Corynebacterium lizhenjunii sp. nov., isolated from the respiratory tract of Marmota himalayana, and Corynebacterium qintianiae sp. nov., isolated from the lung tissue of Pseudois nayaur.

Abstract

Four Gram-stain-positive, non-motile and asporous bacilli (strains ZJ-599T, ZJ-621, MC1420T and MC1482), isolated from animal tissue and environmental samples collected on the Qinghai-Tibet Plateau, PR China, were taxonomically characterized. Based on the results of 16S rRNA gene sequence analyses, the closest relatives of strains ZJ-599T and ZJ-621 were Corynebacterium endometrii LMM-1653T (97.5\u200a%), Corynebacterium phocae M408/89/1T (96.5\u200a%) and Corynebacterium flavescens OJ8T (96.3\u200a%), whereas strains MC1420T and MC1482 were closest to Corynebacterium sanguinis CCUG 58655T (98.9\u200a%), Corynebacterium mycetoides DSM 20632T (98.4\u200a%) and Corynebacterium lipophiloflavum DSM 44291T (97.9\u200a%). The results of rpoB gene sequence similarity analysis indicated that C. phocae M408/89/1T and C. sanguinis CCUG 58655T were closest to strains ZJ-599T/ZJ-621 (83.5\u200a%) and MC1420T/MC1482 (91.8\u200a%), respectively. The two novel type strains shared a similarity of 95.2\u200a% in 16S rRNA and 81.3\u200a% in rpoB gene sequences. The TAP-PCR DNA fingerprint and MALDI-TOF MS spectrum patterns clearly differentiated the novel isolates within and between each pair of strains. Strain ZJ-599T had 21.9-22.4\u200a% digital DNA-DNA hybridization (dDDH) scores with C. endometrii LMM-1653T, C. phocae M408/89/1T and C. flavescens OJ8T, and 72.3-72.9\u200a% of average nucleotide identity (ANI) with them. Similarly, strain MC1420T had 22.9-23.7\u200a%\u2009dDDH values with C. sanguinis CCUG 58655T, C. mycetoides DSM 20632T and C. lipophiloflavum DSM 44291T, and 80.4-81.3\u200a% ANI scores with them. Strain ZJ-599T had a 23.1\u200a% dDDH value and 70.5\u200a% ANI score with strain MC1420T, both below the corresponding thresholds for species delineation. Strains ZJ-599T and MC1420T both contain mycolic acids and have MK-8(H2) and MK-9(H2) as the predominant respiratory quinones, meso-diaminopimelic acid as the diagnostic diamino acid, and C18\u200a:\u200a1 \u2009ω9c as the main fatty acid. C17\u200a:\u200a1 \u2009ω8c and C15\u200a:\u200a1 \u2009ω8c were predominant in strain ZJ-599T in contrast to C17\u200a:\u200a1 \u2009ω7c being predominant in strain MC1420T. The main polar lipids in strain ZJ-599T were diphosphatidylglycerol, phosphatidylinositol and one unidentified glycolipid, while strain MC1420T had diphosphatidylglycerol, phosphatidylglycerol and one unidentified lipid as the major components. Since the two pairs of novel strains (ZJ-599T/ZJ-621, MC1420T/MC1482) distinctly differ from each other and from their nearest relatives, two novel species of the genus Corynebacterium are proposed, namely Corynebacterium lizhenjunii (type strain ZJ-599T=GDMCC 1.1779T=JCM 34341T) and Corynebacterium qintianiae (type strain MC1420T=GDMCC 1.1783T=JCM 34340T), respectively.