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1.
Sci Rep ; 14(1): 11747, 2024 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-38778119

RESUMEN

In winter, the paddy residues become wet during morning and late evening due to dew, which restricts the operation of sowing machines (Happy Seeder and Super Seeder) into paddy residues, as wet residues do not slide on furrow openers/tines. A PAU Smart Seeder (PSS) was developed and evaluated for a four-wheel tractor that can sow wheat with optimum crop establishment in combined harvested rice fields. The PSS were evaluated for its performance under varying straw load, forward speed, and rotor speed in terms of fuel consumption, field capacity, seed emergence, and grain yield. The crop establishment and wheat yield of PSS was also compared with the existing straw management machines Happy Seeder (HS) and Super Seeder (SS) under heavy paddy residue conditions. The effect of the straw load was more pronounced on dependent variables than the effect of the speed index. PSS performance was best at a forward speed of 2.6 km h-1, rotor speed of 127.5 rpm, and a straw load of 6 t ha-1. Average fuel consumption using PSS was lower than SS but higher than HS. Wheat emergence was higher by 15.6 and 25.7% on the PSS plots compared to HS and SS, respectively. Average wheat grain yield in PSS plots was significantly higher by 12.7 and 18.9% than SS and HS, respectively in one experiment, while the grain yield was similar for both PSS and HS in other experiments. PSS has a novel mechanism to manage paddy straw and simultaneously sow wheat into a heavy straw load (> 8 t ha-1) mixture of anchored and loose straw. In conclusion, PSS showed promise for in-situ management of rice straw as it eliminates most of the operational problems encountered by the existing seeders (HS and SS).


Asunto(s)
Oryza , Semillas , Triticum , Oryza/crecimiento & desarrollo , India , Triticum/crecimiento & desarrollo , Semillas/crecimiento & desarrollo , Agricultura/métodos , Grano Comestible , Productos Agrícolas/crecimiento & desarrollo , Producción de Cultivos/métodos
2.
Cerebellum ; 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38769243

RESUMEN

Cerebellum is a key-structure for the modulation of motor, cognitive, social and affective functions, contributing to automatic behaviours through interactions with the cerebral cortex, basal ganglia and spinal cord. The predictive mechanisms used by the cerebellum cover not only sensorimotor functions but also reward-related tasks. Cerebellar circuits appear to encode temporal difference error and reward prediction error. From a chemical standpoint, cerebellar catecholamines modulate the rate of cerebellar-based cognitive learning, and mediate cerebellar contributions during complex behaviours. Reward processing and its associated emotions are tuned by the cerebellum which operates as a controller of adaptive homeostatic processes based on interoceptive and exteroceptive inputs. Lobules VI-VII/areas of the vermis are candidate regions for the cortico-subcortical signaling pathways associated with loss aversion and reward sensitivity, together with other nodes of the limbic circuitry. There is growing evidence that the cerebellum works as a hub of regional dysconnectivity across all mood states and that mental disorders involve the cerebellar circuitry, including mood and addiction disorders, and impaired eating behaviors where the cerebellum might be involved in longer time scales of prediction as compared to motor operations. Cerebellar patients exhibit aberrant social behaviour, showing aberrant impulsivity/compulsivity. The cerebellum is a master-piece of reward mechanisms, together with the striatum, ventral tegmental area (VTA) and prefrontal cortex (PFC). Critically, studies on reward processing reinforce our view that a fundamental role of the cerebellum is to construct internal models, perform predictions on the impact of future behaviour and compare what is predicted and what actually occurs.

3.
Chem Commun (Camb) ; 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38770580

RESUMEN

Metal-organic frameworks (MOFs) integrated with molecular qubits are promising for quantum sensing. In this study, a new UiO-type MOF with a 5,12-diazatetracene (DAT)-containing ligand is synthesized, and the radicals generated in the MOF exhibit high stability and a relatively long coherence time (T2) responsive to the introduction of various guest molecules.

