INTERNATIONALJOURNAL OF SYSTEMATICBACTERIOLOGY, Oct. 1987, p. 327-332 Vol. 37, No. 4 0020-7713187lO40327-06$02. 0010 Copyright 0 1987, International Union of Microbiological Societies

Yersinia rohdei sp. nov. Isolated from and Feces and Surface Water STOJANKA ALEKSIC,l ARNOLD G. STEIGERWALT,2JOCHEN BOCKEMUHL,’ GERALDINE P. HUNTLEY-CARTER,3 AND DON J. BRENNER2* Meningitis and Special Pathogens Branch’ and Enteric Bacteriology Section ,3 Division of Bacterial Diseases, Center for Infectious Diseases, Centers for Disease Control, Atlanta, Georgia 30333, and National Reference Centre for , Medizinaluntersuchungsanstalt, Institute of Hygiene, 2000 Hamburg 28, Federal Republic of Germany’

Yersinia ruhdei sp. nov. was isolated from feces of and and from surface water. The organisms gave the key biochemical reactions typical of Yersinia species, including greater metabolic activity at 25 to 28°C than at 36°C. Y. ruhdei can be distinguished from other yersiniae by its positive reactions in tests for citrate and sucrose and negative reactions in tests for indole, acetoin (Voges-Proskauer), and rhamnose. Two biogroups were found among seven strains investigated, one of which fermented raffinose and melibiose. Deoxyribonucleic acid hybridization tests (hydroxyapatite method) showed average levels of relatedness of 93% at a 60°C incubation temperature and 97% at 75°C. Labeled Y. ruhdei deoxyribonucleic acid showed 30% to 63% relatedness to all Yersinia species except Yersinia ruckeri. The guanine-plus-cytosine contents of five tested strains were 48.7 to 49.4 rho]%. All strains possessed 0 antigens not typable with antisera of the extended typing scheme of Wauters, but most of them had H antigens typical of Yersinia enteruculitica biotype 1. Five tested strains belonged to lysotype X,. Y. ruhdei strains were susceptible to most antimicrobial agents; resistance or intermediate susceptibility was observed for ampicillin, carbenicillin, cephalothin, penicillin, and sulfonamide. Calcium dependency, autoagglutination, and Congo red pigmentation tests, which are indicative of the presence of a virulence plasmid to Y. enteruculitica, were negative in Y. ruhdei. The clinical significance for humans and animals is uncertain and requires further study. The type strain of Y. ruhdei sp. nov. is strain H 271-36/78 (= CDC 3022-85 = ATCC 43380).

The bacterium now known as was raffinose and melibiose. Further studies showed that these first isolated by Schleifstein and Coleman, who called it strains represented a single new Yersinia species. In this “Bacterium enterocoliticum” (26). Subsequent isolates were report we describe this new species, for which the name called “Pasteurella pseudotuberculosis rodentium” (17) and Yersinia rohdei sp. nov. is proposed. “Pasteurella X” (10). Frederiksen systematically studied a large number of strains, concluding that the organism was a MATERIALS AND METHODS member of the in the genus Yersinia (15). After the study of Frederiksen in 1964 and until 1979, Bacterial strains. The Y. rohdei strains are listed in Table Yersinia enterocolitica was a repository for a large number 1. The strains of other Yersinia species that were used in of strains that differed from typical strains of the species in deoxyribonucleic acid (DNA) studies have been previously tests that included sucrose, raffinose, rhamnose, melibiose, described (3-7, 13, 27). Strains were maintained at room and a-methyl-D-glucoside. These strains were termed temperature on nutrient agar (Centers for Disease Control Yersinia enterocolitica-like or atypical Yersinia enteroco- [CDC]) or on tryptone soy agar (Institute of Hygiene). litica. Further studies demonstrated that included among Biochemical tests. Biochemical tests were done on all these strains were four species distinct from Y. enteroco- strains at the Institute of Hygiene and at the CDC. At the litica (5-7, 27). These were Yersinia aldovae (rhamnose CDC biochemical test preparations were incubated at 36 and positive, sucrose negative), Yersinia frederiksenii (rhamnose 25”C, unless otherwise