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PubMed1996

Survey of equine rotaviruses shows conservation of one P genotype in background of two G genotypes.

DIG-labelled ssRNA probes were prepared from variable regions of VP4 and VP7 cognate genes, and used in hybridization assays for P and G genotyping of group A cell culture-adapted equine rotaviruses and fecal samples collected from foals with and without diarrhea. The probes confirmed known P and G serotypes of sixteen cell culture-adapted strains. From one-hundred and twenty-one rotavirus-positive samples, 83 reacted when tested for their P and G genotype specific probes. From these, 71 were found to contain G3 P12 genotypes, and 11 G14 P12 genotypes. No sample reacted with H1 or L338 P and G genotype probes. This suggests that the equine rotavirus population is conservative, containing predominantly one P genotype and two G genotypes. One isolate (26/94) whose dsRNA was visualized in an agarose gel did not react with any of the equine probes, and was found to belong to G8 and P1 genotypes. This is the fourth example of a single unique equine isolate (after H1, L338, and R-22). The remaining thirty-eight untypable field isolates had no detectable dsRNA after storage for 1 to 3 years.

Animals↗
PubMed2006

VKORC1 and CYP2C9 genotypes and acenocoumarol anticoagulation status: interaction between both genotypes affects overanticoagulation.

OBJECTIVE: Our objective was to assess the effects of VKORC1 and CYP2C9 genotypes on severe overanticoagulation and time to achieve stability and their contributions to dose requirement during the initial phase of acenocoumarol treatment. METHODS: A prospective follow-up study was conducted at 2 anticoagulation clinics in The Netherlands. We assessed the CYP2C9 genotype (CYP2C9*2 and CYP2C9*3 polymorphisms) and the VKORC1 C1173T genotype of the subjects and collected data on international normalized ratio, dose, comedication, and comorbidity. RESULTS: Of the 231 patients in the cohort, 150 (64.9%) had a VKORC1 C1173T polymorphism and 84 (36.4%) had a CYP2C9*2 or CYP2C9*3 allele. Only carriers of a combination of a CYP2C9 polymorphism and a VKORC1 polymorphism had an increased risk of severe overanticoagulation compared with subjects with no polymorphism or only 1 polymorphism (hazard ratio, 3.83 [95% confidence interval, 1.62-9.05]). The time to achieve stability was associated with the possession of the CYP2C9 genotype, not with the VKORC1 genotype (hazard ratio for CYP2C9*3 allele compared with CYP2C9 wild type, 0.59 [95% confidence interval, 0.40-0.87]). Patients with a VKORC1 polymorphism required significantly lower doses than VKORC1 CC wild-type patients. A larger part of the variability in dose requirement was explained by the VKORC1 genotype than by the CYP2C9 genotype (21.4% and 4.9%, respectively). CONCLUSION: Being a carrier of a combination of polymorphisms of VKORC1 and CYP2C9, rather than of one of these polymorphisms, is associated with severe overanticoagulation. The time to achieve stability is mainly associated with the CYP2C9 genotype.

Acenocoumarol↗
PubMed2001

Genotyping system of GBV-C/HGV type 1 to type 4 by the polymerase chain reaction using type-specific primers and geographical distribution of viral genotypes.

Based on variation in nucleotide sequence of 5'-untranslated region, GB virus type C (GBV-C) and hepatitis G virus (HGV) can be classified into three major genotypes. In addition to this classification, a novel genotype of GBV-C/HGV was identified and designated type 4. However, genotyping of GBV-C/HGV has been hampered by the lack of suitable assays. In this study, a simple and precise genotyping system based on PCR using the type-specific primers was developed for the determination of genotypes 1, 2, 3, and 4 of GBV-C/HGV. A total of 235 serum samples obtained from 11 different countries were tested by our PCR genotyping system of GBV-C/HGV. The results revealed that type 1 was prevalent mainly in Ghana, type 2 was prevalent in the USA, Spain, Egypt, Nepal and Myanmar, type 3 was prevalent in Japan and Bolivia, and type 4 was prevalent in Vietnam and Myanmar among the countries investigated in the present study. To confirm the specificity of the results of genotyping by PCR, phylogenetic analysis in the 5'-untranslated region of GBV-C/HGV was undertaken in 99 serum samples. By this analysis, the specificity of the genotyping system by PCR was confirmed. This assay system may be useful for rapid typing of GBV-C/HGV RNA when either epidemiological or transmission studies of this agent are carried out.

