Donald V Lightner

The University of Arizona, Tucson, Arizona, United States

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Publications (260)476.38 Total impact

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    ABSTRACT: Antimicrobial resistance is one of the most important problems in public health, veterinary medicine and aquaculture. Importantly, plasmid mediated antibiotic resistance of pathogenic Vibrio parahaemolyticus from shrimp can potentially be transferred through transposition, conjugation and plasmid uptake to different bacterial species in aquaculture systems. In this study, we evaluated the antibiotic resistance pattern in V. parahaemolyticus strains associated with acute hepatopancreatic necrosis disease (AHPND) from penaeid shrimp and identified AHPND strains from Mexico showed a high level of resistance to tetracycline (≥5 μg/mL) and have the tetB gene coding tetracycline resistance. In particular, the tetB gene was carried in a single copy plasmid (named as pTetB-VA1) comprising 5162-bp with 40% G + C content from the strain (13-511/A1). The plasmid pTetB-VA1 consists of 9 ORFs encoding tetracycline resistant and repressor proteins, transcriptional regulatory proteins and transposases and showed a 99% sequence identity to other tet gene plasmids (pIS04_68 and pAQU2).
    Full-text · Article · Nov 2015
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    Full-text · Dataset · Aug 2015
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    ABSTRACT: Acute hepatopancreatic necrosis disease (AHPND) is a severe, newly emergent penaeid shrimp disease caused by Vibrio para- haemolyticus that has already led to tremendous losses in the cultured shrimp industry. Until now, its disease-causing mecha- nism has remained unclear. Here we show that an AHPND-causing strain of V. parahaemolyticus contains a 70-kbp plasmid (pVA1) with a postsegregational killing system, and that the ability to cause disease is abolished by the natural absence or experimental deletion of the plasmid-encoded homologs of the Photorhabdus insect-related (Pir) toxins PirA and PirB. We determined the crystal structure of the V. parahaemolyticus PirA and PirB (PirAvp and PirBvp) proteins and found that the overall structural topology of PirAvp/PirBvp is very similar to that of the Bacillus Cry insecticidal toxin-like pro- teins, despite the low sequence identity (<10%). This structural sim- ilarity suggests that the putative PirABvp heterodimer might emulate the functional domains of the Cry protein, and in particular its pore- forming activity. The gene organization of pVA1 further suggested that pirABvp may be lost or acquired by horizontal gene transfer via transposition or homologous recombination.
    Full-text · Article · Aug 2015 · Proceedings of the National Academy of Sciences
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    Jee Eun Han · Kathy F J Tang · Donald V Lightner
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    ABSTRACT: Acute hepatopancreatic necrosis disease (AHPND) has caused severe mortalities in farmed penaeid shrimp throughout SE Asia and Mexico. The causative agent of AHPND is the marine bacterium Vibrio parahaemolyticus, which secretes PirA- and PirB-like binary toxin that caused deterioration in the hepatopancreas of infected shrimp. The genes responsible for the production of this toxin are located in a large plasmid residing within the bacterial cells. We analyzed the plasmid sequence from the whole genome sequences of AHPND-V. parahaemolyticus isolates and identified 2 regions that exhibit a clear geographical variation: a 4243-bp Tn3-like transposon and a 9-bp small sequence repeat (SSR). The Tn3-like transposon was only found in the isolates from Mexico and 2 unspecified Central American countries, but not in SE Asian isolates from China, Vietnam, and Thailand. We developed PCR methods to characterize AHPND-V. parahaemolyticus isolates as either Mexican-type or SE Asian-type based on the presence of the Tn3-like transposon. The SSR is found within the coding region of a hypothetical protein and has either 4, 5, or 6 repeat units. SSRs with 4 repeat units were found in isolates from Vietnam, China, and Thailand. SSRs with 5 repeat units were found in some Vietnamese isolates, and SSRs with 6 repeat units were only found in the Mexican isolates.
