International Journal of Systematic Bacteriology (1 999), 49, 1433-1 438 Printed in Great Britain

The phylogenetic position of Serratia, -1 -1 Buttiauxella and some other genera of the family

Cathrin Sprber, Ulrike Mendrock, Jolantha Swiderski, Elke Lang and Erko Stackebrandt

Author for correspondence : Erko Stackebrandt. Tel : + 49 53 1 26 16 352. Fax : + 49 53 1 26 16 4 18. e-mail : [email protected]

DSMZ - Deutsche Sammlung The phylogenetic relationships of the type strains of 38 from 15 genera von Mikroorganismen und of the family Enterobacteriaceae were investigated by comparative 16s rDNA Zellkulturen GmbH, Mascheroder Weg 1b, analysis. Several sequences of strains f rom the genera Citrobacter, Erwinia, D-38124Braunschweig, Pantoea, Proteus, Rahnella and Serratia, analysed in this study, have been Germany analysed previously. However, as the sequences of this study differ slightly from the published ones, they were included in the analysis. Of the 23 enterobacterial genera included in an overview dendrogram of relatedness, members of the genera Xenorhabdus, Photorhabdus, Proteus and Plesiomonas were used as a root. The other genera formed two groups which could be separated, although not exclusively, by signature nucleotides at positions 590-649 and 600-638. Group A contains species of Brenneria, Buttiauxella, Citrobacter, Escherichia, Erwinia, Klebsiella, Pantoea, Pectobacterium and Salmonella. All seven type strains of Buttiauxella share 16s rDNA similarities greater than 99 O/O. Group B embraces two phylogenetically separate Serratia clusters, a lineage containing Yersinia species, Rahnella aquatica, Ewingella americana, and also the highly related pair Hafnia alvei and Obesumbacterium pro teus.

Keywords: Enterobacteriaceae, Buttiauxella, Serratia, 16s rDNA analysis

In contrast to other taxon-rich families, such as the ture of the 16s rDNA, this molecule was not thought Clostridiaceae, the Bacillaceae and the Pseudo- to solve taxonomic problems concerning closely re- monadaceae, members of the Enterobacteriaceae have lated species. Extensive phylogenetic analysis of not been subjected to extensive analysis of 16s rDNA. the genera Yersinia, Salmonella, Photorhabdus and While some genera have been investigated in detail, Erwinia, however, have demonstrated that the variable e.g. Xenorhabdus and Photorhabdus (Szallas et al., and highly variable regions of the 16s rDNA molecule 1997), Yersinia (Ibrahim et al., 1994), Salmonella have sufficient phylogenetic powers of discrimination (Chang et al., 1997; Christensen et al., 1998), Serratia to allow the recognition of the same sets of relatedness (Dauga et al., 1990; Harada et al., 1996), and Erwinia as those unravelled by DNA-DNA reassociation (Kwon et al., 1997; Hauben et al., 1998), other genera studies. Furthermore, the phylogenetic incoherence of have been analysed less extensively, e.g. Enterobacter Erwinia has been demonstrated in the studies of Kwon (Hauben et al., 1998), Proteus (Niebel et al., 1987), et al. (1997) and Hauben et al. (1998). Citrobacter (Maidak et al., 1997), and most of the In this work, 16s rDNA-based analysis of the family monospecific genera. The reason for the dismissal of Enterobacteriaceae is extended by adding sequences of many members of the Enterobacteriaceae may stem 38 type strains to the database. Eleven type strains of from knowledge of the high intrafamily related- species investigated in the course of this study ness (Brenner, 1991), as measured by DNA-DNA Erwinia were published by Hauben et al. (1998), and several of hybridization. Because of the conserved primary struc- these species were subsequently reclassified by these authors as species of Pectobacterium and Brenneria.

