scholarly journals Regional variations in the population structure of Pseudomonas syringae pathovar phaseolicola from Spain are revealed by typing with PmeI pulsed-field gel electrophoresis, plasmid profiling and virulence gene complement

Microbiology ◽  
2010 ◽  
Vol 156 (6) ◽  
pp. 1795-1804 ◽  
Author(s):  
Mateo San José ◽  
M. Rosario Rodicio ◽  
M. ángeles Argudín ◽  
M. Carmen Mendoza ◽  
Ana J. González
Keyword(s):  
Population Structure ◽  
Pseudomonas Syringae ◽  
Gel Electrophoresis ◽  
Virulence Gene ◽  
Pulsed Field Gel Electrophoresis ◽  
Epidemiological Surveillance ◽  
Common Beans ◽  
Pulsed Field ◽  
Castilla Y Leon ◽  
Cluster A

One hundred and twenty pathogenic isolates of Pseudomonas syringae pv. phaseolicola recovered in Spain were subjected to biochemical and genomic typing, and investigated for virulence gene complement. Fifty-six were recovered from common beans (Phaseolus vulgaris) of the type Granja Asturiana, grown in a northern Spanish region (Asturias), and 64 from other common beans cultured in the neighbouring region of Castilla y León. Typing by PmeI digestion followed by pulsed-field gel electrophoresis revealed 27 profiles, with only three being common to both regions. Relationships between profiles distributed the isolates into two clusters: A (subdivided into subclusters A1 and A2) and B. Cluster A included all isolates from Granja Asturiana and about a quarter of the isolates from Castilla y León. Isolates from cluster A were negative for mannitol utilization and hybridized to probes for the argK–tox region responsible for phaseolotoxin production. Isolates that grouped in cluster B, which were only found in Castilla y León, were able to utilize mannitol but did not hybridize to probes for the argK–tox region. Separation of the isolates into three genomic groups, subsequently termed PphA1, PphA2 and PphB, was also supported by effector gene complement and location. In PphB, all effector genes tested (hopX1, hopF1, avrB2 and avrD1) mapped on chromosomal fragments, but faint hybridization of avrB2 with plasmids of about 40 kb was also observed. In PphA hopX1 mapped on the chromosome; in PphA1 avrB2 and avrD1 were carried on virulence plasmids (most of approx. 125 kb) and hopF1 was not detected, while in PphA2 the three genes were located on plasmids (approx. 75–160 kb). These results can be used as a framework to investigate the basis of regional variation in population structure, and for further epidemiological surveillance of P. syringae pv. phaseolicola.

scholarly journals Comparison of Virulence Gene Identification, Ribosomal Spacer PCR, and Pulsed-Field Gel Electrophoresis for Typing of Staphylococcus aureus Strains Isolated from Cases of Subclinical Bovine Mastitis in the United States

2016 ◽  
Vol 54 (7) ◽  
pp. 1871-1876 ◽  
Author(s):  
Pamela R. F. Adkins ◽  
John R. Middleton ◽  
Lawrence K. Fox
Keyword(s):  
United States ◽  
Staphylococcus Aureus ◽  
Gel Electrophoresis ◽  
Virulence Gene ◽  
The United States ◽  
Pulsed Field Gel Electrophoresis ◽  
Gene Identification ◽  
Content Type ◽  
Pulsed Field

Staphylococcus aureusis one of the most important pathogens causing contagious mastitis in dairy cattle worldwide. The objectives of this study were to determine if recently describedS. aureusgenotype B was present among previously characterized isolates from cases of bovine intramammary infection in the United States and to compare pulsed-field gel electrophoresis (PFGE) to the combination of ribosomal spacer PCR (RS-PCR) and virulence gene identification for typing ofS. aureusstrains. The hypothesis was that isolates that were previously characterized as contagious would be identified as genotype B and that the results of the two strain-typing methods would be comparable. Isolates were selected from a collection ofS. aureusisolates from eight dairy farms. Mammary quarter milk somatic cell count (SCC) andN-acetyl-β-d-gluconaminidase (NAGase) activity data were known and used to evaluate strain pathogenicity. RS-PCR was performed with conventional gel electrophoresis, and PCR was used for toxin gene identification. RS-PCR patterns were associated with a specific virulence gene pattern, as previously reported. Five RS-PCR banding patterns were identified. None of the isolates were characterized as genotype B. No association between RS-PCR types and milk SCC was found; however, NAGase activity was significantly higher in milk from mammary glands infected with RS-PCR banding type 1 (RSP type 1) than in milk from those infected with RSP type 2. The discriminatory power values were 1.0 and 0.46 for PFGE and RS-PCR, respectively. These data suggest that genotype B may have a limited geographic distribution and that PFGE is more discriminatory than RS-PCR performed with conventional gel electrophoresis for typing ofS. aureusisolates of bovine origin.

