# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 5871 | 0 | 0.9844 | Plasmid-mediated florfenicol resistance in Pasteurella trehalosi. OBJECTIVES: A florfenicol-resistant Pasteurella trehalosi isolate from a calf was investigated for the presence and the location of the gene floR. METHODS: The P. trehalosi isolate 13698 was investigated for its in vitro susceptibility to antimicrobial agents and its plasmid content. A 14.9 kb plasmid, designated pCCK13698, was identified by transformation into Pasteurella multocida to mediate resistance to florfenicol, chloramphenicol and sulphonamides. The plasmid was sequenced completely and analysed for its structure and organization. RESULTS: Plasmid pCCK13698 exhibited extended similarity to plasmid pHS-Rec from Haemophilus parasuis including the region carrying the parA, repB, rec and int genes. Moreover, it revealed similarities to plasmid RSF1010 in the parts covering the mobC and repA-repC genes and to plasmid pMVSCS1 in the parts covering the sul2-catA3-strA gene cluster. Moreover, the floR gene area corresponded to that of transposon TnfloR. In addition, two complete insertion sequences were detected that were highly similar to IS1593 from Mannheimia haemolytica and IS26 from Enterobacteriaceae. Several potential recombination sites were identified that might explain the development of plasmid pCCK13698 by recombination events. CONCLUSIONS: The results of this study showed that in the bovine pathogen P. trehalosi, floR-mediated resistance to chloramphenicol and florfenicol was associated with a plasmid, which also carried functionally active genes for resistance to sulphonamides (sul2) and chloramphenicol (catA3). This is to the best of our knowledge the first report of resistance genes in P. trehalosi and only the second report of the presence of a florfenicol-resistance gene in target bacteria of the family Pasteurellaceae. | 2006 | 16670108 |
| 3061 | 1 | 0.9838 | Tetracycline-resistance encoding plasmids from Paenibacillus larvae, the causal agent of American foulbrood disease, isolated from commercial honeys. Paenibacillus larvae, the causal agent of American foulbrood disease in honeybees, acquires tetracycline-resistance via native plasmids carrying known tetracycline-resistance determinants. From three P. larvae tetracycline-resistant strains isolated from honeys, 5-kb-circular plasmids with almost identical sequences, designated pPL373 in strain PL373, pPL374 in strain PL374, and pPL395 in strain PL395, were isolated. These plasmids were highly similar (99%) to small tetracycline-encoding plasmids (pMA67, pBHS24, pBSDMV46A, pDMV2, pSU1, pAST4, and pLS55) that replicate by the rolling circle mechanism. Nucleotide sequences comparisons showed that pPL373, pPL374, and pPL395 mainly differed from the previously reported P. larvae plasmid pMA67 in the oriT region and mob genes. These differences suggest alternative mobilization and/or conjugation capacities. Plasmids pPL373, pPL374, and pPL395 were individually transferred by electroporation and stably maintained in tetracycline-susceptible P. larvae NRRL B-14154, in which they autonomously replicated. The presence of nearly identical plasmids in five different genera of gram-positive bacteria, i.e., Bhargavaea, Bacillus, Lactobacillus, Paenibacillus, and Sporosarcina, inhabiting diverse ecological niches provides further evidence of the genetic transfer of tetracycline resistance among environmental bacteria from soils, food, and marine habitats and from pathogenic bacteria such as P. larvae. | 2014 | 25296446 |
| 5866 | 2 | 0.9837 | tet(L)-mediated tetracycline resistance in bovine Mannheimia and Pasteurella isolates. OBJECTIVES: Tetracycline-resistant Mannheimia and Pasteurella isolates, which were negative for the tetracycline resistance genes (tet) commonly detected among these bacteria, were investigated for other tet genes present and their location. METHODS: Mannheimia and Pasteurella isolates were investigated for their MICs of tetracycline and their plasmid content. Identification of tet genes was achieved by PCR. Plasmids mediating tetracycline resistance were identified by transformation and hybridization experiments. Plasmid pCCK3259 from Mannheimia haemolytica was sequenced completely and analysed for its structure and organization. RESULTS: All tetracycline-resistant isolates carried the gene tet(L) either