Salmonella Typhimurium Research Articles

Deletion of ttrA and pduA genes in Salmonella enterica serovars induce a comparable immune response to wild-type infection in different chicken lineages

ABSTRACT It was previously reported that utilization of tetrathionate and 1,2-propanediol by Salmonella spp. through the metabolic pathways encoded by ttr and pdu operons are related to overgrowth and out-competing microbiota in an anaerobic environment. However, recent knowledge demonstrated which strains in the absence of ttr and pdu genes provoke both higher intestinal colonization and spreading of bacteria in faeces compared with their respective wild-type strain, and also generate more prominent inflammation. This study evaluated the immune response of different lineages of chicks infected by Salmonella Typhimurium (STM) and Salmonella Enteritidis (SE) with ttrA and pduA gene deletions. Our work was separated into two experiments, one for each strain, utilizing 108 chicks to collect spleen and caecal tonsils for measuring immune response through RT-qPCR. From the immune response analysis, Salmonella Enteritidis mutant and wild-type strains elicited upregulated pro-inflammatory cytokines on the first-day post-infection; the opposite occurred with Salmonella Typhimurium strains (mutant and wild-type). However, the deletions did not impair the immune response produced by mutant strains compared with the respective wild-type in the caecal tonsil and spleen, suggesting that these metabolic pathways are not essential for colonization success. In conclusion, SE and STM, in the absence of ttrA and pduA genes, provoke an immune response with the same intensity as respective wild-type strains. RESEARCH HIGHLIGHTS ttrA and pduA double mutants in Salmonella provoke a similar immune response. SE elicited more intense immune responses than STM. The immune response in the broiler was more intense than in other lineages.

Study on Isolation of Organism and Antibiotic Sensitivity Pattern in Blood Culture of Enteric Fever Patients in a Tertiary Care Hospital in Bangladesh

A cross-sectional, observational study was conducted in the Department of Medicine, Mugda Medical College Hospital, Dhaka, Bangladesh, between March 2022 and September 2023, to observe the changing pattern of antibiotic sensitivity pattern among enteric pathogens causing enteric fever. A total of 50 blood culture and sensitivity reports were analyzed. Blood samples were derived from 50 patients included in this study, who were admitted into the medicine inpatient department of Mugda Medical College Hospital suffering from fever for at least 2 weeks and were confirmed having enteric fever. The predominant growth of two bacteria was observed in all (100%) samples. The most common organisms isolated were Salmonella typhi as typhoid fever pathogens and Salmonella paratyphi A as paratyphoid fever pathogens; these represented 88% and 12% of isolates respectively. Salmonella typhi organisms were found 100% sensitive to amoxycillin, trimethoprim-sulfamethoxazole, chloramphenicol, gentamicin, meropenem, cefepime, followed by imipenem (85%), ampicillin (81%), ceftriaxone (78%), levofloxacin (77%) and cefuroxime (77%). However, amoxicillin, trimethoprimsulfamethoxazole, ceftazidime, cefotaxime, ceftriaxone and chloramphenicol were found 100% sensitive to paratyphoid pathogens. Very high rate of resistance was seen against nalidixic acid (88%), piperacillin-tazobactam (50%), azithromycin (47%), co-amoxiclav (40%) and doxycycline (40%) in salmonella typhi infections, while nalidixic acid and azithromycin were found 100% resistant to Salmonella paratyphi A infection. Mugda Med Coll J. 2024; 7(2): 108-113

Antimicrobial properties of Bifidobacterium animalis subsp. lactis Bb-12 paraprobiotic obtained using ohmic heating against Salmonella enterica: A metabolomic approach.

This study aimed to obtain paraprobiotics from Bifidobacterium animalis subsp. lactis Bb-12 (BB) presenting optimized antimicrobial activity against Salmonella enterica (SE). The paraprobiotics of BB (BBP) were obtained using ohmic heating (OH) under different conditions, and their effects on critical features of Salmonella, such as bacterial growth, biofilm formation, and adherence to Caco-2 cells, were studied. In addition, a metabolomic analysis was performed using 1H NMR spectroscopy to identify the metabolites involved in antimicrobial activity against SE. Through an optimization approach, it was found that the linear model demonstrated the highest predictive potential for the antimicrobial activity (AMA) of BBP among the fitted models. In contrast, the quadratic model was more predictive for the antibiofilm activity (ABA) and anti-adherence activity (AAA). The highest effects on the AMA, ABA, and AAA of BBP were associated with the variables electric field (EF), OH time, and OH temperature, respectively. Glycerol (37.6μmol/g), ethanol (22.6μmol/g), and lactate (9.8μmol/g) were measured as the main metabolites in BB, while glycerol (47.8μmol/g), acetate (34.0μmol/g), and lactate (24.6μmol/g) were the main metabolites in BBP. All the anti-SE characteristics of BBP obtained under the optimal conditions of the OH process were higher than those of BB (the untreated sample), which could be related to the higher levels of detected metabolites. The OH process, EF of 8.7V/cm, OH temperature of 88°C, cell concentration of 8.7 log CFU/mL, and OH time of 3.6min, was the best OH condition for obtaining a BBP effective against SE.

