scholarly journals Active Human and Porcine Serum Induce Competence for Genetic Transformation in the Emerging Zoonotic Pathogen Streptococcus suis

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 156
Author(s):  
Maria Laura Ferrando ◽  
Alex Gussak ◽  
Saskia Mentink ◽  
Marcela Fernandez Gutierrez ◽  
Peter van Baarlen ◽  
...  
Keyword(s):  
Genetic Transformation ◽  
Environmental Dna ◽  
Streptococcus Suis ◽  
Dna Uptake ◽  
Microbial Competition ◽  
Genetic Traits ◽  
Porcine Serum ◽  
Virulent Strains ◽  
Heat Treated ◽  
Genes Encoding

The acquisition of novel genetic traits through natural competence is a strategy used by bacteria in microbe-rich environments where microbial competition, antibiotics, and host immune defenses threaten their survival. Here, we show that virulent strains of Streptococcus suis, an important zoonotic agent and porcine pathogen, become competent for genetic transformation with plasmid or linear DNA when cultured in active porcine and human serum. Competence was not induced in active fetal bovine serum, which contains less complement factors and immunoglobulins than adult serum and was strongly reduced in heat-treated or low-molecular weight fractions of active porcine serum. Late competence genes, encoding the uptake machinery for environmental DNA, were upregulated in the active serum. Competence development was independent of the early competence regulatory switch involving XIP and ComR, as well as sigma factor ComX, suggesting the presence of an alternative stress-induced pathway for regulation of the late competence genes required for DNA uptake.

scholarly journals Complement active human and porcine serum induces natural competence for genetic transformation in the emerging zoonotic pathogen Streptococcus suis

2020 ◽  
Author(s):  
Maria Laura Ferrando ◽  
Alex Gussak ◽  
Saskia Mentink ◽  
Peter van Baarlen ◽  
Jerry Mark Wells
Keyword(s):  
Genetic Transformation ◽  
Environmental Dna ◽  
Streptococcus Suis ◽  
Natural Competence ◽  
Microbial Competition ◽  
Genetic Traits ◽  
Porcine Serum ◽  
Virulent Strains ◽  
Genes Encoding ◽  
Immune Defences

AbstractThe acquisition of novel genetic traits by natural competence is a strategy used by bacteria in microbe-rich environments including animal or human hosts where microbial competition, antibiotics and host immune defences threaten their survival. We show here that several virulent strains of Streptococcus suis, an important porcine pathogen and zoonotic agent, become naturally competent for genetic transformation with plasmid or genomic DNA when cultured in active porcine and human serum, but not when it is pre-heated for 30 minutes at 56°C to inactivate complement. Competence is also not induced in active fetal bovine serum, which contains less complement factors and immunoglobulins than adult serum. Late competence genes, encoding the uptake machinery for environmental DNA, were highly upregulated in active serum. Competence development was independent of the early competence regulatory switch suggesting the presence of an alternative stress-induced pathway for regulation of the transformasome, a type 4-like pilus DNA binding and transport apparatus.

scholarly journals Metaplasmidome-encoded functions of Siberian low-centered polygonal tundra soils

2021 ◽  
Author(s):  
Adrian Gorecki ◽  
Stine Holm ◽  
Mikolaj Dziurzynski ◽  
Matthias Winkel ◽  
Sizhong Yang ◽  
...  
Keyword(s):  
Active Layer ◽  
Bacterial Communities ◽  
Extraction Methods ◽  
Metal Resistance ◽  
Rapid Adaptation ◽  
Tundra Soils ◽  
Genetic Traits ◽  
Functional Potential ◽  
Stress Response Genes ◽  
Genes Encoding

