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July 7, 2019

Molecular characterization of plasmid pMoma1of Moraxella macacae, a newly described bacterial pathogen of macaques.

We report the complete nucleotide sequence and characterization of a small cryptic plasmid of Moraxella macacae 0408225, a newly described bacterial species within the family Moraxellaceae and a causative agent of epistaxis in macaques. The complete nucleotide sequence of the plasmid pMoma1 was determined and found to be 5,375 bp in size with a GC content of 37.4 %. Computer analysis of the sequence data revealed five open reading frames encoding putative proteins of 54.4 kDa (ORF1), 17.6 kDa (ORF2), 13.3 kDa (ORF3), 51.6 kDa (ORF4), and 25.0 kDa (ORF5). ORF1, ORF2, and ORF3 encode putative proteins with high identity (72, 42, and 55 %, respectively) to mobilization proteins of plasmids found in other Moraxella species. ORF3 encodes a putative protein with similarity (about 40 %) to several plasmid replicase (RepA) proteins. The fifth open reading frames (ORF) was most similar to hypothetical proteins with unknown functions, although domain analysis of this sequence suggests it belongs to the Abi-like protein family. Upstream of the repA gene, a 470-bp intergenic region, was identified that contained an AT-rich section and two sets of tandem direct and indirect repeats, consistent with a putative origin of replication site. In contrast to other plasmids of Moraxella, the occurrence of pMoma1 in M. macacae isolates appears to be common as PCR testing of 14 clinical isolates from two different research institutions all contained the plasmid.


July 7, 2019

Finished genome sequence of Collimonas arenae Cal35.

We announce the finished genome sequence of soil forest isolate Collimonas arenae Cal35, which comprises a 5.6-Mbp chromosome and 41-kb plasmid. The Cal35 genome is the second one published for the bacterial genus Collimonas and represents the first opportunity for high-resolution comparison of genome content and synteny among collimonads. Copyright © 2015 Wu et al.


July 7, 2019

Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae at a single institution: insights into endemicity from whole-genome sequencing.

The global emergence of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) multilocus sequence type ST258 is widely recognized. Less is known about the molecular and epidemiological details of non-ST258 K. pneumoniae in the setting of an outbreak mediated by an endemic plasmid. We describe the interplay of blaKPC plasmids and K. pneumoniae strains and their relationship to the location of acquisition in a U.S. health care institution. Whole-genome sequencing (WGS) analysis was applied to KPC-Kp clinical isolates collected from a single institution over 5 years following the introduction of blaKPC in August 2007, as well as two plasmid transformants. KPC-Kp from 37 patients yielded 16 distinct sequence types (STs). Two novel conjugative blaKPC plasmids (pKPC_UVA01 and pKPC_UVA02), carried by the hospital index case, accounted for the presence of blaKPC in 21/37 (57%) subsequent cases. Thirteen (35%) isolates represented an emergent lineage, ST941, which contained pKPC_UVA01 in 5/13 (38%) and pKPC_UVA02 in 6/13 (46%) cases. Seven (19%) isolates were the epidemic KPC-Kp strain, ST258, mostly imported from elsewhere and not carrying pKPC_UVA01 or pKPC_UVA02. Using WGS-based analysis of clinical isolates and plasmid transformants, we demonstrate the unexpected dispersal of blaKPC to many non-ST258 lineages in a hospital through spread of at least two novel blaKPC plasmids. In contrast, ST258 KPC-Kp was imported into the institution on numerous occasions, with other blaKPC plasmid vectors and without sustained transmission. Instead, a newly recognized KPC-Kp strain, ST941, became associated with both novel blaKPC plasmids and spread locally, making it a future candidate for clinical persistence and dissemination. Copyright © 2015, Mathers et al.


July 7, 2019

Complete genome sequence of BS49 and draft genome sequence of BS34A, Bacillus subtilis strains carrying Tn916.

Bacillus subtilis strains BS49 and BS34A, both derived from a common ancestor, carry one or more copies of Tn916, an extremely common mobile genetic element capable of transfer to and from a broad range of microorganisms. Here, we report the complete genome sequence of BS49 and the draft genome sequence of BS34A, which have repeatedly been used as donors to transfer Tn916, Tn916 derivatives or oriTTn916-containing plasmids to clinically important pathogens. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.


July 7, 2019

Defining the sequence requirements for the positioning of base J in DNA using SMRT sequencing.

Base J (ß-D-glucosyl-hydroxymethyluracil) replaces 1% of T in the Leishmania genome and is only found in telomeric repeats (99%) and in regions where transcription starts and stops. This highly restricted distribution must be co-determined by the thymidine hydroxylases (JBP1 and JBP2) that catalyze the initial step in J synthesis. To determine the DNA sequences recognized by JBP1/2, we used SMRT sequencing of DNA segments inserted into plasmids grown in Leishmania tarentolae. We show that SMRT sequencing recognizes base J in DNA. Leishmania DNA segments that normally contain J also picked up J when present in the plasmid, whereas control sequences did not. Even a segment of only 10 telomeric (GGGTTA) repeats was modified in the plasmid. We show that J modification usually occurs at pairs of Ts on opposite DNA strands, separated by 12 nucleotides. Modifications occur near G-rich sequences capable of forming G-quadruplexes and JBP2 is needed, as it does not occur in JBP2-null cells. We propose a model whereby de novo J insertion is mediated by JBP2. JBP1 then binds to J and hydroxylates another T 13 bp downstream (but not upstream) on the complementary strand, allowing JBP1 to maintain existing J following DNA replication. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.


July 7, 2019

Complete sequences of six IncA/C plasmids of multidrug-resistant Salmonella enterica subsp. enterica serotype Newport.

