Vibrio harveyi virulence gene expression in vitro and in vivo during infection in black tiger shrimp Penaeus monodon

2020 ◽  
Vol 139 ◽  
pp. 153-160
Author(s):  
S Peeralil ◽  
TC Joseph ◽  
V Murugadas ◽  
PG Akhilnath ◽  
VN Sreejith ◽  
...  
Keyword(s):  
Gene Expression ◽  
Virulence Genes ◽  
Vibrio Harveyi ◽  
Penaeus Monodon ◽  
Challenge Test ◽  
Virulence Gene ◽  
Economic Losses ◽  
Virulence Gene Expression

Luminescent Vibrio harveyi is common in sea and estuarine waters. It produces several virulence factors and negatively affects larval penaeid shrimp in hatcheries, resulting in severe economic losses to shrimp aquaculture. Although V. harveyi is an important pathogen of shrimp, its pathogenicity mechanisms have yet to be completely elucidated. In the present study, isolates of V. harveyi were isolated and characterized from diseased Penaeus monodon postlarvae from hatcheries in Kerala, India, from September to December 2016. All 23 tested isolates were positive for lipase, phospholipase, caseinase, gelatinase and chitinase activity, and 3 of the isolates (MFB32, MFB71 and MFB68) showed potential for significant biofilm formation. Based on the presence of virulence genes, the isolates of V. harveyi were grouped into 6 genotypes, predominated by vhpA+ flaB+ ser+ vhh1- luxR+ vopD- vcrD+ vscN-. One isolate from each genotype was randomly selected for in vivo virulence experiments, and the LD50 ranged from 1.7 ± 0.5 × 103 to 4.1 ± 0.1 × 105 CFU ml-1. The expression of genes during the infection in postlarvae was high in 2 of the isolates (MFB12 and MFB32), consistent with the result of the challenge test. However, in MFB19, even though all genes tested were present, their expression level was very low and likely contributed to its lack of virulence. Because of the significant variation in gene expression, the presence of virulence genes alone cannot be used as a marker for pathogenicity of V. harveyi.

Quorum sensing regulation of virulence gene expression in Vibrio harveyi in vitro and in vivo during infection of gnotobiotic brine shrimp larvae

2011 ◽  
Vol 3 (5) ◽  
pp. 597-602 ◽  
Author(s):  
H. A. Darshanee Ruwandeepika ◽  
Patit Paban Bhowmick ◽  
Indrani Karunasagar ◽  
Peter Bossier ◽  
Tom Defoirdt
Keyword(s):  
Gene Expression ◽  
Quorum Sensing ◽  
Brine Shrimp ◽  
Vibrio Harveyi ◽  
Virulence Gene ◽  
Virulence Gene Expression

scholarly journals 18β-Glycyrrhetinic Acid Inhibits Methicillin-Resistant Staphylococcus aureus Survival and Attenuates Virulence Gene Expression

2012 ◽  
Vol 57 (1) ◽  
pp. 241-247 ◽  
Author(s):  
Danyelle R. Long ◽  
Julia Mead ◽  
Jay M. Hendricks ◽  
Michele E. Hardy ◽  
Jovanka M. Voyich
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Virulence Gene ◽  
Glycyrrhetinic Acid ◽  
Licorice Root ◽  
Methicillin Resistant ◽  
Content Type ◽  
Virulence Gene Expression

ABSTRACTMethicillin-resistantStaphylococcus aureus(MRSA) has become a major source of infection in hospitals and in the community. Increasing antibiotic resistance inS. aureusstrains has created a need for alternative therapies to treat disease. A component of the licorice rootGlycyrrhizaspp., 18β-glycyrrhetinic acid (GRA), has been shown to have antiviral, antitumor, and antibacterial activity. This investigation explores thein vitroandin vivoeffects of GRA on MRSA pulsed-field gel electrophoresis (PFGE) type USA300. GRA exhibited bactericidal activity at concentrations exceeding 0.223 μM. Upon exposure ofS. aureusto sublytic concentrations of GRA, we observed a reduction in expression of key virulence genes, includingsaeRandhla. In murine models of skin and soft tissue infection, topical GRA treatment significantly reduced skin lesion size and decreased the expression ofsaeRandhlagenes. Our investigation demonstrates that at high concentrations GRA is bactericidal to MRSA and at sublethal doses it reduces virulence gene expression inS. aureusbothin vitroandin vivo.

