Single-cell RNA sequencing reveals surface markers of primordial germ cells in chicken and zebra finch.

Primordial germ cells (PGCs) in avian species exhibit unique developmental features, including the ability to migrate through the bloodstream and colonize the gonads, allowing their isolation at various developmental stages. Several methods have been developed for the isolation of avian PGCs, including density gradient centrifugation, size-dependent separation, and magnetic-activated cell sorting (MACS) or fluorescence-activated cell sorting (FACS) using a stage-specific embryonic antigen-1 (SSEA-1) antibody. However, these methods present limitations in terms of efficiency and applicability across development stages. In particular, the specificity of SSEA-1 decreases in later developmental stages. Furthermore, surface markers that can be utilized for isolating or utilizing PGCs are lacking for wild birds, including zebra finches, and endangered avian species. To address this, we used single-cell RNA sequencing (scRNA-seq) to uncover novel PGC-specific surface markers in chicken and zebra finch. We screened for genes that were primarily expressed in the PGC population within the gonadal cells. Analyses of gene expression patterns and levels based on scRNA-seq, coupled with validation by RT-PCR, identified NEGR1 and SLC34A2 as novel PGC-specific surface markers in chickens and ESYT3 in zebra finches. Notably, these newly identified genes exhibited sustained expression not only during later developmental stages but also in reproductive tissues.

A brief review on models for birds exposed to chemicals.

"A Who's Who of pesticides is therefore of concern to us all. If we are going to live so intimately with these chemicals eating and drinking them, taking them into the very marrow of our bones - we had better know something about their nature and their power."-Rachel Carson, Silent Spring. In her day, Rachel Carson was right: plant protection products (PPP), like all the other chemical substances that humans increasingly release into the environment without further precaution, are among our worst enemies today (Bruhl and Zaller, 2019; Naidu et al., 2021; Tang et al., 2021; Topping et al., 2020). All compartments of the biosphere, air, soil and water, are potential reservoirs within which all species that live there are impaired. Birds are particularly concerned: PPP are recognized as a factor in the decline of their abundance and diversity predominantly in agricultural landscapes. Due to the restrictions on vertebrates testing, in silico-based approaches are an ideal choice alternative given input data are available. This is where the problem lies as we will illustrate in this paper. We performed an extensive literature search covering a long period of time, a wide diversity of bird species, a large range of chemical substances, and as many model types as possible to encompass all our future need to improve environmental risk assessment of chemicals for birds. In the end, we show that poultry species exposed to pesticides are the most studied at the individual level with physiologically based toxicokinetic models. To go beyond, with more species, more chemical types, over several levels of biological organization, we show that observed data are crucially missing (Gilbert, 2011). As a consequence, improving existing models or developing new ones could be like climbing Everest if no additional data can be gathered, especially on chemical effects and toxicodynamic aspects.

Safety and efficacy of a feed additive consisting of Quillaja saponaria Molina and Yucca schidigera Roezl ex Ortgies (Magni-PHI®) for all poultry species (to slaughter age/weight, or to the point of lay) and ornamental birds (Phibro Animal Health Corporation).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a feed additive consisting of Quillaja saponaria powder and Yucca schidigera powder (Magni-Phi®) for all avian species (to slaughter age/weight, or to the point of lay) and ornamental birds, as a zootechnical additive (digestibility enhancer and other zootechnical additives). The EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) concluded that the additive is safe for chickens for fattening at the level of 250 mg/kg complete feed with a margin of safety of 20 assuming that the additive contains 3.58% of saponins. This conclusion was extrapolated to all growing poultry species and ornamental birds. The Panel concluded that the use of the feed additive in animal nutrition at 250 mg/kg complete feed is of no concern for the safety for the consumer and the environment. The Panel also concluded that the additive is not irritant to skin, but irritant to the eyes and to the respiratory system. Due to the lack of data, the FEEDAP Panel could not conclude on the skin sensitisation potential of the additive. The FEEDAP Panel was not in the position to conclude on the efficacy of the additive for all poultry species and ornamental birds.

FcRY is a key molecule controlling maternal blood IgY transfer to yolks during egg development in avian species.

