Birds In Poland Research Articles

West Nile Virus Lineage 2 in Free-Living Corvus cornix Birds in Poland.

The summer temperatures recorded in Poland in 2022 were among the highest in over 30 years and, combined with higher-than-expected rainfall, gave the impression of an almost tropical climate. Such climatic conditions were ideal for the transmission of vector-borne zoonotic diseases such as West Nile fever. In northeastern Poland, in the Mazowieckie region, the Polish event-based surveillance network reported increased fatalities of free-living hooded crows (Corvus corone cornix). West Nile virus (WNV) lineage 2 was identified for the first time as the etiological agent responsible for the death of the birds. WNV was detected in 17 out of the 99 (17.17%) free-living birds tested in this study. All the WNV-infected dead birds were collected in the same area and were diagnosed in September by the NVRI and confirmed by the EURL for equine diseases, ANSES, in October 2022. Unnaturally high temperatures recorded in Poland in 2022 likely favored the infection and spread of the virus in the avian population. A nationwide alert and awareness raising of blood transfusion centers and hospitals was carried out to prevent human infections by WNV.

High Prevalence of Plasmid-Mediated Quinolone Resistance among ESBL/AmpC-Producing Enterobacterales from Free-Living Birds in Poland.

In this study, we investigated the occurrence of plasmid-mediated quinolone resistance (PMQR) in extended-spectrum β-lactamase- (ESBL) and/or AmpC-type β-lactamase-producing Enterobacterales isolates from free-living birds in Poland. The prevalence of the qnrB19 gene was 63%, and the distribution of isolates in terms of bacterial species was as follows: 67% (22/33) corresponded to Escherichia coli, 83% (5/6) to Rahnella aquatilis, 44% (4/9) to Enterobacter cloacae and 33% (1/3) to Klebsiella pneumoniae. The qnrB19 gene was also found in a single isolate of Citrobacter freundii. The molecular characteristics of qnrB19-positive isolates pointed to extended-spectrum beta lactamase CTX-M as the most prevalent one (89%) followed by TEM (47%), AmpC (37%) and SHV (16%). This study demonstrates the widespread occurrence of PMQR-positive and ESBL/AmpC-producing Enterobacterales isolates in fecal samples from wild birds. In this work, plasmid pAM1 isolated from Escherichia coli strain SN25556 was completely sequenced. This plasmid is 3191 nucleotides long and carries the qnrB19 gene, which mediates decreased susceptibility to quinolones. It shares extensive homology with other previously described small qnrB19-harboring plasmids. The nucleotide sequence of pAM1 showed a variable region flanked by an oriT locus and a Xer recombination site. The presence of a putative recombination site was detected, suggesting that interplasmid recombination events might have played a role in the development of pAM1. Our results highlight the broad geographical spread of ColE-type Qnr resistance plasmids in clinical and environmental isolates of Enterobacterales. As expected from the results of phenotypic susceptibility testing, no resistance genes other than qnrB19 were identified.

Prevalence of Enterococcus spp. and the Whole-Genome Characteristics of Enterococcus faecium and Enterococcus faecalis Strains Isolated from Free-Living Birds in Poland.

Enterococci as opportunistic bacteria are important for human health. Due to the prevalence and ease of acquisition and transfer of their genes, they are an excellent indicator of environmental contamination and the spread of antimicrobial resistance. The aim of the study was to assess the prevalence of Enterococcus spp. in wild birds in Poland, determination of antimicrobial susceptibility and WGS analysis of Enterococcus (E.) faecium and E. faecalis. For this purpose, 138 samples from various species of free-living birds were tested, with 66.7% positive results. Fourteen species were detected, with E. faecalis being the most common, followed by E. casseliflavus and E. hirae. In antimicrobial susceptibility testing, 10.0% of E. faecalis and 50.0% of E. faecium showed resistance to one antimicrobial agent, in addition the MDR phenotype which was found in one E. faecium. The most common resistance phenotype included tetracycline and quinupristin/dalfopristin. The WGS analysis confirmed the significant advantage of the virulence gene diversity of E. faecalis strains over E. faecium. In addition, plasmid replicons were found in 42.0% of E. faecalis and 80.0% of E. faecium. The obtained results confirm free-living birds can be a reservoir of Enterococcus spp. with a considerable zoonotic potential.