scholarly journals Activation of theListeria monocytogenesVirulence Program by a Reducing Environment

mBio ◽  
2017 ◽  
Vol 8 (5) ◽  
Author(s):  
Jonathan L. Portman ◽  
Samuel B. Dubensky ◽  
Bret N. Peterson ◽  
Aaron T. Whiteley ◽  
Daniel A. Portnoy
Keyword(s):  
Gene Expression ◽  
Synthetic Medium ◽  
Virulence Gene ◽  
Intracellular Pathogen ◽  
Intracellular Pathogens ◽  
Virulence Gene Expression ◽  
Cell Cytosol ◽  
Host Cell Cytosol

ABSTRACTUpon entry into the host cell cytosol, the facultative intracellular pathogenListeria monocytogenescoordinates the expression of numerous essential virulence factors by allosteric binding of glutathione (GSH) to the Crp-Fnr family transcriptional regulator PrfA. Here, we report that robust virulence gene expression can be recapitulated by growing bacteria in a synthetic medium containing GSH or other chemical reducing agents. Bacteria grown under these conditions were 45-fold more virulent in an acute murine infection model and conferred greater immunity to a subsequent lethal challenge than bacteria grown in conventional media. During cultivationin vitro, PrfA activation was completely dependent on the intracellular levels of GSH, as a glutathione synthase mutant (ΔgshF) was activated by exogenous GSH but not reducing agents. PrfA activation was repressed in a synthetic medium supplemented with oligopeptides, but the repression was relieved by stimulation of the stringent response. These data suggest that cytosolicL. monocytogenesinterprets a combination of metabolic and redox cues as a signal to initiate robust virulence gene expressionin vivo.IMPORTANCEIntracellular pathogens are responsible for much of the worldwide morbidity and mortality from infectious diseases. These pathogens have evolved various strategies to proliferate within individual cells of the host and avoid the host immune response. Through cellular invasion or the use of specialized secretion machinery, all intracellular pathogens must access the host cell cytosol to establish their replicative niches. Determining how these pathogens sense and respond to the intracellular compartment to establish a successful infection is critical to our basic understanding of the pathogenesis of each organism and for the rational design of therapeutic interventions.Listeria monocytogenesis a model intracellular pathogen with robustin vitroandin vivoinfection models. Studies of the host-sensing and downstream signaling mechanisms evolved byL. monocytogenesoften describe themes of pathogenesis that are broadly applicable to less tractable pathogens. Here, we describe how bacteria use external redox states as a cue to activate virulence.

scholarly journals The Effect Hydroquinone Extracted from Sonneratia caseolaris Fruit to Control Vibrio harveyi Artificial Infection on Tiger Shrimp, Penaeus monodon Fab.

2007 ◽  
Vol 3 (1) ◽  
pp. 29
Author(s):  
. Arifuddin ◽  
. Sukenda ◽  
D. Dana
Keyword(s):  
Survival Rate ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Vibrio Harveyi ◽  
Penaeus Monodon ◽  
Challenge Test ◽  
Total Count ◽  
Sonneratia Caseolaris

