Efficacy of Chloroquine against Escherichia Coli and Proteus vulgaris: An in vitro Study

Chloroquine, a 4-aminoquinoline is an effective antimalarial drug and is also used as a systemic amoebicide in the treatment of hepatic amoebiasis (extra intestinal site). The objective of this study is to establish the efficacy of Chloroquine against common pathogenic bacteria such as Escherichia coli, and proteus. A stock solution containing 64 mg Chloroquine phosphate/mL was prepared in distilled water, serial dilution was prepared to obtain 5 mL solution, each having a different concentration of the drug. Whatman No.1 filter paper was used to prepare discs of 6mm diameter. The discs were sterilized and each dilution of the drug was added on the disc at a volume of 10μL per disc. Final concentration of Chloroquine phosphate per disc was 64, 53, 42, 30 and 21μg. Discs were dried and stored at 4C. Disc of amoxicillin-clavulanic acid combination at strength of 30μg was used as a control. Total 100 isolates of bacteria isolates from clinical samples was used in the study. Antimicrobial susceptibility test of these isolates was performed by using Kirby-Bauer’s method. It was observed that E. coli and Proteus were susceptible to chloroquine at higher strengths. Interpretation and chloroquine certainly shows certain degree of antimicrobial efficacy. In-vitro studies can be a stepping stone for further investigations in-vivo.