# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 5988 | 0 | 1.0000 | Enterococcal vanB resistance locus in anaerobic bacteria in human faeces. While developing a rapid method to detect carriers of vancomycin-resistant enterococci (VRE), we found the vanB gene by PCR in 13 of 50 human faecal specimens that did not contain culturable VRE. Passaging under antibiotic selection allowed us to isolate two species of anaerobic bacteria that were vanB PCR positive, vancomycin resistant, and teicoplanin sensitive. Sequence analysis of the 16S rRNA genes showed that one isolate resembled Eggerthella lenta (98% identity), and the other Clostridium innocuum (92% identity). Southern hybridisation and nucleotide sequencing showed a vanB locus homologous to that in VRE. We propose that vanB resistance in enterococci might arise from gene transfer in the human bowel. | 2001 | 11265957 |
| 5968 | 1 | 0.9997 | A PCR assay for rapid detection of vancomycin-resistant enterococci. Since the first report of a vancomycin-resistant enterococcal clinical isolate, these Gram-positive bacteria have emerged as important nosocomial pathogens. Several glycopeptide resistance phenotypes can be distinguished on the basis of the level and inducibility of resistance to vancomycin and teicoplanin. In the present study, we developed a multiplex PCR, which allows the simultaneous identification of enterococci at the genus level and detection of the most frequent glycopeptide resistance genotypes. Five primer sets targeting the genes vanA, vanB, vanC1, vanC2/C3 and tuf were used in one reaction tube with bacterial DNA extracted from three to five colonies. This PCR method is suitable for the rapid detection of vancomycin-resistant enterococci. | 2002 | 12007446 |
| 5972 | 2 | 0.9996 | Method of Selection of Bacteria Antibiotic Resistance Genes Based on Clustering of Similar Nucleotide Sequences. A new method for selection of bacterium antibiotic resistance genes is proposed and tested for solving the problems related to selection of primers for PCR assay. The method implies clustering of similar nucleotide sequences and selection of group primers for all genes of each cluster. Clustering of resistance genes for six groups of antibiotics (aminoglycosides, β-lactams, fluoroquinolones, glycopeptides, macrolides and lincosamides, and fusidic acid) was performed. The method was tested for 81 strains of bacteria of different genera isolated from patients (K. pneumoniae, Staphylococcus spp., S. agalactiae, E. faecalis, E. coli, and G. vaginalis). The results obtained by us are comparable to those in the selection of individual genes; this allows reducing the number of primers necessary for maximum coverage of the known antibiotic resistance genes during PCR analysis. | 2017 | 29063318 |
| 3593 | 3 | 0.9996 | Genes homologous to glycopeptide resistance vanA are widespread in soil microbial communities. The occurrence of d-Ala : d-Lac ligase genes homologous to glycopeptide resistance vanA was studied in samples of agricultural (n=9) and garden (n=3) soil by culture-independent methods. Cloning and sequencing of nested degenerate PCR products obtained from soil DNA revealed the occurrence of d-Ala : d-Ala ligase genes unrelated to vanA. In order to enhance detection of vanA-homologous genes, a third PCR step was added using primers targeting vanA in soil Paenibacillus. Sequencing of 25 clones obtained by this method allowed recovery of 23 novel sequences having 86-100% identity with vanA in enterococci. Such sequences were recovered from all agricultural samples as well as from two garden samples with no history of organic fertilization. The results indicated that soil is a rich and assorted reservoir of genes closely related to those conferring glycopeptide resistance in clinical bacteria. | 2006 | 16734783 |
| 5992 | 4 | 0.9996 | Emergence of Enterococcus gallinarum carrying vanA gene cluster displaying atypical phenotypes. Motile enterococci such as Enterococcus gallinarum has the ability to acquire and transfer antibiotic resistance genes to other enterococci. Even though infections caused by E. gallinarum are rare, the discovery of this bacteria in food sources and in clinical environments is disturbing. Here, we report the isolation and identification of E. gallinarum from the wound of a hospital in-patient. The isolate was identified using 16S rDNA sequencing. Isolate 146 harboured the vanA and vanC1 gene clusters, was vancomycin-susceptible, and displayed resistance to ampicillin, penicillin, erythromycin and teicoplanin. This isolate also showed intermediate resistance to linezolid and sequencing