Epinephrine and norepinephrine regulate the expression of virulence factors in Gallibacterium anatis.

Gallibacterium anatis is a member of the Pasteurellaceae family and is an opportunistic pathogen that causes gallibacteriosis in chickens. Stress plays a relevant role in promoting the development of pathogenicity in G. anatis. Epinephrine (E) and norepinephrine (NE) are relevant to stress; however, their effects on G. anatis have not been elucidated. In this work, we evaluated the effects of E and NE on the growth, biofilm formation, expression of adhesins, and proteases of two G. anatis strains, namely, the hemolytic 12656-12 and the nonhemolytic F149T biovars. E (10 µM/mL) and NE (30 and 50 µM/mL) increased the growth of G. anatis 12656-12 by 20 % and 25 %, respectively. E did not affect the growth of F149T, whereas 40 µM/mL NE decreased bacterial growth by 25 %. E and NE at a dose of 30-50 µM/mL upregulated five fibrinogen adhesins in the 12565-12 strain, whereas no effect was observed in the F149T strain. NE increased proteolytic activity in both strains, whereas E diminished proteolytic activity in the 12656-12 strain. E and NE reduced biofilm formation (30 %) and increased Congo red binding (15 %) in both strains. QseBC is the E and NE two-component detection system most common in bacteria. The qseC gene, which is the E and NE receptor in bacteria, was identified in the genomic DNA of the 12565-12 and F149TG. anatis strains via PCR amplification. Our results suggest that QseC can detect host changes in E and NE concentrations and that catecholamines can modulate the expression of several virulence factors in G. anatis.

Combination of Live and Inactivated Salmonella Vaccines to Protect Against Fowl Typhoid in Laying Hens.

Fowl typhoid (FT) caused by Salmonella Gallinarum (SG) is a poultry disease distributed worldwide that has been eradicated in commercial production of many developed countries but still persists in many developing countries. Vaccination is one of the main strategies to reduce mortality, clinical signs, and vertical or horizontal transmission. The aim of this work was to assess the protection against FT conferred by vaccines based on Salmonella Enteritidis (SE), SG, or a combination. Five experimental groups of birds, vaccinated with different live or inactivated SG and SE vaccines were included in the trial: 1) two doses of a SG-SE bivalent inactivated vaccine; 2) four doses of the live attenuated SE vaccine; 3) three doses of the live attenuated SE vaccine and two doses of the SG-SE bivalent inactivated vaccine; 4) two doses of the live attenuated SG9R vaccine; and 5) unvaccinated birds. At 28 wk of age, all hens were challenged with a virulent strain of SG, and mortality was recorded during the subsequent 15 days. The results showed that the plan that included only the inactivated vaccine did not show significant protection (P = 1), while the plan based on the administration of the attenuated strain of SE significantly reduced mortality in the group of birds (P = 0.0309). However, the highest levels of protection were obtained in the group of hens immunized with the combination of the inactivated vaccine and the live attenuated SE strain (P < 0.0001), which was statistically similar to the homologous protection conferred by the SG 9R strain, a vaccine used in many countries to control FT. These results demonstrate that the combination of existing vaccines together with strict biosecurity measures on farms may help improve the control of the pathogen in countries where FT in an emerging or reemerging disease.

Nota de investigación- Combinación de vacunas vivas e inactivadas contra Salmonella para proteger contra la tifoidea aviar en gallinas de postura. La tifoidea aviar (FT) causada por Salmonella enterica serotipo Gallinarum biovar Gallinarum (SG) es una enfermedad distribuida en todo el mundo que ha sido erradicada de la producción av'icola comercial de muchos pa'ises desarrollados pero que aún persiste en muchos pa'ises en desarrollo. La vacunación es una de las principales estrategias para reducir la mortalidad, los signos cl'inicos y la transmisión vertical u horizontal. El objetivo de este trabajo fue evaluar la protección contra la tifoidea aviar conferida por vacunas elaboradas con Salmonella enterica serotipo Enteritidis (SE), SG o una combinación de ellas. Se incluyeron en el ensayo cinco grupos experimentales de aves, vacunadas con diferentes vacunas de SG y SE vivas o inactivadas: 1) dos dosis de una vacuna bivalente inactivada de SG y SE; 2) cuatro dosis de la vacuna SE viva atenuada; 3) tres dosis de vacuna SE viva atenuada y dos dosis de vacuna bivalente inactivada SG y SE; 4) dos dosis de la vacuna SG 9R viva atenuada; y 5) aves no vacunadas. A las 28 semanas de edad, todas las gallinas fueron expuestas a una cepa virulenta de SG y se registró la mortalidad durante los 15 d'ias siguientes. Los resultados mostraron que el plan que inclu'ia solo la vacuna inactivada no mostró protección significativa (P=1), mientras que el plan basado en la administración de la cepa atenuada de S. Enteritidis redujo significativamente la mortalidad en el grupo de aves (P = 0,0309). Sin embargo, los mayores niveles de protección se obtuvieron en el grupo de gallinas inmunizadas con la combinación de la vacuna inactivada y la cepa viva atenuada de SE (P < 0,0001), la cual fue estad'isticamente similar a la protección homóloga conferida por la cepa de SG 9R, que es una vacuna utilizada en muchos pa'ises para controlar la tifoidea aviar. Estos resultados demuestran que la combinación de las vacunas existentes junto con estrictas medidas de bioseguridad en las granjas puede ayudar a mejorar el control del patógeno en pa'ises donde la tifoidea aviar es una enfermedad emergente o reemergente.

