Comparison of Bis NEG-D and API 20E for the Identification of Gram-negative Bacilli in the Laboratory of the University Hospital of Befelatanana Antananarivo Madagascar

Abstract

In medical analysis laboratories, techniques for identifying bacteria are currently becoming more and more numerous. The objective of this study is to compare the 2 bacterial identification systems Bis NEG-D and Api 20E for the identification of gram-negative bacilli. This is a qualitative evaluation of the Bis NEG-D compared to the gold standard Api 20E. During the study period, 32 Gram-negative bacilli isolates were identified simultaneously using Api 20E and Bis NEG-D. The samples are represented by 12 (37.5%) blood samples for blood culture, 12 (37.5%) urine samples for cytobacteriological examination of the urine, 06 (18.8%) pus samples for bacteriological examination of pus, a sample of the cerebrospinal fluid (3.1%) and a vaginal sample (3.1%).The bacteria identified were represented by Enterobacter spp, Escherichia col,i Klebsiella pneumonia, Shigella spp, Salmonella typhi, Acinetobacter baumannii, Pseudomonas spp, Proteus mirabilis, Raoultella ornithinolytica and Bukholderia cepacia. This study showed a concordance of 90.6% (29/32) and a discordance of 9.4% (3/32) between the results of Api 20E and Bis NEG-D. Concerning the probability scores, they vary between 95% to 100% for Api 20E and between 79.3% to 100% for Bis NEG-D. This study also compared the pros and cons of using Api 20 E and Bis NEG-D. The Bis-NEG-D is valid and can be used by medical analysis laboratories like the Api 20E, especially if these laboratories do not need to perform a lot of bacterial identification tests.