Samanta Michelini

Bifidobacterium myosotis sp. nov., Bifidobacterium tissieri sp. nov. and Bifidobacterium hapali sp. nov., isolated from faeces of baby common marmosets (Callithrix jacchus L.).

In a previous study on bifidobacterial distribution in New World monkeys, six strains belonging to the Bifidobacteriaceae were isolated from faecal samples of baby common marmosets (Callithrix jacchus L.). All the isolates were Gram-positive-staining, anaerobic, asporogenous and fructose-6-phosphate phosphoketolase-positive. Comparative analysis of 16S rRNA gene sequences revealed relatively low levels of similarity (maximum identity 96 %) to members of the genus Bifidobacterium, and placed the isolates in three independent clusters: strains of cluster I (MRM_5.9T and MRM_5.10) and cluster III (MRM_5.18T and MRM_9.02) respectively showed 96.4 and 96.7 % 16S rRNA gene sequence similarity to Bifidobacterium callitrichos DSM 23973T, while strains of cluster II (MRM_8.14T and MRM_9.14) showed 95.4 % similarity to Bifidobacterium stellenboschense DSM 23968T. Phylogenetic analysis of partial hsp60 and clpC gene sequences supported an independent phylogenetic position of each cluster from each other and from the related type strains B. callitrichos DSM 23973T and B. stellenboschense DSM 23968T. Clusters I, II and III respectively showed DNA G+C contents of 64.9-65.1, 56.4-56.7 and 63.1-63.7 mol%. The major cellular fatty acids of MRM_5.9T were C14 : 0, C16 : 0 and C18 : 1ω9c dimethylacetal, while C16 : 0 was prominent in strains MRM_5.18T and MRM_8.14T, followed by C18 : 1ω9c and C14 : 0. Biochemical profiles and growth parameters were recorded for all the isolates. Based on the data provided, the clusters represent three novel species, for which the names Bifidobacterium myosotis sp. nov. (type strain MRM_5.9T = DSM 100196T = JCM 30796T), Bifidobacterium hapali sp. nov. (type strain MRM_8.14T = DSM 100202T = JCM 30799T) and Bifidobacterium tissieri sp. nov. (type strain MRM_5.18T = DSM 100201T = JCM 30798T) are proposed.

Bifidobacterium aerophilum sp. nov., Bifidobacterium avesanii sp. nov. and Bifidobacterium ramosum sp. nov.: Three novel taxa from the faeces of cotton-top tamarin (Saguinus oedipus L.) ☆

Forty-five microorganisms were isolated on bifidobacteria selective medium from one faecal sample of an adult subject of the cotton-top tamarin (Saguinus oedipus L.). All isolates were Gram-positive, catalase-negative, anaerobic, fructose-6-phosphate phosphoketolase positive, and asporogenous rod-shaped bacteria. In this study, only eight out of the forty-five strains were characterized more deeply, whereas the others are still currently under investigation. They were grouped by BOX-PCR into three clusters: Cluster I (TRE 17(T), TRE 7, TRE 26, TRE 32, TRE 33, TRE I), Cluster II (TRE C(T)), and Cluster III (TRE M(T)). Comparative analysis of 16S rRNA gene sequences confirmed the results from the cluster analysis and revealed relatively low level similarities to each other (mean value 95%) and to members of the genus Bifidobacterium. All eight isolates showed the highest level of 16S rRNA gene sequence similarities with Bifidobacterium scardovii DSM 13734(T) (mean value 96.6%). Multilocus sequence analysis (MLSA) of five housekeeping genes (hsp60, rpoB, clpC, dnaJ and dnaG) supported their independent phylogenetic position to each other and to related species of Bifidobacterium. The G+C contents were 63.2%, 65.9% and 63.0% for Cluster I, Cluster II and Cluster III, respectively. Peptidoglycan types were A3α l-Lys-l-Thr-l-Ala, A4β l-Orn (Lys)-d-Ser-d-Glu and A3β l-Orn-l-Ser-l-Ala in Clusters I, II and III, respectively. Based on the data provided, each cluster represented a novel taxon for which the names Bifidobacterium aerophilum sp. nov. (TRE 17(T)=DSM 100689=JCM 30941; TRE 26=DSM 100690=JCM 30942), Bifidobacterium avesanii sp. nov. (TRE C(T)=DSM 100685=JCM 30943) and Bifidobacterium ramosum sp. nov. (TRE M=DSM 100688=JCM 30944) are proposed.

