Experimental infection on the locally isolated avian infectious laryngotracheitis virus

The aim of this study was to evaluate virulence of local isolated avian infectious laryngotracheitis virus in experimentally infected chicken. Forty chickens 10 weeks old were used for the experimental infection with the locally isolated infectious laryngotracheitis virus. Chickens were divided into three groups, the first group consisted from 20 chickens infected with isolated infectious laryngotracheitis virus (2×104.16 TCID 50/50 µl) via eyes and mouth drops (one drop for each). The second group consisted of 10 chickens (non-infected) in contact with infected group inoculated with maintenance media (Minimum essential medium) on their eyes, to observe if the infected group can spread the virus. The third group consisted from 10 chickens (non-infected) were left as a control group separated from other groups, inoculated with maintenance media (Minimum essential medium) on their eyes. Clinical signs and mortality were examined daily up to 12 days post infection. The main clinical signs were depression coughing and gasping with mild conjunctivitis and no mortality. Enzyme linked immunosorbent assay (ELISA) test was conducted on the collected sera of chickens before and after experimental infection with isolated virus. The results of ELISA test was negative for all groups of chickens before experiment and positive results for infected group with titer approximately ranging from (2534-7910); Measure of central tendency and dispersion were used with mean (4874.75) and stander error (355.96\ 13.6%); while negative results for contact group and control group. Eighteen chickens (10 weeks old) separately were divided into three groups (infected, contact and control) treated as mention above and were used for histopathological examination; the chickens were killed, two in each group at 24 hr., 48 hr. and 72 hr. post infection. The histopathological changes on trachea and larynx were intracellur inclusion bodies formation detected at 72hr., post infection for infected group only.

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Investigations of influence of colostral antibodies on development of pathomorphological changes following experimental infection of piglets with classical swine plague virus

Veterinarski glasnik ◽

10.2298/vetgl0606323p ◽

2006 ◽

Vol 60 (5-6) ◽

pp. 323-335

Author(s):

Jasna Prodanov ◽

Radoslav Dosen ◽

Miroslav Valcic ◽

Vladimir Polacek ◽

Tamas Petrovic ◽

...

Keyword(s):

Experimental Infection ◽

Clinical Symptoms ◽

Clinical Signs ◽

Elisa Test ◽

Control Group ◽

Artificial Infection ◽

Organic Systems ◽

Haemorrhagic Diathesis ◽

Virus Antigens

The pathomorphological changes established following infection with the virus of classical swine plague in non-immune individuals are well known. However, piglets present a problem from the clinical-pathological aspect, in which this virus can be multiplied in spite of established colostral antibodies, but without the exhibiting of the clinical symptoms characteristic for the disease. The question of the characteristics of the pathomorphological finding is raised in the event of the breakdown of the colostral immunity of the piglets. With the objective of determining the influence of colostral antibodies on the development of pathomorphological changes in classical swine plague, piglets aged 28, 35, 44, and 54 days, originating from sows that had received a vaccine of the K-strain of the classical swine plague virus, were experimentally infected with a virulent variety of this virus (Becker strain). The control group comprised non-vaccinated animals originating from non-vaccinated sows. Following the death and/or sacrificing of the piglets in the experiment, a pathomorphological examination was performed of all organic systems and the presence of classical swine plague virus antigens was established in organs and tissues of piglets using the immunoenzyme (ELISA) test. Even though clinical signs characteristic for this disease were not found in all animals following artificial infection, the pathomorphological findings following death and/or sacrificing indicated a successful experimental infection and was typical for the acute course of classical swine plague. Bleeding was established in most organs and serous membranes (haemorrhagic diathesis). However, certain variations were also established regarding the expression and distribution of the pathomorphological changes in certain animals.

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Pathogenic and Transmission Potential of Wildtype and Chicken Embryo Origin (CEO) Vaccine Revertant Infectious Laryngotracheitis Virus

Viruses ◽

10.3390/v13040541 ◽

2021 ◽

Vol 13 (4) ◽

pp. 541

Author(s):

Ana Perez-Contreras ◽

Catalina Barboza-Solis ◽

Shahnas M. Najimudeen ◽

Sylvia Checkley ◽

Frank van der Meer ◽

...