<p>The role of hydroquinone extracted from <em>Soneratia caseolaris </em>fruit to control <em>Vibrio harveyi </em>infection on tiger prawn was carried out. <em>In vitro </em>experiment was conducted using disc diffusion and MIC <em>{minimum inhibitory concentration) </em>methods to know the sensitivity of <em>V. harveyi </em>to hydroquinone. Two kinds of <em>in vivo </em>experiments were (1) hydroquinone was injected into shrimps muscle and a week later the shrimps were challenged with <em>V. harveyi </em>(2) the shrimps were challenged with <em>V. harveyi </em>and one day later hidroquinone was injected. Total count of live <em>V. harveyi </em>on the shrimps and survival rate were observed after challenge test. Hydroquinone showed antibacterial activity with MIC at 3000 ppm. Hydroquinone injected shrimp showed higher survival rate compared with control (100% vs 50%). Total count of <em>V. harveyi </em>from injected shrimp, either before or after challenged, decreased by 2,61xl04 cfu/g and l,61xl04 cfu/g, respectively. These findings indicated that crude hydroquinone have anti-bacterial effect to control <em>V. harveyi </em>infection.</p> <p>Key words: hydroquinone, <em>Sonneratia caseolaris, Vibrio harveyi, Penaeus monodon </em></p> <p> </p> <p>ABSTRAK</p> <p>Telaah peran hidrokuinon yang diekstraksi dari buah <em>Soneratia caseolaris </em>untuk mengontrol infeksi <em>Vibrio harveyi </em>pada udang windu dilakukan. Percobaan <em>in vitro </em>dilakukan menggunakan metode difusi cakram dan MIC <em>{minimum inhibitory concentration) </em>untuk mengetahui sensitivitas <em>V. harveyi </em>terhadap hidrokuinon. Percobaan <em>in vivo </em>dilakukan dengan dua cara (1) hidrokuinon disuntikkan pada otot udang dan seminggu kemudian udang diuji tantang dengan <em>V. harveyi </em>(2) udang ditantang terlebih dahulu dengan <em>V. harveyi </em>dan sehari kemudian hidrokuinon disuntikkan. Jumlah total bakteri <em>V. harveyi </em>hidup pada udang dan kelangsungan hidup udang diamati setelah uji tantang. Hidrokuinon menunjukkan aktivitas antibakteri dengan MIC 3000 ppm. Udang yang diinjeksi dengan hidrokuinon mempunyai kelangsungan hidup yang lebih tinggi dibandingkan kontrol (100% vs 50%). Jumlah total <em>V. harveyi </em>pada udang yang diinfeksi, baik sebelum maupun sesudah, masing-masing turun sampai 2,61 x 104 cfu/g dan 1,61 x 104 cfu/g. Hasil ini menunjukkan bahwa hidrokuinon mempunyai efek anti-bakterial untuk mengontrol infeksi <em>V. harveyi. </em></p> <p>Kata kunci: hidrokuinon, <em>Sonneratia caseolaris, Vibrio harveyi, Penaeus monodon</em></p>

scholarly journals Genome-Wide Identification of Genes Regulated by the Rcs Phosphorelay System in Erwinia amylovora

2012 ◽  
Vol 25 (1) ◽  
pp. 6-17 ◽  
Author(s):  
Dongping Wang ◽  
Mingsheng Qi ◽  
Bernarda Calla ◽  
Schuyler S. Korban ◽  
Steven J. Clough ◽  
...  
Keyword(s):  
Gene Expression ◽  
Erwinia Amylovora ◽  
Virulence Gene ◽  
Luria Bertani ◽  
Regulatory Genes ◽  
Bacterial Cells ◽  
Virulence Gene Expression ◽  
Genome Wide

The exopolysaccharide amylovoran is one of the major pathogenicity factors in Erwinia amylovora, the causal agent of fire blight of apples and pears. We have previously demonstrated that the RcsBCD phosphorelay system is essential for virulence by controlling amylovoran biosynthesis. We have also found that the hybrid sensor kinase RcsC differentially regulates amylovoran production in vitro and in vivo. To further understand how the Rcs system regulates E. amylovora virulence gene expression, we conducted genome-wide microarray analyses to determine the regulons of RcsB and RcsC in liquid medium and on immature pear fruit. Array analyses identified a total of 648 genes differentially regulated by RcsCB in vitro and in vivo. Consistent with our previous findings, RcsB acts as a positive regulator in both conditions, while RcsC positively controls expression of amylovoran biosynthetic genes in vivo but negatively controls expression in vitro. Besides amylovoran biosynthesis and regulatory genes, cell-wall and cell-envelope (membrane) as well as regulatory genes were identified as the major components of the RcsBC regulon, including many novel genes. We have also demonstrated that transcripts of rcsA, rcsC, and rcsD genes but not the rcsB gene were up-regulated when bacterial cells were grown in minimal medium or following infection of pear fruits compared with those grown in Luria Bertani medium. Furthermore, using the genome of E. amylovora ATCC 49946, a hidden Markov model predicted 60 genes with a candidate RcsB binding site in the intergenic region, 28 of which were identified in the microarray assay. Based on these findings as well as previous reported data, a working model has been proposed to illustrate how the Rcs phosphorelay system regulates virulence gene expression in E. amylovora.