specificed (see Tables 2 and 3), by positive, sucrose positive), Yersinia intermedia (rhamnose using the methods of Edwards and Ewing (12) with some positive, sucrose positive, melibiose positive, raffinose pos- previously described modifications (18, 19). Unless other- itive), and Yersinia kristensenii (rhamnose negative, sucrose wise specified, all biochemical tests were done at 28°C at the negative). Institute of Hygiene, using the same methods with the Serotyping studies have indicated that Yersinia H antigens following exceptions: carbohydrate fermentation media con- are highly species specific (1). Several strains isolated from tained bromthymol blue as an indicator, and media for dog feces and water in Germany and single human isolates tartrate utilization were prepared as described by Kauffmann from Germany and the United States possessed antigens that and Petersen (22). agglutinated with Y. enterocolitica H antisera, but were Phage typing. Phage typing of five strains was done at the untypable with Y. enterocolitica 0 antisera. These strains World Health Organization Collaborating Centre for differed from Y. enterocolitica by their negative reactions for Yersinia (H. H. Mollaret) at the Institut Pasteur, Paris, indole production and the Voges-Proskauer test and their France. utilization of citrate. Most of these strains also fermented Antimicrobial agent susceptibility tests. Antimicrobial agent susceptibility was determined on Y. rohdei strains by using the disk method of Bauer et al. (2) at the CDC and the * Corresponding author Federal German Standard Methods (11) at the Institute of

327 328 ALEKSIC ET AL. INT. J. SYST.BACTERIOL.

TABLE 1. Y. rohdei strains studied Antigenic formula Straina and lysotypeh Source Location H271-36/78T (= 3022-85T NT: b, d, e, f, i; lysotype X, Dog feces Federal Republic of Germany = ATCC 43380T) H274-36/78 ( = 3023-85) NT: b, i; lysotype X, Dog feces Federal Republic of Germany H276-36/78 ( = 3306-85) NT: b, d, e, f, i; lysotype X, Dog feces Federal Republic of Germany H277-36/78 ( = 3307-85) NT: a, b, d, f, i; lysotype X, Dog feces Federal Republic of Germany H111-36/80 (= 3021-85) NT: b, d, e, f, k; lysotype X, Surface water Federal Republic of Germany H128-36/86 ( = 3435-85) NT: a, b, i' 37-year-old woman, feces United States H297-36/86 ( = 3216-86) NT: a, b, i" 3-year-old child, feces Federal Republic of Germany

~ ~~~ The designation used at the Institute of Hygiene precedes the designation used at the CDC. ATCC, American Type Culture Collection. NT, Nontypable 0 antigen. Lysotype not determined.

Hygiene. The antimicrobial agents and concentrations used carriage in dogs and humans and possibly an occasional are listed in Table 4. infection. Serotyping. The strains were serotyped by slide agglutina- Y. rohdei strains showed the key biochemical reactions tion as described previously (l),using the growth of 18- to typical of the Y. enterocolitica- Y. aldovae- Y. frederiksenii- 24-h cultures from nutrient agar or Kligler iron agar for 0 Y. intermedia- Y. kristensenii group of yersiniae. These in- antigens and soft agar as described by Gard for H antigens. clude greater metabolic activity at 25 to 28°C than at 36"C, Antisera against 60 Yersinia 0 antigens and 38 H antigens motility at 25 to 28°C but not at 36"C, positive reactions at 25 were used (1). to 28°C in tests for methyl red, citrate, urea, and ornithine Virulence factors. Tests to assess virulence included cal- decarboxylase, negative reactions in tests for HZS, lysine cium dependency at 37°C on magnesium-oxalate medium decarboxylase, arginine dihydrolase, phenylalanine (20), autoagglutination at 37°C but not at 22°C in MR-VP deaminase, lipase, and deoxyribonuclease, and production medium (Difco) (23), Congo red pigmentation medium at of little, if any, gas from the fermentation of D-glucose and 28°C (25), and pyrazinamidase activity (21). Production of other carbohydrates. The biochemical reactions of Y. rohdei heat-stable enterotoxin was examined by the suckling mouse strains at both 25 to 28 and 36°C are shown