Antibiotic Resistance and Virulence Profiles of Escherichia coli Strains Isolated from Wild Birds in Poland.

Wild animals are increasingly reported as carriers of antibiotic-resistant and pathogenic bacteria including Enterobacteriaceae. However, the role of free-living birds as reservoirs for potentially dangerous microbes is not yet thoroughly understood. In our work, we examined Escherichia coli strains from wild birds in Poland in relation to their antimicrobial agents susceptibility, virulence and phylogenetic affiliation. Identification of E. coli was performed using MALDI-TOF mass spectrometry. The antibiotic susceptibility of the isolates was determined by the broth microdilution method, and resistance and virulence genes were detected by PCR. E. coli bacteria were isolated from 32 of 34 samples. The strains were most often classified into phylogenetic groups B1 (50%) and A (25%). Resistance to tetracycline (50%), ciprofloxacin (46.8%), gentamicin (34.3%) and ampicillin (28.1%) was most frequently reported, and as many as 31.2% of E. coli isolates exhibited a multidrug resistance phenotype. Among resistance genes, sul2 (31.2% of isolates) and blaTEM (28.1%) were identified most frequently, while irp-2 (31.2%) and ompT (28.1%) were the most common virulence-associated genes. Five strains were included in the APEC group. The study indicates that wild birds can be carriers of potentially dangerous E. coli strains and vectors for the spread of resistant bacteria and resistance determinants in the environment.

Lack of Evidence That Bird Feeders Are a Source of Salmonellosis during Winter in Poland.

Simple SummaryBird feeders are known to be a transfer site for many important bird pathogens, such as zoonotic Salmonella spp., known to be widespread among wild birds in Poland. The aim of the study was to investigate (1) whether feeders can be a source of Salmonella spp., (2) whether the risk is the same for feeders located in cities and rural areas and (3) whether there is a different level of contamination with Salmonella spp. between old and new feeders. Data were collected in winter 2018 in Poland, and in total, 204 feeders were sampled. Material for analysis consisted of the remains of food and feces. We did not find the presence of Salmonella spp. in any of the tested samples collected from bird feeders. Reasons for the isolation of Salmonella spp. from feeders not being successful lie in the low intensity of bacterial shedding by infected wild birds and low survival of bacteria in the environment.Bird feeders are known to be a transfer site for many important bird pathogens, such as zoonotic Salmonella spp., known to be widespread among wild birds in Poland. The aim of the study was to investigate (1) whether feeders can be a source of Salmonella spp., (2) whether the risk is the same for feeders located in cities and rural areas and (3) whether there is a different level of contamination with Salmonella spp. between old and new feeders. Data were collected in the period 12 January–28 February 2018 in four cities in Poland and nearby rural areas. In total, 204 feeders were sampled. The samples from feeders were taken after a 2-week period of feeding birds. Material for analysis consisted of the remains of food and feces. We did not find the presence of Salmonella spp. in any of the tested samples collected from bird feeders. Therefore, the estimated value of the 95% confidence interval for the binary data was 0.000–0.018. Reasons for the isolation of Salmonella spp. from feeders not being successful lie in the low intensity of bacterial shedding by infected wild birds and low survival of bacteria in the environment in bird feces—which are still not well studied.

