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Introduction: Reactive arthritis (ReA) is a joint inflammation that follows an infection at a distant site, often in the gastrointestinal or urogenital tract. Since the emergence of COVID-19 in January 2020, several case reports have suggested a relation between reactive arthritis and severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), due to the novelty of the disease, most findings were reported in the form of case reports or case series, and a comprehensive overview is still lacking. Methods: We searched PubMed/Medline and Embase to identify studies addressing the association between ReA and COVID-19. The following terms were used: [“Reactive Arthritis” OR “Post-Infectious Arthritis” OR “Post Infectious Arthritis”] AND [“COVID-19” OR “SARS-CoV-2” OR “2019-nCoV”]. Results: A total number of 35 reports published up to February 16th, 2022, were included in this study. A wide range of ages was affected (mean 41.0, min 4 max 78), with a higher prevalence of males (61.0%) from 16 countries. The number and location of the affected joints were different in included patients, with a higher prevalence of polyarthritis in 41.5% of all cases. Cutaneous manifestations and visual impairments were found as the most common associated symptoms. Most patients (95.1%) recovered, with a mean recovery time of 24 days. Moreover, arthritis induced by COVID-19 seems to relieve faster than ReA, followed by other infections. Conclusion: ReA can be a possible sequel of COVID-19 infection. Since musculoskeletal pain is a frequent symptom of COVID-19, ReA with rapid onset can easily be misdiagnosed. Therefore, clinicians should consider ReA a vital differential diagnosis in patients with post-COVID-19 joint swelling. Additional studies are required for further analysis and to corroborate these findings.

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.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).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%).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.

Background: The emerging problem of antibiotic resistance in Pseudomonas aeruginosa is a global health concern; hence, revealing innovative therapeutic approaches (such as designing an immunogenic vaccine candidate) is needed. There is no evidence of the availability of an effective vaccine that can combat the infection caused by this microorganism. Objectives: This research was conducted to develop a potential chimeric vaccine against P. aeruginosa using reverse vaccinology approaches. Methods: The present vaccine candidate comprised outer membrane protein F and I (OprF/OprI) and PopB with appropriate linkers. After applying meticulous immune-informatics investigation, the multi-epitope vaccine was created, including helper T lymphocyte (HTL), cytotoxic T lymphocyte (CTL), interferon gamma (IFN-γ), and interleukin 4 (IL-4) epitopes. Then, the physicochemical characteristics, allergenicity, toxicity, and antigenicity were analyzed. After investigating the secondary structure, the tertiary structure (3D) model was generated, refined, and validated via computational methods. Besides, the strong protein-ligand interaction and stability between the vaccine candidate and toll-like receptor 4 (TLR4) were determined via molecular docking and dynamics analyses. Moreover, in silico cloning accompanied by pET-22b (+) was used to achieve high translation efficiency. Results: Our results presumed that the chimeric-designed vaccine was thermostable and contained optimal physicochemical properties. This vaccine candidate was nontoxic and highly soluble and had stable protein and TLR4 interaction, adequately overexpressed in Escherichia coli. Overall, it could induce immune responses and repress this microorganism. Conclusions: Therefore, to inhibit Pseudomonas infections experimentally, the efficacy and safety of the vaccine design need to be validated.

There has been an alarming health-related concern about the growth of New Delhi metallo-β-lactamase. The aims of this study include the phenotypic detection of β-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-β-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, β-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 β-lactamase genes, armA type plasmid-mediated 16S rRNA methylase and CMY-type plasmid-mediated AmpC β-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.

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.

