ORIGIN - Word Related Documents




#
Rank
Similarity
Title + Abs.
Year
PMID
012345
304200.9976Aminoglycoside acetyltransferase 3-IV (aacC4) and hygromycin B 4-I phosphotransferase (hphB) in bacteria isolated from human and animal sources. Members of the family Enterobacteriaceae harboring an enzyme of the aminoglycoside acetyltransferase 3 class (AAC-3-IV) (apramycin and gentamicin resistance) and hygromycin B phosphotransferase 4 (HPH-4-I) (hygromycin B resistance) have been isolated from human clinical sources in Europe. A cluster of genes containing IS140, aacC4, and hphB was found in these strains. We demonstrate by Southern hybridization that this cluster is identical to the operon found in animals that also contains insertion sequences belonging to the ISO family. This provides another example of presumptive transfer of antibiotic resistance genes between bacteria of animal and human origin.19901963287
304110.9976pCERC1, a small, globally disseminated plasmid carrying the dfrA14 cassette in the strA gene of the sul2-strA-strB gene cluster. Commensal Escherichia coli from healthy adult humans were screened for antibiotic resistance genes. Two unrelated strains contained the sul2 sulphonamide resistance gene and strAB streptomyicn resistance genes with the dfrA14 trimethoprim resistance gene cassette in the strA gene and conferred resistance to trimethoprim and sulphamethoxazole. A 6.8 kb plasmid, pCERC1, that contains these resistance genes was recovered and sequenced. Deletions were constructed, and the pCERC1 replication region was confined to a 1 kb segment carrying genes for RNAs that are closely related to the ColE1 replication initiation RNAs. Polymerase chain reaction assays, developed to detect the sul2-strA-strB gene cluster in this context, identified a streptomycin and sulphonamide resistance plasmid, pCERC2, identical to pCERC1 without the dfrA14 cassette in two further E. coli isolates. Bioinformatic analysis revealed plasmids similar to pCERC1 and two more members of this family. One, the probable progenitor, carries only the sul2 gene adjacent to the small mobile element CR2. The other has a variant resistance gene cluster that has evolved from pCERC2 via acquisition of the tet(A) tetracycline resistance determinant. pCERC1 and pCERC2 have been detected in many countries, indicating a global distribution and appear to have been circulating in Gram-negative bacteria for more than 25 years.201222416992
459820.9974Enterococci of animal origin and their significance for public health. Enterococci are commensal bacteria in the intestines of humans and animals, but also cause infections in humans. Most often, Enterococcus faecium isolates from clinical outbreaks belong to different types than E. faecium from animals, food, and humans in the community. The same variants of the vanA gene cluster (Tn1546) encoding vancomycin resistance can be detected in enterococci of both human and animal origin. This could indicate horizontal transfer of Tn1546 between enterococci of different origin. E. faecium isolates of animal origin might not constitute a human hazard in themselves, but they could act as donors of antimicrobial resistance genes for other pathogenic enterococci. Enterococcus faecalis of animal origin seems to be a human hazard, as the same types can be detected in E. faecalis from animals, meat, faecal samples from humans in the community, and patients with bloodstream infections.201222487203
548030.9973Small Antimicrobial Resistance Plasmids in Livestock-Associated Methicillin-Resistant Staphylococcus aureus CC398. Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) isolates of the clonal complex 398 are often resistant to a number of antimicrobial agents. Studies on the genetic basis of antimicrobial resistance in these bacteria identified SCCmec cassettes, various transposons and plasmids of different sizes that harbor antimicrobial resistance genes. While large plasmids that carry multiple antimicrobial resistance genes - occasionally together with heavy metal resistance genes and/or virulence genes - are frequently seen in LA-MRSA ST398, certain resistance genes are also associated with small plasmids of up to 15 kb in size. These small resistance plasmids usually carry only one, but in rare cases also two or three antimicrobial resistance genes. In the current review, we focus on small plasmids that carry the macrolide-lincosamide-streptogramin B resistance genes erm(C) or erm(T), the lincosamide resistance gene lnu(A), the pleuromutilin-lincosamide-streptogramin A resistance genes vga(A) or vga(C), the spectinomycin resistance gene spd, the apramycin resistance gene apmA, or the trimethoprim resistance gene dfrK. The detailed analysis of the structure of these plasmids allows comparisons with similar plasmids found in other staphylococci and underlines in many cases an exchange of such plasmids between LA-MRSA ST398 and other staphylococci including also coagulase-negative staphylococci.201830283407
