Expression of toll-like receptor 4 and its associated cytokines from peripheral blood mononuclear cells in Leghorn chickens.

Background and Aim: Immune cells require toll-like receptor 4 (TLR4) to respond to lipopolysaccharides (LPS) by releasing pro-inflammatory cytokines. Peripheral blood mononuclear cells (PBMCs) are used to assess changes in cytokines released in response to diseases or pathogens. This study aimed to assess TLR4 gene expression in PBMCs from Leghorn chicken and the release of related cytokines. Materials and Methods: Peripheral blood mononuclear cells were isolated from blood samples obtained from Leghorn chicks. The PBMC cultures were stimulated with various concentrations of LPS (0.01-1 µg/ml). Polymerase chain reaction was used to detect TLR4 expression. The production of tumor necrosis factor-alpha (TNF-α) and interleukins (IL-1ß and IL-6) was quantified using an enzyme-linked immunosorbent assay. Results: We found that TLR4 was expressed in both non-stimulated and stimulated Leghorn chicken PBMCs. In addition, the release of TNF-α, IL-1ß, and IL-6 levels in Leghorn chicken PBMCs increased significantly with an increase in LPS concentration (0.01-1 µg/mL) (p < 0.05). Conclusion: Although TLR4 was expressed in both non-stimulated and stimulated Leghorn chicken PBMCs, its expression was significantly higher in LPS-stimulated PBMCs Therefore, the chicken's endotoxin response can be assessed by evaluating the pro-inflammatory cytokine production from PBMCs.

Development of a microencapsulated probiotic containing Pediococcus acidilactici WU222001 against avian pathogenic Escherichia coli.

Background and Aim: Probiotics are beneficial microorganisms for humans and animals. In this study, we developed a microencapsulated probiotic with antibacterial activity against avian pathogenic Escherichia coli (APEC). Materials and Methods: Alignment of the 16S rRNA sequences of the isolate WU222001 with those deposited in GenBank revealed that the isolate was Pediococcus acidilactici with 99.6% homology. This bacterium was characterized as a probiotic based on its tolerance toward in vitro gastrointestinal tract (GIT) conditions, hydrophobicity, and auto-aggregation. The antibacterial activity of the probiotic's culture supernatant against APEC was investigated using a broth microdilution assay. Pediococcus acidilactici was microencapsulated using sodium alginate and agar with diameters ranging from 47 to 61 µm. Then, physicochemical characteristics and stability of the microcapsules were determined. Results: The isolate was characterized as a probiotic based on its resistance to low pH, bile salts, and pancreatin, with relative values of 79.2%, 70.95%, and 90.64%, respectively. Furthermore, the bacterium exhibited 79.56% auto-aggregation and 55.25% hydrophobicity at 24 h. The probiotic's culture supernatant exhibited strong antibacterial activity against clinical APEC isolates with minimum inhibitory concentration and minimum bactericidal concentration of 12.5% and 25% v/v, respectively. Microencapsulation-enhanced bacterial viability in GIT compared to free cells. Moreover, 89.65% of the encapsulated cells were released into the simulated intestinal fluid within 4 h. The viable count in microcapsules was 63.19% after 3 months of storage at 4°C. Conclusion: The results indicated that the culture supernatant of P. acidilactici inhibited the growth of APEC. In addition, microencapsulation extends the viability of P. acidilactici under harsh conditions, indicating its potential application in the feed production.

Virulence factors and quorum sensing as targets of new therapeutic options by plant-derived compounds against bacterial infections caused by human and animal pathogens.

The emergence of antibiotic-resistant bacteria and hospital-acquired bacterial infection has become rampant due to antibiotic overuse. Virulence factors are secondary to bacterial growth and are important in their pathogenesis, and therefore, new antimicrobial therapies to inhibit bacterial virulence factors are becoming important strategies against antibiotic resistance. Here, we focus on anti-virulence factors that act through anti-quorum sensing and the subsequent clearance of bacteria by antimicrobial compounds, especially active herbal extracts. These quorum sensing systems are based on toxins, biofilms, and efflux pumps, and bioactive compounds isolated from medicinal plants can treat bacterial virulence pathologies. Ideally, bacterial virulence factors are secondary growth factors of bacteria. Hence, inhibition of bacterial virulence factors could reduce bacterial pathogenesis. Furthermore, anti-virulence factors from herbal compounds can be developed as novel treatments for bacterial infection. Therefore, this narrative review aims to discuss bacterial virulence factors acting through quorum sensing systems that are preserved as targets for treating bacterial infection by plant-derived compounds.

