RESUMO
Striped bass (Morone saxatilis) in the Chesapeake Bay are currently experiencing a very high prevalence of mycobacteriosis associated with newly described Mycobacterium species, Mycobacterium pseudoshottsii and M. shottsii. The ecology of these mycobacteria outside the striped bass host is currently unknown. In this work, we developed quantitative real-time PCR assays for M. pseudoshottsii and M. shottsii and applied these assays to DNA extracts from Chesapeake Bay water and sediment samples, as well as to tissues from two dominant prey of striped bass, Atlantic menhaden (Brevoortia tyrannus) and bay anchovy (Anchoa mitchilli). Mycobacterium pseudoshottsii was found to be ubiquitous in water samples from the main stem of the Chesapeake Bay and was also present in water and sediments from the Rappahannock River, Virginia. M. pseudoshottsii was also detected in menhaden and anchovy tissues. In contrast, M. shottsii was not detected in water, sediment, or prey fish tissues. In conjunction with its nonpigmented phenotype, which is frequently found in obligately pathogenic mycobacteria of humans, this pattern of occurrence suggests that M. shottsii may be an obligate pathogen of striped bass.
Assuntos
Monitoramento Ambiental/estatística & dados numéricos , Peixes/microbiologia , Água Doce/microbiologia , Sedimentos Geológicos/microbiologia , Mycobacterium/genética , Reação em Cadeia da Polimerase/métodos , Água do Mar/microbiologia , Animais , Sequência de Bases , Primers do DNA/genética , Sequências Repetitivas Dispersas/genética , Maryland , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Análise de Sequência de DNA , Especificidade da Espécie , VirginiaRESUMO
Four blunt-snouted sandbar sharks (Carcharhinus plumbeus) were noted among 555 examined over a 13-yr period. Radiographs of one specimen revealed that the three rostral cartilage rods were abnormally short and failed to join at the anterior tip. The deformity appeared to be congenital. Four cases of vertebral lesions were noted in three species of shark (Carcharhinus plumbeus, Negaprion brevirostris and Odontaspis taurus). The vertebral columns had fused centra, ribs and neural arches, extra deposition and erosion of calcified material in the centra, and in one case, compression of centra. The causes of the vertebral lesions are unknown.