Med. Microbiol. Immunol. 162, 133--136 (1976) 9 by Springer-Verlag 1976
Butandioldchydrogenase in Vibrio parahaemolyticus G. SchrSter, J. Bockem/ihl, a n d I. B e d n a r e k Institute of Hygiene and Microbiology, Wfirzburg Received February 6, 1976
Abstract. 396 strains of V. parahaemolyticus, 345 originating from Togo and 51 from Japan, were submitted to the study of butandiol dehydrogenase (BDH). It was found that 52.3 ~ of the strains were BDH-positive and 44.2 ~ BDH-negative. An intermediate group characterized by weak reactions amounted to 3.5 ~ of the strains. The distribution of this enzyme parallels to a certain dcgree the results of scrotyping. Positive reactions have been found in all or most strains belonging to serotypes 03K29, 04K8, 04K12, 04K55, 05K15 and 012K19, whereas strains of serotypes 03K5 and 04K10 gave negative reactions. In serotype 05K17 both properties were found in nearly equal proportions. The test of BDH, which can supplement serotyping in characterizing strains of V. parah~temolyticus, can be applied as an aid to epidemiological studies. Introduction The b u t a n d i o l d e h y d r o g e n a s e (BDH) of bacteria was first described in 1953 [1]. This e n z y m e is p a r t of a cycle of b u t a n d i o l f o u n d i n bacteria, which is started b y d e h y d r o g e n a t i o n of b u t a n d i o l to acetoin [7]. More detailed studies concerning the gcncra Aeromonas, Plesiomonas, Streptococcus, the Enterobacteriaceae, a n d single s t r a i n s of the genera Xanthomonas, Acetomonas, Comamonas as well as Vibrio showed t h a t the k n o w n t a x o n o m i c u n i t s were regularly characterized b y u n i f o r m reactions of B D H [8--11]. Similar o b s e r v a t i o n s have been m a d e in Eikenella corrodens a n d t h e genus Haemophilus [12]. F u r t h e r m o r e , a new t a x o n o m i c subdivision w i t h i n the genus Aeromonas could be s u p p o r t e d b y this e n z y m e [8]. P r e l i m i n a r y studies of d ' A l m e i d a a n d Schr5ter ( p u b l i c a t i o n in p r e p a r a t i o n ) showed t h a t the species V. parahaemolyticus does n o t bchave u n i f o r m l y with regard to this enzyme. A n a p p r o p r i a t e s t u d y on a larger n u m b e r of strains was u n d e r t a k e n to e x a m i n e if a r e l a t i o n s h i p exists b e t w e e n the B D t t reaction a n d serotypes of V. parahaemolyticus, the same as it has been described in the genus Shigella [lO].
Materials and Methods
Strains. 396 strains of V. Tarahaemolyticus were included in this study, 345 of which originated from Togo and have been described previously [3--5]. Out of these, 101 were isolated from patients with gastroentcritis or from healthy carriers, and 238 from water and fish specimens. The remaining 51 cultures--among them reference strains of all recognized 0 and K antigens--were kindly supplied by Dr. H. Zen-Yoji, Tokyo. Methods. Two methods were employed for the detection of BDH: 1. The method described by Schubert et al. [8] for Aeromonas spec. was referred to as "standard method". The butandiol medium modified for halophilic bacteria has the following formula: Proteosc Peptone No. 3 (Difco) 5 g, K2tIPO 4 5 g, NaC1 20 g, Aqua dest. 1000 mi, meso-2-3-butandiol
134
G. SchrSter et al.
0.5 ml, pH 6.0. The medium was sterilized by Seitz filtration and dispensed in tubes containing 2 ml each. The tubes were inoculated from a fresh culture on Blood Agar Base (Oxoid) with 1.5~ NaCl added. After 24 and 48 h incubation at 37 ~ C the presence of acetein was tested by adding 0.6 ml of a 5~ ethanolic solution of cr 0.2 ml of a 400/0 solution of KOH, and some grains of creatine. The reactions were read twice, i.e. after 15 and 60 min of incubation at 37 ~ C. A positive reaction was indicated by a distinct pink or red colour. 2. All strains were additionally tested by a micromethod which is a modification of that used by Schubert et al. [11] for streptococci. A dense suspension of the strains grown on Blood Agar Base with 1.5 ~ NaCI was prepared in 0.2 ml of butandiol medium. After 3 h incubation at 37~ C in a water bath 0.1 ml of the reagent was added which had been prepared immediately before use by mixing the above mentioned ingredients. Reading was made as described above. All strains were examined at least twice with both methods.