scholarly journals Differential Transcription of the tcpPHOperon Confers Biotype-Specific Control of the Vibrio cholerae ToxR Virulence Regulon

1999 ◽  
Vol 67 (10) ◽  
pp. 5117-5123 ◽  
Author(s):  
Yvette M. Murley ◽  
Patricia A. Carroll ◽  
Karen Skorupski ◽  
Ronald K. Taylor ◽  
Stephen B. Calderwood
Keyword(s):  
Gene Expression ◽  
Vibrio Cholerae ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Environmental Signals ◽  
Virulence Gene Expression ◽  
Response To Temperature ◽  
El Tor ◽  
Differential Transcription

ABSTRACT Epidemic strains of Vibrio cholerae O1 are divided into two biotypes, classical and El Tor. In both biotypes, regulation of virulence gene expression depends on a cascade in which ToxR activates expression of ToxT, and ToxT activates expression of cholera toxin and other virulence genes. In the classical biotype, maximal expression of this ToxR regulon in vitro occurs at 30°C at pH 6.5 (ToxR-inducing conditions), whereas in the El Tor biotype, production of these virulence genes only occurs under very limited conditions and not in response to temperature and pH; this difference between biotypes is mediated at the level of toxT transcription. In the classical biotype, two other proteins, TcpP and TcpH, are needed for maximal toxT transcription. Transcription oftcpPH in the classical biotype is regulated by pH and temperature independently of ToxR or ToxT, suggesting that TcpP and TcpH couple environmental signals to transcription of toxT. In this study, we show a near absence of tcpPH message in the El Tor biotype under ToxR-inducing conditions of temperature and pH. However, once expressed, El Tor TcpP and TcpH appear to be as effective as classical TcpP and TcpH in activating toxTtranscription. These results suggest that differences in regulation of virulence gene expression between the biotypes of V. cholerae primarily result from differences in expression oftcpPH message in response to environmental signals. We present an updated model for control of the ToxR virulence regulon inV. cholerae.

scholarly journals A Systems Biology Approach To Modeling Vibrio cholerae Gene Expression under Virulence-Inducing Conditions

2010 ◽  
Vol 192 (17) ◽  
pp. 4300-4310 ◽  
Author(s):  
Sanjat Kanjilal ◽  
Robert Citorik ◽  
Regina C. LaRocque ◽  
Marco F. Ramoni ◽  
Stephen B. Calderwood
Keyword(s):  
Gene Expression ◽  
Systems Biology ◽  
Vibrio Cholerae ◽  
Regulation Of Gene Expression ◽  
Virulence Gene ◽  
Temporal Separation ◽  
New Members ◽  
Virulence Gene Expression

ABSTRACT Vibrio cholerae is a Gram-negative bacillus that is the causative agent of cholera. Pathogenesis in vivo occurs through a series of spatiotemporally controlled events under the control of a gene cascade termed the ToxR regulon. Major genes in the ToxR regulon include the master regulators toxRS and tcpPH, the downstream regulator toxT, and virulence factors, the ctxAB and tcpA operons. Our current understanding of the dynamics of virulence gene expression is limited to microarray analyses of expression at selected time points. To better understand this process, we utilized a systems biology approach to examine the temporal regulation of gene expression in El Tor V. cholerae grown under virulence-inducing conditions in vitro (AKI medium), using high-resolution time series genomic profiling. Results showed that overall gene expression in AKI medium mimics that of in vivo studies but with less clear temporal separation between upstream regulators and downstream targets. Expression of toxRS was unaffected by growth under virulence-inducing conditions, but expression of toxT was activated shortly after switching from stationary to aerating conditions. The tcpA operon was also activated early during mid-exponential-phase growth, while the ctxAB operon was turned on later, after the rise in toxT expression. Expression of ctxAB continued to rise despite an eventual decrease in toxT. Cluster analysis of gene expression highlighted 15 hypothetical genes and six genes related to environmental information processing that represent potential new members of the ToxR regulon. This study applies systems biology tools to analysis of gene expression of V. cholerae in vitro and provides an important comparator for future studies done in vivo.

