Methanolic extract of Hemidesmus indicus root augments the antibacterial and antibiofilm activity of amoxicillin and clindamycin against methicillin-resistant Staphylococcus aureus of bovine origin

The present study evaluated the antibacterial and antibiofilm activity of methanolic extract of Hemidesmus indicus root (MHIR) in combination with amoxicillin and clindamycin against biofilm-forming methicillin-resistant Staphylococcus aureus (MRSA) isolated from milk samples of mastitic cows. Microdilution susceptibility testing and microtitre plate assays were used to evaluate the in vitro efficacy of MHIR and antibiotic combinations against MRSA (n = 12). Furthermore, in vitro findings were validated in a murine model. Minimum inhibitory concentration and minimum biofilm inhibitory concentration of amoxicillin and clindamycin in combination with MHIR were significantly (P < 0 center dot 05) lower than when used alone against MRSA. In terms of antibacterial activity, MHIR showed additive interaction (fractional inhibitory concentration(index) >0 center dot 5-4) with amoxicillin and clindamycin against all the MRSA isolates, whereas MHIR synergizes (fractional biofilm inhibitory concentration(index) <= 0 center dot 5) the antibiofilm activity of amoxicillin and clindamycin against 58 center dot 33% and 83 center dot 33% of the MRSA isolates respectively. Amoxicillin/clindamycin in combination with MHIR significantly (P < 0 center dot 05) reduced disease activity score, and bacterial load and Gram-positive spots in kidney and liver of MRSA-infected mice. The combined efficacy of MHIR and amoxicillin/clindamycin was comparable to clindamycin alone but superior to amoxicillin alone. Hence, the combination of MHIR with amoxicillin/clindamycin is advocated in the treatment of MRSA-associated infections.

Automated summary

The study evaluated the antibacterial and antibiofilm activity of Hemidesmus indicus root extract in combination with amoxicillin and clindamycin against biofilm-forming MRSA isolated from mastitic cows. The combination significantly reduced disease activity, bacterial load, and Gram-positive spots in MRSA-infected mice. The efficacy of MHIR combined with amoxicillin/clindamycin was comparable to clindamycin alone but superior to amoxicillin alone, suggesting its potential in treating MRSA infections.