Characterization of membrane surface proteins of Mycoplasma agalactiae during natural infection

ABSTRACT A family of abundant surface proteins (Vpmas [variable proteins ofMycoplasma agalactiae]) undergoing phase variation inM. agalactiae has been characterized using monoclonal antibodies and specific polyclonal sera. Two expressed members of 39 kDa (Vpma39) and 34 kDa (Vpma34), which varied in expression between clones of a lineage, shared a common amino-terminal sequence but were immunologically distinct. An amino-terminal oligonucleotide probe identified multiple vpma genes which were clustered within a 14-kb ClaI genomic fragment. Rearrangements were found to have occurred within the vpma locus between clones which correlated with changes in their Vpma phenotype. Two neighboringvpma genes were cloned and sequenced from one M. agalactiae clonal variant expressing Vpma39. The two genes,vpmaX and vpmaY, were orientated divergently and shared highly homologous 5′ untranslated regions, 25-amino-acid (aa) lipoprotein leader sequences, and amino-terminal sequences. ThevpmaY gene coded for 346 aa and 84% of the open reading frame, comprised of 1.5 units of a large repeat of 186 aa. Although the sequence for an entire second vpmaY repeat was present, it was prematurely terminated by insertion of two nucleotides. ThevpmaX gene encoded 221 aa and possessed 102 aa of the 186-aa repeat of vpmaY. Many of the features in common between the vpma genes were also found to be shared by thevsp genes of M. bovis, which also undergo DNA rearrangements concomitant with phenotypic changes. Since M. bovis is the closest phylogenetic relative to M. agalactiae, the vpma and vsp gene families most probably represent homologous systems.

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Development of a Multivalent ISCOM Vaccine against Anaplasmosis

10.32747/1993.7568763.bard ◽

1993 ◽

Author(s):

Guy H. Palmer ◽

Eugene Pipano ◽

Terry F. McElwain ◽

Varda Shkap ◽

Donald P. Knowles, Jr.

Keyword(s):

T Lymphocytes ◽

Outer Membrane ◽

Membrane Surface ◽

Surface Protein ◽

The United States ◽

Surface Proteins ◽

Efficient Production ◽

Major Surface ◽

Homologous Challenge

Anaplasmosis is an arthropod+borne disease of cattle caused by the rickettsia Anaplasma marginale and an impediment to efficient production of healthy livestock in both Israel and the United States. Our research focuses on development of a recombinant membrane surface protein (MSP) immunogen to replace current vaccines derived from the blood of infected cattle. The risk of widespread transmission of both known and newly emergent pathogens has prevented licensure of live blood-based vaccines in the U.S. and is a major concern for their continued use in Israel. Briefly, we accomplished the following in our BARD supported research: i) characterization of the intramolecular and intermolecular relationships of the native Major Surface Proteins (MSP) in the outer membrane; ii) expression, purification, and epitope characterization of the recombinant MSP-2, MSP-3, MSP-4, and MSP-5 proteins required to construct the recombinant ISCOM; iii) demonstration that the outer membrane-Quil A induces CD4+ T lymphocytes specific for the outer membrane polypeptides; iv) identification of CD4+ T lymphocytes that recognize outer membrane polypeptide epitopes conserved among other wise antigenically distinct strains; v) determination that immunization with the outer membrane-Quil A construct does not affect the ability of ticks to acquire or transmit A. marginale; and vi) demonstration that the outer membrane-Quil A construct induces complete protection against rickettsemia upon homologous challenge and significant protection against challenge with antigenically distinct strains, including tick transmission. Importantly, the level of protection against homologous challenge in the MSP vaccinates was comparable to that induced by live blood-based vaccines and demonstrates that development of a new generation of vaccines is feasible.

