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Sample records for edwardsiella tarda pathogenesis

  1. The role of regulator Eha in Edwardsiella tarda pathogenesis and virulence gene transcription.

    PubMed

    Gao, Daqing; Li, Yuhong; Xu, Zeyan; Sheng, Ankang; Zheng, Enjin; Shao, Zeye; Liu, Nian; Lu, Chengping

    2016-06-01

    Edwardsiella tarda is a pathogen with a broad host range that infects both animals and humans. Eha is a new transcriptional regulator identified in ET13, which is involved in the bacterial hemolytic activity. This study explored the effect of the Eha in the pathogenesis of E. tarda and the transcriptional regulation of the bacterial virulence genes (eseC, fliC, pagC and fimA). Our results found that the virulence of the eha mutant was 2.5-fold less than the one of its wild ET13 by LD50 in a murine model of i.p. infection, and the bacterial loads of the mutant displayed a different profile from the one of the wild strain. Most significantly, the mice infected with the mutant have greatly reduced acute inflammation in the liver, spleen and kidney compared to the ones infected with the wild. We further demonstrated that eseC, fliC and pagC were regulated directly by the Eha with qRT-PCR and β-Galactosidase assay, but fimA wasn't done. The promoter regions of the genes modulated and the cly gene reported before had been found to contain a common conserved motif by using software. In addition, we found that the wild strain was more toxic to RAW264.7 macrophages, and induced less the host cell apoptotic responses than the eha mutant did. Altogether, these data suggested that the Eha was required for the bacterial infection and the transcriptive regulation of the important virulence genes of E. tarda. PMID:27038844

  2. Extraintestinal human infection caused by Edwardsiella tarda.

    PubMed Central

    Clarridge, J E; Musher, D M; Fainstein, V; Wallace, R J

    1980-01-01

    Edwardsiella tarda is an uncommon enteric bacterium which has been found generally in animal hosts and occasionally in human feces. Three cases of extraintestinal infection caused by E. tarda which are described herein include a typhoid-like illness, peritonitis with sepsis, and cellulitis from a wound acquired while fishing. The microbiology of E. tarda and the previous reports of infection due to this organism are reviewed. PMID:7381019

  3. Edwardsiella tarda EsaE (Orf19 protein) is required for the secretion of type III substrates, and pathogenesis in fish.

    PubMed

    Zhou, Ying; Liu, Lu Yi; He, Tian Tian; Laghari, Zubair Ahmed; Nie, Pin; Gao, Qian; Xie, Hai Xia

    2016-07-15

    Type III secretion system (T3SS) is a large macromolecular assembly found on the surface of many pathogenic Gram-negative bacteria. Edwardsiella tarda is an important Gram-negative pathogen that employs T3SS to deliver effectors into host cells to facilitate its survival and replication. EseB, EseC, and EseD, when secreted, form a translocon complex EseBCD on host membranes through which effectors are translocated. The orf19 gene (esaE) of E. tarda is located upstream of esaK, and downstream of esaJ, esaI, esaH and esaG in the T3SS gene cluster. When its domains were searched using Delta-Blast, the EsaE protein was found to belong to the T3SS YscJ/PrgK family. In the present study, it is found that EsaE is not secreted into culture supernatant, and the deletion of esaE abolished the secretion of T3SS translocon proteins EseBCD and T3SS effector EseG. Increased steady-state protein level of EseC and EseD was detected in bacterial pellet of ΔesaE strain although a reduced level was observed for the eseC and eseD transcription. EsaE was found to localize on membrane but not in the cytoplasm of E. tarda by fractionation. In blue gourami fish infection model, 87.88% of blue gourami infected with ΔesaE strain survived whereas only 3.03% survived when infected with wild-type strain. Taken together, our study demonstrated that EsaE is probably an apparatus protein of T3SS, which contributes to the pathogenesis of E. tarda in fish. PMID:27283851

  4. Edwardsiella tarda MliC, a Lysozyme Inhibitor That Participates in Pathogenesis in a Manner That Parallels Ivy

    PubMed Central

    Li, Mo-Fei; Wang, Chong

    2014-01-01

    Edwardsiella tarda, a bacterial pathogen to farmed fish as well as humans, possesses the genes of two lysozyme inhibitors, ivy and mliC (ivyEt and mliCEt). We recently studied IvyEt and found it to be implicated in E. tarda virulence. In the present study, we characterized MliCEt in comparison with IvyEt in a turbot model. MliCEt contains the FWSKG motif and two cysteines (C33 and C98) that are highly conserved in subgroup 1 MliCs but are of unknown functional importance. To examine the essentialness of these conserved structural features, recombinant MliCEt (rMliC) and its mutants bearing C33S and W79A (of the FWSKG motif) substitutions were prepared. Subsequent analysis showed that rMliC (i) inhibited lysozyme-induced lysis of a Gram-positive bacterium, (ii) reduced serum-facilitated lysozyme killing of E. tarda, and (iii) when introduced into turbot, promoted bacterial dissemination in fish tissues. The C33S mutation had no influence on the activity of rMliC, while the W79A mutation slightly but significantly enhanced the activity of rMliC. Knockout strains of either mliCEt or ivyEt were severely attenuated for the ability of tissue invasion, host lethality, serum survival, and intracellular replication. The lost virulence of the mliC transformant (TXΔmliC) was restored by complementation with an introduced mliCEt gene. Compared to the ΔivyEt or ΔmliCEt single-knockout strains, the ΔmliCEt ΔivyEt double-knockout strain was significantly impaired in most of the virulence features. Together, these results provide the first evidence that the conserved cysteine is functionally dispensable to a subgroup 1 MliC and that as a virulence factor, MliCEt most likely works in a concerted and parallel manner with Ivy. PMID:25404031

  5. Edwardsiella tarda EscE (Orf13 Protein) Is a Type III Secretion System-Secreted Protein That Is Required for the Injection of Effectors, Secretion of Translocators, and Pathogenesis in Fish.

    PubMed

    Lu, Jin Fang; Wang, Wei Na; Wang, Gai Ling; Zhang, He; Zhou, Ying; Gao, Zhi Peng; Nie, Pin; Xie, Hai Xia

    2016-01-01

    The type III secretion system (T3SS) of Edwardsiella tarda is crucial for its intracellular survival and pathogenesis in fish. The orf13 gene (escE) of E. tarda is located 84 nucleotides (nt) upstream of esrC in the T3SS gene cluster. We found that EscE is secreted and translocated in a T3SS-dependent manner and that amino acids 2 to 15 in the N terminus were required for a completely functional T3SS in E. tarda. Deletion of escE abolished the secretion of T3SS translocators, as well as the secretion and translocation of T3SS effectors, but did not influence their intracellular protein levels in E. tarda. Complementation of the escE mutant with a secretion-incompetent EscE derivative restored the secretion of translocators and effectors. Interestingly, the effectors that were secreted and translocated were positively correlated with the EscE protein level in E. tarda. The escE mutant was attenuated in the blue gourami fish infection model, as its 50% lethal dose (LD50) increased to 4 times that of the wild type. The survival rate of the escE mutant-strain-infected fish was 69%, which was much higher than that of the fish infected with the wild-type bacteria (6%). Overall, EscE represents a secreted T3SS regulator that controls effector injection and translocator secretion, thus contributing to E. tarda pathogenesis in fish. The homology of EscE within the T3SSs of other bacterial species suggests that the mechanism of secretion and translocation control used by E. tarda may be commonly used by other bacterial pathogens. PMID:26459509

  6. Edwardsiella tarda EscE (Orf13 Protein) Is a Type III Secretion System-Secreted Protein That Is Required for the Injection of Effectors, Secretion of Translocators, and Pathogenesis in Fish

    PubMed Central

    Lu, Jin Fang; Wang, Wei Na; Wang, Gai Ling; Zhang, He; Zhou, Ying; Gao, Zhi Peng

    2015-01-01

    The type III secretion system (T3SS) of Edwardsiella tarda is crucial for its intracellular survival and pathogenesis in fish. The orf13 gene (escE) of E. tarda is located 84 nucleotides (nt) upstream of esrC in the T3SS gene cluster. We found that EscE is secreted and translocated in a T3SS-dependent manner and that amino acids 2 to 15 in the N terminus were required for a completely functional T3SS in E. tarda. Deletion of escE abolished the secretion of T3SS translocators, as well as the secretion and translocation of T3SS effectors, but did not influence their intracellular protein levels in E. tarda. Complementation of the escE mutant with a secretion-incompetent EscE derivative restored the secretion of translocators and effectors. Interestingly, the effectors that were secreted and translocated were positively correlated with the EscE protein level in E. tarda. The escE mutant was attenuated in the blue gourami fish infection model, as its 50% lethal dose (LD50) increased to 4 times that of the wild type. The survival rate of the escE mutant-strain-infected fish was 69%, which was much higher than that of the fish infected with the wild-type bacteria (6%). Overall, EscE represents a secreted T3SS regulator that controls effector injection and translocator secretion, thus contributing to E. tarda pathogenesis in fish. The homology of EscE within the T3SSs of other bacterial species suggests that the mechanism of secretion and translocation control used by E. tarda may be commonly used by other bacterial pathogens. PMID:26459509

  7. Comparative analysis of Edwardsiella tarda isolates from fish in the eastern United States suggests the existence of two genetically distinct species, Edwardsiella tarda and Edwardsiella pseudotarda sp. nov

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella tarda, a Gram-negative member of the family Enterobacteriaceae, is often implicated in significant losses in aquaculture facilities worldwide. Here, we assessed the intra-specific variability of a collection of E. tarda isolates from 4 different fish species in the eastern United State...

  8. The macrophage chemotactic activity of Edwardsiella tarda extracellular products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The chemoattractant capabilities of Edwardsiella tarda extracellular products (ECP) were investigated from two isolates, the virulent FL6-60 parent and less virulent RET-04 mutant. Chemotaxis and chemokinesis were assayed in vitro using blind well chambers with peritoneal macrophages obtained from ...

  9. Real-time PCR assays for detection and quactification of Edwardsiella tarda, Edwardsiella piscicida, Edwardsiella piscicida-like sp. in catfish tissues and pond water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Researchers have proposed the adoption of 3 distinct genetic taxa among bacteria previously classified as Edwardsiella tarda; namely E. tarda, E. piscicida, and a taxon presently termed E. piscicida–like. Individual real-time polymerase chain reaction (qPCR) assays were developed, based on published...

  10. Complete genome sequence of Edwardsiella tarda (isolate FL95-01)recovered from channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella tarda is a Gram-negative facultative anaerobe isolated from fish, reptiles, amphibians, and mammals, including humans. This is a report of the complete and annotated genome of E. tarda isolate FL95-01, recovered from channel catfish (Ictalurus punctatus)....

  11. Pathology of Edwardsiella tarda infection in turbot, Scophthalmus maximus (L.).

    PubMed

    Padrós, F; Zarza, C; Dopazo, L; Cuadrado, M; Crespo, S

    2006-02-01

    Macroscopic and histopathological changes in cultured turbot, Scophthalmus maximus (L.), in Spain caused by infection with Edwardsiella tarda are described. Eye tumefaction, inflammation, haemorrhages, ascites and the presence of a purulent fluid were the main macroscopic lesions observed. Histopathological lesions were found in the kidney, spleen and liver. In the kidney and spleen these were characterized by a severe apostematous inflammatory reaction, with a large number of abscesses. The liver was affected to a lesser degree and only some phagocytes loaded with bacteria were observed. Ultrastructural observations indicated that macrophages were the main cell type implicated in the inflammatory response. Most of the bacteria observed within the phagocyte cytoplasm showed no degenerative changes and some were dividing. Degenerative changes observed in macrophages indicate their failure in preventing the infection. PMID:16436119

  12. The serine protease autotransporter Tsh contributes to the virulence of Edwardsiella tarda.

    PubMed

    Hu, Yong-Hua; Zhou, Hai-Zhen; Jin, Qian-Wen; Zhang, Jian

    2016-06-30

    The temperature-sensitive hemagglutinin (Tsh), identified as serine protease autotransporters of the Enterobacteriaceae (SPATEs) proteins, is an important virulence factor for avian-pathogenic Escherichia coli (APEC) and uropathogenic E. coli. However, little is known about the role of Tsh as a virulence factor in Edwardsiella tarda, a severe fish pathogen. In this study, we characterized the Tsh of E. tarda (named TshEt) and examined its function and vaccine potential. TshEt is composed of 1224 residues and has three functional domains typical for autotransporters. Quantitative real-time reverse transcriptase-PCR analysis showed that expression of tshEt was upregulated under conditions of high temperature, increased cell density, high pH, and iron starvation and during the infection of host cells. A markerless tsh in-frame mutant strain, TX01Δtsh, was constructed to determine whether TshEt participates in the pathogenicity of E. tarda, Compared to the wild type TX01, TX01Δtsh exhibited (i) retarded biofilm growth, (ii) decreased resistance against serum killing, (iii) impaired ability to block the host immune response, (iv) attenuated tissue and cellular infectivity. Introduction of a trans-expressed tsh gene restored the lost virulence of TX01Δtsh. The passenger domain of TshEt contains a putative serine protease (PepS) that exhibits apparent proteolytic activity when expressed in and purified from E. coli as a recombinant protein (rPepS). When used as a subunit vaccine to immunize Japanese flounder, rPepS was able to induce effective immune protection. This is the first study of Tsh in a fish pathogen, and the results suggest that TshEt exerts pleiotropic effects on the pathogenesis of E. tarda. PMID:27259829

  13. Edwardsiella tarda-Induced Inhibition of Apoptosis: A Strategy for Intracellular Survival

    PubMed Central

    Zhou, Ze-jun; Sun, Li

    2016-01-01

    Edwardsiella tarda is a Gram-negative bacterial pathogen that can infect a wide range of freshwater and marine fish. One salient feature of E. tarda is the ability to survive and replicate in various host cells. In this study, we observed that E. tarda replicated robustly in the zebrafish cell line ZF4, and that E. tarda-infected cells exhibited no detectable signs of apoptosis. Global transcriptome analysis and quantitative real-time RT-PCR revealed that E. tarda infection generally significantly downregulated pro-apoptotic genes and upregulated anti-apoptotic genes. To investigate the role of apoptosis in E. tarda infection, two upregulated anti-apoptotic genes (Fech and Prx3) and two downregulated pro-apoptotic genes (Brms1a and Ivns1a) were overexpressed in zebrafish. Subsequent infection study showed that Fech and Prx3 overexpression significantly promoted E. tarda dissemination in and colonization of fish tissues, while Brms1a and Ivns1a overexpression significantly reduced E. tarda dissemination and colonization. Consistently, when Fech and Prx3 were knocked down in zebrafish, E. tarda infection was significantly inhibited, whereas Brms1a and Ivns1a knockdown significantly enhanced E. tarda infection. These results indicate for the first time that E. tarda prevents apoptosis in teleost as a strategy for intracellular survival, and that some putative apoptotic genes of teleost function in the apoptosis pathway probably in a manner similar to that in mammalian systems. PMID:27471679

  14. What is a species a species? Genetic variability of Edwardsiella tarda in the Southeastern United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The intra-specific variability of Edwardsiella tarda isolates from fish in the eastern United States was assessed. Repetitive sequence mediated PCR (rep-PCR) and multi-locus sequence analysis identified two distinct genotypes (DNA group I; DNA group II). This was supported by fluorometric estimatio...

  15. Complete genome sequence of channel catfish gastrointestinal sepicemia isolate Edwardsiella tarda C07-087

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella tarda is the etiologic agent of acute to chronic edwardsiellosis in fish and other species (1). It is a gram-negative facultative anaerobe that is motile by peritrichous flagella. Edwardsiellosis is an important fish disease that negatively impacts aquaculture industries throughout the...

  16. Retention of virulence in a viable but nonculturable Edwardsiella tarda isolate.

    PubMed

    Du, Meng; Chen, Jixiang; Zhang, Xiaohua; Li, Aijuan; Li, Yun; Wang, Yingeng

    2007-02-01

    Edwardsiella tarda is pathogen of fish and other animals. The aim of this study was to investigate the viable but nonculturable (VBNC) state and virulence retention of this bacterium. Edwardsiella tarda CW7 was cultured in sterilized aged seawater at 4 degrees C. Total cell counts remained constant throughout the 28-day period by acridine orange direct counting, while plate counts declined to undetectable levels (<0.1 CFU/ml) within 28 days by plate counting. The direct viable counts, on the other hand, declined to ca. 10(9) CFU/ml active cells and remained fairly constant at this level by direct viable counting. These results indicated that a large population of cells existed in a viable but nonculturable state. VBNC E. tarda CW7 could resuscitate in experimental chick embryos and in the presence of nutrition with a temperature upshift. The resuscitative times were 6 days and 8 days, respectively. The morphological changes of VBNC, normal, and resuscitative E. tarda CW7 cells were studied with a scanning electron microscope. The results showed that when the cells entered into the VBNC state, they gradually changed in shape from short rods to coccoid and decreased in size, but the resuscitative cells did not show any obvious differences from the normal cells. The VBNC and the resuscitative E. tarda CW7 cells were intraperitoneally inoculated into turbot separately, and the fish inoculated with the resuscitative cells died within 7 days, which suggested that VBNC E. tarda CW7 might retain pathogenicity. PMID:17189433

  17. Retention of Virulence in a Viable but Nonculturable Edwardsiella tarda Isolate▿

    PubMed Central

    Du, Meng; Chen, Jixiang; Zhang, Xiaohua; Li, Aijuan; Li, Yun; Wang, Yingeng

    2007-01-01

    Edwardsiella tarda is pathogen of fish and other animals. The aim of this study was to investigate the viable but nonculturable (VBNC) state and virulence retention of this bacterium. Edwardsiella tarda CW7 was cultured in sterilized aged seawater at 4°C. Total cell counts remained constant throughout the 28-day period by acridine orange direct counting, while plate counts declined to undetectable levels (<0.1 CFU/ml) within 28 days by plate counting. The direct viable counts, on the other hand, declined to ca. 109 CFU/ml active cells and remained fairly constant at this level by direct viable counting. These results indicated that a large population of cells existed in a viable but nonculturable state. VBNC E. tarda CW7 could resuscitate in experimental chick embryos and in the presence of nutrition with a temperature upshift. The resuscitative times were 6 days and 8 days, respectively. The morphological changes of VBNC, normal, and resuscitative E. tarda CW7 cells were studied with a scanning electron microscope. The results showed that when the cells entered into the VBNC state, they gradually changed in shape from short rods to coccoid and decreased in size, but the resuscitative cells did not show any obvious differences from the normal cells. The VBNC and the resuscitative E. tarda CW7 cells were intraperitoneally inoculated into turbot separately, and the fish inoculated with the resuscitative cells died within 7 days, which suggested that VBNC E. tarda CW7 might retain pathogenicity. PMID:17189433

  18. Edwardsiella tarda sepsis in a live-stranded sperm whale (Physeter macrocephalus).

    PubMed

    Cools, Piet; Haelters, Jan; Lopes dos Santos Santiago, Guido; Claeys, Geert; Boelens, Jerina; Leroux-Roels, Isabel; Vaneechoutte, Mario; Deschaght, Pieter

    2013-09-27

    Whale strandings remain poorly understood, although bacterial infections have been suggested to contribute. We isolated Edwardsiella tarda from the blood of a stranded sperm whale. The pathogen was identified with MALDI-TOF MS, confirmed by 16S rRNA gene sequencing and quantified in blood by qPCR. We report the first case of sepsis in a sperm whale. The zoonotic potential of E. tarda and the possible role of bacterial infections in the enigmatic strandings of cetaceans are discussed. PMID:23827352

  19. Insights into the virulence-related genes of Edwardsiella tarda isolated from turbot in Europe: genetic homogeneity and evidence for vibrioferrin production.

    PubMed

    Castro, N; Osorio, C R; Buján, N; Fuentes, J C; Rodríguez, J; Romero, M; Jiménez, C; Toranzo, A E; Magariños, B

    2016-05-01

    Edwardsiella tarda has long been known as a pathogen that causes severe economic losses in aquaculture industry. Insights gained on E. tarda pathogenesis may prove useful in the development of new methods for the treatment of infections as well as preventive measures against future outbreaks. In this report, we have established the correlation between the presence of virulence genes, related with three aspects typically involved in bacterial pathogenesis (chondroitinase activity, quorum sensing and siderophore-mediated ferric uptake systems), in the genome of E. tarda strains isolated from turbot in Europe and their phenotypic traits. A total of 8 genes were tested by PCR for their presence in 73 E. tarda isolates. High homogeneity was observed in the presence/absence pattern of all the strains. Positive results in the amplification of virulence-related genes were correlated with the detection of chondroitinase activity in agar plates, in vivo AHL production during fish infection and determination of type of siderophore produced by E. tarda. To the best of our knowledge, this is the first study carried out with European strains on potential virulence factors. Furthermore, we demonstrated for the first time that E. tarda produces the siderophore vibrioferrin. PMID:26096159

  20. Characterization of Edwardsiella tarda strains isolated from turbot, Psetta maxima (L.).

    PubMed

    Castro, N; Toranzo, A E; Barja, J L; Núñez, S; Magariños, B

    2006-09-01

    The biochemical, serological and molecular characteristics of a group of 21 Edwardsiella tarda strains isolated from turbot, Psetta maxima, in two different areas of Europe were analysed and compared with a total of 13 strains of this bacterial species with different geographical and host origins. All the turbot isolates were biochemically identical to the E. tarda strains included as reference. The use of different techniques including microagglutination, dot blot and Western blot of lipopolysaccharides allowed us to determine that all the turbot isolates constitute an homogeneous and distinctive serological group. Genetic analysis by randomly amplified polymorphic DNA (RAPD) analysis demonstrated that although the E. tarda strains from turbot were compiled in a unique group using the primers P3 and P6, two clonal lineages could be detected when oligonucleotides P4 and P5 were employed. PMID:16948704

  1. Multi-locus Sequence Analysis (MLSA) of Edwardsiella tarda isolates from fish.

    PubMed

    Abayneh, T; Colquhoun, D J; Sørum, H

    2012-08-17

    Edwardsiella tarda is an enteric fish pathogen that has caused significant economic losses in a range of fish species residing in diverse ecological conditions. Several molecular methods relying on DNA fingerprinting (RAPD, RFLP and ERIC-PCR) and the gyrB gene marker have been used to characterize E. tarda isolates. However, all had drawbacks in resolving power and reproducibility. The present study was aimed at developing a novel Multi-locus Sequence Analysis (MLSA) scheme for genetic characterization of E. tarda isolates originating from multiple sources. MLSA has been described as an effective molecular tool with superior discriminatory power and reproducibility for exploring intra-species genetic diversity of several bacterial species. Nucleotide sequence fragments of eight protein coding housekeeping genes (gyrB, mdh, adk, dnaK, phoR, metG, pyrG and aroE2) were obtained from 23 fish pathogenic E. tarda isolates of different geographical origins, one human isolate and 3 reference strains. The phylogenetic relationships between isolates in individual gene analyses were not consistent, although some common patterns were apparent. Phylogenetic analysis based on concatenated sequences of seven gene loci, however, buffered the conflicting phylogenetic signals and resolved isolates according to their geographical origin and/or fish host. The MLSA revealed two major genetically diverging clusters in E. tarda isolates examined, one cluster representing isolates from fish and the other representing (in the main) human isolates, with E. ictaluri cluster situated in between. The results suggest, therefore, that the fish pathogenic E. tarda isolates may have been previously misclassified and probably represent one or more as yet unrecognized taxa within the genus Edwardsiella. The MLSA described here was robust enough in discriminating E. tarda isolates not only with respect to their geographical origins but also within different hosts from the same geographical location

  2. Multiple brain abscesses in neonate caused by Edwardsiella tarda: case report.

    PubMed

    Takeuchi, Hayato; Fujita, Yuri; Ogawa, Hiroshi; Shiomi, Kozue; Toyokawa, Youichi; Yamamoto, Toru; Furukawa, Taizo; Ebisu, Toshihiko

    2009-02-01

    A neonate presented with multiple brain abscesses caused by very unusual infection with the Gram-negative bacterium, Edwardsiella tarda. Serial changes in magnetic resonance imaging findings including diffusion-weighted imaging demonstrated the development from the late cerebritis to late capsule stages. The patient was successfully treated by external drainage, and has since reached normal development milestones. Early diagnosis with computed tomography, magnetic resonance imaging, and ultrasound tomography, and prompt external drainage were essential to the good outcome of this case. PMID:19246871

  3. Identification and immunoprotective analysis of an in vivo-induced Edwardsiella tarda antigen.

    PubMed

    Jiao, Xu-dong; Dang, Wei; Hu, Yong-hua; Sun, Li

    2009-11-01

    Edwardsiella tarda is a severe aquaculture pathogen that can infect many important fish species cultured worldwide. The aim of this study was to evaluate the vaccine potential of an E. tarda antigen, Eta21, which was identified from a pathogenic E. tarda strain via the method of in vivo-induced antigen technology (IVIAT). Eta21 is 510-amino acid in length and shares approximately 58% sequence identity with a putative peptidase of several bacterial species. eta21 was subcloned into Escherichia coli, and recombinant Eta21 was purified as a histidine-tagged protein. When used as a subunit vaccine, purified recombinant Eta21 was effective against lethal E. tarda challenge in a Japanese flounder model. In order to improve the immunoprotective efficacy of Eta21, the chimera AgaV-Eta21 was constructed, which consists of Eta21 fused in-frame to the secretion domain of AgaV, an extracellular beta-agarase. E. coli DH5alpha harboring plasmid pTAET21, which constitutively expresses agaV-eta21, was able to produce and secret AgaV-Eta21 into the extracellular milieu. Vaccination of Japanese flounder with live DH5alpha/pTAET21 elicited immunoprotection that is significantly higher in level than that induced by vaccination with purified recombinant Eta21. Vaccination with DH5alpha/pTAET21 and recombinant Eta21 both induced the production of specific serum antibodies at four to eight weeks post-vaccination. Taken together, these results demonstrate that Eta21, especially that delivered by DH5alpha/pTAET21, is an effective vaccine candidate against E. tarda infection. PMID:19706328

  4. Analysis of the antibacterial effect of an Edwardsiella tarda LuxS inhibitor.

    PubMed

    Sun, Boguang; Zhang, Min

    2016-01-01

    LuxS/AI-2 quorum sensing is involved in the virulence of many bacterial pathogens, including the fish pathogen Edwardsiella tarda. In a previous study, we identified a small peptide, 5906, which inhibits E. tarda LuxS activity by binding specifically to LuxS in a manner that probably prevents the formation of functional LuxS homodimer. In the present study, using Japanese flounder as the experimental animal, we analyzed the antibacterial effect of 5906 produced by DH5α/p5906 (an Escherichia coli strain that produces 5906) and pID5906 (a mammalian plasmid that functional in flounder constitutively expresses 5906) against different bacterial fish pathogens. We found that fish administered with both DH5α/p5906 and pID5906 exhibited reduced bacterial recovery following E. tarda challenge. We also examined the effect of 5906 on the infection caused by another two fish pathogen, Aeromonas hydrophila and Vibrio harveyi. The results indicated that 5906 produced by DH5α/p5906 inhibited the AI-2 activity of A. hydrophila and V. harveyi, and that fish administered with DH5α/p5906 showed enhanced resistance against challenges with both bacteria. These results suggest that 5906 or its analogues/derivatives may be exploited for the development of broad-spectrum antibacterial agents applied in the prevention and control of fish bacterial diseases. PMID:26848432

  5. Edwardsiella Septicaemias

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Edwardsiella includes two species of bacteria that cause major diseases in fish: Edwardsiella tarda (1965) infects fish and other animals and Edwardsiella ictaluri (Hawke 1979; Hawke et al. 1981) infects primarily fish. A third species, Edwardsiella hoshinae (Grimont et al. 1980), infects ...

  6. Genome Sequence of the Versatile Fish Pathogen Edwardsiella tarda Provides Insights into its Adaptation to Broad Host Ranges and Intracellular Niches

    PubMed Central

    Xiao, Jingfan; Wu, Haizhen; Wang, Xin; Lv, Yuanzhi; Xu, Lili; Zheng, Huajun; Wang, Shengyue; Zhao, Guoping; Liu, Qin; Zhang, Yuanxing

    2009-01-01

    Background Edwardsiella tarda is the etiologic agent of edwardsiellosis, a devastating fish disease prevailing in worldwide aquaculture industries. Here we describe the complete genome of E. tarda, EIB202, a highly virulent and multi-drug resistant isolate in China. Methodology/Principal Findings E. tarda EIB202 possesses a single chromosome of 3,760,463 base pairs containing 3,486 predicted protein coding sequences, 8 ribosomal rRNA operons, and 95 tRNA genes, and a 43,703 bp conjugative plasmid harboring multi-drug resistant determinants and encoding type IV A secretion system components. We identified a full spectrum of genetic properties related to its genome plasticity such as repeated sequences, insertion sequences, phage-like proteins, integrases, recombinases and genomic islands. In addition, analysis also indicated that a substantial proportion of the E. tarda genome might be devoted to the growth and survival under diverse conditions including intracellular niches, with a large number of aerobic or anaerobic respiration-associated proteins, signal transduction proteins as well as proteins involved in various stress adaptations. A pool of genes for secretion systems, pili formation, nonfimbrial adhesions, invasions and hemagglutinins, chondroitinases, hemolysins, iron scavenging systems as well as the incomplete flagellar biogenesis might feature its surface structures and pathogenesis in a fish body. Conclusion/Significance Genomic analysis of the bacterium offered insights into the phylogeny, metabolism, drug-resistance, stress adaptation, and virulence characteristics of this versatile pathogen, which constitutes an important first step in understanding the pathogenesis of E. tarda to facilitate construction of a practical effective vaccine used for combating fish edwardsiellosis. PMID:19865481

  7. A multiplex PCR for the simultaneous detection of Tenacibaculum maritimum and Edwardsiella tarda in aquaculture.

    PubMed

    Castro, Nuria; Toranzo, Alicia E; Magariños, Beatriz

    2014-06-01

    A specific and sensitive multiplex PCR (mPCR) method was developed as a useful tool for the simultaneous detection of two important flatfish pathogens in marine aquaculture, Tenacibaculum maritimum and Edwardsiella tarda. In fish tissues, the average detection limit for these mPCR-amplified organisms was 2 × 10 ⁵ ± 0.2 CFU/g and 4 × 10 ⁵ ± 0.3 CFU/g, respectively. These values are similar or even lower than those previously obtained using the corresponding single PCR. Moreover, mPCR did not produce any nonspecific amplification products when tested against 36 taxonomically related and unrelated strains belonging to 33 different bacterial species. Large amounts of DNA from one of the target bacterial species in the presence of low amounts from the other did not have a significant effect on the amplification sensitivity of the latter. PMID:26418855

  8. Intracellular translocation and localization of Edwardsiella tarda type III secretion system effector EseG in host cells.

    PubMed

    Fang, Shan; Zhang, Lingzhi; Lou, Ying; Yang, Dahai; Wang, Qiyao; Zhang, Yuanxing; Liu, Qin

    2016-08-01

    Edwardsiella tarda, an important fish pathogenic bacterium, could utilize type III secretion system (T3SS) to transfer multiple effector proteins into host cells during infection. EseG was identified to be an E. tarda T3SS effector, which could be injected by T3SS into non-phagocytic cells. Since E. tarda is a facultative intracellular pathogen that resides and replicates in macrophage, it is interesting to expand our knowledge about EseG translocation and localization within phagocytic cells. Here utilizing murine macrophage cell line J774A.1 as the cell model, we demonstrated that EseG could be transported into J774A.1 via T3SS only after E. tarda was internalized into macrophage cells, indicating that extracellular E. tarda could not inject EseG into host cells. Subcellular fractionation analysis gave the evidence that EseG was specifically localized in the membrane fraction of infected host cells. Furthermore, immunofluorescence detection indicated that EseG specifically targeted the E. tarda-containing vacuoles (ECVs) within macrophage cells. Finally the unique features for EseG were also confirmed in non-phagocytic cells. In summarize, this work illuminates internalization-depending translocation and ECV-targeting localization of E. tarda T3SS effector in both non-phagocytic and phagocytic cells, which might be important to interpret the interaction of EseG with host cells upon infection. PMID:27208750

  9. Edwardsiella tarda Endocarditis Confirmed by Indium-111 White Blood Cell Scan: An Unusual Pathogen and Diagnostic Modality

    PubMed Central

    Litton, Kayleigh M.; Rogers, Bret A.

