Susantha Gomis

University of Saskatchewan | U of S · Department of Veterinary Pathology

Background Necrotic enteritis (NE) is an economically important disease of broiler chickens caused by Clostridium perfringens (CP). The pathogenesis, or disease process, of NE is still not clear. This study aimed to identify the alterations of metabolites and metabolic pathways associated with subclinical or clinical NE in CP infected birds and to...

Clostridium perfringens (CP)-induced necrotic enteritis (NE) is an economically important disease in the broiler chicken industry. The incidence of NE is common in 3-to-6-wk-old broiler chickens, once maternal antibodies start declining. Developing an effective vaccination strategy against NE, preferably delivering a single dose of vaccine at hatch...

Oligodeoxynucleotides containing CpG motifs (CpG-ODN) can promote antimicrobial immunity in chickens by enriching immune compartments and activating immune cells. Innate memory, or trained immunity, has been demonstrated in humans and mice, featuring the absence of specificity to the initial stimulus and subsequently cross-protection against pathog...

In the past, we demonstrated that oligodeoxynucleotides containing CpG motifs (CpG-ODN) mimicking bacterial DNA, stimulate the innate immune system of neonatal broiler chickens and protect them against Escherichia coli and Salmonella Typhimurium (S. Typhimurium) septicemia. The first line of innate immune defense mechanism is formed by heterophils...

Background Necrotic enteritis (NE) is a severe intestinal infection that affects both humans and poultry. It is caused by the bacterium Clostridium perfringens (CP), but the precise mechanisms underlying the disease pathogenesis remain elusive. This study aims to develop an NE broiler chicken model, explore the impact of the microbiome on NE pathog...

Variant avian reoviruses (ARVs) are economically important emerging pathogens of poultry, which mainly affect young broiler chickens and cause significant production losses. Currently, there are no effective commercial vaccines available for control and prevention of emerging variant ARVs. In this study, monovalent inactivated adjuvated (20% Emulsi...

The majority of infectious bursal disease virus (IBDV) strains circulating in the broiler chicken industry in Canada are variant strains (varIBDV). Despite high levels of maternally derived antibodies (MtAb), the circulating varIBDVs can establish infection and cause severe immunosuppression in broiler chicks. The objective of this study was to eva...

There is pressure to ban the practice of using beak treatment in laying hens and with this comes the need to find viable alternatives. Natural beak blunting by the inclusion of abrasive materials in the feeder has been suggested as an alternative, but its applicability to leghorn pullets and laying hens is not fully understood. This study investiga...

The poultry industry needs alternatives to antibiotics, as there are growing public concerns about the emergence of antimicrobial resistance owing to antimicrobial use in animal production. We have reported that the administration of neonatal chicks with synthetic DNA oligodeoxynucleotides containing unmethylated cytosine guanine dinucleotide (CpG)...

Enterococci and Escherichia coli are opportunistic pathogens of poultry and are associated with embryo and neonatal chick mortality. We have recently demonstrated that 56% of dead broiler chicken embryos in commercial hatcheries in western Canada were due to the coinfection of Enterococcus species and E. coli. The objective of this study was to inv...

The roles of TonB mediated Fe3+ (ferric iron) uptake via enterobactin (involving biosynthesis genes entABCDEF) and Fe2+ (ferrous iron) uptake through the FeoABC transporter are poorly defined in the context of chicken-Salmonella interactions. Both uptake systems are believed to be the major contributors of iron supply in the Salmonella life cycle....

Newly emerging arthrotropic avian reoviruses (ARVs) are genetically divergent, antigenically heterogeneous, and economically costly. Nevertheless, the mechanism of emerging ARV-induced disease pathogenesis and potential differences in virulence between virus genotypes have not been adequately addressed. In this study, the life cycle of ARV, includi...

Controlling injurious pecking in commercial turkeys remains a significant challenge to producers and the industry. Infrared beak treatment is an effective method of controlling injurious pecking in chickens; however, the effects of infrared beak treatment on turkey performance are still largely unknown. Two experiments were conducted to determine t...

This study aimed to determine the effects of infrared beak treatment on the behavior and welfare of male and female turkeys reared to 12 weeks of age. To do this, poults (236 males and 324 females) were assigned to one of two beak treatments: infrared beak treated on day of hatch (IR) or sham untreated control (C). Data collected included heterophi...

