The effectiveness of endolysin ENDO-1252 from Salmonella bacteriophage-1252 against nontyphoidal Salmonella enterica.

Salmonella enterica (S. enterica) is the most common food and waterborne pathogen worldwide. The growing trend of antibiotic-resistant S. enterica poses severe healthcare threats. As an alternative antimicrobial agent, bacteriophage-encoded endolysins (endolysin) are a potential agent in controlling S. enterica infection. Endolysins are enzymes that particularly target the peptidoglycan layer of bacterial cells, leading to their rupture and destruction. However, the application of bacteriophage-encoded endolysin against Gram-negative bacteria is limited due to the presence of the outer membrane in the cell wall, which hinders the permeation of externally applied endolysins. This study aimed the prokaryotic expression system to produce the recombinant endolysin ENDO-1252, encoded by the Salmonella bacteriophage-1252 associated with S. Enteritidis. Subsequently, ENDO-1252 had strong lytic activity not only against S. Enteritidis but also against S. Typhimurium. In addition, ENDO-1252 showed optimal thermostability and lytic activity at 25°C with a pH of 7.0. In combination with 0.1 mM EDTA, the effect of 120 µg of ENDO-1252 for 6 hours exhibited the highest lytic activity, resulting in a reduction of 1.15 log or 92.87% on S. Enteritidis. These findings suggest that ENDO-1252 can be used as a potential and innovative antibacterial agent for controlling the growth of S. Enteritidis.

AMPs as Host-Directed Immunomodulatory Agents against Skin Infections Caused by Opportunistic Bacterial Pathogens.

Skin is the primary and largest protective organ of the human body. It produces a number of highly evolved arsenal of factors to counter the continuous assault of foreign materials and pathogens from the environment. One such potent factor is the repertoire of Antimicrobial Peptides (AMPs) that not only directly destroys invading pathogens, but also optimally modulate the immune functions of the body to counter the establishment and spread of infections. The canonical direct antimicrobial functions of these AMPs have been in focus for a long time to design principles for enhanced therapeutics, especially against the multi-drug resistant pathogens. However, in recent times the immunomodulatory functions performed by these peptides at sub-microbicidal concentrations have been a point of major focus in the field of host-directed therapeutics. Such strategies have the added benefit of not having the pathogens develop resistance against the immunomodulatory pathways, since the pathogens exploit these signaling pathways to obtain and survive within the host. Thus, this review summarizes the potent immunomodulatory effect of these AMPs on, specifically, the different host immune cells with the view of providing a platform of information that might help in designing studies to exploit and formulate effective host-directed adjunct therapeutic strategies that would synergies with drug regimens to counter the current diversity of drug-resistant skin opportunistic pathogens.

Post-translational modification-dependent oligomerization switch in regulation of global transcription and DNA damage repair during genotoxic stress.

Mechanisms of functional cross-talk between global transcriptional repression and efficient DNA damage repair during genotoxic stress are poorly known. In this study, using human AF9 as representative of Super Elongation Complex (SEC) components, we delineate detailed mechanisms of these processes. Mechanistically, we describe that Poly-Serine domain-mediated oligomerization is pre-requisite for AF9 YEATS domain-mediated TFIID interaction-dependent SEC recruitment at the promoter-proximal region for release of paused RNA polymerase II. Interestingly, during genotoxic stress, CaMKII-mediated phosphorylation-dependent nuclear export of AF9-specific deacetylase HDAC5 enhances concomitant PCAF-mediated acetylation of K339 residue. This causes monomerization of AF9 and reduces TFIID interaction for transcriptional downregulation. Furthermore, the K339 acetylation-dependent enhanced AF9-DNA-PKc interaction leads to phosphorylation at S395 residue which reduces AF9-SEC interaction resulting in transcriptional downregulation and efficient repair of DNA damage. After repair, nuclear re-entry of HDAC5 reduces AF9 acetylation and restores its TFIID and SEC interaction to restart transcription.

