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Aims This study aimed to explore the effectiveness of dietary citronellol, thymol, and trans-cinnamaldehyde (CTC) essential oils blend on broilers' growth performance, immunity, intestinal microbial count, gut integrity, and resistance against Clostridium perfringens utilizing the necrotic enteritis (NE) challenge model. Methods and results A total of 200 Ross 308 male broiler chicks received either a control diet or diet supplemented with three graded levels of CTC blend, including 300, 600, and 900 mg of CTC blend/kg diet and experimentally infected with C. perfringens strain at 23 days of age. Herein, dietary CTC blend fortifications significantly improved the broilers' growth performance, which was supported by upregulating the expression levels of MUC-2 , occludin, and JAM-2 genes. Moreover, dietary CTC blend inclusion significantly enhanced the levels of blood phagocytic percentage and serum IgA, IgG, and MPO, and reduced the values of serum CRP, and NO at 5 days pre-infection, 10-, and 15 days post-infection (dpi) with C. perfringens. At 15 dpi, CTC blend inclusion significantly reduced the intestinal digesta pH, coliforms and C. perfringens loads, and the expression levels of genes related to C. perfringens virulence (cpe, cnaA , and nanI), proinflammatory cytokines (IL-1β and TNF-α), and chemokines (CCL20), in addition to increasing the count of beneficial total Lactobacillus and total aerobic bacteria, and the expression levels of genes related to anti-inflammatory cytokines (IL-10) and chemokines (AvBD6 and AvBD612). Conclusion Our results point to the growth-provoking, immunostimulant, antibacterial, anti-inflammatory, and antivirulence characteristics of the CTC blend, which improves the broilers' resistance to C. perfringens and ameliorates the negative impacts of NE. [ABSTRACT FROM AUTHOR]

Phytochemical nanoemulsions, such as thymoquinone nanoemulsions (TQN), are regarded as innovative alternatives to antimicrobials that significantly improve the performance, digestion, antioxidant potential and immunity of rabbits. Thus, the potential effects of TQN on growth, digestibility, antioxidant potential, immunity and resistance against Pasteurella multocida (P. multocida) in rabbits were assessed. Herein, 240 rabbits were offered either a basal diet or diets fortified with three TQN-graded concentrations. At 60 days of age, rabbits were challenged with multidrug-resistant (MDR) virulent P. multocida strain. Our outcomes described that dietary inclusion of TQN, especially at higher concentrations, significantly enhanced the growth performance of rabbits, which was supported by increasing the levels of jejunal lipase, amylase and trypsin enzymes. Of note, the levels of muscle and jejunal antioxidant enzymes [superoxide dismutase (SOD), glutathione peroxidase (GPX), catalase (CAT) and total antioxidant capacity (T-AOC)], serum immunological markers (IgG, IgG, IgM and total Igs) and blood phagocytic percentage were significantly provoked after TQN fortification; meanwhile, the levels of muscle and jejunal MDA, serum biochemical parameters (total cholesterol, TG and LDL), abdominal fat percentage, breast and thigh cholesterol were significantly decreased following TQN supplementations. Our findings showed that TQN protected rabbits against P. multocida experimental challenge as evidenced by reducing P. multocida counts in rabbits' lungs, downregulating the transcription levels of P. multocida virulence-related genes (ptfA, toxA and nanB) at 48 and 96 h post-infection and ameliorating the expression levels of cytokines-related genes (IL-1β, IL-10, IL-8, IL-6, DEFB1, TNF-α, TLR-4 and TLR-2) at 96 h post-infection. Our findings suggest the utilization of TQN in rabbits' diets due to their stimulating effects on digestibility as well as their growth-promoting, anti-inflammatory, antioxidant, antibacterial, anti-virulence and immunostimulant properties, which enhance the rabbits' P. multocida resistance. [ABSTRACT FROM AUTHOR]

Introduction: There is an urgent need to develop therapeutic options for biofilm-producing Staphylococcus aureus (S. aureus). Therefore, the renewed interest in essential oils (EOs), especially carvacrol, linalool and eugenol, has attracted the attention of our research group. Methods: Multidrug resistance and multivirulence profiles in addition to biofilm production of S. aureus strains isolated from cows with mastitis were evaluated using both phenotypic and genotypic methods. The antimicrobial and antibiofilm activities of EOs were tested using both in vitro and molecular docking studies. Moreover, the interactions between commonly used antibiotics and the tested EOs were detected using the checkerboard method. Results: We found that all our isolates (n= 37) were biofilm methicillin resistant S. aureus (MRSA) producers and 40.5% were vancomycin resistant S. aureus (VRSA). Unfortunately, 73 and 43.2% of the recovered MRSA isolates showed multidrug resistant (MDR) and multivirulence patterns, respectively. The antimicrobial activities of the tested EOs matched with the phenotypic evaluation of the antibiofilm activities and molecular docking studies. Linalool showed the highest antimicrobial and antibiofilm activities, followed by carvacrol and eugenol EOs. Fortunately, synergistic interactions between the investigated EOs and methicillin or vancomycin were detected with fractional inhibitory concentration index (FICI) values = 0.5. Moreover, the antimicrobial resistance patterns of 13 isolates changed to sensitive phenotypes after treatment with any of the investigated EOs. Treatment failure of bovine mastitis with resistant S. aureus can be avoided by combining the investigated EOs with available antimicrobial drugs. Conclusion: We hope that our findings can be translated into a formulation of new pharmaceutical dosage forms against biofilm-producing S. aureus pathogens. [ABSTRACT FROM AUTHOR]