    Full-text · Article · Aug 2015 · Diseases of Aquatic Organisms
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    ABSTRACT: Acute hepatopancreatic necrosis disease (AHPND) is a severe, newly emergent penaeid shrimp disease caused by Vibrio parahaemolyticus that has already led to tremendous losses in the cultured shrimp industry. Until now, its disease-causing mechanism has remained unclear. Here we show that an AHPND-causing strain of V. parahaemolyticus contains a 70-kbp plasmid (pVA1) with a postsegregational killing system, and that the ability to cause disease is abolished by the natural absence or experimental deletion of the plasmid-encoded homologs of the Photorhabdus insect-related (Pir) toxins PirA and PirB. We determined the crystal structure of the V. parahaemolyticus PirA and PirB (PirAvp and PirBvp) proteins and found that the overall structural topology of PirAvp/PirBvp is very similar to that of the Bacillus Cry insecticidal toxin-like proteins, despite the low sequence identity (<10%). This structural similarity suggests that the putative PirABvp heterodimer might emulate the functional domains of the Cry protein, and in particular its pore-forming activity. The gene organization of pVA1 further suggested that pirABvp may be lost or acquired by horizontal gene transfer via transposition or homologous recombination.
    Full-text · Article · Aug 2015 · Proceedings of the National Academy of Sciences
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    ABSTRACT: A microsporidian parasite, Enterocytozoon hepatopenaei (abbreviated as EHP), is an emerging pathogen for penaeid shrimp. EHP has been found in several shrimp farming countries in Asia including Vietnam, Thailand, Malaysia, Indonesia and China, and is reported to be associated with growth retardation in farmed shrimp. We examined the histological features from infected shrimp collected from Vietnam and Brunei, these include the presence of basophilic inclusions in the hepatopancreas tubule epithelial cells, in which EHP is found at various developmental stages, ranging from plasmodia to mature spores. By a PCR targeting the 18S rRNA gene, a 1.1 kb 18S rRNA gene fragment of EHP was amplified, and this sequence showed a 100% identity to EHP found in Thailand and China. This fragment was cloned and labeled with digoxigenin-11-dUTP, and in situ hybridized to tissue sections of infected Penaeus vannamei (from Vietnam) and P. stylirostris (Brunei). The results of in situ hybridization were specific, the probe only reacted to the EHP within the cytoplasmic inclusions, not to a Pleistophora-like microsporidium that is associated with cotton shrimp disease. Subsequently, we developed a PCR assay from this 18S rRNA gene region, this PCR is shown to be specific to EHP, did not react to 2 other parasitic pathogens, an amoeba and the cotton shrimp disease microsporidium, nor to genomic DNA of various crustaceans including polychaetes, squids, crabs and krill. EHP was detected, through PCR, in hepatopancreatic tissue, feces and water sampled from infected shrimp tanks, and in some samples of Artemia biomass. Copyright © 2015. Published by Elsevier Inc.
    Full-text · Article · Jul 2015 · Journal of Invertebrate Pathology
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    ABSTRACT: A quantitative polymerase chain reaction (qPCR) assay was developed, based on a TaqMan probe, to detect and quantify a virulence plasmid harbored by the bacterium Vibrio parahaemolyticus which can cause acute hepatopancreatic necrosis disease (AHPND). The assay uses a pair of PCR primers, which amplify a 135-bp DNA fragment, and a TaqMan probe selected from the plasmid pirA-like gene. This qPCR assay reacted with AHPND-pathogenic isolates of V. parahaemolyticus collected from Vietnam and Mexico, but not with non-pathogenic strains of Vibrio spp. For quantification, a plasmid (pVpPirA-1) containing the target pirA-like gene was constructed, purified and serially diluted to be used as a standard. With this standard, the qPCR assay was then used to quantify the virulence plasmid in shrimp samples collected from different farms. Up to 5.8 × 105 copy per mg tissue were detected in AHPND-affected shrimp collected from Vietnam. Lower quantities, up to 1.5 × 104 copies per mg of tissues were detected in affected shrimp collected from a Chinese farm. In the laboratory bioassays, similar plasmid quantities, 1.8 × 103 to 4.7 × 106 copies of plasmid per mg of tissues were found in the moribund/dead shrimp, 3.5 × 102 to 2.2 × 106 copies of plasmid per mL were detected in the water samples. This assay is specific with high sensitivity (10 copies of virulence plasmid) and can be used to detect AHPND-pathogenic V. parahaemolyticus in shrimp and water samples.
    Full-text · Article · May 2015 · Aquaculture
  • Sidrotun Naim · Kathy F-J Tang · May Yang · Donald V Lightner · Max L Nibert
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    ABSTRACT: New sequencing studies of the nonsegmented dsRNA genome of penaeid shrimp infectious myonecrosis virus (IMNV), a tentatively assigned member of the family Totiviridae, identified previously unread sequences at both genome termini in three previously analyzed IMNV strains, one from Brazil (the prototype strain of IMNV) and two from Indonesia. The new sequence determinations add >600 nt to the 5' end of the genomic plus strand of each strain, increasing the length of the 5' nontranslated region to at least 469-472 nt and the length of the upstream open reading frame (ORF1) translation product by at least 48 aa. These new findings are similar to recent ones for two other IMNV strains (GenBank KF836757.1 and KJ556923.1) and thereby corroborate important amendments to the full-length IMNV genome sequence.