Aghil Bahramian,1,2 Saeed Khoshnood,3,4 Aref Shariati,5 Farahnoosh Doustdar,2 Alireza Salimi Chirani2 Mohsen Heidary5,6 1Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 2Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 3Department of Microbiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; 4Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; 5Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran; 6Student Research Committee, School of Allied Medical Sciences, Iran University of Medical Sciences, Tehran, Iran 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. Keywords: Pseudomonas aeruginosa, pilS2, cystic fibrosis, pKLC102, PAPI-1

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen in burns, cystic fibrosis, hospitalized and immunodeficiency patients. By in-silico algorithms an effective vaccine was designed from outer membrane proteins (OprF and OprI) and type 3 secretion systems (PopB) of P. aeruginosa to combat laboratory barriers and store time, reduce cost, and achieve higher performances. The aim of this study was the construction, expression, and evaluation of recombinant protein containing OprF, OprI, and PopB (FIB). We combined the in-silico immunoinformatics, homology modeling, molecular docking and molecular dynamics (MD) simulations. The linear and conformational B-cell epitopes and T-cell epitopes in the 172 subunit candidates were investigated and the best 16 of them was recognized to create a multi-epitope vaccine. Ultimately, we realized stable interactions between the epitopes of “NATAEGRAINRRVE” OprF in 305–318 and “KAANRQADVQESRAD” PopB in the position of 730–744 as ligands and HLADRB1*04:01 as a receptor. This proposed vaccine constructs a 794aa multi-epitope vaccine containing 66 B-cell epitopes and 106 T-cell epitopes. The levels of IgG (G1, G2a, and G2b) and IgA antibody titers and the level of IL-17, IFN-γ, and IL-4 cytokines were evaluated before and after challenge using the enzyme-linked immunosorbent assay (ELISA) method. Due to enhancing the active immune response, FIB antigen was formulated with Granulocyte-macrophage colony-stimulating factor (GM-CSF) as a potent adjuvant. The comparison of IgG1, IgG2a, IgG2b antibodies, cytokines IL-17, IL-4, and IFN-γ levels indicated a higher rate of Th1 and Th2 oriented responses against P. aeruginosa chimeric FIB antigen. The FIB antigen was a potent IgA inducer in the presence of adjuvant. Also, the immunogenic response against FIB and FIB-GMCSF revealed the useful property of GM-CSF in enhancing the humoral and cell-mediated immune response. Our findings highlighted that FIB plus GM-CSF immunization would be useful as an immunogenic substance for treatment against P. aeruginosa infections.

Background The distributions of methicillin‐susceptible Staphylococcus aureus (MSSA) are divers geographically with different genetic backgrounds. Data related to molecular characteristics of MSSA compare to methicillin‐resistant Staphylococcus aureus (MRSA) is sparse. Methods In this cross‐sectional study, antimicrobial susceptibility testing, virulence genes analysis, biofilm formation, accessory gene regulator (agr) typing, and multilocus sequence typing (MLST) characterized on 75 MSSA isolates. Results Multidrug‐resistance MSSA was found to be 84%. Forty‐eight (64%) isolates were toxinogenic with 34 and 14 isolates carrying pvl and tst representing 45.3% and 18.7%. The most common SE genes were sed (20%), sec (16%), and sea (16%). Fifty‐five (73.3%) isolates were confirmed as biofilm producer with a markedly high prevalence of fnbA (93.3%), fnbB (86.7%), icaA (65.3%), icaD (53.3%), can (24%), ebp (10.7%), and bap (1.3%). A total of 3 agr types (I, 73.3%; III, 16%; II, 10.7%) and 4 clonal complexes (CCs) and sequence types (STs), namely CC8/ST293 (45.3%), CC/ST22 (28%), CC/ST30 (16%), and CC/ST5 (10.7%) were detected in this study. All the high and low‐level mupirocin resistance strains belonged to ST239 and ST22 strains, respectively. All the fusidic acid‐resistant isolates carried fusC and belonged to ST30. Conclusions These findings indicated that ST239 with strong biofilm production ability is the most common type in MSSA strains isolated from patients. It seems that the antimicrobial resistance profiles, toxin, and biofilm formation were closely associated with specific STs. Further studies are required to identify and control of these clonal lineages in our area., Biofilm formation involves first, adhesion to surfaces mediated by the expression of different microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) and second, production of polysaccharide intercellular adhesion (PIA) which mediates cell to cell adhesion. Biofilm protects the bacteria from host defenses and prevents delivery of antibiotics and have an adverse effect on the eradication of infection. Several researchers noted concerns about biofilm formability on biotic and abiotic surfaces especially medical devices, by MSSA strains. It seems that biofilm formability in MSSA strains is most frequently associated with specific clonal lineages. There is a need for the continuous monitoring of these genotypes.