DNA Primers↗
PubMed2003

Collaborative study to calibrate hepatitis C virus genotypes 2-6 against the HCV International Standard, 96/790 (genotype 1).

BACKGROUND AND OBJECTIVES: A major requirement of a hepatitis C virus (HCV) RNA nucleic acid amplification technology (NAT) assay validation is the ability of the assay to detect the six major genotypes of HCV with equivalent sensitivities. The aim of this study was to characterize and calibrate an HCV genotype panel for use in such studies. MATERIALS AND METHODS: Panels consisting of the first International Standard (IS) for HCV RNA NAT assays (96/790; HCV genotype 1a) and isolates of genotypes 2-6 were sent to 17 laboratories worldwide which use a variety of NAT tests, both qualitative and quantitative. The HCV RNA content of each panel member was determined and the mean titre calculated in International Units/ml (IU/ml). RESULTS: The calculated mean titres (calibrated against the HCV International Standard), in log10 IU/ml, of the genotype 2-6 samples were 3.99, 3.81, 4.14, 4.18 and 4.61, respectively. CONCLUSIONS: An HCV genotype panel, calibrated in IU/ml, has been established and should be valuable for assay validation. All the genotypes were detected by all the assays used, but it was not possible to demonstrate that the genotypes were detected with equal efficiencies.

Calibration↗
PubMed2003

Genotype analysis, using PCR with type-specific primers, of hepatitis B virus isolates from patients coinfected with hepatitis delta virus genotype II from Miyako Island, Japan.

OBJECTIVES: The aims of this study were to determine the hepatitis B virus (HBV) genotypes in hepatitis delta virus (HDV) RNA-positive patients and to characterize the HBV nucleotide sequences that may be found on a distant island of Japan. METHODS: This study included three patients with chronic hepatitis who were positive for hepatitis B surface antigen (enzyme-linked immunosorbent assay; ELISA), HDV antibody (ELISA) and HDV RNA by polymerase chain reaction (PCR). The HBV genotype was determined by nested PCR using type-specific primers. The first-round PCR products from two patients were sequenced, followed by an investigation of nucleotide homology. RESULTS: Viruses from all three patients in this study were classified as HBV genotype B. Comparison with HBV isolates from geographically neighboring regions revealed that the two HBV isolates had 97.9-98.6% identity at the nucleotide level to a Chinese isolate, 98.3-98.6% identity to the Okinawa isolate and 98.6-98.8% identity to a Japanese isolate of genotype B. On phylogenetic analysis, the HBV isolates from the two patients were classified as HBV genotype B. The HBV isolates of cases 1 and 3 clustered in the same group as isolates from the Chinese mainland and Japanese mainland, which are geographically near Miyako Island. CONCLUSION: The HBV isolates coinfected with HDV found on Miyako Island were of genotype B. The PCR method based on genotype-specific primers was useful in determining HBV genotypes.

Aged↗
PubMed2006

Laboratory Information Management Software for genotyping workflows: applications in high throughput crop genotyping.

