Myron Christodoulides ^*

• University of Southampton, Southampton, United Kingdom

pathogen causing nosocomial infections (Dolan, 2020), and because of increased carbapenem resistance globally, it is ranked as a 'high priority' organism by the World Health Organisation for the development and introduction or new antibacterials and vaccines (WHO, 2024). P. aeruginosa is a formidable bacterium that can express a plethora of virulence factors, Typesecretion systems, quorum-sensing pathways and exopolysaccharides, and core resistance mechanisms such as drug permeability barriers, a chromosomally encoded AmpC enzyme and six superfamilies of multidrug efflux pumps (Miller and Arias, 2024). Efflux pumps play a major role in the pathogenesis of P. aeruginosa infection and resistance to treatment and clearance. In their mini-review, Fernandes and Jorth discuss the controversial and opposing roles of P. aeruginosa efflux pumps in virulence regulation. Efflux pumps function principally to eject antibiotics from the bacterial cell, although evidence is presented that these pumps may have alternative functions that can influence the virulence of P. aeruginosa. Efflux pumps are recognised targets for therapeutic interventions (Fernandes and Jorth) and they are potential antigens for vaccine development (Silva et al., 2024). The authors conclude that there may be unexpected consequences to targeting efflux pumps in the context of antimicrobial resistance and bacterial pathogenesis that must be considered when developing therapies.Vaccine research was represented by papers on the Gram-negative bacteria Yersinia pestis and Neisseria gonorrhoeae. Y. pestis is a bacterium that has literally plagued humanity throughout our recorded history. It is a significant risk to public health and a potential bioweapon, and outbreaks of the plague are still reported today, but certainly not at pandemic levels. Y. pestis vaccines have consisted of killed whole cells, but these lack efficacy and provide only shortterm protection against bubonic plague (Wang et al., 2013)