Linking S. aureus Immune Evasion Mechanisms to Staphylococcal Vaccine Failures.

Vaccination arguably remains the only long-term strategy to limit the spread of S. aureus infections and its related antibiotic resistance. To date, however, all staphylococcal vaccines tested in clinical trials have failed. In this review, we propose that the failure of S. aureus vaccines is intricately linked to prior host exposure to S. aureus and the pathogen's capacity to evade adaptive immune defenses. We suggest that non-protective immune imprints created by previous exposure to S. aureus are preferentially recalled by SA vaccines, and IL-10 induced by S. aureus plays a unique role in shaping these non-protective anti-staphylococcal immune responses. We discuss how S. aureus modifies the host immune landscape, which thereby necessitates alternative approaches to develop successful staphylococcal vaccines.

Efficacy and Safety of Different Dosing Regimens of Rivaroxaban in Patients With Atrial Fibrillation for Stroke Prevention: A Systematic Review and Meta-Analysis.

Atrial fibrillation (AF) poses a substantial risk of stroke, necessitating effective anticoagulation therapy. This systematic review and meta-analysis (SRMA) evaluates the efficacy and safety of different dosing regimens of rivaroxaban in patients with AF. A comprehensive search of relevant databases, focusing on studies published from 2017 onward, was conducted. Inclusion criteria comprised randomized controlled trials (RCTs) and observational studies comparing standard and reduced dosing of rivaroxaban in AF. Data extraction and risk of bias (ROB) assessment were performed, and a meta-analysis was conducted for relevant outcomes. A total of 21 studies fulfilled the inclusion criteria. Standard dosing demonstrates a slightly lower risk of composite effectiveness outcomes and safety outcomes (HR: 0.79, 95% CI: 0.66-0.94, P=0.01) compared to reduced dosing (HR: 0.83, 95% CI: 0.71-0.97, P=0.02). Notable differences in major bleeding, gastrointestinal bleeding (GIB), and intracranial bleeding favored standard dosing. Hemorrhagic stroke and all-cause stroke rates differed significantly, with standard dosing showing a more favorable profile for ischemic stroke prevention. This study highlights the pivotal role of personalized anticoagulation therapy in AF. Standard dosing of rivaroxaban emerges as a preferred strategy for stroke prevention, balancing efficacy and safety. Clinical decision-making should consider individual patient characteristics and future research should delve into specific subpopulations and long-term outcomes to further refine treatment guidelines. The study bridges evidence from clinical trials to real-world practice, offering insights into the evolving landscape of AF management.

A lightweight and robust authentication scheme for the healthcare system using public cloud server.

Cloud computing is vital in various applications, such as healthcare, transportation, governance, and mobile computing. When using a public cloud server, it is mandatory to be secured from all known threats because a minor attacker's disturbance severely threatens the whole system. A public cloud server is posed with numerous threats; an adversary can easily enter the server to access sensitive information, especially for the healthcare industry, which offers services to patients, researchers, labs, and hospitals in a flexible way with minimal operational costs. It is challenging to make it a reliable system and ensure the privacy and security of a cloud-enabled healthcare system. In this regard, numerous security mechanisms have been proposed in past decades. These protocols either suffer from replay attacks, are completed in three to four round trips or have maximum computation, which means the security doesn't balance with performance. Thus, this work uses a fuzzy extractor method to propose a robust security method for a cloud-enabled healthcare system based on Elliptic Curve Cryptography (ECC). The proposed scheme's security analysis has been examined formally with BAN logic, ROM and ProVerif and informally using pragmatic illustration and different attacks' discussions. The proposed security mechanism is analyzed in terms of communication and computation costs. Upon comparing the proposed protocol with prior work, it has been demonstrated that our scheme is 33.91% better in communication costs and 35.39% superior to its competitors in computation costs.

Experiences of Healthcare Workers in Long-Term Care during COVID-19: A Scoping Review.