This document is a corrigendum for an article titled "Future impact of thymoquinone-loaded nanoemulsion in rabbits: prospects for enhancing growth, immunity, antioxidant potential and resistance against Pasteurella multocida." The corrigendum addresses an error in the funding statement of the original article, where the funding project number was mistakenly written as RSPD2024R700 instead of RSP2024R36. The correct funding statement is provided, and the authors apologize for the error. The corrigendum emphasizes that the error does not affect the scientific conclusions of the article. [Extracted from the article]

Among many avian mycoplasmas, Mycoplasma gallisepticum (MG) and Mycoplasma synoviae (MS) are recognized as the main etiological agents of respiratory diseases and infectious synovitis in chickens and turkeys causing tremendous economic losses worldwide. Therefore, proper treatment is promoted for the control of these diseases. This study was the first in Egypt to evaluate the in vitro efficacy of various antimicrobials against field MG and MS isolates recovered from chicken and turkey flocks using both conventional broth microdilution and quantitative real-time polymerase chain reaction assays. Totally, 47 mycoplasma isolates were recovered from 160 collected tracheal samples (29.4%). Of these, 44 MG (27.5%) and 3 MS (1.9%) were identified using conventional and molecular assays. The in vitro susceptibilities of 4 representative mycoplasma field isolates (3 MG and one MS) to 8 antibiotics and 4 essential oils were investigated. The tested isolates showed various susceptibilities to tested antimicrobials. Toldin CRD, followed by clove, cumin, and cinnamon oils were effective against both MG and MS clinical isolates with minimum inhibitory concentration (MIC) values ranging from 0.49 to 15.63 µg/mL. Similarly, tylvalosin was the most active antibiotic against MG and MS isolates with the lowest MIC values (0.015 to 0.03 µg/mL). DNA loads of both MG mgc2 and MS vlhA genes were markedly decreased upon treatment with majority of the tested antimicrobials confirming their effectiveness as was also evaluated by conventional MIC results. In conclusion, Toldin CRD and tylvalosin were found to be the most effective antimicrobials in this study. This finding highlights the importance of using these antimicrobials in controlling mycoplasma infections in chickens and turkeys. [ABSTRACT FROM AUTHOR]

The increased resistance of vancomycin among methicillin resistant Staphylococcus aureus (MRSA) has produced a major formidable threat in the therapeutic field. The current study analyzed the vancomycin resistance traits among MRSA isolates recovered from 148 samples of animal and human origins in Sharkia Governorate, Egypt. All staphylococci isolates were examined against 8 antimicrobials and vancomycin minimal inhibitory concentrations (MICs) were then determined among phenotypic vancomycin resistant and intermediate S. aureus. Furthermore, all vancomycin-resistant S. aureus (VRSA) isolates were exposed to PCR analysis of mecA and van genes. Herein, 45 of 86 Staphylococcus spp. were identified as S. aureus, while 41 were coagulase negative staphylococci (CoNS). A higher incidence rate of S. aureus was observed in meat products (58.06%), but majority of CoNS isolates were isolated from milk samples (54.54%) with no statistical differences (P < 0.05) in the distribution of S. aureus and CoNS among all samples. Oxacillin and amoxicillin-clavulanic acid recorded the highest resistance percentages among S. aureus (93.33 and 88.89%) and CoNS (75.61 and 87.80%), respectively. Multidrug resistance (MDR) was detected in high proportions of S. aureus (64.4%) and CoNS (34.1%). Forty-two of 45 S. aureus isolates were MRSA, of which 14 were vancomycin resistant with MIC values ranged from 32- 1024 μg/mL. PCR detection of mecA and van genes in the tested isolates revealed that they were all mecA gene positive, while 10 out of them had van genes. The vanB gene was found in 5 isolates with higher MICs (64- 256 μg/mL), while vanA gene was detected in 4 isolates with MICs of 128-512 μg/mL and only one isolate harbored both vanA and vanB genes with MIC value of 1024 μg/mL. According to the upsurge of VRSA prevalence rates, more attentions should be oriented for continuous monitoring of antimicrobial usage with the need for effective drugs against VRSA. [ABSTRACT FROM AUTHOR]

