Antimicrobial Resistance ofSalmonellaSerotypes Isolated from Slaughter-Age Pigs and Environmental Samples

Abstract

The aim of this study was to determine the antimicrobial resistance patterns of Salmonella strains isolated from slaughter-age pigs and environmental samples collected at modern swine raising facilities in Brazil. Seventeen isolates of six serotypes of Salmonella enterica subsp. enterica were isolated out of 1,026 collected samples: Salmonella Typhimurium (1), Salmonella Agona (5), Salmonella Sandiego (5), Salmonella Rissen (1), Salmonella Senftenberg (4), and Salmonella Javiana (1). Resistance patterns were determined to extendedspectrum penicillin (ampicillin), broad-spectrum cephalosporins (cefotaxime and ceftriaxone), aminoglycosides (streptomycin, neomycin, gentamicin, amikacin, and tobramycin), narrow-spectrum quinolone (nalidixic acid), broad-spectrum quinolone (ciprofloxacin and norfloxacin), tetracycline, trimethoprim, and chloramphenicol. Antimicrobial resistance patterns varied among serotypes, but isolates from a single serotype consistently showed the same resistance profile. All isolates were resistant to tetracycline, streptomycin, and nalidixic acid. One isolate, Salmonella Rissen, was also resistant to cefotaxime and tobramycin. All serotypes were susceptible to ceftriaxone, norfloxacin, ciprofloxacin, ampicillin, gentamicin, and chloramphenicol. The high resistance to tetracycline and streptomycin may be linked to their common use as therapeutic drugs on the tested farms. No relation was seen between nalidixic acid and fluoroquinolone resistance. 407

Prevalence, genetic characterization and antimicrobial resistance of Salmonella isolated from fresh pork sausages in Porto Alegre, Brazil

“…In this study, we demonstrated the widespread occurrence of antimicrobial resistance to tetracycline and sulfonamide in Salmonella strains isolated from fresh pork sausages. This finding is in accordance with previous studies of Salmonella strains isolated from slaughtered pigs in Brazil (Michael, Cardoso, & Schwarz, 2006;Oliveira et al, 2002;Bessa et al, 2007). Moreover, a relatively high frequency of chloramphenicol resistance in isolates tested in this study and elsewhere (Bessa et al, 2007) was also detected.…”

Antibiotic resistance of Salmonella spp. isolates from pigs in the Czech Republic

“…In accordance with other authors, we confirmed correlation between high prevalence of antibiotic resistance and the serotype Typhimurium (Baggesen and Aarestrup, 1998;Molbak et al, 1999;Gebreyes et al, 2000;Gebreyes and Altier, 2002;Yang et al, 2002). Only results from Spain and Brazil differed slightly when reporting the most frequent multiresistances in the serotypes Anatum and Agona (Mateu et al, 2002;Oliveira et al, 2002). Unlike the findings of Gebreys et al (2000) and Gebreys and Altier (2002), we found a relatively low frequency of resistance towards amoxycillin/clavulanic acids (18.6%).…”

“…We found a significant relationship between the resistance to nalidixic acid (11.9%) and enrofloxacin (6.8%), in contrast to the data from Brazil. Oliveira et al (2002) found in Salmonella isolates of different serotypes isolated from pigs resistant to nalidixic acid (narrow-spectrum quinolone), while resistance to ciprofloxacin and norfloxacin (broad-spectrum quinolone) was not observed. In the USA and Canada, resistance to ciprofloxacin was not observed either in Salmonella isolates from pigs, food animals and food (Gebreyes et al, 2004;Rajic et al, 2004;Johnson et al, 2005).…”

National survey for Salmonella in pigs, cattle and sheep at slaughter in Great Britain (1999-2000)

“…2001; Farrington et al. 2001; Oliveira et al. 2003), it is not clear that changes in farm medication can bring about reductions (Edrington et al.…”