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. 2022 Jul 18;12(14):1827.
doi: 10.3390/ani12141827.

Corynebacterium conjunctivae: A New Corynebacterium Species Isolated from the Ocular Surface of Healthy Horses

José F Fernández-Garayzábal  1   2 , Stacey LaFrentz  3 , Almudena Casamayor  1 , Eva Abarca  4 , Haitham H Mohammed  5 , Rosemary S Cuming  6 , Cova R Arias  7 , Lucas Domínguez  1   2 , Ana I Vela  1   2
Affiliations

Corynebacterium conjunctivae: A New Corynebacterium Species Isolated from the Ocular Surface of Healthy Horses

José F Fernández-Garayzábal et al. Animals (Basel). .

Abstract

Twenty-two unidentified Gram-positive, rod-shaped organisms were recovered from the conjunctival surface of apparently healthy horses and subjected to a polyphasic taxonomic analysis. Based on cellular morphology and biochemical criteria, the isolates were tentatively assigned to the genus Corynebacterium, although they did not match any recognized species. Comparative 16S rRNA gene sequencing studies demonstrated that all of the isolates were phylogenetically members of the genus Corynebacterium. The isolates shared 99.4 to 100% 16S rRNA gene sequence similarity among the strains and 96.5% similarity with Corynebacterium tapiri 2385/12T, which was the closest phylogenetically related species. The DNA G+C content was 58.4 mol%. The major fatty acids were C15:0, C16:0, C17:1 ω8c and C18:1 ω9c, while the predominant mycolic acids consisted of C30:0, C32:0 and C34:0. The isolates were distinguished from related Corynebacterium species by a number of phenotypic properties. On the basis of phenotypic and phylogenetic evidence, it is proposed that the unknown isolates from horses be classified in the genus Corynebacterium as Corynebacterium conjunctivae sp. nov. The type strain of C. conjunctivae is ICM19-01138T (DSM 109759T = CCUG 73728T).

Keywords: Corynebacterium; conjunctiva; horse; taxonomy.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Neighbor-joining tree based on 16S rRNA showing the phylogenetic relationships within the genus Corynebacterium of Corynebacterium conjunctivae sp. nov. Mycobacterium smegmatis MC2 155T was used as an out-group. Bootstrap values (expressed as a percentage of 1000 replications) higher than 70% are given at the branching points. The nodes (groupings) also obtained in the maximum-likelihood and parsimony trees are indicated by open circles. The corresponding nodes also obtained in the parsimony tree are indicated by filled circles. Bar, 1% sequence divergence.
Figure 2
Figure 2
PFGE patterns of Corynebacterium conjunctivae sp. nov generated after XbaI macrorestriction. Lanes 1 and 12, Salmonella serotype Branderup strain H9812; Lanes 2 to 11, strains ICM19/01138T (four isolates), ICM19/01139 (four isolates), ICM19/01141 (five isolates), ICM19/01144 (two isolates), ICM20/00190, ICM20/00191, ICM20/00193, ICM20/00195 (two isolates), ICM20/00199 and ICM20/00202, respectively.
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References

    1. Leigue L., Montiani-Ferreirm F., Moore B.A. Antimicrobial susceptibility and minimal inhibitory concentration of Pseudomonas aeruginosa isolated from septic ocular surface disease in different animal species. Open Vet. J. 2016;6:215–222. doi: 10.4314/ovj.v6i3.9. - DOI - PMC - PubMed
    1. Willcox M.D. Characterization of the normal microbiota of the ocular surface. Exp. Eye Res. 2013;117:99–105. doi: 10.1016/j.exer.2013.06.003. - DOI - PubMed
    1. Kugadas A., Gadjeva M. Impact of microbiome in ocular health. Ocul. Surf. 2016;14:342–349. doi: 10.1016/j.jtos.2016.04.004. - DOI - PMC - PubMed
    1. Andrew S.E., Nguyen A., Jones G.L., Brooks D.E. Seasonal effects on the aerobic bacterial and fungal conjunctival flora of normal thoroughbred brood mares in Florida. Vet. Ophthalmol. 2003;6:45–50. doi: 10.1046/j.1463-5224.2003.00265.x. - DOI - PubMed
    1. Gemensky-Metzler A.J., Wilkie D.A., Kowalski J.J., Schmall L.M., Willis A.M., Yamagata M. Changes in bacterial and fungal ocular flora of clinically normal horses following experimental application of topical antimicrobial or antimicrobial-corticosteroid ophthalmic preparations. Am. J. Vet. Res. 2005;66:800–811. doi: 10.2460/ajvr.2005.66.800. - DOI - PubMed

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