Whole-genome sequence analysis of clinically isolated carbapenem resistant Escherichia coli from Iran.

BACKGROUND: The emergence of carbapenem-resistant Enterobacterales (CRE) continues to threaten public health due to limited therapeutic options. In the current study the incidence of carbapenem resistance among the 104 clinical isolates of Escherichia coli and the genomic features of carbapenem resistant isolates were investigated. METHODS: The susceptibility to imipenem, tigecycline and colistin was tested by broth dilution method. Susceptibility to other classes of antimicrobials was examined by disk diffusion test. The presence of blaOXA-48, blaKPC, blaNDM, and blaVIM carbapenemase genes was examined by PCR. Molecular characteristics of carbapenem resistant isolates were further investigated by whole-genome sequencing (WGS) using Illumina and Nanopore platforms. RESULTS: Four isolates (3.8%) revealed imipenem MIC of ≥32 mg/L and positive results for modified carbapenem inactivation method and categorized as carbapenem resistant E. coli (CREC). Colistin, nitrofurantoin, fosfomycin, and tigecycline were the most active agents against all isolates (total susceptibility rate of 99, 99, 96 and 95.2% respectively) with the last three compounds being found as the most active antimicrobials for carbapenem resistant isolates (susceptibility rate of 100%). According to Multilocus Sequence Type (MLST) analysis the 4 CREC isolates belonged to ST167 (n = 2), ST361 (n = 1) and ST648 (n = 1). NDM was detected in all CREC isolates (NDM-1 (n = 1) and NMD-5 (n = 3)) among which one isolate co-harbored NDM-5 and OXA-181 carbapenemases. WGS further detected blaCTX-M-15, blaCMY-145, blaCMY-42 and blaTEM-1 (with different frequencies) among CREC isolates. Co-occurrence of NDM-type carbapenemase and 16S rRNA methyltransferase RmtB and RmtC was found in two isolates belonging to ST167 and ST648. A colistin-carbapenem resistant isolate which was mcr-negative, revealed various amino acid substitutions in PmrB, PmrD and PhoPQ proteins. CONCLUSION: About 1.9% of E. coli isolates studied here were resistant to imipenem, colistin and/or amikacin which raises the concern about the outbreaks of difficult-to-treat infection by these emerging superbugs in the future.

The first evidence of an association between a polymorphism in the endocannabinoid-degrading enzyme FAAH (FAAH rs2295633) with attention deficit hyperactivity disorder.

Several single nucleotide polymorphisms (SNPs) of the fatty acid amide hydrolase (FAAH), the degrading enzyme of the endocannabinoids, have been shown to be associated with many neuropsychiatric disorders. Here, FAAH rs2295633 was studied in ADHD and case-control healthy children. There was a significant difference in the allele frequency (P = .04) and genotype distribution (P = .04) of the FAAH rs2295633 between ADHD cases and controls. The ADHD children appeared to have less of TT genotype (OR 0.396, 95% CI 0.178-0.884, p = .024) and T allele (OR 0.658, 95% CI 0.440-0.982, p = .04). To our best knowledge, this is the first statistical significant association between FAAH rs2295633 genotype and ADHD disorder. Larger sample sizes and functional studies are warranted to explore the clinical utility of FAAH genotyping as a possible marker for increased ADHD risk in children.

A Chimeric protein of CFA/I, CS6 subunits and LTB/STa toxoid protects immunized mice against enterotoxigenic Escherichia coli.

Enterotoxigenic Escherichia Coli (ETEC) strains are the commonest bacteria causing diarrhea in children in developing countries and travelers to these areas. Colonization factors (CFs) and enterotoxins are the main virulence determinants in ETEC pathogenesis. Heterogeneity of CFs is commonly considered the bottleneck to developing an effective vaccine. It is believed that broad spectrum protection against ETEC would be achieved by induced anti-CF and anti-enterotoxin immunity simultaneously. Here, a fusion antigen strategy was used to construct a quadrivalent recombinant protein called 3CL and composed of CfaB, a structural subunit of CFA/I, and CS6 structural subunits, LTB and STa toxoid of ETEC. Its anti-CF and antitoxin immunogenicity was then assessed. To achieve high-level expression, the 3CL gene was synthesized using E. coli codon bias. Female BALB/C mice were immunized with purified recombinant 3CL. Immunized mice developed antibodies that were capable of detecting each recombinant subunit in addition to native CS6 protein and also protected the mice against ETEC challenge. Moreover, sera from immunized mice also neutralized STa toxin in a suckling mouse assay. These results indicate that 3CL can induce anti-CF and neutralizing antitoxin antibodies along with introducing CFA/I as a platform for epitope insertion.

Design and characterization of a chimeric multiepitope construct containing CfaB, heat-stable toxoid, CssA, CssB, and heat-labile toxin subunit B of enterotoxigenic Escherichia coli: a bioinformatic approach.

