Download User's Guide

DIATABS ™
05-2007 Ch. 3
Page 120 of 130
3.42 VOGES-PROSKAUER (VP)
REF No. 57711
The Voges-Proskauer test is used in the differentiation among Enterobacteriaceae and in the streptococci group.
Procedure
Prepare a dense bacterial suspension (at least McFarland No. 4) of the strain to be tested in 0.25 ml saline in a tube. Add
one Voges-Proskauer Diagnostic Tablet and close the tube. Incubate at 35-37 °C for not more than 4 hours.
Before reading, add 2 drops of alpha-naphthol solution (5% in ethanol) and afterwards 1 drop of 40% KOH and
shake.
Reading of the test
Positive reaction:
Negative reaction:
Red/pink
Colourless (no change in colour) . Very light pink.
Wait 5 min before a test is considered negative.
Results
1)
Enterobacteriaceae
VP
positive
Enterobacter spp., Klebsiella pneumoniae/oxytoca,
Serratia spp., Hafnia
Citrobacter spp., E. coli, Klebsiella ozaenae/rhinoscleromatis, Morganella morganii, Proteus spp.
(except Pr. mirabilis: V), Providencia spp.,
Salmonella spp., Shigella spp.
2)
negative
Yersinia
Yersinia enterocolitica
Yersinia kristensenii
VP(25°C)
+
0
SUC
+0
0
PZA
0
+
VP(25°C) = Voges Proskauer D.T. (at 25 °C), SUC = Sucrose D.T. and PZA = Pyrazinamidase D.T.
3a) Streptococci beta-haemolytic (human) (8) (Mupi S)
S. pyogenes (Group A)
S. anginosus
(Groups A, C, G, F)
Group B (S. agalactiae)
S .dysgalactiae
subsp. equisimilis (ACG) *
S. iniae (no group)
S. porcinus (E, P, U, V)
S. pseudoporcinus
VP(4h) PYR PGUA
0
+
V
+
0
0
HIP CAMP Colony Size Remarks
SORB 0, MAN 0
0
0
Large
0
0
Small
+
0
0
0
+0
+
+
0w
+
0
⋅
Large
0
+
V
+
+0
0+
+
+
⋅
0
0+
0
+
+
⋅
Small
S. canis (G)
0
V
0
0
+
Large
S. equi
subsp. zooepidemicus (C)
Arcanobact. haemolyticum
0
0
+
0
0
Large
0
0
V
0
⋅
* may be alpha haemolytic sometimes.
© Copyright Rosco Diagnostica A/S
SORB 0, MAN 0
αGAL 0, TRE +,
SORB 0
SORB 0, MAN +
SORB +, MAN +
SORB +, MAN +,
ADH +, ESC +, LAP +
SORB 0, αGAL +,
MAN 0
SORB +, TRE 0
Mupi R