Escherichia albertii is a recently discovered species with a limited number of well characterized strains. The aim of this study was to characterize four of the E. albertii strains, which were among 41 identified Escherichia strains isolated from the feces of living animals on James Ross Island, Antarctica, and Isla Magdalena, Patagonia. Sequencing of 16S rDNA, automated ribotyping, and rep-PCR were used to identify the four E. albertii isolates. Phylogenetic analyses based on multi-locus sequence typing showed these isolates to be genetically most similar to the members of E. albertii phylogroup G3. These isolates encoded several virulence factors including those, which are characteristic of E. albertii (cytolethal distending toxin and intimin) as well as bacteriocin determinants that typically have a very low prevalence in E. coli strains (D, E7). Moreover, E. albertii protein extracts caused cell cycle arrest in human cell line A375, probably because of cytolethal distending toxin activity.

• MeSH
• Charadriiformes microbiology   MeSH
• Escherichia genetics   isolation & purification   metabolism   MeSH
• Feces microbiology   MeSH
• Multilocus Sequence Typing veterinary   MeSH
• Polymerase Chain Reaction veterinary   MeSH
• Electrophoresis, Gel, Pulsed-Field veterinary   MeSH
• Ribotyping veterinary   MeSH
• RNA, Ribosomal, 16S genetics   MeSH
• Spheniscidae microbiology   MeSH
• Seals, Earless microbiology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Antarctic Regions MeSH
• Chile MeSH

Two amoeboid organisms of the genera Sappinia Dangeard, 1896 and Rosculus Hawes, 1963 were identified in a sample containing king penguin guano. This sample, collected in the Subantarctic, enlarges the list of fecal habitats known for the presence of coprophilic amoebae. The two organisms were co-isolated and subcultured for over 6 mo, with continuous efforts being invested to separate each one from the mixed culture. In the mixed culture, Rosculus cells were fast growing, tolerated changes in culturing conditions, formed cysts, and evidently were attracted by Sappinia trophozoites. The separation of the Rosculus strain was accomplished, whereas the Sappinia strain remained intermixed with inseparable Rosculus cells. Sappinia cell populations were sensitive to changes in culturing conditions; they improved with reduction of Rosculus cells in the mixed culture. Thick-walled cysts, reportedly formed by Sappinia species, were not seen. The ultrastructure of both organisms was congruent with the currently accepted generic characteristics; however, some details were remarkable at the species level. Combined with the results of phylogenetic analyses, our findings indicate that the ultrastructure of the glycocalyx and the presence/absence of the Golgi apparatus in differential diagnoses of Sappinia species require a critical re-evaluation.

• MeSH
• Amoebozoa classification   genetics   isolation & purification   ultrastructure   MeSH
• Cercozoa classification   genetics   isolation & purification   ultrastructure   MeSH
• Ecosystem MeSH
• Feces parasitology   MeSH
• Phylogeny MeSH
• Spheniscidae parasitology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Georgia MeSH

Trophically-transmitted parasites are regularly exposed to potential new hosts through food web interactions. Successful colonization, or switching, to novel hosts, occur readily when 'donor' and 'target' hosts are phylogenetically related, whereas switching between distantly related hosts is rare and may result from stochastic factors (i.e. rare favourable mutations). This study investigates a host-switching event between a marine acanthocephalan specific to pinnipeds that is apparently able to reproduce in Magellanic penguins Spheniscus magellanicus from Brazil. Detailed analysis of morphological and morphometrical data from acanthocephalans from penguins indicates that they belong to Corynosoma australe Johnston, 1937. Partial fragments of the 28S rRNA and mitochondrial cox1 genes were amplified from isolates from penguins and two pinniped species (i.e. South American sea lion Otaria flavescens and South American fur seal Arctocephalus australis) to confirm this identification. Infection parameters clearly differ between penguins and the two pinniped species, which were significantly lower in S. magellanicus. The sex ratio of C. australe also differed between penguins and pinnipeds; in S. magellanicus was strongly biased against males, while in pinnipeds it was close to 1:1. Females of C. australe from O. flavescens were smaller than those from S. magellanicus and A. australis. However, fecundity (i.e. the proportion of fully developed eggs) was lower and more variable in females collected from S. magellanicus. At first glance, the occurrence of reproductive individuals of C. australe in Magellanic penguins could be interpreted as an adaptive colonization of a novel avian host through favourable mutations. However, it could also be considered, perhaps more likely, as an example of ecological fitting through the use of a plesimorphic (host) resource, since the ancestors of Corynosoma infected aquatic birds.

• MeSH
• Acanthocephala * MeSH
• Ecology MeSH
• Phylogeny MeSH
• Host-Parasite Interactions physiology   MeSH
• Fur Seals parasitology   MeSH
• Sea Lions parasitology   MeSH
• Sex Ratio MeSH
• Spheniscidae parasitology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

Psychrophilic Antarctic yeasts produce polysaccharides in different concentrations. According to morphological, cultural, physiological and biochemical characteristics, the best producer strain was identified as Cryptococcus flavus A51. The highest values for viscosity (59.1 mPa s) and crude polysaccharide productivity (5.75 g/L) were obtained in a medium containing 5 % sucrose and 0.25 % (NH4)2SO4, at 24 °C for 6 d. The chemical composition and sugar constituents of the crude exopolysaccharide were determined (92.5 % saccharides, 3.34 % protein, and 4.16 % ash). The monosaccharide composition of the exopolysaccharide obtained from C. flavus strain AL51 was established (55.1 % mannose, 26.1 % glucose, 9.60 % xylose, 1.90 % galactose). The microbial biopolymer has a high molar mass and homogeneity: 82 % of it had M 1.01 MDa.

• MeSH
• Financing, Organized MeSH
• Yeasts chemistry   isolation & purification   metabolism   MeSH
• Polysaccharides chemistry   metabolism   MeSH
• Spheniscidae microbiology   MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Geographicals
• Antarctic Regions MeSH