Maternal immunoglobulin transfer plays a key role in conferring passive immunity to neonates. Maternal blood immunoglobulin Y (IgY) in avian species is transported to newly-hatched chicks in two steps: 1) IgY is transported from the maternal circulation to the yolk of maturing oocytes, 2) the IgY deposited in yolk is transported to the circulation of the embryo via the yolk sac membrane. An IgY-Fc receptor, FcRY, is involved in the second step, but the mechanism of the first step is still unclear. We determined whether FcRY was also the basis for maternal blood IgY transfer to the yolk in the first step during egg development. Immunohistochemistry revealed that FcRY was expressed in the capillary endothelial cells in the internal theca layer of the ovarian follicle. Substitution of the amino acid residue in Fc region of IgY substantially changed the transport efficiency of IgY into egg yolks when intravenously-injected into laying quail; the G365A mutant had a high transport efficiency, but the Y363A mutant lacked transport ability. Binding analyses of IgY mutants to FcRY indicated that the mutant with a high transport efficiency (G365A) had a strong binding activity to FcRY; the mutants with a low transport efficiency (G365D, N408A) had a weak binding activity to FcRY. One exception, the Y363A mutant had a remarkably strong binding affinity to FcRY, with a small dissociation rate. The injection of neutralizing FcRY antibodies in laying quail markedly reduced IgY uptake into egg yolks. The neutralization also showed that FcRY was engaged in prolongation of half-life of IgY in the blood; FcRY is therefore a multifunctional receptor that controls avian immunity. The pattern of the transport of the IgY mutants from the maternal blood to the egg yolk was found to be identical to that from the fertilized egg yolk to the newly-hatched chick blood circulation, via the yolk sac membrane. FcRY is therefore a critical IgY receptor that regulates the IgY uptake from the maternal blood circulation into the yolk of avian species, further indicating that the two steps of maternal-newly-hatched IgY transfer are controlled by a single receptor.

Efficacy of a feed additive consisting of Bacillus subtilis FERM BP-07462, Enterococcus lactis FERM BP-10867 and Clostridium butyricum FERM BP-10866 (BIO-THREE®) for chickens for fattening and reared for laying, turkeys for fattening and reared for breeding, and all avian species for rearing/fattening or reared for laying/breeding (TOA BIOPHARMA Co., Ltd.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the efficacy of Bacillus subtilis FERM BP-07462, Enterococcus lactis FERM BP-10867 and Clostridium butyricum FERM BP-10866 (BIO-THREE®) as a zootechnical feed additive to be used as a gut flora stabiliser for chickens for fattening and reared for laying, turkeys for fattening and reared for breeding, and all avian species for rearing/fattening or reared for laying/breeding. In a previous opinion, the FEEDAP Panel could not conclude on the efficacy of BIO-THREE® for the target species at the proposed conditions of use. The applicant has provided a new study in chickens for fattening as supplementary information to support the efficacy of BIO-THREE® for the target species. Considering the previously submitted studies and the new submitted trial, the Panel concluded that the additive is efficacious for chickens for fattening and reared for laying, turkeys for fattening and reared for breeding, and all avian species for rearing/fattening or reared for laying/breeding under the proposed conditions of use.

Pathognomonic features of Pasteurella multocida isolates among various avian species in Sharkia Governorate, Egypt.

The present study aimed to isolate Pasteurella multocida (P. multocida) from pulmonary cases in several avian species and then investigate the histopathological features, antimicrobial resistance determinants, virulence characteristics, and risk factors analysis of the isolates in each species in correlation with epidemiological mapping of pasteurellosis in Sharkia Governorate, Egypt. The obtained data revealed a total occurrence of 9.4% (30/317) of P. multocida among the examined birds (chickens, ducks, quails, and turkeys). The incidence rate was influenced by avian species, climate, breed, age, clinical signs, and sample type. Antimicrobial susceptibility testing revealed that all isolates were sensitive to florfenicol and enrofloxacin, while 86.6 and 73.3% of the isolates displayed resistance to amoxicillin-clavulanic acid and erythromycin, respectively. All of the P. multocida isolates showed a multiple-drug resistant pattern with an average index of 0.43. Molecular characterization revealed that the oma87, sodA, and ptfA virulence genes were detected in the all examined P. multocida isolates. The ermX (erythromycin), blaROB-1 (ß-lactam), and mcr-1(colistin) resistance genes were present in 60, 46.6, and 40% of the isolates, respectively. Ducks and quails were the most virulent and harbored species of antimicrobial-resistant genes. These results were in parallel with postmortem and histopathological examinations which detected more severe interstitial pneumonia lesions in the trachea and lung, congestion, and cellular infiltration especially in ducks. Epidemiological mapping revealed that the Fakous district was the most susceptible to pasteurellosis infection. Thus, farmers are recommended to monitor their flocks for signs of respiratory disease, seek veterinary care promptly if any birds are sick, and avoid the random usage of antibiotics. In conclusion, this study presents a comprehensive picture of the risk factors in correlation to the pathognomonic characteristics of P. multocida infection in poultry sectors to help in developing more effective strategies for prevention and control.

