scholarly journals Extensive Comparative Genomic Analysis of Enterococcus faecalis and Enterococcus faecium Reveals a Direct Association between the Absence of CRISPR–Cas Systems, the Presence of Anti-Endonuclease (ardA) and the Acquisition of Vancomycin Resistance in E. faecium

2021 ◽  
Vol 9 (6) ◽  
pp. 1118
Author(s):  
Kodjovi D. Mlaga ◽  
Vincent Garcia ◽  
Philippe Colson ◽  
Ruimy Raymond ◽  
Jean-Marc Rolain ◽  
...  

Here, we performed a comparative genomic analysis of all available genomes of E. faecalis (n = 1591) and E. faecium (n = 1981) and investigated the association between the presence or absence of CRISPR-Cas systems, endonuclease/anti-endonuclease systems and the acquisition of antimicrobial resistance, especially vancomycin resistance genes. Most of the analysed Enterococci were isolated from humans and less than 14% of them were from foods and animals. We analysed and detected CRISPR–Cas systems in 75.36% of E. faecalis genomes and only 4.89% of E. faecium genomes with a significant difference (p-value < 10−5). We found a negative correlation between the number of CRISPR–Cas systems and genome size (r = −0.397, p-value < 10−5) and a positive correlation between the genome %GC content and the number of CRISPR–Cas systems (r = 0.215, p-value < 10−5). Our findings showed that the presence of the anti-endonuclease ardA gene may explain the decrease in the number of CRISPR–Cas systems in E. faecium, known to deactivate the endonucleases’ protective activities and enable the E. faecium genome to be versatile in acquiring mobile genetic elements, including carriers of antimicrobial resistance genes, especially vanB. Most importantly, we observed that there was a direct association between the absence of CRISPR–Cas, the presence of the anti-CRISPR ardA gene and the acquisition of vancomycin resistance genes.

2007 ◽  
Vol 51 (8) ◽  
pp. 3004-3007 ◽  
Author(s):  
Ying-Tsong Chen ◽  
Tsai-Ling Lauderdale ◽  
Tsai-Lien Liao ◽  
Yih-Ru Shiau ◽  
Hung-Yu Shu ◽  
...  

ABSTRACT A 269-kilobase conjugative plasmid, pK29, from a Klebsiella pneumoniae strain was sequenced. The plasmid harbors multiple antimicrobial resistance genes, including those encoding CMY-8 AmpC-type and CTX-M-3 extended-spectrum β-lactamases in the common backbone of IncHI2 plasmids. Mechanisms for dissemination of the resistance genes are highlighted in comparative genomic analyses.


2017 ◽  
Vol 61 (7) ◽  
Author(s):  
Weihua Huang ◽  
Guiqing Wang ◽  
Robert Sebra ◽  
Jian Zhuge ◽  
Changhong Yin ◽  
...  

ABSTRACT The extended-spectrum-β-lactamase (ESBL)- and Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae represent serious and urgent threats to public health. In a retrospective study of multidrug-resistant K. pneumoniae, we identified three clinical isolates, CN1, CR14, and NY9, carrying both bla CTX-M and bla KPC genes. The complete genomes of these three K. pneumoniae isolates were de novo assembled by using both short- and long-read whole-genome sequencing. In CR14 and NY9, bla CTX-M and bla KPC were carried on two different plasmids. In contrast, CN1 had one copy of bla KPC-2 and three copies of bla CTX-M-15 integrated in the chromosome, for which the bla CTX-M-15 genes were linked to an insertion sequence, ISEcp1, whereas the bla KPC-2 gene was in the context of a Tn4401a transposition unit conjugated with a PsP3-like prophage. Intriguingly, downstream of the Tn4401a-bla KPC-2-prophage genomic island, CN1 also carried a clustered regularly interspaced short palindromic repeat (CRISPR)-cas array with four spacers targeting a variety of K. pneumoniae plasmids harboring antimicrobial resistance genes. Comparative genomic analysis revealed that there were two subtypes of type I-E CRISPR-cas in K. pneumoniae strains and suggested that the evolving CRISPR-cas, with its acquired novel spacer, induced the mobilization of antimicrobial resistance genes from plasmids into the chromosome. The integration and dissemination of multiple copies of bla CTX-M and bla KPC from plasmids to chromosome depicts the complex pandemic scenario of multidrug-resistant K. pneumoniae. Additionally, the implications from this study also raise concerns for the application of a CRISPR-cas strategy against antimicrobial resistance.


Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1025
Author(s):  
Shaohua Zhao ◽  
Cong Li ◽  
Chih-Hao Hsu ◽  
Gregory H. Tyson ◽  
Errol Strain ◽  
...  

Salmonella is a leading cause of bacterial infections in animals and humans. We sequenced a collection of 450 Salmonella strains from diseased animals to better understand the genetic makeup of their virulence and resistance features. The presence of Salmonella pathogenicity islands (SPIs) varied by serotype. S. Enteritidis carried the most SPIs (n = 15), while S. Mbandaka, S. Cerro, S. Meleagridis, and S. Havana carried the least (n = 10). S. Typhimurium, S. Choleraesuis, S. I 4,5,12:i:-, and S. Enteritidis each contained the spv operon on IncFII or IncFII-IncFIB hybrid plasmids. Two S. IIIa carried a spv operon with spvD deletion on the chromosome. Twelve plasmid types including 24 hybrid plasmids were identified. IncA/C was frequently associated with S. Newport (83%) and S. Agona (100%) from bovine, whereas IncFII (100%), IncFIB (100%), and IncQ1 (94%) were seen in S. Choleraesuis from swine. IncX (100%) was detected in all S. Kentucky from chicken. A total of 60 antimicrobial resistance genes (ARGs), four disinfectant resistances genes (DRGs) and 33 heavy metal resistance genes (HMRGs) were identified. The Salmonella strains from sick animals contained various SPIs, resistance genes and plasmid types based on the serotype and source of the isolates. Such complicated genomic structures shed light on the strain characteristics contributing to the severity of disease and treatment failures in Salmonella infections, including those causing illnesses in animals.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xueya Zhang ◽  
Qiaoling Li ◽  
Hailong Lin ◽  
Wangxiao Zhou ◽  
Changrui Qian ◽  
...  

Aminoglycosides are important options for treating life-threatening infections. However, high levels of aminoglycoside resistance (HLAR) among Klebsiella pneumoniae isolates have been observed to be increasing frequently. In this study, a total of 292 isolates of the K. pneumoniae complex from a teaching hospital in China were analyzed. Among these isolates, the percentage of HLAR strains was 13.7% (40/292), and 15 aminoglycoside resistance genes were identified among the HLAR strains, with rmtB being the most dominant resistance gene (70%, 28/40). We also described an armA-carrying Klebsiella variicola strain KP2757 that exhibited a high-level resistance to all aminoglycosides tested. Whole-genome sequencing of KP2757 demonstrated that the strain contained one chromosome and three plasmids, with all the aminoglycoside resistance genes (including two copies of armA and six AME genes) being located on a conjugative plasmid, p2757-346, belonging to type IncHI5. Comparative genomic analysis of eight IncHI5 plasmids showed that six of them carried two copies of the intact armA gene in the complete or truncated Tn1548 transposon. To the best of our knowledge, for the first time, we observed that two copies of armA together with six AME genes coexisted on the same plasmid in a strain of K. variicola with HLAR. Comparative genomic analysis of eight armA-carrying IncHI5 plasmids isolated from humans and sediment was performed, suggesting the potential for dissemination of these plasmids among bacteria from different sources. These results demonstrated the necessity of monitoring the prevalence of IncHI5 plasmids to restrict their worldwide dissemination.