on plasmids or on the chromosome. Two M. haemolytica isolates and one Mannheimia glucosida isolate harboured a common 5.3 kb tet(L) plasmid, designated pCCK3259. This plasmid was similar to the tet(B)-carrying tetracycline resistance plasmid pHS-Tet from Haemophilus parasuis and the streptomycin/spectinomycin resistance plasmid pCCK647 from Pasteurella multocida in the parts coding for mobilization functions. The tet(L) gene was closely related to that of the Geobacillus stearothermophilus plasmid pTB19. However, the translational attenuator responsible for the tetracycline-inducible expression of tet(L) was missing in plasmid pCCK3259. A recombination site was identified downstream of tet(L), which might explain the integration of the tet(L) gene region into a basic pCCK3259 replicon. CONCLUSION: A tet(L) gene was shown for the first time to be responsible for tetracycline resistance in Mannheimia and Pasteurella isolates. This report demonstrates a lateral transfer of a tetracycline efflux gene in Gram-negative bovine respiratory tract pathogens, probably originating from Gram-positive bacteria. | 2005 | 15972309 |
| 3035 | 3 | 0.9836 | Molecular characterization of plasmids with antimicrobial resistant genes in avian isolates of Pasteurella multocida. The complete nucleotide sequences of two plasmids from avian isolates of Pasteurella multocida that caused outbreaks of fowl cholera in Taiwan were determined. The entire sequences of the two plasmids, designated as pJR1 and pJR2, were 6792 bp and 5252 bp. Sequence analysis showed that the plasmid pJR1 contained six major genes: the first gene (sulII) encoded a type II sulfonamide resistant dihydropteroate synthase, the second gene (tetG) encoded a tetracycline resistance protein, the third gene (catB2) encoded a chloramphenicol acetyltransferase, the fourth gene (rep) encoded a replication protein, and the fifth and sixth genes (mbeCy and deltambeAy) encoded proteins involved in the mobilization of plasmid. The plasmid pJR2 contained five major genes: the first gene (deltaintI1) encoded a truncated form of a type I integrase, the second gene (aadA1) encoded an aminoglycoside adenylyltransferase that confers resistance to streptomycin and spectinomycin, the third gene (blaP1) encoded a beta-lactamase that confers resistance to ampicillin and carbenicillin, and the fourth and fifth genes might encode proteins involved in the plasmid replication or segregation. Sequence comparisons showed that the antibiotic resistance genes found in pJR1 and pJR2 exhibited a high degree of sequence homology to the corresponding genes found in a great variety of gram-negative bacteria, including Escherichia coli, Salmonella enterica Typhimurium DT104, Psedomonas spp., P. multocida, Mannheimia spp., and Actinobacills pleuropneumoniae, which suggests that these resistance genes were disseminated in these bacteria. Although sulII and tetG genes were found previously in P. multocida or Mannheimia spp., this is the first report on the presence of catB2, aadA1, and blaP1 genes in bacteria of the family Pasturellaceae. Moreover, the aadA1 and blaP1 genes found in pJR2 were organized into an integron structure, which is a site-specific recombination system capable of capturing and mobilizing antibiotic resistance genes. This is also the first report on the presence of an integron in bacteria of the family Pasteurellaceae. The presence of a P. multocida integron might facilitate the spreading of antibiotic resistance genes between P. multocida and other gram-negative bacteria. | 2003 | 14708986 |
| 820 | 4 | 0.9836 | 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 |
| 3018 | 5 | 0.9832 | The large Bacillus plasmid pTB19 contains two integrated rolling-circle plasmids carrying mobilization functions. Plasmid pTB19 is a 27-kb plasmid originating from a thermophilic Bacillus species. It was shown previously that pTB19 contains an integrated copy of the rolling-circle type plasmid pTB913. Here we describe the analysis of a 4324-bp region of pTB19 conferring resistance to tetracycline. The nucleotide sequence of this region revealed all the characteristics of a second plasmid replicating via the rolling-circle mechanism. This sequence contained (i) the tetracycline resistance marker of pTB19, which is highly similar to other tetL-genes of gram-positive bacteria; (ii) a hybrid mob gene, which bears relatedness to both the mob-genes of pUB110 and pTB913; (iii) a palU type minus origin identical to those of pUB110 and pTB913; and (iv) a plus origin of replication similar to that of pTB913. A repB-type replication initiation gene sequence identical to that of pTB913 was present, which lacked the middle part (492 bp), thus preventing autonomous replication of this region. The hybrid mob gene was functional in conjugative mobilization of plasmids between strains of Bacillus subtilis. | 1991 | 1946749 |
