scholarly journals Enterococcal PrgU Provides Additional Regulation of Pheromone-Inducible Conjugative Plasmids

mSphere ◽  
2021 ◽  
Author(s):  
Lena Lassinantti ◽  
Martha I. Camacho ◽  
Rebecca J. B. Erickson ◽  
Julia L. E. Willett ◽  
Nicholas R. De Lay ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Secretion Systems ◽  
Gram Positive ◽  
Regulation Of Expression ◽  
Conjugative Plasmids ◽  
Gram Positive Bacteria ◽  
Genes Encoding ◽  
Surface Adhesins

Bacteria utilize type 4 secretion systems (T4SS) to efficiently transfer DNA between donor and recipient cells, thereby spreading genes encoding antibiotic resistance as well as various virulence factors. Regulation of expression of the T4SS proteins and surface adhesins in Gram-positive bacteria is crucial, as some of these are highly toxic to the cell.

scholarly journals Conjugative Plasmid Transfer in Gram-Positive Bacteria

2003 ◽  
Vol 67 (2) ◽  
pp. 277-301 ◽  
Author(s):  
Elisabeth Grohmann ◽  
Günther Muth ◽  
Manuel Espinosa
Keyword(s):  
Antibiotic Resistance ◽  
Plasmid Transfer ◽  
Translocator Protein ◽  
Conjugative Plasmid ◽  
Gram Negative Bacteria ◽  
Secretion Systems ◽  
Gram Positive ◽  
Severe Problem ◽  
Gram Negative ◽  
Gram Positive Bacteria

SUMMARY Conjugative transfer of bacterial plasmids is the most efficient way of horizontal gene spread, and it is therefore considered one of the major reasons for the increase in the number of bacteria exhibiting multiple-antibiotic resistance. Thus, conjugation and spread of antibiotic resistance represents a severe problem in antibiotic treatment, especially of immunosuppressed patients and in intensive care units. While conjugation in gram-negative bacteria has been studied in great detail over the last decades, the transfer mechanisms of antibiotic resistance plasmids in gram-positive bacteria remained obscure. In the last few years, the entire nucleotide sequences of several large conjugative plasmids from gram-positive bacteria have been determined. Sequence analyses and data bank comparisons of their putative transfer (tra) regions have revealed significant similarities to tra regions of plasmids from gram-negative bacteria with regard to the respective DNA relaxases and their targets, the origins of transfer (oriT), and putative nucleoside triphosphatases NTP-ases with homologies to type IV secretion systems. In contrast, a single gene encoding a septal DNA translocator protein is involved in plasmid transfer between micelle-forming streptomycetes. Based on these clues, we propose the existence of two fundamentally different plasmid-mediated conjugative mechanisms in gram-positive microorganisms, namely, the mechanism taking place in unicellular gram-positive bacteria, which is functionally similar to that in gram-negative bacteria, and a second type that occurs in multicellular gram-positive bacteria, which seems to be characterized by double-stranded DNA transfer.

scholarly journals Co-existence of virulence factors and antibiotic resistance in new Klebsiella pneumoniae clones emerging in south of Italy

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Teresa Fasciana ◽  
Bernardina Gentile ◽  
Maria Aquilina ◽  
Andrea Ciammaruconi ◽  
Chiara Mascarella ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Virulence Factors ◽  
In Silico ◽  
Geographical Area ◽  
In Silico Analysis ◽  
University Hospital ◽  
Uptake System ◽  
Genes Encoding ◽  
Silico Analysis

