Biomedical subjects

A E Simor

Publications and source records attributed to A E Simor.

118 records · Page 7Linked to original sources

PubMed1987

Disseminated Mycobacterium bovis infection in an elderly patient.

We report a fatal case of disseminated infection due to Mycobacterium bovis occurring in an elderly patient. The greatest incidence of tuberculosis is in the aged, who were likely to have been infected in childhood when the disease was more prevalent. However, the clinical or radiographic presentation of tuberculosis in the older patient may be atypical or nonspecific, contributing to delay in diagnosis, and greater morbidity and mortality.

Aged↗

PubMed1987

Enteritis associated with Campylobacter laridis.

Campylobacter laridis has occasionally been isolated from patients with diarrhea, but its clinical significance in this setting has yet to be established. We report a patient with a self-limited diarrheal illness whose stool cultures yielded C. laridis. The patient also developed a specific serum bactericidal antibody response to this strain of C. laridis, suggesting that the organism was causally related to the enteric illness.

Adult↗

PubMed1986

Evaluation of a blood-free, charcoal-based, selective medium for the isolation of Campylobacter organisms from feces.

A blood-free, charcoal-based selective medium (CSM) consisting of a Columbia agar base, activated charcoal (4 g/liter), hematin (0.032 g/liter), sodium pyruvate (0.1 g/liter), cefoperazone (32 mg/liter), vancomycin (20 mg/liter), and cycloheximide (100 mg/liter) supported the growth of Campylobacter jejuni and C. coli with colony counts equivalent to those obtained on antibiotic-free horse blood agar. CSM was compared to Skirrow medium (SKM) for the recovery of C. jejuni and C. coli from stools of patients with diarrhea, the media being incubated for 2 days under reduced oxygen tension at 43 degrees C. These campylobacters were isolated from 35 (2.9%) of 1,227 stools tested (29 on both media, 5 on CSM alone, and one on SKM alone). Whenever C. jejuni and C. coli were recovered, growth was pure on 29 CSM cultures (85%), but on only 11 SKM cultures (37%). Complete suppression of "contaminating" flora occurred in 704 CSM cultures (57%) compared with 426 SKM cultures (35%). CSM more effectively suppressed contaminating pseudomonads, gram-positive organisms, and yeasts than did SKM; both media failed to suppress members of the family Enterobacteriaceae in about a quarter of the samples. Studies on 20 representative Enterobacteriaceae contaminants showed that susceptibility to cefoperazone and growth on CSM were markedly dependent on inoculum size; 12 strains were inhibited by cefoperazone (32 mg/liter) at inoculum sizes of 5 X 10(2) and 5 X 10(4) but not 5 X 10(6) organisms, indicating that the frequency of contaminants on CSM could probably be reduced further by ensuring that stools were not inoculated too heavily on CSM. Our findings confirm that charcoal is an effective substitute for blood in media for growing campylobacters, and that CSM is a highly effective blood-free selective medium for isolating C. jejuni and C. coli from stools.

Agar↗

PubMed1984

Q fever: hazard from sheep used in research.

The recent recognition that Q fever is endemic in Ontario and the known occupational risk of Q fever to research personnel working with sheep prompted a study to determine the prevalence of antibodies to the causative organism, Coxiella burnetti, in animals and staff at a Toronto animal research institute. Of 37 sheep 34 (92%) were found to be seropositive--that is, to have a titre of complement-fixing antibody to the phase II antigen of 1:8 or greater. Of 331 staff members tested, 18% were found to be seropositive, compared with 0.6% of a random sample of Toronto blood donors. The highest rate of seropositivity, 68%, was in the 28 animal attendants tested. Seropositivity was associated with working with sheep or fetal lamb tissue (p less than 0.0001) and with visiting the animal facility (p less than 0.001). Of the 59 seropositive staff members 63% had had no direct contact with sheep. There were 12 clinically apparent cases of Q fever, 2 of which required admission to hospital. Q fever remains a serious occupational hazard to staff working in research laboratories using sheep, even to those with indirect exposure to infected animals.

Adult↗

PubMed1984

The role of Mycobacterium xenopi in human disease.

Mycobacterium xenopi is infrequently recognized as a cause of pulmonary infection. We isolated this organism from 28 patients over a 3-yr period. It was nonpathogenic in 19 and pathogenic in 9. Clinical illness occurred in middle-aged men with other chronic pulmonary diseases. Therapy was associated with clinical improvement, but most isolates were resistant to first-line antituberculosis drugs. The prevalence of M. xenopi varies geographically, but in the province of Ontario, it is second to M. avium-intracellulare as the most common nontuberculous mycobacterial pathogen.

