http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
Presentation 6: Vibrio parahaemolyticus: genome plasticity, mobile genetic el...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presentation 2.3 Heritability, cross-breeding and inbreeding effects on resis...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
Presentation 8: Vibrio parahaemolyticus: a versatile pathogen that can adapt ...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presentation 2.11 Specific pathogen-free (SPF), specific pathogen-resistant (...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
Presentation 18: Problems other than AHPND in EMS ponds, including the micros...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presentation 6: Vibrio parahaemolyticus: genome plasticity, mobile genetic el...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presentation 2.3 Heritability, cross-breeding and inbreeding effects on resis...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
Presentation 8: Vibrio parahaemolyticus: a versatile pathogen that can adapt ...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presentation 2.11 Specific pathogen-free (SPF), specific pathogen-resistant (...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
Presentation 18: Problems other than AHPND in EMS ponds, including the micros...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presentation 1.7 Transforming farm managers into the “family physicians” of t...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
"http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
Introduction to the Technical Seminar/Workshop and Highlights of the Panama W...FAO
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
Presentation 14: Progress in research on EMS/AHPND (Prof. Timothy W. Flegel, ...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presentation 20: Good aquaculture and biosecurity practices in shrimp farming...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presented by Etienne de Villiers at the African Swine Fever Diagnostics, Surveillance, Epidemiology and Control Workshop, Nairobi, Kenya, 20-21 July 2011
African Swine Fever (ASF) virus genomics and diagnosticsILRI
Presented by Richard Bishop and Cynthia Onzere at the Closing workshop of the BecA‐ILRI‐CSIRO‐AusAID project on Understanding ASF epidemiology as a basis for control, Nairobi, Kenya, 2‐3 October 2013
Presentation 2.4 Genomic analysis of the strains of AHPND-Vp (global) and gen...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
Recent advances in African swine fever vaccine development at the Internation...ILRI
Presentation by Lucilla Steinaa at a Global African Swine Fever Research Alliance (GARA)/International Alliance for Biological Standardization (IABS) webinar on current efforts in African swine fever vaccines, 6 May 2021
Background
Influenza A viruses are medically significant pathogens responsible for higher mortality and morbidity throughout the world. Swine influenza is known to be caused by influenza A subtypes H1N1, H1N2, and H3N2, which are highly contagious, and belongs to the family Orthomyxoviridae. Efficient and accurate diagnosis of influenza A in individuals is critical for monitoring of a constantly evolving pandemic. A rapid result is important, because timely treatment can reduce disease severity and duration. Rapid antigen tests were among the first-line diagnostic tools for the detection of pandemic H1N1 (2009) virus infection during the initial outbreak. Current study focuses on the significant approach of the usage of molecular method utilizing real-time PCR for the detection of type A influenza virus (H1N1 subtype) in humans.
Methods
A total of 2000 mixed nasal/throat swab specimens collected in commercial viral transport from Apollo hospitals, Hyderabad were submitted to Institute of Preventive Medicine for molecular testing by reverse transcriptase polymerase chain reaction (RT-PCR) from 2009 to 2015 from its affiliated primary care clinics.
Results
Among the 2000 samples collected, 700 samples were positive for Human Inf A, swine Inf A, and Swine Inf H1 (fourth table in the article). One thousand two hundred samples were negative for Human Inf A, swine Inf A, and Swine Inf H1, and 100 samples were positive for Influenza A only.
Conclusion
The molecular testing of H1N1 patients helped the clinicians in timely diagnosis and treatment of these patients during the pandemic surveillance. The RT-PCR test has higher sensitivity and specificity; hence it is considered to be the best tool to use during the pandemic surveillance, as compared to the any other commercial antigen-based tests, which show a variable performance, with the sensitivities of tests from different manufacturers ranging from 9 to 77%.
