Acquisition and diffusion of bla CTX-M-9 gene by R478-IncHI2 derivative plasmids

Escherichia coli and Salmonella enterica isolates carrying the bla(CTX-M-9) gene located on plasmids prevailed at the Hospital de la Santa Creu i Sant Pau, Barcelona, Spain in the 1996-1999 period. The bla(CTX-M-9)-carrying plasmids showed a great variability in size, suggesting the mobilization of the gene among different plasmid scaffolds. The aim of the present work was to identify and better characterize the plasmids involved in the spread of the bla(CTX-M-9) gene. Results showed that the majority of these strains carried plasmids belonging to the IncHI2 incompatibility group. The IncHI2 plasmids were further characterized, and found to be related to the reference IncHI2 plasmid R478.     

Evidence for convergent evolution of CTX-M-14 ESBL in Escherichia coli and its prevalence

A total of 2440 Escherichia coli strains isolated in 2003 at the Hospital de la Santa Creu i Sant Pau were evaluated for the presence of extended-spectrum beta-lactamases. Two different nucleotide sequences that encode the same beta-lactamase, CTX-M-14, were detected when the bla(CTX-M-14)-genes of 35 E. coli isolates were analysed. Thirty-two of the 35 had the previously described sequence of the bla(CTX-M-14) (AF252622), named bla(CTX-M-14a), and the remaining three isolates showed a nucleotide sequence identical to that of the bla(CTX-M-9) gene except for one nucleotide, named bla(CTX-M-14b). Characterisation of the regions surrounding the bla(CTX-M-14a) showed the ISEcp1 and the IS903 upstream and downstream, respectively, of the bla gene, whereas the regions surrounding the bla(CTX-M-14b) contained the genetic environment described for the bla(CTX-M-9) gene, the In60. Characterisation by hybridisation showed that the bla(CTX-M-14a) was present in IncK plasmids, whereas the bla(CTX-M-14b) was found in the HI2 Inc group. The CTX-M-14 ESBL in E. coli isolates is the result of the convergence of two different genes.     

Pseudovibrio denitrificans strain Z143-1, a heptylprodigiosin-producing bacterium isolated from a Philippine tunicate

Microbial isolate Z143-1 found to be associated with an unidentified tunicate was characterized due to its significant antimicrobial activity. Z143-1 is similar to Pseudovibrio ascidiaceicola and Pseudovibrio denitrificans in morphological, physiological and biochemical characteristics, except for its ability to ferment glucose and produce a characteristic red pigment. Fatty acid methyl ester analysis revealed a predominance of the fatty acid 18:1 omega7c at 80.55%, at levels slightly lower than the Pseudovibrio denitrificans type strain DN34(T) (87.7%). The mol% G+C of Z143-1 is 54.02, relatively higher than the Pseudovibrio denitrificans type strain DN34(T) and Pseudovibrio ascidiaceicola with mol% G+C of 51.7 and 51.4, respectively. However, phylogenetic analysis of the 16S rRNA gene sequence of Z143-1 showed 100% similarity with the Pseudovibrio denitrificans type strain DN34(T). In this study, the bacterium Z143-1 is reported as a new strain of Pseudovibrio denitrificans. While there is no report of a secondary metabolite for Pseudovibrio denitrificans, Z143-1 produces the red pigment heptylprodigiosin, also known as 16-methyl-15-heptyl-prodiginine, which shows anti-Staphylococcus aureus activity.     

Molecular determination of progesterone receptor’s PROGINS allele (Alu insertion) and its association with the predisposition and susceptibility to polycystic ovary syndrome (PCOS)

Mammalian Genome - Polycystic ovary syndrome, previously known as Stein–Leventhal syndrome, is associated with altered reproductive endocrinology, predisposing a young woman towards the risk...     

