Serological diversity and antimicrobial resistance of Salmonella isolated from different sources in Lithuania

Abstract

Over 57000 samples were tested in order to isolate Salmonella from animals and feedstuffs during the period 1998-2003. Four hundred and nine strains were isolated from poultry, 143 from pigs, 16 from cattle and 99 from feedstuffs. Ninety-two percent of isolated Salmonella from pigs depended to serovar S. Choleraesuis. All Salmonella isolates from cattle depended to serovars S. Dublin and S. Enteritidis. A wider variety of Salmonella serovars was obtained from poultry and feedstuffs. The main source of Salmonella presence in feedstuffs was fish products. Sixty isolates of S. Choleraesuis and 100 isolates of different serovars from poultry were tested for antimicrobial resistance. Only 1.3% of isolated Salmonella were resistant to ceftiofur, 5.6% to enrofloxacin. Thirtyfour percent were resistant to nalidixic acid, 33% to tetracyclines and 8.1% were resistant to aminoglycosides (neomycin and gentamicin). Streptomycin was less effective: 30% of isolated Salmonella were resistant to this antibiotic. S. Choleraesuis has more resistance than Salmonella serovars isolated from poultry. There is evidence that the prevalence of Salmonella has decreased in recent years. However, more attention must be paid to surveillance and monitoring of antimicrobial resistance.