Presentation 19: Covert Mortality Nodavirus (CMNV): the pathogen, pathogenesi...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presentation 17 : Preliminary results on genetic resistance to AHPND andWSSV ...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presentation 1: FAO efforts on shrimp aquaculture health management including...FAO
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
AN OUTLINE ON HERPESVIRAL DISEASES IN MARINE TURTLESICAR-CIFE
Abstract: Marine turtles are calm, long-living reptiles with complicated lifestyle. They have their attendance all over the globe. The survival of turtles became so pathetic by various means of human development exercises. Now, on the other hand, emerging diseases came to the platform. Disease indications are alarming high in the coastal belts where human agitation is heavier. Herpesviridae family members are the top most pathogenic agents that are disturbing the survival of these long-living animals. They are a total of five herpesviruses that are associated with diseases in turtles; in them, Fibropapillomatosis is the catastrophic disease, which is characterized by tumors over smooth surfaces of the body. Disease had turned to be an upcoming invader for the maritime turtle’s community. The establishment and potential of this disease is under the hands of environmental factors. The longevity of marine turtles, coupled with their close association with inshore habitats and seagrass meadows and coral reefs in these habitats, has led to the proposal that they may act as sentinel indicators of marine ecosystem health.
Presentation 1.7 Transforming farm managers into the “family physicians” of t...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
"http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
Introduction to the Technical Seminar/Workshop and Highlights of the Panama W...FAO
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
Presentation 14: Progress in research on EMS/AHPND (Prof. Timothy W. Flegel, ...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presentation 20: Good aquaculture and biosecurity practices in shrimp farming...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presented by Etienne de Villiers at the African Swine Fever Diagnostics, Surveillance, Epidemiology and Control Workshop, Nairobi, Kenya, 20-21 July 2011
African Swine Fever (ASF) virus genomics and diagnosticsILRI
Presented by Richard Bishop and Cynthia Onzere at the Closing workshop of the BecA‐ILRI‐CSIRO‐AusAID project on Understanding ASF epidemiology as a basis for control, Nairobi, Kenya, 2‐3 October 2013
Presentation 2.4 Genomic analysis of the strains of AHPND-Vp (global) and gen...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
FAO Second International Technical Seminar/Workshop on Acute hepatopancreatic necrosis disease (AHPND) There is a way forward! FAO Technical Cooperation Programme: TCP/INT/3501 and TCP/INT/3502.
Recent advances in African swine fever vaccine development at the Internation...ILRI
Presentation by Lucilla Steinaa at a Global African Swine Fever Research Alliance (GARA)/International Alliance for Biological Standardization (IABS) webinar on current efforts in African swine fever vaccines, 6 May 2021
Background
Influenza A viruses are medically significant pathogens responsible for higher mortality and morbidity throughout the world. Swine influenza is known to be caused by influenza A subtypes H1N1, H1N2, and H3N2, which are highly contagious, and belongs to the family Orthomyxoviridae. Efficient and accurate diagnosis of influenza A in individuals is critical for monitoring of a constantly evolving pandemic. A rapid result is important, because timely treatment can reduce disease severity and duration. Rapid antigen tests were among the first-line diagnostic tools for the detection of pandemic H1N1 (2009) virus infection during the initial outbreak. Current study focuses on the significant approach of the usage of molecular method utilizing real-time PCR for the detection of type A influenza virus (H1N1 subtype) in humans.
Methods
A total of 2000 mixed nasal/throat swab specimens collected in commercial viral transport from Apollo hospitals, Hyderabad were submitted to Institute of Preventive Medicine for molecular testing by reverse transcriptase polymerase chain reaction (RT-PCR) from 2009 to 2015 from its affiliated primary care clinics.
Results
Among the 2000 samples collected, 700 samples were positive for Human Inf A, swine Inf A, and Swine Inf H1 (fourth table in the article). One thousand two hundred samples were negative for Human Inf A, swine Inf A, and Swine Inf H1, and 100 samples were positive for Influenza A only.
Conclusion
The molecular testing of H1N1 patients helped the clinicians in timely diagnosis and treatment of these patients during the pandemic surveillance. The RT-PCR test has higher sensitivity and specificity; hence it is considered to be the best tool to use during the pandemic surveillance, as compared to the any other commercial antigen-based tests, which show a variable performance, with the sensitivities of tests from different manufacturers ranging from 9 to 77%.
