scholarly journals Distribution of Serogroups ofNeisseria meningitidisand Antigenic Characterization of Serogroup Y Meningococci in Canada, January 1, 1999 to June 30, 2001

2002 ◽  
Vol 13 (6) ◽  
pp. 391-396 ◽  
Author(s):  
Raymond SW Tsang ◽  
Susan G Squires ◽  
Wendell D Zollinger ◽  
Fraser E Ashton

The relative frequency of serogroups ofNeisseria meningitidisassociated with meningococcal disease in Canada during the period January 1, 1999 to June 30, 2001 was examined. Of the 552 strains ofN meningitidiscollected from clinical specimens of normally sterile sites, 191 (34.6%), 276 (50.0%), 61 (11.1%) and 23 (4.2%) were identified by serological and molecular methods as serogroups B, C, Y and W135, respectively. About half (50.8%) of the serogroup Y isolates were isolated in the province of Ontario. The two most common serotypes found were 2c and 14. Most of the serogroup Y strains isolated from patients in Ontario were serotype 2c, while serotype 14 was the most common serotype associated with disease in the province of Quebec. The two most common serosubtypes found among the serogroup Y meningococci were P1.5 and P1.2,5. Laboratory findings, based on antigenic analysis, did not suggest that these serogroup Y strains arise by capsule switching from serogroups B and C strains. This study documented a higher incidence of finding serogroup Y meningococci in clinical specimens from patients in Ontario compared to the rest of Canada, and parallels the increase in serogroup Y meningococcal disease reported in some parts of the United States.

Virology ◽  
2019 ◽  
Vol 535 ◽  
pp. 279-282 ◽  
Author(s):  
John D. Neill ◽  
Beate M. Crossley ◽  
Ana C. Mosena ◽  
Julia F. Ridpath ◽  
Darrell O. Bayles ◽  
...  

Virology ◽  
1999 ◽  
Vol 256 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Carl D. Kirkwood ◽  
Jon R. Gentsch ◽  
Yasutaka Hoshino ◽  
H.Fred Clark ◽  
Roger I. Glass

Virology ◽  
2012 ◽  
Vol 422 (1) ◽  
pp. 151-160 ◽  
Author(s):  
Bo Shu ◽  
Rebecca Garten ◽  
Shannon Emery ◽  
Amanda Balish ◽  
Lynn Cooper ◽  
...  

2009 ◽  
Vol 75 (7) ◽  
pp. 1892-1900 ◽  
Author(s):  
Joseph M. Bosilevac ◽  
Michael N. Guerini ◽  
Norasak Kalchayanand ◽  
Mohammad Koohmaraie

ABSTRACT Commercially produced ground beef samples (n = 4,136) were collected from seven regions of the United States over a 24-month period (July 2005 to June 2007) and analyzed for the presence of Salmonella enterica by using methods that concurrently provided total prevalence and enumerable levels. The overall prevalence of Salmonella strains was 4.2%. Enumeration showed that 94.2% were present at levels below 2 CFU/g. Regional monthly prevalences of Salmonella strains varied from 1.8% to 6.5% but were not statistically different (P > 0.05). All Salmonella isolates were serotyped and their antibiotic susceptibilities determined and analyzed by pulsed-field gel electrophoresis (PFGE). The most common serotypes identified were Salmonella enterica serotypes Montevideo, Anatum, Muenster, and Mbandaka, with these accounting for one-half of the isolates obtained. The prevalence of multidrug-resistant (MDR) Salmonella was determined to be 0.6%. The most common MDR serotypes were Salmonella enterica serotypes Dublin, Reading, and Typhimurium. MDR strains had resistance to between 2 and 10 antibiotics. There were no regional differences in prevalence of MDR Salmonella. PFGE analysis revealed that indistinguishable XbaI and AvrII restriction digest patterns (RDPs) could be observed in isolates of the same serotype found in different regions and months of sampling. The RDPs of 19 Salmonella strains were compared to RDPs in the PulseNet USA database. Thirteen were indistinguishable from existing patterns, and the number of records for each ranged from 1 to 478. These data show that Salmonella prevalence in commercial ground beef is low and suggest that attempts to identify sources contributing to Salmonella in ground beef by serotype, antibiogram, and PFGE cannot be made without additional documented evidence.