    2016-01-01

    Edwardsiella tarda is a freshwater marine member of the family Enterobacteriaceae which often colonizes fish, lizards, snakes, and turtles but is an infrequent human pathogen. Indium-111- (111In-) labeled white blood cell (WBC) scintigraphy is an imaging modality which has a wide range of reported sensitivity and specificity (from 60 to 100% and from 68 to 92%, resp.) for diagnosing acute and chronic infection. We describe a case of suspected E. tarda prosthetic aortic valve and mitral valve endocarditis with probable vegetations and new mitral regurgitation on transthoracic and transesophageal echocardiograms which was supported with the use of 111In-labeled WBC scintigraphy. PMID:26885418

  10. Edwardsiella tarda Endocarditis Confirmed by Indium-111 White Blood Cell Scan: An Unusual Pathogen and Diagnostic Modality.

    PubMed

    Litton, Kayleigh M; Rogers, Bret A

    2016-01-01

    Edwardsiella tarda is a freshwater marine member of the family Enterobacteriaceae which often colonizes fish, lizards, snakes, and turtles but is an infrequent human pathogen. Indium-111- ((111)In-) labeled white blood cell (WBC) scintigraphy is an imaging modality which has a wide range of reported sensitivity and specificity (from 60 to 100% and from 68 to 92%, resp.) for diagnosing acute and chronic infection. We describe a case of suspected E. tarda prosthetic aortic valve and mitral valve endocarditis with probable vegetations and new mitral regurgitation on transthoracic and transesophageal echocardiograms which was supported with the use of (111)In-labeled WBC scintigraphy. PMID:26885418

  11. Comparative proteomic study of Edwardsiella tarda strains with different degrees of virulence.

    PubMed

    Buján, Noemí; Hernández-Haro, Carolina; Monteoliva, Lucía; Gil, Concha; Magariños, Beatriz

    2015-09-01

    Edwardsiella tarda is an enteric opportunistic pathogen that causes a great loss in aquaculture. This species has been described as a phenotypical homogeneous group; in contrast, serological studies and molecular typing revealed a wide heterogeneity. In this work, a proteomic study of differential expression of a virulent isolate from turbot cultured in the Norwest of Spain in comparison with an avirulent collection strain was performed in order to recognize proteins involved in virulence. One hundred and three proteins that presented different abundance were successfully identified and classified into 11 functional categories according to their biological processes: amino acid, carbohydrate and lipid metabolism, tricarboxylic cycle, stress response and protein fate, protein synthesis, biogenesis of cellular components, cell rescue defence and virulence, cell membrane and transport, signal transduction and purine and pyrimidine metabolism. Twenty three protein spots detected only in turbot isolate were identified. It was shown that the same proteins appeared in different spots in the two isolates. Mass spectra obtained by MALDITOF/TOF of some of these proteins and DNA sequencing explained the changes as a result of different amino acid sequences. Several proteins related with the virulence of E. tarda (FliC, ArnA or FeSODI) were only detected in the turbot European isolate. This article is part of a Special Issue entitled: HUPO 2014. PMID:25979771

  12. ORF13 in the Type III secretion system gene cluster of Edwardsiella tarda binds to the mammalian factor Cugbp2.

    PubMed

    Okuda, Jun; Takeuchi, Yusuke; Yasuda, Masashi; Nakai, Toshihiro

    2016-05-01

    The Type III secretion system (TTSS) is essential for the intracellular replication of Edwardsiella tarda in phagocytes of fish and mammals, and a hypothetical gene (orf13) located in the TTSS gene cluster is required for intracellular replication and virulence of E. tarda. Here, we show that under TTSS-inducing conditions, the protein ORF13 was secreted into culture supernatant. Then, using a yeast 2-hybrid screen, we show that the mammalian factor Cugbp2, which regulates apoptosis in breast cancer cells, directly interacts with ORF13. A pull-down assay revealed that ORF13 binds to the C-terminal region of Cugbp2. Our results suggest that ORF13 may facilitate E. tarda replication in phagocytes by binding to Cugbp2. PMID:27137075

  13. A developing model for Edwardsiella ictaluri pathogenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri, the causative agent of Enteric Septicemia of Catfish (ESC), belongs to a rather short list of bacteria known to survive and replicate in macrophages. Macrophages are ameboid-like cells that engulf and then digest cellular debris and pathogens, including bacteria. The process, ...

  14. Computer-aided vaccine designing approach against fish pathogens Edwardsiella tarda and Flavobacterium columnare using bioinformatics softwares

    PubMed Central

    Mahendran, Radha; Jeyabaskar, Suganya; Sitharaman, Gayathri; Michael, Rajamani Dinakaran; Paul, Agnal Vincent

    2016-01-01

    Edwardsiella tarda and Flavobacterium columnare are two important intracellular pathogenic bacteria that cause the infectious diseases edwardsiellosis and columnaris in wild and cultured fish. Prediction of major histocompatibility complex (MHC) binding is an important issue in T-cell epitope prediction. In a healthy immune system, the T-cells must recognize epitopes and induce the immune response. In this study, T-cell epitopes were predicted by using in silico immunoinformatics approach with the help of bioinformatics tools that are less expensive and are not time consuming. Such identification of binding interaction between peptides and MHC alleles aids in the discovery of new peptide vaccines. We have reported the potential peptides chosen from the outer membrane proteins (OMPs) of E. tarda and F. columnare, which interact well with MHC class I alleles. OMPs from E. tarda and F. columnare were selected and analyzed based on their antigenic and immunogenic properties. The OMPs of the genes TolC and FCOL_04620, respectively, from E. tarda and F. columnare were taken for study. Finally, two epitopes from the OMP of E. tarda exhibited excellent protein–peptide interaction when docked with MHC class I alleles. Five epitopes from the OMP of F. columnare had good protein–peptide interaction when docked with MHC class I alleles. Further in vitro studies can aid in the development of potential peptide vaccines using the predicted peptides. PMID:27284239

  15. Edwardsiella tarda Outer Membrane Protein C: An Immunogenic Protein Induces Highly Protective Effects in Flounder (Paralichthys olivaceus) against Edwardsiellosis.

    PubMed

    Liu, Fuguo; Tang, Xiaoqian; Sheng, Xiuzhen; Xing, Jing; Zhan, Wenbin

    2016-01-01

    Outer membrane protein C of Edwardsiella tarda is a major cell surface antigen and it was identified to be an immunogenic protein by Western blot using flounder (Paralichthys olivaceus) anti-recombinant OmpC (rOmpC), and anti-E. tarda antibodies. rOmpC tested the immune protective effect against E. tarda challenge in a flounder model and produced a relative percentage of survival rate of 85%. The immune response of flounder induced by rOmpC was investigated, and the results showed that: (1) the levels of specific serum antibodies induced by rOmpC were significantly higher than the control group after the second week after immunization, and the peak level occurred at week five after immunization; (2) rOmpC could induce the proliferation of sIg+ lymphocytes, and the peak levels of sIg+ lymphocytes in blood, spleen, and pronephros occurred at 4-5 weeks after immunization; and (3) the MHCIIα, CD4-1, IL-1β, IL-6 and TNF-α genes were significantly induced after being injected with rOmpC. Taken together, these results demonstrated that rOmpC could evoke highly protective effects against E. tarda challenge and induce strong innate immune response and humoral immune response of flounder, which indicated that OmpC was a promising vaccine candidate against E. tarda infection. PMID:27420049

  16. Computer-aided vaccine designing approach against fish pathogens Edwardsiella tarda and Flavobacterium columnare using bioinformatics softwares.

    PubMed

    Mahendran, Radha; Jeyabaskar, Suganya; Sitharaman, Gayathri; Michael, Rajamani Dinakaran; Paul, Agnal Vincent

    2016-01-01

    Edwardsiella tarda and Flavobacterium columnare are two important intracellular pathogenic bacteria that cause the infectious diseases edwardsiellosis and columnaris in wild and cultured fish. Prediction of major histocompatibility complex (MHC) binding is an important issue in T-cell epitope prediction. In a healthy immune system, the T-cells must recognize epitopes and induce the immune response. In this study, T-cell epitopes were predicted by using in silico immunoinformatics approach with the help of bioinformatics tools that are less expensive and are not time consuming. Such identification of binding interaction between peptides and MHC alleles aids in the discovery of new peptide vaccines. We have reported the potential peptides chosen from the outer membrane proteins (OMPs) of E. tarda and F. columnare, which interact well with MHC class I alleles. OMPs from E. tarda and F. columnare were selected and analyzed based on their antigenic and immunogenic properties. The OMPs of the genes TolC and FCOL_04620, respectively, from E. tarda and F. columnare were taken for study. Finally, two epitopes from the OMP of E. tarda exhibited excellent protein-peptide interaction when docked with MHC class I alleles. Five epitopes from the OMP of F. columnare had good protein-peptide interaction when docked with MHC class I alleles. Further in vitro studies can aid in the development of potential peptide vaccines using the predicted peptides. PMID:27284239

  17. Edwardsiella tarda Outer Membrane Protein C: An Immunogenic Protein Induces Highly Protective Effects in Flounder (Paralichthys olivaceus) against Edwardsiellosis

    PubMed Central

    Liu, Fuguo; Tang, Xiaoqian; Sheng, Xiuzhen; Xing, Jing; Zhan, Wenbin

    2016-01-01

    Outer membrane protein C of Edwardsiella tarda is a major cell surface antigen and it was identified to be an immunogenic protein by Western blot using flounder (Paralichthys olivaceus) anti-recombinant OmpC (rOmpC), and anti-E. tarda antibodies. rOmpC tested the immune protective effect against E. tarda challenge in a flounder model and produced a relative percentage of survival rate of 85%. The immune response of flounder induced by rOmpC was investigated, and the results showed that: (1) the levels of specific serum antibodies induced by rOmpC were significantly higher than the control group after the second week after immunization, and the peak level occurred at week five after immunization; (2) rOmpC could induce the proliferation of sIg+ lymphocytes, and the peak levels of sIg+ lymphocytes in blood, spleen, and pronephros occurred at 4–5 weeks after immunization; and (3) the MHCIIα, CD4-1, IL-1β, IL-6 and TNF-α genes were significantly induced after being injected with rOmpC. Taken together, these results demonstrated that rOmpC could evoke highly protective effects against E. tarda challenge and induce strong innate immune response and humoral immune response of flounder, which indicated that OmpC was a promising vaccine candidate against E. tarda infection. PMID:27420049

  18. Presenting a foreign antigen on live attenuated Edwardsiella tarda using twin-arginine translocation signal peptide as a multivalent vaccine.

    PubMed

    Wang, Yamin; Yang, Weizheng; Wang, Qiyao; Qu, Jiangbo; Zhang, Yuanxing

    2013-12-01

    The twin-arginine translocation (Tat) system is a major pathway for transmembrane translocation of fully folded proteins. In this study, a multivalent vaccine to present foreign antigens on live attenuated vaccine Edwardsiella tarda WED using screened Tat signal peptide was constructed. Because the Tat system increases the yields of folded antigens in periplasmic space or extracellular milieu, it is expected to contribute to the production of conformational epitope-derived specific antibodies. E. tarda Tat signal peptides fused with the green fluorescent protein (GFP) was constructed under the control of an in vivo inducible dps promoter. The resulting plasmids were electroporated into WED and the subcellular localizations of GFP were analyzed with Western blotting. Eight signal peptides with optimized GFP translocation efficiency were further fused to a protective antigen glyceraldehyde-3-phosphate dehydrogenase (GapA) from a fish pathogen Aeromonas hydrophila. Signal peptides of DmsA, NapA, and SufI displayed high efficiency for GapA translocation. The relative percent survival (RPS) of turbot was measured with a co-infection of E. tarda and A. hydrophila, and the strain with DmsA signal peptide showed the maximal protection. This study demonstrated a new platform to construct multivalent vaccines using optimized Tat signal peptide in E. tarda. PMID:23994481

  19. Comparison of static immersion and intravenous injection systems for exposure of zebrafish embryos to the natural pathogen Edwardsiella tarda

    PubMed Central

    2011-01-01

    Background The zebrafish embryo is an important in vivo model to study the host innate immune response towards microbial infection. In most zebrafish infectious disease models, infection is achieved by micro-injection of bacteria into the embryo. Alternatively, Edwardsiella tarda, a natural fish pathogen, has been used to treat embryos by static immersion. In this study we used transcriptome profiling and quantitative RT-PCR to analyze the immune response induced by E. tarda immersion and injection. Results Mortality rates after static immersion of embryos in E. tarda suspension varied between 25-75%, while intravenous injection of bacteria resulted in 100% mortality. Quantitative RT-PCR analysis on the level of single embryos showed that expression of the proinflammatory marker genes il1b and mmp9 was induced only in some embryos that were exposed to E. tarda in the immersion system, whereas intravenous injection of E. tarda led to il1b and mmp9 induction in all embryos. In addition, microarray expression profiles of embryos subjected to immersion or injection showed little overlap. E. tarda-injected embryos displayed strong induction of inflammatory and defense genes and of regulatory genes of the immune response. E. tarda-immersed embryos showed transient induction of the cytochrome P450 gene cyp1a. This gene was also induced after immersion in Escherichia coli and Pseudomonas aeruginosa suspensions, but, in contrast, was not induced upon intravenous E. tarda injection. One of the rare common responses in the immersion and injection systems was induction of irg1l, a homolog of a murine immunoresponsive gene of unknown function. Conclusions Based on the differences in mortality rates between experiments and gene expression profiles of individual embryos we conclude that zebrafish embryos cannot be reproducibly infected by exposure to E. tarda in the immersion system. Induction of il1b and mmp9 was consistently observed in embryos that had been systemically

  20. Frequent isolation of Edwardsiella tarda and Pleisiomonas shigelloides from healthy Zairese freshwater fish: a possible source of sporadic diarrhea in the tropics.

    PubMed Central

    Van Damme, L R; Vandepitte, J

    1980-01-01

    The intestinal contents of 59 Zairese freshwater fish were examined for the presence of potential human enteric pathogens. Edwardsiella tarda and Plesiomonas shigelloides were isolated from 57 and 59% of them, respectively. For both microorganisms there was a significant difference between the isolation rates from lake and river fish: whereas E. tarda was much more frequently isolated from lake fish than was P. shigelloides, the reverse was observed for river fish. The authors hypothesize that sporadic cases of tropical diarrhea with E. tarda or P. shigelloides can be traced to contact with or consumption of freshwater fish. PMID:7387150

  1. Vaccine efficacy of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from Edwardsiella ictaluri against E. tarda in tilapia.

    PubMed

    Trung Cao, Thanh; Tsai, Ming-An; Yang, Chung-Da; Wang, Pei-Chyi; Kuo, Tsun-Yung; Gabriel Chen, Hsu-Chung; Chen, Shih-Chu

    2014-01-01

    Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), derived from the outer-membrane protein (OMP) fraction, has been used as a potential candidate for vaccine development. The gene-encoding 37 kDa GAPDH outer membrane protein (OMP) from Edwardsiella ictaluri was amplified using polymerase chain reaction (PCR) and was cloned and expressed in Escherichia coli BL21 (DE3). Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting, and nucleotide and amino acid sequencing were used to analyze the expressed antigenic protein and gene encoding this protein. Comparative DNA and protein sequence analysis of GAPDH from E. ictaluri GAPDHs from several Gram-negative bacterial species within the Enterobacteriaceae family revealed that the GAPDHs within this group are highly conserved and share a sequence similarity of 75-100% with E. ictaluri GDPDH. Rabbit antiserum raised against the E. ictaluri recombinant GAPDH (rGAPDH) protein recognized purified GADPH, indicating that it has a strong immunogenicity. Tilapia fish were intraperitoneally immunized with formalin-killed E. ictaluri whole cells, and rGAPDH (30 μg fish(-1)) from E. ictaluri, both of which were emulsified in ISA 763A adjuvant. At 3 months after immunization, fish were challenged with the E. tarda strain to assess vaccine efficacy; the relative percent survival (RPS) values were found to exceed 71.4%. The specific mean antibody titer log2 level of groups vaccinated with rGAPDH at 3 months was significantly higher than that of non-vaccinated fish (control group). Therefore, this recombinant protein can be considered a multi-purpose candidate vaccine against several pathogenic bacteria. PMID:25742975

  2. Quantitative trait loci detection of Edwardsiella tarda resistance in Japanese flounder Paralichthys olivaceus using bulked segregant analysis

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoxia; Xu, Wenteng; Liu, Yang; Wang, Lei; Sun, Hejun; Wang, Lei; Chen, Songlin

    2016-03-01

    In recent years, Edwardsiella tarda has become one of the most deadly pathogens of Japanese flounder (Paralichthys olivaceus), causing serious annual losses in commercial production. In contrast to the rapid advances in the aquaculture of P. olivaceus, the study of E. tarda resistance-related markers has lagged behind, hindering the development of a disease-resistant strain. Thus, a marker-trait association analysis was initiated, combining bulked segregant analysis (BSA) and quantitative trait loci (QTL) mapping. Based on 180 microsatellite loci across all chromosomes, 106 individuals from the F1333 (♀: F0768 ×♂: F0915) (Nomenclature rule: F+year+family number) were used to detect simple sequence repeats (SSRs) and QTLs associated with E. tarda resistance. After a genomic scan, three markers (Scaffold 404-21589, Scaffold 404-21594 and Scaffold 270-13812) from the same linkage group (LG)-1 exhibited a significant difference between DNA, pooled/bulked from the resistant and susceptible groups (P <0.001). Therefore, 106 individuals were genotyped using all the SSR markers in LG1 by single marker analysis. Two different analytical models were then employed to detect SSR markers with different levels of significance in LG1, where 17 and 18 SSR markers were identified, respectively. Each model found three resistance-related QTLs by composite interval mapping (CIM). These six QTLs, designated qE1-6, explained 16.0%-89.5% of the phenotypic variance. Two of the QTLs, qE-2 and qE-4, were located at the 66.7 cM region, which was considered a major candidate region for E. tarda resistance. This study will provide valuable data for further investigations of E. tarda resistance genes and facilitate the selective breeding of disease-resistant Japanese flounder in the future.

  3. In vitro quenching of fish pathogen Edwardsiella tarda AHL production using marine bacterium Tenacibaculum sp. strain 20J cell extracts.

    PubMed

    Romero, Manuel; Muras, Andrea; Mayer, Celia; Buján, Noemí; Magariños, Beatriz; Otero, Ana

    2014-04-01

    Quorum quenching (QQ) has become an interesting alternative for solving the problem of bacterial antibiotic resistance, especially in the aquaculture industry, since many species of fish-pathogenic bacteria control their virulence factors through quorum sensing (QS) systems mediated by N-acylhomoserine lactones (AHLs). In a screening for bacterial strains with QQ activity in different marine environments, Tenacibaculum sp. strain 20J was identified and selected for its high degradation activity against a wide range of AHLs. In this study, the QQ activity of live cells and crude cell extracts (CCEs) of strain 20J was characterized and the possibilities of the use of CCEs of this strain to quench the production of AHLs in cultures of the fish pathogen Edwardsiella tarda ACC35.1 was explored. E. tarda ACC35.1 produces N-hexanoyl-L-homoserine lactone (C6-HSL) and N-oxohexanoyl-L-homoserine lactone (OC6-HSL). This differs from profiles registered for other E. tarda strains and indicates an important intra-specific variability in AHL production in this species. The CCEs of strain 20J presented a wide-spectrum QQ activity and, unlike Bacillus thuringiensis serovar Berliner ATCC10792 CCEs, were effective in eliminating the AHLs produced in E. tarda ACC35.1 cultures. The fast and wide-spectrum AHL-degradation activity shown by this member of the Cytophaga-Flexibacter-Bacteroidetes group consolidates this strain as a promising candidate for the control of AHL-based QS pathogens, especially in the marine fish farming industry. PMID:24695235

  4. An invasive and low virulent Edwardsiella tarda esrB mutant promising as live attenuated vaccine in aquaculture.

    PubMed

    Yang, Weizheng; Wang, Lixia; Zhang, Lingzhi; Qu, Jiangbo; Wang, Qiyao; Zhang, Yuanxing

    2015-02-01

    Edwardsiella tarda is a leading fish pathogen haunting worldwide aquaculture industry. In E. tarda, two-component system EsrA-EsrB positively regulates type III and VI secretion systems (T3SS and T6SS) and negatively regulates hemolysin EthA, which has been demonstrated to be essential for the invasion processes in fish. In order to develop a live attenuated vaccine (LAV) with high invasiveness to be practically and economically used as immersion-administered vaccine in aquaculture, here, we generated a random mutation library of esrB sequences by error-prone PCR and introduced them into the E. tarda esrB deletion mutant. The mutant YWZ47 with significantly increased hemolytic activity and low T3SS and T6SS secretion was screened. Phenotypes including extracellular protein profiles, invasion in macrophages, lethality toward fish, and infection kinetics were investigated in the wild-type strain EIB202 and the mutants ΔesrB, ΔT3SS, ΔT6SS, ΔT3SS/ΔT6SS, and YWZ47. Compared to the documented LAV strain ΔesrB, YWZ47 showed higher invasive capability and low in vivo virulence toward fish. Significantly higher relative percent survival (RPS) could be generated in turbot (Scophthalmus maximus) against the challenge of the wild-type EIB202 when inoculated through immersion route, and the RPS was comparable with that of ΔesrB through intraperitoneal (i.p.) injection inoculation. Two mutated points, K167M and H197L, were found by sequence analysis of EsrBYWZ47 variant. These structural modifications underpin the variations in the regulatory functions of the mutant and wild-type EsrB. This study promoted understanding of virulence regulation by EsrB in E. tarda and presented a promising candidate of invasive attenuated vaccine used in aquaculture industries. PMID:25431010

  5. Type III Secretion System Translocon Component EseB Forms Filaments on and Mediates Autoaggregation of and Biofilm Formation by Edwardsiella tarda

    PubMed Central

    Gao, Zhi Peng; Nie, Pin; Lu, Jin Fang; Liu, Lu Yi; Xiao, Tiao Yi; Liu, Wei

    2015-01-01

    The type III secretion system (T3SS) of Edwardsiella tarda plays an important role in infection by translocating effector proteins into host cells. EseB, a component required for effector translocation, is reported to mediate autoaggregation of E. tarda. In this study, we demonstrate that EseB forms filamentous appendages on the surface of E. tarda and is required for biofilm formation by E. tarda in Dulbecco's modified Eagle's medium (DMEM). Biofilm formation by E. tarda in DMEM does not require FlhB, an essential component for assembling flagella. Dynamic analysis of EseB filament formation, autoaggregation, and biofilm formation shows that the formation of EseB filaments occurs prior to autoaggregation and biofilm formation. The addition of an EseB antibody to E. tarda cultures before bacterial autoaggregation prevents autoaggregation and biofilm formation in a dose-dependent manner, whereas the addition of the EseB antibody to E. tarda cultures in which biofilm is already formed does not destroy the biofilm. Therefore, EseB filament-mediated bacterial cell-cell interaction is a prerequisite for autoaggregation and biofilm formation. PMID:26116669

  6. Comparative analysis of Edwardsiella isolates from fish in the eastern United States identifies two distinct genetic taxa amongst organisms phenotypically classified as E. tarda

    USGS Publications Warehouse

    Griffin, Matt J.; Quiniou, Sylvie M.; Cody, Theresa; Tabuchi, Maki; Ware, Cynthia; Cipriano, Rocco C.; Mauel, Michael J.; Soto, Esteban

    2013-01-01

    Edwardsiella tarda, a Gram-negative member of the family Enterobacteriaceae, has been implicated in significant losses in aquaculture facilities worldwide. Here, we assessed the intra-specific variability of E. tarda isolates from 4 different fish species in the eastern United States. Repetitive sequence mediated PCR (rep-PCR) using 4 different primer sets (ERIC I & II, ERIC II, BOX, and GTG5) and multi-locus sequence analysis of 16S SSU rDNA, groEl, gyrA, gyrB, pho, pgi, pgm, and rpoA gene fragments identified two distinct genotypes of E. tarda (DNA group I; DNA group II). Isolates that fell into DNA group II demonstrated more similarity to E. ictaluri than DNA group I, which contained the reference E. tarda strain (ATCC #15947). Conventional PCR analysis using published E. tarda-specific primer sets yielded variable results, with several primer sets producing no observable amplification of target DNA from some isolates. Fluorometric determination of G + C content demonstrated 56.4% G + C content for DNA group I, 60.2% for DNA group II, and 58.4% for E. ictaluri. Surprisingly, these isolates were indistinguishable using conventional biochemical techniques, with all isolates demonstrating phenotypic characteristics consistent with E. tarda. Analysis using two commercial test kits identified multiple phenotypes, although no single metabolic characteristic could reliably discriminate between genetic groups. Additionally, anti-microbial susceptibility and fatty acid profiles did not demonstrate remarkable differences between groups. The significant genetic variation (<90% similarity at gyrA, gyrB, pho, phi and pgm; <40% similarity by rep-PCR) between these groups suggests organisms from DNA group II may represent an unrecognized, genetically distinct taxa of Edwardsiella that is phenotypically indistinguishable from E. tarda.

  7. Identification of the interactome between fish plasma proteins and Edwardsiella tarda reveals tissue-specific strategies against bacterial infection.

    PubMed

    Li, Hui; Huang, Xiaoyan; Zeng, Zaohai; Peng, Xuan-Xian; Peng, Bo

    2016-09-01

    Elucidating the complex pathogen-host interaction is essential for a comprehensive understanding of how these remarkable agents invade their hosts and how the hosts defend against these invaders. During the infection, pathogens interact intensively with host to enable their survival, which can be revealed through their interactome. Edwardsiella tarda is a Gram-negative bacterial pathogen causing huge economic loss in aquaculture and a spectrum of intestinal and extraintestinal diseases in humans. E. tarda is an ideal model for host-pathogen investigation as it infects fish in three distinct steps: entering the host, circulating through the blood and establishing infection. We adopted a previous established proteomic approach that inactivated E. tarda cells and covalent crosslink fish plasma proteins were used to capture plasma proteins and bacterial outer membrane proteins, respectively. By the combinatorial use of proteomic and biochemical approaches, six plasma proteins and seven outer membrane proteins (OMPs) were identified. Interactions among these proteins were validated with protein-array, far-Western blotting and co-immunoprecipitation. At last, seventeen plasma protein-bacteria protein-protein interaction were confirmed to be involved in the interaction network, forming a complex interactome. Compared to our previous results, different host proteins were detected, whereas some of the bacterial proteins were similar, which indicates that hosts adopt tissue-specific strategies to cope with the same pathogen during infection. Thus, our results provide a robust demonstration of both bacterial initiators and host receptors or interacting proteins to further explore infection and anti-infective mechanisms between hosts and microbes. PMID:27458055

  8. EseE of Edwardsiella tarda Augments Secretion of Translocon Protein EseC and Expression of the escC-eseE Operon.

    PubMed

    Yi, Jia; Xiao, Shui Bing; Zeng, Zhi Xiong; Lu, Jin Fang; Liu, Lu Yi; Laghari, Zubair Ahmed; Nie, Pin; Yu, Hong Bing; Xie, Hai Xia

    2016-08-01

    Edwardsiella tarda is an important Gram-negative pathogen that employs a type III secretion system (T3SS) to deliver effectors into host cells to facilitate bacterial survival and replication. These effectors are translocated into host cells through a translocon complex composed of three secreted proteins, namely, EseB, EseC, and EseD. The secretion of EseB and EseD requires a chaperone protein called EscC, whereas the secretion of EseC requires the chaperone EscA. In this study, we identified a novel protein (EseE) that also regulates the secretion of EseC. An eseE deletion mutant secreted much less EseC into supernatants, accompanied by increased EseC levels within bacterial cells. We also demonstrated that EseE interacted directly with EseC in a pulldown assay. Interestingly, EseC, EseE, and EscA were able to form a ternary complex, as revealed by pulldown and gel filtration assays. Of particular importance, the deletion of eseE resulted in decreased levels of EseB and EseD proteins in both the bacterial pellet and supernatant fraction. Furthermore, real-time PCR assays showed that EseE positively regulated the transcription of the translocon operon escC-eseE, comprising escC, eseB, escA, eseC, eseD, and eseE These effects of EseE on the translocon components/operon appeared to have a functional consequence, since the ΔeseE strain was outcompeted by wild-type E. tarda in a mixed infection in blue gourami fish. Collectively, our results demonstrate that EseE not only functions as a chaperone for EseC but also acts as a positive regulator controlling the expression of the translocon operon escC-eseE, thus contributing to the pathogenesis of E. tarda in fish. PMID:27271743

  9. Immune response of flounder (Paralichthys olivaceus) was associated with the concentration of inactivated Edwardsiella tarda and immersion time.

    PubMed

    Du, Yang; Tang, Xiaoqian; Sheng, Xiuzhen; Xing, Jing; Zhan, Wenbin

    2015-09-15

    In the optimization of immersion strategy, vaccine concentration and immersion time are two key factors needed to be considered, which largely determined the immune efficacy. In this work, the healthy flounder were vaccinated in formalin-killed Edwardsiella tarda at four concentrations (10(6), 10(7), 10(8), 10(9) CFU ml(-1)) for three immersion times (30, 60, 90 min), respectively. At the 6th week post vaccination, the flounders were challenged with live E. tarda, and the relative percent survival (RPS) of flounder in 10(9)-30, 10(8)-60, 10(8)-90 and 10(7)-90 min groups were 70%, 78%, 74% and 65%, respectively, which were much higher than the other vaccination groups. Meanwhile, the sIg(+) cells in the leucocytes of peripheral blood (PBL), spleen (SL), head kidney (HKL) were monitored by flow cytometry, and the specific sera and mucosal antibodies were measured by indirect ELISA for 6 weeks. The results showed that the proportions of sIg(+) cells in PBL, SL and HKL of vaccinated fish were significantly higher than the untreated fish since the 2nd week (P<0.05), and the fish in 10(9)-30, 10(8)-60, 10(8)-90 and 10(7)-90 min groups exhibited stronger responses than other groups, especially the 10(8)-60 min group displayed the strongest response, which reached the peaks (54.63% in PBL, 37.21% in SL, 36.51% in HKL) at the 5th week. ELISA assay showed that the kinetics of specific antibodies in sera were similar to the variation of sIg(+) cells, and the higher antibody levels were also detected in the four groups with higher RPS and stronger sIg+ response, whereas the mucosal antibody showed a faster response, which were significantly higher than the control since the 1st week (P>0.05). These results demonstrated that the higher RPS was closely associated with stronger immune response, and immersion with formalin-inactivated E. tarda under 10(8) CFU ml(-1) for 60 min induced the highest immune response of flounder against E. tarda bacterin, which might be applied for the

  10. TolC plays a crucial role in immune protection conferred by Edwardsiella tarda whole-cell vaccines.

    PubMed

    Wang, Chao; Peng, Bo; Li, Hui; Peng, Xuan-Xian

    2016-01-01

    Although vaccines developed from live organisms have better efficacy than those developed from dead organisms, the mechanisms underlying this differential efficacy remain unexplored. In this study, we combined sub-immunoproteomics with immune challenge to investigate the action of the outer membrane proteome in the immune protection conferred by four Edwardsiella tarda whole-cell vaccines prepared via different treatments and to identify protective immunogens that play a key role in this immune protection. Thirteen spots representing five outer membrane proteins and one cytoplasmic protein were identified, and it was found that their abundance was altered in relation with the immune protective abilities of the four vaccines. Among these proteins, TolC and OmpA were found to be the key immunogens conferring the first and second highest degrees of protection, respectively. TolC was detected in the two effective vaccines (live and inactivated-30-F). The total antiserum and anti-OmpA titers were higher for the two effective vaccines than for the two ineffective vaccines (inactivated-80-F and inactivated-100). Further evidence demonstrated that the live and inactivated-30-F vaccines demonstrated stronger abilities to induce CD8+ and CD4+ T cell differentiation than the other two evaluated vaccines. Our results indicate that the outer membrane proteome changes dramatically following different treatments, which contributes to the effectiveness of whole-cell vaccines. PMID:27406266

  11. TolC plays a crucial role in immune protection conferred by Edwardsiella tarda whole-cell vaccines

    PubMed Central

    Wang, Chao; Peng, Bo; Li, Hui; Peng, Xuan-xian

    2016-01-01

    Although vaccines developed from live organisms have better efficacy than those developed from dead organisms, the mechanisms underlying this differential efficacy remain unexplored. In this study, we combined sub-immunoproteomics with immune challenge to investigate the action of the outer membrane proteome in the immune protection conferred by four Edwardsiella tarda whole-cell vaccines prepared via different treatments and to identify protective immunogens that play a key role in this immune protection. Thirteen spots representing five outer membrane proteins and one cytoplasmic protein were identified, and it was found that their abundance was altered in relation with the immune protective abilities of the four vaccines. Among these proteins, TolC and OmpA were found to be the key immunogens conferring the first and second highest degrees of protection, respectively. TolC was detected in the two effective vaccines (live and inactivated-30-F). The total antiserum and anti-OmpA titers were higher for the two effective vaccines than for the two ineffective vaccines (inactivated-80-F and inactivated-100). Further evidence demonstrated that the live and inactivated-30-F vaccines demonstrated stronger abilities to induce CD8+ and CD4+ T cell differentiation than the other two evaluated vaccines. Our results indicate that the outer membrane proteome changes dramatically following different treatments, which contributes to the effectiveness of whole-cell vaccines. PMID:27406266

  12. A prebiotic role of Ecklonia cava improves the mortality of Edwardsiella tarda-infected zebrafish models via regulating the growth of lactic acid bacteria and pathogen bacteria.