Cocirculation of Newcastle Disease Virus Genotypes XII and VII Along with Nonvirulent Forms Characterized in Domestic Birds from Peru.

Newcastle disease virus (NDV) is one of the most important pathogens affecting poultry, given its impact on health and production systems worldwide, despite widespread vaccination. Over the past 20 years, NDV has caused severe outbreaks of disease in Peru. These outbreaks primarily affected gamecocks and broiler chickens, with an additional reported case in commercial layers. Therefore, our objective was to identify and characterize the virus responsible for these cases in Peru. We analyzed 14 suspected clinical cases in domestic birds for NDV detection, isolation, and genetic characterization. Among these cases, seven involved gamecocks, with six genotype XII isolates and one genotype VII isolate, representing the first report of NDV genotype VII isolate from fighting roosters in Peru. Additionally, among the six cases in broiler chickens, we detected four genotype XII isolates and three genotype II isolates, including one sample containing both genotypes XII and II. Furthermore, a genotype I viral isolate was identified in a laying hen. Hence, we concluded that two divergent, highly virulent NDV genotypes, genotypes XII and VII, along with avirulent forms such as genotypes I and II are circulating among domestic birds in Peru. Genetic analysis indicates that these viruses are evolving locally within avian species and offers the basis necessary for vaccine adaptation to circulating viruses. Our results highlight the cocirculation of multiple virulent and nonvirulent NDV genotypes in domestic birds in Peru, underscoring the potential role of gamecocks as a viral source of virulent NDV strains in the country and the occurrence of outbreaks in poultry farms.

Cocirculación de los genotipos XII y VII del virus de la enfermedad de Newcastle junto con formas no virulentas caracterizadas en aves domésticas del Perú. El virus de la enfermedad de Newcastle (NDV) es uno de los patógenos más importantes que afectan a la avicultura, dado su impacto en la salud y los sistemas de producción en todo el mundo, a pesar de la vacunación generalizada. Durante los últimos 20 años, el virus de la enfermedad de Newcastle ha causado graves brotes de enfermedades en el Perú. Estos brotes afectaron principalmente a gallos de pelea y pollos de engorde, con un caso adicional reportado en aves de postura comerciales. Por lo tanto, nuestro objetivo fue identificar y caracterizar el virus responsable de estos casos en el Perú. Se analizaron 14 casos cl'inicos sospechosos en aves domésticas para la detección, aislamiento y caracterización genética del virus de Newcastle. Entre estos casos, siete involucraron gallos de pelea, con seis aislamientos del genotipo XII y un aislado del genotipo VII, lo que representa el primer informe de aislamiento del genotipo VII del virus de Newcastle de gallos de pelea en Perú. Además, entre los seis casos en pollos de engorde, se detectaron cuatro aislados del genotipo XII y tres aislados del genotipo II, incluida una muestra que con-ten'ia ambos genotipos XII y II. Además, se identificó un aislado viral de genotipo I en una gallina de postura. Por lo tanto, se concluye que dos genotipos divergentes y altamente virulentos del virus de Newcastle, los genotipos XII y VII, junto con formas avirulentas como los genotipos I y II, están circulando entre las aves domésticas en el Perú. El análisis genético indica que estos virus están evolucionando localmente dentro de las especies aviares y ofrece las bases necesarias para realizar adaptaciones de las vacunas contra los virus circulantes. Nuestros resultados resaltan la cocirculación de múltiples genotipos del virus de Newcastle virulentos y no virulentos en aves domésticas en Perú, subrayando el papel potencial de los gallos de pelea como fuente viral de cepas virulentas del virus de Newcastle en el pa'is y la aparición de brotes en granjas av'icolas.

