# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 530 | 0 | 0.7698 | Location of the genes for anthranilate synthase in Streptomyces venezuelae ISP5230: genetic mapping after integration of the cloned genes. The anthranilate synthase (trpEG) genes in Streptomyces venezuelae ISP5230 were located by allowing a segregationally unstable plasmid carrying cloned S. venezuelae trpEG DNA and a thiostrepton resistance (tsr) marker to integrate into the chromosome. The integrated tsr was mapped by conjugation and transduction to a location close to tyr-2, between arg-6 and trpA13. A genomic DNA fragment containing trpC from S. venezuelae ISP5230 was cloned by complementation of a trpC mutation in Streptomyces lividans. Evidence from restriction enzyme analysis of the cloned DNA fragments, from Southern hybridization using the cloned trp DNA as probes, and from cotransduction frequencies, placed trpEG at a distance of 12-45 kb from the trpCBA cluster. The overall arrangement of tryptophan biosynthesis genes in the S. venezuelae chromosome differs from that in other bacteria examined so far. | 1993 | 8515229 |
| 6363 | 1 | 0.7645 | The effect of tetronasin and monensin on fermentation, microbial numbers and the development of ionophore-resistant bacteria in the rumen. The Gram-negative rumen bacteria Fibrobacter succinogenes S85, Prevotella ruminicola M384 and Veillonella parvula L59 were grown in media containing successively increasing concentrations of the ionophores, monensin and tetronasin. All three species became more resistant to the ionophore with which they were grown. Increased resistance to one ionophore caused increased resistance to the other, and cross-resistance to another ionophore--lasalocid--and an antibiotic--avoparcin. Recovery of tetronasin-resistant bacteria from the rumen of monensin-fed sheep increased and vice versa, indicating that similar cross-resistance occurred in vivo. | 1993 | 8407673 |
| 534 | 2 | 0.7643 | Plasmid shuttle vector with two insertionally inactivable markers for coryneform bacteria. A new shuttle vector pCEM500 replicating in Escherichia coli and in Brevibacterium flavum was constructed. It carries two antibiotic resistance determinants (Kmr/Gmr from plasmid pSa of Gram-negative bacteria and Smr/Spr from plasmid pCG4 of Corynebacterium glutamicum) which are efficiently expressed in both hosts and can be inactivated by insertion of DNA fragments into the unique restriction endonuclease sites located within them. This vector was found to be stably maintained in B. flavum and can be used for transfer of the cloned genes into this amino-acid-producing coryneform bacterium. | 1990 | 2148164 |
| 105 | 3 | 0.7638 | Resistance of the cholera vaccine candidate IEM108 against CTXPhi infection. The cholera toxin (CT) genes ctxAB are carried on a lysogenic phage of Vibrio cholerae, CTXPhi, which can transfer ctxAB between toxigenic and nontoxigenic strains of bacteria. This transfer may pose a problem when live oral cholera vaccine is given to people in epidemic areas, because the toxin genes can be reacquired by the vaccine strains. To address this problem, we have constructed a live vaccine candidate, IEM108, which carries an El Tor-derived rstR gene. This gene encodes a repressor and can render bacterial resistance to CTXPhi infection. In this study, we evaluated the resistance of IEM108 against CTXPhi infection by using a CTXPhi marked for chloramphenicol (CAF) resistance and an in vivo model. We found that the cloned rstR gene rendered IEM108 immune to infection with the marked CTXPhi. In addition, the infection rate of IEM108 was even lower than that of the native CTXPhi-positive strain. These results suggest that the vaccine candidate IEM108 is resistant to infection by CTXPhi. | 2006 | 16343705 |
| 6012 | 4 | 0.7637 | Metal resistance-related genes are differently expressed in response to copper and zinc ion in six Acidithiobacillus ferrooxidans strains. Metal resistance of acidophilic bacteria is very significant during bioleaching of copper ores since high concentration of metal is harmful to the growth of microorganisms. The resistance levels of six Acidithiobacillus ferrooxidans strains to 0.15 M copper and 0.2 M zinc were investigated, and eight metal resistance-related genes (afe-0022, afe-0326, afe-0329, afe-1143, afe-0602, afe-0603, afe-0604, and afe-1788) were sequenced and analyzed. The transcriptional expression levels of eight possible metal tolerance genes in six A. ferrooxidans strains exposed to 0.15 M Cu(2+) and 0.2 M Zn(2+) were determined by real-time quantitative PCR (RT-qPCR), respectively. The copper resistance levels of six A. ferrooxidans strains