04278naa a2200289 a 450000100080000000500110000800800410001910000180006024501090007826000090018752034830019665000260367965000170370565000180372265000170374065000140375765000130377165000180378465000110380265300260381370000170383970000190385670000170387570000160389270000250390877300550393320260502016-06-03       2015    bl uuuu     u00u1 u    #d1 aCAMPOS, T. de  aAntimicrobial resistance of enterococcus isolated from pre-chill swine carcasses.h[electronic resource]  c2015  aBackground: As a result of the extensive use of antimicrobials in agriculture, animals have been implicated as possible reservoirs of resistant strains of bacteria. Enterococci are members of the normal flora of the gastrointestinal tract of human and animals. Because of their ubiquity, enterococci have been introduced in programs to evaluate the hazard of transmission of resistant bacterial strains through the food chain. The aim of this study was to assess the antimicrobial resistance profile of Enterococcus isolated from swine carcasses at the pre-chill step of processing. Material, Methods & Results: Pig carcasses were sampled at three commercial slaughterhouses (A, B and C). On each of two sampling occasions swabs of 100 cm2 areas were taken from each ham, back, belly and jowl of a total of 14 pre-chill carcasses. Enterococci were isolated and counted in KF Streptococcus Agar, and typical colonies were confirmed by PCR assay targeting the tuf gene. Enterococcus isolates were tested for susceptibility to nine different antimicrobial agents by agar disc diffusion. From a total of 252 carcasses sampled, 240 (95.2%) presented presumptive colonies of Enterococcus in counts ranging from 0.02 log CFU.cm-2 to 2.9 log CFU.cm-2. All isolates were confirmed as belonging to the genus Enterococcus, and the great majority was identified as E. faecalis (218/240; 90.83%). Half (125/240; 52.1%) of the Enterococcus isolates were susceptible to all tested antimicrobials. No resistance to ampicillin, vancomycin or teicoplanin was found. The most frequent resistance was to tetracycline (42.5%), followed by erythromycin (26.7%), high level (HLR) streptomycin (20.4%), ciprofloxacin (13.8%), chloramphenicol (12.1%) and HLR-gentamicin (10.4%). Among the 115 resistant Enterococcus isolates, 55 (47.8%) were multi-resistant, and the distribution of the most common profiles was related to the slaughterhouse from which the isolate originated. Discussion: Although foodborne enterococci have not yet been clearly involved in direct clinical infection, antimicrobial-resistant isolates from food can be a reservoir of resistance genes. Therefore, the occurrence of resistant isolates to HLR-streptomycin, HLR-gentamicin, tetracycline, erythromycin and ciprofloxacin in swine carcasses may present a risk of spreading enterococci strains that are resistant to treatment. Several drugs of these groups are used in feed for prophylaxis and treatment of respiratory and enteric diseases in pigs and may thus be exerting a high selective pressure in the intestinal microbiota. The sampled slaughterhouses in this study were supplied by production chains that belong to different agribusiness companies. These companies run contracts with farmers which usually specify a common management protocol, including prophylactic and therapeutic administration of antimicrobial drugs. The selective pressure of antimicrobial usage may also explain the significant difference in the frequency of resistance to most tested agents among the slaughterhouses. It was concluded that although Enterococcus isolates from pre-chill swine carcasses presented a low to moderate frequency of resistance against most antimicrobials used in human treatment, isolates displaying resistance to the aminoglycosides and macrolides classes may present a hazard. The multi-resistance patterns were highly associated with the origin of the isolates and may indicate the extent of antimicrobial use on farm.  aAntibiotic resistance  aBacteriology  aPig carcasses  aAntibiótico  aBactéria  aCarcaça  aMicrobiologia  aSuíno  aEnterococcus porcines1 aPISSETTI, C.1 aWERLANG, G. O.1 aLOPES, G. V.1 aKICH, J. D.1 aCARDOSO, M. R. de I.  tActa Scientiae Veterinariaegv. 43, n. 1259, 2015.