Immunohistochemical identification of T and B lymphocytes in formalin-fixed, paraffin-embedded tissues of 53 avian species using commercial antibodies.

Providing a method to detect avian lymphocytes by immunohistochemistry (IHC) would be helpful for analyzing immune function and diagnosing diseases in birds. In this study, we comprehensively examined the immunohistochemical identification of avian T and B lymphocytes in formalin-fixed, paraffin-embedded tissues from 53 avian species across 15 orders, using eight commercially available lymphocyte markers. T lymphocytes from all 53 avian species tested were specifically detected by IHC using the anti-CD3 antibody (clone F7.2.38). The appropriate antibody for detecting avian B lymphocytes in IHC varied depending on the avian species. B lymphocytes were specifically labeled by IHC in 46 of 53 avian species (86.8%) using any of seven B cell markers. The anti-PAX5 antibody (clone SP34) immunohistochemically detected B lymphocytes from the majority of avian species (41 out of 53 species), excluding those in the orders Falconiformes (falcons) and Passeriformes (oscines). The anti-BAFF-R antibody (clone 2C4) proved suitable for detecting B lymphocytes in the orders Galliformes (landfowls) and Anseriformes (waterfowls) in IHC. Caution is advised when using the anti-BLA36 (clone A27-42) and two anti-CD20 (clone L26 and product No. PA5-16701) antibodies, which are commonly used as B cell markers in mammals, for detecting avian B lymphocytes. These antibodies reacted with cells located in both T and B cell areas in certain avian species. The anti-Bu-1a/b (clone AV20) and anti-CD79a (clone HM57) antibodies were found not to bind to B lymphocytes in various avian species in IHC.

The avian taste system.

Taste or gustation is the sense evolving from the chemo-sensory system present in the oral cavity of avian species, which evolved to evaluate the nutritional value of foods by detecting relevant compounds including amino acids and peptides, carbohydrates, lipids, calcium, salts, and toxic or anti-nutritional compounds. In birds compared to mammals, due to the relatively low retention time of food in the oral cavity, the lack of taste papillae in the tongue, and an extremely limited secretion of saliva, the relevance of the avian taste system has been historically undermined. However, in recent years, novel data has emerged, facilitated partially by the advent of the genomic era, evidencing that the taste system is as crucial to avian species as is to mammals. Despite many similarities, there are also fundamental differences between avian and mammalian taste systems in terms of anatomy, distribution of taste buds, and the nature and molecular structure of taste receptors. Generally, birds have smaller oral cavities and a lower number of taste buds compared to mammals, and their distribution in the oral cavity appears to follow the swallowing pattern of foods. In addition, differences between bird species in the size, structure and distribution of taste buds seem to be associated with diet type and other ecological adaptations. Birds also seem to have a smaller repertoire of bitter taste receptors (T2Rs) and lack some taste receptors such as the T1R2 involved in sweet taste perception. This has opened new areas of research focusing on taste perception mechanisms independent of GPCR taste receptors and the discovery of evolutionary shifts in the molecular function of taste receptors adapting to ecological niches in birds. For example, recent discoveries have shown that the amino acid taste receptor dimer T1R1-T1R3 have mutated to sense simple sugars in almost half of the living bird species, or SGLT1 has been proposed as a part of a T1R2-independent sweet taste sensing in chicken. The aim of this review is to present the scientific data known to date related to the avian taste system across species and its impact on dietary choices including domestic and wild species.

Whole genome sequencing identifies candidate genes and mutations that can explain diluted and other colour varieties of domestic canaries (Serinus canaria).