Physiochemical properties of hemp extract (Cannabis sativa L) inflorescences grown in Northern Alabama.

Medicinal plants are an excellent source of bioactive components and are gaining significant attention for food protection due to their bioactive properties. In this context, hemp (Cannabis sp.) is being explored for such applications because of its well-known antibacterial and antioxidant activities. However, the bioactive efficacy of cultivars currently grown in Northern Alabama has not been widely studied. Therefore, the purpose of this study was to evaluate the physicochemical properties of two hemp cultivars (Hemp 5 and Hemp 17). Hemp inflorescences grown at the Winfred Thomas Agricultural Research Station were used in this study. The antioxidant activity and content of the extracts were determined by ferric reducing antioxidant power, radical scavenging activity, total phenolic content, and total flavonoid content. Antibacterial activity against cocktails of Listeria monocytogenes (LM) and Salmonella enterica (SE) was evaluated by optical density and disc diffusion. All treatments were analyzed in triplicate, and analysis of variance was conducted with statistical significance based on p ≤ 0.05. Results indicated that cultivars and defatting significantly affected (p ≤ 0.05) the antioxidant properties, with Hemp 17 DF (defatted) having the highest RSA (70.51±4.24%) compared to the positive control of ascorbic acid (83.81±5.85%). Antibacterial results based on optical density indicated that hemp extracts had a significantly (p ≤ 0.05) lower optical density compared to the negative controls (LM and SE). These findings suggest that Northern Alabama hemp cultivars can potentially be utilized to enhance food safety and quality. PRACTICAL APPLICATION: Northern Alabama cultivars of hemp extract can be utilized for the enhancement of the safety and quality application due to inherent antioxidant and antimicrobial properties.

A systematised review and evidence synthesis on the broader societal impact of vaccines against Salmonella

Vaccines against Salmonella Typhi are available, while vaccines against invasive non-typhoidal Salmonella are in development. Investments in vaccine development and introduction need to be informed by a full value of vaccines assessment, including consideration of broader societal impacts of salmonellae disease. We reviewed literature on these broader impacts in low- and middle-income countries to inform a conceptual framework. We found 16 studies relevant to Salmonella, but only one study on non-typhoidal Salmonella. Despite variations in study design, methodology, and study quality, salmonellae infections were largely associated with negative broader societal impacts, including detriments in childhood physical development (very weak association), childhood educational development (strong to very strong association), household security (moderate association), public health spending (moderate association), and national income (moderate to strong association). Study quality was low for all impacts except childhood physical development. There were no studies measuring economic impact of antimicrobial resistance, changes in household behaviour or health inequalities.

COMPARATIVE ANTIMICROBIAL ACTIVITIES OF ESSENTIAL OILS OF CYMBOPOGON CITRATUS (LEMON GRASS) AND CITRUS SINENSIS (SWEET ORANGE) PEEL AGAINST SOME PATHOGENS

Essential oils are one of the important natural products derived from plant for their various biological activities, however, the antimicrobial activities vary in potency and usage. Comparative antimicrobial activities of essential oils of lemon grass (Cymbopogon citrtus, and Orange (Citrus sinensis) peel against three bacterial species (Salmonella typhy, Pseudomonas aeruginesa, and Staphylococcus aureus) and two fungal species (Candida albicans, and Aspergillus niger). The essential oils were extracted by steam distillation. Antibacterial and antifungal activities were determined by paper disc diffusion technique and micro-dilution. The results showed both essential oils of lemon grass and orange peels exhibited strong antibacterial and antifungal activities against the test organisms with zones of inhibition ranging from 15.00mm to 28.00 mm. Comparison of the inhibitory activities of the two oils showed orange had lower effect of 15.60mm as against lemon grass 19.00mm at concentration of 20µ/ml against salmonella typhi. Inhibitory activities was 28.30mm highest on Staphylococcus aureus for orange peel and 28.00mm for lemon grass oil. The minimum inhibitory concentration (MIC) and minimum bactericidal (MBC) and minimum fungicidal concentration (MFC) indicated values20µl/ml and 10µ/ml against S.aureus respectively. The result demonstrated that both essential oils of lemon grass and orange have high potential antimicrobial activities that can be developed into potent drugs.

