Vaccine or field strains: the jigsaw pattern of infectious bronchitis virus molecular epidemiology in Poland

Infectious bronchitis (IB), caused by infectious bronchitis virus (IBV), account for severe economic losses in the poultry industry. The continuous emergence of a multitude of IBV variants poses many challenges for its diagnosis and control, and live attenuated vaccines, despite their routine use, still plays a significant role in driving IBV evolution, further complicating the epidemiological scenario. Unfortunately, the impact of different vaccination strategies on IB control, epidemiology, and diagnosis has rarely been investigated. This work presents the results of a large-scale diagnostic survey performed in Poland to study IBV molecular epidemiology and how vaccination may affect the viral circulation in the field. To this purpose, 589 samples were collected between May 2017 and January 2019, tested by reverse transcription-PCR for IBV and sequenced. Vaccine and field strains were discriminated based on genetic and anamnestic information. The most commonly detected lineages were 793B (79%) and variant 2 (17.4%), with sporadic detections of QX, Mass, and D274-like strains. Most of the detected strains had a vaccine origin: 46.3% matched one of the applied vaccines, while 36.5% were genetically related to vaccines not implemented in the respective protocol. Besides their practical value for the proper planning of vaccination protocols in Poland, these results suggest that only a fraction (17.2%) of the circulating strains are field ones, imposing a careful assessment of the actual IBV field menaces. Moreover, phenomena like vaccine spreading and persistence seem to occur commonly, stressing the need to further study the epidemiological consequences of the extensive use of live vaccines

The effects of dietary calcium intake, absorption and age at sexual maturity on bone strength of battery caged laying hens

SIGLEAvailable from British Library Document Supply Centre-DSC:DXN023180 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Supplemental Linseed on Egg Production

Linseed is a rich source of energy, protein, fat, vitamins, minerals, and some antioxidants. It is also one of the richest vegetable sources of omega-3 polyunsaturated fatty acids (PUFA) and has successfully been used in poultry diets to fortify chicken eggs with omega-3 PUFA. Both linseed and its oil can be used in hen's diets to produce omega-3 eggs which are available in super markets under various brand names. The use of linseed in commercial layer diets is limited mainly due to the presence of potential antinutritional factors which can compromise production performance and egg quality in laying hens if fed at too high of a level. However, linseed oil can be used to produce omega 3-enriched eggs without any detrimental effect on hen performance. Therefore, linseed oil is the preferred feed ingredient to use in laying hen diets to produce omega 3-enriched eggs which can bring a premium price at retail. © 2017 Elsevier Inc. All rights reserved

Colibacillosis in poultry: A disease overview and the new perspectives for its control and prevention

Escherichia coli (E.coli) is a common bacterium that can be naturally found in the intestinal tract of birds and as a result in their environment. However, it can cause clinical disease called colibacillosis which is regarded as one of the most common and important diseases in poultry. Strains of E.coli that have the ability to cause clinical disease are described as Avian Pathogenic Escherichia Coli (APEC). Colibacillosis can affect birds of all ages and different types of poultry production including broiler and commercial layers and breeders. The ability of E.coli to cause colibacillosis is not always the same; that is why its role as primary or secondary pathogen triggered by various predisposing factors is contradictory and differs from case to case. Antibiotics have been used as the main tool against colibacillosis for many decades. However, the emergence of increased antibiotic resistance has posed the need of alternative treatment to colibacillosis as well as emphasizing on preventive measures to avoid disease. The scope of this article is to assess recent scientific literature data on avian colibacillosis emphasizing on disease characteristics and recent data on prevention and control of the disease. © 2020. All Rights Reserved

Replacement of canola meal with Moringa oleifera leaf powder affects performance and immune response in broilers