AbstractPlasmids have the potential to transfer genetic traits within bacterial communities and thereby serve as a crucial tool for the rapid adaptation of bacteria in response to changing environmental conditions. Our knowledge of the environmental pool of plasmids (the metaplasmidome) and encoded functions is still limited due to a lack of sufficient extraction methods and tools for identifying and assembling plasmids from metagenomic datasets. Here, we present the first insights into the functional potential of the metaplasmidome of permafrost-affected active-layer soil—an environment with a relatively low biomass and seasonal freeze–thaw cycles that is strongly affected by global warming. The obtained results were compared with plasmid-derived sequences extracted from polar metagenomes. Metaplasmidomes from the Siberian active layer were enriched via cultivation, which resulted in a longer contig length as compared with plasmids that had been directly retrieved from the metagenomes of polar environments. The predicted hosts of plasmids belonged to Moraxellaceae, Pseudomonadaceae, Enterobacteriaceae, Pectobacteriaceae, Burkholderiaceae, and Firmicutes. Analysis of their genetic content revealed the presence of stress-response genes, including antibiotic and metal resistance determinants, as well as genes encoding protectants against the cold.

scholarly journals Non-Penicillin-Susceptible Streptococcus suis Isolated from Humans

Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1178
Author(s):  
Nichari Bamphensin ◽  
Peechanika Chopjitt ◽  
Rujirat Hatrongjit ◽  
Parichart Boueroy ◽  
Nahuel Fittipaldi ◽  
...  
Keyword(s):  
Amino Acid ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Streptococcus Suis ◽  
Amino Acid Substitutions ◽  
Continuous Control ◽  
Antimicrobial Resistance Genes ◽  
Genes Encoding ◽  
Invasive Infections ◽  
Almost All

Streptococcus suis is a pathogen that causes invasive infections in humans and pigs. In this study, 448 S. suis isolates recovered from human infections in Thailand were characterized with regard to their antimicrobial susceptibility and antimicrobial resistance genes, including, for non-penicillin-susceptible isolates, sequence analyses of five genes encoding penicillin-binding proteins (pbp1a, pbp1b, pbp2a, pbp2b, and pbp2x). All 448 isolates were susceptible to cefepime and ceftriaxone, whereas 99.6%, 91.7%, and 72.9% of the isolates were susceptible to levofloxacin, penicillin, and chloramphenicol, respectively. Almost all isolates were resistant to tetracycline (98.2%), clindamycin (94%), erythromycin (92.4%), and azithromycin (82.6%). Genes tet(O) and ermB were the predominant resistance genes detected among macrolide- and tetracycline-resistant isolates. A total of 37 out of 448 isolates (8.2%) showed intermediately resistance to penicillin. Most of these isolates (59.5%) belonged to serotype 2-ST233. Comparison of the predicted translated sequences of five PBP proteins of a penicillin-susceptible isolate (strain P1/7) to the respective PBP sequences of ten non-penicillin-susceptible isolates revealed multiple amino acid substitutions. Isolates of CC221/234 showed highly variable amino acid substitutions in all PBP proteins. An ST104 isolate had a higher number of amino acid substitutions in PBP2X. Isolates belonging to CC233/379 had numerous substitutions in PBP2B and PBP2X. ST25 isolates exhibited fewer amino acid substitutions than isolates of other STs in all five PBPs. The antimicrobial resistance of S. suis is increasing worldwide; therefore, restrictions on antimicrobial use, continuous control, and the surveillance of this bacterium throughout the pork supply chain are crucial for ensuring public health and must be a priority concern.

scholarly journals Chromosomal rearrangements and protein globularity changes inMycobacterium tuberculosisisolates from cerebrospinal fluid

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2484 ◽  
Author(s):  
Seow Hoon Saw ◽  
Joon Liang Tan ◽  
Xin Yue Chan ◽  
Kok Gan Chan ◽  
Yun Fong Ngeow
Keyword(s):  
Cerebrospinal Fluid ◽  
Chromosomal Rearrangements ◽  
Genome Sequences ◽  
Genetic Traits ◽  
Genomic Features ◽  
Synonymous Snps ◽  
Genome Wide ◽  
Genes Encoding ◽  
Transcription Regulators ◽  
Central Nervous System Invasion