Enterotoxigenic Escherichia coli (ETEC) strains are the most common cause of bacterial diarrhea in children in developing countries and travelers to these areas. Enterotoxins and colonization factors (CFs) are two key virulence factors in ETEC pathogenesis, and the heterogeneity of the CFs is the bottleneck in reaching an effective vaccine. In this study, a candidate subunit vaccine, which is composed of CfaB, CssA and CssB, structural subunits of colonization factor antigen I and CS6 CFs, labile toxin subunit B, and the binding subunit of heat-labile and heat-stable toxoid, was designed to provide broad-spectrum protection against ETEC. The different features of chimeric gene, its mRNA stability, and chimeric protein properties were analyzed by using bioinformatic tools. The optimized chimeric gene was chemically synthesized and expressed successfully in a prokaryotic host. The purified protein was used for assessment of bioinformatic data by experimental methods.

Association Between the Endocannabinoid System-Related Gene Variants and Epilepsy.

The endocannabinoid system (ECS) is an intricate network consisting of receptors, enzymes, and endogenous ligands that play a pivotal role in various neurological processes. It has been implicated in the pathophysiology of several neurological disorders, including epilepsy. Extensive research has demonstrated the involvement of genetic factors in influencing the susceptibility to and progression of epilepsy. In this study, we focused on investigating the connection between genetic variations in genes related to the ECS and the occurrence of epilepsy. Some ECS-related gene variants were selected and genotyping was performed using the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) technique. Interestingly, CNR1 rs12720071 genotype (OR 16.33, 95% CI 1.8-149; p = 0.001) showed an association with generalized epilepsy and MGLL rs604300 genotype (OR 2, 95% CI 1.1-3.4; p = 0.013) demonstrated a relationship with females diagnosed with focal epilepsy. So, studying CNR1, MGLL, and their genetic variations provides insights into the role of the endocannabinoid system in health and diseases. Moreover, they hold the potential to pave the way for the development of novel therapeutic approaches specifically targeting them.

Senescence is delayed by selenium in oilseed rape plants.

Leaf senescence is a genetically programmed process that can also be induced by nitrogen (N) deficiency. Although selenium (Se) delays leaf senescence, the underlying mechanisms are still unknown. To explore the mechanisms of Se-mediated delay of leaf senescence, we studied the biochemical and molecular events that occur during developmental and N deficiency-induced senescence. Oilseed rape (Brassica napus L.) plants were grown under adequate N (AN, 16 mM) or low N (LN, 4 mM) conditions during the rosette growth stage and treated with Se (15 µg plant-1 as Na2SeO4) either through roots or leaves for four weeks. Shoot dry matter production was not influenced, while the photosynthetic parameters were improved by Se application in both young and old leaves under both AN and LN conditions. The Se treatment rarely influenced the concentrations of reactive oxygen species (ROS), while it increased the nitric oxide (NO) levels in young and old leaves under both AN and LN conditions. The positive correlation between the NO level and leaf photosynthetic parameters in old leaves of LN plants suggested a role for NO boosting, mediated by Se, in the protection of aging leaves from LN-induced accelerated senescence. This implication was further supported by the clear down-regulation of SAG12-1 and up-regulation of Cab, particularly by root application of Se in old leaves of LN plants. Our results provide the first evidence that Se influences the expression of senescence-associated genes and delays senescence through NO signalling but is independent of the ROS defence system.

Association study of CTLA-4 +49A/G gene polymorphism with recurrent pregnancy loss in the Iranian Azeri Turkish ethnic group.

BACKGROUND/AIM: Recurrent pregnancy loss (RPL) is defined as two or more pregnancy losses. T-regulatory cells play an important role in the feto-maternal interface. Cytotoxic-T-lymphocyte antigen-4 (CTLA-4) is a molecule that downregulates the activation and proliferation of T cells. The objective of the current study was to investigate the possible association of CTLA-4+49A/G gene polymorphism with RPL among patients from the Iranian Azeri Turkish ethnic group. MATERIALS AND METHODS: The study group/patients consisted of 101 women with the experience of two or more pregnancy losses and the control group consisted of 101 women with at least two live births, without any previous history of pregnancy loss and autoimmune diseases from the same ethnic group. The CTLA-4+49A/G was detected by polymerase chain reaction-restriction fragment length polymorphisms assay. RESULTS: The distribution of CTLA-4+49A/G genotype was AA, 38.61%; AG, 51.48%; GG, 9.9% in patients and AA, 37.62%; AG, 47.52%; GG,14.85% in controls (P-value: 0.2). Furthermore, no association in G-allele was observed in the patient and control groups (P-value: 0.5). CONCLUSION: The results of the present study suggest that CTLA-4 does not have any association with RPL in the Iranian Azeri Turkish ethnic group.