Plant-Derived Phenolic Acids Limit the Pathogenesis of Salmonella Typhimurium and Protect Intestinal Epithelial Cells during Their Interactions.

The incidence of gastrointestinal illness attributable to Salmonella enterica serovar Typhimurium (ST) remains a concern for public health worldwide, as it can progress into systemic infections mediated by the type-three secretion system (T3SS), which allows for adherence and invasion to intestinal epithelial cells. The current study evaluates the ability of gallic acid (GA), protocatechuic acid (PA), and vanillic acid (VA) to impair the adhesion and invasion abilities of ST to a human epithelial (INT-407) cell monolayer while also assessing their cytotoxicity. GA, PA, and VA inhibited detectable ST growth at specific concentrations but showed cytotoxicity against INT-407 cells (>20% reduction in viability) after 3 h of treatments. Adjusting the pH of the solutions had a neutralizing effect on cytotoxicity, though it did reduce their antimicrobial potency. Adhesion of ST was reduced significantly when the cells were treated with 4.0 mg/mL of VA, whereas invasion was reduced in all treatments, with GA requiring the lowest concentration (0.5 mg/mL). Relative gene expression of virulence genes after treatment with GA showed downregulation in the T3SS regulator and effector hilA and sipA, respectively. These findings suggest further use of phenolic acids in reducing the activity of key virulence factors critical during ST infection.

Effects of Metabolites of Lactobacillus casei on Expression and Neutralization of Shiga Toxin by Enterohemorrhagic Escherichia coli.

Shiga toxin (stx), produced by enterohemorrhagic Escherichia coli (EHEC) or Shigella, causes hemolytic uremic syndrome (HUS) in humans. EHEC-mediated illnesses are recommended to treat by immune supportive strategies, instead of antibiotic therapy. Widely used probiotic Lactobacillus casei produces many bioactive metabolites, i.e., conjugated linoleic acids (CLAs) which have potential to educate host immunity and control EHEC growth and expression of its virulence genes. In this study, it was found that total metabolites of L. casei exerted a protective effect on Gb3 receptor containing mammalian cells against stx exposure.

Basic techniques associated with studying transcription elongation both in vitro and in vivo within mammalian cells.

All cellular functions and identity of every cell are directly or indirectly depend on its gene expression. Therefore, cells control their gene expression very finely at multiple layers. Cells always fine tune its gene expression profile depending on the internal and external cues to maintain best possible cellular growth condition. Regulation of mRNA production is a major step in the control of gene expression. mRNA production primarily depends on two factors. One is the level of RNA polymerase II (Pol II hereafter) recruitment at the promoter region and another is the amount of Pol II successfully elongating through the whole gene body also known as coding region. There are several proteins (individually or as part of a complex) which control elongation of Pol II both positively or negatively. It is important to understand how different transcription factors regulate this elongation step since this knowledge is important for understanding different cellular functions both under basal and stimulus-dependent contexts. Here, we have discussed both in vitro and in vivo techniques which can be used to study the effect of different factors on Pol II-mediated transcription elongation. In vitro techniques give us valuable information about the ability of a transcription factor or a complex to exert its direct effect on the overall processes. In vivo techniques give us an understanding about the effect of a transcription factor or a complex in its native condition where functions of a transcription factor can be influenced by many other factors including its associated ones.

Space-dependent intermittent feedback can control birhythmicity.

Birhythmicity is evident in many nonlinear systems, which include physical and biological systems. In some living systems, birhythmicity is necessary for response to the varying environment while unnecessary in some physical systems as it limits their efficiency. Therefore, its control is an important area of research. This paper proposes a space-dependent intermittent control scheme capable of controlling birhythmicity in various dynamical systems. We apply the proposed control scheme in five nonlinear systems from diverse branches of natural science and demonstrate that the scheme is efficient enough to control the birhythmic oscillations in all the systems. We derive the analytical condition for controlling birhythmicity by applying harmonic decomposition and energy balance methods in a birhythmic van der Pol oscillator. Further, the efficacy of the control scheme is investigated through numerical and bifurcation analyses in a wide parameter space. Since the proposed control scheme is general and efficient, it may be employed to control birhythmicity in several dynamical systems.

