Isolation and screening of family members as an extremophilic poor investigated and promising natural source of antimicrobial substances.

BACKGROUND AND OBJECTIVES

Recent evidences have shown that methicillin-resistant (MRSA) can cause severe infections and is resistant to almost all commercially available antibiotics. Therefore, screening unknown sources of biological compounds such as the family as extremophilic bacteria may be helpful to find new antimicrobial agents.

MATERIALS AND METHODS

Various samples were collected from different ecosystems, including desert, volcano, compost, and forest. They were cultured on Soil extract agar and Water agar. The antimicrobial activity of the isolates was evaluated using agar overlay and well diffusion methods. Members of the family were selected for further study: Their ability to grow at different temperatures, NaCl concentrations, and pH values, enzyme production ability, antimicrobial secondary screening, fractionation of their supernatants and so on.

RESULTS

According to molecular identification of active isolates against MRSA, three strains, including UTMC 2705, sp. UTMC 2721, and sp. UTMC 2731, belonged to were identified. The minimum inhibitory concentrations of their extracts were tested against some pathogenic bacteria, showing their antimicrobial activity with a broad spectrum. The results of TLC bioautography of the extracts showed that the most active fractions were semi-polar. Also, the results of HPLC analysis showed the existence of several UV-active compounds in their extracts.

CONCLUSION

The present study highlighted the importance and potential of members as a less-known source of antibiotics against pathogenic bacteria.