Disease In Pigeons Research Articles

Pigeon Circovirus over Three Decades of Research: Bibliometrics, Scoping Review, and Perspectives.

The pigeon circovirus (PiCV), first described in the literature in the early 1990s, is considered one of the most important infectious agents affecting pigeon health. Thirty years after its discovery, the current review has employed bibliometric strategies to map the entire accessible PiCV-related research corpus with the aim of understanding its present research landscape, particularly in consideration of its historical context. Subsequently, developments, current knowledge, and important updates were provided. Additionally, this review also provides a textual analysis examining the relationship between PiCV and the young pigeon disease syndrome (YPDS), as described and propagated in the literature. Our examination revealed that usages of the term ‘YPDS’ in the literature are characterizations that are diverse in range, and neither standard nor equivalent. Guided by our understanding of the PiCV research corpus, a conceptualization of PiCV diseases was also presented in this review. Proposed definitions and diagnostic criteria for PiCV subclinical infection (PiCV-SI) and PiCV systemic disease (PiCV-SD) were also provided. Lastly, knowledge gaps and open research questions relevant to future PiCV-related studies were identified and discussed.

Prevalence of diseases of pigeons and responses to treatment of bacterial disease

The prevalence of diseases of pigeon and response to treatment of bacterial disease were studied. One thousand pigeons were collected and examined to diagnose diseases following clinical history and signs, post-mortem lesions and laboratory examination. The overall prevalence of pigeon diseases was 21.9% (n = 219). Parasitic infestation was significantly (P<0.01) higher (30%) followed by bacterial (22.3%), viral (18.9%) nutritional and others (16.3%) and fungal (14.3%). Disease prevalence was higher in female than in male, and higher in birds of 2 to 6-months old than in older or younger birds. The prevalence of diseases was higher (P<0.01) in winter (34%) than summer (16.7%) and rainy (14.3%) seasons. Pigeons of extensive rearing system showed more (23.0%) infection than in intensive (19.7%) system. Prevalence was significantly (P<0.01) higher (25.2%) in nonvaccinated pigeons than vaccinated (17%) pigeons. Treatment with Oxytetracycline hydrochloride (Tetravet-200 WSP), Sulphaclozine Sodium Monohydrate (SCZ WSP) and Doxycycline (DOXY-A VET) were effective against bacterial diseases. It is suggested that scientific management, bio-security and therapeutic measures against infectious diseases are required to combat the maladies in pigeon. The Bangladesh Veterinarian (2020) 37(1 - 2): 21-26

First detection and molecular characterisation of a pigeon aviadenovirus A and pigeon circovirus co-infection associated with Young Pigeon Disease Syndrome (YPDS) in Turkish pigeons (Columba livia domestica).

Pigeon aviadenovirus A and Pigeon circovirus are both DNA viruses, infect and cause severe clinical diseases in pigeons. These viruses are associated with an immunosuppression syndrome similar to ‘Young Pigeon Disease Syndrome’ (YPDS). This study reports the identification of a natural co‐infection, with severe clinical signs (crop vomiting, watery diarrhoea, anorexia and sudden death) of Pigeon aviadenovirus A and Pigeon circovirus in a breeding pigeon flock in Central Anatolia, Turkey. Both viruses were isolated from pigeons pooled internal organs using primary chicken embryo kidney cell cultures (CEKC) and specific pathogen‐free (SPF) embryonated chicken eggs. Also, both viruses were identified by PCR amplification followed by Sanger sequencing whereas histopathological examination showed degenerated hepatocytes with basophilic intranuclear viral inclusions. As known, both viruses typically have similar transmission characteristics and common clinical manifestations; however, co‐infection may exacerbate the disease with devastating outcomes. This is the first report of its kind in Turkey for those viruses and is essential for the protection against these kinds of infections in pigeons.

