Diversity of Infectious Pancreatic Necrosis Virus Strains Isolated from Fish, Shellfish, and Other Reservoirs in Northwestern Spain

Abstract

A comparison was done of 231 strains of birnavirus isolated from fish, shellfish, and other reservoirs in a survey study that began in 1986 in Galicia (northwestern Spain). Reference strains from all of the infectious pancreatic necrosis virus serotypes were included in the comparison, which was done by neutralization tests and agarose and polyacrylamide gel electrophoresis of the viral genome. The neutralization tests with antisera against the West Buxton, Spajarup (Sp), and Abild (Ab) strains showed that most of the Galician isolates were European types Sp and Ab; however, many isolates (30%) could not be typed. Results from agarose gels did not provided information for grouping of the strains, since all were found to have genomic segments of similar sizes. Analysis of polyacrylamide gels, however, allowed six electropherogroups (EGs) to be differentiated on the basis of genome mobility and separation among segments, and a certain relationship between EGs and serotypes was observed. A wide diversity of electropherotypes was observed among the Galician isolates, and as neutralization tests showed, most of the isolates were included in EGs corresponding to European types Ab and Sp. Only 6.5% of the isolates had the electropherotype characteristic of American strains.

Restriction Fragment Length Polymorphisms and Sequence Analysis: an Approach for Genotyping Infectious Pancreatic Necrosis Virus Reference Strains and Other Aquabirnaviruses Isolated from Northwestern Spain

“…On the other hand, it must be noted that the local isolates used in the present study were selected based on the results of previous electropherotyping of their genomes, as reported by Cutrin et al (6). Our results clearly indicate that electropherotyping is an incorrect approach for typing aquabirnaviruses No.…”

“…Based on the electrophoretic mobilities of their genomes, these Galician strains were previously classified into electropherogroups by Cutrin et al (6). All the viruses were propagated in Chinook salmon embryo cells (CHSE-214) at 15°C by using Eagle's minimum essential medium supplemented with 100 IU of penicillin per ml, 100 g of streptomycin per ml, and 10% fetal calf serum.…”

Surveillance of Viruses in Wild Fish Populations in Areas around the Gulf of Cadiz (South Atlantic Iberian Peninsula)

“…However, at present, this geographical distribution has been altered probably because of natural migrations of wild fish populations, the use of fish as feed in aquaculture, and/or commercial movements of fish stocks (3,5). In this sense, a screening for IPNV performed by Cutrín et al (44) in northwestern Spain showed that most of the isolates belonged to genotypes II (Ab) and III (Sp), but some were typed as American strains of genotype I (WB and Jasper type strains), a genotype that could have entered that region through the importation of trout eggs from North America, as the authors hypothesized. The same research team, studying the wild fish populations of the Flemish Cap (Newfoundland) observed that although most of the strains detected were typed as WB, Dry Mills, or Jasper, a few isolates were included in typically European genotype II (Ab strain) (45); those findings were explained by the authors as being due to the migration of fish from Europe to Newfoundland.…”

Enhancement of superoxide dismutase and catalase activity in juvenile brown shrimp, Farfantepenaeus californiensis (Holmes, 1900), fed β 1.3 glucan vitamin E, and β caroteneand infected with white spot syndrome virus

“…These have been isolated mostly from clinical samples of diseased animals from fish farms (Cutrin et al, 2000;Rodríguez-Saint-Jean et al, 2003). A considerable effort has been done in order to establish virulence factors with the purpose of gaining information that may be useful to develop managing tools for fish industry; for instance, if geographic locations of the most virulent strains are established, preventive measures can be apply with more emphasis at those places.…”