of the 23S rRNA peptidyl transferase region did not unveil any known mutations associated to the conferment of linezolid resistance. The presence of vanA did not confer resistance to vancomycin. Structural analyses into the Tn1546 transposon carrying the vanA gene revealed distinct genetic variations in the vanS, vanY and vanS-vanH intergenic region that could be associated to the atypical antibiotic resistance phenotypes of isolate 146. Finding from this study are suggestive of the occurrence of interspecies horizontal gene transfer and that similarities in genotypic characteristic may not necessarily correlate with actual antibiotic resistance pattern of E. gallinarum. | 2016 | 33579083 |
| 5970 | 5 | 0.9996 | DNA microarray for detection of macrolide resistance genes. A DNA microarray was developed to detect bacterial genes conferring resistance to macrolides and related antibiotics. A database containing 65 nonredundant genes selected from publicly available DNA sequences was constructed and used to design 100 oligonucleotide probes that could specifically detect and discriminate all 65 genes. Probes were spotted on a glass slide, and the array was reacted with DNA templates extracted from 20 reference strains of eight different bacterial species (Streptococcus pneumoniae, Streptococcus pyogenes, Enterococcus faecalis, Enterococcus faecium, Staphylococcus aureus, Staphylococcus haemolyticus, Escherichia coli, and Bacteroides fragilis) known to harbor 29 different macrolide resistance genes. Hybridization results showed that probes reacted with, and only with, the expected DNA templates and allowed discovery of three unexpected genes, including msr(SA) in B. fragilis, an efflux gene that has not yet been described for gram-negative bacteria. | 2006 | 16723563 |
| 5969 | 6 | 0.9996 | Microarray-based detection of 90 antibiotic resistance genes of gram-positive bacteria. A disposable microarray was developed for detection of up to 90 antibiotic resistance genes in gram-positive bacteria by hybridization. Each antibiotic resistance gene is represented by two specific oligonucleotides chosen from consensus sequences of gene families, except for nine genes for which only one specific oligonucleotide could be developed. A total of 137 oligonucleotides (26 to 33 nucleotides in length with similar physicochemical parameters) were spotted onto the microarray. The microarrays (ArrayTubes) were hybridized with 36 strains carrying specific antibiotic resistance genes that allowed testing of the sensitivity and specificity of 125 oligonucleotides. Among these were well-characterized multidrug-resistant strains of Enterococcus faecalis, Enterococcus faecium, and Lactococcus lactis and an avirulent strain of Bacillus anthracis harboring the broad-host-range resistance plasmid pRE25. Analysis of two multidrug-resistant field strains allowed the detection of 12 different antibiotic resistance genes in a Staphylococcus haemolyticus strain isolated from mastitis milk and 6 resistance genes in a Clostridium perfringens strain isolated from a calf. In both cases, the microarray genotyping corresponded to the phenotype of the strains. The ArrayTube platform presents the advantage of rapidly screening bacteria for the presence of antibiotic resistance genes known in gram-positive bacteria. This technology has a large potential for applications in basic research, food safety, and surveillance programs for antimicrobial resistance. | 2005 | 15872258 |
| 2441 | 7 | 0.9995 | Phenotypic and molecular assessment of antimicrobial resistance profile of airborne Staphylococcus spp. isolated from flats in Kraków. Bacteria of the genus Staphylococcus were isolated from air sampled from living spaces in Kraków (Poland). In total, 55 strains belonging to the genus Staphylococcus were isolated from 45 sites, and 13 species of coagulase-negative staphylococci were identified. The species composition of studied airborne microbiota contains Staphylococcus species that are rarely infectious to humans. Most commonly isolated species comprised S. hominis and S. warneri. The disk-diffusion tests showed that the collected isolates were most frequently resistant to erythromycin. The PCR technique was employed to search for genes conferring the resistance in staphylococci to antibiotics from the group of macrolides, lincosamides and streptogramins. The analyzed Staphylococcus isolates possessed simultaneously 4 different resistance genes. The molecular analysis with the use of specific primers allowed to determine the most prevalent gene which is mphC, responsible for the resistance to macrolides and for the enzymatic inactivation of the drug by phosphotransferase. The second most often detected gene was msrA1, which confers the resistance of staphylococci to macrolides and is responsible for active pumping of antimicrobial particles out of bacterial cells. | 2017 | 28955110 |
