Abstract

ANTIBACTERIAL POTENTIAL OF EXTRACTS FROM TETRAPLEURA TETRAPTERA (SCHUMACH AND THONN) ON INDUCIBLE CEPHALOSPORINASE-PRODUCING MULTI-DRUG RESISTANT HEALTHCARE SETTING BACTERIA

Joëlle Diane Mbieleu, Pierre René Fotsing Kwetche*, Josué Simo Louokdom, Sandrine Gamwo Dongmo, Armanda Laetitia Kengne Toam and Théophile Dimo

ABSTRACT

The present investigation focused semi-quantitative chemical screening and antibacterial potential of aqueous extracts from the stem bark and fruits of Tetrapleura tetraptera (T. tetreptera) grown in rain forest. Secondary metabolites targeted included alkaloids, anthocyans, anthraquinones, coumarins, flavonoids, saponins, tannins, glycosides, reducing sugars and polyphenols. The antimicrobial potential was tested on six Gram-positive and two Gram-negative multidrug-resistant common hospital hosts expressing inducible cephalosporinases (IC). The parameters regarded included the minimal inhibitory and bactericidal concentrations (MIC and MBC, respectively), the diameters of inhibition zones and the MBC/MIC ratios. All tests were performed according to previous protocols, with Gentamicin as reference for extract activity. Though not as rich as that from the stem bark and unlike it, extract from the fruits displayed effectiveness on all strains. The MICs and MBCs ranged from 12 mg/mL through 200 mg/mL, with global bactericidal effect at varying levels. This bactericidal potential on all strains substantiated the broad spectrum activity that precluded sets of resistance mechanisms including IC production. Though yet to be fully addressed, some interactions likely reduced overall effectiveness of the stem bark extract. It appears from the present findings that the fruits could be regarded as sources for antibacterials which could sustainably be used to improve on patient safety through surface hygiene with reduced resistance selection pressure acknowledged to develop with conventional cleaning in hospitals. Water as solvent would help associate cost-effectiveness and availability, but major challenges in this field remain the low output and standards for extraction and dosage.

Keywords: Fruit, chemical screening, Tetrapleura tetraptera, antibacterial potential