303940.9973Distinct recent lineages of the strA- strB streptomycin-resistance genes in clinical and environmental bacteria. We report the linkage of the strA-strB streptomycin-resistance genes with Class 1 integron sequences on pSTR1, a 75-kb multiple antibiotic-resistance plasmid from Shigella flexneri. strA-strB had previously been detected only within Tn 5393, a Tn 3-family transposon, and on small nonconjugative broad-host-range plasmids such as RSF1010. The geographic range of Tn 5393 was also extended to Pseudomonas spp. isolated from apple trees in New Zealand and soil in the USA. Comparative sequence analyses indicated that strA-strB from Tn 5393 and nonconjugative plasmids constitute distinct recent lineages with strA-strB from pSTR1 intermediate between the other two. The carriage of strA-strB within an integron, a transposon, and on broad-host-range plasmids has facilitated the world-wide dissemination of this determinant among at least 21 bacterial genera.200212029529
545650.9973Detection of the enterococcal oxazolidinone/phenicol resistance gene optrA in Campylobacter coli. The transferable optrA gene encodes an ABC-F protein which confers resistance to oxazolidinones and phenicols, and has so far been detected exclusively in Gram-positive bacteria, including enterococci, staphylococci and streptococci. Here, we identified for the first time the presence of optrA in naturally occurring Gram-negative bacteria. Seven optrA-positive Campylobacter coli were identified from 563 Campylobacter isolates of animal origin from Guangdong (n = 1, chicken) and Shandong (n = 6, duck) provinces of China in 2017-2018. The detected optrA genes were functionally active and mediated resistance or elevated minimal inhibitory concentrations of linezolid, florfenicol and chloramphenicol in the respective C. coli isolates. The optrA gene, together with other transferable resistance genes, such as fexA, catA9, tet(O), tet(L), erm(A)-like, spc, or aadE, was located in two different chromosome-borne multidrug resistance genomic islands (MDRGIs). In both MDRGIs, complete or truncated copies of the insertion sequence IS1216E were present in the vicinity of optrA. The IS1216E-bracketed genetic environment of optrA was almost identical to the optrA regions on enterococcal plasmids, suggesting that the optrA in Campylobacter probably originated from Enterococcus spp.. Moreover, the formation of an optrA-carrying translocatable unit by recombination of IS1216E indicated that this IS element may play an important role in the horizontal transfer of optrA in Campylobacter. Although optrA was only found in a small number of C. coli isolates, enhanced surveillance is needed to monitor the distribution and the potential emergence of optrA in Campylobacter.202032605743
995060.9973Mobile Oxazolidinone Resistance Genes in Gram-Positive and Gram-Negative Bacteria. Seven mobile oxazolidinone resistance genes, including cfr, cfr(B), cfr(C), cfr(D), cfr(E), optrA, and poxtA, have been identified to date. The cfr genes code for 23S rRNA methylases, which confer a multiresistance phenotype that includes resistance to phenicols, lincosamides, oxazolidinones, pleuromutilins, and streptogramin A compounds. The optrA and poxtA genes code for ABC-F proteins that protect the bacterial ribosomes from the inhibitory effects of oxazolidinones. The optrA gene confers resistance to oxazolidinones and phenicols, while the poxtA gene confers elevated MICs or resistance to oxazolidinones, phenicols, and tetracycline. These oxazolidinone resistance genes are most frequently found on plasmids, but they are also located on transposons, integrative and conjugative elements (ICEs), genomic islands, and prophages. In these mobile genetic elements (MGEs), insertion sequences (IS) most often flanked