Commercial kit systems that are available for use are not only expensive but also often have low accuracy for identification of certain strains. Many species are slow growing and biochemically weak or inert and requires considerable experience to interpret equivocal results. Many of the conventional culture media are not suitable for identification and quality control of media may be difficult. Most species are infrequently encountered and therefore, the laboratory personnel may not be familiar with many of the non-fermenters. This is compounded by the factors that contribute to the difficulties in identifying them in the routine clinical microbiology laboratory. Taxonomic confusion prevails as there is a continuous revision and many of the identified strains have no designated species assigned. Published studies from various centres quote varied isolation rates of non-fermenters ranging from 2.18% to 45.9%. Non-fermenters account for 15% of all bacterial isolates from a clinical microbiology laboratory. Emerging challenges of multi-drug resistance, both intrinsic and acquired among them is of serious concern to the treating physician. However, they have now emerged as important healthcare associated pathogens as they have made their niche in the hospital environment. Being ubiquitous in nature, they were disregarded as probable contaminants, when isolated in the laboratory. Non-fermenters are a heterogenous group of Gram-negative bacilli that are aerobic, non-sporing, either do not use carbohydrates as a source of energy or degrade them through metabolic pathways other than fermentation. Non-fermenting Gram-negative bacilli (NFGNB) other than Pseudomonas.
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