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Co-cultivation and transcriptome sequencing of two co-existing fish pathogens Moritella viscosa and Aliivibrio wodanis.

Hjerde E, Karlsen C, Sørum H, Parkhill J, Willassen NP, Thomson NR - BMC Genomics (2015)

Bottom Line: Using bacterial implants in the fish abdomen, we demonstrate that the presence of A. wodanis is altering the gene expression levels of M. viscosa compared to when the bacteria are implanted separately.From expression profiling of the transcriptomes, it is evident that the presence of A. wodanis is altering the global gene expression of M. viscosa.Co-cultivation studies showed that A. wodanis is impeding the growth of M. viscosa, and that the inhibitorial effect is not contact-dependent.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Faculty of Science and Technology, University of Tromsø, N-9037, Tromsø, Norway. erik.hjerde@uit.no.

ABSTRACT

Background: Aliivibrio wodanis and Moritella viscosa have often been isolated concurrently from fish with winter-ulcer disease. Little is known about the interaction between the two bacterial species and how the presence of one bacterial species affects the behaviour of the other.

Results: The impact on bacterial growth in co-culture was investigated in vitro, and the presence of A. wodanis has an inhibitorial effect on M. viscosa. Further, we have sequenced the complete genomes of these two marine Gram-negative species, and have performed transcriptome analysis of the bacterial gene expression levels from in vivo samples. Using bacterial implants in the fish abdomen, we demonstrate that the presence of A. wodanis is altering the gene expression levels of M. viscosa compared to when the bacteria are implanted separately.

Conclusions: From expression profiling of the transcriptomes, it is evident that the presence of A. wodanis is altering the global gene expression of M. viscosa. Co-cultivation studies showed that A. wodanis is impeding the growth of M. viscosa, and that the inhibitorial effect is not contact-dependent.

No MeSH data available.


Related in: MedlinePlus

Growth and inhibition zones from bacterial cross streaks and on soft agar overlays. Representative A. wodanis strains positive for the bacteriocin locus (Aw+) were vertical streaked onto blood agar plates: A) A. wodanis 88/09/441, B) A. wodanis 06/09/139. Prependicular and in horizontal streaks: Mv1, M. viscosa 3632; Mv2, M. viscosa 06/09/139; Aw1+ (positive for the bacteriocin locus), A. wodanis 90/09/325; Aw2, A. wodanis 02/09/569. Reduced growth in the vicinity of Aw+ are illustrated for both M. viscosa (a) with Mv2 and for A. wodanis (b) with Aw2 where a clearly defined inhibition zone is observed. In the agar overlay method (c) and (D Aw1+ and Aw2 were first spotted onto the plates and grown to smal colonies before the agar overlay was added and bacterial suspensions of Mv2 (C) and Aw1+ (d) were plated on top. Colonies (Aw1+) surrounded by inhibition zones (marked with *) in the on-top bacterial lawn indicate bacteriocin activity
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Fig4: Growth and inhibition zones from bacterial cross streaks and on soft agar overlays. Representative A. wodanis strains positive for the bacteriocin locus (Aw+) were vertical streaked onto blood agar plates: A) A. wodanis 88/09/441, B) A. wodanis 06/09/139. Prependicular and in horizontal streaks: Mv1, M. viscosa 3632; Mv2, M. viscosa 06/09/139; Aw1+ (positive for the bacteriocin locus), A. wodanis 90/09/325; Aw2, A. wodanis 02/09/569. Reduced growth in the vicinity of Aw+ are illustrated for both M. viscosa (a) with Mv2 and for A. wodanis (b) with Aw2 where a clearly defined inhibition zone is observed. In the agar overlay method (c) and (D Aw1+ and Aw2 were first spotted onto the plates and grown to smal colonies before the agar overlay was added and bacterial suspensions of Mv2 (C) and Aw1+ (d) were plated on top. Colonies (Aw1+) surrounded by inhibition zones (marked with *) in the on-top bacterial lawn indicate bacteriocin activity

Mentions: Prevalence of four bacteriocin-locus genes were assessed by PCR on a collection of A. wodanis isolates, which allowed the discrimination between bacteriocin-locus positive and negative isolates (Additional file 5). However, the three isolates that were found negative for the bacteriocin-locus produced PCR products from primers targeting bacteriocin secretion genes, although the product from one of the two genes were ~300 bp larger than expected (Additional file 5). Four bacteriocin carrying isolates, including A. wodanis 06/09/139, were screened for bacteriocin production using four M. viscosa isolates as indicator organisms. In parallel, the same screening was performed on A. wodanis that did and that did not carry the genotypes (Additional file 5). Both on the blood agar (BA) streak and in the soft agar overlay assay, inhibitorial activity against several M. viscosa isolates were observed (Fig. 4 and Additional file 6). M. viscosa isolates also appear to be differently affected by A. wodanis, which is illustrated in Fig. 4a where M. viscosa isolates responds differently in growth to one A. wodanis strain. Growth inhibition was reproduced in the overlay assay (Fig. 4c) where the effect was more profound. The inhibitorial activity was also tested against A. wodanis isolates, and cross streaking revealed that the antimicrobial activity was strongest between A. wodanis isolates compared to the more distantly related M. viscosa isolates (Fig. 4ab, Additional file 6). A. wodanis isolates with the bacteriocin operon did not exert any strong inhibitorial effect on itself compared to A. wodanis without the bacteriocin operon when cross streaked simultaneously (Fig. 4b). However, a colony inhibited growth of the same strain when it was plated on the overlay agar (Fig. 4d) indicating that the older colony could inhibit growth on non-adapted cells of the same strain.Fig. 4


Co-cultivation and transcriptome sequencing of two co-existing fish pathogens Moritella viscosa and Aliivibrio wodanis.

