Comparison of virulence genes in Proteus species isolated from human and pet turtle

The current study was aimed to investigate the prevalence of ureC, rsbA, zapA and mrpA virulence genes using polymerase chain reaction (PCR) in Proteus spp. isolated from 5 commercially popular species of pet turtles and comparison of the mrpA gene sequences of Proteus mirabilis isolates with human clinical isolates. A total of 24 isolates in pet turtles were identified, comprised of P. mirabilis (15), Proteus vulgaris (7) and Proteus hauseri (2). The prevalence of ureC, rsbA, zapA and mrpA genes among all identified Proteus spp. isolates were 91.7%, 50%, 45.8% and 45.8%, respectively. The average percentage similarities of mrpA gene sequence of pet turtle P. mirabilis isolates to human urinary and respiratory isolates were 96.35% and 94.85%, respectively. The prevalence of virulence genes and high similarity of mrpA gene sequences between pet turtles and human P. mirabilis isolates revealed that though pet turtles are healthy, these animals may pose a potential risk of urinary and respiratory infections to humans.

Immunoproteomic analysis of capsulate and non-capsulate strains of Lactococcus garvieae

A comparative immunoproteomic study was carried out to investigate the immunogenicity of capsulate (KG9408) and non-capsulate (NSS9310) strains of Lactococcus garvieae. Immunoblot assays, following two-dimensional gel electrophoresis (2-DE) for L. garvieae strains, revealed a significant difference between anti-capsulate and anti-non-capsulate rabbit sera with respect to the number and antigenicity of antigenic spots. Anti-capsulate and anti-non-capsulate rabbit sera reacted with an average of 72 and 127 antigenic spots, respectively. The strong reaction of anti-non-capsulate sera with elongation factor (EF)-G and -Tu, and GMP synthase, of the L. garvieae strains identifies these as specific major antigens. This study clearly demonstrates the differences in 2-DE immunoblot profiles between the capsulate and non-capsulate strains of L. garvieae. These differences may be the reason for variations in immunogenicity between capsulate and non-capsulate strains. Glyceraldehyde-3-phosphate dehydrogenase, phosphoglycerate kinase, arginine deaminase and ornithine carbamoyltransferase were identified from the 2-DE immunoblot profiles of both strains. Therefore, these common antigens are potential markers for the development of vaccines against L. garvieae, irrespective of strain. Immunoproteomics, a powerful tool for studying antigens at the proteomic level, allowed a comparative investigation of the immunogenicity of capsulate and non-capsulate strains of L. garvieae for vaccine development.

Spread of Neoheterobothrium hirame (Monogenea), a serious pest of olive flounder Paralichthys olivaceus, to Korea

Neoheterobothrium hirame is a large, blood-feeding gill-worm infecting the highly prized olive flounder Paralichthys olivaceus in Japan. There is strong evidence that this worm is the primary cause of anaemia, a common and serious condition causing losses among both wild and cultured olive flounders. N. hirame was first detected in Japanese waters less than a decade ago, and its population then proliferated and spread throughout most of Japan, except Hokkaido. In neighbouring Korea, olive flounder is the most important species of cultured marine fish, and production currently exceeds that in Japan. However, until now, there have been no reports of any monogeneans or anaemia among olive flounders in Korea. Our survey conducted in 2000 of 100 cultured individuals from 4 provinces revealed 2 immature specimens of N. hirame: 1 from a land-based pond-culture system in southern Cheju Island (off the SW coast of Korea) and the other from a floating net cage near Yosu (in the mid-S part of the peninsula). The geographic range of this pathogen may have been enlarged as a result of introduction(s) of infected broodstock from Japan, but this seems unlikely. (The raising of this species in hatcheries developed in Korea in 1985, 7 years before the earliest detection of the worm in Japan.) Low numbers of flounders were also clearly anaemic. This, and the current rarity of N. hirame in Korean farms, appears to favour the hypothesis of a more recent, natural dispersal of the worm, during migrations of infected flounder across the narrow and shallow Tsushima and Korea Straits. Regardless of route of entry, we expect this pathogen will have an impact on Korean flounder fisheries equally serious to that being experienced in Japan.