| 2798 | 8 | 0.9995 | The Distribution of Eight Antimicrobial Resistance Genes in Streptococcus oralis, Streptococcus sanguinis, and Streptococcus gordonii Strains Isolated from Dental Plaque as Oral Commensals. It has been proposed that oral commensal bacteria are potential reservoirs of a wide variety of antimicrobial resistance genes (ARGs) and could be the source of pathogenic bacteria; however, there is scarce information regarding this. In this study, three common streptococci of the mitis group (S. oralis, S. sanguinis, and S. gordonii) isolated from dental plaque (DP) were screened to identify if they were frequent reservoirs of specific ARGs (blaTEM, cfxA, tetM, tetW, tetQ, ermA, ermB, and ermC). DP samples were collected from 80 adults; one part of the sample was cultured, and from the other part DNA was obtained for first screening of the three streptococci species and the ARGs of interest. Selected samples were plated and colonies were selected for molecular identification. Thirty identified species were screened for the presence of the ARGs. From those selected, all of the S. sanguinis and S. oralis carried at least three, while only 30% of S. gordonii strains carried three or more. The most prevalent were tetM in 73%, and blaTEM and tetW both in 66.6%. On the other hand, ermA and cfxA were not present. Oral streptococci from the mitis group could be considered frequent reservoirs of specifically tetM, blaTEM, and tetW. In contrast, these three species appear not to be reservoirs of ermA and cfxA. | 2023 | 37999618 |
| 5996 | 9 | 0.9995 | Molecular characterization of intrinsic and acquired antibiotic resistance in lactic acid bacteria and bifidobacteria. The minimum inhibitory concentrations (MICs) of 6 different antibiotics (chloramphenicol, clindamycin, erythromycin, streptomycin, tetracycline and vancomycin) were determined for 143 strains of lactic acid bacteria and bifidobacteria using the Etest. Different MICs were found for different species and strains. Based on the distribution of these MIC values, most of the strains were either susceptible or intrinsically resistant to these antibiotics. However, the MIC range of some of these antibiotics showed a bimodal distribution, which suggested that some of the tested strains possess acquired antibiotic resistance. Screening for resistance genes was performed by PCR using specific primers, or using a DNA microarray with around 300 nucleotide probes representing 7 classes of antibiotic resistance genes. The genes identified encoded resistance to tetracycline [tet(M), tet(W), tet(O) and tet(O/W)], erythromycin and clindamycin [erm(B)] and streptomycin [aph(E) and sat(3)]. Internal portions of some of these determinants were sequenced and found to be identical to genes described in other bacteria. All resistance determinants were located on the bacterial chromosome, except for tet(M), which was identified on plasmids in Lactococcus lactis. The contribution of intrinsic multidrug transporters to the antibiotic resistance was investigated by cloning and measuring the expression of Bifidobacterium breve genes in L. lactis. | 2008 | 17957105 |
| 5903 | 10 | 0.9995 | Screening of virulence determinants in Enterococcus faecium strains isolated from breast milk. In a previous study, the authors isolated lactic acid bacteria from breast milk of healthy mothers. Since some of the identified isolates belonged to the species Enterococcus faecium, the objective of this work was to evaluate their safety. The enterococcal strains were screened by polymerase chain reaction (PCR) and Southern hybridization for the presence of virulence determinants. The potential of the strains to acquire plasmids by conjugation was investigated by screening for genes involved in conjugation processes. Parallel, phenotypic assays were performed. Presence of genes conferring resistance to vancomycin was assessed by PCR. PCR amplifications and Southern hybridizations revealed that all the strains were clear of the majority of potential virulence determinants. None of the strains showed gelatinase activity, hemolysin production, or aggregation phenotype, and none carried the vanA or vanB genes. These findings suggest that milk of healthy mothers may be a source of avirulent E faecium isolates to the newborns. | 2005 | 15886339 |