declined followed by DY26, DX5, DY15, GD-B, GD-0, and YTW. The zinc tolerance levels of six A. ferrooxidans strains exposed to 0.2 M Zn(2+) from high to low were YTW > GD-B > DY26 > GD-0 > DX5 > DY15. Seven metal tolerance-related genes all presented in the genome of six strains, except afe-0604. The metal resistance-related genes showed different transcriptional expression patterns in six A. ferrooxidans strains. The expression of gene afe-0326 and afe-0022 in six A. ferrooxidans strains in response to 0.15 M Cu(2+) showed the same trend with the resistance levels. The expression levels of genes afe-0602, afe-0603, afe-0604, and afe-1788 in six strains response to 0.2 M Zn(2+) did not show a clear correlation between the zinc tolerance levels of six strains. According to the results of RT-qPCR and bioinformatics analysis, the proteins encoded by afe-0022, afe-0326, afe-0329, and afe-1143 were related to Cu(2+) transport of A. ferrooxidans strains. | 2014 | 25023638 |
| 8 | 5 | 0.7635 | The hawthorn CpLRR-RLK1 gene targeted by ACLSV-derived vsiRNA positively regulate resistance to bacteria disease. Virus-derived small interfering RNAs (vsiRNAs) can target not only viruses but also plant genes. Apple chlorotic leaf spot virus (ACLSV) is an RNA virus that infects Rosaceae plants extensively, including apple, pear and hawthorn. Here, we report an ACLSV-derived vsiRNA [vsiR1360(-)] that targets and down-regulates the leucine-rich repeat receptor-like kinase 1 (LRR-RLK1) gene of hawthorn (Crataegus pinnatifida). The targeting and cleavage of the CpLRR-RLK1 gene by vsiR1360(-) were validated by RNA ligase-mediated 5' rapid amplification of cDNA ends and tobacco transient transformation assays. And the CpLRR-RLK1 protein fused to green fluorescent protein localized to the cell membrane. Conserved domain and phylogenetic tree analyses showed that CpLRR-RLK1 is closely related to the proteins of the LRRII-RLK subfamily. The biological function of CpLRR-RLK1 was explored by heterologous overexpression of CpLRR-RLK1 gene in Arabidopsis. The results of inoculation of Pst DC3000 in Arabidopsis leaves showed that the symptoms of CpLRR-RLK1 overexpression plants infected with Pst DC3000 were significantly reduced compared with the wild type. In addition, the detection of reactive oxygen species and callose deposition and the expression analysis of defense-related genes showed that the CpLRR-RLK1 gene can indeed enhance the resistance of Arabidopsis to bacteria disease. | 2020 | 33180701 |
| 2998 | 6 | 0.7625 | Membrane vesicles derived from Enterococcus faecalis promote the co-transfer of important antibiotic resistance genes located on both plasmids and chromosomes. BACKGROUND: Bacterial membrane vesicles (BMVs) are novel vehicles of antibiotic resistance gene (ARG) transfer in Gram-negative bacteria, but their role in the spread of ARGs in Gram-positive bacteria has not been defined. The purpose of this study was to evaluate the role of MVs in the transmission of antimicrobial resistance in Gram-positive bacteria. METHODS: A linezolid-resistant Enterococcus faecalis CQ20 of swine origin was selected as the donor strain. Linezolid-susceptible E. faecalis SC032 of human origin, Enterococcus faecium BM4105 and Escherichia coli were selected as recipient strains. The presence of plasmids (pCQ20-1 and pCQ20-2) and an optrA-carrying transposon Tn6674 in CQ20, MVs and vesiculants was verified by WGS or PCR. MVs were isolated with density gradient centrifugation, and MV-mediated transformation was performed to assess the horizontal transferability of MVs. The MICs for CQ20 and its vesiculants were determined by the broth microdilution method. RESULTS: CQ20-derived MVs (CQ20-MV) were isolated, and PCR identified the presence of two plasmids and the optrA gene in the CQ20-MVs. MV-mediated transformation to E. faecalis SC032 and E. faecium BM4105 was successfully performed, and the WGS data also showed that both plasmids pCQ20-1 and pCQ20-2 and optrA-carrying transposon Tn6674 were transferred to E. faecalis SC032 and E. faecium BM4105, but failed for E. coli. Additionally, vesiculants that had acquired ARGs still had the ability to spread these genes via MVs. CONCLUSIONS: To our knowledge, this is the first report of MV-mediated co-transfer of ARG-carrying plasmids and transposons in the Gram-positive bacterium E. faecium. | 2024 | 38109479 |