Results There was no difference of B D H b e t w e e n strains o r i g i n a t i n g from water a n d fishes a n d those from h u m a n sources. The B D H reactions of the s t r a i n s according to serotypcs of V. parahaemolyticus are s u m m a r i z e d i n Table 1. T h e s t a n d a r d m e t h o d resulted i n a more i n t e n s i v e r e a c t i o n t h a n t h e Inicrom e t h o d . There was no difference b e t w e e n reactions a t 24 a n d 48 h, with the exception of six strains which exhibited only weak e n z y m a t i c activities after 48 h incubation. A n o p t i m a l r e a d i n g of t h e r e a c t i o n could be m a d e 15 rain after t h e a d d i t i o n of t h e rcagcnt. E n z y m a t i c a c t i v i t y was detected generally b y b o t h m e t h o d s ; weak reactions were observed i n 4 strains. I n 10 strains B D H was only d e m o n s t r a t e d b y t h e s t a n d a r d m e t h o d . These strains are s u m m a r i z e d i n a separate c o l u m n of T a b l e 1. On first e x a m i n a t i o n 32 strains could n o t be defined as B D H - p o s i t i v e or -negative because of d o u b t f u l reactions in one of the methods. Despite of r e p e a t e d e x a m i n a t i o n s , the reactions of these s t r a i n s could n o t be d e t e r m i n e d as positive ; therefore t h e y were i n c l u d e d i n t o t h e B D H - n e g a t i v e group. T h e general ratio of B D H - p o s i t i v e t o B D t t - n e g a t i v e s t r a i n s of V. parahaemolyticus was 1.18/1.00. However, positive a n d n e g a t i v e reactions were often associated w i t h certain serotypes. Thus, B D H was f o u n d i n all or most of the s t r a i n s b e l o n g i n g to serotypes 03K29, 04K8, 04K12, 04K55, 05K15 a n d 012K19. On the o t h e r h a n d , s t r a i n s belonging to 03K5, 04K10, a n d - - t a k i n g into a c c o u n t the results of d ' A l m e i d a et a l . - - 0 8 K 2 2 gave m a i n l y n e g a t i v e results. B o t h positive a n d n e g a t i v e reactions were f o u n d in s t r a i n s of serotype 05K17. A n association of positive or n e g a t i v e B D H reactions with other serotypes could n o t be derived from this s t u d y because of t h e small n u m b e r of s t r a i n s e x a m i n e d (Table 1).
Discussion W i t h i n the spccies V. parahaemolyticus with its u n i f o r m biochemical reactions [2, 6] B D H has been f o u n d to be a v a r i a b l e character p e r m i t t i n g a s u b d i v i s i o n i n s t r a i n s p r o d u c i n g or n o t p r o d u c i n g this enzyme. The generally stronger B D H reactions in the s t a n d a r d m e t h o d indicate t h a t m o s t s t r a i n s a d a p t i v e l y e n h a n c e the p r o d u c t i o n of t h e e n z y m e w h e n grown i n
B u t a n d i o l d e h y d r o g c n a s e in T a b l e 1. B D H r e a c t i o n s in s e r o t y p e s o f Serotype 0
K
1
1 20 25 26 32 38 41 46 56 TNKll u.t.~
--
2 1~ 5 1a la 2
Serotype xb
1~ 2 3a 1a 8a 2~
0
K
4
42 49 53 55 u.t. e
5
8
2 6
2
3
4
3 28 30 u. t. e 4 5 6 7 20 29 30 31 33 37 43 45 48 54 56 57 u.t. c 4 8 9 10 11 12 13 29 30 34 37
presence detectable induction.
i 6a 1 6
49 3 14
1
1a 8~
1
1a 1a 1 2
2 16
16 a
15 a 3a 2 3 2
1a
of its substrate,
whereas
by the standard
15 17 30 47 u.t. c
12 a 18 a
18 46 u.t. e
5a
ia 7
1
1a 2 13 3 20 3 5 la 1
9
23 44 9 24 52 u.t. c
Total
1 1
10 a 4
1~ 2a 2a 2a
12
1
5a 1a
20 21 22 39 u.t. ~
1
2
xb
8
11
1 1 1a 6a 2a
--
3a 1
10 1 1~ 1a 1a 1 5a 9
+
19 u.t. c
3~ 2 2 Ia
BDH reaction
7
2a
i1 ~ 3
135
V. parahaemolyticus
BDH reaction +
Vibrio paratmemolyticus
5 1s
1 3 5
1 3a 2
15 22 36 40 50 51 u.t. c
1 5
2
1 1
19 52 u.t. c
6 5a 6
1 1
3a 1a 1a
207
175
14
J a p a n e s e re fe re nc e s t r a i n in t h i s g r o u p . b weak enzymatic reactions. e u. t. = u n t y p a b l e .