    No preview · Article · Apr 2015 · Archives of Virology
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    Jee Eun Han · Kathy F J Tang · Loc H Tran · Donald V Lightner
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    ABSTRACT: The 69 kb plasmid pVPA3-1 was identified in Vibrio parahaemolyticus strain 13‑028/A3 that can cause acute hepatopancreatic necrosis disease (AHPND). This disease is responsible for mass mortalities in farmed penaeid shrimp and is referred to as early mortality syndrome (EMS). The plasmid has a GC content of 45.9% with a copy number of 37 per bacterial cell as determined by comparative quantitative PCR analyses. It consists of 92 open reading frames that encode mobilization proteins, replication enzymes, transposases, virulence-associated proteins, and proteins similar to Photorhabdus insect-related (Pir) toxins. In V. parahaemolyticus, these Pir toxin-like proteins are encoded by 2 genes (pirA- and pirB-like) located within a 3.5 kb fragment flanked with inverted repeats of a transposase-coding sequence (1 kb). The GC content of these 2 genes is only 38.2%, substantially lower than that of the rest of the plasmid, which suggests that these genes were recently acquired. Based on a proteomic analysis, the pirA-like (336 bp) and pirB-like (1317 bp) genes encode for 13 and 50 kDa proteins, respectively. In laboratory cultures of V. parahaemolyticus 13-028/A3, both proteins were secreted into the culture medium. We developed a duplex PCR diagnostic method, with a detection limit of 105 CFU ml-1 and targeting pirA- and pirB-like genes in this strain of V. parahaemolyticus. This PCR protocol can reliably detect AHPND-causing strains of V. parahaemolyticus and does not cross react with non-pathogenic strains or with other species of Vibrio isolated from shrimp ponds.
    Full-text · Article · Feb 2015 · Diseases of Aquatic Organisms
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    Kathy F. J. Tang · Donald V. Lightner
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    ABSTRACT: Three insecticidal toxin complex (tc)-like genes were identified in Vibrio parahaemolyticus 13-028/A3, which can cause acute hepatopancreatic necrosis disease in penaeid shrimp. The three genes are: a tcdA-like gene (7710-bp), predicted to code for a 284 kDa protein; a tcdB-like gene (4272-bp), predicted to code for a 158 kDa protein; and a tccC3-like gene (2916-bp), predicted to encode a 107 kDa protein. All 3 predicted proteins contain conserved domains that are characteristic of their respective Tcs proteins. By RT-PCR, all 3 tc-like genes were found to be expressed in this bacterium. Through genome walking and the use of PCR to join contigs surrounding these 3 genes, a genomic island (87,712-bp, named tc-GIvp) was found on chromosome II localized next to the tRNA-gly. The GC content of this island, which is not found in other Vibrio species, is 40%. The tc-GIvp is characterized to have 60 ORFs encoding regulatory or virulence factors. These include: a type 6 secretion protein VgrG, EAL domain-containing proteins, fimbriae subunits and assembly proteins, invasin-like proteins, peptidoglycan-binding proteins and Tcs proteins. The tc-GIvp also contains 21 transposase genes, suggesting that it was acquired through horizontal transfer from other organisms.This article is protected by copyright. All rights reserved.
    Full-text · Article · Oct 2014 · FEMS Microbiology Letters
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    ABSTRACT: Acute hepatopancreatic necrosis disease (AHPND), which has also been referred to as early mortality syndrome (EMS), initially emerged as a destructive disease of cultured shrimp species in Asia in 2009. The pathogen associated with the disease, Vibrio parahaemolyticus, subsequently spread to the Western Hemisphere and emerged in Mexico in early 2013. The spread to the Western Hemisphere is a major concern to shrimp producers in the region. To date, the only peer-reviewed published method for determining whether mortalities are due to AHPND is through histological examination. A novel PCR detection method was employed to assess samples from Mexico in order to confirm the presence of the pathogen in this country. This manuscript details the detection methods used to confirm the presence of AHPND in Mexico. Both immersion and per os challenge studies were used to expose the Penaeus vannamei to the bacteria in order to induce the disease. Histological analysis confirmed AHPND status following the challenge studies. Also provided are the details of the molecular test by PCR that was used for screening candidate V. parahaemolyticus isolates. A rapid PCR assay for detection of AHPND may help with early detection and help prevent the spread of AHPND to other countries.
