INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY Vol. 23, No. 2 April 1973, p. 122-134 Copyright 0 1973 International Association of Microbiological Societies Printed in U.S.A. Taxonomic Study of the Genus Campylobacter Sebald and Vkron and Designation of the Neotype Strain for the Type Species, Campylobacter fetus (Smith and Taylor) Sebald and Vkon M. @RON’ and R. CHATELAIN Facultk de Me‘decineNecker et Institut Pasteur, Pans, France A critical study of the present state of the classification of vibrio-like, curved, microaerophilic bacteria was made. The species originally described under the names Vibrio coli Doyle, V. jejuni Jones et al., V. sputorum PrCvot, and V. bubulus Florent are transferred to the genus Campylobacter Sebald and VCron 1963. The authors suggest that the type species of this genus, C. fetus, be divided into two subspecies: C. fetus subsp. fetus (Smith and Taylor) comb. nov. (syn. V. fetus subsp. intestinalis Florent), which contains the neotype strain of the species, and C. fetus subsp. venerealis (Florent) comb. nov. The previously described subspecies V. fetus subsp. intermedius Elazhari is regarded as an infrasubspecific taxon with the name C. fetus subsp. venerealis biotype intermedius. CIP 5396 (=ATCC 27374=NCTC 10842) is proposed as the neotype strain of C. fetus subsp. fetus. This strain, then, is also the neotype strain of C. fetus (Smith and Taylor) Sebald and Vkron. In 1913, McFadyean and Stockman (34) The only shared property-curved cells-is now discovered a “vibrio” which seemed to be recognized to be a characteristic of dubious responsible for abortion of pregnant ewes; they taxonomic value (10). obtained an experimental abortion in pregnant For these reasons, Sebald and VCron (47) cows by inoculation with this organism. Subse- proposed a new genus, Campylobacter, with C. quently, Smith (52) recovered a microaere fetus (Smith and Taylor) Sebald and VCron as philic “spirillum” from aborted calves. Smith the type species. The genus Campylobacter is (52) suspected that this organism was identical defined (47, 54) as comprising gram-negative, to that described by McFadyean and Stockman slender, and curved bacteria which are motile (34). It was designated Vibrio fetus by by means of a single, polar flagellum, microaer- Smith and Taylor (53), the generic attribution ophilic with a strictly respiratory metabolism, being based on the fact that comma-shaped produce no acid in media with carbohydrates, cells predominate over spirilloid ones, particu- and which have DNA with a G + C content larly in young cultures. between 29 and 36 mol %. The genus Vibrio, Nevertheless, assignment of this organism to on the other hand, comprises bacteria which the genus Vibrio is unsatisfactory: V. fetus ferment glucose (24, 25, 54) and contain DNA differs greatly in phenotypic. respects from the with a G + C content between 40 and 53%, (J. type species of the genus Vibrio, V. cholerae M.. Shewan and M. VCron, Bergey ’s Manual, 8 th Pacini 1854 (14, 24, 55). Moreover, the G + C ed., in press), the value for V. cholerae being content of the deoxyribonucleic acid (DNA) of about 47 mol% (54). K fetus is very far from that characteristic of Though the taxonomic notion of the family V. cholerae and related Vibrio species (47, 55). among the bacteria is difficult, or even impossi- Laboratoire de Bactkriologie, Facult6 de M6decine ble, to justify by means of genetic arguments, Necker, 156, rue de Vaugirard, 75730, Paris Cedex 15, this taxon is useful for purposes of classifica- France. tion. Thus we have proposed (54, 55) to 122 VOL. 23,1973 TAXONOMIC STUDY OF CAMPYLOBACTER 123 include the genus Campylobacter in the family mild dysentery. Spirillaceae because there is much morpholog- (vi) I/. sputorum Prkvot 1940 (43, p. 123) ical and physiological likeness between the and V. bubulus Florent 1953 (18, p. 2066) genera Campylobacter and Spirillum, In agree- have very similar characteristics; their consoli- ment with this view, striking analogies were dation as two separate subspecies in a single observed (13, 45) between the anatomical species, as proposed by Loesche et al. (33), features of strains belonging to both of these appears desirable. On the basis of priority, the genera, particularly on account of the presence specific epithet to be used in the name of the of: (i) an outer wavy membrane, or “integu- species is sputorum. V. sputorum subsp. spu- ment,” easily separated from the inner mem- torum Pr6vot is an occasionally pathogenic brane with a large vacant space between both human parasite (33, p. 1109); it has been membranes; (ii) a “complex cytoplasmic mem- principally recovered from the oral cavity in brane” consisting of a triple-layered membrane gingivitis or from sputum in bronchitis. V. associated with short bar-like elaborations mak- sputorum subsp. bubulus (Florent) Loesche et ing up centripetally oriented