| 5872 | 6 | 0.9829 | Characterization of the plasmids harbouring the florfenicol resistance gene floR in Glaesserella parasuis and Actinobacillus indolicus. OBJECTIVES: The aim of this study was to characterize the floR-carrying plasmids originating from Glaesserella parasuis and Actinobacillus indolicus isolated from pigs with respiratory disease in China. METHODS: A total of 125 G. parasuis and 28 A. indolicus strains collected between 2009 and 2022 were screened for florfenicol resistance. Characterization of floR-positive isolates and plasmids were determined by antimicrobial susceptibility testing, serotyping, multilocus sequence typing (MLST), conjugation and transformation assays, whole-genome sequencing (WGS), and phylogenetic analysis. RESULTS: One A. indolicus and six G. parasuis were identified as positive for floR. The six G. parasuis were assigned to four different serovars, including serovars 6, 7, 9, and unknown. In addition to strain XP11, six floR genes were located on plasmids. The six floR-bearing plasmids could be transformed into Pasteurella multocida and divided into two different types, including ∼5000 bp and ∼6000 bp plasmids. The ∼5000 bp plasmids consisting of rep, lysR, mobB, and floR genes, exhibited high similarity among Pasteurellaceae bacteria. Furthermore, the ∼6000 bp plasmids, consisting of rep, lysR, mobC, mobA/L, and floR genes, showed high similarity between G. parasuis and Actinobacillus Spp. Notably, WGS results showed that the floR modules of the two types of plasmids could be transferred and integrated into the diverse Pasteurellaceae- origined plasmids. CONCLUSION: This study firstly reported the characterization of floR-carrying plasmids from A. indolicus and a non-virulent serovar of G. parasuis in pigs in China and elucidated the transmission mechanism of the floR resistance gene among the Pasteurellaceae family. | 2023 | 37726088 |
| 3017 | 7 | 0.9824 | The ancient small mobilizable plasmid pALWED1.8 harboring a new variant of the non-cassette streptomycin/spectinomycin resistance gene aadA27. The small mobilizable plasmid pALWED1.8 containing a novel variant of the streptomycin/spectinomycin resistance gene aadA27 was isolated from the permafrost strains of Acinetobacter lwoffii. The 4135bp plasmid carries mobА and mobC genes that mediate its mobilization by conjugative plasmids. The nucleotide sequences of mobА and mobC are similar to those of mobilization genes of the modern plasmid pRAY* and its variants, which contain aadB gene, and are widespread among the pathogenic strains of Acinetobacter baumannii. Almost identical pALWED1.8 variants were detected in modern environmental Аcinetobacter strains. A highly similar plasmid was revealed in a strain of Acinetobacter parvus isolated from mouse intestine. Furthermore, we discovered six previously unidentified variants of plasmids related to pALWED1.8 and pRAY* in public databases. In contrast to most known variants of aadA which are cassette genes associated with integrons, the aadA27 variant harbored by pALWED1.8 is a non-cassette, autonomously transcribed gene. Non-cassette aadA genes with 96% sequence identity to aadA27 were detected in the chromosomes of Acinetobacter gyllenbergii and several uncharacterized strains of Аcinetobacter sp. Moreover, we revealed that the autonomous aadA-like genes are present in the chromosomes of many gram-positive and gram-negative bacteria. The phylogenetic analysis of amino acid sequences of all identified AadA proteins showed the following: (i) cassette aadA genes form a separate monophyletic group and mainly reside on plasmids and (ii) chromosomal non-cassette aadA genes are extremely diverse and can be inherited both vertical and via horizontal gene transfer. | 2016 | 26896789 |
