Psychotic disorders in young adults with perinatally acquired HIV: a UK case series.

BACKGROUND: Increasing numbers of children with perinatally acquired HIV (PaHIV) are transitioning into adult care. People living with behaviourally acquired HIV are known to be at more risk of psychosis than uninfected peers. Young adults living with PaHIV face numerous risk factors; biological: lifelong exposure to a neurotrophic virus, antiretroviral medication and immune dysfunction during brain development, and environmental; social deprivation, ethnicity-related discrimination, and migration-related issues. To date, there is little published data on the prevalence of psychotic illness in young people growing up with PaHIV. METHODS: We conducted a retrospective case note review of all individuals with PaHIV aged over 18 years registered for follow up at a dedicated clinic in the UK (n = 184). RESULTS: In total, 12/184 (6.5%), median age 23 years (interquartile range 21-26), had experienced at least one psychotic episode. The presentation and course of the psychotic episodes experienced by our cohort varied from short-lived symptoms to long term illness and nine (75%) appear to have developed a severe and enduring mental illness requiring long term care. CONCLUSION: The prevalence of psychosis in our cohort was clearly above the lifetime prevalence of psychosis in UK individuals aged 16-34 years, which has been reported to be 0.5-1.0%. This highlights the importance of clinical vigilance regarding the mental health of young people growing up with PaHIV and the need to integrate direct access to mental health services within the HIV centres providing medical care.

A descriptive study of British South Asians living with HIV in North East London.

To our knowledge, no published literature has focused on South Asians living with HIV in the U.K. since 2004. We reviewed the case-notes of all patients self-identifying as South Asian attending two HIV centres in North East London between 1st January and 31st December 2017.Of 131 patients, 107 were male, median age 43 (range 24-72). Most (73.3%) were born outside the U.K., 55.7% were Muslim. 56.5% identified as heterosexual. However, 5.4% of heterosexual men may have become infected from sex between men. More men who have sex with men (MSM) (59.6%) were diagnosed on routine screening rather than when symptomatic or through partner notification, compared to heterosexual men (30.6%) and women (48.0%). Heterosexual men and women were diagnosed with lower CD4 counts than MSM (257 vs 307 vs 456 cells/µL). . Almost all of the sample were on antiretroviral treatment (97.7%), of whom 94.5% had an undetectable viral load (<200 copies/ml). The cohort was highly co-morbid (60.3%) and 38.9% had a history of poor mental health.We describe a diverse sample of British South Asians living with HIV We recommend that culturally specific campaigns encouraging routine HIV testing in the British South Asian population should be developed.

First Report of Potato mop top virus Causing Potato Tuber Necrosis in Colorado and New Mexico.