The domestic canary (Serinus canaria) is one of the most common pet birds and has been extensively selected and bred over the last few centuries to constitute many different varieties. Plumage pigmentation is one of the main phenotypic traits that distinguish canary breeds and lines. Feather colours in these birds, similarly to other avian species, are mainly depended on the presence of two major types of pigments: carotenoids and melanins. In this study, we exploited whole genome sequencing (WGS) datasets produced from five canary lines or populations (Black Frosted Yellow, Opal, Onyx, Opal × Onyx and Mogno, some of which carrying different putative dilute alleles), complemented with other WGS datasets retrieved from previous studies, to identify candidate genes that might explain pigmentation variability across canary breeds and varieties. Sequencing data were obtained using a DNA pool-seq approach and genomic data were compared using window-based FST analyses. We identified signatures of selection in genomic regions harbouring genes involved in carotenoid-derived pigmentation variants (CYP2J19, EDC, BCO2 and SCARB1), confirming the results reported by previous works, and identified several other signatures of selection in the correspondence of melanogenesis-related genes (AGRP, ASIP, DCT, EDNRB, KITLG, MITF, MLPH, SLC45A2, TYRP1 and ZEB2). Two putative causative mutations were identified in the MLPH gene that may explain the Opal and Onyx dilute mutant alleles. Other signatures of selection were also identified that might explain additional phenotypic differences between the investigated canary populations.

Safety and efficacy of a feed additive consisting of the bacteriophages PCM F/00069, PCM F/00070, PCM F/00071 and PCM F/00097 (Bafasal®) for all avian species (Proteon Pharmaceuticals S.A.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a product consisting of four bacteriophages infecting Salmonella enterica ser. Gallinarum B/00111, intended to be used as a zootechnical additive (functional group: other zootechnical additives) for all avian species. The additive (tradename Bafasal®) is not currently authorised in the European Union. Bafasal® is intended to be used in water for drinking and liquid complementary feed to guarantee a minimum daily dose of 2 × 106 PFU/bird, to reduce the Salmonella spp. contamination of poultry carcasses and load in the environment, and to improve the zootechnical performance of the treated animals. In a previous opinion, the FEEDAP Panel could not conclude on the additive's potential to be irritant or a dermal sensitiser, or on its efficacy for any avian species due to insufficient data. The applicant provided supplementary information to address these data gaps. The new data showed that Bafasal® is not a skin or eye irritant. No conclusions could be drawn on its skin sensitisation potential. The Panel was not in the position to conclude on the efficacy of Bafasal® to improve the zootechnical performance of the target species based on the available data. The additive showed the potential to decrease the counts of two strains of Salmonella Enteritidis in boots swabs and caecal digesta of chickens for fattening. No conclusions could be drawn on the capacity of Bafasal® to reduce the contamination of other Salmonella enterica strains, serovars or other species of Salmonella. The potential of Bafasal® to reduce the Salmonella spp. contamination poultry carcasses and/or the environment is limited. The FEEDAP Panel recommended a post-market monitoring plan to address the potential selection and spread of resistant variants of Salmonella to Bafasal®.

Fate Decisions of Chicken Primordial Germ Cells (PGCs): Development, Integrity, Sex Determination, and Self-Renewal Mechanisms.

Primordial germ cells (PGCs) are precursor cells of sperm and eggs. The fate decisions of chicken PGCs in terms of their development, integrity, and sex determination have unique features, thereby providing insights into evolutionary developmental biology. Additionally, fate decisions in the context of a self-renewal mechanism have been applied to establish culture protocols for chicken PGCs, enabling the production of genome-edited chickens and the conservation of genetic resources. Thus, studies on the fate decisions of chicken PGCs have significantly contributed to both academic and industrial development. Furthermore, studies on fate decisions have rapidly advanced owing to the recent development of essential research technologies, such as genome editing and RNA sequencing. Here, we reviewed the status of fate decisions of chicken PGCs and provided insight into other important research issues that require attention.

Nutraceutical Effects of Justicia carnea Leaf Powder Supplementations on Performance, Blood Indices, Heat Shock Protein 70, Oxidative Deoxyribonucleic Acid Damage Biomarkers and Intestinal Microbes of Broiler Chickens, Under Tropical Condition.

