scholarly journals Epidemiology of Rhodococcus equiStrains on Thoroughbred Horse Farms

2001 ◽  
Vol 67 (5) ◽  
pp. 2167-2175 ◽  
Author(s):  
Anna C. Morton ◽  
Angela P. Begg ◽  
Garry A. Anderson ◽  
Shinji Takai ◽  
Christoph Lämmler ◽  
...  
Keyword(s):  
Strain Distribution ◽  
Genotypic Diversity ◽  
Pulsed Field Gel Electrophoresis ◽  
Large Collection ◽  
Horse Farms ◽  
Similar Restriction ◽  
Simultaneous Infection ◽  
Different Strains ◽  
Multiple Strains ◽  
Total Diversity

ABSTRACT Pulsed-field gel electrophoresis of restriction endonuclease-digested genomic DNA from a large collection of clinical isolates of Rhodococcus equi, an important pathogen of foals, was used to compare strain distribution between farms and over time. Forty-four strains were found among 209 isolates, with 5 of these accounting for over half the isolates and the 22 strains isolated more than once accounting for 90% of the isolates. The average genotypic diversity on each farm and in each year was found to be less than the genotypic diversity of the isolates taken as a whole, with 5.2% of the total diversity being due to differences between farms and 5.5% to differences between years. A small number of strains on each farm were found to have caused at least half the clinical cases of disease, and these varied between farms and, to a lesser extent, years. Most strains were found on more than one farm, and some very similar restriction patterns were found among isolates from different continents, indicating that strains can be very widespread. Multiple strains were isolated in five of the six cases in which more than one isolate from a single foal was examined, indicating that disease may commonly be caused by simultaneous infection with multiple strains. It was concluded that there are a number of different strains of R. equi which carry the vapA gene, and these strains tend to be widespread, but individual farms tend to have particular strains associated with them.

scholarly journals Simultaneous Infection with Multiple Strains ofMycobacterium tuberculosis

2001 ◽  
Vol 33 (6) ◽  
pp. e42-e47 ◽  
Author(s):  
Christopher R. Braden ◽  
Glenn P. Morlock ◽  
Charles L. Woodley ◽  
Kammy R. Johnson ◽  
A. Craig Colombel ◽  
...  
Keyword(s):  
Ofmycobacterium Tuberculosis ◽  
Simultaneous Infection ◽  
Multiple Strains

scholarly journals A Comprehensive Method for Accurate Strain Distribution Measurement of Cell Substrate Subjected to Large Deformation

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Hong He ◽  
Rong Zhou ◽  
Yuanwen Zou ◽  
Xuejin Huang ◽  
Jinchuan Li
Keyword(s):  
Digital Image Correlation ◽  
Large Deformation ◽  
Digital Image ◽  
Strain Distribution ◽  
Large Strain ◽  
Image Correlation ◽  
Cell Substrate ◽  
Substrate Stretching ◽  
Different Strains

Cell mechanical stretching in vitro is a fundamental technique commonly used in cardiovascular mechanobiology research. Accordingly, it is crucial to measure the accurate strain field of cell substrate under different strains. Digital image correlation (DIC) is a widely used measurement technique, which is able to obtain the accurate displacement and strain distribution. However, the traditional DIC algorithm used in digital image correlation engine (DICe) cannot obtain accurate result when utilized in large strain measurement. In this paper, an improved method aiming to acquire accurate strain distribution of substrate in large deformation was proposed, to evaluate the effect and accuracy, based on numerical experiments. The results showed that this method was effective and highly accurate. Then, we carried out uniaxial substrate stretching experiments and applied our method to measure strain distribution of the substrate. The proposed method could obtain accurate strain distribution of substrate film during large stretching, which would allow researchers to adequately describe the response of cells to different strains of substrate.

scholarly journals Genotypic Profile of the Outer Membrane Proteins BabA and BabB in Clinical Isolates of Helicobacter pylori

2006 ◽  
Vol 74 (7) ◽  
pp. 4375-4378 ◽  
Author(s):  
Jeffrey C. Colbeck ◽  
Lori M. Hansen ◽  
Julie M. Fong ◽  
Jay V. Solnick
Keyword(s):  
Helicobacter Pylori ◽  
Outer Membrane Proteins ◽  
Genotypic Diversity ◽  
Blood Group Antigen ◽  
Antigen Binding ◽  
Abo Blood Group ◽  
Selective Pressures ◽  
Different Strains ◽  
Genotypic Profile ◽  
Over Time