Detection of fowl adenovirus D strains in wild birds in Poland by Loop-Mediated Isothermal Amplification (LAMP)

BackgroundThe present study on the role of strains of adenovirus in wildlife reservoirs, and their prevalence is under exploration. In several previous studies, the presence of adenovirus strains in wild birds has been investigated. Worldwide distribution and outbreaks of adenovirus infections have been reported by many authors. The present study investigated the prevalence of FAdVs in 317 samples of different bird species from the northwestern region of Poland. An applied specific, sensitive, and efficient, without cross-reactivity loop-mediated isothermal amplification (LAMP) method to gauge the prevalence of fowl adenovirus strains in wild birds was developed and used.ResultsThe method was based on the sequence of the loop L1 HVR1–4 region of the hexon gene of the FAdV genome reference strains FAdV-2 KT862805 (ANJ02325), FAdV-3 KT862807 (ANJ02399) and FAdV-11 KC750784 (AGK29904). The results obtained by LAMP were confirmed by real-time PCR. Among 317 samples obtained from wild birds, eight FAdV isolates (2.52%) were identified and produced a cytopathic effect (CPE) in chicken embryo kidney cells (CEK). Three FAdV types belonging to species Fowl adenovirus D were detected, which were isolated from three adenovirus types 2/3/11, and have been confirmed in three mute swans (Cygnus olor), three wild ducks (Anas platyrhynchos), one owl (Strigiformes), and one common wood pigeon (Columba palumbus).ConclusionsThis study provides the first accurate quantitative data for the replication of fowl adenovirus strains in wild birds in Poland, indicating adenovirus interspecies transmission, and demonstrating the circulation of FAdVs in wild birds.

Birds Wintering in Heterogeneous Farmland of Poland: Weather-Dependent Temporal Changes in Abundance and Habitat Associations

Bird communities wintering in the mosaic-like farming landscapes of SW Poland were studied to assess drivers of intra-seasonal changes in numbers and habitat associations of birds. During two severe winters (November–March) the complete area search method was applied to count birds and link their occurrence with weather and habitat in six plots (320 ha in total). A modelling approach was used to test birds' responses to environmental factors at community and species levels. These farmlands were inhabited by diverse and dense populations of wintering birds, including a significant proportion of species of conservation concern. Bird numbers revealed decreasing trends, with winter- and species-specific fluctuations, affected in particular by snow cover. The lowest population indices were recorded in mid-winter (February) and remained low until mid-March. Field margins (6.6% of the total area) supported 35.6% of individuals and 55.0% of flocks. The preference for field margins over other farmland habitats was particularly prominent during severe weather conditions. Our results suggest that during severe winters, complex farmlands are important areas for birds, enhancing their known importance to breeding birds. Intense snowfall in mid-winter rather than temperature drops lead to immediate population declines, aggravating the effects of natural food depletion. Adverse weather keeps populations at low levels until mid-March, despite the influx of spring migrants. Behavioural adjustments to winter conditions elicit the characteristic habitat distribution of birds, exposing the crucial importance of non-cropped landscape elements. In particular, the variety of field margins significantly contributes to the persistence of internationally important populations of farmland birds in Poland.

Clonal Structure and Antibiotic Resistance of Enterococcus spp. from Wild Birds in Poland.

The purpose of this study was to analyze the antibiotic resistance and genetic diversity of 27 enterococci (Enterococcus faecium, Enterococcus hirae, Enterococcus durans, and Enterococcus casseliflavus) isolated from wild bird species. Resistance to lincomycin was most common, followed by erythromycin, ciprofloxacin, tetracyclines, high level of aminoglycoside, and β-lactam antibiotics. No vancomycin- and chloramphenicol-resistant isolates were identified. The antibiotic resistance was linked to the tet(M), tet(L), erm(A), erm(B), msr(A/B), pbp5, ant(6)-Ia, and aph(3')-IIIa genes. Tn916/Tn1545-like transposons were detected. The high-level resistance to gentamicin was associated with the presence of gene aph(2″)-Id. All 18 E. faecium isolates were divided into 16 pulsotypes and 17 sequence types (STs), among which 7 STs were newly assigned (ST1266-ST1272). A majority of E. faecium isolates possess multilocus sequence typing profiles belonging to clonal complex 17 (CC17), the major epidemic lineage responsible for nosocomial infections. Two ST17 and newly described ST1267 and ST1271 (an SLV and DLV of ST17, respectively) of E. faecium isolates carried the type 1 allele of the housekeeping gene purK detected in hospital-related strains. Our results indicated that wild birds could be a source of resistant E. faecium isolates, belonging to CC17 and may represent a hazard to human health by transmission of these isolates.

