Mannheimia pernigra sp. nov., isolated from bovine respiratory tract

Abstract

Over a period of 1 year, 270 isolates identified as Taxon 39 of Bisgaard were obtained from the nasopharynx of veal calves at 11 epidemiologically independent Swiss fattening farms. Two isolates from each farm and the Australian Taxon 39 reference strain BNO311 were further characterized by genetic and phenotypic methods. Phylogenetic analysis of 16S rRNA and recN gene sequences placed the isolates in a single, distinct cluster within the genus Mannheimia . As to the rpoB gene, most isolates clustered together, but four strains formed a separate cluster close to Mannheimia varigena . Genome sequence analysis of isolates from both rpoB clusters confirmed their species status, with an average nucleotide identity (ANI) >98.9 % between isolates and <84 % to the closest species, M. varigena . Based upon whole genome sequences, the G+C content was determined as 39.1 mol%. Similarly, analysis of MALDI-TOF MS reference spectra clustered the isolates clearly separated from the other Mannheimia species, making this the method of choice for identification. In addition, numerous biochemical markers based on classical as well as commercial identification schemes were determined, allowing separation from other Mannheimia species and identification of the new taxon. Major fatty acids for strain 17CN0883T are C14 : 0, C16 : 0, C16 : 1 ω7c and C18 : 1 ω7c. Major respiratory quinones are ubiquinone-7 and ubiquinone-8. We propose the name Mannheimia pernigra sp. nov. for former Taxon 39 of Bisgaard. The type strain is 17CN0883T (=CCUG 74657T=DSM 111153T) isolated from a veal calf in Switzerland.

Mannheimia indoligenes sp. nov., proposed for clade V organisms of Mannheimia

“…Variations were observed in ornithine decarboxylase ( Phenotypic characters obtained are in accordance with those of Pasteurellaceae and the genus Mannheimia [8]. Isolates of clade V can only be separated from M. varigena by production of indole, while two to seven characters separate clade V from M. haemolytica (2), M. glucosida (3), M. granulomatis (3), M. ruminalis (3), M. caviae (7) [9], M. pernigra (6) [10], and M. cairinae (6) [11] (Table 1).…”

“…Twenty isolates of clade V representing biogroups 6, 7, 8, 9, 10, 11, and 12 of the former [P.] haemolytica-complex were subjected to characterization by MALDI-TOF by generating main spectra profiles (MSPs) as previously reported by Kuhnert et al [10] (Table 2). These strains made up a separate phenon clustering at a distance level of >200 with type strains of other Mannheimia species in the MSP dendrogram, supporting that clade V represents a new species of Mannheimia (Fig.…”

Mannheimia cairinae sp. nov., a novel species of Mannheimia obtained from Muscovy ducks (Cairina moschata) and reclassification of Mannheimia ovis as heterotypic synonym of Mannheimia pernigra

“…This was supported by a high 94.1 % DDH estimated by recN prediction between M. pernigra and M. ovis type strains, indicating species relatedness using the conventional 70 % DDH as threshold [7]. We propose that M. ovis (Li et al 2021) [5,6] should be reclassified as a later heterotypic synonym of M. pernigra (Kuhnert et al 2021) [3], since M. pernigra was validly published before M. ovis.…”

“…Subsequently, 270 isolates identified as taxon 39 of Bisgaard were obtained from the nasopharynx of veal calves at 11 epidemiologically independent Swiss fattening farms. Taxonomic investigations allowed a clear separation from other Mannheimia species and identification of a new species, Mannheimia pernigra [3].…”

“…Phenotypic characteristics separating the species of MannheimiaSpecies: 1, Mannheimia cairinae sp. nov.; 2, Mannheimia pernigra[3]; 3, Mannheimia haemolytica[1]; 4, Mannheimia glucosida[1]; 5, Mannheimia granulomatis[1]; 6, Mannheimia ruminalis[1]; 7, Mannheimia varigena[1]; 8, Mannheimia caviae[4].…”