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Biomedical subjects

D Lindquist

Publications and source records attributed to D Lindquist.

8 recordsLinked to original sources

Multicenter evaluation of the MicroScan Rapid Gram-Negative Identification Type 3 Panel.

The accuracy and performance of the revised MicroScan Rapid Gram-Negative Identification Type 3 Panel (Dade MicroScan Inc., West Sacramento, Calif.) were examined in a multicenter evaluation. The revised panel database includes data for 119 taxa covering a total of 150 species, with data for 12 new species added. Testing was performed in three phases: the efficacy, challenge, and reproducibility testing phases. A total of 405 fresh and stock gram-negative isolates comprising 54 species were tested in the efficacy phase; 96.8% of these species were identified correctly in comparison to the identification obtained either with the API 20E system (bioMérieux Vitek, Hazelwood, Mo.) or by the conventional tube method. The number of correctly identified isolates in the challenge phase, including new species added to the database, was 221 of 247, or 89.5%, in comparison to the number correctly identified by the conventional tube method. A total of 465 isolates were examined for intra- and interlaboratory identification reproducibility and gave an agreement of 464 of 465, or 99.8%. The overall reproducibility of each individual identification test or substrate was 14,373 of 14,384, or 99.9%. The new Rapid Gram-Negative Identification Type 3 Panel gave accurate and highly reproducible results in this multiple-laboratory evaluation.

Evaluation Studies as Topic↗

Identification and characterization of Serpulina pilosicoli isolates recovered from the blood of critically ill patients.

The phenotypic and genetic characteristics of spirochetes isolated from the blood of one U.S. and six French patients with severe clinical disease or impaired immunity were examined. All spirochetes were anaerobic, weakly beta-hemolytic, positive for hippurate hydrolysis, and negative for beta-glucosidase activity. Cell lengths ranged from 4 to 8 microm, and each isolate had between 8 and 12 periplasmic flagella per cell. These features were consistent with the spirochetes' being Serpulina pilosicoli, the agent of intestinal spirochetosis. All isolates were positive in a PCR assay amplifying a portion of the S. pilosicoli 16S rRNA gene, and they all grouped with fecal isolates of S. pilosicoli in multilocus enzyme electrophoresis (MLEE). The blood isolates could be differentiated from each other by MLEE, although the U.S. and two French isolates were closely related. Apparently S. pilosicoli may translocate from the large intestine to establish spirochetemia. The clinical significance of this finding remains uncertain and requires further investigation.

Bacteremia↗

Difficulties encountered in identification of a nutritionally deficient streptococcus on the basis of its failure to revert to streptococcal morphology.

Difficulties were encountered in the recognition of a nutritionally deficient streptococcus which continued to display aberrant morphologic forms (especially bulbous swellings and filament formation) despite provision of growth factors. With isolates displaying diverse morphologic entities not characteristic of a given species, e.g., Streptobacillus moniliformis or Erysipelothrix rhusiopathiae, nutritionally deficient streptococci should be considered.

Bacteremia↗

Structural and pathogenic properties of Aeromonas schubertii.

We investigated the phenotypic, structural, and pathogenic properties of 11 Aeromonas schubertii strains recovered from extraintestinal sites. Most A. schubertii strains were autoagglutination positive, possessed a high surface charge but low hydrophobicity, and fell into one or two biogroups on the basis of carbon substrate utilization patterns. Fatty acid methyl ester analysis of A. schubertii revealed this species to contain a relatively high percentage of branched fatty acids (i-13:0, i-15:0, i-17:1, i-17:0) compared with A. hydrophila. Immunologic and biochemical analysis of the lipopolysaccharides of A. schubertii strains allowed for two groups to be distinguished, namely, (i) a collection of six strains belonging to serogroup O:11 that possessed a characteristic homogeneous O polysaccharide side chain profile by silver staining and immunoblotting techniques and (ii) a second antigenically diverse group (five strains) that either exhibited a heterogeneous side chain profile or were side chain deficient. A, schubertii O:11 strains were all found to contain a 55-kDa major protein associated with the outer membrane fraction which was glycine-hydrochloride extractable; non-O:11 strains did not harbor a similar protein molecule. Screening of A. schubertii strains for reputed virulence factors indicated (i) that slightly more than half of the isolates produce an apparent contact-dependent hemolysin that is not cell associated or released extracellularly, (ii) a potent cytotoxin active against HEp-2 cells that is devoid of hemolytic activity, and (iii) lack of enterotoxigeniclike activity as determined by suckling mouse assays. All A. schubertii strains were pathogenic for mice as determined by 50% lethal dose assays, although no single factor correlated with mouse pathogenicity.

Aeromonas↗

Outbreak of Pontiac fever due to Legionella anisa.

An outbreak of Pontiac fever occurred among 34 of 56 people attending conferences at a hotel in Santa Clara County, California, in 1988. Two groups had an acute febrile upper respiratory illness, with a mean attack rate of 82% and a mean incubation period of 56 hours. Symptoms resolved spontaneously within 5 days. Legionella anisa, which had not previously been associated with outbreaks of Pontiac fever or legionnaires' disease, was isolated from a decorative fountain in the hotel lobby. In addition, 5 of 8 pairs of serum samples from cases showed a more than fourfold rise in antibody titre to the L anisa recovered from the fountain. 42% of hotel employees had titres greater than or equal to 256 against L anisa, whereas none of 48 serum samples from matched controls had titres greater than or equal to 128. The findings raise concern about water treatment protocols for extent of disease that might be caused by exposure to aerosols containing L anisa and other Legionella species.

Acute Disease↗

Behavioral effects of unilateral basal gangliar lesions in neonatal rats.

Two-day-old rats were given unilateral lesions of the caudate-putamen, globus pallidus, or hippocampus and their postural orientation was observed for 30 min immediately after surgery. All groups with damage to the caudate-putamen and/or globus pallidus showed a significant postural deviation toward the side ipsilateral to the lesion. At this age, neurogenesis in the basal ganglia is complete but synapses, neurotransmitters, and enzymes for neurotransmitter synthesis are far below adult levels. These results indicate that the basal ganglia have a role in motor function prior to their full maturation as measured by neuroanatomical and biochemical techniques.

Animals↗