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Keywords = Neisseria gonorrhoeae (gonococcus)

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16 pages, 1975 KB  
Article
MtrR Regulates a Major Lytic Transglycosylase (ltgA) Responsible for Peptidoglycan-Derived Cytotoxin Release and Autolysis in Neisseria gonorrhoeae
by Alaa I. Telchy, Tia Morgan, Kathleen T. Hackett, Ronald K. McMillan, Robert A. Nicholas, Joseph P. Dillard and Daniel Williams
Microorganisms 2026, 14(2), 474; https://doi.org/10.3390/microorganisms14020474 - 14 Feb 2026
Viewed by 753
Abstract
The multiple-transferable resistance protein (MtrR) is a transcriptional repressor of the mtrCDE-encoded drug efflux pump and Type IV pilus biosynthesis (pilM), and an activator of penicillin-binding protein 1 (ponA) expression in Neisseria gonorrhoeae. Previously published microarray data [...] Read more.
The multiple-transferable resistance protein (MtrR) is a transcriptional repressor of the mtrCDE-encoded drug efflux pump and Type IV pilus biosynthesis (pilM), and an activator of penicillin-binding protein 1 (ponA) expression in Neisseria gonorrhoeae. Previously published microarray data suggested that MtrR is also an activator of ltgA expression in the gonococcus. LtgA is a lytic transglycosylase responsible for approximately half of recycled peptidoglycan fragments and released peptidoglycan-derived cytotoxins, which cause ciliary damage and induce specific inflammatory responses. The fragments generated by LtgA during peptidoglycan remodeling can either be recognized by the permease AmpG for uptake into the bacterial cytoplasm and recycled for new cell wall growth and general metabolism or released into the external milieu. Therefore, we sought to define the capacity of MtrR to regulate LtgA expression in gonococci. We show that MtrR binds to the ltgA promoter region in a concentration-dependent manner, and that this binding results both in increased ltgA mRNA transcription and LtgA protein levels during exponential growth. Deletion of mtrR in N. gonorrhoeae decreased peptidoglycan monomer release from growing cells and increased autolysis. These results suggest that MtrR regulation of ltgA impacts peptidoglycan-derived cytotoxin release and autolysis in the gonococcus. This study suggests a central role of MtrR in coordinating aspects of the cellular envelope that may contribute to gonococcal pathogenesis. Full article
(This article belongs to the Special Issue Transcriptional Regulation in Bacteria, 2nd Edition)
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5 pages, 207 KB  
Case Report
HIV-Negative MSM Infected with Two Different Isolates of Drug-Resistant Neisseria gonorrhoeae—Case Report
by Martyna Biała, Bartosz Pencakowski, Beata Mączyńska, Konrad Starzyński and Bartosz Szetela
Pathogens 2024, 13(6), 497; https://doi.org/10.3390/pathogens13060497 - 10 Jun 2024
Cited by 1 | Viewed by 2239
Abstract
The antimicrobial resistance of Neisseria gonorrhoeae (NG) is an increasing public health concern, highlighted by the fact that gonococcus is considered as a ‘high’-priority pathogen by the WHO for research and development of new therapeutic options. According to the data of the European [...] Read more.
The antimicrobial resistance of Neisseria gonorrhoeae (NG) is an increasing public health concern, highlighted by the fact that gonococcus is considered as a ‘high’-priority pathogen by the WHO for research and development of new therapeutic options. According to the data of the European Centre for Disease Prevention and Control (ECDC) in 2022, the rate of NG infections is the highest recorded since European surveillance of sexually transmitted infections began in 2009. We report a brief description of a patient infected with two different isolates of drug-resistant N. gonorrhoeae. N. gonorrhoeae cultures were positive from oropharyngeal and urethral swabs and isolates had different antimicrobial susceptibility. We investigated the antimicrobial susceptibility of these isolates to six antimicrobials (ceftriaxone, cefixime, azithromycin, ciprofloxacin, tetracycline, and benzylpenicillin), and minimum inhibitory concentrations (MICs; mg/L) were determined using Etest on gonococcal isolates. Oropharyngeal isolate was resistant to azithromycin while urethral was resistant to penicillin, ciprofloxacin, and tetracycline. Two different and phylogenetically distinct sequence types of NG isolates were identified. Understanding the dynamics and drivers of resistance spread can provide an improved rationale for antibiotic management, and the level of NG resistance should be monitored closely. Full article
10 pages, 250 KB  
Review
Insight into Prevention of Neisseria Gonorrhoeae: A Short Review
by Vincenza La Fauci, Daniela Lo Giudice, Raffaele Squeri and Cristina Genovese
Vaccines 2022, 10(11), 1949; https://doi.org/10.3390/vaccines10111949 - 18 Nov 2022
Cited by 7 | Viewed by 4675
Abstract
Neisseria gonorrhoeae (gonococcus) and Neisseria meningitidis (meningococcus) are important global pathogens which cause the sexually transmitted diseases gonorrhea and meningitis, respectively, as well as sepsis. We prepared a review according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA), with the [...] Read more.