For decades, vaccinations have been used to limit infectious bronchitis (IB) in both the broiler and layer industries. Depending on the geographical area, live attenuated vaccines are used either alone or in combination with inactivated vaccines to control infectious bronchitis virus (IBV) infections. It has been shown that administering inactivate...

Abstract Synthetic CpG-ODNs can promote antimicrobial immunity in neonatal chicks by enriching immune compartments and activating immune cells. Activated immune cells undergo profound metabolic changes to meet cellular biosynthesis and energy demands and facilitate the signaling processes. We hypothesize that CpG-ODNs induced immune activation can...

Synthetic DNA containing CpG motifs (CpG-ODNs) are potent innate immune stimulators in neonatal and adult broiler chickens against bacterial septicemia. We have recently demonstrated that intrapulmonary (IPL) delivery of CpG-ODN as micro-droplets under laboratory conditions can protect neonatal chickens against lethal Escherichia coli septicemia. T...

1. Moribund or diseased poultry requiring euthanasia are often dehydrated. To understand how dehydration influences the efficacy of various killing methods, this experiment investigated the effect of water deprivation (WD) on times to unconsciousness and death. 2. Broiler chickens (n=179) were water-deprived for 0, 24, 48 or 72 hours to mimic dehyd...

In the last decade, the emergence of variant strains of avian reovirus (ARV) has caused enormous economic impact in the poultry industry across Canada and USA. ARVs are non-enveloped viruses with ten segments of double-stranded RNA genome. So far, only six genotyping cluster groups are identified worldwide based on sequence analysis of the rC prote...

The transition to antibiotic-free poultry production in the face of pathogenic threats is a very challenging task. We recently demonstrated that mucosal delivery of CpG-ODN alone by the intrapulmonary route (IPL) has potential as an effective alternative to antibiotics in neonatal chicks against Escherichia coli septicemia. How exactly mucosal deli...

Antimicrobial resistance (AMR) is a global issue, posing a grave threat to the public, animal, and environmental health. The AMR surveillance at the level of the hatchery is crucial to develop an AMR control strategy in the poultry industry. The objective of this study was to investigate the AMR profiles of bacteria isolated from yolk material of n...

Immunoprotective function of oligodeoxynucleotides containing CpG motifs (CpG-ODN) has been demonstrated in neonatal chickens against common bacterial pathogens such as E.coli and Salmonella sp. Our recent study reported that CpG-ODN administration enriches immune compartments in neonatal chicks. However, a causal relationship between CpG-ODN-induc...

Despite previous research on the impacts of beak treatment on laying hens, little information exists regarding how variation in beak morphology that can occur following beak treatment affects production, behavior, and welfare. Following infrared beak treatment (IRBT), variations in beak shape, such as a shovel beak (bottom beak longer than top), cr...

Infrared beak treatment has less of a negative impact on laying hen welfare compared to other methods of beak treatment; however, it is still not fully understood how infrared beak treatment affects the beak tissue during the first few days post treatment. The objective of this study was to examine the histology of infrared beak treated vs. untreat...

This research examined how infrared beak treatment (IRBT), sloughing of the treated beak tissue, and the variations in beak shape that can occur post-IRBT impact the welfare and mortality of Lohmann LSL-Lite (LW) and Lohmann Brown (LB) pullets and hens. Two experiments were conducted and birds for both experiments were treated on the day of hatch....

Infrared beak treatment (IRBT) results in a change in beak shape; however, it is unclear what effect variations in post-treatment beak shape have on young pullets. Additionally, the impact of sloughing of the treated beak tissue is not fully understood. Two experiments were conducted to determine the effects of beak tissue sloughing and post-treatm...

Stocking density (SD) of turkey toms (n = 2,868 Nicholas Select) was evaluated in 2 16-wk trials. Poults were randomly allocated to 1 of 8 independently ventilated rooms (6.71 × 10.06 m) for each trial, to reach a final target SD of 30, 40, 50, or 60 kg/m². Air quality was monitored (carbon dioxide and ammonia) throughout the trial, and ventilation...

Oligodeoxynucleotides containing CpG motifs (CpG-ODN) induce innate immunity against bacterial infections. Despite recent advances, how CpG-ODN alone protects against bacterial infections remained elusive. Here, we report for the first time, to our knowledge, that CpG-ODN orchestrates anti-microbial protective immunity by inducing a rapid enrichmen...