P-2256. Clinical characteristics and outcomes of non-typhoidal Salmonellosis in patients with hematologic malignancy

Abstract Background Non-typhoidal salmonellosis is a significant cause of foodborne illness in the US, especially in immunocompromised host. Previous studies report a higher incidence in cancer patients; however, advancements in cancer therapy and rising antibiotic resistance have reshaped this association. Salmonellosis in patients with hematologic malignancy (HM) remains poorly characterized. Characteristics of HM patients with non-typhoidal Salmonella infection *Only for those who were not receiving intravenous immunoglobulin therapy **Included culture from splenic abscess, lymph node, soft tissue, and bone Methods We identified non-typhoidal salmonella infections in HM patients from 1/1/2016 to 12/31/2023 at 2 institutions. Clinical, microbiologic and treatment outcomes were collected. Hypogammaglobulinemia (HGG) was defined as having immunoglobulin G (IgG) level < 500 IU/dL or receiving intravenous immunoglobulin for past diagnosis of low IgG. Relapse was defined as confirmed Salmonella infection with symptoms recurring after clinical resolution with an initial antibiotic course. Chi square and Mann-Whitney U tests were used to examine the relationship between clinical parameters and relapse.Table 2.Demographic and clinical characteristics of HM patients by relapse of Salmonella infection * Four patients did not have enough follow-up to determine relapse ** p<0.05 *** Only for those who were not receiving intravenous immunoglobulin therapy Results We identified 53 HM patients with non-typhoidal salmonellosis. Clinical and microbiological variables are shown in Table1. Most individuals were male (54.7%) with median age of 63 years [20-88]. Multiple myeloma was the most common diagnosis (39.6%), followed by acute leukemia/myelodysplastic syndrome (32.1%); 18 patients underwent hematopoietic cell transplantation and 8 patients received chimeric antigen T-cell therapy. Twenty-six patients (45.3%) had HGG. Salmonella was isolated from stool cultures (62.3%), blood cultures (17%), both (13.2%) or another specimen (7.5%). Four patients (7.5%) had musculoskeletal involvement. Relapse occurred in 14 cases (26.4%). In a bivariate analysis (Table 2), HGG was associated with relapse (p=0.002) and those with relapse had a lower median IgG level (p=0.032). Among patients with extraintestinal infection, those who experienced relapse received a shorter initial duration of antimicrobials to those without relapse (p=0.004; figure 1). Duration of antibiotic therapy in days for patients with extra-intestinal salmonella infection Conclusion HM patients are at high risk for non-typhoidal salmonellosis. HGG and shorter course of antibiotics are associated with an increased relapse risk, particularly in those with extraintestinal involvement. Extended duration of antibiotic therapy could be considered for these high-risk patients. Disclosures Elizabeth Hohmann, MD, Astra Zeneca: Grant/Research Support|Laguna Biotherapeutics: Grant/Research Support|MicrobiomeX/Tend: Grant/Research Support Sarah P. Hammond, MD, Cidara: Grant/Research Support|F2G: Grant/Research Support|GSK: Grant/Research Support|Melinta: Advisor/Consultant|Pfizer: Advisor/Consultant|Roche: Advisor/Consultant|Scynexis: Grant/Research Support|Seres Therapeutics: Advisor/Consultant

P-149. Clinical Profile and Antimicrobial Resistance Patterns of Salmonella Infection in Guatemala City

