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  • Author: Grzegorz Woźniakowski x
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Grzegorz Woźniakowski and Elżbieta Samorek-Salamonowicz

Abstract

The study describes construction of five recombinant very virulent (vv) and very virulent plus (vv+) strains lacking meq and viral telomerase (vTR). Deletion of both copies of meq and vTR was achieved by Red E/T recombination in GS1783 E. coli cells. The constructed bacterial artificial chromosome (BAC) clones reconstituted in chicken embryo fibroblasts were examined by immunofluorescence assay to compare the features of recombinant strains with wild-type viruses. The results demonstrated that recombinant BAC strains caused slightly reduced cytophatic effect and decreased level of the fluorescence obtained from the monoclonal antibody in comparison to the parental viruses. Generation of recombinant BAC clones may provide more detailed information on the function of Marek's disease virus oncogenes and the potential use of recombinants for the preparation of the new vaccine against Marek’s disease.

Open access

Grzegorz Woźniakowski, Magdalena Frączyk, Krzysztof Niemczuk and Zygmunt Pejsak

Abstract

African swine fever (ASF) is currently one of the most severe viral infections of domestic pigs, wild boars, and other hosts belonging to Suidae family. ASF is also considered as the most complex and devastating infectious and haemorrhagic disease of swine due to its severe socio-economic impact and transboundary character. ASF it is a notifiable disease and due to the lack of specific treatment and vaccine, the disease can be only limited by the administrative measures comprising wild boar hunting and stamping out of affected pigs. ASF occurred for the first time in Kenya in 1921 while in Europe (Portugal) the virus was detected at the end of the 1950s. In spite of successful eradication of this threat in a number of affected regions, the virus remains endemic in both feral and domestic pigs in Africa and Sardinia. The ‘new era’ of ASF started in 2007 after its re-introduction to Georgia. Following its intensive expansion, the virus spread to other Caucasian countries, including the territory of the Russian Federation. In 2014 the virus reached Ukraine, Belarus, and, consequently, European Union countries: Lithuania, Latvia, Estonia, and Poland. The occurrence of ASF in wild boars and pigs had a severe impact on both epidemiology and economy because of the national and international transport and trade consequences. Up to date, starting from the February 2014, eighty ASF cases in wild boar and three outbreaks in domestic pigs have been diagnosed. Taking into account the diverse rate of spread in Poland, this review aims to present and discuss the current state of knowledge on ASF including its epidemiology, pathology, transmission, and perspectives of control.

Open access

Grzegorz Woźniakowski, Maciej Frant and Andrzej Mamczur

Abstract

Avian reticuloendotheliosis (RE) represents an important immunosuppressive disease of poultry. The occurrence of RE in both chickens and turkeys has an immunosuppressive effect and may lead to vaccination failures. Avian reticuloendotheliosis virus (REV) is widely distributed in different kinds of birds, causing subclinical infections. Another important issue adhering to this disease is contamination of vaccines against fowl pox (FP) and Marek’s disease (MD) with REV. The capability of REV to integrate into the genome of other larger DNA viruses complicates its diagnosis and prevention. There are no efficient vaccines against RE nor treatment, which also complicates how to limit its impact on poultry farming. This paper reviews the current state of knowledge of this important immunosuppressive agent of poultry emphasising the importance of this problem in terms of diagnosis of RE.

Open access

G. Woźniakowski, E. Samorek-Salamonowicz and A. Gaweł

Abstract

During the summer 2012 an incidence of high mortality, above 44 percent, in two flocks of Muscovy ducklings in Poland was noted. The clinical signs included considerable weight loss and inability to walk.

During the post-mortem evaluations dehydration and enteritis, gouty kidneys as well as hemorrhagic liver and spleen lesions were found. The laboratory diagnosis included agar gel precipitation assay (AGP) as well as polymerase chain reaction (PCR) or reverse transcription PCR for the presence of goose parvovirus (GPV), duck circovirus (DuCV), duck reovirus (DRV) and avian reovirus (ARV). Interestingly, the examinations performed by AGP showed partial reactivity of liver homogenates from Muscovy ducklings with chicken S1133 antiserum. The presence of duck reovirus RNA was also detected by real-time RT-PCR targeting the chicken reovirus sigma NS fragment, while the sequencing showed major similarity to chicken S1133, 1733, GX/2010/1 and TARV-MN2 reovirus strains. The virus sequence was also related to a previously isolated TH11 strain from Muscovy ducks in China.

Further study is needed in order to explain the particular epidemiology of the reovirus infection of Muscovy ducklings

Open access

Karolina Tarasiuk, Grzegorz Woźniakowski and Elżbieta Samorek-Salamonowicz

Abstract

The objective of the study was to develop a simple and rapid molecular method for the detection of GPV. Twenty seven goose parvovirus (GPV) isolates collected from geese flocks in Poland were examined. Three pairs of specific primers: two outer primers (F3 and B3), two inner primers (FIP and BIP), and two loop primers (FL and BL) were used to accelerate the reaction. The optimum temperature and time of the reaction were 60°C and 30 min. The sensitivity of the method was 10-times higher than PCR. The method proved to be a sensitive, rapid, and specific assay for detecting GPV.

