Unraveling the immunopotentiation of P. aeruginosa PAPI-1 encoded pilin: From immunoinformatics survey to active immunization.

For protection against Pseudomonas aeruginosa strains, a number of vaccine candidates have been introduced thus far. However, despite significant attempts in recent years, there are currently no effective immunogenic Bacteria components against this pathogen on the market. P. aeruginosa encoding a number of different virulence characteristics, as well as the rapid growth in multiple drug-resistant forms, has raised numerous health issues throughout the world. This pathogen expresses three different subtypes of T4P, including IVa, IVb, and Tad which are involved in various cellular processes. Highly virulent strains of P. aeruginosa can encode well-conserved PAPI-1 associated PilS2 pilus. Designing an efficient pili-based immunotherapy approach targeting P. aeruginosa pilus has remained controversial due to the variability heterogeneousness and hidden well-preserved binding site of T4aP and no approved human study is commercially based on IVa pilin. In this investigation, for the first time, through analytical immunoinformatics, we designed an effective chimeric PilS2 immunogen against numerous clinically important P. aeruginosa strains. Through active immunization against the extremely conserved region of the chimeric PilS2 pilin, we showed that PilS2 chimeric pilin whether administered alone or formulated with alum as an adjuvant could substantially stimulate humoral immunological responses in BALB/c mice. Based on these findings, we conclude that PilS2 pilin is therapeutically effective against a variety of highly virulent strains of P. aeruginosa and can act as a new immunogen for more research towards the creation of efficient immunotherapy techniques against the P. aeruginosa as a dexterous pathogen.

Accuracy of diagnostic assays for the detection of Clostridioides difficile: A systematic review and meta-analysis.

INTRODUCTION: Clostridioides difficile Infection (CDI) has been identified as one of the main causes of nosocomial infection all across the world. Rapid diagnosis of CDI is difficult and poses a significant challenge to physicians worldwide. We undertook a systematic review and meta-analysis to evaluate rapid tests' diagnostic accuracy against toxigenic culture as the reference standard for CDI. METHOD: We searched the PubMed/MEDLINE and EMBASE databases for the relevant records. The QUADAS-2 tool was used to assess the quality of the studies. Diagnostic accuracy measures [i.e., sensitivity, specificity, diagnostic odds ratio (DOR), positive likelihood ratios (PLR), negative likelihood ratios (NLR), and the area under the curve (AUC)] were pooled with a random-effects model. All statistical analyses were performed with Meta-DiSc (Version 1.4, Cochrane Colloquium, Barcelona, Spain) and RevMan (version 5.3; The Nordic Cochrane Centre, the Cochrane Collaboration, Copenhagen, Denmark). RESULTS: We reviewed retrieved records and identified 63 studies that met the inclusion criteria. 26 were about enzyme immunoassay (EIA) (our main index test). The sensitivity of GDH and Tox A/B EIAs were 82% (95% CI: 79-84) and 75% (95% CI: 70-79), respectively. On the other hand, the specificity of GDH EIA was 91% (95% CI: 90-92) and the specificity of Tox A/B EIA was 95% (95% CI: 94-96). Among other index tests, BD Max with 92% has the most sensitivity and cell cytotoxicity neutralization assay (CCNA) has the most specificity (100%). CONCLUSION: This meta-analysis demonstrated that EIAs could be reliable methods for detecting CDI based on their sensitivity, specificity, time and cost-effectiveness, and simplicity in the procedure. Further work to improve rapid tests would benefit from improvements to the methodology.

Impact of educational interventions on the prevention of influenza: A systematic review.

