Resistance and Susceptibility Pattern of Chickpea (Cicer arietinum L) Endophytic Bacteria to Antibiotics

Abstract

Five chickpea (Cicer arietinum) endophytic bacteria, identified as Erwinia herbicola, Enterobacter agglomeraus. Bacillus megaterium and Bacillus sp. and Bacillus circulans were tested for intrinsic antibiotic resistance in order to see if endophytes showed variation in resistance to antibiotics. The resistance pattern was compared with two rhizospheric bacteria viz. Psendomonas fluoresceus and B. subtilis in order to see if the susceptibility of endophytes differed with that of bacteria isolated from rhizosphere. The endophytes seemed to be less resistant to antibiotics. B. circulaus was susceptible to all antibiotics tested except amoxycillin (10μg). However B. megaterium and Bacillus sp, and E. agglomeraus showed some resistance, P. fluorescens and B. subtilis showed resistance to a wide range of antibiotics indicating that they could be better competitors in the rhizosphere. Preliminary screening was done to monitor B. megaterium and Bacillus sp. by using the observed antibiotic resistance. Out of the 25 root/stem/leaf tissues tested, 10 tested positive for the presence of B. megaterium and 11 for Bacillus sp. However, they coutd not be reisolated from the stem tissue, 3 and 2 of the leaf samples showed presence of B. megaterium and Bacillus sp., respectively.