Use of a chiA probe for detection of chitinase genes in bacteria from the Chesapeake Bay

PCR primers specific for the chiA gene were designed by alignment and selection of highly conserved regions of chiA sequences from Serratia marcesens, Alteromonas sp., Bacillus circulans and Aeromonas carviae. These primers were used to amplify a 225 bp fragment of the chiA gene from Vibrio harveyi to produce a chiA gene probe. The chiA PCR primers and probe were used to detect the presence of the chiA gene in an assemblage of 53 reference strains and gave consistent results. Selected chiA fragments amplified bp PCR were cloned and sequenced from nine known strains and from Chesapeake Bay isolates 6d and lid. This confirmed the specificity and utility of the primers for detection of chiA-positive environmental strains. Over 1000 bacterial isolates from Chesapeake Bag. water samples were tested for the presence of the chiA gene which was found to be present in 5-41% (average 21%) of the culturable bacterial community. The approach developed in this study was valuable for isolation and enumeration of chiA-positive bacteria in environmental samples. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.