Introduction: Seasonal influenza, a contagious viral disease affecting the upper respiratory tract, circulates annually, causing considerable morbidity and mortality. The present study investigates the effectiveness of educational interventions to prevent influenza. Methods: We searched PubMed/Medline, Embase, and Cochrane Controlled Register of Trials (CENTRAL) for relevant clinical studies up to March 1 2022. The following terms were used: "influenza," "flu," "respiratory infection," "prevent," "intervention," and "education." Results: Out of 255 studies, 21 articles satisfied the inclusion criteria and were included in our study: 13 parallel randomized controlled trials (RCT) studies, two cross-over RCT studies, two cohort studies, and four quasi-experimental studies. A total of approximately 12,500 adults (18 years old or above) and 11,000 children were evaluated. Educational sessions and reminders were the most common interventions. The measured outcomes were vaccination rates, the incidence of respiratory tract infection (RTI), and preventive behaviors among participants. Eighteen out of 21 articles showed a significant association between educational interventions and the outcomes. Conclusions: The included studies in the current systematic review reported the efficacy of health promotion educational interventions in improving knowledge about influenza, influenza prevention behaviors, vaccination rates, and decreased RTI incidence regardless of the type of intervention and the age of cases.

Immunopotentiation of the engineered low-molecular-weight pilin targeting Pseudomonas aeruginosa: A combination of immunoinformatics investigation and active immunization.

Several vaccine candidates have been introduced for immunization against Pseudomonas aeruginosa strains. Despite extensive efforts in recent decades, there is no accurate immunogenic candidate against this pathogen in the market yet. Due to the rapid increase in several drug-resistant strains, P. aeruginosa has caused various health concerns worldwide. It encodes many specific virulence features, which can be used as an appropriate vaccine candidate. The primary stage of the pathogenesis of P. aeruginosa is the expression of many dynamic adhesive molecules, such as type IV pili (T4P), which acts as a principal colonization factor. It has been confirmed that three different subtypes of T4P, including type IVa (T4aP), type IVb (T4bP) and tight adherence (Tad) pili are expressed by P. aeruginosa. The IVa fimbriae type is almost the main cause of challenges to design an effective pili based-immunotherapy method. Nevertheless, in terms of heterogeneity, variability and hidden conserved binding site of T4aP, this attitude has been remained controversial and there is no permitted human study based on IVa pilin commercially. The engineered synthetic peptide-based vaccines are highly talented to mimic the target. In this research, for the first time, some dominant immunogenic features of the Flp protein, such as both B- and T-cell-associated epitopes, presence of IgE-associated epitopes, solvent-accessible surface area were evaluated by analytical immunoinformatics methods. In addition, we designed the engineered Flp pilin as an effective immunogenic substance against several clinically important P. aeruginosa strains. Moreover, by practical active immunization approaches, the humoral and cellular immune response against the extremely conserved region of the engineered synthetic Flp (EFlp) formulated in Montanide ISA 266 compared to the control group. The results of active immunization against EFlp significantly signified that EFlp-Montanide ISA 266 (EFLP-M) strongly could induce both humoral and cellular immune responses. We concluded that Flp pilin has therapeutic potential against numerous clinically significant P. aeruginosa strains and can be served as a novel immunogen for further investigations for development of effective immunotherapy methods against P. aeruginosa as a dexterous pathogen.

Decreased carO gene expression and OXA-type carbapenemases among extensively drug-resistant Acinetobacter baumannii strains isolated from burn patients in Tehran, Iran.

