-
Nature Reviews. Microbiology Apr 2018The host-adapted human pathogen Neisseria gonorrhoeae is the causative agent of gonorrhoea. Consistent with its proposed evolution from an ancestral commensal bacterium,... (Review)
Review
The host-adapted human pathogen Neisseria gonorrhoeae is the causative agent of gonorrhoea. Consistent with its proposed evolution from an ancestral commensal bacterium, N. gonorrhoeae has retained features that are common in commensals, but it has also developed unique features that are crucial to its pathogenesis. The continued worldwide incidence of gonorrhoeal infection, coupled with the rising resistance to antimicrobials and the difficulties in controlling the disease in developing countries, highlights the need to better understand the molecular basis of N. gonorrhoeae infection. This knowledge will facilitate disease prevention, surveillance and control, improve diagnostics and may help to facilitate the development of effective vaccines or new therapeutics. In this Review, we discuss sex-related symptomatic gonorrhoeal disease and provide an overview of the bacterial factors that are important for the different stages of pathogenesis, including transmission, colonization and immune evasion, and we discuss the problem of antibiotic resistance.
Topics: Adaptation, Physiological; Anti-Bacterial Agents; Drug Resistance, Bacterial; Gonorrhea; Humans; Neisseria gonorrhoeae
PubMed: 29430011
DOI: 10.1038/nrmicro.2017.169 -
Methods in Molecular Biology (Clifton,... 2012Neisseria meningitidis (the meningococcus) causes significant morbidity and mortality in children and young adults worldwide through epidemic or sporadic meningitis... (Review)
Review
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.
Topics: Age Factors; Animals; Bacterial Capsules; Geography; Humans; Meningitis, Meningococcal; Models, Biological; Neisseria meningitidis; Phenotype; Virulence
PubMed: 21993636
DOI: 10.1007/978-1-61779-346-2_1 -
Current Opinion in Infectious Diseases Feb 2021Neisseria meningitidis (Nm) is primarily associated with asymptomatic nasopharyngeal carriage and invasive meningococcal disease (sepsis and meningitis), but like N.... (Review)
Review
PURPOSE OF REVIEW
Neisseria meningitidis (Nm) is primarily associated with asymptomatic nasopharyngeal carriage and invasive meningococcal disease (sepsis and meningitis), but like N. gonorrhoea (Ng), Nm can colonize urogenital and rectal mucosal surfaces and cause disease. First noted in 2015, but with origins in 2011, male urethritis clusters caused by a novel Nm clade were reported in the USA (the US_NmUC). This review describes research developments that characterize this urogenital-tropic Nm.
RECENT FINDINGS
The US_NmUC evolved from encapsulated Nm serogroup C strains. Loss of capsule expression, lipooligosaccharide (LOS) sialylation, genetic acquisition of gonococcal alleles (including the gonococcal anaerobic growth aniA/norB cassette), antimicrobial peptide heteroresistance and high surface expression of a unique factor-H-binding protein, can contribute to the urethra-tropic phenotype. Loss-of-function mutations in mtrC are overrepresented in clade isolates. Similar to Ng, repeat US_NmUC urethritis episodes can occur. The US_NmUC is now circulating in the UK and Southeast Asia. Genomic sequencing has defined the clade and rapid diagnostic tests are being developed for surveillance.
SUMMARY
The US_NmUC emerged as a cause of urethritis due to acquisition of gonococcal genetic determinants and phenotypic traits that facilitate urogenital tract infection. The epidemiology and pathogenesis of this urogenital-tropic pathogen continues to be defined.
Topics: Communicable Diseases, Emerging; Humans; Meningococcal Infections; Neisseria meningitidis; Urethritis
PubMed: 33278178
DOI: 10.1097/QCO.0000000000000697 -
Nature Communications Aug 2022Rod-shaped bacteria typically elongate and divide by transverse fission. However, several bacterial species can form rod-shaped cells that divide longitudinally. Here,...