Mycologia ◽  
2013 ◽  
Vol 105 (6) ◽  
pp. 1524-1534 ◽  
Author(s):  
Meghan A. McCormick ◽  
Larry F. Grand ◽  
Justin B. Post ◽  
Marc A. Cubeta

Plant Disease ◽  
2013 ◽  
Vol 97 (7) ◽  
pp. 873-881 ◽  
Author(s):  
G. Danies ◽  
I. M. Small ◽  
K. Myers ◽  
R. Childers ◽  
W. E. Fry

Phytophthora infestans, the causal agent of late blight disease, has been reported in the United States and Canada since the mid-nineteenth century. Due to the lack of or very limited sexual reproduction, the populations of P. infestans in the United States are primarily reproducing asexually and, thus, show a simple genetic structure. The emergence of new clonal lineages of P. infestans (US-22, US-23, and US-24) responsible for the late blight epidemics in the northeastern region of the United States in the summers of 2009 and 2010 stimulated an investigation into phenotypic traits associated with these genotypes. Mating type, differences in sensitivity to mefenoxam, differences in pathogenicity on potato and tomato, and differences in rate of germination were studied for clonal lineages US-8, US-22, US-23, and US-24. Both A1 and A2 mating types were detected. Lineages US-22, US-23, and US-24 were generally sensitive to mefenoxam while US-8 was resistant. US-8 and US-24 were primarily pathogenic on potato while US-22 and US-23 were pathogenic on both potato and tomato. Indirect germination was favored at lower temperatures (5 and 10°C) whereas direct germination, though uncommon, was favored at higher temperatures (20 and 25°C). Sporangia of US-24 released zoospores more rapidly than did sporangia of US-22 and US-23. The association of characteristic phenotypic traits with genotype enables the prediction of phenotypic traits from rapid genotypic analyses for improved disease management.


2018 ◽  
Vol 84 (23) ◽  
Author(s):  
Carlos A. Loncoman ◽  
Carol A. Hartley ◽  
Mauricio J. C. Coppo ◽  
Glenn F. Browning ◽  
Gabriela Beltrán ◽  
...  

ABSTRACT Infectious laryngotracheitis (ILTV; Gallid alphaherpesvirus 1) causes mild to severe respiratory disease in poultry worldwide. Recombination in this virus under natural (field) conditions was first described in 2012 and more recently has been studied under laboratory conditions. Previous studies have revealed that natural recombination is widespread in ILTV and have also demonstrated that recombination between two attenuated ILTV vaccine strains generated highly virulent viruses that produced widespread disease within poultry flocks in Australia. In the United States, natural ILTV recombination has also been detected, but not as frequently as in Australia. To better understand recombination in ILTV strains originating from the United States, we developed a TaqMan single nucleotide polymorphism (SNP) genotyping assay to detect recombination between two virulent U.S. field strains of ILTV (63140 and 1874c5) under experimental in vivo conditions. We also tested the capacity of the Innovax-ILT vaccine (a recombinant vaccine using herpesvirus of turkeys as a vector) and the Trachivax vaccine (a conventionally attenuated chicken embryo origin vaccine) to reduce recombination. The Trachivax vaccine prevented ILTV replication, and therefore recombination, in the trachea after challenge. The Innovax-ILT vaccine allowed the challenge viruses to replicate and to recombine, but at a significantly lower rate than in an unvaccinated group of birds. Our results demonstrate that the TaqMan SNP genotyping assay is a useful tool to study recombination between these ILTV strains and also show that vaccination can limit the number and diversity of recombinant progeny viruses. IMPORTANCE Recombination allows alphaherpesviruses to evolve over time and become more virulent. Historically, characterization of viral vaccines in poultry have mainly focused on limiting clinical disease, rather than limiting virus replication, but such approaches can allow field viruses to persist and evolve in vaccinated populations. In this study, we vaccinated chickens with Gallid alphaherpesvirus 1 vaccines that are commercially available in the United States and then performed coinoculations with two field strains of virus to measure the ability of the vaccines to prevent field strains from replicating and recombining. We found that vaccination reduced viral replication, recombination, and diversity compared to those in unvaccinated chickens, although the extent to which this occurred differed between vaccines. We suggest that characterization of vaccines could include studies to examine the ability of vaccines to reduce viral recombination in order to limit the rise of new virulent field strains due to recombination, especially for those vaccines that are known not to prevent viral replication following challenge.


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