BACKGROUND: With the advances in DNA sequencer-based technologies, it has become possible to automate several steps of the genotyping process leading to increased throughput. To efficiently handle the large amounts of genotypic data generated and help with quality control, there is a strong need for a software system that can help with the tracking of samples and capture and management of data at different steps of the process. Such systems, while serving to manage the workflow precisely, also encourage good laboratory practice by standardizing protocols, recording and annotating data from every step of the workflow. RESULTS: A laboratory information management system (LIMS) has been designed and implemented at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) that meets the requirements of a moderately high throughput molecular genotyping facility. The application is designed as modules and is simple to learn and use. The application leads the user through each step of the process from starting an experiment to the storing of output data from the genotype detection step with auto-binning of alleles; thus ensuring that every DNA sample is handled in an identical manner and all the necessary data are captured. The application keeps track of DNA samples and generated data. Data entry into the system is through the use of forms for file uploads. The LIMS provides functions to trace back to the electrophoresis gel files or sample source for any genotypic data and for repeating experiments. The LIMS is being presently used for the capture of high throughput SSR (simple-sequence repeat) genotyping data from the legume (chickpea, groundnut and pigeonpea) and cereal (sorghum and millets) crops of importance in the semi-arid tropics. CONCLUSION: A laboratory information management system is available that has been found useful in the management of microsatellite genotype data in a moderately high throughput genotyping laboratory. The application with source code is freely available for academic users and can be downloaded from http://www.icrisat.org/gt-bt/lims/lims.asp.

Algorithms↗
PubMed2003

Hepatitis C virus genotypes in Córdoba, Argentina. Unexpected high prevalence of genotype 2.

To determine hepatitis C virus (HCV) genotypes circulating in the central region of Argentina, 96 consecutive anti-HCV positive subjects were studied. The presence of HCV RNA was detected in 60 samples by RT-nested PCR of the 5' noncoding region (5' NCR). Genotyping was performed by restriction fragment length polymorphism analysis of 5' NCR region combined with PCR using type-specific primers of the core region. The groups of individuals in this study included hemophilia and hemodialysis patients, injecting drug users, screened blood donors, and patients with acute or chronic liver disease, all from Córdoba, Argentina. Overall, genotype 2 was the most prevalent (55.0%), followed by genotypes 1 (38.3%), and 3 (5.0%). Within genotype 1, subtype 1b was the most prevalent. An unexpected high prevalence of genotype 2 (61.9%) was found among patients with acute or chronic HCV infection (without known risk factors). These figures differ from other cohorts from East-Argentina where genotype 1 has been found as the most prevalent. This indicates that regional differences of genotype distribution might exist between Central and East Argentina.

Adolescent↗
PubMed2006

Virological outcomes in patients infected chronically with hepatitis B virus genotype A in comparison with genotypes B and C.

In a single hospital in Tokyo, the 87 patients infected persistently with hepatitis B virus (HBV) genotype A, the 413 with B, and the 3,389 with C were compared for virological outcome. Hepatitis B surface antigen (HBsAg) was cleared from the serum in 12% (3/26), 2% (2/112), and 3% (23/826) of patients with genotypes A, B, and C, respectively, at 5 years of follow-up (P = 0.0395). Hepatitis B e antigen (HBeAg) was cleared from serum more frequently in patients with genotype B than those with A or C (78% [32/41] vs. 58% [11/19] or 45% [251/562], P = 0.00001) at 5 years. Of the 45 individuals infected with genotype A and followed for 3 years or longer, HBeAg was more frequent (16% [3/19] vs. 73% [19/26], P = 0.0002) and levels of HBV DNA higher (median <2.6 [range: <2.6-5.6] vs. >7.6 [<2.6->7.6] log copies/ml, P = 0.001) in the 26 patients with biopsy-proven chronic hepatitis than the 19 asymptomatic carriers. Among the 26 hepatitis patients infected with HBV genotype A, decreases in HBV DNA were less frequent (20% [1/5] vs. 93% [13/14] or 86% [6/7], P = 0.0095) and increases in serum levels of hyaluronic acid > or =10 ng/ml commoner (80% [4/5] vs. 14% [2/14] or 14% [1/7], P = 0.017) in the patients who kept HBeAg than in those who seroconverted or who remained HBeAg-negative. In conclusion, patients persistently infected with HBV genotype A fare better than those with genotype B or C. However, high levels of HBV DNA continue in those in whom HBeAg persists along with fibrosis in the liver.

Adolescent↗
PubMedDate not supplied

Hepatitis B virus genotypes: comparison of genotyping methods.

