Demonstration of IS711 transposition in Brucella ovis and Brucella pinnipedialis

<p>Abstract</p> <p>Background</p> <p>The <it>Brucella </it>genome contains an insertion sequence (IS) element called IS<it>711 </it>or IS<it>6501</it>, which is specific to the genus. The copy number of IS<it>711 </it>varies in the genome of the different <it>Brucella </it>species, ranging from 7 in <it>B. abortus</it>, <it>B. melitensis </it>and <it>B. suis </it>to more than 30 in <it>B. ovis </it>and in <it>Brucella </it>strains isolated from marine mammals. At present, there is no experimental evidence of transposition of IS<it>711</it>, but the occurrence of this element with a high copy number in some species, and the isolation of <it>Brucella </it>strains with "ectopic" copies of IS<it>711 </it>suggested that this IS could still transpose.</p> <p>Results</p> <p>In this study we obtained evidence of transposition of IS<it>711 </it>from the <it>B. ovis </it>and <it>B. pinnipedialis </it>chromosomes by using the "transposon trap" plasmid pGBG1. This plasmid expresses resistance to tetracycline only if the repressor gene that it contains is inactivated. The strains <it>B. melitensis </it>16 M, <it>B. abortus </it>RB51, <it>B. ovis </it>BOC22 (field strain) and <it>B. pinnipedialis </it>B2/94, all containing the plasmid pGBG1, were grown in culture media with tetracycline until the appearance of tetracycline resistant mutants (Tc^R). Tc^Rmutants due to IS<it>711 </it>transposition were only detected in <it>B. ovis </it>and <it>B. pinnipedialis </it>strains.</p> <p>Conclusion</p> <p>Four different copies of IS<it>711 </it>were found to transpose to the same target sequence in the plasmid pGBG1. This demonstrated that IS<it>711 </it>are active <it>in vivo</it>, specially in <it>Brucella </it>species with a high number of IS<it>711 </it>copies as <it>B. ovis </it>and <it>B. pinnipedialis</it>.</p

Isolation of VIM-2-producing Pseudomonas monteilii clinical strains disseminated in a tertiary hospital in northern Spain

We describe here the occurrence of blaVIM-2 in 10 carbapenem-resistant Pseudomonas monteilii strains isolated from different clinical samples from patients at the University Hospital Marqués de Valdecilla in northern Spain. All the blaVIM-2-harboring P. monteilii isolates possessed a class 1 integron, with the cassette array [intI1_blaVIM-2_aac(6')-Ib_qacEΔ1_sul1]. Our results show the emergence of VIM-2-producing multidrug-resistant species other than Pseudomonas aeruginosa or Pseudomonas putida in a Spanish hospital. P. monteilii, although sporadically isolated, should also be considered an important metallo-β-lactamase (MBL) reservoir

Prevalence and Population Diversity of Listeria monocytogenes Isolated from Dairy Cattle Farms in the Cantabria Region of Spain

Listeria monocytogenes is an opportunistic pathogen that is widely distributed in the environment. Here we show the prevalence and transmission of L. monocytogenes in dairy farms in the Cantabria region, on the northern coast of Spain. A total of 424 samples was collected from 14 dairy farms (5 organic and 9 conventional) and 211 L. monocytogenes isolates were recovered following conventional microbiological methods. There were no statistically significant differences in antimicrobial resistance ratios between organic and conventional farms. A clonal relationship among the isolates was assessed by pulsed field gel electrophoresis (PFGE) analysis and 64 different pulsotypes were obtained. Most isolates (89%, n = 187) were classified as PCR serogroup IVb by using a multiplex PCR assay. In this case, 45 isolates of PCR serogroup IVb were whole genome-sequenced to perform a further analysis at genomic level. In silico MLST analysis showed the presence of 12 sequence types (ST), of which ST1, ST54 and ST666 were the most common. Our data indicate that the environment of cattle farms retains a high incidence of L. monocytogenes, including subtypes involved in human listeriosis reports and outbreaks. This pathogen is shed in the feces and could easily colonize dairy products, as a result of fecal contamination. Effective herd and manure management are needed in order to prevent possible outbreaks.This work was supported by Research Project grants RTA08-099, RTA2008-00080-C02, RTA2014-00045-C03-01 (INIA and FEDER) from the Spanish Ministry of Economy and Competitiveness and RTI2018-098267-R-C31 (INIA and FEDER) from the Spanish Ministry of Science and Innovation.S

Evolution of the Pseudomonas aeruginosa mutational resistome in an international Cystic Fibrosis clone

AbstractEmergence of epidemic clones and antibiotic resistance development compromises the management of Pseudomonas aeruginosa cystic fibrosis (CF) chronic respiratory infections. Whole genome sequencing (WGS) was used to decipher the phylogeny, interpatient dissemination, WGS mutator genotypes (mutome) and resistome of a widespread clone (CC274), in isolates from two highly-distant countries, Australia and Spain, covering an 18-year period. The coexistence of two divergent CC274 clonal lineages was revealed, but without evident geographical barrier; phylogenetic reconstructions and mutational resistome demonstrated the interpatient transmission of mutators. The extraordinary capacity of P. aeruginosa to develop resistance was evidenced by the emergence of mutations in &gt;100 genes related to antibiotic resistance during the evolution of CC274, catalyzed by mutator phenotypes. While the presence of classical mutational resistance mechanisms was confirmed and correlated with resistance phenotypes, results also showed a major role of unexpected mutations. Among them, PBP3 mutations, shaping up β-lactam resistance, were noteworthy. A high selective pressure for mexZ mutations was evidenced, but we showed for the first time that high-level aminoglycoside resistance in CF is likely driven by mutations in fusA1/fusA2, coding for elongation factor G. Altogether, our results provide valuable information for understanding the evolution of the mutational resistome of CF P. aeruginosa.</jats:p