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Ultrastructural identification of three types of sensory setae on copepod antennae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141159 ◽

1995 ◽

Vol 53 ◽

pp. 956-957

Author(s):

T. M. Weatherby ◽

P.H. Lenz

Keyword(s):

Phase Locking ◽

Membrane Surface ◽

Reaction Times ◽

High Sensitivity ◽

Structural Features ◽

Calanoid Copepods ◽

Marine Food Webs ◽

Dendritic Membrane ◽

Ultrastructural Characterization

Crustaceans, as well as other arthropods, are covered with sensory setae and hairs, including mechanoand chemosensory sensillae with a ciliary origin. Calanoid copepods are small planktonic crustaceans forming a major link in marine food webs. In conjunction with behavioral and physiological studies of the antennae of calanoids, we undertook the ultrastructural characterization of sensory setae on the antennae of Pleuromamma xiphias.Distal mechanoreceptive setae exhibit exceptional behavioral and physiological performance characteristics: high sensitivity (<10 nm displacements), fast reaction times (<1 msec latency) and phase locking to high frequencies (1-2 kHz). Unusual structural features of the mechanoreceptors are likely to be related to their physiological sensitivity. These features include a large number (up to 3000) of microtubules in each sensory cell dendrite, arising from or anchored to electron dense rods associated with the ciliary basal body microtubule doublets. The microtubules are arranged in a regular array, with bridges between and within rows. These bundles of microtubules extend far into each mechanoreceptive seta and terminate in a staggered fashion along the dendritic membrane, contacting a large membrane surface area and providing a large potential site of mechanotransduction.

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Effect of trypsin on the cell surface proteins of hepatoma tissue culture cells. Characterization of a carbohydrate-rich glycopeptide released from a calcium binding membrane glycoprotein.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)50677-3 ◽

1979 ◽

Vol 254 (10) ◽

pp. 3935-3946 ◽

Cited By ~ 6

Author(s):

H Baumann ◽

D Doyle

Keyword(s):

Tissue Culture ◽

Cell Surface ◽

Calcium Binding ◽

Surface Proteins ◽

Membrane Glycoprotein ◽

Cell Surface Proteins ◽

Culture Cells ◽

Tissue Culture Cells ◽

Hepatoma Tissue

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Isolation and characterization of two virulent Aeromonads associated with haemorrhagic septicaemia and tail-rot disease in farmed climbing perch Anabas testudineus

Scientific Reports ◽

10.1038/s41598-021-84997-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Abhishek Mazumder ◽

Hrishikesh Choudhury ◽

Abhinit Dey ◽

Dandadhar Sarma

Keyword(s):

Natural Infection ◽

Winter Season ◽

Pcr Amplification ◽

Body Parts ◽

Anabas Testudineus ◽

Climbing Perch ◽

Isolation And Characterization ◽

Biochemical Characterisation ◽

Rot Disease

AbstractDiseased Anabas testudineus exhibiting signs of tail-rot and ulcerations on body were collected from a fish farm in Assam, India during the winter season (November 2018 to January 2019). Swabs from the infected body parts were streaked on sterilized nutrient agar. Two dominant bacterial colonies were obtained, which were then isolated and labelled as AM-31 and AM-05. Standard biochemical characterisation and 16S rRNA and rpoB gene sequencing identified AM-31 isolate as Aeromonas hydrophila and AM-05 as Aeromonas jandaei. Symptoms similar to that of natural infection were observed on re-infecting both bacteria to disease-free A. testudineus, which confirmed their virulence. LC50 was determined at 1.3 × 104 (A. hydrophila) and 2.5 × 104 (A. jandaei) CFU per fish in intraperitoneal injection. Further, PCR amplification of specific genes responsible for virulence (aerolysin and enterotoxin) confirmed pathogenicity of both bacteria. Histopathology of kidney and liver in the experimentally-infected fishes revealed haemorrhage, tubular degeneration and vacuolation. Antibiotic profiles were also assessed for both bacteria. To the best of our knowledge, the present work is a first report on the mortality of farmed climbing perch naturally-infected by A. hydrophila as well as A. jandaei, with no records of pathogenicity of the latter in this fish.