Background: Although healthcare workers (HCWs) in long-term care (LTC) have experienced significant emotional and psychological distress throughout the pandemic, little is known about their unique experiences. Objective: This scoping review synthesizes existing research on the experiences of HCWs in LTC during the COVID-19 pandemic. Method: Following Arksey and O'Malley's framework, data published between March 2020 to June 2022, were extracted from six databases. Results: Among 3808 articles screened, 40 articles were included in the final analysis. Analyses revealed three interrelated themes: carrying the load (moral distress); building pressure and burning out (emotional exhaustion); and working through it (a sense of duty to care). Conclusion: Given the impacts of the pandemic on both HCW wellbeing and patient care, every effort must be made to address the LTC workforce crisis and evaluate best practices for supporting HCWs experiencing mental health concerns during and post-COVID-19.

Safety and efficacy of Empagliflozin in Pakistani Muslim patients with type 2 diabetes (SAFE-PAK); a randomized clinical trial.

BACKGROUND: Sodium-Glucose-Co-Transporter 2 (SGLT2) inhibitor (Empagliflozin) is an effective drug in controlling blood glucose through predominantly glycosuria. Glycosuria increases the risk of genitourinary infections in diabetes. This study was aimed to establish the safety and efficacy of Empagliflozin (Group-A) versus standard care (Group-B) in Pakistani Muslim individuals with type 2 diabetes. METHODS: A multicenter, randomized clinical trial was conducted in five cities across Pakistan from July 2019 to August 2020. Patients of both genders aged 18-75 years, body mass index (BMI) ≤ 45 kg/m2, glycosylated hemoglobin (HbA1c) 7-10% (53 mmol/mol to 86 mmol/mol) and treatment-naive to Empagliflozin were included. Treatment was given for 24 weeks, and allocation was done through randomization. RESULTS: Out of 745 screened patients, 333 met the eligibility criteria, and a total of 244 (73.3%) patients were enrolled. More hypoglycemic events were reported in the standard care group, whereas positive urine culture, fungal infection, dehydration, and hypotension occurrence were comparable between the two groups. The 6 months mean HbA1c reduction was significant in both groups; (Group-A: 0.91 ± 0.15; p < 0.001 vs. Group-B2: 0.79 ± 0.14; p < 0.001). Efficacy comparison at 6 months revealed a significant reduction in weight and systolic blood pressure (SBP) in Group A only (Group-A: 1.4 ± 0.4 kg; p < 0.002 vs. Group-B: 0.01 ± 0.5 kg; p < 1.00), (Group-A: 5.1 ± 1.7 mmHg; p < 0.012 vs. Group-B: 2.3 ± 1.7 mmHg; p < 0.526). CONCLUSIONS: Empagliflozin was a safe drug compared to standard care in Pakistani Muslim patients with diabetes. It was as effective as standard care in the clinical setting but achieved glycemic control by reducing weight and SBP in type 2 diabetes patients. TRIAL REGISTRATION: This study was registered in the NIH US National Library of Medicine clinical trials registry at Clinicaltrials.gov with the registration number: NCT04665284 on 11/12/2020.

Efficacy and Safety of Oral GnRh Antagonists in Patients With Uterine Fibroids: A Systematic Review.

OBJECTIVE: This review aimed to assess the efficacy and safety of GnRH antagonists in patients with symptomatic uterine fibroids. DATA SOURCES: A literature search was performed on PubMed, Web of Science, Embase, Cochrane, and ClinicalTrials.gov using the MeSH and Emtree terms "leiomyoma" and "gonadotropin-releasing hormone." STUDY SELECTION: All clinical trials that provided efficacy and safety data in clinical terms (i.e., reduction in menstrual bleeding and discomfort, changes in the size of leiomyoma and uterine volume, etc.) were included. We excluded all preclinical studies, case reports, meta-analyses, review articles, and clinical studies irrelevant to the study question. DATA EXTRACTION AND SYNTHESIS: Two authors extracted data from 9 clinical studies. The extracted data included the study's characteristics, participants' baseline characteristics, treatment drugs, efficacy measures, and toxicity. CONCLUSION: Among oral GnRH antagonists, relugolix, elagolix, and linzagolix were safe in patients with uterine fibroids. These drugs, alone and in combination with E2/NETA (estradiol/norethindrone acetate), showed significantly better efficacy than placebo in improving bleeding, discomfort, uterine/leiomyoma sizes, and quality of life in premenopausal patients with symptomatic uterine fibroids. However, more randomized, double-blind, multicentre clinical trials are needed to confirm these results and to see long-term benefits.

