title: Pseudomonas aeruginosa infection of zebrafish involves both host and pathogen determinants.
abstract: Zebrafish (Danio rerio) have a number of strengths as a host model for infection, including genetic tractability, a vertebrate immune system similar to that of mammals, ease and scale of laboratory handling, which allows analysis with reasonable throughput, and transparency, which facilitates visualization of the infection. With these advantages in mind, we examined whether zebrafish could be used to study Pseudomonas aeruginosa pathogenesis and found that infection of zebrafish embryos with live P. aeruginosa (PA14 or PAO1) by microinjection results in embryonic death, unlike infection with Escherichia coli or heat-killed P. aeruginosa, which has no effect. Similar to studies with mice, P. aeruginosa mutants deficient in type three secretion (pscD) or quorum sensing (lasR and mvfR) are attenuated in zebrafish embryos infected at 50 h postfertilization (hpf), a developmental stage when both macrophages and neutrophils are present. In contrast, embryos infected at 28 hpf, when only macrophages are initially present, succumb to lethal challenge with far fewer P. aeruginosa cells than those required for embryos infected at 50 hpf, are susceptible to infection with lasR and pscD deletion mutants, and are moderately resistant to infection with an mvfR mutant. Finally, we show that we can control the outcome of infection through the use of morpholinos, which allow us to shift immune cell numbers, or small molecules (antibiotics), which rescue embryos from lethal challenge. Thus, zebrafish are a novel host model that is well suited for studying the interactions among individual pathogenic functions of P. aeruginosa, the role of individual components of host immune defense, and small-molecule modulators of infection.
authors.affiliation: Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, 185 Cambridge St., Boston, MA 02114, USA.
authors.forename: Anne E
authors.initials: AE
authors.lastname: Clatworthy
authors.forename: Jenny See-Wai
authors.initials: JS
authors.lastname: Lee
authors.forename: Mark
authors.initials: M
authors.lastname: Leibman
authors.forename: Zachary
authors.initials: Z
authors.lastname: Kostun
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Davidson
authors.forename: Deborah T
authors.initials: DT
authors.lastname: Hung
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000382:microbiology*; D054884:Host-Pathogen Interactions; D006801:Humans; D011552:Pseudomonas Infections / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity* / Q000502:physiology; D053038:Quorum Sensing; D014774:Virulence; D015027:Zebrafish / Q000196:embryology / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins