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S L Walmsley

Publications and source records attributed to S L Walmsley.

25 records · Page 2Linked to original sources
PubMed1994

Surveillance of susceptibility testing methodologies for Haemophilus influenzae in Canada, including evaluation of disk diffusion test.

We surveyed 75 clinical laboratories to determine if National Committee for Clinical Laboratory Standards (NCCLS) were being used for the susceptibility testing of Haemophilus influenzae. Of the 66 laboratories that performed susceptibility testing, all claimed to follow current NCCLS guidelines. However, upon further questioning, only 23, all of which used disk diffusion testing, accurately interpreted and followed the guidelines. Proficiency testing of 22 of these laboratories found that an unacceptable number of interpretive errors (> 10%) occurred. These results query the merit of routine disk diffusion susceptibility testing of H. influenzae to beta-lactam agents.

Anti-Bacterial Agents↗
PubMed1994

The effect of infection and lag screw fixation on the union of membranous bone grafts in a rabbit model.

Infection complicating craniofacial procedures contributes significantly to patient morbidity and health care costs. The role of fixation materials in this setting remains unclear. As foreign material, does fixation hardware increase patients' susceptibility to developing postoperative infection? Furthermore, once infection is established, should fixation hardware be removed? To answer these questions, we performed an onlay membranous bone grafting procedure to the mandible in 94 New Zealand White rabbits, applied lag-screw fixation in half the animals, and inoculated the wounds with different bacterial doses. We quantified the differential rates of infection and rates of graft union in the presence of infection. The infection rates for the rigidly fixated group were not significantly different from the rates for the nonfixated group for a range of bacterial inoculum doses. There was no significant difference in the rates of resolution of infection and sepsis between the two groups. Gross and histologic assessments revealed a significantly lower union rate for infected grafts when compared with uninfected grafts. Furthermore, grafts rigidly fixated with a lag screw showed a higher rate of union when compared with nonfixated grafts in the presence of infection. In the absence of infection, the union rates for fixated and nonfixated groups did not differ significantly. While fixation hardware has been cited as a risk factor for postoperative infection, we were unable to show that lag-screw fixation contributes to this risk. Although infection impaired the union of membranous bone grafts to the recipient mandible, fixation of the grafts with a lag screw significantly decreased this deleterious effect of infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Reactivation and dissemination of blastomycosis complicating Hodgkin's disease: a case report and review of the literature.

Patients presenting with Hodgkin's disease (HD) may show lung involvement characterized by contiguous spread from ipsilateral hilar lymph nodes. Lung consolidation or noncontiguous pulmonary involvement makes an alternative diagnosis more likely. This report describes a patient with HD in whom concurrent pulmonary blastomycosis was recognized only after chemotherapy had started and dissemination had occurred. Although Blastomyces dermatitidis may behave as an opportunist pathogen, there are no previous reports of blastomycosis in patients with HD. Undiagnosed active opportunistic infection at the time of diagnosis of HD may complicate staging as well as treatment. Biopsy of lung lesions with stain and culture for opportunistic pathogens should be considered in patients with newly diagnosed HD disease and atypical patterns of lung involvement.

Adult↗
PubMed1990

In vitro susceptibility of "Campylobacter upsaliensis" to twenty-four antimicrobial agents.

The in vitro susceptibility of 41 strains of "Campylobacter upsaliensis" to 24 antimicrobial agents was determined using a broth microdilution procedure. Most isolates were susceptible to the fluoroquinolones and beta-lactam antibiotics tested, but all strains were resistant to trimethoprim (MBCs greater than or equal to 128 micrograms/ml) and teicoplanin (MBCs greater than or equal to 32 micrograms/ml). These agents may be useful in a selective isolation medium for "Campylobacter upsaliensis".

4-Quinolones↗
PubMed1989

Direct isolation of atypical thermophilic Campylobacter species from human feces on selective agar medium.

Campylobacter upsaliensis is the name which has been proposed for a new group of thermophilic campylobacter strains which differ from C. jejuni and C. coli in having a negative or weak catalase reaction. Primary isolation of these strains from human feces has been achieved only by use of filtration techniques. We report here direct isolation of strains corresponding to C. upsaliensis from stools of six children. The strains were isolated on a newly described campylobacter-selective medium. The strains were oxidase positive, hippurate negative, nitrate positive, negative for H2S in triple sugar iron, and susceptible to cephalothin (30-micrograms disk) and nalidixic acid (30-micrograms disk), and they grew at 37 and 43 degrees C, but not at 25 degrees C. The selective medium used was a blood-free, charcoal-based medium consisting of Columbia agar base, activated charcoal, cefoperazone (32 micrograms/ml), vancomycin (20 micrograms/ml), and cycloheximide (100 micrograms/ml). The medium supported the growth of the weakly reacting or catalase-negative strains, with colony counts equivalent to those obtained on antibiotic-free horse blood agar. These strains could not be isolated directly from stool on Skirrow medium, and colony counts confirmed that this medium could not support a low inoculum of these organisms. The clinical significance of these strains is unknown. We conclude that C. upsaliensis can be isolated directly from stool by using a selective medium, without the need for filtration.

Agar↗