A major challenge in the treatment of infections has been the rise of extensively drug resistance (XDR) and multidrug resistance (MDR) in Acinetobacter baumannii. The goals of this study were to determine the pattern of antimicrobial susceptibility, blaOXA and carO genes among burn-isolated A. baumannii strains. In this study, 100 A. baumannii strains were isolated from burn patients and their susceptibilities to different antibiotics were determined using disc diffusion testing and broth microdilution. Presence of carO gene and OXA-type carbapenemase genes was tested by PCR and sequencing. SDS-PAGE was done to survey CarO porin and the expression level of carO gene was evaluated by Real-Time PCR. A high rate of resistance to meropenem (98%), imipenem (98%) and doripenem (98%) was detected. All tested A. baumannii strains were susceptible to colistin. The results indicated that 84.9% were XDR and 97.9% of strains were MDR. In addition, all strains bore blaOXA-51 like and blaOXA-23 like and carO genes. Nonetheless, blaOXA-58 like and blaOXA-24 like genes were harbored by 0 percent and 76 percent of strains, respectively. The relative expression levels of the carO gene ranged from 0.06 to 35.01 fold lower than that of carbapenem-susceptible A. baumannii ATCC19606 and SDS - PAGE analysis of the outer membrane protein showed that all 100 isolates produced CarO. The results of current study revealed prevalence of blaOXA genes and changes in carO gene expression in carbapenem resistant A.baumannii.

Molecular characterization of the pilS2 gene and its association with the frequency of Pseudomonas aeruginosa plasmid pKLC102 and PAPI-1 pathogenicity island.

INTRODUCTION: Pseudomonas aeruginosa is the most common opportunistic pathogen associated with a broad range of infections, including cystic fibrosis, ocular, otitis media, and burn infections. The aim of this study was to show the frequency of the pilS2 gene, and its association with P. aeruginosa plasmid pKLC102 and PAPI-1 pathogenicity island among P. aeruginosa strains. METHODS: The samples were collected from patients with cystic fibrosis, ocular, otitis media, and burn infections between January 2016 and November 2017. DNA was extracted using the DNA extraction kit and was used for PCR assay. PCR with 4 primer-pairs including 976 F/PAPI-1R, 4542 F/intF, SojR/4541 F, and intF/sojR was performed to identify PAPI-1. pKLC102 was detected using three other primer-pairs including cp10F/cp10R, cp44F/cp44R, and cp97F/cp97R. RESULTS: A total of 112 P. aeruginosa isolates were collected from patients with cystic fibrosis (36), burn (20), otitis media (26), and ocular (30) infections. The results of PCR showed that pilS2 gene was identified in 96 (85%) strains. PAPI-1-attB integration was detected among 38 (33.9%) isolates and the circular form of PAPI-1 detected among 17 (14%) isolates. In addition, 79 (70.5%) strains were found to be positive for pKLC102. CONCLUSION: We found that the majority of the isolates may be susceptible to transfer this significant island and the related element pKLC102 into recipient isolates lacking the island owing to high association of the PilS2 pilus with the islands in the studied strains. It is anticipated that strains isolated from burn and eye with the highest rate of PilS2, PAPI-1, and pKLC102 association have a high level of antibiotic resistance.

First report of New Delhi metallo-ß-lactamase-6 (NDM-6) among Klebsiella pneumoniae ST147 strains isolated from dialysis patients in Iran.

There has been an alarming health-related concern about the growth of New Delhi metallo-ß-lactamase. The aims of this study include the phenotypic detection of ß-lactamases and molecular characterization of NDM in Klebsiella pneumoniae isolates in Tehran, Iran. A total of 120 K. pneumoniae isolates were collected from hospitalized haemodialysis patients, Tehran, Iran from March 2014 to February 2017. Antibiotic susceptibility tests were conducted using Kirby-Bauer disc diffusion and Broth Microdilution methods according to Clinical and Laboratory Standards Institute guidelines. Metallo-ß-lactamase was detected using the Combined Disc Diffusion Test (CDDT), and production of carbapenemase was screened using the Modified Hodge Test. NDM-producing K. pneumoniae strains were screened for the presence of mcr-1 gene, ß-lactamase genes, and 16S rRNA methylase genes by Polymerase Chain Reaction and sequencing. Molecular typing of the strains was determined using Repetitive Sequence Based-PCR and Multilocus Sequence Typing. The blaNDM-6 gene was detected in 3 (2.5%) out of 120 isolates from dialysis patients. Also, the three isolates were positive for blaCTX-M-15,blaTEM extended-spectrum ß-lactamase genes, armA type plasmid-mediated 16S rRNA methylase and CMY-type plasmid-mediated AmpC ß-lactamase. The isolates were identified as MLST sequence type 147 (ST147). This is the first report of blaNDM-6 in K. pneumoniae strains, isolated in Iran.