| 5867 | 8 | 0.9824 | Molecular analysis of florfenicol-resistant Pasteurella multocida isolates in Germany. OBJECTIVES: Three florfenicol-resistant Pasteurella multocida isolates from Germany, two from swine and one from a calf, were investigated for the genetics and transferability of florfenicol resistance. METHODS: The isolates were investigated for susceptibility to antimicrobial agents and plasmid content. Florfenicol resistance plasmids carrying the gene floR were identified by transformation and PCR. Plasmids were mapped, and a novel plasmid type was sequenced completely. PFGE served to determine the clonality of the isolates. RESULTS: In one porcine and the bovine P. multocida isolate, florfenicol resistance was associated with the plasmid pCCK381 previously described in a bovine P. multocida isolate from the UK. The remaining porcine isolate harboured a new type of floR-carrying plasmid, the 10 226 bp plasmid pCCK1900. Complete sequence analysis identified an RSF1010-like plasmid backbone with the mobilization genes mobA, mobB and mobC, the plasmid replication genes repA, repB and repC, the sulphonamide resistance gene sul2 and the streptomycin resistance genes strA and strB. The floR gene area was integrated into a region downstream of strB, which exhibited homology to the floR flanking regions found in various bacteria. PFGE revealed that the floR-carrying P. multocida strains from Germany were unrelated and also different from the UK strain. CONCLUSIONS: After the UK and France, floR-mediated florfenicol resistance has now also been identified in target bacteria from Germany. PFGE data and the analysis of plasmids strongly suggested that the spread of florfenicol resistance is due to the horizontal transfer of plasmids rather than the clonal dissemination of a resistant P. multocida isolate. | 2008 | 18786941 |
| 5440 | 9 | 0.9824 | Molecular structure and evolution of the conjugative multiresistance plasmid pRE25 of Enterococcus faecalis isolated from a raw-fermented sausage. Plasmid pRE25 from Enterococcus faecalis transfers resistances against kanamycin, neomycin, streptomycin, clindamycin, lincomycin, azithromycin, clarithromycin, erythromycin, roxithromycin, tylosin, chloramphenicol, and nourseothricin sulfate by conjugation in vitro to E. faecalis JH2-2, Lactococcus lactis Bu2, and Listeria innocua L19. Its nucleotide sequence of 50237 base pairs represents the largest, fully sequenced conjugative multiresistance plasmid of enterococci (Plasmid 46 (2001) 170). The gene for chloramphenicol resistance (cat) was identified as an acetyltransferase identical to the one of plasmid pIP501 of Streptococcus agalactiae. Erythromycin resistance is due to a 23S ribosomal RNA methyl transferase, again as found in pIP501 (ermB). The aminoglycoside resistance genes are packed in tandem as in transposon Tn5405 of Staphylococcus aureus: an aminoglycoside 6-adenyltransferase, a streptothricin acetyl transferase, and an aminoglycoside phosphotransferase.). Identical resistance genes are known from pathogens like Streptococcus pyogenes, S. agalactiae, S. aureus, Campylobacter coli, Clostridium perfringens, and Clostridium difficile. pRE25 is composed of a 30.5-kbp segment almost identical to pIP501. Of the 15 genes involved in conjugative transfer, 10 codes for putative transmembrane proteins (e.g. trsB, traC, trsF, trsJ, and trsL). The enterococcal part is joined into the pIP501 part by insertion elements IS1216V of E. faecium Tn1545 (three copies), and homologs of IS1062 (E. faecalis) and IS1485 (E. faecium). pRE25 demonstrates that enterococci from fermented food do participate in the molecular communication between Gram-positive and Gram-negative bacteria of the human and animal microflora. | 2003 | 14597005 |
| 1990 | 10 | 0.9824 | Genomic Analysis of Aeromonas veronii C198, a Novel Mcr-3.41-Harboring Isolate from a Patient with Septicemia in Thailand. The resistance of Gram-negative bacteria to colistin, mediated by plasmid-borne mcr genes, is an emerging public health concern. The complete genome sequence (4.55 Mb) of a clinical isolate of Aeromonas veronii biovar veronii obtained from a patient with septicemia was determined using short-read and long-read platforms. This isolate (C198) was found to harbor a novel mcr-3 gene, designated mcr-3.41. Isolate C198 revealed adjacent mcr-3.41 and mcr-3-like genes. It contained one chromosome and two plasmids, both of which encoded a RepB replication protein. Other antimicrobial