in Table 2. test (16), and formation of a heat-labile, choleralike toxin Five Y. rohdei strains fermented raffinose and melibiose was tested by a GM1 enzyme-linked immunosorbent assay (biogroup l), and two strains (biogroup 2) did not. The on microtiter plates, using anti-LT (29). differentiation of these biogroups from one another and from G+C content of DNA. The guanine-plus-cytosine (G+C) other Yersinia species is shown in Table 3. Y. rohdei is contents of Y. rohdei DNAs were determined spectrophoto- separable from Y. enterocolitica by its positive citrate reac- metrically by thermal denaturation (24), with Y. enteroco- tion and negative reactions for indole and Voges-Proskauer litica 497-70 DNA included as a control. At least four tests. Positive citrate and sucrose reactions distinguish Y. separate determinations were done on DNA from each rohdei from Y. kristensenii. Positive reactions for sucrose strain. and citrate tests and negative reactions for rhamnose, indole, DNA hybridization. The hydroxyapatite method was used and Voges-Proskauer tests differentiate Y. rohdei from Y. to determine the DNA relatedness of Y. rohdei strains to aldovae, Y.frederiksenii, and Y. intermedia. Positive citrate, each other and to representative strains of other Yersinia ornithine decarboxylase, sorbitol, and sucrose tests separate species. The methods used have been described previously Y. rohdei from unnamed Yersinia group X1 (3). A complete (8). comparison of the biochemical chracteristics of Y. rohdei with those of other Yersinia species can be obtained by RESULTS AND DISCUSSION comparing the data in Table 2 obtained at 25 to 28°C with previously published data in references 3 through 7, 13, and Y. rohdei strains were isolated first from feces of healthy 27. A comparison of biochemical characteristics obtained at dogs and then from surface water in Germany (Table 1). A 36°C may be obtained by comparing the data in Table 2 with computer search of the biochemical characteristics of all previously published data in reference 13 and 14. strains in the Enteric Laboratory Section at the CDC re- Y. rohdei strains were susceptible to apalcillin, trimetho- vealed no strains similar to Y. rohdei. Shortly thereafter a prim plus sulfamethoxazole, chloramphenicol, colistin, strain isolated from the stool of a 37-year-old woman in gentamicin, kanamycin, nalidixic acid, streptomycin, sulfa- California was identified as Y. rohdei. The woman was diazine, and tetracycline and were resistant or showed suffering from diarrhea and abdominal cramps. A second intermediate susceptibility to ampicillin, carbenicillin, ceph- human strain was isolated from feces of a healthy 3-year-old alothin, penicillin, and sulfonamide (Table 4). There were no child in Germany. Later, six additional strains of Y. rohdei, significant differences in susceptibility patterns in the two Y. not included in this study, were identified among strains of rohdei biogroups. the culture collection of the Institute of Hygiene which were All strains of Y. rohdei possessed 0 antigens that were not biochemically consistent with biogroup 1. These organisms typable with 56 antisera of the extended typing scheme of originated from feces of healthy dogs (strains H269-36/78 and Wauters (28) and 4 provisional 0 group antisera of AleksiC H275-36/78), surface water (H694-36/83 and . H705-36/83), and co-workers (1).Three strains gave weak cross-reactions and stool specimens from patients with enteritis (H375-36/84 with 0:18 of Y. enterocolitica and 0:38 or 0:60 or Y. and H96-36/85). It is not known whether Y. rohdei was the frederiksenii, which were removed by absorption without cause of diarrhea in the human cases. We hypothesize that significant reduction of the homologous titer. All of the the natural habitat of the organisms is water, leading to fecal strains which we studied and two additional isolates from the VOL. 37, 1987 YERSINIA ROHDEI SP. NOV. 329

TABLE 2. Biochemical reactions of seven Y. rohdei strains and of the type strain