Transmission of dominant strains of Campylobacter jejuni and Campylobacter coli between farms and retail stores in Ecuador: Genetic diversity and antimicrobial resistance.

Thermotolerant Campylobacter is an important zoonotic pathogen known for causing gastroenteritis in humans, with poultry as its primary reservoir. A total of 468 samples were collected, of which 335 were chicken carcass samples (representing the food component), and 133 were chicken caeca samples (representing the animal component). These samples underwent culture, with colonies examined under a microscope. Species identification was achieved through multiplex PCR. Additionally, antimicrobial susceptibility profiles were determined using the Kirby-Bauer method, testing for sensitivity to gentamicin, ciprofloxacin, tetracycline, and erythromycin. Additionally, 55 C. jejuni (62.5%) and 33 C. coli (37.5%) isolates were selected for whole genome sequencing (WGS). A High prevalence of Campylobacter was observed, with rates of 95.5% (n = 127, CI95%: 92.5% - 98.5%) in the animal component and 72.5% (n = 243, CI95%: 69.9% - 75.1%) in the food component. Specifically, C. jejuni was detected in 33.1% (n = 42) of poultry farms and 38.3% (n = 93) of chicken carcasses, while C. coli was found in 64.6% (n = 82) of poultry farms and 60.5% (n = 147) of chicken carcasses. Antimicrobials with the highest rates of resistance (67%-100%) were ciprofloxacin and tetracycline, in both animal and food component isolates. Erythromycin resistance was notable, ranging from 22% to 33%, with only two C. jejuni isolates from retail were resistant to gentamicin. Furthermore, multidrug resistance was identified in 23% (20 isolates) of the Campylobacter isolates. Genetic analysis revealed the presence of fourteen resistance genes in both C. jejuni and C. coli isolates, including tet(O), blaOXA-460, blaOXA-184, blaOXA-489, blaOXA-193, blaOXA-784, blaOXA-603, aph(3')-IIIa, aad9, aph(2'')-If, aadE-Cc, sat4, and ant(6)-Ia. Additionally, twenty-five plasmids were detected in the 88 Campylobacter isolates examined. Interestingly, most isolates also harbored genes encoding putative virulence factors associated with pathogenicity, invasion, adherence, and production of cytolethal distending toxin (cdt): cheV, cheA, cheW, cheY, flaA, flgR, flaC, flaD, flgB, flgC, ciaB, ciaC. The WGS analysis showed the presence of several cgSTs in both animal and food components, with nine of them widely disseminated between components. Moreover, C. coli and C. jejuni isolates from different sources presented less than 11 single nucleotide polymorphisms (SNPs), suggesting clonality (16 isolates). Further analysis using SNP tree demonstrated widespread distribution of certain C. jejuni and C. coli clones across multiple farms and retail stores. This study presents, for the first-time, insights into the clonality, plasmid diversity, virulence, and antimicrobial resistance (AMR) of thermotolerant Campylobacter strains originating from the Ecuadorian poultry industry. The identification of AMR genes associated with the main antibiotics used in the treatment of campylobacteriosis in humans, highlights the importance of the prudent use of antimicrobials in the poultry industry. Additionally, this research remarks the need for regional studies to understand the epidemiology of this pathogen.

Impact of increased pre-start diet density on broiler chick behavior, corticosterone levels, and performance responses under cold stress during early life.

This study assessed the effects of increased pre-start diet density on the metabolism, crop filling, and overall performance of broilers under cold stress during their initial 14 days of life. Using 576 one-day-old Cobb500 male chicks from 27-week-old breeders, the experiment employed a 2 × 2 arrangement, varying thermal conditions (thermoneutrality or cold stress at 18 °C for 8 h) and pre-start diet composition (21.5% crude protein, 2970 kcal/kg or 22.5%, 3050 kcal/kg). The cold stress group exhibited lower cloacal temperature and decreased crop filling rate during the first two days (P < 0.05). Chick behavior was significantly affected at 1 and 5 days (P < 0.05), and corticosterone levels in serum were higher for the cold stress group at 7 days (P < 0.05). Feed intake at 7 days was lower in the high-density feed group (P < 0.05). No significant interactions were observed for feed intake, body weight gain, or feed conversion ratio at 7 and 35 days (P > 0.05). Cold stress resulted in performance losses, impacting feed conversion and the Productive Efficiency Index. The dense diet influenced performance only within the first week, with subsequent diets showing no effect, suggesting dietary manipulation alone was insufficient to mitigate cold stress-induced losses.