Crystal Structure of CC Chemokine Receptor 2A in Complex with an Orthosteric Antagonist Provides Insights for the Design of Selective Antagonists

1. Download high-res image (224KB)
2. Download full-size image

     

A Compact,High-Accuracy Cas9 with a Dinucleotide PAM for In Vivo Genome Editing

1. Download high-res image (271KB)
2. Download full-size image

     

Late Cenozoic diversification of the austral genus Lagenophora (Astereae,Asteraceae)

Lagenophora (Astereae, Asteraceae) has 14 species in New Zealand, Australia, Asia, southern South America, Gough Island and Tristan da Cunha. Phylogenetic relationships in Lagenophora were inferred using nuclear and plastid DNA regions. Reconstruction of spatio‐temporal evolution was estimated using parsimony, Bayesian inference and likelihood methods, a Bayesian relaxed molecular clock and ancestral area and habitat reconstructions. Our results support a narrow taxonomic concept of Lagenophora including only a core group of species with one clade diversifying in New Zealand and another in South America. The split between the New Zealand and South American Lagenophora dates from 11.2 Mya [6.1–17.4 95% highest posterior density (HPD)]. The inferred ancestral habitats were openings in beech forest and subalpine tussockland. The biogeographical analyses infer a complex ancestral area for Lagenophora involving New Zealand and southern South America. Thus, the estimated divergence times and biogeographical reconstructions provide circumstantial evidence that Antarctica may have served as a corridor for migration until the expansion of the continental ice during the late Cenozoic. The extant distribution of Lagenophora reflects a complex history that could also have involved direct long‐distance dispersal across southern oceans. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177 , 78–95.     

Length–weight relationships for eight fish species from the Ravi River,north‐western India

Length–weight relationships (LWRs) were evaluated for Badis badis (n = 25), Sperata seenghala (n = 26), Labeo gonius (n = 34), Rasbora rasbora (n = 30), Bagarius bagarius (n = 24), Gagata cenia (n = 27), Glyptothorax stoliczkae (n = 24) and Channa orientalis (n = 28) from the Ravi River tributary in North India. Altogether 218 samples of eight species were obtained between May and November 2014 using cast nets and gill nets. LWRs for these species were unknown to FishBase, and new maximum lengths were recorded for two of these species.     

Length‐weight relationships of 10 fish species from two tributaries of Indus River Basin in Jammu and Kashmir,India

Length‐weight relationships (LWRs) are described for 10 fish species belonging to three families from the Jhelum and Poonch River, tributaries of the Indus river basin in India. LWRs for these species were unknown to FishBase and new maximum lengths are recorded for three species. These results will be useful for fishery research, management and conservation in these tributaries of Jammu and Kashmir.     

ATM-dependent phosphorylation of MRE11 controls extent of resection during homology directed repair by signalling through Exonuclease 1

The MRE11/RAD50/NBS1 (MRN) complex plays a central role as a sensor of DNA double strand breaks (DSB) and is responsible for the efficient activation of ataxia-telangiectasia mutated (ATM) kinase. Once activated ATM in turn phosphorylates RAD50 and NBS1, important for cell cycle control, DNA repair and cell survival. We report here that MRE11 is also phosphorylated by ATM at S676 and S678 in response to agents that induce DNA DSB, is dependent on the presence of NBS1, and does not affect the association of members of the complex or ATM activation. A phosphosite mutant (MRE11S676AS678A) cell line showed decreased cell survival and increased chromosomal aberrations after radiation exposure indicating a defect in DNA repair. Use of GFP-based DNA repair reporter substrates in MRE11S676AS678A cells revealed a defect in homology directed repair (HDR) but single strand annealing was not affected. More detailed investigation revealed that MRE11S676AS678A cells resected DNA ends to a greater extent at sites undergoing HDR. Furthermore, while ATM-dependent phosphorylation of Kap1 and SMC1 was normal in MRE11S676AS678A cells, there was no phosphorylation of Exonuclease 1 consistent with the defect in HDR. These results describe a novel role for ATM-dependent phosphorylation of MRE11 in limiting the extent of resection mediated through Exonuclease 1.