Potato mop top virus (PMTV) is considered the type member of the genus Pomovirus. PMTV is an important pathogen of potato vectored by the plasmodiophorid Spongospora subterranea f. sp. subterranea (Sss), which causes powdery scab of potato (1). Sss and PMTV are usually associated with cool and humid environments. PMTV-infected potato tubers generally exhibit internal hollow necrotic spots or concentric rings, and the virus is known to cause significant economic losses in Northern Europe, North and South America, and Asia (4). PMTV in the United States was first reported in Maine (2). Potato (Solanum tuberosum L.) tubers cv. FL2048 and cv. Atlantic were sent to our laboratory from fields in Saguache County in Colorado and in San Juan County in New Mexico, respectively, during the spring of 2013. The tubers from both locations had multiple, internal, concentric, necrotic arcs and circles. Internal tissue with necrotic lesion from six symptomatic tubers from each location were crushed in liquid nitrogen followed by ribonucleic acid extraction using a Total RNA Isolation kit (Promega Corp., Madison, WI). These extracts were tested by reverse transcription (RT)-PCR using three different sets of previously published primers for molecular detection of PMTV. The primer set H360/C819 targeting the coat protein (CP) on RNA 3 of PMTV yielded an amplicon (H360-CO and H360-NM) of 460 bp (4). The second set of primers, pmtF4/pmtR4 (5), amplified a 417-bp product (PMTF-CO and PMTF-NM) in RNA 2, and the third set, PMTV-P9/PMTV-M9 (3), designed to amplify the region encoding an 8-KD cysteine-rich protein in RNA 3 of PMTV, yielded a 507-bp amplicon (PMTV9-CO and PMTV9-NM). The amplicons generated from RT-PCR using all three sets were cloned (PGEMT-easy) and sequenced. Since the sequences from symptomatic tuber extracts from each location were identical to their respective primer sets, a consensus sequence from each primer set was submitted to National Center for Biotechnology Information (NCBI) GenBank. Sequences obtained from the H360/C819 primer set (GenBank Accession Nos. KM207013 and KM207014 for H360-CO and H360-NM, respectively) were 100% identical to the corresponding CP regions of PMTV isolates from North Dakota (HM776172). Sequences from the pmtF4/pmtR4 primer set (KM207015 and KM207016 for PMTF-CO and PMTF-NM, respectively) were 100% identical to the corresponding protein in RNA2 of PMTV isolates from North Dakota (GenBank HM776171), and sequences from the PMTV-P9/PMTV-M9 primer set (KM207017 and KM207018 for PMTV9-CO and PMTV9-NM respectively) were 99% identical to the corresponding protein in RNA3 of PMTV isolates (AY187010). The 100-99% homology of the sequences from this study to the corresponding PMTV sequences published in NCBI confirmed the occurrence of symptoms in the tubers from both Colorado and New Mexico due to PMTV. None of the symptomatic tubers tested positive for Tobacco rattle virus, Tomato spotted wilt virus, Alfalfa mosaic virus, Potato leafroll virus, or the necrotic strains of Potato virus Y by RT-PCR. To our knowledge, this is the first report of PMTV in potato in states of Colorado and New Mexico. References: (1) R. A. C. Jones and B. D. Harrsion. Ann. Appl. Biol. 63:1, 1969. (2) D. H. Lambert et al. Plant Dis. 87:872, 2003. (3) T. Nakayama et al. Am. J. Pot. Res. 87:218, 2010. (4) J. Santala et al. Ann. Appl. Biol. Online publication. DOI: 10.1111/j.1744-7348.2010.00423.x (5) H. Xu et al. Plant Dis. 88:363, 2004.

Molecular characterization and detection of mutations associated with resistance to succinate dehydrogenase-inhibiting fungicides in Alternaria solani.

Early blight, caused by Alternaria solani, is an economically important foliar disease of potato in several production areas of the United States. Few potato cultivars possess resistance to early blight; therefore, the application of fungicides is the primary means of achieving disease control. Previous work in our laboratory reported resistance to the succinate dehydrogenase-inhibiting (SDHI) fungicide boscalid in this plant pathogen with a concomitant loss of disease control. Two phenotypes were detected, one in which A. solani isolates were moderately resistant to boscalid, the other in which isolates were highly resistant to the fungicide. Resistance in other fungal plant pathogens to SDHI fungicides is known to occur due to amino acid exchanges in the soluble subunit succinate dehydrogenase B (SdhB), C (SdhC), and D (SdhD) proteins. In this study, the AsSdhB, AsSdhC, and AsSdhD genes were analyzed and compared in sensitive (50% effective concentration [EC50] < 5 µg ml(-1)), moderately resistant (EC50 = 5.1 to 20 µg ml(-1)), highly resistant (EC50 = 20.1 to 100 µg ml(-1)), and very highly resistant (EC50 > 100 µg ml(-1)) A. solani isolates. In total, five mutations were detected, two in each of the AsSdhB and AsSdhD genes and one in the AsSdhC gene. The sequencing of AsSdhB elucidated point mutations cytosine (C) to thymine (T) at nucleotide 990 and adenine (A) to guanine (G) at nucleotide 991, leading to an exchange from histidine to tyrosine (H278Y) or arginine (H278R), respectively, at codon 278. The H278R exchange was detected in 4 of 10 A. solani isolates moderately resistant to boscalid, exhibiting EC50 values of 6 to 8 µg ml(-1). Further genetic analysis also confirmed this mutation in isolates with high and very high EC50 values for boscalid of 28 to 500 µg ml(-1). Subsequent sequencing of AsSdhC and AsSdhD genes confirmed the presence of additional mutations from A to G at nucleotide position 490 in AsSdhC and at nucleotide position 398 in the AsSdhD, conferring H134R and H133R exchanges in AsSdhC and AsSdhD, respectively. The H134R exchange in AsSdhC was observed in A. solani isolates with sensitive, moderate, highly resistant, and very highly resistant boscalid phenotypes, and the AsSdhD H133R exchange was observed in isolates with both moderate and very high EC50 value boscalid phenotypes. Detection and differentiation of point mutations in AsSdhB resulting in H278R and H278Y exchanges in the AsSdhB subunit were facilitated by the development of a mismatch amplification mutation assay. Detection of these two mutations in boscalid-resistant isolates, in addition to mutations in AsSdhC and AsSdhD resulting in an H134R and H133R exchange, respectively, was achieved by the development of a multiplex polymerase chain reaction to detect and differentiate the sensitive and resistant isolates based on the single-nucleotide polymorphisms present in all three genes. A single A. solani isolate with resistance to boscalid did not contain any of the above-mentioned exchanges but did contain a substitution of aspartate to glutamic acid at amino acid position 123 (D123E) in the AsSdhD subunit. Among A. solani isolates possessing resistance to boscalid, point mutations in AsSdhB were more frequently detected than mutations in genes coding for any other subunit.