5.
Poult Sci ; 103(7): 103806, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38749104

RESUMEN

Transfer of Salmonella to internal organs of broilers over a 35 d grow-out period was evaluated. A total of 360 one-day old chicks were placed in 18 floor pens of 3 groups with 6 replicate pens each. On d 0, broilers were orally challenged with a cocktail of Salmonella (equal population of marked serovars; nalidixic acid-resistant S. Typhimurium, rifampicin-resistant S. Infantis, and kanamycin-resistant S. Reading) to have 3 groups: L (low; ∼2 log CFU/bird); M (medium; ∼5 log CFU/bird); and H (High; ∼8 log CFU/bird). On d 2, 7 and 35, 4 birds/pen were euthanized and ceca, liver, and spleen samples were collected aseptically. Gizzard samples (4/pen) were collected on d 35. The concentration of Salmonella in liver and spleen were transformed to binary outcomes (positive and negative) and fitted in glm function of R using cecal Salmonella concentrations (log CFU/g) and inoculation doses (L, M, and H) as inputs. On d 2, H group showed greater (P ≤ 0.05) cecal colonization of all 3 serovars compared to L and M groups. However, M group showed greater (P ≤ 0.05) colonization of all 3 serovars in the liver and spleen compared to L group. Salmonella colonization increased linearly in the ceca and quadratically in the liver and spleen with increasing challenge dose (P ≤ 0.05). On d 35, L group had greater (P ≤ 0.05) S. Infantis colonization in the ceca and liver compared to M and H groups (P ≤ 0.05). Moreover, within each group on d 35, the concentration of S. Reading was greater than those of S. Typhimurium and S. Infantis for all 3 doses in the ceca and high dose in the liver and gizzard (P ≤ 0.05). Salmonella colonization diminished in the ceca, liver, and spleen during grow-out from d 0 to d 35 (P ≤ 0.05). On d 35, birds challenged with different doses of Salmonella cocktail showed a similar total Salmonella spp. population in the ceca (ca. 3.14 log CFU/g), liver (ca. 0.54 log CFU/g), spleen (ca. 0.31 log CFU/g), and gizzard (ca. 0.42 log CFU/g). Estimates from the fitted logistic model showed that one log CFU/g increase in cecal Salmonella concentration will result in an increase in relative risk of liver and spleen being Salmonella-positive by 4.02 and 3.40 times (P ≤ 0.01), respectively. Broilers from H or M group had a lower risk (28 and 23%) of being Salmonella-positive in the liver compared to the L group when the cecal Salmonella concentration is the same (P ≤ 0.05). Oral challenge of broilers with Salmonella spp. with various doses resulted in linear or quadratic increases in Salmonella colonization in the internal organs during early age and these populations decreased during grow-out (d 35). This research can provide guidance on practices to effectively mitigate the risk of Salmonella from chicken parts and enhance public health.

6.
Phys Chem Chem Phys ; 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38804505

RESUMEN

The micellization of choline-based anionic surface-active ionic liquids (SAILs) having lauroyl sarcosinate [Sar]-, dodecylsulfate [DS]-, and deoxycholate [Doc]- as counter-ions was investigated in an aqueous medium. Density functional theory (DFT) was employed to investigate the net interactional energy (Enet), extent of non-covalent interactions, and band gap of the choline-based SAILs. The critical micelle concentration (cmc) along with various parameters related to the surface adsorption, counter-ion binding (ß), and polarity of the cores of the micelles were deduced employing surface tension measurements, conductometric titrations and fluorescence spectroscopy, respectively. A dynamic light scattering (DLS) system equipped with zeta-potential measurement set-up and small-angle neutron scattering (SANS) were used to predict the size, zeta-potential, and morphology, respectively, of the formed micelles. Thermodynamic parameters such as standard Gibb's free energy and standard enthalpy change of micellization were calculated using isothermal titration calorimetry (ITC). Upon comparing with sodium salt analogues, it was established that the micellization was predominantly governed by the extent of hydration of [Cho]+, the head groups of the respective anions, and the degree of counter-ion binding (ß). Considering the concentration dependence of the enzyme-SAIL interactions, aqueous solutions of the synthesized SAILs at two different concentrations (below and above the cmc) were utilized as the medium for testing the enzymatic activity of cellulase. The activity of cellulase was found to be ∼7- to ∼13-fold higher compared to that observed in buffers in monomeric solutions of the SAILs and followed the order: [Cho][Sar] > [Cho][DS] > [Cho][Doc]. In the micellar solution, a ∼4- to 5-fold increase in enzymatic activity was observed.

