Actinobacillus pleuropneumoniae (App) (App)

Actinobacillus pleuropneumoniae (App) is a Gram-negative, encapsulated coccobacillus that serves as the primary etiological agent of porcine pleuropneumonia, a severe respiratory disease in swine (Gottschalk, 2012). The bacterium is highly host-specific to pigs and is characterized by its requirement for nicotinamide adenine dinucleotide (V-factor) in most serotypes (Bosse et al., 2002). Its virulence is primarily driven by the secretion of Apx toxins (ApxI, II, and III), which are members of the RTX (Repeats in ToXin) family and cause lysis of host immune cells (Frey, 2011). These toxins, along with the capsule and lipopolysaccharides, facilitate lung tissue necrosis and hemorrhagic lesions (Sassu et al., 2018). In the context of pharmacology, App is the target of various veterinary antibiotics, including macrolides like tulathromycin and beta-lactams like ceftiofur (Nielsen & Sjölund, 2018). These drugs disrupt essential bacterial processes such as protein synthesis and cell wall assembly to control infection (EMA, 2020). Management of the pathogen also involves the use of vaccines, though the existence of 19 distinct serotypes complicates the development of universal protection (Stringer et al., 2021). Increasing antimicrobial resistance among App isolates poses a significant challenge to effective treatment and swine industry productivity (Vanni et al., 2012).

Other names

Haemophilus pleuropneumoniaePorcine pleuropneumonia agent

Inhibition of bacterial cell wall synthesis, protein synthesis, or DNA replication depending on the specific antibiotic class used.