DETECTION OF Lawsonia intracellularis DNA IN ILEAL TISSUES OF DEAD WILD BIRDS IN THE REPUBLIC OF KOREA

Abstract

Lawsonia intracellularis is an etiological agent that causes proliferative enteropathy in various species. Little is known about the mechanisms of transmission of L. intracellularis, especially in wild bird species. The presence of L. intracellularis in dead wild birds in the Republic of Korea was investigated using the polymerase chain reaction method. L. intracellularis DNA was identified in the mucous membrane of the ileum in one Eurasian eagle-owl (Bubo bubo, Strigidae), two black-billed magpies (Pica pica sericea, Corvidae), and one jungle crow (Corvus macrorhynchos, Corvidae) among 745 dead wild birds examined. Although few wild birds in this study were exposed to L. intracellularis, the exposure was likely to be epidemiologically relevant. Regarding the ecological behavior of the bird species found to be exposed to L. intracellularis in the current study (Eurasian eagle-owl, black-billed magpie, and jungle crow), swine or horse farm facilities, which are reservoirs for L. intracellularis, might be easily accessed by such wild birds. Thus, these and similar species could have increased chances of exposure to L. intracellularis and could serve as biological vectors of proliferative enteropathy. Wild bird feeding patterns and previous reports of wild and feral animals exposed to L. intracellularis could be an alternative explanation for the association between L. intracellularis and wild birds. Key words: Lawsonia intracellularis; gene; diagnosis; surveillance; infectious disease; PCR DOLOČANJE DNK BAKTERIJE Lawsonie intracellularis V TKIVU VITEGA ČREVESA MRTVIH PTIC V REPUBLIKI KOREJI Vrsta bakterije Lawsonia intracellularis je vzrok proliferativne enteropatije pri različnih vrstah živali. O mehanizmih prenosa L. intracellularis, še zlasti pri divjih ptičjih vrstah, je na voljo malo podatkov. Prisotnost L. intracellularis pri mrtvih prosto živečih pticah v Republiki Koreji je bila raziskana z metodo verižne reakcije s polimerazo (PCR). DNK L. intracellularis smo dokazali v sluznici vitega črevesja pri veliki uharici (Bubo bubo, Strigidae), dveh korejskih srakah (Pica pica sericea, Corvidae) in eni velekljuni vrani (Corvus macrorhynchos, Corvidae) izmed 745 preiskanih mrtvih divjih ptic. Čeprav je bilo v tej študiji le nekaj prosto živečih ptic izpostavljenih L. Intracellularis, kaže, da je izpostavljenost epidemiološko pomembna. V povezavi z običajnim obnašanjem različnih vrst ptic je verjetno možno domnevati, da so vrste izpostavljene L. intracellularis (velika uharica, korejska sraka in velekljuna vrana) na različnih farmah zlahka dostopale do prašičev ali konj, ki pa so znani rezervoarji za L. Intracellularis. Tako je verjetno, da imajo te in podobne vrste visoko možnost izpostavitvi L. intracellularis in bi lahko služile kot biološki vektorji za proliferativno enteropatijo. Drugo možnost izpostavitve teh ptic L. intracellularis pa so lahko načini prehranjevanja divjih ptic in njihovi stiki z divjimi živalmi, okuženimi z L. Intracellularis. Ključne besede: Lawsonia intracellularis; geni; diagnoza; nadzor; nalezljiva bolezen; PCR