Characterization of Acinetobacter type strains and isolates obtained from wastewater treatment plants by PCR fingerprinting.

Acinetobacter type strains and isolates from wastewater treatment plants were differentiated by PCR fingerprinting. On the first level, PCR fingerprinting with two tRNA-gene specific primers (T5B and T3A) was used for the identification of species (genospecies 1 to 17). On the second level, a single arbitrary primer (DAF 4) was employed for strain differentiation. Upon comparison of Acinetobacter type strains with 28 sewage sludge isolates, 2 could be classified as belonging to A. johnsonii, 8 isolates could be classified as A. lwoffii, 8 could be classified as A. baumannii, and 9 isolates were very closely related to the Acinetobacter species A. junii; only 1 isolate could not be classified as one of the Acinetobacter type strains. The PCR fingerprinting method was found to be a reproducible and fast method for differentiation and identification of Acinetobacter isolates. Because of some resulting discrepancies compared with previously described identification schemes, e.g., DNA-DNA hybridization methods, the original identification experiments should be repeated and the results should be reassessed.