the cfr, optrA, and poxtA genes and were able to generate translocatable units (TUs) that comprise the oxazolidinone resistance genes and occasionally also other genes. MGEs and TUs play an important role in the dissemination of oxazolidinone resistance genes across strain, species, and genus boundaries. Most frequently, these MGEs also harbor genes that mediate resistance not only to antimicrobial agents of other classes, but also to metals and biocides. Direct selection pressure by the use of antimicrobial agents to which the oxazolidinone resistance genes confer resistance, but also indirect selection pressure by the use of antimicrobial agents, metals, or biocides (the respective resistance genes against which are colocated on cfr-, optrA-, or poxtA-carrying MGEs) may play a role in the coselection and persistence of oxazolidinone resistance genes.202134076490
599170.9973Transferable plasmid-mediated antibiotic resistance in Listeria monocytogenes. A strain of Listeria monocytogenes, isolated from a patient with meningoencephalitis, was resistant to chloramphenicol, erythromycin, streptomycin, and tetracycline. The genes conferring resistance to these antibiotics were carried by a 37-kb plasmid, pIP811, that was self-transferable to other L monocytogenes cells, to enterococci-streptococci, and to Staphylococcus aureus. The efficacy of transfer and the stability of pIP811 were higher in enterococci-streptococci than in the other gram-positive bacteria. As indicated by nucleic acid hybridisation, the genes in pIP811 conferring resistance to chloramphenicol, erythromycin, and streptomycin were closely related to plasmid-borne determinants that are common in enterococci-streptococci. Plasmid pIP811 shared extensive sequence homology with pAM beta 1, the prototype broad host range resistance plasmid in these two groups of gram-positive cocci. These results suggest that emergence of multiple antibiotic resistance in Listeria spp is due to acquisition of a replicon originating in enterococci-streptococci. The dissemination of resistance to other strains of L monocytogenes is likely.19901972210
460480.9973Dissemination of the strA-strB streptomycin-resistance genes among commensal and pathogenic bacteria from humans, animals, and plants. Gene transfer within bacterial communities has been recognized as a major contributor in the recent evolution of antibiotic resistance on a global scale. The linked strA-strB genes, which encode streptomycin-inactivating enzymes, are distributed worldwide and confer streptomycin resistance in at least 17 genera of gram-negative bacteria. Nucleotide sequence analyses suggest that strA-strB have been recently disseminated. In bacterial isolates from humans and animals, strA-strB are often linked with the suIII sulfonamide-resistance gene and are encoded on broad-host-range nonconjugative plasmids. In bacterial isolates from plants, strA-strB are encoded on the Tn3-type transposon Tn5393 which is generally borne on conjugative plasmids. The wide distribution of the strA-strB genes in the environment suggests that gene transfer events between human, animal, and plant-associated bacteria have occurred. Although the usage of streptomycin in clinical medicine and animal husbandry has diminished, the persistence of strA-strB in bacterial populations implies that factors other than direct antibiotic selection are involved in maintenance of these genes.19969147689
546090.9973Linezolid Resistance Genes in Enterococci Isolated from Sediment and Zooplankton in Two Italian Coastal Areas. Linezolid is a last-resort antibiotic for the treatment of severe infections caused by multidrug-resistant Gram-positive organisms; although linezolid resistance remains uncommon, the number of linezolid-resistant enterococci has increased in recent years due to worldwide spread of acquired resistance genes (cfr, optrA, and poxtA) in clinical, animal, and environmental settings. In this study, we investigated the occurrence of linezolid-resistant enterococci in marine samples from two coastal areas in Italy. Isolates grown on florfenicol-supplemented Slanetz-Bartley agar plates were investigated for their carriage of optrA, poxtA, and cfr genes; optrA was found in one Enterococcus faecalis isolate, poxtA was found in three Enterococcus faecium isolates and two Enterococcus hirae isolates, and cfr was not found. Two of the three poxtA-carrying