Isolation and identification of cultivable Bifidobacterium spp. from the faeces of 5 baby common marmosets (Callithrix jacchus L.)

Ninety-two bifidobacterial strains were obtained from the faeces of 5 baby common marmosets, three known species Bifidobacterium aesculapii, Bifidobacterium callithricos and Bifidobacterium reuteri and 4 novel putative bifidobacterial species were retrieved. The occurrence of bifidobacteria in non-human primate babies is described for the first time.

Bifidobacterium. eulemuris sp. nov. isolated from the faeces of the black lemur (Eulemur macaco).

Forty-three strains of bifidobacteria were isolated from the faeces of two adult black lemurs, Eulemur macaco. Thirty-four were identified as Bifidobacterium lemurum, recently described in Lemur catta. The nine remaining isolates were Gram-positive-staining, non-spore-forming, fructose-6-phosphate phosphoketolase-positive, microaerophilic, irregular rod-shaped bacteria that often presented Y- or V-shaped cells. Typing techniques revealed that these isolates were nearly identical, and strain LMM_E3T was chosen as a representative and characterized further. Phylogenetic analysis based on 16S rRNA gene sequences clustered this isolate inside the genus Bifidobacterium and showed the highest levels of sequence similarity with B. lemurum DSM 28807T (99.3 %), with Bifidobacterium pullorum LMG 21816T and Bifidobacterium longum subsp. infantis ATCC 15697T (96.4 and 96.3 %, respectively) as the next most similar strains. The hsp60 gene sequence of strain LMM_E3T showed the highest similarity to that of Bifidobacterium stellenboschense DSM 23968T (93.3 %), and 91.0 % similarity to that of the type strain of B. lemurum. DNA-DNA reassociation with the closest neighbour B. lemurum DSM 28807T was found to be 65.4 %. The DNA G+C content was 62.3 mol%. Strain LMM_E3T showed a peptidoglycan structure that has not been detected in bifidobacteria so far: A3α l-Lys-l-Ser-l-Thr-l-Ala. Based on the phylogenetic, genotypic and phenotypic data, strain LMM_E3T represents a novel species within the genus Bifidobacterium, for which the name Bifidobacterium eulemuris sp. nov. is proposed; the type strain is LMM_E3T ( = DSM 100216T = JCM 30801T).

Identification of Bifidobacterium spp. using hsp60 PCR-RFLP analysis: An update

A PCR-RFLP technique has been applied on 13 species of Bifidobacterium in order to update a previous study carried out by Baffoni et al. This method is based on the restriction endonuclease activity of HaeIII on the PCR-amplified hsp60 partial gene sequence, and allows a rapid and efficient identification of Bifidobacterium spp. strains at species and subspecies level.

Bifidobacterium callitrichidarum sp. nov. from the faeces of the emperor tamarin (Saguinus imperator)

Three Gram-stain-positive, non-spore-forming, microaerophilic and fructose-6-phosphate phosphoketolase positive strains were isolated from a faecal sample of an adult subject of the emperor tamarin (Saguinus imperator). Given that the isolates revealed identical BOX PCR profiles, strain TRI 5T was selected as a representative and characterized further. Comparative analysis of 16S rRNA gene sequence similarity revealed that strain TRI 5T was closely related to Bifidobacterium saguini DSM 23967T (96.4 %) and to Bifidobacterium longum subsp. longum ATCC 15708 (96.2 %). Multilocus sequence analyses of five housekeeping genes showed the close phylogenetic relatedness of this strain to Bifidobacterium breve DSM 20213T (hsp60 94.1 %), Bifidobacterium saguini DSM 23967T (clpC 91 %), Bifidobacterium avesanii DSM 100685T (dnaG 80.3 %), Bifidobacterium longumsubsp. infantis ATCC 15697T (dnaJ 85.3 %) and Bifidobacterium longumsubsp. longum ATCC 15708 (rpoB 93 %), respectively. The peptidoglycan type was A3β, with an interpeptide bridge comprising l-Orn (Lys) - l-Ser - l-Ala - l-Thr - l-Ala. The DNA G+C content of strain TRI 5T was 60.9 mol%. Based on the data provided, strain TRI 5T represents a novel species of the genus Bifidobacterium for which the name Bifidobacteriumcallitrichidarum sp. nov. is proposed. The type strain is TRI 5T (=DSM 103152T=JCM 31790T).

