PubMed Health⌕ Search

Biomedical subjects

F Jamieson

Publications and source records attributed to F Jamieson.

At least 19 recordsLinked to original sources
PubMed2006

Detection of severe acute respiratory syndrome coronavirus in stool specimens by commercially available real-time reverse transcriptase PCR assays.

Three commercially available real-time reverse transcriptase PCR assays (the Artus RealArt HPA coronavirus LightCycler, the Artus RealArt HPA coronavirus Rotor-Gene, and the EraGen severe acute respiratory syndrome coronavirus POL assay) and three RNA extraction methodologies were evaluated for the detection of severe acute respiratory syndrome coronavirus RNA from 91 stool specimens. The assays' sensitivities were highest (58% to 75%) for specimens obtained 8 to 21 days after symptom onset. The assays were less sensitive when specimens were obtained less than 8 days or more than 21 days after the onset of symptoms. All assays were 100% specific.

Feces↗
PubMed2006

Genotype and subtype analyses of Cryptosporidium isolates from dairy calves and humans in Ontario.

To assess the importance of dairy cattle as a source of human Cryptosporidium infections in Ontario, Canada, 44 Cryptosporidium isolates from neonatal dairy calves and 11 from sporadic human cases of cryptosporidiosis in the province were genotyped by PCR-RFLP analyses of the Cryptosporidium oocyst wall protein (COWP) and 18S rRNA genes. Isolates were also subtyped by sequence analysis of the 60-kDa glycoprotein (GP60) gene. All bovine isolates successfully subtyped belonged to Cryptosporidium parvum subtype family (allele) IIa. Seven subtypes of this family were identified among the bovine isolates. Four human isolates were Cryptosporidium hominis, of alleles Ia, Id, and Ie. Of the remaining seven human specimens, four were C. parvum allele IIa, two were C. parvum of an undetermined subtype, and one was identified as Cryptosporidium cervine genotype. Three of the C. parvum isolates from humans were the same subtypes as isolates from the calves. These findings suggest that cattle and other ruminants may be a source of sporadic human infections in Ontario. This is the first published description of Cryptosporidium genotypes and subtypes in Ontario, and is the second published report of human infection with Cryptosporidium cervine genotype.

Animals↗
PubMed2006

Multicenter comparison of nucleic acid extraction methods for detection of severe acute respiratory syndrome coronavirus RNA in stool specimens.

The emergence of a novel coronavirus (CoV) as the cause of severe acute respiratory syndrome (SARS) catalyzed the development of rapid diagnostic tests. Stool samples have been shown to be appropriate for diagnostic testing for SARS CoV, although it has been recognized to be a heterogeneous and difficult sample that contains amplification inhibitors. Limited information on the efficiency of extraction methods for the purification and concentration of SARS CoV RNA from stool samples is available. Our study objectives were to determine the optimal extraction method for SARS CoV RNA detection and to examine the effect of increased specimen volume for the detection of SARS CoV RNA in stool specimens. We conducted a multicenter evaluation of four automated and four manual extraction methods using dilutions of viral lysate in replicate mock stool samples, followed by quantitation of SARS CoV RNA using real-time reverse transcriptase PCR. The sensitivities of the manual methods ranged from 50% to 100%, with the Cortex Biochem Magazorb method, a magnetic bead isolation method, allowing detection of all 12 positive samples. The sensitivities of the automated methods ranged from 75% to 100%. The bioMérieux NucliSens automated extractor and miniMag extraction methods each had a sensitivity of 100%. Examination of the copy numbers detected and the generation of 10-fold dilutions of the extracted material indicated that a number of extraction methods retained inhibitory substances that prevented optimal amplification. Increasing the volume of sample input did improve detection. This information could be useful for the extraction of other RNA viruses from stool samples and demonstrates the need to evaluate extraction methods for different specimen types.

Feces↗
PubMed2005

An international outbreak of salmonellosis associated with raw almonds contaminated with a rare phage type of Salmonella enteritidis.

During the winter of 2000 to 2001, an outbreak due to Salmonella Enteritidis (SE) phage type 30 (PT30), a rare strain, was detected in Canada. The ensuing investigation involved Canadian and American public health and food regulatory agencies and an academic research laboratory. Enhanced laboratory surveillance, including phage typing and pulsed-field gel electrophoresis, was used to identify cases. Case questionnaires were administered to collect information about food and environmental exposures. A case-control study with 16 matched case-control pairs was conducted to test the hypothesis of an association between raw whole almond consumption and infection. Almond samples were collected from case homes, retail outlets, and the implicated processor, and environmental samples were collected from processing equipment and associated farms for microbiological testing. One hundred sixty-eight laboratory-confirmed cases of SE PT30 infection (157 in Canada, 11 in the United States) were identified between October 2000 and July 2001. The case-control study identified raw whole almonds as the source of infection (odds ration, 21.1; 95% confidence interval, 3.6 to infinity). SE PT30 was detected in raw whole natural almonds collected from home, retail, distribution, and warehouse sources and from environmental swabs of processing equipment and associated farmers' orchards. The frequent and prolonged recovery of this specific organism from a large agricultural area was an unexpected finding and may indicate significant diffuse contamination on these farms. Identification of almonds as the source of a foodborne outbreak is a previously undocumented finding, leading to a North American recall of this product and a review of current industry practices.

