Search Results

You are looking at 101 - 110 of 1,417 items for :

  • Refine by Access: All Content x
Clear All

To explore the diversity of some DNA viruses in reptiles, a continuous screening is going on, in our laboratory, by PCR using different consensus primers designed for the detection of the most conserved genome regions of adeno-, herpes- and parvoviruses. The test material consists essentially of dead specimens collected randomly from private pet owners, local pet shops, or at occasional exotic pet fairs. Here we report the partial sequence of a putative novel parvovirus obtained from a dead checkerboard worm lizard (Trogonophis wiegmanni) that had been wild-caught in its native habitat. An in-house-developed PCR with consensus primers targeting the gene of the parvoviral capsid protein was used. Other PCRs, intended to detect certain large DNA viruses, remained negative. The sequence of the PCR product indicated the presence of a hitherto unknown parvovirus in the internal organs of the checkerboard worm lizard. In phylogeny reconstruction, the novel sequence clustered with the members of the Dependovirus genus of the Parvoririnae subfamily, closest to the branch of snake adeno-associated virus. Since we could not demonstrate the presence of a potential helper virus, the putative amphisbaenian parvovirus supposedly can replicate autonomously. This is the first virus infection ever detected in any members of the suborder Amphisbaenia, and only the third parvoviral sequence obtained from any reptilian host.

Open access

The occurrence of two important pathogens, equine herpesvirus 1 (EHV1) and equine arteritis virus (EAV) causing abortions, perinatal foal mortality and respiratory disease, was investigated by polymerase chain reaction (PCR) and virus isolation to demonstrate the presence of abortigenic viruses in samples from 248 horse fetuses in Hungary. We found 26 EHV1- and 4 EAV-positive aborted or prematurely born foals from 16 and 4 outbreaks, respectively, proving that despite the widely applied vaccination, EHV1 is a far more important cause of abortions in the studs than EAV. We compared the virus content of different organs of the fetuses by PCR and isolation to identify the organ most suitable for virus demonstration. Our investigations indicate that the quantity of both viruses is highest in the lungs; therefore, according to our observations, in positive cases the probability of detection is highest from lung samples of aborted or newborn foals. Both the PCR and the virus isolation results revealed that the liver, though widely used, is not the best organ to sample either for EHV1 or for EAV detection. From the analysis of the epidemiological data, we tried to estimate the importance of the two viruses in the Hungarian horse population.

Restricted access
Acta Veterinaria Hungarica
Authors:
Zsolt Becskei
,
Sanja Aleksić-Kovačević
,
Miklós Rusvai
,
Gyula Balka
,
Csaba Jakab
,
Tamaš Petrović
, and
Milijana Knežević

The lymphatic organs of 50 pigs from a total of eight farms located at different sites in the epizootiological region of North Bačka County were studied to obtain data on the prevalence of circoviral infections in Serbia. All of the pigs examined had clinical signs suggestive of postweaning multisystemic wasting syndrome (PMWS). All pigs underwent necropsy and tissue samples were taken for histopathological, immunohistochemical (IHC) and PCR analysis. The presence of porcine circovirus 2 (PCV2) was established by PCR analysis in the organs of the pigs tested. The most frequent histopathological lesions of lymphoid tissue linked with the presence of positive immunostaining for PCV2 Cap antigen confirmed the existence of PMWS in all farms tested in North Bačka County. Using PCR, histopathological and IHC techniques, the presence of PMWS was proved in the Republic of Serbia. During necropsy, generalised enlargement of the lymph nodes was evident. The most common histopathological finding was lymphocyte depletion in the follicular and perifollicular areas of lymph nodes. Infiltration by macrophages was also recorded. By IHC analysis, the cytoplasm of macrophages was shown to contain a large amount of the ORF2-coded Cap antigen of PCV2. Lymphocyte depletion and large numbers of macrophages were recorded in the tonsils, spleen, intestinal lymphatic tissue, Peyer’s patches and ileocaecal valve. The presence of typical granulomatous lesions with multinuclear giant cells (MGCs) was also recorded in the lymphatic tissue. Cap antigen was shown to be present in macrophages and less often in lymphocytes.