Molecular and Evolutionary Characteristics of Chicken Parvovirus (ChPV) Genomes Detected in Chickens with Runting-Stunting Syndrome.

Chicken Parvovirus (ChPV) belongs to the genus Aveparvovirus and is implicated in enteric diseases like runting-stunting syndrome (RSS) in poultry. In RSS, chicken health is affected by diarrhea, depression, and increased mortality, causing significant economic losses in the poultry industry. This study aimed to characterize the ChPV genomes detected in chickens with RSS through a metagenomic approach and compare the molecular and evolutionary characteristics within the Aveparvovirus galliform1 species. The intestinal content of broiler flocks affected with RSS was submitted to viral metagenomics. The assembled prevalent genomes were identified as ChPV after sequence and phylogenetic analysis, which consistently clustered separately from Turkey Parvovirus (TuPV). The strain USP-574-A presented signs of genomic recombination. The selective pressure analysis indicated that most of the coding genes in A. galliform1 are evolving under diversifying (negative) selection. Protein modeling of ChPV and TuPV viral capsids identified high conservancy over the VP2 region. The prediction of epitopes identified several co-localized antigenic peptides from ChPV and TuPV, especially for T-cell epitopes, highlighting the immunological significance of these sites. However, most of these peptides presented host-specific variability, obeying an adaptive scenario. The results of this study show the evolutionary path of ChPV and TuPV, which are influenced by diversifying events such as genomic recombination and selective pressure, as well as by adaptation processes, and their subsequent immunological impact.

Detection and Molecular Characterization of GI-1 and GI-23 Avian Infectious Bronchitis Virus in Broilers Indicate the Emergence of New Genotypes in Bolivia.

Infectious Bronchitis Virus (IBV) is a major threat to the poultry industry worldwide, causing significant economic losses. While the virus's genetic structure is well understood, the specific strains circulating in Bolivia have remained uncharacterized until now. This study aimed to identify and characterize new IBV strains in Bolivia. Tissue samples from broilers exhibiting clinical signs of Infectious Bronchitis were screened to detect IBV using real-time RT-PCR (RT-qPCR). Positive samples with low cycle threshold (Ct) values were selected for sequencing the full S1 gene. Of the 12 samples analyzed, 10 were determined to be positive for IBV. However, only four samples yielded sufficient genetic material for sequencing and subsequent phylogenetic analysis. The results revealed the presence of GI-1 and GI-23 lineages, both belonging to genotype I (GI). The GI-1 lineage showed >99% sequence identity to the H120 and Massachusetts vaccine strains, suggesting a close relationship. In contrast, the GI-23 lineage clustered with other IBV strains, showing a distinct subclade that is genetically distant from Brazilian strains. No evidence of recombination was found. Furthermore, amino acid substitution analysis identified specific mutations in the S1 subunit, particularly in the hypervariable regions 1, 2, and 3. These mutations could potentially alter the virus's antigenicity, leading to reduced vaccine efficacy. The findings of this study highlight the importance of continued and broad genomic surveillance of circulating IBV strains and the need to improve vaccination strategies in Bolivia.

Lysosomes accumulate at the perinuclear region of muscle cells during chick myogenesis.

Lysosomes are involved in a myriad of cellular functions, such as degradation of macromolecules, endocytosis and exocytosis, modulation of several signaling pathways, and regulation of cell metabolism. To fulfill these diverse functions, lysosomes can undergo several dynamic changes in their content, size, pH, and location within cells. Here, we studied some of these parameters during embryonic chick skeletal muscle cells. We used an anti-lysosome-associated membrane protein 2 (LAMP2) antibody to specifically determine the intracellular localization of lysosomes in these cells. Our data shows that lysosomes are highly enriched in the perinuclear region of chick embryonic muscle cells. We also showed that the wingless signaling pathway (Wnt)/ß-catenin signaling pathway can modulate the location of LAMP2 in chick myogenic cells. Our results highlight the role of lysosomes during muscle differentiation and particularly the presence of a subcellular population of lysosomes that are concentrated in the perinuclear region of muscle cells.

Turmeric essential oil improves intestinal integrity, immunological parameters, and performance of broiler chickens under cyclic heat stress.

