Gonococcal vaccines: Public health value and preferred product characteristics; report of a WHO global stakeholder consultation, January 2019.

Renewed interest in developing vaccines against Neisseria gonorrhoeae has been sparked by the increasing threat of gonococcal antimicrobial resistance (AMR) and growing optimism that gonococcal vaccines are biologically feasible. Evidence suggests serogroup B Neisseria meningitidis vaccines might provide some cross-protection against N. gonorrhoeae, and new gonococcal vaccine candidates based on several approaches are currently in preclinical development.

Biological feasibility and importance of a gonorrhea vaccine for global public health.

There is a growing public health interest in controlling sexually transmitted infections (STIs) through vaccination due to increasing recognition of the global disease burden of STIs and the role of STIs in women's reproductive health, adverse pregnancy outcomes, and the health and well-being of neonates. Neisseria gonorrhoeae has historically challenged vaccine development through the expression of phase and antigenically variable surface molecules and its capacity to cause repeated infections without inducing protective immunity. An estimated 78 million new N.

-Selected Compensatory Mutations Restore the Fitness Cost of Mosaic Alleles That Confer Ceftriaxone Resistance in .

Resistance to ceftriaxone in is mainly conferred by mosaic alleles that encode penicillin-binding protein 2 (PBP2) variants with markedly lower rates of acylation by ceftriaxone. To assess the impact of these mosaic alleles on gonococcal fitness, we introduced the mosaic alleles from two ceftriaxone-resistant (Cro) clinical isolates (H041 and F89) into a Cro strain (FA19) by allelic exchange and showed that the resultant Cro mutants were significantly outcompeted by the Cro parent strain and in a murine infection model. Four Cro compensatory mutants of FA19 were isolated independently from mice that outcompeted the parent strain both and One of these compensatory mutants (LV41C) displayed a unique growth profile, with rapid log growth followed by a sharp plateau/gradual decline at stationary phase.

Alanine 501 Mutations in Penicillin-Binding Protein 2 from Neisseria gonorrhoeae: Structure, Mechanism, and Effects on Cephalosporin Resistance and Biological Fitness.

Resistance of Neisseria gonorrhoeae to expanded-spectrum cephalosporins such as ceftriaxone and cefixime has increased markedly in the past decade. The primary cephalosporin resistance determinant is a mutated penA gene, which encodes the essential peptidoglycan transpeptidase, penicillin-binding protein 2 (PBP2). Decreased susceptibility and resistance can be conferred by mosaic penA alleles containing upward of 60 amino acid changes relative to wild-type PBP2, or by nonmosaic alleles with relatively few mutations, the most important of which occurs at Ala501 located near the active site of PBP2.

Development of a high throughput assay for indirectly measuring phage growth using the OmniLog(TM) system.

The conventional and most accepted method of measuring the lytic activity of a phage against its bacterial host is the plaque assay. This method is laborious, time consuming and expensive, especially in high throughput analyses where multiple phage-bacterial interactions are required to be monitored simultaneously. It can also vary considerably with the experimenter and by the growth and plating conditions.