Methicillin-resistant Staphylococcus aureus (MRSA) strains that carry the tst gene are disseminated worldwide with varying regional incidences and different genetic backgrounds. The data on molecular characteristics of these strains is insufficient in Iran. The present study aimed to assess the characteristics and distribution of spa types of tst-positive MRSA strains. We investigated 89 MRSA isolates carrying the tst gene with spa typing, resistance gene detection and in vitro antimicrobial susceptibility. Of the 89 tested isolates, 61 (68.5%) were confirmed as multidrug resistant (MDR). The isolates were distributed across seven clonal complexes (CCs) including CC22 (42.7%), CC8 (28.1%), CC5 (11.2%), CC59 (5.6%), CC30 (4.5%), CC80 (4.5%) and CC15 (3.4%). spa typing identified 11 distinct types, with t223 (16.9%) and t790 (15.7%) being the most prevalent. All high-level mupirocin-resistant strains belonged to t002 (n = 8) and low-level mupirocin-resistant strains belonged to t790 (n = 6) spa types. Fusidic-acid-resistant isolates belonged to t437 (n = 3). iMLSB phenotype was observed in t005 (6.7%), t002 (5.6%), t790 (3.4%), and t030, t044 and t084 (each 2.2%). It was found that in the tst-carrying MRSA strains, there were genetic diversities with a majority of the t223 spa type. Indeed, there is a necessity for more constructive surveillance/infection control strategies to address the prevalence and prevention of the emerging spa types.

Background Neglected parasitic diseases (NTDs) like cutaneous leishmaniasis (CL) have caused high mortality and morbidity rate in developing countries. This disease is considered as one of the six major tropical diseases, and has a great importance in HIV infected individuals as an opportunistic infection in those areas that both infections are endemic. This study evaluated the therapeutic effects of the Urtica dioica L (U. dioica) aqueous extract as an anti-leishmanial herbal drug in-vitro and in-vivo, and in addition to that, evaluated two vital immune system cytokines including gamma interferon (IFN-γ) and interleukin-4 (IL-4) plus nitric oxide (NO) and arginase activity against Leishmania major (L. major) infected mice. Methodology/Principal findings In-vitro anti-leishmanial activity of U. dioica aqueous extract was determined using MTT method and also Parasite Rescue Transformation Assay. Also, the footpad lesion size and parasite load in BALB/c mice infected with L. major were quantified for in-vivo assessment. Furthermore, for evaluating the immune responses, the levels of IFN-γ, IL-4, NO and arginase were measured in the BALB/c mice. These results indicated that U. dioica extract significantly reduced the L. major promastigotes viability. According to the in-vitro cytotoxicity assay of the extract on Leishmania parasites (CC50) and infected macrophages (EC50), the extract had no toxicity to the macrophages, however it efficiently killed the L. major amastigotes. In addition, the lesion size, parasite load, IL-4, and ARG were decreased in the treated infected mice, however IFN-γ and NO were significantly increased. Conclusions/Significance This study established satisfactory results in Leishmania parasite clearing both in-vivo and in-vitro. Therefore, U. dioica extract can be considered as an effective and harmless herbal compound for killing the parasite without toxicity to the host macrophages. Furthermore, it also can treat the CL by switching the mouse immune response towards a cell-mediated response (Th1); hence, it may be identified as a perfect therapeutic herbal drug for CL treatment., Author summary Nowadays, neglected tropical diseases (NTDs) like leishmaniasis have increased the mortality and morbidity rate in developing countries, especially in tropical regions, and is considered as responsible for more than 20 million deaths per year. Although, cutaneous leishmaniasis (CL) is rapidly spreading in all over the world, but this disease controlling has remained insufficient because of low-cost treatment and the lack of an effective vaccine. Therefore, new treatment approaches for leishmaniasis are immediately required. Up to now, application of natural herbal products has been considered as one of the major effective ways in treating the protozoan parasitic infections like CL. In this study, we evaluated the therapeutic effects of the Urtica dioica L (U. dioica) aqueous extract as an anti-leishmanial herbal drug in-vitro and in-vivo, and also quantified the immune cytokines IFN-γ, IL-4 against CL caused by Leishmania major (L. major). The in-vitro activity of U. dioica aqueous extract on L. major was determined using MTT method and Parasite Rescue Transformation Assay. Moreover, the footpad lesion size was assessed and parasite load in the mice infected with L. major was quantified for in-vivo. In order to evaluate the immune responses, IFN-γ, IL-4, NO and arginase were measured in the Leishmania infected mice. Accordingly, U. dioica is one of the effective herbal plant in L. major parasite clearing without any harmful toxicity to the murine cells, and can strongly cure the zoonotic CL.