The EMBL accession numbers for the 165 rDNA sequences analysed in this The organisms investigated in this study, their strain paper are AJ233400-AJ233437. designation, and their 16s rDNA accession numbers

01020 0 1999 IUMS 1433 C. Sproer and others

Tabre 1. Strains analysed in this study, and their 165 aligned manually against available sequences for rDNA accession numbers members of the family Enterobacteriaceae. Evolution- ary distances were computed from globally aligned Specieslsubspecies Strain Accession sequences by using the correction of Jukes & Cantor no. (1969), omitting gaps and ambiguous positions. Dendrograms of relatedness were generated by the Budvicia aquatica DSM 5075T A5233407 algorithms of De Soete (1983) and by neighbour- DSM 4586T AJ23 3400 joining and maximum-likelihood analyses using the DSM 9396T A5233401 programs of the PHYLIP package (Felsenstein, 1993). Buttiauxella ferragu tiae DSM 9390T A5233402 Bootstrap values were determined as described else- But tiauxella guviniae DSM 9393’ A5233403 where (Felsenstein, 1993). The following reference But tiauxella izardii DSM 9397T A 5233404 sequences were taken from the EMBL database : DSM 9401T A5233405 Escherichia coli (501695, Brosius et al., 1978); Pecto- Bu ttiauxella warmboldiae DSM 9404T A5233406 bacterium cacticidum LMG 17936T (AJ223409) ; Brenneria alni DSM 11811T A 5233409 Erwinia persicinus ATCC 3599gT (U80205) ; Erwinia Brenneria quercina DSM 4561T A5233416 psidii LMG 7034 (296085) ; Erwinia tracheiphila LMG Brenneria rubrifaciens DSM 4483T A5233418 2906T (Y 13250) ; Ewingella americana NCPPB 3905 Brenneria salicis DSM 3016tjT A5233419 (X88848, entry cited unpublished) ; Hafnia alvei ATCC Citrobacter freundii DSM 30039T A5233408 13337T (M59 155, entry cited unpublished) ; Plesio- Erwinia amylovora DSM 30165T A52334 10 monas shigelloides ATCC 14029T(M59 159, entry cited Erwinia mallotivora DSM 4565T A52334 14 unpublished) ; Salmonella typhimurium ATCC 19430T Erwinia nigrzjhens DSM 30175T A5233415 (247544) ; Yersinia pestis D-28 (X75274), Xenorhabdus Er w inia rhapon t ici DSM 4484T A52334 17 nematophilus DSM 3370T (X8225 l), Photorhabdus Klebsiella pneumoniae subsp. DSM 30104T A5233420 luminescens DSM 3368T (X82248) and Plesiomonas pneumoniae shigelloides ATCC 14029T (X74688). Leminorella grimon t ii DSM 5078T A5233421 Almost complete 16s rDNA sequences were analysed Obesumbacteriumproteus DSM 2777T A5233422 for the type strains of 38 species from the genera Pan toea agglomerans DSM 3493T A5233423 Brenneria, Budvicia, Buttiauxella, Citrobacter, Pectobacterium carotovorum DSM 30168T A523341 1 Erwinia, Klebsiella, Leminorella, Obesumbacterium, subsp. carotovorum Pantoea, Pectobacterium, Pragia, Rahnella, Serratia Pectobacterium chrysanthemi DSM 4610T A5233412 and Tatumella. The lengths of the sequences ranged Pectobacterium cypripedii DSM 3873T A5233413 between 1493 and 1516 nucleotides, corresponding to Pragia fontium DSM 5563T A5233424 95.5 and 98.4Y0, respectively, of the Escherichia coli Proteus vulgaris DSM 301 18T A5233425 sequence. Some of the sequences of type strains of Rahnella aquatica DSM 4594T A5233426 Erwinia, Serratia, Citrobacter, Pan toea and Rahnella Serratia en tomophila DSM 12358T A5233427 species analysed in this study have been published Serratia jicariu DSM 4569T A5233428 recently (Dauga et al., 1990; Harada et al., 1996; Serra tia fonticola DSM 4576T A5233429 Kwon et al., 1997; Maidak et al., 1997), but, as there Serratia grimesii DSM 30063T A5233430 are some nucleotide differences in sequences orig- Serratia marcescens DSM 30121T A523343 1 inating from the same strain (98.8-99-9 Yo sequence Serratia odorifera DSM 4582T A5233432 similarity), sequences determined in this study were Serratia plymuthica DSM 4540T A5233433 deposited in the EMBL database. Sequence similarities Serratia proteamaculans DSM 4543T A5233434 obtained for the sequences of the 11 type strains of subsp. proteamaculans Erwinia, Brenneria and Pectobacterium, published, Serratia proteamaculans DSM 4597T A5233435 during this study, by Hauben et al. (1998), ranged subsp. quinovora between 98.5 and 100 YO.A significant deviation from Serratia rubidaea DSM 4480T A5233436 the data of Kwon et at. (1997) refers to Brenneria Tatumella ptyseos DSM 5000T A5233437 salicis. While the 16s rDNA sequences of strains DSM 30166T (this study) and LMG 269gT (Hauben et al., 1998) are identical, they share only 94-5Yo sequence similarity with strain ATCC 157 12T. The branching are listed in Table 1. Extraction of genomic DNA and the amplification of 16s rDNA were performed as point of Pectobacterium cypripedii DSM 3873Twithin the radiation of authentic Erwinia species differs from described previously (Rainey et al., 1996). The PCR the position of the type strain LMG 5657T of the same products were purified by using the Prep-A-Gene kit (Bio-Rad), as described by the manufacturer. The species within the radiation of cluster 111, which, DyeDeoxy Terminator Cycle Sequencing kit (Applied consequently, has been reclassified as Pectobacterium cypripedii (Hauben et al., 1998). Certainly, the auth- Biosystems) was used for direct sequencing of the PCR enticity of the type strains of these two species requires products, as described by the manufacturer. The investigation. sequence reactions were electrophoresed on an Applied Biosystems 373A DNA Sequencer. Sequences were Comparison of the sequences generated in this study