| 5947 | 11 | 0.9995 | Fluoroquinolone-resistant Streptococcus agalactiae: epidemiology and mechanism of resistance. Quinolone-resistant Streptococcus agalactiae bacteria were recovered from single-patient isolates and found to contain mutations in the gyrase and topoisomerase IV genes. Pulsed-field gel electrophoresis demonstrated that four isolates from the same long-term care facility were closely related; in seven cases, quinolone-resistant Haemophilus influenzae and S. agalactiae bacteria were isolated from the same patient. | 2005 | 15917553 |
| 6065 | 12 | 0.9995 | Screening for enterocins and detection of hemolysin and vancomycin resistance in enterococci of different origins. The inhibitory activity of 122 out of 426 Enterococcus strains of geographically widespread origin and from different sources (food and feed, animal isolates, clinical and nonclinical human isolates) was tested against a wide range of indicator bacteria. Seventy-two strains, mainly belonging to the species Enterococcus faecium and Enterococcus faecalis were bacteriocinogenic. A remarkable variation of inhibitory spectra occurred among the strains tested, including inhibition of, for instance, only closely related enterococci, other lactic acid bacteria (LAB), food spoilage and pathogenic bacteria. No correlation could be found between the origin of the strains and the type of inhibitory spectrum, although a clustering of human isolates from both fecal and clinical origin was observed in the group of strains inhibiting lactic acid bacteria, Listeria, and either Staphylococcus or Clostridium. No relationship could be established between the presence of enterocin structural genes and the origin of the strain either, and hence no correlation seemed to exist between the presence of known enterocin genes and the activity spectra of these enterococci. The structural gene of enterocin A was widely distributed among E. faecium strains, whereas that of enterocin B only occurred in the presence of enterocin A. The vancomycin resistance phenotype as well as the presence of vancomycin resistance genes was also investigated. The vanA gene only occurred among E. faecium strains. The incidence of beta-hemolysis was not restricted to E. faecalis strains, but among the E. faecium strains the structural genes of cytolysin were not detected. beta-Hemolysis occurred in strains both from food and nonfood origin. It has been concluded that bacteriocin-producing E. faecium strains lacking hemolytic activity and not carrying cytolysin nor vancomycin resistance genes may be useful as starter cultures, cocultures, or probiotics. | 2003 | 12810293 |
| 5997 | 13 | 0.9995 | Resistance of potential probiotic lactic acid bacteria and bifidobacteria of African and European origin to antimicrobials: determination and transferability of the resistance genes to other bacteria. Probiotic bacteria and starter cultures of Lactobacillus, Weissella and Bifidobacterium of African and European origins were studied and compared for their susceptibility to antimicrobials. The study included, for all isolates, determination of MICs (Minimal Inhibitory Concentration) for 24 antimicrobials, detection of resistance genes by PCR reactions using specific primers and sequencing of positive amplicons. The ability of Lb. reuteri from Africa to transfer the erythromycin resistance gene erm(B) to closely related bacteria was investigated by conjugation. Variations were observed and high levels of intrinsic resistance were found among the tested species. Positive amplicons were obtained for resistance genes encoding aminoglycoside (aph(3')-III, aadA, aadE) and tetracycline (tet(S)) from isolates from Europe and macrolide (erm(B)) from an isolate from Africa. However, only the erm(B) gene found in Lb. reuteri L4: 12002 from Africa contained a homologous sequence to previously published sequences. This gene could be transferred in vitro to enterococci. Higher prevalence of phenotypic resistance for aminoglycoside was found in isolates from Europe. | 2008 | 18063151 |