This study aimed to examine whether dietary supplementation of broiler chickens with turmeric essential could mitigate the effects of cyclic heat stress conditions. Intestinal and immunological parameters and gene expression were evaluated during the grower phase. A total of 320 21-day-old male Cobb 500 broilers were distributed according to a completely randomized design with a 4 (diet) × 2 (environment) factorial arrangement and eight replications of five birds each. Dietary treatments consisted of a basal diet without essential oil (EO, negative control) and three diets containing low (100 mg kg-1), intermediate (200 mg kg-1), or high (300 mg kg-1) levels of turmeric EO. In the heat stress group, dietary supplementation with turmeric EO at 100 and 200 mg kg-1 improved body weight, feed conversion, breast yield, and relative liver weight. These supplementation levels reduced villus width, increased villus/crypt ratio, reduced the H/L ratio, and improved hepatic (HSP70 and SREBP1) and intestinal (OCLN) gene expression in birds under heat stress. These findings support the hypothesis that turmeric EO can be used to improve or restore intestinal integrity, modulate inflammation parameters, and, consequently, enhance the performance of broilers challenged by cyclic heat stress.

Polymelia and concurrent intestinal duplication and cloacal atresia in a broiler chick: case report and literature review.

Congenital malformations are a highly diverse group of conditions reported in both humans and animals, characterized by defects in morphogenesis observed at birth. Although most cases are idiopathic, genetic and environmental factors may be involved. The frequency of such conditions varies with species, geographic regions, and the specific malformation involved. In polymelia, supernumerary limbs are attached to different parts of the body. Gastrointestinal duplications are described less frequently and can be associated with polymelia. Cloacal atresia is among the least-reported malformations in avian species, described only once in a kiwi. Here we describe a case with these 3 malformations in a single broiler chick (Gallus gallus domesticus) and provide a literature review about the occurrence of these malformations in birds. The 3-d-old chick also had an unidentified structure projecting from the pygostyle region. We performed clinical, radiographic, and postmortem examinations. The intestinal duplication was identified only during the postmortem evaluation. Detailed descriptions of avian congenital malformations are scarce. Although similar cases have been reported, we retrieved no cases of concurrent polymelia, intestinal duplication, and cloacal atresia in broiler chickens in our literature search, suggesting that the simultaneous occurrence of these conditions has not been reported previously in this species.

Clostridium perfringens antigens and challenges for development of vaccines against necrotic enteritis in poultry.

INTRODUCTION: Chickens with Necrotic Enteritis (NE), caused by Clostridium perfringens, exhibit acute and chronic symptoms that are difficult to diagnose, leading to significant economic losses. Vaccination is the best method for controlling and preventing NE. However, only two vaccines based on the CPA and NetB toxins have been commercialized, offering partial protection, highlighting the urgent need for more effective vaccines. OBJECTIVE: This review aimed to identify promising antigens for NE vaccine formulation and discuss factors affecting their effectiveness. METHODS: A systematic review using five scientific databases identified 30 eligible studies through the Rayyan tool, which were included for quality review. RESULTS: We identified 25 promising antigens, including CPA, NetB, FBA, ZMP, CnaA, FimA, and FimB, categorized by their role in disease pathogenesis. This review discusses the biochemical, physiological, and genetic traits of recombinant antigens used in vaccine prototypes, their expression systems, and immunization potential in chickens challenged with virulent C. perfringens strains. Market supply challenges, immunogenic potential, vaccine platforms, adjuvants, and factors related to vaccination schedules-such as administration routes, dosing intervals, and age at immunization-are also addressed. Additionally, the study notes that vaccine formulations tested under mild challenges may not offer adequate field-level protection due to issues replicating aggressive conditions, strain virulence loss, and varied methodologies. CONCLUSIONS: An ideal NE vaccine should incorporate multiple antigens, molecular adjuvants, and delivery systems via in ovo and oral routes. The review underscores the challenges in developing and validating NE vaccines and the urgent need for a standardized protocol to replicate aggressive challenges accurately.

Multidrug-resistant Escherichia coli isolated from free-range chickens in the Caatinga biome.

