Severe bronchiectasis resulting from chronic bacterial bronchitis and bronchopneumonia in a jungle cat.

Bronchiectasis is irreversible bronchial dilation that can be congenital or acquired secondary to chronic airway obstruction. Feline bronchiectasis is rare and, to our knowledge, has not been reported previously in a non-domestic felid. An ~10-y-old female jungle cat (Felis chaus) was presented for evaluation of an abdominal mass and suspected pulmonary metastasis. The animal died during exploratory laparotomy and was submitted for postmortem examination. Gross examination revealed consolidation of the left caudal lung lobe and hila of the cranial lung lobes. Elsewhere in the lungs were several pale-yellow pleural foci of endogenous lipid pneumonia. On cut section, there was severe distension of bronchi with abundant white mucoid fluid. The remaining lung lobes were multifocally expanded by marginal emphysema. Histologically, ectatic bronchi, bronchioles, and fewer alveoli contained degenerate neutrophils, fibrin, and mucin (suppurative bronchopneumonia) with rare gram-negative bacteria. Aerobic culture yielded low growth of Proteus mirabilis and Escherichia coli. There was chronic bronchitis, marked by moderate bronchial gland hyperplasia, lymphoplasmacytic inflammation, and lymphoid hyperplasia. The palpated abdominal mass was a uterine endometrial polyp, which was considered an incidental, but novel, finding. Chronic bronchitis and bronchopneumonia should be considered as a cause of bronchiectasis and a differential diagnosis for respiratory disease in non-domestic felids.

Correlation of clinical and radiographic variables in cats with lower airway disease.

BACKGROUND: Feline lower airway disease (FLAD) is frequently associated with radiographic abnormalities. OBJECTIVES: To evaluate whether radiographic changes in cats with naturally occurring FLAD improve with treatment and if radiographic changes correlate with clinical signs. ANIMALS: Twenty-four client-owned cats newly diagnosed with FLAD, based on medical history, typical clinical signs, radiographic findings, and examination of bronchoalveolar lavage fluid, were included in the prospective study. METHODS: At 2 examination time points (days 0 and 60), an owner questionnaire, clinical examination, and thoracic radiography were carried out. Information from the questionnaire and clinical examination were evaluated on the basis of a 12-point clinical score. Radiographs were assessed using a 10-point radiographic score. Individual treatment was given to all cats over the study period, based on severity of the disease and compliance of the cat. Clinical and radiographic scores were compared statistically for both examination time points and evaluated for correlation. RESULTS: All cats showed radiographic abnormalities at initial presentation. In addition to significant improvement in clinical variables, the total radiographic score improved significantly (P = .01) during the study period, with significant improvement in the severity of bronchial (P = .01) and interstitial lung pattern (P = .04). Improvement of the clinical and radiographic score was not correlated. CONCLUSION AND CLINICAL IMPORTANCE: In addition to clinical signs, repeated radiographic examination can be used as a diagnostic tool to evaluate treatment response in cats with FLAD.

Efficacy of a plant-produced infectious bronchitis virus-like particle vaccine in specific pathogen-free chickens.

Infectious bronchitis (IB) Gammacoronavirus causes a highly contagious respiratory disease in chickens that is listed by the World Organisation for Animal Health (WOAH). Its high mutation ability has resulted in numerous variants against which the commercially available live or recombinant vaccines singly offer limited protection. Agrobacterium-mediated transient expression in Nicotiana benthamiana (tobacco) plants was used here to produce a virus-like particle (VLP) vaccine expressing a modified full-length IBV spike (S) protein of a QX-like IB variant. In a challenge study with the homologous live IB QX-like virus, VLP-vaccinated birds produced S protein-specific antibodies comparable to those produced by live-vaccinated birds seroconverting with mean geometric titers of 6.8 and 7.2 log2, respectively. The VLP-vaccinated birds had reduced oropharyngeal and cloacal viral shedding compared to an unvaccinated challenged control and were more protected against tracheal ciliostasis than the live-vaccinated birds. While the results appeared similar, plant-produced IB VLPs are safer, more affordable, easier to produce and update to antigenically match any emerging IB variant, making them a more suitable alternative to IBV control than live-attenuated vaccines.

The use of RT-PCR in the diagnosis and differentiation of vaccine strains of chicken infectious bronchitis and Newcastle disease.