Moringa oleifera is known as a miracle tree due to its amazing nutritional and therapeutic properties. Considering its nutritional value, Moringa oleifera leaf powder can be used as a non-conventional ingredient in poultry diets. This study was conducted to investigate the effect of the replacement of canola meal (CM) with Moringa oleifera leaf powder (MOLP) on growth performance, blood hematology, and immune response in broilers. Two-hundred-twenty one-day-old Hubbard broiler chicks were reared in one group for a wk (adaptation period). At 8 d of age, 150 chicks of similar body weight (±5g) were selected and randomly divided into 15 experimental units, each comprising 10 chicks. These experimental units were further allocated to 5 treatment groups that were fed Ration A (control), B, C, D, and E, containing 8% CM and 0% MOLP, 6% CM and 2% MOLP, 4% CM and 4% MOLP, 2% CM and 6% MOLP, and 0% CM and 8% MOLP, respectively. The experimental diets were fed to the broilers for a period of 31 d. The results of the present study suggest that replacement of CM with MOLP as a vegetable protein source can enhance the immune response to Newcastle disease and infectious bursal disease vaccination without any change in weight gain, body organ weight, and blood hematology in broilers. The results also indicate that replacement of CM with MOLP results in higher feed intake with some negative effects on FCR in broilers. © 2016 Poultry Science Association Inc

Campylobacter spp. infection in humans and poultry

Campylobacter is well recognized as the leading cause of bacterial foodbornc diarrheal disease worldwide. The infection may be subclinical or cause disease of variable severity. The eating and handling of improperly cooked or raw broiler meat has been shown to be one of the most important sources of human campylobacteriosis. Birds carrying Campylobacter are asymptomatic colonizers without any clinical signs. Broilers are considered Campylobacter free after hatching and become colonized by exposure to viable bacteria from the environment. Several risk factors can result in the introduction of Campylobacter into the flocks making it difficult to keep chicken flocks free of Campylobacter throughout the rearing period. Lack of biosccurity measures, season, age, partial depopulation practices, flock size, type of production system, presence of other animals on farm, water quality, presence of rodents and mechanical transmission via insects are considered to be some of the risk factors associated with horizontal transmission. The control of Campylobacter in poultry seems crucial for the reduction of human campylobactcriosis cases. In Greece, there has been a dearth of information on prevalence and risk factors of Campylobacter in broiler flocks. Therefore, it is essential to initially investigate the prevalence of Campylobacter infection on farms and in poultry carcasses and subsequently the risk factors at all production stages of broiler meat and plan intervention studies to help reducing the disease in humans. This paper review the most recent data reported worldwide on Campylobacter infection in humans and poultry in order to provide an overview of trends, risks, possible causes and mechanisms of transmission routes

Investigation of Serotype Prevalence of Escherichia coli Strains Isolated from Layer Poultry in Greece and Interactions with Other Infectious Agents

Colibacillosis is the most common bacterial disease in poultry and it is caused by avian pathogenic Escherichia coli (APEC), which is assigned to various O-serogroups. Previous studies have shown that APEC strains are more often related to certain O-serogroups such asO78, O2 and O1. E. coli has been reported to act either as a primary or secondary agent in complicating other infections. The aim of this study was to investigate the occurrence of and characterize the O-serogroups of E. coli strains isolated from commercial layer and layer breeder flocks showing macroscopic lesions of colibacillosis and increased or normal mortality in Greece. Furthermore, we attempted to assess the interaction between infectious agents such as Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS), infectious bronchitis (IBV) and infectious laryngotracheitis (ILT) with E. coli infections in layer flocks with increased mortality. Our study revealed that in addition to the common serogroups (O78, O2), many other, and less common serogroups were identified, including O111. The O78, O111 and O2 serogroups were frequently detected in flocks with lesions of colibacillosis and increased mortality whereas O2, O88 and O8 were reported more commonly in birds with colibacillosis lesions but normal mortality rates. These data provide important information for colibacillosis monitoring and define preventative measures, especially by using effective vaccination programs because E. coli vaccines are reported to mainly offer homologous protection. Finally, concerning the association of the four tested infectious agents with E. coli mortality, our study did not reveal a statistically significant effect of the above infectious agents tested with E. coli infection mortality. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

The genus Campylobacter: Detection and isolation methods, species identification & typing techniques

