Inhibition properties of Actinobacteria extracts towards β–lactam resistance

Actinobacteria is one of the most valuable sources of natural products with agricultural, biotechnological, industrial and medicinal importance. They are top producers of antibiotics and have the ability to produce a wide variety of secondary metabolites. The rapid development of resistance bacteria stresses the need to find new adjuvant or resistant modifying agents to combat the growing number of resistant pathogens. In this study, 92 Actinobacteria extracts that were grown in ISP 2 medium were studied for their ability to potentiate the activities of ampillicin, methicillin and oxacillin against Staphylococcus aureus ATCC 43300, a strain that confers resistance to β–lactam drugs. The anti-Staphylococcal activities of the extracts were evaluated using resazurin microtiter-based assay [1] and the minimum inhibitory concentration of the selected antibiotics was initially determined. A 50% sub-inhibitory concentration of the antibiotics was used in combination with the extract to evaluate β–lactamase inhibition potential. The results from this study showed that a number of Actinobacteria extracts was able to enhance the activity of ampillicin at a concentration of 1mg/mL. In addition, the active extracts displayed weak inhibitory activities (<20% cell growth inhibition) when tested against the same resistant strain in the absence of the antibiotic. This implied that Actinobacteria extracts may contain active metabolites that can act as β–lactamase inhibitor and restore the effectiveness of penicillin derivative antibiotics.

• References

• 1 Suhaidi A, Sharifah Aminah Syed M, Mohd Faiz Foong A, Norizan A. An alternative rapid screening technique to detect β-lactamase inhibitor from mangrove actinomycete extracts. Planta Medica Int Open 2017; 4 (S 01): S1-S202