Cumulative % of strains positive" Reaction of type strain Test 25 to 28°C" 36°C ATCC 43380 at:" 2 Days 7 Days 1 Day 2 Days 7 Days 25 to 28°C 36°C Indole production 0 0 Methyl red 100 57 Voges-Proskauer 0 0 Citrate (Simmons) 71 100 0 0 0 H2S on triple sugar iron agar 0 0 0 0 0 H2S on peptone iron agar 0 0 0 0 0 Urea hydrolysis 43 100 43 57 100 Phenylalanine deaminase 0 0 0 0 0 L-Lysine-decarboxylase (Moeller) 0 0 0 0 0 L-Arginine deaminase (Moeller) 0 0 0 0 0 L-Ornithine decarboxylase (Moeller) 86 100 14 14 43 Motility 100 100 0 0 0 Gelatin hydrolysis 0 0 KCN, growth 14 43 0 0 14 Malonate utilization 0 0 0 0 0 D-Glucose, acid 100 100 100 100 100 D-Glucose, gas 0 29d 0 0 0 Acid from: Adonitol 0 0 0 0 0 L-Arabinose 100 100 86 100 100 D- Arabitol 0 0 0 0 0 Cellobiose 100 100 0 14 57 Dulcitol 0 0 0 0 0 Erythritol 0 0 0 0 0 D-Galactose 86 100 43 71 86 Glycerol 71 100 0 29 57 i(rnyo)-inositol 0 0 0 0 0 Lactose 86 86 0 0 14 Maltose 86 86 0 0 29 D-Mannitol 100 100 100 100 100 D-Mannose 100 100 100 100 100 Melibiose 71 71 29 43 71 a-CH3-D-glucoside 0 0 0 0 0 Raffinose 71 71 43 57 71 L-Rhamnose 0 0 0 0 0 Salicin 0 0 0 0 29 D-Sorbitol 100 100 100 100 100 Sucrose 100 100 100 100 100 Trehalose 100 100 100 100 100 D-Xylose 100 100 0 29 71 Esculin hydrolysis 0 14 0 0 0 Mucate, acid 0 0 0 0 0 Tartrate (Jordan) 71 100 14 100 100 Acetate utilization 0 57 0 0 0 Lipase (corn oil) 0 0 0 0 0 Deoxyribonuclease 0 0 0 0 0 N03- + NO2- 100 100 86 86 86 Oxidase 0 0 0 0 0 o-Nitrophenyl-P-D-galactopyranoside 100 100 43 43 43 Citrate (Christensen) 100 100 14 14 71 Tyrosine clearing 0 0 0 0 0 Pigment production 0 0 0 0 0

a A blank space indicates that the test was not read at this time or, in the case of gelatin hydrolysis, was not done at this incubation temperature. Tests were done at 25°C at the CDC and at 28°C at the Institute of Hygiene. Identical results were obtained at both laboratories for most tests. -, Negative after 2 days; + , positive within 2 days; ( + 1, positive in 3 to 7 days. Small amounts of gas.

Institute of Hygiene culture collection had H antigens typical rohdei, as were tests for the detection of known enterotox- of Y. enterocolitica biatype 1. These findings are in contrast ins. These results, tQgether with the demonstration of pyra- to results of previous studies which demonstrated species zinamidase activity, suggest that Y.rohdei is an environmen- specificity of H antigens in Yersinia species. tal organism rather than a pathogen for humans and Five strains tested belonged to lysotype X, (Table 1). warm-blooded animals. Tests for calcium dependency, autoagglutination, and G + C contents were determined spectrophotometrically Congo red pigmentation, which indicate the presence of a for DNAs from five Y. rohdei strains. The G+C range was virulence plasmid in Y. enterocolitica, were negative in Y. 48.7 to 49.4 mol%, There were no significant differences in 330 ALEKSIC ET AL. INT. J. SYST.BACTERIOL.

TABLE 3. Biochemical differentiation of Y. rohdei from other Yersinia species" rohdei Y. entero- Yersinia coliticci Y. pseudo- Test biogroups biotypes Y.j?ederik- y. illtermediei spnii''isten- Y. ddowie group tuberculosis Y. pestis Y. ruckeri senii spnii''isten- Y. ddowie g!yyp tuberculosis Y. pestis Y. ruckeri x1A1 1 2 1-4 5h - - - - - Indole - - (+) - + + d Voge s-Proskauer -- ++ + + - + - - - - Citrate (Simmons) (+) + - - d + - (+) - - - - Ornithine decarboxylase + + + d + + + + - - - + Cellobiose ++++ + + + - + - - - Melibiose +-- - - + - - - + d - a-CH3-D-glucoside --- - - + ------Raffi n o s e +-- - - + - - - (-) - - L-Rhamnose --- - + + - + - + - - D-Sorbito1 +++- + + + + - - - - Sucrose +++d + + ------

~~~~ a All incubations were done at 25 to 28°C for 3 days (2 days of incubation for Y. ruckeri). -. 0 to 10% positive; (-1, 11 to 25% positive: d, 26 to 74% positive; (+), 75 to 89% positive; +, 90 to 100% positive. Data for Yersinia species other than Y. rohdei are from references 3 through 7, 13, and 27. In addition to results shown, Y. enterocoliticci biotype 5 is negative in tests for trehalose and reduction of nitrate to nitrite: Y. rohdei has the reverse reactions.

