scholarly journals First Identification and Characterization of Lactococcus garvieae Isolated from Rainbow Trout (Oncorhynchus mykiss) Cultured in Mexico

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1609
Author(s):  
Cesar Ortega ◽  
Rute Irgang ◽  
Benjamín Valladares-Carranza ◽  
Constanza Collarte ◽  
Ruben Avendaño-Herrera
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Consensus Sequence ◽  
Fish Farming ◽  
16S Rrna Gene Sequencing ◽  
Surveillance Program ◽  
Rrna Gene ◽  
Biochemical Tests ◽  
Lactococcus Garvieae ◽  
Rainbow Trout Oncorhynchus Mykiss

Lactococcosis is a hyperacute hemorrhagic septicemia disease caused by Lactococcus garvieae, which is an emerging pathogen in global fish farming. Between 2016 and 2018, rainbow trout (Oncorhynchus mykiss) from five farms that presented outbreaks were sampled as part of a Mexican surveillance program for the detection of fish diseases. Fourteen L. garvieae isolates were recovered from sampled fish, as confirmed by biochemical tests, 16S rRNA gene sequencing, and clinical and histological insights. The biochemical and protein profiles of the isolates obtained were homogeneous. Repetitive extragenic palindromic—(REP)—and enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) analyses established weak genetic heterogeneity. Rainbow trout challenged with two of the isolates used at different bacterial concentrations (10−2 and 10−4 CFU/mL) showed melanosis, and hemorrhages were observed in the fins, liver, kidney, and spleen. Isolates were obtained from all of the organs sampled, including from surviving fish, as either pure or mixed cultures. The present study is the first to confirm the presence of L. garvieae as the agent of severe lactococcosis outbreaks in the two primary Mexican states for trout farming.

scholarly journals Citrobacter tructae sp. nov. Isolated from Kidney of Diseased Rainbow Trout (Oncorhynchus mykiss)

2021 ◽  
Vol 9 (2) ◽  
pp. 275
Author(s):  
Won Joon Jung ◽  
Hyoun Joong Kim ◽  
Sib Sankar Giri ◽  
Sang Guen Kim ◽  
Sang Wha Kim ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Biochemical Characterization ◽  
Antibiotic Resistance Genes ◽  
Housekeeping Genes ◽  
Rrna Gene ◽  
Bacterial Identification ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
The 16S Rrna Gene ◽  
Genome Distance

A novel Citrobacter species was isolated from the kidney of diseased rainbow trout (Oncorhynchus mykiss) reared on a trout farm. Biochemical characterization and phylogenetic analysis were performed for bacterial identification. Sequencing of the 16S rRNA gene and five housekeeping genes indicated that the strain belongs to the Citrobacter genus. However, multilocus sequence analysis, a comparison of average nucleotide identity, and genome-to-genome distance values revealed that strain SNU WT2 is distinct and forms a separate clade from other Citrobacter species. Additionally, the phenotype characteristics of the strain differed from those of other Citrobacter species. Quinone analysis indicated that the predominant isoprenoid quinone is Q-10. Furthermore, strain virulence was determined by a rainbow trout challenge trial, and the strain showed resistance to diverse antibiotics including β-lactams, quinolone, and aminoglycosides. The complete genome of strain SNU WT2 is 4,840,504 bp with a DNA G + C content of 51.94% and 106,068-bp plasmid. Genome analysis revealed that the strain carries virulence factors on its chromosome and antibiotic resistance genes on its plasmid. This strain represents a novel species in the genus Citrobacter for which the name C. tructae has been proposed, with SNU WT2 (=KCTC 72517 = JCM 33612) as the type strain.

scholarly journals Study of pathogenicity and severity of Lactococcus garvieae isolated from rainbow trout (Oncorhynchus mykiss) farms in Kohkilooieh and Boyerahmad province

2019 ◽  
Vol 22 (1) ◽  
Author(s):  
Esmaeil Karami ◽  
Mojtaba Alishahi ◽  
Taravat Molayemraftar ◽  
Masoud Ghorbanpour ◽  
Mohammad Reza Tabandeh ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Systemic Infection ◽  
Fish Farms ◽  
Pcr Assay ◽  
Biochemical Tests ◽  
High Severity ◽  
Lactococcus Garvieae ◽  
Specific Pcr ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Trout Farms