Multidrug-resistant (MDR) Salmonella enterica subsp. enterica serotype Newport has been a long-standing public health concern in the United States. We present the complete sequences of six IncA/C plasmids from animal-derived MDR S. Newport ranging from 80.1 to 158.5 kb. They shared a genetic backbone with S. Newport IncA/C plasmids pSN254 and pAM04528. Copyright © 2015 Cao et al.


July 7, 2019

Short communication: Single molecule, real-time sequencing technology revealed species- and strain-specific methylation patterns of 2 Lactobacillus strains.

Pacific Biosciences’ (Menlo Park, CA) single molecule, real-time sequencing technology was reported to have some advantages in generating finished genomes and characterizing the epigenome of bacteria. In the present study, this technology was used to sequence 2 Lactobacillus strains, Lactobacillus casei Zhang and Lactobacillus plantarum P-8. Previously, the former bacterium was sequenced by an Applied Biosystems 3730 DNA analyzer (Grand Island, NY), whereas the latter one was analyzed with Roche 454 (Indianapolis, IN) and Illumina sequencing technologies (San Diego, CA). The results showed that single molecule, real-time sequencing resulted in high-quality, finished genomes for both strains. Interestingly, epigenome analysis indicates the presence of 1 active N(6)-methyladenine methyltransferase in L. casei Zhang, but none in L. plantarum P-8. Our study revealed for the first time a completely different methylation pattern in 2 Lactobacillus strains. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.


July 7, 2019

Genomes of Geoalkalibacter ferrihydriticus Z-0531Tand Geoalkalibacter subterraneus Red1T, two haloalkaliphilic metal-reducing Deltaproteobacteria.

We sequenced and annotated genomes of two haloalkaliphilic Deltaproteobacteria, Geoalkalibacter ferrihydriticus Z-0531(T) (DSM 17813) and Geoalkalibacter subterraneus Red1(T) (DSM 23483). During assembly, we discovered that the DSMZ stock culture of G. subterraneus was contaminated. We reisolated G. subterraneus in axenic culture and redeposited it in DSMZ and JCM. Copyright © 2015 Badalamenti et al.


July 7, 2019

Ceftriaxone-resistant Salmonella enterica serotype Typhimurium sequence type 313 from Kenyan patients is associated with the blaCTX-M-15 gene on a novel IncHI2 plasmid.

Multidrug-resistant bacteria pose a major challenge to the clinical management of infections in resource-poor settings. Although nontyphoidal Salmonella (NTS) bacteria cause predominantly enteric self-limiting illness in developed countries, NTS is responsible for a huge burden of life-threatening bloodstream infections in sub-Saharan Africa. Here, we characterized nine S. Typhimurium isolates from an outbreak involving patients who initially failed to respond to ceftriaxone treatment at a referral hospital in Kenya. These Salmonella enterica serotype Typhimurium isolates were resistant to ampicillin, chloramphenicol, cefuroxime, ceftriaxone, aztreonam, cefepime, sulfamethoxazole-trimethoprim, and cefpodoxime. Resistance to ß-lactams, including to ceftriaxone, was associated with carriage of a combination of blaCTX-M-15, blaOXA-1, and blaTEM-1 genes. The genes encoding resistance to heavy-metal ions were borne on the novel IncHI2 plasmid pKST313, which also carried a pair of class 1 integrons. All nine isolates formed a single clade within S. Typhimurium ST313, the major clone of an ongoing invasive NTS epidemic in the region. This emerging ceftriaxone-resistant clone may pose a major challenge in the management of invasive NTS in sub-Saharan Africa. Copyright © 2015, Kariuki et al.


July 7, 2019

Complete genome sequence of Paenibacillus polymyxa strain Sb3-1, a soilborne bacterium with antagonistic activity toward plant pathogens.

The genome of Paenibacillus polymyxa Sb3-1, a strain that shows antagonistic activities against pathogenic fungi and bacteria, consists of one 5.6-Mb circular chromosome and two plasmids of 223 kb and 8 kb. The genome reveals several genes that potentially contribute to its antagonistic and plant growth promotion activity. Copyright © 2015 Rybakova et al.


July 7, 2019

Insights on the emergence of Mycobacterium tuberculosis from the analysis of Mycobacterium kansasii.

By phylogenetic analysis, Mycobacterium kansasii is closely related to Mycobacterium tuberculosis. Yet, although both organisms cause pulmonary disease, M. tuberculosis is a global health menace, whereas M. kansasii is an opportunistic pathogen. To illuminate the differences between these organisms, we have sequenced the genome of M. kansasii ATCC 12478 and its plasmid (pMK12478) and conducted side-by-side in vitro and in vivo investigations of these two organisms. The M. kansasii genome is 6,432,277 bp, more than 2 Mb longer than that of M. tuberculosis H37Rv, and the plasmid contains 144,951 bp. Pairwise comparisons reveal conserved and discordant genes and genomic regions. A notable example of genomic conservation is the virulence locus ESX-1, which is intact and functional in the low-virulence M. kansasii, potentially mediating phagosomal disruption. Differences between these organisms include a decreased predicted metabolic capacity, an increased proportion of toxin-antitoxin genes, and the acquisition of M. tuberculosis-specific genes in the pathogen since their common ancestor. Consistent with their distinct epidemiologic profiles, following infection of C57BL/6 mice, M. kansasii counts increased by less than 10-fold over 6 weeks, whereas M. tuberculosis counts increased by over 10,000-fold in just 3 weeks. Together, these data suggest that M. kansasii can serve as an image of the environmental ancestor of M. tuberculosis before its emergence as a professional pathogen, and can be used as a model organism to study the switch from an environmental opportunistic pathogen to a professional host-restricted pathogen. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.


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