| 359 | 7 | 0.7618 | Construction of shuttle cloning vectors for Bacteroides fragilis and use in assaying foreign tetracycline resistance gene expression. Shuttle vectors capable of replication in both Escherichia coli and Bacteroides fragilis have been developed. Conjugal transfer of these plasmids from E. coli to B. fragilis is facilitated by inclusion of the origin of transfer of the IncP plasmid RK2. The vectors pDK1 and pDK2 provide unique sites for cloning selectable markers in Bacteroides. pOA10 is a cosmid vector containing the replication region of pCP1 necessary for maintenance in Bacteroides. pDK3, pDK4.1, and pDK4.2 contain the Bacteroides clindamycin resistance gene allowing selection and maintenance in B. fragilis of plasmids containing inserted DNA fragments. pDK3 was used to test the expression in B. fragilis of five foreign tetracycline resistance (TcR) genes. The tetA, -B, and -C markers from facultative gram-negative bacteria, as well as a TcR determinant from Clostridium perfringens, did not express TcR in B. fragilis. The tetM gene, originally described in streptococci, encoded a small but reproducible increase of TcR in Bacteroides. These studies demonstrate the utility of shuttle vectors for introducing cloned genes into Bacteroides and underscore the differences in gene expression in these anaerobes. | 1988 | 3071818 |
| 2999 | 8 | 0.7610 | Integrative and conjugative elements in streptococci can act as vectors for plasmids and translocatable units integrated via IS1216E. Mobile genetic elements (MGEs), such as integrative and conjugative elements (ICEs), plasmids and translocatable units (TUs), are important drivers for the spread of antibiotic resistance. Although ICEs have been reported to support the spread of plasmids among different bacteria, their role in mobilizing resistance plasmids and TUs has not yet been fully explored. In this study, a novel TU bearing optrA, a novel non-conjugative plasmid p5303-cfrD carrying cfr(D) and a new member of the ICESa2603 family, ICESg5301 were identified in streptococci. Polymerase chain reaction (PCR) assays revealed that three different types of cointegrates can be formed by IS1216E-mediated cointegration between the three different MGEs, including ICESg5301::p5303-cfrD::TU, ICESg5301::p5303-cfrD, and ICESg5301::TU. Conjugation assays showed that ICEs carrying p5303-cfrD and/or TU successfully transferred into recipient strains, thereby confirming that ICEs can serve as vectors for other non-conjugative MGEs, such as TUs and p5303-cfrD. As neither the TU nor plasmid p5303-cfrD can spread on their own between different bacteria, their integration into an ICE via IS1216E-mediated cointegrate formation not only increases the plasticity of ICEs, but also furthers the dissemination of plasmids and TUs carrying oxazolidinone resistance genes. | 2023 | 36933870 |
| 333 | 9 | 0.7610 | Mutants of Escherichia coli altered in both genes coding for the elongation factor Tu. Genetic analysis of a mutant of Escherichia coli resistant to the antibiotic mocimycin is presented. This resistance is due to alterations in both tuf genes coding for the elongation factor Tu. Mocimycin resistance is recessive. Bacteria carryong only one tuf gene from the resistant mutant are still mocimycin sensitive. If the mutant gene is the tufA gene, the seisitive cells can be made resistant through inactivation of the tufB gene by insertion of the bacteriophage milliunits genome. Conditional mocimycin-resistant mutants ban also be isolated when the tufB gene is altered by an amber or a temperature-sensitive mutation. When only the tufB allele from the original mocimycin-resistant mutant is present, inactivation of the wild-type tufA gene fails to give viable mocimycin-resistant progeny. We conclude that the tufA mutant allele codes for a functional mocimycin-resistant EF-Tu, whereas the mutant tufB gene does not code for a functional product. | 1978 | 360222 |
| 507 | 10 | 0.7607 | Tellurite resistance and reduction by obligately aerobic photosynthetic bacteria. Seven species of obligately aerobic photosynthetic bacteria of the genera Erythromicrobium, Erythrobacter, and Roseococcus demonstrated high-level resistance to tellurite and accumulation of metallic tellurium crystals. High-level resistance without tellurite reduction was observed for Roseococcus thiosulfatophilus and Erythromicrobium ezovicum grown with certain organic carbon sources, implying that tellurite reduction is not essential to confer tellurite resistance. | 1996 | 16535446 |
