, D; Wasfy, M O; Campbell, J R; Oyofo, B A

    2001-01-01

    Antibiotic susceptibilities were determined for 122 Neisseria gonorrheae isolates obtained from 400 sex workers in Jakarta, Indonesia, and susceptibilities to ciprofloxacin, cefuroxime, cefoxitin, cefotaxime, ceftriaxone, chloramphenicol, and spectinomycin were found. All isolates were resistant to tetracycline. A number of the isolates demonstrated decreased susceptibilities to erythromycin (MIC >/= 1.0 microg/ml), thiamphenicol (MIC >/= 1.0 microg/ml), kanamycin (MIC >/= 16.0 microg/ml), penicillin (MIC >/= 2.0 microg/ml), gentamicin (MIC >/= 16.0 microg/ml), and norfloxacin (MIC = 0.5 microg/ml). These data showed that certain antibiotics previously used in the treatment of gonorrhea are no longer effective.

  19. A lipoamide dehydrogenase from Neisseria meningitidis has a lipoyl domain.

    PubMed

    Bringas, R; Fernandez, J

    1995-04-01

    A protein of molecular weight of 64 kDa (p64k) found in the outer membrane of Neisseria meningitidis shows a high degree of homology with both the lipoyl domain of the acetyltransferase and the entire sequence of the lipoamide dehydrogenase, the E2 and E3 components of the dehydrogenase multienzyme complexes, respectively. The alignment of the p64k with lipoyl domains and lipoamide dehydrogenases from different species is presented. The possible implications of this protein in binding protein-dependent transport are discussed. This is the first lipoamide dehydrogenase reported to have a lipoyl domain.

  20. Immunoresponses to Neisseria meningitidis epitopes: primary versus secondary antiphosphorylcholine responses.

    PubMed Central

    Faro, J; Seoane, R; Puentes, E; Martínez Ubeira, F; Regueiro, B J

    1985-01-01

    Specific antiphosphorylcholine immune responses were found to be elicited by different Neisseria meningitidis group B M986 preparations. Our results suggest the functional presence of phosphorylcholine in the bacteria. The immune responses, mostly immunoglobulin M, were measured with a plaque-forming cell assay. The secondary phosphorylcholine-specific immune response induced by intact meningococci was significantly lower than the primary phosphorylcholine-specific immune response induced by the same antigens. This suppression is priming time dependent and does not represent an early switching to the expression of other classes of immunoglobulins. PMID:2580791

  1. Genetic diversity of Neisseria lactamica strains from epidemiologically defined carriers.

    PubMed

    Alber, D; Oberkötter, M; Suerbaum, S; Claus, H; Frosch, M; Vogel, U

    2001-05-01

    We assessed the genetic diversity of 26 Neisseria lactamica strains from epidemiologically related sources, i.e., groups of kindergartens and primary schools in three Bavarian towns, by the partial sequencing of the argF, rho, recA, and 16S ribosomal genes. We found a total of 17 genotypes, of which 12 were found only in one strain. The genotypes comprised 5 alleles of the argF gene, 9 of rho, 8 of recA, and 10 of the 16S ribosomal DNA. Sequence analysis by determination of homoplasy ratios and split decomposition analysis revealed abundant recombination within N. lactamica.

  2. [Antimicrobal resistance of Neisseria gonorrhoeae strains in Hungary].

    PubMed

    Nemes-Nikodém, Éva; Brunner, Alexandra; Tóth, Béla; Tóth, Veronika; Bánvölgyi, András; Ostorházi, Eszter

    2015-02-08

    Bevezetés: A Neisseria gonorrhoeae-infekciók kezelésére kiadott európai ajánlás elsősorban a nyugat-európai adatok alapján készült, és nem egyértelműen használható a magyarországi helyzet ismeretében. Célkitűzés: A szerzők 2011. január és 2014. június közötti időszakban a Semmelweis Egyetem, Bőr-, Nemikórtani és Bőronkológiai Klinika Országos Szexuális Úton Terjedő Betegségek Centrumában izolált Neisseria gonorrhoeae törzsek rezisztenciaadatait összevetették az izolált törzsek molekuláris tipizálási eredményeivel, azzal a céllal, hogy pontos adatokat kapjanak a hazánkban előforduló Neisseria gonorrhoeae törzsek antimikrobiális rezisztenciájáról. Módszer: Az antibiotikumrezisztencia-meghatározás minimális inhibitorkoncentráció-méréssel, a szekvenciameghatározás a Neisseria gonorrhoeae Multi Antigen Sequence Typing módszerrel történt. Eredmények: A jelenleg terápiának ajánlott széles spektrumú cefalosporinok elleni rezisztencia ritka, az utóbbi években az azithromycinrezisztencia előfordulása viszont rohamosan növekedett. Következtetések: Az új terápiás irányelvek készítésekor figyelembe kell venni, hogy a gyakran fertőzést okozó molekuláris típusba sorolható törzsek között kiemelkedően magas az azithromycinrezisztensek aránya. Orv. Hetil., 2015, 156(6), 226–229.

  3. Neisseria cinerea isolates can adhere to human epithelial cells by type IV pilus-independent mechanisms

    PubMed Central

    Wörmann, Mirka E.; Horien, Corey L.; Johnson, Errin; Liu, Guangyu; Aho, Ellen; Tang, Christoph M.

    2016-01-01

    In pathogenic Neisseria species the type IV pili (Tfp) are of primary importance in host–pathogen interactions. Tfp mediate initial bacterial attachment to cell surfaces and formation of microcolonies via pilus–pilus interactions. Based on genome analysis, many non-pathogenic Neisseria species are predicted to express Tfp, but aside from studies on Neisseria elongata, relatively little is known about the formation and function of pili in these organisms. Here, we have analysed pilin expression and the role of Tfp in Neisseria cinerea. This non-pathogenic species shares a close taxonomic relationship to the pathogen Neisseria meningitidis and also colonizes the human oropharyngeal cavity. Through analysis of non-pathogenic Neisseria genomes we identified two genes with homology to pilE, which encodes the major pilin of N. meningitidis. We show which of the two genes is required for Tfp expression in N. cinerea and that Tfp in this species are required for DNA competence, similar to other Neisseria. However, in contrast to the meningococcus, deletion of the pilin gene did not impact the association of N. cinerea to human epithelial cells, demonstrating that N. cinerea isolates can adhere to human epithelial cells by Tfp-independent mechanisms. PMID:26813911

  4. Neisseria cinerea isolates can adhere to human epithelial cells by type IV pilus-independent mechanisms.

    PubMed

    Wörmann, Mirka E; Horien, Corey L; Johnson, Errin; Liu, Guangyu; Aho, Ellen; Tang, Christoph M; Exley, Rachel M

    2016-03-01

    In pathogenic Neisseria species the type IV pili (Tfp) are of primary importance in host-pathogen interactions. Tfp mediate initial bacterial attachment to cell surfaces and formation of microcolonies via pilus-pilus interactions. Based on genome analysis, many non-pathogenic Neisseria species are predicted to express Tfp, but aside from studies on Neisseria elongata, relatively little is known about the formation and function of pili in these organisms. Here, we have analysed pilin expression and the role of Tfp in Neisseria cinerea. This non-pathogenic species shares a close taxonomic relationship to the pathogen Neisseria meningitidis and also colonizes the human oropharyngeal cavity. Through analysis of non-pathogenic Neisseria genomes we identified two genes with homology to pilE, which encodes the major pilin of N. meningitidis. We show which of the two genes is required for Tfp expression in N. cinerea and that Tfp in this species are required for DNA competence, similar to other Neisseria. However, in contrast to the meningococcus, deletion of the pilin gene did not impact the association of N. cinerea to human epithelial cells, demonstrating that N. cinerea isolates can adhere to human epithelial cells by Tfp-independent mechanisms.

  5. Antimicrobial susceptibility/resistance and molecular epidemiological characteristics of Neisseria gonorrhoeae in 2009 in Belarus.

    PubMed

    Glazkova, Slavyana; Golparian, Daniel; Titov, Leonid; Pankratova, Nataliya; Suhabokava, Nataliya; Shimanskaya, Irina; Domeika, Marius; Unemo, Magnus

    2011-08-01

    Increased antimicrobial resistance (AMR) in Neisseria gonorrhoeae is a global concern, and ultimately gonorrhoea may become untreatable. Nonetheless, AMR data from East-Europe are scarce beyond Russia, and no AMR data or other characteristics of gonococci have been reported from Belarus for more than 20 years. The aim was to describe the prevalence of AMR, and report molecular epidemiological characteristics of gonococci circulating in 2009 in Belarus. In a sample of 80 isolates, resistance prevalences to antimicrobials used for gonorrhoea treatment in Belarus were: Ceftriaxone 0%, spectinomycin 0%, azithromycin 17.3%, tetracycline 25.9%, ciprofloxacin 34.6% and erythromycin 59.2%. The isolates displayed no penA mosaic alleles, 38 porB gene sequences and 35 N. gonorrhoeae multiantigen sequence types, of which 20 have not been described before worldwide. Due to the high levels of antimicrobial resistance, only ceftriaxone and spectinomycin can be recommended for empirical treatment of gonorrhoea in Belarus according to WHO recommendations. Continuous gonococcal AMR surveillance in Eastern Europe is crucial. This is now initiated in Belarus using WHO protocols.

  6. Improved Production Process for Native Outer Membrane Vesicle Vaccine against Neisseria meningitidis

    PubMed Central

    van de Waterbeemd, Bas; Zomer, Gijsbert; Kaaijk, Patricia; Ruiterkamp, Nicole; Wijffels, René H.; van den Dobbelsteen, Germie P. J. M.; van der Pol, Leo A.

    2013-01-01

    An improved detergent-free process has been developed to produce vaccine based on native outer membrane vesicles (NOMV) against Neisseria meningitidis serogroup B. Performance was evaluated with the NonaMen vaccine concept, which provides broad coverage based on nine distinct PorA antigens. Scalable aseptic equipment was implemented, replacing undesirable steps like ultracentrifugation, inactivation with phenol, and the use of preservatives. The resulting process is more consistent and gives a higher yield than published reference processes, enabling NOMV production at commercial scale. Product quality met preliminary specifications for 9 consecutive batches, and an ongoing study confirmed real-time stability up to 12 months after production. As the NOMV had low endotoxic activity and induced high bactericidal titres in mice, they are expected to be safe and effective in humans. The production process is not limited to NonaMen and may be applicable for other N. meningitidis serogroups and other gram-negative pathogens. The current results therefore facilitate the late-stage development and clinical evaluation of NOMV vaccines. PMID:23741478

  7. The First Case Report of Acute Cholangitis and Bacteremia Due to Neisseria subflava

    PubMed Central

    Uwamino, Yoshifumi; Sugita, Kayoko; Iwasaki, Eisuke; Fujiwara, Hiroshi; Nishimura, Tomoyasu; Hasegawa, Naoki; Iwata, Satoshi

    2017-01-01

    We herein report a case of acute cholangitis and bacteremia caused by a commensal Neisseria species, Neisseria subflava, in an 82-year-old man with cholangiocarcinoma. Emergency endoscopic nasobiliary drainage and cefoperazone/sulbactam therapy were effective. Gram negative coccobacilli were isolated from both blood and bile cultures on 5% sheep blood agar. The isolate was identified as N. subflava biovar perflava by mass spectrometry, a sequence analysis of the 16S rRNA, and biochemical testing. Although biliary infections due to commensal Neisseria are extremely rare, this case demonstrates the possibility of its occurrence in patients undergoing bile duct treatment. PMID:28090057

  8. Population and Functional Genomics of Neisseria Revealed with Gene-by-Gene Approaches

    PubMed Central

    Harrison, Odile B.

    2016-01-01

    Rapid low-cost whole-genome sequencing (WGS) is revolutionizing microbiology; however, complementary advances in accessible, reproducible, and rapid analysis techniques are required to realize the potential of these data. Here, investigations of the genus Neisseria illustrated the gene-by-gene conceptual approach to the organization and analysis of WGS data. Using the gene and its link to phenotype as a starting point, the BIGSdb database, which powers the PubMLST databases, enables the assembly of large open-access collections of annotated genomes that provide insight into the evolution of the Neisseria, the epidemiology of meningococcal and gonococcal disease, and mechanisms of Neisseria pathogenicity. PMID:27098959

  9. Neisseria lactamica antigens complexed with a novel cationic adjuvant.

    PubMed

    Gaspar, Emanuelle B; Rosetti, Andreza S; Lincopan, Nilton; De Gaspari, Elizabeth

    2013-03-01

    Colonization of the nasopharynx by non-pathogenic Neisseria species, including N. lactamica, has been suggested to lead to the acquisition of natural immunity against Neisseria meningitidis in young children. The aim of this study was to identify a model complex of antigens and adjuvant for immunological preparation against N. meningitidis B, based on cross reactivity with N. lactamica outer membrane vesicles (OMV) antigens and the (DDA-BF) adjuvant. Complexes of 25 µg of OMV in 0.1 mM of DDA-BF were colloidally stable, exhibiting a mean diameter and charge optimal for antigen presentation. Immunogenicity tests for these complexes were performed in mice. A single dose of OMV/DDA-BF was sufficient to induce a (DTH) response, while the same result was achieved only after two doses of OMV/alum. In addition, to achieve total IgG levels that are similar to a single immunization with OMV/DDA-BF, it was necessary to give the mice a second dose of OMV/alum. Moreover, the antibodies induced from a single immunization with OMV/DDA-BF had an intermediate avidity, but antibodies with a similar avidity were only induced by OMV/alum after two immunizations. The use of this novel cationic adjuvant for the first time with a N. lactamica OMV preparation revealed good potential for future vaccine design.

  10. [Carriers of Neisseria meningitidis among children from a primary school].

    PubMed

    Martínez, Isabel; López, Omar; Sotolongo, Franklin; Mirabal, Mayelin; Bencomo, Antonio

    2003-01-01

    A cross-sectional and descriptive study was conducted among 318 children from the "Mártires del Corynthia" Primary School under the authorization of the Municipal Division of Education and the informed consent of their parents aimed at knowing the prevalence of meningoccoco carriers in school children, determining the epidemiological markers of the isolated strains and establishing the possible relation existing between the carrier and variables, such as age, sex, acute respiratory infection history, hacinamiento, amigdalectomy, inhibitory effect of of the accompanying flora and the secretory state of ABH antigens in saliva. All of them underwent nasopharyngeal exudate and a saliva sample was taken. In adition, the paents were surveyed about the risks factors to be investigated. 6.9 % of meningoccoco carriers were found and the NA:NT:P1:NST:L3,7,9 strains predominated. The risk factors with statistically significant results regarding the condition of carrier Neisseria meningitidis carrier were age, acute respiratory infection history, and the presence of Streptococcus pneumoniae and Neisseria lactamica of the accompanying bacterial flora in the nasopharynx of the children under study.

  11. Exemplification of serological cross-reactivity of Neisseria lipopolysaccharides.

    PubMed

    Maeland, J A; Smeland, S

    1986-08-01

    Antibodies against the Gc2 serotype determinant of gonococcal lipopolysaccharides (LPS) and antisera against strains of meningococci were tested by ELISA against the Gc2 LPS, and the antibodies examined for inhibition by bacteria of prototype strains of gonococci and meningococci. From one of the anti-meningococcal sera and anti-lactose (anti-lac) type of antibody was isolated. The results showed that antigenic sites belonging to the serotype, variable, and common sets of determinants as defined for gonococcal LPSs, may cross-react with meningococci. The anti-lac antibody combined with all of 34 strains of gonococci, with 41 out of 44 strains of meningococci tested, and with a Neisseria cinerea strain. The anti-lac showed no reactivity with any of a number of other Gram-negative cocci or bacilli examined. The results indicate that LPS from most strains of the pathogenic Neisseria species share a lactosyl moiety, presumably an inner core structure, of similar or identical configuration.

  12. In vitro inhibition of growth of Neisseria gonorrhoeae by Neisseria meningitidis isolated from the pharynx of homosexual men.

    PubMed

    Bisaillon, J G; Turgeon, P; Dubreuil, D; Beaudet, R; Sylvestre, M; Ashton, F E

    1984-01-01

    Despite the high prevalence of pharyngeal gonorrhea and of meningococcal carriage among homosexual men, Neisseria gonorrhoeae and Neisseria meningitidis are rarely co-isolated from the throat. Forty-seven meningococcal isolates from the pharynx of homosexual men were examined, by a lawn-spotting method, for their ability to inhibit N. gonorrhoeae in vitro. Eight (17%) of the meningococcal isolates were inhibitory when tested against gonococci from the same patient, while 31 (66%) were inhibitory when tested against N. gonorrhoeae strain 650 (T1). The colonial type T1 of a given strain was, in all cases tested, more sensitive to the inhibitory activities than the corresponding T4 type. Since the meningococci co-isolated from the throat with gonococci were at least as inhibitory in vitro as those isolated without gonococci, the natural resistance to gonococcal pharyngitis cannot be explained on the basis of the inhibitory activities produced by the meningococci in vitro. The inhibitory strains of N. meningitidis were identified in decreasing importance as: nonserogroupable, W135, C, B, 29E, and X. The addition of trypsin to the solid medium removed the inhibition produced by the meningococci, an observation suggesting the involvement of protein inhibitors.

  13. Nosocomial pneumonia caused by a glucose-metabolizing strain of Neisseria cinerea.

    PubMed

    Boyce, J M; Taylor, M R; Mitchell, E B; Knapp, J S

    1985-01-01

    We describe what appears to be the first reported case of nosocomial pneumonia caused by Neisseria cinerea. The isolate metabolized glucose when tested in BACTEC Neisseria Differentiation Kits (Johnston Laboratories), but did not produce detectable acid in cystine-Trypticase (BBL Microbiology Systems) agar medium or in modified oxidation-fermentation medium. Clinical laboratories that rely on the BACTEC method for differentiation of pathogenic neisseriae should be aware of the fact that N. cinerea may mimic N. gonorrhoeae when tested in BACTEC Neisseria Differentiation kits. The ability of N. cinerea to grow well on tryptic soy and Mueller-Hinton agars and its inability to grow on modified Thayer-Martin medium are characteristics which help to distinguish N. cinerea from N. gonorrhoeae.

  14. Identification of a new restriction endonuclease R.NciII, from Neisseria cinerea.

    PubMed

    Piekarowicz, A

    1994-01-01

    Site-specific restriction endonuclease R. Nci II has been purified from Neisseria cinerea strain 32615. The enzyme recognizes the sequence 5' GATC 3' and its activity is inhibited by the presence of methylated adenine residue within the recognition sequence.

  15. A common gene pool for the Neisseria FetA antigen

    PubMed Central

    Bennett, Julia S.; Thompson, Emily A. L.; Kriz, Paula; Jolley, Keith A.; Maiden, Martin C. J.

    2014-01-01

    Meningococcal FetA is an iron-regulated, immunogenic outer membrane protein and vaccine component. The most diverse region of this protein is a previously defined variable region (VR) that has been shown to be immunodominant. In this analysis, a total of 275 Neisseria lactamica isolates, collected during studies of nasopharyngeal bacterial carriage in infants were examined for the presence of a fetA gene. The fetA VR nucleotide sequence was determined for 217 of these isolates, with fetA apparently absent from 58 isolates, the majority of which belonged to the ST-624 clonal complex. The VR in N. lactamica was compared to the same region in Neisseria meningitidis, Neisseria gonorrhoeae and a number of other commensal Neisseria. Identical fetA variable region sequences were identified among commensal and pathogenic Neisseria, suggesting a common gene pool, differing from other antigens in this respect. Carriage of commensal Neisseria species, such as N. lactamica, that express FetA may be involved in the development of natural immunity to meningococcal disease. PMID:18718812

  16. Identification of Neisseria spp., Haemophilus spp., and other fastidious gram-negative bacteria with the MicroScan Haemophilus-Neisseria identification panel.

    PubMed

    Janda, W M; Bradna, J J; Ruther, P

    1989-05-01

    The Haemophilus-Neisseria identification (HNID) panel (American MicroScan, Sacramento, Calif.) is a 4-h microdilution format system for identification of Haemophilus and Neisseria spp., Branhamella (Moraxella) catarrhalis, and Gardnerella vaginalis. The HNID panel was evaluated by using 423 clinical isolates and stock strains of these organisms, and HNID identifications were compared with those obtained by conventional methods. In addition, 32 isolates representing six genera not included in the HNID data base were tested to determine whether these organisms would produce unique biotype numbers for possible inclusion in the data base. The HNID panel correctly identified 95.3% of 86 Neisseria gonorrhoeae strains, 96% of 25 G. vaginalis strains, and 100% of 28 Neisseria lactamica strains and 48 B. catarrhalis strains. Only 64.7% of 68 Neisseria meningitidis isolates were identified correctly owing to false-negative or equivocal carbohydrate and/or aminopeptidase reactions. Among the Haemophilus spp., 98.8% of 83 H. influenzae strains, 97.1% of 34 H. parainfluenzae strains, and 80% of 15 H. aphrophilus and H. paraphrophilus strains were correctly identified. Eight strains of Neisseria cinerea, a species not included in the data base, produced profiles identical with those for B. catarrhalis and N. gonorrhoeae. Isolates of other species not included in the data base, including Eikenella corrodens, Kingella spp., and Cardiobacterium hominis, produced unique biochemical reaction patterns on the panel. Modification of interpretative criteria for certain tests, expansion of the data base to include other species, and suggestions for additional confirmatory tests will increase the accuracy and utility of the HNID panel.

  17. In Vitro Antibiotic Susceptibility of Neisseria gonorrhoeae in Jakarta, Indonesia

    PubMed Central

    Lesmana, Murad; Lebron, Carlos I.; Taslim, Djufri; Tjaniadi, Periska; Subekti, Decy; Wasfy, Momtaz O.; Campbell, James R.; Oyofo, Buhari A.

    2001-01-01

    Antibiotic susceptibilities were determined for 122 Neisseria gonorrheae isolates obtained from 400 sex workers in Jakarta, Indonesia, and susceptibilities to ciprofloxacin, cefuroxime, cefoxitin, cefotaxime, ceftriaxone, chloramphenicol, and spectinomycin were found. All isolates were resistant to tetracycline. A number of the isolates demonstrated decreased susceptibilities to erythromycin (MIC ≥ 1.0 μg/ml), thiamphenicol (MIC ≥ 1.0 μg/ml), kanamycin (MIC ≥ 16.0 μg/ml), penicillin (MIC ≥ 2.0 μg/ml), gentamicin (MIC ≥ 16.0 μg/ml), and norfloxacin (MIC = 0.5 μg/ml). These data showed that certain antibiotics previously used in the treatment of gonorrhea are no longer effective. PMID:11120999

  18. High-level tetracycline resistant Neisseria gonorrhoeae isolated in Portugal.

    PubMed

    Ferreira, E; Louro, D; Gomes, J P; Catry, M A; Pato, M V

    1997-05-01

    The first high-level tetracycline resistance (MIC > or = 16 mg/l) isolates of Neisseria gonorrhoeae (TRNG) were reported in 1990 from patients attending a Sexual Transmitted Disease (STD) Center in Lisbon. The TRNG prevalence was 4% in 1991, 5.3% in 1992 and 10,8% in 1994, exploding to 52.2% in 1995. The tet M determinant was evaluated by PCR. The digests of PCRP using HpaII produced the restriction pattern 2 for all the strains, except one (pattern 3). 78.3% of the TRNG strains were beta-lactamase producers and the 4.5 MDa penicillinase plasmid was the dominant (83%), 90% and 93.3% of the TRNG strains belonged to the auxotype NR and to the serogroup IA, respectively. The IA-8/NR class represented 58.3% of the TRNG isolates, suggesting a clonal spreading.

  19. Nasopharyngeal, vaginal and anal carriage of Neisseria meningitidis in Nigeria.

    PubMed

    Gugnani, H C; Uganabo, J A

    1989-03-01

    The incidence of carriers of Neisseria meningitidis was investigated in Borno State, an epidemic area for cerebrospinal meningitis and in Anambra State a non-epidemic area for this disease in Nigeria. The nasopharyngeal carriage rate in Maiduguri in Borno State was 18 per cent as compared with 11.8 per cent and 9.6 per cent in Nsukka and Enugu respectively in Anambra State. N. meningitidis was also isolated from anus and vagina in one and three females respectively. Majority of the isolates (71.9 per cent) belonged to serogroup B. The rare group x was recorded on two occasions. Majority of the isolates were sensitive to tetracycline, streptomycin and chloramphenicol; a few multiple drug resistant strains were also encountered.

  20. Pili-taxis: Clustering of Neisseria gonorrhoeae bacteria

    NASA Astrophysics Data System (ADS)

    Taktikos, Johannes; Zaburdaev, Vasily; Biais, Nicolas; Stark, Holger; Weitz, David A.

    2012-02-01

    The first step of colonization of Neisseria gonorrhoeae bacteria, the etiological agent of gonorrhea, is the attachment to human epithelial cells. The attachment of N. gonorrhoeae bacteria to surfaces or other cells is primarily mediated by filamentous appendages, called type IV pili (Tfp). Cycles of elongation and retraction of Tfp are responsible for a common bacterial motility called twitching motility which allows the bacteria to crawl over surfaces. Experimentally, N. gonorrhoeae cells initially dispersed over a surface agglomerate into round microcolonies within hours. It is so far not known whether this clustering is driven entirely by the Tfp dynamics or if chemotactic interactions are needed. Thus, we investigate whether the agglomeration may stem solely from the pili-mediated attraction between cells. By developing a statistical model for pili-taxis, we try to explain the experimental measurements of the time evolution of the mean cluster size, number of clusters, and area fraction covered by the cells.

  1. Potential Therapy for Neisseria Gonorrhoeae Infections With Human Chorionic Gonadotropin.

    PubMed

    Rao, C V

    2015-12-01

    The scientific evidence suggests that Neisseria gonorrhoeae (NG) infects human fallopian tubes by molecular mimicry in which pathogens act like a ligand to bind to epithelial cell surface human chorionic gonadotrophin (hCG)/luteinizing hormone (LH) receptors. The hCG-like molecule has been identified as ribosomal protein L12 in NG coat surface. Human fallopian tube epithelial cells have been shown to contain functional hCG/LH receptors. As previously shown in human fallopian tube organ and cell culture studies, cellular invasion and infection can be prevented by exposing the cells to excess hCG, which would outnumber and outcompete NG for receptor binding. Based on these data, we suggest testing hCG in clinical trials on infected women.

  2. Neisseria meningitidis Serogroup C Causing Primary Arthritis in a Child

    PubMed Central

    Straticiuc, Sergiu; Ignat, Ancuta; Hanganu, Elena; Lupu, Vasile Valeriu; Ciubara, Alexandru Bogdan; Cretu, Roxana

    2016-01-01

    Abstract Introduction: Neisseria meningitidis (N. meningitidis) is associated with severe invasive infections such as meningitis and fulminant septicemia. Septic arthritis due to N. meningitidis is rare and bone infections have been reported exceptionally. We report the case of a 1-year old girl who presented with a painful, swollen right knee, accompanied by fever and agitation. Arthrocentesis of the right knee, while patient was under anesthesia, yielded grossly purulent fluid, so we made arthrotomy and drainage. The culture from synovial fluid revealed N. meningitidis, sensitive to Ceftriaxone. The patient received intravenous antibiotherapy with Ceftriaxone. The status of the patient improved after surgical drainage and intravenous antibiotic therapy. She recovered completely after 1 month. Conclusion: This observation illustrates an unusual presentation of invasive meningococcal infection and the early identification of the bacteria, combined with the correct treatment, prevent the complications and even death. PMID:26844522

  3. Structure of the Neisseria meningitidis Type IV pilus

    PubMed Central

    Kolappan, Subramania; Coureuil, Mathieu; Yu, Xiong; Nassif, Xavier; Egelman, Edward H.; Craig, Lisa

    2016-01-01

    Neisseria meningitidis use Type IV pili (T4P) to adhere to endothelial cells and breach the blood brain barrier, causing cause fatal meningitis. T4P are multifunctional polymers of the major pilin protein, which share a conserved hydrophobic N terminus that is a curved extended α-helix, α1, in X-ray crystal structures. Here we report a 1.44 Å crystal structure of the N. meningitidis major pilin PilE and a ∼6 Å cryo-electron microscopy reconstruction of the intact pilus, from which we built an atomic model for the filament. This structure reveals the molecular arrangement of the N-terminal α-helices in the filament core, including a melted central portion of α1 and a bridge of electron density consistent with a predicted salt bridge necessary for pilus assembly. This structure has important implications for understanding pilus biology. PMID:27698424

  4. Comparison of the inflammatory responses of human meningeal cells following challenge with Neisseria lactamica and with Neisseria meningitidis.

    PubMed

    Fowler, Mark I; Yin, Kiave Y Ho Wang; Humphries, Holly E; Heckels, John E; Christodoulides, Myron

    2006-11-01

    The rationale for the present study was to determine how different species of bacteria interact with cells of the human meninges in order to gain information that would have broad relevance to understanding aspects of the innate immune response in the brain. Neisseria lactamica is an occasional cause of meningitis in humans, and in this study we investigated the in vitro interactions between N. lactamica and cells derived from the leptomeninges in comparison with the closely related organism Neisseria meningitidis, a major cause of meningitis worldwide. N. lactamica adhered specifically to meningioma cells, but the levels of adherence were generally lower than those with N. meningitidis. Meningioma cells challenged with N. lactamica and N. meningitidis secreted significant amounts of the proinflammatory cytokine interleukin-6 (IL-6), the C-X-C chemokine IL-8, and the C-C chemokines monocyte chemoattractant protein 1 (MCP-1) and RANTES, but it secreted very low levels of the cytokine growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF). Thus, meningeal cells are involved in the innate host response to Neisseria species that are capable of entering the cerebrospinal fluid. The levels of IL-8 and MCP-1 secretion induced by both bacteria were essentially similar. By contrast, N. lactamica induced significantly lower levels of IL-6 than N. meningitidis. Challenge with the highest concentration of N. lactamica (10(8) CFU) induced a small but significant down-regulation of RANTES secretion, which was not observed with lower concentrations of bacteria. N. meningitidis (10(6) to 10(8) CFU) also down-regulated RANTES secretion, but this effect was significantly greater than that observed with N. lactamica. Although both bacteria were unable to invade meningeal cells directly, host cells remained viable on prolonged challenge with N. lactamica, whereas N. meningitidis induced death; the mechanism was overwhelming necrosis with no significant apoptosis. It

  5. Genetic diversity and carriage dynamics of Neisseria lactamica in infants.

    PubMed

    Bennett, Julia S; Griffiths, David T; McCarthy, Noel D; Sleeman, Karen L; Jolley, Keith A; Crook, Derrick W; Maiden, Martin C J

    2005-04-01

    Neisseria lactamica, a harmless human commensal found predominantly in the upper respiratory tracts of infants, is closely related to Neisseria meningitidis, a pathogen of global significance. Colonization with N. lactamica may be responsible for the increase in immunity to meningococcal disease that occurs during childhood, when rates of meningococcal carriage are low. This observation has led to the suggestion that N. lactamica whole cells or components are potential constituents of novel meningococcal vaccines. However, the dynamics of carriage and population diversity of N. lactamica in children are poorly understood, presenting difficulties for the choice of representative isolates for use in vaccine development. This problem was addressed by the multilocus sequence typing of N. lactamica isolates from two longitudinal studies of bacterial carriage in infants. The studies comprised 100 and 216 subjects, with N. lactamica carriage monitored from age 4 weeks until age 96 weeks and from age 2 weeks until age 24 weeks, respectively. The maximum observed carriage rate was 44% at 56 weeks of age, with isolates obtained on multiple visits for the majority (54 of 75, 72%) of carriers. The N. lactamica isolates were genetically diverse, with 69 distinct genotypes recovered from the 75 infants. Carriage was generally long-lived, with an average rate of loss of under 1% per week during the 28 weeks following acquisition. Only 11 of the 75 infants carried more than one genotypically unique isolate during the course of the study. Some participants shared identical isolates with siblings, but none shared identical isolates with their parents. These findings have implications for the design of vaccines based on this organism.

  6. The Stonehouse survey: nasopharyngeal carriage of meningococci and Neisseria lactamica.

    PubMed

    Cartwright, K A; Stuart, J M; Jones, D M; Noah, N D

    1987-12-01

    A total of 6234 nasopharyngeal swabs was collected during a survey of the population of Stonehouse, Gloucestershire in November 1986 as part of an investigation into an outbreak of meningococcal disease. The overall meningococcal carriage rate was 10.9%. The carriage rate rose with age from 2.1% in the 0- to 4-year-olds to a peak of 24.5% in the 15- to 19-year-olds, and thereafter declined steadily with age. Male carriers outnumbered female carriers of meningococci by 3:2. Group B (or non-groupable) type 15 sulphonamide-resistant strains which had caused the outbreak were isolated from 1.4% of subjects. The age distribution of carriers of these strains was similar to that of other meningococci apart from an additional peak in the 5-9-year age group and a more rapid decline in carriage with increasing age. Variations in the carriage rates of the outbreak strain were seen in children attending different schools and in the residents of different areas of the town. The low carriage rate of these strains in a community during a prolonged outbreak supports the hypothesis that these organisms are less transmissible but more virulent than other strains of pathogenic meningococci. Carriage of Neisseria lactamica, which is thought to be important in the development of meningococcal immunity, was most frequent in children under the age of 5 years and was six times commoner in this age group than carriage of Neisseria meningitidis. In older children and adults female carriers of N. lactamica increasingly outnumbered males in contrast to the male preponderance observed with meningococcal carriage.

  7. Genetic characteristics of Neisseria meningitidis serogroup B strains carried by adolescents living in Milan, Italy

    PubMed Central

    Esposito, Susanna; Zampiero, Alberto; Terranova, Leonardo; Montinaro, Valentina; Scala, Alessia; Ansuini, Valentina; Principi, Nicola

    2013-01-01

    Before a protein vaccine is introduced into a country, it is essential to evaluate its potential impact and estimate its benefits and costs. The aim of this study was to determine the genetic characteristics of Neisseria meningitidis B (NmB) in the pharyngeal secretions of 1375 healthy adolescents aged 13–19 y living in Milan, Italy, in September 2012, and the possible protection offered by the two currently available NmB protein vaccines. Ninety-one subjects were Nm carriers (6.6%), 29 (31.9%) of whom carried the NmB capsular gene. The 29 identified strains belonged to eight clonal complexes (CCs), the majority of which were in the ST-41/44/Lin.3 CC (n = 11; 37.9%). All of the identified strains harboured ƒHbp alleles representing a total of 15 sub-variants: the gene for NHBA protein was found in all but three of the studied strains (10.3%) with 13 identified sub-variants. There were 15 porA sub-types, seven of which were identified in just one CC. The findings of this study seem to suggest that both of the protein vaccines proposed for the prevention of invasive disease due to NmB (the 4-protein and the 2-protein products) have a composition that can evoke a theoretically effective antibody response against the meningococcal strains currently carried by adolescents living in Northern Italy. The genetic characteristics of NmB strains can be easily evaluated by means of molecular methods, the results of which can provide an albeit approximate estimate of the degree of protection theoretically provided by the available vaccines, and the possible future need to change their composition. PMID:23880917

  8. Comparison of phenotypically indistinguishable but geographically distinct Neisseria meningitidis Group B isolates in a serum bactericidal antibody assay.

    PubMed

    Findlow, Jamie; Holland, Ann; Andrews, Nick; Weynants, Vincent; Sotolongo, Franklin; Balmer, Paul; Poolman, Jan; Borrow, Ray

    2007-11-01

    The "gold standard" assay for measuring serologic protection against Neisseria meningitidis group B (MenB) is the serum bactericidal antibody (SBA) assay. Of vital importance to the outcome of the SBA assay is the choice of the target strain(s), which is often chosen on the basis of phenotype or genotype. We therefore investigated the effect on the results produced by the SBA assay of using phenotypically indistinguishable but geographically distinct MenB isolates. Nine PorA P1.19,15 and 11 PorA P1.7-2,4 MenB isolates were incorporated into the SBA assay using human complement and were assayed against sera obtained either before or after outer membrane vesicle vaccination. Large differences in the results produced by the isolates in the SBA assay were demonstrated. These included differences as great as 5.8-fold in SBA geometric mean titers and in the proportions of subjects with SBA titers of >/=4. Ranges of as many as 9 SBA titers were achieved by individual sera across the panels of isolates. To determine the reasons for the differences observed, investigations into the expression of capsular polysaccharide, PorA, PorB, Opc, and lipooligosaccharide (LOS) and into LOS sialylation were completed. However, minor differences were found between strains, indicating similar expression and no antigen masking. These results have implications for the choice of MenB target strains for inclusion in future studies of MenB vaccines and highlight the requirement for standardization of target strains between laboratories.

  9. Comparative genomics of Neisseria meningitidis: core genome, islands of horizontal transfer and pathogen-specific genes.

    PubMed

    Dunning Hotopp, Julie C; Grifantini, Renata; Kumar, Nikhil; Tzeng, Yih Ling; Fouts, Derrick; Frigimelica, Elisabetta; Draghi, Monia; Giuliani, Marzia Monica; Rappuoli, Rino; Stephens, David S; Grandi, Guido; Tettelin, Hervé

    2006-12-01

    To better understand Neisseria meningitidis genomes and virulence, microarray comparative genome hybridization (mCGH) data were collected from one Neisseria cinerea, two Neisseria lactamica, two Neisseria gonorrhoeae and 48 Neisseria meningitidis isolates. For N. meningitidis, these isolates are from diverse clonal complexes, invasive and carriage strains, and all major serogroups. The microarray platform represented N. meningitidis strains MC58, Z2491 and FAM18, and N. gonorrhoeae FA1090. By comparing hybridization data to genome sequences, the core N. meningitidis genome and insertions/deletions (e.g. capsule locus, type I secretion system) related to pathogenicity were identified, including further characterization of the capsule locus, bioinformatics analysis of a type I secretion system, and identification of some metabolic pathways associated with intracellular survival in pathogens. Hybridization data clustered meningococcal isolates from similar clonal complexes that were distinguished by the differential presence of six distinct islands of horizontal transfer. Several of these islands contained prophage or other mobile elements, including a novel prophage and a transposon carrying portions of a type I secretion system. Acquisition of some genetic islands appears to have occurred in multiple lineages, including transfer between N. lactamica and N. meningitidis. However, island acquisition occurs infrequently, such that the genomic-level relationship is not obscured within clonal complexes. The N. meningitidis genome is characterized by the horizontal acquisition of multiple genetic islands; the study of these islands reveals important sets of genes varying between isolates and likely to be related to pathogenicity.

  10. Phasevarions Mediate Random Switching of Gene Expression in Pathogenic Neisseria

    PubMed Central

    Srikhanta, Yogitha N.; Dowideit, Stefanie J.; Edwards, Jennifer L.; Falsetta, Megan L.; Wu, Hsing-Ju; Harrison, Odile B.; Fox, Kate L.; Seib, Kate L.; Maguire, Tina L.; Wang, Andrew H.-J.; Maiden, Martin C.; Grimmond, Sean M.; Apicella, Michael A.; Jennings, Michael P.

    2009-01-01

    Many host-adapted bacterial pathogens contain DNA methyltransferases (mod genes) that are subject to phase-variable expression (high-frequency reversible ON/OFF switching of gene expression). In Haemophilus influenzae, the random switching of the modA gene controls expression of a phase-variable regulon of genes (a “phasevarion”), via differential methylation of the genome in the modA ON and OFF states. Phase-variable mod genes are also present in Neisseria meningitidis and Neisseria gonorrhoeae, suggesting that phasevarions may occur in these important human pathogens. Phylogenetic studies on phase-variable mod genes associated with type III restriction modification (R-M) systems revealed that these organisms have two distinct mod genes—modA and modB. There are also distinct alleles of modA (abundant: modA11, 12, 13; minor: modA4, 15, 18) and modB (modB1, 2). These alleles differ only in their DNA recognition domain. ModA11 was only found in N. meningitidis and modA13 only in N. gonorrhoeae. The recognition site for the modA13 methyltransferase in N. gonorrhoeae strain FA1090 was identified as 5′-AGAAA-3′. Mutant strains lacking the modA11, 12 or 13 genes were made in N. meningitidis and N. gonorrhoeae and their phenotype analyzed in comparison to a corresponding mod ON wild-type strain. Microarray analysis revealed that in all three modA alleles multiple genes were either upregulated or downregulated, some of which were virulence-associated. For example, in N. meningitidis MC58 (modA11), differentially expressed genes included those encoding the candidate vaccine antigens lactoferrin binding proteins A and B. Functional studies using N. gonorrhoeae FA1090 and the clinical isolate O1G1370 confirmed that modA13 ON and OFF strains have distinct phenotypes in antimicrobial resistance, in a primary human cervical epithelial cell model of infection, and in biofilm formation. This study, in conjunction with our previous work in H. influenzae, indicates that

  11. Phasevarions mediate random switching of gene expression in pathogenic Neisseria.

    PubMed

    Srikhanta, Yogitha N; Dowideit, Stefanie J; Edwards, Jennifer L; Falsetta, Megan L; Wu, Hsing-Ju; Harrison, Odile B; Fox, Kate L; Seib, Kate L; Maguire, Tina L; Wang, Andrew H-J; Maiden, Martin C; Grimmond, Sean M; Apicella, Michael A; Jennings, Michael P

    2009-04-01

    Many host-adapted bacterial pathogens contain DNA methyltransferases (mod genes) that are subject to phase-variable expression (high-frequency reversible ON/OFF switching of gene expression). In Haemophilus influenzae, the random switching of the modA gene controls expression of a phase-variable regulon of genes (a "phasevarion"), via differential methylation of the genome in the modA ON and OFF states. Phase-variable mod genes are also present in Neisseria meningitidis and Neisseria gonorrhoeae, suggesting that phasevarions may occur in these important human pathogens. Phylogenetic studies on phase-variable mod genes associated with type III restriction modification (R-M) systems revealed that these organisms have two distinct mod genes--modA and modB. There are also distinct alleles of modA (abundant: modA11, 12, 13; minor: modA4, 15, 18) and modB (modB1, 2). These alleles differ only in their DNA recognition domain. ModA11 was only found in N. meningitidis and modA13 only in N. gonorrhoeae. The recognition site for the modA13 methyltransferase in N. gonorrhoeae strain FA1090 was identified as 5'-AGAAA-3'. Mutant strains lacking the modA11, 12 or 13 genes were made in N. meningitidis and N. gonorrhoeae and their phenotype analyzed in comparison to a corresponding mod ON wild-type strain. Microarray analysis revealed that in all three modA alleles multiple genes were either upregulated or downregulated, some of which were virulence-associated. For example, in N. meningitidis MC58 (modA11), differentially expressed genes included those encoding the candidate vaccine antigens lactoferrin binding proteins A and B. Functional studies using N. gonorrhoeae FA1090 and the clinical isolate O1G1370 confirmed that modA13 ON and OFF strains have distinct phenotypes in antimicrobial resistance, in a primary human cervical epithelial cell model of infection, and in biofilm formation. This study, in conjunction with our previous work in H. influenzae, indicates that

  12. Characterization of the Neisseria gonorrhoeae Iron and Fur Regulatory Network

    PubMed Central

    Yu, Chunxiao; McClure, Ryan; Daou, Nadine

    2016-01-01

    ABSTRACT The Neisseria gonorrhoeae ferric uptake regulator (Fur) protein controls expression of iron homeostasis genes in response to intracellular iron levels. In this study, using transcriptome sequencing (RNA-seq) analysis of an N. gonorrhoeae fur strain, we defined the gonococcal Fur and iron regulons and characterized Fur-controlled expression of an ArsR-like DNA binding protein. We observed that 158 genes (8% of the genome) showed differential expression in response to iron in an N. gonorrhoeae wild-type or fur strain, while 54 genes exhibited differential expression in response to Fur. The Fur regulon was extended to additional regulators, including NrrF and 13 other small RNAs (sRNAs), and two transcriptional factors. One transcriptional factor, coding for an ArsR-like regulator (ArsR), exhibited increased expression under iron-replete conditions in the wild-type strain but showed decreased expression across iron conditions in the fur strain, an effect that was reversed in a fur-complemented strain. Fur was shown to bind to the promoter region of the arsR gene downstream of a predicted σ70 promoter region. Electrophoretic mobility shift assay (EMSA) analysis confirmed binding of the ArsR protein to the norB promoter region, and sequence analysis identified two additional putative targets, NGO1411 and NGO1646. A gonococcal arsR strain demonstrated decreased survival in human endocervical epithelial cells compared to that of the wild-type and arsR-complemented strains, suggesting that the ArsR regulon includes genes required for survival in host cells. Collectively, these results demonstrate that the N. gonorrhoeae Fur functions as a global regulatory protein to repress or activate expression of a large repertoire of genes, including additional transcriptional regulatory proteins. IMPORTANCE Gene regulation in bacteria in response to environmental stimuli, including iron, is of paramount importance to both bacterial replication and, in the case of pathogenic

  13. A bacterial siren song: intimate interactions between neutrophils and pathogenic Neisseria

    PubMed Central

    Criss, Alison K.; Seifert, H. Steven

    2012-01-01

    Preface Neisseria gonorrhoeae and Neisseria meningitidis are Gram-negative bacterial pathogens that are exquisitely adapted for growth at human mucosal surfaces and for efficient transmission between hosts. One factor that is essential to neisserial pathogenesis is the interaction between the bacteria and neutrophils, which are recruited in high numbers during infection. Although this vigorous host response could simply reflect effective immune recognition of the bacteria, there is mounting evidence that in fact these obligate human pathogens manipulate the innate immune response to promote infectious processes. This Review summarizes the mechanisms used by pathogenic neisseriae to resist and modulate the antimicrobial activities of neutrophils. It also details some of the major outstanding questions about the Neisseria–neutrophil relationship and proposes potential benefits of this relationship for the pathogen. PMID:22290508

  14. Immunization with live Neisseria lactamica protects mice against meningococcal challenge and can elicit serum bactericidal antibodies.

    PubMed

    Li, Yanwen; Zhang, Qian; Winterbotham, Megan; Mowe, Eva; Gorringe, Andrew; Tang, Christoph M

    2006-11-01

    Natural immunity against Neisseria meningitidis is thought to develop following nasopharyngeal colonization with this bacterium or other microbes expressing cross-reactive antigens. Neisseria lactamica is a commensal of the upper respiratory tract which is often carried by infants and young children; epidemiological evidence indicates that colonization with this bacterium can elicit serum bactericidal activity (SBA) against Neisseria meningitidis, the most validated correlate of protective immunity. Here we demonstrate experimentally that immunization of mice with live N. lactamica protects animals against lethal meningococcal challenge and that some, but not all, strains of N. lactamica elicit detectable SBA in immunized animals regardless of the serogroup of N. meningitidis. While it is unlikely that immunization with live N. lactamica will be implemented as a vaccine against meningococcal disease, understanding the basis for the induction of cross-protective immunity and SBA should be valuable in the design of subunit vaccines for the prevention of this important human infection.

  15. Transfer of plasmid-mediated ampicillin resistance from Haemophilus to Neisseria gonorrhoeae requires an intervening organism.

    PubMed

    McNicol, P J; Albritton, W L; Ronald, A R

    1986-01-01

    Haemophilus species have been implicated as the source of plasmid-mediated ampicillin resistance in Neisseria gonorrhoeae. Previous attempts to transfer conjugally the resistance plasmids from Haemophilus species to N. gonorrhoeae have met with limited success. Using both biparental and triparental mating systems, it was found that transfer will occur if the commensal Neisseria species, Neisseria cinerea, is used as a transfer intermediate. This organism stably maintains resistance plasmids of Haemophilus and facilitates transfer of these plasmids to N. gonorrhoeae, in a triparental mating system, at a transfer frequency of 10(-8). Both Haemophilus ducreyi and N. gonorrhoeae carry mobilizing plasmids capable of mediating conjugal transfer of the same resistance plasmids. However, restriction endonuclease mapping and DNA hybridization studies indicate that the mobilizing plasmids are distinctly different molecules. Limited homology is present within the transfer region of these plasmids.

  16. Molecular characterization of rifampin-resistant Neisseria meningitidis.

    PubMed Central

    Carter, P E; Abadi, F J; Yakubu, D E; Pennington, T H

    1994-01-01

    Primers were designed to amplify the rpoB gene of Neisseria meningitidis. The region of the gene amplified covered clusters I and II of the rifampin resistance (Rifr) mutation sites identified in Escherichia coli. DNAs from six Rifr isolates and 21 rifampin-susceptible isolates from the United Kingdom representing a number of serogroups were amplified and sequenced. All six Rifr isolates had identical DNA sequences and the same amino acid change, a His to an Asn change at position 35 (H35N). This His residue is equivalent to the His residue at position 526 in E. coli, one of the known Rifr mutation sites. DNAs from an additional six Rifr mutations generated in vitro were amplified and sequenced. Three had H35Y changes, one had an H35R change, one had an H35N change and one had an S40F change. The predominance of mutations at the His residue at position 35 in Rifr N. meningitidis isolates suggests that it plays a critical role in the selection of antibiotic-resistant variants. All six Rifr isolates belonged to the same clonal group when analyzed by restriction enzyme analysis and pulsed-field gel electrophoresis. These data suggest that a single clone of Rifr N. meningitidis is present and widespread throughout the United Kingdom. Images PMID:8092823

  17. Antigenic and physical diversity of Neisseria gonorrhoeae lipooligosaccharides.

    PubMed Central

    Mandrell, R; Schneider, H; Apicella, M; Zollinger, W; Rice, P A; Griffiss, J M

    1986-01-01

    We used mouse monoclonal antibodies (MAbs) to characterize Neisseria gonorrhoeae lipooligosaccharide (LOS). LOSs that bound two or more MAbs in a solid-phase radioimmunoassay usually bound them to different LOS components, as separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE); strains with multiple LOS components on SDS-PAGE usually bound more than one MAb. However, the LOS of some strains bound the same MAb to two LOS components with different relative molecular weights, and some individual LOS components bound more than one MAb. LOSs from different strains bound different amounts of the same MAb at saturation, reflecting differences in the quantitative expression of individual LOS components. Not all components recognized by MAbs were stained by silver after periodate oxidation. Treatment with NaOH variously affected epitopes defined by different MAbs. MAb 3F11 completely inhibited and MAb 2-1-L8 partially inhibited the binding of 125I-labeled 06B4 MAb to WR220 LOS and WR220 outer membranes in competitive binding studies. Other MAbs did not compete with the binding of 125I-labeled 06B4 to either antigen. We conclude that a strain of N. gonorrhoeae elaborates multiple LOSs that can be separated by SDS-PAGE and that are antigenically distinct. Epitope expression within these glycolipids is complex. Images PMID:2428752

  18. Characterization of the Neisseria meningitidis Helicase RecG

    PubMed Central

    Beyene, Getachew Tesfaye; Balasingham, Seetha V.; Frye, Stephan A.; Namouchi, Amine; Homberset, Håvard; Kalayou, Shewit; Riaz, Tahira

    2016-01-01

    Neisseria meningitidis (Nm) is a Gram-negative oral commensal that opportunistically can cause septicaemia and/or meningitis. Here, we overexpressed, purified and characterized the Nm DNA repair/recombination helicase RecG (RecGNm) and examined its role during genotoxic stress. RecGNm possessed ATP-dependent DNA binding and unwinding activities in vitro on a variety of DNA model substrates including a Holliday junction (HJ). Database searching of the Nm genomes identified 49 single nucleotide polymorphisms (SNPs) in the recGNm including 37 non-synonymous SNPs (nsSNPs), and 7 of the nsSNPs were located in the codons for conserved active site residues of RecGNm. A transient reduction in transformation of DNA was observed in the Nm ΔrecG strain as compared to the wildtype. The gene encoding recGNm also contained an unusually high number of the DNA uptake sequence (DUS) that facilitate transformation in neisserial species. The differentially abundant protein profiles of the Nm wildtype and ΔrecG strains suggest that expression of RecGNm might be linked to expression of other proteins involved in DNA repair, recombination and replication, pilus biogenesis, glycan biosynthesis and ribosomal activity. This might explain the growth defect that was observed in the Nm ΔrecG null mutant. PMID:27736945

  19. Opa Expression Correlates with Elevated Transformation Rates in Neisseria gonorrhoeae

    PubMed Central

    Hill, Stuart A.

    2000-01-01

    Neisseria gonorrhoeae is naturally competent for DNA transformation. Under most conditions encountered in vivo, gonococci express one or more opacity (Opa) proteins on their surfaces. Recently, it was shown that DNA preferentially binds to the surfaces of Opa-expressing organisms compared to those of isogenic Opa-negative strains, presumably due to the numerous cationic residues in the predicted surface-exposed loops of the Opa protein. This study examined whether Opa-DNA interactions actually influence DNA transformation of the gonococcus. The data show that Opa-expressing gonococci are more efficient recipients of DNA for transformation and are more susceptible to exogenous DNase I treatment at early stages during the DNA transformation process than non-Opa expressors. Furthermore, inhibition of the transformation process was demonstrable for Opa+ populations when either nonspecific DNA or the polyanion heparin was used. Overall, the data suggest that Opa expression, with its presumptive positive surface charge contribution, promotes DNA transformation by causing a more prolonged sequestration of donor DNA at the cell surface, which translates into more efficient transformation over time. PMID:10613877

  20. [MOLECULAR MECHANISMS OF DRUG RESISTANCE NEISSERIA GONORRHOEAE HISTORY AND PROSPECTS].

    PubMed

    Bodoev, I N; Il'ina, E N

    2015-01-01

    Neisseria gonorrhoeae (gonococcus) is a strict human pathogen, which causes gonorrhea--an infectious disease, whose origin dates back to more than two thousand years. Due to the unique plasticity of the genetic material, these bacteria have acquired the capacity to adapt to the host immune system, cause repeated infections, as well as withstand antimicrobials. Since the introduction of antibiotics in 1930s, gonococcus has displayed its propensity to develop resistance to all clinically useful antibiotics. It is important to note that the known resistance determinants of N. gonorrhoeae were acquired through horizontal gene transfer, recombination and spontaneous mutagenesis, and may be located both in the chromosome and on the plasmid. After introduction of a new antimicrobial drug, gonococcus becomes resistant within two decades and replaces sensitive bacterial population. Currently Ceftriaxone is the last remaining antibiotic for first-line treatment of gonorrhea. However, the first gonococcus displaying high-level resistance to Ceftriaxone was isolated in Japan a few years ago. Therefore, in the near future, gonorrhea may become untreatable. In the present review, we discuss the chronology of the anti-gonorrhea drugs (antibiotics) replacement, the evolution of resistance mechanisms emergence and future perspectives of N. gonorrhoeae treatment.

  1. Characteristics of pathogenic Neisseria spp. isolated from homosexual men.

    PubMed Central

    Janda, W M; Morello, J A; Lerner, S A; Bohnhoff, M

    1983-01-01

    Oropharyngeal, urethral, and rectal cultures for pathogenic Neisseria spp. were collected from 815 homosexual men attending a community clinic in Chicago. Meningococci were characterized by serogrouping and antimicrobial susceptibility testing. Gonococci were auxotyped, and susceptibilities to penicillin and tetracycline were determined. Of the 815 men tested, 42.5% carried meningococci in the oropharynx. Gonococci were recovered from the urethra, rectum, and oropharynx of 18.5, 16.3, and 5.6%, respectively. Meningococci were also recovered from the urethra (6 patients) and the rectum (15 patients). Some of these isolates were identical to the isolates from the oropharynges of the same patients, whereas others were distinct from the oropharyngeal isolates by serogroup or antimicrobial susceptibilities. Serogroups B, W135, and C comprised over 90% of the meningococci. Almost 80% of the gonococcal strains required minimal inhibitory concentrations greater than 0.06 micrograms of penicillin per ml, whereas greater than 90% of the meningococci were inhibited at this concentration. Auxotyping demonstrated three major auxotypes: Zero (required none of the nutrients tested), 60%; arginine requiring, 19.4%; and proline requiring, 12.3%. Only four strains (1.2%) required arginine, hypoxanthine, and uracil. PMID:6826712

  2. COMPARISON OF METHODS TO IDENTIFY Neisseria meningitidis IN ASYMPTOMATIC CARRIERS

    PubMed Central

    RIZEK, Camila F.; LUIZ, André Machado; de ASSIS, Gracilene Ramos; COSTA, Silvia Figueiredo; LEVIN, Anna Sara; LOPES, Marta Heloisa

    2016-01-01

    SUMMARY Neisseria meningitidis is a cause of several life-threatening diseases and can be a normal commensal in the upper respiratory tract of healthy carriers. The carrier rate is not well established especially because there is no standard method for the isolation of N. meningitidis. Therefore, the aim of this study was to compare identification methods for the carrier state. Two swabs were collected from 190 volunteers: one was cultured and the other had DNA extracted directly from the sample. The Polymerase Chain Reaction (PCR) was performed to determine species and serogroups and compared the results between the methods. PCR for species determination used two pairs of primers and when there was only one amplicon, it was sequenced. The culture technique was positive in 23 (12.1%) subjects while the direct extraction method was positive in 132 (69.5%), p < 0.001. Among the 135 subjects with positive N. meningitides tests, 88 (65.2%) were serogroup C; 3 (2.2%) serogroup B; 5 (3.7%) were positive for both serogroup B and C, and 39 (28.9%) did not belong to any of the tested serogroups. In this study, PCR from DNA extracted directly from swabs identified more N. meningitidis asymptomatic carriers than the culture technique. PMID:27680165

  3. Analyzing Neisseria gonorrhoeae Pilin Antigenic Variation Using 454 Sequencing Technology

    PubMed Central

    Rotman, Ella; Webber, David M.

    2016-01-01

    ABSTRACT Many pathogens use homologous recombination to vary surface antigens in order to avoid immune surveillance. Neisseria gonorrhoeae, the bacterium responsible for the sexually transmitted infection gonorrhea, achieves this in part by changing the sequence of the major subunit of the type IV pilus in a process termed pilin antigenic variation (Av). The N. gonorrhoeae chromosome contains one expression locus (pilE) and many promoterless, partial-coding silent copies (pilS) that act as reservoirs for variant pilin information. Pilin Av occurs by high-frequency gene conversion reactions, which transfer pilS sequences into the pilE locus. We have developed a 454 sequencing-based assay to analyze the frequency and characteristics of pilin Av that allows a more robust analysis of pilin Av than previous assays. We used this assay to analyze mutations and conditions previously shown to affect pilin Av, confirming many but not all of the previously reported phenotypes. We show that mutations or conditions that cause growth defects can result in Av phenotypes when analyzed by phase variation-based assays. Adapting the 454 sequencing to analyze pilin Av demonstrates the utility of this technology to analyze any diversity generation system that uses recombination to develop biological diversity. IMPORTANCE Measuring and analyzing complex recombination-based systems constitute a major barrier to understanding the mechanisms used to generate diversity. We have analyzed the contributions of many gonococcal mutations or conditions to the process of pilin antigenic variation. PMID:27381912

  4. Natural transformation and phase variation modulation in Neisseria meningitidis.

    PubMed

    Alexander, Heather L; Richardson, Anthony R; Stojiljkovic, Igor

    2004-05-01

    Neisseria meningitidis has evolved the ability to control the expression-state of numerous genes by phase variation. It has been proposed that the process aids this human pathogen in coping with the diversity of microenvironments and host immune systems. Therefore, increased frequencies of phase variation may augment the organism's adaptability and virulence. In this study, we found that DNA derived from various neisserial co-colonizers of the human nasopharynx increased N. meningitidis switching frequencies, indicating that heterologous neisserial DNA modulates phase variation in a transformation-dependent manner. In order to determine whether the effect of heterologous DNA was specific to the Hb receptor, HmbR, we constructed a Universal Rates of Switching cassette (UROS). With this cassette, we demonstrated that heterologous DNA positively affects phase variation throughout the meningococcal genome, as UROS phase variation frequencies were also increased in the presence of neisserial DNA. Overexpressing components of the neisserial mismatch repair system partially alleviated DNA-induced changes in phase variation frequencies, thus implicating mismatch repair titration as a cause of these transformation-dependent increases in switching. The DNA-dependent effect on phase variation was transient and may serve as a mechanism for meningococcal genetic variability that avoids the fitness costs encountered by global mutators.