Keyword(s):

Chicken Embryo ◽

Severe Disease ◽

Clinical Signs ◽

Upper Respiratory Tract ◽

Infectious Laryngotracheitis Virus ◽

Live Attenuated Vaccines ◽

Transmission Potential ◽

Infectious Laryngotracheitis ◽

Laryngotracheitis Virus ◽

Embryo Origin

Infectious laryngotracheitis (ILT) is an infectious upper respiratory tract disease that impacts the poultry industry worldwide. ILT is caused by an alphaherpesvirus commonly referred to as infectious laryngotracheitis virus (ILTV). Vaccination with live attenuated vaccines is practiced regularly for the control of ILT. However, extensive and improper use of live attenuated vaccines is related to vaccine viruses reverting to virulence. An increase in mortality and pathogenicity has been attributed to these vaccine revertant viruses. Recent studies characterized Canadian ILTV strains originating from ILT outbreaks as related to live attenuated vaccine virus revertants. However, information is scarce on the pathogenicity and transmission potential of these Canadian isolates. Hence, in this study, the pathogenicity and transmission potential of two wildtype ILTVs and a chicken embryo origin (CEO) vaccine revertant ILTV of Canadian origin were evaluated. To this end, 3-week-old specific pathogen-free chickens were experimentally infected with each of the ILTV isolates and compared to uninfected controls. Additionally, naïve chickens were exposed to the experimentally infected chickens to mimic naturally occurring infection. Pathogenicity of each of these ILTV isolates was evaluated by the severity of clinical signs, weight loss, mortality, and lesions observed at the necropsy. The transmission potential was evaluated by quantification of ILTV genome loads in oropharyngeal and cloacal swabs and tissue samples of the experimentally infected and contact-exposed chickens, as well as in the capacity to produce ILT in contact-exposed chickens. We observed that the CEO vaccine revertant ILTV isolate induced severe disease in comparison to the two wildtype ILTV isolates used in this study. According to ILTV genome load data, CEO vaccine revertant ILTV isolate was successfully transmitted to naïve contact-exposed chickens in comparison to the tested wildtype ILTV isolates. Overall, the Canadian origin CEO vaccine revertant ILTV isolate possesses higher virulence, and dissemination potential, when compared to the wildtype ILTV isolates used in this study. These findings have serious implications in ILT control in chickens.

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Glycoprotein G is a virulence factor in infectious laryngotracheitis virus

Journal of General Virology ◽

10.1099/vir.0.82194-0 ◽

2006 ◽

Vol 87 (10) ◽

pp. 2839-2847 ◽

Cited By ~ 51

Author(s):

J. M. Devlin ◽

G. F. Browning ◽

C. A. Hartley ◽

N. C. Kirkpatrick ◽

A. Mahmoudian ◽

...

Keyword(s):

Virulence Factor ◽

Clinical Signs ◽

Pcr Analysis ◽

Infectious Laryngotracheitis Virus ◽

Glycoprotein G ◽

Infectious Laryngotracheitis ◽

Laryngotracheitis Virus

Infectious laryngotracheitis virus (ILTV; Gallid herpesvirus 1) is an alphaherpesvirus that causes acute respiratory disease in chickens. The role of glycoprotein G (gG) in vitro has been investigated in a number of alphaherpesviruses, but the relevance of gG in vivo in the pathogenicity of ILTV or in other alphaherpesviruses is unknown. In this study, gG-deficient mutants of ILTV were generated and inoculated into specific-pathogen-free chickens to assess the role of gG in pathogenicity. In chickens, gG-deficient ILTV reached a similar titre to wild-type (wt) ILTV but was significantly attenuated with respect to induction of clinical signs, effect on weight gain and bird mortality. In addition, an increased tracheal mucosal thickness, reflecting increased inflammatory cell infiltration at the site of infection, was detected in birds inoculated with gG-deficient ILTV compared with birds inoculated with wt ILTV. The reinsertion of gG into gG-deficient ILTV restored the in vivo phenotype of the mutant to that of wt ILTV. Quantitative PCR analysis of the expression of the genes adjacent to gG demonstrated that they were not affected by the deletion of gG and investigations in vitro confirmed that the phenotype of gG-deficient ILTV was consistent with unaltered expression of these adjacent genes. This is the first reported study to demonstrate definitively that gG is a virulence factor in ILTV and that deletion of gG from this alphaherpesvirus genome causes marked attenuation of the virus in its natural host.

