Publications

TitleAbstractYear
Filter
PMID
Filter
genome-wide molecular dissection of serotype m3 group a streptococcus strains causing two epidemics of invasive infections.molecular factors that contribute to the emergence of new virulent bacterial subclones and epidemics are poorly understood. we hypothesized that analysis of a population-based strain sample of serotype m3 group a streptococcus (gas) recovered from patients with invasive infection by using genome-wide investigative methods would provide new insight into this fundamental infectious disease problem. serotype m3 gas strains (n = 255) cultured from patients in ontario, canada, over 11 years and repre ...200415282372
risk for severe group a streptococcal disease among patients' household contacts.from january 1997 to april 1999, we determined attack rates for cases of invasive group a streptococcal (gas) disease in household contacts of index patients using data from active bacterial core surveillance sites. of 680 eligible index-patient households, 525 (77.2%) were enrolled in surveillance. of 1,514 household contacts surveyed, 127 (8.4%) sought medical care, 24 (1.6%) required hospital care, and none died during the 30-day reference period. one confirmed gas case in a household contact ...200312702224
m types of group a streptococcal isolates submitted to the national centre for streptococcus (canada) from 1993 to 1999.the national centre for streptococcus (ncs) (canada) determined the group a streptococcal (gas) m types of 4,760 canadian isolates submitted between 1993 and 1999 by classic serotyping. the 10 most frequently identified m types were m1 (26.4%), m12 (9.8%), m28 (8.9%), m3 (6.8%), m4 (6.2%), m11 (4.8%), m89 (3.1%), m6 (3.0%), m2 (2.6%), and m77 (1.9%). nontypeable isolates accounted for 15.4% of the collection. the province of ontario submitted 51.1% of the isolates, followed by quebec (21.2%) and ...200212454137
clinical and epidemiologic features of group a streptococcal pneumonia in ontario, canada.since the 1960s, group a streptococcus (gas) has accounted for less than 1% of cases of community-acquired pneumonia. during the past 2 decades there has been a resurgence of invasive gas infection, but no large study of gas pneumonia has been performed.200312588207
emergence of macrolide resistance in throat culture isolates of group a streptococci in ontario, canada, in 2001.of 500 group a streptococci isolated from pharyngeal swabs, 72 (14.4%) were macrolide resistant, compared to 2.1% in 1997. of these, 66 (92%) were of the m phenotype and 6 (8.3%) were of the mls phenotype. pulsed-field gel electrophoresis found that two clones, with patterns identical to those of serotypes m1 and m4, accounted for 19.4 and 68.1% of the macrolide-resistant isolates, respectively.200312821502
mass antibiotic treatment for group a streptococcus outbreaks in two long-term care facilities. 200314609461
effect on antibiotic prescribing of repeated clinical prompts to use a sore throat score: lessons from a failed community intervention study.infections with group a streptococcus (gas) occur in 10% to 20% of patients with sore throats, whereas antibiotics are prescribed 50% of the time. clinical scoring rules can more accurately predict the likelihood of gas infection, but whether family physicians will adopt such approaches is unclear. this study sought to determine whether repeated clinical prompts to use a scoring approach could help family physicians lower antibiotic use in patients with a sore throat.200211978257
severe group a streptococcal soft-tissue infections in ontario: 1992-1996.a prospective, population-based, surveillance study of invasive soft-tissue infections due to group a streptococci was conducted in ontario, canada, from 1992 through 1996. demographic and clinical information was obtained by patient interview and chart review. isolates were characterized by m protein and t agglutination typing. the incidence of necrotizing fasciitis (nf) increased from 0.08 cases per 100,000 population in 1992 to 0.49 cases per 100,000 population in 1995. the case-fatality rate ...200211797171
invasive group a streptococcal disease in children and association with varicella-zoster virus infection. ontario group a streptococcal study group.to describe the incidence and clinical features of invasive group a streptococcal (gas) disease in children in ontario and determine the risk of invasive gas infection following chickenpox.200010799624
risk of invasive streptococcal disease. 19989846773
invasive group a streptococcal infections in ontario, canada. ontario group a streptococcal study group.several reports suggest that the incidence of invasive group a streptococcal infections, including streptococcal toxic shock syndrome and necrotizing fasciitis, is increasing.19968684408
a cluster of surgical wound infections due to unrelated strains of group a streptococci.group a streptococci account for less than 1% of all surgical wound infections but are an important cause of nosocomial outbreaks. we report here a cluster of four group a streptococcal infections that occurred within an 11-day period on a single surgical service. the index case presented with toxic shock-like syndrome. epidemiologic investigation did not identify any relationship between infections. restriction endonuclease analysis and m and t typing found the four isolates to be unrelated. re ...19938496580
novel superantigens from streptococcal toxic shock syndrome streptococcus pyogenes isolates. 19979331707
population-based surveillance for group a streptococcal necrotizing fasciitis: clinical features, prognostic indicators, and microbiologic analysis of seventy-seven cases. ontario group a streptococcal study.to determine the incidence of group a streptococcal necrotizing fasciitis in ontario, canada, and to describe the clinical features, outcome, and microbiologic characteristics of this infection.19979236481
invasive group a streptococcal infections. 19979019655
severe invasive group a streptococcal infections in ontario, canada: 1987-1991.during the past few years, there has been an apparent increase in serious infections due to group a streptococci (gas) worldwide. we describe our experience with severe invasive gas infections in ontario, canada, during the past 5 years (february 1987 through december 1991). a case was defined as the isolation of gas from blood or normally sterile tissue in association with hypotension (systolic blood pressure, < 90 mm hg). fifty cases were identified in patients ranging in age from 4 to 100 yea ...19938329511