resistance genes, including bla(cphA3), bla(OXA-12), tetA, rsmA, and adeF, were also present. Isolate C198 was resistant to amoxicillin-clavulanate, ampicillin-sulbactam and tetracycline, and showed intermediate resistance to trimethoprim-sulfamethoxazole. The isolate was susceptible to piperacillin-tazobactam, carbapenem, third-generation cephalosporins, fluoroquinolones, chloramphenicol, and aminoglycosides. Putative virulence genes in the C198 genome encoded type II, III, and VI secretion systems; type IV Aeromonas pili; and type I fimbria, flagella, hemagglutinin, aerolysin, and hemolysins. Multilocus sequence typing revealed a novel sequence type (ST), ST720 for C198. Phylogenetic analysis of the single nucleotide polymorphisms in C198 demonstrated that the strain was closely related to A. veronii 17ISAe. The present study provides insights into the genomic characteristics of human A. veronii isolates. | 2020 | 33317051 |
| 3010 | 11 | 0.9823 | Identification of mcr-1 and a novel chloramphenicol resistance gene catT on an integrative and conjugative element in an Actinobacillus strain of swine origin. The aim of this study was to characterize a mcr-1-carrying integrative and conjugative element (ICE) in a novel Pasteurellaceae-like bacteria of swine origin. The mcr-1-positive GY-402 strain, recovered from a pig fecal sample, was subjected to whole genome sequencing with the combination of Illumina Hiseq and MinION platforms. Genome-based taxonomy revealed that strain GY-402 exhibited highest ANI value (84.89 %) to Actinobacillus succinogenes, which suggested that it represented a novel Actinobacillus species. Sequence analysis revealed that mcr-1 was clustered with eight other resistance genes in the MDR region of a novel ICE element, named ICEAsp1. Inverse PCR and mating assays showed that ICEAsp1 is active and transferrable. In addition, six circular forms mediated by four ISApl1 elements were detected with different inverse PCR sets, indicating that flexible composite transposons could be formed by pairwise combinations of multiple IS copies. Cloning experiment and phylogenetic analysis revealed that the novel Cat protein, designated CatT, belongs to type-A family and confers resistance to chloramphenicol. In conclusion, this is, to the best of our knowledge, the first report of mcr-1 gene on ICE structure and also in Pasteurellaceae bacteria. The diverse composite transposons mediated by multicopy IS elements may facilitate the dissemination of different resistance genes. | 2021 | 33486327 |
| 1753 | 12 | 0.9821 | Characterization of a Linezolid- and Vancomycin-Resistant Streptococcus suis Isolate That Harbors optrA and vanG Operons. Linezolid and vancomycin are among the last-resort antimicrobial agents in the treatment of multidrug-resistant Gram-positive bacterial infections. Linezolid- and vancomycin-resistant (LVR) Gram-positive bacteria may pose severe threats to public health. In this study, three optrA- and vanG-positive Streptococcus suis strains were isolated from two farms of different cities. There were only 1 and 343 single-nucleotide polymorphisms in coding region (cSNPs) of HCB4 and YSJ7 to YSJ17, respectively. Mobilome analysis revealed the presence of vanG, erm(B), tet(O/W/32/O), and aadE-apt-sat4-aphA3 cluster on an integrative and conjugative element, ICESsuYSJ17, and erm(B), aphA3, aac(6')-aph(2″), catpC(194), and optrA on a prophage, ΦSsuYSJ17-3. ICESsuYSJ17 exhibited a mosaic structure and belongs to a highly prevalent and transferable ICESa2603 family of Streptococcus species. ΦSsuYSJ17-3 shared conserved backbone to a transferable prophage Φm46.1. A novel composite transposon, IS1216E-araC-optrA-hp-catpC(194)-IS1216E, which can be circulated as translocatable unit (TU) by IS1216E, was integrated on ΦSsuYSJ17-3. Vancomycin resistance phenotype and vanG transcription assays revealed that the vanG operon was inducible. The LVR strain YSJ17 exhibited moderate virulence in a zebrafish infection model. To our knowledge, this is the first report of LVR isolate, which is mediated by acquired resistance genes optrA and vanG operons in Gram-positive bacteria. Since S. suis has been recognized as an antimicrobial resistance reservoir in the spread of resistance genes to major streptococcal pathogens, the potential risks of disseminating of optrA and vanG from S. suis to other Streptococcus spp. are worrisome and routine surveillance should be strengthened. | 2019 | 31551963 |