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Molecular Characterization of Mycoplasma agalactiae Reveals the Presence of an Endemic Clone in Spain

Journal of Clinical Microbiology ◽

10.1128/jcm.02835-12 ◽

2012 ◽

Vol 51 (2) ◽

pp. 656-660 ◽

Cited By ~ 6

Author(s):

J. Ariza-Miguel ◽

D. Rodriguez-Lazaro ◽

M. Hernandez

Keyword(s):

Molecular Characterization ◽

Mycoplasma Agalactiae

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Characterization of Fouled Flat Sheet Membranes by Infrared Thermography

Volume 8B: Heat Transfer and Thermal Engineering ◽

10.1115/imece2014-36761 ◽

2014 ◽

Author(s):

Kennethrex O. Ndukaife ◽

George Agbai Nnanna

Keyword(s):

Surface Temperature ◽

Infrared Thermography ◽

Spectral Power ◽

Membrane Surface ◽

Infrared Camera ◽

Feed Solution ◽

Feed Concentration ◽

Ir Camera ◽

Measure Surface Temperature

An Infrared thermography (IRT) technique for characterization of fouling on membrane surface has been developed. The emitted spectral power from the fouled membrane is a function of emissivity and surface morphology. In this work, a FLIR A320 IR camera was used to measure surface temperature and emissivity. The surface temperature and the corresponding emissivity value of various areas on the fouled membrane surface is measured by the infrared camera and recorded alongside its thermogram. Different fouling experiments were performed using different concentrations of aluminum oxide nanoparticle mixed with deionized water as feed solution (333 ppm, 1833 ppm and 3333 ppm) so as to investigate the effect of feed concentration on the degree of fouling and thus its effect on the emissivity values measured on the membrane surfaces. Surface plots in 3D and Line plots are obtained for the measured emissivity values and thickness of the fouling deposit on the membrane surface respectively. The results indicate that the IRT technique is sensitive to changes that occur on the membrane surface due to deposition of contaminants on the membrane surface and that emissivity is a function of temperature, surface roughness and thickness of the specimen under investigation.

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Vacuolar-type H+-ATPase regulates cytoplasmic pH in Toxoplasma gondii tachyzoites

Biochemical Journal ◽

10.1042/bj3300853 ◽

1998 ◽

Vol 330 (2) ◽

pp. 853-860 ◽

Cited By ~ 44

Author(s):

N. J. Silvia MORENO ◽

Li ZHONG ◽

Hong-Gang LU ◽

Wanderley DE SOUZA ◽

Marlene BENCHIMOL

Keyword(s):

Plasma Membrane ◽

Toxoplasma Gondii ◽

Laser Scanning ◽

Membrane Surface ◽

Surface Proteins ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Dependent Manner ◽

Cytoplasmic Ph ◽

Bafilomycin A1

Cytoplasmic pH (pHi) regulation was studied in Toxoplasma gondii tachyzoites by using the fluorescent dye 2ʹ,7ʹ-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein. Their mean baseline pHi (7.07±0.06; n = 5) was not significantly affected in the absence of extracellular Na+, K+ or HCO3- but was significantly decreased in a dose-dependent manner by low concentrations of N,Nʹ-dicyclohexylcarbodi-imide (DCCD), N-ethylmaleimide (NEM) or bafilomycin A1. Bafilomycin A1 also inhibited the recovery of tachyzoite pHi after an acid load with sodium propionate. Similar concentrations of DCCD, NEM and bafilomycin A1 produced depolarization of the plasma membrane potential as measured with bis-(1,3-diethylthiobarbituric)trimethineoxonol (bisoxonol), and DCCD prevented the hyperpolarization that accompanies acid extrusion after the addition of propionate, in agreement with the electrogenic nature of this pump. Confocal laser scanning microscopy indicated that, in addition to being located in cytoplasmic vacuoles, the vacuolar (V)-H+-ATPase of T. gondii tachyzoites is also located in the plasma membrane. Surface localization of the V-H+-ATPase was confirmed by experiments using biotinylation of cell surface proteins and immunoprecipitation with antibodies against V-H+-ATPases. Taken together, the results are consistent with the presence of a functional V-H+-ATPase in the plasma membrane of these intracellular parasites and with an important role of this enzyme in the regulation of pHi homoeostasis in these cells.

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