A survey on chimeric UreB229-561-HpaA protein targeting Helicobacter pylori: Computational and in vitro urease activity valuation.

Helicobacter pylori (H. pylori) as microaerophilic, Gram-negative bacterium colonize the human gastric milieu, where it impetuses chronic disorders. Vaccination is a complementary plan, along with antibiotic therapy, for clearance of H. pylori. Today, Computer based tools are essential for the evaluation, design, and experiment for novel chimeric targets for immunological administration. The purpose of this experiment was immunoinformatic analysis of UreB and HpaA molecules in a fusion arrangement and also, construction and expression of recombinant protein containing chimeric sequences. The targets sequences were screened by using of standard in silico tools and immunoinformatic web servers. The high-resolution 3D models of the protein were created and were validated; indeed, the B-and T-cell restricted epitopes were mapped on the chimeric protein. The recombinant protein in frame of the expression vector pET28a were expressed and purified successfully. The urease activity and immunoblotting were performed in vitro condition. This study confirmed that the engineered protein as a highly conserved, hydrophilic, non-allergenic contained remarkable B-cell and T-cell epitopes. It was magnificently attained; chimeric UreB229-561-HpaA could provoke both humoral and cellular immunity. The immunoblotting was shown that the chimeric protein could be detected by serum of immunized animal and H.pylori positive patients. In this study, several antigenic patches from UreB and HpaA were identified that could be an efficient immune system activator. The in vitro analysis of our chimeric molecule confirmed its urease activity. It also confirmed that the chimeric protein could be detected by serum of immunized animal and H.pylori positive patients.

The role of bacteria in the inflammatory bowel disease development: a narrative review.

Inflammatory bowel disease (IBD) is a general term used for the ulcerative colitis (UC) and Crohn's disease (CD); in addition, IBD principally refers to a chronic disease of the gastrointestinal tract in which mediated by immune system. Consequently, IBD could progress in individuals who are genetically prone. Infections role in the development of inflammatory disease of the gastrointestinal tract has been studied by quite many clinical studies; furthermore, the possible role of some pathogens in the development and exacerbation of the inflammatory disease of the gastrointestinal tract have been described. Evidently, the most indispensable pathogens that could be associated with the IBD disease, Mycobacterium avium subspecies paratuberculosis, Clostridium difficile, Escherichia coli, Listeria monocytogenes, Campylobacter concisus; as well as viruses, such as, cytomegalovirus, Epstein-Barr Virus, and measles virus are notable. A number of pathogenic parasites may also be involved in the development and progression of the disease. As a matter of fact, overexposure of immune system in the presence of excessive bacterial substances could also lead to the loss of immunological tolerance to the bacteria, which are commonly considered as the normal flora in the intestine; furthermore, it may subsequently elicit bowel inflammation and IBD development. In the current study, we discussed the most common bacterial pathogens that may be involved in the development of IBD; as well as, a comprehensive narrative review related to the evidences which support or ignore the possible role of bacteria in progression of IBD, indeed.

The effect of in silico targeting Pseudomonas aeruginosa patatin-like protein D, for immunogenic administration.