  5. Species status of Neisseria gonorrhoeae: evolutionary and epidemiological inferences from multilocus sequence typing

    PubMed Central

    Bennett, Julia S; Jolley, Keith A; Sparling, P Frederick; Saunders, Nigel J; Hart, C Anthony; Feavers, Ian M; Maiden, Martin CJ

    2007-01-01

    Background Various typing methods have been developed for Neisseria gonorrhoeae, but none provide the combination of discrimination, reproducibility, portability, and genetic inference that allows the analysis of all aspects of the epidemiology of this pathogen from a single data set. Multilocus sequence typing (MLST) has been used successfully to characterize the related organisms Neisseria meningitidis and Neisseria lactamica. Here, the same seven locus Neisseria scheme was used to characterize a diverse collection of N. gonorrhoeae isolates to investigate whether this method would allow differentiation among isolates, and to distinguish these three species. Results A total of 149 gonococcal isolates were typed and submitted to the Neisseria MLST database. Although relatively few (27) polymorphisms were detected among the seven MLST loci, a total of 66 unique allele combinations (sequence types, STs), were observed, a number comparable to that seen among isolate collections of the more diverse meningococcus. Patterns of genetic variation were consistent with high levels of recombination generating this diversity. There was no evidence for geographical structuring among the isolates examined, with isolates collected in Liverpool, UK, showing levels of diversity similar to a global collection of isolates. There was, however, evidence that populations of N. meningitidis, N. gonorrhoeae and N. lactamica were distinct, with little support for frequent genetic recombination among these species, with the sequences from the gdh locus alone grouping the species into distinct clusters. Conclusion The seven loci Neisseria MLST scheme was readily adapted to N. gonorrhoeae isolates, providing a highly discriminatory typing method. In addition, these data permitted phylogenetic and population genetic inferences to be made, including direct comparisons with N. meningitidis and N. lactamica. Examination of these data demonstrated that alleles were rarely shared among the three

  6. Evaluation of an rRNA-derived oligonucleotide probe for culture confirmation of Neisseria gonorrhoeae.

    PubMed Central

    Rossau, R; Duhamel, M; Van Dyck, E; Piot, P; Van Heuverswyn, H

    1990-01-01

    The reliability of an rRNA-derived oligonucleotide probe for Neisseria gonorrhoeae was tested with 187 N. gonorrhoeae isolates, 81 Neisseria meningitidis isolates, and several strains of other bacterial species. The probe proved to be 100% specific and 100% sensitive. N. gonorrhoeae cells could also be reliably identified in contaminated cultures with the oligonucleotide probe. The 2.6-megadalton cryptic plasmid used as a probe for N. gonorrhoeae was shown to be less sensitive, detecting 179 of 181 N. gonorrhoeae isolates. Images PMID:1693630

  7. Resistance to β-Lactams in Neisseria ssp Due to Chromosomally Encoded Penicillin-Binding Proteins

    PubMed Central

    Zapun, André; Morlot, Cécile; Taha, Muhamed-Kheir

    2016-01-01

    Neisseria meningitidis and Neisseria gonorrhoeae are human pathogens that cause a variety of life-threatening systemic and local infections, such as meningitis or gonorrhoea. The treatment of such infection is becoming more difficult due to antibiotic resistance. The focus of this review is on the mechanism of reduced susceptibility to penicillin and other β-lactams due to the modification of chromosomally encoded penicillin-binding proteins (PBP), in particular PBP2 encoded by the penA gene. The variety of penA alleles and resulting variant PBP2 enzymes is described and the important amino acid substitutions are presented and discussed in a structural context. PMID:27690121

  8. Carriage of Neisseria meningitidis and Neisseria lactamica in a school population during an epidemic period in Spain.

    PubMed Central

    Saez-Nieto, J. A.; Dominguez, J. R.; Monton, J. L.; Cristobal, P.; Fenoll, A.; Vazquez, J.; Casal, J.; Taracena, B.

    1985-01-01

    A study was made of the incidence of Neisseria meningitidis and N. lactamica in a school population; 2470 children aged between 5 and 7 years were studied from four schools in Alcala de Henares (Madrid). Nasopharyngeal swabs were taken in June, November and March, between 1979 and 1983. In all the surveys except one, the proportion of carriers of N. lactamica was higher than that of N. meningitidis, reaching a ratio of about 2:1 in the complete study. The predominant serogroup of meningococcus found was B (41%), with nongroupable strains reaching 43%. A study of serotypes within group B showed a predominance of nontypable strains (48.5%), while those strains considered to be most virulent (types 2 and 1, 8, 15) reached 40%. Eighteen per cent of N. lactamica strains were observed to agglutinate with antimeningococcal sera whilst the remainder of the strains were rough. When these strains were studied with the antiserum-agar technique, using antimeningococcal sera, a high percentage of strains cross-reacted with the meningococci. The susceptibility of strains to sulphadiazine, penicillin, ampicillin, chloramphenicol, rifampicin and spiramycin was determined. Finally an analysis was made of the effect that an elevated colonization rate of N. lactamica might have on colonization by meningococci. The necessity of using fine epidemiological markers in tracing virulent strains in a population at risk is stressed. Selective prophylactic measures are also necessary. PMID:3924995

  9. Activation of Exogenous Fatty Acids to Acyl-Acyl Carrier Protein Cannot Bypass FabI Inhibition in Neisseria*

    PubMed Central

    Yao, Jiangwei; Bruhn, David F.; Frank, Matthew W.; Lee, Richard E.; Rock, Charles O.

    2016-01-01

    Neisseria is a Gram-negative pathogen with phospholipids composed of straight chain saturated and monounsaturated fatty acids, the ability to incorporate exogenous fatty acids, and lipopolysaccharides that are not essential. The FabI inhibitor, AFN-1252, was deployed as a chemical biology tool to determine whether Neisseria can bypass the inhibition of fatty acid synthesis by incorporating exogenous fatty acids. Neisseria encodes a functional FabI that was potently inhibited by AFN-1252. AFN-1252 caused a dose-dependent inhibition of fatty acid synthesis in growing Neisseria, a delayed inhibition of growth phenotype, and minimal inhibition of DNA, RNA, and protein synthesis, showing that its mode of action is through inhibiting fatty acid synthesis. Isotopic fatty acid labeling experiments showed that Neisseria encodes the ability to incorporate exogenous fatty acids into its phospholipids by an acyl-acyl carrier protein-dependent pathway. However, AFN-1252 remained an effective antibacterial when Neisseria were supplemented with exogenous fatty acids. These results demonstrate that extracellular fatty acids are activated by an acyl-acyl carrier protein synthetase (AasN) and validate type II fatty acid synthesis (FabI) as a therapeutic target against Neisseria. PMID:26567338

  10. Distribution and diversity of the haemoglobin–haptoglobin iron-acquisition systems in pathogenic and non-pathogenic Neisseria

    PubMed Central

    Harrison, Odile B.; Bennett, Julia S.; Derrick, Jeremy P.; Bayliss, Christopher D.

    2013-01-01

    A new generation of vaccines containing multiple protein components that aim to provide broad protection against serogroup B meningococci has been developed. One candidate, 4CMenB (4 Component MenB), has been approved by the European Medicines Agency, but is predicted to provide at most 70–80 % strain coverage; hence there is a need for second-generation vaccines that achieve higher levels of coverage. Prior knowledge of the diversity of potential protein vaccine components is a key step in vaccine design. A number of iron import systems have been targeted in meningococcal vaccine development, including the HmbR and HpuAB outer-membrane proteins, which mediate the utilization of haemoglobin or haemoglobin–haptoglobin complexes as iron sources. While the genetic diversity of HmbR has been described, little is known of the diversity of HpuAB. Using whole genome sequences deposited in a Bacterial Isolate Genome Sequence Database (BIGSDB), the prevalence and diversity of HpuAB among Neisseria were investigated. HpuAB was widely present in a range of Neisseria species whereas HmbR was mainly limited to the pathogenic species Neisseria meningitidis and Neisseria gonorrhoeae. Patterns of sequence variation in sequences from HpuAB proteins were suggestive of recombination and diversifying selection consistent with strong immune selection. HpuAB was subject to repeat-mediated phase variation in pathogenic Neisseria and the closely related non-pathogenic Neisseria species Neisseria lactamica and Neisseria polysaccharea but not in the majority of other commensal Neisseria species. These findings are consistent with HpuAB being subject to frequent genetic transfer potentially limiting the efficacy of this receptor as a vaccine candidate. PMID:23813677

  11. Distribution and diversity of the haemoglobin-haptoglobin iron-acquisition systems in pathogenic and non-pathogenic Neisseria.

    PubMed

    Harrison, Odile B; Bennett, Julia S; Derrick, Jeremy P; Maiden, Martin C J; Bayliss, Christopher D

    2013-09-01

    A new generation of vaccines containing multiple protein components that aim to provide broad protection against serogroup B meningococci has been developed. One candidate, 4CMenB (4 Component MenB), has been approved by the European Medicines Agency, but is predicted to provide at most 70-80 % strain coverage; hence there is a need for second-generation vaccines that achieve higher levels of coverage. Prior knowledge of the diversity of potential protein vaccine components is a key step in vaccine design. A number of iron import systems have been targeted in meningococcal vaccine development, including the HmbR and HpuAB outer-membrane proteins, which mediate the utilization of haemoglobin or haemoglobin-haptoglobin complexes as iron sources. While the genetic diversity of HmbR has been described, little is known of the diversity of HpuAB. Using whole genome sequences deposited in a Bacterial Isolate Genome Sequence Database (BIGSDB), the prevalence and diversity of HpuAB among Neisseria were investigated. HpuAB was widely present in a range of Neisseria species whereas HmbR was mainly limited to the pathogenic species Neisseria meningitidis and Neisseria gonorrhoeae. Patterns of sequence variation in sequences from HpuAB proteins were suggestive of recombination and diversifying selection consistent with strong immune selection. HpuAB was subject to repeat-mediated phase variation in pathogenic Neisseria and the closely related non-pathogenic Neisseria species Neisseria lactamica and Neisseria polysaccharea but not in the majority of other commensal Neisseria species. These findings are consistent with HpuAB being subject to frequent genetic transfer potentially limiting the efficacy of this receptor as a vaccine candidate.

  12. Neisseria gonorrhoeae and Chlamydia trachomatis among Women Reporting Extragenital Exposures

    PubMed Central

    Trebach, Joshua D.; Chaulk, C. Patrick; Page, Kathleen R.; Tuddenham, Susan; Ghanem, Khalil G.

    2015-01-01

    Introduction The CDC recommends pharyngeal screening of Neisseria gonorrhoeae (GC) and rectal screening of GC and Chlamydia trachomatis (CT) in HIV-infected and at-risk men who have sex with men (MSM). There are currently no recommendations to routinely screen women at extragenital sites. We define the prevalence of extragenital GC and CT in women attending two urban STD clinics in Baltimore City and compare it to the prevalence of extragenital infections in MSM and men who have sex with women (MSW). Methods All patients who reported extragenital exposures in the preceding 3 months, who presented for care between 6/1/2011 and 5/31/2013, and were tested for GC and CT using nucleic acid amplification tests at all sites of exposure were included in the analyses. We used logistic regression models to identify risk factors for extragenital infections. Results 10,389 patients were included in this analysis (88% African American, mean age 29 years, 42% women, 7% MSM, 2.5% HIV infected). The prevalence estimates of any extragenital GC and CT were: 2.4% GC and 3.7% CT in women; 2.6% GC and 1.6% CT in MSW; 18.9% GC and 11.8% CT in MSM. Among women, 30.3% of GC infections and 13.8% of CT infections would have been missed with urogenital-only testing. Unlike MSM, age ≤ 18 years was the strongest predictor of extragenital infections in women. Conclusions Although the prevalence of extragenital gonorrhea and chlamydia is highest in MSM, a significant number of GC and CT infections in young women would be missed with genital-only testing. Cost-effectiveness analyses are needed to help inform national guidelines on extragenital screening in young women. PMID:25868133

  13. Invasive Potential of Nonencapsulated Disease Isolates of Neisseria meningitidis

    PubMed Central

    Johswich, Kay O.; Zhou, Jianwei; Law, Dennis K. S.; St. Michael, Frank; McCaw, Shannon E.; Jamieson, Frances B.; Cox, Andrew D.; Tsang, Raymond S. W.

    2012-01-01

    The capsule of Neisseria meningitidis is the major virulence factor that enables this bacterium to overcome host immunity elicited by complement and phagocytes, rendering it capable of surviving in blood. As such, nonencapsulated N. meningitidis isolates are generally considered nonpathogenic. Here, we consider the inherent virulence of two nonencapsulated N. meningitidis isolates obtained from our national surveillance of infected blood cultures in Canada. Capsule deficiency of both strains was confirmed by serology and PCR for the ctrA to ctrD genes and siaA to siaC genes, as well as siaD genes specific to serogroups B, C, Y, and W135. In both strains, the capsule synthesis genes were replaced by the capsule null locus, cnl-2. In accordance with a lack of capsule, both strains were fully susceptible to killing by both human and baby rabbit complement. However, in the presence of cytidine-5′ monophospho-N-acetylneuraminic acid (CMP-NANA), allowing for lipooligosaccharide (LOS) sialylation, a significant increase of resistance to complement killing was observed. Mass spectrometry of purified LOS did not reveal any uncommon modifications that would explain their invasive phenotype. Finally, in a mouse intraperitoneal challenge model, these nonencapsulated isolates displayed enhanced virulence relative to an isogenic mutant of serogroup B strain MC58 lacking capsule (MC58ΔsiaD). Virulence of all nonencapsulated isolates tested was below that of encapsulated serogroup B strains MC58 and B16B6. However, whereas no mortality was observed with MC58ΔsiaD, 5/10 mice succumbed to infection with strain 2275 and 2/11 mice succumbed to strain 2274. Our results suggest the acquisition of a new virulence phenotype by these nonencapsulated strains. PMID:22508859

  14. History and epidemiology of antibiotic susceptibilities of Neisseria gonorrhoeae.

    PubMed

    Shigemura, Katsumi; Fujisawa, Masato

    2015-01-01

    Neisseria gonorrhoeae is a common causative microorganism of male urethritis. The most important problem with this infectious disease is antibiotic resistance. For instance, in the 1980's-1990's, most studies showed almost 100% susceptibility of N. gonorrhoeae to the representative cephalosporins, cefixime and cefpodoxime. By the late 1990s, the reported susceptibility decreased to 93.3-100% and further decreased to 82.9-100% in the early 2000's. However, reported susceptibility was revived to 95.8-100% in the late 2000's to 2010's. The susceptibility of N. gonorrhoeae to penicillins varied in different countries and regions. A 2002 Japanese study showed a resistance ratio of about 30% and while Laos, China and Korea showed 80-100% resistance. Fluoroquinolones have shown a dramatic change in their effect on N. gonorrhoeae. In the early 1990's, 0.3-1.3% of N. gonorrhoeae showed low susceptibility or resistance to ciprofloxacin in the US but this figure jumped to 9.5% by 1999. In Asia, N. gonorrhoeae ciprofloxacin resistance or lower susceptibility was about 80-90% in the early 2000's and this trend continues to the present day. Azithromycin is currently the possible last weapon for N. gonorrhoeae treatment per oral administration. The susceptibility of N. gonorrhoeae to azithromycin was 100% in Indonesia in 2004 and the latest study from Germany showed 6% resistance in strains from 2010-2011. This review summarizes the history and epidemiology of N. gonorrhoeae antibiotic susceptibilities, for which the most frequently used antibiotics vary between countries or regions.

  15. pilS loci in Neisseria gonorrhoeae are transcriptionally active

    PubMed Central

    Wachter, Jenny; Masters, Thao L.; Wachter, Shaun; Mason, Joanna

    2015-01-01

    Piliation is an important virulence determinant for Neisseria gonorrhoeae. PilE polypeptide is the major protein subunit in the pilus organelle and engages in extensive antigenic variation due to recombination between pilE and a pilS locus. pilS were so-named as they are believed to be transcriptionally silent, in contrast to the pilE locus. In this study, we demonstrate the presence of a small, pil-specific RNA species. Through using a series of pilE deletion mutants, we show by Northern blotting and quantitative reverse transcriptase PCR analysis (qRT-PCR), that these smaller RNA species are not derived from the primary pilE transcript following some processing events, but rather, arose through transcription of the pilS loci. Small transcriptome analysis, in conjunction with analysis of pilS recombinants, identified both sense and anti-sense RNAs originating from most, but not all, of the pilS gene copies. Focusing on the MS11 pilS6 locus, we identified by site-directed mutagenesis a sense promoter located immediately upstream of pilS6 copy 2, as well as an anti-sense promoter immediately downstream of pilS6 copy 1. Whole transcriptome analysis also revealed the presence of pil-specific sRNA in both gonococci and meningococci. Overall, this study reveals an added layer of complexity to the pilE/pilS recombination scheme by demonstrating pil-specific transcription within genes that were previously thought to be transcriptionally silent. PMID:25701734

  16. Genomic Epidemiology of Hypervirulent Serogroup W, ST-11 Neisseria meningitidis

    PubMed Central

    Mustapha, Mustapha M.; Marsh, Jane W.; Krauland, Mary G.; Fernandez, Jorge O.; de Lemos, Ana Paula S.; Dunning Hotopp, Julie C.; Wang, Xin; Mayer, Leonard W.; Lawrence, Jeffrey G.; Hiller, N. Luisa; Harrison, Lee H.

    2015-01-01

    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. PMID:26629539

  17. Absence of mucosal immunity in the human upper respiratory tract to the commensal bacteria Neisseria lactamica but not pathogenic Neisseria meningitidis during the peak age of nasopharyngeal carriage.

    PubMed

    Vaughan, Andrew T; Gorringe, Andrew; Davenport, Victoria; Williams, Neil A; Heyderman, Robert S

    2009-02-15

    The normal flora that colonizes the mucosal epithelia has evolved diverse strategies to evade, modulate, or suppress the immune system and avoid clearance. Neisseria lactamica and Neisseria meningitidis are closely related obligate inhabitants of the human upper respiratory tract. N. lactamica is a commensal but N. meningitidis is an opportunistic pathogen that occasionally causes invasive disease such as meningitis and septicemia. We demonstrate that unlike N. meningitidis, N. lactamica does not prime the development of mucosal T or B cell memory during the peak period of colonization. This cannot be explained by the induction of peripheral tolerance or regulatory CD4(+)CD25(+) T cell activity. Instead, N. lactamica mediates a B cell-dependent mitogenic proliferative response that is absent to N. meningitidis. This mitogenic response is associated with the production of T cell-independent polyclonal IgM that we propose functions by shielding colonizing N. lactamica from the adaptive immune system, maintaining immunological ignorance in the host. We conclude that, in contrast to N. meningitidis, N. lactamica maintains a commensal relationship with the host in the absence of an adaptive immune response. This may prolong the period of susceptibility to colonization by both pathogenic and nonpathogenic Neisseria species.

  18. Description of an Unusual Neisseria meningitidis Isolate Containing and Expressing Neisseria gonorrhoeae-Specific 16S rRNA Gene Sequences

    PubMed Central

    Skvoretz, Rhonda; Montgomery-Fullerton, Megan; Jonas, Vivian; Brentano, Steve

    2013-01-01

    An apparently rare Neisseria meningitidis isolate containing one copy of a Neisseria gonorrhoeae 16S rRNA gene is described herein. This isolate was identified as N. meningitidis by biochemical identification methods but generated a positive signal with Gen-Probe Aptima assays for the detection of Neisseria gonorrhoeae. Direct 16S rRNA gene sequencing of the purified isolate revealed mixed bases in signature regions that allow for discrimination between N. meningitidis and N. gonorrhoeae. The mixed bases were resolved by sequencing individually PCR-amplified single copies of the genomic 16S rRNA gene. A total of 121 discrete sequences were obtained; 92 (76%) were N. meningitidis sequences, and 29 (24%) were N. gonorrhoeae sequences. Based on the ratio of species-specific sequences, the N. meningitidis strain seems to have replaced one of its four intrinsic 16S rRNA genes with the gonococcal gene. Fluorescence in situ hybridization (FISH) probes specific for meningococcal and gonococcal rRNA were used to demonstrate the expression of the rRNA genes. Interestingly, the clinical isolate described here expresses both N. meningitidis and N. gonorrhoeae 16S rRNA genes, as shown by positive FISH signals with both probes. This explains why the probes for N. gonorrhoeae in the Gen-Probe Aptima assays cross-react with this N. meningitidis isolate. The N. meningitidis isolate described must have obtained N. gonorrhoeae-specific DNA through interspecies recombination. PMID:23863567

  19. 21 CFR 866.3390 - Neisseria spp. direct serological test reagents.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neisseria spp. direct serological test reagents. 866.3390 Section 866.3390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents §...

  20. 21 CFR 866.3390 - Neisseria spp. direct serological test reagents.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Neisseria spp. direct serological test reagents. 866.3390 Section 866.3390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents §...

  1. 21 CFR 866.3390 - Neisseria spp. direct serological test reagents.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Neisseria spp. direct serological test reagents. 866.3390 Section 866.3390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents §...

  2. 21 CFR 866.3390 - Neisseria spp. direct serological test reagents.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Neisseria spp. direct serological test reagents. 866.3390 Section 866.3390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents §...

  3. 21 CFR 866.3390 - Neisseria spp. direct serological test reagents.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Neisseria spp. direct serological test reagents. 866.3390 Section 866.3390 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents §...

  4. Effectiveness of Meningococcal B Vaccine against Endemic Hypervirulent Neisseria meningitidis W Strain, England

    PubMed Central

    Giuliani, Marzia Monica; Biolchi, Alessia; Pizza, Mariagrazia; Beebeejaun, Kazim; Lucidarme, Jay; Findlow, Jamie; Ramsay, Mary E.; Borrow, Ray

    2016-01-01

    Serum samples from children immunized with a meningococcal serogroup B vaccine demonstrated potent serum bactericidal antibody activity against the hypervirulent Neisseria meningitidis serogroup W strain circulating in England. The recent introduction of this vaccine into the United Kingdom national immunization program should also help protect infants against this endemic strain. PMID:26811872

  5. Neisseria meningitidis ST11 Complex Isolates Associated with Nongonococcal Urethritis, Indiana, USA, 2015–2016

    PubMed Central

    Toh, Evelyn; Gangaiah, Dharanesh; Batteiger, Byron E.; Williams, James A.; Arno, Janet N.; Tai, Albert; Batteiger, Teresa A.

    2017-01-01

    At a clinic in Indianapolis, Indiana, USA, we observed an increase in Neisseria gonorrhoeae–negative men with suspected gonococcal urethritis who had urethral cultures positive for N. meningitidis. We describe genomes of 2 of these N. meningitidis sequence type 11 complex urethritis isolates. Clinical evidence suggests these isolates may represent an emerging urethrotropic clade. PMID:28098538

  6. Assessment of vaccine potential of the Neisseria-specific protein NMB0938.

    PubMed

    Sardiñas, Gretel; Climent, Yanet; Rodríguez, Yaindrys; González, Sonia; García, Darién; Cobas, Karem; Caballero, Evelin; Pérez, Yusleydis; Brookes, Charlotte; Taylor, Stephen; Gorringe, Andrew; Delgado, Maité; Pajón, Rolando; Yero, Daniel

    2009-11-16

    The availability of complete genome sequence of Neisseria meningitidis serogroup B strain MC58 and reverse vaccinology has allowed the discovery of several novel antigens. Here, we have explored the potential of N. meningitidis lipoprotein NMB0938 as a vaccine candidate, based on investigation of gene sequence conservation and the antibody response elicited after immunization in mice. This antigen was previously identified by a genome-based approach as an outer membrane lipoprotein unique to the Neisseria genus. The nmb0938 gene was present in all 37 Neisseria isolates analyzed in this study. Based on amino acid sequence identity, 16 unique sequences were identified which clustered into three variants with identities ranging from 92 to 99%, with one cluster represented by the Neisseria lactamica strains. Recombinant protein NMB0938 (rNMB0938) was expressed in Escherichia coli and purified after solubilization of the insoluble fraction. Antisera produced in mice against purified rNMB0938 reacted with a range of meningococcal strains in whole-cell ELISA and western blotting. Using flow cytometry, it was also shown that anti-rNMB0938 antibodies bound to the surface of the homologous meningococcal strain and activated complement deposition. Moreover, antibodies against rNMB0938 elicited complement-mediated killing of meningococcal strains from both sequence variants and conferred passive protection against meningococcal bacteremia in infant rats. According to our results, NMB0938 represents a promising candidate to be included in a vaccine to prevent meningococcal disease.

  7. First case report of Neisseria lactamica causing cavitary lung disease in an adult organ transplant recipient.

    PubMed

    Zavascki, Alexandre Prehn; Fritscher, Leandro; Superti, Silvana; Dias, Cícero; Kroth, Leonardo; Traesel, Moacir Alexandre; Antonello, Ivan Carlos Ferreira; Saitovitch, David

    2006-07-01

    We describe a case of an adult organ recipient patient with a pulmonary cavitary lesion due to Neisseria lactamica, a harmless commensal organism that rarely causes human infection. To our knowledge, this is the first report of pulmonary disease caused by this organism and the second case of N. lactamica infection in an adult patient.

  8. A common gene pool for the Neisseria FetA antigen.

    PubMed

    Bennett, Julia S; Thompson, Emily A L; Kriz, Paula; Jolley, Keith A; Maiden, Martin C J

    2009-02-01

    Meningococcal FetA is an iron-regulated, immunogenic outer membrane protein and vaccine component. The most diverse region of this protein is a previously defined variable region (VR) that has been shown to be immunodominant. In this analysis, a total of 275 Neisseria lactamica isolates, collected during studies of nasopharyngeal bacterial carriage in infants, were examined for the presence of a fetA gene. The fetA VR nucleotide sequence was determined for 217 of these isolates, with fetA apparently absent from 58 isolates, the majority of which belonged to the ST-624 clonal complex. The VR in N. lactamica was compared to the same region in N. meningitidis, N. gonorrhoeae, and a number of other commensal Neisseria. Identical fetA variable region sequences were identified among commensal and pathogenic Neisseria, suggesting a common gene pool, differing from other antigens in this respect. Carriage of commensal Neisseria species, such as N. lactamica, that express FetA may be involved in the development of natural immunity to meningococcal disease.

  9. Neisseria gonorrhoeae downregulates expression of the human antimicrobial peptide LL-37.

    PubMed

    Bergman, Peter; Johansson, Linda; Asp, Vendela; Plant, Laura; Gudmundsson, Gudmundur H; Jonsson, Ann-Beth; Agerberth, Birgitta

    2005-07-01

    Neisseria gonorrhoeae is a human pathogen causing the sexually transmitted disease gonorrhoeae. The bacteria preferentially attach to and invade epithelial cells of the genital tract. As these cells previously have been shown to express the human cathelicidin LL-37, we wanted to investigate the role of LL-37 during N. gonorrhoeae infection. The cervical epithelial cell line ME180 was utilized and the expression of LL-37 was confirmed on both peptide and transcriptional levels. Moreover, LL-37 exhibited potent in vitro activity against N. gonorrhoeae. Interestingly, the transcript and peptide levels of LL-37 were downregulated during infection, according to quantitative real-time polymerase chain reaction (PCR) and immunocyto-chemistry. The downregulation was most prominent with pathogenic strains of Neisseria, while non-pathogenic strains such as Neisseria lactamica and Escherichia coli only exhibited moderate effects. Heat-killed N. gonorrhoeae had no impact on the downregulation, emphasizing the importance of live bacteria. The results in this study suggest that pathogenic Neisseria may gain a survival advantage in the female genital tract by downregulating LL-37 expression.

  10. Correia Repeat Enclosed Elements and Non-Coding RNAs in the Neisseria Species

    PubMed Central

    Roberts, Sabrina B.; Spencer-Smith, Russell; Shah, Mahwish; Nebel, Jean-Christophe; Cook, Richard T.; Snyder, Lori A. S.

    2016-01-01

    Neisseria gonorrhoeae is capable of causing gonorrhoea and more complex diseases in the human host. Neisseria meningitidis is a closely related pathogen that shares many of the same genomic features and virulence factors, but causes the life threatening diseases meningococcal meningitis and septicaemia. The importance of non-coding RNAs in gene regulation has become increasingly evident having been demonstrated to be involved in regulons responsible for iron acquisition, antigenic variation, and virulence. Neisseria spp. contain an IS-like element, the Correia Repeat Enclosed Element, which has been predicted to be mobile within the genomes or to have been in the past. This repeat, present in over 100 copies in the genome, has the ability to alter gene expression and regulation in several ways. We reveal here that Correia Repeat Enclosed Elements tend to be near non-coding RNAs in the Neisseria spp., especially N. gonorrhoeae. These results suggest that Correia Repeat Enclosed Elements may have disrupted ancestral regulatory networks not just through their influence on regulatory proteins but also for non-coding RNAs. PMID:27681925

  11. Biological properties of two distinct pilus types produced by isogenic variants of Neisseria gonorrhoeae P9.

    PubMed Central

    Lambden, P R; Robertson, J N; Watt, P J

    1980-01-01

    Isogenic variants from a single strain of Neisseria gonorrhoeae were shown to produce two distinct types of pili. These pili, designated alpha and beta, differed in both subunit molecular weight and in ability to attach to buccal epithelial cells. Images PMID:6101593

  12. Two Cases of Neisseria meningitidis Proctitis in HIV-Positive Men Who Have Sex with Men.

    PubMed

    Gutierrez-Fernandez, José; Medina, Verónica; Hidalgo-Tenorio, Carmen; Abad, Raquel

    2017-03-01

    We report 2 cases from Spain of infectious proctitis caused by Neisseria meningitidis in HIV-positive men who have sex with men. Genetic characterization of the isolates showed that they are unusual strains not found in other more frequent meningococcal locations. This finding suggests an association between specific strains and anogenital tract colonization.

  13. Positive Selection Pressure Drives Variation on the Surface-Exposed Variable Proteins of the Pathogenic Neisseria

    PubMed Central

    Hill, Stuart

    2016-01-01

    Pathogenic species of Neisseria utilize variable outer membrane proteins to facilitate infection and proliferation within the human host. However, the mechanisms behind the evolution of these variable alleles remain largely unknown due to analysis of previously limited datasets. In this study, we have expanded upon the previous analyses to substantially increase the number of analyzed sequences by including multiple diverse strains, from various geographic locations, to determine whether positive selective pressure is exerted on the evolution of these variable genes. Although Neisseria are naturally competent, this analysis indicates that only intrastrain horizontal gene transfer among the pathogenic Neisseria principally account for these genes exhibiting linkage equilibrium which drives the polymorphisms evidenced within these alleles. As the majority of polymorphisms occur across species, the divergence of these variable genes is dependent upon the species and is independent of geographical location, disease severity, or serogroup. Tests of neutrality were able to detect strong selection pressures acting upon both the opa and pil gene families, and were able to locate the majority of these sites within the exposed variable regions of the encoded proteins. Evidence of positive selection acting upon the hypervariable domains of Opa contradicts previous beliefs and provides evidence for selection of receptor binding. As the pathogenic Neisseria reside exclusively within the human host, the strong selection pressures acting upon both the opa and pil gene families provide support for host immune system pressure driving sequence polymorphisms within these variable genes. PMID:27532335

  14. Positive Selection Pressure Drives Variation on the Surface-Exposed Variable Proteins of the Pathogenic Neisseria.

    PubMed

    Wachter, Jenny; Hill, Stuart

    2016-01-01

    Pathogenic species of Neisseria utilize variable outer membrane proteins to facilitate infection and proliferation within the human host. However, the mechanisms behind the evolution of these variable alleles remain largely unknown due to analysis of previously limited datasets. In this study, we have expanded upon the previous analyses to substantially increase the number of analyzed sequences by including multiple diverse strains, from various geographic locations, to determine whether positive selective pressure is exerted on the evolution of these variable genes. Although Neisseria are naturally competent, this analysis indicates that only intrastrain horizontal gene transfer among the pathogenic Neisseria principally account for these genes exhibiting linkage equilibrium which drives the polymorphisms evidenced within these alleles. As the majority of polymorphisms occur across species, the divergence of these variable genes is dependent upon the species and is independent of geographical location, disease severity, or serogroup. Tests of neutrality were able to detect strong selection pressures acting upon both the opa and pil gene families, and were able to locate the majority of these sites within the exposed variable regions of the encoded proteins. Evidence of positive selection acting upon the hypervariable domains of Opa contradicts previous beliefs and provides evidence for selection of receptor binding. As the pathogenic Neisseria reside exclusively within the human host, the strong selection pressures acting upon both the opa and pil gene families provide support for host immune system pressure driving sequence polymorphisms within these variable genes.

  15. Mutation of a single lytic transglycosylase causes aberrant septation and inhibits cell separation of Neisseria gonorrhoeae.

    PubMed

    Cloud, Karen A; Dillard, Joseph P

    2004-11-01

    The function of lytic peptidoglycan transglycosylases is poorly understood. Single lytic transglycosylase mutants of Escherichia coli have no growth phenotype. By contrast, mutation of Neisseria gonorrhoeae ltgC inhibited cell separation without affecting peptidoglycan monomer production. Thus, LtgC has a dedicated function in gonococcal cell division.

  16. Two Cases of Neisseria meningitidis Proctitis in HIV-Positive Men Who Have Sex with Men

    PubMed Central

    Gutierrez-Fernandez, José; Medina, Verónica; Hidalgo-Tenorio, Carmen

    2017-01-01

    We report 2 cases from Spain of infectious proctitis caused by Neisseria meningitidis in HIV-positive men who have sex with men. Genetic characterization of the isolates showed that they are unusual strains not found in other more frequent meningococcal locations. This finding suggests an association between specific strains and anogenital tract colonization. PMID:28221124

  17. Ciprofloxacin Treatment of Bacterial Peritonitis Associated with Chronic Ambulatory Peritoneal Dialysis Caused by Neisseria cinerea

    PubMed Central

    Taegtmeyer, M.; Saxena, R.; Corkill, J. E.; Anijeet, H.; Parry, C. M.

    2006-01-01

    Bacterial peritonitis is a well-recognized complication of chronic ambulatory peritoneal dialysis (CAPD) in patients with end-stage renal failure. We present a case of peritonitis due to an unusual pathogen, Neisseria cinerea, unresponsive to the standard intraperitoneal (i.p.) vancomycin and gentamicin, which responded rapidly to oral ciprofloxacin. PMID:16891538

  18. Serotype distribution, antibiotic susceptibility, and genetic relatedness of Neisseria meningitidis strains recently isolated in Italy.

    PubMed

    Mastrantonio, Paola; Stefanelli, Paola; Fazio, Cecilia; Sofia, Tonino; Neri, Arianna; La Rosa, Giuseppina; Marianelli, Cinzia; Muscillo, Michele; Caporali, Maria Grazia; Salmaso, Stefania

    2003-02-15

    The availability of new polysaccharide-protein conjugate vaccines against Neisseria meningitidis serogroup C prompted European National Health authorities to carefully monitor isolate characteristics. In Italy, during 1999-2001, the average incidence was 0.4 cases per 100,000 inhabitants. Serogroup B was predominant and accounted for 75% of the isolates, followed by serogroup C with 24%. Serogroup C was isolated almost twice as frequently in cases of septicemia than in cases of meningitis, and the most common phenotypes were C:2a:P1.5 and C:2b:P1.5. Among serogroup B meningococci, the trend of predominant phenotypes has changed from year to year, with a recent increase in the frequency of B:15:P1.4. Only a few meningococci had decreased susceptibility to penicillin, and, in the penA gene, all of these strains had exogenous DNA blocks deriving from the DNA of commensal Neisseria flavescens, Neisseria cinerea, and Neisseria perflava/sicca. Fluorescent amplified fragment-length polymorphism analysis revealed the nonclonal nature of the strains with decreased susceptibility to penicillin.

  19. Ciprofloxacin treatment of bacterial peritonitis associated with chronic ambulatory peritoneal dialysis caused by Neisseria cinerea.

    PubMed

    Taegtmeyer, M; Saxena, R; Corkill, J E; Anijeet, H; Parry, C M

    2006-08-01

    Bacterial peritonitis is a well-recognized complication of chronic ambulatory peritoneal dialysis (CAPD) in patients with end-stage renal failure. We present a case of peritonitis due to an unusual pathogen, Neisseria cinerea, unresponsive to the standard intraperitoneal (i.p.) vancomycin and gentamicin, which responded rapidly to oral ciprofloxacin.

  20. Evaluation of a fluorescent DNA hybridization assay for the detection of Neisseria gonorrhoeae.

    PubMed

    Cano, R J; Palomares, J C; Torres, M J; Klem, R E

    1992-07-01

    This study evaluates a four-hour fluorescent DNA hybridization assay using both known bacterial isolates and clinical specimens. A biotinylated oligonucleotide probe from a sequence of the plasmid-encoded gene cppB was used. Hybrids were detected by addition of a streptavidin-alkaline phosphatase conjugate, followed by incubation for 30 min in a fluorescent substrate for alkaline phosphatase. The level of detection of the fluorescent assay was 0.1 pg of cryptic plasmid DNA or 200 cfu of the plasmid-containing strain NG 34/85 of Neisseria gonorrhoeae. A total of 119 reference strains of Neisseria gonorrhoeae and other related bacteria were tested for reactivity with the probe. All Neisseria gonorrhoeae strains, including eight plasmid-free strains, hybridized with the probe. Fluorescence ratios were 2.67 for plasmid-free strains and 3.85 for plasmid-containing strains. Of the heterologous microorganisms tested, only one of six strains of Neisseria cinerea gave a fluorescence ratio above the 2.0 cut-off value for positivity with the probe at a cell density of 1 x 10(4) cfu. The probe was also evaluated using clinical specimens from 100 patients attending a clinic for sexually transmitted diseases. The sensitivity of the assay was 100% while the specificity was 97.5%. Positive and negative predictive values were 91.2% and 100%, respectively. The fluorescent DNA hybridization assay for the detection of Neisseria gonorrhoeae described here thus appears to be a highly specific and sensitive assay.

  1. Lack of Lipid A Pyrophosphorylation and Functional lptA Reduces Inflammation by Neisseria Commensals

    PubMed Central

    John, Constance M.; Liu, Mingfeng; Phillips, Nancy J.; Yang, Zhijie; Funk, Courtney R.; Zimmerman, Lindsey I.; Griffiss, J. McLeod; Stein, Daniel C.

    2012-01-01

    The interaction of the immune system with Neisseria commensals remains poorly understood. We have previously shown that phosphoethanolamine on the lipid A portion of lipooligosaccharide (LOS) plays an important role in Toll-like receptor 4 (TLR4) signaling. For pathogenic Neisseria, phosphoethanolamine is added to lipid A by the phosphoethanolamine transferase specific for lipid A, which is encoded by lptA. Here, we report that Southern hybridizations and bioinformatics analyses of genomic sequences from all eight commensal Neisseria species confirmed that lptA was absent in 15 of 17 strains examined but was present in N. lactamica. Mass spectrometry of lipid A and intact LOS revealed the lack of both pyrophosphorylation and phosphoethanolaminylation in lipid A of commensal species lacking lptA. Inflammatory signaling in human THP-1 monocytic cells was much greater with pathogenic than with commensal Neisseria strains that lacked lptA, and greater sensitivity to polymyxin B was consistent with the absence of phosphoethanolamine. Unlike the other commensals, whole bacteria of two N. lactamica commensal strains had low inflammatory potential, whereas their lipid A had high-level pyrophosphorylation and phosphoethanolaminylation and induced high-level inflammatory signaling, supporting previous studies indicating that this species uses mechanisms other than altering lipid A to support commensalism. A meningococcal lptA deletion mutant had reduced inflammatory potential, further illustrating the importance of lipid A pyrophosphorylation and phosphoethanolaminylation in the bioactivity of LOS. Overall, our results indicate that lack of pyrophosphorylation and phosphoethanolaminylation of lipid A contributes to the immune privilege of most commensal Neisseria strains by reducing the inflammatory potential of LOS. PMID:22949553

  2. Structural, functional and immunogenic insights on Cu,Zn Superoxide Dismutase pathogenic virulence factors from Neisseria meningitidis and Brucella abortus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial pathogens Neisseria meningitidis and Brucella abortus pose threats to human and animal health worldwide, causing meningococcal disease and brucellosis, respectively. Mortality from acute N. meningitidis infections remains high despite antibiotics, and brucellosis presents alimentary and he...

  3. [Healthcare-associated Neisseria meningitidis W135 conjunctivitis].

    PubMed

    Unal Yılmaz, Gülizar; Alkan, Metin; Vatansever Özbek, Ulfet; Tuğrul, H Murat

    2013-10-01

    Neisseria meningitidis is an unusual pathogen among the causes of acute bacterial conjunctivitis. Meningococcal conjunctivitis may present as primary or secondary infection, while primary meningococcal conjunctivitis may emerge as invasive or non-invasive forms. N.meningitidis W135 strain is not common in Turkey, and is rarely reported as the cause of meningitis. Moreover, no cases of conjunctivitis due to N.meningitidis W135 were reported from Turkey. In this report a case of N.meningitidis W135 conjunctivitis has been presented who acquired the infection from another patient with meningococcal meningitis by close contact in the hospital environment. A 2-month-old male infant was admitted to our hospital with poor health condition, feeding difficulty and weight loss. He was hospitalized in intensive care unit and fluid replacement started due to severe dehydration. The infant had stigmata of Down's Syndrome, and since conjunctivitis were detected on physical examination, swab samples were obtained from both eyes for direct microscopic examination and cultivation. Abundant lekocytes and gram-negative diplococci were observed in Gram-stained smears, and bacterial growth were detected in the culture from left eye samples. The isolate have been identified as N.meningitidis by conventional microbiological methods, and serotyping of the isolate yielded W135 strain. The infant was treated with systemic cefotaxime and ampicillin-sulbactam, together with topical tobramycin and gentamycin. Since no symptoms of meningitis appeared during the follow-ups, the case was diagnosed as non-invasive primary meningococcal conjunctivitis. Investigation for a probable source revealed that the infant had close contact with a six-year-old boy with high fever, unconsciousness and vomiting a week ago in the outpatient clinic of Tekirdag State Hospital. N.meningitidis was also isolated from the cerebrospinal fluid culture of probable index case with meningitis and identified as W135 strain

  4. Standardization of Neisseria meningitidis Serogroup B Colorimetric Serum Bactericida Assay

    PubMed Central

    Rodríguez, Tamara; Lastre, Miriam; Cedré, Barbara; Campo, Judith del; Bracho, Gustavo; Zayas, Caridad; Taboada, Carlos; Díaz, Miriam; Sierra, Gustavo; Pérez, Oliver

    2002-01-01

    The correlate of protection for serogroup B meningococci is not currently known, but for serogroup C it is believed to be the serum bactericidal assay (SBA). The current SBAs are labor intensive and the variations in protocols among different laboratories make interpretation of results difficult. A colorimetric SBA (cSBA), based on the ability of Neisseria meningitidis serogroup B to consume glucose, leading to acid production, was standardized by using group B strain Cu385-83 as the target. The cSBA results were compared to those obtained for a traditional colony-counting microassay (mSBA). Glucose and bromocresol purple pH indicator were added to the medium in order to estimate growth of cSBA target cell survivors through color change. Different variants of the assay parameters were optimized: growth of target cells (Mueller Hinton agar plates), target cell number (100 CFU/per well), and human complement source used at a final concentration of 25%. After the optimization, three other group B strains (H44/76, 490/91, and 511/91) were used as targets for the cSBA. The selection of the assay parameters and the standardization of cSBA were done with 13 sera from vaccinated volunteers. The titers were determined as the higher serum dilution that totally inhibited the bacterial growth marked by the color invariability of the pH indicator. This was detected visually as well as spectrophotometrically and was closely related to a significant difference in the growth of target cell survivors determined using Student’s t test. Intralaboratory reproducibility was ±1 dilution. The correlation between bactericidal median titers and specific immunoglobulin G serum concentration by enzyme immunoassay was high (r = 0.910, P < 0.01). The bactericidal titers generated by the cSBA and the mSBA were nearly identical, and there was a high correlation between the two assays (r = 0.974, P < 0.01). The standardized cSBA allows easy, fast, and efficient evaluation of samples. PMID

  5. Characterization of the key antigenic components and pre-clinical immune responses to a meningococcal disease vaccine based on Neisseria lactamica outer membrane vesicles.

    PubMed

    Finney, Michelle; Vaughan, Thomas; Taylor, Stephen; Hudson, Michael J; Pratt, Catherine; Wheeler, Jun X; Vipond, Caroline; Feavers, Ian; Jones, Christopher; Findlow, Jamie; Borrow, Ray; Gorringe, Andrew

    2008-01-01

    Serogroup B strains are now responsible for over 80% of meningococcal disease in the UK and no suitable vaccine is available that confers universal protection against all serogroup B strains. Neisseria lactamica shares many antigens with the meningococcus, except capsule and the surface protein PorA. Many of these antigens are thought to be responsible for providing cross-protective immunity to meningococcal disease. We have developed an N. lactamica vaccine using methods developed for meningococcal outer membrane vesicle (OMV) vaccines. The major antigenic components were identified by excision of 11 major protein bands from an SDS-PAGE gel, followed by mass spectrometric identification. These bands contained at least 22 proteins identified from an unassembled N. lactamica genome, 15 of which having orthologues in published pathogenic Neisseria genomes. Western blotting revealed that most of these bands were immunogenic, and antibodies to these proteins generally cross-reacted with N. meningitidis proteins. Sera from mice and rabbits immunized with either N. lactamica or N. meningitidis OMVs produced comparable cross-reactive ELISA titres against OMVs prepared from a panel of diverse meningococcal strains. Mice immunized with either N. meningitidis or N. lactamica OMVs showed no detectable serum bactericidal activity against the panel of target strains except N. meningitidis OMV sera against the homologous strain. Similarly, rabbit antisera to N. lactamica OMVs elicited little or no bactericidal antibodies against the panel of serogroup B meningococcal strains. However, such antisera did mediate opsonophagocytosis, suggestingthat this may did mediate opsonophagocytosis, suggesting that this may be a mechanism by which this vaccine protects in a mouse model of meningococcal bacteraemia.

  6. Neisseria meningitidis Uses Sibling Small Regulatory RNAs To Switch from Cataplerotic to Anaplerotic Metabolism

    PubMed Central

    Huis in ‘t Veld, Robert A. G.; Schipper, Kim; Bovenkerk, Sandra; Kramer, Gertjan; Brouwer, Matthijs C.; van de Beek, Diederik; Speijer, Dave; van der Ende, Arie

    2017-01-01

    ABSTRACT Neisseria meningitidis (the meningococcus) is primarily a commensal of the human oropharynx that sporadically causes septicemia and meningitis. Meningococci adapt to diverse local host conditions differing in nutrient supply, like the nasopharynx, blood, and cerebrospinal fluid, by changing metabolism and protein repertoire. However, regulatory transcription factors and two-component systems in meningococci involved in adaptation to local nutrient variations are limited. We identified novel sibling small regulatory RNAs (Neisseria metabolic switch regulators [NmsRs]) regulating switches between cataplerotic and anaplerotic metabolism in this pathogen. Overexpression of NmsRs was tolerated in blood but not in cerebrospinal fluid. Expression of six tricarboxylic acid cycle enzymes was downregulated by direct action of NmsRs. Expression of the NmsRs themselves was under the control of the stringent response through the action of RelA. Small sibling regulatory RNAs of meningococci, controlling general metabolic switches, add an exciting twist to their versatile repertoire in bacterial pathogens. PMID:28325760

  7. Pharyngeal Neisseria gonorrhoeae detection in oral-throat wash specimens of male patients with urethritis.

    PubMed

    Takahashi, Satoshi; Kurimura, Yuichiro; Hashimoto, Jiro; Takeyama, Koh; Koroku, Mikio; Tanda, Hitoshi; Nishimura, Masahiro; Tsukamoto, Taiji

    2008-12-01

    Detection of Neisseria gonorrhoeae and Chlamydia trachomatis in the pharynx has been highlighted in the prevention of the unexpected spread of sexually transmitted diseases. We tried to clarify the detection rate of Neisseria gonorrhoeae in the pharynx and the clinical relevance of oral-throat wash specimens to detect the organism in heterosexual men with gonococcal and nongonococcal urethritis. In our cohort of 79 male patients with urethritis, oral throat wash specimens were collected after they had gargled with normal saline for approximately 30 to 60 s. Positive pharyngeal N. gonorrhoeae was defined as a positive result on the strand displacement amplification test for the specimen from the oral-throat wash. N. gonorrhoeae was detected in the oral-throat wash specimens of 13 (31.7%) of the 41 male patients with gonococcal urethritis. Oral-throat wash with a nucleic acid amplification test can detect pharyngeal N. gonorrhoeae easily and efficiently.

  8. Proteomic analysis of Neisseria lactamica and N eisseria meningitidis outer membrane vesicle vaccine antigens.

    PubMed

    Vaughan, Thomas E; Skipp, Paul J; O'Connor, C David; Hudson, Michael J; Vipond, Richard; Elmore, Michael J; Gorringe, Andrew R

    2006-06-19

    Vaccines to prevent meningococcal disease have been developed from the outer membrane vesicles (OMVs) of Neisseria meningitidis and the related commensal organism Neisseria lactamica. In addition to lipopolysaccharide and the major porins, these vaccines contain a large number of proteins that are incompletely characterised. Here we describe comparative proteomic analyses of the N. lactamica OMV vaccine and OMVs from a serogroup B strain of N. meningitidis. Tandem mass-spectrometry data for trypsinised N. lactamica OMV vaccine were matched to an incompletely assembled genome sequence from the same strain to give 65 robust protein identifications and a further 122 single- or two-peptide matches. Fifty-seven N. meningitidis K454 proteins were identified robustly (and a further 68 from single- or two-peptide matches) by inference from the N. meningitidis MC58 genome. The results suggest that OMVs have a hitherto unappreciated complexity and pinpoint novel candidate antigens for further characterisation.

  9. Conserved outer membrane protein of Neisseria meningitidis involved in capsule expression.

    PubMed Central

    Frosch, M; Müller, D; Bousset, K; Müller, A

    1992-01-01

    In Neisseria meningitidis, translocation of capsular polysaccharides to the cell surface is mediated by a transport system that fits the characteristics of ABC (ATP-binding cassette) transporters. One protein of this transport system, termed CtrA, is located in the outer membrane. By use of a CtrA-specific monoclonal antibody, we could demonstrate that CtrA occurs exclusively in N. meningitidis and not in other pathogenic or nonpathogenic Neisseria species. Nucleotide sequence comparison of the ctrA gene from different meningococcal serogroups indicated that CtrA is strongly conserved in all meningococcal serogroups, independent of the chemical composition of the capsular polysaccharide. Secondary structure analysis revealed that CtrA is anchored in the outer membrane by eight membrane-spanning amphipathic beta strands, a structure of proteins that function as porins. Images PMID:1371768

  10. A Case Report of Neisseria Mucosa Peritonitis in a Chronic Ambulatory Peritoneal Dialysis Patient

    PubMed Central

    Awdisho, Alan; Bermudez, Maria

    2016-01-01

    Peritonitis is a leading complication of chronic ambulatory peritoneal dialysis. However, very rarely does Neisseria mucosa cause peritonitis. We describe an unusual case of N. mucosa peritonitis in a chronic ambulatory peritoneal dialysis patient. A 28-year-old Hispanic male presents with diffuse abdominal pain exacerbated during draining of the peritoneal fluid. Peritoneal fluid examination was remarkable for leukocytosis and gramnegative diplococci. Bacterial cultures were positive for N. mucosa growth. The patient was treated with ciprofloxacin with preservation of the dialysis catheter. This case highlights the rarity and importance of Neisseria mucosa causing peritonitis in chronic ambulatory peritoneal dialysis patients’. There seems to be a unique association between N. mucosa peritonitis and chronic ambulatory peritoneal dialysis patients’. The patient was successfully managed with ciprofloxacin along with salvaging of the dialysis catheter. PMID:28191300

  11. Infective Endocarditis Caused by Neisseria elongata on a Native Tricuspid Valve and Confirmed by DNA Sequencing

    PubMed Central

    Yoo, Yeon Pyo; Kang, Ki-Woon; Yoon, Hyeon Soo; Yoo, Seungmin; Lee, Myung-Shin

    2014-01-01

    Neisseria elongata, a common oral bacterium, has been recognized as a cause of infections such as infective endocarditis, septicemia, and osteomyelitis. Neisseria-induced infective endocarditis, although infrequently reported, typically arises after dental procedures. Without antibiotic therapy, its complications can be severe. We report the case of a 27-year-old man who presented with fever, severe dyspnea, and a leg abscess from cellulitis. An echocardiogram showed a vegetation-like echogenic structure on the septal leaflet of the patient's native tricuspid valve, and an insignificant Gerbode defect. Three blood cultures grew gram-negative, antibiotic-susceptible coccobacilli that were confirmed to be N. elongata. Subsequent DNA sequencing conclusively isolated N. elongata subsp nitroreducens as the organism responsible for the infective endocarditis. The patient recovered after 21 days of antibiotic therapy. In addition to the patient's unusual case, we discuss the nature and isolation of N. elongata and its subspecies. PMID:24808790

  12. The in-vitro activity of pristinamycin against Haemophilus influenzae and Neisseria meningitidis.

    PubMed

    Lafaix, C; Bouvet, E; Dublanchet, A; Dabernat, H; Carrere, C; Picq, J J; Etienne, J

    1985-07-01

    The in-vitro activity of erythromycin, oleandomycin, spiramycin, josamycin and pristinamycin was tested by a plate-dilution method against strains of Haemophilus influenzae and Neisseria meningitidis. Pristinamycin was the most active product tested with minimal inhibitory concentrations (MIC) ranging between 0.5 and 4 mg/l for H. influenzae (modal value 1 mg/l) and between 0.03 and 0.12 mg/l for N. meningitidis (modal value 0.06 mg/l).

  13. Neonatal Infection with Neisseria meningitidis: Analysis of a 97-Year Period Plus Case Study

    PubMed Central

    Bülbül, Ali; Cömert, Serdar; Uslu, Sinan; Arslan, Selda; Nuhoglu, Asiye

    2014-01-01

    Neisseria meningitidis is one of the major causes of meningitis in children and adolescents, but it is rarely found during the neonatal period. Here, we describe a neonate with meningococcal sepsis who was admitted to the hospital on postnatal day 10, and we discuss the clinical features of neonatal infection with N. meningitidis in relation to the literature (analysis of a 97-year period). PMID:25031437

  14. Examination of Neisseria Gonorrhoeae Opacity Protein Expression During Experimental Murine Genital Tract Infection

    DTIC Science & Technology

    2005-01-01

    of wild-type Chinese hamster ovary ( CHO ) cells and isogenic mutants with deficiencies in HSPG biosynthesis was used to identify the HSPG-binding...34Vitronectin mediates internalization of Neisseria gonorrhoeae by Chinese hamster ovary cells ." Infect Immun 65(3): 964-70. 57. Duensing, T. D. and J. P...Seifert, Northwestern University) was implemented to insert the opaB::phoA fusion into a non- essential locus of the genome of N. gonorrhoeae strain

  15. Presence of a capsule in Neisseria lactamica, antigenically similar to the capsule of N. meningitidis.

    PubMed

    Martin, P V; Laviotola, A; Ohayon, H; Riou, J Y

    1986-01-01

    Three of thirteen strains of Neisseria lactamica, a species closely related to N. meningitidis, were selected on the basis of their ability to be strongly agglutinated by serogroup B antimeningococcal serum. The presence of a capsule was demonstrated using Alcian blue as a stain for acidic polysaccharide. When reacted with serogroup B antimeningococcal sera, 2 out of 3 N. lactamica B-coagglutanating strains exhibited an extracellular material comparable in size, antigenicity and staining properties to the capsule of serogroup B N. meningitidis.

  16. Efficacy of a Novel Tricyclic Topoisomerase Inhibitor in a Murine Model of Neisseria gonorrhoeae Infection

    PubMed Central

    Savage, Victoria J.; Charrier, Cédric; Salisbury, Anne-Marie; Box, Helen; Chaffer-Malam, Nathan; Huxley, Anthony; Kirk, Ralph; Noonan, Gary M.; Mohmed, Sarfraz; Craighead, Mark W.; Ratcliffe, Andrew J.; Best, Stuart A.

    2016-01-01

    There is an urgent need for new antibiotics to treat multidrug-resistant Neisseria gonorrhoeae. In this report, the microbiology, in vivo pharmacokinetics, and efficacy of REDX05931, a representative novel tricyclic topoisomerase inhibitor, were evaluated. REDX05931 demonstrated high oral bioavailability in mice and reduced N. gonorrhoeae infection after a single dose in a mouse model of gonorrhea. These data support the potential of this series of small molecules as a new treatment for drug-resistant gonorrheal infections. PMID:27324777

  17. Recurrent bacterial peritonitis caused by Neisseria cinerea in a chronic ambulatory peritoneal dialysis (CAPD) patient.

    PubMed

    George, M J; DeBin, J A; Preston, K E; Chiu, C; Haqqie, S S

    1996-10-01

    We present an unusual case of recurrent (chronic ambulatory peritoneal dialysis) CAPD-associated peritonitis caused by Neisseria cinerea. Using DNA restriction fragment length polymorphism (RFLP) analysis, we determined that the recurrent infection was caused by reinfection with a different N. cinerea strain rather than relapse with the index strain and that the probable origin of the reinfecting organism was the patient's upper respiratory tract.

  18. Pneumopathie postoperatoire à association Haemophilus Influenzae et Neisseria meningitidis chez un enfant diabetique

    PubMed Central

    Chemsi, Hicham; Frikh, Mohamed; Lemnouer, Abdelhay; Belfkih, Bouchra; Sekhsokh, Yassine; Chadli, Maryama; Elouennass, Mustapha

    2016-01-01

    Haemophilus influenzae est un hôte saprophyte du rhinopharynx chez près des deux tiers des enfants et les adultes. Neisseria meningitidis est une bactérie strictement humaine qui vit dans le rhinopharynx, pouvant provoquer une rhinopharyngite bénigne ou un état de portage asymptomatique. Nous rapportons le cas d'une pneumopathie postopératoire à association Haemophilus influenzae et Neisseria meningitidis chez un enfant diabétique. Patient âgé de 3 ans, diabétique admis au service de chirurgie cardio-vasculaire pour prise en charge chirurgicale tardive. L'évolution postopératoire a été marquée par une aggravation de l'état respiratoire, devenu encombré avec des secrétions abondantes nécessitant une hospitalisation en réanimation. Un bilan infectieux a été réalisé, notamment un prélèvement distal protégé qui a révélé une association de Neisseria meningitides et Haemophilus influenzae. A travers ce cas, nous discutons les associations bactériennes dans certaines situations à risque. Chacune de ces deux espèces est responsable d'infections diverses. Cependant l'association au même site est rare. PMID:28292047

  19. Phase variable DNA repeats in Neisseria gonorrhoeae influence transcription, translation, and protein sequence variation

    PubMed Central

    Zelewska, Marta A.; Pulijala, Madhuri; Spencer-Smith, Russell; Mahmood, Hiba-Tun-Noor A.; Norman, Billie; Churchward, Colin P.; Calder, Alan

    2016-01-01

    There are many types of repeated DNA sequences in the genomes of the species of the genus Neisseria, from homopolymeric tracts to tandem repeats of hundreds of bases. Some of these have roles in the phase-variable expression of genes. When a repeat mediates phase variation, reversible switching between tract lengths occurs, which in the species of the genus Neisseria most often causes the gene to switch between on and off states through frame shifting of the open reading frame. Changes in repeat tract lengths may also influence the strength of transcription from a promoter. For phenotypes that can be readily observed, such as expression of the surface-expressed Opa proteins or pili, verification that repeats are mediating phase variation is relatively straightforward. For other genes, particularly those where the function has not been identified, gathering evidence of repeat tract changes can be more difficult. Here we present analysis of the repetitive sequences that could mediate phase variation in the Neisseria gonorrhoeae strain NCCP11945 genome sequence and compare these results with other gonococcal genome sequences. Evidence is presented for an updated phase-variable gene repertoire in this species, including a class of phase variation that causes amino acid changes at the C-terminus of the protein, not previously described in N. gonorrhoeae. PMID:28348872

  20. The development of a meningococcal disease vaccine based on Neisseria lactamica outer membrane vesicles.

    PubMed

    Gorringe, Andrew; Halliwell, Denise; Matheson, Mary; Reddin, Karen; Finney, Michelle; Hudson, Michael

    2005-03-18

    Serogroup B meningococcal disease remains a serious problem in many countries and no effective vaccine is currently available. Immunological and epidemiological evidence suggests that carriage of commensal Neisseria species is involved in the development of natural immunity against meningococcal disease. Neisseria lactamica has many surface structures in common with Neisseria meningitidis and may be the most important of these species. We have produced extensive pre-clinical data, which indicate that N. lactamica outer membrane vesicles (OMVs) may provide a vaccine effective against diverse disease-causing meningococcal strains. Immunisation with N. lactamica OMVs protected against lethal challenge with diverse meningococcal isolates in a mouse intraperitoneal challenge model of meningococcal disease and we are developing this vaccine for use in a phase I safety and immunogenicity study in adult volunteers. We have shown that OMVs produced from bacteria grown under iron-limited or iron-rich conditions provide equivalent protection in the mouse infection model and thus OMVs produced from iron-rich will be used. Sterile filtration of N. lactamica OMVs has proved difficult but this has been improved by resuspending the vesicles in a buffer, which increases their surface zeta potential. The vaccine is currently being manufactured and validated ELISA protocols have been developed for the analysis of serological responses.