ABSTRACT Helicobacter pylori BabA is the ABO blood group antigen binding adhesin, which has a closely related paralogue (BabB) whose function is unknown. PCR and DNA sequence analysis showed extensive genotypic diversity in babA and babB across different strains, as well as within a strain colonizing an individual patient. We hypothesize that diverse profiles of babA and babB reflect selective pressures for adhesion, which may differ across different hosts and within an individual over time.

scholarly journals Clonal Population Structure and Antimicrobial Resistance of Campylobacter jejuni in Chicken Meat from Belgium

2009 ◽  
Vol 75 (13) ◽  
pp. 4264-4272 ◽  
Author(s):  
Ihab Habib ◽  
William G. Miller ◽  
Mieke Uyttendaele ◽  
Kurt Houf ◽  
Lieven De Zutter
Keyword(s):  
Campylobacter Jejuni ◽  
Molecular Typing ◽  
Gel Electrophoresis ◽  
Clonal Complex ◽  
Genotypic Diversity ◽  
Pulsed Field Gel Electrophoresis ◽  
Chicken Meat ◽  
Clonal Population ◽  
Clonal Population Structure ◽  
Sequence Types

ABSTRACT Campylobacter jejuni is one of the most important causes of human diarrhea worldwide. In the present work, multilocus sequence typing was used to study the genotypic diversity of 145 C. jejuni isolates from 135 chicken meat preparations sampled across Belgium. Isolates were further typed by pulsed-field gel electrophoresis, and their susceptibilities to six antimicrobials were determined. Fifty-seven sequence types (STs) were identified; 26.8% of the total typed isolates were ST-50, ST-45, or ST-257, belonging to clonal complex CC-21, CC-45, or CC-257, respectively. One clonal group comprised 22% (32/145) of all isolates, originating from five different companies and isolated over seven sampling months. Additionally, 53.1% of C. jejuni isolates were resistant to ciprofloxacin, and 48.2% were resistant to tetracycline; 28.9% (42/145) of all isolates were resistant to both ciprofloxacin and tetracycline. The correlation between certain C. jejuni clonal groups and resistance to ciprofloxacin and tetracycline was notable. C. jejuni isolates assigned to CC-21 (n = 35) were frequently resistant to ciprofloxacin (65.7%) and tetracycline (40%); however, 90% (18/20) of the isolates assigned to CC-45 were pansusceptible. The present study demonstrates that certain C. jejuni genotypes recur frequently in the chicken meat supply. The results of molecular typing, combined with data on sample sources, indicate a possible dissemination of C. jejuni clones with high resistance to ciprofloxacin and/or tetracycline. Whether certain clonal groups are common in the environment and repeatedly infect Belgian broiler flocks or whether they have the potential to persist on farms or in slaughterhouses needs further investigation.

Co-infection with two different strains of Bordetella pertussis in an infant

2008 ◽  
Vol 57 (3) ◽  
pp. 388-391 ◽  
Author(s):  
Pamela K. Cassiday ◽  
Melissa Tobin-D'Angelo ◽  
J. Renee Watson ◽  
Kai-Hui Wu ◽  
Mahin M. Park ◽  
...  
Keyword(s):  
Bordetella Pertussis ◽  
Gene Sequence ◽  
Profile Analysis ◽  
23S Rrna ◽  
Rrna Gene ◽  
Pcr Rflp ◽  
23S Rrna Gene ◽  
History Of ◽  
Simultaneous Infection ◽  
Different Strains

We report co-infection with two phenotypically and genotypically distinct strains of Bordetella pertussis in an infant male hospitalized with a 2-week history of cough, paroxysms and vomiting. Colonies from the two B. pertussis phenotypes were isolated and evaluated by PFGE profile analysis, gene sequence typing and PCR-RFLP of a portion of the 23S rRNA gene. These results demonstrated simultaneous infection with two different strains of B. pertussis.

scholarly journals Spatial Distribution of Rhodopseudomonas palustris Ecotypes on a Local Scale

2003 ◽  
Vol 69 (9) ◽  
pp. 5192-5197 ◽  
Author(s):  
S. J. Bent ◽  
C. L. Gucker ◽  
Y. Oda ◽  
L. J. Forney
Keyword(s):  
Spatial Distribution ◽  
Rhodopseudomonas Palustris ◽  
Sampling Site ◽  
Clonal Diversity ◽  
Genotypic Diversity ◽  
Rrna Gene ◽  
Similarity Coefficients ◽  
16S Rrna Gene Sequences ◽  
Multiple Strains ◽  
Rank Abundance

