Periódicos Brasileiros em Medicina Veterinária e Zootecnia

Transmission of Coxiella burnetii to calves from infected cows

Radinović, MiodragDavidov, IvanaKovačević, ZoranaErdeljan, MihajloPajić, MarijaGalfi , Annamaria

Background: Coxiella burnetii is the causative agent of a very important disease with zoonotic potential. Infected cowsrepresent risk for spreading of infection to humans and to other animals on farm and also to their offspring. There is possibility for calves from infected cows to be infected nearly after parturition or during intrauterine life. Studies have shownthat Coxiella burnetii initially infects the placenta and subsequent spread to the fetus may occur either by haematogenousor by the amniotic-oral route providing congenital infection. The main objective of the present study is to determine thepresence of Coxiella burnetii genome in milk serum of infected cows and blood serum of calves.Materials, Methods & Results: A total of 200 blood serums from dairy cows were tested for presence of antibodies toCoxiella burnetii and nine of those were found positive. These animals compiled experimental group. From animals inexperimental group milk samples during lactation, pregnancy and the postpartum period were collected. Samples wereused for performing PCR test for determination of Coxiella burnetii presence in milk serum. On calving of each cow bloodsamples were taken from calves during first 24 hours after calving, from jugular vein. These blood samples were also usedfor PCR test to determine the presence of Coxiella burnetii. Milk serum analysis showed presence of Coxiella burnetiigenome in serum, indicating on intermittent excretion. During lactation, the excretion of bacteria was greatest in the second stage when 80% of milk serum samples were positive for Coxiella burnetii. In the colostrums stage, there was a highpercentage of Coxiella burnetii excretion through milk (50% of positive milk serum samples). The lowest percentage ofexcretion through milk was in the first stage of lactation. Analyzing blood serum samples from calves, taken on first dayat calving using PCR method, all serums were positive for presence of Coxiella...(AU)

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