Open access

Maciej Frant, Grzegorz Woźniakowski and Zygmunt Pejsak

Abstract

Infectious diseases of swine, particularly zoonoses, have had a significant influence on nutritional safety and availability of pig meat as high-energy protein product since the time that pigs were domesticated back in the 7th century BC. The main sources of swine infectious diseases include the so-called primary sources (direct infection, i.e. through contact with infected and sick animals) and secondary sources (contaminated meat products, slaughter products, and vectors, including ticks). At present, the most serious epidemiological and economic threat to swine breeding in Europe is African swine fever (ASF). This disease, originally coming from Africa, is incurable and causes death of infected pigs and wild boars during 7−10 days after infection. Among the various factors that influence the spread of ASF, important role is played by ticks from the genus Ornithodoros, mainly from the species Ornithodoros moubata. Research on the ASF indicates that other species of ticks can also transmit the virus to healthy pigs in laboratory conditions. Sylvatic and domestic cycles of ASF virus transmission, which have been described so far, require further studies and updating in order to point the potential new vectors in the Caucasus and Eastern Europe affected by the ASF. Effective methods of control and biosecurity may significantly slow down the spread of ASF, which undoubtedly is a major threat to world pig production and international swine trade.

Open access

Wojciech Kozdruń, Grzegorz Woźniakowski, Hanna Czekaj, Wojciech Kozaczyński and Elżbieta Samorek–Salamonowicz

Abstract

Neoplastic changes characteristic of Marek’s disease (MD) in the geese flock were described. The investigations were performed on White Italian reproductive geese kept on a farm where MD was previously diagnosed in broilers. Neither antibodies against MD virus (MDV) were detected by AGID method, nor MDV antigen was found by RID. The histopathological examination revealed the presence of lymphoid infiltrations characteristic of MD in all examined tissues. No lesions typical for avian leukosis or reticuloendotheliosis were observed. PCR products characteristic of meq, and ICP4 and pp38 genes were not observed, but real-time PCR for gB gene of MDV were positive in DNA samples from visceral organs. The realtime PCR results may indicate the presence of a new MDV variant or a new herpesviral infection among geese.

Open access

Jowita Samanta Niczyporuk, Grzegorz Woźniakowski, Elżbieta Samorek-Salamonowicz and Hanna Czekaj

Abstract

The aim of the study was to determine the effect of field strain, serotype 7 (FAdV-7 JN-5/10), of fowl adenovirus infection on the replication of Rispens/CVI988 strain of Marek’s disease virus. Ninety one-day-old SPF chickens were divided into six groups. The chickens from group I were vaccinated against Marek’s disease (MD) and 24 h later infected with the adenovirus; chickens from group II were vaccinated and infected simultaneously; chickens from group III were infected with the adenovirus and 24 h after the infection vaccinated against MD. The chickens from groups IV-VI were: control of infection (IV), control of vaccination (V), and neither vaccinated nor infected (VI). After 3, 7, 14, 21, and 28 d post infection, the number of copies of pp38 gene of Rispens strain and hexon gene of FAdV strain was determined in the bursa of Fabricius and liver using real-time PCR. The results indicated that in all cases the replication of Rispens strain was reduced to about 1.0 log10 - 3.5 log10 in chickens infected with the adenovirus and vaccinated against MD compared with the chickens only vaccinated. Sixty-three one-day-old SPF chickens infected with adenovirus and vaccinated against MD were challenged with vv MD virus field strain. The protection index in this experiment was 55.6%-77.8%.

Open access

Jowita Samanta Niczyporuk, Grzegorz Woźniakowski, Elżbieta Samorek-Salamonowicz and Hanna Czekaj

Abstract

The aim of the study was to determine the influence of simultaneous infection of chicken embryo fibroblasts (CEF) with different doses of adenovirus field strain serotype 7 (FAdV-7 JN-5/10j) and turkey herpesvirus strain FC126 (FC126 HVT) on replication of the herpesvirus in in vitro cultures. Three experiments were performed: simultaneous infection of CEF with adenovirus and HVT; inoculation of CEF culture with adenovirus, followed by infection with HVT after 24 h; and inoculation of CEF with HVT, followed by the infection with adenovirus 24 h later. In order to detect the presence of HVT and adenovirus strains in CEF culture, SORF 1 and hexon genes were determined, respectively. The infection with adenovirus lowered replication of FC126 HVT in chicken embryo fibroblast.

Open access

Ewelina Szacawa, Monika Szymańska-Czerwińska, Krzysztof Niemczuk, Katarzyna Dudek, Grzegorz Woźniakowski and Dariusz Bednarek

Abstract

Introduction: Mycoplasma bovis is one of the main pathogens involved in cattle pneumonia. Other mycoplasmas have also been directly implicated in respiratory diseases in cattle. The prevalence of different Mycoplasma spp. in cattle affected by respiratory diseases and molecular characteristics of M. bovis field strains were evaluated. Material and Methods: In total, 713 nasal swabs from 73 cattle herds were tested. The uvrC gene fragment was amplified by PCR and PCR products were sequenced. PCR/DGGE and RAPD were performed. Results: It was found that 39 (5.5%) samples were positive for M. bovis in the PCR and six field strains had point nucleotide mutations. Additionally, the phylogenetic analysis of 20 M. bovis field strains tested with RAPD showed two distinct groups of M. bovis strains sharing only 3.8% similarity. PCR/DGGE analysis demonstrated the presence of bacteria belonging to the Mollicutes class in 79.1% of DNA isolates. The isolates were identified as: Mycoplasma bovirhinis, M. dispar, M. bovis, M. canis, M. arginini, M. canadense, M. bovoculi, M. alkalescens, and Ureaplasma diversum. Conclusion: Different Mycoplasma spp. strains play a crucial role in inducing respiratory diseases in cattle.