E. faecium isolates and the two E. hirae isolates showed related pulsed-field gel electrophoresis (PFGE) profiles. Two E. faecium isolates belonged to the new sequence type 1710, which clustered in clonal complex 94, encompassing nosocomial strains. S1 PFGE/hybridization assays showed a double (chromosome and plasmid) location of poxtA and a plasmid location of optrA Whole-genome sequencing revealed that poxtA was contained in a Tn6657-like element carried by two plasmids (pEfm-EF3 and pEh-GE2) of similar size, found in different species, and that poxtA was flanked by two copies of IS1216 in both plasmids. In mating experiments, all but one strain (E. faecalis EN3) were able to transfer the poxtA gene to E. faecium 64/3. The occurrence of linezolid resistance genes in enterococci from marine samples is of great concern and highlights the need to improve practices aimed at limiting the transmission of linezolid-resistant strains to humans from environmental reservoirs.IMPORTANCE Linezolid is one of the few antimicrobials available to treat severe infections due to drug-resistant Gram-positive bacteria; therefore, the emergence of linezolid-resistant enterococci carrying transferable resistance determinants is of great concern for public health. Linezolid resistance genes (cfr, optrA, and poxtA), often plasmid located, can be transmitted via horizontal gene transfer and have the potential to spread globally. This study highlights the detection of enterococci carrying linezolid resistance genes from sediment and zooplankton samples from two coastal urban areas in Italy. The presence of clinically relevant resistant bacteria, such as linezolid-resistant enterococci, in marine environments could reflect their spillover from human and/or animal reservoirs and could indicate that coastal seawaters also might represent a source of these resistance genes.202133608287
9954100.9972Mobile genetic elements beyond the VanB-resistance dissemination among hospital-associated enterococci and other Gram-positive bacteria. An increasing resistance to vancomycin among clinically relevant enterococci, such as Enterococcus faecalis and Enterococcus faecium is a cause of a great concern, as it seriously limits treatment options. The vanB operon is one of most common determinants of this type of resistance. Genes constituting the operon are located in conjugative transposons, such as Tn1549-type transposons or, more rarely, in ICEEfaV583-type structures. Such elements show differences in structure and size, and reside in various sites of bacterial chromosome or, in the case of Tn1549-type transposons, are also occasionally associated with plasmids of divergent replicon types. While conjugative transposition contributes to the acquisition of Tn1549-type transposons from anaerobic gut commensals by enterococci, chromosomal recombination and conjugal transfer of plasmids appear to represent main mechanisms responsible for horizontal dissemination of vanB determinants among hospital E. faecalis and E. faecium. This review focuses on diversity of genetic elements harbouring vanB determinants in hospital-associated strains of E. faecium and E. faecalis, the mechanisms beyond vanB spread in populations of these bacteria, and provides an overview of the vanB-MGE distribution among other enterococci and Gram-positive bacteria as potential reservoirs of vanB genes.202133472048
9956110.9972Phylogeny of Transferable Oxazolidinone Resistance Genes and Homologs. Oxazolidinone resistance, especially transmissible resistance, is a major public health concern, and the origin of this resistance mechanism is not yet resolved. This study aims to delve into the phylogenetic origin of the transmissible oxazolidinone resistance mechanisms conferring cross-resistance to other drugs of human and veterinary importance. The amino acid sequences of the five cfr ribosomal methylases and optrA and poxtA were used as queries in searches against 219,549 bacterial proteomes in the NCBI RefSeq database. Hits with >40% amino acid identity and >80% query coverage were aligned, and phylogenetic trees were reconstructed. All five cfr genes yielded highly similar trees, with rlmN housekeeping ribosomal methylases located basal to the sister groups of S-adenosyl-methionine-dependent methyltransferases from various Deltaproteobacteria and Actinomycetia, including antibiotic-producing Streptomyces