scholarly journals Differential expression of key pneumococcal virulence genes in vivo

Microbiology ◽  
2006 ◽  
Vol 152 (2) ◽  
pp. 305-311 ◽  
Author(s):  
Kim S. LeMessurier ◽  
Abiodun David Ogunniyi ◽  
James C. Paton
Keyword(s):  
Gene Expression ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Rt Pcr ◽  
Dynamic Nature ◽  
Virulence Gene Expression ◽  
Bacterial Rna ◽  
Significant Difference ◽  
Time Point

Few studies have examined in vivo virulence gene expression in Streptococcus pneumoniae. In this study, expression of key pneumococcal virulence genes cbpA, pspA, ply, psaA, cps2A, piaA, nanA and spxB in the nasopharynx, lungs and bloodstream of mice was investigated, following intranasal challenge with the serotype 2 strain D39. Bacterial RNA was extracted, linearly amplified and assayed by real-time RT-PCR. At 72 h, cbpA mRNA was present at higher levels in the nasopharynx and lungs than in the blood. At this time-point, the mRNAs for PspA and PiaA were most abundant in the nasopharynx, whereas no significant difference in gene expression between niches was observed for ply, psaA and cps2A. Both nanA and spxB mRNAs were present in higher amounts in the nasopharynx than in the lungs or blood. These findings illustrate the dynamic nature of pneumococcal virulence gene expression in vivo.

scholarly journals Pneumococcal Virulence Gene Expression and Host Cytokine Profiles during Pathogenesis of Invasive Disease

2007 ◽  
Vol 76 (2) ◽  
pp. 646-657 ◽  
Author(s):  
Layla K. Mahdi ◽  
Abiodun D. Ogunniyi ◽  
Kim S. LeMessurier ◽  
James C. Paton
Keyword(s):  
Gene Expression ◽  
Expression Patterns ◽  
Virulence Gene ◽  
Invasive Disease ◽  
Gene Expression Patterns ◽  
Putative Virulence Factor ◽  
Necrosis Factor Alpha ◽  
Virulence Gene Expression

ABSTRACTPneumococcal disease continues to account for significant morbidity and mortality worldwide. For the development of novel prophylactic and therapeutic strategies against the disease spectrum, a complete understanding of pneumococcal behavior in vivo is necessary. We evaluated the expression patterns of the proven and putative virulence factor genesadcR,cbpA,cbpD,cbpG,cpsA,nanA,pcpA,piaA,ply,psaA,pspA, andspxBafter intranasal infection of CD1 mice with serotype 2, 4, and 6A pneumococci by real-time reverse transcription-PCR. Simultaneous gene expression patterns of selected host immunomodulatory molecules, CCL2, CCL5, CD54, CXCL2, interleukin-6, and tomor necrosis factor alpha, were also investigated. We show that pneumococcal virulence genes are differentially expressed in vivo, with some genes demonstrating niche- and serotype-specific differential expression. The in vivo expression patterns could not be attributed to in vitro differences in expression of the genes in transparent and opaque variants of the three strains. The host molecules were significantly upregulated, especially in the lungs, blood, and brains of mice. The pneumococcal-gene expression patterns support their ascribed roles in pathogenesis, providing insight into which protein combinations might be more appropriate as vaccine antigens against invasive disease. This is the first simultaneous comparison of bacterial- and host gene expression in the same animal during pathogenesis. The strategy provides a platform for prospective evaluation of interaction kinetics between invading pneumococci and human patients in culture-positive cases and should be feasible in other infection models.

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