    PubMed

    Lee, WonWoo; Oh, Jae Young; Kim, Eun-A; Kang, Nalae; Kim, Kil-Nam; Ahn, Ginnae; Jeon, You-Jin

    2016-07-01

    In this study, the beneficial prebiotic roles of Ecklonia cava (E. cava, EC) were evaluated on the growth of lactic acid bacteria (LAB) and pathogen bacteria and the mortality of pathogen-bacteria infected zebrafish model. The result showed that the original E. cava (EC) led to the highest growth effects on three LABs (Lactobacillus brevis, L. brevis; Lactobacillus pentosus, L. pentosus; Lactobacillus plantarum; L. plantarum) and it was dose-dependent manners. Also, EC, its Celluclast enzymatic (ECC) and 100% ethanol extracts (ECE) showed the anti-bacterial activities on the fish pathogenic bacteria such as (Edwardsiella tarda; E. tarda, Streptococcus iniae; S. iniae, and Vibrio harveyi; V. harveyi). Interestingly, EC induced the higher production of the secondary metabolites from L. plantarum in MRS medium. The secondary metabolites produced by EC significantly inhibited the growth of pathogen bacteria. In further in vivo study, the co-treatment of EC and L. plantarum improved the growth and mortality of E. tarda-infected zebrafish as regulating the expression of inflammatory molecules such as iNOS and COX2. Taken together, our present study suggests that the EC plays an important role as a potential prebiotic and has a protective effect against the infection caused by E. tarda injection in zebrafish. Also, our conclusion from this evidence is that EC can be used and applied as a useful prebiotic. PMID:27192145

  13. Starvation beneficially influences the liver physiology and nutrient metabolism in Edwardsiella tarda infected red sea bream (Pagrus major).

    PubMed

    Mohapatra, Sipra; Chakraborty, Tapas; Shimizu, Sonoko; Urasaki, Shintaro; Matsubara, Takahiro; Nagahama, Yoshitaka; Ohta, Kohei

    2015-11-01

    Dietary compromises, especially food restrictions, possess species-specific effects on the health status and infection control in several organisms, including fish. To understand the starvation-mediated physiological responses in Edwardsiella tarda infected red sea bream, especially in the liver, we performed a 20-day starvation experiment using 4 treatment (2 fed and 2 starved) groups, namely, fed-placebo, starved-placebo, fed-infected, and starved-infected, wherein bacterial exposure was done on the 11th day. In the present study, the starved groups showed reduced hepatosomatic index and drastic depletion in glycogen storage and vacuole formation. The fed-infected fish showed significant (P<0.05) increase in catalase and superoxide dismutase activity in relation to its starved equivalent. Significant (P<0.05) alteration in glucose and energy metabolism, as evident from hexokinase and glucose-6-phosphate dehydrogenase activity, was recorded in the starved groups. Interestingly, coinciding with the liver histology, PPAR (peroxisome proliferator activated receptors) α transcription followed a time-dependent activation in starved groups while PPARγ exhibited an opposite pattern. The transcription of hepcidin 1 and transferrin, initially increased in 0dai (days after infection) starved fish but reduced significantly (P<0.05) at later stages. Two-color immunohistochemistry and subsequent cell counting showed significant increase in P63-positive cells at 0dai and 5dai but later reduced slightly at 10dai. Similar results were also obtained in the lysosomal (cathepsin D) and non-lysosomal (ubiquitin) gene transcription level. All together, our data suggest that starvation exerts multidirectional responses, which allows for better physiological adaptations during any infectious period, in red sea bream. PMID:26188170

  14. Immune responses of flounder Paralichthys olivaceus vaccinated by immersion of formalin-inactivated Edwardsiella tarda following hyperosmotic treatment.

    PubMed

    Gao, Ying-Li; Tang, Xiao-Qian; Sheng, Xiu-Zhen; Xing, Jing; Zhan, Wen-Bin

    2015-10-16

    The aim of the present study was to evaluate the effects of hyperosmotic immersion (HI) vaccination and determine the optimum hyperosmotic salinity for flounder Paralichthys olivaceus by investigating its immune responses following vaccination. Flounder were immersed in 1 of 3 hyperosmotic solutions at 50, 60 and 70‰ salinity, then transferred into 30‰ salinity normal seawater containing formalin-inactivated Edwardsiella tarda for vaccination (3 HI groups), or were immersed in normal seawater as direct immersion (DI group). The results showed that the percentages of surface membrane immunoglobulin-positive (sIg+) cells in peripheral blood leukocytes and spleen leukocytes induced by HI were significantly higher than that with DI (p < 0.05), and the 50‰ salinity group showed the strongest response among the HI groups, which reached peaks at Week 4. ELISA assay showed that the specific serum antibodies gradually increased after vaccination and reached peak at Day 32, and the fish treated with HI showed stronger antibody responses; among the HI groups, a significantly higher specific antibody level was detected in the 50‰ salinity group at Day 32 (p < 0.05). Similarly, the fish treated with HI showed higher specific mucosal antibody levels compared to the DI group, and the mucosal antibody showed a faster response, with peak time arriving 1 wk earlier than for the serum antibody. The relative percent survival (RPS) of flounder treated with HI at 50, 60 and 70‰ salinities were 79, 71 and 57% respectively, while this was 43% in the DI group. These results demonstrated that HI, especially the 50‰ salinity, could efficiently enhance the immune response of flounder and show higher RPS. This has significant value for immunological prevention of edwardsiellosis in flounder. PMID:26480914

  15. Immunomodulation of Lactobacillus pentosus PL11 against Edwardsiella tarda infection in the head kidney cells of the Japanese eel (Anguilla japonica).

    PubMed

    Birhanu, Biruk Tesfaye; Lee, Joong-Su; Lee, Seung-Jin; Choi, Su-Hee; Hossain, Md Akil; Park, Ji-Yong; Kim, Jong-Choon; Suh, Joo-Won; Park, Seung-Chun

    2016-07-01

    Wild and farm-raised fish can be simultaneously exposed to different types of pathogens in their habitats. Hence, it is important to study their effects, whether isolated or in combination. Therefore, the aim of this study was to evaluate the effects of Lactobacillus pentosus PL11 on the transcription of specific cytokine genes related to immune response, using Japanese eel macrophages as an in vitro model. Head kidney leukocytes were isolated from Japanese eels and cell viability was determined using an MTT reagent. In addition, the Griess reagent was used to determine the nitric oxide (NO) production while, an enzyme-linked immunosobent assay (ELISA) and a quantitative polymerase chain reaction (qPCR) were utilized to quantify the level of proinflammatory cytokines. The results of the study indicated that infection by Edwardsiella tarda alone causes a higher rate of cell death and an increase in the production of proinflammatory cytokines, such as interleukin-1β (IL-1β, 822.67 ± 29.48 pg mL(-1)), interleukin-6 (IL-6, 13.57 ± 0.55 pg mL(-1)), and tumor necrosis factor-α (TNF-α, 2033.67 ± 84.68 pg mL(-1)). However, co-culture with L. pentosus PL11 downregulates the production of NO and the related IL-1β, IL-6, and TNF-α by 46%, 88.4%, 59%, and 77%, respectively. Quantification of the mRNA expression level revealed it to be consistent with the ELISA analysis. Hence, we infer that L. pentosus PL11 plays a significant role in the immunmodulation of the inflammatory responses that arise in fish owing to infection by pathogenic bacteria such as Edwardsiella tarda. PMID:27108377

  16. A cDNA microarray analysis to identify genes involved in the acute-phase response pathway of the olive flounder after infection with Edwardsiella tarda.

    PubMed

    Moon, Ji Young; Hong, Yong-Ki; Kong, Hee Jeong; Kim, Dong-Gyun; Kim, Young-Ok; Kim, Woo-Jin; Ji, Young Joo; An, Cheul Min; Nam, Bo-Hye

    2014-09-15

    The acute-phase response (APR) is an important systemic reaction that occurs within hours of an inflammatory signal caused by physical bodily injury or microbial infection. To investigate the APR of the olive flounder (Paralichthys olivaceus) following infection with a pathogen, we established an expressed sequence tag (EST)-based cDNA microarray chip composed of 13,061 PCR-amplified cDNAs encoding unique genes selected from an olive flounder EST analysis. Microarray analyses showed that the set of genes involved in the APR was strongly up-regulated in the liver of the olive flounder after infection with Edwardsiella tarda. Among the up-regulated genes, catechol-O-methyltransferase domain-containing protein 1, six-transmembrane prostate protein, haptoglobin precursor, and toll-like receptor 5 soluble form were particularly strongly up-regulated. Interestingly, the toll-like receptor 5 soluble form, which has not yet been detected in mammals, was up-regulated as much as 250-fold upon E. tarda infection. These results suggest that the APR mechanism of fish may be regulated differently from that of mammals. The data described here contribute toward our collective understanding of APR, especially in fish. PMID:25063225

  17. Impact of co-deficiency of RpoN and RpoS on stress tolerance, virulence and gene regulation in Edwardsiella tarda.

    PubMed

    Liu, Enfu; Ye, Jiang; Song, ShanShan; Wang, Keping; Zhang, Yuanxing; Zhang, Huizhan

    2014-07-01

    Edwardsiella tarda the etiological agent for edwardsiellosis, a devastating fish disease prevailing in worldwide aquaculture industries was subjected to a molecular genetic study. To research into the influence when RpoN (σ(54) ) and RpoS (σ(38) ) were deleted simultaneously, the double deletion mutant of RpoN (σ(54) ) and RpoS (σ(38) ), namely rnrs, was constructed. Firstly, RpoN and RpoS are both essential for H2 O2 , starvation, high osmotic pressure and acid resistance, which have synergistic effect. Secondly, virulence of rnrs reduces significantly compared to E. tarda EIB 202 WT, ΔrpoN mutant and ΔrpoS mutant. Furthermore, transcriptional control of rpoS by rpoN in stationary phase was observed through qRT-PCR, while rpoS had no influence on rpoN in the level of transcription. Meanwhile, regulation of flagellar sigma factor σ(F) (FliA) and other flagella-related genes including flgA, flgK, flgL, motA, and motB by rpoS, and rpoN was found. fliA and other flagella-related genes were controlled positively by rpoN, while negatively by rpoS. At last, two differential expression genes in transcriptional level of rnrs strain were detected by DD-RT-PCR, namely cheY and narK. This study therefore indicated interaction between sigma factors RpoN and RpoS, which modulates stress response, virulence, motility, and provides new insights into the regulatory networks of E. tarda. PMID:24633758

  18. Recombinant sialidase NanA (rNanA) cleaves α2-3 linked sialic acid of host cell surface N-linked glycoprotein to promote Edwardsiella tarda infection.

    PubMed

    Chigwechokha, Petros Kingstone; Tabata, Mutsumi; Shinyoshi, Sayaka; Oishi, Kazuki; Araki, Kyosuke; Komatsu, Masaharu; Itakura, Takao; Shiozaki, Kazuhiro

    2015-11-01

    Edwardsiella tarda is one of the major pathogenic bacteria affecting both marine and freshwater fish species. Sialidase NanA expressed endogenously in E. tarda is glycosidase removing sialic acids from glycoconjugates. Recently, the relationship of NanA sialidase activity to E. tarda infection has been reported, however, the mechanism with which sialidase NanA aids the pathogenicity of E. tarda remained unclear. Here, we comprehensively determined the biochemical properties of NanA towards various substrates in vitro to provide novel insights on the potential NanA target molecule at the host cell. GAKS cell pretreated with recombinant NanA showed increased susceptibility to E. tarda infection. Moreover, sialidase inhibitor treated E. tarda showed a significantly reduced ability to infect GAKS cells. These results indicate that NanA-induced desialylation of cell surface glycoconjugates is essential for the initial step of E. tarda infection. Among the natural substrates, NanA exhibited the highest activity towards 3-sialyllactose, α2-3 linked sialic acid carrying sialoglycoconjugates. Supporting this finding, intact GAKS cell membrane exposed to recombinant NanA showed changes of glycoconjugates only in α2-3 sialo-linked glycoproteins, but not in glycolipids and α2-6 sialo-linked glycoproteins. Lectin staining of cell surface glycoprotein provided further evidence that α2-3 sialo-linkage of the N-linked glycoproteins was the most plausible target of NanA sialidase. To confirm the significance of α2-3 sialo-linkage desialylation for E. tarda infection, HeLa cells which possessed lower amount of α2-3 sialo-linkage glycoprotein were used for infection experiment along with GAKS cells. As a result, infection of HeLa cells by E. tarda was significantly reduced when compared to GAKS cells. Furthermore, E. tarda infection was significantly inhibited by mannose pretreatment suggesting that the bacterium potentially recognizes and binds to mannose or mannose containing

  19. Edwardsiella tarda bacteremia. A rare but fatal water- and foodborne infection: Review of the literature and clinical cases from a single centre

    PubMed Central

    Hirai, Yuji; Asahata-Tago, Sayaka; Ainoda, Yusuke; Fujita, Takahiro; Kikuchi, Ken

    2015-01-01

    BACKGROUND: Edwardsiella tarda bacteremia (ETB) can be a fatal disease in humans. OBJECTIVES: To determine the significant risk factors associated with death caused by ETB, and to examine the geographical, seasonal, environmental and dietary factors of the disease. METHODS: A retrospective, observational, case control study was performed. The PubMed MEDLINE and Japanese Medical Abstract Society (www.jamas.or.jp) databases were searched for ETB case reports and meeting abstracts. In additon, retrospective chart reviews of patients with ETB at the Tokyo Women’s Medical University Hospital (Tokyo, Japan) were conducted to evaluate the risk factors associated with death using multivariate analyses. RESULTS: The literature search yielded 46 publications, comprising 72 cases from the English (n=30), French (n=1), Spanish (n=1) and Japanese (n=14) literature. Five cases at the Tokyo Women’s Medical University Hospital were also included. Of the included 77 cases, the mean age was 61 years and 39% of patients were female; 77.2% of the cases occurred between June and November, and 45.5% were reported in Japan. Dietary factors (raw fish/meat exposure) were reported for 10.4% of patients and 12.9% reported environmental (ie, brackish water) exposure. The overall mortality rate was 44.6%; however, this rate increased to 61.1% for ETB patients with soft tissue infections. Liver cirrhosis was determined to be an independent risk factor associated with death (OR 12.0 [95% CI 2.46 to 58.6]; P=0.00213) using multivariate analyses. DISCUSSION: To our knowledge, the present analysis was the first and largest multi-language review of ETB. Clinical characteristics of ETB resemble those of Aeromonas, typhoid fever and Vibrio vulnificus infections, in addition to sharing similar risk factors. CONCLUSION: ETB should be categorized as a severe food- and waterborne infection, which results in high mortality for patients with liver cirrhosis. PMID:26744588

  20. Antigen uptake and expression of antigen presentation-related immune genes in flounder (Paralichthys olivaceus) after vaccination with an inactivated Edwardsiella tarda immersion vaccine, following hyperosmotic treatment.

    PubMed

    Gao, Yingli; Tang, Xiaoqian; Sheng, Xiuzhen; Xing, Jing; Zhan, Wenbin

    2016-08-01

    Antigen uptake is a critical process for activation of the immune system, and therefore the ability to enhance antigen uptake is a primary consideration in the development of an immersion vaccination of fish. In the present work, flounders (Paralichthys olivaceus) were immersed in three hyperosmotic solutions with 40, 50 and 60‰ salinities, then transferred into seawater of normal salinity (i.e. 30‰) containing formalin-inactivated Edwardsiella tarda for 30 min. The antigen uptake in vaccinated flounder was determined using an absolute quantitative PCR (qPCR). The results showed significantly higher antigen uptake in the tissues of flounders immersed in solutions with 50‰ and 60‰ salinity compared to the control group directly immersed in vaccine (DI) (P < 0.05), and the highest amount of antigen was detected in flounders immersed in the 50‰ salinity solution, whereas there was no significant difference in antigen uptake between the 40‰ salinity group and the DI group (P > 0.05). A rapid and significant increase in antigen uptake was detected in the mucosal-associated tissues including the gill, skin and intestine (P < 0.05) compared with the spleen, kidney and liver. Antigen uptake in the gill and skin both peaked at 30 min post immersion, which was significantly higher than the levels of uptake measured in the other tissues (P < 0.05), and then quickly declined. In contrast, antigen uptake in the spleen, kidney and liver gradually increased 3 h post immersion (hpi). The expression profiles of four antigen presentation-related immune genes (MHC Iα, MHC IIα, CD4-1 and CD8α) were investigated after immersion. These four genes showed a significantly stronger response in the immersed flounders exposed to 50‰ salinity compared with the DI group (P < 0.05). In the mucosal-associated tissues, the expression of MHC Iα and CD8α genes peaked at 24 hpi, while the expression of MHC IIα and CD4-1 genes showed up-regulation in the gill and skin

  1. Pathogenic properties of Edwardsiella species.

    PubMed Central

    Janda, J M; Abbott, S L; Kroske-Bystrom, S; Cheung, W K; Powers, C; Kokka, R P; Tamura, K

    1991-01-01

    The pathogenic characteristics of 35 Edwardsiella strains from clinical and environmental sources were investigated. Overall, most Edwardsiella tarda strains were invasive in HEp-2 cell monolayers, produced a cell-associated hemolysin and siderophores, and bound Congo red; many strains also expressed mannose-resistant hemagglutination against guinea pig erythrocytes. Edwardsiella hoshinae strains bound Congo red and were variable in their invasive and hemolytic capabilities while Edwardsiella ictaluri strains did not produce either factor; neither E. hoshinae nor E. ictaluri expressed mannose-resistant hemagglutination nor elaborated siderophores under the tested conditions. Selected strains of each species tested for mouse lethality indicated strain variability in pathogenic potential, with E. tarda strains being the most virulent; 50% lethal doses in individual strains did not correlate with plasmid content, chemotactic motility, serum resistance, or expression of selected enzyme activities. The results suggest some potential important differences in pathogenic properties that may help explain their environmental distribution and ability to cause disease in humans. Images PMID:1774326

  2. Phylogenomics characterization of a highly virulent Edwardsiella strain ET080813(T) encoding two distinct T3SS and three T6SS gene clusters: Propose a novel species as Edwardsiella anguillarum sp. nov.

    PubMed

    Shao, Shuai; Lai, Qiliang; Liu, Qin; Wu, Haizhen; Xiao, Jingfan; Shao, Zongze; Wang, Qiyao; Zhang, Yuanxing

    2015-02-01

    As important zoonotic organisms causing infections in humans, Edwardsiella bacteria are also notorious leading fish pathogens haunting worldwide aquaculture industries. However, the taxa are now widely recognized to be misclassified, which hurdled the understanding of the epidemiology and development of effective diagnostics and vaccines. Currently the genus Edwardsiella consists of three species Edwardsiella tarda, E. ictaluri, and E. hoshinae. Previous phylogenomic analysis revealed that E. tarda strains display two major highly divergent genomic types (genotypes), EdwGI and EdwGII, and the former represents a genotype of fish-pathogenic isolates and being recently proposed as a novel species E. piscicida, sp. nov. Here multiple phylogenetic analyses and the genome-level comparisons of EdwGI strains disclose that the phylogroup strains from diseased eel formed an obviously distinct cluster that could be equated with a new species status. The phylogenetic evidence for the new species assignment was also supported by corresponding DNA-DNA hybridization estimation values and by phenotypic characteristics. Interestingly, further comparative genomics reveals that these strains have acquired the locus of enterocyte effacement (LEE) genes and as a result these bacteria contain at least 2 sets of distinct T3SS and 3 sets of T6SS gene clusters, respectively. It is therefore proposed that the phylogroup strains from diseased eel should be classified as Edwardisella anguillarum sp. nov., and the type strain is ET080813(T) (=DSM27202(T)=CCUG 64215(T)=CCTCC AB2013118(T)=MCCC 1K00238(T)). These findings will contribute to development of species-specific control measures against Edwardsiella bacterium in aquatic animals, while also shedding light on the pathogenesis evolution in Edwardsiella bacterium. PMID:25466920

  3. Identification and characterization of an intervening sequence within the 23S ribosomal RNA genes of Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Comparison of the 23S rRNA gene sequences of Edwardsiella tarda and Edwardsiella ictaluri confirmed a close phylogenetic relationship between these two fish pathogen species and a distant relation with the 'core' members of the Enterobacteriaceae family. Analysis of the rrl gene for 23S rRNA in E. i...

  4. Fur-Regulated Iron Uptake System of Edwardsiella ictaluri and Its Influence on Pathogenesis and Immunogenicity in the Catfish Host

    PubMed Central

    Golden, Greg; Wanda, Soo-Young; Curtiss, Roy

    2012-01-01

    The ability of bacterial pathogens to take up iron from the host during infection is necessary for their multiplication within the host. However, host high-affinity iron binding proteins limit levels of free iron in fluids and tissues. To overcome this deficiency of iron during infection, bacterial pathogens have developed iron uptake systems that are upregulated in the absence of iron, typically tightly controlled by the ferric uptake regulator (Fur) protein. The iron uptake system of Edwardsiella ictaluri, a host-restricted pathogen of channel catfish (Ictalurus punctatus) and the main pathogen of this fish in aquaculture, is unknown. Here we describe the E. ictaluri Fur protein, the iron uptake machinery controlled by Fur, and the effects of fur gene deletion on virulence and immunogenicity in the fish host. Analysis of the E. ictaluri Fur protein shows that it lacks the N-terminal region found in the majority of pathogen-encoded Fur proteins. However, it is fully functional in regulated genes encoding iron uptake proteins. E. ictaluri grown under iron-limited conditions upregulates an outer membrane protein (HemR) that shows heme-hemoglobin transport activity and is tightly regulated by Fur. In vivo studies showed that an E. ictaluri Δfur mutant is attenuated and immune protective in zebrafish (Danio rerio) and catfish (Ictalurus punctatus), triggering systemic immunity. We conclude that an E. ictaluri Δfur mutant could be an effective component of an immersion-oral vaccine for the catfish industry. PMID:22615248

  5. Acquired Porphyria Cutanea Tarda

    PubMed Central

    Koval, Andrew; Danby, C. W. E.; Petermann, H.

    1965-01-01

    Currently, the porphyrias are classified in four main groups: congenital porphyria, acute intermittent porphyria, porphyria cutanea tarda hereditaria, and porphyria cutanea tarda symptomatica. The acquired form of porphyria (porphyria cutanea tarda symptomatica) occurs in older males and is nearly always associated with chronic alcoholism and hepatic cirrhosis. The main clinical changes are dermatological, with excessive skin fragility and photosensitivity resulting in erosions and bullae. Biochemically, high levels of uroporphyrin are found in the urine and stools. Treatment to date has been symptomatic and usually unsuccessful. A case of porphyria cutanea tarda symptomatica is presented showing dramatic improvement of both the skin lesions and porphyrin levels in urine and blood following repeated phlebotomy. Possible mechanisms of action of phlebotomy on porphyria cutanea tarda symptomatica are discussed. ImagesFig. 1Fig. 2 PMID:14341652

  6. [Acne tarda. Acne in adults].

    PubMed

    Jansen, T; Janßen, O E; Plewig, G

    2013-04-01

    Acne is one of the most common skin diseases in the general population, especially among adolescents. Acne tarda (adult acne) is defined as acne that develops (late-onset acne) or continues (persistent acne) after 25 years of age. The disease is more common in women. The clinical features are quite specific: inflammatory acne in the lower facial region or macrocomedones (microcysts) spread over the face. Involvement of the trunk is much more common in men. The etiology of acne tarda is still controversial, as cosmetics, drugs, smoking, stress, diet, and endocrine abnormalities have been implicated. Women with acne tarda and other symptoms of hyperandrogenism have a high probability of endocrine abnormalities such as polycystic ovary syndrome. Treatment is similar to that of acne in adolescence. Long-term treatment over years or decades may be required. PMID:23576169

  7. Histologic and molecular characterization of Edwardsiella piscicida infection in largemouth bass (Micropterus salmoides).

    PubMed

    Fogelson, Susan B; Petty, Barbara D; Reichley, Stephen R; Ware, Cynthia; Bowser, Paul R; Crim, Marcus J; Getchell, Rodman G; Sams, Kelly L; Marquis, Hélène; Griffin, Matt J

    2016-05-01

    The genus Edwardsiella is composed of a diverse group of facultative anaerobic, gram-negative bacteria that can produce disease in a wide variety of hosts, including birds, reptiles, mammals, and fish. Our report describes the isolation and identification of Edwardsiella piscicida associated with chronic mortality events in 2 separate captive largemouth bass (Micropterus salmoides) populations in New York and Florida. Wet-mount biopsies of skin mucus, gill, kidney, and spleen from several affected largemouth bass contained significant numbers of motile bacteria. Histologic examination revealed multifocal areas of necrosis scattered throughout the heart, liver, anterior kidney, posterior kidney, and spleen. Many of the necrotic foci were encapsulated or replaced by discrete granulomas and associated with colonies of gram-negative bacteria. Initial phenotypic and matrix-assisted laser desorption ionization-time of flight mass spectrometric analysis against existing spectral databases of recovered isolates identified these bacteria as Edwardsiella tarda Subsequent molecular analysis using repetitive sequence mediated and species-specific PCR, as well as 16S rRNA, rpoB, and gyrB sequences, classified these isolates as E. piscicida As a newly designated taxon, E. piscicida should be considered as a differential for multiorgan necrosis and granulomas in largemouth bass. PMID:26951328

  8. Porphyria Cutanea Tarda and Agent Orange

    MedlinePlus

    ... survivors' benefits . Research on porphyria cutanea tarda and herbicides The Health and Medicine Division (HMD) (formally known ... on " Veterans and Agent Orange: Health Effects of Herbicides Used in Vietnam " that there was sufficient evidence ...

  9. Signature-Tagged Mutagenesis of Edwardsiella ictaluri Identifies Virulence Related Genes, 3 Including a Salmonella Pathogenicity Island-2 Class of Type III Secretion System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri is the leading cause of mortality in channel catfish culture, but little is known about its pathogenesis. The use of signature-tagged mutagenesis in a waterborne infection model resulted in the identification of 50 mutants that were unable to infect/survive in catfish. Nineteen...

  10. Three Cases of Spondyloepiphyseal Dysplasia Tarda in One Korean Family

    PubMed Central

    Chung, Sang Wan; Kang, Eun Ha; Lee, Yun Jong; Ha, You-Jung

    2016-01-01

    Spondyloepiphyseal dysplasia (SED) tarda is an inherited skeletal arthropathy. Because SED tarda involves the joints and resemble the clinical findings of chronic arthropathies, this disease is frequently misdiagnosed as juvenile idiopathic arthritis (JIA). We report here on three patients (father and his two daughters) in one family with SED tarda. All patients had back pain and polyarthralgia. Their radiographs revealed typical changes for SED tarda including platyspondyly and dysplastic bone changes. This rare disease has major clinical importance in that it is similar with JIA or rheumatoid arthritis. PMID:27401665

  11. Three Cases of Spondyloepiphyseal Dysplasia Tarda in One Korean Family.

    PubMed

    Chung, Sang Wan; Kang, Eun Ha; Lee, Yun Jong; Ha, You Jung; Song, Yeong Wook

    2016-09-01

    Spondyloepiphyseal dysplasia (SED) tarda is an inherited skeletal arthropathy. Because SED tarda involves the joints and resemble the clinical findings of chronic arthropathies, this disease is frequently misdiagnosed as juvenile idiopathic arthritis (JIA). We report here on three patients (father and his two daughters) in one family with SED tarda. All patients had back pain and polyarthralgia. Their radiographs revealed typical changes for SED tarda including platyspondyly and dysplastic bone changes. This rare disease has major clinical importance in that it is similar with JIA or rheumatoid arthritis. PMID:27401665

  12. Hepatitis C, Porphyria Cutanea Tarda, and Liver Iron: An Update

    PubMed Central

    Caballes, F Ryan; Sendi, Hossein; Bonkovsky, Herbert L.

