scholarly journals Phytophthora ramorum Colonizes Tanoak Xylem and Is Associated with Reduced Stem Water Transport

2007 ◽  
Vol 97 (12) ◽  
pp. 1558-1567 ◽  
Author(s):  
J. L. Parke ◽  
E. Oh ◽  
S. Voelker ◽  
E. M. Hansen ◽  
G. Buckles ◽  
...  
Keyword(s):  
Specific Conductivity ◽  
Vessel Diameter ◽  
Phytophthora Ramorum ◽  
Heat Diffusion ◽  
Sap Flux ◽  
Tissue Samples ◽  
Lithocarpus Densiflorus ◽  
Polymerase Chain ◽  
Stem Water ◽  
Radial Spread

Isolation, detection with diagnostic polymerase chain reaction (PCR), and microscopy demonstrated the presence of Phytophthora ramorum in the sapwood of mature, naturally infected tanoak (Lithocarpus densiflorus) trees. The pathogen was strongly associated with discolored sapwood (P < 0.001), and was recovered or detected from 83% of discolored sapwood tissue samples. Hyphae were abundant in the xylem vessels, ray parenchyma, and fiber tracheids. Chlamydospores were observed in the vessels. Studies of log inoculation indicated that P. ramorum readily colonized sapwood from inoculum placed in the bark, cambium, or sapwood. After 8 weeks, radial spread of P. ramorum in sapwood averaged 3.0 to 3.3 cm and axial spread averaged 12.4 to 18.8 cm. A field study was conducted to determine if trees with infected xylem had reduced sap flux and reduced specific conductivity relative to noninfected control trees. Sap flux was monitored with heat-diffusion sensors and tissue samples near the sensors were subsequently tested for P. ramorum. Adjacent wood sections were excised and specific conductivity measured. Both midday sap flux and specific conductivity were significantly reduced in infected trees versus noninfected control trees. Vessel diameter distributions did not differ significantly among the two treatments, but tyloses were more abundant in infected than in noninfected trees. Implications for pathogenesis, symptomology, and epidemiology are discussed.

The effects of Phytophthora ramorum infection on hydraulic conductivity and tylosis formation in tanoak sapwood

2009 ◽  
Vol 39 (9) ◽  
pp. 1766-1776 ◽  
Author(s):  
Bradley R. Collins ◽  
Jennifer L. Parke ◽  
Barb Lachenbruch ◽  
Everett M. Hansen
Keyword(s):  
Hydraulic Conductivity ◽  
Water Transport ◽  
Specific Conductivity ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Inoculation Site ◽  
Lithocarpus Densiflorus ◽  
Stem Water ◽  
Spread Of Infection ◽  
Flow Over Time

Tanoak ( Lithocarpus densiflorus (Hook. and Arn.) Rehder) is highly susceptible to sudden oak death, a disease caused by the oomycete Phytophthora ramorum Werres, De Cock & Man in’t Veld. Symptoms include a dying crown, bleeding cankers, and, eventually, death of infected trees. The cause of mortality is not well understood, but recent research indicates that water transport is reduced in infected trees. One possible mechanism causing the reduction in hydraulic conductivity is the presence of tyloses in xylem vessels. The development of tyloses was studied in relation to hydraulic conductivity in P. ramorum-infected sapwood. Inoculated logs showed a greater abundance of tyloses than noninoculated logs after 4 weeks. Inoculated trees with xylem infections had significantly more tyloses than noninoculated trees. In addition, the increase in number of tyloses was associated with a decrease in specific conductivity, suggesting that tyloses induced by infection with P. ramorum may interfere with stem sap flow. Over time, tylosis development increased in tissues farther from the inoculation site, in advance of the vertical spread of infection. The results suggest that infected sapwood contains numerous tyloses, which could significantly impede stem water transport.

scholarly journals Stream Monitoring for Detection of Phytophthora ramorum in Oregon Tanoak Forests

Plant Disease ◽  
2009 ◽  
Vol 93 (11) ◽  
pp. 1182-1186 ◽  
Author(s):  
W. Sutton ◽  
E. M. Hansen ◽  
P. W. Reeser ◽  
A. Kanaskie
Keyword(s):  
Host Plants ◽  
Selective Medium ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Chain Reaction ◽  
Stream Monitoring ◽  
Lithocarpus Densiflorus ◽  
Bait Station ◽  
Mesh Bags ◽  
Polymerase Chain