Background: Infectious diseases of young and adult birds with respiratory syndrome are a significant deterrent to the development of industrial poultry farming due to decreased productivity and significant mortality. The only effective method of combating viral diseases is timely and targeted vaccination, which largely depends on laboratory diagnostic results. Aim: This article aims to study the real-time reverse transcription polymerase chain reaction, (RT-PCR) which has the prospect of more effective diagnosis of vaccine strains of chicken infectious bronchitis and Newcastle disease. Methods: The fastest and most accurate method for the differential diagnosis of pathogens in an associative viral infection is RT-PCR. The method proposed in the article for selecting primers for amplification made it possible to use this method for the simultaneous interspecies differential diagnosis of two or more viral agents, significantly accelerating their diagnosis. Results: The correlation of the nucleotide sequence obtained from sequencing to a specific virus strain is complicated by the lack of a single nomenclature mechanism for separating genetic groups. Conclusion: The results of this study will allow easy and fast typing of sequences into known and databased virus strains and avoid further confusion in the nomenclature of genetic groups in the future.

Outcome of patients with cystic fibrosis colonized by Scedosporium and Lomentospora species: A longitudinal cohort study.

Scedosporium and Lomentospora species rank second among the filamentous fungi colonizing the airways of cystic fibrosis (CF) patients. These fungi could be responsible for allergic bronchopulmonary mycosis (ABPM) and bronchitis before lung transplantation and invasive infections after. However, their role in CF lung disease is debated. This study aimed to identify clinical or environmental factors associated with an airway colonization by Scedosporium/Lomentospora species in patients with CF over a period of 7 years. A longitudinal cohort study was conducted from 2008 to 2014 in the CF reference centre in Lyon, France, to compare the characteristics of patients with Scedosporium/Lomentospora colonized and non-colonized patients. During the study period, 283 patients completed the clinical and microbiological follow-up. The analysis revealed that a higher number and duration of hospitalizations, an increased number of courses of parenteral antibiotic therapy, a history of ABPA, and treatment by itraconazole were significantly associated with an airway colonization by Scedosporium/Lomentospora species. The rate of decline of forced expiratory volume in the first second was not statistically different between colonized and non-colonized patients. This study provides evidence that patients colonized by Scedosporium/Lomentospora species require more medical care than non-colonized patients. Additional care could be in part explained by the management of Scedosporium/Lomentospora-related diseases such as ABPM or bronchitis. However, we did not demonstrate a faster rate of decline of respiratory function or body mass index in colonized patients, suggesting, as previously reported, that colonization of the airways by these fungi does not play a significant role in the progression of CF disease.

This prospective study did not demonstrate a faster rate of decline of respiratory function or body mass index in cystic fibrosis (CF) patients colonized by Scedosporium/Lomentospora species compared to non-colonized patients, suggesting that these fungi do not play a significant role in the progression of CF disease.

[Evaluierung der Langzeittherapie bei Katzen mit felinem Asthma und chronischer Bronchitis]. / Evaluation of long-term therapy in cats with feline asthma and chronic bronchitis.