| 5940 | 13 | 0.9821 | In vitro activities of spectinomycin and comparator agents against Pasteurella multocida and Mannheimia haemolytica from respiratory tract infections of cattle. OBJECTIVES: Prior to the renewal of spectinomycin licensing for veterinary uses in Germany, 154 Pasteurella multocida and 148 Mannheimia haemolytica strains from respiratory tract infections in cattle were investigated for their MICs of spectinomycin and other antimicrobial agents. The data obtained should serve as a baseline from which to judge the future development of resistance. Moreover, the in vitro activity of spectinomycin in comparison with other antimicrobials should be assessed. METHODS: MIC determination for all 302 strains was performed by the broth dilution method and evaluated according to NCCLS standards. MIC(50) and MIC(90) values were calculated. Strains resistant to spectinomycin were subjected to PCR assays for genes known to mediate spectinomycin resistance in Gram-negative and Gram-positive bacteria. RESULTS: With the exception of resistance to sulfamethoxazole in P. multocida and M. haemolytica, and resistance to ampicillin in M. haemolytica, an overall low level of resistance was detected. A total of 93.5% of the P. multocida and 98.6% of the M. haemolytica strains were susceptible to spectinomycin, with MIC(90)s of 32 mg/L. PCR analysis showed that none of the spectinomycin-resistant strains carried any of the aadA gene subtypes, nor the genes spc or aad(9). CONCLUSIONS: Prior to the renewal of spectinomycin, only a small number of spectinomycin-resistant strains was detected among bovine P. multocida and M. haemolytica. The genes responsible for spectinomycin resistance in these strains seemed to be different from those so far known to occur in other Gram-negative and Gram-positive bacteria. | 2004 | 14729757 |
| 5408 | 14 | 0.9821 | Identification and pathogenicity of an XDR Streptococcus suis isolate that harbours the phenicol-oxazolidinone resistance genes optrA and cfr, and the bacitracin resistance locus bcrABDR. One hundred and seven Streptococcus suis isolates were collected from healthy pigs or asymptomatic carriers in Jiangsu, China in 2016-2017. Thirty-eight percent of the isolates were linezolid-resistant and all carried the optrA gene. Among them, one isolate, SFJ44, was resistant to all 20 of the antibiotics tested, except for ceftiofur, and thus exhibited an extensively-drug-resistant phenotype. This isolate carried the optrA gene and the bacitracin resistance locus bcrABDR on an antibiotic-resistance-associated genomic island (ARGI1), and harboured the resistance genes cfr, aadE, sat4, spw-like, aphA3, mef(A), msr(D), erm(A)-like, erm(B), tetAB(P)', tet(M) and catQ on ARGI2∼4. The IS1216E-bcrABDR-ISEnfa1 segment showed >99.9% sequence identity to corresponding sequences from other species. The cfr gene was located on ARGI4, and two IS6 family insertion sequences, IS1216E and ISTeha2, were found upstream and downstream of cfr-ΔISEnfa5, respectively. A circular intermediate of bcrABDR-ISEnfa1 was detected, suggesting the role of ISEnfa1 in dissemination of bcrABDR. Other antibiotic resistance genes might be acquired from different Gram-positive pathogens. Infection of zebrafish showed that SFJ44 exhibited a virulence level comparable to serotype 2 hypervirulent strain SC070731, highlighting the need for surveillance of the pathogenicity of multi-drug-resistant S. suis isolates. This is the first report of the co-existence of optrA and cfr, and of the bcrABDR locus in streptococci. As it has been suggested that S. suis may act as an antibiotic resistance reservoir contributing to the spread of resistance genes to major streptococcal pathogens, the potential dissemination of these resistance genes among Gram-positive bacteria is of concern and routine surveillance should be strengthened. | 2019 | 30981924 |