There are eight genotypes of HBV designated A to H based on greater than 8% nucleotide variation over the entire genome. Hepadnaviruses infecting primates like the chimpanzee, orangutan and gibbon are very similar and can be regarded as genotypes of HBV. The eight genotypes of HBV show a distinct geographical distribution and influence the course of disease and the prognosis of treatment. Due to the variability of HBV, diagnostic procedures risk giving false-negative results or reporting an inaccurately low quantitative result. Thus, the variability of HBV genotypes can influence the interpretation of diagnostic data and the therapeutic decisions thereof in an unwanted way. HBV genotypes differ in the length of their genomes. The old system of numbering HBV nucleotides from the start of a non-conserved EcoRI site in the genome leads to difficulties in comparing nucleotide positions between genotypes. A numbering system is presented which avoids this problem. In addition we discuss the currently available methods for genotyping HBV.

Animals↗
PubMed2001

Host determinants of DNA alkylation and DNA repair activity in human colorectal tissue: O(6)-methylguanine levels are associated with GSTT1 genotype and O(6)-alkylguanine-DNA alkyltransferase activity with CYP2D6 genotype.

There is increasing evidence that alkylating agent exposure may increase large bowel cancer risk and factors which either alter such exposure or its effects may modify risk. Hence, in a cross-sectional study of 78 patients with colorectal disease, we have examined whether (i) metabolic genotypes (GSTT1, GSTM1, CYP2D6, CYP2E1) are associated with O(6)-methyldeoxyguanosine (O(6)-MedG) levels, O(6)-alkylguanine-DNA alkyltransferase (ATase) activity or K-ras mutations, and (ii) there was an association between ATase activity and O(6)-MedG levels. Patients with colon tumours and who were homozygous GSTT1(*)2 genotype carriers were more likely than patients who expressed GSTT1 to have their DNA alkylated (83 versus 32%, P=0.03) and to have higher O(6)-MedG levels (0.178+/-0.374 versus 0.016+/-0.023 micromol O(6)-MedG/mol dG, P=0.04) in normal, but not tumour, DNA. No such association was observed between the GSTT1 genotype and the frequency of DNA alkylation or O(6)-MedG levels in patients with benign colon disease or rectal tumours. Patients with colon tumours or benign colon disease who were CYP2D6-poor metabolisers had higher ATase activity in normal tissue than patients who were CYP2D6 extensive metabolisers or CYP2D6 heterozygotes. Patients with the CYP2E1 Dra cd genotype were less likely to have a K-ras mutation: of 55 patients with the wild-type CYP2E1 genotype (dd), 23 had K-ras mutations, whereas none of the 7 individuals with cd genotype had a K-ras mutation (P=0.04). No other associations were observed between GSTT1, GSTM1, CYP2D6 and CYP2E1 Pst genotypes and adduct levels, ATase activity or mutational status. O(6)-MedG levels were not associated with ATase activity in either normal or tumour tissue. However, in 15 patients for whom both normal and tumour DNA contained detectable O(6)-MedG levels, there was a strong positive association between the normal DNA/tumour DNA adduct ratio and the normal tissue/tumour tissue ATase ratio (r(2)=0.66, P=0.001). These results indicate that host factors can affect levels both of the biologically effective dose arising from methylating agent exposure and of a susceptibility factor, the DNA repair phenotype.

Adenosine Triphosphatases↗
PubMed2003

Direct comparison of hepatitis C virus genotypes tested by INNO-LiPA HCV II and TRUGENE HCV genotyping methods.

BACKGROUND: Hepatitis C virus (HCV) is a major cause of chronic liver disease worldwide. It is associated with the development of end-stage liver disease and hepatocellular carcinoma. Studies have shown that patients infected with different genotypes of HCV may respond to interferon-ribavirin therapy differently and thus HCV genotype information is very important in helping physicians to better managing their patients. OBJECTIVES: Compare the end results of HCV typing of the two commercially available tests. STUDY DESIGN: TRUGENE Genotyping test (Visible Genetics) was used to analyze clinical specimens obtained from North America. The 5' NC was amplified with the Roche COBAS Amplicor HCV Monitor Test. Amplification products were blinded and genotyped by the TRUGENE HCV 5'NC method. Genotype results were compared with those obtained by the reverse hybridization based INNO-LiPA HCV II (Innogenetics) assay. Additional sequencing of the NS5B region was done to resolve discrepancies. RESULTS AND CONCLUSIONS: Among the total of 110 consecutively collected serum specimens submitted for HCV genotyping, 108/110 could be typed by the sequencing method and 107/110 were typable by LiPA HCV II method. Our experiences with the tests suggest that at type level, HCV genotype results are 100% concordant between the two tests studied for those 106 specimens successfully typed by both methods. More sensitive amplification, such as qualitative PCR, is needed to test specimens with viral load lower than 20000 IU/ml. Both tests can be easily adapted by a clinical diagnostic laboratory.