  1. Microbiological Evaluation of the New VITEK 2 Neisseria-Haemophilus Identification Card▿

    PubMed Central

    Valenza, Giuseppe; Ruoff, Claudia; Vogel, Ulrich; Frosch, Matthias; Abele-Horn, Marianne

    2007-01-01

    VITEK 2 is an automated identification system for diverse bacterial and fungal species. A new card (the Neisseria-Haemophilus [NH] card) for the identification of Neisseria spp., Haemophilus spp., and other fastidious gram-negative or gram-variable microorganisms has been developed, but its performance in a routine clinical laboratory has not yet been evaluated. In this study, a total of 188 bacterial strains belonging to the genera Actinobacillus, Campylobacter, Capnocytophaga, Cardiobacterium, Eikenella, Gardnerella, Haemophilus, Kingella, Moraxella, and Neisseria were investigated. The NH card was able to identify 171 strains (91%) correctly without the need for extra tests; one strain (0.5%) was misidentified, and five strains (2.7%) could not be classified. Eleven strains (5.8%) were identified with a low level of discrimination, and simple additional tests were required to increase the correct-identification rate to 96.8%. The results were available within 6 h. Based on these results, the new VITEK 2 NH card appears to be a good method for the identification of diverse groups of fastidious organisms, which would otherwise require testing with multiple systems. However, more work is needed to evaluate the performance of VITEK 2 with regard to Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, and Kingella bacteria because of the insufficient number of strains tested in this study. Moreover, further reduction of the detection time would be desirable. PMID:17728469

  2. Population structure in the Neisseria, and the biological significance of fuzzy species

    PubMed Central

    Corander, Jukka; Connor, Thomas R.; O'Dwyer, Clíona A.; Kroll, J. Simon; Hanage, William P.

    2012-01-01

    Phenotypic and genetic variation in bacteria can take bewilderingly complex forms even within a single genus. One of the most intriguing examples of this is the genus Neisseria, which comprises both pathogens and commensals colonizing a variety of body sites and host species, and causing a range of disease. Complex relatedness among both named species and previously identified lineages of Neisseria makes it challenging to study their evolution. Using the largest publicly available collection of bacterial sequence data in combination with a population genetic analysis and experiment, we probe the contribution of inter-species recombination to neisserial population structure, and specifically whether it is more common in some strains than others. We identify hybrid groups of strains containing sequences typical of more than one species. These groups of strains, typical of a fuzzy species, appear to have experienced elevated rates of inter-species recombination estimated by population genetic analysis and further supported by transformation experiments. In particular, strains of the pathogen Neisseria meningitidis in the fuzzy species boundary appear to follow a different lifestyle, which may have considerable biological implications concerning distribution of novel resistance elements and meningococcal vaccine development. Despite the strong evidence for negligible geographical barriers to gene flow within the population, exchange of genetic material still shows directionality among named species in a non-uniform manner. PMID:22072450

  3. Molecular and Serological Diversity of Neisseria meningitidis Carrier Strains Isolated from Italian Students Aged 14 to 22 Years

    PubMed Central

    Comanducci, Maurizio; Amicizia, Daniela; Ansaldi, Filippo; Canepa, Paola; Orsi, Andrea; Icardi, Giancarlo; Rizzitelli, Emanuela; De Angelis, Gabriella; Bambini, Stefania; Moschioni, Monica; Comandi, Sara; Simmini, Isabella; Boccadifuoco, Giueseppe; Brunelli, Brunella; Giuliani, Marzia Monica; Pizza, Mariagrazia

    2014-01-01

    Neisseria meningitidis is an obligate human commensal that commonly colonizes the oropharyngeal mucosa. Carriage is age dependent and very common in young adults. The relationships between carriage and invasive disease are not completely understood. In this work, we performed a longitudinal carrier study in adolescents and young adults (173 subjects). Overall, 32 subjects (18.5%) had results that were positive for meningococcal carriage in at least one visit (average monthly carriage rate, 12.1%). Only five subjects tested positive at all four visits. All meningococcal isolates were characterized by molecular and serological techniques. Multilocus sequence typing, PorA typing, and sequencing of the 4CMenB vaccine antigens were used to assess strain diversity. The majority of positive subjects were colonized by capsule null (34.4%) and capsular group B strains (28.1%), accounting for 23.5% and 29.4% of the total number of isolates, respectively. The fHbp and nhba genes were present in all isolates, while the nadA gene was present in 5% of the isolates. The genetic variability of the 4CMenB vaccine antigens in this collection was relatively high compared with that of other disease-causing strain panels. Indications about the persistence of the carriage state were limited to the time span of the study. All strains isolated from the same subject were identical or cumulated minor changes over time. The expression levels and antigenicities of the 4CMenB vaccine antigens in each strain were analyzed by the meningococcal antigen typing system (MATS), which revealed that expression can change over time in the same individual. Future analysis of antigen variability and expression in carrier strains after the introduction of the MenB vaccine will allow for a definition of its impact on nasopharyngeal/oropharyngeal carriage. PMID:24648565

  4. Rapid characterization of outer-membrane proteins in Neisseria lactamica by SELDI-TOF-MS (surface-enhanced laser desorption ionization-time-of-flight MS) for use in a meningococcal vaccine.

    PubMed

    Mukhopadhyay, Tarit Kumar; Halliwell, Denise; O'Dwyer, Cliona; Shamlou, Parviz Ayazi; Levy, Myriam Susana; Allison, Nigel; Gorringe, Andrew; Reddin, Karen M

    2005-04-01

    Immunological and epidemiological evidence suggests that the development of natural immunity to meningococcal disease results from colonization of the nasopharynx by commensal Neisseria species, particularly with Neisseria lactamica. We have reported previously that immunization with N. lactamica outer-membrane vesicles containing the major OMPs (outer-membrane proteins) protected mice against lethal challenge with meningococci of diverse serogroups and serotypes and has the potential to form the basis of a vaccine against meningococcal diseases [Oliver, Reddin, Bracegirdle et al. (2002) Infect. Immun. 70, 3621-3626]. In the present study, we have shown that biomass production and the profile of outer-membrane vesicle proteins may be affected by fermentation conditions and, in particular, media composition. Ciphergen SELDI-TOF Protein Chips were used as a rapid and sensitive new method in comparison with conventional SDS/PAGE. SELDI-TOF-MS (surface-enhanced laser-desorption ionization-time-of-flight MS) reproducibly identified three major OMPs (NspA, RmpM and PorB) and detected the changes in the protein profile when the growth medium was altered. The findings of this work indicate that SELDI-TOF-MS is a useful tool for the rapid optimization of OMP production in industrial fermentation processes and can be adapted as a Process Analytical Technology.

  5. The Role of the Transcription Factors MtrR and MtrA in the Fitness of the Pathogen Neisseria gonorrhoeae

    DTIC Science & Technology

    2007-10-19

    diplococci (Fig. 1). The pathogenic species of Neisseria are human-specific colonizers that cause meningitis and septicemia (N. meningitidis) or...gonorrhea (N. gonorrhoeae). There are many differences between the two pathogenic Neisseria species , including different modes of transmission, different...and vaccination methodologies for production of protective IgA antibodies at the mucosal site of infection are currently unavailable. As such

  6. Degradation of heme in gram-negative bacteria: the product of the hemO gene of Neisseriae is a heme oxygenase.

    PubMed

    Zhu, W; Wilks, A; Stojiljkovic, I

    2000-12-01

    A full-length heme oxygenase gene from the gram-negative pathogen Neisseria meningitidis was cloned and expressed in Escherichia coli. Expression of the enzyme yielded soluble catalytically active protein and caused accumulation of biliverdin within the E. coli cells. The purified HemO forms a 1:1 complex with heme and has a heme protein spectrum similar to that previously reported for the purified heme oxygenase (HmuO) from the gram-positive pathogen Corynebacterium diphtheriae and for eukaryotic heme oxygenases. The overall sequence identity between HemO and these heme oxygenases is, however, low. In the presence of ascorbate or the human NADPH cytochrome P450 reductase system, the heme-HemO complex is converted to ferric-biliverdin IXalpha and carbon monoxide as the final products. Homologs of the hemO gene were identified and characterized in six commensal Neisseria isolates, Neisseria lactamica, Neisseria subflava, Neisseria flava, Neisseria polysacchareae, Neisseria kochii, and Neisseria cinerea. All HemO orthologs shared between 95 and 98% identity in amino acid sequences with functionally important residues being completely conserved. This is the first heme oxygenase identified in a gram-negative pathogen. The identification of HemO as a heme oxygenase provides further evidence that oxidative cleavage of the heme is the mechanism by which some bacteria acquire iron for further use.

  7. A misleading false-negative result using Neisseria gonorrhoeae opa MGB multiplex PCR assay in patient's rectal sample due to partial mutations of the opa gene.

    PubMed

    Vahidnia, Ali; van Empel, Pieter Jan; Costa, Sandra; Oud, Rob T N; van der Straaten, Tahar; Bliekendaal, Harry; Spaargaren, Joke

    2015-07-01

    A 53-year-old homosexual man presented at his general practitioner (GP) practice with a suspicion of sexually transmitted infection. Initial NAAT screening was performed for Chlamydia trachomatis and Neisseria gonorrhoeae. The patient was positive for Neisseria gonorrhoeae both for his urine and rectal sample. The subsequent confirmation test for Neisseria gonorrhoeae by a second laboratory was only confirmed for the urine sample and the rectal sample was negative. We report a case of a potential false-negative diagnosis of Neisseria gonorrhoeae due to mutations of DNA sequence in the probe region of opa-MGB assay of the rectal sample. The patient did not suffer any discomfort as diagnosis of Neisseria gonorrhoeae in his urine sample had already led to treatment by prescribing the patient with Ceftriaxone 500 mg IV dissolved in 1 ml lidocaine 2% and 4 mL saline. The patient also received a prescription for Azithromycin (2x500 mg).

  8. Application of Atmospheric Pressure Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry for Rapid Identification of Neisseria Species

    PubMed Central

    Gudlavalleti, Seshu K.; Sundaram, Appavu K; Razumovski, Jane; Doroshenko, Vladimir

    2008-01-01

    Atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry (AP-MALDI MS) was applied to develop a proteomics-based method to detect and identify Neisseria species. Heat-inactivated clinical isolate cell suspensions of Neisseria gonorrhoeae and strains belonging to five serogroups (A, B, C, W135, and Y) of Neisseria meningitidis were subjected to on-probe protein/peptide extraction and tryptic digestion followed by AP-MALDI tandem MS (MS/MS)-based proteomic analysis. Amino acid sequences derived from three protonated peptides with m/z values of 1743.8, 1894.8, and 1946.8 were identified by AP-MALDI MS/MS and MASCOT proteome database search analysis as belonging to neisserial acyl carrier protein, neisserial-conserved hypothetical protein, and neisserial putative DNA binding protein, respectively. These three peptide masses can thus be potential biomarkers for neisserial species identification by AP-MALDI MS. PMID:19137107

  9. Detection of IgG and IgM to meningococcal outer membrane proteins in relation to carriage of Neisseria meningitidis or Neisseria lactamica.

    PubMed

    Kremastinou, J; Tzanakaki, G; Pagalis, A; Theodondou, M; Weir, D M; Blackwell, C C

    1999-05-01

    Carriage of non-serogroupable Neisseria meningitidis or Neisseria lactamica induces antibodies protective against meningococcal disease. Antibodies directed against outer membrane proteins are bactericidal and the serotype and subtype outer membrane protein antigens are being examined for their value as vaccine candidates for serogroup B disease. The aim of this study was to examine the effect of carriage of these two Neisseria species among children and young adults on induction of antibodies to outer membrane components from strains causing disease in Greece. Among 53 patients with meningococcal disease, IgG or IgM antibodies were detected by ELISA in 9 of 13 (69%) from whom the bacteria were isolated and 27 of 40 (67%) who were culture-negative. For military recruits (n = 604), the proportion of carriers of meningococci with IgM or IgG to outer membrane proteins was higher than non-carriers, P < 0.05 and P = 0.000000, respectively. Among school children (n = 319), the proportion with IgM or IgG to outer membrane proteins for carriers of meningococci was higher compared with non-carriers, P = 0.000000 and P = 0000043, respectively. Carriage of N. lactamica was not associated with the presence of either IgM or IgG to the outer membrane proteins in the children. The higher proportion of children (50%) with IgM to outer membrane proteins compared with recruits (10%) might reflect more recent exposure and primary immune responses to the bacteria. The lack of association between antibodies to outer membrane proteins and carriage of N. lactamica could reflect observations that the majority of N. lactamica isolates from Greece and other countries do not react with monoclonal typing reagents. Bactericidal antibodies to meningococci associated with high levels of IgG to N. lactamica were found in a previous study; these are thought to be directed to antigens other than outer membrane proteins or capsules and imply antigens such as lipo-oligosaccharide are involved in

  10. Potential impact of vaccination against Neisseria meningitidis on Neisseria gonorrhoeae in the United States: Results from a decision-analysis model

    PubMed Central

    Régnier, Stéphane A; Huels, Jasper

    2014-01-01

    Components in 4CMenB vaccine against Neisseria meningitidis serogroup B have shown to potentially cross-react with Neisseria gonorrhoeae. We modeled the theoretical impact of a US 4CMenB vaccination program on gonorrhea outcomes. A decision-analysis model was populated using published healthcare utilization and cost data. A two-dose adolescent vaccination campaign was assumed, with protective immunity starting at age 15 years and a base-case efficacy against gonorrhea of 20%. The 20%-efficacy level is an assumption since no clinical data have yet quantified the efficacy of 4CMenB against Neisseria gonorrhoea. Key outcome measures were reductions in gonorrhea and HIV infections, reduction in quality-adjusted life-years (QALYs) lost, and the economically justifiable price assuming a willingness-to-pay threshold of $75,000 per QALY gained. Adolescent vaccination with 4CMenB would prevent 83,167 (95% credible interval [CrI], 44,600–134,600) gonorrhea infections and decrease the number of HIV infections by 55 (95% CrI, 2–129) per vaccinated birth cohort in the USA. Excluding vaccination costs, direct medical costs for gonorrhea would reduce by $28.7 million (95% CrI, $6.8–$70.0 million), and income and productivity losses would reduce by $40.0 million (95% CrI, $8.2–$91.7 million). Approximately 83% of the reduction in lost productivity is generated by avoiding HIV infections. At a cost of $75,000 per QALY gained, and incremental to the vaccine's effect on meningococcal disease, a price of $26.10 (95% CrI, $9.10–$57.20) per dose, incremental to the price of the meningococcal vaccine, would be justified from the societal perspective. At this price, the net cost per infection averted would be $1,677 (95% CrI, $404–$2,564). Even if the cross-immunity of 4CMenB vaccine and gonorrhea is only 20%, the reduction in gonorrhea infections and associated costs would be substantial. PMID:25483706

  11. Neisseria weaveri sp. nov., formerly CDC group M-5, a gram-negative bacterium associated with dog bite wounds.

    PubMed Central

    Andersen, B M; Steigerwalt, A G; O'Connor, S P; Hollis, D G; Weyant, R S; Weaver, R E; Brenner, D J

    1993-01-01

    CDC group M-5 is a rod-shaped, gram-negative, nonmotile bacterium associated with dog bite wounds. DNA-DNA relatedness and biochemical and growth characteristics were studied for 54 strains from the collection at the Centers for Disease Control and Prevention. One typical M-5 strain, 8142, was further studied by 16S rRNA sequencing. DNA from 40 of 53 strains showed 82 to 100% relatedness (hydroxyapatite method) to labeled DNA from strain 8142. The guanine-plus-cytosine (G + C) content in 8 of the 41 highly related M-5 strains was 50.5 to 52 mol%. These 41 strains were oxidase and catalase positive, nonfermentative, nitrite positive, nitrate negative, weakly phenylalanine deaminase positive, aerobic, and alpha-hemolytic (sheep blood). DNA from the 13 remaining strains showed only 7 to 46% DNA relatedness to strain 8142. These 13 non-M-5 strains differed from the M-5 strains in G + C content, growth characteristics, and biochemical profiles. DNA from M-5 strain 8142 was most closely related to DNA from groups EF-4b (47%) and EF-4a (45%). 16S rRNA sequence analysis placed M-5 strain 8142 in the Neisseriaceae cluster of the beta-3 subgroup of the class Proteobacteria. It was most homologous (98.4 to 98.8%) to Neisseria animalis, Neisseria flavescens, Neisseria canis, and Neisseria elongata. All data are consistent with M-5 being a new species of Neisseria, for which we propose the name Neisseria weaveri. PMID:8408570

  12. Neisseria lactamica Causing a Lung Cavity and Skin Rash in a Renal Transplant Patient: First Report from India.

    PubMed

    Changal, Khalid Hamid; Raina, Adnan; Altaf, Sheikh Shoaib

    2016-01-01

    Neisseria lactamica, a commensal, has been very rarely reported to cause diseases in immunocompromised hosts. In medical literature, there is only one report of a cavitatory lung lesion caused by it. The patient was a kidney transplant recipient. Neisseria lactamica was found to be the cause of his pulmonary cavity and a desquamating rash on feet. With the rapidly spreading medical advance, more and more patients are getting organ transplants, so the population of immunocompromised people is on the rise. We expect more sinister and less expected organisms to cause diseases in patients who have organ transplants.

  13. Neisseria lactamica Causing a Lung Cavity and Skin Rash in a Renal Transplant Patient: First Report from India

    PubMed Central

    Raina, Adnan; Altaf, Sheikh Shoaib

    2016-01-01

    Neisseria lactamica, a commensal, has been very rarely reported to cause diseases in immunocompromised hosts. In medical literature, there is only one report of a cavitatory lung lesion caused by it. The patient was a kidney transplant recipient. Neisseria lactamica was found to be the cause of his pulmonary cavity and a desquamating rash on feet. With the rapidly spreading medical advance, more and more patients are getting organ transplants, so the population of immunocompromised people is on the rise. We expect more sinister and less expected organisms to cause diseases in patients who have organ transplants. PMID:27006840

  14. A putatively phase variable gene (dca) required for natural competence in Neisseria gonorrhoeae but not Neisseria meningitidis is located within the division cell wall (dcw) gene cluster.

    PubMed

    Snyder, L A; Saunders, N J; Shafer, W M

    2001-02-01

    A cluster of 18 open reading frames (ORFs), 15 of which are homologous to genes involved in division and cell wall synthesis, has been identified in Neisseria gonorrhoeae and Neisseria meningitidis. The three additional ORFs, internal to the dcw cluster, are not homologous to dcw-related genes present in other bacterial species. Analysis of the N. meningitidis strain MC58 genome for foreign DNA suggests that these additional ORFs have not been acquired by recent horizontal exchange, indicating that they are a long-standing, integral part of the neisserial dcw gene cluster. Reverse transcription-PCR analysis of RNA extracted from N. gonorrhoeae strain FA19 confirmed that all three ORFs are transcribed in gonococci. One of these ORFs (dca, for division cluster competence associated), located between murE and murF, was studied in detail and found to be essential for competence in the gonococcal but not in the meningococcal strains tested. Computer analysis predicts that dca encodes an inner membrane protein similar to hypothetical proteins produced by other gram-negative bacteria. In some meningococcal strains dca is prematurely terminated following a homopolymeric tract of G's, the length of which differs between isolates of N. meningitidis, suggesting that dca is phase variable in this species. A deletion and insertional mutation was made in the dca gene of N. gonorrhoeae strain FA19 and N. meningitidis strain NMB. This mutation abrogated the ability of the gonococci to be transformed with chromosomal DNA. Thus, we conclude that the dca-encoded gene product is an essential competence factor for gonococci.

  15. Independent evolution of the core and accessory gene sets in the genus Neisseria: insights gained from the genome of Neisseria lactamica isolate 020-06

    PubMed Central

    2010-01-01

    Background The genus Neisseria contains two important yet very different pathogens, N. meningitidis and N. gonorrhoeae, in addition to non-pathogenic species, of which N. lactamica is the best characterized. Genomic comparisons of these three bacteria will provide insights into the mechanisms and evolution of pathogenesis in this group of organisms, which are applicable to understanding these processes more generally. Results Non-pathogenic N. lactamica exhibits very similar population structure and levels of diversity to the meningococcus, whilst gonococci are essentially recent descendents of a single clone. All three species share a common core gene set estimated to comprise around 1190 CDSs, corresponding to about 60% of the genome. However, some of the nucleotide sequence diversity within this core genome is particular to each group, indicating that cross-species recombination is rare in this shared core gene set. Other than the meningococcal cps region, which encodes the polysaccharide capsule, relatively few members of the large accessory gene pool are exclusive to one species group, and cross-species recombination within this accessory genome is frequent. Conclusion The three Neisseria species groups represent coherent biological and genetic groupings which appear to be maintained by low rates of inter-species horizontal genetic exchange within the core genome. There is extensive evidence for exchange among positively selected genes and the accessory genome and some evidence of hitch-hiking of housekeeping genes with other loci. It is not possible to define a 'pathogenome' for this group of organisms and the disease causing phenotypes are therefore likely to be complex, polygenic, and different among the various disease-associated phenotypes observed. PMID:21092259

  16. Use of Restriction Fragment Length Polymorphisms to Investigate Strain Variation Within Neisseria Meningitidis.

    NASA Astrophysics Data System (ADS)

    Williams, Shelley Diane

    Similarity within bacterial populations is difficult to assess due to the limited number of characters available for evaluation and the heterogeneity of bacterial species. Currently, the preferred method used to evaluate the structure of bacterial populations is multilocus enzyme electrophoresis. However, this method is extremely cumbersome and only offers an indirect measure of genetic similarities. The development of a more direct and less cumbersome method for this purpose is warranted. Restriction fragment length polymorphism analysis was evaluated as a tool for use in the study of bacterial population structures and in the epidemiology and surveillance of infectious disease. A collection of Neisseria meningitidis was available for use in the investigation of this technique. Neisseria meningitidis is the causative agent of epidemic cerebrospinal meningitis and septicemia as well as a variety of other clinical manifestations. Each isolate in the collection was defined in terms of serogroup specificity, clinical history, geographic source, and date of isolation. Forty -six strains were chosen for this study. The DNA from each strain was restricted with Pst1 and EcoR1 and electrophoresed on agarose gels. The DNA was transferred to nylon filters and hybridized with P ^{32} labeled DNA probes. Two randomly generated probes and a gene-specific probe were used to estimate the genetic similarities between and among the strains in the study population. A total of 28 different restriction fragment migration types were detected by the probes used. Data obtained from the RFLP analysis was analysed by cluster analysis and multivariate statistical methods. A total of 7 clones groups were detected. Two of these appear to be major clones that comprise 35% of the population. This analysis demonstrates the lack of structure within Neisseria meningitidis due primarily to a heterogenous population and the lack of geographic segregation. The potential utility of this technique as a

  17. Divergence and transcriptional analysis of the division cell wall (dcw) gene cluster in Neisseria spp.

    PubMed

    Snyder, Lori A S; Shafer, William M; Saunders, Nigel J

    2003-01-01

    Three of the 18 open reading frames in the division and cell wall synthesis cluster of the pathogenic Neisseria spp. are not present in the clusters of other bacterial species. The region containing two of these, dcaB and dcaC, displays interstrain and interspecies variability uncharacteristic of such clusters. 3' of dcaB is a Correia repeat enclosed element (CREE), which is only present in some strains. It has been suggested that this CREE is a transcriptional terminator, although we demonstrate otherwise. A gearbox-like promoter within this CREE is active in Escherichia coli but not in Neisseria meningitidis. There is an active promoter 5' of dcaC, although its sequence is not conserved. The presence of similarly located promoters has not been demonstrated in other species. In Neisseria lactamica, this promoter involves another dcw-associated CREE, the first demonstration of active promoter generation at the 5' end of this common intergenic, apparently mobile, element. Upstream of this promoter is an inverted pair of neisserial uptake signal sequences, which are commonly considered to be transcriptional terminators. It has been proposed to terminate transcription in this location, although we have demonstrated transcript extending through this uptake signal sequence. dcaC contains a 108 bp tandem repeat, which is present in different copy numbers in the neisserial strains examined. This investigation reveals extensive sequence variation, disputes the presence of transcriptional terminators and identifies active internal promoters in this normally highly conserved cluster of essential genes, and addresses the transcriptional activity of two common neisserial intergenic components.

  18. Multicenter Evaluation of the New Vitek 2 Neisseria-Haemophilus Identification Card▿

    PubMed Central

    Rennie, Robert P.; Brosnikoff, Cheryl; Shokoples, Sandy; Reller, L. Barth; Mirrett, Stanley; Janda, William; Ristow, Kathy; Krilcich, Ann

    2008-01-01

    The new Neisseria-Haemophilus identification (NH) card for Vitek 2 was compared with 16S rRNA gene sequencing (16S) as the reference method for accurate identification of Neisseria spp., Haemophilus spp., and other fastidious gram-negative bacteria. Testing was performed on the Vitek 2 XL system with modified software at three clinical trial laboratories. Reproducibility was determined with nine ATCC quality control strains tested 20 times over a minimum of 10 days at all three sites. A challenge set of 30 strains with known identifications and 371 recent fresh and frozen clinical isolates were also tested. Expected positive and negative biochemical reactions were also evaluated for substrate reproducibility. All microorganisms were tested on the NH card, and all clinical and stock isolates were saved for 16S testing. All reproducibility tests yielded expected results within a 95% confidence interval. For challenge microorganisms, there was 98% overall correct identification, including 8% low discrimination, 2% incorrect identification, and 0% unidentified. For clinical strains, there was 96.5% overall correct identification, including 10.2% low discrimination, 2.7% incorrect identification, and 0.8% unidentified. The 2.7% (10/371) of clinical isolates that gave an incorrect identification consisted of 7 isolates correct to genus and 3 strains incorrect to genus. There were an additional 27 strains (primarily Neisseria species) for which the 16S identification result was different from the NH card result. These were all unclaimed species by the system. The new NH card met all performance criteria within a 95% confidence interval compared to identification of clinical isolates by 16S. PMID:18579712

  19. First Reported Isolation of Neisseria canis from a Deep Facial Wound Infection in a Dog▿

    PubMed Central

    Cantas, Hasan; Pekarkova, Marta; Kippenes, Hege S.; Brudal, Espen; Sorum, Henning

    2011-01-01

    Neisseria canis was isolated in pure culture from a mandibular abscess in a dog. Ultrasound-guided fine-needle aspiration was used to obtain a sample from the abscess. Conventional bacteriological examination techniques followed by 16S rRNA gene sequencing from pure subculture and construction of a phylogenetic tree verified the isolate as N. canis. 16S rRNA sequence analysis revealed that a broader phylogenetic platform is needed in the part of the phylogenetic tree where the canine pathogenic N. canis isolate is located. The canine pathogenic isolate was found to be resistant to cephalexin and trimethoprim. PMID:21411579

  20. Prevalence of cervical Chlamydia trachomatis and Neisseria gonorrhoeae in female adolescents.

    PubMed

    Fraser, J J; Rettig, P J; Kaplan, D W

    1983-03-01

    The prevalence of cervical infection with Chlamydia trachomatis and Neisseria gonorrhoeae was examined in 125 girls receiving primary gynecologic care in a general adolescent clinic. C trachomatis was isolated in 8% of the patients using a microtiter tissue-culture method, and N gonorrhoeae was found in 12%. A significant association was found between the use of oral contraceptives and positive chlamydial cultures. Patients with Chlamydia-positive cultures were frequently asymptomatic and exhibited no positive findings on physical examination. Three of ten women with cervical chlamydial infection developed pelvic inflammatory disease. These results support the use of cervical screening for both of these pathogens in sexually active adolescents.

  1. Biology and pathogenesis of the evolutionarily successful, obligate human bacterium Neisseria meningitidis

    PubMed Central

    Stephens, David S.

    2009-01-01

    For at least two hundred years, Neisseria meningitidis (the meningococcus), the cause of epidemic meningitis and sepsis, has inflicted rapid death, disability and fear on disparate human populations. The meningococcus is also recognized as a highly successful commensal organism exclusively found in humans. The evolution of N. meningitidis to an exclusive human commensal and to a sometimes fulminant and fatal pathogen represents an important case study in microbial pathogenesis. We review the general status of our knowledge of pathogenesis of meningococcal carriage, transmission and virulence behavior with particular emphasis on the relevance of research on this topic to vaccine development. PMID:19477055

  2. Multicenter Investigation of Gepotidacin (GSK2140944) Agar Dilution Quality Control Determinations for Neisseria gonorrhoeae ATCC 49226

    PubMed Central

    Fedler, Kelley A.; Scangarella-Oman, Nicole E.; Ross, James E.; Flamm, Robert K.

    2016-01-01

    Gepotidacin, a novel triazaacenaphthylene antibacterial agent, is the first in a new class of type IIA topoisomerase inhibitors with activity against many biothreat and conventional pathogens, including Neisseria gonorrhoeae. To assist ongoing clinical studies of gepotidacin to treat gonorrhea, a multilaboratory quality assurance investigation determined the reference organism (N. gonorrhoeae ATCC 49226) quality control MIC range to be 0.25 to 1 μg/ml (88.8% of gepotidacin MIC results at the 0.5 μg/ml mode). PMID:27161642

  3. Analysis of penicillinase-producing Neisseria gonorrhoeae isolates in Madrid (Spain) from 1983-85.

    PubMed Central

    Fenoll, A.; Berrón, S.; Vázquez, J. A.

    1987-01-01

    Between April 1983 and December 1985, 576 strains of Neisseria gonorrhoeae were isolated in our laboratory from patients attending Sexually Transmitted Diseases (STD) clinics. Of these, 61 (10.6%) were penicillinase-producing. Studies on these strains by plasmid analysis, auxotyping and serogrouping showed that the predominant type strains harboured the Asian resistance plasmid, were prototrophic, and were of serogroup W II/W III. About half of the strains, both of the African and Asian type, harboured the transfer plasmid. Strains of serogroup W II/W III were less sensitive to tetracycline and cefoxitin than serogroup W I strains. Images Fig. 2 PMID:2960555

  4. Effect of mesoporous silica under Neisseria meningitidis transformation process: environmental effects under meningococci transformation

    PubMed Central

    2011-01-01

    Background This study aimed the use of mesoporous silica under the naturally transformable Neisseria meningitidis, an important pathogen implicated in the genetic horizontal transfer of DNA causing a escape of the principal vaccination measures worldwide by the capsular switching process. This study verified the effects of mesoporous silica under N. meningitidis transformation specifically under the capsular replacement. Methods we used three different mesoporous silica particles to verify their action in N. meningitis transformation frequency. Results we verified the increase in the capsular gene replacement of this bacterium with the three mesoporous silica nanoparticles. Conclusion the mesouporous silica particles were capable of increasing the capsule replacement frequency in N. meningitidis. PMID:21787408

  5. Multitarget PCR Assay for Direct Detection of Penicillinase-Producing Neisseria gonorrhoeae for Enhanced Surveillance of Gonococcal Antimicrobial Resistance

    PubMed Central

    Buckley, Cameron; Trembizki, Ella; Baird, Robert W.; Chen, Marcus; Donovan, Basil; Freeman, Kevin; Goire, Namraj; Guy, Rebecca; Lahra, Monica M.; Regan, David

    2015-01-01

    A multitarget PCR was developed for the direct detection of penicillinase-producing Neisseria gonorrhoeae (PPNG). The assay was validated by testing 342 PPNG isolates and 415 clinical samples. The method is suitable for routine detection of PPNG strains. Its multitarget approach reduces the potential for false-negative results caused by sequence variations. PMID:25994166

  6. Clinical features and outcome of pediatric Neisseria meningitidis serogroup W135 infection: a report of 5 cases.

    PubMed

    Faye, Albert; Mariani-Kurkdjian, Patricia; Taha, Muhamed-Kheir; Angoulvant, François; Antonios, Micheline; Aubertin, Guillaume; Soussan, Valérie; Bingen, Edouard; Bourrillon, Antoine

    2004-06-01

    We describe 5 pediatric cases of Neisseria meningitidis serogroup W135 infection. Infectious and/or reactive extrameningeal involvement was frequent. One patient had a persistent postmeningococcal inflammatory syndrome. Four of 5 isolates belonged to the clonal complex 37. The important risk of extrameningeal complications must be borne in mind when treating children with N. meningitidis W135 infection.

  7. Neisseria arctica sp. nov. isolated from nonviable eggs of greater white-fronted geese (Anser albifrons) in Arctic Alaska

    USGS Publications Warehouse

    Hansen, Cristina M.; Himschoot, Elizabeth; Hare, Rebekah F.; Meixell, Brandt; Van Hemert, Caroline R.; Hueffer, Karsten

    2017-01-01

    During the summers of 2013 and 2014, isolates of a novel Gram-negative coccus in the Neisseria genus were obtained from the contents of nonviable greater white-fronted goose (Anser albifrons) eggs on the Arctic Coastal Plain of Alaska. We used a polyphasic approach to determine whether these isolates represent a novel species. 16S rRNA gene sequences, 23S rRNA gene sequences, and chaperonin 60 gene sequences suggested that these Alaskan isolates are members of a distinct species that is most closely related to Neisseria canis, N. animaloris, and N. shayeganii. Analysis of the rplF gene additionally showed that our isolates are unique and most closely related to N. weaveri. Average nucleotide identity of the whole genome sequence of our type strain was between 71.5% and 74.6% compared to close relatives, further supporting designation as a novel species. Fatty acid methyl ester analysis showed a predominance of C14:0, C16:0, and C16:1ω7c fatty acids. Finally, biochemical characteristics distinguished our isolates from other Neisseria species. The name Neisseria arctica (type strain KH1503T = ATCC TSD-57T = DSM 103136T) is proposed.

  8. A combined mass spectrometry strategy for complete posttranslational modification mapping of Neisseria meningitidis major pilin.

    PubMed

    Gault, Joseph; Malosse, Christian; Duménil, Guillaume; Chamot-Rooke, Julia

    2013-11-01

    Herein, we report a new approach, based on the combination of mass profiling and tandem mass spectrometry, to address the issue of localising all post-translational modifications (PTMs) on the major pilin protein PiIE expressed by the pathogenic Neisseria species. PilE is the main component of type IV pili; filamentous organelles expressed at the surface of many bacterial pathogens and important virulence factors. Previous reports have shown that PilE can harbour various combinations of PTMs and have established strong links between PTM and pathogenesis. Complete PTM mapping of proteins involved in bacterial infection is therefore highly desirable. The methodology we propose here allowed us to fully characterise the PilE proteoforms of Neisseria meningitidis strain 8013, definitively identifying all PTMs present on all proteoforms and localising their position on the protein backbone. These modifications include a processed and methylated N-terminus, disulfide bridge, glycosylation and glycerophosphorylation at two different sites. A key element of our approach is high resolution, intact mass measurement of the proteoforms, a piece of information completely lacking in all classical bottom-up proteomics strategies used for PTM analysis and without which it is difficult to ensure complete PTM mapping.

  9. Synthesis of a select group of proteins by Neisseria gonorrhoeae in response to thermal stress.

    PubMed

    Woods, M L; Bonfiglioli, R; McGee, Z A; Georgopoulos, C

    1990-03-01

    We report the thermal conditions that induce the heat shock response in Neisseria gonorrhoeae. Under conditions of thermal stress, Neisseria gonorrhoeae synthesizes heat shock proteins (hsps), which differ quantitatively from conventionally studied gonococcal proteins. Gonococci accelerate the rate of synthesis of the hsps as early as 5 min after the appropriate stimulus is applied, with synthesis continuing for 30 min, as demonstrated by in vivo labeling experiments with L-[35S]methionine. Two of the gonococcal hsps are immunologically cross-reactive with the hsps of Escherichia coli, DnaK and GroEL, as demonstrated by Western blot (immunoblot) analysis. Ten hsps can be identified on two-dimensional autoradiograms of whole gonococci (total protein). Four hsps can be identified on two-dimensional autoradiograms of 1% N-lauroylsarcosine (sodium salt) (Sarkosyl)-insoluble membrane fractions. Two of the hsps from the 1% Sarkosyl-insoluble fraction are found exclusively in this fraction, suggesting that they are membrane proteins. The identification of this group of proteins will facilitate further study of the function of these proteins and provide insight into the possible role of hsps in disease pathogenesis.

  10. Difference in DNA-binding abilities of Fur-homolog DNA binding protein from Neisseria gonorrhoeae.

    PubMed

    Bagchi, Angshuman

    2016-10-01

    Gonorrhea is a severe disease infecting both men and women worldwide. The causative agent of the disease is Neisseria gonorrhoeae. The organism mostly affects human beings in iron restricted environments. In such an environment the organism produces a set of proteins which are mostly absent in iron rich environments. The expressions of the genes for the proteins are regulated by the transcription factor (TF) belonging to the Fur family. Interestingly, the same TF acts as the activator and repressor of genes. In this present work, an attempt has been made to analyze the molecular details of the differential DNA-binding activities of the TF from Neisseria gonorrhoeae to come up with a plausible molecular reason behind the difference DNA binding activities of the same TF. Computational modelling technique was used to build the three dimensional structure of the TF. Molecular docking and molecular dynamics simulations were employed to determine the binding interactions between the TF and the promoter DNA. With the help of the computational techniques, the biochemical reason behind the different modes of DNA binding by the TF was analyzed. Results from this analysis may be useful to future drug development endeavours to curtail the spread of Gonorrhea.

  11. Will targeting oropharyngeal gonorrhoea delay the further emergence of drug-resistant Neisseria gonorrhoeae strains?

    PubMed

    Lewis, D A

    2015-06-01

    Gonorrhoea is an important sexually transmitted infection associated with serious complications and enhanced HIV transmission. Oropharyngeal infections are often asymptomatic and will only be detected by screening. Gonococcal culture has low sensitivity (<50%) for detecting oropharyngeal gonorrhoea, and, although not yet approved commercially, nucleic acid amplification tests (NAAT) are the assay of choice. Screening for oropharyngeal gonorrhoea should be performed in high-risk populations, such as men-who-have-sex-with-men(MSM). NAATs have a poor positive predictive value when used in low-prevalence populations. Gonococci have repeatedly thwarted gonorrhoea control efforts since the first antimicrobial agents were introduced. The oropharyngeal niche provides an enabling environment for horizontal transfer of genetic material from commensal Neisseria and other bacterial species to Neisseria gonorrhoeae. This has been the mechanism responsible for the generation of mosaic penA genes, which are responsible for most of the observed cases of resistance to extended-spectrum cephalosporins (ESC). As antimicrobial-resistant gonorrhoea is now an urgent public health threat, requiring improved antibiotic stewardship, laboratory-guided recycling of older antibiotics may help reduce ESC use. Future trials of antimicrobial agents for gonorrhoea should be powered to test their efficacy at the oropharynx as this is the anatomical site where treatment failure is most likely to occur. It remains to be determined whether a combination of frequent screening of high-risk individuals and/or laboratory-directed fluoroquinolone therapy of oropharyngeal gonorrhoea will delay the further emergence of drug-resistant N. gonorrhoeae strains.

  12. 16th International Pathogenic Neisseria Conference: recent progress towards effective meningococcal disease vaccines.

    PubMed

    Gorringe, Andrew R; van Alphen, Loek

    2009-02-01

    The report describes developments in meningococcal disease vaccines presented at the 16th International Pathogenic Neisseria Conference, Rotterdam, 7-12 September 2008. Great progress has been made by the Meningitis Vaccine Project to provide an affordable and effective serogroup A conjugate vaccine for use in the meningitis belt of Sub-Saharan Africa. The vaccine has been shown to be safe and to produce excellent immune response in phase 2 clinical trials in India and Africa in the target populations and will be rolled out to the worst affected countries from 2009. This vaccine has the potential to make a huge impact on public health in this region. This conference heard that the use of an epidemic strain-specific outer membrane vesicle (OMV) vaccine in New Zealand has been discontinued. Views for and against this decision were presented. Several MenB vaccines have progressed to clinical evaluation. The most advanced are the Novartis five recombinant protein variants and the Wyeth vaccine based on two factor H binding protein variants. Promising results from both vaccines with genetically-detoxified lipooligosaccharide and overexpressed heterologous antigens, OMV's from Neisseria lactamica and recombinant Opa proteins.

  13. Outer membrane vesicles of Neisseria lactamica as a potential mucosal adjuvant.

    PubMed

    Sardiñas, Gretel; Reddin, Karen; Pajon, Rolando; Gorringe, Andrew

    2006-01-12

    The muscosal delivery of vaccines has many advantages including ease of administration and the induction of a mucosal immune response at the natural site of infection for many pathogens. Mice were immunised with outer membrane vesicles (OMV) prepared from Neisseria lactamica or Neisseria meningitidis by subcutaneous (SC) or intranasal (IN) routes, or live cells of N. lactamica given IN or by SC injection. A systemic IgG and mucosal IgA response was demonstrated and N. lactamica OMV induced antibodies cross-reactive with N. meningitidis; however, a cross-reactive response following IN administration was only evident after three doses of vaccine. OMV from both organisms were also an effective intranasal adjuvant for a co-administered model antigen, hepatitis B surface antigen (HBsAg), inducing systemic IgG against HBsAg and IgA in lung and vaginal washes. IN administration of N. meningitidis OMV elicited serum antibodies that were bactericidal for meningococci and provided passive protection in an infant rat model of meningococcal bacteraemia. The antibody response to N. lactamica OMV given IN was only weakly bactericidal but still afforded passive protection. Thus, OMV from N. lactamica given IN elicit immune responses cross-reactive with N. meningitidis and act as an effective mucosal adjuvant.

  14. Changing Antimicrobial Resistance Profiles among Neisseria gonorrhoeae Isolates in Italy, 2003 to 2012

    PubMed Central

    Carannante, Anna; Renna, Giovanna; Dal Conte, Ivano; Ghisetti, Valeria; Matteelli, Alberto; Prignano, Grazia; Impara, Giampaolo; Cusini, Marco; D'Antuono, Antonietta; Vocale, Caterina; Antonetti, Raffaele; Gaino, Marina; Busetti, Marina; Latino, Maria Agnese; Mencacci, Antonella; Bonanno, Carmen; Cava, Maria Carmela; Giraldi, Cristina

    2014-01-01

    The emergence of Neisseria gonorrhoeae isolates displaying resistance to antimicrobial agents is a major public health concern and a serious issue related to the occurrence of further untreatable gonorrhea infections. A retrospective analysis on 1,430 N. gonorrhoeae isolates, collected from 2003 through 2012, for antimicrobial susceptibility by Etest and molecular characterization by Neisseria gonorrhoeae multiantigen sequence typing (NG-MAST) was carried out in Italy. Azithromycin-resistant gonococci decreased from 14% in 2007 to 2.2% in 2012. Similarly, isolates with high MICs to cefixime (>0.125 mg/liter) decreased from 11% in 2008 to 3.3% in 2012. The ciprofloxacin resistance rate remains quite stable, following an increasing trend up to 64% in 2012. The percentage of penicillinase-producing N. gonorrhoeae (PPNG) significantly declined from 77% in 2003 to 7% in 2012. A total of 81 multidrug-resistant (MDR) gonococci were identified, showing 11 different antimicrobial resistance patterns. These were isolated from men who have sex with men (MSM) and from heterosexual patients. Two sequence types (STs), ST661 and ST1407, were the most common. Genogroup 1407, which included cefixime-, ciprofloxacin-, and azithromycin-resistant isolates, was found. In conclusion, a change in the antimicrobial resistance profiles among gonococci was identified in Italy together with a percentage of MDR isolates. PMID:25070110

  15. Characterization of the ftsZ cell division gene of Neisseria gonorrhoeae: expression in Escherichia coli and N. gonorrhoeae.

    PubMed

    Salimnia, H; Radia, A; Bernatchez, S; Beveridge, T J; Dillon, J R

    2000-01-01

    We cloned the cell division gene ftsZ of the gram-negative coccus Neisseria gonorrhoeae (Ng) strain CH811, characterized it genetically and phenotypically, and studied its localization in N. gonorrhoeae and Escherichia coli (Ec). The 1,179-bp ORF of ftsZ(Ng) encodes a protein with a predicted molecular mass of 41.5 kDa. Protein sequence alignments indicate that FtsZ(Ng) is similar to other FtsZ proteins and contains the conserved GTP binding motif. FtsZ homologues were identified in several N. gonorrhoeae strains and in Neisseria lactamica, Neisseria sicca, Neisseria polysaccharae and Neisseria cinerea either by Western blot or by PCR-Southern blot analysis. Attempts to inactivate the ftsZ(Ng) on the chromosome failed, indicating that it is essential for gonococcal growth. FtsZ(Ng) was synthesized in an in vitro transcription/translation system and was shown to be 43 kDa, the same size as in Western blots. Expression of the ftsZ(Ng) gene from nongonococcal promoters resulted in a filamentous phenotype in E. coli. Under controlled expression, the FtsZ(Ng)-GFP fusion protein localized at the mid-cell division site in E. coli. E. coli expressing high levels of the FtsZ(Ng)-GFP fusion protein formed filaments and exhibited different fluorescent structures including helices, spiral tubules extending from pole to pole, and regularly spaced dots or bands that did not localize at the middle of the cell. Expression of the FtsZ(Ng)-GFP fusion protein in N. gonorrhoeae resulted in abnormal cell division as shown by electron microscopy. FtsZ(Ng)-GFP fusions were also expressed in a gonococcal background using a unique shuttle vector.

  16. Identifying Neisseria Species by Use of the 50S Ribosomal Protein L6 (rplF) Gene

    PubMed Central

    Bennett, Julia S.; Watkins, Eleanor R.; Jolley, Keith A.; Harrison, Odile B.

    2014-01-01

    The comparison of 16S rRNA gene sequences is widely used to differentiate bacteria; however, this gene can lack resolution among closely related but distinct members of the same genus. This is a problem in clinical situations in those genera, such as Neisseria, where some species are associated with disease while others are not. Here, we identified and validated an alternative genetic target common to all Neisseria species which can be readily sequenced to provide an assay that rapidly and accurately discriminates among members of the genus. Ribosomal multilocus sequence typing (rMLST) using ribosomal protein genes has been shown to unambiguously identify these bacteria. The PubMLST Neisseria database (http://pubmlst.org/neisseria/) was queried to extract the 53 ribosomal protein gene sequences from 44 genomes from diverse species. Phylogenies reconstructed from these genes were examined, and a single 413-bp fragment of the 50S ribosomal protein L6 (rplF) gene was identified which produced a phylogeny that was congruent with the phylogeny reconstructed from concatenated ribosomal protein genes. Primers that enabled the amplification and direct sequencing of the rplF gene fragment were designed to validate the assay in vitro and in silico. Allele sequences were defined for the gene fragment, associated with particular species names, and stored on the PubMLST Neisseria database, providing a curated electronic resource. This approach provides an alternative to 16S rRNA gene sequencing, which can be readily replicated for other organisms for which more resolution is required, and it has potential applications in high-resolution metagenomic studies. PMID:24523465

  17. Production of monoclonal antibodies against Neisseria meningitidis using popliteal lymph nodes and in vivo/in vitro immunization: prevalence study of new monoclonal antibodies in greater São Paulo, Brazil.

    PubMed

    Belo, Elza F T; Ferraz, Aline S; Coutinho, Ligia M C C; Oliveira, Ana P; Carmo, Andréia M S; Tunes, Claudia F; Ferreira, Tatiane; Ito, Andre Y; Machado, Marta S F; De L Franco, Daniele; De Gaspari, Elizabeth N

    2007-10-01

    A rapid and efficient method for preparing monoclonal antibody (MAb) serotypes using Neisseria meningitidis outer membrane were used in BALB/c mouse footpads for the immunization. The popliteal lymph nodes were isolated 19 days later for MAb-producing hybridomas, from which the MAbs against the 37 kDa protein were screened. Variations in class 2/3 (PorB) proteins form the basis for meningococcal serotyping. This is the first report on the preparation of MAbs against N. meningitidis that is specific to PorB protein using popliteal lymph nodes. The new monoclonal antibodies were specific for PorB outer membrane protein FL24(PL)Br, a new serotype 24 class 3 antigens of non-typeable (NT:NST) serogroup B strain, and FL14(PL)Br specific for the serotype 14, and reacted with the S3446 reference strain analyzed. A total of 12% of the case isolates reacted with one or more of the monoclonal antibodies. The high-affinity MAbs produced by hybridoma methodology provide a basis for further research on the pathogenesis and early diagnosis of meningococcus.

  18. HexR Controls Glucose-Responsive Genes and Central Carbon Metabolism in Neisseria meningitidis

    PubMed Central

    Antunes, Ana; Golfieri, Giacomo; Ferlicca, Francesca; Giuliani, Marzia M.; Scarlato, Vincenzo

    2015-01-01

    ABSTRACT Neisseria meningitidis, an exclusively human pathogen and the leading cause of bacterial meningitis, must adapt to different host niches during human infection. N. meningitidis can utilize a restricted range of carbon sources, including lactate, glucose, and pyruvate, whose concentrations vary in host niches. Microarray analysis of N. meningitidis grown in a chemically defined medium in the presence or absence of glucose allowed us to identify genes regulated by carbon source availability. Most such genes are implicated in energy metabolism and transport, and some are implicated in virulence. In particular, genes involved in glucose catabolism were upregulated, whereas genes involved in the tricarboxylic acid cycle were downregulated. Several genes encoding surface-exposed proteins, including the MafA adhesins and Neisseria surface protein A, were upregulated in the presence of glucose. Our microarray analysis led to the identification of a glucose-responsive hexR-like transcriptional regulator that controls genes of the central carbon metabolism of N. meningitidis in response to glucose. We characterized the HexR regulon and showed that the hexR gene is accountable for some of the glucose-responsive regulation; in vitro assays with the purified protein showed that HexR binds to the promoters of the central metabolic operons of the bacterium. Based on DNA sequence alignment of the target sites, we propose a 17-bp pseudopalindromic consensus HexR binding motif. Furthermore, N. meningitidis strains lacking hexR expression were deficient in establishing successful bacteremia in an infant rat model of infection, indicating the importance of this regulator for the survival of this pathogen in vivo. IMPORTANCE Neisseria meningitidis grows on a limited range of nutrients during infection. We analyzed the gene expression of N. meningitidis in response to glucose, the main energy source available in human blood, and we found that glucose regulates many genes

  19. Analysis of amino acid sequences of penicillin-binding protein 2 in clinical isolates of Neisseria gonorrhoeae with reduced susceptibility to cefixime and ceftriaxone.

    PubMed

    Osaka, Kazuyoshi; Takakura, Tadakazu; Narukawa, Kayo; Takahata, Masahiro; Endo, Katsuhisa; Kiyota, Hiroshi; Onodera, Shoichi

    2008-06-01

    Neisseria gonorrhoeae strains with reduced susceptibility to cefixime and ceftriaxone, with minimum inhibitory concentrations (MICs) of cefixime of 0.125-0.25 microg/ml and ceftriaxone of 0.031-0.125 microg/ml, were isolated from male urethritis patients in Tokyo, Japan, in 2006. The amino acid sequences of PenA, penicillin-binding protein 2, in these strains were of two types: PenA mosaic and nonmosaic strains. In the PenA mosaic strain, some regions in the transpeptidase-encoding domain in PenA were similar to those of Neisseria perflava/sicca, Neisseria cinerea, Neisseria flavescens, Neisseria polysaccharea, and Neisseria meningitidis. In the PenA nonmosaic strain, there was a mutation of Ala-501 to Val in PenA. In addition, we performed homology modeling of PenA wild-type and mosaic strains and compared them. The results of the modeling studies suggested that reduced susceptibility to cephems such as cefixime and ceftriaxone is due to a conformational alteration of the beta-lactam-binding pocket. These results also indicated that the mosaic structures and the above point mutation in PenA make a major contribution to the reduced susceptibility to cephem antibiotics.

  20. Asymtomatic carriage of Neisseria meningitidis and Neisseria lactamica in relation to Streptococcus pneumoniae and Haemophilus influenzae colonization in healthy children: apropos of 1400 children sampled.

    PubMed

    Bakir, M; Yagci, A; Ulger, N; Akbenlioglu, C; Ilki, A; Soyletir, G

    2001-01-01

    Meningococcal disease is one of the most important causes of morbidity and mortality among children in many parts of the world. Main reservoir of carriage and site of meningococcal dissemination appears to be the upper respiratory tract. Colonization of Neisseria meningitidis and lactamica and factors affecting this carriage were determined in a group of healthy children aged 0-10 years. Meningococcus and N. lactamica carriage were detected in 17 (1.23%) and 245 (17.7%) of 1382 subjects, respectively. Number (%) of serogroups for meningococci was 1 (6), 5 (29), 0 (0), 1 (6), 1 (6), and 9 (53) for A, B, C, D, W135, and Y, respectively. Having more than three household members, elementary school attendance, pharyngeal carriage of Streptococcus pneumoniae and Haemophilus influenzae were associated with carriage of meningococci, whereas age less than 24-month was associated with carriage of N. lactamica. There was a reverse carriage rate between N. meningitidis and N. lactamica by age which may suggest a possible protective role of N. lactamica against meningococcal colonization among pre-school children.

  1. In-vitro comparison of macrolides, lincosamides and synergistins on Neisseria gonorrhoeae.

    PubMed

    Thabaut, A; Meyran, M; Huerre, M

    1985-07-01

    The MIC of erythromycin, oleandomycin, spiramycin, josamycin, lincomycin and pristinamycin was determined for 100 strains of Neisseria gonorrhoeae isolated from cases of acute urethritis in men. The method of dilution in agar was used: blood agar with the addition of 'Polyvitex' and an innoculum of 10(3)-10(4) bacteria per spot. With respect to the break points defined by the C.F.A. all the strains of N. gonorrhoeae studied are sensitive to erythromycin, spiramycin, josamycin and pristinamycin, 12% strains are resistant to oleandomycin and 75% to lincomycin. The active antibiotics are classified as follows according to the active weight expressed by the MIC50: erythromycin, pristinamycin, 0.125 mg/l; josamycin, 0.5 mg/l; spiramycin, oleandomycin, 2 mg/l.

  2. The major anaerobically induced outer membrane protein of Neisseria gonorrhoeae, Pan 1, is a lipoprotein.

    PubMed Central

    Hoehn, G T; Clark, V L

    1992-01-01

    Pan 1 is an acidic outer membrane protein of Neisseria gonorrhoeae that is expressed only when gonococci are grown anaerobically. On silver-stained sodium dodecyl sulfate-polyacrylamide gels, Pan 1 migrates as an intense but diffuse 54-kDa protein. The deduced amino acid sequence of Pan 1 from the aniA (anaerobically induced protein) open reading frame reveals a lipoprotein consensus sequence, Ala-Leu-Ala-Ala-Cys, and a processed molecular mass of 39 kDa. Furthermore, there is strong homology at the N terminus and C terminus of Pan 1 to the termini of the gonococcal outer membrane lipoproteins Lip and Laz. [3H]palmitic acid labeling of gonococci grown under oxygen-limited conditions demonstrated specific incorporation of label into Pan 1, suggesting further that Pan 1 is a lipoprotein. Images PMID:1398981

  3. Sero/subtyping of Neisseria meningitidis isolated from patients in Spain.

    PubMed Central

    Vazquez, J. A.; Marcos, C.; Berron, S.

    1994-01-01

    To know the types of meningococcal strains in Spain, we serotyped and subtyped 743 Neisseria meningitidis isolates recovered between 1990 and 1992 from patients. A great number of serogroup B, serogroup C and non-groupable meningococci reacted with the serotyping reagents while many serogroup C and non-groupable isolates did not react with the serosubtyping reagents (78.2% and 54.8% respectively); only 8.9% of serogroup B meningococci were non-subtypeable (NST). Distribution of serotypes was similar in serogroup C and in non-groupable strains. Isolates showed great variability in antigenic phenotypes (71 in serogroup B, 20 in serogroup C and 25 in non-groupable meningococci). The most frequent antigenic combinations were 4:P1.15 (39.8%) in serogroup B, 2b:NST (55.8%) in serogroup C and 2b:NST (35.6%) in non-groupable meningococci. PMID:7925665

  4. Characterization of epidemic Neisseria meningitidis serogroup C strains in several Brazilian states.

    PubMed Central

    Sacchi, C T; Tondella, M L; de Lemos, A P; Gorla, M C; Berto, D B; Kumiochi, N H; Melles, C E

    1994-01-01

    Epidemic strains of the Neisseria meningitidis C:2b:P1.3 electrophoretic type 11 complex were responsible for an outbreak in Curitiba, Parana State, Brazil, from 1990 to 1991. Strains of this complex were also isolated in other Brazilian states and were responsible for a meningococcal disease epidemic in São Paulo State in 1990. Serotyping both with monoclonal antibodies and by multilocus enzyme electrophoresis was useful for typing these epidemic strains related to the increased incidence of meningococcal disease. The genetic similarity of members of the electrophoretic type 11 complex was confirmed by the ribotyping method by using EcoRI or ClaI endonuclease restriction enzymes. Images PMID:7929775

  5. Ribotyping as an additional molecular marker for studying Neisseria meningitidis serogroup B epidemic strains.

    PubMed Central

    Tondella, M L; Sacchi, C T; Neves, B C

    1994-01-01

    The molecular method of ribotyping was used as an additional epidemiological marker to study the epidemic strains of Neisseria meningitidis serogroup B, referred to as the ET-5 complex, responsible for the epidemic which occurred in greater São Paulo, Brazil. Ribotyping analysis of these strains showed only a single rRNA gene restriction pattern (Rb1), obtained with ClaI restriction enzyme. This method, as well as multilocus enzyme electrophoresis, provided useful information about the clonal characteristics of the N. meningitidis serogroup B strains isolated during this epidemic. The N. meningitidis serogroup B isolates obtained from epidemics which occurred in Norway, Chile, and Cuba also demonstrated the same pattern (Rb1). Ribotyping was a procedure which could be applied to a large number of isolates and was felt to be appropriate for routine use in laboratories, especially because of the convenience of using nonradioactive probes. Images PMID:7852566

  6. Epidemics of serogroup A Neisseria meningitidis of subgroup III in Africa, 1989-94.

    PubMed Central

    Guibourdenche, M.; Høiby, E. A.; Riou, J. Y.; Varaine, F.; Joguet, C.; Caugant, D. A.

    1996-01-01

    A total of 125 strains of Neisseria meningitidis recovered in the course of outbreaks from patients with systemic disease in 11 African countries between 1989 and 1994 were analysed by serogrouping, serotyping and multilocus enzyme electrophoresis. Of the 125 patient strains 115 (92%) belonged to the clone-complex of serogroup A meningococci, designated subgroup III. Among the remaining strains, 4 were also serogroup A, but belonged to the clonal groups I and IV-1 (2 strains each), whilst 6 strains (4 serogroup C and 2 serogroup W135) represented clones of the ET-37 complex. Our results indicated that the second pandemic caused by clones of subgroup III is still spreading in Africa. Towards the West it has reached Niger, Mali, Guinea and The Gambia, and towards the South, the Central African Republic, Uganda, Rwanda, Burundi, Tanzania and Zambia. PMID:8620901

  7. Proposed interpretive criteria and quality control parameters for ofloxacin susceptibility testing of Neisseria gonorrhoeae.

    PubMed Central

    Fuchs, P C; Barry, A L; Baker, C; Murray, P R; Washington, J A

    1992-01-01

    A multilaboratory study designed to determine the in vitro susceptibility criteria and quality control parameters for ofloxacin against Neisseria gonorrhoeae was conducted according to the guidelines of the National Committee for Clinical Laboratory Standards. Proposed susceptibility breakpoints are MICs of less than or equal to 0.25 microgram/ml for the agar dilution test and greater than or equal to 31 mm for the disk diffusion test. A category for resistance could not be defined. Proposed acceptable quality control MICs for N. gonorrhoeae ATCC 49226 and Staphylococcus aureus ATCC 29213 range from 0.004 to 0.03 microgram/ml and 0.25 to 1.0 microgram/ml, respectively. With 5-micrograms ofloxacin disks, acceptable inhibitory zone diameters for S. aureus ATCC 25923 and the N. gonorrhoeae control strains range from 22 to 27 mm and 43 to 51 mm, respectively. PMID:1572960

  8. Meeting the public health challenge of multidrug- and extensively drug-resistant Neisseria gonorrhoeae.

    PubMed

    Tapsall, John W; Ndowa, Francis; Lewis, David A; Unemo, Magnus

    2009-09-01

    Globally, antimicrobial resistance (AMR) in Neisseria gonorrhoeae is increasing in prevalence, both within and across antibiotic classes, including extended-spectrum cephalosporins, raising concerns that gonorrhea may become untreatable in certain circumstances. The AMR surveillance that is essential to optimize standard treatments is often lacking or of poor quality in countries with high disease rates. Recent initiatives by the WHO to enhance global AMR surveillance that focus on multidrug- and extensively drug-resistant N. gonorrhoeae through revision of surveillance standards and use of a new panel of N. gonorrhoeae control strains are described. Keys to meeting these new challenges posed by gonococcal AMR remain the reduction in global burden of gonorrhea combined with implementation of wider strategies for general AMR control, and better understanding of mechanisms of emergence and spread of AMR.

  9. The U.S. military's Neisseria gonorrhoeae resistance surveillance initiatives in selected populations of five countries.

    PubMed

    Tsai, Alice Y; Dueger, Erica; Macalino, Grace E; Montano, Silvia M; Tilley, Drake H; Mbuchi, Margaret; Wurapa, Eyako K; Saylors, Karen; Duplessis, Christopher C; Puplampu, Naiki; Garges, Eric C; McClelland, R Scott; Sanchez, Jose L

    2013-02-01

    Multi-drug resistant Neisseria gonorrhoeae (GC) threatens the successful treatment of gonorrhea. This report presents preliminary findings with regard to the prevalence of laboratory-confirmed GC and the extent of drug-resistance among sample populations in five countries. Between October 2010 and January 2013, 1,694 subjects (54% male; 45% female; 1% unknown) were enrolled and screened for the presence of laboratory-confirmed GC in the United States, Djibouti, Ghana, Kenya, and Peru. Overall, 108 (6%) of enrolled subjects tested positive for GC. Antimicrobial susceptibility testing results were available for 66 GC isolates. Resistance to at least three antibiotics was observed at each overseas site. All isolates tested in Ghana (n=6) were resistant to ciprofloxacin, penicillin, and tetracycline. In Djibouti, preliminary results suggested resistance to penicillin, tetracycline, ciprofloxacin, cefepime, and ceftriaxone. The small sample size and missing data prevent comparative analysis and limit the generalizability of these preliminary findings.