Endoparasitoses of the Eurasian collared dove (Streptopelia decaocto) on the northern Black Sea coast of Ukraine

One of the main tasks of ecological parasitology at the present stage is to determine patterns of spread of invasive diseases of poultry in the environment through a thorough epidemiological examination, as well as to determine the main directions and factors of spread of parasites in Ukraine. Some pigeon health problems can affect their populations, but parasitic infections play an important role. Our research found that 83.3% of Eurasian collared doves examined (Streptopelia decaocto) were affected by endoparasites. The commonest helminths were Raillietina spp. with the average invasion intensity of 4.9 ± 1.3 specimens/ind., Baruscapillaria spp. and Ascaridia columbae with an invasion intensity of 4.6 ± 1.5 and 3.7 ± 2.1 specimens/ind., respectively. The commonest cestodes were Raillietina spp. with the extent of invasion of 52.2% and Davainea proglottina – 6.7%. The Amoebotaenia cuneata cestodes were recorded in 3 (3.3%) doves, and Echinolepis carioca – only in 2 (2.2%) doves. Six doves (6.7%) were infected with the nematode Ascaridia columbae and 5 (5.6%) – Baruscapillaria spp. Eimerian oocysts were found in 9 (10%) collared doves, and Trichomonas gallinae was recorded in 15 (16.7%) birds. According to the results of helminthological autopsy and identification of the isolated pathogens, 8 varieties of mixinvasions were identified. In association with the Rayetins, there were the protozoa Eimeria spp. and Trichomonas gallinae and the nematode Ascaridia columbae. Two-component invasions were registered in 78.6% of doves, three-component infestations in 14.3% and four-component infestations in 7.1% of birds. Mixed infection with Raillietina spp. + Ascaridia columbae was found in the small intestine of Streptopelia decaocto, which was also pathomorphologically observed to have catarrhal-hemorrhagic enteritis, which was accompanied by the formation of a large number of spotted hemorrhages on the mucous membrane, and in the places of attachment of cestodes - necrotic-caseous areas. Temperature and other weather conditions such as humidity, precipitation, etc. of the northern Black Sea coast affect the population size of intermediate host cestodes. Continuous monitoring of invasive diseases of pigeons of different species will help to take the necessary preventive measures against endoparasitoses of birds.

Endoparasitoses of the Eurasian collared dove (Streptopelia decaocto) on the northern Black Sea coast of Ukraine

One of the main tasks of ecological parasitology at the present stage is to determine patterns of spread of invasive diseases of poultry in the environment through a thorough epidemiological examination, as well as to determine the main directions and factors of spread of parasites in Ukraine. Some pigeon health problems can affect their populations, but parasitic infections play an important role. Our research found that 83.3% of Eurasian collared doves examined (Streptopelia decaocto) were affected by endoparasites. The commonest helminths were Raillietina spp. with the average invasion intensity of 4.9 ± 1.3 specimens/ind., Baruscapillaria spp. and Ascaridia columbae with an invasion intensity of 4.6 ± 1.5 and 3.7 ± 2.1 specimens/ind., respectively. The commonest cestodes were Raillietina spp. with the extent of invasion of 52.2% and Davainea proglottina – 6.7%. The Amoebotaenia cuneata cestodes were recorded in 3 (3.3%) doves, and Echinolepis carioca – only in 2 (2.2%) doves. Six doves (6.7%) were infected with the nematode Ascaridia columbae and 5 (5.6%) – Baruscapillaria spp. Eimerian oocysts were found in 9 (10%) collared doves, and Trichomonas gallinae was recorded in 15 (16.7%) birds. According to the results of helminthological autopsy and identification of the isolated pathogens, 8 varieties of mixinvasions were identified. In association with the Rayetins, there were the protozoa Eimeria spp. and Trichomonas gallinae and the nematode Ascaridia columbae. Two-component invasions were registered in 78.6% of doves, three-component infestations in 14.3% and four-component infestations in 7.1% of birds. Mixed infection with Raillietina spp. + Ascaridia columbae was found in the small intestine of Streptopelia decaocto, which was also pathomorphologically observed to have catarrhal-hemorrhagic enteritis, which was accompanied by the formation of a large number of spotted hemorrhages on the mucous membrane, and in the places of attachment of cestodes - necrotic-caseous areas. Temperature and other weather conditions such as humidity, precipitation, etc. of the northern Black Sea coast affect the population size of intermediate host cestodes. Continuous monitoring of invasive diseases of pigeons of different species will help to take the necessary preventive measures against endoparasitoses of birds.