Retromaxillary Cell: Radiological Analysis and Clinical Significance.

Retromaxillary cell (RMC), one of the anatomical variations of the posterior ethmoidal cell and is often overlooked during primary functional endoscopic sinus surgery. The incomplete removal of the disease from RMC leads to need for revision surgery. This study was aimed at analyzing Computed tomography scans of patients' paranasal sinuses for the incidence, types and radiological evaluation of Retromaxillary cell. Incidence of RMC was 74% (74/100 sides). The sex distribution was 31 (62%) males and 19 (38%) females. 34 patients (85%) had bilateral RMC and 6 patients (15%) had unilateral RMC. Lateral extension of RMC ranged from 1.03 to 11.3 mm. Out of 74 sides examined, 20 (27.02) were type I, 36 were type II (48.64%) and 18 (24.32%) were type III. The incidence of maxillary sinus disease on RMC sides and non-RMC sides has no significant difference (p < 0.5). RMC is lateral extension of posterior ethmoidal cell beneath the orbit and posterosuperior to maxillary sinus. The depth of the RMC is highly variable. The risk of residual disease in FESS is high in Type III RMC and one should pay attention to presence or absence of RMC and type of RMC prior to the endoscopic sinus surgery. Radiological study of RMC helps in preoperative planning and therefore intraoperative complete clearance of disease in endoscopic sinus surgery.

Laryngeal Schwannoma Triggered Life-threatening Acute Airway Obstruction- A Rare Case Report with Review of Literature.

Schwannoma in larynx is a rare presentaion. Laryngeal schwannomas are characterstically slow growing benign tumour usually arising from false cord and aryepiglottic fold with globus sensation being the most common presentation. Seldom it can present as stridor which need immediate intervention for survival of the patient. We present a case of 53 year female who presented with stridor at emergency and emergency tracheostomy was done. This patient had a history of dysphagia to solid food, hoarseness of voice and symptoms of aspirations. 70 degree rigid endoscopy and CEMRI of neck was performed to see the extent of the laryngeal lesion causing stridor. Tumor was excised completely by external transcervical approach. Histopathological reports suggested this tumor as schwannoma. Large obstructive laryngeal schwannoma though a unusual presentation but with immediate tracheostomy, proper diagnostic work up and precise surgical approach can give excellent recovery and post operative outcome for the patient.

Assessment of the prevalence, serotype, and antibiotic resistance pattern of Salmonella enterica in integrated farming systems in the Maryland-DC area.

Implementation of organic/pasture farming practices has been increasing in the USA regardless of official certification. These practices have created an increasingly growing demand for marketing safe products which are produced through these systems. Products from these farming systems have been reported to be at greater risk of transmitting foodborne pathogens because of current trends in their practices. Salmonella enterica (SE) is a ubiquitous foodborne pathogen that remains a public health issue given its prevalence in various food products, but also in the environment and as part of the microbial flora of many domestic animals. Monitoring antibiotic resistance and identifying potential sources contamination are increasingly important given the growing trend of organic/pasture markets. This study aimed to quantify prevalence of SE at the pre- and post-harvest levels of various integrated farms and sites in Maryland-Washington D.C. area, as well as identify the most prevalent serovars and antibiotic resistance patterns. Samples from various elements within the farm environment were collected and screened for SE through culture and molecular techniques, which served to identify and serotype SE, using species and serovar-specific primers, while antibiotic resistance was evaluated using an antibiogram assay. Results showed a prevalence of 7.80% of SE pre-harvest and 1.91% post-harvest. These results also showed the main sources of contamination to be soil (2.17%), grass (1.28%), feces (1.42%) and unprocessed produce (1.48%). The most commonly identified serovar was Typhimurium (11.32%) at the pre-harvest level, while the only identified serovar from post-harvest samples was Montevideo (4.35%). With respect to antibiotic resistance, out of the 13 clinically relevant antibiotics tested, gentamycin and kanamycin were the most effective, demonstrating 78.93 and 76.40% of isolates, respectively, to be susceptible. However, ampicillin, amoxicillin and cephradine had the lowest number of susceptible isolates with them being 10.95, 12.36, and 9.83%, respectively. These results help inform farms striving to implement organic practices on how to produce safer products by recognizing areas that pose greater risks as potential sources of contamination, in addition to identifying serotypes of interest, while also showcasing the current state of antibiotic efficacy and how this can influence antibiotic resistance trends in the future.