  10. Evaluation of the Microcult system for isolating and identifying Neisseria gonorrhoeae.

    PubMed Central

    Williams, R J; Ratnatunga, C S; Hamilton-Miller, J M; Brumfitt, W

    1978-01-01

    Specimens from 95 patients attending a venereal diseases clinic were examined for gonococci by three methods--a conventional culture technique using modified Thayer-Martin medium, microscopy of a Gram-stained direct smear, and the Microcult system. For 56% of the specimens the results by all three methods agreed. Assuming the results obtained by culture on Thayer-Martin medium to be correct, the largest source of error was due to false-positive results: microscopy gave 26 and Microcult gave 15 such results. False-negative results were less common: Microcult gave 14, microscopy six. Microcult gave positive results more quickly than the conventional Thayer-Martin cultural method, but the gonococci were difficult to isolate by subculture from the Microcult culture pads. The Microcult medium was not absolutely specific for Neisseria gonorrhoeae. Nevertheless, the Microcult test may well prove to be a useful adjunct to the diagnosis of gonorrhoea, especially when laboratory facilities are not readily available. PMID:417090

  11. Effect of environment on sensitivity of Neisseria gonorrhoeae to Pseudomonas aeruginosa bacteriocins.

    PubMed Central

    Stein, D C; Hebeler, B H; Young, F E

    1980-01-01

    The effect of environmental variation on the susceptibility of Neisseria gonorrhoeae to pyocin produced by Pseudomonas aeruginosa was examined. Susceptibility to at least one pyocin was demonstrated in strains of N. gonorrhoeae (99%), N. meningitidis (35%), and N. lactamica (47%). The degree of sensitivity to pyocin displayed by N. gonorrhoeae was affected by varying the pH of the growth environment. Gonococcal strains were more sensitive to growth inhibition by pyocins at an alkaline pH and less sensitive to growth inhibition at an acid pH. Inhibitory titers fluctuated during nonselective subculture of fresh clinical isolates. There was no apparent correlation between auxotype and sensitivity to pyocin. Also, no relationship between colony morphology and pyocin sensitivity was seen. PMID:6783533

  12. NGMASTER: in silico multi-antigen sequence typing for Neisseria gonorrhoeae

    PubMed Central

    Gonçalves da Silva, Anders; Dyet, Kristin; Williamson, Deborah A.; Stinear, Timothy P.; Howden, Benjamin P.; Seemann, Torsten

    2016-01-01

    Whole-genome sequencing (WGS) provides the highest resolution analysis for comparison of bacterial isolates in public health microbiology. However, although increasingly being used routinely for some pathogens such as Listeria monocytogenes and Salmonella enterica, the use of WGS is still limited for other organisms, such as Neisseria gonorrhoeae. Multi-antigen sequence typing (NG-MAST) is the most widely performed typing method for epidemiological surveillance of gonorrhoea. Here, we present NGMASTER, a command-line software tool for performing in silico NG-MAST on assembled genome data. NGMASTER rapidly and accurately determined the NG-MAST of 630 assembled genomes, facilitating comparisons between WGS and previously published gonorrhoea epidemiological studies. The source code and user documentation are available at https://github.com/MDU-PHL/ngmaster. PMID:28348871

  13. Gene conversion variations generate structurally distinct pilin polypeptides in Neisseria gonorrhoeae.

    PubMed

    Swanson, J; Robbins, K; Barrera, O; Koomey, J M

    1987-04-01

    Pilus+ to pilus- phenotype change occurs in Neisseria gonorrhoeae through gene conversion of the gonococcus' complete, expressed pilin gene by nucleotides homologous to the pilS1 copy 5 partial pilin gene; assembly missense pilin is synthesized but pili are not. Reversion to pilus+ occurs by a subsequent recombinational event that replaces the complete pilin gene's pilS1 copy 5-like sequence with nucleotides from a different partial gene to effect expression of an orthodox (i.e., pilus producing) pilin. Sibling pilus+ revertants of common parentage can carry different sequences in their expressed pilin genes because they have undergone nonidentical gene conversion events such as recombinations with sequences from different partial genes, or recombinations with different length nucleotide stretches of the same partial gene; either can yield structurally and antigenically variant pilin polypeptides.

  14. Homologous prime-boost strategy in neonate mice using Neisseria lactamica.

    PubMed

    Ito, André Y; Néri, Simone; Machado, Marta S S; Tunes, Claudia F; De Gaspari, Elizabeth N

    2009-05-26

    The aim of the present study was to investigate the immune response to native outer membrane vesicles (NOMVs) of Neisseria lactamica with and without Bordetella pertussis (BP) as adjuvant in intranasal (i.n./i.m) immunization. N. lactamica NOMVs delivered intranasally (i.n) to BALB/c mice in a final volume of 5microl that was gradually introduced with a micropipette, Animals received 1, 2, 3, or 4 doses of antigens at 3, 7, 9 and 12 days after birth. On the 35th day, the animals were immunized intramuscularly (i.m.) with (NOMV) of N. lactamica. The prime-booster strategy using NOMV of N. lactamica with BP as adjuvant in the primer (i.n.) and booster (i.m.) is an effective immunization protocol for inducing humoral immune responses producing IgG antibodies of intermediate to high avidity.

  15. Identification of Novel Immunogenic Proteins of Neisseria gonorrhoeae by Phage Display

    PubMed Central

    Connor, Daniel O.; Zantow, Jonas; Hust, Michael; Bier, Frank F.; von Nickisch-Rosenegk, Markus

    2016-01-01

    Neisseria gonorrhoeae is one of the most prevalent sexually transmitted diseases worldwide with more than 100 million new infections per year. A lack of intense research over the last decades and increasing resistances to the recommended antibiotics call for a better understanding of gonococcal infection, fast diagnostics and therapeutic measures against N. gonorrhoeae. Therefore, the aim of this work was to identify novel immunogenic proteins as a first step to advance those unresolved problems. For the identification of immunogenic proteins, pHORF oligopeptide phage display libraries of the entire N. gonorrhoeae genome were constructed. Several immunogenic oligopeptides were identified using polyclonal rabbit antibodies against N. gonorrhoeae. Corresponding full-length proteins of the identified oligopeptides were expressed and their immunogenic character was verified by ELISA. The immunogenic character of six proteins was identified for the first time. Additional 13 proteins were verified as immunogenic proteins in N. gonorrhoeae. PMID:26859666

  16. Crystal structure of the open state of the Neisseria gonorrhoeae MtrE outer membrane channel.

    PubMed

    Lei, Hsiang-Ting; Chou, Tsung-Han; Su, Chih-Chia; Bolla, Jani Reddy; Kumar, Nitin; Radhakrishnan, Abhijith; Long, Feng; Delmar, Jared A; Do, Sylvia V; Rajashankar, Kanagalaghatta R; Shafer, William M; Yu, Edward W

    2014-01-01

    Active efflux of antimicrobial agents is one of the most important strategies used by bacteria to defend against antimicrobial factors present in their environment. Mediating many cases of antibiotic resistance are transmembrane efflux pumps, composed of one or more proteins. The Neisseria gonorrhoeae MtrCDE tripartite multidrug efflux pump, belonging to the hydrophobic and amphiphilic efflux resistance-nodulation-cell division (HAE-RND) family, spans both the inner and outer membranes of N. gonorrhoeae and confers resistance to a variety of antibiotics and toxic compounds. We here describe the crystal structure of N. gonorrhoeae MtrE, the outer membrane component of the MtrCDE tripartite multidrug efflux system. This trimeric MtrE channel forms a vertical tunnel extending down contiguously from the outer membrane surface to the periplasmic end, indicating that our structure of MtrE depicts an open conformational state of this channel.

  17. Role of transition metal exporters in virulence: the example of Neisseria meningitidis.

    PubMed

    Guilhen, Cyril; Taha, Muhamed-Kheir; Veyrier, Frédéric J

    2013-01-01

    Transition metals such as iron, manganese, and zinc are essential micronutrients for bacteria. However, at high concentration, they can generate non-functional proteins or toxic compounds. Metal metabolism is therefore regulated to prevent shortage or overload, both of which can impair cell survival. In addition, equilibrium among these metals has to be tightly controlled to avoid molecular replacement in the active site of enzymes. Bacteria must actively maintain intracellular metal concentrations to meet physiological needs within the context of the local environment. When intracellular buffering capacity is reached, they rely primarily on membrane-localized exporters to maintain metal homeostasis. Recently, several groups have characterized new export systems and emphasized their importance in the virulence of several pathogens. This article discusses the role of export systems as general virulence determinants. Furthermore, it highlights the contribution of these exporters in pathogens emergence with emphasis on the human nasopharyngeal colonizer Neisseria meningitidis.

  18. Neisseria meningitidis colonization of the brain endothelium and cerebrospinal fluid invasion.

    PubMed

    Miller, Florence; Lécuyer, Hervé; Join-Lambert, Olivier; Bourdoulous, Sandrine; Marullo, Stefano; Nassif, Xavier; Coureuil, Mathieu

    2013-04-01

    The brain and meningeal spaces are protected from bacterial invasion by the blood-brain barrier, formed by specialized endothelial cells and tight intercellular junctional complexes. However, once in the bloodstream, Neisseria meningitidis crosses this barrier in about 60% of the cases. This highlights the particular efficacy with which N. meningitidis targets the brain vascular cell wall. The first step of central nervous system invasion is the direct interaction between bacteria and endothelial cells. This step is mediated by the type IV pili, which induce a remodelling of the endothelial monolayer, leading to the opening of the intercellular space. In this review, strategies used by the bacteria to survive in the bloodstream, to colonize the brain vasculature and to cross the blood-brain barrier will be discussed.

  19. Use of restriction fragment length polymorphisms to investigate strain variation within Neisseria meningitidis

    SciTech Connect

    Williams, S.D.

    1989-01-01

    Similarity within bacterial populations is difficult to assess due to the limited number of characters available for evaluation and the heterogeneity of bacterial species. Currently, the preferred method used to evaluate the structure of bacterial populations is multilocus enzyme electrophoresis. However, this method is extremely cumbersome and only offers an indirect measure of genetic similarities. The development of a more direct and less cumbersome method for this purpose is warranted. Restriction fragment length polymorphism analysis was evaluated as a tool for use in the study of bacterial population structures and in the epidemiology and surveillance of infectious disease. A collection of Neisseria meningitidis was available for use in the investigation of this technique. Neisseria meningitidis is the causative agent of epidemic cerebrospinal meningitis and septicemia as well as a variety of other clinical manifestations. Each isolate in the collection was defined in terms of serogroup specificity, clinical history, geographic source, and date of isolation. Forty-six strains were chosen for this study. The DNA from each strain was restricted with Pst1 and EcoR1 and electrophoresed on agarose gels. The DNA was transferred to nylon filters and hybridized with P{sup 32} labeled DNA probes. Two randomly generated probes and a gene-specific probe were used to estimate the genetic similarities between and among the strains in the study population. A total of 28 different restriction fragment migration types were detected by the probes used. Data obtained from the RFLP analysis was analyzed by cluster analysis and multivariate statistical methods. A total of 7 clones groups were detected. Two of these appear to be major clones that comprise 35% of the population.

  20. Genetic Studies of Sulfadiazine-resistant and Methionine-requiring Neisseria Isolated From Clinical Material

    PubMed Central

    Catlin, B. Wesley

    1967-01-01

    Deoxyribonucleate (DNA) preparations were extracted from Neisseria meningitidis (four isolates from spinal fluid and blood) and N. gonorrhoeae strains, all of which were resistant to sulfadiazine upon primary isolation. These DNA preparations, together with others from in vitro mutants of N. meningitidis and N. perflava, were examined in transformation tests by using as recipient a drug-susceptible strain of N. meningitidis (Ne 15 Sul-s Met+) which was able to grow in a methionine-free defined medium. The sulfadiazine resistance typical of each donor was introduced into the uniform constitution of this recipient. Production of p-aminobenzoic acid was not significantly altered thereby. Transformants elicited by DNA from the N. meningitidis clinical isolates were resistant to at least 200 μg of sulfadiazine/ml, and did not show a requirement for methionine (Sul-r Met+). DNA from six strains of N. gonorrhoeae, which were isolated during the period of therapeutic use of sulfonamides, conveyed lower degrees of resistance and, invariably, a concurrent methionine requirement (Sul-r/Met−). The requirement of these transformants, and that of in vitro mutants selected on sulfadiazine-agar, was satisfied by methionine, but not by vitamin B12, homocysteine, cystathionine, homoserine, or cysteine. Sul-r Met+ and Sul-r/Met− loci could coexist in the same genome, but were segregated during transformation. On the other hand, the dual Sul-r/Met− properties were not separated by recombination, but were eliminated together. DNA from various Sul-r/Met− clones tested against recipients having nonidentical Sul-r/Met− mutant sites yielded Sul-s Met+ transformants. The met locus involved is genetically complex, and will be a valuable tool for studies of genetic fine structure of members of Neisseria, and of genetic homology between species. Images PMID:4962305

  1. The Pilin N-terminal Domain Maintains Neisseria gonorrhoeae Transformation Competence during Pilus Phase Variation

    PubMed Central

    2016-01-01

    The obligate human pathogen Neisseria gonorrhoeae is the sole aetiologic agent of the sexually transmitted infection, gonorrhea. Required for gonococcal infection, Type IV pili (Tfp) mediate many functions including adherence, twitching motility, defense against neutrophil killing, and natural transformation. Critical for immune escape, the gonococcal Tfp undergoes antigenic variation, a recombination event at the pilE locus that varies the surface exposed residues of the major pilus subunit PilE (pilin) in the pilus fiber. This programmed recombination system has the potential to produce thousands of pilin variants and can produce strains with unproductive pilin molecules that are completely unable to form Tfp. Saturating mutagenesis of the 3’ third of the pilE gene identified 68 unique single nucleotide mutations that each resulted in an underpiliated colony morphology. Notably, all isolates, including those with undetectable levels of pilin protein and no observable surface-exposed pili, retained an intermediate level of transformation competence not exhibited in ΔpilE strains. Site-directed, nonsense mutations revealed that only the first 38 amino acids of the mature pilin N-terminus (the N-terminal domain or Ntd) are required for transformation competence, and microscopy, ELISAs and pilus purification demonstrate that extended Tfp are not required for competence. Transformation in strains producing only the pilin Ntd has the same genetic determinants as wild-type transformation. The Ntd corresponds to the alternative product of S-pilin cleavage, a specific proteolysis unique to pathogenic Neisseria. Mutation of the S-pilin cleavage site demonstrated that S-pilin cleavage mediated release of the Ntd is required for competence when a strain produces unproductive pilin molecules that cannot assemble into a Tfp through mutation or antigenic variation. We conclude that S-pilin cleavage evolved as a mechanism to maintain competence in nonpiliated antigenic

  2. DNA uptake sequences in Neisseria gonorrhoeae as intrinsic transcriptional terminators and markers of horizontal gene transfer

    PubMed Central

    Gurung, Neesha

    2016-01-01

    DNA uptake sequences are widespread throughout the Neisseria gonorrhoeae genome. These short, conserved sequences facilitate the exchange of endogenous DNA between members of the genus Neisseria. Often the DNA uptake sequences are present as inverted repeats that are able to form hairpin structures. It has been suggested previously that DNA uptake sequence inverted repeats present 3′ of genes play a role in rho-independent termination and attenuation. However, there is conflicting experimental evidence to support this role. The aim of this study was to determine the role of DNA uptake sequences in transcriptional termination. Both bioinformatics predictions, conducted using TransTermHP, and experimental evidence, from RNA-seq data, were used to determine which inverted repeat DNA uptake sequences are transcriptional terminators and in which direction. Here we show that DNA uptake sequences in the inverted repeat configuration occur in N. gonorrhoeae both where the DNA uptake sequence precedes the inverted version of the sequence and also, albeit less frequently, in reverse order. Due to their symmetrical configuration, inverted repeat DNA uptake sequences can potentially act as bi-directional terminators, therefore affecting transcription on both DNA strands. This work also provides evidence that gaps in DNA uptake sequence density in the gonococcal genome coincide with areas of DNA that are foreign in origin, such as prophage. This study differentiates for the first time, to our knowledge, between DNA uptake sequences that form intrinsic transcriptional terminators and those that do not, providing characteristic features within the flanking inverted repeat that can be identified. PMID:28348864

  3. Identification of ZipA, a Signal Recognition Particle-Dependent Protein from Neisseria gonorrhoeae

    PubMed Central

    Du, Ying; Arvidson, Cindy Grove

    2003-01-01

    A genetic screen designed to identify proteins that utilize the signal recognition particle (SRP) for targeting in Escherichia coli was used to screen a Neisseria gonorrhoeae plasmid library. Six plasmids were identified in this screen, and each is predicted to encode one or more putative cytoplasmic membrane (CM) proteins. One of these, pSLO7, has three open reading frames (ORFs), two of which have no similarity to known proteins in GenBank other than sequences from the closely related N. meningitidis. Further analyses showed that one of these, SLO7ORF3, encodes a protein that is dependent on the SRP for localization. This gene also appears to be essential in N. gonorrhoeae since it was not possible to generate null mutations in the gene. Although appearing unique to Neisseria at the DNA sequence level, SLO7ORF3 was found to share some features with the cell division gene zipA of E. coli. These features included similar chromosomal locations (with respect to linked genes) as well as similarities in the predicted protein domain structures. Here, we show that SLO7ORF3 can complement an E. coli conditional zipA mutant and therefore encodes a functional ZipA homolog in N. gonorrhoeae. This observation is significant in that it is the first ZipA homolog identified in a non-rod-shaped organism. Also interesting is that this is the fourth cell division protein (the others are FtsE, FtsX, and FtsQ) shown to utilize the SRP for localization, which may in part explain why the genes encoding the three SRP components are essential in bacteria. PMID:12644481

  4. Attenuation of the Type IV Pilus Retraction Motor Influences Neisseria gonorrhoeae Social and Infection Behavior.

    PubMed

    Hockenberry, Alyson M; Hutchens, Danielle M; Agellon, Al; So, Magdalene

    2016-12-06

    Retraction of the type IV pilus (Tfp) mediates DNA uptake, motility, and social and infection behavior in a wide variety of prokaryotes. To date, investigations into Tfp retraction-dependent activities have used a mutant deleted of PilT, the ATPase motor protein that causes the pilus fiber to retract. ΔpilT cells are nontransformable, nonmotile, and cannot aggregate into microcolonies. We tested the hypothesis that these retraction-dependent activities are sensitive to the strength of PilT enzymatic activity by using the pathogen Neisseria gonorrhoeae as a model. We constructed an N. gonorrhoeae mutant with an amino acid substitution in the PilT Walker B box (a substitution of cysteine for leucine at position 201, encoded by pilTL201C). Purified PilTL201C forms a native hexamer, but mutant hexamers hydrolyze ATP at half the maximal rate. N. gonorrhoeae pilTL201C cells produce Tfp fibers, crawl at the same speed as the wild-type (wt) parent, and are equally transformable. However, the social behavior of pilTL201C cells is intermediate between the behaviors of wt and ΔpilT cells. The infection behavior of pilTL201C is also defective, due to its failure to activate the epidermal growth factor receptor (EGFR)-heparin-binding EGF-like growth factor (HB-EGF) pathway. Our study indicates that pilus retraction, per se, is not sufficient for N. gonorrhoeae microcolony formation or infectivity; rather, these activities are sensitive to the strength of PilT enzymatic activity. We discuss the implications of these findings for Neisseria pathogenesis in the context of mechanobiology.

  5. Attenuation of the Type IV Pilus Retraction Motor Influences Neisseria gonorrhoeae Social and Infection Behavior

    PubMed Central

    Hutchens, Danielle M.; Agellon, Al

    2016-01-01

    ABSTRACT Retraction of the type IV pilus (Tfp) mediates DNA uptake, motility, and social and infection behavior in a wide variety of prokaryotes. To date, investigations into Tfp retraction-dependent activities have used a mutant deleted of PilT, the ATPase motor protein that causes the pilus fiber to retract. ΔpilT cells are nontransformable, nonmotile, and cannot aggregate into microcolonies. We tested the hypothesis that these retraction-dependent activities are sensitive to the strength of PilT enzymatic activity by using the pathogen Neisseria gonorrhoeae as a model. We constructed an N. gonorrhoeae mutant with an amino acid substitution in the PilT Walker B box (a substitution of cysteine for leucine at position 201, encoded by pilTL201C). Purified PilTL201C forms a native hexamer, but mutant hexamers hydrolyze ATP at half the maximal rate. N. gonorrhoeae pilTL201C cells produce Tfp fibers, crawl at the same speed as the wild-type (wt) parent, and are equally transformable. However, the social behavior of pilTL201C cells is intermediate between the behaviors of wt and ΔpilT cells. The infection behavior of pilTL201C is also defective, due to its failure to activate the epidermal growth factor receptor (EGFR)-heparin-binding EGF-like growth factor (HB-EGF) pathway. Our study indicates that pilus retraction, per se, is not sufficient for N. gonorrhoeae microcolony formation or infectivity; rather, these activities are sensitive to the strength of PilT enzymatic activity. We discuss the implications of these findings for Neisseria pathogenesis in the context of mechanobiology. PMID:27923924

  6. Interspecies recombination between the penA genes of Neisseria meningitidis and commensal Neisseria species during the emergence of penicillin resistance in N. meningitidis: natural events and laboratory simulation.

    PubMed

    Bowler, L D; Zhang, Q Y; Riou, J Y; Spratt, B G

    1994-01-01

    The penicillin-binding protein 2 genes (penA) of penicillin-resistant Neisseria meningitidis have a mosaic structure that has arisen by the introduction of regions from the penA genes of Neisseria flavescens or Neisseria cinerea. Chromosomal DNA from both N. cinerea and N. flavescens could transform a penicillin-susceptible isolate of N. meningitidis to increased resistance to penicillin. With N. flavescens DNA, transformation to resistance was accompanied by the introduction of the N. flavescens penA gene, providing a laboratory demonstration of the interspecies recombinational events that we believe underlie the development of penicillin resistance in many meningococci in nature. Surprisingly, with N. cinerea DNA, the penicillin-resistant transformants did not obtain the N. cinerea penA gene. However, the region of the penA gene derived from N. cinerea in N. meningitidis K196 contained an extra codon (Asp-345A) which was not found in any of the four N. cinerea isolates that we examined and which is known to result in a decrease in the affinity of PBP 2 in gonococci.

  7. Whole-Genome Shotgun Sequencing of the First Observation of Neisseria meningitidis Sequence Type 6928 in India

    PubMed Central

    Neeravi, Ayyan Raj; Devanga Ragupathi, Naveen Kumar; Inbanathan, Francis Yesurajan; Pragasam, Agila Kumari; Verghese, Valsan Philip

    2016-01-01

    Neisseria meningitidis is one of the leading global causes of bacterial meningitis. Here, we discuss the draft genome sequences of two N. meningitidis strains, isolated from bloodstream infections in two pediatric patients at a tertiary care hospital in South India. The sequence data indicate that strains VB13856 and VB15548 encode genomes of ~2.09 Mb in size with no plasmids. PMID:27811110

  8. recA and catalase in H sub 2 O sub 2 -mediated toxicity in Neisseria gonorrhoeae

    SciTech Connect

    Hassett, D.J.; Charniga, L.; Cohen, M.S. )

    1990-12-01

    Neisseria gonorrhoeae cells defective in the biosynthesis of the recA gene product are no more sensitive to hydrogen peroxide than wild-type cells. Although gonococci possess nearly 100-fold-greater catalase levels than Escherichia coli, they are more susceptible to hydrogen peroxide than this organism. The natural niche of gonococci undoubtedly results in exposure to oxidant stress; however, they do not demonstrate particularly efficient antioxidant defense systems.

  9. Severe conjunctivitis due to multidrug-resistant Neisseria gonorrhoeae and adenovirus 53 coinfection in a traveler returning from Thailand.

    PubMed

    Tappe, Dennis; Mueller, Andreas; Weißbrich, Benedikt; Schubert, Jörg; Schargus, Marc; Stich, August

    2013-01-01

    A male traveler returning from Thailand with severe bilateral conjunctivitis was tested for causative pathogens by culture and polymerase chain reaction in late 2010. The culturally grown Neisseria gonorrhoeae strain was resistant against penicillin, ciprofloxacin, and tetracycline. The patient was also found to have an eye infection with the unusual and likely recombinant adenovirus type 53. Besides multidrug-resistant gonococcal strains the unusual adenovirus strain is found circulating in Asia and both pathogens may be a risk for travelers.

  10. Bacteraemic pneumonia caused by Neisseria lactamica with reduced susceptibility to penicillin and ciprofloxacin in an adult with liver cirrhosis.

    PubMed

    Wang, Cheng-Yi; Chuang, Yu-Min; Teng, Lee-Jene; Lee, Li-Na; Yang, Pan-Chyr; Kuo, Sow-Hsong; Hsueh, Po-Ren

    2006-08-01

    This report presents a case of bacteraemic pneumonia caused by Neisseria lactamica in an adult patient with liver cirrhosis who was successfully treated with ceftriaxone. The isolate was confirmed as N. lactamica by analysis of a partial sequence of the 16S rRNA gene; it had reduced susceptibilities to penicillin (MIC 0.75 microg ml(-1)) and ciprofloxacin (MIC > or =0.5 mg l(-1)).

  11. Insights into the Enhanced in vivo Fitness of Neisseria gonorrhoeae Driven by a Fluoroquinolone Resistance-Conferring Mutant DNA Gyrase

    DTIC Science & Technology

    2015-02-05

    Insights into the Enhanced in vivo Fitness of Neisseria gonorrhoeae Driven by a Fluoroquinolone Resistance-Conferring Mutant DNA Gyrase...gonorrhoeae Driven by a Fluoroquinolone Resistance-Conferring Mutant DNA Gyrase" Name of Candidate: MAJ Jonathan D’ Ambrozio Doctor of Philosophy Degree...gonorrhoeae Driven by a Fluoroquinolone Resistance-Conferring Mutant DNA Gyrase" is appropriately acknowledged and, bey9nd brief excerpts, is with

  12. Rapid carbohydrate fermentation test for confirmation of the pathogenic Neisseria using a Ba(OH)2 indicator.

    PubMed Central

    Slifkin, M; Pouchet, G R

    1977-01-01

    The Ba(OH)2 indicator system was demonstrated to be a practical procedure in assisting clinical bacteriologists in the accurate and rapid identification of the pathogenic Neisseria from clinical specimens. This system measured the release of CO2, resulting from the metabolism of fermentable carbohydrate, as the precipitated BaCO3, by means of a spectrophotometer, The method was uncomplicated and can be performed in most clinical bacteriology laboratories. PMID:319106

  13. Evaluation of AMPLICOR Neisseria gonorrhoeae PCR using cppB nested PCR and 16S rRNA PCR.

    PubMed

    Farrell, D J

    1999-02-01

    Certain strains of Neisseria subflava and Neisseria cinerea are known to produce false-positive results with the AMPLICOR Neisseria gonorrhoeae PCR (Roche Diagnostic Systems, Branchburg, N.J.). The analytical sensitivity and analytical specificity of three PCR tests were assessed with 3 geographically diverse N. gonorrhoeae strains and 30 non-N. gonorrhoeae Neisseria spp. The sensitivities of the in-house nested cppB gene and the 16S rRNA PCR methods were greater than that of the AMPLICOR N. gonorrhoeae PCR with purified DNA from all 3 N. gonorrhoeae strains. Six of 14 clinical strains of N. subflava (1 from a vaginal swab, 5 from respiratory sites) produced false-positive AMPLICOR N. gonorrhoeae PCR results and were negative by the two other PCR methods. When applied to 207 clinical specimens selected from a population with a high prevalence ( approximately 9%) of infection, the results for 15 of 96 (15.6%) AMPLICOR-positive specimens and 14 of 17 (82.3%) AMPLICOR-equivocal specimens were not confirmed by the more sensitive nested cppB PCR method. Only 2 of 94 (2.1%) of AMPLICOR N. gonorrhoeae PCR-negative specimens from the same population tested positive by the nested cppB method. These results suggest that for this population the AMPLICOR N. gonorrhoeae PCR test is suitable as a screening test only and all positive results should be confirmed by a PCR method that is more specific and at least as sensitive. This study also illustrates that caution should be used when introducing commercially available nucleic acid amplification-based diagnostic tests into the regimens of tests used for populations not previously tested with these products.

  14. Phase I Safety and Immunogenicity Study of a Candidate Meningococcal Disease Vaccine Based on Neisseria lactamica Outer Membrane Vesicles▿

    PubMed Central

    Gorringe, Andrew R.; Taylor, Stephen; Brookes, Charlotte; Matheson, Mary; Finney, Michelle; Kerr, Moyra; Hudson, Michael; Findlow, Jamie; Borrow, Ray; Andrews, Nick; Kafatos, George; Evans, Cariad M.; Read, Robert C.

    2009-01-01

    Natural immunity to meningococcal disease in young children is associated epidemiologically with carriage of commensal Neisseria species, including Neisseria lactamica. We have previously demonstrated that outer membrane vesicles (OMVs) from N. lactamica provide protection against lethal challenge in a mouse model of meningococcal septicemia. We evaluated the safety and immunogenicity of an N. lactamica OMV vaccine in a phase I placebo-controlled, double-blinded clinical trial. Ninety-seven healthy young adult male volunteers were randomized to receive three doses of either an OMV vaccine or an Alhydrogel control. Subsequently, some subjects who had received the OMV vaccine also received a fourth dose of OMV vaccine, 6 months after the third dose. Injection site reactions were more frequent in the OMV-receiving group, but all reactions were mild or moderate in intensity. The OMV vaccine was immunogenic, eliciting rises in titers of immunoglobulin G (IgG) against the vaccine OMVs, together with a significant booster response, as determined by an enzyme-linked immunosorbent assay. Additionally, the vaccine induced modest cross-reactive immunity to six diverse strains of serogroup B Neisseria meningitidis, including IgG against meningococcal OMVs, serum bactericidal antibodies, and opsonophagocytic activity. The percentages of subjects showing ≥4-fold rises in bactericidal antibody titer obtained were similar to those previously reported for the Norwegian meningococcal OMV vaccine against the same heterologous meningococcal strain panel. In conclusion, this N. lactamica OMV vaccine is safe and induces a weak but broad humoral immune response to N. meningitidis. PMID:19553555

  15. Phase I safety and immunogenicity study of a candidate meningococcal disease vaccine based on Neisseria lactamica outer membrane vesicles.

    PubMed

    Gorringe, Andrew R; Taylor, Stephen; Brookes, Charlotte; Matheson, Mary; Finney, Michelle; Kerr, Moyra; Hudson, Michael; Findlow, Jamie; Borrow, Ray; Andrews, Nick; Kafatos, George; Evans, Cariad M; Read, Robert C

    2009-08-01

    Natural immunity to meningococcal disease in young children is associated epidemiologically with carriage of commensal Neisseria species, including Neisseria lactamica. We have previously demonstrated that outer membrane vesicles (OMVs) from N. lactamica provide protection against lethal challenge in a mouse model of meningococcal septicemia. We evaluated the safety and immunogenicity of an N. lactamica OMV vaccine in a phase I placebo-controlled, double-blinded clinical trial. Ninety-seven healthy young adult male volunteers were randomized to receive three doses of either an OMV vaccine or an Alhydrogel control. Subsequently, some subjects who had received the OMV vaccine also received a fourth dose of OMV vaccine, 6 months after the third dose. Injection site reactions were more frequent in the OMV-receiving group, but all reactions were mild or moderate in intensity. The OMV vaccine was immunogenic, eliciting rises in titers of immunoglobulin G (IgG) against the vaccine OMVs, together with a significant booster response, as determined by an enzyme-linked immunosorbent assay. Additionally, the vaccine induced modest cross-reactive immunity to six diverse strains of serogroup B Neisseria meningitidis, including IgG against meningococcal OMVs, serum bactericidal antibodies, and opsonophagocytic activity. The percentages of subjects showing > or =4-fold rises in bactericidal antibody titer obtained were similar to those previously reported for the Norwegian meningococcal OMV vaccine against the same heterologous meningococcal strain panel. In conclusion, this N. lactamica OMV vaccine is safe and induces a weak but broad humoral immune response to N. meningitidis.

  16. A large genomic island allows Neisseria meningitidis to utilize propionic acid, with implications for colonization of the human nasopharynx.

    PubMed

    Catenazzi, Maria Chiara E; Jones, Helen; Wallace, Iain; Clifton, Jacqueline; Chong, James P J; Jackson, Matthew A; Macdonald, Sandy; Edwards, James; Moir, James W B

    2014-07-01

    Neisseria meningitidis is an important human pathogen that is capable of killing within hours of infection. Its normal habitat is the nasopharynx of adult humans. Here we identify a genomic island (the prp gene cluster) in N. meningitidis that enables this species to utilize propionic acid as a supplementary carbon source during growth, particularly under nutrient poor growth conditions. The prp gene cluster encodes enzymes for a methylcitrate cycle. Novel aspects of the methylcitrate cycle in N. meningitidis include a propionate kinase which was purified and characterized, and a putative propionate transporter. This genomic island is absent from the close relative of N. meningitidis, the commensal Neisseria lactamica, which chiefly colonizes infants not adults. We reason that the possession of the prp genes provides a metabolic advantage to N. meningitidis in the adult oral cavity, which is rich in propionic acid-generating bacteria. Data from classical microbiological and sequence-based microbiome studies provide several lines of supporting evidence that N. meningitidis colonization is correlated with propionic acid generating bacteria, with a strong correlation between prp-containing Neisseria and propionic acid generating bacteria from the genus Porphyromonas, and that this may explain adolescent/adult colonization by N. meningitidis.

  17. Novel Genes Related to Ceftriaxone Resistance Found among Ceftriaxone-Resistant Neisseria gonorrhoeae Strains Selected In Vitro

    PubMed Central

    Gong, Zijian; Liu, Min; Hua, Zhengshuang; Sun, Yayin; Xu, Qingfang; Xia, Yue; Zhao, Yue; Xie, Xiaoyuan

    2016-01-01

    The emergence of ceftriaxone-resistant Neisseria gonorrhoeae is currently a global public health concern. However, the mechanism of ceftriaxone resistance is not yet fully understood. To investigate the potential genes related to ceftriaxone resistance in Neisseria gonorrhoeae, we subcultured six gonococcal strains with increasing concentrations of ceftriaxone and isolated the strains that became resistant. After analyzing several frequently reported genes involved in ceftriaxone resistance, we found only a single mutation in penA (A501V). However, differential analysis of the genomes and transcriptomes between pre- and postselection strains revealed many other mutated genes as well as up- and downregulated genes. Transformation of the mutated penA gene into nonresistant strains increased the MIC between 2.0- and 5.3-fold, and transformation of mutated ftsX increased the MIC between 3.3- and 13.3-fold. Genes encoding the ABC transporters FarB, Tfq, Hfq, and ExbB were overexpressed, while pilM, pilN, and pilQ were downregulated. Furthermore, the resistant strain developed cross-resistance to penicillin and cefuroxime, had an increased biochemical metabolic rate, and presented fitness defects such as prolonged growth time and downregulated PilMNQ. In conclusion, antimicrobial pressure could result in the emergence of ceftriaxone resistance, and the evolution of resistance of Neisseria gonorrhoeae to ceftriaxone is a complicated process at both the pretranscriptional and posttranscriptional levels, involving several resistance mechanisms of increased efflux and decreased entry. PMID:26787702

  18. A genomic approach to bacterial taxonomy: an examination and proposed reclassification of species within the genus Neisseria

    PubMed Central

    Jolley, Keith A.; Earle, Sarah G.; Corton, Craig; Bentley, Stephen D.; Parkhill, Julian; Maiden, Martin C. J.

    2012-01-01

    In common with other bacterial taxa, members of the genus Neisseria are classified using a range of phenotypic and biochemical approaches, which are not entirely satisfactory in assigning isolates to species groups. Recently, there has been increasing interest in using nucleotide sequences for bacterial typing and taxonomy, but to date, no broadly accepted alternative to conventional methods is available. Here, the taxonomic relationships of 55 representative members of the genus Neisseria have been analysed using whole-genome sequence data. As genetic material belonging to the accessory genome is widely shared among different taxa but not present in all isolates, this analysis indexed nucleotide sequence variation within sets of genes, specifically protein-coding genes that were present and directly comparable in all isolates. Variation in these genes identified seven species groups, which were robust to the choice of genes and phylogenetic clustering methods used. The groupings were largely, but not completely, congruent with current species designations, with some minor changes in nomenclature and the reassignment of a few isolates necessary. In particular, these data showed that isolates classified as Neisseria polysaccharea are polyphyletic and probably include more than one taxonomically distinct organism. The seven groups could be reliably and rapidly generated with sequence variation within the 53 ribosomal protein subunit (rps) genes, further demonstrating that ribosomal multilocus sequence typing (rMLST) is a practicable and powerful means of characterizing bacteria at all levels, from domain to strain. PMID:22422752

  19. Amino Acid Substitutions in Mosaic Penicillin-Binding Protein 2 Associated with Reduced Susceptibility to Cefixime in Clinical Isolates of Neisseria gonorrhoeae▿

    PubMed Central

    Takahata, Sho; Senju, Nami; Osaki, Yumi; Yoshida, Takuji; Ida, Takashi

    2006-01-01

    The molecular mechanisms of reduced susceptibility to cefixime in clinical isolates of Neisseria gonorrhoeae, particularly amino acid substitutions in mosaic penicillin-binding protein 2 (PBP2), were examined. The complete sequence of ponA, penA, and por genes, encoding, respectively, PBP1, PBP2, and porin, were determined for 58 strains isolated in 2002 from Japan. Replacement of leucine 421 by proline in PBP1 and the mosaic-like structure of PBP2 were detected in 48 strains (82.8%) and 28 strains (48.3%), respectively. The presence of mosaic PBP2 was the main cause of the elevated cefixime MIC (4- to 64-fold). In order to identify the mutations responsible for the reduced susceptibility to cefixime in isolates with mosaic PBP2, penA genes with various mutations were transferred to a susceptible strain by genetic transformation. The susceptibility of partial recombinants and site-directed mutants revealed that the replacement of glycine 545 by serine (G545S) was the primary mutation, which led to a two- to fourfold increase in resistance to cephems. Replacement of isoleucine 312 by methionine (I312M) and valine 316 by threonine (V316T), in the presence of the G545S mutation, reduced susceptibility to cefixime, ceftibuten, and cefpodoxime by an additional fourfold. Therefore, three mutations (G545S, I312M, and V316T) in mosaic PBP2 were identified as the amino acid substitutions responsible for reduced susceptibility to cefixime in N. gonorrhoeae. PMID:16940068

  20. Mosaic-like structure of penicillin-binding protein 2 Gene (penA) in clinical isolates of Neisseria gonorrhoeae with reduced susceptibility to cefixime.

    PubMed

    Ameyama, Satoshi; Onodera, Shoichi; Takahata, Masahiro; Minami, Shinzaburo; Maki, Nobuko; Endo, Katsuhisa; Goto, Hirokazu; Suzuki, Hiroo; Oishi, Yukihiko

    2002-12-01

    Neisseria gonorrhoeae strains with reduced susceptibility to cefixime (MICs, 0.25 to 0.5 micro g/ml) were isolated from male urethritis patients in Tokyo, Japan, in 2000 and 2001. The resistance to cephems including cefixime and penicillin was transferred to a susceptible recipient, N. gonorrhoeae ATCC 19424, by transformation of the penicillin-binding protein 2 gene (penA) that had been amplified by PCR from a strain with reduced susceptibility to cefixime (MIC, 0.5 micro g/ml). The sequences of penA in the strains with reduced susceptibilities to cefixime were different from those of other susceptible isolates and did not correspond to the reported N. gonorrhoeae penA gene sequences. Some regions in the transpeptidase-encoding domain in this penA gene were similar to those in the penA genes of Neisseria perflava (N. sicca), Neisseria cinerea, Neisseria flavescens, and Neisseria meningitidis. These results showed that a mosaic-like structure in the penA gene conferred reductions in the levels of susceptibility of N. gonorrhoeae to cephems and penicillin in a manner similar to that found for N. meningitidis and Streptococcus pneumoniae.

  1. Isolation of Neisseria gonorrhoeae mutants that show enhanced trafficking across polarized T84 epithelial monolayers.

    PubMed

    Hopper, S; Wilbur, J S; Vasquez, B L; Larson, J; Clary, S; Mehr, I J; Seifert, H S; So, M

    2000-02-01

    Initiation of a gonococcal infection involves attachment of Neisseria gonorrhoeae to the plasma membrane of an epithelial cell in the mucosal epithelium and its internalization, transepithelial trafficking, and exocytosis from the basal membrane. Piliation and expression of certain Opa proteins and the immunoglobulin A1 protease influence the transcytosis process. We are interested in identifying other genetic determinants of N. gonorrhoeae that play a role in transcellular trafficking. Using polarized T84 monolayers as a model epithelial barrier, we have assayed an N. gonorrhoeae FA1090 minitransposon (mTn) mutant bank for isolates that traverse the monolayer more quickly than the isogenic wild-type (WT) strain. From an initial screen, we isolated four mutants, defining three genetic loci, that traverse monolayers significantly more quickly than their WT parent strain. These mutants adhere to and invade cells normally and do not affect the integrity of the monolayer barrier. Backcrosses of the mutations into the WT FA1090 strain yielded mutants with a similar fast-trafficking phenotype. In two mutants, the mTns had inserted 370 bp apart into the same locus, which we have named fit, for fast intracellular trafficker. Backcrosses of one of these mutants into the MS11A genetic background also yielded a fast-trafficking mutant. The fit locus contains two overlapping open reading frames, fitA and fitB, whose deduced amino acid sequences have predicted molecular weights of 8.6 and 15.3, respectively. Neither protein contains a signal sequence. FitA has a potential helix-turn-helix motif, while the deduced sequence of FitB offers no clues to its function. fitA or fitB homologues are present in the genomes of Pseudomonas syringae and Rhizobium meliloti, but not Neisseria meningitidis. Replication of the MS11A fitA mutant in A431 and T84 cells is significantly accelerated compared to that of the isogenic WT strain. In contrast, growth of this mutant in liquid media is

  2. Recommendations for the Laboratory-Based Detection of Chlamydia trachomatis and Neisseria gonorrhoeae — 2014

    PubMed Central

    Papp, John R.; Schachter, Julius; Gaydos, Charlotte A.; Van Der Pol, Barbara

    2014-01-01

    Summary This report updates CDC's 2002 recommendations regarding screening tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections (CDC. Screening tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections—2002. MMWR 2002;51[No. RR-15]) and provides new recommendations regarding optimal specimen types, the use of tests to detect rectal and oropharyngeal C. trachomatis and N. gonorrhoeae infections, and circumstances when supplemental testing is indicated. The recommendations in this report are intended for use by clinical laboratory directors, laboratory staff, clinicians, and disease control personnel who must choose among the multiple available tests, establish standard operating procedures for collecting and processing specimens, interpret test results for laboratory reporting, and counsel and treat patients. The performance of nucleic acid amplification tests (NAATs) with respect to overall sensitivity, specificity, and ease of specimen transport is better than that of any of the other tests available for the diagnosis of chlamydial and gonococcal infections. Laboratories should use NAATs to detect chlamydia and gonorrhea except in cases of child sexual assault involving boys and rectal and oropharyngeal infections in prepubescent girls and when evaluating a potential gonorrhea treatment failure, in which case culture and susceptibility testing might be required. NAATs that have been cleared by the Food and Drug Administration (FDA) for the detection of C. trachomatis and N. gonorrhoeae infections are recommended as screening or diagnostic tests because they have been evaluated in patients with and without symptoms. Maintaining the capability to culture for both N. gonorrhoeae and C. trachomatis in laboratories throughout the country is important because data are insufficient to recommend nonculture tests in cases of sexual assault in prepubescent boys and extragenital anatomic site exposure in prepubescent girls. N

  3. CD66-mediated phagocytosis of Opa52 Neisseria gonorrhoeae requires a Src-like tyrosine kinase- and Rac1-dependent signalling pathway.

    PubMed

    Hauck, C R; Meyer, T F; Lang, F; Gulbins, E

    1998-01-15

    The interaction of Neisseria gonorrhoeae with human phagocytes is a hallmark of gonococcal infections. Recently, CD66 molecules have been characterized as receptors for Opa52-expressing gonococci on human neutrophils. Here we show that Opa52-expressing gonococci or Escherichia coli or F(ab) fragments directed against CD66, respectively, activate a signalling cascade from CD66 via Src-like protein tyrosine kinases, Rac1 and PAK to Jun-N-terminal kinase. The induced signal is distinct from Fcgamma-receptor-mediated signalling and is specific for Opa52, since piliated Opa- gonococci, commensal Neisseria cinerea or E.coli do not stimulate this signalling pathway. Inhibition of Src-like kinases or Rac1 prevents the uptake of Opa52 bacteria, demonstrating the crucial role of this signalling cascade for the opsonin-independent, Opa52/CD66-mediated phagocytosis of pathogenic Neisseria.

  4. A Systematic Review of Point of Care Testing for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis

    PubMed Central

    Herbst de Cortina, Sasha; Bristow, Claire C.; Joseph Davey, Dvora; Klausner, Jeffrey D.

    2016-01-01

    Objectives. Systematic review of point of care (POC) diagnostic tests for sexually transmitted infections: Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV). Methods. Literature search on PubMed for articles from January 2010 to August 2015, including original research in English on POC diagnostics for sexually transmitted CT, NG, and/or TV. Results. We identified 33 publications with original research on POC diagnostics for CT, NG, and/or TV. Thirteen articles evaluated test performance, yielding at least one test for each infection with sensitivity and specificity ≥90%. Each infection also had currently available tests with sensitivities <60%. Three articles analyzed cost effectiveness, and five publications discussed acceptability and feasibility. POC testing was acceptable to both providers and patients and was also demonstrated to be cost effective. Fourteen proof of concept articles introduced new tests. Conclusions. Highly sensitive and specific POC tests are available for CT, NG, and TV, but improvement is possible. Future research should focus on acceptability, feasibility, and cost of POC testing. While pregnant women specifically have not been studied, the results available in nonpregnant populations are encouraging for the ability to test and treat women in antenatal care to prevent adverse pregnancy and neonatal outcomes. PMID:27313440

  5. Antimicrobial Resistance in Neisseria gonorrhoeae in the 21st Century: Past, Evolution, and Future

    PubMed Central

    Unemo, Magnus

    2014-01-01

    SUMMARY Neisseria gonorrhoeae is evolving into a superbug with resistance to previously and currently recommended antimicrobials for treatment of gonorrhea, which is a major public health concern globally. Given the global nature of gonorrhea, the high rate of usage of antimicrobials, suboptimal control and monitoring of antimicrobial resistance (AMR) and treatment failures, slow update of treatment guidelines in most geographical settings, and the extraordinary capacity of the gonococci to develop and retain AMR, it is likely that the global problem of gonococcal AMR will worsen in the foreseeable future and that the severe complications of gonorrhea will emerge as a silent epidemic. By understanding the evolution, emergence, and spread of AMR in N. gonorrhoeae, including its molecular and phenotypic mechanisms, resistance to antimicrobials used clinically can be anticipated, future methods for genetic testing for AMR might permit region-specific and tailor-made antimicrobial therapy, and the design of novel antimicrobials to circumvent the resistance problems can be undertaken more rationally. This review focuses on the history and evolution of gonorrhea treatment regimens and emerging resistance to them, on genetic and phenotypic determinants of gonococcal resistance to previously and currently recommended antimicrobials, including biological costs or benefits; and on crucial actions and future advances necessary to detect and treat resistant gonococcal strains and, ultimately, retain gonorrhea as a treatable infection. PMID:24982323

  6. Conservation of peptide structure of outer membrane protein-macromolecular complex from Neisseria gonorrhoeae.

    PubMed Central

    Hansen, M V; Wilde, C E

    1984-01-01

    The structural conservation of an outer membrane protein of Neisseria gonorrhoeae called OMP-MC (outer membrane protein-macromolecular complex) was investigated by determining the isoelectric point and amino-terminal amino acid sequence of the protein and by using high-performance liquid chromatography for comparative tryptic peptide mapping. The 76,000-dalton subunits generated by reduction and alkylation of the native 800,000-dalton complex from six test strains focused in ultrathin gels as bands of restricted heterogeneity at an approximate pI of 7.6. Dansyl chloride labeling indicated that all strains shared glycine as the amino-terminal amino acid. Sequence analysis of OMP-MC from two strains revealed no amino acid differences within the first 11 residues. Dual-label peptide maps revealed an extremely high degree of conservation of peptide structure. The results indicate that (i) OMP-MCs isolated from various strains of N. gonorrhoeae share structural homology and (ii) the 800,000-dalton complex is a homopolymer composed of 10 to 12 apparently identical 76,000-dalton subunits. Images PMID:6421738

  7. [Standardization of the Neisseria meningitidis antibiogram. Detection of strains relatively resistant to penicillin].

    PubMed

    Nicolas, P; Cavallo, J D; Fabre, R; Martet, G

    1998-01-01

    Studying the susceptibility of 189 Neisseria meningitidis strains to penicillin, amoxicillin, cefotaxime, ceftriaxone, chloramphenicol and rifampicin by determination of minimum inhibitory concentrations (MICs) by agar dilution (reference method), E-test and disc diffusion method on Mueller-Hinton agar at 37 degrees C with 5% CO2 enabled us to standardize the antibiograms. While MIC determination by agar dilution is still the reference method, it is possible to obtain exact or approximate MIC values using the E-test. For laboratories that cannot determine penicillin MICs, it is impossible to detect strains that are relatively resistant to penicillin (RRP strains: 0.1 < or = MIC < or = 1 mg/l) using a 10-U penicillin disc. A 1 microgram-oxacillin disc allows MIC to be determined in most cases when the oxacillin inhibition zone is < or = 10 mm. Such strains must be sent to a reference laboratory for exact MIC determination. Based on our results and literature data on pharmacokinetics, we propose critical concentrations for these various antibiotics as well as critical diameters for chloramphenicol and rifampicin discs.

  8. In-vitro activity of 21 antimicrobial agents against Neisseria gonorrhoeae in Brussels.

    PubMed

    Gordts, B; Vanhoof, R; Hubrechts, J M; Dierickx, R; Coignau, H; Butzler, J P

    1982-02-01

    The minimum inhibitory concentrations (MIC) of 21 antimicrobial agents was measured for 80 strains of Neisseria gonorrhoeae isolated in Brussels in 1978. Bimodal distributions were found for penicillin G, ampicillin, amoxycillin, carbenicillin, and cephalexin. Of the strains, 17.5% were relatively resistant to penicillin G (MIC greater than 0.08 microgram/ml) 27.5% to ampicillin (MIC greater than 0.16 microgram/ml), 23.8% to amoxycillin, and 43.3% to carbenicillin. Cefotaxime was the most active antibiotic, with MICs in the nanogram range; 3.8% and 5% of the strains were relatively resistant to cephaloridine and cephalexin respectively, but no strains were resistant to cefazolin, cefuroxime, or cefotaxime. Resistance to tetracycline, doxycycline, minocycline, erythromycin, and spiramycin (MIC greater than 1 microgram/ml) was found in 6.3%, 2.5%, 5%, and 51.3% of the strains respectively. A very good correlation was present between chloramphenicol and thiamphenicol, with 16.3% and 10% of relatively resistant strains respectively. Only two isolates showed an MIC greater than 1.25 microgram/ml for rifampicin, and 10% of the strains needed greater than or equal to 12 microgram/ml of spectinomycin for complete inhibition of growth. A very high energy was found for the 20 : 1 combination of sulphamethoxazole and trimethoprim, with only one isolate resistant to this combination. None of the strains tested produced beta-lactamase.

  9. Metronidazole and spiramycin therapy of mixed Bacteroides spp. and Neisseria gonorrhoeae infection in mice.

    PubMed

    Brook, I

    1989-01-01

    The in vitro and in vivo activity of metronidazole and spiramycin, used singly or in combination, was tested in the eradication of infection caused by Bacteroides spp. and Neisseria gonorrhoeae alone or in combination. The in vitro tests consisted of determinations of the minimal inhibitory concentrations (MIC), carried out with or without the addition of a constant amount of the other antimicrobials. The MIC of both Bacteroides bivius and Bacteroides fragilis for metronidazole were significantly reduced by the addition of spiramycin (from 0.5 to 0.125 micrograms/ml). The in vivo tests were carried out in mice and consisted of measurements of the effects of the antimicrobial agents on the bacterial contents of abscesses induced by subcutaneous injection of bacterial suspension. Synergism between metronidazole and spiramycin was noted against Bacteroides spp. in abscesses caused by either Bacteroides spp. alone, or in combination with N. gonorrhoeae. Furthermore, an additional reduction in the number of N gonorrhoeae was noted in mixed infection with Bacteroides that was treated with metronidazole alone. This study demonstrates the in vitro and in vivo efficacy of the combination of metronidazole and spiramycin in the treatment of infections caused by either Bacteroides spp. alone or in combination with N. gonorrhoeae.

  10. Broad spectrum O-linked protein glycosylation in the human pathogen Neisseria gonorrhoeae

    PubMed Central

    Vik, Åshild; Aas, Finn Erik; Anonsen, Jan Haug; Bilsborough, Shaun; Schneider, Andrea; Egge-Jacobsen, Wolfgang; Koomey, Michael

    2009-01-01

    Protein glycosylation is an important element of biologic systems because of its significant effects on protein properties and functions. Although prominent within all domains of life, O-linked glycosylation systems modifying serine and threonine residues within bacteria and eukaryotes differ substantially in target protein selectivity. In particular, well-characterized bacterial systems have been invariably dedicated to modification of individual proteins or related subsets thereof. Here we characterize a general O-linked glycosylation system that targets structurally and functionally diverse groups of membrane-associated proteins in the Gram-negative bacterium Neisseria gonorrhoeae, the etiologic agent of the human disease gonorrhea. The 11 glycoproteins identified here are implicated in activities as varied as protein folding, disulfide bond formation, and solute uptake, as well as both aerobic and anaerobic respiration. Along with their common trafficking within the periplasmic compartment, the protein substrates share quasi-related domains bearing signatures of low complexity that were demonstrated to encompass sites of glycan occupancy. Thus, as in eukaryotes, the broad scope of this system is dictated by the relaxed specificity of the glycan transferase as well as the bulk properties and context of the protein-targeting signal rather than by a strict amino acid consensus sequence. Together, these findings reveal previously unrecognized commonalities linking O-linked protein glycosylation in distantly related life forms. PMID:19251655

  11. Functional analysis of NsrR, a nitric oxide sensing Rrf2 repressor in Neisseria gonorrhoeae

    PubMed Central

    Isabella, Vincent M.; Lapek, John D.; Kennedy, Edward M.; Clark, Virginia L.

    2008-01-01

    Nitric oxide has been shown to be an important component of the human immune response, and as such, it is important to understand how pathogenic organisms respond to its presence. In Neisseria gonorrhoeae, recent work has revealed that NsrR, an Rrf2-type transcriptional repressor, can sense NO and control the expression of genes responsible for NO metabolism. A highly pure extract of epitope tagged NsrR was isolated and mass spectroscopic analysis suggested that the protein contained a [2Fe-2S] cluster. NsrR/DNA interactions were thoroughly analyzed in vitro. Using EMSA analysis, NsrR::FLAG was shown to interact with predicted operators in the norB, aniA, and nsrR upstream regions with a Kd of 7 nM, 19 nM, and 35 nM respectively. DNase I footprint analysis was performed on the upstream regions of norB and nsrR, where NsrR was shown to protect the predicted 29 bp binding sites. The presence of exogenously added NO inhibited DNA binding by NsrR. Alanine substitution of C90, C97, or C103 in NsrR abrogated repression of norB::lacZ and inhibited DNA binding, consistent with their presumed role in coordination of a NO-sensitive Fe-S center required for DNA binding. PMID:19007408

  12. The Neisseria meningitidis CRISPR-Cas9 System Enables Specific Genome Editing in Mammalian Cells

    PubMed Central

    Lee, Ciaran M; Cradick, Thomas J; Bao, Gang

    2016-01-01

    The clustered regularly-interspaced short palindromic repeats (CRISPR)—CRISPR-associated (Cas) system from Streptococcus pyogenes (Spy) has been successfully adapted for RNA-guided genome editing in a wide range of organisms. However, numerous reports have indicated that Spy CRISPR-Cas9 systems may have significant off-target cleavage of genomic DNA sequences differing from the intended on-target site. Here, we report the performance of the Neisseria meningitidis (Nme) CRISPR-Cas9 system that requires a longer protospacer-adjacent motif for site-specific cleavage, and present a comparison between the Spy and Nme CRISPR-Cas9 systems targeting the same protospacer sequence. The results with the native crRNA and tracrRNA as well as a chimeric single guide RNA for the Nme CRISPR-Cas9 system were also compared. Our results suggest that, compared with the Spy system, the Nme CRISPR-Cas9 system has similar or lower on-target cleavage activity but a reduced overall off-target effect on a genomic level when sites containing three or fewer mismatches are considered. Thus, the Nme CRISPR-Cas9 system may represent a safer alternative for precision genome engineering applications. PMID:26782639

  13. Relative penicillin G resistance in Neisseria meningitidis and reduced affinity of penicillin-binding protein 3.

    PubMed Central

    Mendelman, P M; Campos, J; Chaffin, D O; Serfass, D A; Smith, A L; Sáez-Nieto, J A

    1988-01-01

    We examined clinical isolates of Neisseria meningitidis relatively resistant to penicillin G (mean MIC, 0.3 micrograms/ml; range, 0.1 to 0.7 micrograms/ml), which were isolated from blood and cerebrospinal fluid for resistance mechanisms, by using susceptible isolates (mean MIC, less than or equal to 0.06 micrograms/ml) for comparison. The resistant strains did not produce detectable beta-lactamase activity, otherwise modify penicillin G, or bind less total penicillin. Penicillin-binding protein (PBP) 3 of the six resistant isolates tested uniformly bound less penicillin G in comparison to the same PBP of four susceptible isolates. Reflecting the reduced binding affinity of PBP 3 of the two resistant strains tested, the amount of 3H-labeled penicillin G required for half-maximal binding was increased in comparison with that of PBP 3 of the two susceptible isolates. We conclude that the mechanism of resistance in these meningococci relatively resistant to penicillin G was decreased affinity of PBP 3. Images PMID:3134848

  14. Protocol for the molecular detection of antibiotic resistance mechanisms in Neisseria gonorrhoeae.

    PubMed

    Goire, Namraj; Sloots, Theo P; Nissen, Michael D; Whiley, David M

    2012-01-01

    Gonorrhoea is no longer an easily treatable ailment but rather is now a challenging disease in terms of antimicrobial resistance (AMR) with treatment options rapidly diminishing. The causative agent of gonorrhoea, Neisseria gonorrhoeae, has managed to develop resistance to almost every single drug used against it with the sole exception of extended spectrum cephalosporins. The situation is further exacerbated by the fact that not only are the rates of gonococcal infections on a steady rise globally, but tracking AMR is being undermined by the growing popularity of molecular methods at the expense of traditional bacterial culture in diagnostic laboratories. Recently, concerns have been raised over the emergence of a multi-resistant gonococci and the potential for untreatable gonorrhoea. Maintaining optimal epidemiological surveillance of gonococcal AMR remains an important aspect of gonorrhoea control. The development of molecular tools for tracking AMR in N. gonorrhoeae has the potential to further enhance such surveillance. In this chapter, we discuss nucleic acid amplification-based detection of AMR in gonorrhoea with a particular emphasis on chromosomal-mediated resistance to beta-lactam antibiotics.

  15. Chlamydia trachomatis and Neisseria gonorrhoeae Infections Among Men and Women Entering California Prisons

    PubMed Central

    Bernstein, Kyle T.; Chow, Joan M.; Ruiz, Juan; Schachter, Julius; Horowitz, Evalyn; Bunnell, Rebecca; Bolan, Gail

    2006-01-01

    Objective. We estimated the prevalence of Chlamydia trachomatis and Neisseria gonorrhoeae infection among newly arriving inmates at 6 California prisons. Methods. In this cross-sectional study in 1999, urine specimens collected from 698 men aged 18 to 25 years and 572 women aged 18 years or older were tested at intake for C trachomatis and N gonorrhoeae using ligase chain reaction. An analysis of demographic and arrest-related correlates of C trachomatis and N gonorrhoeae infection was performed. Results. The overall C trachomatis prevalence was 9.9% (95% CI=7.8%, 12.3%) among men aged 18 to 25 years, 8.9% (95% CI = 2.9%, 22.1%) among women aged 18 to 25 years, and 3.3% (95% CI=2.0%, 5.1%) among women overall. Three N gonorrhoeae cases were detected with an overall prevalence of 0.24% (95% CI=0.05%, 0.69%). Conclusions. The prevalence of C trachomatis infection at entry to California prisons, especially among young female and male inmates, was high, which supports routine screening at entry into prison. In addition, screening in a jail setting where most detainees are incarcerated before entry into the prison setting may provide an excellent earlier opportunity to identify these infections and treat disease to prevent complications and burden of infection in this high-risk population. PMID:17008584

  16. Secretory Leukocyte Protease Inhibitor Binds to Neisseria gonorrhoeae Outer Membrane Opacity Protein and is Bactericidal

    PubMed Central

    Cooper, Morris D.; Roberts, Melissa H.; Barauskas, Ona L.; Jarvis, Gary A.

