We announce the complete genome sequence ofBacillussp. strain SDLI1, isolated from larval gut of the stingless beeScaptotrigona depilis The 4.13-Mb circular chromosome harbors biosynthetic gene clusters for the production of antimicrobial compounds. Copyright © 2016 Paludo et al.
Actinomycetes produce the majority of the antibiotics currently in clinical use. The efficiency of antibiotic production is affected by multiple factors such as nutrients, pH, temperature and growth phase. Finding the optimal harvesting time is crucial for successful isolation of the desired bioactive metabolites from actinomycetes, but for this conventional chemical analysis has limitations due to the metabolic complexity. This study explores the utility of NMR-based metabolomics for (1) optimizing fermentation time for the production of known and/or unknown bioactive compounds produced by actinomycetes; (2) elucidating the biosynthetic pathway for microbial natural products; and (3) facilitating the biotransformation of nature-abundant chemicals.
Escherichia colisequence type 131 (ST131) has emerged globally as the most predominant extraintestinal pathogenic lineage within this clinically important species, and its association with fluoroquinolone and extended-spectrum cephalosporin resistance impacts significantly on treatment. The evolutionary histories of this lineage, and of important antimicrobial resistance elements within it, remain unclearly defined. This study of the largest worldwide collection (n= 215) of sequenced ST131E. coliisolates to date demonstrates that the clonal expansion of two previously recognized antimicrobial-resistant clades, C1/H30R and C2/H30Rx, started around 25 years ago, consistent with the widespread introduction of fluoroquinolones and extended-spectrum cephalosporins in clinical medicine. These two clades appear to have emerged in the United States, with the expansion of the C2/H30Rx clade driven by the acquisition of ablaCTX-M-15-containing IncFII-like plasmid that has subsequently undergone extensive rearrangement. Several other evolutionary processes influencing the trajectory of this drug-resistant lineage are described, including sporadic acquisitions of CTX-M resistance plasmids and chromosomal integration ofblaCTX-Mwithin subclusters followed by vertical evolution. These processes are also occurring for another family of CTX-M gene variants more recently observed among ST131, theblaCTX-M-14/14-likegroup. The complexity of the evolutionary history of ST131 has important implications for antimicrobial resistance surveillance, epidemiological analysis, and control of emerging clinical lineages ofE. coli These data also highlight the global imperative to reduce specific antibiotic selection pressures and demonstrate the important and varied roles played by plasmids and other mobile genetic elements in the perpetuation of antimicrobial resistance within lineages.IMPORTANCEEscherichia coli, perennially a major bacterial pathogen, is becoming increasingly difficult to manage due to emerging resistance to all preferred antimicrobials. Resistance is concentrated within specificE. colilineages, such as sequence type 131 (ST131). Clarification of the genetic basis for clonally associated resistance is key to devising intervention strategies. We used high-resolution genomic analysis of a large global collection of ST131 isolates to define the evolutionary history of extended-spectrum beta-lactamase production in ST131. We documented diverse contributory genetic processes, including stable chromosomal integrations of resistance genes, persistence and evolution of mobile resistance elements within sublineages, and sporadic acquisition of different resistance elements. Both global distribution and regional segregation were evident. The diversity of resistance element acquisition and propagation within ST131 indicates a need for control and surveillance strategies that target both bacterial strains and mobile genetic elements. Copyright © 2016 Stoesser et al.
The emergence of vancomycin-resistant enterococci (VRE) has been associated with an increase in multidrug-resistant nosocomial infections. Here, we report the 2.614-Mb genome sequence of the Enterococcus faecium commensal isolate E1002, which will be instrumental in further understanding the determinants of the commensal and pathogenic lifestyle of E. faecium. Copyright © 2016 Tytgat et al.
We present here the complete genome sequence of Streptococcus pyogenes type emm28 strain MEW123, a streptomycin-resistant derivative of a pediatric throat isolate. The genome length is 1,878,699 bp, with 38.29% G+C% content. The genome sequence adds value to this virulent emm28 representative strain and will aid in the investigation of streptococcal pathogenesis. Copyright © 2016 Jacob et al.