    2012-01-01

    Porphyria cutanea tarda (PCT) is the most common form of porphyria across the world. Unlike other forms of porphyria, which are inborn errors of metabolism, PCT is usually an acquired liver disease caused by exogenous factors, chief among which are excess alcohol intake, iron overload, chronic hepatitis C, estrogen therapy, and cigarette smoking. The pathogenesis of PCT is complex and varied, but hereditary or acquired factors that lead to hepatic iron loading and increased oxidative stress are of central importance. Iron loading is usually only mild or moderate in degree (less than that associated with full-blown hemochromatosis) and is usually acquired and/or due to mutations in HFE. Among acquired factors are excessive alcohol intake and chronic hepatitis C infection, which, like mutations in HFE, decrease hepcidin production by hepatocytes. The decrease in hepcidin leads to increased iron absorption from the gut. In the liver, iron-loading and increased oxidative stress leads to the formation of non-porphyrin inhibitor(s) of uroporphyrinogen decarboxylase and to oxidation of porphyrinogens to porphyrins. The treatment of choice of active PCT is iron reduction by phlebotomy and maintenance of a mildly iron-reduced state without anemia. Low-dose anti-malarials (cinchona alkaloids) are also useful as additional therapy or as alternative therapy for active PCT in those without hemochromatosis or chronic hepatitis C. In this review, we provide an update of PCT with special emphasis upon the important role often played by the hepatitis C virus. PMID:22510500

  13. Porphyria cutanea tarda in a HIV- positive patient*

    PubMed Central

    Franzon, Valéria Aparecida Zanela; Mikilita, Emanuella Stella; Camelo, Fernanda Henriques; Camargo, Rosana

    2016-01-01

    This is a case report about Porphyria cutanea tarda (PCT) and its relationship with the infection caused by the human immunodeficiency virus (HIV). Cutaneous porphyria is an illness caused by enzymatic modification that results in partial deficiency of uroporphyrinogen decarboxylase (Urod), which may be hereditary or acquired. Several studies suggest that HIV infection associated with cofactors might trigger the development of porphyria cutanea tarda. In this case report, we present a patient infected with HIV, who after the introduction of antiretroviral therapy (ART) enjoyed clinical improvement of porphyria cutanea tarda symptoms. PMID:27579753

  14. Porphyria cutanea tarda in a HIV- positive patient.

    PubMed

    Franzon, Valéria Aparecida Zanela; Mikilita, Emanuella Stella; Camelo, Fernanda Henriques; Camargo, Rosana

    2016-01-01

    This is a case report about Porphyria cutanea tarda (PCT) and its relationship with the infection caused by the human immunodeficiency virus (HIV). Cutaneous porphyria is an illness caused by enzymatic modification that results in partial deficiency of uroporphyrinogen decarboxylase (Urod), which may be hereditary or acquired. Several studies suggest that HIV infection associated with cofactors might trigger the development of porphyria cutanea tarda. In this case report, we present a patient infected with HIV, who after the introduction of antiretroviral therapy (ART) enjoyed clinical improvement of porphyria cutanea tarda symptoms. PMID:27579753

  15. Inflammatory effects of Edwardsiella ictaluri lipopolysaccharide modifications in catfish gut.

    PubMed

    Santander, Javier; Kilbourne, Jacquelyn; Park, Jie-Yeun; Martin, Taylor; Loh, Amanda; Diaz, Ignacia; Rojas, Robert; Segovia, Cristopher; DeNardo, Dale; Curtiss, Roy

    2014-08-01

    Bacterial lipopolysaccharides (LPS) are structural components of the outer membranes of Gram-negative bacteria and also are potent inducers of inflammation in mammals. Higher vertebrates are extremely sensitive to LPS, but lower vertebrates, like fish, are resistant to their systemic toxic effects. However, the effects of LPS on the fish intestinal mucosa remain unknown. Edwardsiella ictaluri is a primitive member of the Enterobacteriaceae family that causes enteric septicemia in channel catfish (Ictalurus punctatus). E. ictaluri infects and colonizes deep lymphoid tissues upon oral or immersion infection. Both gut and olfactory organs are the primary sites of invasion. At the systemic level, E. ictaluri pathogenesis is relatively well characterized, but our knowledge about E. ictaluri intestinal interaction is limited. Recently, we observed that E. ictaluri oligo-polysaccharide (O-PS) LPS mutants have differential effects on the intestinal epithelia of orally inoculated catfish. Here we evaluate the effects of E. ictaluri O-PS LPS mutants by using a novel catfish intestinal loop model and compare it to the rabbit ileal loop model inoculated with Salmonella enterica serovar Typhimurium LPS. We found evident differences in rabbit ileal loop and catfish ileal loop responses to E. ictaluri and S. Typhimurium LPS. We determined that catfish respond to E. ictaluri LPS but not to S. Typhimurium LPS. We also determined that E. ictaluri inhibits cytokine production and induces disruption of the intestinal fish epithelia in an O-PS-dependent fashion. The E. ictaluri wild type and ΔwibT LPS mutant caused intestinal tissue damage and inhibited proinflammatory cytokine synthesis, in contrast to E. ictaluri Δgne and Δugd LPS mutants. We concluded that the E. ictaluri O-PS subunits play a major role during pathogenesis, since they influence the recognition of the LPS by the intestinal mucosal immune system of the catfish. The LPS structure of E. ictaluri mutants is needed to

  16. Pachyonychia congenita with late onset (PC tarda)

    PubMed Central

    Sravanthi, A.; Srivalli, P.; Gopal, K. V. T.; Rao, T. Narayana

    2016-01-01

    Pachyonychia congenita is a rare type of ectodermal dysplasia further classified into 4 types. Cutaneous manifestations seen in most of the cases of Pachyonychia congenita include palmoplantar keratoderma, follicular hyperkeratosis, wedge shaped nails, oral leukokeratosis and woolly hair. A 25-year-old male presented to us with thickened nails and scanty scalp hair. On examination, we noticed hyperkeratotic plaques over both the soles, palmoplantar hyperhidrosis and yellowish discoloration, wedging with subungual hyperkeratosis of all the nails. Follicular hyperkeratotic papules and steatocystoma multiplex were also observed over the scalp and face. The patient had history of natal teeth and on dental examination, lower central incisors were absent. All cutaneous changes in our case had manifested first in the 2nd decade except for natal teeth. All the above features suggested the diagnosis of pachyonychia congenita with late onset (PC tarda), which is an infrequently reported rare variant. PMID:27559502

  17. Pachyonychia congenita with late onset (PC tarda).

    PubMed

    Sravanthi, A; Srivalli, P; Gopal, K V T; Rao, T Narayana

    2016-01-01

    Pachyonychia congenita is a rare type of ectodermal dysplasia further classified into 4 types. Cutaneous manifestations seen in most of the cases of Pachyonychia congenita include palmoplantar keratoderma, follicular hyperkeratosis, wedge shaped nails, oral leukokeratosis and woolly hair. A 25-year-old male presented to us with thickened nails and scanty scalp hair. On examination, we noticed hyperkeratotic plaques over both the soles, palmoplantar hyperhidrosis and yellowish discoloration, wedging with subungual hyperkeratosis of all the nails. Follicular hyperkeratotic papules and steatocystoma multiplex were also observed over the scalp and face. The patient had history of natal teeth and on dental examination, lower central incisors were absent. All cutaneous changes in our case had manifested first in the 2(nd) decade except for natal teeth. All the above features suggested the diagnosis of pachyonychia congenita with late onset (PC tarda), which is an infrequently reported rare variant. PMID:27559502

  18. Ocular manifestations in porphyria cutanea tarda

    PubMed Central

    Gogri, Pratik Yeshwant; Misra, Neeta Somen; Misra, Somen

    2014-01-01

    A 24-year-old man presented with pain, sticky discharge and loss of vision in the right eye. He has had typical skin manifestations of porphyria cutanea tarda (PCT) since 6 years and ophthalmological symptom for 6 weeks. On ophthalmological examination, visual acuity was light perception in the right eye and 6/12 in the left. There were bilateral, symmetrical temporal scleromalacia along with temporal corneal melting in both eyes and perforation in the right eye. Ultrasonography B-scan (USG B-scan) revealed a retinal detachment in the right eye. Artificial tear instillation was started every hour along with topical antibiotic coverage in both eyes. Additionally, ultraviolet protective sunglasses and hat for photo-protection was advised. The vision in the right eye improved to 5/60 along with subsidence of retinal detachment on repeat USG B-scan after 3 weeks. PMID:24811555

  19. Edwardsiella tarda and Aeromonas hydrophila isolated from diseased Southern flounder (Paralichthys lethostigma) are virulent to channel catfish and Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study is to identify bacterial pathogens isolated from diseased Southern flounder and determine their virulence to channel catfish and Nile tilapia. Twenty five Gram-negative bacteria isolates were recovered from five tissues (skin lesions, brain, liver, intestine, and posterior kidn...

  20. Human Immunodeficiency Virus Associated Sporadic Nonfamilial Porphyria Cutanea Tarda.

    PubMed

    Guha, Sibashish Kamal; Bandyopadhyay, Debabrata; Saha, Abanti; Lal, Niharika Ranjan

    2016-01-01

    Porphyria cutanea tarda (PCT), a relatively uncommon metabolic disease, is the most common cutaneous porphyria. Here, we present the case of a patient diagnosed with sporadic, nonfamilial PCT that presented with classical cutaneous findings and multiple risk factors, including alcohol abuse, human immunodeficiency virus/AIDS, that have been strongly associated with the sporadic form of PCT. PMID:27293254

  1. Photodamage of the conjunctiva in patients with porphyria cutanea tarda.

    PubMed Central

    Hammer, H; Korom, I

    1992-01-01

    Ninety two patients with porphyria cutanea tarda (PCT) were examined ophthalmically in a paired case control study. The incidence of pinguecula and of pterygium was 8 and 2 times higher respectively, in PCT patients than in the control group. The photodamage to the conjunctiva is considered to be a result of the photoactivity of uroporphyrin in the tissues. Images PMID:1358193

  2. Human Immunodeficiency Virus Associated Sporadic Nonfamilial Porphyria Cutanea Tarda

    PubMed Central

    Guha, Sibashish Kamal; Bandyopadhyay, Debabrata; Saha, Abanti; Lal, Niharika Ranjan

    2016-01-01

    Porphyria cutanea tarda (PCT), a relatively uncommon metabolic disease, is the most common cutaneous porphyria. Here, we present the case of a patient diagnosed with sporadic, nonfamilial PCT that presented with classical cutaneous findings and multiple risk factors, including alcohol abuse, human immunodeficiency virus/AIDS, that have been strongly associated with the sporadic form of PCT. PMID:27293254

  3. Towards the intelligent design of a vaccine against Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri is the leading cause of disease loss in the catfish industry in the United States, accounting for an estimated 20.2 % loss in 2009. Previous work to establish live-attenuated vaccines for E. ictaluri demonstrated a relatively weak channel catfish immune response, with better im...

  4. Influence of lipopolysaccharide outer-core in the intrinsic resistance to antimicrobial peptides and virulence in Edwardsiella ictaluri.

    PubMed

    Martin, Taylor; Diaz, Ignacia; Kilbourne, Jacquelyn; Almarza, Oscar; Segovia, Cristopher; Curtiss, Roy; Santander, Javier

    2016-04-01

    The genus Edwardsiella consists of bacteria with an intrinsic resistance to cyclic cationic antimicrobial peptides (CAMPs). Edwardsiella ictaluri, a pathogen of the catfish (Ictalurus punctatus) and the causative agent of a systemic infection, is highly resistant to CAMPs. Previously, we determined that the oligo-polysaccharide (O-PS) of the lipopolysaccharide (LPS) does not play a role in the E. ictaluri CAMP resistance and an intact core-lipid A structure is necessary for CAMPs resistance. Here, we evaluated the influence of the outer-core in the CAMPs resistance and fish virulence. E. ictaluri wabG, a gene that encodes for the UDP-glucuronic acid transferase that links the lipid A-inner-core to the outer-core-oligopolysaccharides, was deleted. Deletion of ΔwabG caused a pleiotropic effect, influencing LPS synthesis, CAMPs resistance, growth, and biofilm formation. E. ictaluri ΔwabG was attenuated in zebrafish indicating the important role of LPS during fish pathogenesis. Also, we evaluated the inflammatory effects of wabG LPS in catfish ligated loop model, showing a decreased inflammatory effect at the gut level respects to the E. ictaluri wild type. We conclude that E. ictaluri CAMPs resistance is related to the molecules present in the LPS outer-core and that fish gut inflammation triggered by E. ictaluri is LPS dependent, reinforcing the hypothesis that fish gut recognizes LPS in an O-PS dependent fashion. PMID:26945561

  5. Spondyloepiphyseal dysplasia tarda with progressive arthropathy associated with subcapsular cataract

    PubMed Central

    Mandal, Sanjay Kumar; Ghosh, Sudip; Mondal, Soumya Sarathi; Chatterjee, Suman

    2014-01-01

    Spondyloepiphyseal dysplasia tarda with progressive arthropathy is a form of inherited skeletal dysplasia involving the axial skeleton along with swelling and deformities of the peripheral joints that mimics juvenile rheumatoid arthritis. We report a case of a 14-year-old school boy who presented with dwarfism, spine deformity, ocular anomaly and peripheral arthropathy with characteristic radiological changes in the vertebrae and multiple other joints. PMID:24862418

  6. Adhesive and invasive capacities of Edwarsiella tarda isolated from South American sea lion

    PubMed Central

    Fernández, Araceli; Villanueva, María Paz; González, Mario; Fernández, Fabiola; Latif, Fadua; Flores, Sandra Nonier; Fernández, Heriberto

    2014-01-01

    Edwarsiella tarda is a zoonotic bacterium that can be isolated from humans, animals and the environment. Although E. tarda is primarily considered a fish pathogen, it is the only species of its genus considered to be pathogenic for humans as well. A survey of zoonotic intestinal bacteria in fresh feces from South American sea lions (SASL) Otaria flavescens, reported E. tarda as the most frequently isolated species. In this study, we used HEp-2 cells to establish in vitro the adherence and invasive ability of 17 E. tarda strains isolated from SASL fecal material. All the strains were able to adhere and invade HEp-2 cells with adhesion and invasion percentages ranging from 56 to 100% and 21 to 74%, respectively. Despite the expression of these pathogenic factors, further investigation is needed to determine whether this bacterium could play a role as primary pathogen for this and other species of pinnipeds. PMID:25477948

  7. Comparative genomic analysis of bacteriophages specific to the channel catfish pathogen Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: The bacterial pathogen Edwardsiella ictaluri is a primary cause of mortality in channel catfish raised commercially in aquaculture farms. Additional treatment and diagnostic regimes are needed for this enteric pathogen, motivating the discovery and characterization of bacteriophages spe...

  8. Compounds with Inhibitory Activity Against the Channel Catfish Pathogens Edwardsiella ictaluri and Flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enteric septicemia of catfish (ESC) and columnaris, the most common channel catfish Ictalurus punctatus diseases in the southeastern United States, are caused by the bacteria Edwardsiella ictaluri and Flavobacterium columnare, respectively. Although producers may rely on antibiotics and certain the...

  9. Flagella Structure and Gene Sequences of the Fish Pathogen Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella icatluri the cause of enteric septicemia in channel catfish (Ictalurus punctatus) are motile by means of peritrichous flagella, a virulence determinant. Molecular composition of this polymeric structure in E. ictaluri remains largely unknown. Methods: Monoclonal antibodies (MAbs) develo...

  10. [Porphyria cutanea tarda: the benefit of additional diagnostics].

    PubMed

    Vossen, Allard R J V; Boesten, Lianne S M; Siersema, Peter D; Nellen, Ruud G L

    2016-01-01

    The porphyrias are a clinically and genetically heterogeneous group of relatively rare metabolic diseases that result from disorders in the biosynthesis of haeme. Porphyria cutanea tarda (PCT) is the most common type, accounting for 80-90% of all porphyrias, and is essentially an acquired disease, although PCT can also occur on a familial basis. We describe a 71-year-old female and a 62-year-old male patient, both of whom had several risk factors for developing PCT, ranging from iron overload due to a mutation in the hereditary haemochromatosis protein (HFE) gene, alcohol use, smoking, and exogenous oestrogen, to persistent hepatitis C infection. The clinical relevance of the several diagnostic modalities is important in PCT. Diagnostic evaluation is important in order to confirm the diagnosis, but also to evaluate the treatment response in the context of long-term follow-up in the prevention of late complications of PCT, i.e. hepatocellular carcinoma. PMID:26840933

  11. Evaluation of an in vitro cell assay to select attenuated bacterial mutants of Aeromonas hydrophila and Edwardsiella tarda to channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To evaluate the feasibility of using an in vitro cell assay to select attenuated bacterial mutants. Using catfish gill cells G1B, the feasibility of using an in vitro assay instead of in vivo virulence assay using live fish to select attenuated bacterial mutants was evaluated in this study. Pearson ...

  12. Edwardsiella piscicida identified in the southeastern United States by gyrB sequence, species specific and repetitive sequence mediated PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new taxa of Edwardsiella has recently been described from fishes of Europe and Asia. Researchers have determined this new strain does not belong to any established taxa within the genus Edwardsiella and have proposed the adoption of a new taxon, E. piscicida. A similar study in the United State...

  13. Chloroquine in the treatment of porphyria cutanea tarda.

    PubMed

    Tsega, E; Besrat, A; Damtew, B; Seyoum, E; Landells, J W

    1981-01-01

    Porphyria cutanea tarda (PCT) is common in Ethiopia and invariably affects the liver. Treatment by abstension from alcohol and avoidance of direct sunlight often failed to achieve lasting improvement. Phlebotomy is unacceptable to most of our patients and impractical as a routine therapy. Chloroquine phosphate 500 mg (300 mg base) given daily for 10 days to 24 patients with confirmed PCT, was found to be uniformly effective. Both clinical and biochemical remissions were complete, The side effects of chloroquine include fever, nausea, vomiting and myalgia which predictably occur on the third day of therapy and subside within 72 hours. Since all other modes of therapy are ineffective or impractical and since the response to chloroquine is prompt, effective and reproducible and the side effects are brief, mild and do not cause permanent hepatic damage, it is suggested that this drug is currently the most practical treatment for PCT in areas where repeated phlebotomy is unacceptable and patient follow-up is unsatisfactory. PMID:7324107

  14. Porphyria variegata and porphyria cutanea tarda in siblings: chemical and genetic aspects.

    PubMed Central

    Watson, C J; Cardinal, R A; Bossenmaier, I; Petryka, Z J

    1975-01-01

    A woman aged 54 was studied because of a severe acute porphyric (neurologic) relapse with clinical and chemical findings characteristic of porphyria variegata. During a family survey, her brother, aged 59, was found to have chemical abnormalities typical of porphyria cutanea tarda, without suggestion of neurologic manifestations. He had mild skin changes compatible with either of these forms of porphyria. The sister exhibited the protocoproporphyria of porphyria variegata, together with a large amount of fecal "x" porphyrin fraction, without demonstrable isocoproporphyrins. The brother had a uro-isocopro-type of porphyria in accord with the diagnosis of porphyria cutanea tarda, and quite at variance with the sister's findings. This occurrence of porphyria variegata and porphyria cutanea tarda in siblings is thus far unique. Certain hypotheses are considered in respect to genetic aspects of the differing prophyrias in this sibling pair. PMID:1061096

  15. Edwardsiella andrillae, a New Species of Sea Anemone from Antarctic Ice

    PubMed Central

    Daly, Marymegan; Rack, Frank; Zook, Robert

    2013-01-01

    Exploration of the lower surface of the Ross Ice Shelf in Antarctica by the Submersible Capable of under-Ice Navigation and Imaging (SCINI) remotely operated vehicle discovered a new species of sea anemone living in this previously undocumented ecosystem. This discovery was a significant outcome of the Coulman High Project’s geophysical and environmental fieldwork in 2010-2011 as part of the ANDRILL (ANtarctic geologic DRILLing) program. Edwardsiella andrillae n. sp., lives with most of its column in the ice shelf, with only the tentacle crown extending into the seawater below. In addition to being the only Antarctic representative of the genus, Edwardsiella andrillae is distinguished from all other species of the genus in the number of tentacles and in the size and distribution of cnidae. The anatomy and histology of Edwardsiella andrillae present no features that explain how this animal withstands the challenges of life in such an unusual habitat. PMID:24349517

  16. Edwardsiella andrillae, a new species of sea anemone from Antarctic ice.

    PubMed

    Daly, Marymegan; Rack, Frank; Zook, Robert

    2013-01-01

    Exploration of the lower surface of the Ross Ice Shelf in Antarctica by the Submersible Capable of under-Ice Navigation and Imaging (SCINI) remotely operated vehicle discovered a new species of sea anemone living in this previously undocumented ecosystem. This discovery was a significant outcome of the Coulman High Project's geophysical and environmental fieldwork in 2010-2011 as part of the ANDRILL (ANtarctic geologic DRILLing) program. Edwardsiella andrillae n. sp., lives with most of its column in the ice shelf, with only the tentacle crown extending into the seawater below. In addition to being the only Antarctic representative of the genus, Edwardsiella andrillae is distinguished from all other species of the genus in the number of tentacles and in the size and distribution of cnidae. The anatomy and histology of Edwardsiella andrillae present no features that explain how this animal withstands the challenges of life in such an unusual habitat. PMID:24349517

  17. A porphomethene inhibitor of uroporphyrinogen decarboxylase causes porphyria cutanea tarda

    PubMed Central

    Phillips, John D.; Bergonia, Hector A.; Reilly, Christopher A.; Franklin, Michael R.; Kushner, James P.

    2007-01-01

    Porphyria cutanea tarda (PCT), the most common form of porphyria in humans, is due to reduced activity of uroporphyrinogen decarboxylase (URO-D) in the liver. Previous studies have demonstrated that protein levels of URO-D do not change when catalytic activity is reduced, suggesting that an inhibitor of URO-D is generated in hepatocytes. Here, we describe the identification and characterization of an inhibitor of URO-D in liver cytosolic extracts from two murine models of PCT: wild-type mice treated with iron, δ-aminolevulinic acid, and polychlorinated biphenyls; and mice with one null allele of Uro-d and two null alleles of the hemochromatosis gene (Uro-d+/−, Hfe−/−) that develop PCT with no treatments. In both models, we identified an inhibitor of recombinant human URO-D (rhURO-D). The inhibitor was characterized by solid-phase extraction, chromatography, UV-visible spectroscopy, and mass spectroscopy and proved to be uroporphomethene, a compound in which one bridge carbon in the uroporphyrinogen macrocycle is oxidized. We synthesized uroporphomethene by photooxidation of enzymatically generated uroporphyrinogen I or III. Both uroporphomethenes inhibited rhURO-D, but the III isomer porphomethene was a more potent inhibitor. Finally, we detected an inhibitor of rhURO-D in cytosolic extracts of liver biopsy samples of patients with PCT. These studies define the mechanism underlying clinical expression of the PCT phenotype, namely oxidation of uroporphyrinogen to uroporphomethene, a competitive inhibitor of URO-D. The oxidation reaction is iron-dependent. PMID:17360334

  18. Porphyria cutanea tarda associated with autoimmune hypothyroidism, vitiligo and alopecia universalis.

    PubMed

    Sabán, J; Rodríguez-García, J L; Gil, J; País, J R; Medina, S

    1991-12-01

    The aetiology of porphyria cutanea tarda (PCT) has not been elucidated, but the possibility of an autoimmune mechanism has been proposed. We report a case of an unknown clinical combination of PCT with autoimmune hypothyroidism, alopecia universalis and vitiligo with thyroid and parietal cell circulating antibodies. This is highly suggestive of underlying autoimmune damage in this patient. PMID:1803247

  19. Identification of differentially regulated proteins of Edwardsiella ictaluri during iron restriction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri is a Gram-negative facultative anaerobe intracellular bacterium that causes enteric septicemia in channel catfish. Iron is an essential inorganic nutrient of bacteria and is crucial for bacterial invasion. Reduced availability of iron by the host may cause a significant stres...

  20. Ichthyophthirius multifiliis as a potential vector of Edwardsiella ictaluri in channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is limited information on whether parasites act as vectors to transmit pathogenic bacteria in fish. In this trial, we used Ichthyophthirius multifiliis and fluorescent Edwardsiella ictaluri as a model to study the interaction between parasite, bacterium and fish host. The percentage (23-39 %)...

  1. Construction, characterization and use of Edwardsiella ictaluri flagella-type three secretion system protein arrays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enteric septicemia of catfish, caused by Edwardsiella ictaluri, is the leading disease in channel catfish (Ictalurus punctatus) that is responsible for $50 - 60 million economic losses to catfish producers annually in the Southeastern U.S. The flagella and type three secretion system (TTSS) in Gram...

  2. Efficacy of florfenicol for control of mortality associated with Edwardsiella ictaluri in three species of catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of florfenicol against Edwardsiella icatluri infection was studied in channel catfish (Ictalurus puntatus (Delta strain)), hybrid catfish (Ictalurus punctatus (Delta strain) x Ictalurus furcatus (D&B strain)), and blue catfish (Ictalurus furcatus (D&B strain) fingerlings in 65L aquaria....

  3. Sequences of a FK-506 binding protein from Edwardsiella ictaluri isolates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A FK-506 binding protein, a member of the immunophilin superfamily of Edwardsiella ictaluri was partially identified by the in-vivo-induced antigen technology. We further cloned and sequenced this FK-506 binding protein gene using a Universal GenomeWalker kit. The complete sequence consisted of 612 ...

  4. INDUCTION OF NITRIC OXIDE IN CHANNEL CATFISH ICALUTUS PUNCTATUS BY EDWARDSIELLA ICTALURI

    EPA Science Inventory

    Channel catfish, Ictalurus punctatus, were injected intraperiloneally with live cells of Edwardsiella ictaluri and held in flow-through tanks for five days. he head kidneys from injected and control fish were removed and the nitric oxide synthase activity measured. ctivities foun...

  5. Cloning, Characterization and Expression of a FK506 Binding Protein from Edwardsiella icatluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Edwardsiella ictaluri is the etiological agent of enteric septicemia of catfish, which is the most common disease of channel catfish (Ictalurus punctatus) and is responsible for $50 - 60 million economic losses to catfish producers annually in the Southeastern U.S. In the course of stud...

  6. Overcoming inconsistencies in mortality rates during winter experimental challenges of channel catfish with Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the goals of the ARS Catfish Genetics Research Unit is to incorporate disease resistance to ESC, caused by the bacterium, Edwardsiella ictaluri, into our selective breeding program. Through repeated experiments we have determined an optimal challenge dose of E. ictaluri that produces 50-70% ...

  7. Modified live Edwardsiella ictaluri vaccine, AQUAVAC-ESC, lacks multidrug resistance plasmids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasmid mediated antibiotic resistance was first discovered in Edwardsiella ictaluri in the early 1990’s, and in 2007 an E. ictaluri isolate harboring an IncA/C plasmid was recovered from a moribund channel catfish infected with the bacterium. Due to the identification of multidrug resistance plasm...

  8. Chemical and electroporated transformation of Edwardsiella ictaluri using three different plasmids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transfer of DNA by conjugation has been the method generally used for genetic manipulation of Edwardsiella ictaluri because, previously, attempts to transform E. ictaluri by the uptake of naked DNA has apparently failed. We report here the successful transformation of seven strains of E. ictaluri us...

  9. Global transcription analysis of vaccinated channel catfish following challenge with virulent Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To determine the identities of genes involved in either innate or adaptive immunity, microarray analysis of 65,182 UniGene transcripts were performed to compare gene expression in vaccinated channel catfish after challenge with a virulent Edwardsiella ictaluri compared to that in sham-vaccinated fis...

  10. Construction, characterization, expression and immune responses of flagellar proteins of channel catfish, important pathogen Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Edwardsiella ictaluri causes enteric septicemia of catfish, which is the leading disease in channel catfish (Ictalurus punctatus)and is responsible for $50 - 60 million economic losses to catfish producers annually in the southeastern U.S. Bacterial flagella are complex polymeric structu...

  11. Organization and sequence of four flagellin-encoding genes of Edwardsiella icataluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri, the cause of enteric septicemia in channel catfish (Ictalurus punctatus), is motile by means of peritrichous flagella. We determined the complete flagellin gene sequences and their organization in E. ictaluri by sequencing genomic segments selected from a lambda-ZAP phage gen...

  12. Experimental Edwardsiella ictaluri Infection Causes Mortality in White Perch (Morone americana)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri, the causative agent of enteric septicemia of catfish (ESC), receives considerable attention due to its negative impact on the production and harvest of channel catfish (Ictaluri punctatus). This bacterium was initially considered a specific pathogen of channel catfish and oth...

  13. Susceptibility of channel catfish, Ictalurus punctatus, to Edwardsiella ictaluri challange following copper sulfate exposure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel catfish, Ictalurus punctatus (Rafinesque) with or without a preliminary 24h exposure to 2 mg copper sulfate L-1, were challenged with 7.5 X 106 colony forming units L-1 of Edwardsiella ictaluri to determine the effect of copper sulfate on disease resistance. Catfish previously exposed to co...

  14. Edwardsiella ictaluri as the causative agent of mortality in cultured Nile tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri was consistently isolated from the spleens, livers, and head kidneys of diseased Nile tilapia Oreochromis niloticus from a farm experiencing mortality events in several culture ponds. We describe the first published outbreak of E. ictaluri–induced Edwardsiellosis in Nile tilapi...

  15. IncA/C Plasmid-Mediated Florfenicol Resistance in the Catfish Pathogen Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Florfenicol has recently been approved for the treatment of enteric septicemia of catfish caused by Edwardsiella ictaluri. Here we report the identification of florfenicol resistance in a clinical isolate of E. ictaluri. Resistance in this isolate is associated with a mobile IncA/C plasmid conferrin...

  16. Effects of Bio-Mos on Growth and Survival of Channel Catfish Challenged with Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major problem in the catfish farming industry has been high disease loss to enteric septicemia of catfish (ESC), caused by the bacterium Edwardsiella ictaluri (E. ictaluri). Methods to control this disease include antibiotic therapy, vaccinations, and management strategies such as taking the fish...

  17. Transferable green fluorescence-tagged pEI2 in Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The pEI2 plasmid of Edwardsiella ictaluri isolate, I49, was tagged using a Tn10-GFP-kan cassette to create the green fluorescence-expressing derivative I49-gfp. The Tn10-GFP-kan insertion site was mapped by plasmid sequencing to 663 bp upstream of orf2 and appeared to be at a neutral site in the pla...

  18. Characterization of the RRN Operons in the Channel Catfish Pathogen Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: To advance diagnostics and phylogenetics of Edwardsiella ictaluri by sequencing and characterizing its rrn operons. Methods and Results: The Edw. ictaluri rrn operons were identified from a 5-7 kb insert lambda library and from Edw. ictaluri fosmid clones. We present the complete sequences...

  19. Bacterial distribution and tissue targets following experimental Edwardsiella ictaluri infection in nile tilapia Oreochromis niloticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri, a Gram-negative enteric bacterium, is the known etiological agent of enteric septicemia of catfish. In the last few years, different strains have been implicated as the causative agent of mortality events in cultured fish, including Nile tilapia Oreochromis niloticus L. Due to...

  20. Chemical and electrophoretic transformation of Edwardsiella ictaluri using three different plasmids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri the cause of enteric septicemia in channel catfish (Ictalurus punctatus) (ESC), is a bacterial pathogen having a considerable economic impact on the cultured catfish industry. Molecular genetic manipulation of this bacterium is important from the perspective of determining viru...

  1. Familial and sporadic porphyria cutanea tarda: clinical and biochemical features and risk factors in 152 patients.

    PubMed

    Muñoz-Santos, Carlos; Guilabert, Antonio; Moreno, Nemesio; To-Figueras, Jordi; Badenas, Celia; Darwich, Esteve; Herrero, Carmen

    2010-03-01

    Porphyria cutanea tarda is the most frequent porphyria and occurs in both sporadic and familial forms. We conducted the current study in a series of 152 consecutive patients with porphyria cutanea tarda attending the Porphyria Unit of the Hospital Clinic of Barcelona, Spain, to update the clinical manifestations of the disease and to study the sex differences, the proportion of familial forms, and the role of different risk factors in this population. Patients were classified as familial and sporadic cases according to erythrocyte uroporphyrinogen-decarboxylase activity and uroporphyrinogen-decarboxylase genotyping. In our cohort, skin fragility and blisters on the hands were the most frequent clinical manifestations. Women more frequently had facial hypertrichosis (84.8%; p = 0.004), affected areas other than the hands and face (33.3%; p = 0.008), and pruritus (27.3%; p = 0.041) compared with men. Of our patients, 11.8% did not present the typical clinical onset of the disease, with facial hypertrichosis and hyperpigmentation the more frequent complaints in these cases. Analysis of risk factors showed a high prevalence of hepatitis C virus infection (65.8%) and alcohol abuse (59.9%), both being more frequent in men (p < 0.001). Hepatitis C virus infection was the only risk factor that showed differences between the sporadic and familial forms in the logistic regression model (odds ratio, 0.05; 95% confidence interval, 0.006-0.46). In conclusion, atypical forms of presentation of porphyria cutanea tarda should be considered in order to prevent delayed diagnosis. We note the sustained role of hepatitis C virus infection in the precipitation of sporadic porphyria cutanea tarda. Therefore, in countries with a high prevalence of hepatitis C virus infection, the absence of such infection in a patient with porphyria cutanea tarda may suggest a possible familial case. PMID:20517178

  2. Treatment options in acute porphyria, porphyria cutanea tarda, and erythropoietic protoporphyria.

    PubMed

    Harper, Pauline; Wahlin, Staffan

    2007-12-01

    The porphyrias are a group of uncommon metabolic diseases caused by enzyme deficiencies within heme biosynthesis that lead to neurotoxic or phototoxic heme precursor accumulation. There are four acute porphyrias characterized by neuropsychiatric symptoms: acute intermittent porphyria, variegate porphyria, hereditary coproporphyria, and 5-aminolevulinic acid dehydratase deficiency porphyria. Treatment includes elimination of any porphyrogenic factor and symptomatic treatment. Carbohydrate and intravenous heme administration constitute specific therapies in the disorders' acute phase. The mainstay treatment in the cutaneous porphyrias is avoidance of sunlight exposure. In porphyria cutanea tarda and the two acute porphyrias with skin manifestations, variegate porphyria and hereditary coproporphyria, care of the vulnerable skin is important. In porphyria cutanea tarda, specific treatment is accomplished by a series of phlebotomies and/or by low-dose chloroquine administration. In erythropoietic protoporphyria, light-protective beta-carotene is prescribed. PMID:18221605

  3. [Solarium-induced pseudoporphyria and variegate porphyria as rare differential diagnoses of porphyria cutanea tarda].