| 6009 | 11 | 0.7598 | Efflux pump inhibitor chlorpromazine effectively increases the susceptibility of Escherichia coli to antimicrobial peptide Brevinin-2CE. Aim: The response of E. coli ATCC8739 to Brevinin-2CE (B2CE) was evaluated as a strategy to prevent the development of antimicrobial peptide (AMP)-resistant bacteria. Methods: Gene expression levels were detected by transcriptome sequencing and RT-PCR. Target genes were knocked out using CRISPR-Cas9. MIC was measured to evaluate strain resistance. Results: Expression of acrZ and sugE were increased with B2CE stimulation. ATCC8739ΔacrZ and ATCC8739ΔsugE showed twofold and fourfold increased sensitivity, respectively. The survival rate of ATCC8739 was reduced in the presence of B2CE/chlorpromazine (CPZ). Combinations of other AMPs with CPZ also showed antibacterial effects. Conclusion: The results indicate that combinations of AMPs/efflux pump inhibitors (EPIs) may be a potential approach to combat resistant bacteria. | 2024 | 38683168 |
| 6011 | 12 | 0.7596 | Identification and characterization of tetracycline resistance in Lactococcus lactis isolated from Polish raw milk and fermented artisanal products. To assess the occurrence of antibiotic-resistant Lactic Acid Bacteria (LAB) in Polish raw milk and fermented artisanal products, a collection comprising 500 isolates from these products was screened. Among these isolates, six strains (IBB28, IBB160, IBB161, IBB224, IBB477 and IBB487) resistant to tetracycline were identified. The strains showing atypical tetracycline resistance were classified as Lactococcus lactis: three of them were identified as L. lactis subsp. cremoris (IBB224, IBB477 and IBB487) and the other three (IBB28, IBB160, IBB161) were identified as L. lactis subsp. lactis. The mechanism involving Ribosomal Protection Proteins (RPP) was identified as responsible for tetracycline resistance. Three of the tested strains (IBB28, IBB160 and IBB224) had genes encoding the TetS protein, whereas the remaining three (IBB161, IBB477 and IBB487) expressed TetM. The results also demonstrated that the genes encoding these proteins were located on genetic mobile elements. The tet(S) gene was found to be located on plasmids, whereas tet(M) was found within the Tn916 transposon. | 2015 | 26204235 |
| 6131 | 13 | 0.7595 | Draft Genome Sequence of Eggerthia catenaformis Strain MAR1 Isolated from Saliva of Healthy Humans. Here, we report the draft genome sequence of Eggerthia catenaformis MAR1 isolated during a screen for d-cycloserine-resistant bacteria from the saliva of healthy humans. Analysis of the genome reveals that the strain has the potential to be a human pathogen and carries genes related to virulence and antibiotic resistance. | 2017 | 28705984 |
| 820 | 14 | 0.7594 | Nucleotide sequence analysis of a transposon (Tn5393) carrying streptomycin resistance genes in Erwinia amylovora and other gram-negative bacteria. A class II Tn3-type transposable element, designated Tn5393 and located on plasmid pEa34 from streptomycin-resistant strain CA11 of Erwinia amylovora, was identified by its ability to move from pEa34 to different sites in plasmids pGEM3Zf(+) and pUCD800. Nucleotide sequence analysis reveals that Tn5393 consists of 6,705 bp with 81-bp terminal inverted repeats and generates 5-bp duplications of the target DNA following insertion. Tn5393 contains open reading frames that encode a putative transposase (tnpA) and resolvase (tnpR) of 961 and 181 amino acids, respectively. The two open reading frames are separated by a putative recombination site (res) consisting of 194 bp. Two streptomycin resistance genes, strA and strB, were identified on the basis of their DNA sequence homology to streptomycin resistance genes in plasmid RSF1010. StrA is separated from tnpR by a 1.2-kb insertion element designated IS1133. The tnpA-res-tnpR region of Tn5393 was detected in Pseudomonas syringae pv. papulans Psp36 and in many other gram-negative bacteria harboring strA and strB. Except for some strains of Erwinia herbicola, these other gram-negative bacteria lacked insertion sequence IS1133. The prevalence of strA and strB could be accounted for by transposition of Tn5393 to conjugative plasmids that are then disseminated widely among gram-negative bacteria. | 1993 | 8380801 |
| 3053 | 15 | 0.7593 | Expression in Escherichia coli of cryptic tetracycline resistance genes from bacteroides R plasmids. The putative clindamycin resistance region of the Bacteroides fragilis R plasmid pBF4 was cloned in the vector R300B in Escherichia coli. This 3.8-kb EcoRI D fragment from pBF4 expressed noninducible tetracycline resistance in E. coli under aerobic but not anaerobic growth conditions. The fragment does not express tetracycline resistance in Bacteroides, a strict anaerobe. The separate tetracycline resistance transfer system in the Bacteroides host strain V479-1 has no homology to the cryptic determinant on pBF4. In addition, this aerobic tetracycline resistance determinant is not homologous to the three major plasmid mediated tetracycline resistance regions found in facultative gram-negative bacteria, represented by R100, RK2, and pBR322. A similar cryptic tetracycline resistance fragment was cloned from pCP1, a separate clindamycin resistance plasmid from Bacteroides that shares homology with the EcoRI D fragment of pBF4. This study identifies cryptic drug resistance determinants in Bacteroides that are expressed when inserted into an aerobically growing organism. | 1984 | 6379711 |