Co-Existence of blaNDM-1, blaOXA-23, blaOXA-64, blaPER-7 and blaADC-57 in a Clinical Isolate of Acinetobacter baumannii from Alexandria, Egypt

The increasing rates of antimicrobial resistance among carbapenem-resistant Acinetobacter baumannii in the Middle East and North Africa are one of the major concerns for healthcare settings. We characterised the first A. baumannii isolate harbouring five β-lactamases identified in Egypt. The isolate Ale25 was obtained from an ICU patient of a hospital from Alexandria. The isolate was phenotypically and genotypically screened for carbapenemase genes. The isolate was resistant to carbapenems, aminoglycosides, fluoroquinolones and cefiderocol. Whole-Genome Sequencing identified five β-lactamase genes, blaNDM-1, blaOXA-23, blaOXA-64, blaPER-7 and blaADC-57, together with other antibiotic resistance genes, conferring resistance to sulfonamides, macrolides, tetracyclines, rifamycin and chloramphenicol. Virulome analysis showed the presence of genes involved in adhesion and biofilm production, type II and VI secretion systems, exotoxins, etc. Multi-Locus Sequence Typing analysis identified the isolate as Sequence Types 113Pas and 2246Oxf, belonging to International Clone 7. Sequencing experiments revealed the presence of four plasmids of 2.7, 22.3, 70.4 and 240.8 Kb. All the β-lactamase genes were located in the chromosome, except the blaPER-7, gene which was found within the plasmid of 240.8 Kb. This study highlights the threat of the emergence and dissemination of these types of isolates.This research was funded by the MINISTRY OF SCIENCE AND INNOVATION (MCIN/AEI/10.13039/501100011033), grant number PID2020-116495RB-I00; the DEPARTMENT OF EDUCATION OF THE BASQUE GOVERNMENT (Research Groups of the Basque University System 2021), grant number Group IT1578-22, GIC21/18; and the ARAB ACADEMY FOR SCIENCE, TECHNOLOGY AND MARITIME TRANSPORT, grant number 2072

The Genome of a Pathogenic Rhodococcus: Cooptive Virulence Underpinned by Key Gene Acquisitions

We report the genome of the facultative intracellular parasite Rhodococcus equi, the only animal pathogen within the biotechnologically important actinobacterial genus Rhodococcus. The 5.0-Mb R. equi 103S genome is significantly smaller than those of environmental rhodococci. This is due to genome expansion in nonpathogenic species, via a linear gain of paralogous genes and an accelerated genetic flux, rather than reductive evolution in R. equi. The 103S genome lacks the extensive catabolic and secondary metabolic complement of environmental rhodococci, and it displays unique adaptations for host colonization and competition in the short-chain fatty acid–rich intestine and manure of herbivores—two main R. equi reservoirs. Except for a few horizontally acquired (HGT) pathogenicity loci, including a cytoadhesive pilus determinant (rpl) and the virulence plasmid vap pathogenicity island (PAI) required for intramacrophage survival, most of the potential virulence-associated genes identified in R. equi are conserved in environmental rhodococci or have homologs in nonpathogenic Actinobacteria. This suggests a mechanism of virulence evolution based on the cooption of existing core actinobacterial traits, triggered by key host niche–adaptive HGT events. We tested this hypothesis by investigating R. equi virulence plasmid-chromosome crosstalk, by global transcription profiling and expression network analysis. Two chromosomal genes conserved in environmental rhodococci, encoding putative chorismate mutase and anthranilate synthase enzymes involved in aromatic amino acid biosynthesis, were strongly coregulated with vap PAI virulence genes and required for optimal proliferation in macrophages. The regulatory integration of chromosomal metabolic genes under the control of the HGT–acquired plasmid PAI is thus an important element in the cooptive virulence of R. equi

First Report of an Extensively Drug-Resistant ST23 <em>Klebsiella pneumoniae</em> of Capsular Serotype K1 Co-Producing CTX-M-15, OXA-48 and ArmA in Spain

An extensively drug-resistant (XDR) Klebsiella pneumoniae isolate MS3802 from a tracheostomy exudate was whole-genome sequenced using MiSeq and Oxford Nanopore MinION platforms in order to identify the antimicrobial resistance and virulence determinates and their genomic context. Isolate MS3802 belonged to the clone ST23 and presented a capsular serotype K1, associated with hypervirulent K. pneumoniae (hvKp) isolates. The isolate harboured a chromosomally encoded blaCTX-M-15 gene and contained a large IncHI1B hybrid virulence/resistance plasmid carrying another copy of the blaCTX-M-15 and the virulence factors iucABCD-iutA, iroBCDN, rmpA and rmpA2. The carbapenemase gene blaOXA-48 was found in a Tn1999-like transposon and the 16S rRNA methylase armA gen located in the vicinity of other antibiotic-resistant genes on an IncM2 plasmid. This study represents, to the best of our knowledge, the first description of a blaCTX-M-15-, blaOXA-48- and armA-harbouring K. pneumoniae of ST23 and capsular serotype K1 in Spain. Our report emphasizes the importance of implementing new surveillance strategies to monitor the risk of emergence and spread of such XDR and hypervirulent K. pneumoniae isolates