F1000Research ◽  
2019 ◽  
Vol 8 ◽  
pp. 1340
Author(s):  
Dickson Aruhomukama ◽  
Ivan Sserwadda ◽  
Gerald Mboowa

Background: Cholera remains a serious public health problem in Uganda and Africa. The aim of this study was to provide the complete array of antimicrobial resistance genes, integrative and conjugative elements, virulence genes, pathogenicity islands, plasmids, and insertion sequences in the strains. In addition, this study also aimed to provide a single nucleotide polymorphism (SNP) based phylogenetic analysis of the strains. Methods: In the analysis, both Linux and web-based bioinformatics approaches were used to analyze the study sequences. Databases used included; FastQC, MultiQC, Snippy, PANTHER, PATRIC, Unicycler, ISFinder, Center for Genomic Epidemiology pipelines (i.e. MLST, PlasmidFinder, MyDbFinder, and ResFinder), MashTree and IcyTree.  Results: The 10 sequenced strains of Vibrio cholerae were found to carry virulence-associated genes including MakA, ctxA, ctxB, carA, carB, trpB, clpB, ace, toxR, zot, rtxA, ompW, ompR, gmhA, fur, hlyA, and rstR. Also identified were: genes of the Type VI secretion system including vasA-L, vgrG-2, vgrG-3, vipA/mglA, and vipB/mglB; alsD (VC1589), involved in the synthesis of 2,3-butanediol; alsR, involved in the acetate-responsive LysR-type regulation; makA, the flagella-mediated cytotoxin gene; Type VI pilus genes including tcpA-F, tcpH-J, tcpN, tcpP-T, and icmF/vasK; adherence genes acfA-D and IlpA; and quorum sensing system genes luxS and cqsA. Pathogenicity islands identified comprised of VSP-1 and VSP-2, as well as VPI-1 and VPI-2. In addition, strA and B, APH(3'')-I, APH(3'')-Ib, APH(6)-Id, APH(6)-Ic, murA, pare, dfrA1, floR, catB, and catB9 were among the antimicrobial resistance genes found in the sequences. Analysis for SNPs shared among the sequences showed that the sequenced strains shared 218 SNPs and of these, 98 SNPs were missense. Gene enrichment analysis of these SNPs showed enrichment in genes that mediate transmembrane-signaling receptor activity, peptidyl-prolyl cis-trans isomerase activity, and phosphor-relay response regulator activity. Conclusions: This study applied bioinformatics approaches to provide comprehensive genomic analysis of V. cholerae genomes obtained from Uganda.


2018 ◽  
Vol 85 (2) ◽  
Author(s):  
Liangzhi Li ◽  
Zhenghua Liu ◽  
Delong Meng ◽  
Xueduan Liu ◽  
Xing Li ◽  
...  

ABSTRACTMembers of the genusAcidithiobacillus, which can adapt to extremely high concentrations of heavy metals, are universally found at acid mine drainage (AMD) sites. Here, we performed a comparative genomic analysis of 37 strains within the genusAcidithiobacillusto answer the untouched questions as to the mechanisms and the evolutionary history of metal resistance genes inAcidithiobacillusspp. The results showed that the evolutionary history of metal resistance genes inAcidithiobacillusspp. involved a combination of gene gains and losses, horizontal gene transfer (HGT), and gene duplication. Phylogenetic analyses revealed that metal resistance genes inAcidithiobacillusspp. were acquired by early HGT events from species that shared habitats withAcidithiobacillusspp., such asAcidihalobacter,Thiobacillus,Acidiferrobacter, andThiomonasspecies. Multicopper oxidase genes involved in copper detoxification were lost in iron-oxidizingAcidithiobacillus ferridurans,Acidithiobacillus ferrivorans, andAcidithiobacillus ferrooxidansand were replaced by rusticyanin genes during evolution. In addition, widespread purifying selection and the predicted high expression levels emphasized the indispensable roles of metal resistance genes in the ability ofAcidithiobacillusspp. to adapt to harsh environments. Altogether, the results suggested thatAcidithiobacillusspp. recruited and consolidated additional novel functionalities during the adaption to challenging environments via HGT, gene duplication, and purifying selection. This study sheds light on the distribution, organization, functionality, and complex evolutionary history of metal resistance genes inAcidithiobacillusspp.IMPORTANCEHorizontal gene transfer (HGT), natural selection, and gene duplication are three main engines that drive the adaptive evolution of microbial genomes. Previous studies indicated that HGT was a main adaptive mechanism in acidophiles to cope with heavy-metal-rich environments. However, evidences of HGT inAcidithiobacillusspecies in response to challenging metal-rich environments and the mechanisms addressing how metal resistance genes originated and evolved inAcidithiobacillusare still lacking. The findings of this study revealed a fascinating phenomenon of putative cross-phylum HGT, suggesting thatAcidithiobacillusspp. recruited and consolidated additional novel functionalities during the adaption to challenging environments via HGT, gene duplication, and purifying selection. Altogether, the insights gained in this study have improved our understanding of the metal resistance strategies ofAcidithiobacillusspp.