ABSTRACT The number, spatial distribution, and significance of genetically distinguishable ecotypes of prokaryotes in the environment are poorly understood. Oda et al. (Y. Oda, B. Star, L. A. Huisman, J. C. Gottschal, and L. J. Forney, Appl. Environ. Microbiol. 69:xxx-xxx, 2003) have shown that Rhodopseudomonas palustris ecotypes were lognormally distributed along a 10-m transect and that multiple strains of the species could coexist in 0.5-g sediment samples. To extend these observations, we investigated the clonal diversity of R. palustris in 0.5-g samples taken from the corners and center of a 1-m square. A total of 35 or 36 clones were recovered by direct plating from each sample and were characterized by BOX A1R repetitive element-PCR genomic DNA fingerprinting. Isolates with fingerprint images that were ≥80% similar to each other were defined as the same genotype. Among the 178 isolates studied, 32 genotypes were identified, and each genotype contained between 1 and 40 isolates. These clusters were consistent with minor variations found in 16S rRNA gene sequences. The Shannon indices of the genotypic diversity within each location ranged from 1.08 (5 genotypes) to 2.18 (13 genotypes). Comparison of the rank abundance of genotypes found in pairs of locations showed that strains from three locations were similar to each other, with Morisita-Horn similarity coefficients ranging from 0.59 to 0.71. All comparisons involving the remaining two locations resulted in coefficients between 0 and 0.12. From these results we inferred that the patterns of ecotype diversity at the sampling site are patchy at a 1-m scale and postulated that factors such as mixing, competitive interactions, and microhabitat variability are likely to be responsible for the maintenance of the similarities between some locations and the differences between others.

scholarly journals More than one variant ofListeria monocytogenesisolated from each of two human cases of invasive listeriosis

2006 ◽  
Vol 135 (5) ◽  
pp. 854-856 ◽  
Author(s):  
W. THAM ◽  
G. LOPEZ VALLADARES ◽  
S. HELMERSSON ◽  
A. ÖSTERLUND ◽  
M.-L. DANIELSSON-THAM
Keyword(s):  
Listeria Monocytogenes ◽  
Molecular Typing ◽  
Gel Electrophoresis ◽  
Blood Cultures ◽  
Pulsed Field Gel Electrophoresis ◽  
The Other ◽  
Dna Profile ◽  
Pulsed Field ◽  
Different Strains

SUMMARYTwo variants ofListeria monocytogeneswere isolated from blood cultures from each of two patients with listeriosis. Each variant displayed a two-band difference in DNA profile from the other by pulsed-field gel electrophoresis. Although this difference in profile is insufficient to distinguish clearly between the variants, the possibility of co-infection with different strains ofL. monocytogenesneeds to be considered. We suggest that more than one colony should be selected for molecular typing to aid interpretation during investigation of the sources and routes ofListeriainfection.

scholarly journals Chromosomal Rearrangements in Salmonella enterica Serotype Typhi Affecting Molecular Typing in Outbreak Investigations

1998 ◽  
Vol 36 (7) ◽  
pp. 2123-2126 ◽  
Author(s):  
M. A. Echeita ◽  
M. A. Usera
Keyword(s):  
Molecular Typing ◽  
Salmonella Enterica ◽  
Chromosomal Rearrangements ◽  
Pulsed Field Gel Electrophoresis ◽  
Partial Digestion ◽  
Outbreak Investigations ◽  
The Stability ◽  
Different Strains ◽  
Excellent Tool ◽  
Genetic Rearrangements

Salmonella enterica serotype Typhi strains belonging to eight different outbreaks of typhoid fever that occurred in Spain between 1989 and 1994 were analyzed by ribotyping and pulsed-field gel electrophoresis. For three outbreaks, two different patterns were detected for each outbreak. The partial digestion analysis by the intron-encoded endonuclease I-CeuI of the two different strains from each outbreak provided an excellent tool for examining the organization of the genomes of epidemiologically related strains.S. enterica serotype Typhi seems to be more susceptible than other serotypes to genetic rearrangements produced by homologous recombinations between rrn operons; these rearrangements do not substantially alter the stability or survival of the bacterium. We conclude that genetic rearrangements can occur during the emergence of an outbreak.