G+C content between human and animal isolates or be- nonpigmented rods with the general characteristics of the tween strains from biogroup 1 and biogroup 2 (strains family Enterobacteriaceae and of the genus Yersinia (Table 3306-85 and 3307-85). The G+C range for Y. rohdei strains 2). They are motile at 25 to 28°C but not at 36°C. All Y. was quite similar to the average of 48.5 k 1.5 mol% reported rohdei strains give positive results in tests at 25 to 28°C for for 22 strains representing Y. enterocolitica, Y.frederiksenii, methyl red, citrate utilization (Simmons [may be delayed Y. intermedia, and Y. kristensenii (19) and the vplue of 48 positive] and Christensen), urea hydrolysis (may be delayed mol% reported for Y. aldovae (2). positive), L-ornithine decarboxylase (Moeller) (may be de- DNA hybridization was done with labeled DNAs from layed positive) tartrate fermenation (Jordan) (may be de- four Y. rohdei strains, including the type strain, a biogroup 2 layed positive), o-nitrophenyl-P-D-galactopyranoside,re- strain, and a human strain (not all strains were tested with duction of nitrate to nitrite, and acid from fermenation of any one labeled DNA [Table 51). All strains of Y. rohdei D-glucose, L-arabinose, cellobiose, D-galactose (may be de- were highly interrelated. The average level of relatedness layed positive), glycerol (may be delayed positive), D- under optimal DNA reassociation criteria (60°C incubation mannitol, D-mannose, D-sorbitol, sucrose, trehalose, and temperature) was 93%; the average level of relatedness in D-xylose. All Y. rohdei strains give negative results after 48 reactions done at 75"C, where only closely related DNA h of incubation at 25 to 28°C in tests for indole production, sequences can reassociate, was 97%, and the percent diver- the Voges-Proskauer reaction, H2S production (triple sugar gence of nucleotides within related DNA sequences was iron agar and peptone iron agar), phenylalanine deaminase, 0.5%. These high relatedness values indicate that all Y. L-lysine decarboxylase (Moeller) , L-arginine dihydrolase rohdei strains, reagardless of source, geographic origin, and (Moeller), gelatin hydrolysis, malonate utilization, esculin biogroup, belong to a single species. Labeled Y. rohdei DNA hydrolysis, acid from mucate, acetate utilization, lipase showed 30% or more relatedness to all Yersinia species other (corn oil), deoxyribonuclease, tyrosine clearing, gas from than Y. ruckeri (which most reasearchers feel should not be D-glucose, and acid from the fermentation of adonitol, in the genus Yersinia [14]). The highest level of relatedness D-arabitol, dulcitol, erythritol, i(rnyo)-inositol, a-methyl-D- (55%, average of three Y. rohdei strains) was to the type strain of Y.frederiksenii. These data are quite comparable to previously obtained values for relatedness among Y. entero- TABLE 4. Susceptibility of seven Y. rohdei strains to antimicrobial agents as determined by agar diffusion colitica, Y. aldovae, Y. frederiksenii, Y. intermedia, and Y. kristensenii (45 to 68%), as are the values obtained between Antibiotic(s) Zone diam (mm) % of strains species for percent divergence the present study (7.5 to (disk concn) in Range Mean SD susceptible 13.0%) and in previous studies (7.0 to 13.0% [5-7, 13, 271). Since the previously described Yersinia species are 30% or Ampicillin (10 pg) 10-16 12 2.2 14 less related to other members of the Enterobacteriaceae (5, Apalcillin (30 pg) 3040 33 3.5 100 9) and Y. rohdei is as much as 55% related to