Abstract Background Salmonella infection is the second most common food-borne disease worldwide, causing over 155,000 deaths per year. Infection rates in low- and middle-income countries surpass those of high-income countries. Several risk factors have been associated with higher mortality rates due to Salmonella infection, such as age, HIV infection, and antimicrobial resistance. Although frequent in Central America, few data on risk factors associated to invasive Salmonellosis and mortality are available in the region. Population General Characteristics Methods A retrospective cohort study was conducted at a third-level reference hospital in Guatemala City from 2022 to 2023. All cases of Salmonella infection identified through blood and stool cultures were included and evaluated for clinical factors and interest outcomes. Antimicrobial resistance patterns were identified according to the Clinical and Laboratory Standard Institute (CLSI) guidelines. Clinical characteristics associated with mortality Results A total of 15 confirmed cases of Salmonella infection were identified. The mean age of the patients was 37.8 years (SD = 17.8). The majority of were male (86.6%). Over 73% had at least one comorbidity, with HIV being the most frequent, followed by chronic alcohol consumption. The most common presentation included fever, diarrhea, and abdominal cramps. Only 6.6% of patients reported constipation. Over 46% of strains exhibited at least one mechanism of resistance, with 40% of showing resistance to fluoroquinolones, suggesting the presence of a GyrA-ParC phenotype. The most common complication identified was Acute Kidney Injury in 46.6% of cases, with Hemolytic Uremic Syndrome present in 13.3% of cases. The overall mortality rate due to salmonellosis was 26.6% (Table 1). Age over 50 years, sex, HIV infection, and ESBL resistance were significantly associated with in-hospital mortality, after adjusting for other clinical variables (Table 3). Adjusted variables associated with mortality Conclusion The study identified a higher resistance to fluoroquinolones and case-mortality compared to other reports in the region. Although ESBL-producing strains were rare in the study, this resistance pattern was significantly associated with mortality due to salmonella infection. The uncontrolled use of antibiotics in the country may present as a major concern in the future treatment and management of salmonellosis. Disclosures All Authors: No reported disclosures

Evaluation of the Effect of Bacteriophages and Organic Acids as a Feed Additive to Reduce Salmonella enteritidis in Challenged Chickens.

This study aimed to compare the effects of dietary supplementation of bacteriophage (BP) and acidifiers on performance, meat quality, morphology, and intestinal microbiota in chickens challenged and unchallenged with Salmonella enteritidis (SE) and also to investigate the possibility of replacing them in the diet with antibiotics. A total of 1760 male Ross (308) chicks were randomly assigned to 11 dietary treatments (8 pens/with 20 male chickens in each). Dietary treatments were as follows: SE-uninfected (negative control (NC), a basal diet without supplemention; NC+ 500 g/t BP (NBP1); NC+ 1000 g/t BP (NBP2); NC+ 300 mg/kg acidifier A (NAA); NC+ 300 mg/kg acidifier B (NAB)) and SE-infected (positive control (PC), a basal diet without supplemention; PC+ 40 mg/kg Antibiotic enrofloxacin (PA); PC+ 500 g/t BP (PBP1); PC+ 1000 g/t BP (PBP2); PC+ 3000 mg/kg acidifier A (PAA); PC+ 3000 mg/kg acidifier B (PAB)). At 13 D birds in challenged groups were orally gavaged with 1 mL bacterial suspension containing approximately 108 CFU Salmonella enterica. The results indicated that chicks challenged with SE impaired performance so that BWG and FI significantly decreased and FCR increased (p < 0.05). Diets containing a high dose of BP increased BW and improved FCR in challenged and unchallenged chickens. The quality of breast meat showed a decline in oxidation in chickens challenged with SE (p < 0.05). The inclusion of bacteriophage in the diet of chickens (1000 g/t) improved the L*, b*, and oxidation of meat. The use of bacteriophage and acidifier A in the diet significantly increased the Lactobacillus, and LAB count, especially in the challenged groups. The challenge of chickens with SE decreased the villus height and crypt depth in different parts of the small intestine (p < 0.05). The results of the present study suggested that 1000 g/t of BP probably improves chicken performance by increasing beneficial bacteria and decreasing pathogenic bacteria. Also, bacteriophage showed an improvement in the performance reduction of chickens with Salmonella infection. In addition, improved meat quality and beneficial changes in the microbiome and intestinal morphology indicate the effectiveness of BP as an alternative antibiotic growth promoter in broiler diets.

Early and delayed STAT1-dependent responses drive local trained immunity of macrophages in the spleen.

Trained immunity (TI) is the process wherein innate immune cells gain functional memory upon exposure to specific ligands or pathogens, leading to augmented inflammatory responses and pathogen clearance upon secondary exposure. While the differentiation of hematopoietic stem cells (HSCs) and reprogramming of bone marrow (BM) progenitors are well-established mechanisms underpinning durable TI protection, remodeling of the cellular architecture within the tissue during TI remains underexplored. Here, we study the effects of peritoneal Bacillus Calmette-Guérin (BCG) administration to find TI-mediated protection in the spleen against a subsequent heterologous infection by the Gram-negative pathogen Salmonella Typhimurium (S.Tm). Utilizing single cell RNA-sequencing and flow cytometry, we discerned STAT1-regulated genes in TI-associated resident and recruited splenic myeloid populations. The temporal dynamics of TI were further elucidated, revealing both early and delayed myeloid subsets with time-dependent, cell-type-specific STAT1 signatures. Using lineage tracing, we find that tissue-resident red pulp macrophages (RPM), initially depleted by BCG exposure, are restored from both tissue-trained, self-renewing macrophages and from bone marrow-derived progenitors, fostering long lasting local defense. Early inhibition of STAT1 activation, using specific JAK-STAT inhibitors, reduces both RPM loss and recruitment of trained monocytes. Our study suggests a temporal window soon after BCG vaccination, in which STAT1-dependent activation of long-lived resident cells in the tissue mediates localized protection.