Sangyod rice bran extract enhances Lacticaseibacillus paracasei growth during the exponential phase and antibacterial activity of L. paracasei supernatant against zoonotic and foodborne pathogens.

Background and Aim: Prebiotics are a group of nutrients or compounds that are degraded by the gut microbiota, including Lacticaseibacillus paracasei. The probiotic plays an important role in adhesion to the gut and is able to produce antimicrobial substances to inhibit pathogens. This study aimed to investigate the effects of Sangyod rice bran extract on the growth promotion of L. paracasei. Furthermore, antibacterial activity of the extract and L. paracasei supernatants cultured in De Man, Rogosa and Sharpe (MRS) medium plus the extract against zoonotic and foodborne pathogens was investigated. Materials and Methods: Antibacterial activity of the crude extract and the oil from Sangyod rice bran against the pathogens, including Bacillus cereus, Staphylococcus aureus, Escherichia coli, Avian pathogenic E. coli, and Pseudomonas aeruginosa was investigated using broth microdilution assay. The effects of the crude extract and the oil on the growth and adhesion of L. paracasei were further determined. The antibacterial activity of L. paracasei supernatant cultured in the medium supplemented with the extract and the oil against the pathogens was determined by agar well diffusion assay, followed by the broth microdilution assay. Finally, the chemical constituents and antioxidant activity of the crude extract and the oil from Sangyod rice bran were investigated. Results: The crude extract and the oil from Sangyod rice bran enhanced L. paracasei growth during the exponential phase. Furthermore, the crude extract at 0.25 mg/mL significantly enhanced the adhesion of L. paracasei to the surface compared with the control. Both minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values of the crude extract against B. cereus and S. aureus were 0.5 and 1.0 mg/mL, respectively. All pathogens were sensitive to the supernatant of L. paracasei with similar MIC and MBC ranging from 12.5% v/v to 50% v/v. However, the MIC and MBC values of L. paracasei supernatant grown in MRS medium plus the crude extract and oil were not significantly different compared to the supernatant obtained from MRS alone. The crude extract had free radical scavenging activities with IC50 values at 0.61 mg/mL. Conclusion: The results suggested the potential benefits of the crude extract from Sangyod rice bran for inducing the growth and the adhesion of L. paracasei and inhibiting zoonotic and foodborne pathogens.

Designer meat production, carcass quality, and hemato-biochemical parameters of broilers fed dietary synbiotic derived from trimmed asparagus by-products combined with probiotic supplementation.

Objective: This experiment investigated the effects of synbiotic supplementation produced from probiotics and prebiotics from trimmed asparagus by-products (TABP) on broiler chicken diets in order to yield designer meat production. Materials and Methods: A total of 320 one-day-old Ross 308® chicks were randomly allocated to dietary treatments with four replications each (n = 20). The dietary treatments were composed of a control group without supplementation and treatment groups fed with 10, 30, and 50 gm/kg of TABP supplementation in diets combined with 2 gm/kg probiotics. Results: The results showed that broilers fed dietary supplementation of TABP with 2 gm/kg had a lower level of total cholesterol and low-density lipoprotein cholesterol in the serum, which reduced the atherogenic indices of the serum, such as cardiac risk ratio and atherogenic coefficient (p < 0.05). In addition, the cholesterol content and the fatty acid profile of breast meat, including palmitic acid, oleic acid, saturated fatty acid, and omega 9 levels, also declined with the increasing levels of TABP inclusion (p < 0.05). Moreover, the supplementation of TABP in diets caused a decline in the atherogenic and thrombogenicity indices and a rise in Δ-9 desaturase (16) index and hypocholesterolemic to the hypercholesterolemic ratio of meat (p < 0.05). Conclusion: Synbiotic supplementation of up to 30 gm/kg TABP combined with 2 gm/kg probiotics in the chicken diet can potentially be utilized for the production of designer meat.