Yersinia Carbenicillin (100 pg) 11-25 15 5.0 14 species, it was not necessary to determine the DNA relat- Cephalothin (30 pg) 6-14 11 2.6 0 Chloramphenicol (30 pg) 2340 31 6.4 100 edness of Y. rohdei to other Enterobacteriaceae. On the Colistin (10 pg) 15-22 19 2.4 100 basis of DNA relatedness Y. rohdei is clearly a new species Gentamicin (10 pg) 28-38 32 4.2 100 in the genus Yersinia. Kanamycin (30 pg) 2840 33 4.3 100 Description of Yersinia rohdei sp. nov. Yersinia rohdei Nalidixic acid (30 pg) 3040 36 4.0 100 (roh de. i. M.L. gen. n. rohdei, of Rohde) is named in honor Penicillin (10 U) 6-8 6 0.8 0 of the late Rolf Rohde, who founded the National Reference Streptomycin (10 pg) 22-30 25 2.9 100 Centre for Salmonella in Hamburg, Federal Republic of Sulfadiazine (250 pg) 16-27 21 4.0 86 Germany, and who made many significant contributions to Sulfonamide (300 pg) 11-28 19 5.6 28 the diagnostic and serological identification of Enterobac- Tetracycline (30 pg) 23-36 28 4.6 100 teriaceae, especially in the genus Salmonella. Strains of Y. Trimethoprim + sulfameth- 24-38 29 4.5 100 oxazole (1.25 23.75 pg) rohdei are gram-negative, oxidase-negative, fermentative, + VOL.37, 1987 YERSINIA ROHDEI SP. NOV. 331

TABLE 5. DNA relatedness of Y. rohdei strains” Relatedness to 32P04-labeledDNAs from Y. ruhdei strains Source of Strain 3022-8-V Strain 3021-85 unlabeled DNA PBR at 60°C” %D RBR at 75°C” RBR at 60°Cb %D‘ RBR at 75°C” Y. rohdei 3022-ST 100 0.0 100 98 1.0 99 Y. rohdei 3021-85 100 0.0 100 Y. rohdei 3023-85 87 0.5 100 Y. rohdei 3306-85 95 1.5 95 Y. rohdei 3307-85 97 0.5 97 Y. rohdei 3435-85 94 1.0 90 Y. rohdei 3216-86 83d 0.5 Y. aldovae 670-83 43 41 10.5 5 Y. enterocolitica 497-70 44 44 10.5 31 Y.frederiksenii IP 6175 53 63 11.0 37 Y.frederiksenii 2581-77 41 58 13.0 24 Y.frederiksenii IP 867 52 39 8.5 17 Y. intermedia IP 48T 45 38 8.0 16 Y. kristensenii IP 1474 44 37 7.5 21 Y. pestis 1122 34 Y. pseudotuberculosis P65 30‘ 14 Y. ruckeri 4535-69 19 10 Y. group XI strain IP 7706 42 40 11.5 17 32P04-labeledDNAs from strains of Y. rohdei were reacted with unlabeled DNAs from the same strain (homologous reaction), from other Y. rohdei strains, and from strains of all previously described Yersinia species. Each reaction was done at least twice. The average level of reassociation in homologous reactions was 55% before normalization. Control reactions, in which labeled DNA was incubated in the absence of unlabeled DNA, showed an average level of binding to hydroxyapatite of 1.0%. The control value was subtracted before normalization. Relative binding ratio (RBR) = [(percentage of DNA bound to hydroxyapatite in heterologous reactions)/(percentage of DNA bound to hydroxyapatite in homologous reactions)] x 100. Percent divergence (%D) was calculated on the assumption that a 1% decrease in the thermal stability of a heterologous DNA duplex compared with that of the homologous duplex was caused by 1% of the bases within the duplex that were unpaired; it was calculated to the nearest 0.5%. This value was obtained with labeled DNA from strain 3216-86 and unlabeled DNA from strain 3022-UT. This value was obtained with labeled DNA from strain 3306-85 and unlabeled DNA from strain P65. Labeled DNA from strain 3306-85 was 92 to 96% related to DNAs from other Y. ruhdei strains (data not shown). glucoside, L-rhamnose, and salicin. Six of our seven strains 2. Baper, A. W., W. M. M. Kirby, J. C. Sherris, and M. Turck. produce acid from fermentation of lactose and maltose. 