Andrzej Kowalczyk, Kinga Urbaniak, Iwona Markowska-Daniel and Zygmunt Pejsak
The aim of the study was to monitor genetic diversity and antigenic changes in the genome of influenza A(H1N1)pdm09 viral isolates detected during the post-pandemic period in Poland. Clinical specimens obtained from three suspected cases of influenza were analysed by sequencing. Among the differences identified in amino acids sequences, nine substitutions were located within the antigenic HA1 sites and in five residues forming receptor-binding pocket. The HA(D222G) mutation was shown in the isolate Swine/Poland/134312/12 obtained from a mild case of the disease. It must be emphasized that, in general, clinically mild cases are caused by the viruses in which that specific mutation, i.e. haemagglutinin (D222G), does not occur.
Andrzej Kowalczyk, Kinga Urbaniak and Iwona Markowska-Daniel
Phylogenetic analysis of the genes determining influenza virus subtype - haemagglutinin (HA) and neuraminidase (NA), was performed. The results showed that the Polish H1N2 isolate (A/Swine/Poland15817/2011) was reassortant of human-like swine H1N1 and human-like swine H3N2 origin. The novel isolate was presented to have a close phylogenic relationship with one of the latest European isolates of H1N2 (A/SW/Gent/102/2007 and A/SW/Hungary/13509/2007). Our evolutionary analyses also suggested that the HA and NA genes evolved in a significantly higher rate of synonymous substitutions after they were introduced from human to swine and established the European H1N2 swine lineage.
Iwona Markowska-Daniel, Krzysztof Kwit, Kinga Urbaniak and Andrzej Kowalczyk
The aim of the study was to estimate the current epidemiological situation concerning swine influenza (SI) in Poland. The study was based on an annual passive survey of 11,770 fatteners’ sera from 584 herds, taken at slaughterhouses within the last 30 months (from January 2010 till June 2012), as well as, an active monitoring conducted in 2011 and 2012, in 25 farms, using 388 sera taken from life pigs of different age/technological groups. The analysis of simultaneous circulation of different swine influenza virus (SIV) subtypes was taken into a deep consideration. The wide spread of SIV in Poland, including the occurrence of multiple SIV infections was demonstrated. In 2010 and 2011, the domination of H1N1 subtype and the most frequently co-circulation of H1N1 and H1N2 viruses was evidenced, while in the first 6 months of 2012, the co-circulation of H1N1 and H3N2 viruses was detected more often. Based on the obtained results, it can be stated that the epidemiological situation concerning SI in Poland is dynamic and similar to that observed in other European regions with high pigs’ density; however, the prevalence of antibodies and the occurrence of mixed SIV infections is lower than in Western Europe.
Małgorzata Pomorska-Mól, Iwona Markowska-Daniel, Krzysztof Kwit, Kinga Urbaniak and Zygmunt Pejsak
The kinetics of C-reactive protein (CRP), haptoglobin (Hp), serum amyloid A (SAA), and pig major acute protein (Pig-MAP) response in pigs co-infected with H3N2 swine influenza virus (SwH3N2) and Bordetella bronchiseptica (Bbr) was studied, with assessment of potential correlations between the concentration of acute phase proteins (APPs) in serum samples, lung lesions, and the clinical course of the disease in co-infected pigs. The standard bacteriological methods for detection of Bbr and PCR technique for identification of Bbr and SwH3N2 were used. The serum concentrations of APPs were measured using ELISA. The concentration of CRP, SAA, and Pig-MAP was significantly higher from 2 to 4 or 5 dpi. The concentration of Hp was elevated until the end of the study. Significant correlations were found between the serum concentration of SAA and Pig-MAP and clinical score, and between the concentration of SAA and lung score. Apart from their potential as biological markers for co-infections, SAA and Pig-MAP levels have additive value since they are related to the severity of infection. The results indicate that measurement of APP (i.e SAA) may prove valuable in assessing the severity of respiratory infection in pigs, and may be of supportive value in the clinical evaluation of animals and in the selection of more appropriate treatment.
Iwona Markowska-Daniel, Karol Wierzchosławski, Kinga Urbaniak and Aandrzej Kowalczyk
The paper describes an outbreak of swine influenza, which was the first H1N2 outbreak confirmed in pig farm in Poland. The outbreak occurred in October 2011 in the farrows to finish farm, first in the fattening units, and subsequently in the reproduction and weaning sectors. Samples of the lungs taken from dead gilts were tested by the use of real time and multiplex PCR, sequencing, and virus isolation methods. The amplification of the genetic material extracted from the lungs confirmed the presence of the M1 gene sequence of type A influenza virus. Using multiplex PCR, the bands of 241 bp, typical for HA1 human-like type, and of 791 bp, typical for NA2, were demonstrated. The new isolates of swine influenza virus, named A/swine/Poland/15817/2011, were obtained in embryonated SPF chicken eggs and MDCK cells. Phylogenetic analysis of the HA and NA genes of the isolate revealed that the virus is of human swine linkage closely related to European human-like viruses. On the basis of such results, it can be stated that A/Swine/Poland/15817/2011 is a new swine influenza virus, representing the H1N2 subtype strain, which emerged in Poland.
Iwona Markowska-Daniel, Kinga Urbaniak, Marian Porowski, Paweł Karbowiak, Andrzej Kowalczyk, Edyta Kozak and Zygmunt Pejsak
The outbreaks of pandemic H1N1 influenza A virus (pdm-like H1N1 2009), detected for the first time in farrow-to-finish farms in Poland, were described. The nasal swabs and lung tissue collected from diseased/dead animals were tested using molecular techniques (RRT-PCR, MRT-PCR, RT-PCR, SSG-PCR, sequencing) and virus isolation. The amplification of the genetic material extracted from the tested samples confirmed the presence of the M1 gene sequence of type A influenza virus. Using MRT-PCRs no products characteristic for HA and NA of any swine influenza virus subtypes were obtained. Using SSGPCR, products specific for pandemic HA and NA gene fragments were detected. Six new pdm-like H1N1 2009 strains were isolated and characterised. Phylogenetic analysis of the HA and NA genes revealed that they belong to one lineage with the pandemic strain A/California/04/2009 and other human strains, including human strains isolated in Poland in 2011.