7.
Indian J Ophthalmol ; 72(6): 844-848, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38804801

RESUMEN

PURPOSE: To find a correlation between the clinical (vision-inflammation-strabismus-appearance [VISA] score) and radiological (apparent diffusion coefficient [ADC] values) scores for evaluating disease activity in patients with thyroid-associated orbitopathy. DESIGN: A prospective comparative study. METHODS: Our study was performed for consecutively diagnosed thyroid-associated orbitopathy (TAO) patients. Clinical evaluation included the VISA classification system with the basic thyroid workup. An inflammatory score of <4/8 was considered inactive and ≥4/8 as an active disease. Every included patient underwent a diffusion-weighted magnetic resonance imaging (DW-MRI) scan of the orbits. The orbital parameters evaluated on imaging included the proptosis, thickness, as well as the ADC values of extraocular muscles. RESULTS: We studied 33 consecutive patients (23 females, 69.7%) with a mean age of 41.8 years. The majority (n = 27, 81.8%) were hyperthyroid, four were hypothyroid, and two were euthyroid. In the VISA classification, nine patients had active TAO (≥4/8 inflammation score), while 24 had inactive disease. There was a positive correlation between the inflammation score and ADC values of medial rectus (MR), inferior rectus (IR) and lateral rectus (LR). We had nine patients with inflammation scores ≥4. With receiver operating characteristic (ROC) curve analysis, we found that the ADC value of IR can predict disease activity with 68% sensitivity and MR-ADC can predict active TAO with 87% sensitivity. CONCLUSION: The ADC parameters of DW-MRI are objective and less operator dependent than the clinical TAO activity scores like VISA classification. A randomized control trial may provide robust data on this correlation.


Asunto(s)
Oftalmopatía de Graves , Músculos Oculomotores , Órbita , Humanos , Oftalmopatía de Graves/diagnóstico , Femenino , Estudios Prospectivos , Masculino , Adulto , Persona de Mediana Edad , Músculos Oculomotores/diagnóstico por imagen , Músculos Oculomotores/fisiopatología , Órbita/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética/métodos , Adulto Joven , Estudios de Seguimiento , Anciano , Índice de Severidad de la Enfermedad
8.
Indian J Ophthalmol ; 72(6): 849-855, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38804802

RESUMEN

PURPOSE: To study the outcomes of balloon dacryoplasty (BD) or (BDCP) in children with persistent congenital nasolacrimal duct obstruction (pCNLDO) by using new and reused balloon catheters. METHODS: Our retrospective analysis focused on managing pCNLDO by using the BD or BDCP technique. The study included children aged >1 year to <12 years who underwent single or multiple probings before. Our specific lacrimal workup included a detailed history and examination, as published earlier. We used conventional, straight, 2 mm × 13 mm/3 mm × 15 mm lacrimal balloons (FCI, Ophthacath). We have described a technique to use the same catheter for three BD procedures (1 new + 2 reuse). The outcomes were categorized as complete success, partial success, and failure. The minimum follow-up of each child was 6 months. RESULTS: We analyzed 64 children (89 eyes) with a mean age of 58 months (15-132 months). All children (100%) had epiphora with discharge and positive FDDT. All children underwent BD under general anesthesia - new balloons in 59 eyes and reused balloons in 30 eyes. The balloons were plasma sterilized akin to vitrectomy cutters and tubings of phaco machines. We noted three leaks from reused balloons (2 from the balloon tip and 1 from the plastic hub). At a mean follow-up of 14.5 months, complete success was noted in 77 eyes (86.5%) (52 new and 25 reuse), while 8 eyes had partial success (8.9%) (4 new and 4 reuse). Failure of BD was noted in four eyes (4.5%) (3 new and 1 reuse). None had significant complications with new or reused balloons. CONCLUSION: BD or BDCP is a quick, safe, easy, and effective procedure that resolves pCNLDO symptoms satisfactorily. Carefully reusing a conventional balloon catheter is possible with comparable efficacy and no additional complications in pCNLDO.


Asunto(s)
Dacriocistorrinostomía , Obstrucción del Conducto Lagrimal , Conducto Nasolagrimal , Humanos , Obstrucción del Conducto Lagrimal/congénito , Obstrucción del Conducto Lagrimal/terapia , Obstrucción del Conducto Lagrimal/diagnóstico , Estudios Retrospectivos , Dacriocistorrinostomía/métodos , Conducto Nasolagrimal/cirugía , Masculino , Femenino , Lactante , Preescolar , Niño , Estudios de Seguimiento , Cateterismo/métodos , Cateterismo/instrumentación , Resultado del Tratamiento , Diseño de Equipo
9.
Digit J Ophthalmol ; 30(1): 11-14, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38601899

RESUMEN

Cavernous hemangioma, currently known as "cavernous venous malformation," is a common, benign, non-infiltrative, slowly progressive vascular malformation of the orbit presenting in adults. We report the case of a 9-year-old girl who presented with a painless palpable mass over the right upper eyelid of 7 years' duration. A computed tomography scan of the orbits revealed a heterogeneously enhancing, well-circumscribed mass in the right upper eyelid with no orbital extension. A transcutaneous excisional biopsy with histopathology disclosed cavernous venous malformation. The majority of cavernous venous malformations are intraconal and present in the fourth to fifth decade of life.


