IDENTIFICATION AND RESISTANCE PROFILE OF ISOLATED MICROORGANISMS FROM SUSPECTED CLINICAL MASTITIS SAMPLES IN THE WESTERN MESOREGION OF PARANÁ

The etiological agents of bacterial origin have been identified as the main cause of bovine mastitis, leading to the indiscriminate use of antibiotics promoting a high index of microbial resistance. Thus, it is necessary to identify the etiologic agent in order to perform the appropriate treatment of the pathology. The objective of this study was to identify the pathogenic microorganisms present in milk samples from animals with clinical suspicion of mastitis coming from municipalities of the western mesoregion of the state of Parana, as well as to observe the potential of antimicrobial resistance of the isolated strains. The analyzes were carried out in the Laboratory of Inspection and Control of Quality of Food and Water (LACOMA) of the Federal University of Paraná, Pallor Sector, from January 2017 to May 2018. After phenotypic and biochemical identification of microorganisms, the isolates were submitted to the antibiogram by the disc-diffusion method, according to manual Clinical & Laboratory Standards Institute (2011). Thirteen antibiotics commonly used for the treatment of mastitis were tested. The antibiotic disks tested in all isolates were Ceftiofur (30 μg), Enrofloxacin (5 μg), Penicillin (10 μg) and Sulfamethoxal + Trimethoprim (25 μg), while Ampicillin (10 μg), Ampicillin 10 μg), Norfloxacin (10 μg), Amoxicillin + Clavulanate (30 μg), Cephalexin (30 μg), Neomycin (30 μg), Ciprofloxacin (5 μg), Doxycycline (30 μg), Gentamicin 30 μg). In total, 32 samples were analyzed, of which 30 presented bacterial growths. The most commonly found microorganisms were coagulase negative Staphylococcus (43.3%), Streptococcus sp. (23.3%), Corynebacterium sp. (20%), Enterococcus sp. (13.3%), Escherichia coli (10%), Bacillus sp. (10%), Enterobacter sp. (3.3%), Actinobacter sp. (3.3%), Micrococcus sp. (3.3%). In 43.3% of the samples there was an associated growth of more than one microorganism, justifying the observed frequencies. Among the isolates, it was possible to observe a high potential for resistance to Penicillin and greater susceptibility to Enrofloxacin and Ceftiofur. It was verified that 69.2% of the strains of Staphylococcus sp., more isolated bacterial genus, showed a greater resistance potential to Amoxicillin (23.07%), Ampicillin (23.07%) and Penicillin (23.07% ). For Streptococcus sp. strains, the antibiotic whose cultures had the greatest resistance was the combination of Sulfamethoxal + Trimethoprim (85.71%). In view of the above, it can be observed that the identification of agents and the performance of the antibiogram are of great importance in the control and proper treatment of mastitis, thus avoiding an increase in microbial resistance.