Streptococcus mitisfrequently causes invasive infections in neutropenic cancer patients, with a subset of patients developing viridans group streptococcal (VGS) shock syndrome. We report here the first complete genome sequence ofS. mitisstrain SVGS_061, which caused VGS shock syndrome, to help elucidate the pathogenesis of severe VGS infection. Copyright © 2016 Petrosyan et al.
Cephalosporin-resistant Vibrio alginolyticus were firstly isolated from food products with ß-lactamases, blaPER-1, blaVEB-1 and blaCMY-2, being the major mechanisms mediating cephalosporin resistance. The complete sequence of a multidrug resistance plasmid, pVAS3-1, harboring the blaCMY-2 and qnrVC4 genes was decoded in this study. Its backbone exhibited genetic homology to known IncA/C plasmids recoverable from Enterobacteriaceae species, suggesting its possible origin from Enterobacteriaceae. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Linezolid is often the drug of last resort for serious methicillin-resistant Staphylococcus aureus (MRSA) infections. Linezolid resistance is mediated by mutations in 23S rRNA and genes for ribosomal proteins, cfr encoding phenicol, lincosamide, oxazolidinone, pleuromutilin and streptogramin A (PhLOPSA) resistance, its homolgue cfr(B) or optrA conferring oxazolidinone and phenicol resistance. Linezolid resistance is rare in S. aureus, and cfr even rarer. This study investigated the clonality and linezolid resistance mechanisms of two MRSA isolates from patients in separate Irish hospitals. Isolates were subjected to cfr PCR, PhLOPSA susceptibility testing, 23S rRNA PCR and sequencing, DNA microarray profiling, spa typing, pulsed-field gel electrophoresis (PFGE), plasmid curing and conjugative transfer. Whole-genome sequencing was used for single nucleotide variant (SNV) analysis, multilocus-sequence typing, L-protein mutation identification, cfr-plasmid sequence analysis and optrA and cfr(B) detection. Isolates M12/0145 and M13/0401 exhibited linezolid MICs of 64 and 16 mg/liter, respectively, and harbored identical 23S rRNA and L22 mutations, but M12/0145 exhibited the mutation in 2/6 23S rRNA alleles compared to 1/5 in M13/0401. Both isolates were ST22-MRSA-IV/t032, harbored cfr, exhibited the PhLOPSA phenotype and lacked optrA and cfr(B). They differed by five PFGE bands and 603 SNVs. Isolate M12/0145 harbored cfr and fexA on a 41-kb conjugative pSCFS3-type plasmid, whereas M13/0401 harbored cfr and lsa(B) on a novel 27-kb plasmid. This is the first report of cfr in the pandemic ST22-MRSA-IV clone. Different cfr plasmids and mutations associated with linezolid resistance in genotypically distinct ST22-MRSA-IV isolates highlights that prudent management of linezolid use is essential. Copyright © 2016 Shore et al.
Massilia sp. NR 4-1 was a violacein producing strain newly isolated from topsoil under nutmeg tree, Torreya nucifera in Korean national monument Bijarim Forest. Violacein is a novel class of drug exhibiting anticancer and antibiotic activities originated from l-tryptophan. Here, we present the complete genome of Massilia sp. strain NR 4-1 of 6,361,416bp and total 5285 coding sequences (CDSs) including a complete violacein biosynthesis pathway, vioABCDE. The genome sequence of Massilia sp. NR 4-1 will provide stable and efficient biotechnological applications of violacein production. Copyright © 2016 Elsevier B.V. All rights reserved.
Enterococcus faecalis LD33 strain was originally isolated from traditional naturally fermented cream in Inner Mongolia of China. Its complete genome sequence was carried out using the Illumina Hiseq and the PacBio RSII platform. The genome only has a circular chromosome and a GC content of 37.58%. Other core information shown in the genome sequencing results further insight on this bacterium’s genetic elements for bacteriocin production and the genes related to respiratory chain. Copyright © 2016 Elsevier B.V. All rights reserved.