There is information regarding the rates of gastric cancer (GC) in different populations and the important role of Helicobacter pylori in GC development; however, no comprehensive study has yet been performed to investigate the prevalence of GC in H. pylori-infected patients. PubMed, Embase, and Cochrane Library through January 1, 2000 were searched without language restrictions. Quality of included studies was assessed with a critical appraisal checklist recommended by the Joanna Briggs Institute. All of the analyses were conducted using Comprehensive Meta-Analysis Software Version 2.0 and Stata 14.0. Forty-four studies from 17 countries were included. The pooled frequency of GC was 17.4% (95% confidence interval: 16.4-18.5) in H. pylori-infected population. The frequency of GC among H. pylori-infected population varied markedly across countries. The highest rate of GC was observed in H. pylori-infected individuals from Asian countries. The frequency of GC was relatively high in H. pylori-infected population in the world. However, the eradication of H. pylori might be a promising strategy for GC prevention, especially in high-risk populations such as Asian countries.

This study aims to investigate the combined effects of Pulsed wave low-level laser therapy (PW LLLT) and human bone marrow mesenchymal stem cell-conditioned medium (hBM-MSC-CM) on the microbial flora and tensiometrical properties of an infected wound model with methicillin-resistant staphylococcal aureus (MRSA) in an experimental model for Type 1 diabetes mellitus (TIDM). TIDM was induced in rats by streptozotocin (STZ). One full-thickness excision was made on the backs of the rats. Next, the rats were divided into the following groups: Group 1 was the control (placebo) group; Group 2 received hBM-MSCs-CM four times; Group 3 were laser PWLLLT (890 nm, 80 Hz, 0.2 J/cm2 ); and Group 4 received hBM-MSCs-CM +LASER. Wounds were infected with MRSA. Microbiological examinations were performed on days 4, 7, and 15. Tensiometerical examinations were carried out on the 15th day. One-way analysis of variance showed that laser and CM alone and/or in combination significantly increases the tensiomerical properties of the repaired wounds compared with control wounds. A combination of PW laser and CM was statistically more effective than other treated groups. Two-way analysis of variance showed that laser and CM alone and/or in combination significantly decreases the colony-forming units (CFUs) compared with the control group. The application of hBM-MSC-CM and PWlaser alone and/or together significantly accelerates the wound-healing process in MRSA-infected cutaneous wounds in TI DM in rats. Additionally, a combined application of hBM-MSC-CM and PWlaser demonstrates a synergistic effect on the wound-healing process in MRSA-infected cutaneous wounds in Type I DM rats.