Antimicrobial-resistant Escherichia coli is a global health challenge from a One Health perspective. However, data on its emergence in the Caatinga biome are limited. This biome is exclusive to the Brazilian Northeast and offers unique epidemiological conditions that can influence the occurrence of infectious diseases and antimicrobial resistance. In this study, the carriage proportion, antimicrobial susceptibility, and population structure of cephalosporin-resistant E. coli were assessed in 300 cloacal swab samples of free-range chickens from three Brazilian states covered by the Caatinga biome. The results showed that 44 (14.7%) samples were positive for cephalosporin-resistant E. coli, and Paraíba state had the highest frequency of isolates (68.2%). Genes encoding cephotaximase-Munich or ampicillin class C (AmpC) enzymes were identified in 30 (68.2%) and 8 (18.2%) isolates, respectively, comprising 31 E. coli isolates. Overall, molecular typing by genome restriction using XbaI endonuclease followed by pulsed-field gel electrophoresis revealed four clusters from two properties of Paraíba state composed by extended-spectrum ß-lactamase-producing and AmpC-producing E. coli carrying blaCTX-M-1-like and blaMIR-1/ACT-1 genes and belonging to different phylogenetic groups. There is a need to control antimicrobial resistance while taking into account the genetic diversity of the strains and their implications for animal and public health, especially in free-range chickens reared in the Brazilian Caatinga biome.

Simultaneous analysis of antimicrobial residues and contaminants in poultry droppings by HPLC-MS/MS: a tool for environmental and food safety monitoring.

Animal waste is a potential pollution hazard as it can harbour contaminants, such as antimicrobial residues, mycotoxins, and pesticides, becoming a risk to the public, animal, and environmental health. To assess this risk, 15 experimental broiler chickens orally received contaminants to evaluate excretion levels. An analytical method was previously developed to detect 18 substances in poultry droppings using high-performance liquid chromatography coupled to a tandem mass spectrometer (HPLC-MS/MS). Contaminants including tetracycline, 4-epi-tetracycline, oxytetracycline, 4-epi-oxytetracycline, chlortetracycline, 4-epi-chlortetracycline, tylosin, erythromycin, enrofloxacin, ciprofloxacin, flumequine, florfenicol, sulfachloropyridazine, sulfadiazine, 2,4-dichlorophenoxyacetic acid, zearalenone, alpha- and beta-zearalenol, were extracted with EDTA-McIlvain and acetonitrile. This method showed a p-value < 0.05, RSD < 25%, and R2 > 0.95 in the calibration curves linearity for all analytes. The limit of quantification, selectivity, decision limit for confirmation, matrix effect, precision, and recovery parameters were validated according to European Union document 2021/808/EC, technical report CEN/TR 16059, SANTE/11813/2017 and according to the Veterinary International Conference on Harmonization: VICH GL2 and GL49. This method confirmed the detection of most analytes 12-36 h post-administration and simultaneously detected and quantified mixed contaminants. Thereby, poultry droppings are a potential matrix for spreading contaminants in animal production before slaughter and their control will minimize environmental impacts and mitigate antimicrobial resistance.

Insights into the global genomic features of Salmonella enterica serovar Gallinarum biovars Gallinarum and Pullorum.

AIMS: Characterize global genomic features of 86 genomes of Salmonella Gallinarum (SG) and Pullorum (SP), which are important pathogens causing systemic infections in poultry. METHODS AND RESULTS: All genomes harbored efflux pump encoding gene mdsA and gold tolerance genes golS and golT. Aminoglycoside (aac(6')-Ib, aadA5, aph(6)-Id, aph(3'')-Ib, ant(2'')-Ia), beta-lactam (blaTEM-1, blaTEM-135), efflux pump (mdsB), fosfomycin (fosA3), sulfonamide (sul1, sul2), tetracycline [tet(A)], trimethoprim (dfrA17), acid (asr), and disinfectant (qacEdelta1) resistance genes, gyrA, gyrB, and parC quinolone resistance point mutations, and mercury tolerance genes (mer) were found in different frequencies. Additionally, 310 virulence genes, pathogenicity islands (including SPI-1, 2, 3, 4, 5, 6, 9, 10, 12, 13, and 14), plasmids [IncFII(S), ColpVC, IncX1, IncN, IncX2, and IncC], and prophages (Fels-2, ST104, 500465-1, pro483, Gifsy-2, 103 203_sal5, Fels-1, RE-2010, vB_SenS-Ent2, and L-413C) were detected. MLST showed biovar-specific sequence types, and core genome MLST showed country-specific and global-related clusters. CONCLUSION: SG and SP global strains carry many virulence factors and important antimicrobial resistance genes. The diverse plasmids and prophages suggest genetic variability. MLST and cgMLST differentiated biovars and showed profiles occurring locally or worldwide.

Comprehensive dynamics of bacterial and fungal diversity throughout concentrated chicken broth processing: Integrating culture-dependent and independent techniques.