Bifidobacterium catulorum sp. nov., a novel taxon from the faeces of the baby common marmoset (Callithrix jacchus)

In our previous study based on hsp60 PCR-restriction fragment length polymorphism and 16S rRNA gene sequencing, we stated that the bifidobacterial strains isolated from the individual faecal samples of five baby common marmosets constituted different phylogenetically isolated groups of the genus Bifidobacterium. In that study, we also proposed that these isolated groups potentially represented novel species of the genus Bifidobacterium. Out of them, Bifidobacterium aesculapii, Bifidobacterium myosotis, Bifidobacterium tissieri and Bifidobacterium hapali, have been described recently. Another strain, designated MRM 8.19T, has been classified as member of the genus Bifidobacterium on the basis of positive results for fructose-6-phosphate phosphoketolase activity and analysis of partial 16S rRNA, hsp60, clpC, dnaJ, dnaG and rpoB gene sequences. Analysis of 16S rRNA and hsp60 gene sequences revealed that strain MRM 8.19T was related to B. tissieri DSM 100201T (95.8 %) and to Bifidobacterium bifidum ATCC 29521T (93.7 %), respectively. The DNA G+C composition was 63.7 mol% and the peptidoglycan structure was l-Orn(Lys)-l-Ser. Based on the phylogenetic, genotypic and phenotypic data reported, strain MRM 8.19T represents a novel taxon within the genus Bifidobacterium for which the name Bifidobacterium catulorum sp. nov. (type strain MRM 8.19T=DSM 103154T=JCM 31794T) is proposed.

Bifidobacterium primatium sp. nov., Bifidobacterium scaligerum sp. nov., Bifidobacterium felsineum sp. nov. and Bifidobacterium simiarum sp. nov.: Four novel taxa isolated from the faeces of the cotton top tamarin (Saguinus oedipus) and the emperor tamarin (Saguinus imperator)

Four novel Gram-stain-positive, non spore forming and fructose-6-phosphate phosphoketolase-positive strains were isolated from the faeces of a cotton top tamarin (Saguinus oedipus) and an emperor tamarin (Saguinus imperator). Phylogenetic analyses based on 16S rRNA revealed that bifidobacterial strains TRE 1T exhibit close phylogenetic relatedness to Bifidobacterium catulorum DSM 103154 (96.0%) and Bifidobacterium tissieri DSM 100201 (96.0%); TRE DT and TRE HT were closely related to Bifidobacterium longum subsp. longum ATCC 15708T with similarity values of 97.4% and 97.5%, respectively; TRI 7T was closely related to Bifidobacterium tissieri DSM 100201 (96.0%). The Average Nucleotide Identity (ANI) and in silico DDH (isDDH) analysis with closest neighbour supported an independent phylogenetic position of all strains with values ranged from 74 to 85% for ANI and from 24 to 28% for isDDH. DNA base composition of the four strains was in the range of 58.3-63.5mol% G+C. Based on the phylogenetic, genotypic and phenotypic data, the strains TRE 1T, TRE DT, TRE HT and TRI 7T clearly represent four novel taxa within the genus Bifidobacterium for which the names Bifidobacterium primatium sp. nov. (type strain TRE 1T=DSM 100687T=JCM 30945T), Bifidobacterium scaligerum sp. nov. (type strain TRE DT=DSM 103140T=JCM 31792T), Bifidobacterium felsineum sp. nov. (type strain TRE HT=DSM 103139T=JCM 31789T) and Bifidobacterium simiarum sp. nov. (type strain TRI 7T=DSM 103153T=JCM 31793) are proposed.