Comparative study of IS711 and bcsp31-based polymerase chain reaction (PCR) for the diagnosis of human brucellosis in whole blood and serum samples.
J Microbiol Methods
; 183: 106182, 2021 04.
Article
in En
| MEDLINE
| ID: mdl-33647359
ABSTRACT
BACKGROUND:
Clinical diagnosis of human brucellosis (HB) is often difficult due to non-specific symptoms. Immunological tests have been the most common method used in HB diagnosis, but molecular methods based on quantitative polymerase chain reaction (qPCR) have largely replaced these diagnostic methods. The aim of this study was to validate a HB diagnostic qPCR method; assessing different target Brucella genes, and the influence of biological matrices (serum vs. whole blood) on analytical parameters. MATERIAL ANDMETHODS:
Two target genes, IS711 and bcsp31, for HB molecular diagnosis were evaluated, together with biological matrix type (whole blood and serum) using samples spiked with Brucella abortus. In addition, diagnostic parameters of this qPCR method were evaluated in paired whole blood and serum samples from patients with suspected HB.RESULTS:
Both genes could be potential diagnostic targets, but IS711 showed a lower limit of detection. In spiked matrix experiments, whole blood showed a lower limit of detection than serum after probit regression (224 vs. 3681 CFU/mL) and ANOVA analysis showed a significant (p < 0.001) difference between the Cq of whole blood at all dilutions and that of serum. In 12 paired clinical samples, no serum samples and only one whole blood sample tested positive for Brucella using this qPCR detection method.CONCLUSIONS:
This standardized qPCR-based Brucella detection method could improve diagnosis of HB, serving as a rapid, highly sensitive, and specific test. Whole blood is better suited to qPCR-based HB diagnosis due to the presence of higher target DNA loads in this matrix, compared to serum.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Bacterial Proteins
/
Blood
/
Brucella
/
Brucellosis
/
Polymerase Chain Reaction
/
Serum
Type of study:
Diagnostic_studies
/
Evaluation_studies
Limits:
Humans
Language:
En
Journal:
J Microbiol Methods
Year:
2021
Document type:
Article
Affiliation country:
Brasil