EN
One of the methods that can reduce the transmission of Salmonella from the reproductive tract to eggs can be the application of antibiotic therapy of infected hens. Studies characterizing the antibiotics effectiveness in salmonellosis therapy have shown that the therapy can only decrease the number of the bacterial population but it does not fully eliminate bacteria. The aim of the study was the assessment of the therapy of hens with selected antibiotics on the presence Salmonella Enteritidis in the content of eggs. The investigations were conducted in two stages. In the first stage the hens were infected experimentally with Salmonella Enteritidis. In the second stage the hens that had been infected were treated with selected antibiotics (enrofloxacine, norfloxacin, flumequine, amoxycillin and amoxicillin-clavulanic acid). In the present study S. Enteritidis was isolated from eggs that were laid during a 12 to 24 day interval post inoculation in all experimental groups but at individual days the quantity of infected eggs varied. On the 24th day post inoculation there was the highest amount (29.4%) of all contaminated eggs. After antibiotic therapy in some groups of hens there were no infected eggs. This pertained to the birds which were treated with enrofloxacine and norfloxacin. The result of the therapy with amoxycilln, amoxicillin-clavulanic acid and flumequine in the other groups was only the reduction of the quantity of infected eggs. The findings presented above demonstrate that the antibiotic therapy of hens infected with Salmonella Enteritidis has not always been effective in the elimination of these bacteria from the tissues of the reproductive tract but the therapy with enrofloxacine and norfloxacin can eliminate the possibility of salmonellas transmission into the contents of the eggs. Moreover, these examinations have shown the correlation between the infection of reproductive tract organs (ovary, oviduct) and the contents of eggs (yolk, white) that were laid by hens infected with Salmonella Enteritidis.