Rod-shaped bacteria typically elongate and divide by transverse fission. However, several bacterial species can form rod-shaped cells that divide longitudinally. Here, we study the evolution of cell shape and division mode within the family Neisseriaceae, which includes Gram-negative coccoid and rod-shaped species. In particular, bacteria of the genera Alysiella, Simonsiella and Conchiformibius, which can be found in the oral cavity of mammals, are multicellular and divide longitudinally. We use comparative genomics and ultrastructural microscopy to infer that longitudinal division within Neisseriaceae evolved from a rod-shaped ancestor. In multicellular longitudinally-dividing species, neighbouring cells within multicellular filaments are attached by their lateral peptidoglycan. In these bacteria, peptidoglycan insertion does not appear concentric, i.e. from the cell periphery to its centre, but as a medial sheet guillotining each cell. Finally, we identify genes and alleles associated with multicellularity and longitudinal division, including the acquisition of amidase-encoding gene amiC2, and amino acid changes in proteins including MreB and FtsA. Introduction of amiC2 and allelic substitution of mreB in a rod-shaped species that divides by transverse fission results in shorter cells with longer septa. Our work sheds light on the evolution of multicellularity and longitudinal division in bacteria, and suggests that members of the Neisseriaceae family may be good models to study these processes due to their morphological plasticity and genetic tractability.
Topics: Animals; Bacterial Proteins; Biological Evolution; Cell Division; Cell Wall; Mammals; Neisseriaceae; Peptidoglycan
PubMed: 35995772
DOI: 10.1038/s41467-022-32260-w -
Frontiers in Cellular and Infection... 2022and are two obligate human pathogens that have evolved to be uniquely adapted to their host. The meningococcus is frequently carried asymptomatically in the... (Review)
Review
and are two obligate human pathogens that have evolved to be uniquely adapted to their host. The meningococcus is frequently carried asymptomatically in the nasopharynx, while gonococcal infection of the urogenital tract usually elicits a marked local inflammatory response. Other members of the genus are abundant in the upper airway where they could engage in co-operative or competitive interactions with both these pathogens. Here, we briefly outline the potential sites of contact between spp. in the body, with emphasis on the upper airway, and describe the growing yet circumstantial evidence for antagonism from carriage studies and human volunteer challenge models with . Recent laboratory studies have characterized antagonistic mechanisms that enable competition between species. Several of these mechanisms, including Multiple Adhesin family (Mafs), Two Partner Secretion Systems, and Type VI secretion system, involve direct contact between bacteria; the genetic organisation of these systems, and the domain structure of their effector molecules have striking similarities. Additionally, DNA from one species of can be toxic to another species, following uptake. More research is needed to define the full repertoire of antagonistic mechanisms in spp., their distribution in strains, their range of activity, and contribution to survival . Understanding the targets of effectors could reveal how antagonistic relationships between close relatives shape subsequent interactions between pathogens and their hosts.
Topics: Conflict of Interest; Humans; Nasopharynx; Neisseria; Neisseria gonorrhoeae; Neisseria meningitidis
PubMed: 35811666
DOI: 10.3389/fcimb.2022.913292 -
FEMS Microbiology Reviews Mar 2006Secreted proteins of pathogenic bacteria are often essential virulence factors. They are involved, for example, in the adherence of the bacteria to host cells or... (Review)
Review
Secreted proteins of pathogenic bacteria are often essential virulence factors. They are involved, for example, in the adherence of the bacteria to host cells or required to suppress the host's defence mechanisms. Until recently, only IgA1 protease had been studied in detail in the NeisseriaceaeNeisseria meningitidis and Neisseria gonorrhoeae. The availability of their genome sequences, however, has boosted research in this area. Here, we present a survey of the secretome of the pathogenic Neisseriaceae, based on the available genome sequences, and the current knowledge of the functions and structures of the secreted proteins. Of the six protein-secretion pathways that are widely disseminated among Gram-negative bacteria, three pathways appear to be present among the Neisseriaceae, i.e. the autotransporter-, the two-partner- and the type I-secretion mechanisms. Comparison of the predicted secretomes reveals a considerable flexibility. As compared with N. meningitidis and the nonpathogen N. lactamica, N. gonorrhoeae appears to have a considerably degenerated secretome, which may reflect its altered niche occupancy. The flexibility of the secretome may be enhanced by the presence of ORFs in the genomes potentially encoding fragments of secreted proteins. We hypothesize that these ORFs may substitute for the corresponding fragments in the full-length genes through genetic recombination, thereby changing the host-cell receptor specificity of the secreted protein.
