It is known that methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) has been a major public health problem. The rising infection rates in communities and hospitals has significantly impacted treatment costs. Complications to this situation have increased with the resistance acquired by MRSA towards antibiotics such as ciprofloxacin (Cipro), commonly prescribed to treat a broad-spectrum of bacterial infections. In need of a new compound with effective antibacterial activity, it was found that a previously reported synthesis of 2-hexadecynoic acid (2-HDA) effectively inhibited the growth of Gram-positive and Gram-negative bacteria, as well as clinical isolates of MRSA (CIMRSA). In this study, combinations of Cipro and 2-HDA were evaluated against various CIMRSA strains in search of the most effective ratio for bacterial inhibition. To determine the most potent ratio of Cipro:2-HDA combinations, minimum inhibitory concentration assays (MICs) were performed against six CIMRSA strains by microdilution susceptibility tests using tryptic soy broth (TSB). Our results revealed that a ratio of 4:1 (2-HDA: Cipro) was the most effective combination with a reported MIC value of 7.8 µg/mL when tested against our most resistant strain of CIMRSA. Although lower MIC values were achieved with these drug ratio combinations, when compared to previous reports, it was shown that 2-HDA alone remains the most effective compound overall. In addition, PCR assays were performed to identify the Cipro-resistance gene in our CIMRSA strains and confirm their resistant identity through a molecular approach. This study opens the possibility to conduct future experiments towards a molecular direction for a more detailed insight of how 2-HDA and combinations of 2-HDA and cipro affect CIMRSA strains at the gene level.

Combinatorial study of the antibacterial activity of ciprofloxacin and 2-hexadecynoic acid against methicillin resistant <i>Staphylococcus aureus</i>

Macromolecular Chemistry: The Second Century

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ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

Combinatorial study of the antibacterial activity of ciprofloxacin and 2-hexadecynoic acid against methicillin resistant Staphylococcus aureus