1434 International Journal of Systematic Bacteriology 49 Phylogeny of enterobacterial genera

Escherichia coli Salmonella typhimurium ATCC 19430 T

Pantoea agglomerans DSM 3493T Eminia cluster I Etwinia tracheiphila LMG 2906T Pectobacterium cypn'pedii DSM 3873T Ewinia mellotivora DSM 4565 T Elwinie psi& LMG 7034T L- Envinia amybwra DSM 30165 Envinia cluster II 70- Ewinia rfiapontici DSM 4484T EIwinia persicinus ATCC 3599aT

Klebsiella pneumoniae DSM 301 04T -1 Citmbader 1zeundii DSM 30039 - Buftiauxella agrestis DSM 4~6~ Brenneria quercina DSM 45611 - Pectobacteriurn carotownrm subsp. carotovorum DSM 301681 - P edobaden'urn cacticidum LMG 17936T Erwinia cluster 111

Erwinia cluster IV

9c Semtia cluster I

Serratia cluster II

Proteus vulgaris DSM 30118 Xenohabdus nematophilus DSM 3370 fbotorhabdus luminescens DSM 3368T Plesiornonas shigelloides ATCC 14029 2%

...... , ., . , . . . . , ., ., , ,...... , ., ...... I...... , ...... , ...... , . . . . , ...... , ...... , .. . ., ., ...... , , , , ...... , ...... , , , . . . . , . , . . , . , . . . Fig. 7. Phylogenetic tree of the 165 rDNA of members of various genera of the family Enterobacteriaceae. The positions of Erwinia clusters I (Pantoea) to IV (Kwon eta/., 1997) in group A and the Serratia clusters I and II in group B, defined in this study, are indicated. A detailed analysis of the Buttiauxella agrestis lineage is shown in Fig. 2. Numbers within the dendrogram indicate the occurrence (%) of the branching order in 200 bootstrapped trees (only values of 60 and above are shown). The scale bar represents 2 nucleotide substitutions per 100 nucleotides.