The complexity of examining laboratory-based biological markers associated with mortality in hospitalized patients during early phase of the COVID-19 pandemic: A systematic review and evidence map.

IMPORTANCE: The measurement of laboratory biomarkers plays a critical role in managing patients with COVID-19. However, to date most systematic reviews examining the association between laboratory biomarkers and mortality in hospitalized patients early in the pandemic focused on small sets of biomarkers, did not account for multiple studies including patients within the same institutions during overlapping timeframes, and did not include a significant number of studies conducted in countries other than China. OBJECTIVE: To provide a comprehensive summary and an evidence map examining the relationship between a wide range of laboratory biomarkers and mortality among patients hospitalized with COVID-19 during the early phase of the pandemic in multiple countries. EVIDENCE REVIEW: MEDLINE, EMBASE, and Web of Science were searched from Dec 2019 to March 9, 2021. A total of 14,049 studies were identified and screened independently by two raters; data was extracted by a single rater and verified by a second. Quality was assessed using the Joanna Briggs Institute (JBI) Case Series Critical Appraisal tool. To allow comparison across biomarkers, standardized mean differences (SMD) were used to quantify the relationship between laboratory biomarkers and hospital mortality. Meta-regression was conducted to account for clustering within institutions and countries. RESULTS: Our systematic review included 94 case-series studies from 30 countries. Across all biomarkers, the largest and most precise SMDs were observed for cardiac (troponin (1.03 (95% CI 0.86 to 1.21)), and BNP/NT-proBNP (0.93 (0.52 to 1.34)), inflammatory (IL-6 (0.97 (0.67 to 1.28) and Neutrophil-to-lymphocyte ratio (0.94 (0.59 to 1.29)), and renal biomarkers (blood urea nitrogen (1.01 (0.79 to 1.23)) and estimated glomerular filtration rate (-0.96 (-1.42 to -0.50)). There was heterogeneity for most biomarkers across countries with studies conducted in China generally having larger effect sizes. CONCLUSIONS AND RELEVANCE: The results of this study provide an early pandemic summary of the relationship between biomarkers and mortality in hospitalized patients. We found our estimated ESs were generally attenuated compared to previous systematic reviews which predominantly included studies conducted in China. Despite using sophisticated methodology to examine studies across countries, heterogeneity in reporting of case-series studies early in the pandemic limits clinical interpretability.

"Fish Gill" Incisions for Severe Periorbital Surgical Emphysema Following Tension Pneumothorax - A Case Report and Review of the Literature.

BACKGROUND: Surgical emphysema refers to the presence of air within the subcutaneous space and is a known complication of chest drain insertion. Symptoms range from mild crepitus of the chest wall to the accumulation of air in the face and neck, which can ultimately result in cardiovascular compromise. OBJECTIVE: The aim of this article is to present a rare case of cervical, facial and periorbital surgical emphysema following chest drain insertion, and describes a novel use of 'fish gill' incisions in the palpebromalar groove with an associated review of the literature. CASE REPORT: A 68-year-old gentleman presented with acute dyspnoea due to a right-sided tension pneumothorax. Emergency decompression with a Seldinger chest drain resulted in persistent cervical, facial and periorbital surgical emphysema causing difficulty in movement, inability to open the eyes and progressive risk to cervical venous return. "Fish gill' incisions at the lateral-most edge of the palpebromalar groove, down to the level of the orbicularis oculi muscle, rapidly released air from the face and neck, alleviating discomfort, reducing venous compression and restoring vision. CONCLUSION: Cervical, fascial and periorbital surgical emphysema may be resolved with the use of "fish gill" incisions at the lateral palpebromalar groove and simple drains. To the best of our knowledge, this method has not been reported previously in the literature.

Anti-Inflammatory Properties of Plasma from Children with Short Bowel Syndrome.