Adult↗

PubMed1983

Endocarditis caused by M6.

M6 is a Moraxella-like organism which is usually of pharyngeal origin and is generally nonpathogenic. Endocarditis caused by M6 occurred in a 31-year-old female with known mitral valve prolapse. The infection quickly responded to ampicillin, but valve replacement was required because of progressive left ventricular failure.

Adult↗

PubMed1983

Gallium-67 scanning in the diagnosis of postoperative sternal osteomyelitis: concise communication.

Sternal osteomyelitis is an uncommon but serious complication of the median sternotomy incision. Definite diagnosis is clinically difficult and radionuclide scanning is of uncertain value in the early postoperative period. We conducted a prospective blind study of gallium scanning in the early period after cardiac surgery and reviewed clinically diagnosed cases that also had scans. Clinical status and scan interpretation were each independently assessed by three raters. Thirty-eight scans included six true positives, five true negatives (no sternotomy) and 27 post-sternotomy, clinically uninfected patients. Using categories of high, medium, and low for scan interpretation, the radiologic assessors agreed 90% of the time. Normal postoperative Ga-67 uptake could usually be differentiated from uptake by an infected sternum. The test had a sensitivity of 83% and specificity 96%. If the clinical (pretest) likelihood of sternal osteomyelitis is 30%, then the gallium scan will have a 90% positive predictive value and a 93% negative predictive value. This study of observer variation and validity indicates that Ga-67 scanning may be useful in confirming the diagnosis of poststernotomy sternal osteomyelitis.

Adult↗

PubMedDate not supplied

The utility of restriction endonuclease analysis and phage typing in the epidemiologic investigation of a Staphylococcus aureus outbreak in a neonatal nursery.

Outbreaks of Staphylococcus aureus infections in neonatal units require prompt investigation and implementation of control measures. From January to March 1990, a marked increase in the number of S. aureus infections was observed in a neonatal nursery. Twenty-seven S. aureus isolates from 23 patients were analyzed by phage typing and restriction endonuclease analysis (REA). Only nine strains were differentiated by phage type. However, REA with HindIII, CfoI, and ClaI differentiated 20 strains. The REA results indicated that the outbreak was due to several different S. aureus strains and did not represent transmission of a single epidemic strain. REA may enable more accurate determination of the presence or absence of an epidemic strain during an outbreak than would traditional methods such as phage typing.

Bacteriophage Typing↗

PubMedDate not supplied

Abortion and perinatal sepsis associated with campylobacter infection.

Fetal loss or neonatal sepsis associated with campylobacter infection during pregnancy is infrequently recognized. As reported herein, one case of premature labor and neonatal sepsis due to Campylobacter fetus subspecies fetus was treated successfully with ampicillin and gentamicin. Only 19 similar cases have been cited in the literature. A review of these 19 cases reveals that the Campylobacter species involved were probably C. fetus subspecies fetus in nine instances, Campylobacter jejuni in nine, and Campylobacter coli in one. There were no significant species-related differences in clinical presentation or outcome. Eighteen of 20 pregnancies (including tht described herein) ended prematurely at 13-32 weeks of gestation. All of the mothers survived, but fetal/neonatal mortality was 80%. The pathogenesis of campylobacter infection in this situation probably involves maternal bacteremia originating from the bowel, with subsequent feto-placental involvement. Early recognition and treatment may improve fetal/neonatal outcome.

Abortion, Spontaneous↗

PubMedDate not supplied

Pseudobacteremia due to Pseudomonas fluorescens.

Pseudomonas fluorescens was recovered from 62 of 22,270 (0.26%) blood cultures, from 57 patients, over a 22-month period at a pediatric hospital. No illness was attributable to the blood culture isolate. A case-control study identified a significant correlation between the recovery of P. fluorescens in blood culture and concomitant coagulation studies (p less than 0.0001). In all cases blood for coagulation studies had been obtained at the same time as the blood culture. A review of venipuncture technique revealed that occasionally the coagulation study tubes (containing 3.8% sodium citrate) were being inoculated before blood culture bottles. P. fluorescens was subsequently isolated from coagulation tubes and from sodium citrate solutions prepared and dispensed in the hospital for use in coagulation studies. In vitro studies confirmed that sodium citrate solutions supported the growth of P. fluorescens, with preferential growth at 25 degrees C and 4 degrees C. This is the first description of P. fluorescens as a cause of pseudobacteremia. Pseudobacteremia was attributed to cross-contamination of blood cultures following inoculation of contaminated citrated collection tubes.

Adolescent↗