Campylobacter species (spp.) are one of the most important causes of human bacterial gastroenteritis in foods of animal origin. Recently, with the spread of multi-drug-resistant (MDR) and extensively drug-resistant (XDR) Campylobacter spp., natural alternative therapeutic methods are urgently required. Phytogenic active principles have gained considerable attention due to their proficiency to enhance gut health and, thereby, performance of broiler chickens. Thus, the current study aims to determine the prevalence and antimicrobial resistance of Campylobacter spp. of different chicken sources in Sharkia Governorate, Egypt, and to assess the growth-promoting, immunostimulant and antimicrobial effects of a mixture of eugenol and trans-cinnamaldehyde in an in vivo approach. A total of 101 (67.3%) campylobacter isolates was identified, according to both phenotypic and genotypic techniques. Moreover, all of the campylobacter isolates were resistant to erythromycin, trimethoprim/sulfamethoxazole, and ampicillin (100% each). Of note, a dietary supplementation of the mixture of eugenol and trans-cinnamaldehyde led to a significant improvement of the feed conversion ratio and body weight gain and a decrease in the cecal C. jejuni loads in the broilers challenged with XDR C. jejuni. Additionally, eugenol and the trans-cinnamaldehyde mixture had protective activities via the down-regulation of XDR C. jejuni (flaA, virB11 and wlaN) virulence genes and proinflammatory cytokines (TNF-α, IL-2, IL-6, and IL-8), and the up-regulation of anti-inflammatory cytokine IL-10. Thus, we recommend the usage of a mixture of eugenol and trans-cinnamaldehyde as an alternative to antimicrobials for the control and treatment of campylobacter infections.

Cryptosporidium parvum (C. parvum) infection is one of the main causes of diarrhea in calves. The current study assessed the role of blood biomarkers (acute-phase proteins (APPs), procalcitonin, neopterin, cytokines, and oxidative stress in the pathogenesis, diagnosis, and prognosis of calves naturally infected with C. parvum. Fifty-seven calves, aged from 10 to 45 days, were detected positive for C. parvum and were allotted into the diseased group; twenty healthy calves were selected as a control group. Serum amyloid A, haptoglobin, cytokines, neopterin, procalcitonin, and stress biomarkers were tested in the diseased and healthy groups. The serum levels of APPs, cytokines, neopterin, procalcitonin, and malondialdehyde increased, whereas antioxidant levels were significantly decreased in diseased calves compared to the healthy group. Moreover, all examined biomarkers were significantly altered towards normal values in infected calves following different treatment protocols. All biomarkers examined were highly effective in discriminating between C. parvum-infected calves and healthy individuals. Furthermore, the area under the curve (AUC) showed that all tested parameters had a higher degree of prognostic accuracy in predicting the treatment response of calves naturally infected with C. parvum. Our data suggest the usefulness of the examined biomarkers in the immune pathogenesis of the C. parvum infection in calves, contributing to diagnosis and treatment efficacy.