Asunto(s)
Hemangioma Cavernoso , Neoplasias Orbitales , Malformaciones Vasculares , Adulto , Femenino , Humanos , Niño , Neoplasias Orbitales/patología , Hemangioma Cavernoso/diagnóstico , Hemangioma Cavernoso/cirugía , Hemangioma Cavernoso/patología , Órbita/patología , Malformaciones Vasculares/diagnóstico , Párpados/patología
10.
J Clin Child Adolesc Psychol ; 53(2): 309-327, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38588602

RESUMEN

Recognition of the importance of irritable mood and outbursts has been increasing over the past several decades. This "Future Directions" aims to develop a set of recommendations for future research emphasizing that irritable mood and outbursts "hang together," but have important distinctions and thus also need to "hang separately." Outbursts that are the outcome of irritable mood may be quite different from outbursts that are the trigger or driving force that make youth and his/her environment miserable. What, then, is the relation between irritable mood and outbursts? As the field currently stands, we not only cannot answer this question, but we may also lack the tools to effectively do so. Here, we will propose recommendations for understanding the phenomenology of irritable mood and outbursts so that more directed and clinically useful assessment tools can be designed. We discuss the transdiagnostic and treatment implications that relate to improvements in measurement. We describe the need to do more than repurpose our current assessment tools, specifically interviews and rating scales, which were designed for different purposes. The future directions of the study and treatment of irritable mood and outbursts will require, among others, using universally accepted nomenclature, supporting the development of tools to measure the characteristics of each irritable mood and outbursts, understanding the effects of question order, informant, development and longitudinal course, and studying the ways in which outbursts and irritable mood respond to treatment.


Asunto(s)
Genio Irritable , Humanos , Adolescente
11.
Biol Trace Elem Res ; 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38619677

RESUMEN

Silicon (Si), a newer trace element, is believed to be important for healthy bone formation and to decrease bone resorption, improving the quality of bone by manipulating several hormones and enzymes. Therefore, the current investigation was conducted to determine the impact of Si supplementation on growth, immunity, antioxidant, hormonal profile and biomarkers of bone health in pre-ruminant crossbred calves. Twenty-four crossbred calves (5-7 days) were selected on the basis of their body weight (BW 31.65 ± 0.46 kg) and divided into 4 groups (n = 6) and fed as per ICAR (2013) feeding standards except that these were additionally supplemented with 0 (Si0), 50 (Si50), 100 (Si100) and 150 (Si150) mg of Si/kg dry matter (DM) in four respective groups for 90 days. Every month, peripheral blood samples were drawn (0, 30, 60 and 90 days post supplementing with Si) and analysed for antioxidant status, hormonal profile and bone health biomarkers. It is reported that dietary Si supplementation improved (P < 0.05) net body weight gain (kg), average daily gain (g) and average dry matter intake (kg), whereas feed intake (kg/100 kg BW), was not altered due to Si supplementation. Structural growth measurements were significantly higher (P < 0.05) in Si100 and Si150 groups as compared to Si50 and control groups. However, immune response (humoral as well as cell-mediated immunity), erythrocytic antioxidant enzymes (superoxide dismutase, SOD, glutathione peroxidase, GPx and catalase), plasma ferric reducing total antioxidant power (FRAP) activity and the plasma concentration of total immunoglobulins (TIg) remained unaffected by Si supplementation. Silicon increased (P < 0.05) the concentration of plasma growth hormone (GH), vitamin D3, bone alkaline phosphatase (BALP) and osteocalcin (OCN) in Si100 and Si150 groups, but the levels of calcitonin, parathyroid hormone (PTH) and hydroxyproline (HYP) remained similar among all the groups. As a result of the current investigation, it can be inferred that the inclusion of 100 and 150 mg of Si/kg DM was effective in improving the growth performance, growth hormone, vitamin D3 and bone health status in pre-ruminant calves. However, supplementation of 150 mg of Si/kg DM had no additional benefit; therefore 100 mg of Si/kg DM is the optimum level of Si supplementation in pre-ruminant calves.