Abstract Background Endemic presence of Klebsiella pneumoniae resistant to carbapenem in Italy has been due principally to the clonal expansion of CC258 isolates; however, recent studies suggest an ongoing epidemiological change in this geographical area. Methods 50 K. pneumoniae strains, 25 carbapenem-resistant (CR-Kp) and 25 susceptible (CS-Kp), collected from march 2014 to march 2016 at the Laboratory of Bacteriology of the Paolo Giaccone Polyclinic University hospital of Palermo, Italy, were characterized for antibiotic susceptibility and fully sequenced by next generation sequencing (NGS) for the in silico analysis of resistome, virulome, multi-locus sequence typing (MLST) and core single nucleotide polymorphism (SNP) genotypes Results MLST in silico analysis of CR-Kp showed that 52% of isolates belonged to CC258, followed by ST395 (12%), ST307 (12%), ST392 (8%), ST348 (8%), ST405 (4%) and ST101 (4%). In the CS-Kp group, the most represented isolate was ST405 (20%), followed by ST392 and ST15 (12%), ST395, ST307 and ST1727 (8%). The in silico β-lactamase analysis of the CR-Kp group showed that the most detected gene was blaSHV (100%), followed by blaTEM (92%), blaKPC (88%), blaOXA (88%) and blaCTX-M (32%). The virulome analysis detected mrk operon in all studied isolates, and wzi-2 was found in three CR-Kp isolates (12%). Furthermore, the distribution of virulence genes encoding for the yersiniabactin system, its receptor fyuA and the aerobactin system did not show significant distribution differences between CR-Kp and CS-Kp, whereas the Klebsiella ferrous iron uptake system (kfuA, kfuB and kfuC genes), the two-component system kvgAS and the microcin E495 were significantly (p < 0.05) prevalent in the CS-Kp group compared to the CR-Kp group. Core SNP genotyping, correlating with the MLST data, allowed greater strain tracking and discrimination than MLST analysis. Conclusions Our data support the idea that an epidemiological change is ongoing in the Palermo area (Sicily, Italy). In addition, our analysis revealed the co-existence of antibiotic resistance and virulence factors in CR-Kp isolates; this characteristic should be considered for future genomic surveillance studies.

scholarly journals Staphylococcus epidermidis MSCRAMM SesJ Is Encoded in Composite Islands

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Srishtee Arora ◽  
Xiqi Li ◽  
Andrew Hillhouse ◽  
Kranti Konganti ◽  
Sara V. Little ◽  
...  
Keyword(s):  
Cell Wall ◽  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Staphylococcus Epidermidis ◽  
Core Genome ◽  
Clinical Isolates ◽  
Modification System ◽  
Content Type ◽  
Genes Encoding ◽  
Staphylococcal Cassette Chromosome

ABSTRACT Staphylococcus epidermidis is a leading cause of nosocomial infections in patients with a compromised immune system and/or an implanted medical device. Seventy to 90% of S. epidermidis clinical isolates are methicillin resistant and carry the mecA gene, present in a mobile genetic element (MGE) called the staphylococcal cassette chromosome mec (SCCmec) element. Along with the presence of antibiotic and heavy metal resistance genes, MGEs can also contain genes encoding secreted or cell wall-anchored virulence factors. In our earlier studies of S. epidermidis clinical isolates, we discovered S. epidermidis surface protein J (SesJ), a prototype of a recently discovered subfamily of the microbial surface component recognizing adhesive matrix molecule (MSCRAMM) group. MSCRAMMs are major virulence factors of pathogenic Gram-positive bacteria. Here, we report that the sesJ gene is always accompanied by two glycosyltransferase genes, gtfA and gtfB, and is present in two MGEs, called the arginine catabolic mobile element (ACME) and the staphylococcal cassette chromosome (SCC) element. The presence of the sesJ gene was associated with the left-hand direct repeat DR_B or DR_E. When inserted via DR_E, the sesJ gene was encoded in the SCC element. When inserted via DR_B, the sesJ gene was accompanied by the genes for the type 1 restriction modification system and was encoded in the ACME. Additionally, the SCC element and ACME carry different isoforms of the SesJ protein. To date, the genes encoding MSCRAMMs have been seen to be located in the bacterial core genome. Here, we report the presence of an MSCRAMM in an MGE in S. epidermidis clinical isolates. IMPORTANCE S. epidermidis is an opportunistic bacterium that has established itself as a successful nosocomial pathogen. The modern era of novel therapeutics and medical devices has extended the longevity of human life, but at the same time, we also witness the evolution of pathogens to adapt to newly available niches in the host. Increasing antibiotic resistance among pathogens provides an example of such pathogen adaptation. With limited opportunities to modify the core genome, most of the adaptation occurs by acquiring new genes, such as virulence factors and antibiotic resistance determinants present in MGEs. In this study, we describe that the sesJ gene, encoding a recently discovered cell wall-anchored protein in S. epidermidis, is present in both ACME and the SCC element. The presence of virulence factors in MGEs can influence the virulence potential of a specific strain. Therefore, it is critical to study the virulence factors found in MGEs in emerging pathogenic bacteria or strains to understand the mechanisms used by these bacteria to cause infections.

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