1966. Antibiotic susceptibility testing by a standardized single Strains vary in reactions for growth in KCN and acid disk method. Am. J. Clin. Pathol. 45493496. production from fermentation of raffinose and melibiose. 3. Bercovier, H., D. J. Brenner, J. Ursing, A. G. Steigerwalt, G. R. The strains formed 2 biogroups on the basis of positive Fanning, J. M. Alonso, G. P. Carter, and H. H. Mollaret. 1980. (biogroup 1) or negative (biogroup 2) reactions for both Characterization of Yersinia enterocolitica sensu stricto. Curr. raffinose and melibiose. Tests that differentiate Y. rohdei Microbiol. 4:201-206. from other Yersinia species are shown in Table 3. Y. rohdei 4. Bercovier, H., H. H. Mollaret, J. M. Alonso, J. Brault, G. R. Fanning, A. G. Steigerwalt, and D. J. Brenner. 1980. Intra- and strains were resistant to or showed intermediate susceptibil- interspecies relatedness of by DNA hybridiza- ity to ampicillin, carbenicillin, cephalothin, and penicillin tion and its relationship to Yersinsia pseudotuberculosis, Curr. and were susceptible to the other antimicrobial agents tested Microbiol. 4:225-229. (Table 4). Y. rohdei strains had G+C content of 48.7 to 49.4 5. Bercovier, H., A. G. Steigerwalt, A. Guiyoule, G. Huntley- mol%. Carter, and D. J. Brenner. 1984. Yersinia aldovae (formerly Y. rohdei strains were isolated from the feces of dogs and Yersinia enterocolitica-like group X2): a new species of Entero- humans and from surface water. The clinical significance of bacteriaceae isolated from aquatic ecosystems. Int. J. Syst. Y. rohdei as a diarrheal agent in humans and animals is Bacteriol. 34:16&172. uncertain and requires further study. 6. Bercovier, H., J. Ursing, D. J. Brenner, A. G. Steigerwalt, G. R. Fanning, G. P. Carter, and H. H. Mollaret. 1980. Yersinia The type strain of Y. rohdei is strain H271-36/78(= 3022-85 = kristensenii: a new species of Enterobacteriaceae composed of ATCC 43380). sucrose-negative strains (formerly called atypical Yersinia en- Description of the type strain. Y. rohdei 3022-MT exhibits terocolitica or Yersinia enterocolitica-like). Curr. Microbiol. the characteristics of the species as given in Tables 2, 4, and 4: 2 19-224. 5. The G+C content of its DNA is 49.1 mol%. It was isolated 7. Brenner, D. J., H. Bercovier, J. Ursing, J. M. Alonso, A. G. from dog feces in Germany in 1978. Steigerwalt, G. R. Fanning, G. P. Carter, and H. H. Mollaret. 1980. Yersiniu intermedia: a new species of Enterobucteriaceae ACKNOWLEDGMENTS composed of rhamnose-positive, melibiose-positive, raffinose- positive strains (formerly called Yersinia enterocolitica or We thank H. H. Mollaret for phage typing of Y. rohdei strains and Yersinia enterocolitica-like). Curr. Microbiol. 4:207-212. J. J. Farmer 111 for critically reading the manuscript. 8. Brenner, D. J., A. C. McWhorter, J. K. Leete Knutson, and A. G. Steigerwalt. 1982. Escherichia vulneris: a new species of LITERATURE CITED Enterobacteriaceae associated with human wounds. J. Clin. 1. AleksiC, S., J. Bockemuhl, and F. Lange. 1986. Studies on the Microbiol. 151133-1140. serology of flagellar antigens of Yersinia enterocolitica and 9. Brenner, D. J., J. Ursing, H. Bercovier, A. G. Steigerwalt, G. R. related Yersinia species. Zentralbl. Bakteriol. Parasitenkd. Fanning, J. M. Alonso, and H. H. Mollaret. 1980. Deoxyribonu- Infektionskr. Hyg. Abt. 1 Orig. Reihe A 261:299-310. cleic acid relatedness in Yersinia enterocolitica and Yersinia 332 ALEKSIC ET AL. INT. J. SYST.BACTERIOL.

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