5' Untranslated Regions↗
PubMed2003

IL-1 RN 2/2 genotype and simultaneous carriage of genotypes IL-1 RN 2/2 and IL-1beta-511 T/T associated with oesophagitis in Helicobacter pylori-negative patients.

BACKGROUND: Interleukin-1 receptor antagonist genotype 2/2 is associated with a prolonged and enhanced inflammatory response. It is suspected of being a risk factor for atrophic gastritis and gastric cancer and for some autoimmune diseases. No specific genetic risk factors for oesophagitis have been identified so far and there are no reports of IL-1 polymorphism in relation to oesophageal disease. METHODS: We studied the IL-1RN, IL-1beta-511 and IL-1beta + 3953 polymorphisms in an unselected series of 142 adult patients scheduled for gastrointestinal endoscopy because of dyspepsia. The control group consisted of university staff and students (n = 179). Helicobacter pylori status was determined by antibody testing and bacterial detection. RESULTS: Endoscopic oesophagitis was noted in 40 patients. The IL-1RN 2/2 genotype was significantly more prevalent in the patients with H. pylori-negative oesophagitis than in the control subjects (27% versus 9%; OR 3.574, CI 1.23-10.35, P = 0.034) or in the dyspeptic patients (27% versus 7%; OR 5.089. CI 1.51-17.11, P = 0.009). IL-1beta-511 T/T genotype tended to be more frequent in the H. pylori-negative patients with oesophagitis than in the control subjects (P = 0.071). The strongest association was between the simultaneous carriage of genotypes IL-1RN 2/2 and IL-1beta -511 T/T and H. pylori-negative oesophagitis. where the combined genotype was more prevalent than in the control subjects (23% versus 6%; OR 4.492, CI 1.40-14.46, P = 0.012) or the dyspeptic patients without oesophagitis (23% versus 3%: OR 9.706. CI 2.12-44.42, P = 0.003). CONCLUSIONS: The results indicate that the IL-1RN 2/2 genotype and the carriage of combined genotypes IL-1RN 2/2 + IL-1beta-511 T/T are associated with H. pylori-negative oesophagitis. This is the first report on the association between IL-1 gene polymorphism and oesophagitis.

Adult↗
PubMed2006

Hepatitis B virus genotypes in Alaska Native people with hepatocellular carcinoma: preponderance of genotype F.

BACKGROUND: The development of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B virus (HBV) infection has been associated with specific HBV genotypes and the presence of specific mutations. METHODS: From a cohort of Alaska Native people with chronic HBV infection, we genotyped 47 patients with HCC and 1129 patients without HCC, and we tested patients with HCC and control patients for mutations in the basal core promoter and precore regions. RESULTS: Genotype F was found in 68% of patients with HCC, versus 18% of those without HCC (P<.001). For patients with genotype F, the median age at diagnosis of HCC was lower than that for patients with other genotypes (22.5 vs. 60 years, respectively; P=.002). Overall, there were no significant differences in the number of basal core promoter and precore region mutations between patients with HCC and control patients. CONCLUSIONS: We found a significant association between genotype F and the development of HCC among Alaska Native people with chronic HBV infection but no significant association between HCC and basal core promoter or precore mutations in genotype F.

Adolescent↗
PubMed2000

Acetylator phenotype and genotype in patients infected with HIV: discordance between methods for phenotype determination and genotype.