    PubMed

    Kochs, C; Mühlenstädt, E; Neumann, N J; Hanneken, S

    2009-10-01

    Three patients presented with typical porphyria cutanea tarda-like vesicles, erosions and scars as well as increased fragility, primarily on the back of the hands. In two of the three, porphyrin workup was normal. Skin biopsy was compatible with porphyria cutanea tarda (PCT) or pseudoporphyria. The common aspect in the patients' history was the frequent use of solaria for many years, so that UV-induced pseudoporphyria was diagnosed. Treatment was strict abstention from UV radiation and regular dermatologic controls for signs of skin damage. Porphyrin analysis in the third patient showed normal excretion of total urine porphyrins and precursors; however, fecal porphyrins were elevated with dominating coproporphyrins in HPLC and the plasma fluorescence scan yielded a peak at 625 nm. Subsequent mutation analysis showed a mutation in the protoporphyrinogen oxidase gene, thereby confirming the diagnosis of variegate porphyria. Five months after the initial diagnosis the patient presented with the first acute attack. Further investigations revealed a metastasized carcinoma of the colon, which probably triggered the acute attack. Our cases show rare differential diagnoses in patients presenting with typical PCT-like skin lesions. The discrimination between porphyria cutanea tarda and its differential diagnoses is very important since it has an important impact not only on the treatment modality but also on the course and the prognosis of the disease. PMID:19756434

  4. Precipitating factors of porphyria cutanea tarda in Brazil with emphasis on hemochromatosis gene (HFE) mutations. Study of 60 patients*

    PubMed Central

    Vieira, Fatima Mendonça Jorge; Nakhle, Maria Cristina; Abrantes-Lemos, Clarice Pires; Cançado, Eduardo Luiz Rachid; dos Reis, Vitor Manoel Silva

    2013-01-01

    BACKGROUND Porphyria cutanea tarda is the most common form of porphyria, characterized by the decreased activity of the uroporphyrinogen decarboxylase enzyme. Several reports associated HFE gene mutations of hereditary hemochromatosis with porphyria cutanea tarda worldwide, although up to date only one study has been conducted in Brazil. OBJECTIVES Investigation of porphyria cutanea tarda association with C282Y and H63D mutations in the HFE gene. Identification of precipitating factors (hepatitis C, HIV, alcoholism and estrogen) and their link with HFE mutations. METHODS An ambispective study of 60 patients with PCT was conducted during the period from 2003 to 2012. Serological tests for hepatitis C and HIV were performed and histories of alcohol abuse and estrogen intake were investigated. HFE mutations were identified with real-time PCR. RESULTS Porphyria cutanea tarda predominated in males and alcohol abuse was the main precipitating factor. Estrogen intake was the sole precipitating factor present in 25% of female patients. Hepatitis C was present in 41.7%. All HIV-positive patients (15.3%) had a history of alcohol abuse. Allele frequency for HFE mutations, i.e., C282Y (p = 0.0001) and H63D (p = 0.0004), were significantly higher in porphyria cutanea tarda patients, compared to control group. HFE mutations had no association with the other precipitating factors. CONCLUSIONS Alcohol abuse, hepatitis C and estrogen intake are prevalent precipitating factors in our porphyria cutanea tarda population; however, hemochromatosis in itself can also contribute to the outbreak of porphyria cutanea tarda, which makes the research for HFE mutations necessary in these patients PMID:24068123

  5. Genome sequence of Edwardsiella ictaluri 93-146 a strain associated with a natural channel catfish outbreak of enteric septicemia of catifsh

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri is the cause of extensive mortalities and economic losses to the channel catfish industry of the southeast United States. Here we report the complete genome of Edwardsiella ictaluri 93-146. Whole-genome sequence analysis of E. ictaluri provides a tool for understanding the geno...

  6. Anthrax Pathogenesis.

    PubMed

    Moayeri, Mahtab; Leppla, Stephen H; Vrentas, Catherine; Pomerantsev, Andrei P; Liu, Shihui

    2015-01-01

    Anthrax is caused by the spore-forming, gram-positive bacterium Bacillus anthracis. The bacterium's major virulence factors are (a) the anthrax toxins and (b) an antiphagocytic polyglutamic capsule. These are encoded by two large plasmids, the former by pXO1 and the latter by pXO2. The expression of both is controlled by the bicarbonate-responsive transcriptional regulator, AtxA. The anthrax toxins are three polypeptides-protective antigen (PA), lethal factor (LF), and edema factor (EF)-that come together in binary combinations to form lethal toxin and edema toxin. PA binds to cellular receptors to translocate LF (a protease) and EF (an adenylate cyclase) into cells. The toxins alter cell signaling pathways in the host to interfere with innate immune responses in early stages of infection and to induce vascular collapse at late stages. This review focuses on the role of anthrax toxins in pathogenesis. Other virulence determinants, as well as vaccines and therapeutics, are briefly discussed. PMID:26195305

  7. H-NS binding to evpB and evpC and repressing T6SS expression in fish pathogen Edwardsiella piscicida.

    PubMed

    Cui, Shilei; Xiao, Jingfan; Wang, Qiyao; Zhang, Yuanxing

    2016-09-01

    Edwardsiella piscicida is an important causative agent of hemorrhagic septicemia in fish and infects both cultured and wild fish species. Type VI secretion system (T6SS) was proved to play important roles in pathogenesis of E. piscicida. In this study, it was demonstrated that the expression of T6SS genes evpB and evpC was under control of the global regulator H-NS in E. piscicida and the transcriptional level of evpB and evpC was significantly down-regulated by H-NS. Compared to the wild type, the transcriptional levels of evpB and evpC were up-regulated in hns null mutant, while down-regulated in hns overexpression strain. The results of EMSA and DNase I footprinting revealed that H-NS protein directly bound to upstream region of evpC at multiple sites. A high-affinity motif with a 9-nucleotide sequence 5'-ATATAAAAT-3' was defined for H-NS preferential recognition based on the feature of the binding sites. These results indicated that H-NS acted cooperatively to form extended nucleoprotein filaments on target DNA. Site-directed mutagenesis of H-NS further showed that R86 played an essential role in T6SS gene binding. These findings highlighted the mechanisms underlying the complex regulation network of T6SS by H-NS in E. piscicida. PMID:27125651

  8. Edwardsiellosis Caused by Edwardsiella ictaluri in Laboratory Populations of Zebrafish Danio rerio

    PubMed Central

    Hawke, John P.; Kent, Michael; Rogge, Matt; Baumgartner, Wes; Wiles, Judy; Shelley, Johnny; Savolainen, L. Christine; Wagner, Robert; Murray, Katy; Peterson, Tracy S.

    2014-01-01

    We report the first cases of Edwardsiella ictaluri causing epizootics in laboratory populations of Zebrafish Danio rerio. Edwardsiella ictaluri is primarily recognized as a disease of catfish species and is known to cause an economically important bacterial disease of farm-raised catfish in the USA and abroad; however, it has been isolated on occasion from 10 other genera of nonictalurid fishes. We isolated E. ictaluri from moribund Zebrafish held in quarantine at two different universities in two states and from a research facility in a third state between February 23 and December 6, 2011. Edwardsiellosis in Zebrafish can be described as a severe systemic disease characterized by tissue necrosis and the presence of large numbers of extracellular and intracellular bacteria, often within macrophages. The kidneys (pronephros and mesonephros), spleen, nares, and forebrain were the most commonly and severely affected tissues. In outbreaks, mortality was acute and numerous fish died over a 1–2 week period. Mortality continued until the majority of the population was lost, at which time the remaining fish were euthanized. In addition to these cases, four cultures of bacteria isolated from Zebrafish by another diagnostic laboratory were submitted to the Louisiana Aquatic Diagnostic Laboratory for identification and were confirmed as E. ictaluri. In total, eight cultures of E. ictaluri from Zebrafish from Louisiana, Massachusetts, Pennsylvania, and Florida were identified. The isolates were confirmed as E. ictaluri by biochemical phenotype, API 20E (bioMérieux), and amplification and sequencing of a portion of the 16S rRNA gene. Edwardsiella ictaluri isolates from Zebrafish are believed to comprise a unique group and were differentiated from catfish isolates by exhibiting weaker motility, autoaggregation in broth, a different plasmid profile (two plasmids of 4.0 and 3.5 kb), a different API 20E code (4204000), and lack of lipopolysaccharide recognition with Mab Ed9

  9. Edwardsiellosis caused by Edwardsiella ictaluri in laboratory populations of Zebrafish Danio rerio.

    PubMed

    Hawke, John P; Kent, Michael; Rogge, Matt; Baumgartner, Wes; Wiles, Judy; Shelley, Johnny; Savolainen, L Christine; Wagner, Robert; Murray, Katy; Peterson, Tracy S

    2013-09-01

    We report the first cases of Edwardsiella ictaluri causing epizootics in laboratory populations of Zebrafish Danio rerio. Edwardsiella ictaluri is primarily recognized as a disease of catfish species and is known to cause an economically important bacterial disease of farm-raised catfish in the USA and abroad; however, it has been isolated on occasion from 10 other genera of nonictalurid fishes. We isolated E. ictaluri from moribund Zebrafish held in quarantine at two different universities in two states and from a research facility in a third state between February 23 and December 6, 2011. Edwardsiellosis in Zebrafish can be described as a severe systemic disease characterized by tissue necrosis and the presence of large numbers of extracellular and intracellular bacteria, often within macrophages. The kidneys (pronephros and mesonephros), spleen, nares, and forebrain were the most commonly and severely affected tissues. In outbreaks, mortality was acute and numerous fish died over a 1-2 week period. Mortality continued until the majority of the population was lost, at which time the remaining fish were euthanized. In addition to these cases, four cultures of bacteria isolated from Zebrafish by another diagnostic laboratory were submitted to the Louisiana Aquatic Diagnostic Laboratory for identification and were confirmed as E. ictaluri. In total, eight cultures of E. ictaluri from Zebrafish from Louisiana, Massachusetts, Pennsylvania, and Florida were identified. The isolates were confirmed as E. ictaluri by biochemical phenotype, API 20E (bioMérieux), and amplification and sequencing of a portion of the 16S rRNA gene. Edwardsiella ictaluri isolates from Zebrafish are believed to comprise a unique group and were differentiated from catfish isolates by exhibiting weaker motility, autoaggregation in broth, a different plasmid profile (two plasmids of 4.0 and 3.5 kb), a different API 20E code (4204000), and lack of lipopolysaccharide recognition with Mab Ed9. PMID

  10. 38 CFR 3.813 - Interim benefits for disability or death due to chloracne or porphyria cutanea tarda.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... veteran who served in the active military, naval or air service in the Republic of Vietnam during the... section dies as a result of chloracne or porphyria cutanea tarda, the veteran's survivors shall be paid... most recent departure from the Republic of Vietnam during active military, naval or air service and...

  11. 38 CFR 3.813 - Interim benefits for disability or death due to chloracne or porphyria cutanea tarda.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... veteran who served in the active military, naval or air service in the Republic of Vietnam during the... section dies as a result of chloracne or porphyria cutanea tarda, the veteran's survivors shall be paid... most recent departure from the Republic of Vietnam during active military, naval or air service and...

  12. Complete genome sequence of Methanolinea tarda NOBI-1T, a hydrogenotrophic methanogen isolated from methanogenic digester sludge

    DOE PAGESBeta

    Yamamoto, Kyosuke; Tamaki, Hideyuki; Cadillo-Quiroz, Hinsby; Imachi, Hiroyuki; Kyrpides, Nikos; Woyke, Tanja; Goodwin, Lynne; Zinder, Stephen H.; Kamagata, Yoichi; Liu, Wen -Tso

    2014-09-04

    In this study, we report a 2.0-Mb complete genome sequence of Methanolinea tarda NOBI-1T, a methanogenic archaeon isolated from an anaerobic digested sludge. This is the first genome report of the genus Methanolinea isolate belonging to the family Methanoregulaceae, a recently proposed novel family within the order Methanomicrobiales.

  13. Effects of a phytogenic feed additive on susceptibility of channel catfish to Edwardsiella ictaluri and levels of mannose binding lectin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to investigate the effect of a phytogenic feed additive (Digestarom® P.E.P. MGE) on growth performance and disease susceptibility to Edwardsiella ictaluri. Two hundred and fifty juvenile channel catfish (7.2 ± 0.1 g) were allotted into the following treatments: Control (float...

  14. Edwardsiella ictaluri Encodes an Acid Activated Urease that is Required for Intracellular Replication in Channel Catfish Ictalurus punctatus Macrophages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genomic analysis indicated that Edwardsiella ictaluri encodes a putative ureasepathogenicity island containing 9 open reading frames, including urea and ammonium transporters. In vitro studies with the wild-type E. ictaluri and a ureG::kan urease mutant strain indicated that E. ictaluri is significa...

  15. Identification of over-expressed genes in modified live vaccine strain of Edwardsiella ictaluri compared to virulent strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 41 expressed sequence tags (ESTs) were isolated from a modified live vaccine strain (AQUAVAC-ESC, formerly RE-33) vs a virulent parent strain (EILO) of Edwardsiella ictaluri. Transcriptional levels of the 41 ESTs in the vaccine strain and th...

  16. Changes of serum myeloperoxidase and nitric oxide in the early stage of Edwardsiella ictaluri infection in channel catfish, Ictalurus punctatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enteric septicemia of catfish (ESC), caused by Edwardsiella ictaluri, is an important farm-raised channel catfish, Ictalurus punctatus (Rafinesque), disease. The development of a monitoring system for assessing the catfish health status in hatcheries and ponds is in great demanding. Because of the...

  17. Simultaneous Detection of Bacterial Fish Pathogens, Edwardsiella ictaluri, Flavobacterium columnnare and Aeromonas Hydrophila by Multiplex-PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri, Flavobacterium columnare and Aeromonas hydrophila are three major bacterial pathogens of fish that cause diseases with significant economic impact on the aquaculture industry world-wide. Rapid detection of multiple infections with these bacteria in the same host is important f...

  18. Feeding Lactobacillus spp. and Bacillus spp. Does Not Improve Growth or Survival of Channel Catfish Experimentally Challenged with Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major problem in the channel catfish industry has been high disease loss to enteric septicemia of catfish, caused by the bacterium Edwardsiella ictaluri. Feeding probiotics may prove beneficial in improving disease resistance. The first study examined the effects of a Lactobacillus probiotic (Flor...

  19. Oral vaccination of channel catfish against enteric septicemia of catfish (ESC) using a live attenuated Edwardsiella ictaluri isolate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enteric septicemia of catfish (ESC), caused by Edwardsiella ictaluri, is the most problematic bacterial disease affecting catfish aquaculture in the southeastern United States. Efforts to develop an effective ESC vaccine have had limited industrial success. In commercial settings, ESC vaccines are t...

  20. Oral vaccination of channel catfish against enteric septicemia of catfish using a live attenuated Edwardsiella ictaluri isolate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enteric septicemia of catfish (ESC), caused by Edwardsiella ictaluri, is the most problematic bacterial disease affecting catfish aquaculture in the southeastern United States. Efforts to develop an effective ESC vaccine have had limited industrial success. In commercial settings, ESC vaccines are...

  1. Roles for mannose binding lectin and rhamnose binding lectin in channel catfish fed essential oils and challenged with Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major problem in the catfish farming industry has been high disease loss to enteric septicemia of catfish (ESC), caused by the bacterium Edwardsiella ictaluri. Methods to control this disease include vaccination, antibiotic therapy, and restricted feeding. Another method that has been examined i...

  2. Proteomic analysis of head kidney tissue from high and low susceptibility families of channel catfish following challenge with Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was performed to compare proteomic profiles of channel catfish from families with high and low susceptibility to Edwardsiella ictaluri following an immersion challenge. Total protein was isolated from head kidney samples, collected at 2 and 6 hours post exposure, and analyzed by 2-D-gel elec...

  3. Effects of Ichthyophthirius multifiliis parasitism on the survival, hematology and bacterial load in channel catfish previously exposed to Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of Ichthyophthirius multifiliis (Ich) parasitism on survival, hematology and bacterial load in channel catfish, Ictalurus punctatus, previously exposed to Edwardsiella ictaluri was studied. Fish were exposed to E. ictaluri one day prior to Ich in the following treatments: 1)- infected by...

  4. Identification of overexpressed immune-related genes in the anterior kidney of channel catfish induced by Edwardsiella ictaluri vaccination.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 57 expressed sequence tags (ESTs) were isolated from 240 clones of a modified live Edwardsiella ictaluri-vaccinated vs sham-vaccinated channel catfish anterior kidney subtractive library. The transcription levels of the 57 ESTs in response t...

  5. Comparative catfish macrophage function in families expressing high and low survivor phenotype following experimental challenge with Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two channel catfish families were identified as displaying a high (>90%) or low (<10%) survival phenotype in repeated experimental challenge with Edwardsiella ictaluri. In order to gain understanding of the biological basis of these phenotypes, primary macrophages were prepared from head kidney tiss...

  6. An Attenuated Strain of Edwardsiella ictaluri is Killed by Channel Catfish (Ictalurus punctatus) Macrophages and Confers Protection in Few Days

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Edwardsiella ictaluri is able to survive inside macrophages. Several studies have demonstrated that in channel catfish protective immunity against E. ictaluri is mediated by a cellular immune response. Methods: A virulent strain and an attenuated strain (used as a modified live vaccine) ...

  7. Binding and Phagocytosis by Opsonized and Nonopsonized Channel Catfish Macrophages of Viable DsRed-fluorescent-labeled Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phagocyte-mediated killing of bacterial pathogens is one of the major defensive mechanisms in fish. The binding, uptake and destruction of recombinant fluorescent protein DsRed transformed Edwardsiella ictaluri by opsonized and nonopsonized channel catfish (Ictalurus punctatus) macrophages was chara...

  8. Production of a reference transcriptome and transcriptomic database (EdwardsiellaBase) for the lined sea anemone, Edwardsiella lineata, a parasitic cnidarian

    PubMed Central

    2014-01-01

    Background The lined sea anemone Edwardsiella lineata is an informative model system for evolutionary-developmental studies of parasitism. In this species, it is possible to compare alternate developmental pathways leading from a larva to either a free-living polyp or a vermiform parasite that inhabits the mesoglea of a ctenophore host. Additionally, E. lineata is confamilial with the model cnidarian Nematostella vectensis, providing an opportunity for comparative genomic, molecular and organismal studies. Description We generated a reference transcriptome for E. lineata via high-throughput sequencing of RNA isolated from five developmental stages (parasite; parasite-to-larva transition; larva; larva-to-adult transition; adult). The transcriptome comprises 90,440 contigs assembled from >15 billion nucleotides of DNA sequence. Using a molecular clock approach, we estimated the divergence between E. lineata and N. vectensis at 215–364 million years ago. Based on gene ontology and metabolic pathway analyses and gene family surveys (bHLH-PAS, deiodinases, Fox genes, LIM homeodomains, minicollagens, nuclear receptors, Sox genes, and Wnts), the transcriptome of E. lineata is comparable in depth and completeness to N. vectensis. Analyses of protein motifs and revealed extensive conservation between the proteins of these two edwardsiid anemones, although we show the NF-κB protein of E. lineata reflects the ancestral structure, while the NF-κB protein of N. vectensis has undergone a split that separates the DNA-binding domain from the inhibitory domain. All contigs have been deposited in a public database (EdwardsiellaBase), where they may be searched according to contig ID, gene ontology, protein family motif (Pfam), enzyme commission number, and BLAST. The alignment of the raw reads to the contigs can also be visualized via JBrowse. Conclusions The transcriptomic data and database described here provide a platform for studying the evolutionary developmental genomics

  9. Genetic structure of the threatened West-Pannonian population of Great Bustard (Otis tarda)

    PubMed Central

    Raab, Rainer; Spakovszky, Péter; Alonso, Juan Carlos

    2016-01-01

    The genetic diversity, population structure and gene flow of the Great Bustards (Otis tarda) living in Austria-Slovakia-West Hungary (West-Pannonian region), one of the few populations of this globally threatened species that survives across the Palaearctic, has been assessed for the first time in this study. Fourteen recently developed microsatellite loci identified one single population in the study area, with high values of genetic diversity and gene flow between two different genetic subunits. One of these subunits (Heideboden) was recognized as a priority for conservation, as it could be crucial to maintain connectivity with the central Hungarian population and thus contribute to keeping contemporary genetic diversity. Current conservation efforts have been successful in saving this threatened population from extinction two decades ago, and should continue to guarantee its future survival. PMID:26966677

  10. Illness Perception and Psychological Distress in Persons with Porphyria Cutanea Tarda.

    PubMed

    Andersen, Janice; Nordin, Karin; Sandberg, Sverre

    2016-06-15

    Porphyria cutanea tarda (PCT) requires long-term treatment and follow-up, although many patients experience life-long remission. The aim of this cross-sectional postal survey was to describe and investigate the association between illness perception, health complaints, self-reported symptoms and distress in persons with PCT. The participants perceived PCT as a chronic condition with high levels of personal and treatment control. Persons who reported active symptoms scored higher on perceived illness threat, total health complaints and psychological distress compared with those in remission or latent phases. However, a higher perception of illness threat and the total burden of health complaints were more closely associated with psychological distress than were perceived PCT symptoms activity. This has implications for clinical consultation; dermatologists should be attentive to symptoms activity, but also recognize that patients in remission with a high perceived illness threat and multiple health complaints might be especially vulnerable to psychological distress with regards to PCT. PMID:26775575

  11. Liver Cirrhosis Induced by Porphyria Cutanea Tarda: A Case Report and Review

    PubMed Central

    Lee, Kwang Gyun; Hyun, Jong Jin; Seo, Yeon Seok; Keum, Bora; Yim, Hyung Joon; Jeen, Yoon Tae; Lee, Hong Sik; Chun, Hoon Jai; Kim, Chang Duck; Ryu, Ho Sang

    2010-01-01

    Porphyria cutanea tarda (PCT) is a metabolic disorder that results in a decrease in uroporphyrinogen decarboxylase activity. It is characterized by photosensitivity, bullae formation, and skin pigmentation. There are four types of PCT: acquired, familial, toxic, and hepatoerythropoietic. Uroporphyrin levels are elevated in the urine of PCT patients. PCT can be differentiated from other porphyrias by its clinical characteristics and the porphyrin levels in the serum, erythrocytes, urine, and feces. This metabolic disorder can lead to liver dysfunction as well as histological changes such as fatty infiltration or hepatic fibrosis. PCT rarely manifests as liver cirrhosis. We report herein a case of PCT-induced liver cirrhosis that progressed to hepatic failure. PMID:21253308

  12. Co-existence of hereditary coproporphyria and porphyria cutanea tarda: The importance of genetic testing.

    PubMed

    Rudd, Alice; Grant, Janine; Varigos, George; Morgan, Vanessa; Winship, Ingrid

    2013-05-01

    The porphyrias are a group of inherited disorders that result in defects in the enzymes of the haem biosynthetic pathway, causing photosensitive bullous skin eruptions or abdominal and neurological attacks. Enzymatic defects result in specific porphyrin excretory patterns that are diagnosed biochemically and can be confirmed by genetic testing. Defects in the coproporphyrinogen oxidase (CPOX) enzyme result in the autosomal dominant hereditary coproporphyria. Multiple mutations have been identified in the CPOX gene and incomplete penetrance is noted. Latent carriers without clinical evidence of disease are at risk of life-threatening attacks. Porphyria cutanea tarda may be inherited, but is more commonly acquired. Occasionally two forms of porphyria may co-exist. The importance of genetic testing is discussed. PMID:23582006

  13. Identification and Characterization of Putative Translocated Effector Proteins of the Edwardsiella ictaluri Type III Secretion System.

    PubMed

    Dubytska, Lidiya P; Rogge, Matthew L; Thune, Ronald L

    2016-01-01

    Edwardsiella ictaluri, a major pathogen in channel catfish aquaculture, encodes a type III secretion system (T3SS) that is essential for intracellular replication and virulence. Previous work identified three putative T3SS effectors in E. ictaluri, and in silico analysis of the E. ictaluri genome identified six additional putative effectors, all located on the chromosome outside the T3SS pathogenicity island. To establish active translocation by the T3SS, we constructed translational fusions of each effector to the amino-terminal adenylate cyclase (AC) domain of the Bordetella pertussis adenylate cyclase toxin CyaA. When translocated through the membrane of the Edwardsiella-containing vacuole (ECV), the cyclic AMP produced by the AC domain in the presence of calmodulin in the host cell cytoplasm can be measured. Results showed that all nine effectors were translocated from E. ictaluri in the ECV to the cytoplasm of the host cells in the wild-type strain but not in a T3SS mutant, indicating that translocation is dependent on the T3SS machinery. This confirms that the E. ictaluri T3SS is similar to the Salmonella pathogenicity island 2 T3SS in that it translocates effectors through the membrane of the bacterial vacuole directly into the host cell cytoplasm. Additional work demonstrated that both initial acidification and subsequent neutralization of the ECV were necessary for effector translocation, except for two of them that did not require neutralization. Single-gene mutants constructed for seven of the individual effectors were all attenuated for replication in CCO cells, but only three were replication deficient in head kidney-derived macrophages (HKDM). IMPORTANCE The bacterial pathogen Edwardsiella ictaluri causes enteric septicemia of catfish (ESC), an economically significant disease of farm-raised channel catfish. Commercial catfish production accounts for the majority of the total fin fish aquaculture in the United States, with almost 300,000

  14. Identification and Characterization of Putative Translocated Effector Proteins of the Edwardsiella ictaluri Type III Secretion System

    PubMed Central

    Dubytska, Lidiya P.; Rogge, Matthew L.

    2016-01-01

    ABSTRACT Edwardsiella ictaluri, a major pathogen in channel catfish aquaculture, encodes a type III secretion system (T3SS) that is essential for intracellular replication and virulence. Previous work identified three putative T3SS effectors in E. ictaluri, and in silico analysis of the E. ictaluri genome identified six additional putative effectors, all located on the chromosome outside the T3SS pathogenicity island. To establish active translocation by the T3SS, we constructed translational fusions of each effector to the amino-terminal adenylate cyclase (AC) domain of the Bordetella pertussis adenylate cyclase toxin CyaA. When translocated through the membrane of the Edwardsiella-containing vacuole (ECV), the cyclic AMP produced by the AC domain in the presence of calmodulin in the host cell cytoplasm can be measured. Results showed that all nine effectors were translocated from E. ictaluri in the ECV to the cytoplasm of the host cells in the wild-type strain but not in a T3SS mutant, indicating that translocation is dependent on the T3SS machinery. This confirms that the E. ictaluri T3SS is similar to the Salmonella pathogenicity island 2 T3SS in that it translocates effectors through the membrane of the bacterial vacuole directly into the host cell cytoplasm. Additional work demonstrated that both initial acidification and subsequent neutralization of the ECV were necessary for effector translocation, except for two of them that did not require neutralization. Single-gene mutants constructed for seven of the individual effectors were all attenuated for replication in CCO cells, but only three were replication deficient in head kidney-derived macrophages (HKDM). IMPORTANCE The bacterial pathogen Edwardsiella ictaluri causes enteric septicemia of catfish (ESC), an economically significant disease of farm-raised channel catfish. Commercial catfish production accounts for the majority of the total fin fish aquaculture in the United States, with almost 300,000

  15. Efficacy of Florfenicol for Control of Mortality Associated with Edwardsiella ictaluri in Three Species of Catfish.

    PubMed

    Gaunt, Patricia S; Chatakondi, Nagaraj; Gao, Dana; Endris, Richard

    2015-03-01

    The efficacy of florfenicol for control of mortality associated with Edwardsiella icatluri was studied in fingerlings of Channel Catfish Ictalurus puntatus (Delta strain), Blue Catfish I. furcatus (D&B strain), and a hybrid catfish (Delta strain Channel Catfish × D&B strain Blue Catfish). On day 0, fish were immersion challenged in 65-L aquaria. For each of the three species of catfish, 10 aquaria were randomly assigned to two treatment groups, either treated with florfenicol at 0 mg/kg of body weight (unmedicated feed) or at 10 mg/kg (medicated feed). Fish were treated for 10 consecutive days, monitored for mortality during this treatment period, and observed for 14 d afterwards. Post observation, all survivors were humanely euthanized in tricaine methanesulfonate, cultured for E. ictaluri, and examined for gross pathology. The mean cumulative percent mortality from enteric septicemia of catfish (ESC) challenge among the three genotypes of catfish did not differ between Blue Catfish, hybrid, and Channel Catfish in treated or control groups. However, the florfenicol-treated fish had a significantly lower mean cumulative mortality (6%) than the controls (78%). All genotypes of catfish tested were responsive to treatment with florfenicol-medicated feed for control of mortality associated with ESC. There were no significant differences in mortality associated with hybrid catfish, blue catfish, and Channel Catfish (Delta strain). PMID:26306332

  16. Transcriptome of intraperitoneal organs of starry flounder Platichthys stellatus challenged by Edwardsiella ictaluri JCM1680

    NASA Astrophysics Data System (ADS)

    Tong, Yanli; Sun, Xiuqin; Wang, Bo; Wang, Ling; Li, Yan; Tian, Jinhu; Zheng, Fengrong; Zheng, Minggang

    2014-09-01

    Platichthys stellatus is an economically important marine bony fish species that is cultured in China on a large scale. However, very little is known about its immune-related genes. In this study, the transcriptome of the immune organs of P. stellatus that were intraperitoneally challenged with the pathogen Edwardsiella ictaluri JCM1680 is analyzed. Total RNA from four tissues (spleen, kidney, liver, and intestine) was mixed equally and then sequenced on an Illumina HiSeq 2000 platform. Overall, 28 465 813 quality reads were generated and assembled into 43 061 unigenes. Similarity searches against public protein sequence databases were used to annotate 28 291 unigenes (65.7% of the total), 368 of which were associated with immunoregulation, including 188 related to immunity response. Additionally, the transcript levels of immunity response unigenes annotated as related to tumor necrosis factor (TNF), TNF receptor, chemokine, major histocompatibility complex, and interleukin-6 were investigated in the different tissues of normal and infected P. stellatus by real-time quantitative PCR. The results confirmed that the unigenes identified in the transcriptome database were indeed expressed and up-regulated in infected P. stellatus. To our knowledge, this is the first report of the sequencing and analysis of the transcriptome of P. stellatus. These findings provide insights into the transcriptomics and immunogenetics of bony fish.

  17. Identification of Differentially Abundant Proteins of Edwardsiella ictaluri during Iron Restriction

    PubMed Central

    Dumpala, Pradeep R.; Peterson, Brian C.; Lawrence, Mark L.; Karsi, Attila

    2015-01-01

    Edwardsiella ictaluri is a Gram-negative facultative anaerobe intracellular bacterium that causes enteric septicemia in channel catfish. Iron is an essential inorganic nutrient of bacteria and is crucial for bacterial invasion. Reduced availability of iron by the host may cause significant stress for bacterial pathogens and is considered a signal that leads to significant alteration in virulence gene expression. However, the precise effect of iron-restriction on E. ictaluri protein abundance is unknown. The purpose of this study was to identify differentially abundant proteins of E. ictaluri during in vitro iron-restricted conditions. We applied two-dimensional difference in gel electrophoresis (2D-DIGE) for determining differentially abundant proteins and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF/TOF MS) for protein identification. Gene ontology and pathway-based functional modeling of differentially abundant proteins was also conducted. A total of 50 unique differentially abundant proteins at a minimum of 2-fold (p ≤ 0.05) difference in abundance due to iron-restriction were detected. The numbers of up- and down-regulated proteins were 37 and 13, respectively. We noted several proteins, including EsrB, LamB, MalM, MalE, FdaA, and TonB-dependent heme/hemoglobin receptor family proteins responded to iron restriction in E. ictaluri. PMID:26168192

  18. Porphyria cutanea tarda associated with HFE C282Y homozygosity, iron overload, and use of a contraceptive vaginal ring.