Introduction: Pseudomonas aeruginosa (P. aeruginosa) modulates the expression of a myriad of virulence factors via two complicated hierarchical quorum-sensing (QS) cascade. This study shed light on the interrelation between P. aeruginosa QS systems and pyocyanin production. Methodology: Transcription analysis of lasR, rhlR, rhlI and phz genes using quantitative real time-reverse transcriptase PCR (qRT-PCR) assay, followed by sequencing of the autoinducer synthase (lasI gene) were applied for 15 P. aeruginosa strains recovered from diverse animal clinical sources. Results: Expression studies revealed that most P. aeruginosa strains demonstrated statistically significant differences (p < 0.05) with a very wide range of transcript levels of QS and phz genes in comparison to P. aeruginosa ATCC 27853. We have identified significant positive correlations (r = 0.3) between the expressions of QS and phz genes in eleven analyzed strains, whereas pyocyanin production positively correlated with the expression of lasR only in three strains (r = 0.6). We further found that there was a negative correlation between the transcript levels of QS and phz genes in one bacterial strain. Analysis of lasI sequences showed point mutations explaining the alterations in pyocyanin expression. The deficiencies of lasI, lasR and rhlI with rhlR-dependent expression of phz in one strain were also recorded. Conclusions: These results provided new insights to the pivotal role of QS signal molecules on pyocyanin production presenting the las system as the dominant regulator. [ABSTRACT FROM AUTHOR]

The oxidative stress facing fish during intensive production brings about diseases and mortalities that negatively influence their performance. Along with that, the increased awareness of omega-3 polyunsaturated fatty acids (omega-3-PUFAs) health benefits has been triggered the introduction of alternative additives in aqua feed that cause not only modulation in fish immune response but also fortification of their fillet. In this context, the role of microalgae mix (NSS) containing Nannochloropsis oculate and Schizochytrium and Spirulina species, which were enriched with bioactive molecules, especially EPA and DHA, was assessed on Nile tilapia's performance, fillet antioxidant stability, immune response, and disease resistance. Varying levels of NSS (0.75, 1.5, and 3%) were added to Nile tilapia's diet for 12 weeks and then a challenge of fish with virulent Aeromonas hydrophila (A. hydrophila) was carried out. Results showed that groups fed NSS, especially at higher levels, showed an improved WG and FCR, which corresponded with enhanced digestive enzymes' activities. Higher T-AOC was detected in muscle tissues of NSS 3 . 0% fed fish with remarkable reduction in ROS, H 2 O 2 , and MDA contents, which came in parallel with upregulation of GSH-Px, CAT, and SOD genes. Notably, the contents of EPA and DHA in fillet were significantly increased with increasing the NSS levels. The mean log 10 counts of pathogenic Vibrio and Staphylococcus species were reduced, and conversely, the populations of beneficial Lactobacillus and Bacillus species were increased more eminent after supplementation of NSS 3 . 0% and NSS 1 . 5% . Moreover, regulation of the immune response (lysozyme, IgM, ACH50, NO, and MPO), upregulation of IL-10 , TGF-β , and IgM , and downregulation of IL-1β , TNF-α , HSP70 ,and COX-2 were observed following dietary higher NSS levels. After challenge, reduction in A. hydrophila counts was more prominent, especially in NSS 3 . 0% supplemented group. Taken together, the current study encourages the incorporation of such microalgae mix in Nile tilapia's diet for targeting maximum performance, superior fillet quality, and protection against A. hydrophila., Competing Interests: The authors declare no conflict of interest.

Recently, the concept of incorporating natural products into nanocarriers has been intended to promote fish growth and health via modulating their stability and bioavailability. In this concern, the potential role of reformulated quercetin into nanocarriers was examined, for the first time, on Nile tilapia's performance and immunity, flesh quality and antioxidant indices and disease resistance. Five hundred fish assigned into five experimental groups with formulated diets containing quercetin nanoparticles (QT-NPs) at levels of 0, 100, 200, 300 and 400 mg/kg were challenged with Aeromonas hydrophila (A. hydrophila) after 12 weeks feeding trial. Fish final body weight gain and feed efficiency were significantly maximized in groups enriched with 300 and 400 mg/kg of QT-NPs. Significant reduction in total saturated fatty acids and an elevation in polyunsaturated fatty acids' contents were noticed in fish fed higher QT-NPs doses. The levels of Hydrogen peroxide, reactive oxygen species and malondialdehyde, the markers of meat antioxidant capacity, were reduced by higher inclusion levels of QT-NPs. Accordingly, serum activities and transcriptional levels of GSH-Px, CAT and SOD genes were increased with elevated QT-NPs levels. Immune responses mediated by upregulation of IL-10 and TGF-β and downregulation of IL-1β, IL-8 and TNF-α mRNA levels were found to be positively affected by QT-NPs. Dietary QT-NPs downregulated the expression of ahyI and ahyR quorum sensing genes conferring protection against A. hydrophila challenge. This study concluded that supplementation of quercetin in encapsulated nanoparticles could improve its efficacy making it as a compelling approach to improve fish performance and as a promising drug candidate against A. hydrophila virulence., (Copyright © 2021 Elsevier Ltd. All rights reserved.)