SO(10) GUTs with gauge mediated supersymmetry breaking

We explore the phenomenology of supersymmetric SO(10) grand unified theories with gauge mediated supersymmetry breaking. We show that if SO(10) breaking proceeds through intermediate left-right symmetric gauge groups which are broken at the supersymmetry breaking scale, then perturbative unification allows the existence of only a few consistent models with very similar phenomenological consequences. We list and discuss some distinctive signatures of these theories. The most remarkable feature of the class of theories introduced here is that, unlike in models with simpler symmetry breaking chains, the allowed messenger spectrum is practically unique.Comment: 5 pages, no figures, uses REVTeX (replaced to match the version to be published in PLB: some typos corrected and a reference updated, a minor clarifying modification to the text

Genetic structure of four plasmids found in Acinetobacter baumannii isolate D36 belonging to lineage 2 of global clone 1

© 2018 Hamidian, Hall.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Four plasmids ranging in size from 4.7 to 44.7 kb found in the extensively antibiotic resistant Acinetobacter baumannii isolate D36 that belongs to lineage 2 of global clone 1 were examined. D36 includes two cryptic plasmids and two carrying antibiotic resistance genes. The smallest plasmid pD36-1 (4.7 kb) carries no resistance genes but includes mobA and mobC mobilisation genes related to those found in pRAY∗(pD36-2, 6,078 bp) that also carries the aadB gentamicin, kanamycin and tobramycin resistance gene cassette. These two plasmids do not encode a Rep protein. Plasmid pRAY∗ was found to be mobilised at high frequency by the large conjugative plasmid pA297-3 but a pRAY∗ derivative lacking the mobA and mobC genes was not. The two larger plasmids, pD36-3 and pD36-4, encode Rep3 family proteins (Pfam1051). The cryptic plasmid pD36-3 (6.2 kb) has RepAci1 and pD36-4 (44.7 kb) encodes two novel Rep3 family proteins suggesting a co-integrate. Plasmid pD36-4 includes the sul2 sulfonamide resistance gene, the aphA1a kanamycin/neomycin resistance gene in Tn4352::ISAba1 and a mer module in a hybrid Tn501/Tn1696 transposon conferring resistance to mercuric ions. New examples of dif modules flanked by pdif sites (XerC-XerD binding sites) that are part of many A. baumannii plasmids were also identified in pD36-3 and pD36-4 which carry three and two dif modules, respectively. Homologs of three dif modules, the sup sulphate permease module in pD36-3, and of the abkAB toxin-antitoxin module and the orf module in pD36-4, were found in different contexts in diverse Acinetobacter plasmids, consistent with module mobility. A novel insertion sequence named ISAba32 found next to the pdif site in the abkAB dif module is related to members of the ISAjo2 group which also are associated with the pdif sites of dif modules. Plasmids found in D36 were also found in some other members of GC1 lineage 2

Emergence, molecular mechanisms and global spread of carbapenem-resistant acinetobacter baumannii

© 2019 The Authors. Acinetobacter baumannii is a nosocomial pathogen that has emerged as a global threat because of high levels of resistance to many antibiotics, particularly those considered to be last-resort antibiotics, such as carbapenems. Although alterations in the efflux pump and outer membrane proteins can cause carbapenem resistance, the main mechanism is the acquisition of carbapenem-hydrolyzing oxacillinase-encoding genes. Of these, oxa23 is by far the most widespread in most countries, while oxa24 and oxa58 appear to be dominant in specific regions. Historically, much of the global spread of carbapenem resistance has been due to the dissemination of two major clones, known as global clones 1 and 2, although new lineages are now common in some parts of the world. The analysis of all publicly available genome sequences performed here indicates that ST2, ST1, ST79 and ST25 account for over 71% of all genomes sequenced to date, with ST2 by far the most dominant type and oxa23 the most widespread carbapenem resistance determinant globally, regardless of clonal type. Whilst this highlights the global spread of ST1 and ST2, and the dominance of oxa23 in both clones, it could also be a result of preferential selection of carbapenem-resistant strains, which mainly belong to the two major clones. Furthermore, ~70% of the sequenced strains have been isolated from five countries, namely the USA, PR China, Australia, Thailand and Pakistan, with only a limited number from other countries. These genomes are a vital resource, but it is currently difficult to draw an accurate global picture of this important superbug, highlighting the need for more comprehensive genome sequence data and genomic analysis

Dissemination of novel Tn<i>7</i> family transposons carrying genes for synthesis and uptake of fimsbactin siderophores among <i>Acinetobacter baumannii</i> isolates.