Campylobacter is well recognized as the leading cause of bacterial foodborne diarrheal disease worldwide; while, poultry has been identified as a significant cause of campylobacter infection in humans. The C. jejuni has been found to be the predominant species isolated from poultry samples and, yet, responsible for the majority of human campylobacteriosis. Campylobacter spp. are small, oxidase positive, microaerophilic, curved gram-negative rods exhibiting corkscrew motility and colonize the intestinal tract of most mammalian and avian species. From its very first description in late 19th century by Theodor Escherich until nowadays, a lot of research has been carried out providing a wealth of information regarding its microbiological properties. Since novel technologies constantly emerge, increasingly advanced methods for detection, identification and typing of Campylobacter spp. are becoming available. The aim of this article is to review the recent bibliography on Campylobacter focusing, especially, on its survival and growth characteristics, the laboratory methods used for its detection and isolation from clinical, animal, environmental, and food samples, the reported methods applied for its speciation, as well as the typing systems developed for subtyping of Campylobacter. © 2019 Hellenic Veterinary Medical Society. All rights reserved

Antimicrobial resistance, flaa sequencing, and phylogenetic analysis of campylobacter isolates from broiler chicken flocks in greece

Human campylobacteriosis caused by thermophilic Campylobacter species is the most commonly reported foodborne zoonosis. Consumption of contaminated poultry meat is regarded as the main source of human infection. This study was undertaken to determine the antimicrobial susceptibility and the molecular epidemiology of 205 Campylobacter isolates derived from Greek flocks slaughtered in three different slaughterhouses over a 14-month period. A total of 98.5% of the isolates were resistant to at least one antimicrobial agent. In terms of multidrug resistance, 11.7% of isolates were resistant to three or more groups of antimicrobials. Extremely high resistance to fluoroquinolones (89%), very high resistance to tetracycline (69%), and low resistance to macrolides (7%) were detected. FlaA sequencing was performed for the subtyping of 64 C. jejuni and 58 C. coli isolates. No prevalence of a specific flaA type was observed, indicating the genetic diversity of the isolates, while some flaA types were found to share similar antimicrobial resistance patterns. Phylogenetic trees were constructed using the neighbor-joining method. Seven clusters of the C. jejuni phylogenetic tree and three clusters of the C. coli tree were considered significant with bootstrap values >75%. Some isolates clustered together were originated from the same or adjacent farms, indicating transmission via personnel or shared equipment. These results are important and help further the understanding of the molecular epidemiology and antimicrobial resistance of Campylobacter spp. derived from poultry in Greece. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

An assessment of the level of protection against colibacillosis conferred by several autogenous and/or commercial vaccination programs in conventional pullets upon experimental challenge

The prevention of avian colibacillosis has historically been investigated through vaccination, with variable outcomes. Commercial live (attenuated) and inactivated vaccines are reported to have limited efficacy in the context of heterologous challenge. Autogenous vaccination, using field isolates, is widely used, but scarcely documented. Different vaccination programs, including a live commercial vaccine and/or an inactivated autogenous vaccine, were compared for three different avian pathogenic Escherichia coli (APEC) strain (serotypes O78, O18 and O111) challenges. On the pullet farm, four groups of conventional pullets received different vaccination protocols. Group A was kept unvaccinated (control group). Group B was vaccinated three times with a live commercial O78 E. coli vaccine (at one day old, 59 and 110 days of age). Group C was immunized twice (at 79 and 110 days) with a three-valence autogenous vaccine (O78, O18 and O111). Group D was vaccinated first with the commercial vaccine (at one day old and 59 days), then with the autogenous vaccine (110 days). Birds were transferred to the experimental facility at 121 days of age and were challenged 10 days later. In each group, 20 birds were challenged with one of the three APEC strains (O78, O18, O111); in total, 80 birds were challenged by the same strains (20 per group). The recorded outcomes were: mortality rate, macroscopic lesion score in target organs and the bacterial recovery of the challenge strain from bone marrow and pooled organs. When challenged with O78 or O111 strains, birds from groups C and D proved to be significantly better protected, in terms of lesion scoring and bacteriological isolation, than those of groups A and B. With the O18 challenge, only birds of group D presented a statistically significant reduction of their lesion score. To the authors' knowledge, this is the first report on the efficacy of an immunization program in poultry that combines commercial and autogenous vaccines. © 2020 by the authors