Degradation of CDK9 by Ubiquitin E3 Ligase STUB1 Regulates P-TEFb Level and Its Functions for Global Target Gene Expression within Mammalian Cells.

Positive transcription elongation factor b (P-TEFb) regulates expression of diverse sets of genes within mammalian cells that have implications in several human disease pathogeneses. However, mechanisms of functional regulation of P-TEFb complex through regulation of its stability are poorly known. In this study, we show an important role of C-terminus of Hsc70-interacting protein (CHIP aka STUB1) in regulation of overall level of CDK9 and thus P-TEFb complex within mammalian cells. STUB1 acts as a ubiquitin E3 ligase for proteasomal degradation of CDK9 involving N-terminal lysine 3 (K3) residue. Whereas, overexpression of STUB1 enhances, its knockdown reduces overall CDK9 degradation kinetics within mammalian cells. Interestingly, owing to the same region of binding within CDK9, CyclinT1 protects CDK9 from STUB1-mediated degradation. Factors that cooperatively bind with CyclinT1 to form functional complex also protects CDK9 from degradation by STUB1. Knockdown of STUB1 enhances CDK9 expression and thus P-TEFb complex formation that leads to global increase in RNA polymerase II CTD phosphorylation and transcriptional activation of diverse P-TEFb target genes. Thus, we describe an important functional role of STUB1 in regulation of transcription through modulation of overall level of P-TEFb complex formation within mammalian cells.

Promoter-proximal regulation of gene transcription: Key factors involved and emerging role of general transcription factors in assisting productive elongation.

The pausing of RNA polymerase II (Pol II) at the promoter-proximal sites is a key rate-limiting step in gene expression. Cells have dedicated a specific set of proteins that sequentially establish pause and then release the Pol II from promoter-proximal sites. A well-controlled pausing and subsequent release of Pol II is crucial for the fine tuning of expression of genes including signal-responsive and developmentally-regulated ones. The release of paused Pol II broadly involves its transition from initiation to elongation. In this review article, we will discuss the phenomenon of Pol II pausing, the underlying mechanism, and also the role of different known factors, with an emphasis on general transcription factors, involved in this overall regulation. We will further discuss some recent findings suggesting a possible role (underexplored) of initiation factors in assisting the transition of transcriptionally-engaged paused Pol II into productive elongation.

Fine tuning of the transcription juggernaut: A sweet and sour saga of acetylation and ubiquitination.

Among post-translational modifications of proteins, acetylation, phosphorylation, and ubiquitination are most extensively studied over the last several decades. Owing to their different target residues for modifications, cross-talk between phosphorylation with that of acetylation and ubiquitination is relatively less pronounced. However, since canonical acetylation and ubiquitination happen only on the lysine residues, an overlap of the same lysine residue being targeted for both acetylation and ubiquitination happens quite frequently and thus plays key roles in overall functional regulation predominantly through modulation of protein stability. In this review, we discuss the cross-talk of acetylation and ubiquitination in the regulation of protein stability for the functional regulation of cellular processes with an emphasis on transcriptional regulation. Further, we emphasize our understanding of the functional regulation of Super Elongation Complex (SEC)-mediated transcription, through regulation of stabilization by acetylation, deacetylation and ubiquitination and associated enzymes and its implication in human diseases.