Sepsis, resulting from a dysregulated host immune response to invading pathogens, is the leading cause of mortality in critically ill patients worldwide. Immunomodulatory treatment for sepsis is currently lacking. Children with short bowel syndrome (SBS) may present with less severe symptoms during gram-negative bacteremia. We, therefore, tested the hypothesis that plasma from children with SBS could confer protection against Escherichia coli sepsis. We showed that SBS plasma at 5% and 10% concentrations significantly (p < 0.05) inhibited the production of both TNF-α and IL-6 induced by either E. coli- or LPS-stimulated host cells when compared to plasma from healthy controls. Furthermore, mice treated intravenously with select plasma samples from SBS or healthy subjects had reduced proinflammatory cytokine levels in plasma and a significant survival advantage after E. coli infection. However, SBS plasma was not more protective than the plasma of healthy subjects, suggesting that children with SBS have other immunomodulatory mechanisms, in addition to neutralizing antibodies, to alleviate their symptoms during gram-negative sepsis.

Secure Patient Authentication Framework in the Healthcare System Using Wireless Medical Sensor Networks.

Biosensor is a means to transmit some physical phenomena, like body temperature, pulse, respiratory rate, electroencephalogram (EEG), electrocardiogram (ECG), and blood pressure. Such transmission is performed via Wireless Medical Sensor Network (WMSN) while diagnosing patients remotely through Internet-of-Medical-Things (IoMT). The sensitive data transmitted through WMSN from IoMT over an insecure channel is vulnerable to several threats and needs proper attention to be secured from adversaries. In contrast to addressing the security of all associated entities involving patient monitoring in the healthcare system or ensuring the integrity, authorization, and nonrepudiation of information over the communication line, no one can guarantee its security without a robust authentication protocol. Therefore, we have proposed a lightweight and robust authentication scheme for the network-enabled healthcare devices (IoMT) that mitigate all the identified weaknesses posed in the recent literature. The proposed protocol's security has been analyzed formally using BAN logic and ProVerif2.02 and informally using pragmatic illustration. Simultaneously, at the end of the paper, the performance analysis result shows a delicate balance of security with performance that is often missing in the current protocols.

Asymptomatic urinary tract infections and associated risk factors in Pakistani Muslim type 2 diabetic patients.

BACKGROUND: One of the leading long-term complications of type 2 diabetes mellitus (T2DM) includes renal dysfunction and urinary tract infections (UTI) which are considered to be prevalent in uncontrolled diabetes. Moreover, physiological factors like age, gender, duration of diabetes, other diabetic complications like neuropathy, autonomic neuropathy and glycosuria are also considered as predisposing factors for increased prevalence of UTI in diabetes which can be symptomatic or asymptomatic. METHODS: This was a cross-sectional, multi-centre study including diabetic patients from 12 clinical sites spread across major cities of Pakistan. The inclusion criteria were adult Pakistani population of age between 18 to 75 years both genders and suffering from T2DM irrespective of duration. A detailed clinical history of the past 3 months was recorded and, biochemical investigations of blood samples were conducted. Urine culture analysis performed identified the type of pathogen present and was done only for asymptomatic patients. RESULTS: A total of 745 type 2 diabetic patients were initially screened, out of 545 patients considered for final analysis 501 (91.92%) were negative and the rest 44 (8.08%) had positive urine culture. Female gender had a significantly higher proportion of positive urine culture (77.27%, p-value< 0.001). Body mass index and mean age had insignificant distribution among the two groups of positive and negative urine culture, with age 40-59 years having higher proportion (70.45%) in the positive group. Escherichia coli was detected in most of the positive samples (52.3%). All bacterial samples were found resistant to Ciprofloxacin. CONCLUSION: Diabetic Pakistani muslim female patients are identified to be at high risk of suffering from asymptomatic UTI and age more than 40 years is an important risk factor. Escherichia coli was the most common causative organism among people living in this geographical area.

Oral immunization with an attenuated Salmonella Gallinarum encoding the H9N2 haemagglutinin and M2 ectodomain induces protective immune responses against H9N2 infection in chickens.