In this study, we report the insertion sequence ISPpu21 in the oprD porin gene of carbapenem-resistant Pseudomonas aeruginosa isolates from burn patients in Tehran, Iran. Antibiotic susceptibility tests for P. aeruginosa isolates were determined. Production of metallo-β-lactamases (MBLs) and carbapenemase was evaluated and the β-lactamase-encoding and aminoglycoside-modifying enzyme genes were investigated by PCR and sequencing methods. The mRNA transcription level of oprD and mex efflux pump genes were evaluated by real-time PCR. The outer membrane protein profile was determined by SDS–PAGE. The genetic relationship between the P. aeruginosa isolates was assessed by random amplified polymorphic DNA PCR. In all, 10.52% (10/95) of clinical isolates of P. aeruginosa harboured the ISPpu21 insertion element in the oprD gene. The extended-spectrum β-lactamase-encoding gene in ISPpu21-carrying isolates was blaTEM. PCR assays targeting MBL and carbapenemase-encoding genes were also negative in all ten isolates. The rmtA, aadA, aadB and armA genes were positive in all ISPpu21 harbouring isolates. The relative expression levels of the mexX, mexB, mexT and mexD genes in ten isolates ranged from 0.1- to 1.4-fold, 1.1- to 3.68-fold, 0.3- to 8.22-fold and 1.7- to 35.17-fold, respectively. The relative expression levels of the oprD in ten isolates ranged from 0.57- to 35.01-fold, which was much higher than those in the control strain P. aeruginosa PAO1. Evaluation of the outer membrane protein by SDS–PAGE suggested that oprD was produced at very low levels by all isolates. Using random amplified polymorphic DNA PCR genotyping, eight of the ten isolates containing ISPpu21 were shown to be clonally related. The present study describes a novel molecular mechanism, ISPpu21 insertion of the oprD gene, associated with carbapenem resistance in clinical P. aeruginosa isolates. Keywords: Burn, ISPpu21, OprD porin, Pseudomonas aeruginosa, carbapenem

Interference with bacterial adhesion is a new means to prevent or treat bacterial infections. In this experimental study we evaluated the immunogenic properties of a chimeric protein composed of PilQ and disulphide turn region of PilA from Pseudomonas aeruginosa in mice as an anti-adhesion based vaccine. First of all, a chimeric bivalent protein composed of PilQ and PilA was constructed and following subcutaneous immunization with merely the purified protein or in its admixed form with alum, the immunogenicity of the chimeric antigen was assessed in BALB/c mice. Then, the characteristics of the developed antibodies were studied by ELISA. Furthermore, the immunoreactivity of the purified recombinant protein was confirmed by immunoblotting. Alum as a common adjuvant boosted immunogenicity of the construct, resulting significantly greater anti-pili IgG titre. Mice antibody response consisted of IgG1, IgG2a, IgG2b and IgG3 subtypes with predominance of IgG1 subclass. The developed antibodies were capable to inhibit motility of PAO1 strain. In conclusion, our primary results revealed that the designed recombinant protein is a protective construct and may be used as a potential candidate for prophylactic purposes against P. aeruginosa infection. SIGNIFICANCE AND IMPACT OF THE STUDY In this study we examined the potential of integrated PilQ/PilA (QA) antigen as a vaccine candidate against Pseudomonas aeruginosa. Nowadays, anti-adhesion based vaccines are considered as new means to prevent or treat bacterial infections. Our study revealed that chimeric protein PilQ and disulphide turn region of PilA triggers production of specific antibodies. This humoral immune responses augmented when QA was administered in combination with an adjuvant. The results demonstrated efficacy of the designed recombinant chimeric antigen as an effective candidate in prevention of P. aeruginosa infection.

Acinetobacter baumannii has gained attention for years as a significant clinical problem due to the increase of antibiotic-resistant strain. Indeed, A. baumannii OmpA is one of the highly conserved membrane proteins among Gram-negative bacteria that has multiple roles in interacting with the host during infection, thereby representing an effective target for the development of novel an-tibacterial or vaccination therapies. Nowadays, finding suitable epitope-specific antigens inside the conserved proteins such as OmpA is a promising method for successful vaccination programs. Therefore, in the present study, the coding sequence of the 240 to 356 amino acid residues of A. baumannii OmpA (AbOmpA240-356) was cloned into the vector pET-28a and purified using nickel affinity chromatography. In addition, the anti-His tag antibody is used to validate its production. This system of protein expression and purification may be useful for further characterization of AbOmpA240-356 protein fraction. Therefore, this study can lead to the introduction of suitable candidates for the development of an effective vaccine based on OmpA against this bacterium for further analysis. © 2019, Archives of Clinical Infectious Diseases.

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.

