African Journal of Biotechnology Vol. 5 (11), pp. 1072-1077, 2 June 2006   

ISSN 1684–5315 © 2006 Academic Journals        

Full Length Research Paper

Bacteriocinogenicity and production of pyocins from  Pseudomonas species isolated in Lagos, Nigeria

Iwalokun B.A.¹*, Akinsinde, K.A.², Lanlenhin, O.¹ and Onubogu, C.C.³

¹Biochemistry Department, Lagos State University, PMB, 1087, Apapa, Lagos, Nigeria.

²Genetic Division, National Institute of Medical Research (N.I.M.R.), PMB, 2016, Lagos, Nigeria.

³Department of Microbiology, National Institute of Medical Research (N.I.M.R.), PMB 2016, Lagos, Nigeria.

*Corresponding author. E-mail: bamwal@yahoo.com. Tel: 23418504327.

Accepted 18 May, 2006

A total of 52 strains of Pseudomonas identified as P. aeruginosa (27), P. putida (9), P. fluorescens (13) and P. stutzeri (3) were isolated from Nigerian patients with burns, wound and skin infections, UTI, diarrhoea and eye infections.  81.5, 55.6, 76.9 and 33.3% of these species produced pyocins at a range of 410 – 670 g/ml.  High yields of pyocins at 35 – 37^oC, which declined sharply at temperatures above 37^oC were obtained from all the producing strains.  The strains also displayed significant pyocin expression (P < 0.05) under UV irradiation. Pyocins from a total of 25 producing strains; P. aeruginosa (14/27), P. putida (4/9), P. fluorescens (7/13) were inhibitory to the growth of P. putida indicator strain with four strains: PA02, PA20, PP03 and PF01 producing inhibition zone diameter >3 mm.  These pyocins also displayed growth inhibitory activity against some Nigerian isolates of Gram-positive and Gram-negative bacteria when undiluted and at 1:2 - 1:16 dilutions.  The susceptible organisms include Bacillus cereus, Listeria monocytogenes, Klebsiella spp., Staphylococcus aureus, S. epidermidis, Proteus spp. and Vibrio parahaemolyticus. The results of this study have provided evidence for broad-spectrum antibacterial activity of pyocins elicited by Pseudomonas species from Nigeria.

Key words: Pyocins, antibacterial activity, Pseudomonas species, Nigeria.