Applications of Flow Cytometry to Clinical Microbiology

Microbiology in general and clinical microbiology in particular have witnessed important changes during the last few years. Traditional methods of bacteriology and mycology require the isolation of the organism prior to identification and other possible testing. In most cases, culture results are available in 48 to 72 h. Virus isolation in cell cultures and detection of specific antibodies have been widely used for the diagnosis of viral infections (Weinstein, 2007). These methods are sensitive and specific, but, the time required for virus isolation is quite long and is governed by viral replication times. Additionally, serological assays on serum from infected patients have often most limits in specificity and sensitivity. Life-threatening infections require prompt antimicrobial therapy and therefore need rapid and accurate diagnostic tests. Procedures which do not require culture and which detect the presence of antigens or the host's specific immune response have shortened the diagnostic time. More recently, the emergence of molecular biology techniques, particularly those based on nucleic acid probes combined with amplification techniques, has provided speediness and specificity to microbiological diagnosis. These techniques have led to a revolutionary change in many of the traditional routine tests used in clinical microbiology laboratories.