BackgroundMeningitis is a major cause of mortality in tuberculosis (TB). It is not clear what factors promote central nervous system invasion and pathology but it has been reported that certain strains ofMycobacterium tuberculosis(Mtb) might have genetic traits associated with neurotropism.MethodsIn this study, we generated whole genome sequences of eight clinical strains ofMtbthat were isolated from the cerebrospinal fluid (CSF) of patients presenting with tuberculous meningitis (TBM) in Malaysia, and compared them to the genomes of H37Rv and other respiratoryMtbgenomes either downloaded from public databases or extracted from local sputum isolates. We aimed to find genomic features that might be distinctly different between CSF-derived and respiratoryMtb.ResultsGenome-wide comparisons revealed rearrangements (translocations, inversions, insertions and deletions) and non-synonymous SNPs in our CSF-derived strains that were not observed in the respiratoryMtbgenomes used for comparison. These rearranged segments were rich in genes for PE (proline-glutamate)/PPE (proline-proline-glutamate), transcriptional and membrane proteins. Similarly, most of the ns SNPs common in CSF strains were noted in genes encoding PE/PPE proteins. Protein globularity differences were observed among mycobacteria from CSF and respiratory sources and in proteins previously reported to be associated with TB meningitis. Transcription factors and other transcription regulators featured prominently in these proteins. Homologs of proteins associated withStreptococcus pneumoniaemeningitis andNeisseria meningitidisvirulence were identified in neuropathogenic as well as respiratory mycobacterial spp. examined in this study.DiscussionThe occurrence of in silico genetic differences in CSF-derived but not respiratoryMtbsuggests their possible involvement in the pathogenesis of TBM. However, overall findings in this comparative analysis support the postulation that TB meningeal infection is more likely to be related to the expression of multiple virulence factors on interaction with host defences than to CNS tropism associated with specific genetic traits.

scholarly journals Functional metagenomic analysis of dust-associated microbiomes above the Red Sea

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Nojood A. Aalismail ◽  
David K. Ngugi ◽  
Rubén Díaz-Rúa ◽  
Intikhab Alam ◽  
Michael Cusack ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Dna Sequences ◽  
Biofilm Formation ◽  
Atmospheric Transport ◽  
Taxonomic Diversity ◽  
Functional Metagenomics ◽  
Genetic Traits ◽  
Gene Catalogue ◽  
Range Transport ◽  
Genes Encoding

Abstract Atmospheric transport is a major vector for the long-range transport of microbial communities, maintaining connectivity among them and delivering functionally important microbes, such as pathogens. Though the taxonomic diversity of aeolian microorganisms is well characterized, the genomic functional traits underpinning their survival during atmospheric transport are poorly characterized. Here we use functional metagenomics of dust samples collected on the Global Dust Belt to initiate a Gene Catalogue of Aeolian Microbiome (GCAM) and explore microbial genetic traits enabling a successful aeolian lifestyle in Aeolian microbial communities. The GCAM reported here, derived from ten aeolian microbial metagenomes, includes a total of 2,370,956 non-redundant coding DNA sequences, corresponding to a yield of ~31 × 106 predicted genes per Tera base-pair of DNA sequenced for the aeolian samples sequenced. Two-thirds of the cataloged genes were assigned to bacteria, followed by eukaryotes (5.4%), archaea (1.1%), and viruses (0.69%). Genes encoding proteins involved in repairing UV-induced DNA damage and aerosolization of cells were ubiquitous across samples, and appear as fundamental requirements for the aeolian lifestyle, while genes coding for other important functions supporting the aeolian lifestyle (chemotaxis, aerotaxis, germination, thermal resistance, sporulation, and biofilm formation) varied among the communities sampled.

scholarly journals Identification of an Inducible Bacteriophage in a Virulent Strain of Streptococcus suis Serotype 2