The main reason preventing broiler chickens from reaching their genetic potential and hurting their performance in the tropics is heat stress. This study aimed to ascertain how Justicia carnea leaf powder (JLP) supplementation affects broiler chickens' performance, blood indices, antioxidant status, and gut microflora in tropical environments. A completely randomized method was used to assign 240 Cobb 500 broiler chicks to the experimental diets (6 replicates per diet, 10 birds per replication). Diet 1 included no supplement (negative control), diet 2 included 200 mg/kg vitamin C (positive control), diet 3 included 2,500 mg/kg JLP, and diet 4 included 5,000 mg/kg JLP. On day 42, the body weight gain (BWG) of the birds fed on diet 4 was significantly higher than those on diet 1. The packed cell volume, red blood cell count, and hemoglobin concentration of the birds fed on diets 3 and 4 were significantly higher than those of the control (P<0.05). The serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and cholesterol were lower in birds fed on diets 3 and 4, compared to those on diet 1 (P<0.05). The serum heat shock protein 70 (HSP 70) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were lower in birds fed on diets 3 and 4, compared to those on diet 1 (P<0.05). The lactic acid-producing bacteria (LAB) population was higher in birds fed on diets 3 and 4, compared to those on diet 1(P<0.05). However, the Coliform bacteria population was reduced in birds fed on diets 3 and 4, compared to those on diet 1. The 2,500 and 5,000 mg/kg JLP dietary supplementations enhanced BWG, improved erythrogram indices, and reduced blood AST, ALT, cholesterol, HSP 70, 8-OHdG, and caeca Coliform population but increased the caeca LAB population.

A Survey of Diseases in Different Species of Wild, Captive, and Illegally Traded Birds in Brazil.

Native and exotic avian species can act as reservoirs of pathogens, including bacteria and viruses, with conservation and public health implications. A retrospective study on the diagnosis and frequency of diseases in wild and exotic avian species was conducted. The occurrence of particular diseases was associated with the type of captivity or the bird's origin. The investigation included macroscopic and microscopic descriptions and the molecular determination of the causative agent(s). Additional immunohistochemical (IHC) analysis, PCR, and genetic sequencing were conducted. A total of 243 cases were compiled for the study, mainly consisting of native wild species (39.1%) obtained from illegal trade. Primary infectious diseases, mainly parasitic (18.1%) and viral (17.7%), were the most common, although coinfections were substantial (18.1%) in birds rescued from trafficking. Fractures and neoplasms accounted for 3.7% and 3.3% of the cases, respectively. Parasitic and viral diseases were the most common in both exotic and wild birds. Chlamydia psittaci, a lethal and zoonotic bacterium, was an important cause of death, especially in native Psittaciformes. The recent detection of Psittacid alphaherpesvirus 5 (PsAHV 5) in exotic psittacines and the diagnosis of coinfections in trafficked birds highlight the importance of monitoring avian health to control potential pathogens that may endanger conservation efforts.

Monitoring Wind-Borne Particle Matter Entering Poultry Farms via the Air-Inlet: Highly Pathogenic Avian Influenza Virus and Other Pathogens Risk.

Wind-supported transport of particle matter (PM) contaminated with excreta from highly pathogenic avian influenza virus (HPAIv)-infected wild birds may be a HPAIv-introduction pathway, which may explain infections in indoor-housed poultry. The primary objective of our study was therefore to measure the nature and quantity of PM entering poultry houses via air-inlets. The air-inlets of two recently HPAIv-infected poultry farms (a broiler farm and a layer farm) were equipped with mosquito-net collection bags. PM was harvested every 5 days for 25 days. Video-camera monitoring registered wild bird visits. PM was tested for avian influenza viruses (AIV), Campylobacter and Salmonella with PCR. Insects, predominantly mosquitoes, were tested for AIV, West Nile, Usutu and Schmallenberg virus. A considerable number of mosquitoes and small PM amounts entered the air-inlets, mostly cobweb and plant material, but no wild bird feathers. Substantial variation in PM entering between air-inlets existed. In stormy periods, significantly larger PM amounts may enter wind-directed air-inlets. PM samples were AIV and Salmonella negative and insect samples were negative for all viruses and bacteria, but several broiler and layer farm PM samples tested Campylobacter positive. Regular wild (water) bird visits were observed near to the poultry houses. Air-borne PM and insects-potentially contaminated with HPAIv or other pathogens-can enter poultry air-inlets. Implementation of measures limiting this potential introduction route are recommended.

What evidence exists for the use of urban forest management in nature-based carbon solutions and bird conservation. A systematic map protocol.