2019 ◽  
Author(s):  
Liu Bin ◽  
Zhiqiu Yin ◽  
Chao Yuan ◽  
Yuhui Du ◽  
Pan Yang ◽  
...  

Abstract Background The Hafnia genus is an opportunistic pathogen that has been implicated in both nosocomial and community-acquired infections. Although Hafnia is fairly often isolated from clinical material, its taxonomy has remained an unsolved riddle, and the involvement and importance of Hafnia in human disease is also uncertain. Here, we used comparative genomic analysis to define the taxonomy of Hafnia, identify species-specific genes that may be the result of ecological and pathogenic specialization, and reveal virulence-related genetic profiles that may contribute to pathogenesis. Results One complete genome sequence and 19 draft genome sequences for Hafnia strains were generated and combined with 27 publicly available genomes. We provided high-resolution typing methods by constructing phylogeny and population structure based on single-copy core genes in combination with whole genome average nucleotide identity to identify two distant Hafnia species (alvei and paralvei) and one mislabeled strain. The open pan-genome and the presence of numerous mobile genetic elements reveal that Hafnia has undergone massive gene rearrangements. Presence of species-specific core genomes associated with metabolism and transport suggests the putative niche differentiation between alvei and paralvei. We also identified possession of diverse virulence-related profiles in both Hafnia species., including the macromolecular secretion system, virulence, and antimicrobial resistance. In the macromolecular system, T1SS, Flagellum 1, Tad pilus and T6SS-1 were conserved in Hafnia, whereas T4SS, T5SS, and other T6SSs exhibited the evolution of diversity. The virulence factors in Hafnia are related to adherence, toxin, iron uptake, stress adaptation, and efflux pump. The identified resistance genes are associated with beta-lactamases and tetracycline. These virulence-related profiles identified at the genomic level provide insights into Hafnia pathogenesis and the differentiation between alvei and paralvei. Conclusions Our research using core genome phylogeny and comparative genomics analysis of a larger collection of strains provides a comprehensive view of the taxonomy and species-specific traits between Hafnia species. Deciphering the genome of Hafnia strains possessing a reservoir of macromolecular secretion systems, virulence factors, and resistance genes related to pathogenicity may provide insights into addressing its numerous infections and devising strategies to combat the pathogen.


Author(s):  
Xiaoting Hua ◽  
Qian Liang ◽  
Jintao He ◽  
Meixia Wang ◽  
Wenjie Hong ◽  
...  

AbstractWhole genome sequencing (WGS) of bacteria has become a routine method in diagnostic laboratories. One of the most exciting advantages of WGS is the ability to predict antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs) in a variety of bacteria, which may allow comprehensive investigations of genetic features but also serve for epidemiological studies. A plethora of softwares have been developed for the detailed annotation of DNA sequences, such as RAST (Rapid Annotation using Subsystem Technology), Resfinder, ISfinder, INTEGRALL and The Transposon Registry. Unfortunately, up to now, a reliable annotation tool of the combination of ARGs and MGEs is not available to researchers, and the generation of genbank files requires much manual input. Here, we present a new webserver which allows the annotation of ARGs, ISs, integron, and transposable elements at the same time. The algorithm generates genbank files automatically, which are compatible with easyfig for comparative genomic analysis.Key PointsThere exist a number of software for DNA sequence annotation, RAST (Rapid Annotation using Subsystem Technology), Resfinder, ISfinder, INTEGRALL and The Transposon Registry.A reliable annotation tool of the combination of ARGs and MGEs is not available to researchers, and the generation of genbank files requires much manual input.We present a new webserver which allows the annotation of ARGs, ISs, integron, and transposable elements at the same time. The algorithm generates genbank files automatically, which are compatible with easyfig for comparative genomic analysis.


Sign in / Sign up

Export Citation Format

Share Document