    2012-01-01

    Problem Secretory leukocyte protease inhibitor (SLPI) is an innate immune peptide present on the genitourinary tract mucosa which has antimicrobial activity. In this study, we investigated the interaction of SLPI with Neisseria gonorrhoeae. Method of study ELISA and far-western blots were used to analyze binding of SLPI to gonococci. The binding site for SLPI was identified by tryptic digests and mass spectrometry. Antimicrobial activity of SLPI for gonococci was determined using bactericidal assays. SLPI protein levels in cell supernatants were measured by ELISA, and SLPI mRNA levels were assessed by quantitative RT-PCR. Results SLPI bound directly to the gonococcal Opa protein and was bactericidal. Epithelial cells from the reproductive tract constitutively expressed SLPI at different levels. Gonococcal infection of cells did not affect SLPI expression. Conclusion We conclude that SLPI is bactericidal for gonococci and is expressed by reproductive tract epithelial cells and thus is likely to play a role in the pathogenesis of gonococcal infection. PMID:22537232

  17. Homologous recombination drives both sequence diversity and gene content variation in Neisseria meningitidis.

    PubMed

    Kong, Ying; Ma, Jennifer H; Warren, Keisha; Tsang, Raymond S W; Low, Donald E; Jamieson, Frances B; Alexander, David C; Hao, Weilong

    2013-01-01

    The study of genetic and phenotypic variation is fundamental for understanding the dynamics of bacterial genome evolution and untangling the evolution and epidemiology of bacterial pathogens. Neisseria meningitidis (Nm) is among the most intriguing bacterial pathogens in genomic studies due to its dynamic population structure and complex forms of pathogenicity. Extensive genomic variation within identical clonal complexes (CCs) in Nm has been recently reported and suggested to be the result of homologous recombination, but the extent to which recombination contributes to genomic variation within identical CCs has remained unclear. In this study, we sequenced two Nm strains of identical serogroup (C) and multi-locus sequence type (ST60), and conducted a systematic analysis with an additional 34 Nm genomes. Our results revealed that all gene content variation between the two ST60 genomes was introduced by homologous recombination at the conserved flanking genes, and 94.25% or more of sequence divergence was caused by homologous recombination. Recombination was found in genes associated with virulence factors, antigenic outer membrane proteins, and vaccine targets, suggesting an important role of homologous recombination in rapidly altering the pathogenicity and antigenicity of Nm. Recombination was also evident in genes of the restriction and modification systems, which may undermine barriers to DNA exchange. In conclusion, homologous recombination can drive both gene content variation and sequence divergence in Nm. These findings shed new light on the understanding of the rapid pathoadaptive evolution of Nm and other recombinogenic bacterial pathogens.

  18. Molecular and phenotypic characterization of penicillinase-producing Neisseria gonorrhoeae from Canadian sources.

    PubMed Central

    Dillon, J R; Duck, P; Thomas, D Y

    1981-01-01

    The incidence of penicillinase-producing Neisseria gonorrhoeae (PPNG) infections has increased in Canada during the past 2 years. Most of these cases were imported from abroad. The PPNG strains from these cases were characterized with respect to susceptibility to 11 antibiotics, auxotype, and plasmid content. Rosaramicin and cefuroxime proved to be the most potent of the antibiotics tested. The molecular characterization of the isolates indicated that all carried a 2.6-megadalton cryptic plasmid. Most of the PPNG isolates (87%) harbored a 4.5-megadalton penicillinase-producing plasmid, whereas only 13% harbored the 3.2-megadalton penicillinase-producing plasmid. In those cases where contact tracing was possible, the correlation linking strains of Far Eastern etiology with carriage of the 4.5-megadalton plasmid was upheld. The penicillinase-producing strains were typed auxanographically in either the proline-requiring (57%) or prototrophic groups (42%). Substrate hydrolysis profiles and analytical isoelectric focusing of crude beta-lactamase extracts of several isolates has reconfirmed that these strains elaborate a type TEM-1 enzyme. Several of the penicillinase-producing plasmids were also examined for plasmid stability. PMID:6791587

  19. Preformulation study of the vaccine candidate P64k against Neisseria meningitidis.

    PubMed

    Expósito Raya, N; Mestre Luaces, M; Silva Rodriguez, R; Nazábal Gálvez, C; Peña Rivero, M; Martínez de la Puente, N; Font Batista, M; Guillén Nieto, G

    1999-04-01

    We have previously isolated, cloned and expressed in Escherichia coli the lpdA gene coding for a high-molecular-mass protein (P64k) common to many meningococcal strains. P64k is an outer membrane lipoamide dehydrogenase that is highly immunogenic in animals. Here we describe a preformulation study of the recombinant protein as a vaccine candidate against Neisseria meningitidis, in which six variants containing the candidate were tested. Three assays were used to identify the most suitable variant for further evaluation: percentage of adsorption, identification of P64k by SDS/PAGE, and immunogenicity in mice. All the preformulation variants studied showed more than 98% of adsorption of P64k on the aluminium gel. After desorption, P64k was also identified by SDS/PAGE in the six preformulation variants. Seroconversion was attained in all groups analysed. On the basis of these results, the most effective variant consisted of 20 microg/ml P64k plus 0.5 mg/ml aluminium hydroxide.

  20. Anaerobiosis increases resistance of Neisseria gonorrhoeae to O2-independent antimicrobial proteins from human polymorphonuclear granulocytes.

    PubMed Central

    Casey, S G; Shafer, W M; Spitznagel, J K

    1985-01-01

    We investigated the in vitro resistance of Neisseria gonorrhoeae FA19 to the O2-independent antimicrobial systems of human polymorphonuclear leukocytes. Acid extracts of polymorphonuclear leukocyte granules (crude granule extracts) and a purified granule protein (57 kilodaltons) were, at low concentrations, bactericidal for gonococci under aerobic conditions that permitted growth. However, they were less effective under anaerobic conditions that imposed bacteriostasis. We found that adding sodium nitrite to reduced growth media permitted the growth of strain FA19 in an anaerobic environment. Under these conditions with nitrite, anaerobic cultures of strain FA19 were no more resistant to the crude granule extract and the 57-kilodalton protein than aerobic cultures. In contrast, Salmonella typhimurium SL-1004, a facultative anaerobe, was readily killed by both the crude granule extract and the 57-kilodalton antimicrobial protein regardless of the presence or absence of free molecular oxygen. This is the first demonstration that an isolated antimicrobial protein from polymorphonuclear leukocyte granules is active against bacteria under anaerobic conditions. Our results also indicated that the efficacy of human polymorphonuclear leukocyte O2-independent killing of N. gonorrhoeae may, in part, be inhibited by bacteriostatic conditions imposed by hypoxia. Images PMID:3917976

  1. Fur-mediated activation of gene transcription in the human pathogen Neisseria gonorrhoeae.

    PubMed

    Yu, Chunxiao; Genco, Caroline Attardo

    2012-04-01

    It is well established that the ferric uptake regulatory protein (Fur) functions as a transcriptional repressor in diverse microorganisms. Recent studies demonstrated that Fur also functions as a transcriptional activator. In this study we defined Fur-mediated activation of gene transcription in the sexually transmitted disease pathogen Neisseria gonorrhoeae. Analysis of 37 genes which were previously determined to be iron induced and which contained putative Fur boxes revealed that only 30 of these genes exhibited reduced transcription in a gonococcal fur mutant strain. Fur-mediated activation was established by examining binding of Fur to the putative promoter regions of 16 Fur-activated genes with variable binding affinities observed. Only ∼50% of the newly identified Fur-regulated genes bound Fur in vitro, suggesting that additional regulatory circuits exist which may function through a Fur-mediated indirect mechanism. The gonococcal Fur-activated genes displayed variable transcription patterns in a fur mutant strain, which correlated with the position of the Fur box in each (promoter) region. These results suggest that Fur-mediated direct transcriptional activation is fulfilled by multiple mechanisms involving either competing with a repressor or recruiting RNA polymerase. Collectively, our studies have established that gonococcal Fur functions as an activator of gene transcription through both direct and indirect mechanisms.

  2. Neisseria gonorrhoeae Elicits Extracellular Traps in Primary Neutrophil Culture While Suppressing the Oxidative Burst

    PubMed Central

    Gunderson, Carl W.

    2015-01-01

    ABSTRACT  Neisseria gonorrhoeae (the gonococcus) causes gonorrhea and is uniquely adapted to survive within the human reproductive tract. Gonococci evade host immune surveillance in part by varying their pili and opacity-associated proteins. These variable surface antigens influence interactions with host epithelial and immune cells. A potent polymorphonuclear leukocyte (PMN) response is a hallmark of symptomatic gonococcal infection, with vast numbers of PMNs recruited to the site of infection. A large body of literature describes gonococcus-PMN interactions, but the factors driving the outcome of infection are not fully understood. Gonococci have been described to both induce and suppress the PMN oxidative burst, but we determined that gonococci differentially affect induction of the PMN oxidative burst depending on the multiplicity of infection (MOI). Infecting PMN at an MOI of <20 gonococci elicits an oxidative burst, while an MOI of >20 suppresses the burst. Oxidative burst in response to gonococci is enhanced by, but does not require, expression of pili or opacity proteins. Neutrophil extracellular traps (NETs) were observed in gonococcus-infected PMNs, a process which requires an oxidative burst, yet gonococci induced NETs under suppressing conditions. The NETs were unable to kill gonococci despite killing the common vaginal bacterium Lactobacillus crispatus. Thus, gonococci influence PMN biology to promote their own survival by suppressing the oxidative burst of PMNs and stimulating the formation of NETs, which do not effectively kill gonococci, illustrating how N. gonorrhoeae has evolved to modulate PMN responses to promote infection. PMID:25670773

  3. The primary transcriptome of Neisseria meningitidis and its interaction with the RNA chaperone Hfq.

    PubMed

    Heidrich, Nadja; Bauriedl, Saskia; Barquist, Lars; Li, Lei; Schoen, Christoph; Vogel, Jörg

    2017-03-17

    Neisseria meningitidis is a human commensal that can also cause life-threatening meningitis and septicemia. Despite growing evidence for RNA-based regulation in meningococci, their transcriptome structure and output of regulatory small RNAs (sRNAs) are incompletely understood. Using dRNA-seq, we have mapped at single-nucleotide resolution the primary transcriptome of N. meningitidis strain 8013. Annotation of 1625 transcriptional start sites defines transcription units for most protein-coding genes but also reveals a paucity of classical σ70-type promoters, suggesting the existence of activators that compensate for the lack of -35 consensus sequences in N. meningitidis. The transcriptome maps also reveal 65 candidate sRNAs, a third of which were validated by northern blot analysis. Immunoprecipitation with the RNA chaperone Hfq drafts an unexpectedly large post-transcriptional regulatory network in this organism, comprising 23 sRNAs and hundreds of potential mRNA targets. Based on this data, using a newly developed gfp reporter system we validate an Hfq-dependent mRNA repression of the putative colonization factor PrpB by the two trans-acting sRNAs RcoF1/2. Our genome-wide RNA compendium will allow for a better understanding of meningococcal transcriptome organization and riboregulation with implications for colonization of the human nasopharynx.

  4. Structural and Biochemical Characterization of the Oxidoreductase NmDsbA3 from Neisseria meningitidis

    SciTech Connect

    Vivian, Julian P.; Scoullar, Jessica; Robertson, Amy L.; Bottomley, Stephen P.; Horne, James; Chin, Yanni; Wielens, Jerome; Thompson, Philip E.; Velkov, Tony; Piek, Susannah; Byres, Emma; Beddoe, Travis; Wilce, Matthew C.J.; Kahler, Charlene M.; Rossjohn, Jamie; Scanlon, Martin J.

    2009-09-02

    DsbA is an enzyme found in the periplasm of Gram-negative bacteria that catalyzes the formation of disulfide bonds in a diverse array of protein substrates, many of which are involved in bacterial pathogenesis. Although most bacteria possess only a single essential DsbA, Neisseria meningitidis is unusual in that it possesses three DsbAs, although the reason for this additional redundancy is unclear. Two of these N. meningitidis enzymes (NmDsbA1 and NmDsbA2) play an important role in meningococcal attachment to human epithelial cells, whereas NmDsbA3 is considered to have a narrow substrate repertoire. To begin to address the role of DsbAs in the pathogenesis of N. meningitidis, we have determined the structure of NmDsbA3 to 2.3-{angstrom} resolution. Although the sequence identity between NmDsbA3 and other DsbAs is low, the NmDsbA3 structure adopted a DsbA-like fold. Consistent with this finding, we demonstrated that NmDsbA3 acts as a thiol-disulfide oxidoreductase in vitro and is reoxidized by Escherichia coli DsbB (EcDsbB). However, pronounced differences in the structures between DsbA3 and EcDsbA, which are clustered around the active site of the enzyme, suggested a structural basis for the unusual substrate specificity that is observed for NmDsbA3.

  5. Neisseria gonorrhoeae Induces a Tolerogenic Phenotype in Macrophages to Modulate Host Immunity

    PubMed Central

    Candia, Enzo; Reyes-Cerpa, Sebastian; Villegas-Valdes, Bélgica; Neira, Tanya; Lopez, Mercedes; Maisey, Kevin; Tempio, Fabián; Ríos, Miguel; Acuña-Castillo, Claudio; Imarai, Mónica

    2013-01-01

    Neisseria gonorrhoeae is the etiological agent of gonorrhoea, which is a sexually transmitted disease widespread throughout the world. N. gonorrhoeae does not improve immune response in patients with reinfection, suggesting that gonococcus displays several mechanisms to evade immune response and survive in the host. N. gonorrhoeae is able to suppress the protective immune response at different levels, such as B and T lymphocytes and dendritic cells. In this study, we determined whether N. gonorrhoeae directly conditions the phenotype of RAW 264.7 murine macrophage cell line and its response. We established that gonococcus was effectively phagocytosed by the RAW 264.7 cells and upregulates production of immunoregulatory cytokines (IL-10 and TGF-β1) but not the production of proinflammatory cytokine TNF-α, indicating that gonococcus induces a shift towards anti-inflammatory cytokine production. Moreover, N. gonorrhoeae did not induce significant upregulation of costimulatory CD86 and MHC class II molecules. We also showed that N. gonorrhoeae infected macrophage cell line fails to elicit proliferative CD4+ response. This implies that macrophage that can phagocytose gonococcus do not display proper antigen-presenting functions. These results indicate that N. gonorrhoeae induces a tolerogenic phenotype in antigen-presenting cells, which seems to be one of the mechanisms to induce evasion of immune response. PMID:24204097

  6. Antimicrobial susceptibility and genotyping analysis of Hungarian Neisseria gonorrhoeae strains in 2013.

    PubMed

    Nemes-Nikodém, Éva; Brunner, Alexandra; Pintér, Dóra; Mihalik, Noémi; Lengyel, György; Marschalkó, Márta; Kárpáti, Sarolta; Szabó, Dóra; Ostorházi, Eszter

    2014-12-01

    Emergence and spread of antimicrobial resistance in Neisseria gonorrhoeae is a major public health concern worldwide. The current study aims to determine the antimicrobial resistance in N. gonorrhoeae and associated molecular typing to enhance gonococcal antimicrobial surveillance in Hungary. In the National N. gonorrhoeae Reference Laboratory of Hungary 187 N. gonorrhoeae infections were detected in 2013, antibiograms were determined for all the isolated strains, and 52 (one index strain from every sexually contact related group) of them were also analysed by the N. gonorrhoeae multi-antigen sequence typing (NG-MAST) method. Twenty-two different NG-MAST sequence types (STs) were identified, of which 8 STs had not been previously described. In Hungary, the highly diversified gonococcal population displayed high resistance to penicillin, ciprofloxacin and tetracycline (the antimicrobials previously recommended for gonorrhoea treatment). Resistance to the currently recommended extended spectrum cephalosporines were rare: only two of the expected strains, an ST 1407 and an ST 210, had cefixime MIC above the resistance breakpoint. By the revision of our National Treatment Guideline, it must be considered, that the azithromycin resistance is about 60% among the four most frequently isolated STs in Hungary.

  7. Manganese regulation of virulence factors and oxidative stress resistance in Neisseria gonorrhoeae

    PubMed Central

    Wu, Hsing-Ju; Seib, Kate L.; Srikhanta, Yogitha N.; Edwards, Jennifer; Kidd, Stephen P.; Maguire, Tina L .; Hamilton, Amanda; Pan, Kuan-Tin; Hsiao, He-Hsuan; Yao, Chen-Wen; Grimmond, Sean M.; Apicella, Michael A.; McEwan, Alastair G.; Wang, Andrew H-J.; Jennings, Michael P.

    2014-01-01

    Neisseria gonorrhoeae has evolved a complex and novel network of oxidative stress responses, including defense mechanisms that are dependent on manganese (Mn). We performed systematic analyses at the transcriptomic and proteomic (1D SDS-PAGE and Isotope-Coded Affinity Tag [ICAT]) levels to investigate the global expression changes that take place in a high Mn environment, which results in a Mn-dependent oxidative stress resistance phenotype. These studies revealed that 97 proteins are regulated at the post-transcriptional level under conditions of increased Mn concentration, including proteins involved in virulence (eg. Pilin, a key adhesin), oxidative stress defence (eg. superoxide dismutase), cellular metabolism, protein synthesis, RNA processing and cell division. Mn regulation of inorganic pyrophosphatase (Ppa) indicated the potential involvement of phosphate metabolism in the Mn-dependent oxidative stress defense. A detailed analysis of the role of Ppa and polyphosphate kinase (Ppk) in the gonococcal oxidative stress response revealed that ppk and ppa mutant strains showed increased resistance to oxidative stress. Investigation of these mutants grown with high Mn suggests that phosphate and pyrophosphate are involved in Mn-dependent oxidative stress resistance. PMID:20004262

  8. Molecular characterization of the 98-kilodalton iron-regulated outer membrane protein of Neisseria meningitidis.

    PubMed Central

    Pettersson, A; van der Ley, P; Poolman, J T; Tommassen, J

    1993-01-01

    When grown under iron limitation, Neisseria meningitidis expresses several additional outer membrane proteins (OMPs), which were studied to assess their vaccine potential. Two monoclonal antibodies were obtained against a 98-kDa OMP of strain 2996 (B:2b:P1.2). Cross-reactivity studies revealed that the two antibodies reacted with 44 and 42 of 74 meningococcal strains, respectively. The antibodies did not block the binding of transferrin or lactoferrin to intact cells. The structural gene for the protein, tentatively designated iroA, was isolated and sequenced. Computer analysis revealed homology to the ferric siderophore receptors in the outer membrane of Escherichia coli and to gonococcal transferrin-binding protein 1 (TbpA). The high degree of cross-reactivity and the results of Southern blot analyses, which showed that the iroA gene is also present in strains that did not react with the monoclonal antibodies, suggest that the 98-kDa OMP is well conserved among meningococci and that it is a suitable vaccine candidate. However, the antibodies were not bactericidal in an in vitro assay with human complement. Images PMID:8406871

  9. A vaccine carrier derived from Neisseria meningitidis with mitogenic activity for lymphocytes.

    PubMed Central

    Liu, M A; Friedman, A; Oliff, A I; Tai, J; Martinez, D; Deck, R R; Shieh, J T; Jenkins, T D; Donnelly, J J; Hawe, L A

    1992-01-01

    Protein carriers vary in their ability to increase the immunogenicity of poorly immunogenic or T-lymphocyte-independent antigens. We examined one such carrier, the outer membrane protein complex derived from Neisseria meningitidis serogroup B strain B11, in an attempt to determine why this outer membrane protein complex was more immunogenic in young infants and in relevant animal models than two other carriers used in conjugates made with Haemophilus influenzae type b polysaccharide, a T-cell-independent antigen. A single protein of the outer membrane protein complex, the class 2 porin protein, was purified and shown to function as a T-helper lymphocyte carrier protein. Unexpectedly, it was also found to have mitogenic activity for lymphocytes that was not due to lipopolysaccharide. This mitogenic activity appears to date to be unique to this carrier protein of the carrier proteins tested and may contribute to the ability of the H. influenzae type b conjugate vaccine made with the outer membrane protein complex to generate IgG anti-polysaccharide antibody responses in mice and infant monkeys and protective immune responses in infants less than 6 months of age. Images PMID:1533934

  10. Carriage rates of Neisseria meningitidis serogroups: determination among freshmen conscripts before vaccination

    PubMed Central

    Ataee, Ramezan Ali; Mehrabi-Tavana, Ali; Hosseini, Seyed Mohammad Javad; Kaviani, Farshad

    2016-01-01

    Background and Objectives: Neisseria meningitidis is transmitted from person-to-person. Thus, close contact with a healthy carrier can facilitate the spread of the bacteria and lead to life-threatening meningococcal disease. The aim of this study was to identify oropharyngeal carriers of N. meningitidis in volunteers preparing for military service before vaccination. Materials and Methods: In a cross-sectional study, 226 volunteers entering military service were referred to the Shemiranat Health Center for meningococcal vaccination and assayed. Before vaccination, the participants underwent sampling of the throat using separate swabs. Thayer-Martin Agar medium and microbiological standard methods were used for culture and isolation of the organisms. The bacterial isolates were subjected to DNA extraction and polymerase chain reaction. The obtained data were descriptively analyzed. Results: Out of the 226 (100%) young volunteers, only 18 (8%) yielded Gram-negative diplococci. The results showed the presence of N. meningitidis (carriage rate: 8%) in their oropharyngeal regions. The isolated serogroups were C, A, Y, W-135, and X with frequencies of 50, 22.2, 16.6, 5.5, and 5.5, respectively. Discussion: This study showed that the carriage rate in young volunteers for military service is around 8% before vaccination. Although the rates for serogroups A and C were dominant, the existence of serogroups Y and W indicate the necessary revision of the A/C vaccine. More research is needed to determine serogroup diversity and decrease the risk of meningococcal disease in individual groups. PMID:27928488

  11. Direct detection and serogroup characterization of Neisseria meningitidis from outbreak of meningococcal meningitis in Delhi

    PubMed Central

    Negi, SS; Grover, SS; Rautela, SS; Rawat, DS; Gupta, S; Khare, S; Lal, S; Rai, A

    2010-01-01

    Background and Objectives Rapid clinical manifestation/progression of the meningococcal meningitis and lacunae in conventional bacteriological test often encourages indiscriminate use of antibiotics much before the etiology is established. Accordingly this study was planned to evaluate ctrA PCR for rapid molecular detection. In addition, multiplex PCR and sequencing was done for serogroup prediction to provide essential epidemiological and laboratory evidence for decision makers of health department of the country for choosing appropriate vaccine and phylogenetic analysis to establish its lineage. Materials and Methods 73 CSF samples, collected from equal number of suspected cases, were investigated by both bacteriological (microscopy, culture, LA and drug sensitivity testing) as well as molecular tests i.e. PCR targeting conserved ctrA gene, multiplex PCR for serogroup characterization and DNA sequencing. Results ctrA PCR revealed sensitivity, specificity, positive predictive value and negative predictive values of 93.15%, 100%,100%, and 88.23% respectively. Multiplex PCR based genogrouping followed by DNA sequencing, BLAST and phylogenetic analysis revealed complete homology with earlier submitted Neisseria meningitidis serogroup A strain Z2491 to suggest the sole involvement of only serogroup A in the outbreak. Two strains showed resistance to cefuroxime, ciprofloxacin, nalidixic acid. Only one strain showed resistance to ciprofloxacin, emphasizing the need for a constant surveillance system. Conclusion These diagnostic molecular tools are of paramount importance in establishing etiology, serogrouping, and epidemiological surveillance especially in developing countries like India. PMID:22347552

  12. Microwave-Accelerated Method for Ultra-Rapid Extraction of Neisseria gonorrhoeae DNA for Downstream Detection

    PubMed Central

    Melendez, Johan H.; Santaus, Tonya M.; Brinsley, Gregory; Kiang, Daniel; Mali, Buddha; Hardick, Justin; Gaydos, Charlotte A.; Geddes, Chris D.

    2016-01-01

    Nucleic acid-based detection of gonorrhea infections typically require a two-step process involving isolation of the nucleic acid, followed by the detection of the genomic target often involving PCR-based approaches. In an effort to improve on current detection approaches, we have developed a unique two-step microwave-accelerated approach for rapid extraction and detection of Neisseria gonorrhoeae (GC) DNA. Our approach is based on the use of highly-focused microwave radiation to rapidly lyse bacterial cells, release, and subsequently fragment microbial DNA. The DNA target is then detected by a process known as microwave-accelerated metal-enhanced fluorescence (MAMEF), an ultra-sensitive direct DNA detection analytical technique. In the present study, we show that highly focused microwaves at 2.45 GHz, using 12.3 mm gold film equilateral triangles, are able to rapidly lyse both bacteria cells and fragment DNA in a time- and microwave power-dependent manner. Detection of the extracted DNA can be performed by MAMEF, without the need for DNA amplification in less than 10 minutes total time or by other PCR-based approaches. Collectively, the use of a microwave-accelerated method for the release and detection of DNA represents a significant step forward towards the development of a point-of-care (POC) platform for detection of gonorrhea infections. PMID:27325503

  13. Prevalence of Neisseria meningitidis carriers in the school population of Catalonia, Spain.

    PubMed Central

    Domínguez, A.; Cardeñosa, N.; Izquierdo, C.; Sánchez, F.; Margall, N.; Vázquez, J. A.; Salleras, L.

    2001-01-01

    The aim of this study was to determine the prevalence of healthy Neisseria meningitidis pharyngeal carriers in a representative sample of the Catalonian school population, as well as its associated factors. The sample was divided into age groups: < or = 5, 6-7 and 13-14 years old. Parents were given a questionnaire to collect information on sociodemographic and epidemiological variables. Oropharyngeal swabs were collected with a cotton-tipped swab in an Amies transport medium and cultured on Thayer Martin plates at 35 degrees C in 5% CO2. The isolates were serogrouped and sero/subtyped. Of the 1406 children studied, 75 (5.34%) meningococcal carriers were detected: 63 B (4.5%), 9 non groupable (0.7%), 2 29E (0.1%) and 1X (0.07%). No serogroup C meningococci were found in this study, probably due to the high A+C vaccination coverage of up to 68.9% in children 6-7 years old. Bivariate analysis identified six statistically significant risk factors for meningococcal carriage: increasing age, recent upper respiratory tract infection, previous antibiotic treatment, number of students in the class, size of the classroom and social class. Multivariate analysis found that only age and previous antibiotic treatment remained statistically significant when the other factors were controlled. PMID:11811875

  14. In vitro activity of tigecycline alone and antimicrobial combinations against clinical Neisseria gonorrhoeae isolates.

    PubMed

    Lee, Hyukmin; Kim, Hyunsoo; Seo, Young Hee; Yong, Dongeun; Jeong, Seok Hoon; Lee, Kyungwon; Chong, Younsop

    2017-02-01

    In this study, we determined the in vitro activity of various combinations of antimicrobial agents against 54 Neisseria gonorrhoeae isolates. The combined activity of ceftriaxone (CRO) and azithromycin (AZM), CRO and doxycycline (DOX), CRO and spectinomycin (SPT), cefixime (CFX) and AZM, CFX and DOX, and CFX and SPT was determined using a checkerboard method. The fractional inhibitory concentration index (FICI) values for all combinations were either additive or indifferent, and no synergistic or antagonistic effects were found. The FICI comparison in each combination did not show any difference according to the N.gonorrhoeae-resistant phenotypes and genotypic characteristics, including penicillinase-producing N. gonorrhoeae, tetracycline-resistant N. gonorrhoeae, stratified MIC of all antibiotics, and N. gonorrhoeae multiantigen sequence typing. MIC50 and MIC90 of tigecycline by agar dilution were 0.5 mg/L and 0.5 mg/L, respectively, which were lower than that of tetracycline and DOX. Additive/indifference results could suggest that combinations that include CRO may be used safely without a significant likelihood of generating resistance.

  15. Bacteriocins and other bioactive substances of probiotic lactobacilli as biological weapons against Neisseria gonorrhoeae.

    PubMed

    Ruíz, Francisco O; Pascual, Liliana; Giordano, Walter; Barberis, Lucila

    2015-04-01

    In the search of new antimicrobial agents against Neisseria gonorrhoeae, the bacteriocins-producing probiotic lactobacilli deserve special attention. The inhibitory effects of biosubstances such as organic acids, hydrogen peroxide and each bacteriocin-like inhibitory substance (BLIS) L23 and L60 on the growth of different gonococcal strains were investigated. Different non-treated and treated cell-free supernatants of two probiotic lactobacilli containing these metabolites were used. The aims of this work were (i) to evaluate the antimicrobial activity of the biosubstances produced by two probiotic lactobacilli, estimating the proportion in which each of them is responsible for the inhibitory effect, (ii) to define their minimum inhibitory concentrations (MICs) and, (iii) to determine the potential interactions between these biosubstances against N. gonorrhoeae. The main antimicrobial metabolites were the BLIS-es L23 and L60 in comparison with other biosubstances. Proportionally, their contributions to the inhibition on the gonococcal growth were 87.28% and 80.66%, respectively. The MIC values of bacteriocins were promising since these substances, when diluted, showed considerable inhibitory activity for all gonococci. In the interaction between bacteriocins, 100% of synergism was found on the gonococcal growth. In summary, this study indicates that both L23 and L60 could potentially serve to design new bioproducts against N. gonorrhoeae.

  16. Effects of multi-walled carbon nanotubes (MWCNT) under Neisseria meningitidis transformation process

    PubMed Central

    2011-01-01

    Background This study aimed at verifying the action of multi-walled carbon nanotubes (MWCNT) under the naturally transformable Neisseria meningitidis against two different DNA obtained from isogenic mutants of this microorganism, an important pathogen implicated in the genetic horizontal transfer of DNA, causing the escape of the principal vaccination measured worldwide by the capsular switching process. Materials and methods The bacterium receptor strain C2135 was cultivated and had its mutant DNA donor M2 and M6, which received a receptor strain and MWCNT at three different concentrations. The inhibition effect of DNAse on the DNA in contact with nanoparticles was evaluated. Results The results indicated an in increase in the transformation capacity of N. meninigtidis in different concentrations of MWCNT when compared with negative control without nanotubes. A final analysis of the interaction between DNA and MWCNT was carried out using Raman Spectroscopy. Conclusion These increases in the transformation capacity mediated by MWCNT, in meningococci, indicate the interaction of these particles with the virulence acquisition of these bacteria, as well as with the increase in the vaccination escape process. PMID:22088149

  17. Homology modelling of transferrin-binding protein A from Neisseria meningitidis.

    PubMed

    Oakhill, Jonathan S; Sutton, Brian J; Gorringe, Andrew R; Evans, Robert W

    2005-05-01

    Neisseria meningitidis, a causative agent of bacterial meningitis, obtains transferrin-bound iron by expressing two outer membrane located transferrin-binding proteins, TbpA and TbpB. TbpA is thought to be an integral outer membrane pore that facilitates iron uptake. Evidence suggests that TbpA is a useful antigen for inclusion in a vaccine effective against meningococcal disease, hence the identification of regions involved in ligand binding is of paramount importance to design strategies to block uptake of iron. The protein shares sequence and functional similarities to the Escherichia coli siderophore receptors FepA and FhuA, whose structures have been determined. These receptors are composed of two domains, a 22-stranded beta-barrel and an N-terminal plug region that sits within the barrel and occludes the transmembrane pore. A three-dimensional TbpA model was constructed using FepA and FhuA structural templates, hydrophobicity analysis and homology modelling. TbpA was found to possess a similar architecture to the siderophore receptors. In addition to providing insights into the highly immunogenic nature of TbpA and allowing the prediction of potentially important ligand-binding epitopes, the model also reveals a narrow channel through its entire length. The relevance of this channel and the spatial arrangement of external loops, to the mechanism of iron translocation employed by TbpA is discussed.

  18. Neisserial Heparin Binding Antigen (NHBA) Contributes to the Adhesion of Neisseria meningitidis to Human Epithelial Cells

    PubMed Central

    Vacca, Irene; Del Tordello, Elena; Gasperini, Gianmarco; Pezzicoli, Alfredo; Di Fede, Martina; Rossi Paccani, Silvia; Marchi, Sara; Mubaiwa, Tsisti D.; Hartley-Tassell, Lauren E.; Jennings, Michael P.; Seib, Kate L.; Masignani, Vega; Pizza, Mariagrazia; Serruto, Davide; Aricò, Beatrice; Delany, Isabel

    2016-01-01

    Neisserial Heparin Binding Antigen (NHBA) is a surface-exposed lipoprotein ubiquitously expressed by Neisseria meningitidis strains and an antigen of the Bexsero® vaccine. NHBA binds heparin through a conserved Arg-rich region that is the target of two proteases, the meningococcal NalP and human lactoferrin (hLf). In this work, in vitro studies showed that recombinant NHBA protein was able to bind epithelial cells and mutations of the Arg-rich tract abrogated this binding. All N-terminal and C-terminal fragments generated by NalP or hLf cleavage, regardless of the presence or absence of the Arg-rich region, did not bind to cells, indicating that a correct positioning of the Arg-rich region within the full length protein is crucial. Moreover, binding was abolished when cells were treated with heparinase III, suggesting that this interaction is mediated by heparan sulfate proteoglycans (HSPGs). N. meningitidis nhba knockout strains showed a significant reduction in adhesion to epithelial cells with respect to isogenic wild-type strains and adhesion of the wild-type strain was inhibited by anti-NHBA antibodies in a dose-dependent manner. Overall, the results demonstrate that NHBA contributes to meningococcal adhesion to epithelial cells through binding to HSPGs and suggest a possible role of anti-Bexsero® antibodies in the prevention of colonization. PMID:27780200

  19. Activation of NOD receptors by Neisseria gonorrhoeae modulates the innate immune response

    PubMed Central

    Mavrogiorgos, Nikolaos; Mekasha, Samrawit; Yang, Yibin; Kelliher, Michelle A.; Ingalls, Robin R.

    2013-01-01

    Nucleotide-binding oligomerization domain (NOD)-1 and NOD2 are members of the NOD-like receptor family of cytosolic pattern recognition receptors that recognize specific fragments of the bacterial cell wall component peptidoglycan. Neisseria species are unique amongst Gram-negative bacteria in that they turn over large amounts of peptidoglycan during growth. In this study we examined the ability of NOD1 and NOD2 to recognize N. gonorrhoeae, and determined the role of NOD-dependent signaling in regulating the immune response to gonococcal infection. We found that gonococci, as well as conditioned medium from mid-logarithmic phase grown bacteria, were capable of activating both human NOD1 and NOD2, as well as mouse NOD2, leading to the activation of the transcription factor NF-κB and polyubiquitination of the adaptor receptor-interacting serine-threonine kinase 2 (RIPK2). We identified a number of cytokines and chemokines that were differentially expressed in wild type vs. NOD2 deficient macrophages in response to gonococcal infection. Moreover, NOD2 signaling upregulated complement pathway components and cytosolic nucleic acid sensors, suggesting a broad impact of NOD activation on innate immunity. These data demonstrate that NOD1 and NOD2 are important intracellular regulators of the immune response to infection with N. gonorrhoeae. Given the intracellular lifestyle of this pathogen, we believe these cytosolic receptors may provide a key innate immune defense mechanism for the host during gonococcal infection. PMID:23884094

  20. Parameter and state estimation in a Neisseria meningitidis model: A study case of Niger

    NASA Astrophysics Data System (ADS)

    Bowong, S.; Mountaga, L.; Bah, A.; Tewa, J. J.; Kurths, J.

    2016-12-01

    Neisseria meningitidis (Nm) is a major cause of bacterial meningitidis outbreaks in Africa and the Middle East. The availability of yearly reported meningitis cases in the African meningitis belt offers the opportunity to analyze the transmission dynamics and the impact of control strategies. In this paper, we propose a method for the estimation of state variables that are not accessible to measurements and an unknown parameter in a Nm model. We suppose that the yearly number of Nm induced mortality and the total population are known inputs, which can be obtained from data, and the yearly number of new Nm cases is the model output. We also suppose that the Nm transmission rate is an unknown parameter. We first show how the recruitment rate into the population can be estimated using real data of the total population and Nm induced mortality. Then, we use an auxiliary system called observer whose solutions converge exponentially to those of the original model. This observer does not use the unknown infection transmission rate but only uses the known inputs and the model output. This allows us to estimate unmeasured state variables such as the number of carriers that play an important role in the transmission of the infection and the total number of infected individuals within a human community. Finally, we also provide a simple method to estimate the unknown Nm transmission rate. In order to validate the estimation results, numerical simulations are conducted using real data of Niger.

  1. Phosphoethanolamine Modification of Neisseria gonorrhoeae Lipid A Reduces Autophagy Flux in Macrophages

    PubMed Central

    Zughaier, Susu M.; Kandler, Justin L.; Balthazar, Jacqueline T.; Shafer, William M.

    2015-01-01

    Autophagy, an ancient homeostasis mechanism for macromolecule degradation, performs an important role in host defense by facilitating pathogen elimination. To counteract this host defense strategy, bacterial pathogens have evolved a variety of mechanisms to avoid or otherwise dysregulate autophagy by phagocytic cells so as to enhance their survival during infection. Neisseria gonorrhoeae is a strictly human pathogen that causes the sexually transmitted infection, gonorrhea. Phosphoethanolamine (PEA) addition to the 4' position of the lipid A (PEA-lipid A) moiety of the lipooligosaccharide (LOS) produced by gonococci performs a critical role in this pathogen’s ability to evade innate defenses by conferring decreased susceptibility to cationic antimicrobial (or host-defense) peptides, complement-mediated killing by human serum and intraleukocytic killing by human neutrophils compared to strains lacking this PEA decoration. Heretofore, however, it was not known if gonococci can evade autophagy and if so, whether PEA-lipid A contributes to this ability. Accordingly, by using murine macrophages and human macrophage-like phagocytic cell lines we investigated if PEA decoration of gonococcal lipid A modulates autophagy formation. We report that infection with PEA-lipid A-producing gonococci significantly reduced autophagy flux in murine and human macrophages and enhanced gonococcal survival during their association with macrophages compared to a PEA-deficient lipid A mutant. Our results provide further evidence that PEA-lipid A produced by gonococci is a critical component in the ability of this human pathogen to evade host defenses. PMID:26641098

  2. Microwave-accelerated method for ultra-rapid extraction of Neisseria gonorrhoeae DNA for downstream detection.

    PubMed

    Melendez, Johan H; Santaus, Tonya M; Brinsley, Gregory; Kiang, Daniel; Mali, Buddha; Hardick, Justin; Gaydos, Charlotte A; Geddes, Chris D

    2016-10-01

    Nucleic acid-based detection of gonorrhea infections typically require a two-step process involving isolation of the nucleic acid, followed by detection of the genomic target often involving polymerase chain reaction (PCR)-based approaches. In an effort to improve on current detection approaches, we have developed a unique two-step microwave-accelerated approach for rapid extraction and detection of Neisseria gonorrhoeae (gonorrhea, GC) DNA. Our approach is based on the use of highly focused microwave radiation to rapidly lyse bacterial cells, release, and subsequently fragment microbial DNA. The DNA target is then detected by a process known as microwave-accelerated metal-enhanced fluorescence (MAMEF), an ultra-sensitive direct DNA detection analytical technique. In the current study, we show that highly focused microwaves at 2.45 GHz, using 12.3-mm gold film equilateral triangles, are able to rapidly lyse both bacteria cells and fragment DNA in a time- and microwave power-dependent manner. Detection of the extracted DNA can be performed by MAMEF, without the need for DNA amplification, in less than 10 min total time or by other PCR-based approaches. Collectively, the use of a microwave-accelerated method for the release and detection of DNA represents a significant step forward toward the development of a point-of-care (POC) platform for detection of gonorrhea infections.

  3. The Neisseria meningitidis CRISPR-Cas9 System Enables Specific Genome Editing in Mammalian Cells.

    PubMed

    Lee, Ciaran M; Cradick, Thomas J; Bao, Gang

    2016-03-01

    The clustered regularly-interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) system from Streptococcus pyogenes (Spy) has been successfully adapted for RNA-guided genome editing in a wide range of organisms. However, numerous reports have indicated that Spy CRISPR-Cas9 systems may have significant off-target cleavage of genomic DNA sequences differing from the intended on-target site. Here, we report the performance of the Neisseria meningitidis (Nme) CRISPR-Cas9 system that requires a longer protospacer-adjacent motif for site-specific cleavage, and present a comparison between the Spy and Nme CRISPR-Cas9 systems targeting the same protospacer sequence. The results with the native crRNA and tracrRNA as well as a chimeric single guide RNA for the Nme CRISPR-Cas9 system were also compared. Our results suggest that, compared with the Spy system, the Nme CRISPR-Cas9 system has similar or lower on-target cleavage activity but a reduced overall off-target effect on a genomic level when sites containing three or fewer mismatches are considered. Thus, the Nme CRISPR-Cas9 system may represent a safer alternative for precision genome engineering applications.

  4. Toxicological Assessment of the Cochleate Derived from Neisseria meningitidis Proteoliposome in Sprague Dawley Rats

    PubMed Central

    Infante-Bourzac, Juan Francisco; Sifontes-Rodríguez, Sergio; Arencibia-Arrebola, Daniel Francisco; Hernández-Salazar, Tamara; Fariñas-Medina, Mildrey; Pérez, Oliver

    2012-01-01

    Background: The AFCo1 cochleate is a potential novel adjuvant derived from Neisseria meningitidis B proteoliposome. Aim: The aim was to assessing the safety of AFCo1 by single and repeated doses in Sprague Dawley rats. Materials and Methods: Rats were grouped for treatment with AFCo1, placebo formulation or control. The first study was a single intranasal dose of 100 μl and monitoring body weight, water, and food intakes as well as clinical symptoms. Fourteen days later the rats were killed and anatomopathological studies were conducted. In a second study, four similar doses of the test substance were instilled every 5 days. Clinical observations were carried out as for the single dose study and a number of rats from each group were killed 3 and 14 days after the last dose in order to conduct hematological, hemochemical, and anatomopathological studies. Results: No variable showed differences of toxicological relevance; the histological changes found were mild and similarly frequently in the three groups. According to the irritability index calculated form histology of the nasal region, AFCo1 was also classified as nonirritating. Conclusion: AFCo1 is potentially safe for human use by nasal route as evidenced by the absence of local and systemic signs of toxicity in Sprague Dawley rats. PMID:22454827

  5. Serogroup and Clonal Characterization of Czech Invasive Neisseria meningitidis Strains Isolated from 1971 to 2015

    PubMed Central

    Jandova, Zuzana; Musilek, Martin; Vackova, Zuzana; Kozakova, Jana; Krizova, Pavla

    2016-01-01

    Background This study presents antigenic and genetic characteristics of Neisseria meningitidis strains recovered from invasive meningococcal disease (IMD) in the Czech Republic in 1971–2015. Material and Methods A total of 1970 isolates from IMD, referred to the National Reference Laboratory for Meningococcal Infections in 1971–2015, were studied. All isolates were identified and characterized by conventional biochemical and serological tests. Most isolates (82.5%) were characterized by multilocus sequence typing method. Results In the study period 1971–2015, the leading serogroup was B (52.4%), most often assigned to clonal complexes cc32, cc41/44, cc18, and cc269. A significant percentage of strains were of serogroup C (41.4%), with high clonal homogeneity due to hyperinvasive complex cc11, which played an important role in IMD in the Czech Republic in the mid-1990s. Serogroup Y isolates, mostly assigned to cc23, and isolates of clonally homogeneous serogroup W have also been recovered more often over the last years. Conclusion The incidence of IMD and distribution of serogroups and clonal complexes of N. meningitidis in the Czech Republic varied over time, as can be seen from the long-term monitoring, including molecular surveillance data. Data from the conventional and molecular IMD surveillance are helpful in refining the antimeningococcal vaccination strategy in the Czech Republic. PMID:27936105

  6. The Neisseria gonorrhoeae biofilm matrix contains DNA, and an endogenous nuclease controls its incorporation.

    PubMed

    Steichen, Christopher T; Cho, Christine; Shao, Jian Q; Apicella, Michael A

    2011-04-01

    Neisseria gonorrhoeae has been shown to produce biofilms both in experimental flow chambers and in the human host. Our laboratory has shown that extracellular DNA is an essential component of the gonococcal matrix. We have also identified a gene in N. gonorrhoeae, which we designated nuc. This gene has homology with the staphylococcus-secreted thermonuclease. Our laboratory has characterized nuc through phenotypic analysis of a nuc deletion mutant. Biofilms grown with this strain are significantly thicker and of greater biomass than the N. gonorrhoeae 1291 parent strain. Confocal microscopy indicates that the increased size of the mutant biofilms appears to be due to elevated amounts of extracellular DNA in the biofilm matrix. Chromosomal complementation of the nuc mutation restored the wild-type biofilm phenotype. In addition, we have cloned and expressed the Nuc protein in Escherichia coli, and our data indicate that it has the ability to digest multiple forms of DNA and is a thermonuclease. The ability of Nuc to digest DNA also extends to its ability to disrupt established gonococcal biofilms through degradation of the DNA in the biofilm matrix. Our studies indicate that the N. gonorrhoeae biofilm contains DNA and that the Nuc protein appears to play a role in biofilm formation and remodeling.

  7. Neisseria gonorrhoeae survives within and modulates apoptosis and inflammatory cytokine production of human macrophages.

    PubMed

    Château, Alice; Seifert, H Steven

    2016-04-01

    The human-adapted organism Neisseria gonorrhoeae is the causative agent of gonorrhoea, a sexually transmitted infection. It readily colonizes the genital, rectal and nasalpharyngeal mucosa during infection. While it is well established that N. gonorrhoeae recruits and modulates the functions of polymorphonuclear leukocytes during infection, how N. gonorrhoeae interacts with macrophages present in infected tissue is not fully defined. We studied the interactions of N. gonorrhoeae with two human monocytic cell lines, THP-1 and U937, and primary monocytes, all differentiated into macrophages. Most engulfed bacteria were killed in the phagolysosome, but a subset of bacteria was able to survive and replicate inside the macrophages suggesting that those cells may be an unexplored cellular reservoir for N. gonorrhoeae during infection. N. gonorrhoeae was able to modulate macrophage apoptosis: N. gonorrhoeae induced apoptosis in THP-1 cells whereas it inhibited induced apoptosis in U937 cells and primary human macrophages. Furthermore, N. gonorrhoeae induced expression of inflammatory cytokines in macrophages, suggesting a role for macrophages in recruiting polymorphonuclear leukocytes to the site of infection. These results indicate macrophages may serve as a significant replicative niche for N. gonorrhoeae and play an important role in gonorrheal pathogenesis.

  8. Characterization of invasive Neisseria meningitidis strains isolated at the Children's Hospital of Tunis, Tunisia.

    PubMed

    Saguer, A; Smaoui, H; Taha, M-K; Kechrid, A

    2016-08-18

    Neisseria meningitidis, a leading cause of bacterial meningitis and other serious infections, is responsible for approximately one-third of cases of bacterial meningitis in the Children's Hospital of Tunis. The serogroup distribution, antibiotic susceptibility and antigenic and molecular characteristics of N. meningitidis isolates were determined in patients aged 3 days-13 years between February 1998 and June 2013. In all 107 invasive strains of N. meningitidis were isolated. Reduced susceptibility to penicillin G was seen in 55.7% of isolates, with a low level of resistance in all cases; 28.4% showed a low level of resistance to amoxicillin. Serogroup B isolates were the most frequent (80.4%), followed by serogroups C (12.2%) and A (5.6%). Isolates of serogroup A had the same antigenic formula (A:4:P1.9), the same variable regions VR1, VR2 and VR3, and belonged to the same clonal complex (CC5). Isolates of serogroups B and C were more heterogeneous with several antigenic formulae. The most frequent clonal complex in these isolates was CC35. Serogroup B accounted for a large percentage of our isolates with marked diversity.

  9. [Antimicrobial resistance of Neisseria gonorrhoeae strains isolated from sex workers in Ankara].

    PubMed

    Zarakolu, Pinar; Sakizligil, Bülent; Unal, Serhat

    2006-01-01

    The prevalence of gonococcal infections among sexually transmitted infections is decreasing particularly in developed countries, but the increase in antimicrobial resistance of Neisseria gonorrhoeae is an emerging issue. There is lack of data about the epidemiology and the resistance pattern of the pathogen in our country. Gonococcal infections are recently included among the reportable diseases in Turkey. The specific laboratory tests are difficult, expensive and seldomly used for diagnosis in our country. The infection is usuallly treated empirically. In this study, 30 N. gonorrhoeae strains isolated from clinical samples (endocervical, rectal and urethral swabs) obtained from registered/unregistered sex workers admitted to Ankara Municipiality Hospital of Dermatology and Venereal Diseases were tested for beta-lactamase production and the susceptibility to various antimicrobials. The susceptibility testing was performed by agar dilution method, and the results were evaluated according to Clinical and Laboratory Standards Institute (CLSI) recommendations. Of the isolates, 70% was found resistant to penicilin and beta-lactamase production was observed in 48% of them. The susceptibility rates of the isolates to ceftriaxone, cefixime, ciprofloxacin, and tetracycline were found as 100%, 100%, 97%, and 40%, respectively.

  10. Neisseria gonorrhoeae breaches the apical junction of polarized epithelial cells for transmigration by activating EGFR.

    PubMed

    Edwards, Vonetta L; Wang, Liang-Chun; Dawson, Valerie; Stein, Daniel C; Song, Wenxia

    2013-06-01

    Neisseria gonorrhoeae initiates infection at the apical surface of columnar endocervical epithelial cells in the female reproductive tract. These cells provide a physical barrier against pathogens by forming continuous apical junctional complexes between neighbouring cells. This study examines the interaction of gonococci (GC) with polarized epithelial cells. We show that viable GC preferentially localize at the apical side of the cell-cell junction in polarized endometrial and colonic epithelial cells, HEC-1-B and T84. In GC-infected cells, continuous apical junctional complexes are disrupted, and the junction-associated protein β-catenin is redistributed from the apical junction to the cytoplasm and to GC adherent sites; however, overall cellular levels remain unchanged. This redistribution of junctional proteins is associated with a decrease in the 'fence' function of the apical junction but not its 'gate' function. Disruption of the apical junction by removing calcium increases GC transmigration across the epithelial monolayer. GC inoculation induces the phosphorylation of both epidermal growth factor receptor (EGFR) and β-catenin, while inhibition of EGFR kinase activity significantly reduces both GC-induced β-catenin redistribution and GC transmigration. Therefore, the gonococcus is capable of weakening the apical junction and polarity of epithelial cells by activating EGFR, which facilitates GC transmigration across the epithelium.

  11. Polysaccharide Production in Pilot Scale Bioreactor Cultivations of Neisseria meningitidis Serogroup C

    PubMed Central

    Baruque-Ramos, Julia; Juncioni de Arauz, Luciana; Fossa da Paz, Marcelo; Vicentin, Marcio Alberto; Hiss, Haroldo

    2016-01-01

    Serogroup C polysaccharide from Neisseria meningitidis (PS) constitutes the antigen for the respective vaccine production. In order to investigate the enhancement of the final PS concentration (Pf), as well as the overall yield factor (PS/biomass) (YP/X), 13 total cultivations distributed in 6 series (from A to F) were carried out in Frantz medium (40 L plus inoculum) in a 80L bioreactor at 35oC, 0.4 atm, 120 rpm, airflow rate of 5 L/min and KLa = 4.2 h-1. The series (A-F) correspond to different experimental conditions as follows: A) without pH and dissolved O2 controls; B) pH control at 6.5; C) pH control at 6.5 and glucose pulse at the 10th hour; D) dissolved O2 control at 10% saturation value; E) pH control at 7.4; F) dissolved O2 limitation (set rotation at 55 rpm). Concentrations of dry biomass, PS, cellular nitrogen, residual glucose, organic and inorganic nitrogen in the medium were measured. The best results were represented by series A (averages of Pf = 0.15 g/L and YP/X = 107 mg/g). The presented findings could be useful for a proper Frantz medium reformulation in order to obtain a greater amount of PS and improve the vaccine development in industrial scale-up production.

  12. Detection and characterisation of the genes encoding glyoxalase I and II from Neisseria meningitidis.

    PubMed

    Kizil, G; Wilks, K; Wells, D; Ala'Aldeen, D A

    2000-07-01

    Glyoxalase enzymes I and II are involved in a detoxification process consisting of conversion of reactive dicarbonyl compounds (e.g., methylglyoxal) to less reactive hydroxy acids. The structural gene for meningococcal glyoxalase I (gloA) was identified by screening an expression library with a rabbit antiserum. The meningococcal gloA gene consisted of 138 deduced amino acids, with a calculated mol. wt of 15.7 kDa. The DNA and deduced protein sequence of gloA was compared to known sequences of glyoxalase I enzymes and showed high homology with gloA of several eukaryotic and prokaryotic species. Insertion of a gloA-containing plasmid in Escherichia coli increased the host organism's tolerance to methylglyoxal from <2 mM to >4 mM, thus demonstrating its functional identity. A databank search also revealed the presence of a putative gloB gene, encoding glyoxalase II (GlxII), in the recently released genomic sequences of Neisseria meningitidis and N. gonorrhoeae.

  13. Neisseria gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR): a novel antimicrobial resistance multilocus typing scheme for tracking the global dissemination of N. gonorrhoeae strains.

    PubMed

    Demczuk, W; Sidhu, S; Unemo, M; Whiley, D M; Allen, V G; Dillon, J R; Cole, M; Seah, C; Trembizki, E; Trees, D L; Kersh, E N; Abrams, A J; de Vries, H J C; van Dam, A P; Medina, I; Bharat, A; Mulvey, M R; Van Domselaar, G; Martin, I

    2017-02-22

    A curated web-based user-friendly sequence typing tool based on antimicrobial resistance determinants in Neisseria gonorrhoeae was developed and is publicly accessible at https://ngstar.canada.ca The N. gonorrhoeae Sequence Typing for Antimicrobial Resistance (NG-STAR) molecular typing scheme uses the DNA sequences of 7 genes (penA, mtrR, porB, ponA, gyrA, parC, 23S rRNA) associated with resistance to β-lactam antimicrobials, macrolides, or fluoroquinolones. NG-STAR uses the entire penA sequence combining the historical nomenclature for penA types I-XXXVIII with novel nucleotide sequence designations; the full mtrR sequence and a portion of its promoter region; portions of ponA, porB, gyrA and parC; and 23S rRNA sequences. NG-STAR grouped 768 isolates into 139 sequence types (STs) (n=660) consisting of 29 CCs having a maximum of a single locus variation; and 76 NG-STAR STs (n=109) were identified as unrelated singletons. NG-STAR had a high Simpson's diversity index of 96.5% (CI 95%=0.959-0.969). The most common STs were NG-STAR: ST-90 (n=100, 13.0%), ST-42 and ST-91 (n=45, 5.9%), ST-64 (n=44, 5.72%), and ST-139 (n=42, 5.5%). Decreased susceptibility to azithromycin was associated with NG-STAR ST-58, ST-61, ST-64, ST-79, ST-91 and ST-139(n=156, 92.3%); decreased susceptibility to cephalosporins with NG-STAR ST-90, ST-91 and ST-97 (n=162, 94.2%); and ciprofloxacin resistance with NG-STAR ST-26, ST-90, ST-91, ST-97, ST-150 and ST-158 (n=196, 98.0%). All isolates of NG-STAR ST-42, ST-43, ST-63, ST-81, and ST-160 (n=106) were susceptible to all four antimicrobials. The standardization of nomenclature associated with antimicrobial resistance determinants through an internationally available database will facilitate the monitoring of the global dissemination of antimicrobial resistant N. gonorrhoeae strains.

  14. Notes from the Field: Increase in Neisseria meningitidis-Associated Urethritis Among Men at Two Sentinel Clinics - Columbus, Ohio, and Oakland County, Michigan, 2015.

    PubMed

    Bazan, Jose A; Peterson, Amy S; Kirkcaldy, Robert D; Briere, Elizabeth C; Maierhofer, Courtney; Turner, Abigail Norris; Licon, Denisse B; Parker, Nicole; Dennison, Amanda; Ervin, Melissa; Johnson, Laura; Weberman, Barbara; Hackert, Pamela; Wang, Xin; Kretz, Cecilia B; Abrams, A Jeanine; Trees, David L; Del Rio, Carlos; Stephens, David S; Tzeng, Yih-Ling; DiOrio, Mary; Roberts, Mysheika Williams

    2016-06-03

    Neisseria meningitidis (Nm) urogenital infections, although less common than infections caused by Neisseria gonorrhoeae (Ng), have been associated with urethritis, cervicitis, proctitis, and pelvic inflammatory disease. Nm can appear similar to Ng on Gram stain analysis (gram-negative intracellular diplococci) (1-5). Because Nm colonizes the nasopharynx, men who receive oral sex (fellatio) can acquire urethral Nm infections (1,3,5). This report describes an increase in Nm-associated urethritis in men attending sexual health clinics in Columbus, Ohio, and Oakland County, Michigan.

  15. Multiplex Real-Time PCR Assay with High-Resolution Melting Analysis for Characterization of Antimicrobial Resistance in Neisseria gonorrhoeae

    PubMed Central

    Donà, Valentina; Kasraian, Sara; Lupo, Agnese; Guilarte, Yuvia N.; Hauser, Christoph; Furrer, Hansjakob; Unemo, Magnus; Low, Nicola

    2016-01-01

    Resistance to antibiotics used against Neisseria gonorrhoeae infections is a major public health concern. Antimicrobial resistance (AMR) testing relies on time-consuming culture-based methods. Development of rapid molecular tests for detection of AMR determinants could provide valuable tools for surveillance and epidemiological studies and for informing individual case management. We developed a fast (<1.5-h) SYBR green-based real-time PCR method with high-resolution melting (HRM) analysis. One triplex and three duplex reactions included two sequences for N. gonorrhoeae identification and seven determinants of resistance to extended-spectrum cephalosporins (ESCs), azithromycin, ciprofloxacin, and spectinomycin. The method was validated by testing 39 previously fully characterized N. gonorrhoeae strains, 19 commensal Neisseria species strains, and an additional panel of 193 gonococcal isolates. Results were compared with results of culture-based AMR determination. The assay correctly identified N. gonorrhoeae and the presence or absence of the seven AMR determinants. There was some cross-reactivity with nongonococcal Neisseria species, and the detection limit was 103 to 104 genomic DNA (gDNA) copies/reaction. Overall, the platform accurately detected resistance to ciprofloxacin (sensitivity and specificity, 100%), ceftriaxone (sensitivity, 100%; specificity, 90%), cefixime (sensitivity, 92%; specificity, 94%), azithromycin (sensitivity and specificity, 100%), and spectinomycin (sensitivity and specificity, 100%). In conclusion, our methodology accurately detects mutations that generate resistance to antibiotics used to treat gonorrhea. Low assay sensitivity prevents direct diagnostic testing of clinical specimens, but this method can be used to screen collections of gonococcal isolates for AMR more quickly than current culture-based AMR testing. PMID:27225407

  16. Multiplex Real-Time PCR Assay with High-Resolution Melting Analysis for Characterization of Antimicrobial Resistance in Neisseria gonorrhoeae.

    PubMed

    Donà, Valentina; Kasraian, Sara; Lupo, Agnese; Guilarte, Yuvia N; Hauser, Christoph; Furrer, Hansjakob; Unemo, Magnus; Low, Nicola; Endimiani, Andrea

    2016-08-01

    Resistance to antibiotics used against Neisseria gonorrhoeae infections is a major public health concern. Antimicrobial resistance (AMR) testing relies on time-consuming culture-based methods. Development of rapid molecular tests for detection of AMR determinants could provide valuable tools for surveillance and epidemiological studies and for informing individual case management. We developed a fast (<1.5-h) SYBR green-based real-time PCR method with high-resolution melting (HRM) analysis. One triplex and three duplex reactions included two sequences for N. gonorrhoeae identification and seven determinants of resistance to extended-spectrum cephalosporins (ESCs), azithromycin, ciprofloxacin, and spectinomycin. The method was validated by testing 39 previously fully characterized N. gonorrhoeae strains, 19 commensal Neisseria species strains, and an additional panel of 193 gonococcal isolates. Results were compared with results of culture-based AMR determination. The assay correctly identified N. gonorrhoeae and the presence or absence of the seven AMR determinants. There was some cross-reactivity with nongonococcal Neisseria species, and the detection limit was 10(3) to 10(4) genomic DNA (gDNA) copies/reaction. Overall, the platform accurately detected resistance to ciprofloxacin (sensitivity and specificity, 100%), ceftriaxone (sensitivity, 100%; specificity, 90%), cefixime (sensitivity, 92%; specificity, 94%), azithromycin (sensitivity and specificity, 100%), and spectinomycin (sensitivity and specificity, 100%). In conclusion, our methodology accurately detects mutations that generate resistance to antibiotics used to treat gonorrhea. Low assay sensitivity prevents direct diagnostic testing of clinical specimens, but this method can be used to screen collections of gonococcal isolates for AMR more quickly than current culture-based AMR testing.