This study presents comprehensive insights into the microbiological profile across all concentrated chicken broth processing stages, utilizing a combination of amplicon sequencing based on metataxonomic and culturing techniques. Samples were systematically collected throughout the production chain, with each batch yielding 10 samples per day across eight different dates. These samples underwent thorough analysis, including 16S rRNA and ITS sequencing (n = 30), culture-dependent microbiological tests (n = 40), and physical-chemical characterization (n = 10). Culturing analysis revealed the absence of Listeria monocytogenes and Salmonella spp. at any stage of processing, counts of various microorganisms such as molds, yeasts, Enterobacteria, and others remained below detection limits. Notably, spore counts of selected bacterial groups were observed post-processing, indicating the persistence of certain species, including Bacillus cereus and Clostridium perfringens, albeit in low counts. Furthermore, the study identified a diverse array of bacterial and fungal species throughout the processing chain, with notable occurrence of spore-forming bacteria. The presence of spore-forming bacteria in the final product, despite thermal processing, suggests the need for enhanced strategies to mitigate their introduction and persistence in the processing premises. Thus, this study offers valuable insights into microbial dynamics and diversity through processing concentrated chicken broth.

Deletions of ttrA and pduA genes in Salmonella enterica affect survival within chicken-derived HD-11 macrophages.

In mammals, enteric salmonellas can use tetrathionate (ttr), formed as a by-product from the inflammatory process in the intestine, as electron acceptor in anaerobic respiration, and it can fuel its energy metabolism by degrading the microbial fermentation product 1,2-propanediol. However, recent studies have shown that this mechanism is not important for Salmonella infection in the intestine of poultry, while it prolongs the persistence of Salmonella at systemic sites in this species. In the current study, we show that ΔttrApduA strains of Salmonella enterica have lower net survival within chicken-derived HD-11 macrophages, as CFU was only 2.3% (S. Enteritidis ΔttrApduA), 2.3% (S. Heidelberg ΔttrApduA), and 3.0% (S. Typhimurium ΔttrApduA) compared to wild-type strains after 24 h inside HD-11 macrophage cells. The difference was not related to increased lysis of macrophages, and deletion of ttrA and pduA did not impair the ability of the strains to grow anaerobically. Further studies are indicated to determine the reason why Salmonella ΔttrApduA strains survive less well inside macrophage cell lines.

Effect of arginine, glycine + serine concentrations, and guanidinoacetic acid supplementation in vegetable-based diets for chickens.

The study investigated guanidinoacetic acid (GAA) supplementation with varying dietary digestible arginine (Arg) and glycine+serine (Gly+Ser) concentrations in the starter phase, exploring respective carry-over effects on growth performance, blood chemistry, incidence of pectoral myopathies and proximate composition in broilers. A total of 2,800 one-day-old male broiler chicks were distributed in a central composite design with 2 factors and double experimental mesh, represented by supplementation or omission of 0.6 g per kg of GAA, with a central point represented by 107% of Arg and 147% of Gly+Ser, 4 factorial points (combinations of Arg/Gly+Ser concentrations: 96.4/132.5%; 117.6/132.5%; 96.4/161.5%, and 117.6/132.5%), and 4 axial points (combinations of axial points estimated for Arg and Gly+Ser, with the central points of 92/147%; 122/147%; 107/126.5, and 107/167.5%), totaling 18 treatments, 4 repetitions to factorial and axial points, 24 replicates to the central point, and 25 birds per pen. Feed conversion ratio (FCR) from d 1 to 10 had a linear response (P = 0.009) for the decreasing Arg content and a quadratic response (P = 0.047) for Gly+Ser concentrations. Broilers supplemented GAA had lower FCR compared with nonsupplemented groups from d 1 to 10 (P = 0.048) and d 1 to 42 (P = 0.026). Aspartate aminotransferase (AST) exhibited increasing and decreasing linear effects as a function of Arg (P = 0.008) and Gly+Ser (P = 0.020) concentrations, respectively. Guanidinoacetic acid decreased serum AST (P = 0.028). Guanidinoacetic acid reduced moderate + severe (P = 0.039) and mild (P = 0.015) Wooden Breast scores. The occurrence of normal White Striping increased (P = 0.002), while severe score was reduced (P = 0.029) with GAA supplementation. In conclusion, increased digestible Arg:Lys and 14% and 6% above the recommendations (107% and 147%), respectively, provided improved FCR during the starter phase. Dietary GAA supplementation (0.6 g per kg) improved FCR, reduced severity of breast myopathies and appears to have reduced muscle damage in broilers fed plant-based diets.

