IDENTIFIKASI DAN UJI RESISTANSI BAKTERI TERHADAP ANTIBIOTIK PADA SEMEN BEKU SAPI LOKAL

Abstract

Kontaminasi bakteri pada semen beku sapi dapat menurunkan kualitas spermatozoa dan mengganggu keberhasilan inseminasi buatan. Penelitian ini bertujuan mengidentifikasi bakteri yang terdapat pada semen beku sapi lokal serta mengevaluasi resistansinya terhadap beberapa antibiotik yang umum digunakan dalam pengencer semen. Sampel berupa empat straw semen beku sapi lokal diisolasi pada media selektif dan nonselektif, kemudian diidentifikasi melalui pengamatan morfologi koloni, pewarnaan Gram, uji KOH 3%, serta uji biokimia. Uji resistansi antibiotik dilakukan menggunakan metode difusi cakram dan difusi sumur. Hasil penelitian menunjukkan bahwa 16 isolat bakteri yang diperoleh terdiri atas Klebsiella pneumoniae, Enterobacter cloacae, dan Staphylococcus epidermidis. Isolat Gram negatif, terutama E. cloacae dan K. pneumoniae, menunjukkan resistansi tinggi terhadap beberapa antibiotik yang diuji, sedangkan S. epidermidis relatif lebih sensitif terhadap gentamisin dan streptomisin. Resistansi tersebut diduga berkaitan dengan produksi enzim beta-laktamase, perubahan permeabilitas membran, mekanisme pompa efluks, serta modifikasi target antibiotik.

Bacterial contamination in frozen bovine semen can reduce spermatozoa quality and interfere with the success of artificial insemination. This study aimed to identify bacteria present in local bovine frozen semen and evaluate their resistance to several antibiotics commonly used in semen extenders. Samples consisting of four straws of local bovine frozen semen were isolated on selective and non- selective media, then identified through colony morphology observation, Gram staining, 3% KOH test, and biochemical tests. Antibiotic resistance testing was conducted using disc diffusion and well diffusion methods. The results showed that the bacterial 16 isolates obtained consisted of Klebsiella pneumoniae, Enterobacter cloacae, and Staphylococcus epidermidis. Gram-negative isolates, particularly E. cloacae and K. pneumoniae, exhibited high resistance to several tested antibiotics, whereas S. epidermidis was relatively more sensitive to gentamicin and streptomycin. This resistance was presumed to be associated with beta-lactamase enzyme production, changes in membrane permeability, efflux pump mechanisms, and modification of antibiotic targets.