Clinical presentation with consequences and laboratory diagnosis of multi and extensive drug resistance in typhoid cases

Background: Enteric fever is among the major problem in the health care settings of developing countries like Pakistan. Unjudicial use and over the counter availability of antibiotics lead to the emergence of multi drug resistant and extensive drug-resistant strains of salmonella outbreak which demonstrate severity of disease of the disease. Our objective is to determine the clinical presentation, consequences and antibiotic susceptibility patterns of Multi Drug Resistant (MDR) typhoid and Extensive drug resistance (XDR) typhoid cases. Methods: The study was conducted in the department of Microbiology, Dow Diagnostic Reference and Research Laboratory, Dow University of Health Sciences. All laboratory proven Salmonella positive cultures samples were selected from laboratory that were either fully or partially treated, or were taking anti-Salmonella. Clinical trends along with clinical outcomes were assessed from clinical presentation. Furthermore, Demographic details were noted. Detailed history about the presenting illness with examination findings and medications were recorded. Results: A total of 333 patients had positive blood culture for enteric fever, in which maximum number of XDR cases 84% (n=281) were observed in blood cultures followed by MDR salmonella in 16 % (n=52). Meropenem and azithromycin didn’t show any resistance in our study. Conclusion: Our study has demonstrated that pediatric population is more vulnerable for developing salmonella infection. Carbapenems and azithromycin are among the last choices for the treatment of XDR cases. Analysis of our results imply stress on the implementation of preventive measures for spread of enteric fever including proper diagnosis, vaccination and good sanitation system

‘Breaking the biofilm barrier: vitamin C as a novel strategy against multidrug-resistant salmonella Typhimurium’

Abstract The emergence of multidrug-resistant (MDR), biofilm-forming strains of Salmonella Typhimurium poses a significant threat to food safety due to their persistence on food surfaces and equipment, complicating eradication efforts and increasing the risk of contamination. This study explored the antibiofilm activity of Vitamin C (VC) against MDR biofilm-forming Salmonella Typhimurium. Vitamin C inhibited S. Typhimurium biofilms in a dose-dependent manner, with a minimum inhibitory concentration of 125 mM. Treatment with Vitamin C significantly disrupted the bacterial biofilm structure, creating cannonball-like pores in the cell wall as observed through electron microscopy. The antibiofilm mechanism of Vitamin C was mediated by reactive oxygen species (ROS) generation, leading to sugar and protein leakage, reduced exopolysaccharide (EPS) production, and decreased quorum sensing (QS) activity. Transcriptional analysis revealed that Vitamin C downregulated expression of biofilm-related genes responsible for initial cellular attachment and EPS production (fimA, adrA) and upregulated genes associated with adhesion and multidrug efflux pumps (csgA, ipfE, and arcA). Importantly, the application of Vitamin C on coated Paneer significantly extended its shelf life. These findings highlight the potential of Vitamin C in combating Salmonella biofilms, enhancing food safety, and providing a framework for the development of antibiotic-independent therapies to address MDR strains of Salmonella.

Synergistic impact of Salmonella typhimurium and Eimeria spp. coinfection on turkey poults: Growth performance, salmonella colonization, and ceca microbiota insights.

