Biological and physiological characterization of in vitro blood feeding in nymph and adult stages of Ornithodoros turicata (Acari: Argasidae)

2015 ◽  
Vol 75 ◽  
pp. 73-79 ◽  
Author(s):  
Hongyuan Zheng ◽  
Andrew Y. Li ◽  
Pete D. Teel ◽  
Adalberto A. Pérez de León ◽  
Janakiram Seshu ◽  
...  
2011 ◽  
Vol 78 (5) ◽  
pp. 1544-1555 ◽  
Author(s):  
John T. Wertz ◽  
Eunji Kim ◽  
John A. Breznak ◽  
Thomas M. Schmidt ◽  
Jorge L. M. Rodrigues

ABSTRACTPreviously we reported the cultivation of novel verrucomicrobia, including strain TAV2 (93% 16S rRNA gene identity to its nearest cultivated representative,Opitutus terreaePB90-1) from the gut of the termiteReticulitermes flavipes. To gain better insight into theVerrucomicrobiaas a whole and understand the role of verrucomicrobia within the termite gut ecosystem, we analyzed a draft genome and undertook a physiological characterization of TAV2. Strain TAV2 is an autochthonous member of theR. flavipesgut microbiota and groups phylogenetically among diverseVerrucomicrobiafromR. flavipesand other termites that are represented by 16S rRNA gene sequences alone. TAV2 is a microaerophile, possessing a high-affinitycbb3-type terminal oxidase-encoding gene and exhibiting an optimum growth rate between 2 and 8% (vol/vol) oxygen. It has the genetic potential to degrade cellulose, an important function within termite guts, but itsin vitrosubstrate utilization spectrum was limited to starch and a few mono- and disaccharides. Growth occurred on nitrogen-free medium, and genomic screening revealed genes for dinitrogenases, heretofore detected in only a few members of theVerrucomicrobia. This represents the first (i) characterization of a verrucomicrobial species from the termite gut, (ii) report ofnifandanfgenes in a nonacidophilic verrucomicrobial species, and (iii) description of a microaerophilic genotype and phenotype in this phylum of bacteria. The genetic and physiological distinctiveness of TAV2 supports its recognition as the type strain of a new genus and species, for which the nameDiplosphaera colitermitumgen. nov., sp. nov., is proposed.


Plant Science ◽  
2000 ◽  
Vol 150 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Geraldina Santandrea ◽  
Tiziana Pandolfini ◽  
Andrea Bennici

2017 ◽  
Author(s):  
Joey Kuok Hoong Yam ◽  
Thet Tun Aung ◽  
Song Lin Chua ◽  
Yingying Cheng ◽  
Gurjeet Singh Kohli ◽  
...  

AbstractBiofilms are extremely tolerant toward antimicrobial treatment and host immune clearance due to their distinct physiology and protection by extracellular polymeric substances. Bis-(3´-5´)-cyclic dimeric guanosine monophosphate (c-di-GMP) is an essential messenger that regulates biofilm formation by a wide range of bacteria. However, there is a lack of physiological characterization of biofilmsin vivoas well as the roles of c-di-GMP signaling in mediating host-biofilm interactions. Here, we employed dual RNA-Seq to characterize the host and pathogen transcriptomes duringPseudomonas aeruginosainfection using a mouse keratitis model.In vivo P. aeruginosabiofilms maintained a distinct physiology compared within vitro P. aeruginosabiofilms, with enhanced virulence and iron uptake capacity. C-di-GMP synthesis was enhanced inP. aeruginosacellsin vivo,potentially due to down-regulation of the expression of several phosphodiesterases (e.g., DipA, NbdA). Increased intracellular c-di-GMP levels were required for long-term ocular colonization ofP. aeruginosaand impaired host innate immunity.


2016 ◽  
Vol 173 (2) ◽  
pp. 1355-1370 ◽  
Author(s):  
Enrico Teardo ◽  
Luca Carraretto ◽  
Stephan Wagner ◽  
Elide Formentin ◽  
Smrutisanjita Behera ◽  
...  

2011 ◽  
Vol 47 (3) ◽  
pp. 428-433 ◽  
Author(s):  
Guillermo Pérez ◽  
Andrew Mbogholi ◽  
Fernando Sagarra ◽  
Carlos Aragón ◽  
Justo González ◽  
...  

Author(s):  
H. J. Kirch ◽  
G. Spates ◽  
R. Droleskey ◽  
W.J. Kloft ◽  
J.R. DeLoach

Blood feeding insects have to rely on the protein content of mammalian blood to insure reproduction. A substantial quantity of protein is provided by hemoglobin present in erythrocytes. Access to hemoglobin is accomplished only via erythrocyte lysis. It has been shown that midgut homogenates from the blood feeding stable fly, Stomoxys calcitrans, contain free fatty acids and it was proposed that these detergent-like compounds play a major role as hemolysins in the digestive physiology of this species. More recently sphingomyelinase activity was detected in midgut preparations of this fly, which would provide a potential tool for the enzymatic cleavage of the erythrocyte's membrane sphingomyelin. The action of specific hemolytic factors should affect the erythrocyte's morphology. The shape of bovine erythrocytes undergoing in vitro hemolysis by crude midgut homogenates from the stable fly was examined by scanning and transmission electron microscopy.


1991 ◽  
Vol 66 (04) ◽  
pp. 453-458 ◽  
Author(s):  
John T Brandt

SummaryLupus anticoagulants (LAs) are antibodies which interfere with phospholipid-dependent procoagulant reactions. Their clinical importance is due to their apparent association with an increased risk of thrombo-embolic disease. To date there have been few assays for quantifying the specific activity of these antibodies in vitro and this has hampered attempts to purify and characterize these antibodies. Methods for determining phospholipid-dependent generation of thrombin and factor Xa are described. Isolated IgG fractions from 7 of 9 patients with LAs were found to reproducibly inhibit enzyme generation in these assay systems, permitting quantitative expression of inhibitor activity. Different patterns of inhibitory activity, based on the relative inhibition of thrombin and factor Xa generation, were found, further substantiating the known heterogeneity of these antibodies. These systems may prove helpful in further purification and characterization of LAs.


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