Survey on prevalence of common diseases in pigeon (Columba livia domestica) in Tuticorin district, Tamil Nadu, India

The aim of the study is to estimate the prevalence of diseases in Tuticorin district and to get an insight in pigeon production, disease management and vaccination status. A sample of 50 pigeon fanciers was randomly selected from different taluks in Tuticorin district and face to face interviews were conducted among them using a standard questionnaire. Among these a total of 202 diseased pigeons was examined. According to age, they were classified into three categories squab (1-2 weeks), young (30-90 days) and adult (>90 days). Those diseases were identified by conducting the survey with a standard questionnaire among the pigeon fanciers and the study duration was from July 2016 to December 2016 and September 2t017 to November 2017. Out of 202 diseased pigeons 35.64% were raniket disease or Newcastle disease (paramyxovirus), 18.11%were canker disease, and 11.38% were one eye cold disease. In most of the lofts, the owners didn’t vaccinate their pigeons against the common diseases, even though many of them were aware of the diseases. Pigeon fancier’s education and awareness of pigeon diseases needs to be improved through veterinary public health and health promotion approach. Non pharmaceutical preventive measures such as hand washing and avoidance of eye, nose and mouth touching after handling of diseased pigeons must be improved. The present study has demonstrated that a study solely based on the questionnaire is not adequate in determining the prevalence of diseases in pigeon and also the results concluded that pigeon fanciers of Tuticorin district do not maintain the regular preventive measures or vaccination against the common diseases and to control the diseases.

Hematologic values in domestic pigeons naturally infected with Mycobacterium avium subsp. avium.

Avian mycobacteriosis is an important disease of birds and is most often caused by Mycobacterium avium or Mycobacterium genavense. However, little information on the hematologic changes associated with this infectious disease in pigeons has been published. The aim of this investigation was to compare the hematologic parameters of domestic pigeons (Columba livia var. domestica) naturally infected with Mavium subsp. avium (MAA) with clinically healthy pigeons. Blood samples were collected from 12 pigeons with suspected mycobacteriosis and 12 clinically healthy pigeons. All the birds with suspect infections were necropsied, and affected organs were cultured and examined on histopathology for mycobacteriosis. Total leukocyte and erythrocyte counts were performed on each blood sample with the Natt and Herrick method using a Neubauer hemocytometer. White blood cell (WBC) differential counts were performed on Giemsa-stained blood smears. Packed cell volumes (PCVs) were measured using the microhematocrit technique. Hemoglobin concentrations were measured with a spectrophotometer using the cyanomethemoglubin method. Mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentrations (MCHCs), and mean cell volumes (MCVs) were calculated manually. All of the infected birds had typical histopathologic findings of avian mycobacteriosis, which were confirmed using microbiologic and molecular methods to detect MAA. The hematologic data from the two groups were compared. The total WBC, heterophil, lymphocyte, and monocyte counts were significantly higher, and the PCV, HGB, MCH, and MCHC values were significantly lower in the infected birds compared with the clinically healthy pigeons.

A cytopathological study of the role of liver impression as a diagnostic tool in pigeons

The aim of the current study is to investigate any pathological changes which affect local pigeon liver by using liver impression and providing data base for the results of cytological and morphological features of hepatic impressions of local pigeon also to Study the relation between cellular contents and bacterial profiles at those impressions for that purpose about 20 birds of local pigeon were used in current study. the result showed presence of including heterophil 21.53% monocyte 1.52%, eosinophil 1.04%, basophil 0.01%, macrophage 4.01%. RBC 31.9% and vacuolated hepatocyte 4.94%. We also recorded presence of undifferentiated cells0.19% bacterial infection and parasite infestation of blood protozoa represented by presence of plasmodium parasite inside red blood cell in 4 samples out of 20 samples, G+ Staphylococcus and streptococcus and G- Bacteria coccobacilli as a bacterial. Bacteria including Staphylococci, Streptococci and Coccobacilli were noticed with in different densities between sections, the protozoal parasite as Plasmodium infestation were also detected in 20% of samples We concluded that, the hepatic impression give a diagnostic tool to aim in final diagnosis for inflammatory diseases in pigeons, in addition this impression give a primary idea about bacteria and parasitic infection that can be present in infected pigeons

Impact of Subclinical Haemoproteus columbae Infection on Farmed Domestic Pigeons from Central Java (Yogyakarta), Indonesia, with Special Reference to Changes in the Hemogram