in the few strains with enzymatic
method,
BDH
seems to be exclusively
activity produced
only by
136
G. SchrSter et al.
I n a c c o r d a n c e w i t h t h e findings of d ' A h n e i d a et al. a r e l a t i o n of B D H r e a c t i o n to c e r t a i n s e r o t y p e s o f V. parahaemolyticus has been observed. S i m i l a r s e r o t y p e a n d s e r o g r o u p - r e l a t e d e n z y m a t i c a c t i v i t i e s have been r e p o r t e d p r e v i o u s l y w i t h i n t h e genera Shigella a n d Streptococcus, r e s p e c t i v e l y [10,11]. I t could be s u s p e c t e d t h a t t h e r a t h e r u n i f o r m e n z y m a t i c r e a c t i o n s d e m o n s t r a t e d w i t h i n some s e r o t y p e s m i g h t be due to g e o g r a p h i c or epidemiological pecularities. H o w e v e r , t h e reference s t r a i n s f r o m J a p a n g e n e r a l l y gave t h e s a m e results as t h e s t r a i n s f r o m Togo. F u r t h e r m o r e , m o s t cases o f g a s t r o e n t e r i t i s due to V. parahaemolyticus in Togo o c c u r r e d s p o r a d i c a l l y , a n d t h e s t r a i n s f r o m clinical a n d e n v i r o n m e n t a l origin h a v e been collected over a 2 y e a r s ' p e r i o d [4]. The B D H r e a c t i o n m i g h t be a useful b i o c h e m i c a l m a r k e r in epidemiological i n v e s t i g a t i o n s . F u r t h e r s t u d y o f t h e r e l a t i o n o f B D I t t o c e r t a i n s e r o t y p e s is suggested.
References 1. Aubert, J. 1)., Gavard, 1~.: Le m6tabolisme du 2--3 butandiol at de l'ac6toine par les microbes: Cas de Neisseria Winogradskyi. I. Etude de la 2--3 butandiol d6shydrog6nase. Ann. Inst. Pasteur 84, 735--744 (1953) 2. Baumann, P., Baumann, L., Reiehelt, J. L.: Taxonomy of marine bacteria: Beneckea parahaemolytica and Beneckea alginolytica. J. Bact. 113, 1144--1155 (1973) 3. Bockemfihl, J., Triemer, A. : Ecology and epidemiology of Vibrio parahaemolyticus on the coast of Togo. Bull. Wld Hlth Org. 51, 353--360 (1974) 4. Boekemfihl, J., Am6dom6, A., Triemer, A. : Vibrio parahaemolyticus gastroenteritis during the El Tot cholera epidemic in Togo (West Africa). J. trop. hie& Hyg. 24, 101--104 (1975) 5. Bockemfihl, J., Triemer, A.: Serotypes of Vibrio parahaemolyticus from clinical and environmental sources in Togo (West Africa). Jap. J. reed. Sci. Biol. 28, 215--221 (1975) 6. Fujino, T., Sakazaki, R., Tamura, K.: Designation of the type strain of Vibrio parahaemolyticus and description of 200 strains of the species. Int. J. Syst. Bact. 24, 447--449
(1974) 7. Juni, E., Iteym, O. A. : A cyclic pathway for the bacterial dissimulation of 2,3-butandiol, acetylmethylearbinol, and diacetyl. J. Bact. 71, 425--432 (1956) 8. Schubert, t~. H. W.: Zur Taxonomic der Voges-Proskauer-negativen ,,hydrophila"-~hnlichen Aeromonaden. Zbl. Bakt., I. Abt. Orig. 198, 482--490 (1964) 9. Schubert, R. H. W., Kexel, G.: Der Ausfall der Butandioldehydrogenase-Reaktion bei einigen 1)seudomonadaceen und Vibrionen. Zbl. Bakt., I. Abt. Orig. 194, 130--132 (1964) 10. Schubert, ~ . H. W.: t~ber alas Vorkommen eines Butandiol dehydrierenden Ferment~s bei Bakterien tier Familie Enterobacteriaceae und dessen Bedeutung ffir die Taxonomic der Gattung Shigella. Zbl. Bakt., I. Abt. Orig. 196, 61"67 (1964/65) 11. Schubert, l ~ . H . W . , Kexel, G.: Untersuchungen fiber die ButandioldehydrogenaseReaktion bei Streptokokken. Zbl. Bakt., I. Abt. Orig. 206, 187--192 (1968) 12. Schrbter, G. : Bakteriologisch-serologische Untersuchungen an Eikenella corroder~s (Eiken) Jackson and Goodman. Habilitationssehrift, Wiirzburg 1974 Dr. G. Schrbter Institute of Hygiene and Microbiology Josef Schneider-StraBe 2 D-8700 Wfirzburg Federal Republic of Germany
