BackgroundMaggot therapy has been in practice for effective debridement, disinfection and healing of chronic wounds. Due to their antiseptic action during wound healing, their metabolites have been investigated in the past for antibacterial activity. They have been particularly useful for treatment of wounds infected with multi-drug resistant Staphylococcus aureus. Antibiotics, on the other hand, can predispose bacteria to develop resistance. Substances that are able to modulate or delay the occurrence of resistance in bacteria are under investigation by many researchers around the world. In the present study, antibacterial activity in excretions/secretions (ES) from maggots of Lucilia cuprina blowfly was demonstrated. The extracts were also screened in combination with antibiotic, ciprofloxacin.MethodsL. cuprina blowfly maggots were reared for extraction of its metabolites. The ES extracted was screened against S. aureus, alone and in combination with ciprofloxacin, both for short term and long term exposure analysis. A microchannel-based device and system was used for experiments instead of conventional techniques.ResultsThe original ES had shown partial bacterial growth inhibition. However, in combination with ciprofloxacin, at sub-inhibitory concentrations, certain combinations revealed anti-staphylococcal activity, with bacterial reduction of up to 50%, after 24 hours. The six day study on S. aureus exposed to ES-ciprofloxacin combination suggested a potential delay in development of adaptive resistance as opposed to when ciprofloxacin was used as single agent.ConclusionsThe combination effect of ES and ciprofloxacin at sub-MIC levels showed enhanced antibacterial activity compared to the effect of ES and ciprofloxacin as single agents. Based on the results of ES-ciprofloxacin combinations, a more effective means of treatment for S. aureus can be proposed.

Emergence and rapid spread of antibiotic resistance has become one of the leading causes of treatment failures in case of bacterial infections. Antibiotic combinations are generally used to enhance the overall efficacy of therapy with the aim to generate synergistic outcomes. It further helps in reduction of total antibiotic dosage. Phytochemicals are known to have multiple bacterial targets that modulate or modify resistance in bacteria. In the present study, a microchannel-based device and monitoring system was used to demonstrate and investigate short and long term effects of antibioticphytochemical combinations in different proportions on Staphylococcus aureus as test organism. Novel and unconventional combinations of antibiotic ciprofloxacin with the phytochemicals, quercetin, rutin, protocatechuic acid and ethyl gallate, were tested. Based on the experimental results, the strains exposed the antibiotic, generated resistant strains in four days, with 8 to 64 fold increase in their minimum inhibitory concentration (MIC) from the parent strain. The strains exposed to antibioticphytochemical combinations, however, showed no resistance causing mutations. The results were verified by standard laboratory practices such as disk-diffusion, mutation frequency, population profiling and molecular studies on the exposed strains. The phytochemicals were able to potentiate antibiotic activity; thereby, increasing the antibacterial efficacy and time span of the treatment with a common antibiotic.