Pigeon haemoproteosis caused by Haemoproteus columbae (Apicomplexa: Haemosporida: Haemoproteidae) is globally prevalent in rock doves (Columba livia), although little is known regarding this disease in pigeons and doves in Indonesia. Blood samples of 35 farmed domestic pigeons (C. livia f. domestica) from four localities in Yogyakarta Special Region, Central Java, Indonesia, were collected from March to June, 2016, subjected to a hemogram, and analyzed for the presence of hemoprotozoan infections. Microscopic examination of blood smears revealed a prevalence of 62.5–100% of H. columbae at the four localities (n = 8–10 for each locality), and geometric means of 3.0–5.6% of erythrocytes were parasitized by young and mature gametocytes, suggesting that all infected pigeons were in the chronic phase of infection with repeated recurrences and/or reinfections. Nucleotide sequencing of mitochondrial cytochrome b gene (cytb) for haemosporidian species demonstrated the distribution of four major cytb lineages of H. columbae (mainly HAECOL1, accompanied by COLIV03, COQUI05, and CXNEA02 according to the MalAvi database). Hemogram analysis, involving the estimation of packed cell volume, erythrocyte counts, mean corpuscular volume, mean corpuscular hemoglobin concentration, and plasma protein and fibrinogen levels of 20 parasitized pigeons and five non-infected pigeons demonstrated significant macrocytic hypochromic anemia with hypoproteinemia and hyperfibrinogenemia in the infected pigeons. This study shows the profound impact of long-lasting subclinical pigeon haemoproteosis caused by H. columbae on the health of farmed domestic pigeons.

In Vitro and In Vivo Characterization of a Pigeon Paramyxovirus Type 1 Isolated from Domestic Pigeons in Victoria, Australia 2011.

Significant mortalities of racing pigeons occurred in Australia in late 2011 associated with a pigeon paramyxovirus serotype 1 (PPMV-1) infection. The causative agent, designated APMV-1/pigeon/Australia/3/2011 (P/Aus/3/11), was isolated from diagnostic specimens in specific pathogen free (SPF) embryonated eggs and was identified by a Newcastle Disease virus (NDV)-specific RT-PCR and haemagglutination inhibition (HI) test using reference polyclonal antiserum specific for NDV. The P/Aus/3/11 strain was further classified as PPMV-1 using the HI test and monoclonal antibody 617/161 by HI and phylogenetic analysis of the fusion gene sequence. The isolate P/Aus/3/11 had a slow haemagglutin-elution rate and was inactivated within 45 min at 56 °C. Cross HI tests generated an R value of 0.25, indicating a significant antigenic difference between P/Aus/3/11 and NDV V4 isolates. The mean death time (MDT) of SPF eggs infected with the P/Aus/3/11 isolate was 89.2 hr, characteristic of a mesogenic pathotype, consistent with other PPMV-1 strains. The plaque size of the P/Aus/3/11 isolate on chicken embryo fibroblast (CEF) cells was smaller than those of mesogenic and velogenic NDV reference strains, indicating a lower virulence phenotype in vitro and challenge of six-week-old SPF chickens did not induce clinical signs. However, sequence analysis of the fusion protein cleavage site demonstrated an 112RRQKRF117 motif, which is typical of a velogenic NDV pathotype. Phylogenetic analysis indicated that the P/Aus/3/11 isolate belongs to a distinct subgenotype within class II genotype VI of avian paramyxovirus type 1. This is the first time this genotype has been detected in Australia causing disease in domestic pigeons and is the first time since 2002 that an NDV with potential for virulence has been detected in Australia.

Immunogenicity and Protective Activity of Pigeon Circovirus Recombinant Capsid Protein Virus-Like Particles (PiCV rCap-VLPs) in Pigeons (Columba livia) Experimentally Infected with PiCV.