    Full-text · Article · Aug 2014 · Diseases of Aquatic Organisms
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    ABSTRACT: Timely pond-side detection of white spot syndrome virus (WSSV) plays a critical role in the implementation of bio-security measures to help minimize economic losses caused by white spot syndrome disease, an important threat to shrimp aquaculture industry worldwide. A portable device, namely POCKIT™, became available recently to complete fluorescent probe-based insulated isothermal PCR (iiPCR), and automatic data detection and interpretation within one hour. Taking advantage of this platform, the IQ Plus™ WSSV Kit with POCKIT system was established to allow simple and easy WSSV detection for on-site users. The assay was first evaluated for its analytical sensitivity and specificity performance. The 95% limit of detection (LOD) of the assay was 17 copies of WSSV genomic DNA per reaction (95% confidence interval [CI], 13 to 24 copies per reaction). The established assay has detection sensitivity similar to that of OIE-registered IQ2000™ WSSV Detection and Protection System with serial dilutions of WSSV-positive Litopenaeus vannamei DNA. No cross-reaction signals were generated from infectious hypodermal and haematopoietic necrosis virus (IHHNV), monodon baculovirus (MBV), and hepatopancreatic parvovirus (HPV) positive samples. Accuracy analysis using700 L. vannamei of known WSSV infection status shows that the established assayhassensitivity93.5% (95% CI: 90.61-95.56%) and specificity 97% (95% CI: 94.31-98.50%). Furthermore, no discrepancy was found between the two assays when 100 random L. vannamei samples were tested in parallel. Finally, excellent correlation was observed among test results of three batches of reagents with 64 samples analyzed in three different laboratories. Working in a portable device, IQ Plus™ WSSV Kit with POCKIT system allows reliable, sensitive and specific on-site detection of WSSV in L. vannamei.
    Full-text · Article · Mar 2014 · PLoS ONE
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    Kathy F J Tang · Marc Le Groumellec · Donald V Lightner
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    ABSTRACT: White spot syndrome virus (WSSV) is highly pathogenic to penaeid shrimp and has caused significant economic losses in the aquaculture industry around the world. During 2010 to 2012, WSSV caused severe mortalities in cultured penaeid shrimp in Saudi Arabia, Mozambique and Madagascar. To investigate the origins of these WSSV, we performed genotyping analyses at 5 loci: the 3 open reading frames (ORFs) 125, 94 and 75, each containing a variable number of tandem repeats (VNTR), and deletions in the 2 variable regions, VR14/15 and VR23/24. We categorized the WSSV genotype as {N125, N94, N75, ΔX14/15, ΔX23/24} where N is the number of repeat units in a specific ORF and ΔX is the length (base pair) of deletion within the variable region. We detected 4 WSSV genotypes, which were characterized by a full-length deletion in ORF94/95, a relatively small ORF75 and one specific deletion length in each variable region. There are 2 closely related genotypes in these 3 countries: {6125, del94, 375, Δ595014/15, Δ1097123/24} and {7125, del94, 375, Δ595014/15, Δ1097123/24}, where del is the full-length ORF deletion. In Saudi Arabia, 2 other related types of WSSV were also found: {6125, 794, 375, Δ595014/15, Δ1097123/24} and {8125, 1394, 375, Δ595014/15, Δ1097123/24}. The identical patterns of 3 loci in these 4 types indicate that they have a common lineage, and this suggests that the WSSV epidemics in these 3 countries were from a common source, possibly the environment.
