scholarly journals Characterization of tetracycline and erythromycin resistance determinants in Treponema denticola.

1996 ◽  
Vol 40 (7) ◽  
pp. 1690-1694 ◽  
Author(s):  
M C Roberts ◽  
W O Chung ◽  
D E Roe
Keyword(s):  
Host Range ◽  
Enterococcus Faecalis ◽  
Blot Hybridization ◽  
Southern Blot Hybridization ◽  
Culture Collection ◽  
Treponema Denticola ◽  
Erythromycin Resistance ◽  
Resistance Determinants ◽  
Pcr Assays

Treponema denticola isolates were evaluated for the presence of known tetracycline and erythromycin resistance determinants by Southern blot hybridization of whole-cell DNA and PCR assays. We examined all isolates available, which included 12 clinical and 4 American Type Culture Collection isolates. Two isolates carried the Tet B determinant, five isolates carried both the Tet B and Erm F determinants, seven isolates carried the Erm F determinant, and two did not carry any of the Tet or Erm determinants tested. Both the Tet B and Erm F determinants appeared to be associated with the chromosome. Neither of the two T. denticola donors tested could transfer the Tet B determinant, but three of four T. denticola tested transferred the Erm F determinant to an Enterococcus faecalis recipient. This extends the host range of both the tetB and ermF genes into the genus Treponema.

scholarly journals Characterization of two BHV-4 strains isolated in the Czech Republic

2010 ◽  
Vol 55 (No. 3) ◽  
pp. 106-112 ◽  
Author(s):  
V. Fichtelova ◽  
K. Kovarcik
Keyword(s):  
Reference Strain ◽  
Fragment Size ◽  
Blot Hybridization ◽  
Size Variation ◽  
Southern Blot Hybridization ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
The Czech Republic ◽  
Herpesvirus 4

This study describes the isolation of bovine herpesvirus 4 (BHV-4) from the respiratory tract of animals suffering from respiratory disease. DNA of new isolates, CH and Ni, was cleaved with <I>Bam</I>HI, <I>Eco</I>RI and <I>Hind</I>III in restriction enzyme analysis and the fragments were identified by co-migration with the restriction profile of the reference strain Movar 33/63 cleaved with the appropriate endonuclease. Typical profiles with polyrepetitive DNA (prDNA) fragments were detected. In order to localize the size variation within the obtained digestion fragments, Southern blot hybridization was performed. Differences between the isolates CH, Ni were localized in both the prDNAs and the unique central part of the genome and were restricted to fragment size variation.

Characterization of a vancomycin-resistant Enterococcus faecium isolate and a vancomycin-susceptible E. faecium isolate from the same blood culture

2020 ◽  
Author(s):  
Kyriaki Xanthopoulou ◽  
Julia Wille ◽  
Janine Zweigner ◽  
Kai Lucaßen ◽  
Thorsten Wille ◽  
...  
Keyword(s):  
Blood Culture ◽  
Enterococcus Faecium ◽  
Core Genome ◽  
Blot Hybridization ◽  
Southern Blot Hybridization ◽  
Vana Gene ◽  
Plasmid Analysis ◽  
Vancomycin Resistant ◽  
Faecium Isolate

Abstract Objectives To characterize two Enterococcus faecium isolates with different resistance phenotypes obtained from the same blood culture. Methods The isolates were identified by MALDI-TOF MS and antimicrobial susceptibility testing (AST) was performed using a VITEK® 2 AST P592 card and Etest. WGS was performed on the MiSeq and MinION sequencer platforms. Core-genome MLST (cgMLST) and seven-loci MLST were performed. Plasmid analysis was performed using S1-PFGE followed by Southern-blot hybridization. Results Both E. faecium isolates were ST203. AST revealed that one was a vancomycin-resistant E. faecium (VREfm) isolate and the other was a vancomycin-susceptible E. faecium (VSEfm) isolate. The VREfm isolate harboured the vanA gene cluster as part of a Tn1546-type transposon encoded on a 49 kb multireplicon (rep1, rep2 and rep7a) plasmid (pAML0157.1). On the same plasmid, ant(6)-Ia, cat-like and erm(B) were encoded. The VSEfm isolate harboured a rep2 plasmid (pAML0158.1), 12 kb in size, which was present in full length as part of pAML0157.1 from the VREfm isolate. The vanA-encoding pAML0157.1 was a chimera of the rep2 pAML0158.1 and a second DNA segment harbouring vanA, ant(6)-Ia, erm(B) and cat-like, as well as the replicons rep1 and rep7a. By cgMLST analysis, the VREfm and VSEfm isolates were identical. Conclusions Our results demonstrate that the VREfm and VSEfm blood culture isolates represented ST203 and were identical. The investigated heterogeneous resistance phenotypes resulted from the acquisition or loss of plasmid segments in the enterococcal isolates. These data illustrate that mobile genetic elements may contribute to the spread of vancomycin resistance among enterococci and to the genotypic and phenotypic variation within clonal isolates.