scholarly journals Streptococcus bovis Clone Causing Two Episodes of Endocarditis 8 Years Apart

1999 ◽  
Vol 37 (3) ◽  
pp. 862-863 ◽  
Author(s):  
Kathrin Mühlemann ◽  
Susanne Graf ◽  
Martin G. Täuber
Keyword(s):  
Population Structure ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Heterogeneous Population ◽  
Streptococcus Bovis ◽  
Pulsed Field

A patient had endocarditis caused by Streptococcus bovis twice 8 years apart. According to pulsed-field gel electrophoresis (PFGE) the two isolates were identical. Seven unrelated blood isolates of S. bovis yielded unique PFGE patterns. Considering this heterogeneous population structure our findings demonstrate the long-term persistence of an S. bovis clone in a patient with recurrent endocarditis.

scholarly journals Polyclonal Population Structure of Streptococcus pneumoniae Isolates in Spain Carrying mef and mef plus erm(B)

2008 ◽  
Vol 52 (6) ◽  
pp. 1964-1969 ◽  
Author(s):  
Elia Gómez G. de la Pedrosa ◽  
María-Isabel Morosini ◽  
Mark van der Linden ◽  
Patricia Ruiz-Garbajosa ◽  
Juan Carlos Galán ◽  
...  
Keyword(s):  
Population Structure ◽  
Streptococcus Pneumoniae ◽  
Diffusion Approximation ◽  
Gel Electrophoresis ◽  
Pulsed Field Gel Electrophoresis ◽  
Macrolide Resistance ◽  
Penicillin G ◽  
Geographic Locations ◽  
Pulsed Field ◽  
Multilocus Sequencing

ABSTRACT The population structure (serotypes, pulsed-field gel electrophoresis [PFGE] types, and multilocus sequencing types) of 45 mef-positive Streptococcus pneumoniae isolates [carrying mef alone (n = 17) or with the erm(B) gene n = 28)] were studied. They were selected from among all erythromycin-resistant isolates (n = 244) obtained from a collection of 712 isolates recovered from different Spanish geographic locations in the prevaccination period from 1999 to 2003. The overall rates of resistance (according to the criteria of the CLSI) among the 45 mef-positive isolates were as follows: penicillin G, 82.2%; cefotaxime, 22.2%; clindamycin, 62.2%; and tetracycline, 68.8% [mainly in isolates carrying erm(B) plus mef(E); P < 0.001]. No levofloxacin or telithromycin resistance was found. Macrolide resistance phenotypes (as determined by the disk diffusion approximation test) were 37.7% for macrolide resistance [with all but one due to mef(E)] and 62.2% for constitutive macrolide-lincosamide-streptogramin B resistance [cMLSB; with all due to mef(E) plus erm(B)]. Serotypes 14 (22.2%), 6B (17.7%), 19A (13.3%), and 19F (11.1%) were predominant. Twenty-five different DNA patterns (PFGE types) were observed. Our mef-positive isolates were grouped (by eBURST analysis) into four clonal complexes (n = 18) and 19 singleton clones (n = 27). With the exception of clone Spain9V-3, all clonal complexes (clonal complexes 6B, Spain6B-2, and Sweden15A-25) and 73.6% of singleton clones carried both the erm(B) and the mef(E) genes. The international multiresistant clones Spain23F-1 and Poland6B-20 were represented as singleton clones. A high proportion of mef-positive S. pneumoniae isolates presented the erm(B) gene, with all isolates expressing the cMLSB phenotype. A polyclonal population structure was demonstrated within our Spanish mef-positive S. pneumoniae isolates, with few clonal complexes overrepresented within this collection.

scholarly journals Population genetics ofMycobacterium tuberculosiscomplex in Scotland analysed by pulsed-field gel electrophoresis

1995 ◽  
Vol 114 (1) ◽  
pp. 153-160 ◽  
Author(s):  
E. S. Olson ◽  
K. J. Forbes ◽  
B. Watt ◽  
T. H. Pennington
Keyword(s):  
Genetic Diversity ◽  
Population Genetics ◽  
Mycobacterium Tuberculosis ◽  
Population Structure ◽  
Gel Electrophoresis ◽  
Distinct Species ◽  
Pulsed Field Gel Electrophoresis ◽  
Pulsed Field ◽  
Limited Genetic Diversity

SUMMARYThe results of typing of 121 strains in theMycobacterium tuberculosiscomplex by PFGE are presented. Every isolate from patients in Scotland over a 3-month period forM. tuberculosisand for 1 year forM. boviswere included along with several laboratory strains including those of BCG. The PFGE results suggest that the population structure of all the strains in this complex is distinctly simple with limited genetic diversity and also suggest thatM. bovisis not a distinct species.

scholarly journals Extraintestinal Pathogenic and Antimicrobial-Resistant Escherichia coli Contamination of 56 Public Restrooms in the Greater Minneapolis-St. Paul Metropolitan Area

