Lapis ISSN 2398-2969

Lawsonia intracellularis

Contributor(s): Vetstream Ltd

Introduction

Classification

Taxonomy

  • Family: Desulfovibrionaceae.
  • Delta subdivision of Class: Proteobacteria.
  • Genus:Lawsonia.
  • Speciesintracellularis.

Etymology

  • Lawson- G H K Lawson, the discoverer of the bacterium.
  • L:intra- within.
  • L:cell- store room, chamber.

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Clinical Effects

Epidemiology

Habitat

  • Obligate intracellular bacterium.
  • Found in many animal species, including wild and domesticated rabbits.

Lifecycle

  • Reproduces in the cytoplasm of infected cells.

Transmission

  • Probably feco-oral.

Pathological effects

  • Most studies have been carried out in pigs and hamsters; little information is available from rabbit cases.
  • It is assumed that the bacterium is motile, and attaches to enterocytes in the crypts of the intestine, particularly the lower ileum.
  • Bacteria initially enter cells in vacuoles, but then live and divide freely in the cytoplasm.
  • Infected cells are stimulated to proliferate and produce hyperplastic intestinal glands; the cell population may increase up to three times that of normal mucosa.
  • In affected rabbits, diffuse thickening of the mucosa of the jejunum, ileum and duodenum, and swollen mesenteric lymph nodes has been reported.
  • Histopathology shows hyperplastic and degenerative mucosal epithelium with severe infiltration of inflammatory cells, and no lesions in any other visceral organs.

Other Host Effects

  • Endemic infection occurs in pig herds; variable numbers of animals show clinical disease.

Control

Control via animal

  • Supportive therapy - definitive diagnosis is obtained post mortem.

Control via chemotherapies

  • The preferred antibiotics in other species are erythromycin with or without rifampicin, however oral macrolides are contraindicated in rabbits.
  • Fluoroquinolones such as enrofloxacin are more appropriate, given for at least 2 weeks.
  • However, treatment is not well described in rabbits, although some success with chloramphenicol is reported.

Control via environment

  • Avoid contamination of environment with feces of swine and free-ranging domestic or wild animals that can serve as reservoirs of the bacteria.

Other countermeasures

  • Supportive care with fluid therapy.

Diagnosis

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Further Reading

Publications

Refereed papers

  • Recent references fromPubMed.
  • Horiuchi N, Watarai M, Kobayashi Y, Omata Y & Furuoka H (2008)Proliferative enteropathy involvingLawsonia intracellularisinfection in rabbits (Oryctolagus cuniculus).J Vet Med Sci70(4), 389-392PubMed.
  • Watarai M, Yoshiya M, Sato A & Furuoka H (2008)Cultivation and characterization ofLawsonia intracellularisisolated from rabbit and pig.J Vet Med Sci70(7), 731-733PubMed.
  • Watarai M, Yamato Y, Horiuchi N, Kim S, Omata Y, Shirahata T & Furuoka H (2004)Enzyme-linked immunosorbent assay to detectLawsonia intracellularisin rabbits with proliferative enteropathy.J Vet Med Sci 66(6), 735-737PubMed.
  • Duhamel G E, Klein E C, Elder R O & Gebhart C J (1998) Subclinical proliferative enteropathy in sentinel rabbits associated withLawsonia intracellularis.Vet Pathol 35(4), 300-303PubMed.
  • Schauer D B, McCathey S N, Daft B M, Jha S S, Tatterson L E, Taylor N S & Fox J G (1998) Proliferative enterocolitis associated with dual infection with enteropathogenicEscherichia coliandLawsonia intracellularisin rabbits.J Clin Microbiol36(6), 1700-1703PubMed.
  • Hotchkiss C E, Shames B, Perkins S E & Fox J G (1996)Proliferative enteropathy of rabbits: the intracellularCampylobacter-like organism is closely related toLawsonia intracellularis.Lab Anim Sci46(6), 623-627PubMed.

Other sources of information

  • Brenner D J, Krieg N R & Staley J R (2005)Bergeys Manual of Systematic Bacteriology. 2nd edn. Vol 2. pp 940-943.

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