BACKGROUND: There is global interest in finding innovative solutions that address current climate and societal challenges in an urban context. Cities are often on the front lines of environmental change, meaning urban greening strategies have high potential to provide benefits across human communities, while protecting global biodiversity. There is growing consensus that nature-based solutions can provide multiple benefits to people and nature while also mitigating the effects of climate change. Urban forest management is well-suited to a nature-based solutions framework due to the wide variety of services trees provide our communities. Effective approaches to urban forest management also have the potential to promote other forms of urban biodiversity, particularly birds and species at risk. However, studies that integrate strategies for both climate and biodiversity conservation are rare. The goal of this systematic map is to gather and describe information on two desired outcomes of urban forest management: (1) conserving avian diversity and species at risk (2) carbon storage and sequestration (i.e., nature-based climate solutions). METHODS: We will identify relevant articles from two separate searches for inclusion in our systematic map that address (1) urban forestry and avian and species at risk conservation and, (2) urban forestry and carbon storage and sequestration. We will search two bibliographic databases, consult 20 relevant organizational websites, and solicit grey literature through an open call for evidence. Eligibility screening will be conducted at two stages: (1) title and abstract and (2) full text. Relevant information from included papers will be extracted and entered in a searchable, coded database. Synthesis of evidence will describe the key characteristics of each study (e.g., geographic locations, interventions, outcomes, species studied) and identify knowledge gaps and clusters of evidence. Our systematic map will guide further research on opportunities for multiple benefits using nature-based solutions, particularly as they relate to urban forest management. Furthermore, our evidence base will support both management and funding decisions to ensure the effective use of resources for maximum benefits across people and ecosystems.

Safety and efficacy of a feed additive consisting of Bacillus velezensisDSM 15544 (Calsporin®) for piglets (suckling and weaned), pigs for fattening, sows in order to have benefit in piglets, ornamental fish, dogs and all avian species (Asahi Biocycle Co.).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Bacillus velezensis DSM 15544 (Calsporin®) when used as a feed additive for piglets (suckling and weaned), pigs for fattening, sows in order to have benefit in piglets, ornamental fish, dogs and all avian species. The additive is authorised for use in sows, suckling and weaned piglets, pigs for fattening, chickens for fattening, laying hens, ornamental fish and dogs. With this application the company requested a new authorisation for all avian species and the modification of the current authorisations as regards the strain taxonomy from Bacillus subtilis DSM 15544 to B. velezensis DSM 15544. The FEEDAP Panel concluded that the active agent of Calsporin® should be taxonomically designated as Bacillus velezensis DSM 15544. The Panel also concluded that Calsporin® is presumed safe for the target species, consumers and the environment. Calsporin® is not a dermal/eye irritant or a skin sensitiser but should be considered a respiratory sensitiser. Calsporin® when supplemented at 3 × 108 CFU/kg complete feed has the potential to be efficacious in all avian species for rearing, fattening, laying and breeding purposes.

Virulence genes and enterobacterial repetitive intergenic consensus region (ERIC) profiling reveals highly diverse genetic population among avian strains of Pasteurella multocida.

Pasteurella multocida is a multispecies pathogen with certain host specific capsular types but interspecies transmission cannot be overlooked. Knowing the diversity of P. multocida in a geographical location is essential to formulate a vaccination programme. Diversity among the P. multocida isolates from different avian species recovered in the state of Tamil Nadu, India was studied using enterobacterial repetitive intergenic consensus region (ERIC)-PCR and virulence gene profiling (VP). Capsular typing revealed that 44 (97.78%) strains belonged to capsular type A while only one (2.22%) strain belonged to capsular type B. ERIC-PCR analysis showed eight different clusters and four individual strains. The index of discrimination (D value) was found to be 0.8899. Virulence profiling showed that genes fimA, pfhA, hsf-2 and pmHAS were found in 100% of the strains while ompH, omp87, ompA, plpB, sodA, sodC, ptfA, hsf-1, exbB, fur, hgbA and hgbB were found in ≥90% of the strains. Dermonecrotoxin gene toxA was present only in 4.44% of the strains, while nanH in 68.89% and nanB in 88.89% of the strains. One strain each from turkey and Guinea fowl had toxA gene. Correlation analysis revealed a positive correlation between ptfA and hgbA gene, exbB and fur gene, ptfA and sodC gene, exbB and hsf-1 gene, ompA and ompH gene. Majority of duck strains clustered together both in ERIC and virulence gene profiles. Turkey strains were highly diverse with different VPs and ERIC-PCR patterns.

Safety and efficacy of a feed additive consisting on the bacteriophages PCM F/00069, PCM F/00070, PCM F/00071 and PCM F/00097 infecting Salmonella Gallinarum B/00111 (Bafasal®) for all avian species (Proteon Pharmaceuticals S.A.).