| 3036 | 15 | 0.9821 | Complete nucleotide sequences of 84.5- and 3.2-kb plasmids in the multi-antibiotic resistant Salmonella enterica serovar Typhimurium U302 strain G8430. The multi-antibiotic resistant (MR) Salmonella enterica serovar Typhimurium phage type U302 strain G8430 exhibits the penta-resistant ACSSuT-phenotype (ampicillin, chloramphenicol, streptomycin, sulfonamides and tetracycline), and is also resistant to carbenicillin, erythromycin, kanamycin, and gentamicin. Two plasmids, 3.2- and 84.5-kb in size, carrying antibiotic resistance genes were isolated from this strain, and the nucleotide sequences were determined and analyzed. The 3.2-kb plasmid, pU302S, belongs to the ColE1 family and carries the aph(3')-I gene (Kan(R)). The 84.5-kb plasmid, pU302L, is an F-like plasmid and contains 14 complete IS elements and multiple resistance genes including aac3, aph(3')-I, sulII, tetA/R, strA/B, bla(TEM-1), mph, and the mer operon. Sequence analyses of pU302L revealed extensive homology to various plasmids or transposons, including F, R100, pHCM1, pO157, and pCTX-M3 plasmids and TnSF1 transposon, in regions involved in plasmid replication/maintenance functions and/or in antibiotic resistance gene clusters. Though similar to the conjugative plasmids F and R100 in the plasmid replication regions, pU302L does not contain oriT and the tra genes necessary for conjugal transfer. This mosaic pattern of sequence similarities suggests that pU302L acquired the resistance genes from a variety of enteric bacteria and underscores the importance of a further understanding of horizontal gene transfer among the enteric bacteria. | 2007 | 16828159 |
| 2019 | 16 | 0.9820 | Characterization of small plasmids carrying florfenicol resistance gene floR in Actinobacillus pleuropneumoniae and Pasteurella multocida isolates from swine in China. Actinobacillus pleuropneumoniae and Pasteurella multocida are two important bacterial pathogens in swine industry. In the present study, resistance profiles of nine commonly used antibiotics of A. pleuropneumoniae and P. multocida isolates of swine origin from different regions of China were investigated by determination of minimum inhibitory concentrations (MICs). In addition, genetic relationship of the florfenicol-resistant A. pleuropneumoniae and P. multocida isolates was determined by pulsed-field gel electrophoresis (PFGE). The genetic basis of florfenicol resistance in these isolates were explored by floR detection and whole genome sequencing. High resistance rates (>25%) of florfenicol, tetracycline and trimethoprim- sulfamethoxazole were observed for both bacteria. No ceftiofur- and tiamulin- resistant isolates were detected. Furthermore, all the 17 florfenicol-resistant isolates (nine for A. pleuropneumoniae and eight for P. multocida) were positive for floR gene. The presence of similar PFGE types in these isolates suggested that clonal expansion of some floR-producing strains occurred in the pig farms from same regions. WGS and PCR screening showed that three plasmids, named pFA11, pMAF5, and pMAF6, were the cargos of the floR genes in the 17 isolates. Plasmid pFA11 exhibited novel structure and carried several resistance genes, including floR, sul2, aacC2d, strA, strB, and bla (ROB - 1). Plasmids pMAF5 and pMAF6 were presented in A. pleuropneumoniae and P. multocida isolates from different regions, suggesting horizontal transfer of the two plasmids are important for the floR dissemination in these Pasteurellaceae pathogens. Further studies of florfenicol resistance and its transfer vectors in Pasteurellaceae bacteria of veterinary origin are warranted. | 2023 | 36793377 |
| 5386 | 17 | 0.9820 | Antibiotic resistance of lactic acid bacteria isolated from Chinese yogurts. The aim of this study was to evaluate the susceptibility of 43 strains of lactic acid bacteria, isolated from Chinese yogurts made in different geographical areas, to 11 antibiotics (ampicillin, penicillin G, roxithromycin, chloramphenicol, tetracycline, chlortetracycline, lincomycin, kanamycin, streptomycin, neomycin, and gentamycin). The 43 isolates (18 Lactobacillus bulgaricus and 25 Streptococcus thermophilus) were identified at species level and were typed by random amplified polymorphic DNA analysis. Thirty-five genotypically different strains were detected and their antimicrobial resistance to 11 antibiotics was determined using the agar dilution method. Widespread resistance to ampicillin, chloramphenicol, chlortetracycline, tetracyclines, lincomycin, streptomycin, neomycin, and gentamycin was found among the 35 strains tested. All of the Strep. thermophilus strains tested were susceptible to penicillin G and roxithromycin, whereas 23.5 and 64.7% of Lb. bulgaricus strains, respectively, were resistant. All of the Strep. thermophilus and