2003 ◽  
Vol 71 (10) ◽  
pp. 6104-6108 ◽  
Author(s):  
J. Harel ◽  
G. Martinez ◽  
A. Nassar ◽  
H. Dezfulian ◽  
S. J. Labrie ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Virulent Strain ◽  
Streptococcus Suis ◽  
Swine Industry ◽  
Subtraction Hybridization ◽  
Gram Positive Bacteria ◽  
Virulence Markers ◽  
Virulent Strains ◽  
Phage Dna ◽  
Suis Serotype

ABSTRACT Streptococcus suis infection is considered to be a major problem in the swine industry worldwide. Most virulent Canadian isolates of S. suis serotype 2 do not produce the known virulence markers for this pathogen. PCR-based subtraction hybridization was adapted to isolate unique DNA sequences which were specific to virulent strains of S. suis isolated in Canada. Analysis of some subtracted DNA clones revealed significant homology with bacteriophages of gram-positive bacteria. An inducible phage (named Ss1) was observed in S. suis following the incubation of the virulent strain 89-999 with mitomycin C. Phage Ss1 has a long noncontractile tail and a small isometric nucleocapsid and is a member of the Siphoviridae family. Ss1 phage DNA appears to be present in most Canadian S. suis strains tested in this study, which were isolated from diseased pigs or had proven virulence in mouse or pig models. To our knowledge, this is the first report of the isolation of a phage in S. suis.

scholarly journals Identification of Novel Benzoylformate Decarboxylases by Growth Selection

2006 ◽  
Vol 72 (12) ◽  
pp. 7510-7517 ◽  
Author(s):  
Helge Henning ◽  
Christian Leggewie ◽  
Martina Pohl ◽  
Michael Müller ◽  
Thorsten Eggert ◽  
...  
Keyword(s):  
Environmental Dna ◽  
Selective Medium ◽  
The Novel ◽  
Selection System ◽  
Dna Library ◽  
Benzoylformate Decarboxylase ◽  
Growth Deficiency ◽  
Growth Selection ◽  
Genes Encoding ◽  
Encoding Genes

ABSTRACT A growth selection system was established using Pseudomonas putida, which can grow on benzaldehyde as the sole carbon source. These bacteria presumably metabolize benzaldehyde via the β-ketoadipate pathway and were unable to grow in benzoylformate-containing selective medium, but the growth deficiency could be restored by expression in trans of genes encoding benzoylformate decarboxylases. The selection system was used to identify three novel benzoylformate decarboxylases, two of them originating from a chromosomal library of P. putida ATCC 12633 and the third from an environmental-DNA library. The novel P. putida enzymes BfdB and BfdC exhibited 83% homology to the benzoylformate decarboxylase from P. aeruginosa and 63% to the enzyme MdlC from P. putida ATCC 12633, whereas the metagenomic BfdM exhibited 72% homology to a putative benzoylformate decarboxylase from Polaromonas naphthalenivorans. BfdC was overexpressed in Escherichia coli, and the enzymatic activity was determined to be 22 U/ml using benzoylformate as the substrate. Our results clearly demonstrate that P. putida KT2440 is an appropriate selection host strain suitable to identify novel benzoylformate decarboxylase-encoding genes. In principle, this system is also applicable to identify a broad range of different industrially important enzymes, such as benzaldehyde lyases, benzoylformate decarboxylases, and hydroxynitrile lyases, which all catalyze the formation of benzaldehyde.