| 5974 | 14 | 0.9995 | Use of a bacterial antimicrobial resistance gene microarray for the identification of resistant Staphylococcus aureus. As diagnostic and surveillance activities are vital to determine measures needed to control antimicrobial resistance (AMR), new and rapid laboratory methods are necessary to facilitate this important effort. DNA microarray technology allows the detection of a large number of genes in a single reaction. This technology is simple, specific and high-throughput. We have developed a bacterial antimicrobial resistance gene DNA microarray that will allow rapid antimicrobial resistance gene screening for all Gram-positive and Gram-negative bacteria. A prototype microarray was designed using a 70-mer based oligonucleotide set targeting AMR genes of Gram-negative and Gram-positive bacteria. In the present version, the microarray consists of 182 oligonucleotides corresponding to 166 different acquired AMR gene targets, covering most of the resistance genes found in both Gram-negative and -positive bacteria. A test study was performed on a collection of Staphylococcus aureus isolates from milk samples from dairy farms in Québec, Canada. The reproducibility of the hybridizations was determined, and the microarray results were compared with those obtained by phenotypic resistance tests (either MIC or Kirby-Bauer). The microarray genotyping demonstrated a correlation between penicillin, tetracycline and erythromycin resistance phenotypes with the corresponding acquired resistance genes. The hybridizations showed that the 38 antimicrobial resistant S. aureus isolates possessed at least one AMR gene. | 2010 | 21083822 |
| 5989 | 15 | 0.9994 | Presence of the vancomycin resistance gene cluster vanC1, vanXYc, and vanT in Enterococcus casseliflavus. The three chromosomally located clustered genes vanC1, vanXYc, and vanT confer intrinsic resistance to vancomycin and are used for species identification of Enterococcus gallinarum. In this study, 28 strains belonging to the E. gallinarum/casseliflavus group isolated from cloacal swabs from laying hens were screened for the presence of vanC1. As confirmed by species-specific multiplex PCR, 11 vanC1-positive strains were identified as E. gallinarum. Surprisingly, one yellow pigmented strain, verified as E. casseliflavus by species-specific multiplex PCR, was also vanC1 positive; vanXYc and vanT were additionally detectable in this strain. To our knowledge, this is the first report of vanC1, vanXYc, and vanT in E. casseliflavus. The minimum inhibitory concentration of vancomycin was 4 mg/L. Real-time reverse transcription-PCR revealed that none of the clustered genes was expressed in this strain. Even if the genes seem not to be active, there is a certain risk that they will be transferred to other bacteria where they might be functionally expressed. Therefore, it may be advisable to expand the search for vanC1, vanXYc, and vanT from E. gallinarum to other (enterococcal) species. This study confirms that enterococci live up to their name as being reservoir bacteria and should therefore always be closely monitored. | 2014 | 24266667 |
| 3594 | 16 | 0.9994 | Directed Recovery and Molecular Characterization of Antibiotic Resistance Plasmids from Cheese Bacteria. Resistance to antimicrobials is a growing problem of worldwide concern. Plasmids are thought to be major drivers of antibiotic resistance spread. The present work reports a simple way to recover replicative plasmids conferring antibiotic resistance from the bacteria in cheese. Purified plasmid DNA from colonies grown in the presence of tetracycline and erythromycin was introduced into plasmid-free strains of Lactococcus lactis, Lactiplantibacillus plantarum and Lacticaseibacillus casei. Following antibiotic selection, the plasmids from resistant transformants were isolated, analyzed by restriction enzyme digestion, and sequenced. Seven patterns were obtained for the tetracycline-resistant colonies, five from L. lactis, and one each from the lactobacilli strains, as well as a single digestion profile for the erythromycin-resistant transformants obtained in L. lactis. Sequence analysis respectively identified tet(S) and ermB in the tetracycline- and erythromycin-resistance plasmids from L. lactis. No dedicated resistance genes were detected in plasmids conferring tetracycline resistance to L. casei and L. plantarum. The present results highlight the usefulness of the proposed methodology for isolating functional plasmids that confer antibiotic resistance to LAB species, widen our knowledge of antibiotic resistance in the bacteria that inhabit cheese, and emphasize the leading role of plasmids in the spread of resistance genes via the food chain. | 2021 | 34360567 |
