Epidemiologic and phylogenetic analyses suggest that the virus was repeatedly introduced and that the disease is maintained in wild boar.
Wild birds are considered as a reservoir for avian chlamydiosis posing a potential infectious threat to domestic poultry and humans. Analysis of 894 cloacal or fecal swabs from free-living birds in Poland revealed an overall Chlamydiaceae prevalence of 14.8% (n = 132) with the highest prevalence noted in Anatidae (19.7%) and Corvidae (13.4%). Further testing conducted with species-specific real-time PCR showed that 65 samples (49.2%) were positive for C. psittaci whereas only one was positive for C. avium. To classify the non-identified chlamydial agents and to genotype the C. psittaci and C. avium-positive samples, specimens were subjected to ompA-PCR and sequencing (n = 83). The ompA-based NJ dendrogram revealed that only 23 out of 83 sequences were assigned to C. psittaci, in particular to four clades representing the previously described C. psittaci genotypes B, C, Mat116 and 1V. Whereas the 59 remaining sequences were assigned to two new clades named G1 and G2, each one including sequences recently obtained from chlamydiae detected in Swedish wetland birds. G1 (18 samples from Anatidae and Rallidae) grouped closely together with genotype 1V and in relative proximity to several C. abortus isolates, and G2 (41 samples from Anatidae and Corvidae) grouped closely to C. psittaci strains of the classical ABE cluster, Matt116 and M56. Finally, deep molecular analysis of four representative isolates of genotypes 1V, G1 and G2 based on 16S rRNA, IGS and partial 23S rRNA sequences as well as MLST clearly classify these isolates within the C. abortus species. Consequently, we propose an expansion of the C. abortus species to include not only the classical isolates of mammalian origin, but also avian isolates so far referred to as atypical C. psittaci or C. psittaci/C. abortus intermediates.
African swine fever virus (ASFV) was detected in wild boar in eastern Poland in early 2014. So far, 65 cases of ASFV infection in wild boar have been recognised. The methods used for ASFV detection included highly specific real-time PCR with a universal probe library (UPL), enzyme-linked immunosorbent assay (ELISA), and an immunoperoxidase test (IPT) for identification of anti-ASFV antibodies. The positive ASF cases were located near the border with Belarus in Sokółka and Białystok counties. Some of the countermeasures for disease prevention include early ASF diagnosis by ASFV DNA identification as well as detection of specific antibodies by systematic screening. The aim of this study was to assess the current ASF status in a Polish population of wild boar during the last two years (2014-2015).
The purpose of this paper is to provide characteristics of the spread of African Swine Fever (ASF) in Poland from February to August, 2014. The samples from dead wild boar and domestic pigs were submitted to the National Veterinary Research Institute, National Reference Laboratory for ASF in Pulawy, Poland, for testing by PCR and ELISA methods. In the studied period, fourteen cases of ASF in wild boar and two outbreaks in backyard pigs were confirmed. In addition to the results of laboratory tests performed in 2014, the article describes the ASF surveillance programme in wild boar and pigs in Poland carried out in 2011-2013. The spread of ASF in Poland is compared with the epidemiological situation in Lithuania, Latvia, Belarus and the Russian Federation.
African swine fever (ASF) is a contagious, notifiable viral disease, which is considered a significant threat not only for European, but also for worldwide pork production, since recently the virus emerged within numerous Chinese pig herds. The disease was introduced in Poland in 2014 and up to the end of 2018, 213 outbreaks in pigs and 3347 cases in wild boars have been reported. The presented study describes the whole genome sequencing of seven Polish isolates, collected between 2016 and 2017, using next generation sequencing (NGS) technology. The complete, genomic sequences of these isolates were compared against five other closely related ASFV genomes, annotated in the NCBI database. The obtained sequences were from 189.393 to 189.405 bp long and encoded 187–190 open reading frames (ORFs). The isolates were grouped within genotype II and showed 99.941 to 99.956% nucleotide identity to the Georgia 2007/1 reference strain.