species, and the monophyletic group of cfr genes. The basal branches of the latter contained paenibacilli and other soil bacteria; they then could be split into the clades [cfr(C):cfr(E)] and [[cfr:cfr(B)]:cfr(D)], always with different Bacillaceae in their stems. Lachnospiraceae were encountered in the basal branches of both optrA and poxtA trees. The ultimate origin of the cfr genes is the rlmN housekeeping ribosomal methylases, which evolved into a suicide-avoiding methylase in antibiotic producers; a soil organism (Lachnospiraceae, Paenibacilli) probably acted as a transfer organism into pathogenic bacteria. In the case of optrA, the porcine pathogenic Streptococcus suis was present in all branches, while the proteins closest to poxtA originated from Clostridia.202438666987
1766120.9972A novel group of IncQ1 plasmids conferring multidrug resistance. The IncQ is a group of non-conjugative but mobilisable plasmids that are found and stably maintained in a wide range of bacteria contributing to the spread of antimicrobial resistance genes and to the insurgence of multidrug resistant bacteria. Here we report the identification, in clinical Salmonella Typhimurium strains, of an IncQ1 plasmid (pNUC) which confers resistance to sulfamethoxazole, streptomycin and tetracycline through the presence of sul2, strAB and tetA genes, respectively. pNUC was detected in five multidrug resistant S. Typhimurium strains collected in Southern Italy from various hospitals and years of isolation. Bioinformatics analyses highlighted the presence of pNUC-like plasmids in pathogenic bacteria of various Enterobacteriaceae genera or species. Taken as a whole, these plasmids constitute a novel group of IncQ1 plasmids that might have originated through recombination events between a tetR-tetA gene cluster (possibly derived from a Tn1721) and a recipient IncQ1 plasmid related to RSF1010. Our findings raise concerns regarding the possible contribution of the newly identified group of IncQ1 plasmids to the spread of tetracycline resistance.201727916622
9949130.9971Presence and dissemination of the multiresistance gene cfr in Gram-positive and Gram-negative bacteria. The emergence of the multiresistance gene cfr in staphylococci is of global concern. In addition to conferring resistance to phenicols, lincosamides, pleuromutilins, streptogramin A antibiotics and selected 16-membered macrolides, the cfr gene also confers resistance to the oxazolidinone linezolid. Linezolid is a last-resort antimicrobial agent for the treatment of serious infections in humans caused by resistant Gram-positive bacteria. The cfr gene is often located on plasmids and several cfr-carrying plasmids have been described, which differ in their structure, their size and the presence of additional resistance genes. These plasmids are important vehicles that promote the spread of the cfr gene not only among bacteria of the same species, but also among those of different species and genera. Moreover, the cfr gene has been identified in close proximity to different insertion sequences, which most probably also play an important role in its dissemination. This review summarizes current knowledge on the genetic environment of the multiresistance gene cfr with particular reference to mobile genetic elements and co-located resistance genes that may support its emergence.201323543608
5475140.9971Genomic Insights of Enterococcus faecium UC7251, a Multi-Drug Resistant Strain From Ready-to-Eat Food, Highlight the Risk of Antimicrobial Resistance in the Food Chain. The presence of multi-drug resistant (MDR) bacteria in ready-to-eat foods comprises a threat for public health due to their ability to acquire and transfer antibiotic-resistant determinants that could settle in the microbiome of the human digestive tract. In this study, Enterococcus faecium UC7251 isolated from a fermented dry sausage was characterized phenotypically and genotypically to hold resistance to multiple antibiotics including aminoglycosides, macrolides, β-lactams, and tetracyclines. We further investigated this strain following a hybrid sequencing and assembly approach (short and long reads) and determined the presence of various mobile genetic elements (MGEs) responsible of horizontal gene transfer (HGT). On the chromosome of UC7251, we found one integrative and conjugative element (ICE) and a conjugative transposon Tn916-carrying