Presentation 19: Covert Mortality Nodavirus (CMNV): the pathogen, pathogenesi...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presentation 17 : Preliminary results on genetic resistance to AHPND andWSSV ...ExternalEvents
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Presentation 1: FAO efforts on shrimp aquaculture health management including...FAO
http://www.fao.org/documents/card/en/c/28b6bd62-5433-4fad-b5a1-8ac61eb671b1/
International Technical Seminar/Workshops on Acute hepatopancreatic necrosis disease (AHPND)
Similar to Presentation 2.5 Ecology, virulence factors and global spread of pathogenic Vibrio parahaemolyticus and related Vibrio spp. (Dr Iddya Karunasagar)
AN OUTLINE ON HERPESVIRAL DISEASES IN MARINE TURTLESICAR-CIFE
Abstract: Marine turtles are calm, long-living reptiles with complicated lifestyle. They have their attendance all over the globe. The survival of turtles became so pathetic by various means of human development exercises. Now, on the other hand, emerging diseases came to the platform. Disease indications are alarming high in the coastal belts where human agitation is heavier. Herpesviridae family members are the top most pathogenic agents that are disturbing the survival of these long-living animals. They are a total of five herpesviruses that are associated with diseases in turtles; in them, Fibropapillomatosis is the catastrophic disease, which is characterized by tumors over smooth surfaces of the body. Disease had turned to be an upcoming invader for the maritime turtle’s community. The establishment and potential of this disease is under the hands of environmental factors. The longevity of marine turtles, coupled with their close association with inshore habitats and seagrass meadows and coral reefs in these habitats, has led to the proposal that they may act as sentinel indicators of marine ecosystem health.
My presentation in the "CME on Sickle Cell Disease" at Government Medical College, Akola, Maharashtra, India on 19th December 2012 organized by MMC-CME Committee of GMC, Akola and the Department of Pediatrics, GMC, Akola.
Complete description of virus right from Introduction, description, Virus Classification, Epidemiology, Structure, Replication, Genetic variants, Distribution, Host range, Genomic organisation, Mode of Transmission, Mechanical vectors, Target organs, Disease cycle, Diagnosis, Control and Treatment methods
Similar to Presentation 2.5 Ecology, virulence factors and global spread of pathogenic Vibrio parahaemolyticus and related Vibrio spp. (Dr Iddya Karunasagar) (20)
Item 9: Soil mapping to support sustainable agricultureExternalEvents
SOIL ATLAS OF ASIA
2ND EDITORIAL BOARD MEETING
RURAL DEVELOPMENT ADMINISTRATION, NATIONAL INSTITUTE OF AGRICULTURAL SCIENCES,
JEONJU, REPUBLIC OF KOREA | 29 APRIL – 3 MAY 2019
Markus Anda (Indonesia)
Item 8: WRB, World Reference Base for Soil ResoucesExternalEvents
SOIL ATLAS OF ASIA
2ND EDITORIAL BOARD MEETING
RURAL DEVELOPMENT ADMINISTRATION, NATIONAL INSTITUTE OF AGRICULTURAL SCIENCES,
JEONJU, REPUBLIC OF KOREA | 29 APRIL – 3 MAY 2019
Satira Udomsri (Thailand)
SOIL ATLAS OF ASIA
2ND EDITORIAL BOARD MEETING
RURAL DEVELOPMENT ADMINISTRATION, NATIONAL INSTITUTE OF AGRICULTURAL SCIENCES,
JEONJU, REPUBLIC OF KOREA | 29 APRIL – 3 MAY 2019
Shree Prasad Vista (Nepal)
Item 6: International Center for Biosaline AgricultureExternalEvents
SOIL ATLAS OF ASIA
2ND EDITORIAL BOARD MEETING
RURAL DEVELOPMENT ADMINISTRATION, NATIONAL INSTITUTE OF AGRICULTURAL SCIENCES,
JEONJU, REPUBLIC OF KOREA | 29 APRIL – 3 MAY 2019
Students, digital devices and success - Andreas Schleicher - 27 May 2024..pptxEduSkills OECD
Andreas Schleicher presents at the OECD webinar ‘Digital devices in schools: detrimental distraction or secret to success?’ on 27 May 2024. The presentation was based on findings from PISA 2022 results and the webinar helped launch the PISA in Focus ‘Managing screen time: How to protect and equip students against distraction’ https://www.oecd-ilibrary.org/education/managing-screen-time_7c225af4-en and the OECD Education Policy Perspective ‘Students, digital devices and success’ can be found here - https://oe.cd/il/5yV
How to Split Bills in the Odoo 17 POS ModuleCeline George
Bills have a main role in point of sale procedure. It will help to track sales, handling payments and giving receipts to customers. Bill splitting also has an important role in POS. For example, If some friends come together for dinner and if they want to divide the bill then it is possible by POS bill splitting. This slide will show how to split bills in odoo 17 POS.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Ethnobotany and Ethnopharmacology:
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Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
This is a presentation by Dada Robert in a Your Skill Boost masterclass organised by the Excellence Foundation for South Sudan (EFSS) on Saturday, the 25th and Sunday, the 26th of May 2024.