Pigeon circovirus (PiCV) is the most recurrent virus diagnosed in pigeons and is among the major causative agents of young pigeon disease syndrome (YPDS). Due to the lack of an established laboratory protocol for PiCV cultivation, development of prophylaxis is hampered. Alternatively, virus-like particles (VLPs), which closely resemble native viruses but lack the viral genetic material, can be generated using a wide range of expression systems and are shown to have strong immunogenicity. Therefore, the use of VLPs provides a promising prospect for vaccine development. In this study, transfected human embryonic kidney (HEK-293) cells, a mammalian expression system, were used to express the PiCV capsid protein (Cap), which is a major component of PiCV and believed to contain antibody epitopes, to obtain self-assembled VLPs. The VLPs were observed to have a spherical morphology with diameters ranging from 12 to 26 nm. Subcutaneous immunization of pigeons with 100 µg PiCV rCap-VLPs supplemented with water-in-oil-in-water (W/O/W) adjuvant induced specific antibodies against PiCV. Observations of the cytokine expression and T-cell proliferation levels in spleen samples showed significantly higher T-cell proliferation and IFN- γ expression in pigeons immunized with VLPs compared to the controls (p < 0.05). Experimentally infected pigeons that were vaccinated with VLPs also showed no detectable viral titer. The results of the current study demonstrated the potential use of PiCV rCap-VLPs as an effective vaccine candidate against PiCV.

CIRCULATION OF PARAMIXOVIRAL INFECTION AMONG DECORATIVE PIGEONS OF SOUTH UKRAINE

The article presents information on the results of monitoring regarding paramyxovirus diseases of fancy pigeons in the South Ukraine. Seropositivity to the PMV-1 virus was stated in the blood of fancy pigeons and their young (average antibody titer 3.2 log2 and 9.7 log2, respectively), while clinical signs of the disease were not ob-served in all birds, the infection being manifested in a subclinical form.

Gambaran Mikroskopis Berbagai Organ Merpati yang Menunjukkan Gejala Tortikolis dan Identifikasi Virus Penyakit Tetelo Berdasarkan Uji Agar Gel Presipitasi

This study aimed to determine the microscopic conditions of organs of pigeons that suffered from torticollis and identify the cause of disease in torticollis pigeons. Three pigeons showed torticollis symptoms were obtained as sample and marked as pigeon A, B and C, respectively. Isolation of pathogen with inoculation into embryonated pigeon eggs obtained from parents with no history of vaccination and not indicated ND. Identification of ND with agar gel precipitation (AGP) test. Observation of microscopical changes with histopathologic preparation using hematoxylin and eosin staining. Histopathological examination showed that pigeons was done severe neuritis vagus, trakheitis, pneumonia, air sacculitis, hepatitis, pankreatitis, nefritis, jejunoileitis, ileocolitis and orchitis. Perivascular cuffing found in brain. Degenerative changes found in the hepar and ren. Cardiac severe necrotic lesion, and depletion in white pulp area of spleen. Proventricular tissue showed flattening of mucosal epithelium, congestion lesions found in pulmonary tissue. The results of slow hemagglutination test of pigeon egg allantoic fluid, which tested for hemagglutination (HA) showed positive HA result with titers varying between 2, 32, and 64. Serological identification carried out with the AGP test on all culture samples against ND antiserum showing positive results of ND virus. Based on these dara, it can be concluded that the pigeons with symptoms of torticollis is caused by ND virus.

Web-Based Expert System for Diagnosis of Pigeon Disease by Naïve Bayes Method

Pigeons are very close to human life, therefore doves are often pets or livestock. Caring for pigeons because of their uniqueness and care is not that difficult. Care that is not so difficult is not that doves are immune to chicks. Many people do not know how to treat pigeons with disease first. Therefore we need advice from experts on pigeons to treat the disease. Because the disease in pigeons can attack humans, it must be treated first. To overcome this problem, an expert system was built which was equipped with 10 diseases and 33 symptoms obtained from experts or experts. The Naïve Bayes method is a simple classification method which results in a probability value for each disease that appears. This system is made with the advantages of a user friendly display on the gejela selection page. The final result of the diagnosis is according to the first treatment method before being taken to the vet, using a web-based system which can make it easier for users to get information for disease diagnosis in pigeons.

Can domestic pigeon be a potential carrier of zoonotic Salmonella?