A Survey on West Nile and Usutu Viruses in Horses and Birds in Poland.

West Nile virus (WNV) and Usutu virus (USUV) are members of the family Flaviviridae which, natural life cycles involve mosquito–bird–mosquito transmission. Both represent emerging viruses in Europe with potential to cause neuroinvasive disease in humans. This study investigates the seroprevalence of serum neutralizing antibodies to WNV and to USUV in birds and in horses in Poland. Antibodies against WNV and USUV were detected in 5 (35.7%) and in 1 (7.14%) of 14 birds and in 62 (15.08%) and in 115 (27.98%) of 411 horses, respectively. Twenty-one WNV serologically positive horses (33.87%) and 67 USUV serologically positive horses (58.26%) did not travel outside Polish borders. Given the high abundance of potentially competent mosquito species in Poland, high populations of horses and different bird species, our findings highlight implementation of active control programs, including monitoring of geographic spread and dynamics of WNV and USUV transmission in both primary and accidental hosts. It is also important to improve public health awareness about the disease these viruses may cause.

Long-term changes in the numbers of waterbirds at an important European wintering site

Waterbirds were regularly monitored in north-western Poland from 2002 to 2018. Counts took place in the most important areas where wintering waterbirds concentrate in this region, the most important wintering ground for this group of birds in Poland and one of the most important in Europe. In addition to the wintering function, this area also has a very important function as a stopover site for significant numbers of African-Eurasian Flyway migrants. The average number of all waterbirds covered by the study from 2002 to 2018 was 117,000. Numbers in recent years (2011–2018) have increased significantly (P < 0.001) compared to the first half of the study (2002–2010). The most important species found here during the non-breeding period were: Greater Scaup Aythya marila (mean number for 2002–2018: 20,600), Tufted Duck A. fuligula (26,700), Common Pochard A. ferina (1,500), Smew Mergellus albellus (1,400), Goosander Mergus merganser (7,700), Great Crested Grebe Podiceps cristatus (840), Eurasian Coot Fulica atra (8,400), Mute Swan Cygnus olor (1,100), Whooper Swan C. cygnus (890), Bean Goose Anser fabalis (13,000) and White-fronted Goose A. albifrons (6,500). The importance of this region at the European scale for migratory and wintering waterbirds has increased, and this presents new challenges to the institutions responsible for protecting these areas.

Phylogenetic Study of H5 Low Pathogenic Avian Influenza Viruses Detected in Wild Birds in Poland in 2010-2015.

IntroductionThe genomes of nine H5 subtypes of low pathogenic avian influenza virus (LPAIV) strains identified in wild birds in Poland between 2010 and 2015 were sequenced, and their phylogenetic relationship was determined.Material and MethodsAIV genome segments were amplified by RT-PCR and the PCR products were sequenced using Sanger method. Phylogenetic trees were generated in MEGA6 software and digital genotyping approach was used to visualise the relationship between analysed strains and other AIVs.ResultsHigh genetic diversity was found in the analysed strains as multiple subgroups were identified in phylogenetic trees. In the HA tree, Polish strains clustered in two distinct subclades. High diversity was found for PB2, PB1, PA and NP, since 5-8 sublineages could be distinguished. Each strain had a different gene constellation, although relationship of as much as six out of eight gene segments was observed between two isolates. A relationship with poultry isolates was found for at least one segment of each Polish strain.ConclusionThe genome configuration of tested strains indicates extensive reassortment, although the preference for specific gene constellation could be noticed. A significant relationship with isolates of poultry origin underlines the need for constant monitoring of the AIV gene pool circulating in the natural reservoir.

Antimicrobial Susceptibility and Genotypic Characteristic of Campylobacter spp. Isolates from Free-Living Birds in Poland.