Alternative approaches to therapeutics and subtherapeutics for sustainable poultry production.

The world population is growing rapidly and thus its demand for food is growing as well. To meet the demand of the ever-increasing number of consumers, the poultry industry and both of its main sectors-conventional and organic/cage-free farming-are expanding in parallel. Due to increasing demand of poultry products and higher mortality rate of chicks (an average 0.3% increase of mortality over last 5 yr), both conventional and organic poultry farming systems struggle with various issues; animal welfare, environmental sustainability, and antibiotic resistance of the prevailing zoonotic/enteric pathogens are common issues for conventional farming whereas slow growth rate, higher costs, inefficient land use, different diseases of the chicken, and cross-contamination with bacterial pathogens into the final products are the major issues for organic poultry farming. On top of these issues, the use of subtherapeutic antibiotics was recently banned in conventional farming systems and by definition the organic farming system cannot use the antibiotics/synthetic chemicals even for therapeutic use. In conventional farming system, use of therapeutic antibiotics may result in residuals antibiotics in the final products. As a result, sustainable alternatives are in demand to mitigate the prevailing issues for both conventional and organic farming. Potential alternatives may include bacteriophages, vaccination, probiotics, plant-derived prebiotics, and synbiotics. These alternatives have beneficial attributes and shortcomings of their use in both conventional and organic poultry production system. In this review, we'll discuss the scope of these potential alternatives as therapeutics and subtherapeutics in sustainable poultry production and ways to improve their efficacy.

Combined effect of metabolites produced by a modified Lactobacillus casei and berry phenolic extract on Campylobacter and microbiome in chicken cecum contents.

Campylobacter is one of the most common foodborne bacterial pathogens causing illness, known as campylobacteriosis, in the United States. More than 70% of the campylobacteriosis cases have direct or indirect relation with poultry/poultry products. Currently, both conventional and organic/pasture poultry farmers are searching for sustainable alternative to antibiotics which can reduce colonization and cross-contamination of poultry products with Campylobacter and promote poultry health and growth. Probiotic and their nutritional supplement, known as prebiotic, have become consumers' preferences as alternatives to antibiotics/chemicals. In this study, we evaluated the combined effect of plant-derived prebiotic and probiotic-derived metabolites in reducing growth of Campylobacter in cecum contents, a simulated chicken gut condition. Cecum contents were collected from chickens pre-inoculated with kanamycin-resistant Campylobacter (CJRMKm), were incubated over 48 h time period, while being supplemented with either berry phenolic extract (BPE), cell free cultural supernatant from an engineered probiotic, Lactobacillus casei, or their combination. It was found that combine treatments were able to reduce both inoculated and naturally colonized Campylobacter more effectively. Microbiome analysis using 16S rRNA sequencing also revealed that combine treatments were capable to alter natural microflora positively within chicken cecum contents. Differences were observed in bacterial abundance at both phylum and genus level but did not show significant alteration in alpha diversity due to this treatment. PRACTICAL APPLICATION: The results of this study provide critical information for understanding the potential of synbiotic as an alternative in sustainable poultry farming. The outcomes of this study will lead future direction of using combination of probiotic-derived metabolites and BPE in poultry farming.

Purified Plant-Derived Phenolic Acids Inhibit Salmonella Typhimurium without Alteration of Microbiota in a Simulated Chicken Cecum Condition.

