Seronegative bacteremic melioidosis caused by Burkholderia pseudomallei with ambiguous biochemical profile: clinical importance of accurate identification by 16S rRNA gene and groEL gene sequencing.
An aerobic gram-negative bacterium was isolated from the blood and sputum of an 84-year-old, chair-bound nursing home resident with acute bacteremic pneumonia. Although the phenotypic characteristics suggested that the bacterium could be Burkholderia pseudomallei, the Vitek 1 system (GNI+), which can successfully identify 99% of B. pseudomallei strains, showed that the bacterium was "unidentified." Immunoglobulin G against the lipopolysaccharide (LPS) of B. pseudomallei, as detected by an LPS-based enzyme-linked immunosorbent assay with 95% sensitivity, was negative in both the acute-phase and convalescent-phase sera. Sequencing of the groEL gene showed that the isolate was B. pseudomallei. Proper identification of the bacterium in this study is crucial, since there would be a radical difference in the duration of antimicrobial therapy.
Woo
Patrick C Y
PC
Department of Microbiology, The University of Hong Kong, University Pathology Building, Queen Mary Hospital, Hong Kong.
Lau
Susanna K P
SK
Woo
Gibson K S
GK
Fung
Ami M Y
AM
Ngan
Antonio H Y
AH
Hui
Wai-Ting
WT
Yuen
Kwok-Yung
KY
D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D016957:Burkholderia pseudomallei / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D018834:Chaperonin 60 / Q000235:genetics*; D017931:DNA Primers; D004275:DNA, Ribosomal / Q000235:genetics; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008554:Melioidosis / Q000175:diagnosis*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics*
D018834:Chaperonin 60; D017931:DNA Primers; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S