Campylobacter spp. is the most commonly reported, bacterial cause of human foodborne infection worldwide. Commercial poultry and free-living birds are natural reservoirs of three particular species: Campylobacter jejuni, Campylobacter coli, and Campylobacter lari. The aim of this study was to determine the genotypic characteristics and antibiotic susceptibility of 43 Campylobacter strains, obtained from free-living birds, in Poland. In total, 700 birds were examined. The strains were isolated from 43 birds (6.14%) from the feces of 7 wild bird species: Mallard ducks Anas platyrhynchos (29 positive/121 tested), great cormorants Phalacrocorax carbo (5/77), velvet scoters Melanitta fusca (4/30), tawny owls Strix aluco (2/5), common buzzard Buteo buteo (1/3), rook Corvus frugilegus (1/6), and Eurasian tree sparrow Passer montanus (1/30). Thirty-eight (88.37%) of obtained strains belonged to C. jejuni and five (11.63%) to C. coli. Other 428 examined birds from different bird species were Campylobacter negative. The antimicrobial susceptibility to nine antimicrobials was also studied in investigated isolates of Campylobacter spp. Sixteen of the examined strains (37.21% of all positive samples) showed susceptibility to all of the nine antimicrobials. Moreover, the prevalence of selected virulence genes, such as flaA, cadF, ceuE, virB11, cdtA, cdtB, and cdtC were all analyzed. The virulence gene that was found most frequently in total number of Campylobacter strains was ceuE (72.10%) and other genes, such as flaA, cadF, cdtA, cdtB, and cdtC, were found in over 60% of all examined strains. Variable antimicrobial susceptibility and the presence of different virulence genes of examined strains, isolated from free-living birds, suggest that special attention should be given to wild birds and any potential approaches to the control of antibiotic-resistant Campylobacter should be discussed.

Detection of Avian Reoviruses in Wild Birds in Poland.

IntroductionThe purpose of this study was to determine the occurrence of avian reovirus (ARV) infections in wild birds in Poland and attempt to propagate the selected ARV strains in chicken embryo kidney (CEK) cells or chicken SPF embryos.Material and MethodsThe study included 192 wild birds representing 32 species, collected between 2014 and 2016. A part of the S4 segment encoding the σNS protein of avian reoviruses (ARVs) isolated from different species of wild birds from that period was amplified.ResultsThe presence of ARV was demonstrated in 58 (30.2%) wild birds belonging to nine orders. The isolated strains were propagated in chicken embryos by yolk sac inoculation, and CPE was induced in the infected CEK monolayer. Agar gel precipitation showed that two ARV isolates from rock pigeon and mute swan shared a common group-specific antigen with chicken reovirus S1133. Specific products of predicted size were found in two ARV isolates from the chicken embryo passage and 13 ARVs isolated from CEK cells.ConclusionThe study indicates the high prevalence of ARV among wild birds in Poland and its possible transmission to farmed birds.

Dissemination and genetic diversity of chlamydial agents in Polish wildfowl: Isolation and molecular characterisation of avian Chlamydia abortus strains

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.

Detection of Bordetella avium by TaqMan real-time PCR in tracheal swabs from wildlife birds.

Bordetella avium, the causing agent of bordetellosis, a highly contagious infection of the respiratory tract in young poultry, causes significant losses in poultry farming throughout the world. Wildlife birds can be a reservoir of various pathogens that infect farm animals. For this reason the studies were conducted to estimate the prevalence of Bordetella avium in wildlife birds in Poland. Tracheal swab samples were collected from 650 birds representing 27 species. The bacterial DNA was isolated directly from the swabs and screened for Bordetella avium by TaqMan real-time PCR. The assay specificity was evaluated by testing DNA isolated from 8 other bacteria that can be present in avian respiratory tract, and there was no amplification from non-Bordetella avium agents. Test sensitivity was determined by preparing standard tenfold serial dilutions of DNA isolated from positive control. The assay revealed to be sensitive, with detection limit of approximately 4.07x10^2 copies of Bordetella avium DNA. The genetic material of Bordetella avium was found in 54.54% of common pheasants, in 9.09% of Eurasian coots, in 3.22% of black-headed gulls and in 2.77% of mallard ducks. The results of this study point to low prevalence of Bordetella avium infections in wildlife birds. The results also show that described molecular assay proved to be suitable for the rapid diagnosis of bordetellosis in the routine diagnostic laboratory.