H9N2, a low pathogenic avian influenza virus, causes significant economic losses in the poultry industry worldwide. Herein, we describe the construction of an attenuated Salmonella Gallinarum (SG) strain for expression and delivery of H9N2 haemagglutinin (HA) 1 (SG-HA1), HA2 (SG-HA2) and/or the conserved matrix protein 2 ectodomain (SG-M2e). We demonstrated that recombinant SG strains expressing HA1, HA2 and M2e antigens were immunogenic and safe in a chicken model. Chickens (n = 8) were vaccinated once orally with SG alone, SG-HA1, SG-HA2, SG-M2e, or mixture of SG-HA1, SG-HA2 and SG-M2e, or vaccinated once intramuscularly with an oil-adjuvant inactivated H9N2 vaccine. Our results demonstrated that vaccination with SG mutants encoding influenza antigens, administered individually or as a mixture, elicited significantly (P < 0.05) greater antigen-specific humoral and cell-mediated immune responses in chickens compared with those vaccinated with SG alone. A conventional H9N2 vaccine induced significantly (P < 0.05) greater HA1 and HA2 antibody responses than SG-based H9N2 vaccine strains, but significantly (P < 0.05) less robust M2e-specific responses. Upon challenge with the virulent H9N2 virus on day 28 post-vaccination, chickens vaccinated with either the SG-based H9N2 or conventional H9N2 vaccines exhibited comparable lung inflammation and viral loads, although both were significantly lower (P < 0.05) than in the group vaccinated with SG alone. In conclusion, our results showed that SG-based vaccination stimulated efficient immune responses against virulent H9N2. Further studies are needed to fully develop this approach as a preventive strategy for low pathogenic avian influenza viruses affecting poultry. RESEARCH HIGHLIGHTS S. gallinarum expressing HA1, HA2 and M2e antigens are immunogenic and safe. Salmonella has dual function of acting as a delivery system and as a natural adjuvant. Vaccine constructs elicit specific humoral and cell-mediated immune responses.

Intranasally administered protein coated chitosan nanoparticles encapsulating influenza H9N2 HA2 and M2e mRNA molecules elicit protective immunity against avian influenza viruses in chickens.

Chitosan nanoparticles (CNPs) represent an efficient vaccination tool to deliver immunogenic antigens to the antigen-presenting cells (APCs), which subsequently stimulate protective immune responses against infectious diseases. Herein, we prepared CNPs encapsulating mRNA molecules followed by surface coating with conserved H9N2 HA2 and M2e influenza proteins. We demonstrated that CNPs efficiently delivered mRNA molecules into APCs and had effectively penetrated the mucosal barrier to reach to the immune initiation sites. To investigate the potential of CNPs delivering influenza antigens to stimulate protective immunity, we intranasally vaccinated chickens with empty CNPs, CNPs delivering HA2 and M2e in both mRNA and protein formats (CNPs + RNA + Pr) or CNPs delivering antigens in protein format only (CNPs + Pr). Our results demonstrated that chickens vaccinated with CNPs + RNA + Pr elicited significantly (p < 0.05) higher systemic IgG, mucosal IgA antibody responses and cellular immune responses compared to the CNPs + Pr vaccinated group. Consequently, upon challenge with either H7N9 or H9N2 avian influenza viruses (AIVs), efficient protection, in the context of viral load and lung pathology, was observed in chickens vaccinated with CNPs + RNA + Pr than CNPs + Pr vaccinated group. In conclusion, we show that HA2 and M2e antigens elicited a broad spectrum of protection against AIVs and incorporation of mRNAs in vaccine formulation is an effective strategy to induce superior immune responses.

Human antigen presenting cells stimulated with Salmonella delivered influenza antigens induce cytokine production and proliferation of human CD4+ T cells in vitro.

This study aimed to investigate whether the human antigen presenting cells (APCs) can process and present Salmonella expressing H7N9 hemagglutinin (Sal-HA), neuraminidase (Sal-NA) or M2 ectodomain (Sal-M2e) to T cells and subsequently activate CD4+ T cell responses in vitro. In this study, APCs generated from human peripheral blood mononuclear cells (PBMCs) were first treated with mitomycin-C, followed by stimulation with Sal-HA, Sal-M2e, Sal-NA or Salmonella alone for 24 h. Subsequently, stimulated APCs were coincubated with untreated PBMCs (1:10) of the same individual for 24 or 72 h and then analysed for cytokine induction and T cell proliferations by qRT-PCR assay and flow cytometry, respectively. Our results demonstrated that APCs stimulated with Sal-HA, Sal-M2e or Sal-NA induced significantly (p < .05) higher CD3+CD4+ T cell proliferations compared to the APCs treated with Salmonella alone. Our data further revealved that APCs treated with Sal-HA induced significantly (p < .05) higher CD3+CD4+ T cell responses compared to the APCs treated with either Sal-M2e or Sal-NA, which both induced almost comparable levels. The T cell proliferation responses were further measured by lymphocyte proliferation assay and the results showed that Sal-HA and Sal-M2e stimulated APCs induced significantly (p < .05) higher proliferations in T cells compared to the APCs stimulated with either Sal-NA or Salmonella alone. With respect to cytokine inductions, APCs treated with either Sal-HA or Sal-M2e induced significantly (p < .05) higher mRNA transcription levels of proinflammatory (IL-1ß, IL-6, IL-12 and IL-23), Th1 (IFN-γ), Th17 (IL-17 and IL-21) and Th2 (IL-10 and TGF-ß) cytokines in T cells compared to Sal-NA or Salmonella alone treated APCs. In conclusion, we show that Salmonella system can efficiently deliver vaccine antigens to APCs and is, thus, capable to elicit heterologous antigen-specific adaptive immunity.