Butandioldchydrogenase in Vibrio parahaemolyticus G. SchrSter, J. Bockem/ihl, a n d I. B e d n a r e k Institute of Hygiene and Microbiology, Wfirzburg Received February 6, 1976
Abstract. 396 strains of V. parahaemolyticus, 345 originating from Togo and 51 from Japan, were submitted to the study of butandiol dehydrogenase (BDH). It was found that 52.3 ~ of the strains were BDH-positive and 44.2 ~ BDH-negative. An intermediate group characterized by weak reactions amounted to 3.5 ~ of the strains. The distribution of this enzyme parallels to a certain dcgree the results of scrotyping. Positive reactions have been found in all or most strains belonging to serotypes 03K29, 04K8, 04K12, 04K55, 05K15 and 012K19, whereas strains of serotypes 03K5 and 04K10 gave negative reactions. In serotype 05K17 both properties were found in nearly equal proportions. The test of BDH, which can supplement serotyping in characterizing strains of V. parah~temolyticus, can be applied as an aid to epidemiological studies. Introduction The b u t a n d i o l d e h y d r o g e n a s e (BDH) of bacteria was first described in 1953 [1]. This e n z y m e is p a r t of a cycle of b u t a n d i o l f o u n d i n bacteria, which is started b y d e h y d r o g e n a t i o n of b u t a n d i o l to acetoin [7]. More detailed studies concerning the gcncra Aeromonas, Plesiomonas, Streptococcus, the Enterobacteriaceae, a n d single s t r a i n s of the genera Xanthomonas, Acetomonas, Comamonas as well as Vibrio showed t h a t the k n o w n t a x o n o m i c u n i t s were regularly characterized b y u n i f o r m reactions of B D H [8--11]. Similar o b s e r v a t i o n s have been m a d e in Eikenella corrodens a n d t h e genus Haemophilus [12]. F u r t h e r m o r e , a new t a x o n o m i c subdivision w i t h i n the genus Aeromonas could be s u p p o r t e d b y this e n z y m e [8]. P r e l i m i n a r y studies of d ' A l m e i d a a n d Schr5ter ( p u b l i c a t i o n in p r e p a r a t i o n ) showed t h a t the species V. parahaemolyticus does n o t bchave u n i f o r m l y with regard to this enzyme. A n a p p r o p r i a t e s t u d y on a larger n u m b e r of strains was u n d e r t a k e n to e x a m i n e if a r e l a t i o n s h i p exists b e t w e e n the B D t t reaction a n d serotypes of V. parahaemolyticus, the same as it has been described in the genus Shigella [lO].
Materials and Methods
Strains. 396 strains of V. Tarahaemolyticus were included in this study, 345 of which originated from Togo and have been described previously [3--5]. Out of these, 101 were isolated from patients with gastroentcritis or from healthy carriers, and 238 from water and fish specimens. The remaining 51 cultures--among them reference strains of all recognized 0 and K antigens--were kindly supplied by Dr. H. Zen-Yoji, Tokyo. Methods. Two methods were employed for the detection of BDH: 1. The method described by Schubert et al. [8] for Aeromonas spec. was referred to as "standard method". The butandiol medium modified for halophilic bacteria has the following formula: Proteosc Peptone No. 3 (Difco) 5 g, K2tIPO 4 5 g, NaC1 20 g, Aqua dest. 1000 mi, meso-2-3-butandiol