    PubMed

    Barton, James C; Edwards, Corwin Q

    2016-01-01

    Porphyria cutanea tarda (PCT) is characterized by decreased uroporphyrinogen decarboxylase activity in hepatocytes, uroporphyrin I and heptacarboxyl porphyrin III accumulation, photosensitivity dermatitis, and increased storage iron. In women, estrogen therapy, including oral contraceptives, postmenopausal hormone replacement, and tamoxifen for breast cancer treatment, is a risk factor for PCT. We report the case of a woman who presented with PCT, HFE C282Y homozygosity, and hepatic iron overload and was using a contraceptive vaginal ring containing ethinyl estradiol, an estrogen. We discuss this case in the context of characteristics of other persons with PCT, including common HFE mutations, iron overload, and estrogen exposure. PMID:26908385

  19. Porphyria cutanea tarda associated with HFE C282Y homozygosity, iron overload, and use of a contraceptive vaginal ring

    PubMed Central

    Barton, James C.; Edwards, Corwin Q.

    2016-01-01

    Porphyria cutanea tarda (PCT) is characterized by decreased uroporphyrinogen decarboxylase activity in hepatocytes, uroporphyrin I and heptacarboxyl porphyrin III accumulation, photosensitivity dermatitis, and increased storage iron. In women, estrogen therapy, including oral contraceptives, postmenopausal hormone replacement, and tamoxifen for breast cancer treatment, is a risk factor for PCT. We report the case of a woman who presented with PCT, HFE C282Y homozygosity, and hepatic iron overload and was using a contraceptive vaginal ring containing ethinyl estradiol, an estrogen. We discuss this case in the context of characteristics of other persons with PCT, including common HFE mutations, iron overload, and estrogen exposure. PMID:26908385

  20. Viral diseases and pathogenesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It includes classification of viral infection. It describes common ways of virus entry, replication, and transmission. It introduces the routes of viral invasion and molecular basis for viral pathogenesis....

  1. Mechanisms of intrinsic resistance to antimicrobial peptides of Edwardsiella ictaluri and its influence on fish gut inflammation and virulence

    PubMed Central

    Martin, Taylor; Loh, Amanda; Pohlenz, Camilo; Gatlin, Delbert M.; Curtiss, Roy

    2013-01-01

    The genus Edwardsiella comprises a genetically distinct taxon related to other members of the family Enterobacteriaceae. It consists of bacteria differing strongly in their biochemical and physiological features, natural habitats, and pathogenic properties. Intrinsic resistance to cationic antimicrobial peptides (CAMPs) is a specific property of the genus Edwardsiella. In particular, Edwardsiella ictaluri, an important pathogen of the catfish (Ictalurus punctatus) aquaculture and the causative agent of a fatal systemic infection, is highly resistant to CAMPs. E. ictaluri mechanisms of resistance to CAMPs are unknown. We hypothesized that E. ictaluri lipopolysaccharide (LPS) plays a role in both virulence and resistance to CAMPs. The putative genes related to LPS oligo-polysaccharide (O-PS) synthesis were in-frame deleted. Individual deletions of wibT, gne and ugd eliminated synthesis of the O-PS, causing auto-agglutination, rough colonies, biofilm-like formation and motility defects. Deletion of ugd, the gene that encodes the UDP-glucose dehydrogenase enzyme responsible for synthesis of UDP-glucuronic acid, causes sensitivity to CAMPs, indicating that UDP-glucuronic acid and its derivatives are related to CAMP intrinsic resistance. E. ictaluri OP-S mutants showed different levels of attenuation, colonization of lymphoid tissues and immune protection in zebrafish (Danio rerio) and catfish. Orally inoculated catfish with O-PS mutant strains presented different degrees of gut inflammation and colonization of lymphoid tissues. Here we conclude that intrinsic resistance to CAMPs is mediated by Ugd enzyme, which has a pleiotropic effect in E. ictaluri influencing LPS synthesis, motility, agglutination, fish gut inflammation and virulence. PMID:23676433

  2. Propioniciclava tarda gen. nov., sp. nov., isolated from a methanogenic reactor treating waste from cattle farms.

    PubMed

    Sugawara, Yoshimichi; Ueki, Atsuko; Abe, Kunihiro; Kaku, Nobuo; Watanabe, Kazuya; Ueki, Katsuji

    2011-09-01

    Two facultatively anaerobic bacterial strains, designated WR061(T) and WR054, were isolated from rice-straw residue in a methanogenic reactor treating waste from cattle farms in Japan. The two strains were phylogenetically positioned close to one another and had almost the same phenotypic properties. Cells were Gram-reaction-positive, non-motile, non-spore-forming, irregular rods. Cobalamin (vitamin B₁₂) was required for growth. The strains utilized various carbohydrates, including hexoses and disaccharides, and produced acetate and propionate from these carbohydrates. Pentoses and polysaccharides were not utilized. They grew at 20-37 °C (optimum 35 °C) and pH 5.3-8.0 (optimum pH 6.8-7.5). Catalase and nitrate-reducing activities were detected. Aesculin was hydrolysed. The major cellular fatty acids were anteiso-C₁₅:₀ and C₁₅:₀ DMA, the major respiratory quinone was menaquinone MK-9(H₄) and the genomic DNA G+C content was 69.3-69.5  mol%. The diagnostic diamino acid in the peptidoglycan was meso-diaminopimelic acid. Phylogenetic analysis based on 16S rRNA gene sequences placed the strains in the phylum Actinobacteria. Both strains were remotely related to the species in the family Propionibacteriaceae and Propionibacterium propionicum JCM 5830(T) was the most closely related type strain with a sequence similarity of 91.6 %. Based on phylogenetic, physiological and chemotaxonomic analyses, the two novel strains together represent a novel species of a new genus, for which the name Propioniciclava tarda gen. nov., sp. nov. is proposed. The type strain is WR061(T) ( = JCM 15804(T)  = DSM 22130(T)). PMID:20971831

  3. IMMUNIZATION OF EYED CHANNEL CATFISH, ICTALURUS PUNCTATUS, EGGS WITH MONOVALENT FLAVOBACTERIUM COLUMNARE VACCINE AND BIVALENT F. COLUMNARE AND EDWARDSIELLA ICTALURI VACCINE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of a modified live monovalent Flavobacterium columnare vaccine and bivalent F. columnare and Edwardsiella ictaluri vaccines were evaluated following immersion vaccination of eyed channel catfish (Ictalurus punctatus) eggs. The modified live F. columnare vaccine was grown in modified Sh...

  4. Identification of in vitro upregulated genes in a modified live vaccine strain of Edwardsiella ictaluri compared to a virulent parent strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 41 expressed sequence tags (ESTs) were isolated from a modified live vaccine strain (AQUAVAC-ESC©, formerly RE-33) vs a virulent parent strain (EILO) of Edwardsiella ictaluri. Transcriptional levels of the 41 ESTs in the vaccine strain and t...

  5. Identification of upregulated genes in a modified live vaccine strain of Edwardsiella ictaluri compared to a virulent parent strain and characterization of novel DNA vaccine candidates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 41 expressed sequence tags (EST's) were isolated from a modified live vaccine strain (AQUAVAC-ESC formerly RD-33) vs a virulent parent strain (EILO) of Edwardsiella ictaluri. Transcriptional levels of the 41 ESTs in the vaccine strain and th...

  6. Evaluation of a loop-mediated isothermal amplification method for rapid detection of channel catfish Ictalurus punctatus important bacterial pathogen Edwardsiella ictaluri.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel catfish Ictalurus punctatus infected with Edwardsiella ictaluri results in $40 - 50 million annual losses in profits to catfish producers. Early detection of this pathogen is necessary for disease control and reduction of economic loss. In this communication, the loop-mediated isothermal a...

  7. Antibiotic sensitivity and molecular analyses demonstrate a lack of IncA/C plasmid in modified live Edwardsiella ictaluri vaccine strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasmid mediated antibiotic resistance was first discovered in Edwardsiella ictaluri in the early 1990’s and in 2007, an E. ictaluri strain harboring an IncA/C plasmid was isolated from a moribund channel catfish infected with the bacterium. Due to the recent identification of IncA/C plasmids in aqu...

  8. TLR5, NRAMP, TNF, AND Hepcidin Response to Challenge with Edwardsiella ictaluri in Channel Catfish Families with High and Low Susceptibility to Infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Responses of toll-like receptor 5 (TLR5), tumor necrosis factor (TNF), natural resistance-associated macrophage protein (Nramp), and hepcidin to experimental challenge with Edwardsiella ictaluri in two families of channel catfish were measured in order to understand the mechanisms through which E. i...

  9. In vitro and in vivo interaction of macrophages from vaccinated and non-vaccinated channel catfish (Ictalurus punctatus) to Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Macrophages from modified live vaccinated and non-vaccinated catfish were used in in vitro and in vivo studies with red fluorescent Edwardsiella ictaluri to assess phagocytic ability, reactive oxygen and nitric oxide production and bactericidal activity. In the in vitro experiment, macrophages were...

  10. Vaccination of full-sib channel catfish families against enteric septicemia of catfish with an oral live attenuated Edwardsiella ictaluri vaccine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study evaluated the efficacy of an oral live-attenuated Edwardsiella ictaluri vaccine against enteric septicemia of catfish in 20 full-sib fingerling channel catfish families. Each family was split into vaccinated and non-vaccinated groups. The vaccine was delivered orally by feeding fish diet...

  11. Spleen size and plasma levels of mannose binding lectin in channel catfish Ictalurus punctatus families exhibiting different susceptibilities to Flavobacterium columnare and Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two major problems in the channel catfish (Ictalurus punctatus) aquaculture industry have been high disease losses to enteric septicemia of catfish (ESC), caused by the bacterium Edwardsiella ictaluri and columnaris disease, caused by the bacterium Flavobacterium columnare. Methods to control these...

  12. Identification and expression profile of multiple genes in the anterior kidney of channel catfish induced by modified live Edwardsiella ictaluri vaccination.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 57 expressed sequence tags (ESTs) were isolated from 240 clones of a modified live Edwardsiella ictaluri-vaccinated vs sham-vaccinated channel catfish anterior kidney subtractive library. The transcription levels of the 57 ESTs in response t...

  13. Growth Performance and Resistance to Edwardsiella ictaluri of Channel Catfish (Ictalurus punctatus)Fed Diets Containing Distiller's Dried Grains with Solubles

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to examine the effect of dietary levels of distiller’s dried grains with solubles (DDGS) on growth, body composition, hematology, immune response and resistance of channel catfish, Ictalurus punctatus, to Edwardsiella ictaluri challenge. Five diets containing 0, 10, 20, 30 and ...

  14. Effects of a phytogenic feed additive on growth and susceptibility of channel catfish to Edwardsiella ictaluri and levels of mannose and rhamnose binding lectin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to investigate the effect of essential oils (EO) on growth and disease susceptibility to Edwardsiella ictaluri. Weight gain and food conversion ratio were similar. After exposing fish to virulent E. ictaluri, survival was higher (69.5 vs 48.4%) in fish fed EO (P < 0.05). In ...

  15. Identification and expression profile of multiple genes in the anterior kidney of channel catfish induced by modified live Edwardsiella ictaluri vaccination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using PCR-select subtractive cDNA hybridization technique, 57 expressed sequence tags (ESTs) were isolated from 240 clones of a modified live Edwardsiella ictaluri-vaccinated vs sham-vaccinated channel catfish anterior kidney subtractive library. The transcription levels of the 57 ESTs in response t...

  16. Spleen index and mannose-binding lectin levels in four channel catfish Ictalurus punctatus families exhibiting different susceptibilities to Flavobacterium columnare and Edwardsiella ictaluri

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Edwardsiella ictaluri and Flavobacterium columnare are two bacterial pathogens that impact the channel catfish Ictalurus punctatus aquaculture. Some progress has been made at the USDA-ARS Catfish Genetics Research Unit in selectively breeding for resistance to E. ictaluri; however, the susceptibili...

  17. Modified live Edwardsiella ictaluri vaccine, AQUAVAC-ESC, lacks multidrug resistance plasmids.

    PubMed

    Lafrentz, Benjamin R; Welch, Timothy J; Shoemaker, Craig A; Drennan, John D; Klesius, Phillip H

    2011-12-01

    Plasmid-mediated antibiotic resistance was first discovered in Edwardsiella ictaluri in the early 1990s, and in 2007 an E. ictaluri isolate harboring an IncA/C plasmid was recovered from a moribund channel catfish Ictalurus punctatus infected with the bacterium. Due to the identification of multidrug resistance plasmids in aquaculture and their potential clinical importance, we sought to determine whether the modified live E. ictaluri vaccine strain in AQUAVAC-ESC harbors such plasmids, so that the use of this vaccine will not directly contribute to the pool of bacteria carrying plasmid-borne resistance. Antimicrobial sensitivity testing of the E. ictaluri parent isolate and vaccine strain demonstrated that both were sensitive to 15 of the 16 antimicrobials tested. Total DNA from each isolate was analyzed by polymerase chain reaction (PCR) using a set of 13 primer pairs specific for conserved regions of the IncA/C plasmid backbone, and no specific products were obtained. PCR-based replicon typing of the parent isolate and vaccine strain demonstrated the absence of the 18 commonly occurring plasmid incompatibility groups. These results demonstrate that the vaccine strain does not carry resistance to commonly used antimicrobials and provide strong support for the absence of IncA/C and other commonly occurring plasmid incompatibility groups. Therefore, its use should not directly contribute to the pool of bacteria carrying plasmid-borne resistance. This work highlights the importance of thoroughly investigating potential vaccine strains for the presence of plasmids or other transmissible elements that may encode resistance to antibiotics. PMID:22372247

  18. Immunofluorescent test for simultaneous detection of Edwardsiella ictaluri and Flavobacterium columnare.

    PubMed

    Panangalal, Victor S; Shelby, Richard A; Shoemaker, Craig A; Klesius, Phillip H; Mitra, Amitava; Morrison, Edward E

    2006-03-01

    Enteric septicemia of catfish (ESC) and columnaris disease are 2 bacterial diseases significantly affecting the aquaculture industry, and thus rapid diagnosis of disease is imperative for making judicious management decisions. A rapid indirect fluorescent antibody (IFA) test with antibody conjugated fluorochromes having 2 different spectral properties (Alexa Fluor 488-emitting green fluorescence, and Alexa Fluor 594-emitting red fluorescence) was compared with bacteriological culture (accepted standard) for simultaneous detection of Edwardsiella ictaluri (EI) and Flavobacterium columnare (FC) in 3 groups of experimentally infected channel catfish (Ictalurus punctatus Rafinesque), and a fourth group that acquired an aquarium-infection with F. columnare. A total of 303 samples (derived from kidney, brain and nares) from 101 fish were concurrently examined by both tests. Fish in the 3 experimentally infected groups (I to III) were culture positive for the bacteria with which they were infected, and fish in Group IV, (the spontaneously infected fish) revealed F. columnare only. The IFA test compared favorably in sensitivity (EI= 80.7 %; FC = 87.2%) and specificity (EI = 83.9%; FC = 88.9%) with the standard bacteriological culture. The positive predictive value (EI = 96.2% Group I, 90.8% Group II, 93.7% Groups I and II combined; FC = 95.2% Group II, 95.3% Groups II, III and IV combined) was high, while the negative predictive value (EI = 66.7% Group I, 31.3% Group II, 59.5% Groups I and II combined; FC = 73.7% Group II, 72.7% Groups II, III and IV combined) was relatively low. The IFA test will serve as an efficient tool for rapid simultaneous detection of E. ictaluri and F. columnare in outbreaks of disease. PMID:16610585

  19. Pathogenesis of Hepatic Encephalopathy

    PubMed Central

    Ciećko-Michalska, Irena; Szczepanek, Małgorzata; Słowik, Agnieszka; Mach, Tomasz

    2012-01-01

    Hepatic encephalopathy can be a serious complication of acute liver failure and chronic liver diseases, predominantly liver cirrhosis. Hyperammonemia plays the most important role in the pathogenesis of hepatic encephalopathy. The brain-blood barrier disturbances, changes in neurotransmission, neuroinflammation, oxidative stress, GABA-ergic or benzodiazepine pathway abnormalities, manganese neurotoxicity, brain energetic disturbances, and brain blood flow abnormalities are considered to be involved in the development of hepatic encephalopathy. The influence of small intestine bacterial overgrowth (SIBO) on the induction of minimal hepatic encephalopathy is recently emphasized. The aim of this paper is to present the current views on the pathogenesis of hepatic encephalopathy. PMID:23316223

  20. Pathogenesis of Castleman's Disease.

    PubMed

    Zhang, Lu; Li, Jian

    2016-02-01

    Castleman's disease (CD) is a rare lymphoproliferative disorder that comprises at least two distinct clinical subtypes (unicentric and multicentric). Three pathologic variants (hyaline vascular variant, plasma cell variant, and mixed variant) have been recognized. In addition to interleukin-6 and human herpes virus 8, some other cytokines and viruses may also be involved in the pathogenesis of CD. This review summarizes the recent advances in the underlying pathogenesis of CD, with an attempt to provide evidence for new treatment options that may change the current treatment strategies and improve patients' outcomes. PMID:26956866

  1. Inflammatory bowel disease: Pathogenesis

    PubMed Central

    Zhang, Yi-Zhen; Li, Yong-Yu

    2014-01-01

    Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, is characterized by chronic relapsing intestinal inflammation. It has been a worldwide health-care problem with a continually increasing incidence. It is thought that IBD results from an aberrant and continuing immune response to the microbes in the gut, catalyzed by the genetic susceptibility of the individual. Although the etiology of IBD remains largely unknown, it involves a complex interaction between the genetic, environmental or microbial factors and the immune responses. Of the four components of IBD pathogenesis, most rapid progress has been made in the genetic study of gut inflammation. The latest internationally collaborative studies have ascertained 163 susceptibility gene loci for IBD. The genes implicated in childhood-onset and adult-onset IBD overlap, suggesting similar genetic predispositions. However, the fact that genetic factors account for only a portion of overall disease variance indicates that microbial and environmental factors may interact with genetic elements in the pathogenesis of IBD. Meanwhile, the adaptive immune response has been classically considered to play a major role in the pathogenesis of IBD, as new studies in immunology and genetics have clarified that the innate immune response maintains the same importance in inducing gut inflammation. Recent progress in understanding IBD pathogenesis sheds lights on relevant disease mechanisms, including the innate and adaptive immunity, and the interactions between genetic factors and microbial and environmental cues. In this review, we provide an update on the major advances that have occurred in above areas. PMID:24415861

  2. Hepatitis E Pathogenesis.

    PubMed

    Lhomme, Sébastien; Marion, Olivier; Abravanel, Florence; Chapuy-Regaud, Sabine; Kamar, Nassim; Izopet, Jacques

    2016-01-01

    Although most hepatitis E virus (HEV) infections are asymptomatic, some can be severe, causing fulminant hepatitis and extra-hepatic manifestations, including neurological and kidney injuries. Chronic HEV infections may also occur in immunocompromised patients. This review describes how our understanding of the pathogenesis of HEV infection has progressed in recent years. PMID:27527210

  3. [Pathogenesis of hypophosphatemia].

    PubMed

    Takeuchi, Yasuhiro

    2016-02-01

    Chronic hypophosphatemia is seriously involved in several disorders of musculoskeletal system. Symptoms of patients are usually non-specific, such as pain with or without muscle weakness on lower extremities and are often hard to be correctly diagnosed. It is clinically important for physicians to understand pathogenesis and clinical features of hypophosphatemia and its related diseases. PMID:26813499

  4. Hepatitis E Pathogenesis

    PubMed Central

    Lhomme, Sébastien; Marion, Olivier; Abravanel, Florence; Chapuy-Regaud, Sabine; Kamar, Nassim; Izopet, Jacques

    2016-01-01

    Although most hepatitis E virus (HEV) infections are asymptomatic, some can be severe, causing fulminant hepatitis and extra-hepatic manifestations, including neurological and kidney injuries. Chronic HEV infections may also occur in immunocompromised patients. This review describes how our understanding of the pathogenesis of HEV infection has progressed in recent years. PMID:27527210

  5. Schwannomas and their pathogenesis.

    PubMed

    Hilton, David A; Hanemann, Clemens Oliver

    2014-04-01

    Schwannomas may occur spontaneously, or in the context of a familial tumor syndrome such as neurofibromatosis type 2 (NF2), schwannomatosis and Carney's complex. Schwannomas have a variety of morphological appearances, but they behave as World Health Organization (WHO) grade I tumors, and only very rarely undergo malignant transformation. Central to the pathogenesis of these tumors is loss of function of merlin, either by direct genetic change involving the NF2 gene on chromosome 22 or secondarily to merlin inactivation. The genetic pathways and morphological features of schwannomas associated with different genetic syndromes will be discussed. Merlin has multiple functions, including within the nucleus and at the cell membrane, and this review summarizes our current understanding of the mechanisms by which merlin loss is involved in schwannoma pathogenesis, highlighting potential areas for therapeutic intervention. PMID:24450866

  6. Chronic rhinosinusitis pathogenesis.

    PubMed

    Stevens, Whitney W; Lee, Robert J; Schleimer, Robert P; Cohen, Noam A

    2015-12-01

    There are a variety of medical conditions associated with chronic sinonasal inflammation, including chronic rhinosinusitis (CRS) and cystic fibrosis. In particular, CRS can be divided into 2 major subgroups based on whether nasal polyps are present or absent. Unfortunately, clinical treatment strategies for patients with chronic sinonasal inflammation are limited, in part because the underlying mechanisms contributing to disease pathology are heterogeneous and not entirely known. It is hypothesized that alterations in mucociliary clearance, abnormalities in the sinonasal epithelial cell barrier, and tissue remodeling all contribute to the chronic inflammatory and tissue-deforming processes characteristic of CRS. Additionally, the host innate and adaptive immune responses are also significantly activated and might be involved in pathogenesis. Recent advancements in the understanding of CRS pathogenesis are highlighted in this review, with special focus placed on the roles of epithelial cells and the host immune response in patients with cystic fibrosis, CRS without nasal polyps, or CRS with nasal polyps. PMID:26654193

  7. [Pathogenesis of psoriasis].

    PubMed

    Schäkel, K; Schön, M P; Ghoreschi, K

    2016-06-01

    Psoriasis is an inflammatory T cell-mediated autoimmune disease of skin and joints that affects 2-4 % of the adult population and 0.1-1 % of children. Genetic susceptibility, environmental triggering factors, and innate immune processes initiate psoriasis pathogenesis that results in an adaptive autoreactive response. The T cell response is orchestrated by CD 8(+) T cells in the epidermis and by CD 4(+) T cells in the dermis that predominantly produce interleukin-17 (IL‑17). Research of the past 15 years unraveled cellular and molecular mechanisms as well as cytokines like TNF-α or IL‑23 that contribute to psoriatic inflammation. This knowledge has been translated into clinical practice and a number of antipsoriatic small molecules and immunobiologics are now available. Here, we discuss the current principles of psoriasis pathogenesis in the context of modern therapies. PMID:27246016

  8. Complete genome sequence of Methanolinea tarda NOBI-1T, a hydrogenotrophic methanogen isolated from methanogenic digester sludge

    SciTech Connect

    Yamamoto, Kyosuke; Tamaki, Hideyuki; Cadillo-Quiroz, Hinsby; Imachi, Hiroyuki; Kyrpides, Nikos; Woyke, Tanja; Goodwin, Lynne; Zinder, Stephen H.; Kamagata, Yoichi; Liu, Wen -Tso

    2014-09-04

    In this study, we report a 2.0-Mb complete genome sequence of Methanolinea tarda NOBI-1T, a methanogenic archaeon isolated from an anaerobic digested sludge. This is the first genome report of the genus Methanolinea isolate belonging to the family Methanoregulaceae, a recently proposed novel family within the order Methanomicrobiales.

  9. Pathogenesis of Necrotizing Enterocolitis

    PubMed Central

    Tanner, Scott M.; Berryhill, Taylor F.; Ellenburg, James L.; Jilling, Tamas; Cleveland, Dava S.; Lorenz, Robin G.; Martin, Colin A.

    2016-01-01

    Necrotizing enterocolitis (NEC) is a major cause of morbidity and mortality in premature infants. The pathophysiology is likely secondary to innate immune responses to intestinal microbiota by the premature infant's intestinal tract, leading to inflammation and injury. This review provides an updated summary of the components of the innate immune system involved in NEC pathogenesis. In addition, we evaluate the animal models that have been used to study NEC with regard to the involvement of innate immune factors and histopathological changes as compared to those seen in infants with NEC. Finally, we discuss new approaches to studying NEC, including mathematical models of intestinal injury and the use of humanized mice. PMID:25447054

  10. Complement and Viral Pathogenesis

    PubMed Central

    Stoermer, Kristina A.; Morrison, Thomas E.

    2011-01-01

    The complement system functions as an immune surveillance system that rapidly responds to infection. Activation of the complement system by specific recognition pathways triggers a protease cascade, generating cleavage products that function to eliminate pathogens, regulate inflammatory responses, and shape adaptive immune responses. However, when dysregulated, these powerful functions can become destructive and the complement system has been implicated as a pathogenic effector in numerous diseases, including infectious diseases. This review highlights recent discoveries that have identified critical roles for the complement system in the pathogenesis of viral infection. PMID:21292294

  11. Pathogenesis of Arrhythmogenic Cardiomyopathy.

    PubMed

    Asimaki, Angeliki; Kleber, Andre G; Saffitz, Jeffrey E

    2015-11-01

    Arrhythmogenic cardiomyopathy (ACM) is a primary myocardial disease. It is characterized by frequent ventricular arrhythmias and increased risk of sudden cardiac death typically arising as an early manifestation before the onset of significant myocardial remodelling. Myocardial degeneration, often confined to the right ventricular free wall, with replacement by fibrofatty scar tissue, develops in many patients. ACM is a familial disease but genetic penetrance can be low and disease expression is highly variable. Inflammation might promote disease progression. It also appears that exercise increases disease penetrance and accelerates its development. More than 60% of probands harbour mutations in genes that encode desmosomal proteins, which has raised the possibility that defective cell-cell adhesion might play a role in disease pathogenesis. Recent advances have implicated changes in the canonical wingless-type mouse mammary tumour virus integration site (Wnt)/β-catenin and Hippo signalling pathways and defects in forwarding trafficking of ion channels and other proteins to the intercalated disk in cardiac myocytes. In this review we summarize the current understanding of the pathogenesis of ACM and highlight future research directions. PMID:26199027

  12. Update on mucormycosis pathogenesis

    PubMed Central

    Ibrahim, Ashraf S.; Kontoyiannis, Dimitrios P.

    2014-01-01

    Purpose of review Mucormycosis is an increasingly common fungal infection with unacceptably high mortality. The recent sequencing genome projects of Mucorales and the development of gene manipulation have enabled significant advances in understanding the pathogenesis of mucormycosis. Therefore, we review the pathogenesis of mucormycosis and highlight potential development of novel diagnostic and therapeutic modalities against this lethal disease. Recent findings Much of the work has been focused on the role of iron uptake in the virulence of Mucorales. Additionally, host receptors and fungal ligands involved in the process of tissue invasion as well as sporangiospore size and sex loci and their contribution to virulence of Mucorales are discussed. Finally, the role of innate and adaptive immunity in protection against Mucorales and new evidence about drug-induced apoptosis in these fungi are discussed. Summary Recent discoveries introduce several potentially novel diagnostic and therapeutic modalities, which are likely to improve management and outcome for mucormycosis. Future preclinical and clinical research is warranted to develop these diagnostic and therapeutic strategies. PMID:24126718

  13. Microbial pathogenesis meets biomechanics.

    PubMed

    Charles-Orszag, Arthur; Lemichez, Emmanuel; Tran Van Nhieu, Guy; Duménil, Guillaume

    2016-02-01

    Introducing concepts from soft matter physics and mechanics has largely contributed to our understanding of a variety of biological processes. In this review, we argue that this holds true for bacterial pathogenesis. We base this argument on three examples of bacterial pathogens and their interaction with host cells during infection: (i) Shigella flexneri exploits actin-dependent forces to come into close contact with epithelial cells prior to invasion of the epithelium; (ii) Neisseria meningitidis manipulates endothelial cells to resist shear stress during vascular colonization; (iii) bacterial toxins take advantage of the biophysical properties of the host cell plasma membrane to generate transcellular macroapertures in the vascular wall. Together, these examples show that a multidisciplinary approach integrating physics and biology is more necessary than ever to understand complex infectious phenomena. Moreover, this avenue of research will allow the exploration of general processes in cell biology, highlighted by pathogens, in the context of other non-communicable human diseases. PMID:26849533

  14. Molecular pathogenesis of emphysema

    PubMed Central

    Taraseviciene-Stewart, Laimute; Voelkel, Norbert F.

    2008-01-01

    Emphysema is one manifestation of a group of chronic, obstructive, and frequently progressive destructive lung diseases. Cigarette smoking and air pollution are the main causes of emphysema in humans, and cigarette smoking causes emphysema in rodents. This review examines the concept of a homeostatically active lung structure maintenance program that, when attacked by proteases and oxidants, leads to the loss of alveolar septal cells and airspace enlargement. Inflammatory and noninflammatory mechanisms of disease pathogenesis, as well as the role of the innate and adaptive immune systems, are being explored in genetically altered animals and in exposure models of this disease. These recent scientific advances support a model whereby alveolar destruction resulting from a coalescence of mechanical forces, such as hyperinflation, and more recently recognized cellular and molecular events, including apoptosis, cellular senescence, and failed lung tissue repair, produces the clinically recognized syndrome of emphysema. PMID:18246188

  15. Pathogenesis of glomerular haematuria

    PubMed Central

    Yuste, Claudia; Gutierrez, Eduardo; Sevillano, Angel Manuel; Rubio-Navarro, Alfonso; Amaro-Villalobos, Juan Manuel; Ortiz, Alberto; Egido, Jesus; Praga, Manuel; Moreno, Juan Antonio

    2015-01-01

    Haematuria was known as a benign hallmark of some glomerular diseases, but over the last decade, new evidences pointed its negative implications on kidney disease progression. Cytotoxic effects of oxidative stress induced by hemoglobin, heme, or iron released from red blood cells may account for the tubular injury observed in human biopsy specimens. However, the precise mechanisms responsible for haematuria remain unclear. The presence of red blood cells (RBCs) with irregular contours and shape in the urine indicates RBCs egression from the glomerular capillary into the urinary space. Therefore glomerular haematuria may be a marker of glomerular filtration barrier dysfunction or damage. In this review we describe some key issues regarding epidemiology and pathogenesis of haematuric diseases as well as their renal morphological findings. PMID:25949932

  16. Controversies in dengue pathogenesis.

    PubMed

    Halstead, Scott B

    2012-05-01

    Research into the pathogenesis of dengue fever has exploded over the last half-century, with issues that were considered simple becoming more complex as additional data are found. This has led to the development of a number of controversies that are being studied across the globe and debated in the literature. In this paper, the following six controversies are analysed and, where possible, resolved: the 1997 World Health Organization (WHO) case definition of dengue haemorrhagic fever (DHF) is not useful; DHF is not significantly associated with secondary dengue infection; DHF results from infection with a 'virulent' dengue virus; DHF is owing to abnormal T-cell responses; DHF results from auto-immune responses; and DHF results from direct infection of endothelial cells. PMID:22668442

  17. Molecular pathogenesis of emphysema.

    PubMed

    Taraseviciene-Stewart, Laimute; Voelkel, Norbert F

    2008-02-01

    Emphysema is one manifestation of a group of chronic, obstructive, and frequently progressive destructive lung diseases. Cigarette smoking and air pollution are the main causes of emphysema in humans, and cigarette smoking causes emphysema in rodents. This review examines the concept of a homeostatically active lung structure maintenance program that, when attacked by proteases and oxidants, leads to the loss of alveolar septal cells and airspace enlargement. Inflammatory and noninflammatory mechanisms of disease pathogenesis, as well as the role of the innate and adaptive immune systems, are being explored in genetically altered animals and in exposure models of this disease. These recent scientific advances support a model whereby alveolar destruction resulting from a coalescence of mechanical forces, such as hyperinflation, and more recently recognized cellular and molecular events, including apoptosis, cellular senescence, and failed lung tissue repair, produces the clinically recognized syndrome of emphysema. PMID:18246188

  18. Pathogenesis of pituitary tumors.

    PubMed

    Yu, Run; Melmed, Shlomo

    2010-01-01

    Pituitary tumors are common and mostly benign neoplasia which cause excess or deficiency of pituitary hormones and compressive damage to adjacent organs. Oncogene activation [e.g. PTTG (pituitary tumor-transforming gene) and HMGA2], tumor suppressor gene inactivation (e.g. MEN1 and PRKAR1A), epigenetic changes (e.g. methylation) and humoral factors (e.g. ectopic production of stimulating hormones) are all possible pituitary tumor initiators; the micro-environment of pituitary tumors including steroid milieu, angiogenesis and abnormal cell adhesion further promote tumor growth. Senescence, a cellular defence mechanism against malignant transformation, may explain the benign nature of at least some pituitary tumors. We suggest that future research on pituitary tumor pathogenesis should incorporate systems approaches, and address regulatory mechanisms for pituitary cell proliferation, development of new animal models of pituitary tumor and isolation of functional human pituitary tumor cell lines. PMID:20541667

  19. Pathogenesis of Osteoporosis

    PubMed Central

    Khosla, Sundeep

    2013-01-01

    As for most multifactorial disorders, the pathogenesis of osteoporosis is complex, and a different set of mechanisms may be operative in any given individual. However, there are certain common causes of bone loss and increased fracture risk with aging in most people. These include genetic factors contributing to the acquisition of peak bone mass, illnesses affecting skeletal growth and development, sex steroid deficiency following the menopause in women and with aging in men, and intrinsic, age-related changes in bone metabolism. Superimposed on these factors are specific secondary causes of bone loss, such as corticosteroid use or other illnesses affecting bone metabolism that may contribute to fracture risk in individuals exposed to these factors. The past decade has witnessed tremendous advances in our understanding of each of these various causes of bone loss, leading to the development of novel, mechanism-based therapeutic approaches to prevent and treat this important public health disorder. PMID:25243055

  20. Pathogenesis of Lassa Fever

    PubMed Central

    Yun, Nadezhda E.; Walker, David H.