Wide distrubution of multidrug-resistant Acinetobacter baumannii strains has become a foremost concern in hospital environments. Treatment of infections caused by multidrug resistant strains has conventionally involved the use of β-lactams such as carbapenems. In this study, we report the distribution of carbapenemase genes in A. baumannii isolated from hospitalized patients. The study was conducted on 110 non-repetitive A. baumannii isolates collected from hospitalized patients, over a nine-month period. Clinical isolates were examined by conventional susceptibility testing, using the disk-diffusion method and multiplex polymerase chain reaction to detect acquired carbapenemase genes. All of the isolates were completely resistant to TOB, SXT, IPM, MEM, CTX, CRO, FEP, CAZ, CIP, PTZ, PIP and were susceptible to colistin, but moderately susceptible TET (2.72%), AK (4.54%) and GEN (3.63%). The prevalence of bla-OXA-51like, bla-OXA-23like, bla-OXA-24like, bla-OXA-58like, blaSIM and blaSPM genes was 100%, 96.36%, 35.45%, 7.27%, 7.27% and 3.63%, respectively. bla-GIM and bla-VIM genes were not detected among the strains. Our results suggest that OXA-type carbapenemase genes plus class B β-lactamases contribute to carbapenem resistance in the collected isolates. Therefore, quick identification of these resistant genes using molecular approaches is critical in limiting the spread of infections caused by A. baumannii. Drug administration correction of the physicians, based on antibiotic susceptibility testing and more knowledge on the nosocomial infection control policies as essential need.

Introduction: Ethambutol (EMB) is an anti-mycobacterial agent that is most commonly used in combination with other anti-tuberculosis (TB) drugs in the treatment of TB. Studies have shown that primary resistance rates of Mycobacterium tuberculosis to EMB vary widely, that is, from 1% to as high as 14%. In this study, we aimed to determine the exact prevalence of primary EMB resistance among pulmonary TB cases. Methods: Several databases, including Medline, Embase, and Iranian databases, were searched from March 2000 to January 2016 to identify studies addressing EMB-resistant TB in Iran. Comprehensive meta-analysis (V2.2, Biostat) software was used to analyze the data. Results: Of the 112 records identified from the databases, 10 studies fulfilled the eligibility criteria. The pooled prevalence of primary EMB-resistant TB was estimated at 4.2% [95% confidence interval (CI) 1.8–9.0]. No evidence of publication bias was observed among the included studies ( p = 0.4 for Begg rank correlation analysis; p = 0.2 for Egger weighted regression analysis). Conclusion: Results of systematic review and meta-analyses indicated that effective strategies to minimize the acquired drug resistance, to improve the drug susceptibility testing (DST) capability, and to control the transmission of resistance should be attached importance for control of TB in Iran.

Objective Nowadays, Pseudomonas aeruginosa ( P. aeruginosa ), the highly regarded opportunistic pathogen, is the leading cause of morbidity and mortality worldwide. The P. aeruginosa type IV pili (T4P) as a multiple functional surface organelle in the development of acute P. aeruginosa infections have been well documented. Today, in silico analysis is a quick, and cost-effective tool for vaccine development. Methods In present study, several turns' motifs along with the chimeric protein were predicted. Based on the hydropathy analysis, numerous antibody-accessible hydrophilic regions were characterized in the chimeric protein. A synthetic chimeric gene, encoding integrated PilQ and disulphide loop region of PilA, was designed. Modeling was done to predict the 3D structure of protein. The model was validated by using Ramachandran plot statistics and by ProSA server. Identification of B-cell and T-cell corresponding epitopes was done by using appropriate servers. Results The closer 3D model to the native form of the chimeric protein was achieved. Validation results showed that 95.1% residues were in favor region and 3.6% of amino acid residues were in the allowed region. The B-cell epitope mappings showed that almost all the epitopes had irregular enriched structures. The major histocompatibility complex binding sequence prediction identified several human major histocompatibility complex class I and II restricted T-cell epitopes. The integrated PilQ and PilA disulphide loop encoding regions in the frame of pET28a(+) vector were expressed and purified efficiently. Conclusions We expect that the two recognized antigenic determinants from our chimeric protein, “AYHKGNWSGYGKDGNIGIKDEDGMNCGPIAGSCTFPTTGTSKSPSPFVDLGAKDATSG” and “GPIAGSCTFPTTGTSKSPSP”, can be able to evoke strong both humoral and cell-mediated immune responses in mouse models.