Restricted access

Six strains (Bi11, Bi30, Bi36, Bi50, Bi52 and Bi55) isolated from bio-yoghurts and two strains (KD10 and KD11) derived from human faeces were identified by genus- and species specific polymerase chain reaction (PCR) with reference to the type strains of B. animalis subsp. lactis DSM 10140 and B. animalis subsp. animalis DSM 20104. The isolates were differentiated by using Bcu I ( Spe I), Xba I and Dra I endonucleases for subsequent pulsed field gel electrophoresis (PFGE) technique and by API 50 CHL tests.All the isolates tested were classified to B. animalis subsp. lactis species. The reliable identification as B. animalis subsp. lactis (by PCR with Bflact2/Bflact5 primers), however, required confirmation by a negative result of B. animalis subsp. animalis -specific PCR.Differentiation of the B. animalis subsp. lactis isolates with PFGE method enabled to distinguish KD11 strain with all the restriction enzymes applied, and Bi11 and Bi30 — exclusively with Dra I and Spe I enzymes, respectively. The biochemical tests, however, revealed that all the strains tested were characterised by a unique fermentation pattern. It was concluded that differentiation of the B. animalis subsp. lactis strains should be carried out on the basis of both genetic and phenotypic features.

Restricted access
Acta Biologica Hungarica
Authors:
Á. Horváth
,
P. Sántha
,
V. Horváth
,
Nóra Török
,
I. Nagy
,
G. Jancsó
,
Cs. Vágvölgyi
, and
F. Somogyvári

Burkhart, C. A., Norris, M. D., Haber, M. (2002) A simple method for the isolation of genomic DNA from mouse tail free of real-time PCR inhibitors. J. Biochem. Biophys. Meth. 52 , 145

Restricted access
Acta Veterinaria Hungarica
Authors:
Ching-Yang Cheng
,
Jing-Ruei Chi
,
Sin-Rong Lin
,
Chi-Chiang Chou
, and
Chin-Cheng Huang

The objective of this study was to use a 5′-nuclease (TaqMan) real-time PCR method with primers and probe specific to the spaQ gene as a rapid approach to quantitatively determine Salmonella Typhimurium. The result showed that the correlation coefficient between real-time PCR estimates and bovine serum albumin (BSA) plate counts of S . Typhimurium was 0.99, independently of 10 5 -fold numbers of bystander Escherichia coli O157:H7 or total viable counts. The sensitivity of the real-time quantitative PCR assay was 10 CFU/mL for pure S . Typhimurium culture without enrichment. A known number of S . Typhimurium target cells were inoculated to dumpling fillings and chicken nuggets and DNA was extracted for real-time PCR analysis. The sensitivity was 60 CFU/g for S . Typhimurium inoculated to the food samples without any preceding procedure of enrichment. The duration of the entire experiment from DNA isolation and purification to PCR amplification was less than 12 h. This study demonstrated that realtime PCR is a rapid and reliable technique for quantifying S . Typhimurium possessing the spaQ gene in pure culture and in meat products.

Restricted access

Up to now, only a single adenovirus (AdV) isolate seemingly specific for pigeons, hence named pigeon AdV-1 (PiAdV-1), has been characterised at DNA sequence level. In the present work, the prevalence and diversity of AdVs occurring in domestic pigeon were examined by a survey performed on randomly collected samples using a very efficient, consensus nested PCR targeting the viral DNA polymerase gene. The newly detected viruses were characterised by sequencing and phylogeny analysis. Amplification of additional genome fragments was attempted by the use of several other PCR methods aiming at the hexon gene. During a 4-year survey, samples from dead or live, healthy pigeons originating from 27 lofts were examined in Hungary. Almost 50% of the samples (48 out of 97) proved to be positive for AdV. Sequence analysis revealed the presence of four hitherto unknown pigeon AdV types. PiAdV-1 was also identified in one sample. Two novel viruses named PiAdV-2 and -3 were found to belong to the genus Aviadenovirus, and two other novel types (PiAdV-4 and -5) to the genus Siadenovirus. This is the first report on the occurrence of siadenoviruses in birds belonging to the order Columbiformes. Approximately two-thirds of the PiAdV-2 genome was sequenced and analysed.

