Interleukin gene expression in broiler chickens infected by different Escherichia coli serotypes

Abstract

Background and Aim: Escherichia coli is the cause of avian colibacillosis, a significant threat to the poultry industry and public health. Thus, this study investigated the prevalence of E. coli in diseased chicken broilers, pathological effects of these bacteria, and interleukin (IL) gene expression of different serotypes of E. coli (O78, O26, O44, and O55) on experimentally infected chickens. Materials and Methods: A total of 295 organ samples (liver, lungs, heart, and spleen) from 59 diseased broiler chickens were used for conventional identification of E. coli. Chickens were orally infected with one of the following E. coli serotypes (O78, O26, O44, or O55) and examined for clinical signs, mortality, macroscopic and microscopic lesions, and IL gene expression using real-time quantitative polymerase chain reaction. Results: E. coli was isolated from 53.2% of broiler chicken organs with a high prevalence in lungs (26.1%). The most prevalent serotypes were O78, O26, O44, O55, O157, and O127 prevalence of 27.8, 22.2, 16.7, 16.7, 5.6, and 5.6%, respectively. In the experimental design, five groups (G1-G5) of birds were established. G1 served as the negative control group, while G2-G5 were challenged orally with E. coli O78, O26, O55, or O44, respectively. Chickens infected with E. coli O78 or O26 showed significant clinical signs in comparison to the other infected birds. Mortality (13.3%) was only observed in birds infected with E. coli O78. Necropsy of dead birds after E. coli O78 infection showed pericarditis, enteritis, airsacculitis, and liver and lung congestion. More severe histopathological changes were observed in intestines, spleen, liver, and lung from chickens infected with either E. coli O78 or O26 than for birds infected with other serotypes. On the 2nd day post-infection, E. coli challenge, particularly with E. coli O78, displayed significantly upregulated levels of ileal IL-6 and IL-8, but ileal IL-10 level tended to be downregulated in comparison to the control group. Conclusion: This study assessed the application of cytokines as therapeutic agents against infectious diseases, particularly colibacillosis.

Phenotypic and Genotypic Screening of Colistin Resistance Associated with Emerging Pathogenic Escherichia coli Isolated from Poultry

“…with the serotype with the highest incidence being O125 (n = 18), followed by O55 (n = 8) and O86 (n = 7), while the other serotypes were O111 (n = 6), O127 (n = 5), O159 (n = 4), O18 (n = 4), O157 (n = 2) and O166 (n = 2). These findings coincide with previous studies [18,21] but differ from those isolated in Jordan (O1, O2, O25 and O78) [22]. Multiple E. coli serotypes, specified as "avian pathogenic E. coli" (APEC), are the etiology of colibacillosis, which is considered one of the major causes implicated in mortality (up to 20%) as well as morbidity and which results in the lowering of meat and egg production among poultry flocks worldwide [23].…”

Investigating the Effect of Pulicaria jaubertii as a Natural Feed Additive on the Growth Performance, Blood Biochemistry, Immunological Response, and Cecal Microbiota of Broiler Chickens

“…Gene expression of the cDNA samples was performed by real-time quantitative PCR (7300 Real-Time PCR System, Applied Biosystems, Foster City, CA, USA), using primers to determine the expression of TNF-α , IL-1β , IL-4 , IL-6 , IL-2 , IL-10 , INF-Y , sIgA , MUC-2 , and β-actin genes ( Table 2 ; by Basic Local Alignment Search Tool) and addition of SYBR Green PCR Master Mix (Applied Biosystems, Thermo Fisher Scientific, Foster, CA, USA). The fold change in gene expression for each target gene was calculated using the 2 −ΔΔCt method compared to the control group [ 26 ].…”

Gene expression of pro-inflammatory (IL-8, IL-18, TNF-α, and IFN-γ) and anti-inflammatory (IL-10) cytokines in the duodenum of broiler chickens exposed to lipopolysaccharides from Escherichia coli and Bacillus subtilis

“…The presence of E. coli implies the suppression of cytokines, especially IL-10 but not TNF-α, which increases in the intestine of chickens fed with a diet with LPS [ 24 ]. Similar results were presented in this study with diets to which LPS from E. coli was added.…”