<i>Acinetobacter </i>Strain KUO11TH, a Unique Organism Related to <i>Acinetobacter pittii</i> and Isolated from the Skin Mucus of Healthy Bighead Catfish and Its Efficacy Against Several Fish Pathogens

• Main Authors: Anurak Bunnoy, Uthairat Na-Nakorn, Pattanapon Kayansamruaj, Prapansak Srisapoome
• Format: Article
• Language: English
• Published: MDPI AG 2019-11-01
• Series: Microorganisms
• Subjects: acinetobacter; 16s rrna; gyrb; rpob; genome sequence; ani; in silico ddh; clarias microcephalus; probiotics; antagonists; acb complex
• Online Access: https://www.mdpi.com/2076-2607/7/11/549

The bacterial strain KU011TH was isolated from the skin mucus of healthy bighead catfish. The strain is a Gram-negative coccobacillus that is nonmotile, aerobic, catalase positive, oxidase negative, and nonhemolytic. Sequence analyses of the housekeeping genes <i>16S rRNA</i>, <i>gyrB</i> and <i>rpoB</i> indicate that this strain is a new member of the Acb complex of the genus <i>Acinetobacter</i> and is closely related to <i>Acinetobacter </i><i>pittii</i><i> </i>and <i>Acinetobacter </i><i>lactucae</i><i>. </i>In addition<i>, </i>the genome relatedness-associated ANIb (&lt;95&#8722;96%) and <i>in silico</i> DDH (&lt;70%) values clearly supported the new member of the genus <i>Acinetobacter </i>and the Acb complex. The genome of the strain KU011TH was approximately 3.79 Mbp in size, comprising 3619 predicted genes, and the DNA G+C content was 38.56 mol%. The major cellular fatty acids were C18:1&#969;9c, C16:0, C16:1, C20:2, C18:2&#969;6c and C18:1&#969;9t. The whole-genome sequences and phenotypic, phylogenetic, and chemotaxonomic data clearly support the classification of the strain KU011TH as a new member in the genus <i>Acinetobacter</i> which is closest to <i>A. pittii.</i> Additionally, the new bacterial strain exhibited strong activity against a broad range of freshwater fish pathogens <i>in vitro</i>.