Stream monitoring using leaf baits for early detection of Phytophthora ramorum has been an important part of the Oregon Sudden Oak Death (SOD) program since 2002. Sixty-four streams in and near the Oregon quarantine area in the southwest corner of the state were monitored in 2008. Leaves of rhododendron (Rhododendron macrophyllum) and tanoak (Lithocarpus densiflorus) were placed in mesh bags, and bags were floated in streams. Leaf baits were exchanged every 2 weeks throughout the year. Leaves were assayed by isolation on selective medium and by multiplex rDNA internal transcribed spacer polymerase chain reaction (ITS PCR). The two methods gave comparable results, but multiplex PCR was more sensitive. P. ramorum was regularly recovered at all seasons of the year from streams draining infested sites 5 years after eradication treatment. In streams with lower inoculum densities, recovery was much higher in summer than in winter. P. ramorum was isolated from streams in 23 watersheds. When P. ramorum was detected, intensive ground surveys located infected tanoaks or other host plants an average of 306 m upstream from the bait station. P. ramorum was isolated from stream baits up to 1,091 m from the probable inoculum source.

scholarly journals Occurrence of abortions induced by Neospora caninum in dairy cattle from Santa Catarina, southern Brazil

2017 ◽  
Vol 26 (3) ◽  
pp. 292-298 ◽  
Author(s):  
Cesar Augusto Barbosa de Macedo ◽  
Madlaine Frigo Silveira Barbosa de Macedo ◽  
Ana Carolina Miura ◽  
Alessandra Taroda ◽  
Sergio Tosi Cardim ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Dairy Cows ◽  
High Frequency ◽  
Neospora Caninum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Southern Brazil ◽  
Chain Reaction ◽  
Santa Catarina ◽  
Tissue Samples ◽  
Polymerase Chain

Abstract The aim of the present study was to investigate the occurrence of N. caninum associated with abortions of dairy cattle from Santa Catarina state, southern Brazil by using enzyme-linked immunosorbent assay (ELISA), immunohistochemistry (IHC), and polymerase chain reaction (PCR). Blood from dairy cows that aborted along with intrathoracic fluid and tissue samples (brain, heart, liver, and lung) from their fetuses were collected and used for serology; PCR, histopathological, and immunohistochemistry (IHC) evaluations were also conducted. Twenty-one cows (51.2%) out of 41, and eight fetuses (26.7%) out of 30 were ELISA (HerdCheck, IDEXX) positive for N. caninum. Dams > 36 months of age had a higher risk of being serum positive than younger animals. PCR and IHC revealed that 38.8% (14/36) and 25.0% (9/36) of the fetuses were positive for N. caninum, respectively for each of the tests. Seropositive cows had a higher frequency of fetuses that were also positive by either intrathoracic fluid, PCR, or IHC. In summary, the present study observed a high frequency of N. caninum in abortions from dairy cows from southern Brazil, with a higher N. caninum prevalence found in cows that were older than 36 months. In addition, serology, PCR, and IHC should be used all together for better diagnosis of neosporosis in cattle.

scholarly journals Development of Quantitative Real-Time Polymerase Chain Reaction for Detection of and Discrimination between Erysipelothrix Rhusiopathiae and Other Erysipelothrix Species

2009 ◽  
Vol 21 (5) ◽  
pp. 701-706 ◽  
Author(s):  
Ho To ◽  
Tomohiro Koyama ◽  
Shinya Nagai ◽  
Kotaro Tuchiya ◽  
Tetsuo Nunoya
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
Limit Of Detection ◽  
Enrichment Culture ◽  
Bacterial Species ◽  
Erysipelothrix Rhusiopathiae ◽  
Chain Reaction ◽  
Tissue Samples ◽  
Practical Applications ◽  
Polymerase Chain

Quantitative real-time polymerase chain reaction (qPCR) assays were developed and validated in combination with enrichment culture for the detection and discrimination of Erysipelothrix rhusiopathiae and other Erysipelothrix species from tissue samples. The targets for SYBR green qPCR assays were the 16S ribosomal RNA gene for Erysipelothrix species and a gene involved in capsular formation for E. rhusiopathiae. The specificity of the assays was assessed with Erysipelothrix species and other related bacterial species. The limit of detection was found to be 5 colony-forming units per reaction. Amplification of DNA extracted from spleen and joint samples spiked with increasing quantities of Erysipelothrix cells was shown to be equally sensitive to DNA extracted from a pure bacterial culture. The assays were evaluated with 88 tissue samples from 3 experimentally infected pigs and 50 mice and with 36 tissue samples from 3 naturally infected pigs and 11 noninfected pigs. Results were compared with those of direct qPCR and conventional culture. The qPCR after enrichment increased the diagnostic sensitivity over that of culture and qPCR, thereby significantly reducing the total time taken for the detection of E. rhusiopathiae and other Erysipelothrix species. Therefore, this technique could be used for practical applications.