Sir,Escherichia coli sequence type 131 (ST131) producing CTX- M-type [3-lactamases are the most common extended-spectrum [3-lactamase (ESBL)-producing strains and are of high virulence potential. In particular, the blal-;X.M.[5 gene is often encoded on a conjugative plasmid and less frequently on the chromo- some. The presence of identical bluCTX.M.[5 alleles on both the chromosome and on a plasmid in the same strain has been reported [1], suggesting transfer ofthese genes between these two locations.
Since our first report on plasmid- mediated colistin resistance gene mcr-1,1 strains previously collected in seven countries (Denmark, the Netherlands, Laos, Nigeria, Thailand, France, and the UK) have been found to carry mcr-1.2–6 Furthermore, the sequences in GenBank show that mcr-1 might also be circulating in Portugal and Malaysia. The earliest mcr-1- positive strain was collected from cattle in France in 2008 (GenBank accession number LMBK01000308). These findings confirm our initial concern that mcr-1 could have already disseminated worldwide.
Background. The honey bee (Apis mellifera) is the most important pollinator in agriculture worldwide. However, the number of honey bees has fallen significantly since 2006, becoming a huge ecological problem nowadays. The principal cause is CCD, or Colony Collapse Disorder, characterized by the seemingly spontaneous abandonment of hives by their workers. One of the characteristics of CCD in honey bees is the alteration of the bacterial communities in their gastrointestinal tract, mainly due to the decrease of Firmicutes populations, such as the Lactobacilli. At this time, the causes of these alterations remain unknown. We recently isolated a strain of Lactobacillus kunkeei (L. kunkeei strain MP2) from the gut of Chilean honey bees. L. kunkeei, is one of the most commonly isolated bacterium from the honey bee gut and is highly versatile in different ecological niches. In this study, we aimed to elucidate in detail, the L. kunkeei genetic background and perform a comparative genome analysis with other Lactobacillus species. Methods. L. kunkeei MP2 was originally isolated from the guts of Chilean A. mellifera individuals. Genome sequencing was done using Pacific Biosciences single-molecule real-time sequencing technology. De novo assembly was performed using Celera assembler. The genome was annotated using Prokka, and functional information was added using the EggNOG 3.1 database. In addition, genomic islands were predicted using IslandViewer, and pro-phage sequences using PHAST. Comparisons between L. kunkeei MP2 with other L. kunkeei, and Lactobacillus strains were done using Roary. Results. The complete genome of L. kunkeei MP2 comprises one circular chromosome of 1,614,522 nt. with a GC content of 36,9%. Pangenome analysis with 16 L. kunkeei strains, identified 113 unique genes, most of them related to phage insertions. A large and unique region of L. kunkeei MP2 genome contains several genes that encode for phage structural protein and replication components. Comparative analysis of MP2 with other Lactobacillus species, identified several unique genes of L. kunkeei MP2 related with metabolism, biofilm generation, survival under stress conditions, and mobile genetic elements (MGEs). Discussion. The presence of multiple mobile genetic elements, including phage sequences, suggest a high degree of genetic variability in L. kunkeei. Its versatility and ability to survive in different ecological niches (bee guts, flowers, fruits among others) could be given by its genetic capacity to change and adapt to different environments. L. kunkeei could be a new source of Lactobacillus with beneficial properties. Indeed, L. kunkeei MP2 could play an important role in honey bee nutrition through the synthesis of components as isoprenoids.
Lactobacillus rhamnosus BPL5 (CECT 8800), is a probiotic strain suitable for the treatment of bacterial vaginosis. Here, we report its complete genome sequence deciphered by PacBio single-molecule real-time (SMRT) technology. Analysis of the sequence may provide insight into its functional activity. Copyright © 2016 Chenoll et al.
Aeromicrobium erythreumNRRL B-3381 has a 3,629,239-bp circular genome that has 72% G+C content. There are at least 3,121 coding sequences (CDSs), two rRNA gene operons, and 47 tRNAs. The genome and erythromycin (ery) biosynthetic gene sequences provide resources for metabolic and combinatorial engineering of polyketides. Copyright © 2016 Harrell and Miller.
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