Salmonella contamination in poultry products is a significant concern due to its potential to cause severe economic losses and public health problems. On the other side, coccidiosis is induced by Eimeria (E.) species. involves the destruction of host intestinal epithelial cells and subsequent invasion of pathogens, resulting in performance reduction and enhanced pathogen infection in poultry and economic losses for the poultry industry. A study was conducted to evaluate the impact of Eimeria infection and Salmonella typhimurium (ST) on growth performance, Salmonella colonization, and ceca microbiota in turkey poult. A total of 420 one-day-old male turkey poults were randomly allocated into six treatments, with five replicated cages for each treatment, over a 21-day experimental period. The study followed a 2 × 3 factorial design. Treatments consisted of NC, negative control without any challenge; T1, challenged with 8000 oocysts of E. meleagrimitis and E. adenoeides at d 8; T2, challenged with 16,000 oocysts of E. meleagrimitis and E. adenoeides at d 8; T3, challenged with nalidixic acid-resistant Salmonella typhimurium (ST) at d 0; T4, challenged with ST at d 0 and 8000 oocysts of E. meleagrimitis and E. adenoeides at d 8; T5, challenged with ST at d 0 and 16,000 oocysts of E. meleagrimitis and E. adenoeides at d 8. The Eimeria challenge groups significantly reduced the BW compared to the non-challenge group (P < 0.001). The challenged groups decreased FI during 9-14 days of age (P < 0.01). Salmonella typhimurium did not affect BW entire trial period (P > 0.05). Gut permeability (GP) increased in the challenge groups compared to the NC group (P < 0.001). Both ST and Eimeria significantly decreased superoxide dismutase (SOD) in the liver (P < 0.01). The challenge groups had lower villus height (VH) and higher crypt depth (CD) compared to the NC group, resulting in decreased VH:CD ratio in the duodenum and jejunum (P < 0.01). The groups T1, T2, and T4 had significantly higher fat deposition than the NC group (P < 0.05). The coinfected groups (T4 and T5) had higher salmonella colonization in the spleen compared to the ST-infected group (T3, P < 0.05). The ST challenge significantly decreased alpha diversity, including pielou evenness and Shannon entropy (P < 0.05). The Proteobacteria phylum and Enterobacteriaceae family significantly increased in T5 compared to the NC, T1, T2, and T3 (P < 0.05). In conclusion, Eimeria infection negatively impacted growth, gut health, intestine barrier integrity, and histology, while Salmonella had a milder effect on performance. Coinfection with Salmonella and Eimeria spp. led to changes in gut microbiota and increased liver Salmonella colonization and fat deposition in turkey poults.

A new vaccination approach for Salmonellosis employing a multi-epitope vaccine based on live microbial cell factory from Lactococcus lactis.

A major health and financial burden in the chicken sector is salmonella infection. It is difficult to create an oral vaccination that can provide strong intestinal mucosal immunity in birds, particularly cross-protection against several Salmonella serotypes. As a result, the poultry industry needs a powerful oral vaccination platform that uses live bacterial vectors to prevent various Salmonella serotypes. The genetically engineered L. lactis was given orally to birds as a vaccine after a multi-epitope vector was created using a reverse vaccinology technique. After the plasmid was digested, the target group produced a 72 kDa protein called multi-epitop. Birds that received the L. lactis/pNZ8121-Multi epitope vaccination showed increased levels of interferon (IFN-γ) and NFkB1α, increased transcription rates of cytokines, and a significant presence of IgY antibodies specific to the multi epitope gene in their serum. Salmonella infection is a severe health and economic burden in the poultry industry, according to spleen sections from the L. lactis/pNZ8121-Multi epitope. Developing an oral vaccine that can provide birds robust intestinal mucosal immunity-specifically, cross-protection against many Salmonella serotypes-is challenging. The results provide a fresh method for creating new immunological candidate multi-epitome genes by using the food-grade, non-pathogenic Lactococcus lactis as a protein cell factory. This method provides a unique technique to assess the long-term sustainability, cost, safety, and usefulness of experimental pharmaceutical products.

Research Note: Evaluation of selected chlorhexidine salts/product and/or cetylpyridinium chloride as potential pre-slaughter crop disinfection agents using an in vitro assay simulating crop contents.

Salmonellae remain a prominent issue for poultry products regarding food safety. A predominant source of broiler carcass contamination at processing is from crop rupturing and subsequent contamination of the carcass during evisceration. Chlorhexidine (CHX) salts are commonly used in dental products for their antimicrobial capabilities. We evaluated CHX gluconate and CHX digluconate alongside cetylpyridinium chloride (CPC), a common disinfectant to test their antimicrobial properties and any possible synergistic effects between the two. These effects were evaluated using an in vitro assay simulating the crop contents of poultry. CHX digluconate, CHX gluconate, commercially available CHX gluconate and CPC were tested at 0.1 %, 0.2 %, 1 %, 1.8 %, and 2 %. Borosilicate tubes containing 2.5 g of chicken mash feed, pasteurized to remove unwanted bacteria, were used for assay. Pasteurized feed within tubes were suspended in CHX, CPC, CHX + CPC, or saline vehicle alone (control). Tubes were then inoculated with Salmonella Typhimurium (ST) (except non-inoculated controls) and allowed to statically incubate for 2 h at 37°C. Tube contents were then serially diluted for CFU enumeration. CHX and CPC, when used individually, demonstrated meaningful and significant (p < 0.05) reduction in ST recovery, especially at higher concentrations (1-2 %). Combinations of CHX + CPC at lower concentrations (0.1-0.2 %) were shown to have major antimicrobial effects and either reduced (p < 0.05) or eliminated ST recovery in this assay. These lower concentrations might be used for antemortem disinfection of crop contents prior to live haul at processing in future studies. In vivo efficacy may be affected by limitations on voluntary ingestion of drinking water during pre-slaughter feed withdrawal and was not evaluated in these studies.