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the feed additive consisting of four bacteriophages infecting Salmonella Gallinarum B/00111 (PCM F/00069, PCM F/00070, PCM F/00071 and PCM F/00097, trade name: Bafasal®) when used as a zootechnical additive in water for drinking and liquid complementary feed for all avian species. The effects sought are the reduction of the Salmonella spp. carriage in chickens for fattening, the improvement of their performance, or both. The host strain harbours an acquired antimicrobial resistance gene. No viable cells or DNA from the host organism were found in the additive. The four phages proved to be strictly lytic and to have a machinery allowing to package a unit-length of the viral genome. The manufacturing process excludes the presence of remnants from the propagation process in the final additive. Consequently, no concerns are expected from the nature and manufacture of the product. Considering this and the results of the tolerance study with chickens for fattening, the Panel concluded that Bafasal® is safe for all avian species. Considering the nature and manufacturing process of the additive, Bafasal® is not expected to pose a risk for consumers. The results of the subchronic oral toxicity study and genotoxicity studies provided support this conclusion. Exposure of users via inhalation is expected to be low, but Bafasal® should be considered a respiratory sensitiser. No conclusions were drawn on the irritancy of Bafasal® to skin and eyes or on its dermal sensitisation potential due to lack of data. Considering the nature and manufacturing process of the additive, Bafasal® is safe for the environment. The Panel was not in the position to conclude on the efficacy of Bafasal® for any avian species due to insufficient data.

Safety and efficacy of a feed additive consisting of a preparation of benzoic acid, calcium formate and fumaric acid (AviMatrix® Z) for all avian species other than laying birds (Novus Europe S.A. / N.V).

The additive AviMatrix® Z is a preparation of benzoic acid, calcium formate and fumaric acid and is authorised as a feed additive in chickens for fattening and reared for laying. The applicant has requested to extend the use of the additive to all avian species other than laying birds at a concentration range from 500 to 1,000 mg/kg of complete feed. The safety of the additive was previously assessed by the FEEDAP Panel that concluded that there were no concerns for the consumers and no risks for the environment. Given the particle size distribution and low dusting potential of the additive, the exposure of workers by inhalation and the subsequent health risks were expected to be low. AviMatrix® Z is not considered to be a skin/eye irritant or a skin sensitiser. The FEEDAP Panel is not aware of any new information that would lead to reconsider the conclusions drawn previously. The results of a new tolerance study showed that the additive is tolerated by turkeys for fattening at threefold the highest recommended dose (1,000 mg/kg feed). Therefore, the FEEDAP Panel concluded that the additive is safe for turkeys for fattening at the maximum recommended dose and this conclusion was extended to turkeys reared for breeding. Due to the absence of a margin of safety in a trial in chickens for fattening previously evaluated, the FEEDAP Panel could not extrapolate this conclusion to all other avian species up to the point of lay. The FEEDAP Panel concluded that the additive has the potential to be efficacious in all avian species other than laying and breeding birds.

Comparative Mapping of the Macrochromosomes of Eight Avian Species Provides Further Insight into Their Phylogenetic Relationships and Avian Karyotype Evolution.

Avian genomes typically consist of ~10 pairs of macro- and ~30 pairs of microchromosomes. While inter-chromosomally, a pattern emerges of very little change (with notable exceptions) throughout evolution, intrachromosomal changes remain relatively poorly studied. To rectify this, here we use a pan-avian universally hybridising set of 74 chicken bacterial artificial chromosome (BAC) probes on the macrochromosomes of eight bird species: common blackbird, Atlantic canary, Eurasian woodcock, helmeted guinea fowl, houbara bustard, mallard duck, and rock dove. A combination of molecular cytogenetic, bioinformatics, and mathematical analyses allowed the building of comparative cytogenetic maps, reconstruction of a putative Neognathae ancestor, and assessment of chromosome rearrangement patterns and phylogenetic relationships in the studied neognath lineages. We observe that, as with our previous studies, chicken appears to have the karyotype most similar to the ancestor; however, previous reports of an increased rate of intrachromosomal change in Passeriformes (songbirds) appear not to be the case in our dataset. The use of this universally hybridizing probe set is applicable not only for the re-tracing of avian karyotype evolution but, potentially, for reconstructing genome assemblies.