Development and Validation of a Real-Time PCR Assay for the Quantification of Verticillium dahliae in Potato.

An increase in the stringency for higher quality potato tubers and restrictions on the use of soil fumigants, among other factors, has garnered renewed interest in Verticillium wilt, particularly in russet-skinned cultivars grown for processing. In response to the needs of producers, breeders have increased efforts in the development of potato cultivars with resistance to Verticillium dahliae Kleb., the primary cause of Verticillium wilt. These efforts have resulted in the release of numerous russet-skinned cultivars with purported resistance to the pathogen. However, because efficient and effective methods to screen germplasm for true resistance do not exist, breeders typically have reported resistance based on the development of wilt symptoms alone. The studies reported here demonstrate the efficiency and practicality of a QPCR method for quantification of V. dahliae in potato stem tissue. This method, developed to detect the target trypsin protease gene of the pathogen, was compared with traditional methods for V. dahliae quantification which involve plating stem tissue or sap onto semi-selective media, as well as to a recently developed QPCR assay which amplifies a region of the ß-tubulin gene of V. dahliae. The QPCR assay developed in the studies reported here was demonstrated to be sensitive to 0.25 pg of DNA. Use of the duplex real-time PCR assay, utilizing the potato actin gene to normalize quantification, resulted in clearer differentiation of levels of resistance among eight russet-skinned potato cultivars inoculated in greenhouse trials when compared with traditional plating assays. However, relative levels of resistance among cultivars were similar between traditional plating and QPCR methods, resulting in correlation coefficients greater than 0.93. The assay described here also detected the pathogen in inoculated stem tissue at higher frequencies than both traditional plating assays and a previously developed QPCR assay. The QPCR assay developed here demonstrates rapid, efficient, and accurate quantification of V. dahliae, providing a tool amenable for use by breeding programs on large numbers of clones and selections, and will aid researchers evaluating other control strategies for Verticillium wilt.

First Report of Tobacco rattle virus Associated with Corky Ringspot in Potatoes Grown in North Dakota.