Acinetobacter baumannii is a successful opportunistic pathogen that can compete for iron under iron-limiting conditions. Here, large novel transposons that carry genes for synthesis and transport of the fimsbactin siderophores present in some A. baumannii strains were examined. Tn6171, originally found in the A. baumannii global clone 1 (GC1) lineage 2 isolate D36, includes tns genes encoding proteins related to the TnsA, TnsB, TnsC transposition proteins (50-59 % identity), TnsD targeting protein (43 % identity) and TnsE (31 % identity) of Tn7, and is found in the chromosome downstream of the glmS gene, the preferred location for Tn7, flanked by a 5 bp target site duplication. Tn6171 is bounded by 29 bp inverted repeats and, like Tn7, includes additional TnsB binding sites at each end. Tn6171 or minor variants were detected in the equivalent location in complete or draft genomes of several further A. baumannii isolates belonging to GC1 [sequence type (ST) 1, ST81, ST94, ST328, ST623, ST717], GC2 (ST2) and ST10. However, in some of these isolates the surrounding glmS region was clearly derived from a different A. baumannii lineage, indicating that the transposon may have been acquired by replacement of a segment of the chromosome. A recombination-free phylogeny revealed that there were several transposon acquisition events in GC1. The GC1 isolates were mainly lineage 2, but a potential third lineage was also detected. A related transposon, designated Tn6552, was detected in ATCC 17978 (ST437) and other ST437 isolates. However, the Tn6552 tnsD targeting gene was interrupted by an ISAba12, and Tn6552 is not downstream of glmS

Synthesis of novel azo compounds containing 5(4H)-oxazolone ring as potent tyrosinase inhibitors

Six new azo dyes containing of 5(4H)-oxazolone ring were prepared by diazotization of 4-aminohippuric acid and coupling with N,N-dimethylaniline, 1-naphthol and 2-naphthol and condensation with 4-fluoro benzaldehyde or 4-trifluoromethoxy benzaldehyde. The new compounds were fully characterized by spectroscopic techniques. All synthesized compounds exhibited high tyrosinase inhibitory behavior. The results of mushroom tyrosinase inhibition assays indicate that the 4-trifluoromethoxy derivatives have high degrees of inhibition and N,N-dimethylaniline derivatives are better for tyrosinase inhibition than 1-naphthol and 2-naphthol derivatives. All synthesized azo compounds (4a-4f) showed the most potent mushroom tyrosinase inhibition, comparable to that of Kojic acid and l-mimosine, as reference standard inhibitors. © 2013 Elsevier Ltd. All rights reserved

Metal bioaccumulation in representative organisms from different trophic levels of the Caspian Sea

The bioaccumulations of metals Cu, Cd, Ni, Cr, Co, Mn, Zn and Fe were measured in bivalves, Cerastoderma glaucum, and four species of fishes including Alburnus chalcoides, Liza aurata, Rutilus frisii and Sander lucioperca from various trophic levels of the Caspian food web. The concentrations of Cd, Cr, Co and Ni in most samples of fish were below the detection limits; while the concentrations were detected in most samples of bivalve C. glaucum. The stable nitrogen isotope ratios varied among the samples from C. glaucum (δ^15N=3.5 ‰) to S. lucioperca (δ^15N=13.1‰). Among the four fish species, while the highest concentrations of Mn, Ni and Fe were observed in L. aurata, the lowest concentrations of Mn and Fe were observed in S. lucioperca. These species also had the lowest and highest trophic levels with an average of 3.3 and 4.2, respectively. No accumulation of metals with increase in body size was observed in muscles of species from different trophic levels. The comparison of metal concentrations with the health guidelines for human consumption showed that those intakes were lower than the legislated limits. While there was a strong relationship between trophic levels and body size of A. chalcoides and R. frisii, no significant slopes were observed between the total lengths (TLs) and the Ln concentrations of metals. It is necessary to determine metal concentrations in food resources of fish species, particularly in R. frisii that has significantly different δ^15N in relation to body size