Background Infectious bronchitis virus (IBV) is one of the leading causes of mortality and morbidity in chickens. There are numerous serotypes and variants, which do not confer cross protection resulting in failure of currently used IBV vaccines. Although variant IBV isolates with major genetic differences have been subjected to comparative studies...

The in ovo delivery of cytosine-guanosine (CpG) oligodeoxynucleotides (ODNs) protects chickens against many bacterial and viral infections, by activating the toll-like receptor (TLR)21 signaling pathway. Although the delivery of CpG ODNs in ovo at embryo day (ED) 18 has been shown to reduce infectious bronchitis virus (IBV) loads in embryonic chick...

A disease with a sudden drop in egg production and shell-less eggs called, shell-less egg syndrome (SES) has been observed in Western Canada egg layer flocks since 2010. The etiology of this disease is not known. We hypothesize that SES is caused by an infectious bronchitis virus (IBV) strain since it is known that IBV replicates in the shell gland...

Cytosine-guanosine deoxynucleotides (CpG) DNA can be delivered in ovo at embryo day (ED)18 for the stimulation of toll-like receptor (TLR)21 signaling pathway that ultimately protects chickens against a number of bacterial and viral infections. There is a dearth of information understanding the mechanisms of protection induced by in ovo delivered C...

Historically, fowl adenovirus (FAdV) associated inclusion body hepatitis (IBH) was considered a secondary disease in broiler chickens associated with immunosuppression. However, we previously reported the occurrence of IBH as a primary disease in the broiler chicken industry in Canada as a result of infections with various FAdV serotypes. Therefore...

Infectious bronchitis virus (IBV) infection is a major cause of economic losses to the poultry industry. Due to limitations in current control measures, alternative approaches, based on thorough understanding of the host responses are required. As one of the key component of the avian immune system, the innate immune system has a crucial role in li...

Fowl adenovirus (FAdV) is comprised of five species (A to E) and 12 serotypes (1-7, 8a, 8b, 9-11). Inclusion body hepatitis (IBH) is caused by FAdV-7, 8a, 8b (species E) and FAdV-2 and 11 (species D). Commercial vaccines against IBH are not available in Canada. Autogenous FAdV broiler breeder vaccines are now used in some areas where outbreaks of I...

The emergence of enterococcal infections in neonatal broiler chickens in the poultry industry has become common in many countries, including Canada. The objective of this study was to examine the bacterial infections in nonviable broiler chicken embryos in three western Canadian poultry hatcheries using matrix-assisted laser desorption/ionization t...

Synthetic oligodeoxynucleotides (ODN) containing unmethylated cytosine phosphodiester guanine (CpG) motifs (CpG-ODN) are effective immunostimulatory agents against a variety of viral, bacterial, and protozoan diseases in different animals including poultry. We have recently demonstrated that in ovo injection of CpG-ODN confers protection in neonata...

Infectious bronchitis virus (IBV) causes respiratory disease leading to loss of egg and meat production in chickens. Although it is known that macrophage numbers are elevated in the respiratory tract of IBV infected chickens, the role played by macrophages in IBV infection, particularly as a target cell for viral replication, is unknown. In this st...

Veterinary vaccine development has several similarities with human vaccine development to improve the overall health and well-being of species. However, veterinary goals lean more toward feasible large-scale administration methods and low cost to high benefit immunization. Since the respiratory mucosa is easily accessible and most infectious agents...

In recent years, emerging strains of pathogenic arthrogenic avian reovirus (ARV) have become a challenge to the chicken industry across USA and Canada causing significant economic impact. In this study, we characterized emerging variant ARV strains and examined their genetic and antigenic relationship with reference strains. We isolated 37 emerging...

Fusarium mycotoxins, namely deoxynivalenol, can negatively impact the nutritional quality of grains. This study evaluated the effects of feeding three naturally contaminated Fusarium-downgraded wheat sources on immunological parameters in broiler chickens. Sources were individually sorted into three fractions: outlier, high mycotoxin, and low mycot...

Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections in infants and young children. There are no licensed RSV vaccines available, and the few treatment options for high-risk individuals are either extremely costly or cause severe side effects and toxicity. Immunomodulation mediated by a novel formulatio...

While the prevalence of infectious bursal disease virus (IBDV) on chicken farms in some provinces of Canada has been documented, the economic impact of variant IBDV infection on the broiler chicken industry in Saskatchewan has not. The objectives of this study were to identify the variant strains of IBDV circulating on Saskatchewan chicken farms an...

