Evaluation of in vitro anti-clostridial effect of 8-hydroxyquinoline and its derivatives.

B.Sc. Hayford Osei-Owusu

Master's thesis

Abstract:

The clostridia species are one of the major pathogenic agents causing different kinds of infections in human and animals. These opportunistic bacteria are strictly anaerobic to aerotolerant, gram-positive and gram-negative species, although the majority of isolates are gram-positive. Some common infections caused in human included tetanus, food poison and diarrhea. In this study, in vitro anti-clostridial effect of 8-hydroxyquinoline and its derivatives (8-hydroxy-5-nitroquinoline and 8-hydroxy-7-iodo-5 quinoline sulfonic acid) against C. dificile and C. perfrinfens in comparison with main representatives of conventional antibiotics (cefamandole, ciprofloxacin, erythromycin, oxytetrecycline, penicillin G, streptomycin, sulfanilamide, tetracycline, and vancomycin), were evaluated using broth microdilution method. The MICs were calculated as the lowest concentration that showed ≥80% reduction of microbial growth compared to extract-free growth control after 24 h of growth. It was found that, 8-hydroxy-5-nitroquinoline, 8-hydroxy-7-iodo-5 quinoline sulfonic acid and 8HQ showed in vitro growth-inhibitory effect against C. perfringens (MICs = 2, 8 and 512 µg/ml) and C. difficile (MICs = 16, 64 and 512 µg/ml) respectively in comparison with the representatives of main classes of conventional antibiotics The comparison of MICs of the plant-derived compounds with conventional antibiotics suggested that, 8-hydroxy-5-nitroquinoline (MIC = 2 µg/ml) showed significant in vitro growth-inhibitory effect on C. perfringens comparable with penicillin G(MIC = 0.125 µg/ml) , ciprofloxacin (MIC = 1 µg/ml) and vancomycin (MIC = 1 µg/ml), and proved effectiveness against C. difficile at MIC = 16 µg/ml closely related to oxytetrecycline (MIC = 0.5 µg/ml), tetracycline(MIC = 0.25 µg/ml), and vancomycin(MIC = 1 µg/ml). With this result, the compounds could be suggested for further research focused on development of novel pharmaceutical and veterinary anti-clostridial drugs as well as additives and sterilizers in food and nutrition because of its ability to inhibit clostridia growth without effect on beneficial bifidobacteria.

Keywords

Gas gangrene, Clostridia, Antibiotics, 8-hydroxyquinoline, Growth- inhibitory effect

Jazyk práce: English

Datum vytvoření / odevzdání či podání práce: 24. 8. 2017

Obhajoba závěrečné práce

• Vedúci: prof. Ing. Ladislav Kokoška, Ph.D.
• Oponent: Ivo Doskočil, Ph.D.

Czech University of Life Sciences Prague

Faculty of Tropical AgriSciences

Master programme / odbor:
Tropical Agriculture / Tropical Crop Management and Ecology