Action of methicillin on the "in vitro" growth of bacteria Staphyloccocus aureus methicillin-resistance previously treated with homeopathic dilutions

Abstract

Background: Methicillin-resistant Staphylococcus aureus (MRSA) causes nosocomial infections, and it has been considered as a worldwide epidemic. The medical system seeks new strategies to fight against MRSA that do not generate resistant strains to antibiotics. Homeopathy has been explored as one of these new strategies, which may play a pivotal role. In this context, we conducted studies on the action of homeopathy on growth of MRSA bacteria in vitro. The results showed a decrease in growth of bacterial strains with homeopathic dilutions of Belladonna and the S. aureus nosode. Now we have proposed to evaluate the minimum inhibitory concentration (MIC) of the antibiotic methicillin or oxacillin on S. aureus MRSA, previously incubated with the homeopathic dilutions of Belladonna or S. aureus nosode. Methods: The Clinical and Laboratory Standards Institute (CLSI 2014) standards were followed according to the determination of the minimum inhibitory concentration (MIC). In 5 mL of cation adjusted Mueller Hinton (CAMH) broth, it was added 420 μl of 30% alcohol or Belladonna and S. aureus' nosode in the dilutions 6cH, 12cH and 30cH. Then a 20μl of bacterial suspension of MRSA was added to 0.5 McFarland range and diluted to 1/10. The tubes were incubated in an oven at 37°C for three hours. The plates were previously prepared with 50μl per well of serial dilutions of the antibiotic oxacillin in concentrations of 128 μg/mL to 0.5 μg/mL in CAMH broth. Then it was added 50 μl per well of bacterial cultures. The plate was incubated in an oven at 37°C for 24 hours and the bacterial growth measured in a spectrophotometer 600nm. The point of the MIC of oxacillin for S. aureus is 4 μg/mL, according to CLSI 2014 criteria. Results: We did not observe the total inhibition of bacterial growth when incubated with the homeopathic medicine and oxacillin. In evaluation of the spectrophotometer culture, we observed significant changes in the growth, compared to the control (30% alcohol). Cultures treated with Belladonna 6cH and the antibiotic in the dilution 4 μg/mL showed a decrease of 40% of the growth, while in the 30cH the drop was of 75%. Cultures treated with the S. aureus nosode 30cH and the antibiotic at 4 μg/mL dilution, showed a decrease of 60% in bacterial growth in vitro. Conclusion: The results suggest that bacterial cultures the S. aureus (MRSA) incubated with the homeopathic medicines would be more susceptible to oxacillin's antimicrobial action.