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Isolation and molecular identification of the etiological agents of streptococcosis in Nile tilapia (Oreochromis niloticus) cultured in net cages in Lake Sentani, Papua, Indonesia.

Anshary H, Kurniawan RA, Sriwulan S, Ramli R, Baxa DV - Springerplus (2014)

Bottom Line: The latter species has not been previously isolated or reported from fish streptococcosis in Indonesia.Experimental infections and reisolation of the bacteria from morbid and dead fish suggest they are the causative agents of streptococcosis, which rendered high mortality among cage cultured Nile tilapia in Lake Sentani.Our results suggest the need for developing diagnostic tools for accurate identification of the agents of streptococcosis.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Fish Parasites and Diseases, Department of Fisheries, Faculty of Marine Science and Fisheries, Hasanuddin University, Makassar, Indonesia.

ABSTRACT
Infections with Streptococcus spp. were observed in Nile tilapia cultured in net cages in Lake Sentani, Papua, Indonesia. Clinical signs included exophthalmia, erratic swimming, ascites in abdominal cavity, and external hemorrhages. Four types of bacterial colonies (SK, K10, P20, and M12) were isolated from the brain, kidney, and eyes. Based on phenotypic and genetic (16S rDNA sequencing) characteristics, the isolates were identified as Streptococcus iniae (SK), Streptococcus agalactiae (K10 and P20) and Lactococcus garvieae (M12). The latter species has not been previously isolated or reported from fish streptococcosis in Indonesia. Intraperitoneal injection of healthy tilapia with the bacterial species caused significant morbidity (70%) within 3 days and 100% mortality at 6 days post injection. Experimental infections and reisolation of the bacteria from morbid and dead fish suggest they are the causative agents of streptococcosis, which rendered high mortality among cage cultured Nile tilapia in Lake Sentani. Our results suggest the need for developing diagnostic tools for accurate identification of the agents of streptococcosis. As tilapia aquaculture continues to expand as a means of food production and livelihood in Indonesia, it becomes crucial to ensure that fish resources are monitored and protected from the adverse effects of infectious diseases.

No MeSH data available.


Related in: MedlinePlus

Phylogenetic tree ofStreptococcus iniae(SK − KM209199) andS. agalactiae(K10 − KM209200; P20− KM209201) from the present study (*) and otherStreptococcusspp. based on 16S rRNA gene sequences. Neighbor-joining tree was constructed using MEGA 6 maximum composite likelihood method and 1000 bootstrap number with complete deletion. Percentages ≥50% are shown at the internal nodes. Bacillus subtilis was used as an outgroup.
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Fig2: Phylogenetic tree ofStreptococcus iniae(SK − KM209199) andS. agalactiae(K10 − KM209200; P20− KM209201) from the present study (*) and otherStreptococcusspp. based on 16S rRNA gene sequences. Neighbor-joining tree was constructed using MEGA 6 maximum composite likelihood method and 1000 bootstrap number with complete deletion. Percentages ≥50% are shown at the internal nodes. Bacillus subtilis was used as an outgroup.

Mentions: A phylogenetic tree was constructed using the Neighbor-joining method which showed that S. agalactiae (K10 and P20) and S. iniae (SK) in the present study was placed in the same clade with respective species in GenBank (Figure 2). The same result was observed in the phylogenetic analysis of L. garvieae (M12) in that it was placed in the same clade as other L. garvieae reported from fish and shrimp (Figure 3).Figure 2


Isolation and molecular identification of the etiological agents of streptococcosis in Nile tilapia (Oreochromis niloticus) cultured in net cages in Lake Sentani, Papua, Indonesia.

Anshary H, Kurniawan RA, Sriwulan S, Ramli R, Baxa DV - Springerplus (2014)

Phylogenetic tree ofStreptococcus iniae(SK − KM209199) andS. agalactiae(K10 − KM209200; P20− KM209201) from the present study (*) and otherStreptococcusspp. based on 16S rRNA gene sequences. Neighbor-joining tree was constructed using MEGA 6 maximum composite likelihood method and 1000 bootstrap number with complete deletion. Percentages ≥50% are shown at the internal nodes. Bacillus subtilis was used as an outgroup.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4216822&req=5

Fig2: Phylogenetic tree ofStreptococcus iniae(SK − KM209199) andS. agalactiae(K10 − KM209200; P20− KM209201) from the present study (*) and otherStreptococcusspp. based on 16S rRNA gene sequences. Neighbor-joining tree was constructed using MEGA 6 maximum composite likelihood method and 1000 bootstrap number with complete deletion. Percentages ≥50% are shown at the internal nodes. Bacillus subtilis was used as an outgroup.
Mentions: A phylogenetic tree was constructed using the Neighbor-joining method which showed that S. agalactiae (K10 and P20) and S. iniae (SK) in the present study was placed in the same clade with respective species in GenBank (Figure 2). The same result was observed in the phylogenetic analysis of L. garvieae (M12) in that it was placed in the same clade as other L. garvieae reported from fish and shrimp (Figure 3).Figure 2

Bottom Line: The latter species has not been previously isolated or reported from fish streptococcosis in Indonesia.Experimental infections and reisolation of the bacteria from morbid and dead fish suggest they are the causative agents of streptococcosis, which rendered high mortality among cage cultured Nile tilapia in Lake Sentani.Our results suggest the need for developing diagnostic tools for accurate identification of the agents of streptococcosis.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Fish Parasites and Diseases, Department of Fisheries, Faculty of Marine Science and Fisheries, Hasanuddin University, Makassar, Indonesia.

ABSTRACT
Infections with Streptococcus spp. were observed in Nile tilapia cultured in net cages in Lake Sentani, Papua, Indonesia. Clinical signs included exophthalmia, erratic swimming, ascites in abdominal cavity, and external hemorrhages. Four types of bacterial colonies (SK, K10, P20, and M12) were isolated from the brain, kidney, and eyes. Based on phenotypic and genetic (16S rDNA sequencing) characteristics, the isolates were identified as Streptococcus iniae (SK), Streptococcus agalactiae (K10 and P20) and Lactococcus garvieae (M12). The latter species has not been previously isolated or reported from fish streptococcosis in Indonesia. Intraperitoneal injection of healthy tilapia with the bacterial species caused significant morbidity (70%) within 3 days and 100% mortality at 6 days post injection. Experimental infections and reisolation of the bacteria from morbid and dead fish suggest they are the causative agents of streptococcosis, which rendered high mortality among cage cultured Nile tilapia in Lake Sentani. Our results suggest the need for developing diagnostic tools for accurate identification of the agents of streptococcosis. As tilapia aquaculture continues to expand as a means of food production and livelihood in Indonesia, it becomes crucial to ensure that fish resources are monitored and protected from the adverse effects of infectious diseases.

No MeSH data available.


Related in: MedlinePlus