compartments; al. 1965 (33, p. 1 109) appears to be nonpatho- and (iii) individual flagellar basal granules. genic; it has been isolated from vaginal and Since Smith and Taylor’s description of V. preputial secretions, sperm, fetuses, and fetal fetus (53), there have appeared descriptions of membranes, and from stools of sheep, horses, several other species or subspecies of microaero- and cattle. philic curved bacteria which should also be At times, another species, Vibrio metschniko- included in the genus Campylobacter. These uii Gamaleia 1888 (23, p. 485), has been taxa are the following: improperly included in this group of bacteria (i) Vibrio fetus subsp. intestinalis Florent because it was recovered from the intestinal 1959 (20, p. 7), the strains of which occur tract of poultry suffering from dysentery. In principally in the intestinal tracts of sheep, fact, the reference strains of this species possess cattle, swine, birds, and humans, where it is a G + C content of DNA of about 46 mol% usually commensal. It has also been isolated (47) and a fermentative metabolism of glucose occasionally from the genital tract, the viscera, like that of V. cholerae (55). Consequently, this or the blood. All strains can cause sporadic species belongs to the genus Vibrio and not to abortion (principally in cows and sheep) (1, 20) the genus Campylobacter. because they are able to multiply in the Finally, the genus Campylobacter, at present, placenta after passage from the intestine into appears to comprise four species: C. fetus the viscera. Human infection is very often due (Smith and Taylor) Sebald and V6ron 1963 to this subspecies. Some strains are able to be (47, p. 907), which contains several subspecies, transferred by venereal contact and to survive C. coli (Doyle) comb. nov., C. jejuni (Jones et in genital tracts of cattle (13, 2 1, 39). al.) comb. nov., C. sputorum subsp. sputorum (ii) V. fetus subsp. venerealis Florent 1959 (Prkvot) comb. nov., and C. sputorum subsp. (20, p. 7) seems strictly adapted to the bovine bubulus (Florent) comb. nov. The inclusion of genital tract (preputial and vaginal cavities) and these last subspecies in the genus Campylo- is unable to survive in the intestinal tract (8). It bacter was previously suggested by Loesche et causes enzootic venereal sterility in cows (49) al. (33). and, contingently, abortion in pregnant cows In the course of our work on this genus, we (20). examined the properties of 40 Campylobacter (iii) V. fetus subsp. intermedius Elazhary strains, and we shall describe here the charac- 1968 (13, p. 17), first described by Florent (2 1, teristics that permit the recognition or differ- p. 1072) as “intermediate group,” is adapted in entiation of species and subspecies. cattle to the genital tract as well as to the When they proposed the creation of the intestines (2 1). Strains of this subspecies could genus Campylobacter, Sebald and VCron (47) be transferred by venereal processes (39). selected C. fetus (Smith and Taylor) Sebald and (iv) V. coli Doyle 1948 (11, p. 51) is a Vkron as the type species, but failed to indicate normal inhabitant of the intestines of swine, a type strain. No type strain was proposed by poultry, and (occasionally) man, but it is absent Smith and Taylor (53), who originally de- in sheep and cattle (13). It can cause dysentery scribed the species, and none of their strains is in swine, hepatitis in birds, and bloody diar- now in culture. We have therefore selected a rhoea in man. neotype strain, the characteristics of which are (v) V. jejuni Jones et al. 1931 (26, p. 861) in full conformity with the rather fragmentary frequently occurs in the intestinal tracts of original description of the species (53) and of cattle and sheep (13), in which it can cause which a complete description follows. 124 VERON AND CHATELAIN INT. J. SYST. BACTERIOL. MATERIALS AND METHODS the cells from each medium were suspended in 8 ml of 0.3% formalinized saline. The optical density (OD) Bacterial strains. Forty strains of Campylobacter was determined in a Meunier photometer at 550 nm. species were examined, the designations and origins of A comparison of growth was made in different which are indicated in Table 1. Strain CIP (Collection atmospheres (air; 10% CO, in air; 5% 0,, plus 10% of the Pasteur Institute, Paris) 5396 was isolated in CO, , in nitrogen) and at various temperatures (25, 37, 1952 by Doctor Vinzent (Le Havre), who referred to and 45 C) in fluid Albimi broth. it as “souche mouton 1.” It was found in the brain of Microscope investigations. The cells were examined a sheep fetus belonging to a flock in which repeated after 40 h of growth on blood agar and nutrient agar. abortions occurred; this enzootic was described by Motility was determined in hangingdrop preparations, Vinzent and Alloy (56). This strain appears to be the and flagella were stained by Rhodes’ method (44).