Perfil de sensibilidade in vitro de Staphylococcus spp frente a antimicrobianos e desinfetantes utilizados no controle da mastite bovina

Abstract

The goal of this research was to evaluate the occurrence and the sensitivity of Staphylococcus spp to antibiotics and disinfectants used in the control of bovine mastitis. Fifteen dairy farms located in the Metropolitan Recife regions (A), Agreste (B) and Zona de Mata (C), of the state of Pernambuco were studied. A total of 1,080 milk samples were collected and submitted to microbiological culture in order to isolate and identify Staphylococcus spp. To study the sensitivity and resistance of Staphylococcus spp to antimicrobials the diffusion disk technique with the following antibiotics was used: amoxiciline (10 mcg), ampiciline (10 mcg), azitromicine (15 mcg), cefquinome (30 mcg), cephalonium (30 mcg), ciprofloxacine (5mcg), cloxacillin (25 mcg), danofloxacine (10 mcg), enrofloxacine (5 mcg), eritromicine (15 mcg),florfenicol (30mcg), gentamicine (10 mcg), penicillin + novobiocine (10 mcg), sulfa (25 mcg) + trimetoprim (5 mcg),tobramicine (10 mcg) e tetraciclina (30 mcg) + neomicine (30 mcg) + bacitracine (10 mcg). For the in vitro study of sensitivity and resistance of S. aureus and Staphylococcus coagulase positive to the disinfectants, the following products were used: iodine (0.5%), chlorine (2.5%), quaternary ammonium (4%), lactic acid and chlorhexidine (2.0%). Of the 1,080 samples analyzed, 740 (68.5%) were positive and 340 (31.5%) negative. From the positive samples, Staphylococcus were isolated in 291 (39.3%). Of these, 170 (58.4%) were classified as coagulase negative Staphylococcus (SCN), 84(28.9%) as Staphylococcus aureus (S. aureus), and 37(12.7%) as coagulase positive Staphylococcus (SCP). The most efficient antibiotic in vitro was the combination between neomicine (98.4%), and bacitracine (99.3%) and tetracycline (89.7%) for regions A, B e C, respectively. The least efficient was ampicillin, which only showed a resistance of 56.5% to the isolates from region A, 72.8% for region B e 71.8% for region C. With respect to the disinfectants, iodine proved to be the most effective for S. aureus and SCP. The least effective was chlorine. Based on the results, it can be concluded with the epidemiological importance of Staphylococcus spp in subclinical mastitis in dairy cows in the regions chosen and the need for periodic evaluation of the antibiotics and disinfectants used to control mastitis.