(untitled) (Majalah Kedokteran Bandung, 2015)
Lactobacillus bulgaricus menghasilkan asam laktat dan bakteriosin yang memiliki efek farmakologik, di antaranya sebagai antibakteri. Klebsiella pneumoniae penyebab pneumonia masih merupakan masalah kesehatan masyarakat di negara tropis. Penelitian ini bertujuan untuk mengetahui daya antibakteri asam laktat dan bakteriosin L. bulgaricus terhadap berbagai strain K. pneumoniae secara in vitro dengan menggunakan teknik agar tuang dan difusi cakram, selanjutnya data dianalisis dengan ANAVA yang dilanjutkan dengan uji Duncan’s multiple range test (DMRT). Penelitian dilakukan di Laboratorium Mikrobiologi Rumah Sakit Pendidikan Universitas Padjadjaran, Bandung pada bulan Agustus–Oktober 2012. Hasil menunjukkan bahwa konsentrasi 30% filtrat asam laktat dan 20% filtrat bakteriosin L. bulgaricus bersifat bakterisidal terhadap berbagai strain K. pneumoniae. Semakin besar konsentrasi filtrat asam laktat dan bakteriosin L. bulgaricus menunjukkan pengaruh peningkatan daerah hambat berbagai strain K. pneumoniae. Analisis data dengan ANAVA yang dilanjutkan dengan uji Duncan’s multiple range test (DMRT) menunjukkan bahwa pengaruh konsentrasi filtrat terbesar terhadap daerah hambat K. pneumoniae diperoleh pada perlakuan konsentrasi 90% filtrat asam laktat L. bulgaricus, sedangkan daerah hambat terbesar diperoleh K. pneumoniae strain ATCC 700603 pada konsentrasi 90% filtrat bakteriosin sebesar 16,667 mm. Simpulan, filtrat asam laktat dan bakteriosin L. bulgaricus memiliki daya antibakteri terhadap pertumbuhan K. pneumoniae. Besar daya antibakteri L. bulgaricus terhadap pertumbuhan K. pneumoniae dipengaruhi oleh jenis filtrat, konsentrasi filtrat L. bulgaricus, dan strain bakteri K. pneumoniae. [MKB. 2015;47(1):35–41] Kata kunci: Antibakteri, asam laktat, bakteriosin, Klebsiella pneumoniae, Lactobacillus bulgaricus Antibacterial Effect of Lactic Acid Filtrate and Bacteriocins of Lactobacillus bulgaricus KS1 on Inhibiting the Growth of Klebsiella pneumoniae ATCC 700603, CT1538, and S941 Strains Lactobacillus bulgaricus produces lactic acid and bacteriocin which have been reported to have various pharmacologic properties, including their role an antibacterial agent. Klebsiella pneumoniae, as an agent of pneumonia, remains a public health problem in tropical countries. This study was aimed to observe the antibacterial activities of lactic acid filtrate and bacteriocins of L. bulgaricus toward againsts K. pneumoniae strains by in vitro experiment. The experiment took place in Microbiology Laboratory, Teaching Hospital, Padjadjaran University, Bandung, August–October 2012. In vitro laboratory analytic study has been conducted on lactic acid filtrate and bacteriocins of L. bulgaricus against the K. pneumoniae strains. The study used agar pour plate and agar disk diffusion method and analyzed by ANAVA followed by Duncan’s multiple range test (DMRT). The 30% lactic acid filtrate and 20% bacteriocins filtrate concentrations of L. bulgaricus showed bactericidal characteristics againts the growth of K. pneumoniae strains. Greater concentration of lactic acid filtrate and bacteriocins of L. bulgaricus led toincreasing effect of growth inhibition zones of K. pneumoniae strains. Statistical analysis of variance (ANOVA) showed that the greatest concentration effect of L. bulgaricus filtratefor inhibiting K. pneumoniae strains was achieved in 90% lactic acid filtrate concentration treatment, whereas the greatest inhibition zones for K. pneumoniae ATCC 700603 was obtaubed in 90% bacteriocins filtrate concentration, amounting 16.667 mm. In conclusion, lactic acid filtrate and bacteriocins L. bulgaricus have antibacterial effects on K. pneumoniae. The level of antibacterial effect of L. bulgaricus against the growth of K. pneumoniae strains depends on the type of filtrate, L. bulgaricus filtrate concentration, and K. pneumoniae strain. [MKB. 2015;47(1):35–41] Key words: Antibacterial, bacteriocins, Klebsiella pneumoniae, lactic acid, Lactobacillus bulgaricus DOI: 10.15395/mkb.v47n1.395