Intranasally administered polyethylenimine adjuvanted influenza M2 ectodomain induces partial protection against H9N2 influenza A virus infection in chickens.

This study aimed to investigate whether intranasally coadministered four tandem copies of extracellular domains of M2 (M2e) and polyethyleneimine (PEI), a mucosal adjuvant, can protect chickens against H9N2 influenza A virus infection. Groups of chickens were intranasally vaccinated with M2e plus PEI adjuvant, M2e alone or PEI adjuvant, and antibody (serum IgG and mucosal IgA) and cellular (CD4+ T cells and IFN-γ levels) immune responses were measured post-vaccination. We demonstrated that the chickens vaccinated with M2e plus PEI adjuvant showed significantly (p < 0.05) higher M2e-specific systemic IgG and mucosal IgA responses compared to the chickens that received either M2e alone or PEI adjuvant. The IgA responses measured in lungs were almost comparable to that of the serum IgG levels. Upon restimulation of the vaccinated peripheral blood mononuclear cells (PBMCs) with M2e antigen, significantly (p < 0.05) higher IFN-γ levels were observed only in M2e plus PEI adjuvant vaccinated group. Lymphoproliferative and CD4+ T cell responses, as measured by MTT-based assay and flow cytometry, respectively, were also observed significantly (p < 0.05) higher in M2e plus PEI adjuvant vaccinated chickens. On challenge with the H9N2 virus (104TCID50) at 28th day post-vaccination, M2e plus PEI adjuvant vaccinated group exhibited lower lung inflammation and viral load compared to the chickens treated with either M2e alone or PEI adjuvant. In summary, we show that intranasally coadministered M2e and PEI adjuvant can elicit humoral and cell-mediated immune responses and can reduce viremia levels in chickens post H9N2 infection in chickens.

Salmonella Gallinarum delivering M2eCD40L in protein and DNA formats acts as a bivalent vaccine against fowl typhoid and H9N2 infection in chickens.

Fowl typhoid (FT), a septicemic disease caused by Salmonella Gallinarum (SG), and H9N2 influenza infection are two economically important diseases that affect poultry industry worldwide. Herein, we exploited a live attenuated SG mutant (JOL967) to deliver highly conserved extracellular domains of H9N2 M2 (M2e) to induce protective immunity against both H9N2 infection and FT. To increase the immunogenicity of M2e, we physically linked it with CD40L and cloned the fusion gene into either prokaryotic constitutive expression vector pJHL65 or mammalian expression vector pcDNA3.1+. Then pJHL65-M2eCD40L or pcDNA-M2eCD40L recombinant plasmid was electroporated into JOL967 strain and the resultant clones were designated as JOL2074 and JOL2076, respectively. We demonstrated that the chickens vaccinated once orally with a co-mix of JOL2074 and JOL2076 strains elicited significantly (p < 0.05) higher M2e-specific humoral and cell-mediated immunity compared to JOL2074 alone vaccinated group. However, SG-specific immune responses were comparable in both the vaccination groups. On challenge with the virulent H9N2 virus (105 TCID50) at 28th day post-vaccination, chickens that received a co-mix of JOL2074 plus JOL2076 strains exhibited significantly (p < 0.05) lower lung inflammation and viral load in both lungs and cloacal samples than JOL2074 alone vaccinated group. Against challenge with the lethal wild-type SG, both the vaccination groups exhibited only 12.5% mortality compared to 75% mortality observed in the control group. In conclusion, we show that SG delivering M2eCD40L can act as a bivalent vaccine against FT and H9N2 infection and further studies are warranted to develop this SG-M2eCD40L vaccine as a broadly protective vaccine against avian influenza virus subtypes.