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Changes in serum adenosine deaminase and isoenzyme levels in addition to routine liver biochemical parameters in sheep with chronic fascioliasis

Ciência Rural ◽

10.1590/0103-8478cr20210152 ◽

2022 ◽

Vol 52 (4) ◽

Author(s):

Nuri Altuğ ◽

Yıldıray Başbuğan ◽

Nazmi Yuksek

Keyword(s):

Bile Duct ◽

Adenosine Deaminase ◽

Total Protein ◽

Biochemical Parameters ◽

Total Bilirubin ◽

Clinical Signs ◽

Infected Group ◽

Direct Bilirubin ◽

Control Group ◽

And Control

ABSTRACT: This study assessed changes in the levels of adenosine deaminase (ADA) and its isoenzymes in addition to routine liver biochemical parameters in sheep with fascioliasis. The study was conducted on 35 Akkaraman sheep. Of these, 25 sheep were diagnosed with fascioliasis based on anamnesis and clinical signs, and had endoparasites based on parasitological examinations (Fasciola-infected group). The remaining 10 sheep that were sampled from a single healthy herd (same flock) different from the infected group did not have any clinical signs or endoparasites (control group). Total protein (TP), albumin (ALB), and globulin (GLB) levels gradually increased on days after treatment compared to the values measured before treatment; the increases were statistically significant on all days for TP levels but only on day 14 after treatment for GLB levels (P < 0.05). Although, the ALB levels did not increase significantly on days after treatment, the ALB level and ALB/GLB ratio on days 7 and 14 after treatment were still lower than the values of day 21 after treatment and control group (P < 0.05). Total bilirubin (T-Bil) and direct bilirubin (D-Bil) levels on days 14 and 21 were significantly lower than that of day 0 (before treatment) and day 7 after treatment (P < 0.05). These results indicated that the increase in adenosine deaminase (ADA) and ADA1 levels may be due to possible concomitant infection of Fasciola larvae (in the parenchyma) and adults (in the bile duct).

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Evaluation of Recombinant Herpesvirus of Turkey Laryngotracheitis (rHVT-LT) Vaccine against Genotype VI Canadian Wild-Type Infectious Laryngotracheitis Virus (ILTV) Infection

Vaccines ◽

10.3390/vaccines9121425 ◽

2021 ◽

Vol 9 (12) ◽

pp. 1425

Author(s):

Catalina Barboza-Solis ◽

Shahnas M. Najimudeen ◽

Ana Perez-Contreras ◽

Ahmed Ali ◽

Tomy Joseph ◽

...

Keyword(s):

Mononuclear Cells ◽

Clinical Signs ◽

Wild Type ◽

Infectious Laryngotracheitis Virus ◽

Peripheral Blood Mononuclear ◽

Live Attenuated Vaccine ◽

Common Causes ◽

Specific Pathogen ◽

Infectious Laryngotracheitis ◽

Laryngotracheitis Virus

In Alberta, infectious laryngotracheitis virus (ILTV) infection is endemic in backyard poultry flocks; however, outbreaks are only sporadically observed in commercial flocks. In addition to ILTV vaccine revertant strains, wild-type strains are among the most common causes of infectious laryngotracheitis (ILT). Given the surge in live attenuated vaccine-related outbreaks, the goal of this study was to assess the efficacy of a recombinant herpesvirus of turkey (rHVT-LT) vaccine against a genotype VI Canadian wild-type ILTV infection. One-day-old specific pathogen-free (SPF) White Leghorn chickens were vaccinated with the rHVT-LT vaccine or mock vaccinated. At three weeks of age, half of the vaccinated and the mock-vaccinated animals were challenged. Throughout the experiment, weights were recorded, and feather tips, cloacal and oropharyngeal swabs were collected for ILTV genome quantification. Blood was collected to isolate peripheral blood mononuclear cells (PBMC) and quantify CD4+ and CD8+ T cells. At 14 dpi, the chickens were euthanized, and respiratory tissues were collected to quantify genome loads and histological examination. Results showed that the vaccine failed to decrease the clinical signs at 6 days post-infection. However, it was able to significantly reduce ILTV shedding through the oropharyngeal route. Overall, rHVT-LT produced a partial protection against genotype VI ILTV infection.

