Intestinal colonization and acute immune response in commercial turkeys following inoculation with Campylobacter jejuni constructs encoding antibiotic-resistance markers

Consumption of contaminated poultry products is one of the main sources of human campylobacteriosis, of which Campylobacter jejuni subsp. jejuni (C. jejuni) is responsible for approximately 90% of the cases. At slaughter, the ceca of commercial chickens and turkeys are the main anatomical site where C. jejuni asymptomatically colonizes. We have previously colonized commercial turkey poults with different isolates of C. jejuni and evaluated different media to best enumerate Campylobacter from intestinal samples, but the host-response is unknown in turkeys. Enumeration of Campylobacter(colony forming units (cfu)/gram of intestinal contents) can be challenging, and can be confounded if animals are colonized with multiple species of Campylobacter. In order to precisely enumerate the C. jejuni isolate used to experimentally colonize turkeys, constructs of C. jejuni (NCTC 11,168) were tagged with different antibiotic resistance markers at the CmeF locus (chloramphenicol (CjCm) or kanamycin (CjK)). We sought to examine the kinetics of intestinal colonization using the antibiotic resistant constructs, and characterize the immune response in cecal tissue of turkeys. In vitroanalysis of the tagged antibiotic-resistant constructs demonstrated no changes in motility, morphology, or adherence and invasion of INT-407 cells compared to the parent isolate NCTC 11,168. Two animal experiments were completed to evaluate intestinal colonization by the constructs. In experiment 1, three-week old poults were colonized after oral gavage for 14 days, and CjCm and CjK cfu were recovered from cecal, but not ileal contents. In experiment 2, nine-week old poults were orally inoculated with CjCm, and the abundance of CjCm cfu/g of cecal contents significantly decreased beyond 14 days after inoculation. Significant lesions were detected in CjCm colonized poults at day 2 post-colonization. Using immunohistochemistry, Campylobacter antigen was detected in between cecal villi by day 7 of CjCm colonized poults. Quantitative RT-PCR of CjCm-colonized cecal tissue demonstrated significant down-regulation of IL-1β, IL-10 and IL-13 mRNA, and significant up-regulation of IL-6, IL-8, IL-17 A, IL-22 and IFNγ mRNA on day 2, and for some on day 7 post-colonization. All differentially expressed genes were similar to mock-infected poults by day 14. These data suggest that C. jejuni induced a brief inflammatory response in the cecum of poults that quickly resolved. Results from this study provide valuable insight into host-response and persistent colonization of the turkey cecum. These findings will help to develop and test strategies to promote food safety in commercial turkeys

Effects of broiler chilling methods on the occurrence of pale, soft, exudative (PSE) meat and comparison of detection methods for PSE meat using traditional and Nix colorimeters

ABSTRACT: The aims of this study were to i) estimate the occurrence of pale, soft, and exudative (PSE) meat in modern commercial Ontario broiler flocks, ii) determine the effects of the chilling method (water vs. air) on PSE meat, and iii) investigate a new inexpensive colorimeter (10% of the price of traditional color meters), the Nix Color Sensor, as an objective color measurement of chicken meat. Between June 2019 to March 2020, a total of 17 different broiler flocks were processed. The color of 1,700 boneless skinless Pectoralis major muscles was randomly measured (100/flock), where 255 samples were also measured for pH, water-holding capacity (WHC), cooking loss, and penetration force. In addition, a traditional Minolta colorimeter was used to measure random 95 samples from a single water-chilled flock and subsequently compared the values obtained with the Nix Color Sensor. Strong correlations of L* values (rho = 0.75; P < 0.001), a* values (rho = 0.72; P < 0.001), and b* values (rho = 0.80; P < 0.001) were observed. When an L* value of 43 was used as the cut-off for the Nix, 12.5% of fillets were classified as PSE meat. Statistical differences (P < 0.05) were observed between the air and water-chill methods for L*, pH, and WHC. However, there were no significant differences observed between the 2 methods for cooking loss and penetration force values. The study indicated that PSE meat is still a challenge in Ontario broilers, and that the L*, pH, and WHC of breast meat (all indicate meat quality) are affected by the chilling method. In addition, the Nix was found to be an affordable, objective, and convenient sensor for measuring chicken meat color

Restoring Functionalities in Chicken Breast Fillets with Spaghetti Meat Myopathy by Using Dairy Proteins Gels

The use of caseinate, whole milk powder, and two whey protein preparations (WP; 2% w/w) was studied in minced meat made with normal breast (NB), and ones showing spaghetti meat (SM). SM is an emerging myopathy known for muscle fiber separation and lower protein content, costing $100s of millions to the industry. Using SM without dairy proteins resulted in a higher cooking loss (SM: 3.75%, NB: 2.29%; p < 0.05), and lower hardness (SM: 29.83 N, NB: 34.98 N), and chewiness (SM: 1.29, NB: 1.56) compared to NB. Using dairy proteins, except WP concentrate and WP isolate, significantly improved yield and increased hardness. Adding WP isolate to SM resulted in a similar texture profile as NB samples without dairy proteins (34 and 35 N hardness; 0.22 and 0.24 springiness; 1.57 and 1.59 chewiness values, respectively). Adding caseinate and whole milk to SM showed a more substantial effect of improving water-holding capacity, increasing hardness, gumminess, and chewiness compared to adding WP; i.e., adding caseinate and milk powder resulted in higher values for those parameters compared to NB without additives. Overall, it is shown that dairy proteins can be added to SM to produce minced poultry meat products with similar or higher yield and texture profiles compared to using normal breast fillets