Oral immunization with a novel attenuated Salmonella Gallinarum encoding infectious bronchitis virus spike protein induces protective immune responses against fowl typhoid and infectious bronchitis in chickens.

Fowl typhoid (FT), a septicemic disease caused by Salmonella Gallinarum (SG), and infectious bronchitis (IB) are two economically important avian diseases that affect poultry industry worldwide. Herein, we exploited a live attenuated SG mutant, JOL967, to deliver spike (S) protein 1 of IB virus (V) to elicit protective immunity against both FT and IB in chickens. The codon optimized S1 nucleotide sequence was cloned in-frame into a prokaryotic constitutive expression vector, pJHL65. Subsequently, empty pJHL65 or recombinant pJHL65-S1 plasmid was electroporated into JOL967 and the resultant clones were designated as JOL2068 and JOL2077, respectively. Our results demonstrated that the chickens vaccinated once orally with JOL2077 elicited significantly (p < 0.05) higher IBV-specific humoral and cell-mediated immunity compared to JOL2068 and PBS control groups. Consequently, on challenge with the virulent IBV strain at 28th day post-vaccination, JOL2077 vaccinated birds displayed significantly (p < 0.05) lower inflammatory lesions in virus-targeted tissues compared to control groups. Furthermore, 33.3% (2 of 6) of birds vaccinated with JOL2077 vaccine had shown virus recovery from tracheal tissues compared to 100% (6 of 6) recovery obtained in both the control groups. Against wild-type SG lethal challenge, both JOL2077 and JOL2068 vaccinated groups exhibited only 10% mortality compared to 80% mortality observed in PBS control group. In conclusion, we show that JOL2077 can induce efficient IBV- and carrier-specific protective immunity and can act as a bivalent vaccine against FT and IB. Further studies are warranted to investigate the potential of JOL2077 vaccine in broiler and young layer birds.

Chemokine CCL20 plasmid improves protective efficacy of the Montanide ISA™ 206 adjuvanted foot-and-mouth disease vaccine in mice model.

This study aimed to investigate the chemokine CCL20, a macrophage inflammatory protein-3 alpha, for adjuvant potential in inactivated foot-and-mouth disease (FMD) vaccine. Groups of mice were injected intramuscularly with either murine CCL20 DNA or CCL20 protein two days ahead of the immunization with Montanide ISA206 adjuvanted inactivated FMD vaccine and humoral and cellular immune responses were measured in post-vaccinal sera. We demonstrated that the mice immunized with CCL20 plasmid plus FMD vaccine showed earlier and significantly (p < 0.05) higher neutralizing antibody responses compared to the mice vaccinated with CCL20 protein plus FMD vaccine. In fact, CCL20 as a protein did not show any adjuvant effect and the immune responses induced in this group were comparable to that of the mice vaccinated with FMD vaccine alone. All the vaccination groups showed serum IgG1 and IgG2 antibody responses; however, the mice vaccinated with CCL20 plasmid plus FMD vaccine showed significantly (p < 0.05) higher IgG1 and IgG2 responses and the responses remained high at all-time points post vaccination, although not always statistically significant. Upon restimulation of the vaccinated splenocytes with the inactivated FMD viral antigen, significantly (p < 0.05) higher IFN-γ and IL-2 levels in culture supernatants were found in animals vaccinated with the CCL20 plasmid plus FMD vaccine, which is indicative of the TH1 type of cellular immunity. On challenge with the homologous FMD virus on 28th day post immunization, CCL20 plasmid plus FMD vaccine showed complete protection (100%) while animals immunized with CCL20 protein plus FMD vaccine or FMD vaccine alone showed 66% protection. In summary, we show that prior injection of CCL20 plasmid improved protective efficacy of the inactivated FMD vaccine and thus offers a valuable strategy to modulate the efficacy and polarization of specific immunity against inactivated vaccines.

