Urease production correlates with possession of the trh gene in Vibrio parahaemolyticus strains isolated in Thailand.
A total of 489 Vibrio parahaemolyticus isolates from patients in Thailand with diarrhea was examined for the presence of thermostable direct hemolysin (TDH) and TDH-related hemolysin genes (tdh and trh, respectively), their serovars, TDH production, and urease activity. Of the strains, 81% were positive only for the tdh gene, 6% for both trh and tdh genes, and 2% for the trh gene only. Thirty-seven (8%) of the 489 isolates were positive for urease production. Of special interest, all urease-positive strains possessed the trh gene, and conversely, urease-negative strains lacked the gene, indicating that urease production by V. parahaemolyticus strains strongly correlates with the possession of the trh gene. Thus, the urease-positive phenotype of V. parahaemolyticus can be considered an indication of virulent (trh-possessing) V. parahaemolyticus strains in clinical diagnosis.
Suthienkul
O
O
Department of Microbiology (Faculty of Public Health), Mahidol University, Bangkok, Thailand.
Ishibashi
M
M
Iida
T
T
Nettip
N
N
Supavej
S
S
Eampokalap
B
B
Makino
M
M
Honda
T
T
D001426:Bacterial Proteins; D001483:Base Sequence; D017931:DNA Primers; D003967:Diarrhea / Q000382:microbiology; D005798:Genes, Bacterial; D006460:Hemolysin Proteins / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012703:Serotyping; D013785:Thailand; D014510:Urease / Q000096:biosynthesis*; D014735:Vibrio Infections / Q000382:microbiology*; D014736:Vibrio parahaemolyticus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification
D001426:Bacterial Proteins; D017931:DNA Primers; D006460:Hemolysin Proteins; C088609:thermostable direct hemolysin-related hemolysin protein, Vibrio parahaemolyticus; D014510:Urease