    Full-text · Article · Sep 2013 · Diseases of Aquatic Organisms
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    ABSTRACT: A new emerging disease in shrimp, first reported in 2009, was initially named early mortality syndrome (EMS). In 2011, a more descriptive name for the acute phase of the disease was proposed as acute hepatopancreatic necrosis syndrome (AHPNS). Affecting both Pacific white shrimp Penaeus vannamei and black tiger shrimp P. monodon, the disease has caused significant losses in Southeast Asian shrimp farms. AHPNS was first classified as idiopathic because no specific causative agent had been identified. However, in early 2013, the Aquaculture Pathology Laboratory at the University of Arizona was able to isolate the causative agent of AHPNS in pure culture. Immersion challenge tests were employed for infectivity studies, which induced 100% mortality with typical AHPNS pathology to experimental shrimp exposed to the pathogenic agent. Subsequent histological analyses showed that AHPNS lesions were experimentally induced in the laboratory and were identical to those found in AHPNS-infected shrimp samples collected from the endemic areas. Bacterial isolation from the experimentally infected shrimp enabled recovery of the same bacterial colony type found in field samples. In 3 separate immersion tests, using the recovered isolate from the AHPNS-positive shrimp, the same AHPNS pathology was reproduced in experimental shrimp with consistent results. Hence, AHPNS has a bacterial etiology and Koch's Postulates have been satisfied in laboratory challenge studies with the isolate, which has been identified as a member of the Vibrio harveyi clade, most closely related to V. parahemolyticus.
    Full-text · Article · Jul 2013 · Diseases of Aquatic Organisms
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    Kathy F.J. Tang · Carlos R Pantoja · Rita M Redman · Donald V Lightner
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    ABSTRACT: White spot syndrome virus (WSSV) is highly pathogenic to penaeid shrimp. The major targets of WSSV infection are tissues of ectodermal and mesodermal embryonic origin, predominantly the cuticular epithelium and subcuticular connective tissues. Recently, we discovered a WSSV variant in Penaeus indicus that heavily infects the subcuticular connective tissue, with very slight indications in the cuticular epithelium. The variant was also unusual in that WSSV accumulations were found in the interstitial spaces of both the subcuticular connective tissue and the lymphoid organ. This WSSV variant was confirmed through immunohistochemistry with an anti-WSSV VP28 monoclonal antibody, and also by in situ hybridization with a VP28 DNA probe. By in situ hybridization, shrimp with variant and typical histology were shown a deletion in ORF94, which is characteristic of a new type of WSSV found in Saudi Arabia; apparently, the loss of this ORF is not associated with the variant's reduced capability of infecting the cuticular epithelium cells.
    Full-text · Article · Feb 2013 · Journal of Invertebrate Pathology
  • D.V. Lightner · R.M. Redman
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    ABSTRACT: According to the FAO, global production of marine penaeid shrimp from farms reached nearly 3.5 million tonnes in 2009, accounting for nearly half of the world's total shrimp supply. With most of the world's shrimp fisheries at maximum sustainable yield, the ratio of farmed to fished shrimp appears likely to continue to increase. This production is from a very young food producing industry that began to emerge in the mid-1970s. The remarkable growth of sustainable shrimp farming has been accomplished in part through the successful development of domesticated shrimp stocks, many of which are free of specific diseases, and the development of the necessary infrastructure, in terms of biosecurity, diagnostic methods and trained personnel, to successfully prevent disease or to manage disease outbreaks when they occur.
    No preview · Chapter · Dec 2012
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    ABSTRACT: The bacteria that cause necrotizing hepatopancreatitis in Penaeus vannamei adversely affect penaeid shrimp cultured in the western hemisphere. 16S rRNA and gyrase B gene analyses determined the taxonomic position of these bacteria. The name “Candidatus Hepatobacter penaei” is proposed for these pathogenic bacteria, which are members of the Rickettsiales order.
    Full-text · Article · Dec 2012 · Applied and Environmental Microbiology
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    ABSTRACT: Three Litopenaeus vannamei families, from a breeding program in Panama and with possible WSSV resistance, were challenged per os with a reference isolate of White spot syndrome virus originally obtained from China in 1995 (WSSV-CN95). These F8, F9 and F12 generation families were developed from founder stocks a decade ago and were survivors of white spot disease. Juvenile shrimp used for WSSV challenge averaged 1.5 g, and they were stocked at 50 to 96 animals per tank into nine 1000 L fiberglass tanks containing artificial seawater at 30 ppt salinity and 26 °C. Three of the 1000 L tanks were used as negative control tanks, with one tank for each family. Six 1000 L tanks were used for challenging the three families with WSSV, with two replicate tanks for each family. A positive control consisting of 20 “Kona” SPF reference line L. vannamei (average weight 1.5 g) was included and challenged with WSSV in a 90 L glass aquarium. The Kona stock was fed the same batch of WSSV infected tissue as the three Panamanian families to confirm infectivity and to provide a basis with which to compare final survival. WSSV infected minced frozen shrimp tissue was fed at a rate of 5% of average body weight one time on day 0. All tanks were equipped with air diffusers to provide sufficient aeration and an acclimated crushed oyster shell internal recirculating biological filter. Each tank was covered with a plastic sheet to contain aerosols and minimize water temperature fluctuations. The experimental tanks were checked daily and moribund animals were collected when observed and preserved in Davidson's AFA fixative. Mortalities in the three Panamian families ceased at 17 days post challenge. Two survivors from each tank were preserved for histology and five shrimp per tank were individually tested by qPCR to determine their WSSV status and viral load. Survival at termination in the negative control families was 95%, 98% and 100%. Survival in the Kona line WSSV positive control was 0% with all the Kona line shrimp dead by day 6 post infection. At termination on day 17, survival of Panamanian selected families in the WSSV challenged groups was 23%, 57% and 26% for families LP-1, LP-2 and LP-3, respectively. This is the first time in the scientific literature that significant resistance of L. vannamei against WSSV under controlled conditions is reported.
