ANTIBACTERIAL ACTIVITY OF THE LEAF EXTRACTS OF ALCHORNEA CORDIFOLIA (Euphorbiaceae) AGAINST ISOLATES FROM PATIENTS WITH RESPIRATORY TRACT INFECTION IN AHMADU BELLO UNIVERSITY TEACHING HOSPITAL ZARIA, NIGERIA

ABTRACT

Many bacterial species have been reported to develop resistance to antibiotics commonly prescribed for respiratory tract infections. Therefore, the need to search for natural products for remedy of this problem cannot be overemphasized.

One hundred and eighty (180) specimens were collected from throat (68) and ear swabs (57) as well as sputum (55) from patients with respiratory tract infection in Ahmadu Bello University Teaching Hospital Zaria, Nigeria. Isolation and identification of the bacterial isolates were carried out using standard microbiological methods. MicroGen identification kit was used for confirmatory identification of the isolates. The ethanol and aqueous extracts of Alchornea cordifolia was carried out using cold maceration extraction method. Agar well diffusion, agar dilution and spread plate methods were employed to determine the zone of inhibition, minimum inhibitory concentration, minimum bactericidal concentration and rate of kill respectively.The aqueous extracts was fractionated using column chromatography. Thin layer Chromatography method was used to identify the phytochemical constituents of the active fraction F2.

The bacterial isolates identified were Staphylococcus aureus (7), Pseudomonas aeruginosa (2), Klebsiella pneumoniae (2), Escherichia coli (1) and Streptococcus spps (5). The two extracts showed broad spectrum of activity but the aqueous extract had larger zones of inhibition ranging from 32. 5 mm – 11. 5 mm and lower M.I.C and M.B.C values ranging from 5 mg/ml – 20 mg/ml.