Tobacco rattle virus (TRV) belongs to the genus Tobravirus and causes a stem mottle of potato (Solanum tuberosum) foliage and necrotic arcs and rings in tubers referred to as corky ringspot. This virus is generally transmitted by a number of species of stubby-root nematode. The virus is widespread and has been reported in California, Colorado, Florida, Idaho, Michigan, Oregon, Washington, Minnesota, and Wisconsin (2). In the spring of 2009, we received potato tubers of cv. Russet Burbank with internal necrotic arcs very similar to those caused by TRV from potato storages located in Grand Forks and Dickey counties of North Dakota. Total RNA was extracted from the necrotic lesions of two tubers from each location using the Total RNA Isolation kit (Promega Corp., Madison WI). These extracts were tested for TRV by reverse transcription (RT)-PCR using primers complementary to nucleotides 6555 to 6575 (Primer A) and identical to nucleotides 6113 to 6132 (Primer B) within the 3' terminus of TRV-SYM RNA-1 (GenBank Accession No. X06172) (3). The expected 463-bp amplicons from two separate tuber samples from each county were cloned (TOPO Cloning; Invitrogen, Carlsbad, CA) and sequenced. The sequences obtained from the four clones at both locations were found to be identical to each other and were 99% identical to the corresponding regions of TRV isolates from Michigan and Florida (GenBank Accession Nos. EU315226.1 and AF055912.1, respectively). Since sequences from all four clones were identical, only one of the sequences was submitted to Genbank (Accession No. GQ223114) and thus represents a consensus sequence. The extracts also tested positive in RT-PCR with a second set of primers corresponding to sequences in TRV RNA-2 yielding a 3.8-kbp amplicon (1). No evidence was found by RT-PCR for several other viruses that cause tuber necrosis in potato (Potato mop top virus, Tomato spotted wilt virus, Alfalfa mosaic virus, and tuber necrosis strains of Potato virus Y). The virus was mechanically transmitted by inoculating sap from symptomatic tubers from both counties to tobacco cv. Samsun NN, which showed typical bright yellow patches and spots on leaves 2 weeks postinoculation. TRV was confirmed in tobacco by RT-PCR from total RNA extracted from tobacco leaves with both sets of the aforementioned primers. To our knowledge, this is the first report of TRV in North Dakota and the first report of corky ringspot disease of potato in this state. References: (1) J. M. Crosslin et al. Virus Res. 96:99, 2003. (2) N. C. Gudmestad et al. Plant Dis. 92:1254, 2008. (3) D. J. Robinson. J. Virol. Methods 40:57, 1992.

First Report of Potato mop-top virus in North Dakota.

Potato mop-top virus (PMTV) is the type member of the genus Pomovirus. PMTV is an important pathogen of potato, causing significant economic losses in Northern Europe, North and South America, and Asia (3). PMTV in the United States was first reported in Maine (2). PMTV is vectored by the plasmodiophoromycete Spongospora subterranea cv. subterranea, which causes powdery scab of potato (1). S. subterranea and PMTV are usually associated with cool and humid environments. In the spring of 2010, six potato tubers of cv. Russet Burbank were received from a commercial potato farm in Grand Forks County in North Dakota. The tubers had multiple, internal, concentric, necrotic arcs and circles. The presence of PMTV in the necrotic lesions was verified by a positive double-antibody sandwich-ELISA (Agden Ltd., Ayr, Scotland). The tuber lesions had an absorbance value (405 nm) at least two times greater than that of the negative control sample, which consisted of a healthy tuber. Total RNA was extracted from lesions of six different tubers that tested positive by ELISA using a Total RNA Isolation kit (Promega Corp. Madison, WI). These extracts were tested for PMTV by reverse transcription (RT)-PCR using two different sets of primers. The primer set H360/C819 targeted the coat protein (CP) of PMTV and yielded an amplicon of 460 bp (4). The amplicons generated from the necrotic lesions were cloned (TOPO Cloning; Invitrogen, Carlsbad, CA) and sequenced. Another set of primers, pmtF4/pmtR4, designed to bind to a region in RNA 2 of PMTV, yielded a 417-bp amplicon that also was cloned and sequenced (3). The sequences from all six tuber lesions were identical for the respective primer sets. A consensus sequence for each primer pair was submitted to GenBank (Accession No. HM776171 for primers pmtF4/pmtR4 and No. HM776172 for primers H360/C819). The sequences obtained from the H360/C819 and pmtF4/pmtR4 amplicons were 99% identical to the corresponding regions of PMTV isolates from Northern Europe (GenBank Accession Nos. AM503629 and AJ277556, respectively). Freeze-dried, necrotic tuber tissue from all six tubers was also tested at a USDA Laboratory in Prosser, WA by RT-PCR with the H360/C819 primer pair (4), confirming the results above. Cloning and sequencing of one of the amplicons revealed 100% similarity to the sequence described above for these primers (GenBank Accession No. HM776172), confirming the presence of PMTV in the symptomatic tubers. None of the symptomatic tubers tested positive for Tobacco rattle virus, Tomato spotted wilt virus, Alfalfa mosaic virus, Potato leafroll virus, or the necrotic strains of Potato virus Y by RT-PCR. To our knowledge this is the first report of PMTV in North Dakota. References: (1) R. A. C. Jones and B. D. Harrsion. Ann. Appl. Biol. 63:1, 1969. (2) D. H. Lambert et al. Plant Dis. 87:872, 2003. (3) J. Santala et al. Ann. Appl. Biol. Online publication. DOI: 10.1111/j.1744-7348.2010.00423.x (4) H. Xu et al. Plant Dis. 88:363, 2004.