He discussed the concept of quality improvement, emphasizing its applicability to various aspects of life, including personal, project, and program improvements. He defined quality as doing the right thing at the right time in the right way to achieve the best possible results and discussed the concept of the "gap" between what we know and what we do, and how this gap represents the areas we need to improve. He explained the scientific approach to quality improvement, which involves systematic performance analysis, testing and learning, and implementing change ideas. He also highlighted the importance of client focus and a team approach to quality improvement.
How to Create Map Views in the Odoo 17 ERPCeline George
The map views are useful for providing a geographical representation of data. They allow users to visualize and analyze the data in a more intuitive manner.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
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How libraries can support authors with open access requirements for UKRI fund...
Presentation 2.5 Ecology, virulence factors and global spread of pathogenic Vibrio parahaemolyticus and related Vibrio spp. (Dr Iddya Karunasagar)
1. ECOLOGY, VIRULENCE FACTORS
AND GLOBAL SPREAD OF
PATHOGENIC VIBRIO
PARAHAEMOLYTICUS AND
RELATED VIBRIO SPP
Iddya Karunasagar
Iddya.Karunasagar@gmail.com
2. Virulence factors of AHPND causing strains
• A 69kbp plasmid (pVA1, pVPA3-1) found in V. parahaemolyticus
causing AHPND (Lee et al., 2015; Han et al., 2015).
• Two proteins with 33% identity to PirA and PirB toxins shown to be
essential to cause characteristic pathology.
• Five transposase genes were found on this plasmid
• The plasmid has a cluster of genes involved in conjugal transfer of
plasmid
3. Virulence factors of AHPND causing strains
• On plasmid pVPA3-1, the two Pir genes are located within a 3.5 kb-
long insertion element (IS) flanked with inverted repeats.
• these inverted repeats are from an insertion element of IS903 family.
Mobile/transposable elements (TEs) such as IS5 family are involved in
the spread of pathogenicity via horizontal gene transfer (HGT).
4. Virulence factors of AHPND causing strains may be present in
other Vibrio spp.
• These suggest potential for mobility of plasmid and gene clusters within the
plasmid.
• Strain 13.17.5 isolated from AHPND affected shrimp in Vietnam carried virulence
plasmid. This strain has been sequenced and based on 16S rRNA sequence, has
been identified as V. harveyi (Kondo et al., 2015).
• V. owensii strain SH14 isolated from AHPND affected shrimp in China carried the
69kb plasmid with virulence genes (Liu et al., 2015).
• Hepatopancreatitis reported from Australia did not meet the case definition of
AHPND. Member of V. harveyi clade carrying PirAB genes, but not other plasmid
markers has been isolated.
• Can virulence gene cluster integrate into chromosome?
5. Genetic diversity of AHPND causing strains
• Multi locus sequence typing (MLST) of AHPND strains from Thailand show that
they are genetically diverse (Chonsin et al., 2016)
• Loss of virulence gene in plasmid carrying strains reported (Lee et al., 2015).
• V. harveyi clade lacking plasmid markers, but positive for PirAB toxin genes
reported from Australia.
6. Are the toxin genes found in AHPND causing V.
parahaemolyticus new to marine environment?
• The binary toxin gene of AHPND V. parahaemolyticus has 33% identity with
PirAB gene
• These toxins have 40% -44% identity to two hypothetical proteins of
Shewanella violacea!
• Shiwanella violacea was isolated from marine trench at a depth of 5110m.
It is an obligate psychrotroph.
• Thus the toxin genes may not be new to aquatic and marine environment.
• These PirAB genes have a G+C content of 38.2%, substantially lower than
45.9% in the plasmid. This suggests that this gene cluster is recently
acquired by the plasmid (Han et al., 2015).