Pro-inflammatory cytokine release from chicken peripheral blood mononuclear cells stimulated with lipopolysaccharide.

Background and Aim: The principal cytokines released by the host on infection include pro-inflammatory cytokines such as interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF). These cytokines were regarded as regulators of the host's response to infection. This study aimed to determine the release of pro-inflammatory cytokines from chicken peripheral blood mononuclear cells (PBMCs) following lipopolysaccharide (LPS) stimulation. Materials and Methods: Blood samples were collected from six Betong chickens. To isolate PBMCs, density gradient centrifugation was utilized. PBMC culture in RPMI1640 with 10% fetal bovine serum was stimulated with various concentrations of LPS (0, 0.01, 0.1, and 1.0 µg/mL). The production of TNF-α, IL-1ß, and IL-6 was determined using an enzyme-linked immunosorbent assay. Results: When the PBMCs were cultured for 24 h with varying doses of LPS, there was no significant variation in cell viability. TNF-α, IL-1ß, and IL-6 levels were measured in Betong chicken PBMC. The release of these cytokines increased considerably as LPS concentration (0.01-1 µg/mL) increased (p<0.05). Conclusion: In vitro studies of the chicken immune response, notably the release of pro-inflammatory cytokines, can be conducted using PBMCs obtained from chicken blood.

Effect of trimmed asparagus by-products supplementation in broiler diets on performance, nutrients digestibility, gut ecology, and functional meat production.

Background and Aim: Trimmed asparagus by-products (TABP) is the resultant waste from asparagus possessing. TABP has fructans, such as inulins and fructooligosaccharide, which can be utilized as an alternative prebiotic. This study was conducted to examine the effect of TABP dietary supplementation on the productive performance, nutrient digestibility, gut microbiota, volatile fatty acid (VFA) content, small-intestine histology, and meat quality of broilers. Materials and Methods: A total of 320 1-day-old broiler chicks (Ross 308®) were raised under ambient temperature and assigned through a completely randomized design to one of four dietary treatments, with four replicates per treatment. The dietary treatments comprised corn-soybean basal diet supplemented with 0 (control), 10, 30, or 50 g/kg TABP. All birds were provided drinking water and feed ad libitum to meet the standard nutritional requirements of National Research Council for broiler chickens. Results: TABP supplementation to the broilers significantly increased the apparent ether extract, crude fiber, and gross energy digestibility (p<0.05). TABP supplementation significantly increased lactic bacteria and Enterococcus spp. numbers as well as acetic, propionic, butyric, and total VFA levels (p<0.01); on the other hand, it also significantly decreased Salmonella spp. and Escherichia coli contents in the cecum compared with the control group (p<0.01). Moreover, TABP supplementation increased villus height in the duodenum and jejunum (p<0.01), cryptal depth in the jejunum and ileum (p<0.01), and villus surface areas in the duodenum, jejunum, and ileum (p<0.01). Overall, 0-35 day TABP supplementation significantly increased the feed intake (p<0.01) and average daily gain of broilers (p<0.05), but not significantly affected the viability, productive index, and economic benefit return (p>0.05). The carcass characteristics, pH, color, and water holding capacity of the chicken meat between groups were not significantly different (p>0.05). All levels of TABP supplementation appeared to be a feasible means of producing broilers with the lower serum low-density lipoprotein cholesterol and triglyceride levels as well as atherogenic indices of serum compared with the control (p<0.05). Cholesterol contents and palmitic acid, oleic acid, saturated fatty acids, and Monounsaturated fatty acids levels decreased with an increase of TABP supplementation (p<0.05). Furthermore, TABP supplementation decreased atherogenic index (AI) and thrombogenicity index (TI) of meat (p<0.05). Conclusion: Supplementation of 30 g/kg TABP in broiler diet could enhance broiler performance and provide chicken meat with beneficial properties, with decreased AI and TI resulted from altered cholesterol and fatty acid profiles.

Antibacterial, antibiofilm, and anti-adhesion activities of Piper betle leaf extract against Avian pathogenic Escherichia coli.

