Antimicrobial Activity of Bacterial Intracellular and Extracellular Pigment Extract Against Potent Pathogens

A strain of pigmented Pseudomonas aeruginosa was isolated from soil and was analyzed for its pigment’santimicrobial properties. The isolated bacteriaum was able to produce two types of pigments viz,extracellulat and intracellular. The extracellular pigment was green and was water soluble andintracellular pigment was dark red and was not diffusible in water. Both these pigments were extractedand extracted pigments were used for antimicrobial studies. Many potent pathogens were used for thisstudy. Both Gram positive, negative and fungal pathogens were used in this study. The antimicrobialproperties were explored by using well diffusion method. MIC values for extracellular pigment againstmany pathogens were also determined. The extracellular pigment showed notable antimicrobial activityagainst C. albicans ATCC10231 followed by M. luteus ATCC9341, S. aureus ATCC 6538, E.coli ATCC8739 and P. aeruginosa ATCC9027. The lowest MIC value was recorded forC.albicans (360±00 µg/mL), E. coli ATCC8739 (433.3±0.4 µg/mL). The results of this studyshowed that the bacterium produces extracellular pigment as a protective weapon against manypathogens and competitors on the other hand the intracellular pigment’s role is different fromextracellular pigment.

Antibacterial activity of the Antarctic bacterium Janthinobacterium sp: SMN 33. 6 against multi-resistant Gram-negative bacteria

Background The increment of resistant strains to commonly used antibiotics in clinical practices places in evidence the urgent need to search for new compounds with antibacterial activity. The adaptations that Antarctic microorganisms have developed, due to the extreme environment that they inhabit, promote them as a potential new source of active compounds for the control of microorganisms causing infections associated with health care. The aim of this study was to evaluate the antibacterial activity of an ethanol extract of the Antarctic bacterium Janthinobacterium sp., strain SMN 33.6, against nosocomial multi-resistant Gram-negative bacteria. Results Inhibitory activity against human Gram-negative bacterial pathogens, with concentrations that varied between 0.5 and 16 µg ml- 1, was demonstrated. Conclusions The ethanolic extract of Janthinobacterium sp. SMN 33.6 possesses antibacterial activity against a chromosomal AmpC beta-lactamase-producing strain of Serratia marcescens, an extended-spectrum beta-lactamase-producing Escherichia coli and also against carbapenemase-producing strains of Acinetobacter baumannii and Pseudomonas aeruginosa. This becomes a potential and interesting biotechnological tool for the control of bacteria with multi-resistance to commonly used antibiotics.