Textural and physical properties of breast fillets with myopathies (wooden breast, white striping, spaghetti meat) in Canadian fast-growing broiler chickens

The combined effects of different severities of Wooden Breast (WB), White Striping (WS), and Spaghetti Meat (SM) were examined in 300 chicken breast fillets from 10 flocks. Severity (0 = absent, 1 = mild, noticeable upon close inspection, 2 = severe), noticeably altered from normal breast fillet (NB). Results showed that any combination of myopathies and severity resulted in significantly elevated compression force, pH and peak counts measured by the shear force test. With the exception of mild WB + mild WS, all combinations resulted in significantly higher drip loss, cooking loss and lightness value. Overall, the quality of fillets was affected the least by WS, while negatively affected the most by SM. There were limited effects on fillet quality from mild WB but major deleterious effects from severe WB

In Vitro and In Ovo Host Restriction of Aquatic Bird Bornavirus 1 in Different Avian Hosts

Aquatic bird bornavirus 1 (ABBV-1) is associated with chronic meningoencephalitis and ganglioneuritis. Although waterfowl species act as the natural host of ABBV-1, the virus has been sporadically isolated from other avian species, showing the potential for a broad host range. To evaluate the host restriction of ABBV-1, and its potential to infect commercial poultry species, we assessed the ability of ABBV-1 to replicate in cells and embryos of different avian species. ABBV-1 replication was measured using multi- and single-step growth curves in primary embryo fibroblasts of chicken, duck, and goose. Embryonated chicken and duck eggs were infected through either the yolk sac or chorioallantoic cavity, and virus replication was assessed by immunohistochemistry and RT-qPCR in embryonic tissues harvested at two time points after infection. Multi-step growth curves showed that ABBV-1 replicated and spread in goose and duck embryo fibroblasts, establishing a population of persistently infected cells, while it was unable to do so in chicken fibroblasts. Single-step growth curves showed that cells from all three species could be infected; however, persistence was only established in goose and duck fibroblasts. In ovo inoculation yielded no detectable viral replication or lesion in tissues. Data indicate that although chicken, duck, and goose embryo fibroblasts can be infected with ABBV-1, a persistent infection is more easily established in duck and goose cells. Therefore, ABBV-1 may be able to infect chickens in vivo, albeit inefficiently. Additionally, our data indicate that an in ovo model is inadequate to investigating ABBV-1 host restriction and pathogenesis

Comparing three textural measurements of chicken breast fillets affected by severe wooden breast and spaghetti meat

In this study, we compared three popular textural tests: the compression, Meullenet\u2013Owens razor blade (MORS), and Allo\u2013Kramer (AK) tests, which are used to detect the wooden breast (WB) and spaghetti meat (SM) myopathies. A total of 209 fillets (71 WB, 71 SM, 67 normal) were selected from three different flocks at a large commercial plant. Thawed fillets were subjected to 20% compression tests before and after cooking, and cooked samples were subjected to the MORS and AK tests. The compression test on raw samples showed that normal and SM fillets had lower force (5.61 and 4.69 vs. 9.52 N), work (25 and 22 vs. 45N mm), and Young\u2019s modulus (2.71 and 2.11 vs. 4.29 N/s, p<.001) values than those of WB. The results of the compression test were confirmed by the cooked fillet results. The MORS test showed that SM had lower shear force (12.8 vs. 14.7N) and work (249 vs. 288N mm) values than those of the normal fillets, while WB showed intermediate values. The AK test results showed that SM had lower shear force (10.5 vs. 14.5N) and Young\u2019s modulus (31.0 vs. 46.0 N/s; p.01) values than those of WB fillets, whereas normal fillets had intermediate values. The compression test can be used to identify WB in both raw and cooked meat. The MORS test could distinguish cooked SM fillets from normal fillets, whereas the AK test differentiated SM from WB

Demographic, Husbandry, and Biosecurity-related Risk Factors for Mycoplasma gallisepticum in Small Poultry Flocks in Ontario, Canada

This study is part of a 2-year disease surveillance project conducted to determine the prevalence of poultry and zoonotic pathogens in Ontario’s small flocks. Our objective was to investigate factors associated with the presence of Mycoplasma gallisepticum in Ontario’s small flocks. Flock owners (n = 145) completed a husbandry and biosecurity questionnaire, and the Animal Health Laboratory tested pooled tracheal swab samples from submitted birds for M. gallisepticum using real-time PCR. Our study found that the odds of M. gallisepticum were significantly higher (p &amp;lt; 0.05) in small flocks with layers (compared to no layers), in small flocks with breeding stock (compared to no breeding stock), in small flocks in which birds were housed in a mixed group with different species and/ or types of birds (compared to birds not housed in a mixed group), and in small flocks in which new birds were not isolated (compared to new birds isolated for more than 2 weeks or reared under an all-in-all-out management system). Our results suggest that management strategies, such as isolating new birds, keeping only one species and type of poultry, and preventing the introduction of M. gallisepticum into flocks with long-lived birds, might help to reduce the risk