Antibiotic-free and safe animal products are most desirable among consumers. However, ensuring safe poultry products is a challenging task when the chicken immune system is compromised. Infectious bursal disease virus (IBDV) causes immunosuppression and predisposes chickens to secondary infections. Breeder vaccination against IBDV is routinely prac...

Respiratory syncytial virus (RSV) is a major cause of bronchiolitis and pneumonia in infants and pneumonia virus of mice (PVM) causes similar disease. BALB/c mice are highly susceptible, while C57BL/6 mice are more resistant to PVM. IL-12 was significantly more up-regulated in response to PVM infection in BALB/c than in C57BL/6 mice. IL-12p40-defic...

Objective: The objective of this study is to investigate the structural and functional ocular changes that develop in turkeys exposed to a photoperiod of 23 h of light (23L) compared with a photoperiod of 14 h of light (14L). Procedures: Ten-day-old Nicholas heavy strain poults were exposed to either a 14L or 23L photoperiod. Between 16 and 18 w...

The impact of graded levels of day length on turkey health and behavior was determined in hens and toms raised to 18 wk of age. Birds were allocated to one of 4 lighting treatments (trt) providing 14 (14L), 17 (17L), 20 (20L), and 23 (23L) h of day length. Two time-replicated trials were completed with each, providing 2 rooms per lighting trt and e...

The impact of graded levels of day-length on the productivity of hens and toms was studied in two trials. Daylength treatments (trts) were 14 (14L), 17 (17L), 20 (20L), and 23 (23L) h and were started at 10 d of age. Turkeys (720 hens and 480 toms) were randomly allocated to 8 rooms (2 rooms per lighting trt) with six pens (3 hen – 30 per pen and 3...

The objective of this study was to identify the causative agents of hepatitis observed in broiler chickens at processing. Livers of chickens from 16 broiler farms in Saskatchewan with gross lesions of hepatitis were collected at processing. In addition to routine bacterial isolation and histopathological examination, serologic studies for infectiou...

Respiratory syncytial virus is a major cause of bronchiolitis in infants and pneumonia virus of mice (PVM) causes similar disease in mice. The impact of PVM infection in BALB/c and C57BL/6 neonates, and upon re-infection as elderly mice, was compared. As previously shown for adult mice, PVM caused more disease in BALB/c than in C57BL/6 neonates. Af...

Ducks are a natural reservoir for H5N1 highly pathogenic avian influenza (HPAI) viruses, which produces a range of clinical outcomes from asymptomatic infections to severe disease with mortality. Vaccination against HPAI is one of the few methods available for controlling avian influenza virus (AIV) infection in domestic ducks; therefore, it is nec...

Society is increasingly concerned about the welfare of animals kept for food production, for this reason, invasive procedures such as toe trimming in turkeys must be studied to assess the corresponding welfare implications and to ensure such procedures are acceptable for continued use. To this end, research was conducted to evaluate the welfare eff...

RESUMEN Protección temprana en pollos de engorde después de la aplicación in ovo de oligodesoxinucleótidos que contienen motivos CpG (CpG ODN) formulados con nanotubos de carbono o liposomas. Se ha demostrado que los oligodesoxinucleótidos (ODN) no formulados que contienen motivos CpG (CpG-ODN) pueden estimular el sistema inmune innato contra una v...

Classen, H., Cho, M., Hucl, P., Gomis, S. and Patterson, C. A. 2014. Performance, health and tissue weights of broiler chickens fed graded levels of hairless hulled yellow and brown canary seed (Phalaris canariensis L.). Can. J. Anim. Sci. 94: 669–678. Research examined the effects of dietary levels (0, 15, 30 and 45%) of hulled yellow (C05041) and...

Trimming the 3 anterior toes on both feet at day of hatch to remove the claws, reduce bird scratching, and improve carcass grades is a common practice in the turkey industry. Changes in the method of trimming and the growth potential of turkeys since the majority of research on this topic was completed motivated this study with the objective of est...

This report confirms a recent outbreak of a Leucocytozoon caulleryi infection in a commercial broiler breeder flock in South Korea. Seven, 18-day-old broiler breeders (Gallus gallus) were necropsied following a history of depression, sudden death, and subcutaneous hemorrhages. On necropsy, subcutaneous hemorrhages were identified in the wings and l...

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