    Full-text · Article · Nov 2012 · Aquaculture
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    ABSTRACT: Prior to 2004, Colombian shrimp farming benefited from a selection program in which Penaeus vannamei stocks were developed with resistance to Taura syndrome disease (TS). However since 2004, TS reappeared as a significant disease. In 2010, an apparently new strain of TSV (designated as CO 10) was collected in Colombia. Its genome was sequenced and compared with six other fully sequenced isolates. This analysis revealed that the TSV CO 10 is closely related to the isolates from Hawaii and Venezuela. Phylogenetic analysis based on capsid protein 2 (CP2) region from 59 TSV isolates shows that the recent Colombian isolates (2006-2010) form a new cluster and differ from the previous Colombia isolates (1994-1998) by 4% in nucleotide sequence. The virulence of this CO 10 isolate was similar to a Belize TSV determined through experimental infection in P. vannamei showing 100% mortalities and similar survival curves. By RT-qPCR for TSV, the viral loads were also close in the infected shrimp from both CO 10 and Belize at the order of 1×10(10)copies per μl RNA. To develop TSV-resistant lines, the candidate shrimp should be challenged with virus strains that have been isolated most recently from the regions where they will be cultured. This study suggests that the TSV present in Colombian shrimp farms during the last 5years is a new TSV strain with high virulence.
    Full-text · Article · Sep 2012 · Journal of Invertebrate Pathology
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    ABSTRACT: White spot syndrome virus (WSSV) and Taura syndrome virus (TSV) are highly pathogenic to penaeid shrimp and have caused significant economic losses in the shrimp culture industry around the world. During 2010 and 2011, both WSSV and TSV were found in Saudi Arabia, where they caused severe mortalities in cultured Indian white shrimp Penaeus indicus. Most outbreaks of shrimp viruses in production facilities can be traced to the importation of infected stocks or commodity shrimp. In an attempt to determine the origins of these viral outbreaks in Saudi Arabia, we performed variable number of tandem repeat (VNTR) analyses for WSSV isolates and a phylogenetic analysis for TSV isolates. From the WSSV genome, the VNTR in open reading frames (ORFs) 125 and 94 were investigated with PCR followed by DNA sequence analysis. The genotypes were categorized as {N125, N94} where N is the number of repeat units in a specific ORF, and the subscript indicates the ORF (i.e. ORFs 125 and 94 in this case). From 15 Saudi Arabia WSSV isolates, we detected 3 genotypes: {6125, 794}, {7125, del94}, and {8125, 1394}. The WSSV genotype of {7125, del94} appears to be a new variant with a 1522 bp deletion encompassing complete coding regions of ORF 94 and ORF 95 and the first 82 bp of ORF 93. For TSV genotyping, we used a phylogenetic analysis based on the amino acid sequence of TSV capsid protein 2 (CP2). We analyzed 8 Saudi Arabian isolates in addition to 36 isolates from other areas: SE Asia, Mexico, Venezuela and Belize. The Saudi Arabian TSV clustered into a new, distinct group. Based on these genotyping analyses, new WSSV and TSV genotypes were found in Saudi Arabia. The data suggest that they have come from wild shrimp Penaeus indicus from the Red Sea that are used for broodstock.
    Full-text · Article · Jul 2012 · Diseases of Aquatic Organisms

Publication Stats

8k Citations
476.38 Total Impact Points

Institutions

  • 1977-2015
    • The University of Arizona
      • • Department of Veterinary Sciences and Microbiology
      • • Department of Pharmacology and Toxicology
      Tucson, Arizona, United States
  • 1973-1975
    • National Marine Fisheries Service
      Silver Spring, Maryland, United States