Case study: P.aeruginosa

Gram-negative, rod shaped, with flagella

Desribe the morphology of P.aeruginosa

Heterotroph using a broad range of carbon compounds. Faculative aerobe that grows best in oxygen but can use nitrate as a terminal electron acceptor. May ferment arginine. Grows 4-42 degrees celsius so is psychrotolerant

Use scientific terminology to describe metabolic properties of P.a. You should refer to oxygen utilisation and potential carbon sources

core genome contains genes essential to the species survival which are shared by all strains. Pan genome is the total of all genes any strains may have (core genome plus all accessory genomes)

What is the difference between pan genome and core genome?

Immunocompromised and chronically ill patients. Individuals with cystic fibrosis, burns patients

P.aeruginosa is an opportunistic pathogen. Give examples of situations where the organism might cause infection

Carbapenamase resistant strains

Which strain of antimicrobial resistant P.aeruginosa is a WHO priority pathogen

Examples include: surface structures (pili, flagella), lipopolysaccharide, secretion of toxins and other virulence factors, Quorum sensing, biofilm formation

outline two characteristics discussed in the paper that contribute to virulence of this species

Pili help bacteria to bind to epithilial cells. Flagella provide motlility and may help with binding to mucin found in CF sputum

Explain the role of flagella and pili when P. aeurginosa sets up an infection

Examples include proteases, exotoxins and hydrogen cyanide

Name types of molecules secreted by P. aeurginosa that might contribute to virulence

Acquisition of resistance genes via horizontal gene transfer, or mutations in genes already present in the genome, leading to up-regulation of efflux pumps, beta-lactamase’s or changes in porins

What characteristics contribute to the antimicrobial resistance observed in P. aeruginosa

Aggregates form where exopolysaccharide surrounds the cells and protects against stressors such as the host immune response and antibiotics

What are biofilms and how do they contribute to antimicrobial resistance in P.aeurginosa

It produces a compound known as pyocyanin

Why does P.aeurigonosa habe a distinct green colour