Topics: Bacterial Proteins; Bacterial Vaccines; Genome, Bacterial; Neisseria gonorrhoeae; Neisseriaceae; Neisseriaceae Infections
PubMed: 16472308
DOI: 10.1111/j.1574-6976.2006.00013.x -
Clinical Microbiology Reviews Jan 2015Kingella kingae is a common etiology of pediatric bacteremia and the leading agent of osteomyelitis and septic arthritis in children aged 6 to 36 months. This... (Review)
Review
Kingella kingae is a common etiology of pediatric bacteremia and the leading agent of osteomyelitis and septic arthritis in children aged 6 to 36 months. This Gram-negative bacterium is carried asymptomatically in the oropharynx and disseminates by close interpersonal contact. The colonized epithelium is the source of bloodstream invasion and dissemination to distant sites, and certain clones show significant association with bacteremia, osteoarthritis, or endocarditis. Kingella kingae produces an RTX (repeat-in-toxin) toxin with broad-spectrum cytotoxicity that probably facilitates mucosal colonization and persistence of the organism in the bloodstream and deep body tissues. With the exception of patients with endocardial involvement, children with K. kingae diseases often show only mild symptoms and signs, necessitating clinical acumen. The isolation of K. kingae on routine solid media is suboptimal, and detection of the bacterium is significantly improved by inoculating exudates into blood culture bottles and the use of PCR-based assays. The organism is generally susceptible to antibiotics that are administered to young patients with joint and bone infections. β-Lactamase production is clonal, and the local prevalence of β-lactamase-producing strains is variable. If adequately and promptly treated, invasive K. kingae infections with no endocardial involvement usually run a benign clinical course.
Topics: Anti-Bacterial Agents; Bacteremia; Genome, Bacterial; Humans; Kingella kingae; Neisseriaceae Infections; Virulence Factors
PubMed: 25567222
DOI: 10.1128/CMR.00028-14 -
Pathogens and Disease Jun 2017Bacteria and archaea possess numerous defense systems to combat viral infections and other mobile genetic elements. Uniquely among these, CRISPR-Cas (clustered,... (Review)
Review
Bacteria and archaea possess numerous defense systems to combat viral infections and other mobile genetic elements. Uniquely among these, CRISPR-Cas (clustered, regularly interspaced short palindromic repeats-CRISPR associated) provides adaptive genetic interference against foreign nucleic acids. Here we review recent advances on the CRISPR-Cas9 system in Neisseria spp, with a focus on its biological functions in genetic transfer, its mechanistic features that establish new paradigms and its technological applications in eukaryotic genome engineering.
Topics: CRISPR-Cas Systems; Gene Targeting; Neisseria
PubMed: 28369433
DOI: 10.1093/femspd/ftx036 -
Frontiers in Cellular and Infection... 2022
Topics: Neisseria; Virulence; Neisseria gonorrhoeae; Neisseria meningitidis; Vaccines; Drug Resistance, Microbial
PubMed: 36683679
DOI: 10.3389/fcimb.2022.1119244 -
Emerging Infectious Diseases May 2014During the past decade, transmission of the bacterium Kingella kingae has caused clusters of serious infections, including osteomyelitis, septic arthritis, bacteremia,... (Review)
Review
During the past decade, transmission of the bacterium Kingella kingae has caused clusters of serious infections, including osteomyelitis, septic arthritis, bacteremia, endocarditis, and meningitis, among children in daycare centers in the United States, France, and Israel. These events have been characterized by high attack rates of disease and prevalence of the invasive strain among asymptomatic classmates of the respective index patients, suggesting that the causative organisms benefitted from enhanced colonization fitness, high transmissibility, and high virulence. After prophylactic antibacterial drugs were administered to close contacts of infected children, no further cases of disease were detected in the facilities, although test results showed that some children still carried the bacterium. Increased awareness of this public health problem and use of improved culture methods and sensitive nucleic acid amplification assays for detecting infected children and respiratory carriers are needed to identify and adequately investigate outbreaks of K. kingae disease.
Topics: Anti-Bacterial Agents; Antibiotic Prophylaxis; Child; Child Day Care Centers; Child, Preschool; Disease Outbreaks; Disease Reservoirs; Humans; Incidence; Kingella kingae; Neisseriaceae Infections
PubMed: 24750782
DOI: 10.3201/eid2005.131633