Quadruplex qPCR for detection and discrimination of C. Coli,C. fetus, and C. Jejuni from other Campylobacter species in chicken and sheep meat.

Campylobacter is gram-negative bacteria considered the predominant genera isolated from poultry samples and associated with gastroenteritis. Due to the problems in conventional cultural methods of time-consuming and technically demanding requirements, a rapid and feasible method for their identification and discrimination of the closely related spp. Including Campylobacter coli, Campylobacter fetus, and Campylobacter jejuni is needed. This study analyzes the chicken and sheep meats samples (n = 125) using culture and pre-enrichment-based Quadraplex real-time PCR by targeting OrfA, CstA, HipO, and 16 S rRNA genes of C. coli, C. fetus, C. jejuni and Campylobacter spp. Respectively. The analysis of 125 chicken and sheep meat samples by culture and real-time PCR showed high concordance between the results of the two methods. The present study show high prevalence of Campylobacter species (35% and 32% from chicken and meat respectively) of which C. jejuni were the most abundant. Reaction efficiencies were between 90 and 110%, and detect as low as 8.9 fg in C. jejuni. The need for quick detection and discrimination methods in sheep and chicken meat can be met using the described Quadraplex real-time PCR methodology.

Effects of a mixed additive based on Saccharomyces cerevisiae and Lactobacillus rhamnosus on broilers exposed to aflatoxin B1 by contaminated feed.

The objective of the present study was to explore the influence of dietary supplementation with a mixed additive (MA) containing a probiotic and anti-mycotoxin (Saccharomyces cerevisiae RC016 and Lactobacillus rhamnosus RC007) and its interaction on the performance and health (biochemistry and liver/intestine histopathology) of broilers fed diets contaminated with aflatoxin B1 (AFB1) at 506000±22.1ng/kg. The MA contained S. cerevisiae RC016 (1×107cells/g) and L. rhamnosus RC007 (1×108cells/g) in relation 1:1. A total of sixty-one-day-old Cobb broilers were randomly allocated into four treatment groups with three replicates of 5 birds each for a five-week-old feeding experiment. The experimental diet for each treatment (T) was formulated as follows: T1, a commercial diet (CD); T2, CD+AFB1; T3, CD+0.1% MA; T4, CD+AFB1+0.1% MA. The MA improved (p<0.01) production parameters (weight gain, conversion rate, and carcass yield) and reduced (p<0.01) the toxic effect of AFB1 on the relative weight of the livers. In addition, the macro and microscopic alterations of livers and the possible intestinal injury related to histological damage in the presence of mycotoxin were reduced. The use of probiotic MA based on S. cerevisiae RC016 and L. rhamnosus RC007 in animal feed provides greater protection against mycotoxin contamination and is safe for use as a supplement in animal feed, providing beneficial effects that improve animal health and productivity. This is of great importance at the economic level for the avian production system.

Advancing Neurosurgical Skills: A Comparative Study of Training Models for Intra-Extracranial Cerebral Bypass.

BACKGROUND: Training in anastomosis is fundamental in neurosurgery due to the precision and dexterity required. Biological models, although realistic, present limitations such as availability, ethical concerns, and the risk of biological contamination. Synthetic models, on the other hand, offer durability and standardized conditions, although they sometimes lack anatomical realism. This study aims to evaluate and compare the efficiency of anastomosis training models in the intra-extracranial cerebral bypass procedure, identifying those characteristics that enhance optimal microsurgical skill development and participant experience. METHODS: A neurosurgery workshop was held from March 2024 to June 2024 with 5 vascular techniques and the participation of 22 surgeons. The models tested were the human placenta, the Wistar rat, the chicken wing artery, the nasogastric feeding tube, and the UpSurgeOn Mycro simulator. The scales used to measure these models were the Main Characteristics Score and the Evaluation Score. These scores allowed us to measure, qualitatively and quantitatively, durability, anatomical similarity, variety of simulation scenarios, risk of biological contamination, ethical considerations and disadvantages with specific infrastructure. RESULTS: The human placenta model, Wistar rat model, and UpSurgeOn model were identified as the most effective for training. The human placenta and Wistar rat models were highly regarded for anatomical realism, while the UpSurgeOn model excelled in durability and advanced simulation scenarios. Ethical and cost implications were also considered. CONCLUSIONS: The study identifies the human placenta and UpSurgeOn models as optimal for training in intra-extracranial bypass procedures, emphasizing the need for diverse and effective training models in neurosurgery.