Antimicrobial resistance in Salmonella enteritidis strains isolated from broiler carcasses, food, human and poultry-related samples

Antimicrobial resistance was investigated in 91 Salmonella enteritidis isolates from broiler carcasses, food, human and poultry-related samples originated from South of Brazil. A great proportion of resistant strains was found, 90.1% showing resistance to at least one antimicrobial drug. There was a high resistance to sulfonamides (75.8%) and nitrofurantoin (52.8%). Lower levels of resistance were found for tetracycline (15.4%), streptomycin (7.7%), nalidixic acid (7.7%), gentamicin (5.5%), norfloxacin (3.3%), trimethoprim (3.3%), cefalotin (2.2%), ampicillin (1.1%), and chloramphenicol (1.1%). Resistance to ciprofloxacin was not detected. A total of 51.6% of S. enteritidis strains were multiresistant (resistance to two or more antimicrobial agents) and 18 resistance patterns were found. The highest resistance was found in strains isolated from poultry-related samples, where all strains were resistant to at least one antimicrobial agent. No predominant resistance pattern was related to phage type in our isolates. The high number of antimicrobial resistant S. enteritidis found in Southern Brazil indicates the need for the prudent drugs uses to diminish the development and spread of antimicrobial resistance.