tetracycline resistance. UC7251 carries two plasmids: one small plasmid harboring a rolling circle replication and one MDR megaplasmid. The latter was identified as mobilizable and containing a putative integrative and conjugative element-like region, prophage sequences, insertion sequences, heavy-metal resistance genes, and several antimicrobial resistance (AMR) genes, confirming the phenotypic resistance characteristics. The transmissibility potential of AMR markers was observed through mating experiments, where Tn916-carried tetracycline resistance was transferred at intra- and inter-species levels. This work highlights the significance of constant monitoring of products of animal origin, especially RTE foodstuffs, to stimulate the development of novel strategies in the race for constraining the spread of antibiotic resistance.202235814695
9962150.9971Metadata Analysis of mcr-1-Bearing Plasmids Inspired by the Sequencing Evidence for Horizontal Transfer of Antibiotic Resistance Genes Between Polluted River and Wild Birds. We sequenced the whole genomes of three mcr-1-positive multidrug-resistant E. coli strains, which were previously isolated from the environment of egret habitat (polluted river) and egret feces. The results exhibit high correlation between antibiotic-resistant phenotype and genotype among the three strains. Most of the mobilized antibiotic resistance genes (ARGs) are distributed on plasmids in the forms of transposons or integrons. Multidrug-resistant (MDR) regions of high homology are detected on plasmids of different E. coli isolates. Therefore, horizontal transfer of resistance genes has facilitated the transmission of antibiotic resistance between the environmental and avian bacteria, and the transfer of ARGs have involved multiple embedded genetic levels (transposons, integrons, plasmids, and bacterial lineages). Inspired by this, systematic metadata analysis was performed for the available sequences of mcr-1-bearing plasmids. Among these plasmids, IncHI2 plasmids carry the most additional ARGs. The composition of these additional ARGs varies according to their geographical distribution. The phylogenetic reconstruction of IncI2 and IncX4 plasmids provides the evidence for their multiregional evolution. Phylogenetic analysis at the level of mobile genetic element (plasmid) provides important epidemiological information for the global dissemination of mcr-1 gene. Highly homologous mcr-1-bearing IncI2 plasmids have been isolated from different regions along the East Asian-Australasian Flyway, suggesting that migratory birds may mediate the intercontinental transportation of ARGs.202032210943
4599160.9971Global acquisition of genetic material from different bacteria into the staphylococcal cassette chromosome elements of a Staphylococcus epidermidis isolate. Staphylococcus epidermidis has been suggested as a main reservoir of methicillin resistance and virulence genes facilitating the evolution of Staphylococcus aureus as a successful pathogen. However, it remains a mystery where and how S. epidermidis obtains these numerous genes to serve as the reservoir. In this study, methicillin-resistant S. epidermidis isolate NW32 from a mastitic milk sample was sequenced and its staphylococcal cassette chromosome (SCC) elements were characterised. The SCC composite island covered 3.5% of the genome and consisted of three intact SCC elements carrying resistance genes against β-lactam antibiotics, several heavy metals and polyamines as well as genes for utilisation of sorbitol as a carbon source. Analysis of the postulated evolutionary route suggested that the three SCC elements were assembled from genetic material from various bacterial species (staphylococci, streptococci, salinicocci and Lysinibacillus) from three habitats (human, soil and cow) in different countries (Asia, North America, South America and Europe). We propose that the hsdS restriction-modification profile and the lack of CRISPR (clustered regularly interspaced short palindromic repeat) sequences in this bacterium may facilitate the genetic exchange of SCC elements among different staphylococcal species.201728705673