Salmonella genomic island 1 is broadly disseminated within gammaproteobacteriaceae

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Salmonella genomic island 1 (SGI1) is an integrative mobilisable element that plays an important role in the capture and spread of multiple drug resistance. To date, SGI1 has been found in clinical isolates of Salmonella enterica serovars, Proteus mirabilis, Morganella morganii, Acinetobacter baumannii, Providencia stuartii, Enterobacter spp, and recently in Escherichia coli. SGI1 preferentially targets the 3´-end of trmE, a conserved gene found in the Enterobacteriaceae and among members of the Gammaproteobacteria. It is, therefore, hypothesised that SGI1 and SGI1‐related elements (SGI1-REs) may have been acquired by diverse bacterial genera. Here, Bitsliced Genomic Signature Indexes (BIGSI) was used to screen the NCBI Sequence Read Archive (SRA) for putative SGI1-REs in Gammaproteobacteria. Novel SGI‐REs were identified in diverse genera including Cronobacter spp, Klebsiella spp, and Vibrio spp and in two additional isolates of Escherichia coli. An extensively drug‐resistant human clonal lineage of Klebsiella pneumoniae carrying an SGI1‐RE in the United Kingdom and an SGI1-RE that lacks a class 1 integron were also identified. These findings provide insight into the origins of this diverse family of clinically important genomic islands and expand the knowledge of the potential host range of SGI1-REs within the Gammaproteobacteria

IncM Plasmid R1215 Is the Source of Chromosomally Located Regions Containing Multiple Antibiotic Resistance Genes in the Globally Disseminated Acinetobacter baumannii GC1 and GC2 Clones.

Clear similarities between antibiotic resistance islands in the chromosomes of extensively antibiotic-resistant isolates from the two dominant, globally distributed Acinetobacter baumannii clones, GC1 and GC2, suggest a common origin. A close relative of the likely progenitor of both of these regions was found in R1215, a conjugative IncM plasmid from a Serratia marcescens strain isolated prior to 1980. The 37.8-kb resistance region in R1215 lies within the mucB gene and includes aacC1, aadA1, aphA1b, bla TEM, catA1, sul1, and tetA(A), genes that confer resistance to gentamicin, streptomycin and spectinomycin, kanamycin and neomycin, ampicillin, chloramphenicol, sulfamethoxazole, and tetracycline, respectively. The backbone of this region is derived from Tn1721 and is interrupted by a hybrid Tn2670 (Tn21)-Tn1696-type transposon, Tn6020, and an incomplete Tn1. After minor rearrangements, this R1215 resistance island can generate AbGRI2-0*, the predicted earliest form of the IS26-bounded AbGRI2-type resistance island of GC2 isolates, and to the multiple antibiotic resistance region (MARR) of AbaR0, the precursor of this region in AbaR-type resistance islands in the GC1 group. A 29.9-kb circle excised by IS26 has been inserted into the A. baumannii chromosome to generate AbGRI2-0*. To create the MARR of AbaR0, a different circular form, again generated by IS26 from an R1215 resistance region variant, has been opened at a different point by recombination with a copy of the sul1 gene already present in the AbaR precursor. Recent IncM plasmids related to R1215 have a variant resistance island containing a bla SHV gene in the same location. IMPORTANCE Two lineages of extensively antibiotic-resistant A. baumannii currently plaguing modern medicine each acquired resistance to all of the original antibiotics (ampicillin, tetracycline, kanamycin, and sulfonamides) by the end of the 1970s and then became resistant to antibiotics from newer families after they were introduced in the 1980s. Here, we show that, in both of the dominant globally disseminated A. baumannii clones, a related set of antibiotic resistance genes was acquired together from the same resistance region that had already evolved in an IncM plasmid. In both cases, the action of IS26 was important in this process, but homologous recombination was also involved. The findings highlight the fact that complex regions carrying several resistance genes can evolve in one location or organism and all or part of the evolved region can then move to other locations and other organisms, conferring resistance to several antibiotics in a single step