7.
8. AHPND virulence plasmid
• The pVA1 plasmid also carries the pndA gene, which is associated with a post-
segregational killing (psk) system.
• With a bacterium that harbours a plasmid with the psk system (PSK+), only
progeny that inherit the PSK+ plasmid will be viable.
• Progeny that do not inherit the PSK+ plasmid will die because the stable pndA
mRNA will be translated to PndA toxin that will kill the bacterium.
• The presence of a psk system on a plasmid thus ensures that the plasmid is
inherited during bacterial replication.
• The pVA1 plasmid will therefore be passed on to subsequent generations of VP-
AHPND producing PirAB toxin.
9. Is the Mexican AHPND strain different from Asian strain?
• Clear genetic variation exists between Asian and Latin American strains
(Han et al., 2015).
• A 4243bp TN3 like transposon element found in Mexican and Central
American strains, but not in strains from Vietnam, Thailand and China.
• The number of 9bp small sequence repeats (SSR) found within the coding
region of a hypothetical protein vary in Asian and Latin American strains.
• SSR with 6 repeats found in Mexican strains, 5 repeats in Vietnamese
strains and 4 repeats in China, Thailand and Vietnamese strains.
• PCR based on SSRs could differentiate Mexican type and SE Asian type
strains.
11. V. parahaemolyticus – occurrence and distribution
• Estuarine and coastal environments
• Global occurrence
• Associated with all types of animals in brackish water environments –
zooplankton, molluscs, crustaceans, shellfish and finfish
• Ecology influenced by temperature and salinity.
• In tropical environments, detected throughout the year, provided salinity and
other conditions are available.
• In temperate climate, detected mostly in summer. The organism undergoes
overwintering in sediments.
12. V. parahaemolyticus – occurrence and distribution
• During the 1990’s, the organism was considered mainly tropical.
• In international fish trade, there were even rejections due to the mere presence
of the organism (though most environmental organisms are non-pathogenic to
humans)
• An outbreak of V. parahaemolyticus gastroenteritis in Alaska in 2004 from locally
grown oysters changed the thinking on the distribution of this organism.
• Alaska is 1000KM north of places from where any previous V. parahaemolyticus
illness was reported.
• In 2004, temperatures in Alaska were higher that 15°C.
14. Metabolic versatality of Vibrio spp
• Capable of both oxidative and fermentative metabolism.
• Quick reproduction (15-20 min), high content of tRNA genes (126 in V.
parahaemolyticus) compared to bacteria in general (around 50 genes).
• tRNA genes also hotspots for insertion of novel DNA and gene acquisition.
• Presence of two chromosomes, larger chromosome carries most essential genes
and the smaller chromosome carries species specific genes.
• Quorum sensing adaptive mechanism to stress such as low nutrient, exposure to
UV, predation, salinity fluctuation. In V. parahaemolyticus, the regulatory protein
is LuxO.
15. Metabolic versatality of Vibrio spp
• Ability to form biofilms for survival in different environments. Syp gene cluster in
V. parahaemolyticus.
• Survival of acid stress mediated by proteins encoded by cadBAC and heat stress
mediated by GroEL heat shock protein.
• Production of proteins to enable the organism to tolerate cold stress, osmotic
stress.
• Ability to bind to and degrade chitin.
16. Interaction between V. parahaemolyticus and molluscs and
crustacea
• When temperatures are favourable, V. parahaemolyticus can grow in American
oysters Crassostrea virginica.
• No growth is observed in Sydney rock oysters stored at 30°C for seven days.
• Studies done in Mangalore, India indicate presence of V. parahaemolyticus in
oysters at levels ranging from 102 to 104 per gram throughout the year.
• Can be detected in shrimp farms in India throughout the year accounting for 3-
10% of the flora (Gopal et al., 2005)
17. Interaction between V. parahaemolyticus and plankton
• V. parahaemolyticus can adhere to and degrade chitin and adsorption of the
organism to chitin or plankton occurs with higher efficiency under conditions of
low estuarine salinity.
• Adherence to chitin could explain the relation between abundance of
zooplankton and presence of this organism.
• In a study in Galacia, Spain (Martinez-Urtaza et al., 2011), 80% of V.
parahaemolyticus biomass was associated with zooplankton. The presence of
cnidarians accounted for 52% of variation in abundance, though they constituted
only 2% of zooplankton.