Salmonella enterica serovar Typhimurium (ST) remains a predominant zoonotic pathogen because of its colonization in poultry, survivability in the environment, and increasing antibiotic-resistance pattern. Plant-derived phenolics, gallic acid (GA), protocatechuic acid (PA), and vanillic acids (VA) have demonstrated antimicrobial activity in vitro; therefore, this study collected chicken cecal fluid and supplemented it with these phenolics to evaluate their potential for eliminating ST and mod-ulating the microbiota of complex environments. ST was quantified through plating, while micro-biome analysis was performed through pair-end 16S-rRNA gene sequencing. CFU/mL of ST in cecal fluid with GA was significantly reduced by 3.28 and 2.78 log at 24 h and 48 h, while PA only had a slight numerical decrease. VA significantly reduced ST by 4.81 and 5.20 log at 24 h and 48 h. Changes in relative abundance of major phyla were observed at 24 h for samples with GA and VA as Firmicute levels increased 8.30% and 20.90%, while Proteobacteria decreased 12.86% and 18.48%, respectively. Significant changes in major genre were observed in Acinetobacter (3.41% for GA) and Escherichia (13.53% for VA), while Bifidobacterium increased (3.44% for GA) and Lactobacillus remained unchanged. Results suggest that phenolic compounds exert different effects on certain pathogens, while supporting some commensal bacteria.

Diarrheagenic Escherichia coli and Their Antibiotic Resistance Patterns in Dairy Farms and Their Microbial Ecosystems.

Ruminants are the largest reservoir for all types of Escherichia coli, including the pathogenic ones, which can potentially be transmitted to humans via the food chain and environment. A longitudinal study was performed to estimate the prevalence and antibiotic-resistant pattern of pathogenic E. coli (pE.coli) strains in dairy farm environments. A total of 846 environmental samples (water, lagoon slurry, bedding, feed, feces, soil, and compost) were collected in summer over two years from five dairy farms in Maryland, USA. An additional 40 soil samples were collected in winter and summer seasons for evaluating microbiome composition. Collected environmental samples were screened for the presence of pE.coli, which was isolated using a selective culture medium, for later confirmation and virotyping using PCR with specific primers. The overall prevalence of pE.coli in dairy farms was 8.93% (71/846), with the most common virotype identified in isolates being ETEC, followed by STEC. The highest pE.coli prevalence were recorded in lagoon slurry (21.57%) while the lowest was in compost heap (2.99%). Among isolates, 95.87% of the virotypes were resistant to 9 classes of antibiotics whereas only 4.12% were sensitive. The highest proportion (68.04%) of resistance was found for quinolones (e.g., ciprofloxacin). The resulting metagenomic analysis at the phylum and genus levels of the grazing land soil suggests that climatic conditions actively influence the abundance of bacteria. Proteobacteria, which contains many Gram-negative foodborne pathogens (including pE.coli), was the most predominant phylum, accounting for 26.70% and 24.93% of soil bacteria in summer and winter, respectively. In addition to relative abundance, there was no significant difference in species diversity between seasons when calculated via Simpson (D) and Shannon (H) index. This study suggests that antibiotic-resistant E. coli virotypes are present in the dairy farm environment, and proper steps are warranted to control its transmission irrespective of seasonality.

A Highly Effective Bacteriophage-1252 to Control Multiple Serovars of Salmonella enterica.

Salmonella enterica (S. enterica) is the most common foodborne pathogen worldwide, leading to massive economic loss and a significant burden on the healthcare system. The primary source of S. enterica remains contaminated or undercooked poultry products. Considering the number of foodborne illnesses with multiple antibiotic resistant S. enterica, new controlling approaches are necessary. Bacteriophage (phage) therapies have emerged as a promising alternative to controlling bacterial pathogens. However, the limitation on the lysis ability of most phages is their species-specificity to the bacterium. S. enterica has various serovars, and several major serovars are involved in gastrointestinal diseases in the USA. In this study, Salmonella bacteriophage-1252 (phage-1252) was isolated and found to have the highest lytic activity against multiple serovars of S. enterica, including Typhimurium, Enteritidis, Newport, Heidelberg, Kentucky, and Gallinarum. Whole-genome sequencing analysis revealed phage-1252 is a novel phage strain that belongs to the genus Duplodnaviria in the Myoviridae family, and consists of a 244,421 bp dsDNA, with a G + C content of 48.51%. Its plaque diameters are approximately 2.5 mm to 0.5 mm on the agar plate. It inhibited Salmonella Enteritidis growth after 6 h. The growth curve showed that the latent and rise periods were approximately 40 min and 30 min, respectively. The burst size was estimated to be 56 PFU/cell. It can stabilize and maintain original activity between 4 °C and 55 °C for 1 h. These results indicate that phage-1252 is a promising candidate for controlling multiple S. enterica serovars in food production.

