This study investigated the phytochemical constituents and antibacterial activities of
Lantana trifolia flower extracts against bacterial isolates from surgical and diabetic wounds of patients. Phytochemical investigation was done by standard procedure, antimicrobial screening by agar well diffusion method and antibiotics susceptibility of isolates by Kirby-Bauer disc diffusion test. Phytochemicals present include flavonoids, tannins, phenylethanoid glycosides, reducing sugars, terpenoids, saponins, anthraquinones alkaloids and steroids. Bacterial wound isolates were mainly gram +ve and include
Staphylococcus aureus
,
S. epidermidis
,
Enterococcus faecalis
,
Corynebacterium
sp.,
Enterobacter aerogenes
,
Pseudomonas aeruginosa
,
Mycobacterium
sp. and
Escherichia coli
. Inhibition diameter was concentration. The range of inhibition diameter was significantly (P<0.05) lower in the aqueous extract (15.2±1.5 to 35.5 ±0.9 mm) than the ethanolic (28.3± 3.4 to 49.1±8.9mm). Antibacterial activity occurred at very low concentrations (18.75mg/ml) for ethanolic extract only. The most
L trifolia extract sensitive bacterial isolate was
S. aureus (35.5±0.9mm and 49.1±8.9mm for aqueous and ethanolic extracts respectively at 300mg/ml), while the least sensitive were
Corynebacterium sp. (15.2±1.5mm) and
Mycobacterium sp. (28.3±3.4) at 300mg/ml for aqueous and ethanolic extracts respectively. The minimum inhibitory concentration was lower for ethanolic extract, 18.75/ml to 37.5mg/ml than the aqueous extract (37.5 to 150mg/ml). The minimum bacterial concentration range from 37.5mg/ml to 150mg/ml for ethanolic extract and 75 to 300mg/ml for aqueous extract.
S. aureus was the most antibiotic resistant strain (72%), while
P. aeruginosa and
Mycobacterium sp. were the least resistant (9.1%) strains.
L. trifolia was more bacteriostatic than the most effective antibiotics, Ciprofloxacin, Rocephin, Nitrofurantoin, and deserves further investigation.