First Report of Tomato spotted wilt virus Causing Potato Tuber Necrosis in Texas.

In the summer of 2008, potato (Solanum tuberosum L.) tubers (cvs. FL1867, FL2053, and FL1922) from commercial fields near Dalhart, TX were observed with distinct external erumpent rings and severe internal discolorations including blotches, spots, and dry, cork-like tissue. The presence of rings suggested the possible involvement of one or more viruses. Nucleic acid from seven of eight symptomatic tubers received in Washington (cvs. FL1867 and FL1922) tested positive for Tomato spotted wilt virus (TSWV) by reverse transcription (RT)-PCR with primers TSWV 1 and 2 (3). Similarly, tubers (cvs. FL1867 and FL2053) received in North Dakota tested positive for TSWV with forward (S1983) and reverse (S2767) primers of Tsompana et al. (4). The 777-bp amplicon obtained with primers TSWV 1 and 2 and the 803-bp amplicon obtained with primers S1983 and S2767 were cloned and three clones of each were sequenced. Analysis of the consensus sequences and BLAST comparisons confirmed the Washington and North Dakota sequences were indeed TSWV in origin and were each 98 to 99% identical to the corresponding nucleocapsid region of a number of TSWV isolates and most closely related to an isolate detected in eastern black nightshade from Colorado (GenBank No. AY777475). The deduced amino acid sequences of the 777-bp nucleocapsid open reading frame differed from AY777475 at only two residues in each of the Washington and North Dakota sequences. The Washington and North Dakota derived sequences were deposited with GenBank (Nos. FJ882069 and FJ882070, respectively). None of the eight symptomatic tubers tested positive for Tobacco rattle virus (TRV), Alfalfa mosaic virus (AMV), or the necrotic strains of Potato virus Y (PVY) by RT-PCR. Mechanical transmission tests were conducted by grinding symptomatic tissue of a TSWV-positive FL1867 tuber in 10 volumes of 30 mM potassium phosphate buffer, pH 8.0, containing 10 mM of sodium diethyldithiocarbamate and 10 mM of sodium thioglycollate and rub inoculated onto Carborundum-dusted leaves of Samsun NN tobacco. Approximately 10 days after inoculation, chlorotic-necrotic rings were present on the inoculated leaves and circular necrotic lesions developed on the upper leaves. Dark stem lesions were also present on inoculated tobacco, and after 3 weeks, the upper leaves developed severe, spreading lesions. Tissue from the symptomatic tobacco tested positive for TSWV by RT-PCR (primers TSWV 1 and 2) and also with a TSWV-specific ImmunoStrip (Agdia, Inc., Elkhart, IN), but tested negative for TRV, AMV, and PVY by RT-PCR. TSWV has been reported on field-grown potatoes in North Carolina (1) and has been reported on potatoes in Australia (2) and in other parts of the world (referenced in 1). To our knowledge, this is the first report associating TSWV with tuber necrosis on potatoes in Texas. References: (1) J. A. Abad et al. Am. J. Potato Res. 82:255, 2005. (2) L. J. Latham and R. A. C. Jones. Aust. J. Agric. Res. 48:359, 1997. (3) R. Navarre et al. Am. J. Potato Res. 86:88, 2009. (4) M. Tsompana et al. Mol. Ecol. 14:53, 2005.