    2012-01-01

    Lassa virus, an Old World arenavirus (family Arenaviridae), is the etiological agent of Lassa fever, a severe human disease that is reported in more than 100,000 patients annually in the endemic regions of West Africa with mortality rates for hospitalized patients varying between 5-10%. Currently, there are no approved vaccines against Lassa fever for use in humans. Here, we review the published literature on the life cycle of Lassa virus with the specific focus put on Lassa fever pathogenesis in humans and relevant animal models. Advancing knowledge significantly improves our understanding of Lassa virus biology, as well as of the mechanisms that allow the virus to evade the host’s immune system. However, further investigations are required in order to design improved diagnostic tools, an effective vaccine, and therapeutic agents. PMID:23202452

  1. Pathogenesis of Lassa fever.

    PubMed

    Yun, Nadezhda E; Walker, David H

    2012-10-01

    Lassa virus, an Old World arenavirus (family Arenaviridae), is the etiological agent of Lassa fever, a severe human disease that is reported in more than 100,000 patients annually in the endemic regions of West Africa with mortality rates for hospitalized patients varying between 5-10%. Currently, there are no approved vaccines against Lassa fever for use in humans. Here, we review the published literature on the life cycle of Lassa virus with the specific focus put on Lassa fever pathogenesis in humans and relevant animal models. Advancing knowledge significantly improves our understanding of Lassa virus biology, as well as of the mechanisms that allow the virus to evade the host's immune system. However, further investigations are required in order to design improved diagnostic tools, an effective vaccine, and therapeutic agents. PMID:23202452

  2. Pathogenesis of nasal polyposis

    PubMed Central

    Hulse, K. E.; Stevens, W. W.; Tan, B. K.; Schleimer, R. P.

    2015-01-01

    Summary Chronic rhinosinusitis with nasal polyps (CRSwNP) is a complex inflammatory condition that affects a large proportion of the population world-wide and is associated with high cost of management and significant morbidity. Yet, there is a lack of population-based epidemiologic studies using current definitions of CRSwNP, and the mechanisms that drive pathogenesis in this disease remain unclear. In this review, we summarize the current evidence for the plethora of factors that likely contribute to CRSwNP pathogenesis. Defects in the innate function of the airway epithelial barrier, including diminished expression of antimicrobial products and loss of barrier integrity, combined with colonization by fungi and bacteria likely play a critical role in the development of chronic inflammation in CRSwNP. This chronic inflammation is characterized by elevated expression of many key inflammatory cytokines and chemokines, including IL-5, thymic stromal lymphopoietin and CCL11, that help to initiate and perpetuate this chronic inflammatory response. Together, these factors likely combine to drive the influx of a variety of immune cells, including eosinophils, mast cells, group 2 innate lymphoid cells and lymphocytes, which participate in the chronic inflammatory response within the nasal polyps. Importantly, however, future studies are needed to demonstrate the necessity and sufficiency of these potential drivers of disease in CRSwNP. In addition to the development of new tools and models to aid mechanistic studies, the field of CRSwNP research also needs the type of robust epidemiologic data that has served the asthma community so well. Given the high prevalence, costs and morbidity, there is a great need for continued research into CRS that could facilitate the development of novel therapeutic strategies to improve treatment for patients who suffer from this disease. PMID:25482020

  3. Pathogenesis of nasal polyposis.

    PubMed

    Hulse, K E; Stevens, W W; Tan, B K; Schleimer, R P

    2015-02-01

    Chronic rhinosinusitis with nasal polyps (CRSwNP) is a complex inflammatory condition that affects a large proportion of the population world-wide and is associated with high cost of management and significant morbidity. Yet, there is a lack of population-based epidemiologic studies using current definitions of CRSwNP, and the mechanisms that drive pathogenesis in this disease remain unclear. In this review, we summarize the current evidence for the plethora of factors that likely contribute to CRSwNP pathogenesis. Defects in the innate function of the airway epithelial barrier, including diminished expression of antimicrobial products and loss of barrier integrity, combined with colonization by fungi and bacteria likely play a critical role in the development of chronic inflammation in CRSwNP. This chronic inflammation is characterized by elevated expression of many key inflammatory cytokines and chemokines, including IL-5, thymic stromal lymphopoietin and CCL11, that help to initiate and perpetuate this chronic inflammatory response. Together, these factors likely combine to drive the influx of a variety of immune cells, including eosinophils, mast cells, group 2 innate lymphoid cells and lymphocytes, which participate in the chronic inflammatory response within the nasal polyps. Importantly, however, future studies are needed to demonstrate the necessity and sufficiency of these potential drivers of disease in CRSwNP. In addition to the development of new tools and models to aid mechanistic studies, the field of CRSwNP research also needs the type of robust epidemiologic data that has served the asthma community so well. Given the high prevalence, costs and morbidity, there is a great need for continued research into CRS that could facilitate the development of novel therapeutic strategies to improve treatment for patients who suffer from this disease. PMID:25482020

  4. Pathogenesis of Candida vulvovaginitis.

    PubMed

    Sobel, J D

    1989-01-01

    The occurrence of candida vulvovaginitis (CVV) has been estimated based on statistical data from Great Britain to be an increase to 200/100,000 over 10 years to 1984. CVV in the US is the 2nd commonest cause of vaginal infection, with bacterial vaginosis occurring twice as often. 85-90% of the yeasts isolated from the vagina are candida albicans, based on biotyping rather that the newer methods of DNA hybridization. The pathogenesis of CVV is discussed in terms of the microbiology (virulence factors, adherence, germ tube and mycelium formation, proteinase secretion, and switching colonies), asymptomatic vaginal colonization, transformation to symptomatic vaginitis, host predisposing factors (pregnancy, oral contraceptives, diabetes mellitus, antimicrobes, and other), vaginal defense mechanisms (humoral system, phagocytic system, cell mediated immunity, vaginal flora, other), and pathogenesis of recurrent and chronic CVV (internal reservoir, sexual transmission, vaginal relapse, and experimental models) The discussion of the development of virulent symptoms is capsuled in the following comments. Vaginal cell receptivity varies among individuals, but all strains of C. Albicans adhere to both exfoliated vaginal and buccal epithelial cells, or mucosal surfaces, through the yeast surface mannoprotein. It is suggested from in vitro studies that germ tube and mycelium formation facilitates vaginal mucosal invasion. Exogenous and endogenous factors may enhance germination and precipitate symptomatic vaginitis, or inhibit germination. Increased proteinase secretion may be a result of the transformation from the blastoconidium/colonization phase to the germinated invasive vaginitis stage or an independent virulence factor. It is reported that hereditable spontaneous switching may occur spontaneously in vivo also. Colonizing yeasts with a change in environment can transform to a more virulent phase. Colonization rates vary from 10-25%, and the critical issue is understanding

  5. Pathogenesis of liver cirrhosis

    PubMed Central

    Zhou, Wen-Ce; Zhang, Quan-Bao; Qiao, Liang

    2014-01-01

    Liver cirrhosis is the final pathological result of various chronic liver diseases, and fibrosis is the precursor of cirrhosis. Many types of cells, cytokines and miRNAs are involved in the initiation and progression of liver fibrosis and cirrhosis. Activation of hepatic stellate cells (HSCs) is a pivotal event in fibrosis. Defenestration and capillarization of liver sinusoidal endothelial cells are major contributing factors to hepatic dysfunction in liver cirrhosis. Activated Kupffer cells destroy hepatocytes and stimulate the activation of HSCs. Repeated cycles of apoptosis and regeneration of hepatocytes contribute to pathogenesis of cirrhosis. At the molecular level, many cytokines are involved in mediation of signaling pathways that regulate activation of HSCs and fibrogenesis. Recently, miRNAs as a post-transcriptional regulator have been found to play a key role in fibrosis and cirrhosis. Robust animal models of liver fibrosis and cirrhosis, as well as the recently identified critical cellular and molecular factors involved in the development of liver fibrosis and cirrhosis will facilitate the development of more effective therapeutic approaches for these conditions. PMID:24966602

  6. Pathogenesis of Mucormycosis

    PubMed Central

    Spellberg, Brad; Walsh, Thomas J.; Kontoyiannis, Dimitrios P.

    2012-01-01

    Mucormycosis is a life-threatening infection that occurs in patients who are immunocompromised because of diabetic ketoacidosis, neutropenia, organ transplantation, and/or increased serum levels of available iron. Because of the increasing prevalence of diabetes mellitus, cancer, and organ transplantation, the number of patients at risk for this deadly infection is increasing. Despite aggressive therapy, which includes disfiguring surgical debridement and frequently adjunctive toxic antifungal therapy, the overall mortality rate is high. New strategies to prevent and treat mucormycosis are urgently needed. Understanding the pathogenesis of mucormycosis and the host response to invading hyphae ultimately will provide targets for novel therapeutic interventions. In this supplement, we review the current knowledge about the virulence traits used by the most common etiologic agent of mucormycosis, Rhizopus oryzae. Because patients with elevated serum levels of available iron are uniquely susceptible to mucormycosis and these infections are highly angioinvasive, emphasis is placed on the ability of the organism to acquire iron from the host and on its interactions with endothelial cells lining blood vessels. Several promising therapeutic strategies in preclinical stages are identified. PMID:22247441

  7. Pathogenesis of Nonalcoholic Steatohepatitis.

    PubMed

    Machado, Mariana Verdelho; Diehl, Anna Mae

    2016-06-01

    Nonalcoholic steatohepatitis (NASH) is a necro-inflammatory response that ensues when hepatocytes are injured by lipids (lipotoxicity). NASH is a potential outcome of nonalcoholic fatty liver (NAFL), a condition that occurs when lipids accumulate in hepatocytes. NASH may be reversible, but it can also result in cirrhosis and primary liver cancer. We are beginning to learn about the mechanisms of progression of NAFL and NASH. NAFL does not inevitably lead to NASH because NAFL is a heterogeneous condition. This heterogeneity exists because different types of lipids with different cytotoxic potential accumulate in the NAFL, and individuals with NAFL differ in their ability to defend against lipotoxicity. There are no tests that reliably predict which patients with NAFL will develop lipotoxicity. However, NASH encompasses the spectrum of wound-healing responses induced by lipotoxic hepatocytes. Differences in these wound-healing responses among individuals determine whether lipotoxic livers regenerate, leading to stabilization or resolution of NASH, or develop progressive scarring, cirrhosis, and possibly liver cancer. We review concepts that are central to the pathogenesis of NASH. PMID:26928243

  8. Pathogenesis of rhinitis.

    PubMed

    Eifan, A O; Durham, S R

    2016-09-01

    Rhinitis is a heterogeneous condition that has been associated with inflammatory responses as in allergic rhinitis but can also occur in the absence of inflammation such as in so-called idiopathic (previously 'vasomotor') rhinitis. Allergic rhinitis affects approximately one in four of the population of westernized countries and is characterized by typical symptoms of nasal itching, sneezing, watery discharge and congestion. The intention of this review is to illustrate key concepts of the pathogenesis of rhinitis. Imbalance in innate and adaptive immunity together with environmental factors is likely to play major roles. In allergic rhinitis, initial allergen exposure and sensitization involves antigen-presenting cells, T and B lymphocytes and results in the generation of allergen-specific T cells and allergen-specific IgE antibodies. On re-exposure to relevant allergens, cross-linking of IgE on mast cells results in the release of mediators of hypersensitivity such as histamine and immediate nasal symptoms. Within hours, there is an infiltration by inflammatory cells, particularly Th2 T lymphocytes, eosinophils and basophils into nasal mucosal tissue that results in the late-phase allergic response. Evidence for nasal priming and whether or not remodelling may be a feature of allergic rhinitis will be reviewed. The occurrence of so-called local allergic rhinitis in the absence of systemic IgE will be discussed. Non-allergic (non-IgE-mediated) rhinitis will be considered in the context of inflammatory and non-inflammatory disorders. PMID:27434218

  9. Recent progress in melasma pathogenesis.

    PubMed

    Lee, Ai-Young

    2015-11-01

    Melasma is a common skin pigmentation condition. Given therapeutic difficulty as one of the biggest concerns, understanding of the etiology and pathogenesis of melasma becomes essential. UV irradiation, female sex hormones, and inflammatory processes are addressed as triggering factors with genetic predisposition. The mechanism of UV-induced melanogenesis has been extensively investigated as a model system to study melasma pathogenesis. Hitherto, treatment modalities for melasma are similar to other hyperpigmentation disorders. However, individual triggering factors induce a separate pigmentation disease, whose pathogenic mechanisms and clinical phenotypes are different from the ones encountered in melasma. Fortunately, there have been ongoing updates on melasma pathogenesis with regard to major triggering factors. Presence of certain factors working independently of UV exposure and role of dermal factors and microRNAs are being identified as novel discoveries about melasma pathogenesis. In this review, the melasma pathogenesis is reviewed in association with updated and new findings. PMID:26230865

  10. The pathogenesis of sepsis.

    PubMed

    Bone, R C

    1991-09-15

    Sepsis and its sequelae (sepsis syndrome and septic shock) are increasingly common and are still potentially lethal diagnoses. Many mediators of the pathogenesis of sepsis have recently been described. These include tumor necrosis factor alpha (TNF alpha), interleukins, platelet activating factor, leukotrienes, thromboxane A2, and activators of the complement cascade. Neutrophil and platelet activation may also play a role. Other agents that may participate in the sepsis cascade include adhesion molecules, kinins, thrombin, myocardial depressant substance, beta-endorphin, and heat shock proteins. Endothelium-derived relaxing factor and endothelin-1 are released from the endothelium and seem to exert a regulatory effect, counterbalancing each other. A central mediator of sepsis does not seem to exist, although TNF alpha has been commonly proposed for this role. Animal studies are difficult to extrapolate to the clinical setting because of cross-species differences and variations in experimental design. Rather than being caused by any single pathogenic mechanism, it is more likely that sepsis is related to the state of activation of the target cell, the nearby presence of other mediators, and the ability of the target cell to release other mediators. Also important is the downregulation or negative feedback of these mediators or the generation of natural inflammation inhibitors, such as interleukin-4 and interleukin-8. Endothelial damage in sepsis probably results from persistent and repetitive inflammatory insults. Eventually, these insults produce sufficient damage that downregulation can no longer occur; this leads to a state of metabolic anarchy in which the body can no longer control its own inflammatory response. PMID:1872494

  11. Multiplex-PCR for simultaneous detection of 3 bacterial fish pathogens, Flavobacterium columnare, Edwardsiella ictaluri, and Aeromonas hydrophila.

    PubMed

    Panangala, Victor S; Shoemaker, Craig A; Van Santen, Vicky L; Dybvig, Kevin; Klesius, Phillip H

    2007-03-13

    A multiplex PCR (m-PCR) method was developed for simultaneous detection of 3 important fish pathogens in warm water aquaculture. The m-PCR to amplify target DNA fragments from Flavobacterium columnare (504 bp), Edwardsiella ictaluri (407 bp) and Aeromonas hydrophila (209 bp) was optimized by adjustment of reaction buffers and a touchdown protocol. The lower detection limit for each of the 3 bacteria was 20 pg of nucleic acid template from each bacteria per m-PCR reaction mixture. The sensitivity threshold for detection of the 3 bacteria in tissues ranged between 3.4 x 10(2) and 2.5 x 10(5) cells g(-1) of tissue (channel catfish Ictalurus punctatus Rafinesque). The diagnostic sensitivity and specificity of the m-PCR was evaluated with 10 representative isolates of each of the 3 bacteria and 11 other Gram-negative and 2 Gram-positive bacteria that are taxonomically related or ubiquitous in the aquatic environment. Except for a single species (A. salmonicida subsp. salmonicida), each set of primers specifically amplified the target DNA of the cognate species of bacteria. m-PCR was compared with bacteriological culture for identification of bacteria in experimentally infected fish. The m-PCR appears promising for the rapid, sensitive and simultaneous detection of Flavobacterium columnare, E. ictaluri and A. hydrophila in infected fish compared to the time-consuming traditional bacteriological culture techniques. PMID:17465305

  12. The effects of feeding β-glucan to Pangasianodon hypophthalmus on immune gene expression and resistance to Edwardsiella ictaluri.

    PubMed

    Sirimanapong, Wanna; Thompson, Kim D; Ooi, Ei Lin; Bekaert, Michaël; Collet, Bertrand; Taggart, John B; Bron, James E; Green, Darren M; Shinn, Andrew P; Adams, Alexandra; Leaver, Michael J

    2015-11-01

    Pangasianodon hypophthalmus (striped catfish) is an important aquaculture species and intensification of farming has increased disease problems, particularly Edwardsiella ictaluri. The effects of feeding β-glucans on immune gene expression and resistance to E. ictaluri in P. hypophthalmus were explored. Fish were fed 0.1% fungal-derived β-glucan or 0.1% commercial yeast-derived β-glucan or a basal control diet without glucan. After 14 days of feeding, the mRNA expression of immune genes (transferrin, C-reactive protein, precerebellin-like protein, Complement C3 and factor B, 2a MHC class II and interleukin-1 beta) in liver, kidney and spleen were determined. Following this fish from each of the three diet treatment groups were infected with E. ictaluri and further gene expression measured 24 h post-infection (h.p.i.), while the remaining fish were monitored over 2 weeks for mortalities. Cumulative percentage mortality at 14 days post-infection (d.p.i.) was less in β-glucan fed fish compared to controls. There was no difference in gene expression between dietary groups after feeding for 14 days, but there was a clear difference between infected and uninfected fish at 24 h.p.i., and based on principal component analysis β-glucans stimulated the overall expression of immune genes in the liver, kidney and spleen at 24 h.p.i. PMID:26439415

  13. Antimicrobial susceptibility pattern of Edwardsiella ictaluri isolates from natural outbreaks of bacillary necrosis of Pangasianodon hypophthalmus in Vietnam.

    PubMed

    Tu, Thanh Dung; Haesebrouck, Freddy; Nguyen, Anh Tuan; Sorgeloos, Patrick; Baele, Margo; Decostere, Annemie

    2008-12-01

    The purpose of this study was to assess the in vitro susceptibility of 64 Vietnamese isolates of Edwardsiella ictaluri, the causal agent of the infectious disease Bacillus Necrosis Pangasius in Pangasianodon hypophthalmus, using the agar dilution technique. All isolates originated from different farms and were collected between 2002 and 2005. None of the isolates displayed acquired resistance to amoxicillin, amoxicillin-clavulanic acid, chloramphenicol, florfenicol, gentamicin, kanamycin, neomycin, and nitrofurantoin. Acquired resistance to streptomycin was detected in 83%, to oxytetracycline in 81%, and to trimethoprim in 71% of the isolates, as indicated by a bimodal distribution of the minimal inhibitory concentrations (MICs) of these antimicrobials. The MICs of enrofloxacin displayed a monomodal distribution with tailing toward the higher MIC values, possibly indicating reduced susceptibility of a minority of isolates (3 out of the 64). For the quinolone antimicrobial agents flumequin and oxolinic acid, acquired resistance was encountered in 8% and 6% of the strains, respectively. All strains were intrinsically resistant to the polypeptide antimicrobial agent colistin. Seventy-three percent of the isolates were shown to have acquired resistance to at least three antimicrobial agents. The results of this study emphasize the strict need to control both the prophylactic and curative use of antimicrobial agents in Vietnamese aquaculture. PMID:19090723

  14. Intraspecific diversity of Edwardsiella ictaluri isolates from diseased freshwater catfish, Pangasianodon hypophthalmus (Sauvage), cultured in the Mekong Delta, Vietnam.

    PubMed

    Bartie, K L; Austin, F W; Diab, A; Dickson, C; Dung, T T; Giacomini, M; Crumlish, M

    2012-09-01

    A molecular epidemiology study was conducted on 90 Edwardsiella ictaluri isolates recovered from diseased farmed freshwater catfish, Pangasianodon hypophthalmus, cultured in the Mekong Delta, Vietnam. Thirteen isolates of E. ictaluri derived from diseased channel catfish, Ictalurus punctatus, cultured in the USA were included for comparison. All the E.ictaluri isolates tested were found to be biochemically indistinguishable. A repetitive (rep)-PCR using the single (GTG)(5) primer was shown to possess limited discriminatory power, yielding two similar DNA profiles categorized as (GTG)(5) -PCR group 1 or 2 among the Vietnam isolates and (GTG)(5) -PCR group 1 within the USA isolates. Macrorestriction analysis identified 14 and 22 unique pulsotypes by XbaI and SpeI, respectively, among a subset of 59 E. ictaluri isolates. Numerical analysis of the combined macrorestriction profiles revealed three main groups: a distinct cluster formed exclusively of the USA isolates, and a major and minor cluster with outliers contained the Vietnam isolates. Antibiotic susceptibility and plasmid profiling supported the existence of the three groups. The results indicate that macrorestriction analysis may be regarded as a suitable typing method among the E. ictaluri species of limited intraspecific diversity. Furthermore, the findings suggest that E. ictaluri originating from Vietnam may constitute a distinct genetic group. PMID:22804634

  15. Mortality and pathology in brown bullheads Amieurus nebulosus associated with a spontaneous Edwardsiella ictaluri outbreak under tank culture conditions

    USGS Publications Warehouse

    Iwanowicz, L.R.; Griffin, A.R.; Cartwright, Deborah D.; Blazer, V.S.

    2006-01-01

    Brown bullheads Amieurus nebulosus (family Ictaluridae) are commonly used as a sentinel of environmental contamination. These fish are not generally cultured under laboratory conditions and little is known about their disease susceptibility. Here we report an outbreak of disease due to Edwardsiella ictaluri in a laboratory population of tank-reared, wild-caught brown bullheads. The isolate was positively identified as E. ictaluri using standard bacteriological substrate utilization tests and a monoclonal antibody specific for this bacterium. This pathogen causes a significant disease in channel catfish Ictalurus punctatus and is associated with disease in other ictalurid and non-ictalurid fishes. It appears that E. ictaluri is also a significant pathogen in brown bullheads and produces clinical signs and lesions similar but not identical to those observed in channel catfish. Since commercial sources of bullheads for laboratory tank studies are not available, precautions should be taken to prevent potential E. ictaluri disease outbreaks from wild-caught bullheads intended for laboratory research. ?? Inter-Research 2006.

  16. Highlights in pathogenesis of vitiligo

    PubMed Central

    Mohammed, Ghada F; Gomaa, Amal HA; Al-Dhubaibi, Mohammed Saleh

    2015-01-01

    Vitiligo is a common pigmentary disorder. Many studies across decades and all over the world have attempted to illustrate the pathogenesis behind it; however, the pathogenesis of vitiligo remains elusive. This review article, we present the findings behind the most and updated theories behind this psychologically debilitating and disfiguring disease. The discussion begun with the role of genetic predisposition followed by neural theory first proposed in the 1950s. We highlight the autoimmune hypothesis, followed by the reactive oxygen species model, zinc-α2-glycoprotein deficiency hypothesis, viral theory, intrinsic theory and biochemical, molecular and cellular alterations accounting for loss of functioning melanocytes in vitiligo. Many theories were elaborated to clarify vitiligo pathogenesis. It is a multifactorial disease involving the interplay of several factors. Future research is needed to clarify the interaction of these factors for better understanding of vitiligo pathogenesis and subsequent successful treatment. PMID:25789295

  17. Highlights in pathogenesis of vitiligo.

    PubMed

    Mohammed, Ghada F; Gomaa, Amal Ha; Al-Dhubaibi, Mohammed Saleh

    2015-03-16

    Vitiligo is a common pigmentary disorder. Many studies across decades and all over the world have attempted to illustrate the pathogenesis behind it; however, the pathogenesis of vitiligo remains elusive. This review article, we present the findings behind the most and updated theories behind this psychologically debilitating and disfiguring disease. The discussion begun with the role of genetic predisposition followed by neural theory first proposed in the 1950s. We highlight the autoimmune hypothesis, followed by the reactive oxygen species model, zinc-α2-glycoprotein deficiency hypothesis, viral theory, intrinsic theory and biochemical, molecular and cellular alterations accounting for loss of functioning melanocytes in vitiligo. Many theories were elaborated to clarify vitiligo pathogenesis. It is a multifactorial disease involving the interplay of several factors. Future research is needed to clarify the interaction of these factors for better understanding of vitiligo pathogenesis and subsequent successful treatment. PMID:25789295

  18. Concepts in viral pathogenesis II

    SciTech Connect

    Notkins, A.L.; Oldstone, M.B.A.

    1986-01-01

    This paper contains papers divided among 10 sections. The section titles are: Viral Structure and Function; Viral Constructs; Oncogenes, Transfection, and Differentiation; Viral Tropism and Entry into Cells; Immune Recognition of Viruses; Evolving Concepts in Viral Pathogenesis Illustrated by Selected Plant and Animal Models; Evolving Concepts in Viral Pathogenesis Illustrated by Selected Diseases in Humans; New Trends in Diagnosis and Epidemiology; and Vaccines and Antiviral Therapy.

  19. Preonset studies of spondyloepiphyseal dysplasia tarda caused by a novel 2-base pair deletion in SEDL encoding sedlin.

    PubMed

    Mumm, S; Zhang, X; Gottesman, G S; McAlister, W H; Whyte, M P

    2001-12-01

    Spondyloepiphyseal dysplasia tarda (SEDT), an X-linked recessive skeletal disorder, presents with disproportionate short stature and "barrel-chest" deformity in affected (hemizygous) adolescent boys. In four reported families to date, mutations in a gene designated SEDL (spondyloepiphyseal dysplasia late) cosegregate with SEDT. We diagnosed SEDT in a short-stature, kyphotic 15-year-old boy because of his characteristic vertebral malformations. Clinical manifestations of SEDT were evident in at least four previous generations. A novel 2-base pair (bp) deletion in exon 5 of SEDL was found in the propositus by polymerase chain reaction (PCR) amplification and sequencing of all four coding exons. The mutation ATdel241-242 cosegregated with the kindred's skeletal disease. The deletion is adjacent to a noncanonical splice site for exon 5 but does not alter splicing. Instead, it deletes 2 bp from the coding sequence, causing a frameshift. A maternal aunt and her three young sons were investigated subsequently. Radiographs showed subtle shaping abnormalities of her pelvis and knees, suggesting heterozygosity. X-rays of the spine and pelvis of her 8-year-old son revealed characteristic changes of SEDT, but her younger sons (aged 6 years and 3 years) showed no abnormalities. SEDL analysis confirmed that she and only her eldest boy had the 2-bp deletion. Molecular testing of SEDL enables carrier detection and definitive diagnosis before clinical or radiographic expression of SEDT. Although there is no specific treatment for SEDT, preexpression molecular testing of SEDL could be helpful if avoiding physical activities potentially injurious to the spine and the joints proves beneficial. PMID:11760838

  20. Modulation of Vacuolar pH Is Required for Replication of Edwardsiella ictaluri in Channel Catfish Macrophages

    PubMed Central

    Baumgartner, Wes A.; Dubytska, Lidiya; Rogge, Matthew L.; Mottram, Peter J.

    2014-01-01

    Previous in vitro work demonstrated that Edwardsiella ictaluri produces an acid-activated urease that can modulate environmental pH through the production of ammonia from urea. Additional work revealed that expression of the E. ictaluri type III secretion system (T3SS) is upregulated by acidic pH. Both the urease and the T3SS were previously shown to be essential to intracellular replication. In this work, fluorescence microscopy with LysoTracker Red DND-99 (LTR) indicated that E. ictaluri-containing vacuoles (ECV) became acidified following ingestion by head kidney-derived macrophages (HKDM). In vivo ratiometric imaging demonstrated a lowered ECV pH, which fell to as low as pH 4 but subsequently increased to pH 6 or greater. Inhibition of vacuolar H+-ATPases by use of the specific inhibitor bafilomycin A1 abrogated both ECV acidification and intracellular replication in HKDM. Failure of an E. ictaluri urease knockout mutant to increase the ECV pH in the in vivo ratiometric assay suggests that ammonia produced by the urease reaction mediates the pH increase. Additionally, when the specific arginase inhibitor l-norvaline was used to treat E. ictaluri-infected HKDM, the ECV failed to neutralize and E. ictaluri was unable to replicate. This indicates that the HKDM-encoded arginase enzyme produces the urea used by the E. ictaluri urease enzyme. Failure of the ECV to acidify would prevent both upregulation of the T3SS and activation of the urease enzyme, either of which would prevent E. ictaluri from replicating in HKDM. Failure of the ECV to neutralize would result in a vacuolar pH too low to support E. ictaluri replication. PMID:24664505

  1. The Aspartate-Semialdehyde Dehydrogenase of Edwardsiella ictaluri and Its Use as Balanced-Lethal System in Fish Vaccinology

    PubMed Central

    Santander, Javier; Xin, Wei; Yang, Zhao; Curtiss, Roy

    2010-01-01

    asdA mutants of Gram-negative bacteria have an obligate requirement for diaminopimelic acid (DAP), which is an essential constituent of the peptidoglycan layer of the cell wall of these organisms. In environments deprived of DAP, i.e., animal tissues, they will undergo lysis. Deletion of the asdA gene has previously been exploited to develop antibiotic-sensitive strains of live attenuated recombinant bacterial vaccines. Introduction of an Asd+ plasmid into a ΔasdA mutant makes the bacterial strain plasmid-dependent. This dependence on the Asd+ plasmid vector creates a balanced-lethal complementation between the bacterial strain and the recombinant plasmid. E. ictaluri is an enteric Gram-negative fish pathogen that causes enteric septicemia in catfish. Because E. ictaluri is a nasal/oral invasive intracellular pathogen, this bacterium is a candidate to develop a bath/oral live recombinant attenuated Edwardsiella vaccine (RAEV) for the catfish aquaculture industry. As a first step to develop an antibiotic-sensitive RAEV strain, we characterized and deleted the E. ictaluri asdA gene. E. ictaluri ΔasdA01 mutants exhibit an absolute requirement for DAP to grow. The asdA gene of E. ictaluri was complemented by the asdA gene from Salmonella. Several Asd+ expression vectors with different origins of replication were transformed into E. ictaluri ΔasdA01. Asd+ vectors were compatible with the pEI1 and pEI2 E. ictaluri native plasmids. The balanced-lethal system was satisfactorily evaluated in vivo. Recombinant GFP, PspA, and LcrV proteins were synthesized by E. ictaluri ΔasdA01 harboring Asd+ plasmids. Here we constructed a balanced-lethal system, which is the first step to develop an antibiotic-sensitive RAEV for the aquaculture industry. PMID:21209920

  2. Oral Vaccination of Channel Catfish against Enteric Septicemia of Catfish Using a Live Attenuated Edwardsiella ictaluri Isolate.

