Identification of Francisella noatunensis in novel host species French grunt (Haemulon flavolineatum) and Caesar grunt (Haemulon carbonarium).

Francisella noatunensis is an emerging pathogen of fish that has been isolated from several cultured species worldwide. Here presented is a case involving several hundred marine grunts that were caught near the Florida Keys for display in public aquaria. These fish were maintained in a recirculating system where they began to experience mortalities approximately two weeks post-stocking. Postmortem examination revealed disseminated systemic granulomatous disease most severely affecting spleen and kidney. Splenic and renal tissue homogenates inoculated in modified Thayer Martin agar media yielded colonies consistent with F. noatunensis 4 days post inoculation. Bacterial colonies and tissues were confirmed positive after real-time PCR amplification of the intracellular growth loci gene (iglC) specific for F. noatunensis subspecies orientalis. Consequently, multiple novel host species for this pathogen were identified, including the French grunt (Haemulon flavolineatum) and the Caesar grunt (Haemulon carbonarium).

Comparison of cloacal and oropharyngeal samples for the detection of avian influenza virus in wild birds.

This study was conducted to compare oropharyngeal (OP) and cloacal samples of wild birds (n = 137) for the detection and isolation of avian influenza virus (AIV). A total of 39 (28.5%) cloacal and 85 (62.0%) OP samples were positive for AIV by real-time reverse transcription-PCR (RRT-PCR). The AIV nucleic acid was detected in both cloacal and OP samples from 27 (19.7%) birds, in cloacal samples only from 12 (8.8%) birds, and in OP samples only from 58 (42.3%) birds. Thus, a total of 97 (70.8%) birds were AIV positive by RRT-PCR. The cycle threshold values for the cloacal samples ranged from 16.6 to 36.9 (mean 31.5), and those for OP samples ranged from 18 to 38.9 (mean 34.9). Of the cloacal samples, 12 were positive for H5 subtype influenza virus by RRT-PCR, with one being low pathogenic H5N1. In contrast, five of the OP samples were H5 positive, but none was H5N1. None of the cloacal or OP samples was H7 positive. Eight cloacal samples yielded AIV on inoculation in embryonated chicken eggs, while only one isolate was obtained from OP samples. Thus, from testing of 137 birds, only nine (6.6%) AIV isolates were obtained. The isolates from cloacal samples were subtyped as H6N1 (n = 5), H3N8 (n = 2), and H4N8 (n = 1), and the isolate from OP sample was subtyped as H6N1. No virus was isolated from the corresponding cloacal sample of the bird whose OP sample yielded AIV on virus isolation. These results suggest that surveillance programs for detection of AIV by RRT-PCR may include both sample types (cloacal and OP) to obtain a better picture of AIV prevalence, and OP samples may yield additional isolates of AIV when tested in conjunction with cloacal samples.

Regional specification in the early embryo of the brittle star Ophiopholis aculeata.

Early embryogenesis has been examined experimentally in several echinoderm and hemichordate classes. Although these studies suggest that the mechanisms which underlie regional specification have been highly conserved within the echinoderm + hemichordate clade, nothing is known about these mechanisms in several other echinoderm classes, including the Ophiuroidea. In this study, early embryogenesis was examined in a very little studied animal, the ophiuroid Ophiopholis aculeata. In O. aculeata, the first two cleavage planes do not coincide with the animal-vegetal axis but rather form approximately 45 degrees off this axis. A fate map of the early embryo was constructed using microinjected lineage tracers. Most significantly, this fate map indicates that there is a major segregation of ectodermal from endomesodermal fates at first cleavage. The distribution of developmental potential in the early embryo was also examined by isolating different regions of the early embryo and following these isolates though larval development. These analyses indicate that endomesodermal developmental potential segregates unequally at first, second, and third cleavage in O. aculeata. These results provide insight into the mechanisms of regional specification in O. aculeata and yield new material for the study of the evolution of echinoderm development.