Genetic Competence and Transformation in Oral Streptococci

2001 ◽  
Vol 12 (3) ◽  
pp. 217-243 ◽  
Author(s):  
D.G. Cvitkovitch
Keyword(s):  
Genetic Transformation ◽  
Genetic Information ◽  
Physiological State ◽  
Oral Streptococci ◽  
Dna Uptake ◽  
Genetic Competence ◽  
Gram Positive Bacteria ◽  
Oral Biofilms ◽  
Foreign Dna ◽  
Natural Genetic Transformation

The oral streptococci are normally non-pathogenic residents of the human microflora. There is substantial evidence that these bacteria can, however, act as "genetic reservoirs" and transfer genetic information to transient bacteria as they make their way through the mouth, the principal entry point for a wide variety of bacteria. Examples that are of particular concern include the transfer of antibiotic resistance from oral streptococci to Streptococcus pneumoniae. The mechanisms that are used by oral streptococci to exchange genetic information are not well-understood, although several species are known to enter a physiological state of genetic competence. This state permits them to become capable of natural genetic transformation, facilitating the acquisition of foreign DNA from the external environment. The oral streptococci share many similarities with two closely related Gram-positive bacteria. S. pneumoniae and Bacillus subtilis. In these bacteria, the mechanisms of quorum-sensing, the development of competence, and DNA uptake and integration are well-charaterized. Using this knowledge and the data available in genome databases allowed us to identify putative genes involved in these processes in the oral organism Streptococcus mutans. Models of competence development and genetic transformation in the oral streptococci and strategies to confirm these models are discussed. Future studies of competence in oral biofilms, the natural environment of oral streptococci, will be discussed.

scholarly journals Bacitracin resistance and enhanced virulence of Streptococcus suis via a novel efflux pump

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Jiale Ma ◽  
Jin Liu ◽  
Yue Zhang ◽  
Dan Wang ◽  
Runxia Liu ◽  
...  
Keyword(s):  
Efflux Pump ◽  
Animal Feed ◽  
Streptococcus Suis ◽  
Bactericidal Effect ◽  
Infection Model ◽  
Growth Promoter ◽  
Necrotic Enteritis ◽  
Virulent Strains ◽  
Animal Infection ◽  
Almost All

Abstract Background Streptococcus suis is a prominent pathogen causing septicemia and meningitis in swine and humans. Bacitracin is used widely as a growth promoter in animal feed and to control the spread of necrotic enteritis in most developing countries. This study aimed to characterize a novel membrane transporter module Sst comprising SstE, SstF, and SstG for bacitracin resistance. Results Comparative genomics and protein homology analysis found a potential efflux pump SstFEG encoded upstream of well-known bacitracin-resistance genes bceAB and bceRS. A four-fold decrease in bacitracin susceptibility was observed in sstFEG deletion mutant comparing with S. suis wildtype strain CZ130302. Further studies indicated that the bacitracin tolerance mediated by SstFEG is not only independent of the BceAB transporter, but also regulated by the two-component system BceSR. Given that SstFEG are harbored by almost all virulent strains, but not in the avirulent strains, we managed to explore its potential role in bacterial pathogencity. Indeed, our results showed that SstFEG is involved in S. suis colonization and virulence in animal infection model by its potential competitive survival advantage against host bactericidal effect. Conclusion To our knowledge, this is the first study to functionally characterize the bacitracin efflux pump in S. suis to provide evidence regarding the important roles of the novel ABC transporter system SstFEG with respect to drug resistance and virulence.

Streptococci deficient in genetic transformation

1971 ◽  
Vol 17 (10) ◽  
pp. 1251-1257 ◽  
Author(s):  
R. Pakula ◽  
L. R. Spencer ◽  
P. A. Goldstein
Keyword(s):  
Drug Resistance ◽  
Genetic Transformation ◽  
Dna Uptake ◽  
Low Efficiency

Three strains of group H streptococci have been found to produce competence factors (CF's) similar to that synthesized by the highly transformable strain Challis. All these factors efficiently converted to competency for DNA uptake the spontaneously nontransformable strain Wicky. Two of the three strains could be transformed to drug resistance with an extremely low efficiency and one strain was nontransformable. When the bacteria were exposed to tritium-labeled DNA, it was found that a viable unit of the three strains contained about 10 times less radioactivity than a viable unit of Challis and Wicky in the competent state. The probability that CF may not be the only factor required for DNA uptake is discussed.

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