5454170.9971Identification of an Enterococcus faecium strain isolated from raw bovine milk co-harbouring the oxazolidinone resistance genes optrA and poxtA in China. Oxazolidinones are potent antimicrobial agents used to treat human infections caused by multidrug-resistant Gram-positive bacteria. The growing resistance to oxazolidinones poses a significant threat to public health. In August 2021, a linezolid-resistant Enterococcus faecium BN83 was isolated from a raw milk sample of cow in Inner Mongolia, China. This isolate exhibited a multidrug resistance phenotype and was resistant to most of drugs tested including linezolid and tedizolid. PCR detection showed that two mobile oxazolidinones resistance genes, optrA and poxtA, were present in this isolate. Whole genome sequencing analysis revealed that the genes optrA and poxtA were located on two different plasmids, designated as pBN83-1 and pBN83-2, belonging to RepA_N and Inc18 families respectively. Genetic context analysis suggested that optrA gene on plasmid pBN83-1 was located in transposon Tn6261 initially found in E. faecalis. Comprehensive analysis revealed that Tn6261 act as an important horizontal transmission vector for the spread of optrA in E. faecium. Additionally, poxtA-bearing pBN83-2 displayed high similarity to numerous plasmids from Enterococcus of different origin and pBN83-2-like plasmid represented a key mobile genetic element involved in movement of poxtA in enterococcal species. The presence of optrA- and poxtA-carrying E. faecium in raw bovine milk represents a public health concern and active surveillance is urgently warranted to investigate the prevalence of oxazolidinone resistance genes in animal-derived food products.202438718528
4605180.9971Self-transmissible multidrug resistance plasmids in Escherichia coli of the normal intestinal flora of healthy swine. The resistance genes and their surroundings on three self-transmissible plasmids found in Escherichia coli of the enteric normal flora of healthy pigs have been characterized. The resistance elements found are similar to those commonly found in clinical isolates, like the transposon Tn1721 including the Tet A tetracycline resistance determinant, Tn10 with the Tet B determinant, Tn21 including a class 1 integron with the aadA1a cassette inserted, sulII encoding sulfonamide resistance, and the strA-strB genes responsible for streptomycin resistance. The plasmids were able to mobilize into various recipients, including swine pathogens, zoonotic bacteria, and commensals when conjugation experiments were carried out. Transfer of plasmids did not require optimal conditions concerning nutrition and temperature as plasmids were transferred in 0.9% saline at room temperature, suggesting that in vivo transfer might be possible. This study shows that transferable resistance elements appearing in normal flora bacteria from animals are similar to those commonly found in clinical isolates of human origin. The results indicate a probable communication between pathogens and the normal flora with respect to exchange of resistance factors.200111442346
3769190.9971Clostridioides difficile as a Dynamic Vehicle for the Dissemination of Antimicrobial-Resistance Determinants: Review and In Silico Analysis. The present paper is divided into two parts. The first part focuses on the role of Clostridioides difficile in the accumulation of genes associated with antimicrobial resistance and then the transmission of them to other pathogenic bacteria occupying the same human intestinal niche. The second part describes an in silico analysis of the genomes of C. difficile available in GenBank, with regard to the presence of mobile genetic elements and antimicrobial resistance genes. The diversity of the C. difficile genome is discussed, and the current status of resistance of the organisms to various antimicrobial agents is reviewed. The role of transposons associated with antimicrobial resistance is appraised; the importance of plasmids associated with antimicrobial resistance is discussed, and the significance of bacteriophages as a potential shuttle for antimicrobial resistance genes is presented. In the in silico study, 1101 C. difficile genomes were found to harbor mobile genetic elements; Tn6009, Tn6105, CTn7 and Tn6192, Tn6194 and IS256 were the ones more frequently identified. The genes most commonly harbored therein were: ermB, blaCDD, vanT, vanR, vanG and vanS. Tn6194 was likely associated with resistance to erythromycin, Tn6192 and CTn7 with resistance to the β-lactams and vancomycin, IS256 with resistance to aminoglycoside and Tn6105 to vancomycin.202134202117