Isolation and characterization of genetic expression and secretion signals from Enterococcus faecalis through the use of broad-host-range α-amylase probe vectors

Gene ◽  
1992 ◽  
Vol 118 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Pascal Hols ◽  
Alain Baulard ◽  
Dominique Garmyn ◽  
Brigitte Delplace ◽  
Stéphane Hogan ◽  
...  
Keyword(s):  
Host Range ◽  
Enterococcus Faecalis ◽  
Broad Host Range ◽  
Genetic Expression ◽  
Isolation And Characterization

Characterization of the Opisthorchis viverrini genome

1991 ◽  
Vol 65 (1) ◽  
pp. 51-54 ◽  
Author(s):  
R. Sermswan ◽  
S. Mongkolsuk ◽  
S. Sirisinha
Keyword(s):  
Southern Blot ◽  
Genomic Dna ◽  
Blot Hybridization ◽  
Restriction Enzymes ◽  
Southern Blot Hybridization ◽  
Fasciola Gigantica ◽  
Opisthorchis Viverrini ◽  
Repeated Dna ◽  
Dna Elements

ABSTRACTThe methylations of trematode genomic DNA were analyzed using restriction enzymes and Southern blot hybridization. Restriction enzymes MspI, HpaII, HhaI were used to probe CpG methylation while MboI, Sau3A, DpnI were used for A methylation. The results revealed that Opisthorchis viverrini, Fasciola gigantica and Gigantocotyle siamensis had neither CpG nor A methylations. The presence of highly repeated DNA elements was also demonstrated in O. viverrini genomic DNA.

scholarly journals Characterization of plasmid-mediated quinolone resistance by the qnrS gene in Escherichia coli isolated from healthy chickens and pigs

2009 ◽  
Vol 54 (No. 10) ◽  
pp. 473-482 ◽  
Author(s):  
H.-C. Kuo ◽  
C.-C. Chou ◽  
C. Tu ◽  
S.-R. Gong ◽  
C.-L. Han ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Blot Hybridization ◽  
Southern Blot Hybridization ◽  
Quinolone Resistance ◽  
E Coli ◽  
Sequence Variations ◽  
Southern Blot Hybridization Analysis ◽  
Ciprofloxacin Resistance ◽  
Polymerase Chain

The prevalence of <I>qnr</I> and <I>qepA</I> genes in 660 <I>Escherichia coli</I> isolates was investigated in healthy animals from 30 pig farms and 30 chicken farms in Taiwan from January 2005 to February 2006 by the polymerase chain reaction. The <I>qnrS</I> gene, but not <I>qnrA, qnrB, </I> and <I>qepA</I> were detected in 12/360 pig isolates (3.33%) and in 6/300 chicken isolates (2%). Southern blot hybridization analysis indicated that <I>qnrS</I> was located on plasmids ranging in size from 50–165 kb. Eleven of the 18 <I>qnrS</I> positive isolates which showed a high ciprofloxacin resistance phenotype (minimum inhibitory concentration ≥ 8 mg/l) also had amino acid sequence variations in chromosomal quinolone resistance-determining regions of <I>gyrA</I> and <I>parC</I>. Only two <I>qnrS</I>-positive isolates carried the <I>aac(6’)-Ib-cr</I>variant that mediates FQ acetylation. For the high percentage resistance of cephalosporins, the<I> bla</I><sub>CTX-M</sub> gene was also examined in <I>qnrS</I>-positive isolates. The <I>bla</I><sub>CTX-M</sub> gene was detected in fifteen isolates (15/18, 83.3%) of which 12 isolates were <I>bla</I><sub>CTX-M-1</sub> and three isolates were <I>bl</I><sub>CTX-M-15</sub>. This study demonstrated a close linkage between the <I>qnrS</I> gene and <I>bla</I><sub>CTX-M-1</sub>, suggesting CTX-M and Qnr-based mechanisms might be co-emerging in <I>E. coli</I> strains isolated from healthy chickens and pigs under selective pressure of quinolone and cephalosporine administration.