Salmonellosis is one of the most important bacterial diseases in pigeons. This study aimed to estimate the prevalence of Salmonella spp. in domestic pigeons (Columba livia f. domestica) in Poland, its antimicrobial susceptibility (both phenotypic and genotypic), and its capability for biofilm formation. The presence of selected virulence genes, nucleotide homology of selected genes, and susceptibility to bacteriophages were investigated as well. From the 585 pigeons tested, 5.47% turned out positive. All isolated strains were recognized as Salmonella enterica ser. Typhimurium. The asymptomatic pigeons were carriers of 37.5% of the isolates. The dominant variants were as follows: 1,4,[5],12,:i:1,2 (53.13%) and 1,4,[5],12,:‐:‐ (31.25%). Most of the strains analysed showed the ability to produce biofilm after 24 and 48 hr of incubation (59.38% and 53.13%, respectively). Over 90% of the strains were confirmed for lpfA, agafA, invA, sivH, and avrA virulence genes. Also, of the thirteen antimicrobial susceptibility genes, the following were confirmed: sul1, tet(A), blaTEM‐1 , floR, strA, and strB. The most common were the strB (18%) and tet(A) (12%) genes that are responsible for coding resistance to aminoglycosides and tetracyclines, respectively. Most of the strains were phenotypically resistant to oxytetracycline (46.88%), neomycin (53.13%) and tylosin (100%). The susceptibility of the investigated Salmonella strains to the bacteriophages was between 33% and 100%. MLST, PCR MP and ERIC PCR analyses indicated a very high genetic similarity of the investigated strains (over 99%). Results of our study indicate that Salmonella enterica ser. Typhimurium is still an important agent in domestic pigeons and that its antimicrobial resistance increases. Alarming is also the confirmation of a single‐phase variant 1,4,[5],12:i,‐, which could have increased virulence and multi‐drug resistance encoded on the plasmid. Most importantly, however, such strains have been isolated from humans with clinical symptoms of Salmonella infection.

Fatal Chlamydia avium Infection in Captive Picazuro Pigeons, the Netherlands.

In 2016, an outbreak of Chlamydia avium infection occurred among Picazuro pigeons (Patagioenas picazuro) living in an aviary in the Netherlands. Molecular typing revealed a unique strain of C. avium. Our findings show that C. avium infection, which usually causes subclinical infection, can cause fatal disease in pigeons.

دراسة علاج الحمام المصاب بفيروس التواء العنق وتأثيراته على معدل الوفيات

يُعد فيروس نيوكاسل من الفيروسات المعدية الخطيرة التي تسبب خسائر اقتصادية عالية في الطيور مثل الحمام والدجاج وغيرها. هدفت الدراسة الحالية إلى علاج مرض التواء العنق وتسجيل تأثيراته المرضية على أجنة الحمام المعالج ولعدة أجيال. استخرج الدم المتخثر من رقاب الطيور المصابة باستخدام إبرة معقمة، ودعم نظامهم الغذائي بالثوم وعصير البرتقال وإطعامهم يدويا لمدة تتراوح بين 2-1 أسبوع. سجلت الدراسة الحالية شفاء جميع الطيور المعاملة قيد الدراسة، إذ قلً التواء العنق وعادت قدرتهم على الأكل بأنفسهم وتم وضع البيض بعد 8-10 أسابيع بعد العلاج. لوحظ في الدراسة الحالية إصابة إناث الحمام فقط بالفيروس خلال فترة الدراسة التي امتدت من أيلول 2019إلى نيسان 2020, وقد وضعت الطيور المعالجة عدة أجيال، وكانت نسبة الوفيات في الأجنة 50%, 100%, 100%, و50% للجيل الأول والثاني والثالث والرابع على التوالي. لوحظت بعض التغييرات السلوكية على 2 من الأفراخ الحية للجيل الأول، إما بالنسبة إلى الجيل الرابع فقد لوحظ إصابة 5 منهم بعد الفقس مباشرة وماتوا بعمر 7-5 أيام إما البقية كانت طبيعية المظهر. استنتجت الدراسة الحالية أن إزالة الخثرة مع الحمية الغذائية لعبت دورا فعالا في معالجة الحمام المصاب، كذلك سَبب مرض التواء العنق وفيات 75% في أجنة الحمام المعالج. واستنادا للنتائج أوصت الدراسة بالحذر الشديد عند إزالة الخثرة كما يجب عزل الأفراخ المصابة.