Adolescent↗
PubMed2001

Persistence of a distinct Corynebacterium diphtheriae clonal group within two communities in the United States and Canada where diphtheria is endemic.

Molecular characterization of 53 U.S. and Canadian Corynebacterium diphtheriae isolates by multilocus enzyme electrophoresis, ribotyping, and random amplified polymorphic DNA showed that strains with distinct molecular subtypes have persisted in the United States and Canada for at least 25 years. These strains are endemic rather than imported from countries with current endemic or epidemic diphtheria.

Bacterial Typing Techniques↗
PubMed2000

Increasing drug resistance of Mycobacterium tuberculosis isolates in Ontario, Canada, 1987-1998.

We examined trends in resistance to first-line antituberculous agents for Mycobacterium tuberculosis strains isolated in Ontario, Canada from 1987 through 1998 (n=8069). The proportions resistant were as follows: isoniazid, 9.6%; rifampin, 1.9%; streptomycin, 4. 9%; ethambutol, 1.3%; and pyrazinamide, 1.7%. Resistance to isoniazid has increased markedly since 1990, whereas resistance to streptomycin, ethambutol, and pyrazinamide increased from 1997 through 1998. Resistance to both isoniazid and rifampin did not increase. The incidence of persistence and reactivation (early or late treatment failure) was 1-2 per 100 person-years (PY) in the first 7-12 months and 0.3-0.9 per 100 PY from 13 months to 5 years thereafter. For initially susceptible strains, the incidence of resistance to isoniazid was 0.11 per 100 PY and for and rifampin was 0.06 per 100 PY in the first year and negligible thereafter, with an overall risk of 0.14% for isoniazid and 0.10% for rifampin. Resistance of M. tuberculosis to antituberculous agents, and in particular to isoniazid, is a growing problem in Ontario and is higher than elsewhere in Canada.

Antitubercular Agents↗
PubMed1999

Methicillin-resistant Staphylococcus aureus carriage in a child care center following a case of disease. Toronto Child Care Center Study Group.

OBJECTIVES: To study the prevalence of methicillin sodium-resistant and methicillin-sensitive Staphylococcus aureus colonization in a child care center following the diagnosis of community-acquired methicillin-resistant S. aureus (MRSA) disease in a previously well 2 1/2-year-old attendee and to determine the optimal site of detection of S. aureus. DESIGN: Point prevalence survey and questionnaire administration. SETTING: A Toronto, Ontario, child care center. INTERVENTIONS: Parents were provided with general information. Consenting parents completed a questionnaire and permitted screening of their child at 1 or more of throat, nose, and perianal sites. Families of children who were culture positive for MRSA were offered screening and suppressive therapy. Nasal and perianal swabs were obtained from child care center staff and screened. RESULTS: Of 201 children, 164 (81.6%) had completed questionnaires and had undergone screening at 1 or more sites; 38 staff members (100%) completed questionnaires and were screened. A 26-month-old classroom contact with chronic dermatitis had MRSA detected only on perianal swab. Of 3 adult household contacts of the index case and 2 adult and 1 child contacts of the classroom contact, only the 7-year-old sibling of the classroom contact was positive for MRSA. By pulse-field gel electrophoresis, these isolates were identical and not related to any of the common strains circulating in regional health care institutions. Of 40 children with S. aureus (24.4%), 33 had cultures at 3 sites, of which the throat was more sensitive (22 [67%]) than the nostrils (15 [46%]) or perianal sites (8 [24%]). There was a tendency for higher carriage of S. aureus in children with certain risk factors, including personal hospitalization (prevalence ratio, 2.9; 95% confidence interval, 0.6-12.1), family member hospitalization (prevalence ratio, 2.0; 95% confidence interval, 0.6-6.6), and visiting the hospital emergency department (prevalence ratio, 3.2; 95% confidence interval, 0.7-14.5), all in the previous 6 months. CONCLUSIONS: To our knowledge, this is one of the first recognized cases of MRSA disease and apparent transmission in a child care center. Throat and perianal site screenings have a higher sensitivity in identifying children colonized with S. aureus than nasal culturing. Infection with MRSA should be suspected in disease unresponsive to standard antibiotic therapy.

Adolescent↗
PubMed1998

Etiology of acute childhood encephalitis at The Hospital for Sick Children, Toronto, 1994-1995.