SURVEILLANCE FOR AVIAN INFLUENZA VIRUS IN WILD BIRDS IN POLAND, 2008-15.

We tested wild birds in Poland during 2008-15 for avian influenza virus (AIV). We took 10,312 swabs and feces samples from 6,314 live birds representing 12 orders and 84 bird species, mostly from orders Anseriformes and Charadriiformes, for testing and characterization by various PCR methods. From PCR-positive samples, we attempted to isolate and subtype the virus. The RNA of AIV was detected in 1.8% (95% confidence interval [CI], 1.5-2.1%) of birds represented by 48 Mallards ( Anas platyrhynchos ), 11 Mute Swans ( Cygnus olor ), 48 Common Teals ( Anas crecca ), three Black-headed Gulls (Chroicocephalus ridibundus), one Common Coot ( Fulica atra ), one Garganey (Spatula querquedula), and one unidentified bird species. Overall, the prevalence of AIV detection in Mallards and Mute Swans (the most frequently sampled species) was 2.0% (95% CI, 1.4-2.5%) and 0.5% (95% CI, 0.2-0.8%), respectively; the difference was statistically significant (P=0.000). Hemagglutinin subtypes from H1 to H13 were identified, including H5 and H7 low pathogenic AIV subtypes. Mallards and Common Teals harbored the greatest diversity of subtypes. We observed seasonality of viral detection in Mallards, with higher AIV prevalence in late summer and autumn than in winter and spring. In addition, two peaks in AIV prevalence in summer (August) and autumn (November) were demonstrated for Mallards. The prevalence of AIV in Mute Swans did not show any statistically significant seasonal patterns.

Preliminary survey of the occurrence of goose haemorrhagic polyomavirus (GHPV) in wild birds in Poland

Abstract Introduction: The aim of the study was to investigate the occurrence of goose haemorrhagic polyomavirus (GHPV) in wild birds inhabiting Poland. Material and Methods: Samples from 508 birds of different species were obtained between 2010 and 2015. The internal organ sections were homogenised and then total cellular DNA was isolated. The study was performed by means of PCR assay using primers complementary to the VP1 gene of the GHPV. Results: The presence of genetic material of GHPV was detected in 22 (4.33%) samples. Conclusion: It was the first such study in Poland to emphasise the role of wild birds as a potential source of GHPV infection for farmed geese.

Evaluating conservation tools in Polish grasslands: The occurrence of birds in relation to agri-environment schemes and Natura 2000 areas

To halt the decline of biodiversity in European farmland, two major tools are available: the Natura 2000 network and agri-environment schemes (AES). We investigated the effect of these two measures on local species richness, single species occurrence and beta diversity of grassland birds in Poland. We counted birds on AES parcels (with less intensive grassland management) and control parcels, both within and outside Special Protection Areas (SPAs, part of Natura 2000), during 2013–2014. Local species richness of AES-target birds was not associated with AES. Similarly, the turnover of AES-target species among sites was comparable at AES and control parcels. Furthermore, no positive interaction between AES and SPAs was observed, indicating a general lack of effect of AES. Local species richness of SPA-target birds was not higher within than outside SPAs, but two SPA-target species were more common and the beta diversity of SPA-target species was higher within than outside SPAs. Thus, our study showed no positive effects of AES on the occurrence of their target species, but confirmed some positive effects of SPAs on their target species. The decision to restrict AES to Special Protection Areas in 2015–2020 has no justification in our analyses. Actually, many AES-target species will be protected within SPAs irrespective of whether the area is an AES or not, but future AES should also include parcels outside SPAs, as many target species occur there. However, to improve the effectiveness of AES management prescriptions should be diversified and customized to meet the largely different habitat preferences of present target species (such as, for instance, the lapwing and corncrake).

