RESUMO
The mechanism by which Helicobacter species are transmitted remains unclear. To examine the possible role of environmental transmission in marine mammals, we sought the presence of Helicobacter spp. and non-Helicobacter bacteria within the order Campylobacterales in water from the aquatic environment of marine mammals, and in fish otoliths regurgitated by dolphins. Water was collected from six pools, two inhabited by dolphins and four inhabited by seals. Regurgitated otoliths were collected from the bottom of dolphins' pools. Samples were evaluated by culture, PCR and DNA sequence analysis. Sequences from dolphins' water and from regurgitated otoliths clustered with 99.8-100% homology with sequences from gastric fluids, dental plaque and saliva from dolphins living in those pools, and with 99.5% homology with H. cetorum. Sequences from seals' water clustered with 99.5% homology with a sequence amplified from a Northern sea lion (AY203900). Control PCR on source water for the pools and from otoliths dissected from feeder fish were negative. The findings of Helicobacter spp. DNA in the aquatic environment suggests that contaminated water from regurgitated fish otoliths and perhaps other tissues may play a role in Helicobacter transmission among marine mammals.
Assuntos
Campylobacter/isolamento & purificação , Helicobacter/isolamento & purificação , Água do Mar/microbiologia , Animais , Campylobacter/genética , Golfinhos , Peixes/microbiologia , Otárias , Helicobacter/genética , Filogenia , Focas VerdadeirasRESUMO
Gastrointestinal lesions with uncertain etiology have been widely described among pinnipeds. The aim of our study was to investigate the presence of Helicobacter spp. in the gastric mucosa of South American fur seals (Arctocephalusaustralis). Gastric biopsies from thirteen seals, stranded on the shores of the Southwestern Atlantic Ocean in Argentina, were evaluated for the presence of Helicobacter spp. by PCR and DNA sequence analysis. Six gastric biopsies were positive for Helicobacter spp. Pairwise sequence comparisons showed less than 95% identity to novel Helicobacter spp. described from pinnipeds from North America and Australia. However, phylogenetic analysis revealed that the South American fur seal sequences clustered with 99-100% homology with H. cetorum, a species isolated from dolphins and whales. The presence of H. cetorum in pinnipeds, if confirmed by its isolation from the gastric mucosa of these mammals, demonstrates the wide host range of this bacterium in the marine environment.
Assuntos
Otárias/microbiologia , Infecções por Helicobacter/veterinária , Helicobacter/isolamento & purificação , Gastropatias/veterinária , Animais , Argentina , Sequência de Bases , Biópsia/veterinária , DNA Bacteriano/química , DNA Bacteriano/genética , Mucosa Gástrica/microbiologia , Helicobacter/genética , Infecções por Helicobacter/microbiologia , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , Alinhamento de Sequência , Gastropatias/microbiologiaRESUMO
The essentiality of zinc for humans was first documented by Prasad in the 1960s. The main clinical manifestations associated with zinc deficiency are growth retardation, hypogonadism, diarrhea, and increased susceptibility to infectious diseases. Thus, in the past 25 yr, there was an increased interest of researchers in studying the role of zinc in human immunity. Although mechanistic research has been carried out using animal models, there are several studies in humans with similar results. This work is an attempt to review the information available in this field to understand the important role that zinc plays in the normal development and function of the immune system.