It is unknown whether there is an epidemiological connection between disease in aquarium fish and reef fish, e.g. due to capture of reef fish or release of aquarium fish into the wild. Using standard eBURST group definitions, ST260 but not ST261 is recognized as part of CC552 (Figure 2). However, ST261 is a DLV of multiple CC552 members and could be considered a member of the same group (Figure 3). This group also includes ST246, which has been isolated from trout, and ST257 and 259, which have been isolated from tilapia [14, 16]. ST258, which has been isolated from striped bass [16], is loosely connected to this group,

which does not include any isolates from homeothermic host species. Using the 3-set genotyping system, no surface protein genes or MGEs were detected check details among isolates from this group, further supporting learn more that it is not closely related to any of the known clonal complexes

of S. agalactiae found in humans. ST261 was recently discovered in doctor fish (Gara rufa) that are used in foot spas to remove dead skin from people’s feet and concern has been expressed that repeated exposure of fish-adapted SU5402 purchase strains to such an environment could eventually lead to human infections [45]. In the laboratory, members of the group that includes ST260 and ST261 do not grow well at 37°C, which may explain their current absence from homeothermic species. A vaccine to protect fish from non-haemolytic S. agalactiae is commercially available, but this vaccine does not provide protection to haemolytic strains [14]. Thus, vaccination of fish can be used to limit production losses in some situations, but it does not protect against the most commons strains in Southeast Asia or against zoonotic infections from fish or fish products. Conclusions Based on standardized molecular typing of housekeeping genes and virulence genes, S. agalactiae strains that have previously been associated with asymptomatic carriage and adult invasive disease in humans can also be found in

fish, frogs and sea mammals. In particular, strains belonging to ST23, which is a common carriage strain in humans, were associated with seals, where they may be indicators of environmental pollution rather than causative agents of disease. ST23 was not identified in any fish. Strains belonging to ST7 were associated with a bullfrog and Astemizole fish from South-East Asia whilst strains belonging to ST283 and showing the same virulence gene profile as human invasive isolates were isolated from fish in Asia. This suggests that there may be exposure of humans and fish to similar environmental sources of ST7 and ST283, or transmission of S. agalactiae between the different host species. Finally, strains belonging to ST260 and ST261 were associated with fish from the Americas, Europe and Australia. These strains, and other members of their clonal complex, have only been reported from poikilotherms.