Lb. bulgaricus strains were found to be resistant to kanamycin. The presence of the corresponding resistance genes in the resistant isolates was investigated through PCR, with the following genes detected: tet(M) in 1 Lb. bulgaricus and 2 Strep. thermophilus isolates, ant(6) in 2 Lb. bulgaricus and 2 Strep. thermophilus isolates, and aph(3')-IIIa in 5 Lb. bulgaricus and 2 Strep. thermophilus isolates. The main threat associated with these bacteria is that they may transfer resistance genes to pathogenic bacteria, which has been a major cause of concern to human and animal health. To our knowledge, the aph(3')-IIIa and ant(6) genes were found in Lb. bulgaricus and Strep. thermophilus for the first time. Further investigations are required to analyze whether the genes identified in Lb. bulgaricus and Strep. thermophilus isolates might be horizontally transferred to other species. | 2012 | 22916881 |
| 1752 | 18 | 0.9820 | Genetic Characterization of a Linezolid- and Penicillin-Resistant Enterococcus hirae Isolate Co-Harboring poxtA and pbp5fm. Linezolid and penicillin are critical for treating multidrug resistant (MDR) Gram-positive infections, but the emergence of resistance to both seriously threatens public health. Here, we first report the cocarrying poxtA (oxazolidinone resistance) and pbp5fm (β-lactam resistance) genes by the plasmid in a strain of Enterococcus hirae HDC14-2 derived from porcine. The isolate also exhibits MDR phenotypes to phenicols, oxazolidinones, tetracyclines, β-lactams, aminoglycosides, macrolides, and lincosamides. Whole-genome sequencing (WGS) revealed these resistance genes, along with tet(L), tet(M), catA, erm(B), aac(6)-aph(2"), aadE, spw, lsa(E), lnu(B), sat4, and aphA3, were clustered in a novel MDR region flanked by IS1216 elements on plasmid pHDC14-2.133K. This IS1216-bounded MDR region formed translocatable units (TUs), including an IS1216-poxtA TU that was also identified on a secondary plasmid, pHDC14-2.27K. Functional assays demonstrated the excisability and mobility of these TUs, indicating its potential ability integration into other plasmids or chromosomes. Critically, electrotransformation confirmed the transfer of pHDC14-2.27K (poxtA-carrying) to Enterococcus faecalis JH2-2, with retained TU activity and minimal fitness cost. This study provides the evidence of colocalized poxtA and pbp5fm on plasmids in enterococci, highlighting their role in disseminating pan-resistance among bacteria. Although E. hirae is not an important pathogenic bacterium to humans and animals, but its potential risk to horizontally spread of these resistance genes important in medicine still cannot be ignored. | 2025 | 40692874 |
| 4525 | 19 | 0.9818 | Integrative and Conjugative Elements (ICEs) in Pasteurellaceae Species and Their Detection by Multiplex PCR. Strains of the Pasteurellaceae bacteria Pasteurella multocida and Mannheimia haemolytica are major etiological agents of bovine respiratory disease (BRD). Treatment of BRD with antimicrobials is becoming more challenging due to the increasing occurrence of resistance in infecting strains. In Pasteurellaceae strains exhibiting resistance to multiple antimicrobials including aminoglycosides, beta-lactams, macrolides and sulfonamides, the resistance determinants are often chromosomally encoded within integrative and conjugative elements (ICEs). To gain a more comprehensive picture of ICE structures, we sequenced the genomes of six strains of P. multocida and four strains of M. haemolytica; all strains were independent isolates and eight of them were multiple-resistant. ICE sequences varied in size from 49 to 79 kb, and were comprised of an array of conserved genes within a core region and varieties of resistance genes within accessory regions. These latter regions mainly account for the variation in the overall ICE sizes. From the sequence data, we developed a multiplex PCR assay targeting four conserved core genes required for integration and maintenance of ICE structures. Application of this assay on 75 isolates of P. multocida and M. haemolytica reveals how the presence and structures of ICEs are related to their antibiotic resistance phenotypes. The assay is also applicable to other members of the Pasteurellaceae family including Histophilus somni and indicates how clustering and dissemination of the resistance genes came about. | 2018 | 29997583 |