Prevalence of Pigeon Diseases in Sylhet District, Bangladesh

The study was conducted to determine the occurrence of different diseases in pigeon from January to December 2019 at Sylhet District in Bangladesh. A total of 723 pigeons either infected or dead were collected and examined to diagnose the diseases followed by clinical history, clinical signs, and postmortem lesions and laboratory examination. The data were analyzed by using chi-square test. The result, the proportion of bacterial diseases, viral diseases and parasitic diseases were 22.48%, 66.06% and 11.46% in young and 53.31% of viral, 17.4% of bacterial and 29.27% in adult pigeon respectively.

Role of LsrR in the regulation of antibiotic sensitivity in avian pathogenic Escherichia coli

Avian pathogenic Escherichia coli (APEC) is a specific group of extraintestinal pathogenic E. coli that causes a variety of extraintestinal diseases in chickens, ducks, pigeons, turkeys, and other avian species. These diseases lead to significant economic losses in the poultry industry worldwide. However, owing to excessive use of antibiotics in the treatment of infectious diseases, bacteria have developed antibiotic resistance. The development of multidrug efflux pumps is one important bacterial antibiotic resistance mechanism. A multidrug efflux pump, MdtH, which belongs to the major facilitator superfamily of transporters, confers resistance to quinolone antibiotics such as norfloxacin and enoxacin. LsrR regulates hundreds of genes that participate in myriad biological processes, including mobility, biofilm formation, and antibiotic susceptibility. However, whether LsrR regulates mdtH transcription and then affects bacterial resistance to various antibiotics in APEC has not been reported. In the present study, the lsrR mutant was constructed from its parent strain APECX40 (WT), and high-throughput sequencing was performed to analyze the transcriptional profile of the WT and mutant XY10 strains. The results showed that lsrR gene deletion upregulated the mdtH transcript level. Furthermore, we also constructed the lsrR- and mdtH-overexpressing strains and performed antimicrobial susceptibility testing, antibacterial activity assays, real-time reverse transcription PCR, and electrophoretic mobility shift assays to investigate the molecular regulatory mechanism of LsrR on the MdtH multidrug efflux pump. The lsrR mutation and the mdtH-overexpressing strain decreased cell susceptibility to norfloxacin, ofloxacin, ciprofloxacin, and tetracycline by upregulating mdtH transcript levels. In addition, the lsrR-overexpressing strain increased cell susceptibility to norfloxacin, ofloxacin, ciprofloxacin, and tetracycline by downregulating mdtH transcript levels. Electrophoretic mobility shift assays indicated that LsrR directly binds to the mdtH promoter. Therefore, this study is the first to demonstrate that LsrR inhibits mdtH transcription by directly binding to its promoter region. This action subsequently increases susceptibility to the aforementioned four antibiotics in APECX40.

Complete Genome Sequencing, Molecular Epidemiological, and Pathogenicity Analysis of Pigeon Paramyxoviruses Type 1 Isolated in Guangxi, China during 2012-2018.

Newcastle disease is an important poultry disease that also affects Columbiform birds. The viruses adapted to pigeons and doves are referred to as pigeon paramyxoviruses 1 (PPMV-1). PPMV-1 are frequently isolated from pigeons worldwide and have the potential to cause disease in chickens. The complete genomes of 18 PPMV-1 isolated in China during 2012–2018 were sequenced by next-generation sequencing (NGS). Comprehensive phylogenetic analyses showed that five of the viruses belong to sub-genotype VI1.2.1.1.2.1 and 13 isolates belong to sub-genotype VI.2.1.1.2.2. The results demonstrate that these sub-genotypes have been predominant in China during the last decade. The viruses of these sub-genotypes have been independently maintained and continuously evolved for over 20 years, and differ significantly from those causing outbreaks worldwide during the 1980s to 2010s. The viral reservoir remains unknown and possibilities of the viruses being maintained in both pigeon farms and wild bird populations are viable. In vivo characterization of the isolates’ pathogenicity estimated mean death times between 62 and 114 h and intracerebral pathogenicity indices between 0.00 and 0.63. Cross-reactivity testing showed minor antigenic differences between the studied viruses and the genotype II LaSota vaccine. These data will facilitate PPMV-1 epidemiology studies, vaccine development, and control of Newcastle disease in pigeons and poultry.