GEGENSTAND UND ZIEL: Felines Asthma (FA) und chronische Bronchitis (CB) sind häufige entzündliche Erkrankungen der Atemwege der Katze. Obwohl beide Krankheitsbilder durch eine Infiltration mit unterschiedlichen Entzündungszelltypen gekennzeichnet sind, sind die therapeutischen Maßnahmen oft ähnlich. Über mögliche Unterschiede im therapeutischen Management dieser beiden Atemwegserkrankungen ist wenig bekannt. Ziel der Studie war es daher, bei Katzen mit FA und CB die Erst- und Langzeitbehandlung, Therapieerfolg, Nebenwirkungen und Besitzerzufriedenheit zu vergleichen. MATERIAL UND METHODEN: 35 Katzen mit FA und 11 Katzen mit CB wurden in die retrospektive Querschnittstudie eingeschlossen. Einschlusskriterien waren kompatible klinische und radiologische Befunde sowie der zytologische Nachweis einer eosinophilen Entzündung (FA) oder einer sterilen neutrophilen Entzündung (CB) in der bronchoalveolären Lavage-Flüssigkeit (BALF). Katzen mit CB wurden ausgeschlossen, wenn Hinweise auf pathologische Bakterien vorlagen. Besitzer wurden gebeten einen standardisierten Fragebogen zum therapeutischen Management und Ansprechen auf die Behandlung auszufüllen. ERGEBNISSE: Im Gruppenvergleich wurden keine statistisch signifikanten Unterschiede der Therapie festgestellt. Die meisten Katzen wurden anfänglich mit Kortikosteroiden mittels einer oralen (FA 63%/CB 64%, p=1), inhalativen (FA 34%/CB 55%, p=0,296) oder injizierbaren Applikationsform (FA 20%/CB 0%, p=0,171) behandelt. Zusätzlich wurden in einigen Fällen orale Bronchodilatatoren (FA 43%/CB 45%, p=1) und Antibiotika (FA 20%/CB 27%, p=0,682) verabreicht. In der Langzeittherapie erhielten 43% der Katzen mit FA und 36% der Katzen mit CB inhalative Kortikosteroide (p=1), orale Kortikosteroide (FA 17%/CB 36%, p=0,220) und orale Bronchodilatatoren (FA 6%/CB 27%, p=0,084) sowie phasenweise Antibiotika (FA 6%/CB 18%, p=0,238). Behandlungsbedingte Nebenwirkungen (Polyurie/Polydipsie, Pilzinfektion im Gesicht und Diabetes mellitus) wurden bei 4 Katzen mit FA und 2 Katzen mit CB registriert. Die Mehrheit der Besitzer gab an, mit dem Ansprechen auf die Behandlung äußerst oder sehr zufrieden zu sein (FA 57%/CB 64%, p=1). SCHLUSSFOLGERUNG: Signifikante Unterschiede hinsichtlich des Managements und des Therapieansprechens konnten bei beiden Erkrankungen laut Besitzerbefragung nicht festgestellt werden. KLINISCHE RELEVANZ: Laut Besitzerumfrage können chronische Bronchialerkrankungen der Katze wie Asthma und chronische Bronchitis können mit einer ähnlichen Behandlungsstrategie erfolgreich therapiert werden.

Pathogenesis of Bohle iridovirus infection in Krefft's freshwater turtle hatchlings (Emydura macquarii krefftii).

Ranaviruses have been detected in over 12 families of reptiles including many genera of turtles, tortoises, and terrapins, but the pathogenesis of these infections is still poorly understood. Krefft's river turtle hatchlings (N = 36; Emydura macquarii krefftii) were inoculated intramuscularly with Bohle iridovirus (BIV, Ranavirus, isolate) or saline, and euthanized at 9 timepoints (3 infected and 1 control per timepoint) over a 24-day period. Samples of lung, liver, kidney, and spleen were collected for quantitative polymerase chain reaction (PCR); internal organs, skin, and oral cavity samples were fixed for histopathological examination. The earliest lesions, at 8 days postinoculation (dpi), were lymphocytic inflammation of the skin and fibrinoid necrosis of regional vessels at the site of inoculation, and mild ulcerative necrosis with lymphocytic and heterophilic inflammation in the oral, nasal, and tongue mucosae. Fibrinonecrotic foci with heterophilic inflammation were detected in spleen and gonads at 16 dpi. Multifocal hepatic necrosis, heterophilic inflammation, and occasional basophilic intracytoplasmic inclusion bodies were observed at 20 dpi, along with ulcerative lymphocytic and heterophilic tracheitis and bronchitis. Tracheitis, bronchitis, and rare bone marrow necrosis were present at 24 dpi. Of the viscera tested for ranaviral DNA by PCR, the liver and spleen had the highest viral loads throughout infection, and thus appeared to be major targets of viral replication. Testing of whole blood by qPCR was the most-effective ante-mortem method for detecting ranaviral infection compared with oral swabs. This study represents the first time-dependent pathogenesis study of a ranaviral infection in turtles.

Evaluation of Cholera Toxin Adjuvanticity Effect on the Production of Specific Antibodies Induced by Avian Infectious Bronchitis Vaccine in Chickens.

Cholera toxin (CT) is one of the most well-known immunostimulants. Mammalian studies have shown that CT can generate immune responses against antigen. However, it has not exhibited a definite effect on poultry yet. In this study, focusing on a cost-effective method, the effect of different concentrations of CT obtained from Vibrio cholerae biotype El Tor and serotype Inaba was investigated on the immunogenicity of infectious bronchitis vaccine. After culturing and concentrating CT, different concentrations of CT (0.1, 1, 2, and 5 micrograms) were combined with avian infectious bronchitis vaccine strain H120 produced by Razi Vaccine and Serum Research Institute (RVSRI) and, at 7 days of age, inoculated via the eye drop administration in 42 specific-pathogen-free chickens (seven groups of six chicks that included four experimental groups, two negative control groups (PBS and toxin), and one positive control group). Blood samples were taken weekly from the wing veins of the chickens, and the immunoglobulin G (IgG) titer was checked by enzyme-linked immunosorbent assay. The results showed that 2 µg of CT in comparison with other concentrations caused a significant increase in the antibody titer against avian infectious bronchitis in the blood serums of the chickens. One-way ANOVA test showed that all the results of this study were significant at P<0.05 level. Our data show that CT has the potential to further stimulate the immune system of chickens and may increase the immunogenicity of the infectious bronchitis vaccine. However, more research is needed to examine all aspects of the use of this toxin in animal vaccines.