13.
Innov Clin Neurosci ; 21(1-3): 52-60, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38495603

RESUMEN

The 1983 Orphan Drug Act in the United States (US) changed the landscape for development of therapeutics for rare or orphan diseases, which collectively affect approximately 300 million people worldwide, half of whom are children. The act has undoubtedly accelerated drug development for orphan diseases, with over 6,400 orphan drug applications submitted to the US Food and Drug Administration (FDA) from 1983 to 2023, including 350 drugs approved for over 420 indications. Drug development in this population is a global and collaborative endeavor. This position paper of the International Society for Central Nervous System Clinical Trials and Methodology (ISCTM) describes some potential best practices for the involvement of key stakeholder feedback in the drug development process. Stakeholders include advocacy groups, patients and caregivers with lived experience, public and private research institutions (including academia and pharmaceutical companies), treating clinicians, and funders (including the government and independent foundations). The authors articulate the challenges of drug development in orphan diseases and propose methods to address them. Challenges range from the poor understanding of disease history to development of endpoints, targets, and clinical trials designs, to finding solutions to competing research priorities by involved parties.

14.
Chem Asian J ; 19(8): e202400033, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38403870

RESUMEN

The work presented in the manuscript describes a simple strategy for transforming thermally activated delayed fluorescent organic light-emitting diodes (TADF OLEDs) compound 10-(dibenzo[a,c]phenazin-11-yl)-10H-phenoxazine (DPZ-PXZ) into type I photosensitizer 10-(dibenzo[a,c]phenazin-11-yl)-10H-phenothiazine (DPZ-PHZ) by strategically introducing sulfur atom in the photosensitizing core. The synthesized compound DPZ-PHZ exhibits aggregation-induced enhancement (AIE) and through-space charge transfer (TSCT) characteristics and generates red emissive assemblies in mixed aqueous media. The original compound DPZ-PXZ exhibits well-separated HOMO and LUMO levels and is reported to have highly efficient reverse intersystem crossing (RISC). In comparison, the incorporation of sulfur atom in the phenothiazine donor regulates the electronic communication between donor and acceptor units and promotes the intersystem crossing (ISC) in DPZ-PHZ molecules. Interestingly, compound DPZ-PHZ exhibits rapid activation of aerial oxygen for instant generation of superoxide radical anion. Backed by excellent type I photosensitizing activity, DPZ-PHZ assemblies have high catalytic potential for the synthesis of benzimidazoles, benzothiazoles and quinazolines derivatives under mild reaction conditions. The work presented in the manuscript provides an insight into the combination of heavy atom approach and TSCT for achieving adequate electronic communication between donor and acceptor units, balanced RISC/ISC, and stabilized-charge separated state for the development of efficient type I photosensitizing assemblies.

15.
Poult Sci ; 103(4): 103492, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38335673

RESUMEN

Salmonella and Campylobacter are common bacterial hazards causing foodborne illnesses worldwide. A large proportion of Salmonella and Campylobacter illnesses are attributed to contaminated poultry products that are mishandled or under cooked. Processing interventions such as chilling and post-chill dip are critical to reducing microbial contamination of poultry. A comprehensive search of the literature published between 2000 and 2021 was conducted in the databases Web of Science, Academic Search Complete, and Academic OneFile. Studies were included if they were in English and investigated the effects of interventions against Salmonella and/or Campylobacter on whole carcasses and/or parts during the chilling or post-chill stages of poultry processing. Random-effects meta-analyses were performed using the "meta" package in the R programming language. Subgroup analyses were assessed according to outcome measure reported, microorganism tested, processing stage assessed, and chemical treatment used. The results included 41 eligible studies. Eighteen studies reported results of 28 separate interventions against Salmonella and 31 reported results of 50 separate interventions against Campylobacter. No significant difference (P> 0.05) was observed when comparing the combined mean difference of all interventions targeting Salmonella to the combined mean difference of all interventions targeting Campylobacter or when comparing chilling times within each pathogen subgroup. For analyses examining antimicrobial additives, peroxyacetic acid (PAA) had the largest reduction against Salmonella population regardless of chilling time (P< 0.05). PAA also had the largest reduction against Campylobacter population and prevalence during primary chilling (P< 0.01). Air chilling showed a lower reduction for Campylobacter than any immersion chilling intervention (P< 0.05). Chilling time and antimicrobial used during poultry processing had varying effects depending on the pathogen and outcome measure investigated (concentration or prevalence). High heterogeneity and low sample numbers in most analyses suggest that more high-quality research that is well-designed and has transparent reporting of methodology and results is needed to corroborate the results.