134
G. SchrSter et al.
0.5 ml, pH 6.0. The medium was sterilized by Seitz filtration and dispensed in tubes containing 2 ml each. The tubes were inoculated from a fresh culture on Blood Agar Base (Oxoid) with 1.5~ NaCl added. After 24 and 48 h incubation at 37 ~ C the presence of acetein was tested by adding 0.6 ml of a 5~ ethanolic solution of cr 0.2 ml of a 400/0 solution of KOH, and some grains of creatine. The reactions were read twice, i.e. after 15 and 60 min of incubation at 37 ~ C. A positive reaction was indicated by a distinct pink or red colour. 2. All strains were additionally tested by a micromethod which is a modification of that used by Schubert et al. [11] for streptococci. A dense suspension of the strains grown on Blood Agar Base with 1.5 ~ NaCI was prepared in 0.2 ml of butandiol medium. After 3 h incubation at 37~ C in a water bath 0.1 ml of the reagent was added which had been prepared immediately before use by mixing the above mentioned ingredients. Reading was made as described above. All strains were examined at least twice with both methods.
Results There was no difference of B D H b e t w e e n strains o r i g i n a t i n g from water a n d fishes a n d those from h u m a n sources. The B D H reactions of the s t r a i n s according to serotypcs of V. parahaemolyticus are s u m m a r i z e d i n Table 1. T h e s t a n d a r d m e t h o d resulted i n a more i n t e n s i v e r e a c t i o n t h a n t h e Inicrom e t h o d . There was no difference b e t w e e n reactions a t 24 a n d 48 h, with the exception of six strains which exhibited only weak e n z y m a t i c activities after 48 h incubation. A n o p t i m a l r e a d i n g of t h e r e a c t i o n could be m a d e 15 rain after t h e a d d i t i o n of t h e rcagcnt. E n z y m a t i c a c t i v i t y was detected generally b y b o t h m e t h o d s ; weak reactions were observed i n 4 strains. I n 10 strains B D H was only d e m o n s t r a t e d b y t h e s t a n d a r d m e t h o d . These strains are s u m m a r i z e d i n a separate c o l u m n of T a b l e 1. On first e x a m i n a t i o n 32 strains could n o t be defined as B D H - p o s i t i v e or -negative because of d o u b t f u l reactions in one of the methods. Despite of r e p e a t e d e x a m i n a t i o n s , the reactions of these s t r a i n s could n o t be d e t e r m i n e d as positive ; therefore t h e y were i n c l u d e d i n t o t h e B D H - n e g a t i v e group. T h e general ratio of B D H - p o s i t i v e t o B D t t - n e g a t i v e s t r a i n s of V. parahaemolyticus was 1.18/1.00. However, positive a n d n e g a t i v e reactions were often associated w i t h certain serotypes. Thus, B D H was f o u n d i n all or most of the s t r a i n s b e l o n g i n g to serotypes 03K29, 04K8, 04K12, 04K55, 05K15 a n d 012K19. On the o t h e r h a n d , s t r a i n s belonging to 03K5, 04K10, a n d - - t a k i n g into a c c o u n t the results of d ' A l m e i d a et a l . - - 0 8 K 2 2 gave m a i n l y n e g a t i v e results. B o t h positive a n d n e g a t i v e reactions were f o u n d in s t r a i n s of serotype 05K17. A n association of positive or n e g a t i v e B D H reactions with other serotypes could n o t be derived from this s t u d y because of t h e small n u m b e r of s t r a i n s e x a m i n e d (Table 1).
Discussion W i t h i n the spccies V. parahaemolyticus with its u n i f o r m biochemical reactions [2, 6] B D H has been f o u n d to be a v a r i a b l e character p e r m i t t i n g a s u b d i v i s i o n i n s t r a i n s p r o d u c i n g or n o t p r o d u c i n g this enzyme. The generally stronger B D H reactions in the s t a n d a r d m e t h o d indicate t h a t m o s t s t r a i n s a d a p t i v e l y e n h a n c e the p r o d u c t i o n of t h e e n z y m e w h e n grown i n
B u t a n d i o l d e h y d r o g c n a s e in T a b l e 1. B D H r e a c t i o n s in s e r o t y p e s o f Serotype 0
K
1
1 20 25 26 32 38 41 46 56 TNKll u.t.~
--
2 1~ 5 1a la 2
Serotype xb
1~ 2 3a 1a 8a 2~
0
K
4
42 49 53 55 u.t. e
5
8
2 6
2
3
4
3 28 30 u. t. e 4 5 6 7 20 29 30 31 33 37 43 45 48 54 56 57 u.t. c 4 8 9 10 11 12 13 29 30 34 37
presence detectable induction.