Modulation of the innate immune system by lipopolysaccharide in the proventriculus of chicks inoculated with or without Newcastle disease and infectious bronchitis vaccine.

This study aimed to determine whether the innate immune system in the proventriculus of broiler chicks responds to lipopolysaccharide (LPS) and whether this response is affected by Newcastle disease and infectious bronchitis (ND/IB) vaccination. Chicks were divided into 4 groups: nonvaccinated and injected with PBS or LPS (V-L- and V-L+), and vaccinated and injected with PBS or LPS (V+L- and V+L+). Vaccination was performed on d 1, and LPS was intraperitoneally injected on d 11 of age. The gene expression and protein levels of immune molecules, including toll-like receptors (TLRs), antimicrobial peptides, interleukin-1ß (IL-1B), and immunoglobulin A (IgA) in the proventriculus and serum were analyzed. The results showed that the expression levels of TLR21 were higher in vaccinated (V+L-) group than in nonvaccinated (V-L-) group. Gene expression levels of avian ß-defensin (AvBDs) and cathelicidin1 (Cath1) were not different among the 4 groups. However, the results of LC/MS analysis showed that the levels of AvBD2, 6, and 7 significantly increased after the LPS challenge in nonvaccinated and vaccinated chicks; the levels were higher in V-L+ and V+L+ than in V-L- and V+L-, respectively. Immunohistochemistry analysis revealed the localization of AvBD1 protein in the epithelial cells of the surface glands and AvBD2 and CATH1 in the heterophil-like cells in the lamina propria of surface glands. Although IL-1B gene expression and protein concentration in the proventriculus tissues were not different among the 4 groups, serum IL-1B levels were upregulated by LPS in both the nonvaccinated and vaccinated groups (V-L- vs. V-L+, V+L- vs. V+L+). Moreover, IgA levels in the proventriculus and serum were not affected by vaccination or LPS challenge. Taken together, we conclude that LPS derived from gram-negative bacteria upregulates the innate immune system, including antimicrobial peptide synthesis in the proventriculus. ND/IB vaccination may not significantly affect antimicrobial peptide synthesis in response to LPS; however, TLR21 expression is upregulated by that vaccination. The antimicrobial peptides synthesized in the proventriculus probably prevent pathogenic microbes from entering the intestine.

Comparative trachea transcriptome analysis in SPF broiler chickens infected with avian infectious bronchitis and avian influenza viruses.

Infectious bronchitis virus (IBV) and avian influenza virus (AIV) are two major respiratory infections in chickens. The coinfection of these viruses can cause significant financial losses and severe complications in the poultry industry across the world. To examine transcriptome profile changes during the early stages of infection, differential transcriptional profiles in tracheal tissue of three infected groups (i.e., IBV, AIV, and coinfected) were compared with the control group. Specific-pathogen-free chickens were challenged with Iranian variant-2-like IBV (IS/1494), UT-Barin isolates of H9N2 (A/chicken/Mashhad/UT-Barin/2017), and IBV-AIV coinfection; then, RNA was extracted from tracheal tissue. The Illumina RNA-sequencing (RNA-seq) technique was employed to investigate changes in the Transcriptome. Up- and downregulated differentially expressed genes (DEGs) were detected in the trachea transcriptome of all groups. The Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology databases were examined to identify possible relationships between DEGs. In the experimental groups, upregulated genes were higher compared to downregulated genes. A more severe immune response was observed in the coinfected group; further, cytokine-cytokine receptor interaction, RIG-I-like receptor signaling, Toll-like receptor signaling, NOD-like receptor signaling, Janus kinase/signal transducer, and activator of transcription, and apoptotic pathways were important upregulated genes in this group. The findings of this paper may give a better understanding of transcriptome changes in the trachea during the early stages of infection with these viruses.

Research Note: Effects of Escherichia coli co-infection on the protective efficacy assessment of two common infectious bronchitis vaccines.