scholarly journals Co-existence of multiple strains of two novel porcine bocaviruses in the same pig, a previously undescribed phenomenon in members of the family Parvoviridae, and evidence for inter- and intra-host genetic diversity and recombination

2011 ◽  
Vol 92 (9) ◽  
pp. 2047-2059 ◽  
Author(s):  
Susanna K. P. Lau ◽  
Patrick C. Y. Woo ◽  
Cyril C. Y. Yip ◽  
Kenneth S. M. Li ◽  
Clara T. Y. Fu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Complete Genome ◽  
Nucleotide Polymorphisms ◽  
Porcine Bocavirus ◽  
Distinct Cluster ◽  
Faecal Samples ◽  
The Family ◽  
Host Genetic ◽  
Different Strains ◽  
Multiple Strains

Despite the recent discovery of novel bocaviruses from porcine samples, their genetic evolution and diversity are poorly understood. This study reports the identification and complete genome characterization of two novel parvoviruses, porcine bocavirus 3 (PBoV3) and porcine bocavirus 4 (PBoV4), from various porcine tissues/samples, displaying marked intra- and inter-host genetic diversity, with recombination events. Bocaviruses were detected by PCR among 16.5 % (55/333) of porcine samples (lymph nodes, serum, nasopharyngeal and faecal samples) from healthy, sick or deceased pigs from farms and a slaughterhouse in Hong Kong. As marked nucleotide polymorphisms were observed in the partial VP1 sequences, complete VP1 genes from one nasopharyngeal and three faecal specimens were cloned and sequenced, which suggested the presence of two different bocaviruses and demonstrated significant intra- and inter-host genetic diversity. Complete genome sequences revealed the presence of two bocaviruses, PBoV3 and PBoV4, in a faecal and nasopharyngeal specimen, respectively, with two genotypes, PBoV4-1 and PBoV4-2, in the latter. Their genomes encoded three ORFs, characteristic of bocaviruses. Phylogenetic analysis showed that they were distantly related to other bocaviruses, forming a distinct cluster within the genus. Recombination analysis showed possible recombination events among VP1 sequences of PBoV4 strains from a faecal specimen, with two breakpoints identified (with a 68 and 71 bp region), suggesting that different strains/variants within the same host could have arisen from recombination. This is the first report describing marked sequence diversity and the co-existence of two viruses of the family Parvoviridae within the same host, which may have originated from and, in turn, facilitated recombination.

scholarly journals Intermediately virulent Rhodococcus equi isolates from pigs in Slovenia: discovery of new plasmid types and assessment of genetic diversity by pulsed-field gel electrophoresis

2009 ◽  
Vol 54 (No. 3) ◽  
pp. 111-117 ◽  
Author(s):  
M. Pate ◽  
M. Ocepek ◽  
I. Zdovc ◽  
C. Minato ◽  
Y. Ohtsu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gel Electrophoresis ◽  
Detailed Comparison ◽  
Rhodococcus Equi ◽  
Pulsed Field Gel Electrophoresis ◽  
High Genetic Diversity ◽  
Pulsed Field ◽  
Large Plasmids ◽  
Multiple Strains ◽  
Pfge Profiles

The presence of large plasmids in 30 <I>Rhodococcus equi</I> strains isolated from pig lymph nodes with granulomatous changes was investigated. Plasmid DNAs were isolated and digested with the restriction endonucleases <I>Bam</I>HI, <I>Eco</I>RI, <I>Eco</I>T22I and <I>Hind</I>III for detailed comparison and estimation of plasmid sizes. A total of nine isolates were identified as intermediately virulent (VapB-positive), harbouring large plasmids of type 5 (<I>n</I> = 5) and four new variants that we tentatively designated as type 19 (<I>n</I> = 1), 20 (<I>n</I> = 1), 21 (<I>n</I> = 1) and 24 (<I>n</I> = 1). All isolates were subjected to genotyping with pulsed-field gel electrophoresis (PFGE). High genetic diversity was observed: 21 distinct genotypes were detected; five were found in multiple isolates and the others were unique. Isolates of the same plasmid type exhibited different PFGE profiles and vice versa. In a few cases, multiple strains from certain farms were analysed, the majority of which exhibited diverse PFGE profiles. Our findings demonstrate the presence of a wide variety of <I>R. equi</I> strains even in small confined environments such as farms. This is the first molecular epidemiology study of intermediately virulent <I>R. equi</I> isolates from Slovenian pigs.

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