STUDIES ON THE COMPLEXES OF ISONICOTINOYL 2-CHLOROBENZALDEHYDE HYDRAZONES WITH CU II AND MN II AND THEIR ANTIMICROBIAL STUDIES

Complexes isonicotinoyl 2-chlorobenzaldehyde hydrazone with Mn II and Cu II were synthesized and characterized using UV visible spectrophotometry, Infrared spectrophotometry Atomic Absorption Spectrophotometry, melting point, solubility test, conductivity measurement, magnetic susceptibility. Some bacterial and fungal strains were used to screen for the biological activities of the ligands and complexes. The melting point of the ligand (216 – 218) °C is higher than 106 – 107.80C of the Mn complex. The Cu complex decomposed at 174°C.The solubility showed that the ligand and complexes were soluble in dimethyl sulphoxide, but insoluble in water. The conductivity test showed that the Cu complex are conductors with higher value (9.934) µS/cm, while the Mn complexes are non-conductor with lower value (1.346) µS/cm. The magnetic susceptibility measurement pointed out that the complexes are paramagnetic with unpaired electrons. There was coordination via the azomethine nitrogen and carbonyl oxygen in all the complexes with a square planar geometries stoichiometrically combined in the ratio of ML 1:2 for the metal and ligand respectively. The ligand and complexes showed appreciable activities against Methicillin resistant staphlococus aureus (MRSA), Escherichia coli, Helicobacter pylori, salmonella typhi Aspergillus fumigatus and aspergillus niger

Typhoid fever and medicinal plants review: A case study in Nigeria

Lack of waste management and antibiotic overuse make typhoid a major disease in Nigeria. According to many studies, typhoid fever and other salmonella infections are common in Nigeria. Due to multidrug resistance and development of carrier status of Salmonella typhi (the causative organism of typhoid fever) herbal medicines is becoming increasingly popular and widely accepted by Nigerians. However, information on plant usage for specific illnesses and diseases is fragmented, and consolidation is needed to understand and share herbal disease management information. Aim: This review compiles medicinal plants used in treating typhoid fever in Nigeria. Method: Based on inclusion criteria, Google Scholar, PubMed, and Scopus were searched for published publications. Results: A total of 166 plant species from 66 families were documented for treating typhoid fever across the six geopolitical zones of Nigeria. Fabaceae is the most employed family, followed closely by Euphorbiaceae and Poaceae. Ten plants (Mangifera indica L., Carica papaya L., Cymbopogon citratus (DC.) Stapf, Psidium guajava L., Citrus aurantifolia Christm, Ananas comosus (L.) Merr, Ocimumgratissimum L., Vernonia amygdalina (Wild) Darke, Alstonia boonei De Wild. and Azadirachta indica A. Juss) are widely used across the country. All parts of plants are reported to be relevant in treating typhoid fever. Leaves are mostly used alone or in combination with other plant parts. Conclusion: A wide variety of plants are used to treat typhoid in Nigeria. It is expected that this documentation of medicinal plants used for the treatment of typhoid fever will further promote bioprospecting and pharmacological research.

Effects of Supplementing Yeast Fermentation Products on Growth Performance, Colonic Metabolism, and Microbiota of Pigs Challenged with Salmonella Typhimurium.