Avian infectious bronchitis (IB), a highly contagious disease hazardous to the poultry industry, is caused by an etiological agent called the infectious bronchitis virus (IBV). Some IBV strains (IBVs) alone usually do not cause high mortality in field conditions if not with secondary pathogens including Escherichia coli (E. coli). Herein, we established an IBV and E. coli co-infection model to evaluate the protective efficacy of two IBV vaccine strains against a new emerging genotype GVI-1 with mild virulence in experimental conditions. Chickens were inoculated with IBV field isolate ZQX (genotype GVI-1) and challenged 4 dlater with the E. coli strain MS160427 (serotype O8). Subsequently, these chickens were euthanized at seven days postchallenge (d.p.c.) with E. coli. An autopsy revealed that lesions in the IBV plus E. coli co-infection group were more severe than those in the IBV-infected group. This pathological model was used to assess the protective effect of two commonly used vaccine strains (H120 and 4/91) against the IBV ZQX strain, and a significantly better protective efficacy was observed for 4/91 compared with H120. Thus, IBV and E. coli co-infection could be employed in assessing the protective efficacy of IBV vaccines.

Avian Infectious Bronchitis in China: Epidemiology, Vaccination, and Control.

Avian infectious bronchitis (IB) causes great economic losses to the chicken industry worldwide. IB virus (IBV) exhibits extensive variability, and differing serotypes are often prevalent in different countries or regions. Therefore, the identification of local circulating strains is essential for the selection of appropriate vaccines. China is a worldwide leader in poultry meat and egg production, and IBV is one of the most important infectious diseases affecting this industry. In this review, the history and current IB occurrence in China, as well as the development and use of vaccines, are summarized. Based on recent epidemics, reasonable vaccination strategies are recommended, and some inadequate measures commonly used in the field are analyzed.

Estudio recapitulativo- Bronquitis infecciosa aviar en China: Epidemiología, vacunación y control. La bronquitis infecciosa aviar causa grandes pérdidas económicas en la industria avícola en todo el mundo. El virus de la bronquitis infecciosa presenta una amplia variabilidad y a menudo, prevalecen diferentes serotipos en diferentes países o regiones. Por lo tanto, la identificación de cepas circulantes locales es esencial para la selección de vacunas adecuadas. China es líder mundial en la producción de huevo y carne de aves comerciales y el virus de la bronquitis infecciosa es una de las enfermedades infecciosas más importantes que afectan a la industria avícola. En esta revisión, se presenta un resumen de la historia y la aparición actual de la bronquitis infecciosa en China, así como el desarrollo y uso de vacunas. Con base en epizootias recientes, se recomiendan estrategias de vacunación viables y se analizan algunas medidas inadecuadas que son comúnmente utilizadas en el campo.

The Pathology of Infectious Bronchitis.

Infectious bronchitis (IB) is an acute disease of chickens caused by a gammacoronavirus, infectious bronchitis virus (IBV). Infection of the nasal and tracheal mucosa causes a rapid loss of ciliated epithelium and impaired mucociliary clearance that predispose chickens to secondary bacterial infections. In poultry production, disease progression and severity are influenced by other live virus vaccines, immunosuppression, and coexisting pathogens. The digestive tract supports viral replication in the proventriculus, intestines, cloaca, and the bursa of Fabricius. Acute enteritis and stunted growth in young chickens are caused by an enterotropic IBV. IBV spreads systemically by infection of tracheal macrophages and blood monocytes, deep respiratory infections, and potentially ascending viral infection from the cloaca. Nephrotropic IBV causes severe disease in the kidney with necrosis of tubular epithelial cells, inflammation, and renal failure. Viral infection of the female reproductive tract in the first 2 weeks of life causes necrosis and scarring of the oviduct mucosa, resulting in a chronic cystic oviduct that precludes egg formation when the hen matures. Virus infection of mature hens causes necrosis and inflammation of the oviduct mucosa, leading to the deterioration of egg quality and transient interruption of egg production. In males, IBV infection of seminiferous tubules in the testicle and efferent ductules in the epididymis results in epididymitis and epididymal lithiasis, decreases in sperm production and fertility, and viral shed to semen, leading to venereal transmission. The role IBV in gastrointestinal and urogenital disease merits further study.