InternationalJournal of Systematic Bacteriology 49 1435 C. Sproer and others with those published previously for members of the B. gaviniae DSM 9393T family Enterobacteriaceae revealed a high degree of B. noackiae DSM 9401T relatedness. The most unrelated members of the family were those of the rooting species, Photorhabdus and B. izardii DSM 9397T Xenorhabdus (90-94-5 YOsimilarity), Proteus vulgaris B. warmboldiae DSM 9404T (92-95-6 YO)and Plesiomonas shigelloides (92.8- 95-5%), but these values were not significantly higher 8. ferragutiae DSM 9390T than those separating members of different genera B. agrestis DSM 4586T (94-97 Yo). Phylogenetic trees obtained with two B. brennerae DSM 9396T different additive treeing algorithms and by maximum- likelihood analysis showed only slight differences in 1% the branching pattern. The few deviations were found k for deeply rooting lineages, such as those of Klebsiella and and the lineage of Fig. 2. Phylogenetic tree of 165 rDNA of type strains of pneumoniae Citrobacter freundii, Buttiauxella species. Sequences of members of group A served Leminorella, Pragia and Budvicia species. Bootstrap as a root. The scale bar represents 1 nucleotide substitution per values were low for almost all branching points. The 100 nucleotides. decision to depict phylogenetic relatedness according to the algorithm of De Soete (1983) (Fig. 1) is based on experience with actinobacteria and many other phylo- genetic groups of mainly Gram-positive in al., 1993). In a recent extensive study, Hauben et al. which patterns of chemotaxonomic markers and (1998) analysed additional type strains of Erwinia and the distribution of signature nucleotides strongly reclassified four and six species as members of Pecto- supported the emergence of phylogenetic clusters bacterium and Brenneria, respectively, which corre- (Stackebrandt et al., 1997a, b). spond to the clusters I11 and IV of Kwon et al. (1997). Analysis of sequences according to the occurrence of Sequences of strains originally received in this study as cluster-specific signature nucleotides reveals no strong Erwinia strains do not change the internal structure of pattern for any of the clusters. The most interesting clusters, now defined by the genera Erwinia, Brenneria two pairs of nucleotides are located at positions 590 and Pectobacterium. All of these genera are members and 649 and at positions 600 and 638 (Escherichia coli of group A. Four species sequenced in the course of the nomenclature; Brosius et al., 1978). These two pairs present study were members of cluster 11 [Erwinia enable separation of the organisms investigated into amylovora, Erwinia mallotivora, Erwinia rhapontici and two groups. Group A ranges from the top (in Fig. 1) to Erwinia cypripedii (see above)], one was a member of Brenneria rubrfaciens, while all species between cluster IV (Erwinia alni, reclassified as Brenneria alni), Budvicia aquatica and Plesiomonas shigelloides form Erwinia tracheiphila branched slightly outside the cluster B. Members of group A are defined by the Erwinia cluster, and Brenneria quercina branched at nucleotide composition C/u-G (small letters indicate the root of clusters containing the genera Brenneria minority composition) at positions 590-649 (the and Pectobacterium. In contrast to the data of Kwon et exceptions are Escherichia coli, its close relatives, and al. (1997) and Hauben et al. (1998), in which the latter DSM 9393, all of which have a two clusters and genera, respectively, are phylo- U-A base pair) and the pair G/a-C/u at positions genetically well separated, all treeing algorithms used 600-638. Members of this group which possess a A-U in this study depict the origin of Brenneria species as pair at the latter positions are Escherichia coli and being within the radiation of Pectobacterium species. close relatives, all members of Erwinia cluster I (Pantoea), and Erwinia mallotivora. All members of group B possess the nucleotide pairs U-A and A-U at The genus Buttiauxella positions 590-649 and 600-638, respectively. Brenneria The type species of this genus, Buttiauxella agrestis, quercina, which branches deeply within group A, has been described for strains of a group (Ferragut et exhibits the base pairs U-G and A-U at the relevant al., 1981) that in some phenotypic respects resembled positions. members of Citrobacter, but differed from Citrobacter strains in terms of certain metabolic characteristics The genera Erwinia, Brenneria and Pectobacterium and the base ratio of the DNA. Low DNA-DNA reassociation values generally less than 40 % were Four clusters of Erwinia species have recently been obtained with Citrobacter species and a large range of defined and their structure discussed in detail, and in representatives of the Enterobacteriaceae (Ferragut et the light of DNA-DNA reassociation data, by Kwon al., 1981). Recently, six new species (isolated from soil, et al. (1997). Cluster I contains former Erwinia species snails, and human sputum) were added to the genus that are now classified as Pantoea species or united Buttiauxella (Muller et al., 1996). Analysis of 16s with Pantoea species, such as Erwinia herbicola and rDNA (Fig. 2) reveals a very high degree of phylo- Erwinia milletiae with Pantoea agglomerans, and genetic relatedness among the type strains of the seven Erwinia uredovora with Pantoea ananatis (Mergaert et Buttiauxella species (99-1-99-7YO similarity). The __ 1436 International Journal of Systematic Bacteriology 49 Phylogeny of enterobacterial genera dendrogram of relatedness (Fig. 2) does not permit a The genera Tatumella, Budvicia, Pragia, Leminorella detailed intrageneric clustering of type strains, as the and Obesumbacterium bootstrap value