Studies on Diagnosis of Bovine Brucellosis by Immunocyto-chemistry and Immunohistochemistry

2021 ◽  
Author(s):  
K.S. Lakshmikanth ◽  
N.S. Sharma ◽  
D. Pathak ◽  
Paviter Kaur
Keyword(s):  
Biochemical Analysis ◽  
Placental Tissue ◽  
Diagnostic Techniques ◽  
Clinical Samples ◽  
Bovine Brucellosis ◽  
Reproductive Disorders ◽  
Chain Reaction ◽  
Tissue Samples ◽  
Polymerase Chain ◽  
Positive Results

Background: Brucellosis is a major threat to livestock economy and an important zoonotic disease. A rapid and accurate diagnosis is a necessity to curb the spread and progress of the disease. The current study aimed to evaluate sensitivity of Immunocytochemistry and Immunohistochemistry methods for detection of Brucella spp.Methods: A total of 50 samples comprising of fetal stomach content, vaginal discharges and placenta were collected from cattle and buffaloes suffering from abortions and other reproductive disorders in and around Ludhiana, Punjab during the period 2017-2018. All the samples were processed for isolation and confirmed with biochemical analysis and Polymerase chain reaction (PCR). The isolates obtained and 43 clinical samples excluding placental samples were subjected to Immunocytochemistry (ICC). Immunohistochemistry (ICH) was performed on placental samples.Result: A total of four isolates were recovered from the screened samples. The four isolates also yielded positive results in Immunocytochemistry. Among the 43 clinical samples screened by Immunocytochemistry, five were positive, however only 3 isolates were recovered on isolation. A total of seven placental tissue samples were processed and subjected to immunohistochemistry. Of the three placental samples positive by immunohistochemistry, only one sample was isolated on culture. The results suggest that both immunocytochemistry and immunohistochemistry are sensitive diagnostic techniques in comparison to isolation.

scholarly journals Isolation ofMycobacterium aviumsubspeciesparatuberculosisfrom non-ruminant wildlife living in the sheds and on the pastures of Greek sheep and goats

2007 ◽  
Vol 136 (5) ◽  
pp. 644-652 ◽  
Author(s):  
M. FLOROU ◽  
L. LEONTIDES ◽  
P. KOSTOULAS ◽  
C. BILLINIS ◽  
M. SOFIA ◽  
...  
Keyword(s):  
Type Strain ◽  
Insertion Sequence ◽  
Small Ruminants ◽  
Dairy Sheep ◽  
Chain Reaction ◽  
Tissue Samples ◽  
Sheep And Goats ◽  
Faecal Samples ◽  
Polymerase Chain ◽  
Type Strains

SUMMARYThis study aimed to: (1) investigate whether non-ruminant wildlife interfacing with dairy sheep and goats of four Greek flocks endemically infected withMycobacterium aviumsubspeciesparatuberculosis(MAP) harboured MAP and (2) genetically compare the strains isolated from the wildlife to those isolated from the small ruminants of these flocks. We cultured and screened, by polymerase chain reaction (PCR), pooled-tissue samples from 327 wild animals of 11 species for the MAP-specific IS900insertion sequence. We also cultured faecal samples from 100 sheep or goats from each of the four flocks. MAP was detected in samples from 11 sheep, 12 goats, two mice, two rats, a hare and a fox. Only one rat had histopathological findings. Genetic typing categorized 21 isolates as cattle-type strains and two, from a house mouse and a goat respectively, as sheep-type strains; this is the first report of a rodent harbouring a sheep-type strain. The MAP types that were most frequently isolated amongst the sheep and goats of each flock were also the ones isolated from sympatric rodents; those isolated from the fox and hare also belonged to the predominant ruminant strains.

Phytophthora ramorum. [Distribution map].