  17. Identification of TEM-135 β-Lactamase in Neisseria gonorrhoeae Strains Carrying African and Toronto Plasmids in Argentina

    PubMed Central

    Gianecini, R.; Oviedo, C.; Littvik, A.; Mendez, E.; Piccoli, L.; Montibello, S.

    2014-01-01

    One hundred forty-three penicillinase-producing Neisseria gonorrhoeae (PPNG) isolates obtained in Argentina from 2008 and 2012 were examined to detect blaTEM-135 genes and to investigate plasmid profiles and multiantigen sequence types. Forty-two PPNG isolates were found to carry TEM-135, and two contained a new TEM derivative characterized as TEM-220. The blaTEM-135 allele was carried by the Toronto/Rio and African plasmids. Molecular epidemiology revealed that two blaTEM-135 isolates were related to previously described isolates from Thailand and China, indicating a common evolutionary origin. PMID:25367903

  18. Identification of TEM-135 β-lactamase in Neisseria gonorrhoeae strains carrying African and Toronto plasmids in Argentina.

    PubMed

    Gianecini, R; Oviedo, C; Littvik, A; Mendez, E; Piccoli, L; Montibello, S; Galarza, P

    2015-01-01

    One hundred forty-three penicillinase-producing Neisseria gonorrhoeae (PPNG) isolates obtained in Argentina from 2008 and 2012 were examined to detect blaTEM-135 genes and to investigate plasmid profiles and multiantigen sequence types. Forty-two PPNG isolates were found to carry TEM-135, and two contained a new TEM derivative characterized as TEM-220. The blaTEM-135 allele was carried by the Toronto/Rio and African plasmids. Molecular epidemiology revealed that two blaTEM-135 isolates were related to previously described isolates from Thailand and China, indicating a common evolutionary origin.

  19. Comparative evaluation of New York City and modified Thayer-Martin media for isolation of Neisseria gonorrhoeae.

    PubMed

    Greenwood, J R; Voss, J; Smith, R F; Wallace, H; Peter, C; Nachtigall, M; Maier, T; Wilber, J; Butsumyo, A

    1986-12-01

    Commercially manufactured New York City (NYC) medium and modified Thayer-Martin (MTM) medium were compared for their ability to isolate Neisseria gonorrhoeae from clinical specimens. Twenty-seven public health laboratories throughout California evaluated 4,802 specimens collected from patients attending either sexually transmitted disease or family planning clinics. Total of 726 and 737 N. gonorrhoeae isolates were recovered from NYC and MTM medium, respectively. Although less contamination was noted on NYC medium, MTM medium was equivalent to commercially prepared NYC medium for the isolation of N. gonorrhoeae from clinical specimens.

  20. Molecular mechanisms involved in the interaction of Neisseria meningitidis with cells of the human blood-cerebrospinal fluid barrier.

    PubMed

    Schubert-Unkmeir, Alexandra

    2017-03-03

    Neisseria meningitidis is one of the most common aetiological agents of bacterial meningitis, affecting predominantly children and young adults. The interaction of N. meningitidis with human endothelial cells lining blood vessels of the blood-cerebrospinal-fluid barrier (B-CSFB) is critical for meningitis development. In recent decades, there has been a significant increase in understanding of the molecular mechanisms involved in the interaction of N. meningitidis with brain vascular cells. In this review, we will describe how N. meningitidis adheres to the brain vasculature, may enter inside these cells, hijack receptor signalling pathways and alter host-cell responses in order to traverse the B-CSFB.

  1. Crystallization and preliminary crystallographic analysis of the (cytosine-5)-DNA methyltransferase NlaX from Neisseria lactamica.

    PubMed

    Kachalova, Galina S; Artyukh, Rimma I; Lavrova, Natalia V; Ryazanova, Elena M; Karyagina, Anna S; Kubareva, Elena A; Bartunik, Hans D

    2005-09-01

    Crystals of the (cytosine-5)-DNA methyltransferase NlaX from Neisseria lactamica (molecular weight 36.5 kDa) have been grown at 291 K using 2.5 M NaCl as precipitant. The crystals diffract to 3.0 A resolution at 100 K. The crystals belong to space group P321, with unit-cell parameters a = 121.98, b = 121.98, c = 56.71 A. There is one molecule in the asymmetric unit and the solvent content is estimated to be 62.1% by volume.

  2. Recall of LCx Neisseria gonorrhoeae assay and implications for laboratory testing for N. gonorrhoeae and Chlamydia trachomatis.

    PubMed

    2002-08-16

    On July 18, 2002, Abbott Laboratories (Abbott Park, IL) initiated a voluntary recall of its LCx Neisseria gonorrhoeae Assay (List Numbers 8A48-81 and 8A48-82) because, during routine quality assurance testing, several reagent lots failed to meet the analytical sensitivity described in the product insert. The cause of the failure is under investigation by the company. Abbott Laboratories has sent a letter to its customers informing them of this recall and the specific reagent lot numbers not meeting the analytical sensitivity.

  3. The β-Barrel Outer Membrane Protein Assembly Complex of Neisseria meningitidis▿

    PubMed Central

    Volokhina, Elena B.; Beckers, Frank; Tommassen, Jan; Bos, Martine P.

    2009-01-01

    The evolutionarily conserved protein Omp85 is required for outer membrane protein (OMP) assembly in gram-negative bacteria and in mitochondria. Its Escherichia coli homolog, designated BamA, functions with four accessory lipoproteins, BamB, BamC, BamD, and BamE, together forming the β-barrel assembly machinery (Bam). Here, we addressed the composition of this machinery and the function of its components in Neisseria meningitidis, a model organism for outer membrane biogenesis studies. Analysis of genome sequences revealed homologs of BamC, BamD (previously described as ComL), and BamE and a second BamE homolog, Mlp. No homolog of BamB was found. As in E. coli, ComL/BamD appeared essential for viability and for OMP assembly, and it could not be replaced by its E. coli homolog. BamE was not essential but was found to contribute to the efficiency of OMP assembly and to the maintenance of OM integrity. A bamC mutant showed only marginal OMP assembly defects, but the impossibility of creating a bamC bamE double mutant further indicated the function of BamC in OMP assembly. An mlp mutant was unaffected in OMP assembly. The results of copurification assays demonstrated the association of BamC, ComL, and BamE with Omp85. Semi-native gel electrophoresis identified the RmpM protein as an additional component of the Omp85 complex, which was confirmed in copurification assays. RmpM was not required for OMP folding but stabilized OMP complexes. Thus, the Bam complex in N. meningitidis consists of Omp85/BamA plus RmpM, BamC, ComL/BamD, and BamE, of which ComL/BamD and BamE appear to be the most important accessory components for OMP assembly. PMID:19767435

  4. Primary pyogenic ventriculitis caused by Neisseria meningitidis: case report and review of the literature

    PubMed Central

    Hassan, Ibrahim; Newton, Pippa

    2017-01-01

    Background. Pyogenic ventriculitis is a well-known complication of meningitis, brain abscesses and intraventricular drains. Primary pyogenic ventriculitis is a rare entity and few cases have been described so far. We report the first case of primary pyogenic ventriculitis in an adult caused by Neisseria meningitidis and present an overview of all reported adult primary pyogenic ventriculitis cases in the English literature. Methods. A PubMed search was performed using the terms ependymitis, ventricular empyema, pyocephalus and ventriculitis. Filter was set for adults and English. Articles in which pyogenic ventriculitis was a complication of well-known risk factors were excluded. A total of five cases of primary pyogenic ventriculitis were identified. Results. There were seven adult patients. Only one patient showed signs of meningeal irritation. Four patients had positive blood cultures with Escherichia coli (one patient), methicillin-resistant Staphylococcus aureus (one patient), one patient was bacteraemic with Enterococcus faecalis, Escherichia coli and Peptostreptococcus spp., and N. meningitidis (our patient). In four patients cerebrospinal fluid was sent for culture, which yielded methicillin-sensitive Staphylococcus aureus (one patient), Peptostreptococcus spp. (one patient), Streptococcus intermedius (one patient, identified via 16S PCR) and Listeria monocytogenes (one patient). Cerebrospinal fluid cell count was determined in four patients and showed pleocytosis in all four cases. Ventricular drainage was performed in four patients. Five patients survived. Discussion. We report the first case of pyogenic ventriculitis caused by N. meningitidis. Primary pyogenic ventriculitis is a rare entity with various clinical presentations caused by various bacterial species. Treatment consists of adequate antimicrobial therapy, and ventricular drainage may be necessary. PMID:28348798

  5. Purification and characterization of the major iron-regulated protein expressed by pathogenic Neisseriae

    PubMed Central

    1987-01-01

    This report describes a method to purify the major iron-regulated protein (MIRP) expressed by N. gonorrhoeae and N. meningitidis. This purification procedure involves maximal expression of the MIRP by growing the organisms on iron-limited media; cellular disruption by sonication followed by centrifugal fractionation; selective solubilization of the MIRP with the cationic detergent hexadecyltrimethylammonium bromide; cation-exchange chromatography in the presence of this detergent; and gel filtration chromatography. The MIRP purified by this technique migrates as a single band when analyzed by SDS-PAGE. The purified MIRP displayed an unusually basic isoelectric point, this value being greater than 9.35. Further biochemical analysis revealed the highly conserved nature of this protein isolated from the two pathogenic species of the genus Neisseria. For example, the amino acid composition of the meningococcal and gonococcal MIRPs were nearly identical and amino terminal sequence analysis showed that both shared the identical primary sequence through residue 48. Surprisingly, the first five NH2-terminal residues of the MIRPs exhibited homology with the first five residues of the gonococcal porin, protein I. Purified preparations of the MIRP exhibited a characteristic pink color reminiscent of the basic iron-binding protein lactoferrin. This observation coupled with the property of iron-regulation prompted us to analyze purified MIRP for iron-content. Approximately 0.5 mol iron per 1 mol of MIRP was detected. This study is the first to show that iron is associated with the MIRP, a property that may implicate this protein as playing a direct role in neisserial iron assimilation. While the precise function of the MIRP is not known, the availability of this protein in pure and biologically relevant quantities will allow further studies to elucidate its pathobiologic function. PMID:3559476

  6. In-vitro activity of antimicrobial agents against Neisseria gonorrhoeae in Brussels.

    PubMed

    Vanhoof, R; Vanderlinden, M P; Hubrechts, J M; Butzler, J P; Yourassowsky, E

    1978-10-01

    The minimum inhibitory concentrations (MICs) of 18 antimicrobial agents against 104 strains of Neisseria gonorrhoeae isolated in the Brussels area between January and October 1976 have been measured. The MICs for penicillin G, ampicillin, amoxycillin, carbenicillin, and cephalexin showed a bimodal distribution. The second modus strains of cephalexin (MIC = 6.25 microgram/ml) were relatively resistant to penicillin G (MIC greater than or equal to 0.08 microgram/ml). About 51% of all strains were relatively resistant to penicillin G, 40.5% to ampicillin (MIC greater than or equal to 0.16 microgram/ml), 46% to amoxycillin, and 47.5% to carbenicillin. For cephalexin and cephaloridine, 25% and 8.5% respectively of all strains were relatively resistant (MIC greater than 3.12 microgram/ml). For cefazolin all MICs fell into a range of 0.097--3.12 microgram/ml. Resistance to tetracycline, doxycycline, minocycline, erythromycin, and spiramycin (MIC greater than or equal to 1 microgram/ml) was found in 9.5%, 7%, 6%, 36.5%, and 71% respectively of all isolates. No strains were resistant to rifampicin. For chloramphenicol and thiamphenicol the MICs ranged from 0.39 to 12.5 microgram/ml and from 0.195 to 3.12 microgram/ml respectively. The results for sulphamethoxazole, trimethoprim, and the combination of sulphamethoxazole and trimethoprim in a 20:1 ratio are given and discussed. The fractional inhibitory concentration (FIC) indices have also been calculated. No beta-lactamase-producing strains were found, and a contingency coefficient C has been determined for all the pairs of antibiotics investigated.

  7. Impact of Calcium Signaling during Infection of Neisseria meningitidis to Human Brain Microvascular Endothelial Cells

    PubMed Central

    Asmat, Tauseef M.; Tenenbaum, Tobias; Jonsson, Ann-Beth

    2014-01-01

    The pili and outer membrane proteins of Neisseria meningitidis (meningococci) facilitate bacterial adhesion and invasion into host cells. In this context expression of meningococcal PilC1 protein has been reported to play a crucial role. Intracellular calcium mobilization has been implicated as an important signaling event during internalization of several bacterial pathogens. Here we employed time lapse calcium-imaging and demonstrated that PilC1 of meningococci triggered a significant increase in cytoplasmic calcium in human brain microvascular endothelial cells, whereas PilC1-deficient meningococci could not initiate this signaling process. The increase in cytosolic calcium in response to PilC1-expressing meningococci was due to efflux of calcium from host intracellular stores as demonstrated by using 2-APB, which inhibits the release of calcium from the endoplasmic reticulum. Moreover, pre-treatment of host cells with U73122 (phospholipase C inhibitor) abolished the cytosolic calcium increase caused by PilC1-expressing meningococci demonstrating that active phospholipase C (PLC) is required to induce calcium transients in host cells. Furthermore, the role of cytosolic calcium on meningococcal adherence and internalization was documented by gentamicin protection assay and double immunofluorescence (DIF) staining. Results indicated that chelation of intracellular calcium by using BAPTA-AM significantly impaired PilC1-mediated meningococcal adherence to and invasion into host endothelial cells. However, buffering of extracellular calcium by BAPTA or EGTA demonstrated no significant effect on meningococcal adherence to and invasion into host cells. Taken together, these results indicate that meningococci induce calcium release from intracellular stores of host endothelial cells via PilC1 and cytoplasmic calcium concentrations play a critical role during PilC1 mediated meningococcal adherence to and subsequent invasion into host endothelial cells. PMID:25464500

  8. Identification of regulatory elements that control expression of the tbpBA operon in Neisseria gonorrhoeae.

    PubMed

    Vélez Acevedo, Rosuany N; Ronpirin, Chalinee; Kandler, Justin L; Shafer, William M; Cornelissen, Cynthia Nau

    2014-08-01

    Iron is an essential nutrient for survival and establishment of infection by Neisseria gonorrhoeae. The neisserial transferrin binding proteins (Tbps) comprise a bipartite system for iron acquisition from human transferrin. TbpA is the TonB-dependent transporter that accomplishes iron internalization. TbpB is a surface-exposed lipoprotein that makes the iron uptake process more efficient. Previous studies have shown that the genes encoding these proteins are arranged in a bicistronic operon, with the tbpB gene located upstream of tbpA and separated from it by an inverted repeat. The operon is under the control of the ferric uptake regulator (Fur); however, promoter elements necessary for regulated expression of the genes have not been experimentally defined. In this study, putative regulatory motifs were identified and confirmed by mutagenesis. Further examination of the sequence upstream of these promoter/operator motifs led to the identification of several novel repeats. We hypothesized that these repeats are involved in additional regulation of the operon. Insertional mutagenesis of regions upstream of the characterized promoter region resulted in decreased tbpB and tbpA transcript levels but increased protein levels for both TbpA and TbpB. Using RNA sequencing (RNA-Seq) technology, we determined that a long RNA was produced from the region upstream of tbpB. We localized the 5' endpoint of this transcript to between the two upstream insertions by qualitative RT-PCR. We propose that expression of this upstream RNA leads to optimized expression of the gene products from within the tbpBA operon.

  9. Lipooligosaccharide Structures of Invasive and Carrier Isolates of Neisseria meningitidis Are Correlated with Pathogenicity and Carriage.

    PubMed

    John, Constance M; Phillips, Nancy J; Din, Richard; Liu, Mingfeng; Rosenqvist, Einar; Høiby, E Arne; Stein, Daniel C; Jarvis, Gary A

    2016-02-12

    The degree of phosphorylation and phosphoethanolaminylation of lipid A on neisserial lipooligosaccharide (LOS), a major cell-surface antigen, can be correlated with inflammatory potential and the ability to induce immune tolerance in vitro. On the oligosaccharide of the LOS, the presence of phosphoethanolamine and sialic acid substituents can be correlated with in vitro serum resistance. In this study, we analyzed the structure of the LOS from 40 invasive isolates and 25 isolates from carriers of Neisseria meningitidis without disease. Invasive strains were classified as groups 1-3 that caused meningitis, septicemia without meningitis, and septicemia with meningitis, respectively. Intact LOS was analyzed by high resolution matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Prominent peaks for lipid A fragment ions with three phosphates and one phosphoethanolamine were detected in all LOS analyzed. LOS from groups 2 and 3 had less abundant ions for highly phosphorylated lipid A forms and induced less TNF-α in THP-1 monocytic cells compared with LOS from group 1. Lipid A from all invasive strains was hexaacylated, whereas lipid A of 6/25 carrier strains was pentaacylated. There were fewer O-acetyl groups and more phosphoethanolamine and sialic acid substitutions on the oligosaccharide from invasive compared with carrier isolates. Bioinformatic and genomic analysis of LOS biosynthetic genes indicated significant skewing to specific alleles, dependent on the disease outcome. Our results suggest that variable LOS structures have multifaceted effects on homeostatic innate immune responses that have critical impact on the pathophysiology of meningococcal infections.

  10. Zinc piracy as a mechanism of Neisseria meningitidis for evasion of nutritional immunity.

    PubMed

    Stork, Michiel; Grijpstra, Jan; Bos, Martine P; Mañas Torres, Carmen; Devos, Nathalie; Poolman, Jan T; Chazin, Walter J; Tommassen, Jan

    2013-10-01

    The outer membrane of Gram-negative bacteria functions as a permeability barrier that protects these bacteria against harmful compounds in the environment. Most nutrients pass the outer membrane by passive diffusion via pore-forming proteins known as porins. However, diffusion can only satisfy the growth requirements if the extracellular concentration of the nutrients is high. In the vertebrate host, the sequestration of essential nutrient metals is an important defense mechanism that limits the growth of invading pathogens, a process known as "nutritional immunity." The acquisition of scarce nutrients from the environment is mediated by receptors in the outer membrane in an energy-requiring process. Most characterized receptors are involved in the acquisition of iron. In this study, we characterized a hitherto unknown receptor from Neisseria meningitidis, a causative agent of sepsis and meningitis. Expression of this receptor, designated CbpA, is induced when the bacteria are grown under zinc limitation. We demonstrate that CbpA functions as a receptor for calprotectin, a protein that is massively produced by neutrophils and other cells and that has been shown to limit bacterial growth by chelating Zn²⁺ and Mn²⁺ ions. Expression of CbpA enables N. meningitidis to survive and propagate in the presence of calprotectin and to use calprotectin as a zinc source. Besides CbpA, also the TonB protein, which couples energy of the proton gradient across the inner membrane to receptor-mediated transport across the outer membrane, is required for the process. CbpA was found to be expressed in all N. meningitidis strains examined, consistent with a vital role for the protein when the bacteria reside in the host. Together, our results demonstrate that N. meningitidis is able to subvert an important defense mechanism of the human host and to utilize calprotectin to promote its growth.

  11. Burden of Neisseria meningitidis infections in China: a systematic review and meta–analysis

    PubMed Central

    Zhang, Yaowen; Wei, Dong; Guo, Xinzhen; Han, Mai; Yuan, Lichao; Kyaw, Moe H

    2016-01-01

    Background Neisseria meningitidis is a leading cause of bacterial meningitis and septicemia in children and young adults worldwide. The disease burden associated with N. meningitidis infections has not been systematically assessed in China. Therefore, we undertook this study to determine the burden of meningococcal disease in China. Method We performed a systematic review and meta–analysis of articles on N. meningitidis incidence, carriage, seroprevalence and mortality rates in China by searching the Chinese BioMedical Database (CBM), China National Knowledge Infrastructure (CNKI), Wanfang database and PubMed for publications from January 2005 to Aug 2015. Results In total, 50 articles were included in our analysis. The overall incidence of meningococcal disease and associated mortality were estimated to be 1.84 (95% confidence interval (CI) 0.91–3.37) per 100 000 persons per year and 0.33 (95% CI 0.12–0.86) per 100 000 persons per year, respectively. N. meningitidis carriage rate among the healthy population was estimated to be 2.7% (95% CI 2.0–3.5%). Prevalence of antibodies against N. meningitidis serogroup A and C were estimated to be 77.3% (95% CI 72.4%–81.6%) and 33.5% (95% CI 27.0%–40.8%), respectively. No studies were found for serogroup specific disease burden. Conclusions The overall incidence of meningococcal disease in China is low. The lower seroprevalence of serogroup C within the population suggests that it may pose a greater risk for meningococcal disease outbreak than serogroup A. The lack of data on serogroup disease burden by age groups suggests the implementation of laboratory based meningococcal surveillance systems are urgently needed in China. PMID:27909580

  12. Deep sequencing-based analysis of the anaerobic stimulon in Neisseria gonorrhoeae

    PubMed Central

    2011-01-01

    Background Maintenance of an anaerobic denitrification system in the obligate human pathogen, Neisseria gonorrhoeae, suggests that an anaerobic lifestyle may be important during the course of infection. Furthermore, mounting evidence suggests that reduction of host-produced nitric oxide has several immunomodulary effects on the host. However, at this point there have been no studies analyzing the complete gonococcal transcriptome response to anaerobiosis. Here we performed deep sequencing to compare the gonococcal transcriptomes of aerobically and anaerobically grown cells. Using the information derived from this sequencing, we discuss the implications of the robust transcriptional response to anaerobic growth. Results We determined that 198 chromosomal genes were differentially expressed (~10% of the genome) in response to anaerobic conditions. We also observed a large induction of genes encoded within the cryptic plasmid, pJD1. Validation of RNA-seq data using translational-lacZ fusions or RT-PCR demonstrated the RNA-seq results to be very reproducible. Surprisingly, many genes of prophage origin were induced anaerobically, as well as several transcriptional regulators previously unknown to be involved in anaerobic growth. We also confirmed expression and regulation of a small RNA, likely a functional equivalent of fnrS in the Enterobacteriaceae family. We also determined that many genes found to be responsive to anaerobiosis have also been shown to be responsive to iron and/or oxidative stress. Conclusions Gonococci will be subject to many forms of environmental stress, including oxygen-limitation, during the course of infection. Here we determined that the anaerobic stimulon in gonococci was larger than previous studies would suggest. Many new targets for future research have been uncovered, and the results derived from this study may have helped to elucidate factors or mechanisms of virulence that may have otherwise been overlooked. PMID:21251255

  13. Proteomics of Neisseria gonorrhoeae: the treasure hunt for countermeasures against an old disease

    PubMed Central

    Baarda, Benjamin I.; Sikora, Aleksandra E.

    2015-01-01

    Neisseria gonorrhoeae is an exquisitely adapted, strictly human pathogen and the causative agent of the sexually transmitted infection gonorrhea. This ancient human disease remains a serious problem, occurring at high incidence globally and having a major impact on reproductive and neonatal health. N. gonorrhoeae is rapidly evolving into a superbug and no effective vaccine exists to prevent gonococcal infections. Untreated or inadequately treated gonorrhea can lead to severe sequelae, including pelvic inflammatory disease and infertility in women, epididymitis in men, and sight-threatening conjunctivitis in infants born to infected mothers. Therefore, there is an immediate need for accelerated research toward the identification of molecular targets for development of drugs with new mechanisms of action and preventive vaccine(s). Global proteomic approaches are ideally suited to guide these studies. Recent quantitative proteomics (SILAC, iTRAQ, and ICAT) have illuminated the pathways utilized by N. gonorrhoeae to adapt to different lifestyles and micro-ecological niches within the host, while comparative 2D SDS-PAGE analysis has been used to elucidate spectinomycin resistance mechanisms. Further, high-throughput examinations of cell envelopes and naturally released membrane vesicles have unveiled the ubiquitous and differentially expressed proteins between temporally and geographically diverse N. gonorrhoeae isolates. This review will focus on these different approaches, emphasizing the role of proteomics in the search for vaccine candidates. Although our knowledge of N. gonorrhoeae has been expanded, still far less is known about this bacterium than the closely related N. meningitidis, where genomics- and proteomics-driven studies have led to the successful development of vaccines. PMID:26579097

  14. Conservation and Accessibility of an Inner Core Lipopolysaccharide Epitope of Neisseria meningitidis

    PubMed Central

    Plested, Joyce S.; Makepeace, Katherine; Jennings, Michael P.; Gidney, Margaret Anne J.; Lacelle, Suzanne; Brisson, J.-R.; Cox, Andrew D.; Martin, Adele; Bird, A. Graham; Tang, Christoph M.; Mackinnon, Fiona M.; Richards, James C.; Moxon, E. Richard

    1999-01-01

    We investigated the conservation and antibody accessibility of inner core epitopes of Neisseria meningitidis lipopolysaccharide (LPS) because of their potential as vaccine candidates. An immunoglobulin G3 murine monoclonal antibody (MAb), designated MAb B5, was obtained by immunizing mice with a galE mutant of N. meningitidis H44/76 (B.15.P1.7,16 immunotype L3). We have shown that MAb B5 can bind to the core LPS of wild-type encapsulated MC58 (B.15.P1.7,16 immunotype L3) organisms in vitro and ex vivo. An inner core structure recognized by MAb B5 is conserved and accessible in 26 of 34 (76%) of group B and 78 of 112 (70%) of groups A, C, W, X, Y, and Z strains. N. meningitidis strains which possess this epitope are immunotypes in which phosphoethanolamine (PEtn) is linked to the 3-position of the β-chain heptose (HepII) of the inner core. In contrast, N. meningitidis strains lacking reactivity with MAb B5 have an alternative core structure in which PEtn is linked to an exocyclic position (i.e., position 6 or 7) of HepII (immunotypes L2, L4, and L6) or is absent (immunotype L5). We conclude that MAb B5 defines one or more of the major inner core glycoforms of N. meningitidis LPS. These findings support the possibility that immunogens capable of eliciting functional antibodies specific to inner core structures could be the basis of a vaccine against invasive infections caused by N. meningitidis. PMID:10496924

  15. Inhibition of Neisseria gonorrhoeae Type II Topoisomerases by the Novel Spiropyrimidinetrione AZD0914.

    PubMed

    Kern, Gunther; Palmer, Tiffany; Ehmann, David E; Shapiro, Adam B; Andrews, Beth; Basarab, Gregory S; Doig, Peter; Fan, Jun; Gao, Ning; Mills, Scott D; Mueller, John; Sriram, Shubha; Thresher, Jason; Walkup, Grant K

    2015-08-21

    We characterized the inhibition of Neisseria gonorrhoeae type II topoisomerases gyrase and topoisomerase IV by AZD0914 (AZD0914 will be henceforth known as ETX0914 (Entasis Therapeutics)), a novel spiropyrimidinetrione antibacterial compound that is currently in clinical trials for treatment of drug-resistant gonorrhea. AZD0914 has potent bactericidal activity against N. gonorrhoeae, including multidrug-resistant strains and key Gram-positive, fastidious Gram-negative, atypical, and anaerobic bacterial species (Huband, M. D., Bradford, P. A., Otterson, L. G., Basrab, G. S., Giacobe, R. A., Patey, S. A., Kutschke, A. C., Johnstone, M. R., Potter, M. E., Miller, P. F., and Mueller, J. P. (2014) In Vitro Antibacterial Activity of AZD0914: A New Spiropyrimidinetrione DNA Gyrase/Topoisomerase Inhibitor with Potent Activity against Gram-positive, Fastidious Gram-negative, and Atypical Bacteria. Antimicrob. Agents Chemother. 59, 467-474). AZD0914 inhibited DNA biosynthesis preferentially to other macromolecules in Escherichia coli and induced the SOS response to DNA damage in E. coli. AZD0914 stabilized the enzyme-DNA cleaved complex for N. gonorrhoeae gyrase and topoisomerase IV. The potency of AZD0914 for inhibition of supercoiling and the stabilization of cleaved complex by N. gonorrhoeae gyrase increased in a fluoroquinolone-resistant mutant enzyme. When a mutation, conferring mild resistance to AZD0914, was present in the fluoroquinolone-resistant mutant, the potency of ciprofloxacin for inhibition of supercoiling and stabilization of cleaved complex was increased greater than 20-fold. In contrast to ciprofloxacin, religation of the cleaved DNA did not occur in the presence of AZD0914 upon removal of magnesium from the DNA-gyrase-inhibitor complex. AZD0914 had relatively low potency for inhibition of human type II topoisomerases α and β.

  16. Inhibition of Neisseria gonorrhoeae Type II Topoisomerases by the Novel Spiropyrimidinetrione AZD0914*

    PubMed Central

    Kern, Gunther; Palmer, Tiffany; Ehmann, David E.; Shapiro, Adam B.; Andrews, Beth; Basarab, Gregory S.; Doig, Peter; Fan, Jun; Gao, Ning; Mills, Scott D.; Mueller, John; Sriram, Shubha; Thresher, Jason; Walkup, Grant K.

    2015-01-01

    We characterized the inhibition of Neisseria gonorrhoeae type II topoisomerases gyrase and topoisomerase IV by AZD0914 (AZD0914 will be henceforth known as ETX0914 (Entasis Therapeutics)), a novel spiropyrimidinetrione antibacterial compound that is currently in clinical trials for treatment of drug-resistant gonorrhea. AZD0914 has potent bactericidal activity against N. gonorrhoeae, including multidrug-resistant strains and key Gram-positive, fastidious Gram-negative, atypical, and anaerobic bacterial species (Huband, M. D., Bradford, P. A., Otterson, L. G., Basrab, G. S., Giacobe, R. A., Patey, S. A., Kutschke, A. C., Johnstone, M. R., Potter, M. E., Miller, P. F., and Mueller, J. P. (2014) In Vitro Antibacterial Activity of AZD0914: A New Spiropyrimidinetrione DNA Gyrase/Topoisomerase Inhibitor with Potent Activity against Gram-positive, Fastidious Gram-negative, and Atypical Bacteria. Antimicrob. Agents Chemother. 59, 467–474). AZD0914 inhibited DNA biosynthesis preferentially to other macromolecules in Escherichia coli and induced the SOS response to DNA damage in E. coli. AZD0914 stabilized the enzyme-DNA cleaved complex for N. gonorrhoeae gyrase and topoisomerase IV. The potency of AZD0914 for inhibition of supercoiling and the stabilization of cleaved complex by N. gonorrhoeae gyrase increased in a fluoroquinolone-resistant mutant enzyme. When a mutation, conferring mild resistance to AZD0914, was present in the fluoroquinolone-resistant mutant, the potency of ciprofloxacin for inhibition of supercoiling and stabilization of cleaved complex was increased greater than 20-fold. In contrast to ciprofloxacin, religation of the cleaved DNA did not occur in the presence of AZD0914 upon removal of magnesium from the DNA-gyrase-inhibitor complex. AZD0914 had relatively low potency for inhibition of human type II topoisomerases α and β. PMID:26149691

  17. Identification of sRNAs expressed by the human pathogen Neisseria gonorrhoeae under disparate growth conditions.

    PubMed

    McClure, Ryan; Tjaden, Brian; Genco, Caroline

    2014-01-01

    In the last several years, bacterial gene regulation via small RNAs (sRNAs) has been recognized as an important mechanism controlling expression of essential proteins that are critical to bacterial growth and metabolism. Technologies such as RNA-seq are rapidly expanding the field of sRNAs and are enabling a global view of the "sRNAome" of several bacterial species. While numerous sRNAs have been identified in a variety of both Gram-negative and Gram-positive bacteria, only a very small number have been fully characterized in the human pathogen Neisseria gonorrhoeae, the etiological agent of the STD gonorrhea. Here we present the first analysis of N. gonorrhoeae specifically focused on the identification of sRNAs through RNA-seq analysis of the organism cultured under different in vitro growth conditions. Using a new computational program, Rockhopper, to analyze prokaryotic RNA-seq data obtained from N. gonorrhoeae we identified several putative sRNAs and confirmed their expression and size through Northern blot analysis. In addition, RNA was collected from four different growth conditions (iron replete and deplete, as well as with and without co-culture with human endocervical cells). Many of the putative sRNAs identified shoed varying expression levels relative to the different growth conditions examine or were detected only under certain conditions but not others. Comparisons of identified sRNAs with the regulatory pattern of putative mRNA targets revealed possible functional roles for these sRNAs. These studies are the first to carry out a global analysis of N. gonorrhoeae specifically focused on sRNAs and show that RNA-mediated regulation may be an important mechanism of gene control in this human pathogen.

  18. Role of Hfq in iron-dependent and -independent gene regulation in Neisseria meningitidis.

    PubMed

    Mellin, J R; McClure, Ryan; Lopez, Delia; Green, Olivia; Reinhard, Bjorn; Genco, Caroline

    2010-08-01

    In Neisseria meningitidis, iron-responsive gene regulation is mediated primarily by the ferric uptake regulator (Fur) protein. When complexed with iron, Fur represses gene expression by preventing transcription initiation. Fur can also indirectly activate gene expression via the repression of regulatory small RNAs (sRNA). One such Fur- and iron-regulated sRNA, NrrF, was previously identified in N. meningitidis and shown to repress expression of the sdhA and sdhC genes encoding subunits of the succinate dehydrogenase complex. In the majority of Gram-negative bacteria, sRNA-mediated regulation requires a cofactor RNA-binding protein (Hfq) for proper gene regulation and stabilization. In this study, we examined the role of Hfq in NrrF-mediated regulation of the succinate dehydrogenase genes in N. meningitidis and the effect of an hfq mutation on iron-responsive gene regulation more broadly. We first demonstrated that the stability of NrrF, as well as the regulation of sdhC and sdhA in vivo, was unaltered in the hfq mutant. Secondly, we established that iron-responsive gene regulation of the Fur-regulated sodB gene was dependent on Hfq. Finally, we demonstrated that in N. meningitidis, Hfq functions in a global manner to control expression of many ORFs and intergenic regions via iron-independent mechanisms. Collectively these studies demonstrate that in N. meningitidis, iron- and NrrF-mediated regulation of sdhC and sdhA can occur independently of Hfq, although Hfq functions more globally to control regulation of other N. meningitidis genes primarily by iron-independent mechanisms.

  19. Transcriptional and Functional Analysis of the Neisseria gonorrhoeae Fur Regulon▿ †

    PubMed Central

    Jackson, Lydgia A.; Ducey, Thomas F.; Day, Michael W.; Zaitshik, Jeremy B.; Orvis, Joshua; Dyer, David W.

    2010-01-01

    To ensure survival in the host, bacteria have evolved strategies to acquire the essential element iron. In Neisseria gonorrhoeae, the ferric uptake regulator Fur regulates metabolism through transcriptional control of iron-responsive genes by binding conserved Fur box (FB) sequences in promoters during iron-replete growth. Our previous studies showed that Fur also controls the transcription of secondary regulators that may, in turn, control pathways important to pathogenesis, indicating an indirect role for Fur in controlling these downstream genes. To better define the iron-regulated cascade of transcriptional control, we combined three global strategies—temporal transcriptome analysis, genomewide in silico FB prediction, and Fur titration assays (FURTA)—to detect genomic regions able to bind Fur in vivo. The majority of the 300 iron-repressed genes were predicted to be of unknown function, followed by genes involved in iron metabolism, cell communication, and intermediary metabolism. The 107 iron-induced genes encoded hypothetical proteins or energy metabolism functions. We found 28 predicted FBs in FURTA-positive clones in the promoters and within the open reading frames of iron-repressed genes. We found lower levels of conservation at critical thymidine residues involved in Fur binding in the FB sequence logos of FURTA-positive clones with intragenic FBs than in the sequence logos generated from FURTA-positive promoter regions. In electrophoretic mobility shift assay studies, intragenic FBs bound Fur with a lower affinity than intergenic FBs. Our findings further indicate that transcription under iron stress is indirectly controlled by Fur through 12 potential secondary regulators. PMID:19854902

  20. Comparative Genome Sequencing Reveals Within-Host Genetic Changes in Neisseria meningitidis during Invasive Disease

    PubMed Central

    Klughammer, Johanna; Dittrich, Marcus; Blom, Jochen; Mitesser, Vera; Vogel, Ulrich; Frosch, Matthias; Goesmann, Alexander; Müller, Tobias

    2017-01-01

    Some members of the physiological human microbiome occasionally cause life-threatening disease even in immunocompetent individuals. A prime example of such a commensal pathogen is Neisseria meningitidis, which normally resides in the human nasopharynx but is also a leading cause of sepsis and epidemic meningitis. Using N. meningitidis as model organism, we tested the hypothesis that virulence of commensal pathogens is a consequence of within host evolution and selection of invasive variants due to mutations at contingency genes, a mechanism called phase variation. In line with the hypothesis that phase variation evolved as an adaptation to colonize diverse hosts, computational comparisons of all 27 to date completely sequenced and annotated meningococcal genomes retrieved from public databases showed that contingency genes are indeed enriched for genes involved in host interactions. To assess within-host genetic changes in meningococci, we further used ultra-deep whole-genome sequencing of throat-blood strain pairs isolated from four patients suffering from invasive meningococcal disease. We detected up to three mutations per strain pair, affecting predominantly contingency genes involved in type IV pilus biogenesis. However, there was not a single (set) of mutation(s) that could invariably be found in all four pairs of strains. Phenotypic assays further showed that these genetic changes were generally not associated with increased serum resistance, higher fitness in human blood ex vivo or differences in the interaction with human epithelial and endothelial cells in vitro. In conclusion, we hypothesize that virulence of meningococci results from accidental emergence of invasive variants during carriage and without within host evolution of invasive phenotypes during disease progression in vivo. PMID:28081260

  1. Organization and transcription of the division cell wall (dcw) cluster in Neisseria gonorrhoeae.

    PubMed

    Francis, F; Ramirez-Arcos, S; Salimnia, H; Victor, C; Dillon, J R

    2000-06-27

    A cluster of genes involved in cell division and cell wall (dcw) biosynthesis was identified in Neisseria gonorrhoeae using genomic analysis and through verification of gene order by polymerase chain reaction (PCR) analysis. The gonococcal dcw cluster consists of 17 genes, in the order 5'-mraZ-mraW-ftsI-murE-hyp1-murF- mraY-hyp2-murD-ftsW-murG-murC-ddl -ft sQ-ftsA-ftsZ-hyp3-3'. The gene organization of the dcw cluster of N. gonorrhoeae is more similar to that observed in Gram-negative rods such as Escherichia coli and Haemophilus influenzae than in Gram-positive bacteria. The cluster is characterized by several intergenic spaces. Compared with E. coli, two genes, ftsL and envA, are absent in the gonococcal dcw cluster and three hypothetical genes are novel to the cluster. The cluster is flanked by two transcriptional terminators consisting of paired neisserial uptake sequences and also includes four internal terminators, three of which are paired neisserial uptake sequences. We also found that a repeated sequence on the gonococcal genome, commonly called a Correia element, acts as the fourth transcriptional terminator. All termination sequences were shown to be fully functional by using reverse transcription PCR experiments. Transcriptional start sites upstream of ftsQ, ftsA and ftsZ were determined by primer extension and six promoters were identified; three promoters were located upstream of ftsZ in the intergenic space, two were upstream of ftsA within ftsQ and one was upstream of ftsQ within ddl. Some of these promoters were preferentially used under anaerobic conditions. The location of these promoters differed from those described in E. coli indicating dissimilar transcriptional regulation.

  2. Emergence of decreased susceptibility and resistance to extended-spectrum cephalosporins in Neisseria gonorrhoeae in Korea

    PubMed Central

    Lee, Hyukmin; Unemo, Magnus; Kim, Hyo Jin; Seo, Younghee; Lee, Kyungwon; Chong, Yunsop

    2015-01-01

    Objectives Antimicrobial resistance (AMR) in Neisseria gonorrhoeae is a major concern globally; however, no comprehensive AMR data for gonococcal isolates cultured after 2006 in Korea have been published internationally. We determined the susceptibility of N. gonorrhoeae isolates cultured in 2011–13, the mechanism of extended-spectrum cephalosporin (ESC) resistance and the molecular epidemiology of gonococcal strains in Korea. Methods In 2011–13, 210 gonococcal isolates were collected in Korea and their AMR profiles were examined by the agar dilution method. The penA, mtrR, penB, ponA and pilQ genes were sequenced in 25 isolates that were resistant to ESCs and 70 randomly selected isolates stratified by year. For molecular epidemiology, N. gonorrhoeae multiantigen sequence typing and MLST were performed. Results None of the N. gonorrhoeae isolates was susceptible to penicillin G and most were resistant to tetracycline (50%) and ciprofloxacin (97%). The rates of resistance to ceftriaxone, azithromycin, cefpodoxime and cefixime were 3%, 5%, 8% and 9%, respectively. However, all isolates were susceptible to spectinomycin. Twenty-one (84%) of the 25 ESC-resistant isolates contained the non-mosaic PBP2 XIII allele; however, the remaining 4 (16%) possessed the mosaic PBP2 X allele, which has been previously associated with ESC resistance including treatment failures. Conclusions In Korea, susceptibility to spectinomycin remains high. However, the recent emergence of ESC-resistant N. gonorrhoeae strains, including strains possessing the PBP2 mosaic X and non-mosaic XIII alleles, is a major concern and enhanced AMR surveillance is necessary to prevent transmission of these strains. PMID:26084303

  3. Population-Based Surveillance of Neisseria meningitidis Antimicrobial Resistance in the United States

    PubMed Central

    Harcourt, Brian H.; Anderson, Raydel D.; Wu, Henry M.; Cohn, Amanda C.; MacNeil, Jessica R.; Taylor, Thomas H.; Wang, Xin; Clark, Thomas A.; Messonnier, Nancy E.; Mayer, Leonard W.

    2015-01-01

    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. PMID:26357666

  4. Extragenital Infections Caused by Chlamydia trachomatis and Neisseria gonorrhoeae: A Review of the Literature.

    PubMed

    Chan, Philip A; Robinette, Ashley; Montgomery, Madeline; Almonte, Alexi; Cu-Uvin, Susan; Lonks, John R; Chapin, Kimberle C; Kojic, Erna M; Hardy, Erica J

    2016-01-01

    In the United States, sexually transmitted diseases due to Chlamydia trachomatis and Neisseria gonorrhoeae continue to be a major public health burden. Screening of extragenital sites including the oropharynx and rectum is an emerging practice based on recent studies highlighting the prevalence of infection at these sites. We reviewed studies reporting the prevalence of extragenital infections in women, men who have sex with men (MSM), and men who have sex only with women (MSW), including distribution by anatomical site. Among women, prevalence was found to be 0.6-35.8% for rectal gonorrhea (median reported prevalence 1.9%), 0-29.6% for pharyngeal gonorrhea (median 2.1%), 2.0-77.3% for rectal chlamydia (median 8.7%), and 0.2-3.2% for pharyngeal chlamydia (median 1.7%). Among MSM, prevalence was found to be 0.2-24.0% for rectal gonorrhea (median 5.9%), 0.5-16.5% for pharyngeal gonorrhea (median 4.6%), 2.1-23.0% for rectal chlamydia (median 8.9%), and 0-3.6% for pharyngeal chlamydia (median 1.7%). Among MSW, the prevalence was found to be 0-5.7% for rectal gonorrhea (median 3.4%), 0.4-15.5% for pharyngeal gonorrhea (median 2.2%), 0-11.8% for rectal chlamydia (median 7.7%), and 0-22.0% for pharyngeal chlamydia (median 1.6%). Extragenital infections are often asymptomatic and found in the absence of reported risk behaviors, such as receptive anal and oral intercourse. We discuss current clinical recommendations and future directions for research.

  5. Phenotypic and Genotypic Characteristics of Neisseria meningitidis Disease-Causing Strains in Argentina, 2010

    PubMed Central

    Sorhouet-Pereira, Cecilia; Efron, Adriana; Gagetti, Paula; Faccone, Diego; Regueira, Mabel; Corso, Alejandra; Gabastou, Jean-Marc; Ibarz-Pavón, Ana Belén

    2013-01-01

    Phenotypic and genotypic characterization of 133 isolates of Neisseria meningitidis obtained from meningococcal disease cases in Argentina during 2010 were performed by the National Reference Laboratory as part of a project coordinated by the PAHO within the SIREVA II network. Serogroup, serotype, serosubtype and MLST characterization were performed. Minimum Inhibitory Concentration to penicillin, ampicillin, ceftriaxone, rifampin, chloramphenicol, tetracycline and ciprofloxacin were determined and interpreted according to CLSI guidelines. Almost 49% of isolates were W135, and two serotype:serosubtype combinations, W135∶2a:P1.5,2:ST-11 and W135∶2a:P1.2:ST-11 accounted for 78% of all W135 isolates. Serogroup B accounted for 42.1% of isolates, and was both phenotypically and genotypically diverse. Serogroup C isolates represented 5.3% of the dataset, and one isolate belonging to the ST-198 complex was non-groupable. Isolates belonged mainly to the ST-11 complex (48%) and to a lesser extent to the ST-865 (18%), ST-32 (9,8%) and the ST-35 complexes (9%). Intermediate resistance to penicillin and ampicillin was detected in 35.4% and 33.1% of isolates respectively. Two W135∶2a:P1.5,2:ST-11:ST-11 isolates presented resistance to ciprofloxacin associated with a mutation in the QRDR of gyrA gene Thr91-Ile. These data show serogroup W135 was the first cause of disease in Argentina in 2010, and was strongly associated with the W135∶2a:P1.5,2:ST-11 epidemic clone. Serogroup B was the second cause of disease and isolates belonging to this serogroup were phenotypically and genotypically diverse. The presence of isolates with intermediate resistance to penicillin and the presence of fluorquinolone-resistant isolates highlight the necessity and importance of maintaining and strengthening National Surveillance Programs. PMID:23483970

  6. Extragenital Infections Caused by Chlamydia trachomatis and Neisseria gonorrhoeae: A Review of the Literature

    PubMed Central

    Chan, Philip A.; Montgomery, Madeline; Almonte, Alexi; Lonks, John R.; Chapin, Kimberle C.; Kojic, Erna M.; Hardy, Erica J.

    2016-01-01

    In the United States, sexually transmitted diseases due to Chlamydia trachomatis and Neisseria gonorrhoeae continue to be a major public health burden. Screening of extragenital sites including the oropharynx and rectum is an emerging practice based on recent studies highlighting the prevalence of infection at these sites. We reviewed studies reporting the prevalence of extragenital infections in women, men who have sex with men (MSM), and men who have sex only with women (MSW), including distribution by anatomical site. Among women, prevalence was found to be 0.6–35.8% for rectal gonorrhea (median reported prevalence 1.9%), 0–29.6% for pharyngeal gonorrhea (median 2.1%), 2.0–77.3% for rectal chlamydia (median 8.7%), and 0.2–3.2% for pharyngeal chlamydia (median 1.7%). Among MSM, prevalence was found to be 0.2–24.0% for rectal gonorrhea (median 5.9%), 0.5–16.5% for pharyngeal gonorrhea (median 4.6%), 2.1–23.0% for rectal chlamydia (median 8.9%), and 0–3.6% for pharyngeal chlamydia (median 1.7%). Among MSW, the prevalence was found to be 0–5.7% for rectal gonorrhea (median 3.4%), 0.4–15.5% for pharyngeal gonorrhea (median 2.2%), 0–11.8% for rectal chlamydia (median 7.7%), and 0–22.0% for pharyngeal chlamydia (median 1.6%). Extragenital infections are often asymptomatic and found in the absence of reported risk behaviors, such as receptive anal and oral intercourse. We discuss current clinical recommendations and future directions for research. PMID:27366021

  7. DNA Methylation Assessed by SMRT Sequencing Is Linked to Mutations in Neisseria meningitidis Isolates

    PubMed Central

    Sater, Mohamad R. Abdul; Lamelas, Araceli; Wang, Guilin; Clark, Tyson A.; Röltgen, Katharina; Mane, Shrikant; Korlach, Jonas; Pluschke, Gerd; Schmid, Christoph D.

    2015-01-01

    The Gram-negative bacterium Neisseria meningitidis features extensive genetic variability. To present, proposed virulence genotypes are also detected in isolates from asymptomatic carriers, indicating more complex mechanisms underlying variable colonization modes of N. meningitidis. We applied the Single Molecule, Real-Time (SMRT) sequencing method from Pacific Biosciences to assess the genome-wide DNA modification profiles of two genetically related N. meningitidis strains, both of serogroup A. The resulting DNA methylomes revealed clear divergences, represented by the detection of shared and of strain-specific DNA methylation target motifs. The positional distribution of these methylated target sites within the genomic sequences displayed clear biases, which suggest a functional role of DNA methylation related to the regulation of genes. DNA methylation in N. meningitidis has a likely underestimated potential for variability, as evidenced by a careful analysis of the ORF status of a panel of confirmed and predicted DNA methyltransferase genes in an extended collection of N. meningitidis strains of serogroup A. Based on high coverage short sequence reads, we find phase variability as a major contributor to the variability in DNA methylation. Taking into account the phase variable loci, the inferred functional status of DNA methyltransferase genes matched the observed methylation profiles. Towards an elucidation of presently incompletely characterized functional consequences of DNA methylation in N. meningitidis, we reveal a prominent colocalization of methylated bases with Single Nucleotide Polymorphisms (SNPs) detected within our genomic sequence collection. As a novel observation we report increased mutability also at 6mA methylated nucleotides, complementing mutational hotspots previously described at 5mC methylated nucleotides. These findings suggest a more diverse role of DNA methylation and Restriction-Modification (RM) systems in the evolution of

  8. Study of various presentation forms for a peptide mimetic of Neisseria meningitidis serogroup B capsular polysaccharide.

    PubMed

    Garay, Hilda; Menéndez, Tamara; Cruz-Leal, Yoelys; Coizeau, Edelgis; Noda, Jesus; Morera, Vivian; Guillén, Gerardo; Albericio, Fernando; Reyes, Osvaldo

    2011-01-19

    The formulation of a broadly protective vaccine to prevent the serogroup B Neisseria meningitidis (MenB) disease is still an unmet medical need. We have previously reported the induction of bactericidal and protective antibodies against MenB after immunization of mice with a phage-displayed peptide named 4 L-5. This peptide mimics a capsular polysaccharide (CPS) epitope in MenB. With the aim of developing vaccine formulations that could be used in humans, we evaluate in this study various forms of presentation to the immune system of the 4 L-5 sequence, based on synthetic peptides. We synthesized the following: (i) a linear 4 L-5 peptide, (ii) a multiple antigen peptide containing four copies of the 4 L-5 sequence (named MAP), which was then dimerized, and the product named dimeric MAP, and (iii) a second multiple antigen peptide, in this case with two copies of the 4 L-5 sequence and a copy of a T-helper cell epitope of tetanus toxoid, which was then dimerized and the product named MAP-TT. The linear peptide, the MAP, and the dimeric MAP were conjugated to the carrier protein P64K by different conjugation methods. Plain antigens and antigens coupled to P64K were used to immunize BALB/c mice. Of those variants that gave immunogenic results, MAP-TT rendered the highest levels of specific antipeptide IgG antibodies and serum bactericidal activity. These results can find application in the development of meningococcal vaccine candidates and in peptide-based vaccines strategies.

  9. [Laboratory practices: diagnostics and antibiotics resistance testing of Neisseria gonorrhoeae in Germany].

    PubMed

    Loenenbach, Anna; Dudareva-Vizule, S; Buder, S; Sailer, A; Kohl, P K; Bremer, V

    2015-08-01

    Recent years have seen a world-wide increase in antimicrobial resistance (AMR) in cases of infection with Neisseria gonorrhoeae (NG). NG infection is not notifiable in Germany and there is a lack of information available about the spread and AMR of NG infections. The objective of the study was to provide information on diagnostic methods and AMR testing in cases of NG infections in German laboratories. A cross-sectional survey was undertaken in Germany between June and August 2013 using an online questionnaire. Laboratories performing NG diagnostics were identified and described with regard to the diagnostic methods used, the number of tests performed, the antibiotics tested and the AMR observed, in addition to general laboratory information. In total, 188 of the 521 participating laboratories performed NG diagnostics; these were included in the further statistical analysis. 92.6 % of the 188 laboratories performed culture. A median of 60 (IQR 15-270) samples per quarter (SPQ) were tested, with an overall positivity rate of 4.1 and 6.9 % among men. Most (82.1 %) of the 151 laboratories performing NG culture tested for AMR as well. The most frequently tested antibiotics were ciprofloxacin (94.8 %), penicillin (93.1 %), doxycycline (70.0 %) and ceftriaxone (67.2 %). The most frequently observed AMR ever were those against ciprofloxacin (87.1 %), penicillin (78.3 %), doxycycline (56.6 %) and azithromycin (35.1 %; all percentages refer to laboratories). The laboratories used different standards regarding susceptibility criteria. The emergence and spread of AMR shows that it is crucial to assess and monitor the scope and trends of multidrug-resistant gonorrhea. The data collected on diagnostic methods and AMR testing in cases of NG infections in German laboratories constitute an important basis for future monitoring.

  10. Binding to DNA protects Neisseria meningitidis fumarate and nitrate reductase regulator (FNR) from oxygen.

    PubMed

    Edwards, James; Cole, Lindsay J; Green, Jasper B; Thomson, Melanie J; Wood, A Jamie; Whittingham, Jean L; Moir, James W B

    2010-01-08

    Here, we report the overexpression, purification, and characterization of the transcriptional activator fumarate and nitrate reductase regulator from the pathogenic bacterium Neisseria meningitidis (NmFNR). Like its homologue from Escherichia coli (EcFNR), NmFNR binds a 4Fe-4S cluster, which breaks down in the presence of oxygen to a 2Fe-2S cluster and subsequently to apo-FNR. The kinetics of NmFNR cluster disassembly in the presence of oxygen are 2-3x slower than those previously reported for wild-type EcFNR, but similar to constitutively active EcFNR* mutants, consistent with earlier work in which we reported that the activity of FNR-dependent promoters in N. meningitidis is only weakly inhibited by the presence of oxygen (Rock, J. D., Thomson, M. J., Read, R. C., and Moir, J. W. (2007) J. Bacteriol. 189, 1138-1144). NmFNR binds to DNA containing a consensus FNR box sequence, and this binding stabilizes the iron-sulfur cluster in the presence of oxygen. Partial degradation of the 4Fe-4S cluster to a 3Fe-4S occurs, and this form remains bound to the DNA. The 3Fe-4S cluster is converted spontaneously back to a 4Fe-4S cluster under subsequent anaerobic reducing conditions in the presence of ferrous iron. The finding that binding to DNA stabilizes FNR in the presence of oxygen such that it has a half-life of approximately 30 min on the DNA has implications for our appreciation of how oxygen switches off FNR activatable genes in vivo.

  11. Proteolysis of bacterial membrane proteins by Neisseria gonorrhoeae type 2 immunoglobulin A1 protease.

    PubMed Central

    Shoberg, R J; Mulks, M H

    1991-01-01

    The immunoglobulin A1 (IgA1) proteases of Neisseria gonorrhoeae have been defined as having human IgA1 as their single permissive substrate. However, in recent years there have been reports of other proteins which are susceptible to the proteolytic activity of these enzymes. To examine the possibility that gonococcal membrane proteins are potential substrates for these enzymes, isolated outer and cytoplasmic membranes of N. gonorrhoeae were treated in vitro with exogenous pure IgA1 protease. Analysis of silver-stained sodium dodecyl sulfate-polyacrylamide gels of outer membranes indicated that there were two outer membrane proteins of 78 and 68 kDa which were cleaved by IgA1 protease in vitro in GCM 740 (a wild-type strain) and in two isogenic IgA1 protease-negative variants. Similar results were observed with a second gonococcal strain, F62, and its isogenic IgA1 protease-negative derivative. When GCM 740 cytoplasmic membranes were treated with protease, three minor proteins of 24.5, 23.5, and 21.5 kDa were cleaved. In addition, when outer membranes of Escherichia coli DH1 were treated with IgA1 protease, several proteins were hydrolyzed. While the identities of all of these proteolyzed proteins are unknown, the data presented indicate that there are several proteins found in the isolated membranes of gram-negative bacteria which are permissive in vitro substrates for gonococcal IgA1 protease. Images PMID:1713195

  12. Neisseria gonorrhoeae Modulates Immunity by Polarizing Human Macrophages to a M2 Profile

    PubMed Central

    Ortiz, María Carolina; Lefimil, Claudia; Rodas, Paula I.; Vernal, Rolando; Lopez, Mercedes; Acuña-Castillo, Claudio; Imarai, Mónica; Escobar, Alejandro

    2015-01-01

    Current data suggest that Neisseria gonorrhoeae is able to suppress the protective immune response at different levels, such as B and T lymphocytes and antigen-presenting cells. The present report is focused on gonococcus evasion mechanism on macrophages (MФ) and its impact in the subsequent immune response. In response to various signals MФ may undergo classical-M1 (M1-MФ) or alternative-M2 (M2-MФ) activation. Until now there are no reports of the gonococcus effects on human MФ polarization. We assessed the phagocytic ability of monocyte-derived MФ (MDM) upon gonococcal infection by immunofluorescence and gentamicin protection experiments. Then, we evaluated cytokine profile and M1/M2 specific-surface markers on MФ challenged with N. gonorrhoeae and their proliferative effect on T cells. Our findings lead us to suggest N. gonorrhoeae stimulates a M2-MФ phenotype in which some of the M2b and none of the M1-MФ-associated markers are induced. Interestingly, N. gonorrhoeae exposure leads to upregulation of a Programmed Death Ligand 1 (PD-L1), widely known as an immunosuppressive molecule. Moreover, functional results showed that N. gonorrhoeae-treated MФ are unable to induce proliferation of human T-cells, suggesting a more likely regulatory phenotype. Taken together, our data show that N. gonorroheae interferes with MФ polarization. This study has important implications for understanding the mechanisms of clearance versus long-term persistence of N. gonorroheae infection and might be applicable for the development of new therapeutic strategies. PMID:26125939

  13. Specificity of antibodies against Neisseria gonorrhoeae that stimulate neutrophil chemotaxis. Role of antibodies directed against lipooligosaccharides.