is low at any branching point. Both the high degree of relatedness among the species and These five genera have been described and verified, the low resolution of the relatedness are in accordance respectively, on the basis of a combination of low with the results of DNA-DNA reassociation studies values for DNA-DNA reassociation with other (Muller et al., 1996). These data indicated mean members of the Enterobacteriaceae and a unique intrageneric DNA-DNA relatedness values of about pattern of biochemical reactions. Phylogenetic analysis 53 YO,while interspecies similarity values ranged be- indicates that, except for Obesumbacteriurn, these tween 50 and 56 %. genera form lineages that are well separated from other genera in the family (the 16s rDNA similarity At intrafamily level, the genus Buttiauxella is clearly values ranging between 94 and 97%). Tatumella separated from other members of other genera in the ptyseos (Hollis et al., 1981) is a member of family- family (>97 % 16s rDNA similarity), which sup- cluster A, branching close to members of Escherichia, ports earlier reports of low intrafamily DNA-DNA Salmonella and Erwinia clusters I (Pantoea) and 11. relatedness values (Gavini et al., 1983). The The three genera Budvicia (Aldovi et al., 1984), Pragia Buttiauxella lineage (represented by Buttiauxella (Aldovi et al., 1988) and Leminorella (Hickman- agrestis in Fig. 1) branches at a position that is Brenner et al., 1985) form a separate cluster that is intermediate to Erwinia clusters I1 and III/IV and their phylogenetically placed at the base of family-cluster B. respective relatives, but bootstrap values are low. The three species are well separated within this cluster, confirming their affiliation to different genera. Obesum- bacterium proteus shares 99.5 % 16s rDNA sequence similarity with According to Brenner (1991), The genus Serratia H. alvei. a type strain of 0. proteus does not exist, as the The type strains of all nine species have been analysed; deposited type strain is a strain of H. alvei. On the basis the phylogenetic branching pattern is very similar to of DNA-DNA reassociation values of 70 % obtained that described by Dauga et al. (1990). As the des- for the two type strains, Priest et a/. (1973) suggested criptions of the Serratia species are supported by low the reclassification of 0.proteus as Hafnia protea. The values for DNA-DNA reassociation with their nearest data presented here confirm the strong degree of neighbours (Gavini et al., 1979; Grimont et al., 1978, relatedness between the type strains of the two species, 1979, 1988), is not surprising to see most of them well but decisions about changes in must await separated in the phylogenetic tree. The species form additional characterization. two phylogenetic clusters - abbreviated Serratia clusters I and I1 (Fig. 1) - both of which are members of group B. The presence of two clusters could not be References unravelled in the study of Dauga et a/. (1990), as Aldovd, E., Hausner, 0. & Gabrhelov6, M. (1984). Budvicia - a Serratia species were analysed exclusively. All treeing new genus of Enterobacteriaceae. Data on phenotypic charac- algorithms place the species pair H. alvei and Obesum- terization. J Hyg Epidemiol Microbiol Immunol (Prague) 28, bacterium proteus at the root of cluster 11. Serratia 234-237. odorifera, Serratia rnarcescens and Serratia rubidaea Aldov6, E., Hausner, O., Brenner, D. J., Kocmoud, Z., Schindler, J., are members of cluster I (97-98 YOsequence similarity). Potuzikova, B. & Petrag, P. (1988). Pragiafontium gen. nov. of the Under stringent reassociation conditions, members of family Enterobacteriaceae, isolated from water. Int J Syst the three species show less than 37% relative binding Bacteriol38, 183-1 89. (similarity), which characterizes them as genomically Brenner, D. J. (1991). Additional genera of the Entero- well-defined species (Steigerwalt et al., 1976 ; Grimont bacteriaceae. In The Prokaryotes. A Handbook on the Biology of et al., 1978). Members of cluster I1 contain the other Bacteria: Ecophysiology, Isolation, IdentiJcation, Applications, species, of which Serratia proteamaculans subsp. 2nd edn, pp. 2922-2937. Edited by A. Balows, H. G. Triiper, M. proteamaculans, Serratia proteamaculans subsp. Dworkin, W. Harder & K.-H. Schleifer. New York: Springer. quinovora and Serratia grimesii have almost identical Brosius, J., Palmer, M. L., Kennedy, P. 1. & Noller. H. F. (1978). 16s rDNA sequences ( > 99.7 YOsimilarity). These taxa Complete nucleotide sequence of the 16s ribosomal RNA gene share strong biochemical similarities (Grimont et al., from Escherichia coli. Proc Nut1 Acad Sci USA 75, 48014305. 1982b) but the separation of S. grimesii from S. Chang, H. R., Loo, Y. K., Jeyaseelan, K., Earnest, L. & proteamaculans is supported by moderate DNA-DNA Stackebrandt, E. (1 997). Phylogenetic relationships of Salmonella reassociation values (Grimont et al., 1982a). Another typhi and Salmonella typhimurium based on 16s rDNA sequence pair of closely related species is Serratia entomophila analysis. Int J Syst Bacteriol47, 1253-1254. and Serratia jicaria (99.5 % similarity) which, under Christensen, H., Nordentoft, S. & Olsen, 1. E. (1998). Phylogenetic stringent DNA reassociation conditions, also share a relationships of Salmonella based on rRNA sequences. Int J high degree of DNA relatedness. While the type strains Syst Bacteriol48, 1605-1610. share 72 YODNA similarity, other strains of S.Jicaria Dauga, C., Grimont, F. & Grimont, P. A. D. (1990). Nucleotide are somewhat less closely related with the type strain of sequences of 16s rRNA from ten Serratia species. Res Microbiol S. entomophila (Grimont et al., 1988). 141, 1139-1 149.