Estudio recapitulativo- La patología de la bronquitis infecciosa: una revisión La bronquitis infecciosa es una enfermedad aguda de los pollos causada por un gammacoronavirus, el virus de la bronquitis infecciosa (IBV). La infección de la mucosa nasal y traqueal provoca una pérdida rápida del epitelio ciliado y la alteración de la función mucociliar que predispone a los pollos a infecciones bacterianas secundarias. En la producción avícola, el desarrollo y la severidad de la enfermedad están influenciadas por otras vacunas con virus vivos, inmunosupresión y patógenos coexistentes. En el tracto digestivo se lleva a cabo la replicación viral en el proventrículo, los intestinos, la cloaca y en la bolsa de Fabricio. La enteritis aguda y el retraso del crecimiento en pollos jóvenes son causados por virus de bronquitis infecciosa enterotrópicos. El virus de la bronquitis infecciosa se propaga sistémicamente por infección de macrófagos traqueales y monocitos sanguíneos, infecciones respiratorias profundas e infección viral potencialmente ascendente desde la cloaca. Los virus de la bronquitis infecciosa nefrotrópicos causan una enfermedad severa en el riñón con necrosis de las células epiteliales tubulares, inflamación e insuficiencia renal. La infección viral del aparato reproductor femenino en las primeras dos semanas de vida causa necrosis y cicatrización de la mucosa del oviducto, lo que resulta en un oviducto quístico crónico que impide la formación de huevos cuando la gallina llega a la madurez. La infección por el virus en gallinas maduras causa necrosis e inflamación de la mucosa del oviducto, lo que conduce al deterioro de la calidad del huevo y la interrupción transitoria de la producción de huevos. En los machos, la infección por bronquitis infecciosa de los túbulos seminíferos en el testículo y los conductos eferentes en el epidídimo da como resultado epididimitis y litiasis epididimaria, disminución de la producción y fertilidad de espermatozoides, y la diseminación viral al semen, lo que lleva a la transmisión venérea. El papel del virus de la bronquitis en las enfermedades gastrointestinales y urogenitales merece un estudio más a fondo.

Global Control of Infectious Bronchitis Requires Replacing Live Attenuated Vaccines by Alternative Technologies.

Despite continuous and extensive efforts to control infectious bronchitis (IB) throughout the century, the disease continues to be one of the most economically relevant diseases affecting the poultry production worldwide. Since the early 1990s, numerous scientists have explicitly warned about the role of attenuated vaccines on IB virus (IBV) evolution and the detrimental consequences of their use to the poultry industry. Herein, we review evidence indicating that the use of live vaccines increases genetic/phenotypic diversity of IBV, enhances their fitness in the environment, and ultimately aggravates and perpetuates the problem for the poultry industry. The available evidence leads to the unequivocal conclusion that attenuated IBV vaccines should be replaced by vaccines using alternative technologies if IBV is to be controlled effectively.

Estudio recapitulativo- El control global de la bronquitis infecciosa requiere reemplazar las vacunas atenuadas por tecnologías alternativas. A pesar de los continuos y extensos esfuerzos para controlar el virus de la bronquitis infecciosa a lo largo del siglo, la bronquitis infecciosa sigue siendo una de las enfermedades de mayor relevancia económica que afecta a la producción avícola en todo el mundo. Desde principios de la década de los 1990s, numerosos científicos han advertido explícitamente sobre el papel de las vacunas atenuadas en la evolución del virus de la bronquitis infecciosa y las consecuencias perjudiciales de su uso para la industria avícola. En este artículo, se revisa la evidencia que indica que el uso de vacunas vivas aumenta la diversidad genética y fenotípica del virus de la bronquitis infecciosa, mejora su aptitud en el medio ambiente y en última instancia, agrava y perpetúa el problema para la industria avícola. La evidencia disponible lleva a la conclusión inequívoca de que las vacunas atenuadas contra este virus deben ser reemplazadas por vacunas que utilicen tecnologías alternativas si se quiere controlar eficazmente a este virus.

Impact of feeding n-3 fatty acids to layer breeders and their offspring on concentration of antibody titres against infectious bronchitis, and Newcastle diseases and plasma fatty acids in the offspring.