A chimeric gene encoding an immunogenic region of PilQ and the PilA-DSL was synthesized. Following bacterial expression and purification, the protein was administered to mice and the humoral immune response analyzed. The resulting antibodies were analyzed using an opsonophagocytic killing assay.The anti-recombinant protein antibody titer was significantly greater in immunized mice than in controls. In addition, antibody titers were significantly increased after booster immunizations, and the immunizations induced opsonophagocytosis ofThese results suggest that an anti-adhesion-based vaccination may be effective in preventing

Background: Type 4 pili (T4P) is an important virulence factor of Pseudomonas aeruginosa (P. aeruginosa). T4P pass the outer membrane through a large oligomeric channel made of a single PilQ protein that is most highly conserved at their C-termini. To develop a functional vaccine that can be used in clinical application, the secretin domain of the PilQ (PilQ380-706) was produced as a recombinant protein. Methods: A 981 bp fragment of C-terminal of the pilQ secretin (pilQ1138-2118) from was designed into the prokaryotic expression vector pET28a. The presence of the pilQ1138-2118 gene in the recombinant construct (pET28a/pilQ) was assessed by double digestion and PCR. After transformation, expression of the recombinant PilQ was induced by addition of IPTG. The expressed recombinant protein was purified by a modified method using a HisTrap affinity column and finally confirmed by SDS-PAGE. The functional activities of the produced PilQ380-706 confirmed by Western blot analysis and twitching inhibition assay. Results: The PCR and enzymatic digestion results showed the presence of the pilQ1138-2118 gene in the construct. The protein electrophoresis showed that the molecular weight of the recombinant PilQ380-706 is approximately 37 kDa. The Western blot analysis confirmed the specificity of specific IgG against the PilQ380-706 protein. The PilQ380-706 protein showed high biological activity in all of these standard assays. Conclusion: Since, the PilQ380-706 protein plays an important role in the biogenesis of pili; and thus, the primary establishment of P. aeruginosa; it seems that it can be used as a candidate vaccine or an adjuvant in the future studies.

Background: Neisseria meningitidis, a life-threatening human pathogen with the potential to cause large epidemics, can be isolated from the nasopharynx of 5–15% of adults. The aim of the current study was to evaluate biophysical and biochemical properties and immunological aspects of chimeric acyl-carrier protein-macrophage infectivity potentiator protein-type IV pilus biogenesis protein antigen (ACP-MIP-PilQ) from N. meningitidis serogroup B strain. Methods: Biochemical properties and multiple alignments were predicted by appropriate web servers. Secondary molecular structures were predicted based on Chou and Fasman, Garnier-Osguthorpe-Robson, and Neural Network methods. Tertiary modeling elucidated conformational properties of the chimeric protein. Proteasome cleavage and transporter associated with antigen processing (TAP) binding sites, and T- and B-cell antigenic epitopes, were predicted using bioinformatic web servers. Results: Based on our in silico and immunoinformatics analyses, the ACP-MIP-PilQ protein (AMP) can induce high-level cross-strain bactericidal activity. In addition, several immune proteasomal cleavage sites were detected. The 22 epitopes associated with MHC class I and class II (DR) alleles were confirmed in the AMP. Thirty linear B-cell epitopes as antigenic regions were predicted from the full-length protein. Conclusion: All predicted properties of the AMP indicate it could be a good candidate for further immunological in vitro and in vivo studies.

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 UreB

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.

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.

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.