The vaccine candidates that have been introduced for immunization against Pseudomonas aeruginosa (P. aeruginosa) strains are quite diverse. In fact, there has been no proper antigen to act as an effective immunogenic substance against this ubiquitous pathogen in the market as yet. The complications caused by this bacterium due to the rapid development of multiple drug resistant strains have led to clinical problems worldwide. P. aeruginosa encodes many specific virulence elements that could be used as appropriate vaccine candidates. Type Vd secretion system, also known as patatin-like protein D, is a novel P. aeruginosa auto-transporter system. It is known that cellular or humoral immune responses could be elevated by chimeric proteins carrying epitopes. It has been recognized that in silico tools are essential for the evaluation of new chimeric antigens. In this study, we have considered the patatin-like protein D (PlpD) molecule from P. aeruginosa and predicted some immunogenic properties of this strong cytotoxic phospholipase A2 with the use of in-depth computational and immunoinformatics assessment methods The novelty of our in silico study is the modeling and assessment of both humoral and cellular immune potential against the PlpD molecule. The molecule was considered by multiple sequence alignment and homology valuation. The extremely conserved regions in the PlpD were predicted. The allergenic and physicochemical property predictions on the PlpD state that the molecule is a non-allergic and stable molecule. High-resolution secondary and tertiary conformations were created. Indeed, the B-cell and T-cell epitope mapping on the chimeric target protein confirmed that the engineered protein contained a tremendous number of both B-cell and T-cell corresponding epitopes. This investigation magnificently attained the chimeric molecule as being a potent lipolytic enzyme composed of numerous B-cell and T-cell restricted epitopes and could induce both humoral and cellular immune responses. The results indicated that this molecule has therapeutic potential against several potent pathogenic P. aeruginosa strains.

Comprehensive review on the antimicrobial potency of the plant polyphenol Resveratrol.

Treatment of some infectious diseases are becoming more complicated because of increasing drug resistance rate and lack of proper antibiotics. Because of the rapid increase in drug-resistance trend, there is an urgent need for alternative microbicides to control infectious diseases. Resveratrol (RSV) is a small plant polyphenol that is naturally produced and distributed in 72 particular families of plants. The usage of natural derivatives such as RSV, have become popular among researchers for curing acute and chronic diseases. The purpose of the preset study was to comprehensively review and survey the antimicrobial potency of RSV. The present study demonstrates RSV as a natural antimicrobial agent.

Isoniazid-resistant tuberculosis in Iran: A systematic review.

Isoniazid (INH) is one of the most potent anti-tuberculosis (TB) agents. INH resistance is an obstacle to the treatment of TB disease and the National TB control Program (NTP). We aimed to determine the true prevalence of INH-resistant TB in Iran. Several databases including Embase, Medline, Cochrane library and Iranian databases were searched to identify studies addressing INH-resistant tuberculosis in Iran. We identified 156 articles, of which 129 records were excluded based on their titles and abstracts. In a secondary screening, we assessed the eligibility of 27 full-text articles of which, 6 did not report usage data. Finally, 21 studies published from different regions of Iran from March 1999 until July 2015 were included in this study. Comprehensive meta-analysis (V2.2, Biostat) software was used to analyze the data. The meta-analysis showed that 12.8% (95% CI 9.4-15.8; I(2) = 87.8; P < 0.001 test for heterogeneity) of new TB cases and 40.1% (95% CI 28.5-53.0; I(2) = 88.2; P < 0.001 test for heterogeneity) of previously treated cases were resistant to INH. High prevalence of INH resistance among TB patients has been reported in many health-care settings, suggesting that better management of such cases, use of effective treatment regimens and establishing advanced diagnostic facilities are needed to avoid further emergence of INH-resistant TB.

Facile regioselective synthesis of novel bioactive thiazolyl-pyrazoline derivatives via a three-component reaction and their antimicrobial activity.

A series of novel 2-(3,5-diphenyl-4,5-dihydro-1H-pyrazol-1-yl)-4-phenylthiazoles have been prepared by a three-component cyclo-condensation of various chalcones, thiosemicarbazide and phenacyl bromide. The easy work-up of the products, rapid reaction, and mild conditions are notable features of this protocol. The reaction was efficiently catalyzed in one-pot by a few drops of HCl in EtOH under reflux conditions providing the title compounds in moderate to high yields. The antibacterial activity of the selected products was examined. Some products exhibit promising activities.