1. The impact of feeding sources of n-3 fatty acids (FA) to ISA Brown and Shaver White breeders and their offspring on antibody titres and plasma FA profile was examined.2. Breeders were fed either a control diet (CON); CON + 1% microalgae (DMA: Aurantiochytrium limacinum) as a source of docosahexaenoic acid; or CON + 2.6% of a co-extruded mixture of full-fat flaxseed (FFF) as a source of α-linolenic acid. Day-old female offspring were assigned to diets (breeder-offspring): 1) CON-CON, 2) CON-DMA, 3) CON - FFF, 4) DMA - CON, 5) DMA - DMA, 6) FFF - CON or 7) FFF - FFF, followed by a standard layer diet through 18 weeks of age (WOA) to 42 WOA.3. Antibody titres against infectious bronchitis (IBV) and Newcastle disease (NDV) were measured at six days and six WOA, and plasma FA profile was measured at 18 and 42 WOA.4. Pullets from FFF-fed breeders had higher antibody titres against IBV and NDV than pullets fed DMA (P < 0.05). Feeding FFF to offspring increased plasma ∑n-3 FA at 18 and 42 WOA, whereas feeding DMA to offspring reduced ∑n-6 FA at 18 WOA.5. In conclusion, independent of breeder strain, alpha linoleic acid (ALA) and DHA sources showed varied responses. Feeding breeders FFF increased plasma concentration of antibody titres and n-3 FA whereas DMA reduced plasma concentration of ∑n-6 FA.

Experimental study of Forsythoside A on prevention and treatment of avian infectious bronchitis.

Forsythoside A is the main active ingredient in the Chinese medicine Forsythia suspensa, which has antiviral, anti-inflammatory, antioxidation, and immunoregulatory effects. It is reported that Forsythoside A can significantly inhibit the replication of the avian infectious bronchitis virus(IBV) in cells, but there is no report in chickens. The present study aimed to investigate the effect of Forsythoside A on IBV-M41, experiments were designed using 120 chickens at 12 days of age. The chickens were randomly divided into eight groups: Forsythoside A high-, medium-, and low-dose prevention groups, Forsythoside A high-, medium-, and low-dose treatment groups, model control group and normal control group. All chickens, except the normal control group, were inoculated with 0.2 ml of IBV-M41 at 15 days of age.The antiviral effects were evaluated by clinical signs, weight, histopathology, T-,B-lymphocyte proliferation, T-lymphocyte subsets and cytokine levels.The results showed that the infection rate in each Forsythoside A prevention group was significantly lower than that in the treatment group and model control group (P < 0.05). The recovery rate in each Forsythoside A treatment group was significantly higher than that in the model control group (P < 0.05), and the recovery rate in high- and medium-dose treatment group was the highest, at up to 86.67%. Lymphocytic transformation ability significantly improved in the prevention and treatment groups. Forsythoside A significantly improved the CD3+, CD4+, and CD8+ T-lymphocyte of infected chickens. The cytokine level was able to maintain high concentrations of IL-2 and IFN-α for a long time and maintain a dynamic IL-4-concentration balance. A number of results showed that Forsythoside A had both preventive and therapeutic effects in IBV-M41-infected chickens, among which the high-dose (80 mg/kg/d) prevention group，the high- (80 mg/kg/d) and medium (40 mg/kg/d) -dose treatment group had significant effects.

Effects of avian infectious bronchitis with Newcastle disease and Marek's disease vaccinations on the expression of toll-like receptors and avian ß-defensins in the kidneys of broiler chicks.

The aim of this study was to determine the effect of vaccinations for avian infectious bronchitis with Newcastle disease (IB/ND) and Marek's disease (MD) on the expression of toll-like receptors (TLR) that recognize viral RNA and microbial DNA, and AvBD in chick kidneys. Day-old chicks were vaccinated with MD or IB/ND vaccines or received no treatment (control group). The gene expression of TLR and AvBD in the kidneys of 3-day-old chicks and 10-day-old chicks was examined using real-time PCR. The localization of AvBD2 and AvBD4 was examined by immunohistochemistry at day three only. At 3 days of age, the expression of TLR7 and TLR21 was significantly higher in the IB/ND group (but not in the MD group) than in the control group. Conversely, at 10 days of age there was no significant difference in the expression of the three TLR between groups. In the 3-day-old chicks the expression levels of AvBD4, 5, 6, and 7 were higher in the MD group than in the control group. Furthermore, at this age, the expression levels of other AvBD were not significantly different between the control and vaccination (MD and IB/ND) groups. At 10 days of age, no AvBD expression was affected by MD and IB/ND vaccinations. Immunohistochemistry results localized AvBD2 in the leukocytes in the interstitial tissue and AvBD4 in the surface of microvillus epithelial cells of renal tubules, and in the epithelial cells of the collecting ducts and ureter. The localization of AvBD2 and AvBD4 was identified in all chicks. We suggest that the expression of innate immune molecules (including TLR and AvBD) in kidneys could be modulated by MD and IB/ND vaccination when performed at the day-old stage. Although the effects of both vaccinations may subside within 10 days, the enhanced expression of those innate immune molecules may support the innate immunodefense function in the kidneys of young chicks.