International Journal of Systematic Bacteriology 49 1437 C. Sproer and others

De Soete, G. (1983). A least squares algorithm for fitting additive based on 16s rDNA sequences. FEMS Microbiol Lett 112, trees to proximity data. Psychometrika 48, 62 1-626. 43 5438. Felsenstein, 1. (1993). PHYLIP : Phylogeny inference package, Jukes, T. H. & Cantor, C. R. (1969). Evolution of protein version 3.5.1. Department of Genetics, University of molecules. In Mammalian Protein Metabolism, pp. 2 1-1 32. Washington, Seattle, WA, USA. Edited by H. N. Munro. New York: Academic Press. Ferragut, C., Izard, D., Gavini, F., Lefebvre, B. & Leclerc, H. (1981). Kwon, S.-W., Go, S.-I., Kang, H.-W., Ryu, J.4. & lo, J.-K. (1997). Buttiauxella, a new genus of the family Enterobacteriaceae. Phylogenetic analysis of Erwinia species based on 16s rDNA Zentbl Bakteriol Hyg 1 Abt Orig C 2, 33-44. gene sequences. Int J Syst Bacteriol47, 1061-1067. Gavini, F., Ferragut, C., Izard, D.,Trinel, P. A., Leclerc, H., Lefebvre, Maidak, B. L., Larsen, N., McCaughey, M. J., Overbeek, R., Olsen, B. & Mossel, D. A. A. (1979). Serratia fontico/a, a new species G. J. & Woese, C. R. (1997). The Ribosomal Database Project. from water. Int J Syst BacterioZ29, 92-101. Nucleic Acids Res 25, 109-1 11. Gavini, F., Izard, D., Ferragut, C., Farmer, 1. J. & Leclerc, H. (1983). Mergaert, J., Verdonck, L. & Kersters, 5. K. (1993). Transfer of Separation of Kluyvera and Buttiauxella by biochemical and Erwinia ananas (synonym, Erwinia uredovora) and Erwinia nucleic acid methods. int J Syst Bacteriol33, 880-882. stewartii to the genus Pantoea emend. as Pantoea ananas Grimont, P. A. D., Grimont, F., Richard, C., Davis, B. R., (Serrano 1928) comb. nov. and Pantoea stewartii (Smith 1898) Steigerwalt, A. G. & Brenner, D. J. (1978). Deoxyribonucleic acid comb. nov., respectively, and description of Pantoea stewartii relatedness between Serratia plymuthica and other Serratia subsp. indologenes subsp. nov. Int J Syst Bacteriol43, 162-173. species, with a description of Serratia odorifera sp. nov. (type Miiller, H. E., Brenner, D. J., Fanning, G. R., Grimont, P. A. D. & strain: ICPB 3995.) Int J Syst Bacteriol28, 453-463. Kampfer, P. (1996). Emended description of Buttiauxella agrestis Grimont, P. A. D., Grimont, F. & Starr, M. P. (1979). Serratia with recognition of six new species of Buttiauxella and two Jicaria sp. nov., a bacterial species associated with Smyrna figs new species of Kluyvera : Buttiauxella ferragutiae sp. nov., and the wasp Blastophaga psenes. Curr MicrobioE2, 277-282. Buttiauxella gaviniae sp. nov., Buttiauxella brennerae sp. nov., Grimont, P. A. D., Irino, K. & Grimont, F. (1982a). The Serratia sp. nov., Buttiauxella noackiae sp. nov., liquefaciens-S. proteamaculans-S. grimesii complex : DNA Buttiauxella warrnboldiae sp. nov., Kluyvera cochleae sp. nov., relatedness. Curr Microbiol7, 63-68. and Kluyvera georgiana sp. nov. Int J Syst Bacteriol46, 5&63. Grimont, P. A. D., Grimont, F. & Irino, K. (1982b). Biochemical Niebel, H., Dorsch, M. & Stackebrandt, E. (1987). Cloning and characterization of S. liquefaciens sensu stricto, Serratia expression of rDNA from Proteus mirabilis in Escherichia coli. proteamaculans, and Serratia grimesii sp. nov. Curr Microbiol7, J Gen Microbioll33, 2401-2409. 