IntroductionSince April 2020, when the first SARS-CoV-2 infection was reported in mink and subsequently in mink farm workers in the Netherlands, it has been confirmed that human-to-mink and mink-to-human transmission can occur. Later, SARS-CoV-2 infections in mink were reported in many European and North American countries.Material and methodsSamples from 590 mink from a total of 28 farms were tested by real-time RT-PCR. Whole genome sequences from one positive farm were generated and genetic relatedness was established.ResultsSARS-CoV-2 RNA was detected on a breeder farm with stock of 5,850 mink. Active viraemia was confirmed in individually tested samples with Ct values respectively between 19.4 and 29.6 for E and N gene fragments. Further testing of samples from culled animals revealed 70% positivity in throat swabs and 30% seropositivity in blood samples. Phylogenetic analysis of full-length nucleotide sequences of two SARS-CoV-2 isolates revealed that they belong to the 20B Nextstrain clade. Several nucleotide mutations were found in analysed samples compared to the reference Wuhan HU-1 strain and some of them were nonsynonymous.ConclusionWe report the infection of mink with SARS-CoV-2 on one farm in Poland and the results of subsequent analysis of virus sequences from two isolates. These data can be useful for assessment of the epidemiological situation of SARS-CoV-2 in Poland and how it endangers public health.
IntroductionThe study was conducted to investigate the prevalence and genetic diversity of Chlamydia spp. in poultry in Poland and estimate possible transmission to humans.Material and MethodsMolecular diagnostic methods followed by sequencing and strain isolation were used on cloacal/faecal swabs collected from 182 apparently healthy poultry flocks including chickens, turkeys, ducks, and geese. Serum samples obtained from people exposed (study group) and non-exposed (control group) to birds were tested by complement fixation test to acquire data on Chlamydia spp. antibody level.ResultsOverall, 15.9% of the tested flocks were Chlamydiaceae-positive and three Chlamydia spp. were identified. Predominant chlamydial agent found was C. gallinacea occurring in 65.5% of all positive poultry flocks and in 73.0% of positive chicken flocks. The sequences from four chicken flocks were assigned to C. abortus, whereas C. psittaci was confirmed in one duck and one goose flock. The analysis of ompA variable domains revealed at least nine genetic variants of C. gallinacea. Chlamydial antibodies were detected in 19.2% of human serum samples in the study group in comparison with 10.8% in the controls.ConclusionThe obtained results confirm that chlamydiae are common among chicken flocks in Poland with C. gallinacea as a dominant species. Moreover, the presence of C. abortus in chickens is reported here for the first time. Further investigation should focus on possible zoonotic transmission of C. gallinacea and C. abortus as well as potential pathogenic effects on birds’ health and poultry production.
African swine fever (ASF) was first described in 1921 in Kenya. The latest epidemic of ASF started in 2007 in Georgia. The virus was introduced to Poland in 2014. Since the beginning of the epidemics, the National Veterinary Research Institute in Pulawy (NVRI) has been testing wild boar samples from restricted areas and other parts of Poland to conduct passive and active surveillance for ASFV in these groups of animals. The aim of this study was to summarise the last two years of the ASF epidemiological status in Poland and the attempt to find disease patterns in the wild boar population. The period between 2017 and 2018 brought a massive number of new ASF cases in Poland. The number of ASF-positive wild boars jumped from 91 in 2016 to 1 140 in 2017 (approximately a 12 × increase), and 2018 was even worse, with the disease affecting 4 083 animals (2 435 cases; one case could even be 10 animals or more if they are found in one place next to each other). The percentage of positive wild boars found dead (passive surveillance) in the restricted area increased in 2018 to 73.1% from 70.8% in 2017. The chance of obtaining positive results in this group was six times higher in December and 4.5 times higher in January than in August and September. The percentage of positive wild boars detected through active surveillance reached 1.5% in 2018. The data suggested that, not only in Poland, but also in other ASF-affected countries, during the epizootic stage of the disease spread the most important measure is an effective passive surveillance of dead wild boars especially, in the winter season rather than in the summer.
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