The acetylator phenotype and genotype of AIDS patients, with and without an acute illness, was compared with that of healthy control subjects (30 per group). Two probe drugs, caffeine and dapsone, were used to determine the phenotype in the acutely ill cohort. Polymerase chain reaction amplification and restriction fragment length polymorphism analysis served to distinguish between the 26 known NAT2 alleles and the 21 most common NAT1 alleles. The distribution (%) of slow:rapid acetylator phenotype seen among acutely ill AIDS patients differed with the probe substrate used: 70:30 with caffeine versus 53:47 with dapsone. Phenotype assignment differed considerably between the two methods and there were numerous discrepancies between phenotype and genotype. The NAT2 genotype distribution was 45:55 slow:rapid. Control subjects, phenotyped only with caffeine, were 67:33 slow:rapid versus 60:40 genotypically. Stable AIDS patients, phenotyped only with dapsone, were 55:45 slow:rapid versus 46:54 genotypically. Following resolution of their acute infections, 12 of the acutely ill subjects were rephenotyped with dapsone. Phenotype assignment remained unchanged in all cases. The distribution of NAT1 alleles was similar in all three groups. It is evident from the amount of discordance between caffeine phenotype and dapsone phenotype or genotype that caution should be exercised in the use of caffeine as a probe for NAT2 in acutely ill patients. It is also clear that meaningful study of the acetylation polymorphism requires both phenotypic and genotypic data.

Acetylation↗
PubMed2006

APOE genotype and cholesterol levels in lewy body dementia and Alzheimer disease: investigating genotype-phenotype effect on disease risk.

BACKGROUND: APOE is the most recognized genetic risk factor for sporadic late-onset Alzheimer disease (AD). The role of APOE genotype in Lewy body dementia (LBD) is still unknown as well as the relationship between APOE genotype and cholesterol levels. OBJECTIVE: The objective of this study was to explore the association between APOE genotype and cholesterol levels in patients with LBD and those with AD. METHODS: Eighty-two patients with LBD were consecutively enrolled as well as a comparable number of patients with AD and comparison group. Each subject underwent a clinical and neuropsychologic evaluation and APOE genotyping. RESULTS: The distribution of APOE genotypes significantly differed between AD and LBD cases compared with the comparison group, with the APOE epsilon4+ (epsilon4+/epsilon4 + or epsilon4+/epsilon4-) genotype more frequent in patient subgroups. Different models have been fitted, and total APOE epsilon4-hypercholesterolemia complete interaction effect was claimed in predicting their relationship on disease outcome. Subjects with hypercholesterolemia and heterozygous for APOE epsilon4 allele had more than threefold risk to develop AD compared both with the comparison group and with those with LBD. The risk to develop AD in hypercholesterolemic and APOE epsilon4 homozygous subjects was 13-fold compared with the comparison group and those with LBD. Conversely, there was not evidence for APOE epsilon4-hypercholesterolemia complete interaction effect in LBD and in the comparison group. CONCLUSIONS: This study highlighted that APOE is a risk factor not only for AD, but also for LBD, and that the APOE-cholesterol pathway differently affects AD and LBD. This approach may aid the search for the identification of an interactive effect of APOE genotype and modifiable risk factors, i.e., hypercholesterolemia, eventually resulting in individualized and effective cholesterol-lowering therapy in at-risk subjects.

Alzheimer Disease↗
PubMed2005

Acanthamoeba genotype T4 from the UK and Iran and isolation of the T2 genotype from clinical isolates.

The majority of the keratitis-causing Acanthamoeba isolates are genotype T4. In an attempt to determine whether predominance of T4 isolates in Acanthamoeba keratitis is due to greater virulence or greater prevalence of this genotype, Acanthamoeba genotypes were determined for 13 keratitis isolates and 12 environmental isolates from Iran. Among 13 clinical isolates, eight (61.5%) belonged to T4, two (15.3%) belonged to T3 and three (23%) belonged to the T2 genotype. In contrast, the majority of 12 environmental isolates tested in the present study belonged to T2 (7/12, 58.3%), followed by 4/12 T4 isolates (33.3%). In addition, the genotypes of six new Acanthamoeba isolates from UK keratitis cases were determined. Of these, five (83.3%) belonged to T4 and one was T3 (16.6%), supporting the expected high frequency of T4 in Acanthamoeba keratitis. In total, the genotypes of 24 Acanthamoeba keratitis isolates from the UK and Iran were determined. Of these, 17 belonged to T4 (70.8%), three belonged to T2 (12.5%), three belonged to T3 (12.5%) and one belonged to T11 (4.1%), confirming that T4 is the predominant genotype (S2=4.167; P=0.0412) in Acanthamoeba keratitis.