2006 ◽  
Author(s):  
Keyword(s):  
South Carolina ◽  
Phytophthora Ramorum ◽  
Distribution Map ◽  
Quercus Agrifolia ◽  
Quercus Kelloggii ◽  
Live Oak ◽  
Lithocarpus Densiflorus ◽  
Black Oak ◽  
New Distribution ◽  
Distribution In Europe

Abstract A new distribution map is provided for Phytophthora ramorum Werres, de Cock & Man in't Veld. Oomycota: Pythiales. Hosts include California black oak (Quercus kelloggii), California live oak (Quercus agrifolia), Rhododendron, shreve oak (Quercus parvula var. shrevei), tanoak (Lithocarpus densiflorus) and Viburnum. Information is given on the geographical distribution in Europe (Belgium, Denmark, France, Germany, Ireland, Italy, Netherlands, Norway, Poland, Slovenia, Spain, Sweden, Switzerland, UK) and North America (Canada (British Columbia), USA (California, Florida, Georgia, Louisiana, Oregon, South Carolina, Tennessee, Virginia, Washington)).

A Microdissection and Molecular Genotyping Assay to Confirm the Identity of Tissue Floaters in Paraffin-Embedded Tissue Blocks

2003 ◽  
Vol 127 (2) ◽  
pp. 213-217 ◽  
Author(s):  
Jennifer L. Hunt ◽  
Patricia Swalsky ◽  
E. Sasatomi ◽  
Laura Niehouse ◽  
Anke Bakker ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Tissue Sample ◽  
Small Samples ◽  
Allelic Loss ◽  
Chain Reaction ◽  
Neoplastic Tissue ◽  
Tissue Samples ◽  
Genotyping Assay ◽  
Tissue Identification ◽  
Polymerase Chain

Abstract Context.—A recurring problem in surgical pathology practice is specimen mix-up and floater contamination. While many cases can be resolved histologically, a significant number remain unclear and may have serious clinical and medicolegal implications. Objectives.—To design a microdissection and genotyping assay to identify contaminating floater tissues in paraffin-embedded tissues that is optimized for small samples, and to use the assay to resolve a series of clinical cases with floater tissues. Materials and Methods.—Twenty-one cases of possible tissue floater contamination in paraffin-embedded tissue blocks were included. Using 4 unstained, 4-μm-thick histologic sections, multiple sites were microdissected under direct visualization either by hand or by laser capture microdissection. Nonneoplastic and neoplastic tissues were sampled. Polymerase chain reaction was performed for a panel of 10 polymorphic microsatellite markers at 1p34, 3p26, 5q21, 9p21, 10q23, and 17p13. Allele size and content were analyzed semiquantitatively by fluorescent capillary electrophoresis, and the genotypes for the tissues in the paraffin-embedded tissue blocks were compared for identity. Results.—Tissue identification was successful in all cases, despite small tissue sample size and fixation effects. Comparative analysis of neoplastic tissue floaters and the presumptive source tumor was performed when possible to control for possible allelic loss or microsatellite instability. Conclusions.—Microdissection and genotyping are effective and reliable means to objectively resolve problems of possible floater contamination. Even minute tissue samples provide sufficient DNA template for polymerase chain reaction microsatellite analysis. Because of the potential clinical implications of floaters, we recommend that all suspected floaters that would change a diagnosis from benign to malignant be subjected to genotyping assay to confirm the identity of the floater tissue.

Alphaviruses

2010 ◽  
pp. 557-561
Author(s):  
E.E. Ooi ◽  
L.R. Petersen ◽  
D.J. Gubler
Keyword(s):  
Mosquito Species ◽  
Clinical Manifestations ◽  
Febrile Illness ◽  
Domestic Animals ◽  
Human Infection ◽  
Tissue Samples ◽  
The Family ◽  
Polymerase Chain ◽  
Complex Transmission ◽  
Diagnosis Of Infection

There are 29 registered alphaviruses belonging to the family Togaviridae, 16 of which are known to cause human infection. They are RNA viruses with global geographical distribution and complex transmission cycles between wild or domestic animals or birds and one or more mosquito species; humans are infected by mosquito bites. They cause a spectrum of clinical manifestations ranging from nonspecific febrile illness to acute encephalitis and death. Diagnosis of infection is made serologically by detection of IgM and IgG antibodies, virus isolation, and polymerase chain reaction, or by immunohistochemistry on tissue samples....

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