    PubMed Central

    Densen, P; Gulati, S; Rice, P A

    1987-01-01

    Five strains each of Neisseria gonorrhoeae sensitive or resistant to complement (C) dependent killing by normal human serum (NHS) were examined for their ability to stimulate chemotaxis of polymorphonuclear leukocytes (PMNs) after preincubation with NHS; or IgM or IgG derived from NHS. Serum-sensitive N. gonorrhoeae stimulated C-dependent chemotaxis when opsonized with IgM, but not IgG, however, serum-resistant strains, taken as a whole, failed to promote chemotaxis when opsonized with either isotype. IgM titers in NHS against lipooligosaccharide (LOS) antigens from individual serum-sensitive, but not serum-resistant strains, correlated with the magnitude of chemotaxis generated by the corresponding opsonized strains (r = 0.99). Western blots demonstrated that IgM and IgG from NHS recognized different antigenic determinants on LOS from serum-sensitive gonococci. IgM from NHS immunopurified against serum-sensitive LOS accounted for two-thirds of the chemotaxis promoting activity present in whole serum. IgG titers in NHS against LOS antigens from individual serum-resistant strains also correlated with magnitude of chemotaxis generated by the corresponding opsonized strains (r = 0.87), although most opsonized serum-resistant strains did not generate significantly higher magnitudes of chemotaxis than controls. In contrast, a serum-resistant isolate from a patient with disseminated gonococcal infection (DGI) stimulated chemotaxis when opsonized with IgG obtained from the patient's convalescent serum. By Western blot, convalescent IgG antibody recognized an additional determinant on serum-resistant LOS not seen by normal IgG. Images PMID:2439546

  14. Global Effect of Interleukin-10 on the Transcriptional Profile Induced by Neisseria meningitidis in Human Monocytes

    PubMed Central

    Øvstebø, Reidun; Olstad, Ole Kristoffer; Brusletto, Berit; Dalsbotten Aass, Hans Christian; Kierulf, Peter; Brandtzaeg, Petter; Berg, Jens Petter

    2012-01-01

    In meningococcal septic shock, the dominant inducer of inflammation is lipopolysaccharide (LPS) in the outer membrane of Neisseria meningitidis, while interleukin-10 (IL-10) is the principal anti-inflammatory cytokine. We have used microarrays and Ingenuity Pathway Analysis to study the global effects of IL-10 on gene expression induced by N. meningitidis, after exposure of human monocytes (n = 5) for 3 h to N. meningitidis (106 cells/ml), recombinant human IL-10 (rhIL-10) (25 ng/ml), and N. meningitidis combined with rhIL-10. N. meningitidis and IL-10 differentially expressed 3,579 and 648 genes, respectively. IL-10 downregulated 125 genes which were upregulated by N. meningitidis, including NLRP3, the key molecule of the NLRP3 inflammasome. IL-10 also upregulated 270 genes which were downregulated by N. meningitidis, including members of the leukocyte immunuglobulin-like receptor (LIR) family. Fifty-three genes revealed a synergistically increased expression when N. meningitidis and IL-10 were combined. AIM2 (the principal molecule of the AIM2 inflammasome) was among these genes (fold change [FC], 18.3 versus 7.4 and 9.4 after stimulation by N. meningitidis and IL-10, respectively). We detected reduced concentrations (92% to 40%) of six cytokines (IL-1b, IL-6, IL-8, tumor necrosis factor alpha [TNF-α], macrophage inflammatory protein alpha [MIP-α], MIP-β) in the presence of IL-10, compared with concentrations with stimulation by N. meningitidis alone. Our data analysis of the effects of IL-10 on gene expression induced by N. meningitidis suggests that high plasma levels of IL-10 in meningococcal septic shock plasma may have a profound effect on a variety of functions and cellular processes in human monocytes, including cell-to-cell signaling, cellular movement, cellular development, antigen presentation, and cell death. PMID:22966040

  15. Cellular and molecular biology of Neisseria meningitidis colonization and invasive disease.

    PubMed

    Hill, Darryl J; Griffiths, Natalie J; Borodina, Elena; Virji, Mumtaz

    2010-02-09

    The human species is the only natural host of Neisseria meningitidis, an important cause of bacterial meningitis globally, and, despite its association with devastating diseases, N. meningitidis is a commensal organism found frequently in the respiratory tract of healthy individuals. To date, antibiotic resistance is relatively uncommon in N. meningitidis isolates but, due to the rapid onset of disease in susceptible hosts, the mortality rate remains approx. 10%. Additionally, patients who survive meningococcal disease often endure numerous debilitating sequelae. N. meningitidis strains are classified primarily into serogroups based on the type of polysaccharide capsule expressed. In total, 13 serogroups have been described; however, the majority of disease is caused by strains belonging to one of only five serogroups. Although vaccines have been developed against some of these, a universal meningococcal vaccine remains a challenge due to successful immune evasion strategies of the organism, including mimicry of host structures as well as frequent antigenic variation. N. meningitidis express a range of virulence factors including capsular polysaccharide, lipopolysaccharide and a number of surface-expressed adhesive proteins. Variation of these surface structures is necessary for meningococci to evade killing by host defence mechanisms. Nonetheless, adhesion to host cells and tissues needs to be maintained to enable colonization and ensure bacterial survival in the niche. The aims of the present review are to provide a brief outline of meningococcal carriage, disease and burden to society. With this background, we discuss several bacterial strategies that may enable its survival in the human respiratory tract during colonization and in the blood during infection. We also examine several known meningococcal adhesion mechanisms and conclude with a section on the potential processes that may operate in vivo as meningococci progress from the respiratory niche through

  16. Neisseria meningitidis Type IV Pili Composed of Sequence Invariable Pilins Are Masked by Multisite Glycosylation

    PubMed Central

    Gault, Joseph; Ferber, Mathias; Machata, Silke; Imhaus, Anne-Flore; Malosse, Christian; Charles-Orszag, Arthur; Millien, Corinne; Bouvier, Guillaume; Bardiaux, Benjamin; Péhau-Arnaudet, Gérard; Klinge, Kelly; Podglajen, Isabelle; Ploy, Marie Cécile; Seifert, H. Steven; Nilges, Michael; Chamot-Rooke, Julia; Duménil, Guillaume

    2015-01-01

    The ability of pathogens to cause disease depends on their aptitude to escape the immune system. Type IV pili are extracellular filamentous virulence factors composed of pilin monomers and frequently expressed by bacterial pathogens. As such they are major targets for the host immune system. In the human pathogen Neisseria meningitidis, strains expressing class I pilins contain a genetic recombination system that promotes variation of the pilin sequence and is thought to aid immune escape. However, numerous hypervirulent clinical isolates express class II pilins that lack this property. This raises the question of how they evade immunity targeting type IV pili. As glycosylation is a possible source of antigenic variation it was investigated using top-down mass spectrometry to provide the highest molecular precision on the modified proteins. Unlike class I pilins that carry a single glycan, we found that class II pilins display up to 5 glycosylation sites per monomer on the pilus surface. Swapping of pilin class and genetic background shows that the pilin primary structure determines multisite glycosylation while the genetic background determines the nature of the glycans. Absence of glycosylation in class II pilins affects pilus biogenesis or enhances pilus-dependent aggregation in a strain specific fashion highlighting the extensive functional impact of multisite glycosylation. Finally, molecular modeling shows that glycans cover the surface of class II pilins and strongly decrease antibody access to the polypeptide chain. This strongly supports a model where strains expressing class II pilins evade the immune system by changing their sugar structure rather than pilin primary structure. Overall these results show that sequence invariable class II pilins are cloaked in glycans with extensive functional and immunological consequences. PMID:26367394

  17. Extreme Substrate Promiscuity of the Neisseria Oligosaccharyl Transferase Involved in Protein O-Glycosylation*S⃞

    PubMed Central

    Faridmoayer, Amirreza; Fentabil, Messele A.; Haurat, M. Florencia; Yi, Wen; Woodward, Robert; Wang, Peng George; Feldman, Mario F.

    2008-01-01

    Neisseria meningitidis PglL belongs to a novel family of bacterial oligosaccharyltransferases (OTases) responsible for O-glycosylation of type IV pilins. Although members of this family are widespread among pathogenic bacteria, there is little known about their mechanism. Understanding the O-glycosylation process may uncover potential targets for therapeutic intervention, and can open new avenues for the exploitation of these pathways for biotechnological purposes. In this work, we demonstrate that PglL is able to transfer virtually any glycan from the undecaprenyl pyrophosphate (UndPP) carrier to pilin in engineered Escherichia coli and Salmonella cells. Surprisingly, PglL was also able to interfere with the peptidoglycan biosynthetic machinery and transfer peptidoglycan subunits to pilin. This represents a previously unknown post-translational modification in bacteria. Given the wide range of glycans transferred by PglL, we reasoned that substrate specificity of PglL lies in the lipid carrier. To test this hypothesis we developed an in vitro glycosylation system that employed purified PglL, pilin, and the lipid farnesyl pyrophosphate (FarPP) carrying a pentasaccharide that had been synthesized by successive chemical and enzymatic steps. Although FarPP has different stereochemistry and a significantly shorter aliphatic chain than the natural lipid substrate, the pentasaccharide was still transferred to pilin in our system. We propose that the primary roles of the lipid carrier during O-glycosylation are the translocation of the glycan into the periplasm, and the positioning of the pyrophosphate linker and glycan adjacent to PglL. The unique characteristics of PglL make this enzyme a promising tool for glycoengineering novel glycan-based vaccines and therapeutics. PMID:18930921

  18. Portable exhausters POR-004 SKID B, POR-005 SKID C, POR-006 SKID D storage plan

    SciTech Connect

    Nelson, O.D.

    1997-09-04

    This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage.

  19. Genetic, Structural, and Antigenic Analyses of Glycan Diversity in the O-Linked Protein Glycosylation Systems of Human Neisseria Species▿ †

    PubMed Central

    Børud, Bente; Aas, Finn Erik; Vik, Åshild; Winther-Larsen, Hanne C.; Egge-Jacobsen, Wolfgang; Koomey, Michael

    2010-01-01

    Bacterial capsular polysaccharides and lipopolysaccharides are well-established ligands of innate and adaptive immune effectors and often exhibit structural and antigenic variability. Although many surface-localized glycoproteins have been identified in bacterial pathogens and symbionts, it not clear if and how selection impacts associated glycoform structure. Here, a systematic approach was devised to correlate gene repertoire with protein-associated glycoform structure in Neisseria species important to human health and disease. By manipulating the protein glycosylation (pgl) gene content and assessing the glycan structure by mass spectrometry and reactivity with monoclonal antibodies, it was established that protein-associated glycans are antigenically variable and that at least nine distinct glycoforms can be expressed in vitro. These studies also revealed that in addition to Neisseria gonorrhoeae strain N400, one other gonococcal strain and isolates of Neisseria meningitidis and Neisseria lactamica exhibit broad-spectrum O-linked protein glycosylation. Although a strong correlation between pgl gene content, glycoform expression, and serological profile was observed, there were significant exceptions, particularly with regard to levels of microheterogeneity. This work provides a technological platform for molecular serotyping of neisserial protein glycans and for elucidating pgl gene evolution. PMID:20363948

  20. First Neisseria gonorrhoeae Genotyping Analysis in France: Identification of a Strain Cluster with Reduced Susceptibility to Ceftriaxone ▿

    PubMed Central

    Monfort, Laura; Caro, Valérie; Devaux, Zaelle; Delannoy, Anne-Sophie; Brisse, Sylvain; Sednaoui, Patrice

    2009-01-01

    Sexually transmitted infections are a major public health problem in France and other European countries. Particularly, surveillance data about Neisseria gonorrhoeae infections have clearly indicated an increase in the incidence of gonorrhoea in France in 2006. The French laboratories participated on voluntary basis in the RENAGO (Réseau National du Gonocoque) network and sent all of their collected strains to the National Reference Center for Neisseria gonorrhoeae. In this first French molecular epidemiological study, 93 isolates collected in 2006 and representative of the French gonorrhoea epidemiology were selected. Antibiotic susceptibility to six antibiotics was determined, and serotyping and N. gonorrhoeae multiantigen sequence typing (NG-MAST) were performed. NG-MAST identified 53 sequence types (STs), of which 13 STs contained 2 to 16 isolates. The major STs identified in France were previously described elsewhere. However, two newly described STs, ST1479 and ST1987, had only been found in France until now. ST1479 was characterized by a multiple-resistance phenotype, whereas ST1987 presented a susceptibility phenotype. Moreover, among the predominant French STs, ST225, which had already been described in many countries, comprised isolates (14/16) resistant to ciprofloxacin and with reduced susceptibility to ceftriaxone. Thus, the surveillance of resistance to antibiotics is a priority in order to adapt treatment and decrease the transmission of resistant strains. Of note, no predominant ST was identified among rectal isolates from men who have sex with men. PMID:19794054

  1. Expression of the Gene for Autotransporter AutB of Neisseria meningitidis Affects Biofilm Formation and Epithelial Transmigration

    PubMed Central

    Arenas, Jesús; Paganelli, Fernanda L.; Rodríguez-Castaño, Patricia; Cano-Crespo, Sara; van der Ende, Arie; van Putten, Jos P. M.; Tommassen, Jan

    2016-01-01

    Neisseria meningitidis is a Gram-negative bacterium that resides as a commensal in the upper respiratory tract of humans, but occasionally, it invades the host and causes sepsis and/or meningitis. The bacterium can produce eight autotransporters, seven of which have been studied to some detail. The remaining one, AutB, has not been characterized yet. Here, we show that the autB gene is broadly distributed among pathogenic Neisseria spp. The gene is intact in most meningococcal strains. However, its expression is prone to phase variation due to slipped-strand mispairing at AAGC repeats located within the DNA encoding the signal sequence and is switched off in the vast majority of these strains. Moreover, various genetic disruptions prevent autB expression in most of the strains in which the gene is in phase indicating a strong selection against AutB synthesis. We observed that autB is expressed in two of the strains examined and that AutB is secreted and exposed at the cell surface. Functionality assays revealed that AutB synthesis promotes biofilm formation and delays the passage of epithelial cell layers in vitro. We hypothesize that this autotransporter is produced during the colonization process only in specific niches to facilitate microcolony formation, but its synthesis is switched off probably to evade the immune system and facilitate human tissue invasion. PMID:27921012

  2. Genome Wide Expression Profiling Reveals Suppression of Host Defence Responses during Colonisation by Neisseria meningitides but not N. lactamica

    PubMed Central

    Wong, Hazel En En; Li, Ming-Shi; Kroll, J. Simon; Hibberd, Martin L.; Langford, Paul R.

    2011-01-01

    Both Neisseria meningitidis and the closely related bacterium Neisseria lactamica colonise human nasopharyngeal mucosal surface, but only N. meningitidis invades the bloodstream to cause potentially life-threatening meningitis and septicaemia. We have hypothesised that the two neisserial species differentially modulate host respiratory epithelial cell gene expression reflecting their disease potential. Confluent monolayers of 16HBE14 human bronchial epithelial cells were exposed to live and/or dead N. meningitidis (including capsule and pili mutants) and N. lactamica, and their transcriptomes were compared using whole genome microarrays. Changes in expression of selected genes were subsequently validated using Q-RT-PCR and ELISAs. Live N. meningitidis and N. lactamica induced genes involved in host energy production processes suggesting that both bacterial species utilise host resources. N. meningitidis infection was associated with down-regulation of host defence genes. N. lactamica, relative to N. meningitidis, initiates up-regulation of proinflammatory genes. Bacterial secreted proteins alone induced some of the changes observed. The results suggest N. meningitidis and N. lactamica differentially regulate host respiratory epithelial cell gene expression through colonisation and/or protein secretion, and that this may contribute to subsequent clinical outcomes associated with these bacteria. PMID:22028815

  3. Locus NMB0035 codes for a 47-kDa surface-accessible conserved antigen in Neisseria.

    PubMed

    Arenas, Jesús; Abel, Ana; Sánchez, Sandra; Alcalá, Belén; Criado, María T; Ferreirós, Carlos M

    2006-12-01

    A47 kDa neisserial outer-membrane antigenic protein (P47) was purified to homogeneity and used to prepare polyclonal anti-P47 antisera. Protein P47 was identified by MALDI-TOF fingerprinting analysis as the hypothetical lipoprotein NMB0035. Two-dimensional diagonal SDS-PAGE results suggested that, contrary to previous findings, P47 is not strongly associated with other proteins in membrane complexes. Western blotting with the polyclonal monospecific serum showed that linear P47 epitopes were expressed in similar amounts in the 27 Neisseria meningitidis strains tested and, to a lesser extent, in commensal Neisseria, particularly N. lactamica. However, dot-blotting assays with the same serum demonstrated binding variability between meningococcal strains, indicating differences in surface accessibility or steric hindrance by other surface structures. Specific anti-P47 antibodies were bactericidal against the homologous strain but had variable activity against heterologous strains, consistent with the results from dot-blotting experiments. An in-depth study of P47 is necessary to evaluate its potential as a candidate for new vaccine designs.

  4. Genome wide expression profiling reveals suppression of host defence responses during colonisation by Neisseria meningitides but not N. lactamica.

    PubMed

    Wong, Hazel En En; Li, Ming-Shi; Kroll, J Simon; Hibberd, Martin L; Langford, Paul R

    2011-01-01

    Both Neisseria meningitidis and the closely related bacterium Neisseria lactamica colonise human nasopharyngeal mucosal surface, but only N. meningitidis invades the bloodstream to cause potentially life-threatening meningitis and septicaemia. We have hypothesised that the two neisserial species differentially modulate host respiratory epithelial cell gene expression reflecting their disease potential. Confluent monolayers of 16HBE14 human bronchial epithelial cells were exposed to live and/or dead N. meningitidis (including capsule and pili mutants) and N. lactamica, and their transcriptomes were compared using whole genome microarrays. Changes in expression of selected genes were subsequently validated using Q-RT-PCR and ELISAs. Live N. meningitidis and N. lactamica induced genes involved in host energy production processes suggesting that both bacterial species utilise host resources. N. meningitidis infection was associated with down-regulation of host defence genes. N. lactamica, relative to N. meningitidis, initiates up-regulation of proinflammatory genes. Bacterial secreted proteins alone induced some of the changes observed. The results suggest N. meningitidis and N. lactamica differentially regulate host respiratory epithelial cell gene expression through colonisation and/or protein secretion, and that this may contribute to subsequent clinical outcomes associated with these bacteria.

  5. Secreted single-stranded DNA is involved in the initial phase of biofilm formation by Neisseria gonorrhoeae.

    PubMed

    Zweig, Maria; Schork, Sabine; Koerdt, Andrea; Siewering, Katja; Sternberg, Claus; Thormann, Kai; Albers, Sonja-Verena; Molin, Søren; van der Does, Chris

    2014-04-01

    Neisseria gonorrhoeae is an obligate human pathogen that colonizes the genital tract and causes gonorrhoea. Neisseria gonorrhoeae can form biofilms during natural cervical infections, on glass and in continuous flow-chamber systems. These biofilms contain large amounts of extracellular DNA, which plays an important role in biofilm formation. Many clinical isolates contain a gonococcal genetic island that encodes a type IV secretion system (T4SS). The T4SS of N. gonorrhoeae strain MS11 secretes ssDNA directly into the medium. Biofilm formation, studied in continuous flow-chamber systems by confocal laser scanning microscopy (CLSM), was strongly reduced, especially in the initial phases of biofilm formation, in the presence of Exonuclease I, which specifically degrades ssDNA or in a ΔtraB strain that does not secrete ssDNA. To specifically detect ssDNA in biofilms using CLSM, a novel method was developed in which thermostable fluorescently labelled ssDNA- and ss/dsDNA-binding proteins were used to visualize ssDNA and total DNA in biofilms and planktonic cultures. Remarkably, mainly dsDNA was detected in biofilms of the ssDNA secreting strain. We conclude that the secreted ssDNA facilitates initial biofilm formation, but that the secreted ssDNA is not retained in mature biofilms.

  6. Genomic Epidemiology and Molecular Resistance Mechanisms of Azithromycin-Resistant Neisseria gonorrhoeae in Canada from 1997 to 2014

    PubMed Central

    Demczuk, Walter; Martin, Irene; Peterson, Shelley; Bharat, Amrita; Van Domselaar, Gary; Graham, Morag; Lefebvre, Brigitte; Allen, Vanessa; Hoang, Linda; Tyrrell, Greg; Horsman, Greg; Wylie, John; Haldane, David; Archibald, Chris; Wong, Tom; Unemo, Magnus

    2016-01-01

    The emergence of Neisseria gonorrhoeae strains with decreased susceptibility to cephalosporins and azithromycin (AZM) resistance (AZMr) represents a public health threat of untreatable gonorrhea infections. Genomic epidemiology through whole-genome sequencing was used to describe the emergence, dissemination, and spread of AZMr strains. The genomes of 213 AZMr and 23 AZM-susceptible N. gonorrhoeae isolates collected in Canada from 1989 to 2014 were sequenced. Core single nucleotide polymorphism (SNP) phylogenomic analysis resolved 246 isolates into 13 lineages. High-level AZMr (MICs ≥ 256 μg/ml) was found in 5 phylogenetically diverse isolates, all of which possessed the A2059G mutation (Escherichia coli numbering) in all four 23S rRNA alleles. One isolate with high-level AZMr collected in 2009 concurrently had decreased susceptibility to ceftriaxone (MIC = 0.125 μg/ml). An increase in the number of 23S rRNA alleles with the C2611T mutations (E. coli numbering) conferred low to moderate levels of AZMr (MICs = 2 to 4 and 8 to 32 μg/ml, respectively). Low-level AZMr was also associated with mtrR promoter mutations, including the −35A deletion and the presence of Neisseria meningitidis-like sequences. Geographic and temporal phylogenetic clustering indicates that emergent AZMr strains arise independently and can then rapidly expand clonally in a region through local sexual networks. PMID:26935729

  7. Improved purification of native meningococcal porin PorB and studies on its structure/function.

    PubMed

    Massari, Paola; King, Carol A; MacLeod, Heather; Wetzler, Lee M

    2005-12-01

    The outer membrane protein PorB of Neisseria meningitidis is a pore-forming protein which has various effects on eukaryotic cells. It has been shown to (1) up-regulate the surface expression of the co-stimulatory molecule CD86 and of MHC class II (which are TLR2/MyD88 dependent and related to the porin's immune-potentiating ability), (2) be involved in prevention of apoptosis by modulating the mitochondrial membrane potential, and (3) form pores in eukaryotic cells. As an outer membrane protein, its native trimeric form isolation is complicated by its insoluble nature, requiring the presence of detergent throughout the whole procedure, and by its tight association with other outer membrane components, such as neisserial LOS or lipoproteins. In this study, an improved chromatographic purification method to obtain an homogeneous product free of endotoxin and lipoprotein is described, without loss of any of the above-mentioned properties of the porin. Furthermore, we have investigated the requirement of the native trimeric structure for the porin's activity. Inactivation of functional PorB trimers into non-functional monomers was achieved by incubation on ice. Thus, routine long- and medium-term storage at low temperature may be a cause of porin inactivation.

  8. Detection of relatively penicillin G-resistant Neisseria meningitidis by disk susceptibility testing.

    PubMed Central

    Campos, J; Mendelman, P M; Sako, M U; Chaffin, D O; Smith, A L; Sáez-Nieto, J A

    1987-01-01

    Beginning in 1985, relatively penicillin G-resistant (Penr) meningococci which did not produce beta-lactamase were isolated from the blood and cerebrospinal fluid of patients in Spain. We identified 16 Penr (mean MIC, 0.3 microgram/ml; range, 0.1 to 0.7 microgram/ml) and 12 penicillin-susceptible (Pens; mean MIC, less than or equal to 0.06 microgram/ml) strains of Neisseria meningitidis by the agar dilution technique using an inoculum of 10(4) CFU and questioned which disk susceptibility test would best differentiate these two populations. We compared the disk susceptibility of these strains using disks containing 2 (P2) and 10 (P10) U of penicillin G, 2 (Am2) and 10 (Am10) micrograms of ampicillin, and 1 microgram of oxacillin (OX1). We also investigated susceptibility with disks containing 30 micrograms of each of cephalothin (CF30), cefoxitin (FOX30), cefuroxime (CXM30), and cefotaxime (CTX30) and 75 micrograms of cefoperazone (CFP75) and determined by cluster analysis any correlation with the zone diameters obtained with P2 disks. Using the P2 and AM2 disks (in contrast to the P10 and AM10 disks), we correctly differentiated all the Penr from Pens isolates. In addition, the zone diameters with the P2 disk gave the best correlation with the penicillin G MIC determinations. All 16 Penr strains and 3 of 12 Pens strains showed zone diameters of 6 mm around OX1 disks, limiting the usefulness of OX1 disks. The zone diameters obtained with CF30, CXM30, and OX1 disks correlated with those obtained with the P2 disk, which suggests that these antibiotics have similar effects on these strains. In contrast, the data obtained with FOX30, CTX30, and CFP75 disks did not cluster with those obtained with the P2 disk, which suggests that there was a difference in the bacterial target or reflects their greater activity. We conclude that the P2 disk tests more readily identify Penr meningococci than do the standard P10 disk tests. PMID:3124729

  9. Patterns of structural and sequence variation within isotype lineages of the Neisseria meningitidis transferrin receptor system

    PubMed Central

    Adamiak, Paul; Calmettes, Charles; Moraes, Trevor F; Schryvers, Anthony B

    2015-01-01

    Neisseria meningitidis inhabits the human upper respiratory tract and is an important cause of sepsis and meningitis. A surface receptor comprised of transferrin-binding proteins A and B (TbpA and TbpB), is responsible for acquiring iron from host transferrin. Sequence and immunological diversity divides TbpBs into two distinct lineages; isotype I and isotype II. Two representative isotype I and II strains, B16B6 and M982, differ in their dependence on TbpB for in vitro growth on exogenous transferrin. The crystal structure of TbpB and a structural model for TbpA from the representative isotype I N. meningitidis strain B16B6 were obtained. The structures were integrated with a comprehensive analysis of the sequence diversity of these proteins to probe for potential functional differences. A distinct isotype I TbpA was identified that co-varied with TbpB and lacked sequence in the region for the loop 3 α-helix that is proposed to be involved in iron removal from transferrin. The tightly associated isotype I TbpBs had a distinct anchor peptide region, a distinct, smaller linker region between the lobes and lacked the large loops in the isotype II C-lobe. Sequences of the intact TbpB, the TbpB N-lobe, the TbpB C-lobe, and TbpA were subjected to phylogenetic analyses. The phylogenetic clustering of TbpA and the TbpB C-lobe were similar with two main branches comprising the isotype 1 and isotype 2 TbpBs, possibly suggesting an association between TbpA and the TbpB C-lobe. The intact TbpB and TbpB N-lobe had 4 main branches, one consisting of the isotype 1 TbpBs. One isotype 2 TbpB cluster appeared to consist of isotype 1 N-lobe sequences and isotype 2 C-lobe sequences, indicating the swapping of N-lobes and C-lobes. Our findings should inform future studies on the interaction between TbpB and TbpA and the process of iron acquisition. PMID:25800619

  10. Outer membrane biogenesis in Escherichia coli, Neisseria meningitidis, and Helicobacter pylori: paradigm deviations in H. pylori

    PubMed Central

    Liechti, George; Goldberg, Joanna B.

    2012-01-01

    The bacterial pathogen Helicobacter pylori is capable of colonizing the gastric mucosa of the human stomach using a variety of factors associated with or secreted from its outer membrane (OM). Lipopolysaccharide (LPS) and numerous OM proteins have been shown to be involved in adhesion and immune stimulation/evasion. Many of these factors are essential for colonization and/or pathogenesis in a variety of animal models. Despite this wide array of potential targets present on the bacterial surface, the ability of H. pylori to vary its OM profile limits the effectiveness of vaccines or therapeutics that target any single one of these components. However, it has become evident that the proteins comprising the complexes that transport the majority of these molecules to the OM are highly conserved and often essential. The field of membrane biogenesis has progressed remarkably in the last few years, and the possibility now exists for targeting the mechanisms by which β-barrel proteins, lipoproteins, and LPS are transported to the OM, resulting in loss of bacterial fitness and significant altering of membrane permeability. In this review, the OM transport machinery for LPS, lipoproteins, and outer membrane proteins (OMPs) are discussed. While the principal investigations of these transport mechanisms have been conducted in Escherichia coli and Neisseria meningitidis, here these systems will be presented in the genetic context of ε proteobacteria. Bioinformatic analysis reveals that minimalist genomes, such as that of Helicobacter pylori, offer insight into the smallest number of components required for these essential pathways to function. Interestingly, in the majority of ε proteobacteria, while the inner and OM associated apparatus of LPS, lipoprotein, and OMP transport pathways appear to all be intact, most of the components associated with the periplasmic compartment are either missing or are almost unrecognizable when compared to their E. coli counterparts. Eventual

  11. Costs of Neisseria meningitidis Group A Disease and Economic Impact of Vaccination in Burkina Faso

    PubMed Central

    Colombini, Anaïs; Trotter, Caroline; Madrid, Yvette; Karachaliou, Andromachi; Preziosi, Marie-Pierre

    2015-01-01

    Background. Five years since the successful introduction of MenAfriVac in a mass vaccination campaign targeting 1- to 29-year-olds in Burkina Faso, consideration must be given to the optimal strategies for sustaining population protection. This study aims to estimate the economic impact of a range of vaccination strategies in Burkina Faso. Methods. We performed a cost-of-illness study, comparing different vaccination scenarios in terms of costs to both households and health systems over a 26-year time horizon. These scenarios are (1) reactive vaccination campaign (baseline comparator); (2) preventive vaccination campaign; (3) routine immunization at 9 months; and (4) a combination of routine and an initial catchup campaign of children under 5. Costs were estimated from a literature review, which included unpublished programmatic documents and peer-reviewed publications. The future disease burden for each vaccination strategy was predicted using a dynamic transmission model of group A Neisseria meningitidis. Results. From 2010 to 2014, the total costs associated with the preventive campaign targeting 1- to 29-year-olds with MenAfriVac were similar to the estimated costs of the reactive vaccination strategy (approximately 10 million US dollars [USD]). Between 2015 and 2035, routine immunization with or without a catch-up campaign of 1- to 4-year-olds is cost saving compared with the reactive strategy, both with and without discounting costs and cases. Most of the savings are accrued from lower costs of case management and household costs resulting from a lower burden of disease. After the initial investment in the preventive strategy, 1 USD invested in the routine strategy saves an additional 1.3 USD compared to the reactive strategy. Conclusions. Prevention strategies using MenAfriVac will be significantly cost saving in Burkina Faso, both for the health system and for households, compared with the reactive strategy. This will protect households from

  12. The dam replacing gene product enhances Neisseria gonorrhoeae FA1090 viability and biofilm formation.

    PubMed

    Kwiatek, Agnieszka; Bacal, Pawel; Wasiluk, Adrian; Trybunko, Anastasiya; Adamczyk-Poplawska, Monika

    2014-01-01

    Many Neisseriaceae do not exhibit Dam methyltransferase activity and, instead of the dam gene, possess drg (dam replacing gene) inserted in the leuS/dam locus. The drg locus in Neisseria gonorrhoeae FA1090 has a lower GC-pairs content (40.5%) compared to the whole genome of N. gonorrhoeae FA1090 (52%). The gonococcal drg gene encodes a DNA endonuclease Drg, with GmeATC specificity. Disruption of drg or insertion of the dam gene in gonococcal genome changes the level of expression of genes as shown by transcriptome analysis. For the drg-deficient N. gonorrhoeae mutant, a total of 195 (8.94% of the total gene pool) genes exhibited an altered expression compared to the wt strain by at least 1.5 fold. In dam-expressing N. gonorrhoeae mutant, the expression of 240 genes (11% of total genes) was deregulated. Most of these deregulated genes were involved in translation, DNA repair, membrane biogenesis and energy production as shown by cluster of orthologous group analysis. In vivo, the inactivation of drg gene causes the decrease of the number of live neisserial cells and long lag phase of growth. The insertion of dam gene instead of drg locus restores cell viability. We have also shown that presence of the drg gene product is important for N. gonorrhoeae FA1090 in adhesion, including human epithelial cells, and biofilm formation. Biofilm produced by drg-deficient strain is formed by more dispersed cells, compared to this one formed by parental strain as shown by scanning electron and confocal microscopy. Also adherence assays show a significantly smaller biomass of formed biofilm (OD570 = 0.242 ± 0.038) for drg-deficient strain, compared to wild-type strain (OD570 = 0.378 ± 0.057). Dam-expressing gonococcal cells produce slightly weaker biofilm with cells embedded in an extracellular matrix. This strain has also a five times reduced ability for adhesion to human epithelial cells. In this context, the presence of Drg is more advantageous for N. gonorrhoeae biology than

  13. Current and future antimicrobial treatment of gonorrhoea - the rapidly evolving Neisseria gonorrhoeae continues to challenge.

    PubMed

    Unemo, Magnus

    2015-08-21

    Neisseria gonorrhoeae has developed antimicrobial resistance (AMR) to all drugs previously and currently recommended for empirical monotherapy of gonorrhoea. In vitro resistance, including high-level, to the last option ceftriaxone and sporadic failures to treat pharyngeal gonorrhoea with ceftriaxone have emerged. In response, empirical dual antimicrobial therapy (ceftriaxone 250-1000 mg plus azithromycin 1-2 g) has been introduced in several particularly high-income regions or countries. These treatment regimens appear currently effective and should be considered in all settings where local quality assured AMR data do not support other therapeutic options. However, the dual antimicrobial regimens, implemented in limited geographic regions, will not entirely prevent resistance emergence and, unfortunately, most likely it is only a matter of when, and not if, treatment failures with also these dual antimicrobial regimens will emerge. Accordingly, novel affordable antimicrobials for monotherapy or at least inclusion in new dual treatment regimens, which might need to be considered for all newly developed antimicrobials, are essential. Several of the recently developed antimicrobials deserve increased attention for potential future treatment of gonorrhoea. In vitro activity studies examining collections of geographically, temporally and genetically diverse gonococcal isolates, including multidrug-resistant strains particularly with resistance to ceftriaxone and azithromycin, are important. Furthermore, understanding of effects and biological fitness of current and emerging (in vitro induced/selected and in vivo emerged) genetic resistance mechanisms for these antimicrobials, prediction of resistance emergence, time-kill curve analysis to evaluate antibacterial activity, appropriate mice experiments, and correlates between genetic and phenotypic laboratory parameters, and clinical treatment outcomes, would also be valuable. Subsequently, appropriately designed

  14. Multilaboratory evaluation of disk diffusion antimicrobial susceptibility testing of Neisseria meningitidis isolates.

    PubMed

    Jorgensen, James H; Crawford, Sharon A; Fulcher, Letitia C; Glennen, Anita; Harrington, Susan M; Swenson, Jana; Lynfield, Ruth; Murray, Patrick R; Tenover, Fred C

    2006-05-01

    In 2005, the Clinical and Laboratory Standards Institute published MIC interpretive criteria for 13 antimicrobial agents used for either therapy or prophylaxis of Neisseria meningitidis infections. The MIC method includes the use of lysed horse blood-supplemented Mueller-Hinton broth with incubation in 5% CO2 for 20 to 24 h. Since some clinical laboratories might prefer the option of disk diffusion testing for infrequently encountered isolates a multicenter collaborative study was conducted to evaluate the reproducibility of a disk diffusion method for testing isolates of N. meningitidis. Interpretive criteria were developed for 12 antimicrobial agents. Four laboratories tested a common collection of 50 meningococcal strains and then tested 25 unique isolates per laboratory. Isolates were tested using Mueller-Hinton sheep blood agar plates incubated for 20 to 24 h in 5% CO2; they were also tested by the reference broth microdilution method in parallel. Pooling of the MIC and disk diffusion data from the common and unique isolates provided a sufficient sample size to develop susceptible, intermediate, and resistant zone diameter interpretive criteria using the error rate-bounded method for the following agents: chloramphenicol, trimethoprim-sulfamethoxazole, ciprofloxacin, and rifampin. Due to the lack of resistant strains at the present time, "susceptible only" interpretive criteria were proposed for cefotaxime, ceftriaxone, meropenem, azithromycin, and minocycline. The numbers of minor interpretive errors with penicillin and ampicillin disk tests were unacceptably high and precluded recommended testing of those agents by the disk method. However, amdinocillin, an agent that preferentially binds to the altered penicillin binding protein responsible for diminished penicillin susceptibility, has potential utility as a surrogate screening reagent for ampicillin resistance. A disk diffusion breakpoint was derived for nalidixic acid to serve as a surrogate marker for

  15. The dam replacing gene product enhances Neisseria gonorrhoeae FA1090 viability and biofilm formation

    PubMed Central

    Kwiatek, Agnieszka; Bacal, Pawel; Wasiluk, Adrian; Trybunko, Anastasiya; Adamczyk-Poplawska, Monika

    2014-01-01

    Many Neisseriaceae do not exhibit Dam methyltransferase activity and, instead of the dam gene, possess drg (dam replacing gene) inserted in the leuS/dam locus. The drg locus in Neisseria gonorrhoeae FA1090 has a lower GC-pairs content (40.5%) compared to the whole genome of N. gonorrhoeae FA1090 (52%). The gonococcal drg gene encodes a DNA endonuclease Drg, with GmeATC specificity. Disruption of drg or insertion of the dam gene in gonococcal genome changes the level of expression of genes as shown by transcriptome analysis. For the drg-deficient N. gonorrhoeae mutant, a total of 195 (8.94% of the total gene pool) genes exhibited an altered expression compared to the wt strain by at least 1.5 fold. In dam-expressing N. gonorrhoeae mutant, the expression of 240 genes (11% of total genes) was deregulated. Most of these deregulated genes were involved in translation, DNA repair, membrane biogenesis and energy production as shown by cluster of orthologous group analysis. In vivo, the inactivation of drg gene causes the decrease of the number of live neisserial cells and long lag phase of growth. The insertion of dam gene instead of drg locus restores cell viability. We have also shown that presence of the drg gene product is important for N. gonorrhoeae FA1090 in adhesion, including human epithelial cells, and biofilm formation. Biofilm produced by drg-deficient strain is formed by more dispersed cells, compared to this one formed by parental strain as shown by scanning electron and confocal microscopy. Also adherence assays show a significantly smaller biomass of formed biofilm (OD570 = 0.242 ± 0.038) for drg-deficient strain, compared to wild-type strain (OD570 = 0.378 ± 0.057). Dam-expressing gonococcal cells produce slightly weaker biofilm with cells embedded in an extracellular matrix. This strain has also a five times reduced ability for adhesion to human epithelial cells. In this context, the presence of Drg is more advantageous for N. gonorrhoeae biology than

  16. Approach to the Discovery, Development, and Evaluation of a Novel Neisseria meningitidis Serogroup B Vaccine.

    PubMed

    Green, Luke R; Eiden, Joseph; Hao, Li; Jones, Tom; Perez, John; McNeil, Lisa K; Jansen, Kathrin U; Anderson, Annaliesa S

    2016-01-01

    In this chapter, we describe a research and development pathway to identify and demonstrate the efficacy of a Neisseria meningitidis non-capsular vaccine, the recently licensed N. meningitidis serogroup B (MnB) vaccine, Trumenba(®). While other approaches have been followed in the identification of a MnB vaccine (Pizza et al. Science 287:1816-1820, 2000), the methods described here reflect the distinctive approach and experiences in discovering and developing Trumenba(®). In contrast to the development and licensure of polysaccharide-conjugate vaccines against meningococcal serotypes A, C, W, and Y, the development of a vaccine to produce broadly protective antibodies against meningococcal serogroup B has proved difficult, due to the antigenic mimicry of the serogroup B polysaccharide capsule, which is composed of polysialic acid structures similar to those expressed on human neuronal cells. Early development efforts for these vaccines failed because the MnB polysaccharide structures resemble autoantigens and thus were poorly immunogenic. The development of an MnB vaccine has therefore focused on non-polysaccharide approaches. It was critical to identify MnB cell surface-exposed antigens capable of inducing a protective response against diverse, circulating strains of invasive MnB to ensure global coverage. Once candidate antigens were identified, it was important to characterize antigenic variation and expression levels, and subsequently to assure that antigens were expressed broadly among diverse clinical isolates. Prior to the initiation of clinical trials in humans, candidate vaccine antigens were tested in functional immunogenicity assays and yielded responses that were correlated with protection from meningococcal disease. These functional immunogenicity assays (serum bactericidal assays using human complement, hSBAs) measure the titer of complement-dependent bactericidal antibodies in serum from immunized test animals using diverse clinical MnB isolates as

  17. Characterization of a Novel Antisense RNA in the Major Pilin Locus of Neisseria meningitidis Influencing Antigenic Variation

    PubMed Central

    Tan, Felicia Y. Y.; Wörmann, Mirka E.; Tang, Christoph M.

    2015-01-01

    ABSTRACT Expression of type four pili (Tfp) is essential for virulence in Neisseria meningitidis. Pili mediate adhesion, bacterial aggregation, and DNA uptake. In N. meningitidis, the major pilin subunit is encoded by the pilE gene. In some strains, PilE is subject to phase and antigenic variation, which can alter Tfp properties and together offer a possible mechanism of immune escape. Pilin expression and antigenic variation can be modulated in response to environmental cues; however, the precise mechanisms of such regulation remain unclear. We identified a promoter in the pilE locus, 3′ of the pilE coding sequence, on the antisense (AS) strand which is conserved in meningococci. We show that this promoter directs transcription of an AS RNA that is expressed during specific growth phases and in response to salt stress. Furthermore, we demonstrate that the transcript encompasses sequences complementary to the entire pilE coding sequence and 5′ untranslated region. AS RNAs can regulate the gene on the sense strand by altering transcript stability or translation. However, by using Northern blotting, quantitative reverse transcription-PCR (RT-PCR), and Western blotting, we found no significant AS RNA-dependent changes in pilE transcript or protein level. Instead, our data indicate that the AS RNA influences pilin antigenic variation. This work provides further insights into the complex regulation of pilin expression and variation in pathogenic Neisseria. IMPORTANCE Pathogenic Neisseria spp. express type four pili (Tfp) which are important for adhesion, aggregation and transformation. Some strains of N. meningitidis are able to vary the sequence of the major subunit (PilE) of the Tfp. The mechanisms underlying this variation are not fully defined, but the process requires several noncoding elements that are found adjacent to the pilE gene. In this work, we identified a cis-encoded RNA antisense to pilE in N. meningitidis. By using Northern blotting and RT

  18. [Detection of Neisseria meningitidis group B antigens by MB-Dot-Elisa test in patients with meningitis].

    PubMed

    Alkmin, M G; Landgraf, I M; Shimizu, S H

    1997-03-01

    Infection with Neisseria meningitidis group B has been difficult to detect, partly because this bacterial group's polysaccharide is a weak immunogen. This article describes work carried out to test a new procedure (MB-Dot-ELISA) employing a high-titered horse antiserum for detection of N. meningitidis group B antigens. The study assayed cerebrospinal fluid samples from 585 subjects, 574 with suspected meningitis cases and 11 with neurologic disorders. The results of the assay indicated a sensitivity of 0.991 and a specificity of 0.826. These results were superior to those obtained with latex agglutination and in substantial agreement with the results of counterimmunoelectrophoresis and bacteriologic methods. Overall, the MB-Dot-ELISA was found to be sensitive, inexpensive, and suitable for public health laboratory investigations.

  19. Neisseria gonorrhoeae isolates from four centres in Papua New Guinea remain susceptible to amoxycillin-clavulanate therapy.

    PubMed

    Toliman, Pamela J; Lupiwa, Tony; Law, Gregory J; Reeder, John C; Siba, Peter M

    2010-01-01

    Antibiotic-resistant strains of Neisseria gonorrhoeae have the potential to undermine treatment and control of gonorrhoea, which remains a highly prevalent sexually transmitted infection (STI) in Papua New Guinea (PNG). The standard treatment regimen for gonorrhoea in PNG based on amoxycillin and clavulanic acid (amoxycillin-clavulanate) was introduced about 15 years ago and there is some concern that over time circulating strains may have developed resistance to this therapy. To investigate this, N. gonorrhoeae isolates (n = 52) were collected from STI clinics in geographically representative centres in PNG and tested for their in vitro susceptibility to a range of antibiotics. All 52 isolates tested were found susceptible to amoxycillin-clavulanate, despite 40% (n = 21) being penicillinase producers and thus resistant to penicillin. These findings indicate that amoxycillin-clavulanate therapy remains an effective treatment for gonococcal infections in PNG, and support the maintenance of the present standard treatment for gonorrhoea in PNG.

  20. Expression of proinflammatory cytokines and receptors by human fallopian tubes in organ culture following challenge with Neisseria gonorrhoeae.

    PubMed

    Maisey, Kevin; Nardocci, Gino; Imarai, Monica; Cardenas, Hugo; Rios, Miguel; Croxatto, Horacio B; Heckels, John E; Christodoulides, Myron; Velasquez, Luis A

    2003-01-01

    Infection of the Fallopian tubes (FT) by Neisseria gonorrhoeae can lead to acute salpingitis, an inflammatory condition, which is a major cause of infertility. Challenge of explants of human FT with gonococci induced mRNA expression and protein secretion for the proinflammatory cytokines interleukin (IL)-1alpha, IL-1beta, and tumor necrosis factor alpha (TNF-alpha) but not for granulocyte-macrophage colony-stimulating factor. In contrast, FT expression of IL-6 and of the cytokine receptors IL-6R, TNF receptor I (TNF-RI), and TNF-RII was constitutive and was not increased by gonococcal challenge. These studies suggest that several proinflammatory cytokines are likely to contribute to the cell and tissue damage observed in gonococcal salpingitis.

  1. Expression of Proinflammatory Cytokines and Receptors by Human Fallopian Tubes in Organ Culture following Challenge with Neisseria gonorrhoeae

    PubMed Central

    Maisey, Kevin; Nardocci, Gino; Imarai, Monica; Cardenas, Hugo; Rios, Miguel; Croxatto, Horacio B.; Heckels, John E.; Christodoulides, Myron; Velasquez, Luis A.

    2003-01-01

    Infection of the Fallopian tubes (FT) by Neisseria gonorrhoeae can lead to acute salpingitis, an inflammatory condition, which is a major cause of infertility. Challenge of explants of human FT with gonococci induced mRNA expression and protein secretion for the proinflammatory cytokines interleukin (IL)-1α, IL-1β, and tumor necrosis factor alpha (TNF-α) but not for granulocyte-macrophage colony-stimulating factor. In contrast, FT expression of IL-6 and of the cytokine receptors IL-6R, TNF receptor I (TNF-RI), and TNF-RII was constitutive and was not increased by gonococcal challenge. These studies suggest that several proinflammatory cytokines are likely to contribute to the cell and tissue damage observed in gonococcal salpingitis. PMID:12496205

  2. Use of Dorset egg medium for maintenance and transport of Neisseria meningitidis and Haemophilus influenzae type b.

    PubMed

    Wasas, A D; Huebner, R E; Klugman, K P

    1999-06-01

    Studies of bacterial meningitis are hampered by the inability to maintain the viability of etiological agents during transport to reference laboratories. The long-term survival rate of 20 isolates of Neisseria meningitidis and Haemophilus influenzae type b (Hib) on Dorset egg medium, supplemented Columbia agar base medium, chocolate agar, and Amies medium was compared with that on 70% GC agar (chocolate) transport medium. N. meningitidis isolates were also inoculated onto 5% horse blood agar, and Hib was inoculated onto Haemophilus test medium. All of the N. meningitidis isolates remained viable on Dorset egg medium for 21 days; viability on the other media was poor after only 7 days. Recovery rates of Hib isolates were similar on Dorset egg and Haemophilus test media (100% after 21 days) and significantly better than on the other media. Dorset egg medium is inexpensive and easy to make and may be invaluable for studies of bacterial meningitis in developing countries.

  3. [Real-time PCR detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae DNA in clinical specimens].

    PubMed

    Vacková, Z; Lžičařová, D; Stock, N K; Kozáková, J

    2015-10-01

    The study aim was to implement a molecular real-time polymerase chain reaction (PCR) assay recommended by the CDC (Centers for Disease Control and Prevention) for the detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae in clinical (culture negative) specimens from patients with suspected invasive bacterial disease. Clinical specimens are referred to the National Reference Laboratory (NRL) for Meningococcal Infections, Unit for Airborne Bacterial Infections, Centre for Epidemiology and Microbiology, National Institute of Public Health from various regions of the Czech Republic. Clinical specimens are, in particular, cerebrospinal fluid, anti-coagulated blood or serum and, exceptionally, post-mortem specimens. The NRL has implemented molecular diagnosis of these bacterial pathogens involved in meningitis and sepsis from clinical specimens since 1999. The first diagnostic method was semi-nested PCR followed by electrophoretic analysis. In 2014, a molecular qualitative real-time PCR assay was implemented.

  4. Stable shuttle vectors for Neisseria gonorrhoeae, Haemophilus spp. and other bacteria based on a single origin of replication.

    PubMed

    Pagotto, F J; Salimnia, H; Totten, P A; Dillon, J R

    2000-02-22

    An origin of replication (ori) was obtained from a naturally occurring beta-lactamase-producing plasmid isolated from Neisseria gonorrhoeae and used to construct shuttle vectors capable of replicating in N. gonorrhoeae, Haemophilus ducreyi, Haemophilus influenzae and Escherichia coli. Using the gonococcal proAB genes, we complemented proline-requiring N. gonorrhoeae F62 and E. coli HB101 in trans. The first demonstration of the expression of the green fluorescent protein (GFP) in either N. gonorrhoeae or H. ducreyi was shown using this vector, indicating that GFP may be a useful tool in the analysis of these organisms. This is the first report of a gonococcal vector based on a broad host range, genetically defined ori, and should facilitate the molecular analysis of gonococcal and Haemophilus genes.

  5. Critical aspects of analysis of Micrococcus luteus, Neisseria cinerea, and Pseudomonas fluorescens by means of capillary electrophoresis.

    PubMed

    Hoerr, Verena; Stich, August; Holzgrabe, Ulrike

    2004-10-01

    Within the frame of our study we investigated Microccocus luteus, Neisseria cinerea, and Pseudomonas fluorescens by means of capillary zone electrophoresis (CZE). They form chains and clusters on a different scale, which can be reflected in the electropherograms. A low buffer concentration of Tris-borate and Na2EDTA containing a polymeric matrix of 0.0125% poly(ethylene) oxide (PEO) was used. Key factors were the standardization and optimization of CE conditions, buffer solution, and pretreatment of bacterial samples, which are not transferable to different bacterial strains, in general. The different compositions of the cell wall of on the one hand Gram-positive (M. luteus) and Gram-negative (N. cinerea) cocci and on the other hand Gram-negative, rod-shaped bacteria (P. fluorescens), are probably responsible for the different pretreatment conditions.

  6. Mutation of the Conserved Calcium-Binding Motif in Neisseria gonorrhoeae PilC1 Impacts Adhesion but Not Piliation

    PubMed Central

    Cheng, Yuan; Johnson, Michael D. L.; Burillo-Kirch, Christine; Mocny, Jeffrey C.; Anderson, James E.; Garrett, Christopher K.; Redinbo, Matthew R.

    2013-01-01

    Neisseria gonorrhoeae PilC1 is a member of the PilC family of type IV pilus-associated adhesins found in Neisseria species and other type IV pilus-producing genera. Previously, a calcium-binding domain was described in the C-terminal domains of PilY1 of Pseudomonas aeruginosa and in PilC1 and PilC2 of Kingella kingae. Genetic analysis of N. gonorrhoeae revealed a similar calcium-binding motif in PilC1. To evaluate the potential significance of this calcium-binding region in N. gonorrhoeae, we produced recombinant full-length PilC1 and a PilC1 C-terminal domain fragment. We show that, while alterations of the calcium-binding motif disrupted the ability of PilC1 to bind calcium, they did not grossly affect the secondary structure of the protein. Furthermore, we demonstrate that both full-length wild-type PilC1 and full-length calcium-binding-deficient PilC1 inhibited gonococcal adherence to cultured human cervical epithelial cells, unlike the truncated PilC1 C-terminal domain. Similar to PilC1 in K. kingae, but in contrast to the calcium-binding mutant of P. aeruginosa PilY1, an equivalent mutation in N. gonorrhoeae PilC1 produced normal amounts of pili. However, the N. gonorrhoeae PilC1 calcium-binding mutant still had partial defects in gonococcal adhesion to ME180 cells and genetic transformation, which are both essential virulence factors in this human pathogen. Thus, we conclude that calcium binding to PilC1 plays a critical role in pilus function in N. gonorrhoeae. PMID:24002068

  7. Carriage of Neisseria lactamica in 1- to 29-Year-Old People in Burkina Faso: Epidemiology and Molecular Characterization

    PubMed Central

    Kristiansen, Paul A.; Diomandé, Fabien; Ouédraogo, Rasmata; Sanou, Idrissa; Sangaré, Lassana; Ouédraogo, Abdoul-Salam; Ba, Absatou Ky; Kandolo, Denis; Dolan Thomas, Jennifer; Clark, Thomas A.; Préziosi, Marie-Pierre; LaForce, F. Marc

    2012-01-01

    Neisseria lactamica is a true commensal bacterium occupying the same ecological niche as the pathogenic Neisseria meningitidis, which is responsible for outbreaks and large epidemics, especially in sub-Saharan Africa. To better understand the epidemiology of N. lactamica in Africa and its relationship to N. meningitidis, we studied N. lactamica carriage in 1- to 29-year-old people living in three districts of Burkina Faso from 2009 to 2011. N. lactamica was detected in 18.2% of 45,847 oropharyngeal samples. Carriage prevalence was highest among the 2-year-olds (40.1%) and decreased with age. Overall prevalence was higher for males (19.1%) than females (17.5%) (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.04 to 1.18), while among the 18- to 29-year-olds, carriage prevalence was significantly higher in women (9.1%) than in men (3.9%) (OR, 2.49; 95% CI, 1.94 to 3.19). Carriage prevalence of N. lactamica was remarkably homogeneous in the three districts of Burkina Faso and stable over time, in comparison with carriage of N. meningitidis (P. A. Kristiansen et al., Clin. Vaccine Immunol. 18:435–443, 2011). There was no significant seasonal variation of N. lactamica carriage and no significant change in carriage prevalence after introduction of the serogroup A meningococcal conjugate vaccine, MenAfriVac. Multilocus sequence typing was performed on a selection of 142 isolates. The genetic diversity was high, as we identified 62 different genotypes, of which 56 were new. The epidemiology of N. lactamica carriage and the molecular characteristics of carried isolates were similar to those reported from industrialized countries, in contrast to the particularities of N. meningitidis carriage and disease epidemiology in Burkina Faso. PMID:23035186

  8. Infection of Human Fallopian Tube Epithelial Cells with Neisseria gonorrhoeae Protects Cells from Tumor Necrosis Factor Alpha-Induced Apoptosis

    PubMed Central

    Morales, Priscilla; Reyes, Paz; Vargas, Macarena; Rios, Miguel; Imarai, Mónica; Cardenas, Hugo; Croxatto, Horacio; Orihuela, Pedro; Vargas, Renato; Fuhrer, Juan; Heckels, John E.; Christodoulides, Myron; Velasquez, Luis

    2006-01-01

    Following infection with Neisseria gonorrhoeae, bacteria may ascend into the Fallopian tubes (FT) and induce salpingitis, a major cause of infertility. In the FT, interactions between mucosal epithelial cells and gonococci are pivotal events in the pathogen's infection cycle and the inflammatory response. In the current study, primary FT epithelial cells were infected in vitro with different multiplicities of infection (MOI) of Pil+ Opa+ gonococci. Bacteria showed a dose-dependent association with cells and induced the secretion of tumor necrosis factor alpha (TNF-α). A significant finding was that gonococcal infection (MOI = 1) induced apoptosis in approximately 30% of cells, whereas increasing numbers of bacteria (MOI = 10 to 100) did not induce apoptosis. Apoptosis was observed in only 11% of cells with associated bacteria, whereas >84% of cells with no adherent bacteria were apoptotic. TNF-α was a key contributor to apoptosis, since (i) culture supernatants from cells infected with gonococci (MOI = 1) induced apoptosis in naïve cultures, suggesting that a soluble factor was responsible; (ii) gonococcal infection-induced apoptosis was inhibited with anti-TNF-α antibodies; and (iii) the addition of exogenous TNF-α induced apoptosis, which was inhibited by the presence of increasing numbers of bacteria (MOI = 10 to 100). These data suggest that TNF-α-mediated apoptosis of FT epithelial cells is likely a primary host defense mechanism to prevent pathogen colonization. However, epithelial cell-associated gonococci have evolved a mechanism to protect the cells from undergoing TNF-α-mediated apoptosis, and this modulation of the host innate response may contribute to establishment of infection. Understanding the antiapoptotic mechanisms used by Neisseria gonorrhoeae will inform the pathogenesis of salpingitis and could suggest new intervention strategies for prevention and treatment of the disease. PMID:16714596

  9. Carriage of Neisseria lactamica in 1- to 29-year-old people in Burkina Faso: epidemiology and molecular characterization.

    PubMed

    Kristiansen, Paul A; Diomandé, Fabien; Ouédraogo, Rasmata; Sanou, Idrissa; Sangaré, Lassana; Ouédraogo, Abdoul-Salam; Ba, Absatou Ky; Kandolo, Denis; Dolan Thomas, Jennifer; Clark, Thomas A; Préziosi, Marie-Pierre; Laforce, F Marc; Caugant, Dominique A

    2012-12-01

    Neisseria lactamica is a true commensal bacterium occupying the same ecological niche as the pathogenic Neisseria meningitidis, which is responsible for outbreaks and large epidemics, especially in sub-Saharan Africa. To better understand the epidemiology of N. lactamica in Africa and its relationship to N. meningitidis, we studied N. lactamica carriage in 1- to 29-year-old people living in three districts of Burkina Faso from 2009 to 2011. N. lactamica was detected in 18.2% of 45,847 oropharyngeal samples. Carriage prevalence was highest among the 2-year-olds (40.1%) and decreased with age. Overall prevalence was higher for males (19.1%) than females (17.5%) (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.04 to 1.18), while among the 18- to 29-year-olds, carriage prevalence was significantly higher in women (9.1%) than in men (3.9%) (OR, 2.49; 95% CI, 1.94 to 3.19). Carriage prevalence of N. lactamica was remarkably homogeneous in the three districts of Burkina Faso and stable over time, in comparison with carriage of N. meningitidis (P. A. Kristiansen et al., Clin. Vaccine Immunol. 18:435-443, 2011). There was no significant seasonal variation of N. lactamica carriage and no significant change in carriage prevalence after introduction of the serogroup A meningococcal conjugate vaccine, MenAfriVac. Multilocus sequence typing was performed on a selection of 142 isolates. The genetic diversity was high, as we identified 62 different genotypes, of which 56 were new. The epidemiology of N. lactamica carriage and the molecular characteristics of carried isolates were similar to those reported from industrialized countries, in contrast to the particularities of N. meningitidis carriage and disease epidemiology in Burkina Faso.

  10. The MisR Response Regulator Is Necessary for Intrinsic Cationic Antimicrobial Peptide and Aminoglycoside Resistance in Neisseria gonorrhoeae

    PubMed Central

    Kandler, Justin L.; Holley, Concerta L.; Reimche, Jennifer L.; Dhulipala, Vijaya; Balthazar, Jacqueline T.; Muszyński, Artur; Carlson, Russell W.

    2016-01-01

    During infection, the sexually transmitted pathogen Neisseria gonorrhoeae (the gonococcus) encounters numerous host-derived antimicrobials, including cationic antimicrobial peptides (CAMPs) produced by epithelial and phagocytic cells. CAMPs have both direct and indirect killing mechanisms and help link the innate and adaptive immune responses during infection. Gonococcal CAMP resistance is likely important for avoidance of host nonoxidative killing systems expressed by polymorphonuclear granulocytes (e.g., neutrophils) and intracellular survival. Previously studied gonococcal CAMP resistance mechanisms include modification of lipid A with phosphoethanolamine by LptA and export of CAMPs by the MtrCDE efflux pump. In the related pathogen Neisseria meningitidis, a two-component regulatory system (2CRS) termed MisR-MisS has been shown to contribute to the capacity of the meningococcus to resist CAMP killing. We report that the gonococcal MisR response regulator but not the MisS sensor kinase is involved in constitutive and inducible CAMP resistance and is also required for intrinsic low-level resistance to aminoglycosides. The 4- to 8-fold increased susceptibility of misR-deficient gonococci to CAMPs and aminoglycosides was independent of phosphoethanolamine decoration of lipid A and the levels of the MtrCDE efflux pump and seemed to correlate with a general increase in membrane permeability. Transcriptional profiling and biochemical studies confirmed that expression of lptA and mtrCDE was not impacted by the loss of MisR. However, several genes encoding proteins involved in membrane integrity and redox control gave evidence of being MisR regulated. We propose that MisR modulates the levels of gonococcal susceptibility to antimicrobials by influencing the expression of genes involved in determining membrane integrity. PMID:27216061

  11. Transfer of a gonococcal beta-lactamase plasmid to conjugation-deficient Neisseria cinerea strains by transformation.

    PubMed

    Genco, C A; Clark, V L

    1988-12-01

    We have previously shown that some strains of Neisseria cinerea can serve as recipients in conjugation (Con+) with Neisseria gonorrhoeae while others cannot (Con-). To determine if a replication defect contributes to the inability of certain strains of N. cinerea to serve as recipients in conjugation, we attempted to introduce a naturally occurring gonococcal beta-lactamase plasmid into N. cinerea by transformation. Various methods were employed, and all proved unsuccessful. Since specific sequences are required for DNA uptake in transformation of N. gonorrhoeae, we constructed a number of hybrid plasmids containing N. cinerea chromosomal DNA inserted into the N. gonorrhoeae/Escherichia coli beta-lactamase shuttle vector, pLES2. When nine randomly selected plasmids with inserts were used to transform an N. cinerea strain which did not accept the gonococcal beta-lactamase plasmid by conjugation, transformants were observed with four of the hybrid plasmids. The presence of one of the hybrid plasmids, pCAG9, in transformants was confirmed by agarose gel electrophoresis, Southern hybridization, and beta-lactamase production. When an N. gonorrhoeae donor strain containing pCAG9 was used in conjugation with several N. cinerea strains, only those strains that were previously shown to act as recipients could accept and maintain pCAG9. The ability of pCAG9 and the other three hybrid plasmids to transform Con- strains demonstrates that the beta-lactamase plasmid can replicate in Con- strains, and, therefore, the Con- phenotype is due to a block in some other stage of the conjugation process.

  12. Rapid identification of pathogenic species of Neisseria by carbohydrate degradation tests. Importance of glucose in media used for preparation of inocula.

    PubMed Central

    Tapsall, J W; Cheng, J K

    1981-01-01

    Pathogenic species of Neisseria were identified more readily by carbohydrate degradation tests when 0.5% glucose was used in media from which inocula for the test were obtained. This improved the performance of both non-growth and growth-dependent methods for these tests. One of the three techniques used a non-nutrient buffered salt solution and depended on the presence of preformed enzymes. This test was more accurate and rapid than the two growth-dependent techniques. PMID:7023603

  13. Neisseria gonorrhoeae activates the proteinase cathepsin B to mediate the signaling activities of the NLRP3 and ASC-containing inflammasome.

    PubMed

    Duncan, Joseph A; Gao, Xi; Huang, Max Tze-Han; O'Connor, Brian P; Thomas, Christopher E; Willingham, Stephen B; Bergstralh, Daniel T; Jarvis, Gary A; Sparling, P Frederick; Ting, Jenny P-Y

    2009-05-15

    Neisseria gonorrhoeae is a common sexually transmitted pathogen that significantly impacts female fertility, neonatal health, and transmission of HIV worldwide. N. gonorrhoeae usually causes localized inflammation of the urethra and cervix by inducing production of IL-1beta and other inflammatory cytokines. Several NLR (nucleotide-binding domain, leucine-rich repeat) proteins are implicated in the formation of pro-IL-1beta-processing complexes called inflammasomes in response to pathogens. We demonstrate that NLRP3 (cryopyrin, NALP3) is the primary NLR required for IL-1beta/IL-18 secretion in response to N. gonorrhoeae in monocytes. We also show that N. gonorrhoeae infection promotes NLRP3-dependent monocytic cell death via pyronecrosis, a recently described pathway with morphological features of necrosis, including release of the strong inflammatory mediator HMBG1. Additionally, N. gonorrhoeae activates the cysteine protease cathepsin B as measured by the breakdown of a cathepsin B substrate. Inhibition of cathepsin B shows that this protease is an apical controlling step in the downstream activities of NLRP3 including IL-1beta production, pyronecrosis, and HMGB1 release. Nonpathogenic Neisseria strains (Neisseria cinerea and Neisseria flavescens) do not activate NLRP3 as robustly as N. gonorrhoeae. Conditioned medium from N. gonorrhoeae contains factors capable of initiating the NLRP3-mediated signaling events. Isolated N. gonorrhoeae lipooligosaccharide, a known virulence factor from this bacterium that is elaborated from the bacterium in the form of outer membrane blebs, activates both NLRP3-induced IL-1beta secretion and pyronecrosis. Our findings indicate that activation of NLRP3-mediated inflammatory response pathways is an important venue associated with host response and pathogenesis of N. gonorrhoeae.