i 6a 1 6
49 3 14
1
1a 8~
1
1a 1a 1 2
2 16
16 a
15 a 3a 2 3 2
1a
of its substrate,
whereas
by the standard
15 17 30 47 u.t. c
12 a 18 a
18 46 u.t. e
5a
ia 7
1
1a 2 13 3 20 3 5 la 1
9
23 44 9 24 52 u.t. c
Total
1 1
10 a 4
1~ 2a 2a 2a
12
1
5a 1a
20 21 22 39 u.t. ~
1
2
xb
8
11
1 1 1a 6a 2a
--
3a 1
10 1 1~ 1a 1a 1 5a 9
+
19 u.t. c
3~ 2 2 Ia
BDH reaction
7
2a
i1 ~ 3
135
V. parahaemolyticus
BDH reaction +
Vibrio paratmemolyticus
5 1s
1 3 5
1 3a 2
15 22 36 40 50 51 u.t. c
1 5
2
1 1
19 52 u.t. c
6 5a 6
1 1
3a 1a 1a
207
175
14
J a p a n e s e re fe re nc e s t r a i n in t h i s g r o u p . b weak enzymatic reactions. e u. t. = u n t y p a b l e .
in the few strains with enzymatic
method,
BDH
seems to be exclusively
activity produced
only by
136
G. SchrSter et al.
I n a c c o r d a n c e w i t h t h e findings of d ' A h n e i d a et al. a r e l a t i o n of B D H r e a c t i o n to c e r t a i n s e r o t y p e s o f V. parahaemolyticus has been observed. S i m i l a r s e r o t y p e a n d s e r o g r o u p - r e l a t e d e n z y m a t i c a c t i v i t i e s have been r e p o r t e d p r e v i o u s l y w i t h i n t h e genera Shigella a n d Streptococcus, r e s p e c t i v e l y [10,11]. I t could be s u s p e c t e d t h a t t h e r a t h e r u n i f o r m e n z y m a t i c r e a c t i o n s d e m o n s t r a t e d w i t h i n some s e r o t y p e s m i g h t be due to g e o g r a p h i c or epidemiological pecularities. H o w e v e r , t h e reference s t r a i n s f r o m J a p a n g e n e r a l l y gave t h e s a m e results as t h e s t r a i n s f r o m Togo. F u r t h e r m o r e , m o s t cases o f g a s t r o e n t e r i t i s due to V. parahaemolyticus in Togo o c c u r r e d s p o r a d i c a l l y , a n d t h e s t r a i n s f r o m clinical a n d e n v i r o n m e n t a l origin h a v e been collected over a 2 y e a r s ' p e r i o d [4]. The B D H r e a c t i o n m i g h t be a useful b i o c h e m i c a l m a r k e r in epidemiological i n v e s t i g a t i o n s . F u r t h e r s t u d y o f t h e r e l a t i o n o f B D I t t o c e r t a i n s e r o t y p e s is suggested.
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(1974) 7. Juni, E., Iteym, O. A. : A cyclic pathway for the bacterial dissimulation of 2,3-butandiol, acetylmethylearbinol, and diacetyl. J. Bact. 71, 425--432 (1956) 8. Schubert, t~. H. W.: Zur Taxonomic der Voges-Proskauer-negativen ,,hydrophila"-~hnlichen Aeromonaden. Zbl. Bakt., I. Abt. Orig. 198, 482--490 (1964) 9. Schubert, R. H. W., Kexel, G.: Der Ausfall der Butandioldehydrogenase-Reaktion bei einigen 1)seudomonadaceen und Vibrionen. Zbl. Bakt., I. Abt. Orig. 194, 130--132 (1964) 10. Schubert, ~ . H. W.: t~ber alas Vorkommen eines Butandiol dehydrierenden Ferment~s bei Bakterien tier Familie Enterobacteriaceae und dessen Bedeutung ffir die Taxonomic der Gattung Shigella. Zbl. Bakt., I. Abt. Orig. 196, 61"67 (1964/65) 11. Schubert, l ~ . H . W . , Kexel, G.: Untersuchungen fiber die ButandioldehydrogenaseReaktion bei Streptokokken. Zbl. Bakt., I. Abt. Orig. 206, 187--192 (1968) 12. Schrbter, G. : Bakteriologisch-serologische Untersuchungen an Eikenella corroder~s (Eiken) Jackson and Goodman. Habilitationssehrift, Wiirzburg 1974 Dr. G. Schrbter Institute of Hygiene and Microbiology Josef Schneider-StraBe 2 D-8700 Wfirzburg Federal Republic of Germany
