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Holothuria
About: Holothuria is a research topic. Over the lifetime, 362 publications have been published within this topic receiving 4982 citations.
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TL;DR: The domain of bacterial and limited fungal contamination confirms the results that showed strong antifungal activity of investigated extract, and the presence of isolates of five human Gram-negative pathogenic bacteria representing five genera is confirmed.
Abstract: Microbiological studies were carried out on microbial contamination and antimicrobial activity of sea cucumber Holothuria polii collected from Mediterranean Sea at Abu-kir shore of Alexandria, Egypt. The obtained results revealed the presence of isolates of five human Gram-negative pathogenic bacteria, representing five genera were identified to species level, including, Esherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella sp. and Shigella sp. In addition, an yeast Candida albicans was isolated. The pathogenic bacteria were identified using API 20E strip system (BioMereux). All collected H. polii specimens were healthy with no external signs of infection. Histopathological study of the tegument, intestine and gonads showed no abnormal changes. The antimicrobial activity of two tegumental ethanol extracts (A and B, differ in the method of dehydration) were tested against wide range of pathogenic bacteria and fungi, including intestinal, skin and nosocomial pathogens and one plant fungal pathogen. The results revealed a remarkable antifungal activity of the extract B at 2.5 mg/ml MIC90, especially on Aspergillus niger, Scloretium sp, C. albicans, Aspergillus flavus and Malassezia furfur, and limited antibacterial activity against Gram-negative bacteria (Salmonella choleraesuis ATCC 14028 and Aeromonas hydrophila). The domain of bacterial and limited fungal contamination confirms the results that showed strong antifungal activity of investigated extract.
25 citations
TL;DR: Progenitor cells lacking elaborate cytoplasmic specialization and with a probable staminal function are also normal circulating coelomocytes of Holothuria polii.
Abstract: The ultrastructure of Holothuria polii coelomocytes is described and related to cell functions. Amebocytes, spherule cells and progenitor cells are the major circulating cellular types. Two morphological phases (bladder and filipodial) of the amebocytes are distinguished. Type I and Type II spherule cells are described on the basis of the morphological and ultrastructural characteristics of their granules. Maturative stages of these cells are also observed. Probably a third type of spherule cell is present. It could correspond to the acidophilic and Schmorl's positive cells. Progenitor cells lacking elaborate cytoplasmic specialization and with a probable staminal function are also normal circulating coelomocytes of Holothuria polii.
25 citations
TL;DR: Results highlight that the wounds were responsible for the stress condition with the induction of cellular and biochemical responses, and produced, compared with controls, a significant increase in HSP27 and HSP70 expression in coelomocytes.
25 citations
TL;DR: The Holothuria polii coelomocyte lysate contains two trypsin-resistant lytic proteins having different chemico-physical properties: a calcium dependent and heat-labile hemolysin and the sphingomyelin, which seems to be the membrane receptor with which both hemolysins interact producing lysis.
Abstract: The Holothuria polii coelomocyte lysate contains two trypsin-resistant lytic proteins having different chemico-physical properties : a calcium dependent and heat-labile hemolysin that is probably a constitutive component of the coelomic fluid, and another calcium independent and heat-stable one that is released after immunological stimulation; it is therefore not detectable in natural conditions. The sphingomyelin seems to be the membrane receptor with which both hemolysins interact producing lysis.
24 citations
TL;DR: The results for the COI gene showed many recent and exclusive haplotypes with few mutational changes, suggesting recent or ongoing population expansion, and the Western and Eastern Mediterranean populations exhibited slight but significant genetic differentiation (COI gene) with higher genetic diversity in the East.
Abstract: We studied the genetic structure of the sea cucumber Holothuria (Roweothuria) polii (Delle Chiaje 1823) by analysing the mitochondrial DNA variation in two fragments of cytochrome oxidase I (COI) and 16S genes. Individuals were collected in seven locations along the Mediterranean Sea, which cover a wide range of the species distribution. We found high haplotype diversity for COI and moderate diversity for 16S, and low nucleotide diversity for both genes. Our results for the COI gene showed many recent and exclusive haplotypes with few mutational changes, suggesting recent or ongoing population expansion. The Western and Eastern Mediterranean populations exhibited slight but significant genetic differentiation (COI gene) with higher genetic diversity in the East. The most ancient haplotype was not present in the westernmost sampling location (SE Spain). The oldest expansion time was observed in Turkey, corresponding to mid-Pleistocene. Turkey had also the highest genetic diversity (number of total and exclusive haplotypes, polymorphisms, haplotype and nucleotide diversity). This suggests that this region could be the origin of the subsequent colonizations through the Mediterranean Sea, a hypothesis that should be assessed with nuclear markers in future research.
24 citations