Acanthamoeba↗
PubMed2006

Genotype 1 and genotype 2 bovine noroviruses are antigenically distinct but share a cross-reactive epitope with human noroviruses.

The bovine enteric caliciviruses Bo/Jena/1980/DE and Bo/Newbury2/1976/UK represent two distinct genotypes within a new genogroup, genogroup III, in the genus Norovirus of the family Caliciviridae. In the present study, the antigenic relatedness of these two genotypes was determined for the first time to enable the development of tests to detect and differentiate between both genotypes. Two approaches were used. First, cross-reactivity was examined by enzyme-linked immunosorbent assay (ELISA) using recombinant virus-like particles (VLPs) and convalescent-phase sera from calves infected with either Jena (genotype 1) or Newbury2 (genotype 2). Second, cross-reactivity was examined between the two genotypes with a monoclonal antibody, CM39, derived using Jena VLPs. The two genotypes, Jena and Newbury2, were antigenically distinct with little or no cross-reactivity by ELISA to the heterologous VLPs using convalescent calf sera that had homologous immunoglobulin G titers of log10 3.1 to 3.3. CM39 reacted with both Jena and heterologous Newbury2 VLPs. The CM39 epitope was mapped to nine amino acids (31PTAGAQIAA39) in the Jena capsid protein, which was not fully conserved for Newbury2 (31PTAGAPVAA39). Molecular modeling showed that the CM39 epitope was located within the NH2-terminal arm inside the virus capsid. Surprisingly, CM39 also reacted with VLPs from two genogroup II/3 human noroviruses by ELISA and Western blotting. Thus, although the bovine noroviruses Jena and Newbury2 corresponded to two distinct antigenic types or serotypes, they shared at least one cross-reactive epitope. These findings have relevance for epidemiological studies to determine the prevalence of bovine norovirus serotypes and to develop vaccines to bovine noroviruses.

Amino Acid Sequence↗
PubMed2001

Evaluation and use of a nested polymerase chain reaction assay in cats experimentally infected with Bartonella henselae genotype I and Bartonella henselae genotype II.

Cats have been shown to be infected with Bartonella henselae genotype I, B. henselae genotype II, and B. clarridgeiae. Feline bartonellosis infections and the strains involved in these infections are important in both veterinary and human medicine. Nucleic acid amplification methods such as polymerase chain reaction (PCR) are being used in both research and diagnostics as tools for understanding many infectious diseases. Bartonella bacteremia in cats is detected by blood culture; however, because of the limitations of culture (delayed turnaround time and sensitivity limits), PCR may be a more efficient method for identifying infected cats. Three distinct PCR assays that could differentiate among B. henselae genotype I, B. henselae genotype II. and B. clarridgeiae were developed and used to detect as few as 3.2 organisms. Fourteen cats experimentally infected with B. henselae genotype I and B. henselae genotype II were followed by bacterial culture and PCR through the course of infection, including periods of primary and relapsing bacteremia. The PCR assay was positive in 11 of the 14 cats for periods of 1-9 weeks after culture became negative. Of the 223 blood specimens that were culture negative, the PCR assay was positive in 38 (17%) of the specimens. Two of the 14 cats developed relapsing bacteremia. The 2 B. henselae genotypes were amplified in the cats and the bacteremic phase of these infections as determined by PCR lasted for a longer period than previously determined by culture. Using laboratory assays such as PCR to understand the strains involved in feline bartonellosis and the course of the infection is important in the understanding of these zoonotic agents.

Animals↗