. The infected captive cetaceans were either subclinical, or clinical signs included intermittent regurgitation, inappetance, weight loss, and lethargy. Ulcers were observed in the esophagus and forestomach during endoscopic examination in two of the three captive animals. In the third animal, esophageal linear erosions were visualized endoscopically, and histopathological evaluation of the main stomach revealed multifocal lymphoplasmacytic gastritis with silver-stained spiral-shaped bacteria. Helicobacter cetorum is a fusiform gram-negative bacterium with a single bipolar flagellum. The isolates grow under microaerobic conditions at 37 and 42°C but not at 25°C. H. cetorum is urease, catalase, and oxidase positive, and it is sensitive to cephalothin. The isolates from the wild, stranded dolphins were sensitive to nalidixic acid, whereas the isolates from the collection animals were resistant. By 16S rRNA sequencing it was determined that H. cetorum represented a distinct taxon that clusters most closely with H. pylori. Further studies are necessary to determine the role of H. cetorum in the development of gastric ulcers and gastritis of cetaceans. This is the first description and formal naming of a novel Helicobacter species from a marine mammal. More than 24Helicobacter species have been identified and named in a wide variety of animals, as well as in humans (13,39). Members of the genus Helicobacter are microaerobic, have a fusiform or curved to spiral rod morphology, and are motile by flagella that vary in number and location among different species (13,20,21,26,39,40). Helicobacters colonize the gastrointestinal tract of humans and animals and are known to cause gastrointestinal disease in various hosts, whereas others appear to be nonpathogenic (13,20,30). In humans, Helicobacter pylori is a significant cause of peptic ulcer disease, gastritis, and gastric tumors (25,39,40). In animals, Helicobacter spp. may cause ulcerative or nonulcerative gastritis, typhlocolitis, and hepatitis and can lead to tumors in chronic infections (13,14,17). The ability of gastric Helicobacter spp. to colonize the stomach is largely dependent on the production of urease (4). Urease hydrolyzes urea into ammonia, resulting in alkalinization of the gastric mucosa, which promotes bacterial colonization and survival (4).Gastric ulcers have been reported in cetaceans for several decades (8,33,37,38). Parasitic infections have been associated with some lesions, but in other cases no clearly defined etiologies have been identified. We previously described a novel urease-positive Helicobacter sp. cultured from the main stomachs of stranded Atlantic white-sided dolphins that died on the beach in Cape Cod, Mass., and a beluga whale from Mystic Aquarium, Conn. (23,24). Since then, additional strains of this species were cultured from the feces of a Pacific whitesided dolphin, and an Atlantic bottlenose dolphin from various aquaria in the United States (23). Based on morphological, biochemical, and growth characteristics, as well as 16S rRN...
The Standing stock of seaweeds, including the commercially important species, Chondrus crispus (Irish moss) and Furcellaria lumbricalis, was studied seasonally over a five-year period, 1977 through 1981, in northeastern Prince Edward Island, in the southern Gulf of St. Lawrence. Both C. crispus and F. lumbricalis have been harvested äs cast weed ('storm-tossed') in this region. From 1967 through 1981 the annual harvest was quite variable, ranging from around 3000 to 10000 wet tonnes. Estimates of Standing Stocks indicate that there was, however, little annual Variation of either total biomass or individual components, with the Standing stock of all species of seaweeds being around 70000 wet tonnes distributed over an area of 155 km 2 . There is considerable sand within this area, hence the Vegetation was not uniformly distributed, either horizontally or vertically, and the estimated cover of plants was usually 50% or less. Standing Stocks in quantities that could be estimated extended to around 20 m depth, but at depths greater than 15m the Vegetation was sparse. The greatest biomass was in the 2.5 to 5 m depth ränge where C. crispus was the dominant species, whereas F. lumbricalis was the dominant alga in the 7.5 to 10m zone. Together these two species contributed up to 50% of the total Standing stock. The other major individual perennial components included Fucus serratus, F. vesiculosus, Laminaria saccharina, Phyllophora pseudoceranoides and P. truncata. It was not possible to correlate variations of harvest with abiotic or biotic factors.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.