Of 145 patients admitted to our hospital because of encephalitis-like illness, 50 patients hospitalized for > or =72 hours underwent standardized microbiological investigations. A confirmed or probable etiologic agent was identified in 20 cases (40%), including Mycoplasma pneumoniae (9 cases). M. pneumoniae and enterovirus (2), herpes simplex virus (4), Epstein-Barr virus (1), human herpes-virus 6 (HHV-6) (1), HHV-6 and influenza virus type A (1), influenza virus type A (1), and Powassan virus (1). In 13 cases (26%), a possible pathogen was identified, including M. pneumoniae in nine cases. Presenting features included fever (80% of patients), seizures (78%), focal neurological findings (78%), and decreased consciousness (47%). The frequency of findings at the time of admission vs. later in hospitalization was as follows: pleocytosis, 59% vs. 63%; electroencephalogram abnormalities, 87% vs. 96%; and neuroimaging abnormalities, 37% vs. 69%, respectively. The outcomes at the time of discharge were as follows: normal results of physical examination, 32% (16) of the patients; death, 2% (1); motor difficulties, 26% (13); global neurological deficits, 16% (severe, 6; mild, 2); mental status changes, 14% (7); visual defects, 8% (4); and hearing impairment, 2% (1).

Acute Disease↗
PubMed1996

Seasonal affective disorder among psychiatric nurses in Aberdeen.

The Seasonal Pattern Assessment Questionnaire was posted to psychiatric nurses in Aberdeen, and 443 (73% of eligible subjects) responded. The rate of Seasonal Affective Disorder (SAD) was 2.9% and for subsyndromal SAD (S-SAD) was 9.5%. When rates were age and sex adjusted to the Aberdeen population aged 15 to 64, this yielded a prevalence of 1.9% for SAD and 7.2% for S-SAD. As in other studies, there was a preponderance of young female sufferers, but being married appeared to be protective. Comparisons with epidemiological studies elsewhere lead to the conclusion that population rates of winter depression relate to a combination of genetic susceptibility/selection, latitude of residence and geographical mobility.

Adolescent↗
PubMed1996

Longitudinal study of molecular epidemiology of small round-structured viruses in a pediatric population.

Small round-structured viruses (SRSV), recently designated members of the family Caliciviridae, can now be readily subtyped by amplification of a defined portion of their genome by reverse transcription-PCR and then by identification of the amplicons with specific probes by Southern blotting. A longitudinal survey (from 1991 to 1995) was conducted to determine the genotypes of the SRSV present in pediatric stool specimens from patients with sporadic cases of gastroenteritis. It was found that almost all viruses were of the G-2 genotype, and on probing, the subtype P2-B was predominant but the frequencies of the different subtypes varied from year to year. A survey of the genotypes of SRSV from community outbreaks from 1995 showed that the G-2 genotype was also predominant and that the distribution of its subtypes was similar to that seen in sporadic cases of diarrhea in pediatric patients over the same time period. It was concluded that there is a succession of subtypes of SRSV in our pediatric population over time. This distribution of genotypes in sporadic cases of pediatric gastroenteritis may reflect the distribution in community outbreaks occurring at the same time.

Caliciviridae Infections↗
PubMed1995

A prolonged outbreak of exfoliative toxin A-producing Staphylococcus aureus in a newborn nursery.

An outbreak of erythromycin-resistant, exfoliative toxin-producing Staphylococcus aureus infection in a neonatal unit is described. The organism was coagulase positive but staphyloslide negative, and this unusual phenotype facilitated early recognition of the organism in the routine laboratory. In the initial outbreak there were 77 probable or confirmed cases, with a peak attack rate of 66%. Increased infection control measures were put in place and attempts were made to identify a staff carrier. No carriers were found and the major outbreak subsided. Sporadic cases occurred over the following 10 months, until May 1992, when a colonized staffperson was discovered. She was treated and no further cases occurred. The causative organism was subjected to typing by phage, enterobacterial repetitive intergenic consensus sequence polymerase chain reaction, and pulsed-field gel electrophoresis with two separate enzymes. The phage typing and genomic tests confirmed the presence of the same clone in the unit for 9 months. The organism possessed genes encoding exfoliative toxin A as determined by polymerase chain reaction.

Bacterial Toxins↗
PubMed1993

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 years (median age, 47 years); 29 (58%) of the patients died. A primary focus of infection was identified in 38 cases (76%), with soft tissue being the site involved most frequently (68%). No focus of infection was found in 12 patients, and 36 patients (72%) were bacteremic. Complications included acute respiratory distress syndrome (21 of 50), acute renal failure (20 of 50), hypocalcemia (19 of 24), elevated creatinine kinase values (21 of 27), coagulation abnormalities (15 of 21), and hepatitis (15 of 24). Eleven cases (22%) were nosocomial; one of these was secondary to another nosocomial case. Thirty-three isolates were available for M and T typing and for determination of the presence of the genes for streptococcal pyrogenic exotoxin (SPE). The most frequent types were M1T1 (10) and M12/T12 (8). Twelve isolates possessed the speA gene, and 16 isolates had the speC gene. Only three isolates possessed both speA and speC. All isolates possessed the speB gene.

Adolescent↗