scholarly journals Differences in Virulence and Genomic Features of Strains of ‘Candidatus Phytoplasma mali’, the Apple Proliferation Agent

2007 ◽  
Vol 97 (8) ◽  
pp. 964-970 ◽  
Author(s):  
Erich Seemüller ◽  
Bernd Schneider
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
Blot Hybridization ◽  
Pcr Amplification ◽  
Restriction Enzymes ◽  
Southern Blot Hybridization ◽  
Apple Proliferation ◽  
Candidatus Phytoplasma Mali ◽  
Polymerase Chain

Root and shoot samples from 24 symptomatic or nonsymptomatic apple trees infected with ‘Candidatus Phytoplasma mali’ were collected at different locations in Germany and France and used to inoculate rootstock M11 top grafted with cv. Golden Delicious. Inoculated trees were monitored over a 12-year period for apple proliferation (AP) symptoms and categorized as not or slightly, moderately, or severely affected. Based on symptomatology, the phytoplasma strains were defined as being avirulent to mildly, moderately, or highly virulent. Determination of phytoplasma titers by quantitative polymerase chain reaction (PCR) with DNA from roots revealed similar phytoplasma concentrations in all virulence groups. Molecular characterization of the strains by differential PCR amplification with five sets of primers resulted in 13 profiles. Six strains that were maintained in periwinkle and tobacco were molecularly characterized in more detail. The genome sizes of these strains as determined by pulsed-field gel electrophoresis using yeast chromosomes as size references ranged between 640 and 680 kb. Cleavage of the chromosome with the rare cutting restriction enzymes ApaI, BamHI, BssHII, MluI, and SmaI resulted in macro fragment patterns distinctly different in all strains. Similar results were obtained by Southern blot hybridization with three probes derived from strain AT. Differential PCR amplification at an annealing temperature of 52°C using eight primer pairs derived from strain AT revealed heterogeneity of target sequences among all strains. Based on these results, there is considerable variability in virulence and genomic traits in ‘Ca. P. mali’. However, correlations between molecular markers and virulence or phytoplasma titer could not be identified.

scholarly journals Phenotypic and molecular characterization of Vibrio cholerae O1 isolated in Samutsakorn, Thailand before, during and after the emergence of V. cholerae O139

1998 ◽  
Vol 121 (2) ◽  
pp. 259-268 ◽  
Author(s):  
A. DALSGAARD ◽  
O. SERICHANTALERGS ◽  
A. FORSLUND ◽  
C. PITARANGSI ◽  
P. ECHEVERRIA
Keyword(s):  
Vibrio Cholerae ◽  
Blot Hybridization ◽  
Southern Blot Hybridization ◽  
Pulsed Field Gel Electrophoresis ◽  
Port City ◽  
Pfge Typing ◽  
Vibrio Cholerae O1 ◽  
Low Levels ◽  
Identical Strain

Seventy clinical strains of Vibrio cholerae O1 isolated from 1982–96 in Samutsakorn, a port city 30 km southwest of Bangkok where cholera occurs at low levels with regular seasonality, were characterized to investigate if there were any differences among the O1 strains isolated before, during and after the O139 epidemic. Pulsed-field gel electrophoresis (PFGE) typing, ribotyping and southern blot hybridization with a cholera toxin probe (CT genotyping) demonstrated several genotypes among O1 strains isolated before the emergence of V. cholerae O139. However, O1 strains isolated during and after the advent of O139 showed identical ribotypes which were distinctly different from the types identified in strains isolated before the emergence of O139. Ribotypes identified in strains during and after the advent of O139 were also demonstrated by O1 strains isolated immediately before the emergence of O139. Considering the seasonality of cholera in Samutsakorn, the identical ribotype and CT genotype and the closely related PFGE types shown by all O1 strains isolated during and after the appearance of O139 is remarkable and suggest that the V. cholerae O1 strain may reemerge from an environmental source. A subgroup of V. cholerae O1 strains isolated before the emergence of the O139 epidemic had a ribotype identical to a type demonstrated by O139 strains isolated in Thailand. Our results support similar findings in Bangladesh and India that a distinct O1 strain appeared during the O139 epidemic. However, compared with the apparent identical strain which replaced O139 in Bangladesh and India, the emerged O1 strain in Samutsakorn showed a different ribotype and CT genotype.

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