Introduction Emergence of vancomycin-intermediate Staphylococcus aureus (VISA) and vancomycin-resistant S. aureus (VRSA) strains has led to great concern in global public health in both developing and developed countries. This study investigated distribution and molecular characterization of VRSA strains in Tehran's hospitals using a combination of molecular typing methods. Materials and methods A total of 1789 S. aureus isolates obtained between 2014 and 2017 and were characterized using antibiogram, SCCmec typing, spa typing, and multilocus-sequence typing. Resistance to vancomycin was determined by E-test method. After confirmation of the isolated VRSA strain, genetic analysis was performed by evaluating vanA and vanB genes presence.The presence of resistance (ermA, ermB, ermC, mupA, msrA, msrB, tetM, ant (4΄)-Ia, aac (6΄)-Ie/aph (2˝), aph (3΄)-IIIa) and toxin (etb, eta, pvl, tst) encoding genes was investigated by the polymerase chain reaction (PCR) technique. Results Of all S. aureus tested isolates, four isolates were confirmed as VRSA isolates and two isolates confirmed as VISA isolates. ST5- SCCmec II/t002 and ST239-SCCmec III/t037 strains had MIC values of 512μg/ml, ST239-SCCmec III/t037 and ST8-SCCmecIV/t008 strains had MIC values of 64μg/ml and ST22-SCCmec IV/t790 and ST239-SCCmec III/t030 strains had MIC values ≥ 8 μg/ml. pvl-encoding gene was confirmed in ST8-SCCmecIV/t008 and ST22-SCCmec IV/t790 strains. The isolates differed in the carriage of resistance and toxin encoding genes. Conclusions The study revealed the existence of VRSA strains in capital of Iran, Tehran. To our knowledge, this is the first report of ST239-SCCmec III/t037 as VRSA strain. These findings support the need for future surveillance studies on VRSA strains to keep the emergence and transmission of these isolates to a minimum.

Acinetobacter baumannii is a major opportunistic pathogen in healthcare settings worldwide. In Iran, there are only few reports on the prevalence of aminoglycoside resistance genes among A. baumannii isolates. The aim of this study was to investigate the existence of aminoglycoside-modifying enzyme (AME) genes from A. baumannii strains collected at a university teaching hospital in Iran. One hundred A. baumannii strains were collected between 2014 and 2015 from hospitalized patients at Loghman Hakim Hospital, Tehran, Iran. Antimicrobial susceptibility was determined by disk diffusion method according to the Clinical and Laboratory Standards Institute recommendations. The DNA was extracted using a kit obtained from Bioneer Co. (Korea) and was used as a template for polymerase chain reaction. The most active antimicrobial agent against these strains was colistin. The rate of extended-spectrum cephalosporin resistance was 97%. The aadA1, aadB, aac(6′)-Ib, and aac(3)-IIa genes were found in 85%, 77%, 72%, and 68% of A. baumannii isolates, respectively. This study showed a high prevalence rate of AME genes in A. baumannii. This prevalence rate has explained that further aminoglycoside resistance genes may have role in the resistance of clinical isolates of A. baumannii. Therefore, control and treatment of serious infections caused by this opportunistic pathogen should be given more consideration.

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.

Background: The increasing emergence of resistance among clinical isolates of Klebsiella pneumoniae (K. pneumoniae) has limited the therapeutic options used to treat infections caused by these bacteria. Objectives: The aim of this study was the molecular detection of quinolone resistance genes acrA, acrB, qepA, and aac(6’)-Ib-cr in K. pneumoniae strains isolated from hospitalized patients in selected hospitals in Tehran during 2013 - 2014. Methods: One hundred and seventeen strains of K. pneumoniae were isolated between August 2013 and March 2014 from hospitalized patients in Taleghani hospital, Mofid children’s hospital, and Imam Hossein hospital in Tehran. Antimicrobial susceptibility tests were performed using disk diffusion and broth microdilution methods based on CLSI guidelines. The identification of the genes that encode efflux pumps acrA, acrB, qepA, and aac(6’)-Ib-cr was done using the PCR technique. Results: Antimicrobial susceptibility tests showed that colistin and tigecycline had the best effect against clinical isolates of K. pneumoniae. The PCR assay detected the acrA and acrB genes in 110 (94%) and 102 (87%) isolates, respectively. Additionally, the qepA and aac(6’)-Ib-cr genes were detected in 5 (4%) and 100 (85%) isolates, respectively. Conclusions: The prevalence of the acrA, acrB, qepA, and aac(6’)-Ib-cr genes in K. pneumoniae, which causes resistance to fluoroquinolones, in this study is cause for concern. Based on our results, accurate identification of resistant Gram-negative bacteria such as K. pneumoniae and detection of its susceptibility to common antibiotics could lead to proper treatment and control of resistant nosocomial infections.

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