Neisseria gonorrhoeae (gonococcus) and Neisseria meningitidis (meningococcus) are important global pathogens which cause the sexually transmitted diseases gonorrhea and meningitis, respectively, as well as sepsis. We prepared a review according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA), with the aims of (a) evaluating the data on the MenB vaccination as protection against sexually transmitted infections by N. gonorrhoeae and (b) to briefly comment on the data of ongoing studies of new vaccines. We evaluated existing evidence on the effect of 4CMenB, a multi-component vaccine, on invasive diseases caused by different meningococcal serogroups and on gonorrhea. Non-B meningococcal serogroups showed that the 4CMenB vaccine could potentially offer some level of protection against non-B meningococcal serogroups and N. gonorrhoeae. The assessment of the potential protection conferred by 4CMenB is further challenged by the fact that further studies are still needed to fully understand natural immune responses against gonococcal infections. A further limitation could be the potential differences between the protection mechanisms against N. gonorrhoeae, which causes local infections, and the protection mechanisms against N. meningitidis, which causes systemic infections. Full article
15 pages, 2245 KB  
Article
The Neisseria gonorrhoeae Vaccine Candidate NHBA Elicits Antibodies That Are Bactericidal, Opsonophagocytic and That Reduce Gonococcal Adherence to Epithelial Cells
by Evgeny A. Semchenko, Christopher J. Day and Kate L. Seib
Vaccines 2020, 8(2), 219; https://doi.org/10.3390/vaccines8020219 - 13 May 2020
Cited by 36 | Viewed by 6393
Abstract
Due to the continuing emergence of multidrug resistant strains of Neisseria gonorrhoeae there is an urgent need for the development of a gonococcal vaccine. We evaluated the gonococcal Neisseria heparin binding antigen (NHBA) as a potential vaccine candidate, in terms of its sequence [...] Read more.
Due to the continuing emergence of multidrug resistant strains of Neisseria gonorrhoeae there is an urgent need for the development of a gonococcal vaccine. We evaluated the gonococcal Neisseria heparin binding antigen (NHBA) as a potential vaccine candidate, in terms of its sequence conservation and expression in a range of N. gonorrhoeae strains, as well as its immunogenicity and the functional activity of antibodies raised to either the full length NHBA or a C-terminal fragment of NHBA (NHBA-c). The gene encoding NHBA is highly conserved and expressed in all N. gonorrhoeae strains investigated. Recombinant NHBA is immunogenic, and mice immunized with either NHBA or NHBA-c adjuvanted with either Freund’s or aluminium hydroxide (alum) generated a humoral immune response, with predominantly IgG1 antibodies. Antibodies generated by both NHBA and NHBA-c antigens promoted complement activation and mediated bacterial killing via both serum bactericidal activity and opsonophagocytic activity, with slightly higher titers seen for the NHBA-c antigen. Anti-NHBA was also able to block the functional activity of NHBA by reducing binding to heparin and adherence to cervical and urethral epithelial cells. These data suggest that the gonococcal NHBA is a promising vaccine antigen to include in a vaccine to control N. gonorrhoeae. Full article
(This article belongs to the Section Vaccines Against Tropical and Other Infectious Diseases)
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18 pages, 2100 KB  
Article
Inactivation of Genes Encoding MutL and MutS Proteins Influences Adhesion and Biofilm Formation by Neisseria gonorrhoeae
by Jagoda Płaczkiewicz, Monika Adamczyk-Popławska, Robert Lasek, Pawel Bącal and Agnieszka Kwiatek
Microorganisms 2019, 7(12), 647; https://doi.org/10.3390/microorganisms7120647 - 4 Dec 2019
Cited by 10 | Viewed by 4293
Abstract
Neisseria gonorrhoeae is an etiological agent of gonorrhea, which remains a global health problem. This bacterium possesses MutL and MutS DNA repair proteins encoded by mutL and mutS genes, whose inactivation causes a mutator phenotype. We have demonstrated the differential gene expression in [...] Read more.
Neisseria gonorrhoeae is an etiological agent of gonorrhea, which remains a global health problem. This bacterium possesses MutL and MutS DNA repair proteins encoded by mutL and mutS genes, whose inactivation causes a mutator phenotype. We have demonstrated the differential gene expression in N. gonorrhoeae mutL and mutS mutants using DNA microarrays. A subset of differentially expressed genes encodes proteins that can influence adhesion and biofilm formation. Compared to the wild-type strain, N. gonorrhoeae mutL and mutS mutants formed denser biofilms with increased biofilm-associated biomass on the abiotic surface. The N. gonorrhoeae mutS::km, but not the mutL mutant, was also more adherent and invasive to human epithelial cells. Further, during infection of epithelial cells with N. gonorrhoeae mutS::km, the expression of some bacterial genes encoding proteins that can influence gonococcal adhesion was changed compared with their expression in cells infected with the wild-type gonococcus, as well as of human genes’ encoding receptors utilized by N. gonorrhoeae (CD46, CEACAM 1, HSPG 2). Thus, deficiency in the mutS gene resulting in increased mutation frequency in singular organisms can be beneficial in populations because these mutants can be a source of features linked to microbial fitness. Full article
(This article belongs to the Section Molecular Microbiology and Immunology)
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