| 5498 | 17 | 0.9994 | The prevalence of multidrug resistance in Staphylococcus hominis isolated from clinical materials. The treatment of infections caused by Staphylococcus hominis remains a challenge, mainly due to the increasing resistance of these bacteria to antibiotics. The aim of the study was to determine antibiotic resistance in 62 strains S. hominis isolated from clinical materials, and to identify the molecular basis of resistance to antibiotics. Forty-six strains were both methicillin-resistant and harbored the mecA gene. Twenty-three of these strains had mec complex A and ccr complex AB1. Such a combination of the mec and ccr complexes does not correspond to any cassettes that have been demonstrated so far. However, over 80% of the tested strains were multidrug-resistant, of which as many as 12 were resistant to at least seven antibiotics. More than a half of strains harbored the tetK, acc(6')-Ie aph(2''), and ant(4')-I genes. erm(C) was the most common resistant gene to antibiotics from the MLS group. Two strains had as many as five antibiotic resistance genes from the tested groups (erm(C), msr(A), msr(B), mph(C), lnu(A)). The presence of the vga gene encoding resistance to streptogramins A was detected in one strain. All of strains were sensitive to vancomycin. However, 11 of them had reduced sensitivity to this antibiotic and eight of them were characterized by a heterogeneous resistance profile to this antibiotic. Our results clearly shows increasing threat of S. hominis caused by their multi-resistance. Moreover, these bacteria can constitute a reservoir of resistance genes for more pathogenic bacteria. | 2025 | 39747570 |
| 5937 | 18 | 0.9994 | Association of mutation patterns in GyrA and ParC genes with quinolone resistance levels in lactic acid bacteria. The quinolone resistance of 19 lactic acid bacterial strains belonging to the genera Enterococcus and Lactobacillus isolated from the natural fermented koumiss and yoghurt were investigated. The objective of this study was to determine the quinolone resistance levels and to explore the association of the resistance with the mutation patterns in gyrA and parC genes, as is currently recommended by the Food and Agriculture Organization/World Health Organization Joint Expert Committee in Guidelines for Evaluation of Probiotics in Food for probiotic lactic acid bacteria drug resistance in 2001. The Oxford Cup method and double-tube dilution method were used to determine the quinolone resistance levels of the isolated strains. Generally, all of the 19 strains showed resistance towards norfloxacin and ciprofloxacin when the Oxford cup method was used, whereas the incidence was lower (to norfloxacin 89.5% and to ciprofloxacin 68.4%) when minimum inhibitory concentration breakpoints (CLSI M100-S23) were tested. Furthermore, gene sequencing was conducted on gyrA and parC of topoisomerase II of these isolated strains. The genetic basis for quinolone resistance may be closely related to mutations in gyrA genes as there were 10 mutation sites in amino-acid sequences encoded by gyrA genes in 10 quinolone resistance strains and 14 mutation sites in Enterococcus durans HZ28, whereas no typical mutations were detected in parC genes. | 2015 | 25204345 |
| 5990 | 19 | 0.9994 | Presence of the resistance genes vanC1 and pbp5 in phenotypically vancomycin and ampicillin susceptible Enterococcus faecalis. Ampicillin and vancomycin are important antibiotics for the therapy of Enterococcus faecalis infections. The ampicillin resistance gene pbp5 is intrinsic in Enterococcus faecium. The vanC1 gene confers resistance to vancomycin and serves as a species marker for Enterococcus gallinarum. Both genes are chromosomally located. Resistance to ampicillin and vancomycin was determined in 484 E. faecalis of human and porcine origin by microdilution. Since E. faecalis are highly skilled to acquire resistance genes, all strains were investigated for the presence of pbp5 (and, in positive strains, for the penicillin-binding protein synthesis repressor gene psr) and vanC1 (and, in positive strains, for vanXYc and vanT) by using polymerase chain reaction (PCR). One porcine and one human isolate were phenotypically resistant to ampicillin; no strain was vancomycin resistant. Four E. faecalis (3/1 of porcine/human origin) carried pbp5 (MIC=1 mg/L), and four porcine strains were vanC1 positive (minimum inhibitory concentration [MIC]=1 mg/L). Real-time reverse transcriptase (RT)-PCR revealed that the genes were not expressed. The psr gene was absent in the four pbp5-positive strains; the vanXYc gene was absent in the four vanC1-positive strains. However, vanT of the vanC gene cluster was detected in two vanC1-positive strains. To our knowledge, this is the first report on the presence of pbp5, identical with the "E. faecium pbp5 gene," and of vanC1/vanT in E. faecalis. Even if resistance is not expressed in these strains, this study shows that E. faecalis have a strong ability to acquire resistance genes-and potentially to spread them to other bacteria. Therefore, close monitoring of this species should be continued. | 2012 | 22524613 |