  14. Sequence diversity within the argF, fbp and recA genes of natural isolates of Neisseria meningitidis: interspecies recombination within the argF gene.

    PubMed

    Zhou, J; Spratt, B G

    1992-08-01

    Studies of natural populations of Neisseria meningitidis using multilocus enzyme electrophoresis have shown extensive genetic variation within this species, which, it has been proposed, implies a level of sequence diversity within meningococci that is greater than that normally considered as the criterion for species limits in bacteria. To obtain a direct measure of the sequence diversity among meningococci, we obtained the nucleotide sequences of most of the argF, recA and fbp genes of eight meningococci of widely differing electrophoretic type (from the reference collection of Caugant). Sequence variation between the meningococcal strains ranged from 0-0.6% for fbp, 0-1.3% for argF, and 0-3.3% for recA. These levels of diversity are no greater than those found within Escherichia coli 'housekeeping' genes and suggest that multilocus enzyme electrophoresis may overestimate the extent of nucleotide sequence diversity within meningococci. The average sequence divergence between the Neisseria meningitidis strains and N. gonorrhoeae strain FA19 was 1.0% for fbp and 1.6% for recA. The argF gene, although very uniform among the eight meningococcal isolates, had a striking mosaic structure when compared with the gonococcal argF gene: two regions of the gene differed by greater than 13% in nucleotide sequence between meningococci and gonococci, whereas the rest of the gene differed by less than 1.7%. One of the diverged regions was shown to have been introduced from the argF gene of a commensal Neisseria species that is closely related to Neisseria cinerea. The source of the other region was unclear.

  15. Origin of the diversity in DNA recognition domains in phasevarion associated modA genes of pathogenic Neisseria and Haemophilus influenzae.

    PubMed

    Gawthorne, Jayde A; Beatson, Scott A; Srikhanta, Yogitha N; Fox, Kate L; Jennings, Michael P

    2012-01-01

    Phase variable restriction-modification (R-M) systems have been identified in a range of pathogenic bacteria. In some it has been demonstrated that the random switching of the mod (DNA methyltransferase) gene mediates the coordinated expression of multiple genes and constitutes a phasevarion (phase variable regulon). ModA of Neisseria and Haemophilus influenzae contain a highly variable, DNA recognition domain (DRD) that defines the target sequence that is modified by methylation and is used to define modA alleles. 18 distinct modA alleles have been identified in H. influenzae and the pathogenic Neisseria. To determine the origin of DRD variability, the 18 modA DRDs were used to search the available databases for similar sequences. Significant matches were identified between several modA alleles and mod gene from distinct bacterial species, indicating one source of the DRD variability was via horizontal gene transfer. Comparison of DRD sequences revealed significant mosaicism, indicating exchange between the Neisseria and H. influenzae modA alleles. Regions of high inter- and intra-allele similarity indicate that some modA alleles had undergone recombination more frequently than others, generating further diversity. Furthermore, the DRD from some modA alleles, such as modA12, have been transferred en bloc to replace the DRD from different modA alleles.

  16. Characterization of a Unique Tetrasaccharide and Distinct Glycoproteome in the O-Linked Protein Glycosylation System of Neisseria elongata subsp. glycolytica

    PubMed Central

    Anonsen, Jan Haug; Vik, Åshild; Børud, Bente; Viburiene, Raimonda; Aas, Finn Erik; Kidd, Shani W. A.; Aspholm, Marina

    2015-01-01

    ABSTRACT Broad-spectrum O-linked protein glycosylation is well characterized in the major Neisseria species of importance to human health and disease. Within strains of Neisseria gonorrhoeae, N. meningitidis, and N. lactamica, protein glycosylation (pgl) gene content and the corresponding oligosaccharide structure are fairly well conserved, although intra- and interstrain variability occurs. The status of such systems in distantly related commensal species, however, remains largely unexplored. Using a strain of deeply branching Neisseria elongata subsp. glycolytica, a heretofore unrecognized tetrasaccharide glycoform consisting of di-N-acetylbacillosamine-glucose-di-N-acetyl hexuronic acid-N-acetylhexosamine (diNAcBac-Glc-diNAcHexA-HexNAc) was identified. Directed mutagenesis, mass spectrometric analysis, and glycan serotyping confirmed that the oligosaccharide is an extended version of the diNAcBac-Glc-based structure seen in N. gonorrhoeae and N. meningitidis generated by the successive actions of PglB, PglC, and PglD and glucosyltransferase PglH orthologues. In addition, a null mutation in the orthologue of the broadly conserved but enigmatic pglG gene precluded expression of the extended glycoform, providing the first evidence that its product is a functional glycosyltransferase. Despite clear evidence for a substantial number of glycoprotein substrates, the major pilin subunit of the endogenous type IV pilus was not glycosylated. The latter finding raises obvious questions as to the relative distribution of pilin glycosylation within the genus, how protein glycosylation substrates are selected, and the overall structure-function relationships of broad-spectrum protein glycosylation. Together, the results of this study provide a foundation upon which to assess neisserial O-linked protein glycosylation diversity at the genus level. IMPORTANCE Broad-spectrum protein glycosylation systems are well characterized in the pathogenic Neisseria species N. gonorrhoeae

  17. Vaccine Potential and Diversity of the Putative Cell Binding Factor (CBF, NMB0345/NEIS1825) Protein of Neisseria meningitidis

    PubMed Central

    Akoto, Charlene; Hill, Alison; Tan, Wei-Ming; Heckels, John Edward; Christodoulides, Myron

    2016-01-01

    The cbf gene from Neisseria meningitidis strain MC58 encoding the putative Cell Binding Factor (CBF, NMB0345/NEIS1825) protein was cloned into the pRSETA system and a ~36-kDa recombinant (r)CBF protein expressed in Escherichia coli and purified by metal affinity chromatography. High titres of rCBF antibodies were induced in mice following immunization with rCBF-saline, rCBF-Al(OH)3, rCBF-Liposomes or rCBF-Zwittergent (Zw) 3–14 micelles, both with and without incorporated monophosphoryl lipid A (MPLA) adjuvant. Anti-rCBF sera reacted in western blots of meningococcal lysates with a single protein band of molecular mass ~29.5 kDa, indicative of mature CBF protein, but did not react with a lysate of a Δnmb0345 mutant (CBF-), demonstrating specificity of the murine immune responses. CBF protein was produced by all strains of meningococci studied thus far and the protein was present on the surface of MC58 (CBF+) bacteria, but absent on Δnmb0345 mutant (CBF-) bacteria, as judged by FACS reactivity of anti-rCBF sera. Analysis of the NEIS1825 amino acid sequences from 6644 N. meningitidis isolates with defined Alleles in the pubmlst.org/Neisseria database showed that there were 141 ST types represented and there were 136 different allelic loci encoding 49 non-redundant protein sequences. Only 6/6644 (<0.1%) of N. meningitidis isolates lacked the nmb0345 gene. Amongst serogroup B isolates worldwide, ~68% and ~20% expressed CBF encoded by Allele 1 and 18 respectively, with the proteins sharing >99% amino acid identity. Murine antisera to rCBF in Zw 3–14 micelles + MPLA induced significant serum bactericidal activity (SBA) against homologous Allele 1 and heterologous Allele 18 strains, using both baby rabbit serum complement and human serum complement (h)SBA assays, but did not kill strains expressing heterologous protein encoded by Alelle 2 or 3. Furthermore, variable bactericidal activity was induced by murine antisera against different meningococcal strains in the h

  18. Structural, functional and immunogenic insights on Cu,Zn superoxide dismutase pathogenic virulence factors from Neisseria meningitidis and Brucella abortus

    DOE PAGES

    Pratt, Ashley J.; DiDonato, Michael; Shin, David S.; ...

    2015-10-12

    Bacterial pathogens Neisseria meningitidis and Brucella abortus pose threats to human and animal health worldwide, causing meningococcal disease and brucellosis, respectively. Mortality from acute N. meningitidis infections remains high despite antibiotics, and brucellosis presents alimentary and health consequences. Superoxide dismutases are master regulators of reactive oxygen, general pathogenicity factors and therefore therapeutic targets. Cu,Zn superoxide dismutases (SODs) localized to the periplasm promote survival by detoxifying superoxide radicals generated by major host antimicrobial immune responses. We discovered that passive immunization with an antibody directed at N. meningitidis SOD (NmSOD) was protective in a mouse infection model. To define the relevant atomicmore » details and solution assembly states of this important virulence factor, we report high-resolution and X-ray scattering analyses of NmSOD and SOD from B. abortus (BaSOD). The NmSOD structures revealed an auxiliary tetrahedral Cu-binding site bridging the dimer interface; mutational analyses suggested that this metal site contributes to protein stability, with implications for bacterial defense mechanisms. Biochemical and structural analyses informed us about electrostatic substrate guidance, dimer assembly and an exposed C-terminal epitope in the NmSOD dimer. In contrast, the monomeric BaSOD structure provided insights for extending immunogenic peptide epitopes derived from the protein. These collective results reveal unique contributions of SOD to pathogenic virulence, refine predictive motifs for distinguishing SOD classes and suggest general targets for anti-bacterial immune responses. The identified functional contributions, motifs, and targets distinguishing bacterial and eukaryotic SOD assemblies presented here provide a foundation for efforts to develop SOD-specific inhibitors or vaccines against these harmful pathogens. IMPORTANCE By protecting microbes against reactive oxygen

  19. Structural, Functional, and Immunogenic Insights on Cu,Zn Superoxide Dismutase Pathogenic Virulence Factors from Neisseria meningitidis and Brucella abortus

    PubMed Central

    Pratt, Ashley J.; DiDonato, Michael; Shin, David S.; Cabelli, Diane E.; Bruns, Cami K.; Belzer, Carol A.; Gorringe, Andrew R.; Langford, Paul R.; Tabatabai, Louisa B.; Kroll, J. Simon; Tainer, John A.

    2015-01-01

    ABSTRACT Bacterial pathogens Neisseria meningitidis and Brucella abortus pose threats to human and animal health worldwide, causing meningococcal disease and brucellosis, respectively. Mortality from acute N. meningitidis infections remains high despite antibiotics, and brucellosis presents alimentary and health consequences. Superoxide dismutases are master regulators of reactive oxygen and general pathogenicity factors and are therefore therapeutic targets. Cu,Zn superoxide dismutases (SODs) localized to the periplasm promote survival by detoxifying superoxide radicals generated by major host antimicrobial immune responses. We discovered that passive immunization with an antibody directed at N. meningitidis SOD (NmSOD) was protective in a mouse infection model. To define the relevant atomic details and solution assembly states of this important virulence factor, we report high-resolution and X-ray scattering analyses of NmSOD and of SOD from B. abortus (BaSOD). The NmSOD structures revealed an auxiliary tetrahedral Cu-binding site bridging the dimer interface; mutational analyses suggested that this metal site contributes to protein stability, with implications for bacterial defense mechanisms. Biochemical and structural analyses informed us about electrostatic substrate guidance, dimer assembly, and an exposed C-terminal epitope in the NmSOD dimer. In contrast, the monomeric BaSOD structure provided insights for extending immunogenic peptide epitopes derived from the protein. These collective results reveal unique contributions of SOD to pathogenic virulence, refine predictive motifs for distinguishing SOD classes, and suggest general targets for antibacterial immune responses. The identified functional contributions, motifs, and targets distinguishing bacterial and eukaryotic SOD assemblies presented here provide a foundation for efforts to develop SOD-specific inhibitors of or vaccines against these harmful pathogens. IMPORTANCE By protecting microbes against

  20. [Molecular epidemiology of Neisseria gonorrhoeae: effect of sex and sexual orientation on the distribution of gonococcal types].

    PubMed

    Kohl, P K; Henze, I; Kamionek, I; Krahl, D; Petzoldt, D

    1994-05-01

    Auxotype/serovar (A/S) classification enables precise characterisation of Neisseria gonorrhoeae. In the present study we evaluated whether sex and sexual preference of the patient influence the auxotype/serovar class of the infecting gonococcal strain. In male patients prototrophic/IB-3 was the most frequently isolated A/S class. By contrast, in female patients the A/S class (P)AH(U)/IA-1/2 was significantly (p < 0.005) more frequently isolated than in male patients. Analysis of our data according to sexual preference of the patients showed that in heterosexual patients the two mentioned A/S classes were leading, whereas in homo- and bisexual patients A/S classes prototrophic/IB-2 (p < 0.0001) and Pro/IB-2/16 (p < 0.0001) were isolated significantly more often. Our data are a strong indication that the host environment is also responsible for the selection of N. gonorrhoeae strains with certain typing characteristics.

  1. Molecular analyses of TEM genes and their corresponding penicillinase-producing Neisseria gonorrhoeae isolates in Bangkok, Thailand.

    PubMed

    Nakayama, Shu-Ichi; Tribuddharat, Chanwit; Prombhul, Sasiprapa; Shimuta, Ken; Srifuengfung, Somporn; Unemo, Magnus; Ohnishi, Makoto

    2012-02-01

    Neisseria gonorrhoeae is a major public health problem globally, especially because the bacterium has developed resistance to most antimicrobials introduced for first-line treatment of gonorrhea. In the present study, 96 N. gonorrhoeae isolates with high-level resistance to penicillin from 121 clinical isolates in Thailand were examined to investigate changes related to their plasmid-mediated penicillin resistance and their molecular epidemiological relationships. A β-lactamase (TEM) gene variant, bla(TEM-135), that may be a precursor in the transitional stage of a traditional bla(TEM-1) gene into an extended-spectrum β-lactamase (ESBL), possibly causing high resistance to all extended-spectrum cephalosporins in N. gonorrhoeae, was identified. Clonal analysis using multilocus sequence typing (MLST) and N. gonorrhoeae multiantigen sequence typing (NG-MAST) revealed the existence of a sexual network among patients from Japan and Thailand. Molecular analysis of the bla(TEM-135) gene showed that the emergence of this allele might not be a rare genetic event and that the allele has evolved in different plasmid backgrounds, which results possibly indicate that it is selected due to antimicrobial pressure. The presence of the bla(TEM-135) allele in the penicillinase-producing N. gonorrhoeae population may call for monitoring for the possible emergence of ESBL-producing N. gonorrhoeae in the future. This study identified a bla(TEM) variant (bla(TEM-135)) that is a possible intermediate precursor for an ESBL, which warrants international awareness.

  2. Multiplexed nanoplasmonic biosensor for one-step simultaneous detection of Chlamydia trachomatis and Neisseria gonorrhoeae in urine.

    PubMed

    Soler, Maria; Belushkin, Alexander; Cavallini, Andrea; Kebbi-Beghdadi, Carole; Greub, Gilbert; Altug, Hatice

    2017-03-21

    Development of rapid and multiplexed diagnostic tools is a top priority to address the current epidemic problem of sexually transmitted diseases. Here we introduce a novel nanoplasmonic biosensor for simultaneous detection of the two most common bacterial infections: Chlamydia trachomatis and Neisseria gonorrhoeae. Our plasmonic microarray is composed of gold nanohole sensor arrays that exhibit the extraordinary optical transmission (EOT), providing highly sensitive analysis in a label-free configuration. The integration in a microfluidic system and the precise immobilization of specific antibodies on the individual sensor arrays allow for selective detection and quantification of the bacteria in real-time. We achieved outstanding sensitivities for direct immunoassay of urine samples, with a limit of detection of 300 colony forming units (CFU)/mL for C. trachomatis and 1500CFU/mL for N. gonorrhoeae. The multiplexing capability of our biosensor was demonstrated by analyzing different urine samples spiked with either C. trachomatis or N. gonorrhoeae, and also containing both bacteria. We could successfully detect, identify and quantify the levels of the two bacteria in a one-step assay, without the need for DNA extraction or amplification techniques. This work opens up new possibilities for the implementation of point-of-care biosensors that enable fast, simple and efficient diagnosis of sexually transmitted infections.

  3. [Development of the sensitivity to antibiotics in strains of Neisseria gonorrhea isolated in Touraine over a 5-year period].

    PubMed

    Pinon, G; Quentin, R; Laudat, P; Vargues, R

    1985-06-01

    347 Neisseria gonorrhoeae strains isolated in Touraine, France, from December 1978 to March 1984 were tested for susceptibility to seven antibiotics using an agar dilution method. Percentage of strains with a penicillin G MIC = 0.06 micrograms/ml rose from 58% in 78-80 to 69% in 82-84. Consistent amoxicillin MICs were found throughout the survey (MIC 50: 0.125 and MIC 90: 0.5 micrograms/ml). Three penicillinase-producing strains were recovered from patients contaminated outside the study area. For tetracycline, minocycline, chloramphenicol and spectinomycin, variations of MICs 50 and 90 did not exceed one dilution either way. For spiramycin, MICs 50 and 90 fell from 2 and 8 micrograms/ml respectively in 78-80 to 1 and 2 micrograms/ml in 82-84. Our findings show that susceptibility of Gonococci to the main antibiotics used for treating gonococcal infections in our area has not changed significantly over the last five years. Moreover, implantation and diffusion of penicillinase-producing strains has failed to occur.

  4. A Novel Loop-Mediated Isothermal Amplification Assay for Serogroup Identification of Neisseria meningitidis in Cerebrospinal Fluid

    PubMed Central

    Lee, DoKyung; Kim, Eun Jin; Kilgore, Paul E.; Takahashi, Hideyuki; Ohnishi, Makoto; Tomono, Jun; Miyamoto, Shigehiko; Omagari, Daisuke; Kim, Dong Wook; Seki, Mitsuko

    2016-01-01

    We have developed a novel Neisseria meningitidis serogroup-specific loop-mediated isothermal amplification (LAMP) assay for six of the most common meningococcal serogroups (A, B, C, W, X, and Y). The assay was evaluated using a set of 31 meningococcal LAMP assay positive cerebrospinal fluid (CSF) specimens from 1574 children with suspected meningitis identified in prospective surveillance between 1998 and 2002 in Vietnam, China, and Korea. Primer specificity was validated using 15 N. meningitidis strains (including serogroups A, B, C, E, W, X, Y, and Z) and 19 non-N. meningitidis species. The N. meningitidis serogroup LAMP detected down to ten copies and 100 colony-forming units per reaction. Twenty-nine CSF had N. meningitidis serogroup identified by LAMP compared with two CSF in which N. meningitidis serogroup was identified by culture and multi-locus sequence typing. This is the first report of a serogroup-specific identification assay for N. meningitidis using the LAMP method. Our results suggest that this assay will be a rapid, sensitive, and uniquely serogroup-specific assay with potential for application in clinical laboratories and public health surveillance systems. PMID:26793181

  5. Opa+ Neisseria gonorrhoeae Exhibits Reduced Survival in Human Neutrophils Via Src Family Kinase-Mediated Bacterial Trafficking Into Mature Phagolysosomes

    PubMed Central

    Johnson, M. Brittany; Ball, Louise M.; Daily, Kylene P.; Martin, Jennifer N.; Columbus, Linda; Criss, Alison K.

    2015-01-01

    Summary During gonorrheal infection, there is a heterogeneous population of Neisseria gonorrhoeae (Gc) varied in their expression of opacity-associated (Opa) proteins. While Opa proteins are important for bacterial attachment and invasion of epithelial cells, Opa+ Gc has a survival defect after exposure to neutrophils. Here, we use constitutively Opa- and OpaD+ Gc in strain background FA1090 to show that Opa+ Gc is more sensitive to killing inside adherent, chemokine-treated primary human neutrophils due to increased bacterial residence in mature, degradative phagolysosomes that contain primary and secondary granule antimicrobial content. Although Opa+ Gc stimulates a potent oxidative burst, neutrophil killing of Opa+ Gc was instead attributable to non-oxidative components, particularly neutrophil proteases and the bactericidal/permeability-increasing protein. Blocking interaction of Opa+ Gc with carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) or inhibiting Src family kinase signaling, which is downstream of CEACAM activation, enhanced the survival of Opa+ Gc in neutrophils. Src family kinase signaling was required for fusion of Gc phagosomes with primary granules to generate mature phagolysosomes. Conversely, ectopic activation of Src family kinases or coinfection with Opa+ Gc resulted in decreased survival of Opa- Gc in neutrophils. From these results, we conclude that Opa protein expression is an important modulator of Gc survival characteristics in neutrophils by influencing phagosome dynamics and thus bacterial exposure to neutrophils’ full antimicrobial arsenal. PMID:25346239

  6. Antigenic diversity of the serotype antigen complex of Neisseria gonorrhoeae: analysis by an indirect enzyme-linked immunoassay.

    PubMed Central

    Johnston, K H

    1980-01-01

    An indirect enzyme-linked immunoassay (ELISA) has been developed to analyze the antigenic profile of the outer membrane serotype complex of Neisseria gonorrhoeae. Antisera raised in rabbits to serotype-specific vesicles (SSV) reacted primarily with homologous SSV; however, there was significant cross-reactivity (less than 50%) with heterologous SSV. N. meningitidis SSV cross-reacted with all antigonococcal SSV but at a lower degree (less than 20%). Preimmune sera did not cross-react significantly with all antigonoccoccal SSV. The sensitivity of the ELISA was enhanced when the integral SSV proteins 1a and 2 were used as adsorbed antigen. Heterologous anti-SSV cross-reacted slightly, having ELISA values less than 15% of the homologous reaction. Antisera prepared by immunoabsorbent affinity columns were highly specific. Homologous affinity anti-SSV reacted only with proteins 1a and 2. The reaction of immune sera was inhibited by homologous proteins 1a and 2; lipopolysaccharide and proteins 1a and 2 isolated from heterologous serotypes did not inhibit the reaction. The reaction of affinity-purified antisera could be inhibited only by homologous protein 1a. By the use of affinity-purified antisera, a specific and highly sensitive ELISA was developed to analyze the antigenic profile of strains of N. gonorrhoeae. PMID:6769815

  7. The risk of transmission of genital Chlamydia trachomatis infection is less than that of genital Neisseria gonorrhoeae infection.

    PubMed

    Lycke, E; Löwhagen, G B; Hallhagen, G; Johannisson, G; Ramstedt, K

    1980-01-01

    A total of 211 men with 237 female sexual partners and a total of 155 women with 156 male consorts were examined for genital infection with Chlamydia trachomatis and Neisseria gonorrhoeae. The index patients had either single chlamydial or gonococcal infections or dual infections with both microorganisms. Analysis of recovery rates for groups of sexual consorts indicated that gonorrhea was contracted more frequently than chlamydial infection. Thus, when index patients had dual infections, 45% and 28% of their female and male consorts, respectively, had chlamydial infection, but 64% and 77%, respectively, had gonorrhea. When index patients had single infections with C. trachomatis or N. gonorrhoeae, chlamydial infections were observed in consorts of 45% (women) and 28% (men), but gonococcal infections were observed in 80% (women) and 81% (men). Moreover, a significantly larger proportion of consorts of patients with chlamydial infection eluded infection than did partners of patients with gonorrhea. Women who used an intrauterine contraceptive device had chlamydial and gonococcal infections more often than those who used other forms of contraception, or no contraceptive.

  8. Identification of penicillinase producing Neisseria gonorrhoeae in Chile during clinical and microbiological study of gonococcal susceptibility to antimicrobial agents.

    PubMed Central

    Garcia Moreno, J; Dillon, J R; Arroyave, R; Maldonado, A; Fich, F; Salvo, A; Villalobos, D; Vincent, P; Pauze, M

    1987-01-01

    The first penicillinase producing isolates of Neisseria gonorrhoeae (PPNG) identified in Chile were discovered during a clinical and microbiological study to compare the efficacy of penicillin (4.8 MIU aqueous procaine penicillin G plus 1 g oral probenecid) and tetracycline (1.5 g followed by 500 mg four times daily for four days) treatment regimens for acute uncomplicated gonorrhoea. Penicillin treatment was effective in 93.1% (282) of 303 patients, whereas tetracycline was effective in 98.3% (233) of 237 patients. Six of the penicillin treatment failures were attributable to PPNG strains. In all, 21 PPNG strains were identified during the study. They were genetically identical, having a wild type auxotype, a WII/III serotype (serovar Bajk), and carrying cryptic and transfer plasmids and an Asian type penicillinase producing plasmid. In addition, 674 non-PPNG isolates were tested for their susceptibility to eight antimicrobials. Over 95% were sensitivie to 1 mg/l of penicillin, ampicillin, cefotaxime, cefuroxime, and erythromycin, over 90% were sensitive to 1 mg/l of tetracycline and 2 mg/l of thiamphenicol, and all were sensitive to spectinomycin. Of 226 non-PPNG isolates characterised for plasmid content and auxotype, 90% (205) were either wild type or proline requiring, 67% (153) carried only the cryptic plasmid, and a further 31% (71) carried both cryptic and transfer plasmids. Unusually, three of four isolates lacking the cryptic plasmid carried only the transfer plasmid. Images PMID:3102348

  9. Adhesion of Neisseria meningitidis to Dermal Vessels Leads to Local Vascular Damage and Purpura in a Humanized Mouse Model

    PubMed Central

    Melican, Keira; Michea Veloso, Paula; Martin, Tiffany; Bruneval, Patrick; Duménil, Guillaume

    2013-01-01

    Septic shock caused by Neisseria meningitidis is typically rapidly evolving and often fatal despite antibiotic therapy. Further understanding of the mechanisms underlying the disease is necessary to reduce fatality rates. Postmortem samples from the characteristic purpuric rashes of the infection show bacterial aggregates in close association with microvessel endothelium but the species specificity of N. meningitidis has previously hindered the development of an in vivo model to study the role of adhesion on disease progression. Here we introduced human dermal microvessels into SCID/Beige mice by xenografting human skin. Bacteria injected intravenously exclusively associated with the human vessel endothelium in the skin graft. Infection was accompanied by a potent inflammatory response with the secretion of human inflammatory cytokines and recruitment of inflammatory cells. Importantly, infection also led to local vascular damage with hemostasis, thrombosis, vascular leakage and finally purpura in the grafted skin, replicating the clinical presentation for the first time in an animal model. The adhesive properties of the type IV pili of N. meningitidis were found to be the main mediator of association with the dermal microvessels in vivo. Bacterial mutants with altered type IV pili function also did not trigger inflammation or lead to vascular damage. This work demonstrates that local type IV pili mediated adhesion of N. meningitidis to the vascular wall, as opposed to circulating bacteria, determines vascular dysfunction in meningococcemia. PMID:23359320

  10. Towards New Drug Targets? Function Prediction of Putative Proteins of Neisseria meningitidis MC58 and Their Virulence Characterization

    PubMed Central

    Shahbaaz, Mohd.; Bisetty, Krishna; Ahmad, Faizan

    2015-01-01

    Abstract Neisseria meningitidis is a Gram-negative aerobic diplococcus, responsible for a variety of meningococcal diseases. The genome of N. meningitidis MC58 is comprised of 2114 genes that are translated into 1953 proteins. The 698 genes (∼35%) encode hypothetical proteins (HPs), because no experimental evidence of their biological functions are available. Analyses of these proteins are important to understand their functions in the metabolic networks and may lead to the discovery of novel drug targets against the infections caused by N. meningitidis. This study aimed at the identification and categorization of each HP present in the genome of N. meningitidis MC58 using computational tools. Functions of 363 proteins were predicted with high accuracy among the annotated set of HPs investigated. The reliably predicted 363 HPs were further grouped into 41 different classes of proteins, based on their possible roles in cellular processes such as metabolism, transport, and replication. Our studies revealed that 22 HPs may be involved in the pathogenesis caused by this microorganism. The top two HPs with highest virulence scores were subjected to molecular dynamics (MD) simulations to better understand their conformational behavior in a water environment. We also compared the MD simulation results with other virulent proteins present in N. meningitidis. This study broadens our understanding of the mechanistic pathways of pathogenesis, drug resistance, tolerance, and adaptability for host immune responses to N. meningitidis. PMID:26076386

  11. Porphyrin-based compounds exert antibacterial action against the sexually transmitted pathogens Neisseria gonorrhoeae and Haemophilus ducreyi.

    PubMed

    Bozja, J; Yi, K; Shafer, W M; Stojiljkovic, I

    2004-12-01

    A series of porphyrin based compounds without (nMP) or with (MP) metals were found to have potent bactericidal action in vitro against the sexually transmitted pathogens Neisseria gonorrhoeae and Haemophilus ducreyi. nMP and MP did not show bactericidal activity against five species of lactobacilli. An MP containing gallium had the capacity to block a gonococcal infection in a murine vaginal model, indicating that its development as a topical microbicide to block sexually transmitted bacterial infections is warranted. In contrast to other bacterial species, loss of the gonococcal haemoglobin uptake system encoded by hpuB or energy supplied through the TonB-ExbB-ExbD system did not significantly affect levels of MP-susceptibility in gonococci. In contrast, mutations in gonococci that inactivate the mtrCDE-encoded efflux pump were found to enhance gonococcal susceptibility to nMPs and MPs while over-production of this efflux pump decreased levels of gonococcal susceptibility to these compounds.

  12. First description of a rifampicin-resistant Neisseria meningitidis serogroup Y strain causing recurrent invasive meningococcal disease in Hungary.

    PubMed

    Tóth, Ákos; Berta, Brigitta; Tirczka, Tamás; Jekkel, Csilla; Ábrahám, Anita; Prohászka, Zoltán; Bognár, Zsófia; Erdősi, Tímea

    2017-02-21

    A Hungarian soldier previously immunized against Neisseria meningitidis by quadrivalent polysaccharide vaccine was twice infected with meningococci within six weeks. The patient was treated with ceftriaxone during both episodes and he successfully recovered. His close contacts received rifampicin prophylaxis. An investigation was performed to characterize the genetic background of the pathogens to ascertain if the recurrent invasive meningococcal disease was caused by the same strain and to find out the reason for reinfection. Both meningococci belonged to the fine type Y:P1.5-2,10-1:F4-1:ST-23. This is the first description of the Europe-wide prevalent N. meningitidis serogroup Y in Hungary. In the first episode, we found wild-type rpoB allele in the non-culturable sample implying the susceptibility to rifampicin. The culturable isolate from the second episode proved resistant to rifampicin and had a point mutation in the rpoB gene. The rifampicin resistance might have evolved during the prophylactic treatment of contacts. Previous immunization of the patient with polysaccharide vaccine was ineffective due to his immunodeficiency, thus immunization with conjugate vaccine was proposed. We have proposed the implementation of centralized rifampicin susceptibility testing of N. meningitidis strains within a defined time frame to intervene and administer appropriate prophylaxis to close contacts.

  13. Insight into proteomic investigations of Neisseria meningitidis serogroup C strain L91543 from analysis of its genome sequence.

    PubMed

    Karlyshev, Andrey V; Snyder, Lori A S; McFadden, Johnjoe; Griffin, Ruth

    2015-05-01

    Here, we describe the draft sequence of a virulent isolate of Neisseria meningitidis strain L91543, belonging to serogroup C. The findings from previous proteomic and metabolomic studies of this strain can now be further interpreted with genomic analysis. Comparative analysis of the genome sequence revealed close similarity and localized synteny with the genome sequence of N. meningitidis serogroup C strain, FAM18. Polymorphisms were identified in the signal peptide sequence of factor H binding protein, a target for new meningococcal vaccines, which may result in its inefficient translocation across the cytoplasmic membrane affecting its processing (lipidation and cleavage of the signal peptide) and transportation to the outer membrane in strain L91543. This would explain the unusual proteomic data for factor H binding protein for this strain. NadA, another target for new vaccines, and the MtrR regulator, which controls expression of NadA, both contain SNPs between strains L91543 and FAM18. The genome sequence data were generated using Ion Torrent PGM sequencing, assembled into 50 contigs with 64× coverage and annotated with 2262 genes, 14 rRNAs and 56 tRNAs. The availability of the genome of N. meningitidis strain L91543 will aid our understanding of the proteome of this organism, importantly its vaccine antigens.

  14. In vitro growth of multidrug-resistant Neisseria gonorrhoeae isolates is inhibited by ETX0914, a novel spiropyrimidinetrione.

    PubMed

    Papp, John R; Lawrence, Kenneth; Sharpe, Samera; Mueller, John; Kirkcaldy, Robert D

    2016-09-01

    Antimicrobial resistance in Neisseria gonorrhoeae has severely limited the number of treatment options, and the emergence of extended-spectrum cephalosporin resistance threatens the effectiveness of the last remaining recommended treatment regimen. This study assessed the in vitro susceptibility of N. gonorrhoeae to ETX0914, a novel spiropyrimidinetrione that inhibits DNA biosynthesis. In vitro activity was determined by agar dilution against 100 N. gonorrhoeae isolates collected from men presenting with urethritis in the USA during 2012-2013 through the Gonococcal Isolate Surveillance Project. The minimum inhibitory concentration (MIC) that inhibited growth in 50% (MIC50) and 90% (MIC90) of isolates was calculated for each antimicrobial agent. ETX0914 demonstrated a high level of antimicrobial activity against N. gonorrhoeae, including isolates with decreased susceptibility or resistance to currently available agents. The ability of ETX0914 to inhibit the growth of N. gonorrhoeae was similar to ceftriaxone, which is currently recommended in combination with azithromycin to treat gonorrhoea. The data presented in this study strongly suggest that ETX0914 should be evaluated in a clinical trial for the treatment of N. gonorrhoeae.

  15. Functional Characterization of Lpt3 and Lpt6, the Inner-Core Lipooligosaccharide Phosphoethanolamine Transferases from Neisseria meningitidis▿

    PubMed Central

    Wenzel, Cory Q.; St. Michael, Frank; Stupak, Jacek; Li, Jianjun; Cox, Andrew D.; Richards, James C.

    2010-01-01

    The lipooligosaccharide (LOS) of Neisseria meningitidis contains heptose (Hep) residues that are modified with phosphoethanolamine (PEtn) at the 3 (3-PEtn) and/or 6 (6-PEtn) position. The lpt3 (NMB2010) and lpt6 (NMA0408) genes of N. meningitidis, which are proposed to encode the required HepII 3- and 6-PEtn transferases, respectively, were cloned and overexpressed as C-terminally polyhistidine-tagged fusion proteins in Escherichia coli and found to localize to the inner membrane, based on sucrose density gradient centrifugation. Lpt3-His6 and Lpt6-His6 were purified from Triton X-100-solubilized membranes by nickel chelation chromatography, and dot blot analysis of enzymatic reactions with 3-PEtn- and 6-PEtn-specific monoclonal antibodies demonstrated conclusively that Lpt3 and Lpt6 are phosphatidylethanolamine-dependent LOS HepII 3- and 6-PEtn transferases, respectively, and that both enzymes are capable of transferring PEtn to both fully acylated LOS and de-O-acylated (de-O-Ac) LOS. Further enzymatic studies using capillary electrophoresis-mass spectrometry (MS) demonstrated that both Lpt3 and Lpt6 are capable of transferring PEtn to de-O-Ac LOS molecules already containing PEtn at the 6 and 3 positions of HepII, respectively, demonstrating that there is no obligate order of PEtn addition in the generation of 3,6-di-PEtn LOS moieties in vitro. PMID:19854897

  16. Neisseria gonorrhoeae Modulates Cell Death in Human Endocervical Epithelial Cells through Export of Exosome-Associated cIAP2

    PubMed Central

    Massari, Paola

    2015-01-01

    Several bacterial pathogens persist and survive in the host by modulating host cell death pathways. We previously demonstrated that Neisseria gonorrhoeae, a Gram-negative pathogen responsible for the sexually transmitted infection gonorrhea, protects against exogenous induction of apoptosis in human cervical epithelial cells. However, induction of cell death by N. gonorrhoeae has also been reported in other cell types. The mechanisms by which N. gonorrhoeae modulates cell death are not clear, although a role for the inhibitor of apoptosis-2 (cIAP2) has been proposed. In this study, we confirmed that N. gonorrhoeae induces production of cIAP2 in human cervical epithelial cells. High levels of intracellular cIAP2 were detected early after N. gonorrhoeae stimulation, which was followed by a marked decrease at 24 h. At this time point, we observed increased levels of extracellular cIAP2 associated with exosomes and an overall increase in production of exosomes. Inhibition of cIAP2 in N. gonorrhoeae-stimulated epithelial cells resulted in increased cell death and interleukin-1β (IL-1β) production. Collectively these results indicate that N. gonorrhoeae stimulation of human endocervical epithelial cells induces the release of cIAP2, an essential regulator of cell death and immune signaling. PMID:26077759

  17. Neisseria gonorrhoeae Modulates Cell Death in Human Endocervical Epithelial Cells through Export of Exosome-Associated cIAP2.

    PubMed

    Nudel, Kathleen; Massari, Paola; Genco, Caroline A

    2015-09-01

    Several bacterial pathogens persist and survive in the host by modulating host cell death pathways. We previously demonstrated that Neisseria gonorrhoeae, a Gram-negative pathogen responsible for the sexually transmitted infection gonorrhea, protects against exogenous induction of apoptosis in human cervical epithelial cells. However, induction of cell death by N. gonorrhoeae has also been reported in other cell types. The mechanisms by which N. gonorrhoeae modulates cell death are not clear, although a role for the inhibitor of apoptosis-2 (cIAP2) has been proposed. In this study, we confirmed that N. gonorrhoeae induces production of cIAP2 in human cervical epithelial cells. High levels of intracellular cIAP2 were detected early after N. gonorrhoeae stimulation, which was followed by a marked decrease at 24 h. At this time point, we observed increased levels of extracellular cIAP2 associated with exosomes and an overall increase in production of exosomes. Inhibition of cIAP2 in N. gonorrhoeae-stimulated epithelial cells resulted in increased cell death and interleukin-1β (IL-1β) production. Collectively these results indicate that N. gonorrhoeae stimulation of human endocervical epithelial cells induces the release of cIAP2, an essential regulator of cell death and immune signaling.

  18. Crystallization and preliminary X-ray diffraction analysis of the multidrug efflux transporter NorM from Neisseria gonorrhoeae

    SciTech Connect

    Su, Chih-Chia; Long, Feng; McDermott, Gerry; Shafer, William M.; Yu, Edward W.

    2008-04-01

    The multidrug efflux transporter NorM from N. gonorrhoeae has been crystallized and X-ray diffraction data have been collected to a resolution of 6.5 Å. The crystallization and preliminary X-ray data analysis of the NorM multidrug efflux pump produced by Neisseria gonorrhoeae are reported. NorM is a cytoplasmic membrane protein that consists of 459 amino-acid residues. It is a member of the recently classified multidrug and toxic compound extrusion (MATE) family of transporters and recognizes a number of cationic toxic compounds such as ethidium bromide, acriflavin, 2-N-methylellipticinium and ciprofloxacin. Recombinant NorM protein was expressed in Escherichia coli and purified by metal-affinity and gel-filtration chromatography. The protein was crystallized using hanging-drop vapor diffusion. X-ray diffraction data were collected from cryocooled crystals at a synchrotron light source. The best crystal diffracted anisotropically to 3.8 Å and diffraction data were complete to 6.5 Å resolution. The space group was determined to be C2, with unit-cell parameters a = 81.5, b = 164.4, c = 111.5 Å.

  19. Crystallization and preliminary X-ray diffraction analysis of the multidrug efflux transporter NorM from Neisseria gonorrhoeae

    SciTech Connect

    Su, C.C.; Long, F.; McDermott, G.; Shafer, W.M.; Yu, E.W.

    2008-06-03

    The crystallization and preliminary X-ray data analysis of the NorM multidrug efflux pump produced by Neisseria gonorrhoeae are reported. NorM is a cytoplasmic membrane protein that consists of 459 amino-acid residues. It is a member of the recently classified multidrug and toxic compound extrusion (MATE) family of transporters and recognizes a number of cationic toxic compounds such as ethidium bromide, acriflavin, 2-N-methylellipticinium and ciprofloxacin. Recombinant NorM protein was expressed in Escherichia coli and purified by metal-affinity and gel-filtration chromatography. The protein was crystallized using hanging-drop vapor diffusion. X-ray diffraction data were collected from cryocooled crystals at a synchrotron light source. The best crystal diffracted anisotropically to 3.8 {angstrom} and diffraction data were complete to 6.5 {angstrom} resolution. The space group was determined to be C2, with unit-cell parameters a = 81.5, b = 164.4, c = 111.5 {angstrom}.

  20. Neisseria gonorrhoeae isolated from disseminated and localised infections in pre-penicillin era. Auxotypes and antibacterial drug resistances.

    PubMed Central

    Catlin, B W; Reyn, A

    1982-01-01

    Interest in the evolution of gonococcal auxotrophy led to a study of 72 strains isolated between 1935 and 1948 from the urogenital tract (57 patients), the eye (two patients), and from disseminated gonococcal infections (11 patients and probably two others). Two cervical isolates with nutritional requirements for proline, arginine, histidine, and biotin were oxidase-positive, Gram-negative diplococci, but their identity as Neisseria gonorrhoeae was uncertain because they were atypically susceptible to colistin and did not produce acid in glucose media. The N gonorrhoeae strains were highly susceptible to 11 other antibacterial drugs but not to sulphadiazine. Defects of one or more pathways for the biosynthesis of methionine, proline, arginine, threonine, lysine, the branched-chain amino acids, hypoxanthine, and thiamine pyrophosphate were found in 39 of the 70 strains, including four isolated in the presulphanilamide era. Unexpectedly, methionine was required for the growth of 11 (21%) of the 52 Danish strains and for 13 (72%) of 18 strains isolated in the USA. The Danish strains included 28 (54%) that did not require any of the compounds used for differentiating auxotypes, whereas this type was represented by only three (17%) of the USA strains. None of the gonococci required uracil or other pyrimidines. This suggests that the requirements for arginine, hypoxanthine, and uracil commonly found in recent isolates from disseminated gonococcal infections probably evolved treatment with sulphonamide was replaced by penicillin. PMID:6805848

  1. Structure and mechanism of a molecular rheostat, an RNA thermometer that modulates immune evasion by Neisseria meningitidis

    PubMed Central

    Barnwal, Ravi Pratap; Loh, Edmund; Godin, Katherine S.; Yip, Jordan; Lavender, Hayley; Tang, Christoph M.; Varani, Gabriele

    2016-01-01

    Neisseria meningitidis causes bacterial meningitis and septicemia. It evades the host complement system by upregulating expression of immune evasion factors in response to changes in temperature. RNA thermometers within mRNAs control expression of bacterial immune evasion factors, including CssA, in the 5′-untranslated region of the operon for capsule biosynthesis. We dissect the molecular mechanisms of thermoregulation and report the structure of the CssA thermometer. We show that the RNA thermometer acts as a rheostat, whose stability is optimized to respond in a small temperature range around 37°C as occur within the upper airways during infection. Small increases in temperature gradually open up the structure to allow progressively increased access to the ribosome binding site. Even small changes in stability induced by mutations of imperfect base pairs, as in naturally occurring polymorphisms, shift the thermometer response outside of the desired temperature range, suggesting that its activity could be modulated by pharmacological intervention. PMID:27369378

  2. Restriction Endonucleases from Invasive Neisseria gonorrhoeae Cause Double-Strand Breaks and Distort Mitosis in Epithelial Cells during Infection

    PubMed Central

    Weyler, Linda; Engelbrecht, Mattias; Mata Forsberg, Manuel; Brehwens, Karl; Vare, Daniel; Vielfort, Katarina; Wojcik, Andrzej; Aro, Helena

    2014-01-01

    The host epithelium is both a barrier against, and the target for microbial infections. Maintaining regulated cell growth ensures an intact protective layer towards microbial-induced cellular damage. Neisseria gonorrhoeae infections disrupt host cell cycle regulation machinery and the infection causes DNA double strand breaks that delay progression through the G2/M phase. We show that intracellular gonococci upregulate and release restriction endonucleases that enter the nucleus and damage human chromosomal DNA. Bacterial lysates containing restriction endonucleases were able to fragment genomic DNA as detected by PFGE. Lysates were also microinjected into the cytoplasm of cells in interphase and after 20 h, DNA double strand breaks were identified by 53BP1 staining. In addition, by using live-cell microscopy and NHS-ester stained live gonococci we visualized the subcellular location of the bacteria upon mitosis. Infected cells show dysregulation of the spindle assembly checkpoint proteins MAD1 and MAD2, impaired and prolonged M-phase, nuclear swelling, micronuclei formation and chromosomal instability. These data highlight basic molecular functions of how gonococcal infections affect host cell cycle regulation, cause DNA double strand breaks and predispose cellular malignancies. PMID:25460012

  3. Neisseria lactamica attenuates TLR-1/2-induced cytokine responses in nasopharyngeal epithelial cells using PPAR-γ.

    PubMed

    Tezera, L B; Hampton, J; Jackson, S K; Davenport, V

    2011-04-01

    The upper respiratory tract commensal Neisseria lactamica (Nlac) induces protective humoral immunity against pathogenic Nmen serogroup B (Nmen), but whether it also affords anti-inflammatory mucosal protection, as reported for several gut commensals, has not been investigated. Here we demonstrate for the first time that Nlac weakly induces inflammatory responses compared with Nmen in the nasopharyngeal epithelial cell line, Detroit 562, and that Nlac achieves this by attenuation of secretory cytokine (TNF-α and IL-6) and to a lesser extent chemokine (IL-8 and RANTES) responses. Culture of Detroit cells with Nlac inhibited the induction of cytokine-chemokine mRNA by Nmen, reduced Nmen-induced NF-κβ activity and increased constitutive PPAR-γ protein expression. Pretreatment of Detroit cells with a PPAR-γ antagonist abrogated the attenuation of inflammatory IL-6 by Nlac, as did heat-killing of the organisms and preventing their invasion with cytochalasin D. Inflammatory responses from Detroit cells were readily attenuated by Nlac following stimulation with pathogenic Nmen but more specifically following stimulation with the TLR-1/2 agonist Pam3Cys and pro-inflammatory cytokines (IL-1β, TNF-α) but not LTA or LPS. These results indicate that Nlac plays an important role in suppressing pathogen-induced inflammation in the nasopharyngeal mucosa, mediated through TLR-1/2 stimulation, by activating PPAR-γ and inhibiting NF-κβ activity.

  4. The NlaIV restriction and modification genes of Neisseria lactamica are flanked by leucine biosynthesis genes.

    PubMed

    Lau, P C; Forghani, F; Labbé, D; Bergeron, H; Brousseau, R; Höltke, H J

    1994-04-01

    The genes encoding the Neisseria lactamica restriction endonuclease IV (R.NlaIV) and its cognate DNA methyltransferase (M.NlaIV), both of which recognize the sequence GGNNCC, have been cloned in Escherichia coli and overexpressed using the T7 polymerase/promoter system. Analysis of a sequenced 3.58 kb fragment established the gene order, leuD-M.NlaIV-R.NlaIV-leuB. The predicted primary sequence of M.NlaIV (423 amino acids) shows the highest degree of identity to a pair of cytosine-specific methyltransferases, M.BanI (44.9%) and M.HgiCI (44.3%), which recognize the sequence GGYRCC (Y, pyrimidines; R, purines). In contrast, the R.NlaIV protein sequence (243 amino acids) is unique in the existing data-base, a situation that holds for most endonucleases. Flanking the NlaIV modification and restriction genes are homologues of the leuD and leuB genes of enteric bacteria, which code for enzymes in the leucine biosynthesis pathway. This gene context implies a possible new mode of gene regulation for the RM.NlaIV system, which would involve a mechanism similar to the recently discovered leucine/Lrp regulon in E. coli.

  5. MetQ of Neisseria gonorrhoeae Is a Surface-Expressed Antigen That Elicits Bactericidal and Functional Blocking Antibodies

    PubMed Central

    Semchenko, Evgeny A.; Day, Christopher J.

    2016-01-01

    ABSTRACT Neisseria gonorrhoeae, the causative agent of the sexually transmitted infection (STI) gonorrhea, is a growing public health threat for which a vaccine is urgently needed. We characterized the functional role of the gonococcal MetQ protein, which is the methionine binding component of an ABC transporter system, and assessed its potential as a candidate antigen for inclusion in a gonococcal vaccine. MetQ has been found to be highly conserved in all strains investigated to date, it is localized on the bacterial surface, and it binds l-methionine with a high affinity. MetQ is also involved in gonococcal adherence to cervical epithelial cells. Mutants lacking MetQ have impaired survival in human monocytes, macrophages, and serum. Furthermore, antibodies raised against MetQ are bactericidal and are able to block gonococcal adherence to epithelial cells. These data suggest that MetQ elicits both bactericidal and functional blocking antibodies and is a valid candidate antigen for additional investigation and possible inclusion in a vaccine for prevention of gonorrhea. PMID:27895130

  6. Whole-Genome Characterization of Epidemic Neisseria meningitidis Serogroup C and Resurgence of Serogroup W, Niger, 2015

    PubMed Central

    Kretz, Cecilia B.; Retchless, Adam C.; Sidikou, Fati; Issaka, Bassira; Ousmane, Sani; Schwartz, Stephanie; Tate, Ashley H.; Pana, Assimawè; Njanpop-Lafourcade, Berthe-Marie; Nzeyimana, Innocent; Nse, Ricardo Obama; Deghmane, Ala-Eddine; Hong, Eva; Brynildsrud, Ola Brønstad; Novak, Ryan T.; Meyer, Sarah A.; Oukem-Boyer, Odile Ouwe Missi; Ronveaux, Olivier; Caugant, Dominique A.; Taha, Muhamed-Kheir

    2016-01-01

    In 2015, Niger reported the largest epidemic of Neisseria meningitidis serogroup C (NmC) meningitis in sub-Saharan Africa. The NmC epidemic coincided with serogroup W (NmW) cases during the epidemic season, resulting in a total of 9,367 meningococcal cases through June 2015. To clarify the phylogenetic association, genetic evolution, and antibiotic determinants of the meningococcal strains in Niger, we sequenced the genomes of 102 isolates from this epidemic, comprising 81 NmC and 21 NmW isolates. The genomes of 82 isolates were completed, and all 102 were included in the analysis. All NmC isolates had sequence type 10217, which caused the outbreaks in Nigeria during 2013–2014 and for which a clonal complex has not yet been defined. The NmC isolates from Niger were substantially different from other NmC isolates collected globally. All NmW isolates belonged to clonal complex 11 and were closely related to the isolates causing recent outbreaks in Africa. PMID:27649262

  7. Development of an automated, high-throughput bactericidal assay that measures cellular respiration as a survival readout for Neisseria meningitidis.

    PubMed

    Mak, Puiying A; Santos, George F; Masterman, Kelly-Anne; Janes, Jeff; Wacknov, Bill; Vienken, Kay; Giuliani, Marzia; Herman, Ann E; Cooke, Michael; Mbow, M Lamine; Donnelly, John

    2011-08-01

    Complement-mediated bactericidal activity has long been regarded as the serological correlate of protective immunity against Neisseria meningitidis. This was affirmed in 2005 at a WHO-sponsored meningococcal serology standardization workshop. The assay currently employed by most laboratories involves determining surviving bacterial colony counts on agar as a readout which is labor-intensive, time-consuming, and not amendable to rapid data analysis for clinical trials. Consequently, there is an acute need to develop a sensitive, high-throughput bactericidal assay to enable a rapid and robust assessment of the effectiveness of vaccine candidates. To this end, we have developed an automated, kinetic assay based on the fluorescent respiration product of resazurin which reduces assay volume, shortens assay time, and facilitates automation of data analysis. We demonstrate proof of concept for applicability of this high-throughput system with multiple meningococcal strains and utilizing different lots of human complement. The assay is robust and highly reproducible. Titers obtained by the fluorescence readout method are strongly correlated with the data obtained using the conventional, agar plate-based assay. These results demonstrate that the detection of bacteria that have survived the bactericidal reaction by measuring metabolic activity using a fluorescent dye as an alternative readout is a promising approach for the development of a high-throughput bactericidal assay.

  8. TaqMan real-time quantitative PCR assay for detection of fluoroquinolone-resistant Neisseria gonorrhoeae.

    PubMed

    Zhao, LiHong; Zhao, ShuPing

    2012-12-01

    It is noted that more than 99 % of fluoroquinolone resistance in Neisseria gonorrhoeae (QRNG) specimens have been shown to have the mutation of Ser91/Phe in the gyrA gene. In order to detect QRNG isolates as quickly as possible, the real-time TaqMan quantitative PCR assay was established for detection of the point mutation of Ser91/Phe in gyrA gene. The standard curve was generated automatically on ABI Prism PE7500. The correlation coefficient (r) of the standard curve was -0.9984 (R(2) = 0.9968), indicating a quietly precise log-linear relationship between the concentration of target DNA and the Ct value. Presently, correlated, cultured antimicrobial susceptibility testing of N. gonorrhoeae isolates continues to be the gold standard method for the detection of antimicrobial resistance. Comparison to the correlated, cultured antimicrobial susceptibility testing, the sensitivity and specificity of the established TaqMan assay for the detection of the QRNG specimens were 100 and 99 %, respectively. The TaqMan assay also allows for rapid detection of QRNG isolates without complex laboratory techniques. Therefore, real-time TaqMan quantitative PCR assay is a rapid, simple, highly sensitive, highly specific, and easy-to-perform method for the detection of the QRNG specimens. It can be applied as a quick screening method for QRNG isolates to help clinical determination of optimal treatment prescription.

  9. Cervical Infection with Herpes simplex Virus, Chlamydia trachomatis, and Neisseria gonorrhoeae among Symptomatic Women, Dubai, UAE: A Molecular Approach.

    PubMed

    Mehrabani, Davood; Behzadi, Mohammad Amin; Azizi, Saeed; Payombarnia, Hamid; Vahdani, Ali; Namayandeh, Mandana; Ziyaeyan, Mazyar

    2014-01-01

    Tragically, genital tract infections are still a major public health problem in many regions. This study was undertaken to determine the prevalence of cervical infection with Herpes simplex virus (HSV), Chlamydia trachomatis (CT), and Neisseria gonorrhoeae (NG) among married women referring to Iranian Hospital, Dubai, UAE. In a retrospective cross-sectional survey, 201 female patients aged 16-80 years who referred to the Obstetrics and Gynecology Department of Iranian Hospital, Dubai, UAE, in 2010 were enrolled. The patients were categorized into three age groups: 15-30 (group I), 31-40 (group II), and ≥41 years old (group III). A cervical swab sample was collected from each woman and the prevalence of cervical infection with HSV, CT, and NG was determined by PCR method. HSV, CT, and NG were detected in 6.5%, 10.4%, and 5.5% of swab samples, respectively. Regarding age, a significant difference was noticed for prevalence of NG and HSV between groups I and III. Because of public health importance of sexual transmitted diseases (STDs), their long-lasting impact on quality of life, and their economic burden, preventing measures and education of women seem necessary.

  10. Loop structures in the 5' untranslated region and antisense RNA mediate pilE gene expression in Neisseria gonorrhoeae.

    PubMed

    Masters, Thao L; Wachter, Jenny; Hill, Stuart A

    2016-11-01

    Regulation of the Neisseria gonorrhoeae pilE gene is ill-defined. In this study, post-transcriptional effects on expression were assessed. In silico analysis predicts the formation of three putative stable stem-loop structures with favourable free energies within the 5' untranslated region of the pilE message. Using quantitative reverse transcriptase PCR analyses, we show that each loop structure forms, with introduced destabilizing stem-loop mutations diminishing loop stability. Utilizing a series of pilE translational fusions, deletion of either loop 1 or loop 2 caused a significant reduction of pilE mRNA resulting in reduced expression of the reporter gene. Consequently, the formation of the loops apparently protects the pilE transcript from degradation. Putative loop 3 contains the pilE ribosomal binding site. Consequently, its formation may influence translation. Analysis of a small RNA transcriptome revealed an antisense RNA being produced upstream of the pilE promoter that is predicted to hybridize across the 5' untranslated region loops. Insertional mutants were created where the antisense RNA is not transcribed. In these mutants, pilE transcript levels are greatly diminished, with any residual message apparently not being translated. Complementation of these insertion mutants in trans with the antisense RNA gene facilitates pilE translation yielding a pilus + phenotype. Overall, this study demonstrates a complex relationship between loop-dependent transcript protection and antisense RNA in modulating pilE expression levels.

  11. The crystal structure of Neisseria gonorrhoeae PriB reveals mechanistic differences among bacterial DNA replication restart pathways

    SciTech Connect

    Dong, Jinlan; George, Nicholas P.; Duckett, Katrina L.; DeBeer, Madeleine A.P.; Lopper, Matthew E.

    2010-05-25

    Reactivation of repaired DNA replication forks is essential for complete duplication of bacterial genomes. However, not all bacteria encode homologs of the well-studied Escherichia coli DNA replication restart primosome proteins, suggesting that there might be distinct mechanistic differences among DNA replication restart pathways in diverse bacteria. Since reactivation of repaired DNA replication forks requires coordinated DNA and protein binding by DNA replication restart primosome proteins, we determined the crystal structure of Neisseria gonorrhoeae PriB at 2.7 {angstrom} resolution and investigated its ability to physically interact with DNA and PriA helicase. Comparison of the crystal structures of PriB from N. gonorrhoeae and E. coli reveals a well-conserved homodimeric structure consisting of two oligosaccharide/oligonucleotide-binding (OB) folds. In spite of their overall structural similarity, there is significant species variation in the type and distribution of surface amino acid residues. This correlates with striking differences in the affinity with which each PriB homolog binds single-stranded DNA and PriA helicase. These results provide evidence that mechanisms of DNA replication restart are not identical across diverse species and that these pathways have likely become specialized to meet the needs of individual organisms.

  12. Endotoxin, capsule, and bacterial attachment contribute to Neisseria meningitidis resistance to the human antimicrobial peptide LL-37.

    PubMed

    Jones, Allison; Geörg, Miriam; Maudsdotter, Lisa; Jonsson, Ann-Beth

    2009-06-01

    Pathogenic bacteria have evolved numerous mechanisms to evade the human immune system and have developed widespread resistance to traditional antibiotics. We studied the human pathogen Neisseria meningitidis and present evidence of novel mechanisms of resistance to the human antimicrobial peptide LL-37. We found that bacteria attached to host epithelial cells are resistant to 10 microM LL-37 whereas bacteria in solution or attached to plastic are killed, indicating that the cell microenvironment protects bacteria. The bacterial endotoxin lipooligosaccharide and the polysaccharide capsule contribute to LL-37 resistance, probably by preventing LL-37 from reaching the bacterial membrane, as more LL-37 reaches the bacterial membrane on both lipooligosaccharide-deficient and capsule-deficient mutants whereas both mutants are also more susceptible to LL-37 killing than the wild-type strain. N. meningitidis bacteria respond to sublethal doses of LL-37 and upregulate two of their capsule genes, siaC and siaD, which further results in upregulation of capsule biosynthesis.

  13. Comparison of Virulence Markers of Peritoneal and Fallopian Tube Isolates with Endocervical Neisseria gonorrhoeae Isolates from Women with Acute Salpingitis

    PubMed Central

    Draper, D. L.; James, J. F.; Brooks, G. F.; Sweet, R. L.

    1980-01-01

    Neisseria gonorrhoeae strains which cause acute salpingitis are presumed to ascend the genital tract from the cervix. Previous studies utilized isolates obtained from endocervical canal cultures, although it was not known if the isolates truly represented the organisms present in the fallopian tubes. In this study, we compared N. gonorrhoeae isolates from endocervical canal cultures with fallopian tube or peritoneal cul-de-sac isolates or isolates from both sites obtained at laparoscopy. Potential virulence markers were studied, including colony phenotype, auxotype, antimicrobial agent susceptibility, protein patterns on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and susceptibility to normal human serum. Six of seven cervical isolates had the same antibiograms and molecular weight for major outer membrane proteins as those of the corresponding peritoneal isolates. Auxotypes also were the same and included prototrophic, proline-requiring, and proline-and-arginine-requiring isolates. The isolates as a group appeared to be very susceptible to the bactericidal action of pooled serum from normal women. Colony phenotypes varied between sites; the fallopian tubecul-de-sac isolates were predominantly of transparent phenotype and piliated. The cervical isolates were either mixtures of equal quantities of opaque and transparent phenotypes or predominantly opaque phenotype. By these markers, patients' N. gonorrhoeae cervical isolates appeared to be the same as their isolates from fallopian tubes except for a difference or shift in colony phenotype. Images Fig. 1 PMID:6769811

  14. Hypomorphic Glycosyltransferase Alleles and Recoding at Contingency Loci Influence Glycan Microheterogeneity in the Protein Glycosylation System of Neisseria Species

    PubMed Central

    Johannessen, Camilla; Koomey, Michael

    2012-01-01

    As more bacterial protein glycosylation systems are identified and characterized, a central question that arises is, what governs the prevalence of particular glycans associated with them? In addition, accumulating evidence shows that bacterial protein glycans can be subject to the phenomenon of microheterogeneity, in which variant glycan structures are found at specific attachment