Incorporation of membrane-anchored flagellin into Salmonella Gallinarum bacterial ghosts induces early immune responses and protection against fowl typhoid in young layer chickens.

The present study aimed to investigate whether the incorporation of flagellin, a TLR5 agonist, in the bacterial ghosts (BGs) of Salmonella Gallinarum can enhance protective immune responses against fowl typhoid, a septicemic disease of poultry, in chickens. BGs are empty cell envelopes derived from Gram-negative bacteria through the bacteriophage phiX174 gene E mediated lysis. In this study, the S. Gallinarum ghosts carrying flagellin were genetically constructed utilizing a lysis plasmid pJHL184-flagellin, designed for the coexpression of the flagellin and the lysis protein E. The adjuvant effect of flagellin was evaluated by immunizing seven day old brown nick layer chicks once orally with either S. Gallinarum-flagellin (SG-fliC) ghosts or S. Gallinarum (SG) ghosts alone. Our results showed that immunization with the SG-fliC ghosts elicited early and higher systemic (IgG) and mucosal (IgA) antibody responses compared to the SG ghosts alone, although not always statistically significant. Flow cytometric analysis of the CD3 + CD4+ and the CD3 + CD8+ T cell populations in peripheral blood mononuclear cells were higher in chickens immunized with the SG-fliC ghosts compared to the chickens vaccinated with the SG ghosts alone. Furthermore, the chickens immunized with SG-fliC ghosts exhibited significantly (p < 0.05) higher IL-6 and IFN-γ responses compared to the chickens vaccinated with the SG ghosts alone. On challenge with the virulent S. Gallinarum wild type strain at 28th day post immunization, 5 of 10 birds died (50%) in case of SG-fliC ghost group while 60% (6 of 10 birds died) mortality was observed in the SG ghost group. Collectively, these results suggest that the expression of flagellin in SG ghosts improves antigen-specific humoral and cell mediated immune responses, and can enhance protective efficacy of the BG-based vaccines against the virulent challenges.

Immunomodulatory effects of probiotics and prilled fat supplementation on immune genes expression and lymphocyte proliferation of transition stage Karan Fries cows.

BACKGROUND AND AIM: Probiotics are the living microorganism which when administered improves the digestion and health of the animal. Saccharomyces cerevisiae (SC) improves the humoral and innate immunity of the animal. Prilled fat is a hydrogenated palm oil triglyceride which has been reported to promote the release of cytokines from macrophages. The aim of the study was to evaluate the immunomodulatory effect of probiotic and prilled fat during transition stage in Karan Fries (KF) cows. MATERIALS AND METHODS: A total of 12 KF cows at 21 days prepartum were selected and divided into two groups of six animals each. The control group was fed as per the standard feeding practices and the supplemented group cows were supplemented daily with prilled fat at 100 g/cow, SC at 25 g/cow, and sweetener at 1 g/cow in addition to the standard feeding practices from -30 days of prepartum to 21 days of lactation. The sweetener was added to improve the palatability of the feed. The natural sweetener of an African plant leave had 105 times more sweetness than glucose with good aroma. The dry matter intake of the animal was recorded. Plasma samples were collected weekly from all cows for the analysis of blood metabolite beta-hydroxybutyric acid (BHBA). Lymphocytes were isolated from the blood for studying the expression of tumor necrosis factor alpha (TNF-α) and interleukin-1ß (IL-1ß) and for estimating lymphocyte proliferation index (LPI). RESULTS: The upregulated IL-1ß and TNF-α around calving might be possibly associated to the metabolic changes occurring during the transition period and suggest a higher degree of inflammation around parturition. High concentrations of BHBA caused increased expression and synthesis of the pro-inflammatory factors such as TNF-α and IL-1ß in supplemented group in primary calf hepatocytes. The LPI was higher in supplemented group as compared to control which suggests a stimulatory effect of unsaturated fatty acids on mitogen-stimulated T-cell proliferation. CONCLUSION: Dietary supplementation of probiotics, prilled fat, and sweetener alleviated negative energy balance by stimulating feed intake and modulating hepatic lipid metabolism; and both of these additives improved the postpartum health (antioxidant status and immune function) of transition dairy cows.