69-74. Priest, F. G., Somerville, H. J., Cole, 1. A. & Hough, 1. 5. (1973). The Grimont, P. A. D., Jackson, T. A., Ageron, E. & Noonan, M. J. taxonomic position of Obesumbacterium proteus, a common (1988). Serratia entomophila sp. nov. associated with amber brewery contaminant. J Gen Microbiol75, 295-307. disease in the New Zealand grass grub Costelytra zealandica. Int Rainey, F. A., Ward-Rainey, N., Kroppenstedt, R. M. & J Syst Bacteriol38, 1-6. Stackebrandt, E. (1996). The genus Nocardiopsis represents a Harada, H., Oyaizu, H. & Ishikawa, H. (1996). A consideration phylogenetically coherent taxon and a distinct actinomycete about the origin of aphid intracellular symbiont in connection lineage : proposal of Nocardiopsaceae fam. nov. Int J Syst with gut bacterial flora. J Gen Appl Microbiol42, 17-26. Bacteriol46, 1088-1092. Hauben, L., Moore, E. R. B., Vauterin, L., Steenackers, M., Stackebrandt, E., Rainey, F. A. & Ward-Rainey, N. L. (1997a). Mergaert, J., Verdonck, L. & Swings, J. (1998). Phylogenetic Proposal for a new hierarchic classification system, Actino- position of phytopathogens within the Enterobacteriaceae. Syst bacteria classis nov. Int J Syst Bacteriol47, 479491. Appl Microbiol21, 384397. Stackebrandt, E., Sprikr, C., Rainey, F. A., Burghardt, J., Pauker, Hickman-Brenner, F. W., Wohra, M. P., Huntley-Carter, G. P., 0. & Hippe, H. (1997b). Phylogenetic analysis of the genus Fanning, G. R., Lowery, V. A., 111, Brenner, D. 1. & Farmer, J. J., 111 Desulfotomaculum: evidence for the misclassification ofDesulfo- (1985). Leminorella, a new genus in the family Entero- tomaculum guttoideum and description of Desulfotomaculum bacteriaceae : identification of Leminorella grimontii sp. nov. orientis as Desulfosporosinus orientis gen. nov. comb. nov. Int J and L. richardii sp. nov. found in clinical specimens. J Clin Syst BacterioZ47, 1134-1 139. Microbiol21, 234-239. Steigerwalt, A. G., Fanning, G. R., Fife-Ashbury, M. & Brenner, Hollis, D. G., Hickman, F. W., Fanning, G. R., Farmer, J. J., 111, D. J. (1976). DNA relatedness among species of Enterobacter Weaver, R. E. & Brenner, D. 1. (1981). Tatumella ptyseos gen. and Serratia. Can J Microbiol22, 121-137. nov., sp. nov., a member of the family Enterobacteriaceae found Szallk, E., Koch, C., Fodor, A., Burghardt, J., Buss, O., Szentirmai, in clinical specimens. J Clin Microbiol 14, 79-88. A., Nealson, K. H. & Stackebrandt, E. (1997). Phylogenetic Ibrahim, A., Goebel, B. M., Liesack, W., Griffith, M. & evidence for the taxonomic heterogeneity of Photorhabdus Stackebrandt, E. (1994). The phylogeny of the genus Yersinia luminescens. Int J Syst Bacteriol47, 402407.

1438 International Journal of Systematic Bacteriology 49