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Effects of E.coli O157:H7 Experimental Infections on Rabbits

The Iraqi Journal of Veterinary Medicine ◽

10.30539/iraqijvm.v43i1.468 ◽

2019 ◽

Vol 43 (1) ◽

pp. 34-42

Author(s):

Afaf Abdulrahman Yousif

Keyword(s):

Alkaline Phosphatase ◽

Body Weight ◽

Total Protein ◽

Post Infection ◽

Clinical Signs ◽

Alanine Transaminase ◽

Infected Group ◽

Control Group ◽

Biochemical Tests ◽

Liver And Kidney

The study aimed to show the effect of experimental infection with E.coli O157:H7 on some liver and kidney function in adult rabbits. Twenty five domestic rabbits (males and females), aged 6-8 weeks and weighing 1500-2000g, had a negative fecal bacteriological culture of E.coli O157:H7 were used. The rabbits were randomly divided into two groups: infected group (15 rabbits), each animal was drenched orally with 1ml of Phosphate buffer saline containing (2×109CFU) of E.coli O157:H7, while the control group (10 rabbits) were drenched orally (1ml) of Phosphate buffer saline, the clinical signs were daily observed for 30 days, recording of body weight and blood samples were collected at (0, 3, 15 and 30) days for serum to evaluate biochemical tests including Alanine transaminase, Aspartate aminotransaminase and alkaline phosphatase, creatinine, urea and total serum protein. The results showed different clinical signs after inoculation, including diarrhea, lethargy, weight loss, inability to eat or drink, urine was cloudy or milky, while control group remains in normal condition. The serum biochemical tests in infected group showed a significant increase of three enzymes at 15, and 30 days, the highest values of Alanine transaminase; Aspartate aminotransaminase and alkaline phosphatase showed at 30 days post infection as compared with the control group. Serum creatinine and urea recorded a significant increase (P< 0.05) at 30 day post infection as compared with control group. However, total protein revealed a significant decrease in the infected group, and a significant decrease was noticed at 15 day post infection, while the control group showed an increase in total protein co-ordinated with increase of body weight and progressing age. This study concluded that the infection with E. coli O157:H7may cause changes in liver and kidney functions which were more sever at 15,30 days post infection.

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Effect of Pullet Vaccination on Development and Longevity of Immunity

Viruses ◽

10.3390/v11020135 ◽

2019 ◽

Vol 11 (2) ◽

pp. 135 ◽

Cited By ~ 5

Author(s):

Emily Aston ◽

Brian Jordan ◽

Susan Williams ◽

Maricarmen García ◽

Mark Jackwood

Keyword(s):

Clinical Signs ◽

Vaccination Program ◽

Economic Losses ◽

Respiratory Pathogens ◽

Infectious Laryngotracheitis Virus ◽

Vaccination Programs ◽

Live Attenuated Vaccines ◽

Specific Pathogen ◽

Infectious Laryngotracheitis ◽

Laryngotracheitis Virus

Avian respiratory disease causes significant economic losses in commercial poultry. Because of the need to protect long-lived poultry against respiratory tract pathogens from an early age, vaccination programs for pullets typically involve serial administration of a variety of vaccines, including infectious bronchitis virus (IBV), Newcastle disease virus (NDV), and infectious laryngotracheitis virus (ILTV). Often the interval between vaccinations is only a matter of weeks, yet it is unknown whether the development of immunity and protection against challenge when vaccines are given in short succession occurs in these birds, something known as viral interference. Our objective was to determine whether serially administered, live attenuated vaccines against IBV, NDV, and ILTV influence the development and longevity of immunity and protection against challenge in long-lived birds. Based on a typical pullet vaccination program, specific-pathogen-free white leghorns were administered multiple live attenuated vaccines against IBV, NDV, and ILTV until 16 weeks of age (WOA), after which certain groups were challenged with IBV, NDV, or ILTV at 20, 24, 28, 32, and 36 WOA. Five days post-challenge, viral load, clinical signs, ciliostasis, tracheal histopathology, and antibody titers in serum and tears were evaluated. We demonstrate that pullets serially administered live attenuated vaccines against IBV, NDV, and ILTV were protected against homologous challenge with IBV, NDV, or ILTV for at least 36 weeks, and conclude that the interval between vaccinations used in this study (at least 2 weeks) did not interfere with protection. This information is important because it shows that a typical pullet vaccination program consisting of serially administered live attenuated vaccines against multiple respiratory pathogens can result in the development of protective immunity against each disease agent.

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