Asunto(s)
Antiinfecciosos , Campylobacter , Animales , Aves de Corral , Carne/microbiología , Microbiología de Alimentos , Pollos/microbiología , Manipulación de Alimentos/métodos , Salmonella , Antiinfecciosos/farmacología , Ácido Peracético/farmacología
16.
Front Psychol ; 15: 1293943, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38362251

RESUMEN

Introduction: Flourishing is an evolving wellbeing construct and outcome of interest across the social and biological sciences. Despite some conceptual advancements, there remains limited consensus on how to measure flourishing, as well as how to distinguish it from closely related wellbeing constructs, such as thriving and life satisfaction. This paper aims to provide an overview and comparison of the diverse scales that have been developed to measure flourishing among adolescent and adult populations to provide recommendations for future studies seeking to use flourishing as an outcome in social and biological research. Methods: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), we conducted a scoping review across PubMed and EMBASE of studies introducing original flourishing scales (defined as a previously unpublished measure of mental health or wellbeing that used "flourishing" in its definition). Studies focusing on adult populations that were published before April 28, 2023 were considered eligible for inclusion. Results: Out of 781 studies retrieved, we identified seven eligible studies covering seven unique flourishing scales. We find that all seven scales are multidimensional and assess features over monthly or yearly intervals. While most of the scales (six out of seven) include indicators of both hedonic and eudaimonic wellbeing, the operationalization of these dimensions of wellbeing varies considerably between scales. Several of the scales have been translated and validated across multiple geographical contexts, including higher- and lower-income countries. Discussion: Complementing self-report measures with other social, economic, regional, and biological indicators of flourishing may be useful to provide holistic and widely applicable measures of wellbeing. This review contributes to concept validation efforts that can guide strategies to sustain flourishing societies.

20.
J Food Prot ; 87(3): 100238, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38331218

RESUMEN

Campylobacter is a leading cause of enteric disease worldwide. No antibiotics ever (NAE) poultry has become increasingly popular, yet little is known about the incidence and antimicrobial resistance (AMR) of Campylobacter in this production system. This study was conducted to determine the prevalence, concentration, and AMR of Campylobacter in conventional (CV) and NAE-raised broilers. Two CV and two NAE commercial broiler flocks were included in this study. Cecum (n = 420) and ileum (n = 420) of chickens were collected at different stages during the broiler grow-out phase and following transportation to the processing plant. Samples of litter (n = 24), feed (n = 24), and water (n = 24) were also collected. Screening for Campylobacter was conducted using real-time PCR assay, and enumeration was performed by direct plating on Campy Cefex agar. Campylobacter isolates were confirmed by real-time PCR, and antimicrobial susceptibility was evaluated following the National Antimicrobial Resistance Monitoring System (NARMS) methods. Whole Genome Sequencing (WGS) was used to identify AMR genes carried by the resistant isolates. Campylobacter prevalence reached 100% within the first 3 weeks of summer production under both NAE and CV rearing. A lower Campylobacter prevalence was detected in conventionally raised broilers during fall (P ≤ 0.05), yet no change in prevalence was observed in NAE birds (P > 0.05). Populations were high in the cecum, carrying an average of 6.6 Log10 CFU/g after transportation, and antimicrobial-resistant Campylobacter was isolated from CV broilers during the fall. Three isolates (1.2%), identified as C. coli, carrying the gyrA and tet(O) genes, exhibited simultaneous resistance to ciprofloxacin, tetracycline, and nalidixic acid. Results from this study can help identify important shifts in gut microbial community dynamics and Campylobacter prevalence associated with antibiotic administration within commercial poultry operations.


Asunto(s)
Infecciones por Campylobacter , Campylobacter jejuni , Campylobacter , Animales , Antibacterianos/farmacología , Pollos , Prevalencia , Granjas , Farmacorresistencia Bacteriana , Aves de Corral , Infecciones por Campylobacter/epidemiología , Infecciones por Campylobacter/veterinaria , Pruebas de Sensibilidad Microbiana
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