| 3024 | 16 | 0.7591 | Identification of ISVlu1-derived translocatable units containing optrA and/or fexA genes generated by homologous or illegitimate recombination in Lactococcus garvieae of porcine origin. The optrA gene encodes an ABC-F protein which confers cross-resistance to oxazolidinones and phenicols. Insertion sequence ISVlu1, a novel ISL3-family member, was recently reported to be involved in the transmission of optrA in Vagococcus lutrae. However, the role of ISVlu1 in mobilizing resistance genes has not yet fully explored. In this study, two complete and three truncated copies of ISVlu1 were found on plasmid pBN62-optrA from Lactococcus garvieae. Analysis of the genetic context showed that both optrA and the phenicols resistance gene fexA were flanked by the complete or truncated ISVlu1 copies. Moreover, three different-sized ISVlu1-based translocatable units (TUs) carrying optrA and/or fexA, were detected from pBN62-optrA. Sequence analysis revealed that the TU-optrA was generated by homologous recombination while TU-fexA and TU-optrA+fexA were the products of illegitimate recombinations. Importantly, conjugation assays confirmed that pBN62-optrA was able to successfully transfer into the recipient Enterococcus faecalis JH2-2. To our knowledge, this is the first report about an optrA-carrying plasmid in L. garvieae which could horizontally transfer into other species. More importantly, the ISVlu1-flanked genetic structures containing optrA and/or fexA were also observed in bacteria of different species, which underlines that ISVlu1 is highly active and plays a vital role in the transfer of some important resistance genes, such as optrA and fexA. | 2024 | 38479301 |
| 811 | 17 | 0.7591 | Genomic analysis of five antibiotic-resistant bacteria isolated from the environment. Our study presents the whole-genome sequences and annotation of five bacteria isolates, each demonstrating distinct antibiotic resistance. These isolates include Bacillus paranthracis RIT 841, Atlantibacter hermanii RIT 842, Pantoea leporis RIT 844, Enterococcus casseliflavus RIT 845, and Pseudomonas alkylphenolica RIT 846, underscoring the importance of understanding antimicrobial resistance. | 2024 | 39189722 |
| 5998 | 18 | 0.7590 | Complete genome sequence of a tetracycline-resistant Streptococcus mutans strain carrying the tet(M) gene. INTRODUCTION: Tetracyclines are widely used in dental treatment. Here, we report the genomic information of the tetracycline-resistant Streptococcus mutans strain, HSM45, for the first time. METHODS: Susceptibility to tetracycline was determined using the microdilution method. The complete genome sequence of HSM45 was determined and compared with public genome data. RESULTS: HSM45 was resistant to tetracycline. The tetracycline resistance gene tet(M) was carried by Tn916, a conjugative transposon that is widely found in Gram-positive bacteria. CONCLUSION: This study showed that S. mutans can acquire tetracycline resistance and it can also be a source of horizontal transfer of resistance genes. | 2025 | 40545135 |
| 502 | 19 | 0.7586 | A highly specialized flavin mononucleotide riboswitch responds differently to similar ligands and confers roseoflavin resistance to Streptomyces davawensis. Streptomyces davawensis is the only organism known to synthesize the antibiotic roseoflavin, a riboflavin (vitamin B2) analog. Roseoflavin is converted to roseoflavin mononucleotide (RoFMN) and roseoflavin adenine dinucleotide in the cytoplasm of target cells. (Ribo-)Flavin mononucleotide (FMN) riboswitches are genetic elements, which in many bacteria control genes responsible for the biosynthesis and transport of riboflavin. Streptomyces davawensis is roseoflavin resistant, and the closely related bacterium Streptomyces coelicolor is roseoflavin sensitive. The two bacteria served as models to investigate roseoflavin resistance of S. davawensis and to analyze the mode of action of roseoflavin in S. coelicolor. Our experiments demonstrate that the ribB FMN riboswitch of S. davawensis (in contrast to the corresponding riboswitch of S. coelicolor) is able to discriminate between the two very similar flavins FMN and RoFMN and shows opposite responses to the latter ligands. | 2012 | 22740651 |