    PubMed

    Wise, David J; Greenway, Terrence E; Byars, Todd S; Griffin, Matt J; Khoo, Lester H

    2015-06-01

    Enteric septicemia of catfish (ESC), caused by Edwardsiella ictaluri, is the most problematic bacterial disease affecting catfish aquaculture in the southeastern United States. Efforts to develop an effective ESC vaccine have had limited industrial success. In commercial settings, ESC vaccines are typically administered by immersion when fry are transferred from the hatchery to rearing ponds. While this approach is a practical method of mass delivery, this strategy administers vaccines to very young fish, which lack a fully developed immune system. To circumvent this limitation, an oral vaccination strategy was evaluated as a means of immunizing catfish at the fingerling stage of production, when fish possess a more complete immune arsenal. A virulent E. ictaluri isolate (S97-773) was attenuated by successive passage on media containing increasing concentrations of rifamycin. In laboratory trials, cultured vaccine was diluted and mixed with feed (100 mL diluted vaccine/454 g feed). This mixture was then fed to Channel Catfish Ictalurus punctatus fingerlings. Two separate dilutions of cultured vaccine (1:10 and 1:100) were used to create the vaccine-feed mixture, equating to estimated doses of 5 × 10⁷ and 5 × 10⁶ CFU/g of feed, respectively. After 30 d, catfish were exposed by immersion (1 × 10⁶ CFU/mL) to the virulent parental strain of E. ictaluri. The target dose (1:100 dilution, ∼5 × 10⁶ CFU/g of feed) offered exceptional protection (relative percent survival = 82.6-100%). In addition, negligible deaths occurred in fish vaccinated at 10 times the target dose (1:10 dilution, ∼5 × 10⁷ CFU/g of feed). In pond trials, antibody production increased 18-fold in orally vaccinated fish. When compared with nonvaccinated controls, vaccination significantly improved survival, feed fed, feed conversion, biomass produced, and total harvest. This research demonstrates Channel Catfish can be successfully immunized in a commercial setting against E. ictaluri

  3. Pathogenesis of arenavirus hemorrhagic fevers.

    PubMed

    Moraz, Marie-Laurence; Kunz, Stefan

    2011-01-01

    Viral hemorrhagic fevers (VHFs) caused by arenaviruses belong to the most devastating emerging human diseases and represent serious public health problems. Arenavirus VHFs in humans are acute diseases characterized by fever and, in severe cases, different degrees of hemorrhages associated with a shock syndrome in the terminal stage. Over the past years, much has been learned about the pathogenesis of arenaviruses at the cellular level, in particular their ability to subvert the host cell's innate antiviral defenses. Clinical studies and novel animal models have provided important new information about the interaction of hemorrhagic arenaviruses with the host's adaptive immune system, in particular virus-induced immunosuppression, and have provided the first hints towards an understanding of the terminal hemorrhagic shock syndrome. The scope of this article is to review our current knowledge on arenavirus VHF pathogenesis with an emphasis on recent developments. PMID:21171877

  4. Epigenetics and Colorectal Cancer Pathogenesis

    PubMed Central

    Bardhan, Kankana; Liu, Kebin

    2013-01-01

    Colorectal cancer (CRC) develops through a multistage process that results from the progressive accumulation of genetic mutations, and frequently as a result of mutations in the Wnt signaling pathway. However, it has become evident over the past two decades that epigenetic alterations of the chromatin, particularly the chromatin components in the promoter regions of tumor suppressors and oncogenes, play key roles in CRC pathogenesis. Epigenetic regulation is organized at multiple levels, involving primarily DNA methylation and selective histone modifications in cancer cells. Assessment of the CRC epigenome has revealed that virtually all CRCs have aberrantly methylated genes and that the average CRC methylome has thousands of abnormally methylated genes. Although relatively less is known about the patterns of specific histone modifications in CRC, selective histone modifications and resultant chromatin conformation have been shown to act, in concert with DNA methylation, to regulate gene expression to mediate CRC pathogenesis. Moreover, it is now clear that not only DNA methylation but also histone modifications are reversible processes. The increased understanding of epigenetic regulation of gene expression in the context of CRC pathogenesis has led to development of epigenetic biomarkers for CRC diagnosis and epigenetic drugs for CRC therapy. PMID:24216997

  5. Porphyria Cutanea Tarda (PCT)

    MedlinePlus

    ... of UROD in the liver. Hemochromatosis, an iron overload disorder, also can predispose individuals to PCT. Symptoms ... centers regardless of whether there is confirmed iron overload. A phlebotomy is a simple and safe procedure ...

  6. Porphyria Cutanea Tarda

    MedlinePlus

    ... Sections of the JAOCD JAOCD Archive Published Members Online Dermatology Journals Edit This Favorite Name: Category: Share: Yes ... 2/2017 2017 AOCD Spring Current Concepts in Dermatology Meeting more Latest News ... Surveys About AOCD The AOCD was recognized in ...

  7. Molecular pathogenesis of hereditary hemochromatosis.

    PubMed

    Liu, Jingqi; Pu, Chunwen; Lang, Lang; Qiao, Liang; Abdullahi, Mohanud Abukar Haji; Jiang, Chunmeng

    2016-08-01

    Hereditary hemochromatosis (HH) is an inherited iron overload disorder characterized by normal iron-driven erythropoiesis and abnormal iron metabolism, leading to excess iron deposited in parenchymal cells of liver, heart, and endocrine glands. Iron hormone, hepcidin, plays a critical role in iron homeostasis through interaction with ferroportin (FPN), a major cellular iron exporter. Hepcidin is encoded by hepcidin antimicrobial peptide (HAMP). Mutations in hepcidin and any genes that regulate the biology of hepcidin, including hemochromatosis genes (HFE), Hemojuvelin (HJV), transferring receptor 2 (TFR2) and FPN, result in hemochromatosis. The identification of hepcidin and its role will provide a better understanding for pathogenesis of HH. PMID:27031690

  8. [Pathogenesis of atypical femoral fracture].

    PubMed

    Iwata, Ken; Mashiba, Tasuku

    2016-01-01

    We demonstrated microdamage accumulation in the fracture sites in the patients of subtrochanteric atypical femoral fracture with long term bisphosphonate therapy and of incomplete shaft fracture of lateral femoral bowing without bisphosphonate therapy. Based on these findings, pathogenesis of atypical femoral fracture is revealed stress fracture caused by accumulation of microdamages between distal to the lesser trochanter and proximal to the supracondylar flare in the femur in association with severely suppressed bone turnover and/or abnormal lower limb alignment, that causes stress concentration on the lateral side cortex of the femur. PMID:26728533

  9. FAMMM syndrome: pathogenesis and management.

    PubMed

    Czajkowski, Rafał; Placek, Waldemar; Drewa, Gerard; Czajkowska, Aldona; Uchańska, Grazyna

    2004-02-01

    Familial atypical multiple mole melanoma (FAMMM) syndrome is an autosomal dominant disorder with variable incomplete penetrance of the clinical phenotypes. Pathogenesis of this syndrome has not been fully investigated. Across multiple studies, germline mutations in the INK4a antioncogene encoding p16 protein were found on average in approximately 40% of the FAMMM syndrome. Patients with the FAMMM syndrome are genetically loaded with an increased risk of developing melanoma and other malignant neoplasms, for example, a pancreatic cancer. Melanoma can develop from numerous atypical moles as well as de novo. A proper diagnosis of the syndrome and early application of prophylactics decreases the risk of neoplastic transformation of melanocytes. PMID:14871223

  10. Biology and pathogenesis of Acanthamoeba

    PubMed Central

    2012-01-01

    Acanthamoeba is a free-living protist pathogen, capable of causing a blinding keratitis and fatal granulomatous encephalitis. The factors that contribute to Acanthamoeba infections include parasite biology, genetic diversity, environmental spread and host susceptibility, and are highlighted together with potential therapeutic and preventative measures. The use of Acanthamoeba in the study of cellular differentiation mechanisms, motility and phagocytosis, bacterial pathogenesis and evolutionary processes makes it an attractive model organism. There is a significant emphasis on Acanthamoeba as a Trojan horse of other microbes including viral, bacterial, protists and yeast pathogens. PMID:22229971

  11. Pathogenesis of Alcoholic Liver Disease.

    PubMed

    Dunn, Winston; Shah, Vijay H

    2016-08-01

    Alcoholic liver disease includes a broad clinical-histological spectrum from simple steatosis, cirrhosis, acute alcoholic hepatitis with or without cirrhosis to hepatocellular carcinoma as a complication of cirrhosis. The pathogenesis of alcoholic liver disease can be conceptually divided into (1) ethanol-mediated liver injury, (2) inflammatory immune response to injury, (3) intestinal permeability and microbiome changes. Corticosteroids may improve outcomes, but this is controversial and probably only impacts short-term survival. New pathophysiology-based therapies are under study, including antibiotics, caspase inhibition, interleukin-22, anakinra, FXR agonist and others. These studies provide hope for better future outcomes for this difficult disease. PMID:27373608

  12. Pathogenesis of Varicelloviruses in primates

    PubMed Central

    Ouwendijk, Werner J.D.; Verjans, Georges M.G.M.

    2014-01-01

    Varicelloviruses in primates comprise the prototypic human varicella-zoster virus (VZV) and its non-human primate homologue simian varicella virus (SVV). Both viruses cause varicella as a primary infection, establish latency in ganglionic neurons and reactivate later in life to cause herpes zoster in their respective hosts. VZV is endemic worldwide and although varicella is usually a benign disease in childhood, VZV reactivation is a significant cause of neurological disease in the elderly and in immunocompromised individuals. The pathogenesis of VZV infection remains ill-defined, mostly due to the species restriction of VZV that impedes studies in experimental animal models. SVV infection of non-human primates parallels virological, clinical, pathological and immunological features of human VZV infection, thereby providing an excellent model to study the pathogenesis of varicella and herpes zoster in its natural host. In this review, we discuss recent studies that provided novel insight in both the virus and host factors involved in the three elementary stages of Varicellovirus infection in primates: primary infection, latency and reactivation. PMID:25255989

  13. Pathogenesis of chronic rhinosinusitis: inflammation.

    PubMed

    Van Crombruggen, Koen; Zhang, Nan; Gevaert, Philippe; Tomassen, Peter; Bachert, Claus

    2011-10-01

    Chronic rhinosinusitis (CRS) is a heterogeneous group of inflammatory diseases of the nasal and paranasal cavities either accompanied by polyp formation (CRSwNP) or without polyps (CRSsNP). CRSsNP and CRSwNP are prevalent medical conditions associated with substantial impaired quality of life, reduced workplace productivity, and serious medical treatment costs. Despite recent research evidence that contributes to further unveiling the pathophysiology of these chronic airway conditions, the cause remains poorly understood and appears to be multifactorial. A diverse spectrum of alterations involving histopathology, inflammatory cell and T-cell patterns, remodeling parameters (eg, TGF-β), eicosanoid and IgE production, microorganisms, and epithelial barrier malfunctions is reported in the search to describe the pathogenesis of this heterogeneous group of upper airway diseases. Furthermore, novel evidence indicates considerable heterogeneity within the CRSwNP subgroup determining the risk of comorbid asthma. The characterization of specific disease subgroups is a challenging scientific and clinical task of utmost importance in the development of diagnostic tools and application of individualized treatments. This review focuses on recent evidence that sheds new light on our current knowledge regarding the inflammatory process of CRS to further unravel its pathogenesis. PMID:21868076

  14. Molecular pathogenesis of intrahepatic cholangiocarcinoma.

    PubMed

    Andersen, Jesper B

    2015-02-01

    Cholangiocarcinoma (CCA) is an orphan cancer of the hepatobiliary tract, the incidence of which has increased in the past decade. The molecular pathogenesis of this treatment-refractory disease is poorly understood. Desmoplasia is a key causal feature of CCA; however, a majority of tumors develop with no apparent etiological background. The impact of the stromal compartment on tumor progression as well as resistance to therapy is in vogue, and the epithelial-stromal crosstalk may present a target for novel treatment strategies. As such, the complexity of tumor cellularity and the molecular mechanisms underlying the diversity of growth patterns of this malignancy remain a clinical concern. It is crucial to advance our present understanding of the molecular pathogenesis of CCA to improve current clinical strategies and patient outcome. This will facilitate the delineation of patient subsets and individualization for precision therapies. Many questions persevere as to the evolutionary process and cellular origin of the initial transforming event, the context of intratumoral plasticity and the causal driver action. Next-generation sequencing has begun to underline the persistent alterations, which may be the trigger of acquired drug resistance, and the cause of metastasis and disease recurrence. A complex issue that remains is to account for the heterogeneous pool of "backseat" aberrations, which in chromosomal proximity to the causative variant are likely to influence, for example, drug response. This review explores the recent advances in defining the molecular pathways implicated in the development of this devastating disease and, which present putative clinical strategies. PMID:25174625

  15. Pathogenesis and Immunobiology of Brucellosis

    PubMed Central

    de Figueiredo, Paul; Ficht, Thomas A.; Rice-Ficht, Allison; Rossetti, Carlos A.; Adams, L. Garry

    2016-01-01

    This review of Brucella–host interactions and immunobiology discusses recent discoveries as the basis for pathogenesis-informed rationales to prevent or treat brucellosis. Brucella spp., as animal pathogens, cause human brucellosis, a zoonosis that results in worldwide economic losses, human morbidity, and poverty. Although Brucella spp. infect humans as an incidental host, 500,000 new human infections occur annually, and no patient-friendly treatments or approved human vaccines are reported. Brucellae display strong tissue tropism for lymphoreticular and reproductive systems with an intracellular lifestyle that limits exposure to innate and adaptive immune responses, sequesters the organism from the effects of antibiotics, and drives clinical disease manifestations and pathology. Stealthy brucellae exploit strategies to establish infection, including i) evasion of intracellular destruction by restricting fusion of type IV secretion system-dependent Brucella-containing vacuoles with lysosomal compartments, ii) inhibition of apoptosis of infected mononuclear cells, and iii) prevention of dendritic cell maturation, antigen presentation, and activation of naive T cells, pathogenesis lessons that may be informative for other intracellular pathogens. Data sets of next-generation sequences of Brucella and host time-series global expression fused with proteomics and metabolomics data from in vitro and in vivo experiments now inform interactive cellular pathways and gene regulatory networks enabling full-scale systems biology analysis. The newly identified effector proteins of Brucella may represent targets for improved, safer brucellosis vaccines and therapeutics. PMID:25892682

  16. Arterivirus molecular biology and pathogenesis.

    PubMed

    Snijder, Eric J; Kikkert, Marjolein; Fang, Ying

    2013-10-01

    Arteriviruses are positive-stranded RNA viruses that infect mammals. They can cause persistent or asymptomatic infections, but also acute disease associated with a respiratory syndrome, abortion or lethal haemorrhagic fever. During the past two decades, porcine reproductive and respiratory syndrome virus (PRRSV) and, to a lesser extent, equine arteritis virus (EAV) have attracted attention as veterinary pathogens with significant economic impact. Particularly noteworthy were the 'porcine high fever disease' outbreaks in South-East Asia and the emergence of new virulent PRRSV strains in the USA. Recently, the family was expanded with several previously unknown arteriviruses isolated from different African monkey species. At the molecular level, arteriviruses share an intriguing but distant evolutionary relationship with coronaviruses and other members of the order Nidovirales. Nevertheless, several of their characteristics are unique, including virion composition and structure, and the conservation of only a subset of the replicase domains encountered in nidoviruses with larger genomes. During the past 15 years, the advent of reverse genetics systems for EAV and PRRSV has changed and accelerated the structure-function analysis of arterivirus RNA and protein sequences. These systems now also facilitate studies into host immune responses and arterivirus immune evasion and pathogenesis. In this review, we have summarized recent advances in the areas of arterivirus genome expression, RNA and protein functions, virion architecture, virus-host interactions, immunity, and pathogenesis. We have also briefly reviewed the impact of these advances on disease management, the engineering of novel candidate live vaccines and the diagnosis of arterivirus infection. PMID:23939974

  17. Henipavirus pathogenesis and antiviral approaches.

    PubMed

    Mathieu, Cyrille; Horvat, Branka

    2015-03-01

    Hendra virus and Nipah virus are closely related, recently emerged zoonotic paramyxoviruses, belonging to the Henipavirus genus. Both viruses induce generalized vasculitis affecting particularly the respiratory tract and CNS. The exceptionally broad species tropism of Henipavirus, the high case fatality rate and person-to-person transmission associated with Nipah virus outbreaks emphasize the necessity of effective antiviral strategies for these intriguing threatening pathogens. Current therapeutic approaches, validated in animal models, target early steps in viral infection; they include the use of neutralizing virus-specific antibodies and blocking membrane fusion with peptides that bind the viral fusion protein. A better understanding of Henipavirus pathogenesis is critical for the further advancement of antiviral treatment, and we summarize here the recent progress in the field. PMID:25634624

  18. Melioidosis: Molecular Aspects of Pathogenesis

    PubMed Central

    Stone, Joshua K.; DeShazer, David; Brett, Paul J.; Burtnick, Mary N.

    2015-01-01

    SUMMARY Burkholderia pseudomallei is a Gram-negative bacterium that causes melioidosis, a multifaceted disease that is highly endemic in Southeast Asia and northern Australia. This facultative intracellular pathogen possesses a large genome that encodes a wide array of virulence factors that promote survival in vivo by manipulating host cell processes and disarming elements of the host immune system. Antigens and systems that play key roles in B. pseudomallei virulence include capsular polysaccharide, lipopolysaccharide, adhesins, specialized secretion systems, actin-based motility and various secreted factors. This review provides an overview of the current and steadily expanding knowledge regarding the molecular mechanisms used by this organism to survive within a host and their contribution to the pathogenesis of melioidosis. PMID:25312349

  19. Neuroblastoma: Molecular Pathogenesis and Therapy

    PubMed Central

    Louis, Chrystal U; Shohet, Jason M

    2015-01-01

    Neuroblastoma is a developmental tumor of young children arising from the embryonic sympathoadrenal lineage of the neural crest. Currently neuroblastoma is the primary cause of death from pediatric cancer for children between the age of 1 and 5 years and accounts for approximately 13% of all pediatric cancer mortality. Its clinical impact and its unique biology have made this aggressive malignancy the focus of a large concerted translational research effort. New insights into tumor biology are driving the development of new classification schemas; novel targeted therapeutic approaches include small molecule inhibitors, epigenetic, non-coding RNA, and cell-based immunologic therapies. Recent insights regarding the pathogenesis and biology of neuroblastoma will be placed in context with the current understanding of tumor biology and tumor/host interactions. Systematic classification of patients coupled with therapeutic advances point to a future of improved clinical outcomes for this biologically distinct and highly aggressive pediatric malignancy. PMID:25386934

  20. Pathogenesis of Brain Arteriovenous Malformations

    PubMed Central

    KOMIYAMA, Masaki

    2016-01-01

    Brain arteriovenous malformations (bAVMs) represent a high risk of intracranial hemorrhages, which are substantial causes of morbidity and mortality of bAVMs, especially in children and young adults. Although a variety of factors leading to hemorrhages of bAVMs are investigated extensively, their pathogenesis is still not well elucidated. The author has reviewed the updated data of genetic aspects of bAVMs, especially focusing on clinical and experimental knowledge from hereditary hemorrhagic telangiectasia, which is the representative genetic disease presenting with bAVMs caused by loss-of-function in one of the two genes: endoglin and activin receptor-like kinase 1. This knowledge may allow us to infer the pathogensis of sporadic bAVMs and in the development of new medical therapies for them. PMID:27076383

  1. Endothelial Glycocalyx: Shedding Light on Malaria Pathogenesis.

    PubMed

    Hempel, Casper; Pasini, Erica M; Kurtzhals, Jørgen A L

    2016-06-01

    Malaria is estimated to kill 438 000 people annually, mostly due to severe malaria, which is closely associated with microcirculatory vasculopathy, although its pathogenesis remains incompletely understood. Here, we propose that the largely ignored glycocalyx of the vascular endothelium plays an important role in facilitating the pathogenesis of severe malaria. PMID:27161599

  2. Pathogenesis of Helicobacter pylori infection.

    PubMed

    Backert, Steffen; Neddermann, Matthias; Maubach, Gunter; Naumann, Michael

    2016-09-01

    Helicobacter pylori is estimated to infect more than half of the worlds human population and represents a major risk factor for chronic gastritis, peptic ulcer disease, MALT lymphoma, and gastric adenocarcinoma. H. pylori infection and clinical consequences are controlled by highly complex interactions between the host, colonizing bacteria, and environmental parameters. Important bacterial determinants linked with gastric disease development include the cag pathogenicity island encoding a type IV secretion system (T4SS), the translocated effector protein CagA, vacuolating cytotoxin VacA, adhesin BabA, urease, serine protease HtrA, secreted outer membrane vesicles, and many others. The high quantity of these factors and allelic changes in the corresponding genes reveals a sophisticated picture and problems in evaluating the impact of each distinct component. Extensive work has been performed to pinpoint molecular processes related to H. pylori-triggered pathogenesis using Mongolian gerbils, mice, primary tissues, as well as novel in vitro model systems such as gastroids. The manipulation of host signaling cascades by the bacterium appears to be crucial for inducing pathogenic downstream activities and gastric disease progression. Here, we review the most recent advances in this important research area. PMID:27531534

  3. FVIII inhibitors: pathogenesis and avoidance

    PubMed Central

    2015-01-01

    The pathogenesis of inhibitory antibodies has been the focus of major scientific interest over the last decades, and several studies on underlying immune mechanisms and risk factors for formation of these antibodies have been performed with the aim of improving the ability to both predict and prevent their appearance. It seems clear that the decisive factors for the immune response to the deficient factor are multiple and involve components of both a constitutional and therapy-related nature. A scientific concern and obstacle for research in the area of hemophilia is the relatively small cohorts available for studies and the resulting risk of confounded and biased results. Careful interpretation of data is recommended to avoid treatment decisions based on a weak scientific platform. This review will summarize current concepts of the underlying immunological mechanisms and risk factors for development of inhibitory antibodies in patients with hemophilia A and discuss how these findings may be interpreted and influence our clinical management of patients. PMID:25712994

  4. Pathogenesis of benign adrenocortical tumors.

    PubMed

    Vezzosi, Delphine; Bertherat, Jérôme; Groussin, Lionel

    2010-12-01

    Most adrenocortical tumors (ACT) are benign unilateral adrenocortical adenomas, often discovered incidentally. Exceptionally, ACT are bilateral. However bilateral ACT have been very helpful to progress in the pathophysiology of ACT. Although most ACT are of sporadic origin, they may also be part of syndromic and/or hereditary disorders. The identification of the genetics of familial diseases associated with benign ACT has been helpful to define somatic alterations in sporadic ACT: for example, identification of PRKAR1A mutations in Carney complex or alterations of the Wnt/β-catenin pathway in Familial Adenomatous Polyposis Coli. Components of the cAMP signaling pathway-for example, adrenocorticotropic-hormone receptors and other membrane receptors, Gs protein, phosphodiesterases and protein kinase A-can be altered to various degrees in benign cortisol-secreting ACT. These progress have been important for the understanding of the pathogenesis of benign ACT, but already have profound implications for clinical management, for example in unraveling the genetic origin of disease in some patients with ACT. They also have therapeutic consequences, and should help to develop new therapeutic options. PMID:21115158

  5. Pathogenicity Islands in Bacterial Pathogenesis

    PubMed Central

    Schmidt, Herbert; Hensel, Michael

    2004-01-01

    In this review, we focus on a group of mobile genetic elements designated pathogenicity islands (PAI). These elements play a pivotal role in the virulence of bacterial pathogens of humans and are also essential for virulence in pathogens of animals and plants. Characteristic molecular features of PAI of important human pathogens and their role in pathogenesis are described. The availability of a large number of genome sequences of pathogenic bacteria and their benign relatives currently offers a unique opportunity for the identification of novel pathogen-specific genomic islands. However, this knowledge has to be complemented by improved model systems for the analysis of virulence functions of bacterial pathogens. PAI apparently have been acquired during the speciation of pathogens from their nonpathogenic or environmental ancestors. The acquisition of PAI not only is an ancient evolutionary event that led to the appearance of bacterial pathogens on a timescale of millions of years but also may represent a mechanism that contributes to the appearance of new pathogens within a human life span. The acquisition of knowledge about PAI, their structure, their mobility, and the pathogenicity factors they encode not only is helpful in gaining a better understanding of bacterial evolution and interactions of pathogens with eukaryotic host cells but also may have important practical implications such as providing delivery systems for vaccination, tools for cell biology, and tools for the development of new strategies for therapy of bacterial infections. PMID:14726454

  6. Systems approaches to coronavirus pathogenesis

    PubMed Central

    Schäfer, Alexandra; Baric, Ralph S.; Ferris, Martin T.

    2014-01-01

    Coronaviruses comprise a large group of emergent human and animal pathogens, including the highly pathogenic SARS-CoV and MERS-CoV strains that cause significant morbidity and mortality in infected individuals, especially the elderly. As emergent viruses may cause episodic outbreaks of disease over time, human samples are limited. Systems biology and genetic technologies maximize opportunities for identifying critical host and viral genetic factors that regulate susceptibility and virus-induced disease severity. These approaches provide discovery platforms that highlight and allow targeted confirmation of critical targets for prophylactics and therapeutics, especially critical in an outbreak setting. Although poorly understood, it has long been recognized that host regulation of virus-associated disease severity is multigenic. The advent of systems genetic and biology resources provide new opportunities for deconvoluting the complex genetic interactions and expression networks that regulate pathogenic or protective host response patterns following virus infection. Using SARS-CoV as a model, dynamic transcriptional network changes and disease-associated phenotypes have been identified in different genetic backgrounds, leading to the promise of population-wide discovery of the underpinnings of Coronavirus pathogenesis. PMID:24842079

  7. Candida albicans, plasticity and pathogenesis.

    PubMed

    Poulain, Daniel

    2015-06-01

    The yeast Candida albicans has emerged as a major public health problem during the past two decades. The spectrum of diseases caused by this species ranges from vaginal infections, which affect up to 75% of the women at least once in their lifetime, to deep infections in hospitalized patients which lead to high morbidity and mortality rates. Candida albicans may also play a role in the persistence or worsening of some chronic inflammatory bowel diseases. Active research is now improving our understanding of the molecular mechanisms and genetic factors in the yeast and its host which influence the development of disease. Despite these advances and the availability of a more extensive therapeutic arsenal, current progress in the control of nosocomial infections due to Candida remains limited, mainly due to the difficulties in diagnosing these infections. The biologist has a key role to play in establishing a dialogue with the clinician in order to identify the saprophyte/pathogen transition in patients as early as possible. This review provides a quick synopsis of the modern concepts of Candida pathogenesis with some representative examples illustrating the specifics traits of this yeast in terms of pathogenic adaptation. PMID:23962107

  8. CELLULAR PATHOGENESIS OF DIABETIC GASTROENTEROPATHY

    PubMed Central

    Ördög, Tamás; Hayashi, Yujiro; Gibbons, Simon J.

    2010-01-01

    SUMMARY Gastroenteropathy manifesting in upper gastrointestinal symptoms, delayed gastric emptying, constipation, diarrhea and fecal incontinence occurs frequently in patients with diabetes mellitus and represents a significant health care burden. Current treatments are largely symptomatic and ineffective. Better understanding of the cellular and molecular pathogenesis of these disorders is required for the development of more effective therapies. Recent advances in our understanding of the inherent, high-level complexities of the control systems that execute and regulate gastrointestinal motility, together with the utilization of new experimental models and sophisticated physiological, morphological and molecular techniques have lead to the realization that diabetic gastroenteropathies cannot be ascribed to any singular defect or dysfunction. In fact, these disorders are multifactorial and involve a spectrum of metabolic and dystrophic changes that can potentially affect all key components of motor control including the systemic autonomic and enteric nervous systems, interstitial cells of Cajal and smooth muscle cells. Candidate pathomechanisms are also varied and include imbalance between pro- and anti-oxidative factors, altered trophic stimuli to mature cells and their progenitors, and, possibly, autoimmune factors. The goal of this paper is to review the cellular changes underlying diabetic gastroenteropathies and their potential causes, with particular focus on functional interactions between various cell types. It is proposed that diabetic gastroenteropathies should be considered a form of gastrointestinal neuromuscular dystrophy rather than a “functional” disorder. Future research should identify ways to block cytotoxic factors, support the regeneration of damaged cells and translate the experimental findings into new treatment modalities. PMID:19829287

  9. Redox biology of tuberculosis pathogenesis.

    PubMed

    Trivedi, Abhishek; Singh, Nisha; Bhat, Shabir Ahmed; Gupta, Pawan; Kumar, Ashwani

    2012-01-01

    Mycobacterium tuberculosis (Mtb) is one of the most successful human pathogens. Mtb is persistently exposed to numerous oxidoreductive stresses during its pathogenic cycle of infection and transmission. The distinctive ability of Mtb, not only to survive the redox stress manifested by the host but also to use it for synchronizing the metabolic pathways and expression of virulence factors, is central to its success as a pathogen. This review describes the paradigmatic redox and hypoxia sensors employed by Mtb to continuously monitor variations in the intracellular redox state and the surrounding microenvironment. Two component proteins, namely, DosS and DosT, are employed by Mtb to sense changes in oxygen, nitric oxide, and carbon monoxide levels, while WhiB3 and anti-sigma factor RsrA are used to monitor changes in intracellular redox state. Using these and other unidentified redox sensors, Mtb orchestrates its metabolic pathways to survive in nutrient-deficient, acidic, oxidative, nitrosative, and hypoxic environments inside granulomas or infectious lesions. A number of these metabolic pathways are unique to mycobacteria and thus represent potential drug targets. In addition, Mtb employs versatile machinery of the mycothiol and thioredoxin systems to ensure a reductive intracellular environment for optimal functioning of its proteins even upon exposure to oxidative stress. Mtb also utilizes a battery of protective enzymes, such as superoxide dismutase (SOD), catalase (KatG), alkyl hydroperoxidase (AhpC), and peroxiredoxins, to neutralize the redox stress generated by the host immune system. This chapter reviews the current understanding of mechanisms employed by Mtb to sense and neutralize redox stress and their importance in TB pathogenesis and drug development. PMID:22633061

  10. Rethinking Mechanisms of Autoimmune Pathogenesis

    PubMed Central

    Pillai, Shiv

    2016-01-01

    Why exactly some individuals develop autoimmune disorders remains unclear. The broadly accepted paradigm is that genetic susceptibility results in some break in immunological tolerance, may enhance the availability of autoantigens, and may enhance inflammatory responses. Some environmental insults that occur on this background of susceptibility may then contribute to autoimmunity. In this review we discuss some aspects related to inhibitory signaling and rare genetic variants, as well as additional factors that might contribute to autoimmunity including the possible role of clonal somatic mutations, the role of epigenetic events and the contribution of the intestinal microbiome. Genetic susceptibility alleles generally contribute to the loss of immunological tolerance, the increased availability of asutoantigens, or an increase in inflammation. Apart from common genetic variants, rare loss-of-function genetic variants may also contribute to the pathogenesis of autoimmunity. Studies of an inhibitory signaling pathway in B cells helped identify a negative regulatory enzyme called sialic acid acetyl esterase. The study of rare genetic variants of this enzyme provides an illustrative example showing the importance of detailed functional analyses of variant alleles and the need to exclude functionally normal common or rare genetic variants from analysis. It has also become clear that pathways that are functionally impacted by either common or rare defective variants can also be more significantly compromised by gene expression changes that may result from epigenetic alterations. Another important and evolving area that has been discussed relates to the role of the intestinal microbiome in influencing helper T cell polarization and the development of autoimmunity. PMID:23809879