• Chlorophyll-A may influence the ecology of the organism by influencing the
population of zooplankton.
• In finfish, higher prevalence is observed in the gut compared to gills and surface.
18. Role of plankton in oceanic spread of V. parahaemolyticus
• Aquatic birds may be carriers of V. parahaemolyticus. Studies in Japan and other
countries show the presence of this organism in feces of aquatic birds, though the
concentrations could be low.
• Studies done in Galecia, Spain indicate that V. parahaemolyticus is found even in
off-shore areas in association with zooplankton.
• Genetically similar organisms were found in zooplankton in estuaries and off-
shore regions spread over 1500 KM suggesting a role for zooplankton in the
spread of this organism.
20. Global spread of pathogenic strains
• Ballast water?
• Seafood transport?
• Some insights into the global spread of V. parahaemolyticus has been provided by
studies performed on the strains that caused outbreaks of infection in Chile in
2004.
• The pandemic strain belonging to O3:K6 serovar arrived in Peru in 1997 and
infections were reported in northern part of the country, but spread southward
along more than 1500 KM of the coast till it reached the Chilean city of
Antofagasta.
21. Global spread of pathogenic strains
• Molecular studies of the strains suggest that the 1997 El Nino episode provided
the corridor for the displacement of the Asian pandemic V. parahaemolyticus
strains to America.
• The El Nino phenomenon is characterized by the arrival of equatorial warm
waters in a sequence of waves. In 1997, El Nino affected South American coast for
about 6 months.
• It has been suggested that recurrent invasion of tropical masses of water might
have resulted in repetitive sources of V. parahaemolyticus populations that would
have established there.
22.
23.
24.
25. Molecular genetic studies show the sequence types that have spread with the El Nino
event
Gonzales-Escalona et al., 2015
26. Outbreak of V. parahaemolyticus infection in Spain involving
strains previously associated with outbreaks in US
• Martinez-Urtaza et al. (2016), investigated strains of V. parahaemolyticus involved
in an outbreak that affected 100 of 114 passengers travelling in a food banquet
cruise in Galacia, Spain in 2012.
• Strains were positive for both tdh and trh genes (usually they are positive for one
of them) and were never detected in Europe before.
• Molecular typing using PFGE, MLST showed that the strains are highly related to
those associated with human cases in Pacific North West of United States.
• This supports theory of oceanic spread, though the route of spread has not yet
been established.
27. Questions with respect of AHPND causing strains
• Ecology and distribution, association with aquatic animals, zooplankton.
• The environmental source of the plasmid found in these strains.
• Can the plasmid be integrated into chromosome? What are the implications for
virulence?
• Can the plasmid be transferred to human pathogenic strains of V.
parahaemolyticus?
• Did the Mexican strain originate in Mexico or is it derived from Asian strains?
• Are other Vibrio spp carrying the virulence plasmid equally virulent?
28. Is the Mexican AHPND strain different from Asian strain?
• Clear genetic variation exists between Asian and Latin American strains (Han et
al., 2015).
• A 4243bp TN3 like transposon element found in Mexican and Central American
strains, but not in strains from Vietnam, Thailand and China.
• The number of 9bp small sequence repeats (SSR) found within the coding region
of a hypothetical protein vary in Asian and Latin American strains.
• SSR with 6 repeats found in Mexican strains, 5 repeats in Vietnamese strains and
4 repeats in China, Thailand and Vietnamese strains.
• PCR based on SSRs could differentiate Mexican type and SE Asian type strains.
6/25/2016
International Technical Seminar/Workshop “EMS/AHPND:
Government, Scientist and Farmer Responses”
28
29. Summary
• Virulence genes associated with AHPND V. parahaemolyticus may be found in
other Vibrio spp such as V. harveyi and V. owensii.
• Genetically diverse strains of Vibro spp may carry the virulence plasmid.
• Vibrio parahaemolyticus is a very versatile organism adapting to a number of
environments.
• The organism is capable of acquiring gene clusters to adapt to different hosts.
• Association of the organism with zooplakton facilitates its global spread through
ocean currents like El Nino phenomenon.
• It is also possible that Latin American strains emerged independent of Asian
strains.