Prevalence of Chlamydia psittaci and Other Chlamydia Species in Wild Birds in Poland.

Avian chlamydiosis is a zoonotic disease occurring in humans, poultry, and exotic birds. It has been suggested that some wild bird species play an important role as reservoirs for Chlamydia, especially Chlamydia psittaci. Whereas C. psittaci is the predominant chlamydial agent in birds, in the present study we have determined the prevalence of different species of Chlamydia among selected wild bird species in Poland using a rapid and sensitive real-time PCR method. In total, 369 free-living birds from 35 bird species and 15 orders were examined. Samples from 27 birds (7.3%) were positive for chlamydial DNA in the PCR; 22 positive samples (81.5%) belonged to C. psittaci, three to Chlamydia trachomatis (11.1%), and two (7.4%) classified only to the genus Chlamydia. Most of C. psittaci-positive samples belonged to five orders: Anseriformes, Columbiformes, Gruiformes, Phasianiformes, and Passeriformes. All C. trachomatis samples were obtained from Eurasian coots (Gruiformes). Two Chlamydia-positive samples not classified to any Chlamydia species were obtained from a common wood pigeon (Columbiformes) and a common buzzard (Accipitriformes). Detection of C. psittaci and C. trachomatis in free-living bird populations force to think on significance of birds as reservoir of varied Chlamydia species and their epidemiological importance.

Prevalence and genetic characteristics of Salmonella in free-living birds in Poland.

BackgroundSalmonella species are widespread in the environment, and occur in cattle, pigs, and birds, including poultry and free-living birds. In this study, we determined the occurrence of Salmonella in different wild bird species in Poland, focusing on five Salmonella serovars monitored in poultry by the European Union: Salmonella serovars Enteritidis, Typhimurium, Infantis, Virchow, and Hadar. We characterized their phenotypic and genetic variations.Isolates were classified into species and subspecies of the genus Salmonella with a polymerase chain reaction (PCR) assay. The prevalence of selected virulence genes (spvB, spiA, pagC, cdtB, msgA, invA, sipB, prgA, spaN, orgA, tolC, ironN, sitC, ipfC, sifA, sopB, and pefA) among the isolated strains was determined. We categorized all the Salmonella ser. Typhimurium strains with enterobacterial repetitive intergenic consensus (ERIC)-PCR.ResultsSixty-four Salmonella isolates were collected from 235 cloacal swabs, 699 fecal samples, and 66 tissue samples (6.4% of 1000 samples) taken from 40 different species of wild birds in Poland between September 2011 and August 2013. The largest numbers of isolates were collected from Eurasian siskin and greenfinch: 33.3% positive samples for both. The collected strains belonged to one of three Salmonella subspecies: enterica (81.25%), salamae (17.19%), or houtenae (1.56%). Eighteen strains belonged to Salmonella ser. Typhimurium (28.13%), one to ser. Infantis (1.56%), one to ser. Virchow (1.56%), and one to ser. Hadar (1.56%). All isolates contained spiA, msgA, invA, lpfC, and sifA genes; 94.45% of isolates also contained sitC and sopB genes. None of the Salmonella ser. Typhimurium strains contained the cdtB gene. The one Salmonella ser. Hadar strain contained all the tested genes, except spvB and pefA; the one Salmonella ser. Infantis strain contained all the tested genes, except tspvB, pefA, and cdtB; and the one Salmonella ser. Virchow strain contained all the tested genes, except spvB, pefA, cdtB, and tolC.The Salmonella ser. Typhimurium strains varied across the same host species, but similarity was observed among strains isolated from the same environment (e.g., the same bird feeder or the same lake).ConclusionsOur results confirm that some wild avian species are reservoirs for Salmonella serotypes, especially Salmonella ser. Typhimurium.