Development and immunogenic potentials of chitosan-saponin encapsulated DNA vaccine against avian infectious bronchitis coronavirus.

Infectious Bronchitis (IB) is an economically important avian disease that considerably threatens the global poultry industry. This is partly, as a result of its negative consequences on egg production, weight gain as well as mortality rate.The disease is caused by a constantly evolving avian infectious bronchitis virus whose isolates are classified into several serotypes and genotypes that demonstrate little or no cross protection. In order to curb the menace of the disease therefore, broad based vaccines are urgently needed. The aim of this study was to develop a recombinant DNA vaccine candidate for improved protection of avian infectious bronchitis in poultry. Using bioinformatics and molecular cloning procedures, sets of monovalent and bivalent DNA vaccine constructs were developed based on the S1 glycoprotein from classical and variants IBV strains namely, M41 and CR88 respectively. The candidate vaccine was then encapsulated with a chitosan and saponin formulated nanoparticle for enhanced immunogenicity and protective capacity. RT-PCR assay and IFAT were used to confirm the transcriptional and translational expression of the encoded proteins respectively, while ELISA and Flow-cytometry were used to evaluate the immunogenicity of the candidate vaccine following immunization of various SPF chicken groups (A-F). Furthermore, histopathological changes and virus shedding were determined by quantitative realtime PCR assay and lesion scoring procedure respectively following challenge of various subgroups with respective wild-type IBV viruses. Results obtained from this study showed that, groups vaccinated with a bivalent DNA vaccine construct (pBudCR88-S1/M41-S1) had a significant increase in anti-IBV antibodies, CD3+ and CD8+ T-cells responses as compared to non-vaccinated groups. Likewise, the bivalent vaccine candidate significantly decreased the oropharyngeal and cloacal virus shedding (p < 0.05) compared to non-vaccinated control. Chickens immunized with the bivalent vaccine also exhibited milder clinical signs as well as low tracheal and kidney lesion scores following virus challenge when compared to control groups. Collectively, the present study demonstrated that bivalent DNA vaccine co-expressing dual S1 glycoprotein induced strong immune responses capable of protecting chickens against infection with both M41 and CR88 IBV strains. Moreso, it was evident that encapsulation of the vaccine with chitosan-saponin nanoparticle further enhanced immune responses and abrogates the need for multiple booster administration of vaccine. Therefore, the bivalent DNA vaccine could serve as efficient and effective alternative strategy for the control of IB in poultry.

Emerging lethal infectious bronchitis coronavirus variants with multiorgan tropism.

Infectious bronchitis virus (IBV) causes respiratory diseases in chickens and poses an economic threat to the poultry industry worldwide. Despite vaccine use, there have been field outbreaks of IBV in Taiwan. This study aimed to characterize the emerging IBV variants circulating in Taiwan. The analysis of the structural protein genes showed that these variants emerged through frequent recombination events among Taiwan strains, China strains, Japan strains and vaccine strains. Cross-neutralization tests revealed that two of the variants exhibited novel serotypes. Clinicopathological assessment showed that two of the variants caused high fatality rates of 67% and 20% in one-day-old SPF chicks, and all the variants possessed multiorgan tropisms, including trachea, proventriculus and urogenital tissues. Furthermore, the commercial live-attenuated Mass-type vaccine conferred poor protection against these variants. This study identified novel genotypes, serotypes and pathotypes of emerging IBV variants circulating in Taiwan. There is an urgent need for effective countermeasures against these variant strains.

Molecular characteristics and pathogenicity analysis of QX-like avian infectious bronchitis virus isolated in China in 2017 and 2018.

Proportions of QX-like genotype infectious bronchitis virus (IBV) isolates have increased over time. Here, to better understand the epidemiology and pathogenicity of IBV in China and control the spread of infectious bronchitis (IB), we conducted sequence analyses and examined the pathogenicity of 5 field isolates from diseased flocks in 2017 and 2018. Sequence analyses revealed that all the 5 strains, as well as many recent field isolates from other researchers, belonged to the QX-like IBV genotype, which were distantly related to commercial vaccine strains. Viral pathogenicity experiments showed that the isolates caused high morbidity and severe ciliostasis in chickens, although they caused milder lethality. This provides further evidence that QX-like IBV emergence remains a major problem in the poultry industry, and information on IBV epidemiology and pathogenicity may help to control IB.