Piper betle leaves have traditionally been used to treat many diseases, including bacterial infections. The present study aimed to investigate the antibacterial, antibiofilm, and anti-adhesion activities of P. betle extract against avian pathogenic Escherichia coli (APEC). The ethanol extract of P. betle leaves demonstrated strong antibacterial activity against clinical isolates of APEC with MIC and MBC values ranging from 0.5 to 1.0 mg/mL as compared with 1% DMSO, a negative control. Disruption and breakdown of the bacterial cells were detected when the cells were challenged with the extract at 2 × MIC. Bacterial cells treated with the extract demonstrated longer cells without a septum, compared to the control. The extract at 1/8, 1/4, and 1/2 × MIC significantly inhibited the formation of the bacterial biofilm of all the tested isolates except the isolate CH10 (P < 0.05) without inhibiting growth. At 1/2 × MIC, 55% of the biofilm inhibition was detected in APEC CH09, a strong biofilm producer. At 32 × MIC, 88% of the inhibition of viable cells embedded in the mature biofilm was detected in APEC CH09. Reduction in the bacterial adhesion to surfaces was shown when APEC were treated with sub-MICs of the extract as observed by SEM. Hydroxychavicol was found to be the major compound presented in the leaf extract as detected by GC-MS analysis. The information suggested potential medicinal benefits of P. betle extract to inhibit the growth, biofilm, and adhesion of avian pathogenic E. coli.

Assessment of chicken peripheral blood mononuclear cells isolated from freshly drawn blood versus 24 h refrigerated blood.

BACKGROUND AND AIM: The peripheral blood mononuclear cell (PBMC) is an excellent cell source for in vitro studies, particularly those involving immunology. The aim of this study was to determine the quality and quantity of chicken PBMCs isolated from freshly drawn blood as well as blood that had been chilled for 24 h. In addition, the survival of PBMCs cultured in medium was investigated. MATERIALS AND METHODS: Blood samples were collected from 12 Betong and 12 Leghorn chickens. Hemograms were analyzed. Density gradient centrifugation was used to isolate PBMCs. PBMCs (2×106 cells/mL) were cultured in a culture medium and incubated in a CO2 incubator for 5 consecutive days. The number of viable cells was determined using the trypan blue dye exclusion method. RESULTS: Blood samples were obtained from healthy chickens. There was no statistically significant difference in the total amount of PBMC between fresh and refrigerated blood samples from both chicken breeds. The viability of PBMCs isolated from fresh blood (95%) was significantly greater than blood refrigerated for 24 h (90-92%) in both breeds. Furthermore, the viability of PBMCs isolated from both blood samples decreased significantly over time, from 90-95% to 60-65%. CONCLUSION: The total number of PBMC in fresh and refrigerated blood was not significantly different. Fresh blood-derived PBMCs had significantly higher viability than 24 h refrigerated blood PBMCs. Furthermore, the viability of PBMCs decreased significantly over time.

Analysis of culling reasons during the breeding cycle and lifetime performance: The strategy to remove crossbred Landrace and Large White sows under tropical climate.

BACKGROUND AND AIM: Sow culling is an important practice in commercial swine production because it is directly associated with the economic efficiency of the breeding herd. This study was conducted to analyze the reasons for sow culling and quantify the factors affecting culling in crossbred Landrace and Large White sows under tropical climate. MATERIALS AND METHODS: A total of 4887 culled sows from one parent stock farm located in Ratchaburi province, Western Thailand, were examined in this study. Culling reasons were grouped into the following eight categories according to farm management: (1) Reproductive disorders, (2) old age, (3) low performance, (4) diseases, (5) lameness, (6) udder problems, (7) body condition, and (8) other illnesses. Logistic regression analysis was used to explore the relationship between culling sows and environmental factors. Effects of parity and season of culling were considered as fixed effects in a statistical model. RESULTS: Descriptive statistics indicated the following factors accounting for sow removals: Old age (34.93%, n=1707), reproductive disorders (29.32%, n=1433), low performance (12.62%, n=617), lameness (12.56%, n=614), diseases (4.8%, n=235), body condition (4.68%, n=229), udder problems (0.79%, n=39), and other illnesses (0.26%, n=13). Parity and season of culling were also found to have a significant effect on sow culling (p<0.05). The majority of culling sows in this population were of old age and high parity. CONCLUSION: This study indicated that the purposeful culling of sows on this farm was within the targeted range. However, the incidence of reproductive disorders was too high and required further investigations.