Host-Guest Encapsulation of RIBO with TSC4X: Synthesis, Characterization, and Its Application by Physicochemical and Computational Investigations.

In our present work, we synthesized a new encapsulated complex denoted as RIBO-TSC4X, which was derived from an important vitamin riboflavin (RIBO) and p-sulfonatothiacalix[4]arene(TSC4X). The synthesized complex RIBO-TSC4X was then characterized by utilizing several spectroscopic techniques such as 1H-NMR, FT-IR, PXRD, SEM, and TGA. Job's plot has been employed to show the encapsulation of RIBO (guest) with TSC4X (host) having a 1:1 molar ratio. The molecular association constant of the complex entity (RIBO-TSC4X) was found to be 3116.29 ± 0.17 M-1, suggesting the formation of a stable complex. The augment in aqueous solubility of the RIBO-TSC4X complex compared to pure RIBO was investigated by UV-vis spectroscopy, and it was viewed that the newly synthesized complex has almost 30 times enhanced solubility over pure RIBO. The enhancement of thermal stability upto 440 °C for the RIBO-TSC4X complex was examined by TG analysis. This research also forecasts RIBO's release behavior in the presence of CT-DNA, and at the same time, BSA binding study was also carried out. The synthesized RIBO-TSC4X complex exhibited comparatively better free radical scavenging activity, thereby minimizing oxidative injury of the cell as evident from a series of antioxidant and anti-lipid peroxidation assay. Furthermore, the RIBO-TSC4X complex showed peroxidase-like biomimetic activity, which is very useful for several enzyme catalyst reactions.

Unveiling the Potential Ways to Apply Citrus Oil to Control Causative Agents of Pullorum Disease and Fowl Typhoid in Floor Materials.

This study investigates the potential role of Cold-pressed Valencia Terpeneless citrus oil (CO), as a natural antimicrobial, in controlling causative agents of pullorum disease and fowl typhoid in floor materials for poultry farming, specifically wooden chips. The study addresses the issues that have arisen as a result of the reduction in antibiotic use in poultry farming, which has resulted in the re-emergence of bacterial diseases including salmonellosis. CO efficiently inhibits the growth of pathogens including various serovars of Salmonella enterica (SE), including SE serovar Gallinarum (S. Gallinarum) and SE serovar Pullorum (S. Pullorum), in a dose-dependent manner. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of CO showed potential for controlling diverse S. Gallinarum and S. Pullorum isolates. Growth inhibition assays demonstrated that 0.4% (v/w) CO eliminated S. Pullorum and S. Gallinarum from 24 h onwards, also impacting poultry gut microbiota and probiotic strains. Floor material simulation, specifically wooden chips treated with 0.4% CO, confirmed CO's effectiveness in preventing S. Gallinarum and S. Pullorum growth on poultry house floors. This study also investigated the effect of CO on the expression of virulence genes in S. Gallinarum and S. Pullorum. Specifically, the study revealed that the application of CO resulted in a downregulation trend in virulence genes, including spiA, invA, spaN, sitC, and sifA, in both S. Pullorum and S. Gallinarum, implying that CO may alter the pathogenicity of these bacterial pathogens. Overall, this study reveals that CO has the potential to be used as a natural antimicrobial in the prevention and management of Salmonella-related infections in chicken production, offering a viable alternative to control these re-emerging diseases.