Comparing the Efficacy of Kings B, Cetrimide and Chloramphenicol-nutrient Agar Medium in the Isolation of Pseudomonas Species

Abstract

Background and Objective: It is sometimes necessary to acquire Pseudomonas species from the environment for research and application. In the acquisition of Pseudomonas species from samples certain media have been used. Certain components of these media instigate greenish pigment production in selected species of Pseudomonas. The efficacy of some of these media in indicating if a sample contains Pseudomonas species is unknown. The aim of this study was thus to compare the efficacy of some media used in the selective isolation of Pseudomonas species. The objectives include determining the percentage of greenish pigment producing bacterial population that can be obtained using the different media. Materials and Methods: Differential enumeration of greenish pigment producing Pseudomonas species in selected samples were carried out using Cetrimide agar (CA), Kings B agar (KBA) and Nutrient agar supplemented with 50 µg mLG1 Chloramphenicol (NC). One-way analysis of variance at p<0.05 was used to determine if there was any significant difference between the proportions of total bacterial population producing greenish pigment obtained through the use of the different media. Selected greenish pigment producing bacterial colonies were identified using selected physicochemical/biochemical tests. Results: The proportion of bacterial population producing greenish pigments (PBG) obtained using KBA ranged from 1.37-3.92%, the PBG obtained using CA ranged from 31.71-100%, while the PBG obtained using NC ranged from 0.86-14.29 %. Statistical analysis of the PBG obtained using the three media showed that the difference between the percentages obtained using the different media is significant (p<0.05). The different greenish pigment producing bacteria isolates were all identified as Pseudomonas species. Conclusion: From the obtained results, it is concluded that Cetrimide agar is a better medium for the selective enumeration and isolation of greenish pigment producing Pseudomonas species.