This study reports the first isolation of Streptococcus agalactiae and an aquatic birnavirus from the doctor fish, G. rufa in Ireland. As the fish examined in this study did not show clinical signs of disease, the cause of the mortality was most likely due to transport stress exacerbated by the presence of both pathogens. However it should be noted that acute mortalities can often occur following viral/bacterial infections with little or no clinical signs of disease. The increased popularity of health spas using these fish for pedicures has resulted in a dramatic rise in the demand for their supply. A 2012 report from the UK  stated that between 15,000–20,000 G. rufa were imported each week through Heathrow Airport, the main border inspection post for the import of live fish into the UK. Despite the large numbers of fish coming into the EU, there is very little published information available on the requirements of these fish, either in terms of fish welfare (transport, husbandry etc.), or in terms of the risk they pose to native fish stocks and to customers who use these fish at health spas. Mortality of G. rufa in fish hatcheries has been associated with the aquatic pathogens Aeromonas sobria and Citrobacter freundii. This study reported the isolation of S. agalactiae from moribund fish without clinical signs of disease, although it is known that this bacteria may be pathogenic for fish species including G. rufa[11, 14]. These bacteria, also known as Lancefield group B streptococcus, have a broad host range and can cause meningoencephalitis in fish, mastitis in cattle and meningitis in human neonates. Although there is a high genetic diversity between strains of S. agalactiae, experimental transmission studies have shown that isolates from human, bovine and piscine origins can cause clinical disease in fish [15, 16]. A range of other bacteria with the potential to cause zoonotic infections have been isolated from doctor fish  including vibrio and mycobacteria species. As these bacteria do not have optimal growth at 37°C, infections are mostly confined to the superficial, cooler body tissues of the extremities. Reports of infections are rare however and have mostly been confined to fish handlers and aquarium hobbyists , however at least one infection due to a pedicure treatment has been reported . The UK Health Protection Agency has published guidelines for the management of health risks associated with fish pedicures and has classified the risk of zoonotic infection as low . The G. rufa isolate was also found to be resistant to four out of six antibiotics tested and the susceptibility to the remaining two antibiotics is questionable due to the small size of the inhibition zones and the general lack of data in which to calculate epidemiological cut-off values for determining sensitivity. Antimicrobial resistance of bacteria isolated from tropical fish is well known due to the widespread use of antibiotics in the transport water [11, 20].
The birnavirus family are double-stranded, non-enveloped RNA viruses consisting of four genera, two of which contain aquatic viruses, Aquabirnavirus (type species: infectious pancreatic necrosis virus IPNV) and Blosnavirus (type species: blotched snakehead virus BSNV). Aquabirnaviruses have been isolated from aquatic animals throughout the world and infectious pancreatic necrosis is a significant disease of farmed salmonids in Ireland . Although this is the first isolation in Ireland of an aquatic birnavirus, other than IPNV, mortalities due to birnavirus infections in tropical fish have been reported previously [10, 22]. Sequence analysis indicated that the isolate was similar to other viruses, such as BSNV, isolated from tropical fish  and initially assigned to a separate serogroup (C) within the genus Aquabirnavirus. Studies on BSNV  showed that it was distinct from other aquabirnaviruses and was assigned to its own genus, Blosnavirus. Although further characterisation of the virus isolate from this study is required, the results would suggest that the birnavirus isolated from G. rufa is more related to blosnavirus than aquabirnavirus.