Effectiveness of microbial culture supernatants against multi-drug resistant microbes

Abstract

The experiment started with collecting microorganisms from different sources like soil samples from 10 different places and storing them on CMCA, & SA, and MRS agar for yogurt samples from 7 different places. Among the soil samples, 20 cellulolytic and 15 amylolytic bacteria were found and 12 cellulolytic and 6 amylolytic bacteria showed clear zones when treated with gram’s iodine and indicated that they were able to produce enzymes that can degrade cellulose and starch and these probiotics could be a possible source for treating multidrug-resistant bacteria. Then, the same types of broth: CMC broth, starch broth, and MRS broth, Luria Broth & lactose broth media according to selectivity were used. After 48 hours of incubation, the bacterial culture broths were centrifuged and the culture supernatants were collected and the supernatants were used to check the effectiveness of the supernatants against several multidrug-resistant bacteria in different compositions of the cell-free culture supernatants. The main goal of the experiment was to perform an antibiogram within the Mueller-Hinton agar medium and observe the zone of inhibition after an 18-22 hours incubation against several MDR bacteria with the presence of different supernatant compositions. Almost against 11 MDR bacteria, the culture supernatants from specific yogurt samples could inhibit the growth of superbugs as indicated by the zone of inhibition in Muller Hinton Agar, but neither amylolytic nor cellulolytic bacterial culture supernatants have shown any desired effect against the superbugs, it also decreased the effect of LAB supernatant’s zone of inhibition if they were mixed in different compositions. After biochemical tests of the LAB, it can be called Lactobacillus bulgaricus (presumptive) the culture supernatants of which had shown positive output against most of the MDR bacteria.