Restricted access
Acta Microbiologica et Immunologica Hungarica
Authors:
Mojtaba Moosavian
,
Sakineh Seyed-Mohammadi
,
Ahmad Farajzadeh Sheikh
,
Saeed Khoshnood
,
Aram Asarehzadegan Dezfuli
,
Morteza Saki
,
Gholamreza Ghaderian
,
Fatemeh Shahi
,
Mahtab Abdi
, and
Fariba Abbasi

Shigella spp. are a major cause of bacillary dysentery, particularly among children in developing countries such as Iran. This study aimed to investigate the presence of two important Shigella enterotoxins (ShET-1 and ShET-2), encoded by the set and sen genes, respectively, by polymerase chain reaction (PCR) assay among Shigella species isolated from children affected by shigellosis in Ahvaz, southwest of Iran. In this cross-sectional study, from June 2016 to April 2017, altogether 117 Shigella isolates were collected from fecal specimens of children aged <15 years with diarrhea in Ahvaz, southwest Iran. All isolates were identified by standard microbiological and molecular methods. The presence of enterotoxin genes was determined by PCR. The most prevalent isolate was Shigella flexneri (47.9%), followed by Shigella sonnei (41%) and Shigella boydii (11.1%), respectively. Shigella dysenteriae was not detected in patients’ samples. The frequencies of set1A, set1B, and sen genes were 5.1% (6/117), 15.4% (18/117), and 76.9% (90/117), respectively. This study provides initial background on the prevalence and distribution of the Shigella enterotoxin genes in Shigella isolates in southwest of Iran. In addition, this study revealed a high prevalence of sen enterotoxin gene in Shigella species.

Restricted access

A total of 146 Pasteurella multocida strains isolated from swine in Hungary in the last 20 years were examined. Biochemical characterisation and PCR-based techniques were used to determine species, subspecies, biovar, capsule type and presence of the toxA gene. Eighty-seven percent of the isolates belonged to P. multocida ssp. multocida , and 98% of these had biovar 3 or were trehalose-or lactose-fermenting or ornithine decarboxylase negative variants of that. Ten percent of the strains were P. multocida ssp. septica , and within this group 80% of the strains showed sorbitol-negative biovars (5, 6 and 7). The rest of the strains (20%) were lactose positive. Only 3% of the porcine isolates were P. multocida ssp. gallicida and 3 out of the 4 strains belonged to the dulcitol-fermenting biovar 8. Using a capsule-specific multiplex PCR, 60% of the strains belonged to capsule type D, 38% to capsule type A, and only 1 isolate had capsule type F. In contrast with data published in the literature, only 3% of capsule type D isolates carried the toxA gene, while this ratio was 41% for the type A strains. A remarkable regional distribution of toxA gene positive strains was observed. All but two isolates were found in swine herds located in the Transdanubian region, separated from other parts of Hungary by the river Danube.

Restricted access

A real-time PCR assay was evaluated for the rapid detection (10 h) of Salmonella in meats using molecular beacon probes available as a commercial kit (iQ-Check, Bio-Rad laboratories). Raw (chicken, pork) and ready-to-eat (RTE) meats were artificially contaminated with Salmonella enterica serovar Typhimurium at the estimated level of 2 to 4 cells per 25 g. After 8 h of pre-enrichment in buffered peptone water, a molecular beacon-based PCR assay was performed to detect contamination in raw and RTE meats. The sensitivity and accuracy of the assay were compared with the conventional USDA microbiological procedure. Comparative evaluation of the USDA procedure with the rapid PCR assay for meat samples (n = 63) revealed 1 false negative pork sample with the PCR assay. All uninoculated controls (n = 34) but one sample were negative by both the 10-h PCR assay and the USDA procedure. Developing rapid pathogen detection methods with shorter pre-enrichment times (8-h) and real-time data monitoring capabilities will benefit the industry in preventing recall of contaminated meats by stopping the contaminated products from being introduced into the marketplace.

Restricted access