Detection, Distribution, and Genetic Variability of 'Candidatus Liberibacter' Species Associated with Zebra Complex Disease of Potato in North America.

The specificity and sensitivity of polymerase chain reaction (PCR) primers developed for 'Candidatus Liberibacter solanacearum' and 'Candidatus Liberibacter psyllaurous' were evaluated in conventional and real-time PCR assays. All PCR primers were specific for 'Ca. L. psyllaurous' and 'Ca. L. solanacearum' insomuch as they did not detect other prokaryotic plant pathogens that affect potato except for the putative pathogens associated with psyllid-yellows and haywire. Conventional PCR assays were capable of detecting 0.19 to 1.56 ng of total DNA per reaction, and real-time PCR was found capable of detecting 1.56 to 6.25 ng of total DNA per reaction, depending on the specific PCR primer set used. 'Ca. Liberibacter' species associated with zebra complex disease (ZC) was confirmed in plants affected by this disease throughout Texas from 2005 to 2008, in seed tubers produced in Wyoming in 2007, and in Colorado, Kansas, Nebraska, and Mexico in 2008. A multiplex PCR assay using 'Ca. L. solanacearum'-specific primers and primers specific for the ß-tubulin DNA regions from potato was developed, providing possible utility of the multiplex assay for 'Ca. Liberibacter' detection in different solanaceous plant species. Preliminary studies suggest silverleaf nightshade (Solanum elaeagnifolium), wolfberry (Lycium barbarum), black nightshade (S. ptychanthum), and jalapeno pepper (Capsicum annuum) as additional solanaceous hosts for the ZC-associated bacterium. The 'Ca. Liberibacter' species detected in all samples divided into two clusters sharing similarity of 99.8% in their partial 16S rRNA gene sequences and 99.3% in their partial intergenic spacer region (ISR)-23S rRNA gene sequences. Genetic variation in the 16S rDNA region consistently matched that of the ISR-23S rDNA region. In this partial 16S-ISR-23S rDNA region, there was a total of eight single nucleotide polymorphisms among 'Ca. L. psyllaurous' and 'Ca. L. solanacearum' "strains" investigated in this study. 'Ca. L. solanacearum' and 'Ca. L. psyllaurous' were shown to be very closely related bacteria, if not the same, by successful amplification using a combination of forward primer of 'Ca. L. solanacearum' and reverse primer of 'Ca. L. psyllaurous' in ZC-affected potato samples. This finding clarifies the current taxonomic status of 'Ca. L. solanacearum' and 'Ca. L. psyllaurous'. The detection of 'Ca. L. solanacearum' from haywire-symptomatic potato samples demonstrates that this bacterium might also be associated with this disease.

Pathotypes, Distribution, and Metalaxyl Sensitivity of Phytophthora sojae from North Dakota.

Phytophthora root rot, caused by Phytophthora sojae, is the most important disease of soybean (Glycine max) in North Dakota. Because of the expansion of soybean hectares and appearance of disease on cultivars with resistance genes, we investigated the pathotypes, distribution, and metalaxyl sensitivity of P. sojae in North Dakota. Soil from 347 soybean fields in 20 counties in eastern North Dakota was collected between 2002 and 2004, and P. sojae was baited from the soil with the susceptible cultivar McCall. The virulence phenotype of each isolate was determined on eight differentials, and all isolates were tested for sensitivity to metalaxyl incorporated into V8 agar. The pathogen was recovered from 80 fields located in five counties. Sixteen pathotypes, which included 14 known races and two previously reported pathotypes that had not been assigned a race, were identified out of 157 isolates. A single pathotype was recovered from 61 fields, 2 pathotypes from 14 fields, 3 pathotypes from 4 fields, and 4 pathotypes from 1 field. Pathotypes with virulence phenotypes 1a,1c,7 (race 4; 39%) and 1a,7 (race 3; 28%) were the most common, representing 67% of the total isolates. One or both of these pathotypes was found in 79% of the fields where P. sojae was recovered. Seven of the 157 isolates showed limited growth on metalaxyl after 14 days of incubation. In the past 10 years, the number of pathotypes of P. sojae in North Dakota has increased from 4 to 16, and pathotypes have developed that can attack the three most common resistance genes found in soybean cultivars for the region.