temporal variation in bacterial disease frequency: molecular population genetic analysis of scarlet fever epidemics in ottawa and in eastern germany.in an effort to understand the molecular genetic basis of temporal variation in frequency and severity of bacterial disease, genetic relationships among strains of streptococcus pyogenes that caused scarlet fever epidemics in canada in the early 1940s and in eastern germany in the 1960s to 1980s were studied. application of multilocus enzyme electrophoresis and comparative sequencing of the gene (spea) encoding streptococcal pyrogenic exotoxin a (scarlet fever toxin) revealed that new waves of s ...19938440944
severe group a streptococcal disease--southern ontario. ontario streptococcal study group. 19911934142
apparent lower rates of streptococcal toxic shock syndrome and lower mortality in children with invasive group a streptococcal infections compared with adults.since 1985 there have been worldwide reports of increases in severe invasive group a streptococcal (igas) infections. we reviewed the charts of all children with igas infections (defined as isolation of group a streptococcus from a normally sterile site) presenting to our institution over a 7-year period (january, 1985, to december, 1991) and the literature. streptococcal toxic shock syndrome required hypotension and multisystem organ involvement. twenty-four patients (mean age, 4.96 +/- 4.4 yea ...19948170732
severe group a streptococcal disease--toronto, ontario. 19902073701
the role of fomites in the transmission of vaginitis.a role for fomites such as toilet seats in the transmission of vaginitis has never been proved or disproved. a compilation of clinical data from a university community showed that the organisms found in vaginal cultures of patients with vaginitis were, in order of frequency. candida albicans, escherichia coli, beta-hemolytic streptococci, hemophilus vaginalis and trichomonas vaginalis. in a concurrent bacteriologic survey of washroom fixtures, staphylococci and other micrococci were isolated mos ...19751092449
hospital-acquired invasive group a streptococcal infections in ontario, canada, 1992-2000.a significant proportion of invasive group a streptococcal infections are hospital acquired. no large, prospective studies have characterized this subgroup of cases and evaluated the risk of transmission in hospitals.200516007530
summaries for patients. invasive streptococcal infections in hospitals in ontario, canada, 1992 to 2000. 200717709756
surveillance for hospital outbreaks of invasive group a streptococcal infections in ontario, canada, 1992 to 2000.streptococcus pyogenes can cause severe disease in the individual patient and dramatic hospital outbreaks.200717709757
outbreak of invasive group a streptococcal disease in two hospitals, ontario, 2003. 200818800411
morbidity and mortality of patients with invasive group a streptococcal infections admitted to the icu.to describe the clinical features and outcome of patients with invasive group a streptococcal (gas) infections admitted to the icu.200617166982
prevalence and characterization of invasive isolates of streptococcus pyogenes with reduced susceptibility to fluoroquinolones.fluoroquinolone susceptibility testing was performed on invasive group a streptococcus isolates from 1992-1993 and 2003 from ontario, canada. none were nonsusceptible to levofloxacin. two of 153 (1.3%) from 1992-1993 and 7 of 160 (4.4%) from 2003 had a levofloxacin mic of 2 mug/ml; all nine had parc mutations, and eight were serotype m6.200515855546
epidemic of group a streptococcus m/emm59 causing invasive disease in canada.the incidence of invasive group a streptococcus (gas) disease can vary over time and geographic region, possibly reflecting the population's susceptibility to particular strains but also variation in the predominant m/emm types. canadian surveillance documented an epidemic of an uncommon m/emm59 type from 2006 to 2009.201021034198
prevalence and mechanisms of macrolide resistance in clinical isolates of group a streptococci from ontario, canada.a total of 3,205 group a streptoccal isolates were collected in 1997 through a private laboratory which serves community physicians in southern ontario and which represents a population base of 6 million people. nonsusceptibility to erythromycin was detected for 67 (2.1%) isolates both by disk diffusion and by broth microdilution. of these, 47 (70%) were susceptible to clindamycin and were found by pcr to possess the mef gene. of the other 20 strains, 18 and 2 showed inducible and constitutive r ...199910471555
growing number of "jim henson's" disease cases worries ontario doctors. 19911998936
molecular complexity of successive bacterial epidemics deconvoluted by comparative pathogenomics.understanding the fine-structure molecular architecture of bacterial epidemics has been a long-sought goal of infectious disease research. we used short-read-length dna sequencing coupled with mass spectroscopy analysis of snps to study the molecular pathogenomics of three successive epidemics of invasive infections involving 344 serotype m3 group a streptococcus in ontario, canada. sequencing the genome of 95 strains from the three epidemics, coupled with analysis of 280 biallelic snps in all 3 ...201020142485
cooking with gas. 201020234375
the epidemiology, antibiotic resistance and post-discharge course of peritonsillar abscesses in london, ontario.peritonsillar abscesses (pta) are a common complication of tonsillitis. recent global epidemiological data regarding ptas have demonstrated increasing antimicrobial resistance patterns. no similar studies have been conducted in canada and no canadian study has examined the post-discharge course of treated patients.201323663820
severe invasive group a streptococcal infections in ontario, 1990-1994. 19947920359
mortality in patients with necrotizing fasciitis.the prognostic factors that determine outcome in patients with necrotizing fasciitis remain poorly understood. the aim of this study was to analyze the variables that affect the mortality and morbidity of patients with necrotizing fasciitis and to create a simple method for estimating the probability of mortality.200717440360
Displaying items 1 - 35 of 35