Identification of genus Acinetobacter: Standardization of in-house PCR and its comparison with conventional phenotypic methods

BACKGROUND: Acinetobacter is grouped under nonfermenting Gram-negative bacilli. It is increasingly isolated from pathological samples. The ability of this genus to acquire drug resistance and spread in the hospital settings is posing a grave problem in healthcare. Specific treatment protocols are advocated for Acinetobacter infections. Hence, rapid identification and drug susceptibility profiling are critical in the management of these infections. AIMS: To standardize an in-house polymerase chain reaction (PCR) for identification of genus Acinetobacter and to compare PCR with two protocols for its phenotypic identification. METHODOLOGY: A total of 96 clinical isolates of Acinetobacter were included in the study. An in-house PCR for genus level identification of Acinetobacter was standardized. All the isolates were phenotypically identified by two protocols. The results of PCR and phenotypic identification protocols were compared. RESULTS: The in-house PCR standardized was highly sensitive and specific for the genus Acinetobacter. There was 100% agreement between the phenotypic and molecular identification of the genus. The preliminary identification tests routinely used in clinical laboratories were also in complete agreement with phenotypic and molecular identification. CONCLUSION: The in-house PCR for genus level identification is specific and sensitive. However, it may not be essential for routine identification as the preliminary phenotypic identification tests used in the clinical laboratory reliably identify the genus Acinetobacter.