Applications of Flow Cytometry to Clinical Microbiology

Clinical Microbiology Reviews ◽

10.1128/cmr.13.2.167 ◽

2000 ◽

Vol 13 (2) ◽

pp. 167-195 ◽

Cited By ~ 67

Author(s):

Alberto Álvarez-Barrientos ◽

Javier Arroyo ◽

Rafael Cantón ◽

César Nombela ◽

Miguel Sánchez-Pérez

Keyword(s):

Flow Cytometry ◽

Clinical Microbiology ◽

Ex Vivo ◽

Analytical Techniques ◽

Clinical Samples ◽

Clinical Microbiology Laboratory ◽

Commercial Kits ◽

Antimicrobial Treatments ◽

Near Future

SUMMARY Classical microbiology techniques are relatively slow in comparison to other analytical techniques, in many cases due to the need to culture the microorganisms. Furthermore, classical approaches are difficult with unculturable microorganisms. More recently, the emergence of molecular biology techniques, particularly those on antibodies and nucleic acid probes combined with amplification techniques, has provided speediness and specificity to microbiological diagnosis. Flow cytometry (FCM) allows single- or multiple-microbe detection in clinical samples in an easy, reliable, and fast way. Microbes can be identified on the basis of their peculiar cytometric parameters or by means of certain fluorochromes that can be used either independently or bound to specific antibodies or oligonucleotides. FCM has permitted the development of quantitative procedures to assess antimicrobial susceptibility and drug cytotoxicity in a rapid, accurate, and highly reproducible way. Furthermore, this technique allows the monitoring of in vitro antimicrobial activity and of antimicrobial treatments ex vivo. The most outstanding contribution of FCM is the possibility of detecting the presence of heterogeneous populations with different responses to antimicrobial treatments. Despite these advantages, the application of FCM in clinical microbiology is not yet widespread, probably due to the lack of access to flow cytometers or the lack of knowledge about the potential of this technique. One of the goals of this review is to attempt to mitigate this latter circumstance. We are convinced that in the near future, the availability of commercial kits should increase the use of this technique in the clinical microbiology laboratory.

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An alternative for urine cultures: Direct identification of uropathogens from urine by MALDI-TOF MS

Acta Microbiologica et Immunologica Hungarica ◽

10.1556/030.2020.01184 ◽

2020 ◽

Author(s):

Arzu Akşit İlki ◽

Sevim Özsoy ◽

Gulşen Gelmez ◽

Burak Aksu ◽

Güner Söyletir

Keyword(s):

Flow Cytometry ◽

Antibiotic Susceptibility ◽

Clinical Microbiology ◽

Urine Samples ◽

Clinical Microbiology Laboratory ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Susceptibility Tests ◽

Tract Infections ◽

Tof Ms

AbstractUrinary tract infections are one of the most common bacterial infections and rapid diagnosis of the infection is essential for appropriate antibiotic therapy. The goal of our study was to identify urinary pathogens directly by MALDI-TOF MS and to perform antibiotic susceptibility tests in order to shorten the period spent for culturing.Urine samples submitted for culture to the Clinical Microbiology Laboratory were enrolled in this study. Urine samples were screened for leukocyte and bacteria amount by flow cytometry. Samples with bacterial load of 106–107/mL were tested directly by MALDI-TOF MS and antibiotic susceptibility tests (AST) were performed.In total, 538 positive urine samples were evaluated in our study. MALDI-TOF MS identified the microorganism directly from the urine sample in 91.8% of these samples and the concordance rate of conventional identification and direct detection was 95.8% for Gram-negatives at the genus and species level. Escherichia coli (n:401) was the most frequently isolated microorganism, followed by Klebsiella pneumoniae (n:57). AST results were generated for 111 of these urine samples and the concordance was 90% and 87% for E. coli and K. pneumoniae, respectively.Our results showed that screening of urine samples with flow cytometry to detect positive samples and identification of uropathogens directly by MALDI-TOF MS with an accuracy of over 90% can be a suitable method particularly for Gram-negative bacteria in clinical microbiology laboratories.

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