Hjerde E, Karlsen C, Sørum H, Parkhill J, Willassen NP, Thomson NR - BMC Genomics (2015)

Growth and inhibition zones from bacterial cross streaks and on soft agar overlays. Representative A. wodanis strains positive for the bacteriocin locus (Aw+) were vertical streaked onto blood agar plates: A) A. wodanis 88/09/441, B) A. wodanis 06/09/139. Prependicular and in horizontal streaks: Mv1, M. viscosa 3632; Mv2, M. viscosa 06/09/139; Aw1+ (positive for the bacteriocin locus), A. wodanis 90/09/325; Aw2, A. wodanis 02/09/569. Reduced growth in the vicinity of Aw+ are illustrated for both M. viscosa (a) with Mv2 and for A. wodanis (b) with Aw2 where a clearly defined inhibition zone is observed. In the agar overlay method (c) and (D Aw1+ and Aw2 were first spotted onto the plates and grown to smal colonies before the agar overlay was added and bacterial suspensions of Mv2 (C) and Aw1+ (d) were plated on top. Colonies (Aw1+) surrounded by inhibition zones (marked with *) in the on-top bacterial lawn indicate bacteriocin activity
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4462113&req=5

Fig4: Growth and inhibition zones from bacterial cross streaks and on soft agar overlays. Representative A. wodanis strains positive for the bacteriocin locus (Aw+) were vertical streaked onto blood agar plates: A) A. wodanis 88/09/441, B) A. wodanis 06/09/139. Prependicular and in horizontal streaks: Mv1, M. viscosa 3632; Mv2, M. viscosa 06/09/139; Aw1+ (positive for the bacteriocin locus), A. wodanis 90/09/325; Aw2, A. wodanis 02/09/569. Reduced growth in the vicinity of Aw+ are illustrated for both M. viscosa (a) with Mv2 and for A. wodanis (b) with Aw2 where a clearly defined inhibition zone is observed. In the agar overlay method (c) and (D Aw1+ and Aw2 were first spotted onto the plates and grown to smal colonies before the agar overlay was added and bacterial suspensions of Mv2 (C) and Aw1+ (d) were plated on top. Colonies (Aw1+) surrounded by inhibition zones (marked with *) in the on-top bacterial lawn indicate bacteriocin activity
Mentions: Prevalence of four bacteriocin-locus genes were assessed by PCR on a collection of A. wodanis isolates, which allowed the discrimination between bacteriocin-locus positive and negative isolates (Additional file 5). However, the three isolates that were found negative for the bacteriocin-locus produced PCR products from primers targeting bacteriocin secretion genes, although the product from one of the two genes were ~300 bp larger than expected (Additional file 5). Four bacteriocin carrying isolates, including A. wodanis 06/09/139, were screened for bacteriocin production using four M. viscosa isolates as indicator organisms. In parallel, the same screening was performed on A. wodanis that did and that did not carry the genotypes (Additional file 5). Both on the blood agar (BA) streak and in the soft agar overlay assay, inhibitorial activity against several M. viscosa isolates were observed (Fig. 4 and Additional file 6). M. viscosa isolates also appear to be differently affected by A. wodanis, which is illustrated in Fig. 4a where M. viscosa isolates responds differently in growth to one A. wodanis strain. Growth inhibition was reproduced in the overlay assay (Fig. 4c) where the effect was more profound. The inhibitorial activity was also tested against A. wodanis isolates, and cross streaking revealed that the antimicrobial activity was strongest between A. wodanis isolates compared to the more distantly related M. viscosa isolates (Fig. 4ab, Additional file 6). A. wodanis isolates with the bacteriocin operon did not exert any strong inhibitorial effect on itself compared to A. wodanis without the bacteriocin operon when cross streaked simultaneously (Fig. 4b). However, a colony inhibited growth of the same strain when it was plated on the overlay agar (Fig. 4d) indicating that the older colony could inhibit growth on non-adapted cells of the same strain.Fig. 4

Bottom Line: Using bacterial implants in the fish abdomen, we demonstrate that the presence of A. wodanis is altering the gene expression levels of M. viscosa compared to when the bacteria are implanted separately.From expression profiling of the transcriptomes, it is evident that the presence of A. wodanis is altering the global gene expression of M. viscosa.Co-cultivation studies showed that A. wodanis is impeding the growth of M. viscosa, and that the inhibitorial effect is not contact-dependent.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Faculty of Science and Technology, University of Tromsø, N-9037, Tromsø, Norway. erik.hjerde@uit.no.

ABSTRACT

Background: Aliivibrio wodanis and Moritella viscosa have often been isolated concurrently from fish with winter-ulcer disease. Little is known about the interaction between the two bacterial species and how the presence of one bacterial species affects the behaviour of the other.

Results: The impact on bacterial growth in co-culture was investigated in vitro, and the presence of A. wodanis has an inhibitorial effect on M. viscosa. Further, we have sequenced the complete genomes of these two marine Gram-negative species, and have performed transcriptome analysis of the bacterial gene expression levels from in vivo samples. Using bacterial implants in the fish abdomen, we demonstrate that the presence of A. wodanis is altering the gene expression levels of M. viscosa compared to when the bacteria are implanted separately.

Conclusions: From expression profiling of the transcriptomes, it is evident that the presence of A. wodanis is altering the global gene expression of M. viscosa. Co-cultivation studies showed that A. wodanis is impeding the growth of M. viscosa, and that the inhibitorial effect is not contact-dependent.

No MeSH data available.


Related in: MedlinePlus