Abstract Background Lactococcus garvieae is one of the most important risk factors in the rainbow trout culture. Therefore, the purpose of this study was to identify and detect strains isolated from rainbow trout suspected of having Lactococcus garvieae using biochemical characteristics and PCR and determination of the degree of severity of isolated strains. Methods In this study, the cause of lactococcosis in selected rainbow trout farms in Kohkilooieh and Boyerahmad province was assayed. Gram-positive and catalase-negative bacterial isolates were first obtained from selected trout fish farms using conventional biochemical tests and PCR assay. The 10-day LD50 method (concentration causing 50% mortality in 10 days) was used to determine the severity of the isolated bacteria. Results One bacterial isolate was detected from all sampled fish which confirmed as Lactococcus garvieae using a specific PCR assay based on the 16S rDNA gene by producing a single band of 1107 bp. Analysis of the rate of mortality showed that the 10-day LD50 was 4.6 × 105 CFU/fish. The results of this study showed that isolated bacteria had high severity for rainbow trout. The presence of bacteria in internal organs of suspected fish showed a severe systemic infection in challenged fish. Antibiogram assay also indicated that the isolated Lactococcus garvieae were resistant to some mostly used antibiotics in rainbow trout. Conclusions According to current research, it can be concluded that the condition of lactococcosis in the studied area is not suitable, and despite the presence of disease, there is no proper action to control and prevent the disease. Unfortunately, isolated bacteria from the studied area have a very high severity compared to bacteria isolated from other regions of the country or other countries. Therefore, further investigation is needed to determine the cause of this difference and possibly in the design of the vaccine.

Depletion of selected polychlorinated biphenyl, dibenzodioxin, and dibenzofuran congeners in farmed rainbow trout (Oncorhynchus mykiss): A hint for safer fish farming

Chemosphere ◽  
2007 ◽  
Vol 66 (6) ◽  
pp. 1019-1030 ◽  
Author(s):  
Gianfranco Brambilla ◽  
Elena Dellatte ◽  
Igor Fochi ◽  
Nicola Iacovella ◽  
Roberto Miniero ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Polychlorinated Biphenyl ◽  
Fish Farming ◽  
Rainbow Trout Oncorhynchus Mykiss

scholarly journals Growth of rainbow trout (oncorhynchus mykiss) in the conditions of Tashkent province, Uzbekistan

2021 ◽  
Vol 258 ◽  
pp. 04040
Author(s):  
SH Sulaymonov ◽  
G Abdullaev ◽  
S Saidumarov
Keyword(s):  
Water Quality ◽  
Rainbow Trout ◽  
Dissolved Oxygen ◽  
Oncorhynchus Mykiss ◽  
Water Temperature ◽  
Fish Farming ◽  
Local Conditions ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Fish Productivity ◽  
Feed Coefficient

Rainbow trout is a new fish farming object for Uzbekistan, the adaptability of which (first of all, growth) to local conditions should be carefully studied. We analyzed the growth of rainbow trout in the conditions of flowing pools and cages in the foothill zone of Tashkent province of Uzbekistan. From March to October, the water temperature in the Khojikent reservoir varied from 4.9 to 13.1 °C, the amount of dissolved oxygen was 8.4 to 11.5 mg/l, and the pH was 7.40 to 7.67. In the flowing basin, the temperature was 15-18 °C, pH 7.2-7.5, the amount of dissolved oxygen 6.1-11.2 mg/l. The conditions of the foothill zones of Uzbekistan in terms of water quality are favorable for the development of trout breeding. During the season, fish in cages increased from 250 g to 623 g, in pools from 25 g to 390 g on average. The waste was 1.7%. The actual fish productivity of the basin is 39 kg/m3, the cage is 30 kg/m3 and the feed coefficient in the basin is 1.2, in the cages - 1.09.

Sign in / Sign up

Export Citation Format

Share Document