Yeast fermentation products (YFPs) are known to contain bioactive compounds, such as nutritional metabolites and cell wall polysaccharides (specifically glucan and mannan), which have been demonstrated to exert positive effects on the growth performance and immunity of livestock and poultry. However, the impact of YFPs on intestinal inflammation and microflora composition in pigs infected with Salmonella typhimurium remains unclear. To investigate this, a total of 18 weaned pigs were divided into three treatment groups: a non-challenged control group (Con), a group challenged with Salmonella typhimurium (ST), and a group challenged with Salmonella typhimurium and supplemented with 0.4% YFP (YFP). The experiment spanned five weeks, encompassing a period of 21 days prior to and 14 days subsequent to the initial Salmonella typhimurium challenge. The findings indicated that the YFP group exhibited an increase in average daily gain (ADG) and a decrease in the feed-gain ratio (F/G) in comparison to the ST group following the Salmonella challenge. Additionally, the YFP group demonstrated a reduction in the levels of inflammatory cytokines in plasma and a decrease in the expression of inflammatory genes in the colon. Treatment with YFP also resulted in improved colon histomorphology, heightened alpha diversity of the gut microbiota, augmented the abundance of butyrate-producing bacteria, and elevated concentrations of short-chain fatty acids (SCFAs). In addition, YFP reprogrammed energy metabolism in colon epithelial cells by blunting glycolysis. Together, dietary YFP supplementation alleviated colon inflammation in weaned pigs challenged with Salmonella typhimurium, and shaped the beneficial microbiota, thereby maintaining gut homeostasis. The results provided evidence supporting the application of yeast fermentation products in livestock production.

Longitudinal study on the influence of sow and piglet vaccination on seroprevalence of Salmonella Typhimurium in rearing pigs and at slaughter in a farrow-to-finish production system

BackgroundSalmonella is widespread in pig husbandry and pork is an important source for human salmonellosis. Surveillance programmes are conducted in many European countries and various management measures are implemented on farm level to control Salmonella. Piglet or maternal vaccination can reduce Salmonella shedding and lower the likelihood of piglet infection. Proper management of risk factors can help to maintain low infection pressure. The aim of the study was to evaluate the effect of sow vaccination and piglet vaccination on Salmonella seroprevalence at slaughter.ResultsDifferent vaccination strategies were evaluated for their effect on seroprevalences in nursery (serum) and slaughter pigs (meat juice) in a farrow-to-finish production chain tested positive for Salmonella Typhimurium (ST). Antibody levels of four piglet groups from one rearing farm and of pigs from four downstream fattening farms were measured by Salmonella LPS-ELISA in a longitudinal study (UNVAC: no vaccination against Salmonella; PIGVAC: piglets vaccinated twice with an attenuated Salmonella Cholerasuis (SC) live vaccine; SOWVAC-1: piglets born from sows vaccinated twice before farrowing with attenuated ST live vaccine; SOWVAC-2: Piglets from vaccinated sows (ST) which had been vaccinated twice already as a piglet (ST). Results revealed significantly lower ELISA optical density (OD) values (p < 0.05) and fewer serological positive piglets (OD > 40) from groups PIGVAC, SOWVAC-1 and SOWVAC-2 compared to group UNVAC at the end of rearing period. Summarizing results from pigs of all fattening farms revealed that pigs from group PIGVAC had significantly lower ELISA OD values in meat juice samples than all other groups (p < 0.05).ConclusionPiglet (SC) and sow vaccination (ST) led to significant reduction in detectable antibodies in a ST positive production chain and thus to reduced likelihood of infection during rearing. The results reflect that vaccination with a live attenuated SC vaccine resulted in cross-protection against ST without producing antibodies detectable by standard Salmonella LPS-ELISA. Summarizing all fattening farms, piglet vaccination reduced seroprevalence at the time of slaughter. In conclusion, sow and piglet vaccination with attenuated live vaccines against Salmonella are good instruments to reduce the infection pressure in the rearing period but need additional management measures to show effect on seroprevalence at slaughter.

Controlling functional homeostasis of ileal resident macrophages by vitamin B12 during steady state and Salmonella infection in mice

Dietary micronutrients, particularly vitamin B12 (VB12), profoundly influence the physiological maintenance and function of intestinal cells. However, it is still unclear whether VB12 modulates the transcriptional and metabolic programming of ileal macrophages (iMacs), thereby contributing to intestinal homeostasis. Using multiomic approaches, we demonstrated that VB12 primarily supports the cell cycle activity and mitochondrial metabolism of iMacs, resulting in increased cell frequency compared to VB12 deficiency. VB12 also retained the ability to promote maintenance and metabolic regulation of iMacs during intestinal infection with Salmonella Typhimurium (STm). On the contrary, depletion of iMacs by inhibiting CSF1R signaling significantly increased host susceptibility to STm and prevented VB12-mediated pathogen reduction. These results thus suggest that regulation of VB12-dependent iMacs critically controls STm expansion, which may be of new relevance to advance our understanding of this vitamin and to strategically formulate sustainable therapeutic nutritional regimens that improve human gut health.