First Report of Tobacco rattle virus Causing Corky Ringspot in Potatoes Grown in Minnesota and Wisconsin.

In July 2007, potato tubers cv. Russet Burbank (RB) with necrotic arcs and spots were detected in three fields in Buffalo County, Wisconsin and one field in Benson County, Minnesota. Umatilla Russet (UR) potatoes harvested from the west half of a field in Swift County, MN had similar, but visually distinct necrotic lesions. Portions of one field in Minnesota were abandoned, and the stored potato crop from two fields in Wisconsin was rejected by processors, representing a total crop loss due to tuber necrosis. Tuber symptoms displayed in both cultivars resembled those described for corky ringspot caused by Tobacco rattle virus (TRV) (4). Total RNA was isolated from necrotic tuber tissue crushed in liquid nitrogen and extracted using the Total RNA Isolation Kit (Promega Corp., Madison, WI). These extracts were tested for the presence of TRV by reverse transcription (RT)-PCR using primers complementary to nucleotides 6555 to 6575 and identical to nucleotides 6113 to 6132 within the 3' terminal open reading frame of TRV RNA-1 (3). The expected 463-bp fragments were amplified from RB tubers. Nucleotide sequences from a Wisconsin and Minnesota isolate (GenBank Accession Nos. EU569290 and EU569291, respectively) were 99 to 100% identical to the corresponding region in a published TRV sequence (GenBank Accession No. AF055912). A 396-bp fragment was amplified from UR tubers and sequence data (GenBank Accession No. EU569292) indicated a unique 63 nucleotide sequence was substituted for a 129 nucleotide sequence spanning residues 227 to 357 of the 463-bp amplicon from the RB TRV isolates. Seven fragments were sequenced from different UR tubers and the 396-bp fragment was identical among them. The sequence outside the substituted region had 92% identity to the published TRV sequence. Amplification of the full-length TRV RNA2 using primers 179/180 located in the 5' and 3' untranslated regions (2) was successful for 28 and 0% of the RB and UR samples, respectively, suggesting that the RNA2 is not present in these strains or has undergone significant mutation. TRV-infected sap from both potato cultivars was mechanically transmitted to tobacco cv. Samsun NN and these plants subsequently tested positive for TRV by ELISA using ATCC antiserum PVAS 820. Ninety tubers exhibiting mild to severe symptoms of TRV were planted in the greenhouse. Each tuber was bisected laterally; necrotic tissue was removed from one half of the tuber and tested for the presence of TRV using RT-PCR protocols described above for RNA1. The remaining half was bisected horizontally and both sections were planted. Foliage from each emerged plant was subsequently also tested by RT-PCR for TRV RNA1. All RB tubers from Wisconsin tested positive for TRV, but only 7 of 24 emerged plants tested positive. Only 72% of the UR tubers and 4 of 25 emerged plants tested positive. TRV has been confirmed in California, Colorado, Florida, Idaho, Michigan (1), Oregon, and Washington. To our knowledge, this is the first report of corky ringspot in potato caused by TRV in Minnesota and Wisconsin. References: (1) W. W. Kirk et al. Plant Dis. 92:485, 2008. (2) S. A. MacFarlane. J. Virol. Methods. 56:91, 1996. (3) D. J. Robinson. J. Virol. Methods 40:57, 1992. (4) S. A. Slack. Tobacco rattle virus. Page 71 in: Compendium of Potato Diseases. 2nd ed. W. R. Stevenson et al., eds. The American Phytopathological Society, St. Paul, MN, 2001.