2015 ◽  
Vol 81 (13) ◽  
pp. 4498-4506 ◽  
Author(s):  
Muhanad Mohamed ◽  
Kris Owens ◽  
Abby Gajewski ◽  
Connie Clabots ◽  
Brian Johnston ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Metropolitan Area ◽  
Gel Electrophoresis ◽  
Virulence Gene ◽  
Pulsed Field Gel Electrophoresis ◽  
Ecological Data ◽  
Content Type ◽  
Pulsed Field ◽  
E Coli ◽  
Sequence Types

ABSTRACTHow extraintestinal pathogenicEscherichia coli(ExPEC) and antimicrobial-resistantE. colidisseminate through the population is undefined. We studied public restrooms for contamination withE. coliand ExPEC in relation to source and extensively characterized theE. coliisolates. For this, we cultured 1,120 environmental samples from 56 public restrooms in 33 establishments (obtained from 10 cities in the greater Minneapolis-St. Paul, MN, metropolitan area in 2003) forE. coliand compared ecological data with culture results. Isolates underwent virulence genotyping, phylotyping, clonal typing, pulsed-field gel electrophoresis (PFGE), and disk diffusion antimicrobial susceptibility testing. Overall, 168 samples (15% from 89% of restrooms) fluoresced, indicating presumptiveE. coli: 25 samples (2.2% from 32% of restrooms) yieldedE. coliisolates, and 10 samples (0.9% from 16% of restrooms) contained ExPEC. Restroom category and cleanliness level significantly predicted only fluorescence, gender predicted fluorescence andE. coli, and feces-like material and toilet-associated sites predicted all three endpoints. Of the 25E. coliisolates, 7 (28%) were from phylogenetic group B2(virulence-associated), and 8 (32%) were ExPEC. ExPEC isolates more commonly represented group B2 (50% versus 18%) and had significantly higher virulence gene scores than non-ExPEC isolates. Six isolates (24%) exhibited ≥3-class antibiotic resistance, 10 (40%) represented classic human-associated sequence types, and one closely resembled reference human clinical isolates by pulsed-field gel electrophoresis. Thus,E. coli, ExPEC, and antimicrobial-resistantE. colisporadically contaminate public restrooms, in ways corresponding with restroom characteristics and within-restroom sites. Such restroom-sourceE. colistrains likely reflect human fecal contamination, may pose a health threat, and may contribute to population-wide dissemination of such strains.

Pulsed-Field Gel Electrophoresis Used To Investigate Genetic Diversity of Haemophilus influenzae Type b Isolates in Australia Shows Differences between Aboriginal and Non-Aboriginal Isolates

1999 ◽  
Vol 37 (5) ◽  
pp. 1524-1531 ◽  
Author(s):  
Patricia Ezekiel Moor ◽  
Peter C. Collignon ◽  
Gwendolyn L. Gilbert
Keyword(s):  
Population Structure ◽  
Haemophilus Influenzae ◽  
Gel Electrophoresis ◽  
Strong Association ◽  
Pulsed Field Gel Electrophoresis ◽  
Haemophilus Influenzae Type ◽  
Type B ◽  
Pulsed Field ◽  
Rflp Type ◽  
Aboriginal Children

We used pulsed-field gel electrophoresis to study the epidemiology and population structure of Haemophilus influenzae type b. DNAs from 187 isolates recovered between 1985 and 1993 from Aboriginal children (n = 76), non-Aboriginal children (n = 106), and non-Aboriginal adults (n = 5) in urban and rural regions across Australia were digested with the SmaI restriction endonuclease. Patterns of 13 to 17 well-resolved fragments (size range, ∼8 to 500 kb) defining 67 restriction fragment length polymorphism (RFLP) types were found. Two types predominated. One type (n = 37) accounted for 35 (46%) of the isolates from Aboriginals and 2 (2%) of the isolates from non-Aboriginals, and the other type (n = 41) accounted for 2 (3%) of the isolates from Aboriginals and 39 (35%) of the isolates from non-Aboriginals. Clustering revealed seven groups at a genetic distance of ∼50% similarity in a tree-like dendrogram. They included two highly divergent groups representing 50 (66%) isolates from Aboriginals and 6 (5%) isolates from non-Aboriginals and another genetically distinct group representing 7 (9%) isolates from Aboriginals and 81 (73%) isolates from non-Aboriginals. The results showed a heterogeneous clonal population structure, with the isolates of two types accounting for 42% of the sample. There was no association between RFLP type and the diagnosis of meningitis or epiglottitis, age, sex, date of collection, or geographic location, but there was a strong association between the origin of isolates from Aboriginal children and RFLP type F2a and the origin of isolates from non-Aboriginal children and RFLP type A8b. The methodology discriminated well among the isolates (D = 0.91) and will be useful for the monitoring of postvaccine isolates of H. influenzae type b.

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