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Biomedical subjects

A E Simor

Publications and source records attributed to A E Simor.

At least 109 records · Page 6Linked to original sources

Comparative in vitro activities of sparfloxacin (CI-978; AT-4140) and other antimicrobial agents against staphylococci, enterococci, and respiratory tract pathogens.

The in vitro activity of sparfloxacin (CI-978; AT-4140) was compared with those of other antimicrobial agents against isolates of staphylococci, enterococci, and various respiratory tract pathogens. Sparfloxacin was the most active drug tested against staphylococci (MIC for 90% of the strains tested [MIC90], 0.125 micrograms/ml) and enterococci (MIC90, 1.0 microgram/ml). It was also active against Haemophilus influenzae (MIC90, less than or equal to 0.06 microgram/ml), Moraxella (Branhamella) catarrhalis (MIC90, 0.125 microgram/ml), Streptococcus pneumoniae (MIC90, 0.5 microgram/ml), and Streptococcus pyogenes (MIC90, 1.0 microgram/ml).

4-Quinolones↗

Comparative in vitro activities of several new fluoroquinolones and beta-lactam antimicrobial agents against community isolates of Streptococcus pneumoniae.

The in vitro susceptibilities of 551 community isolates of Streptococcus pneumoniae from the Canadian province of Ontario to several new fluoroquinolones and beta-lactam antimicrobial agents were determined by a broth microdilution technique. Eight (1.5%) of these isolates were moderately susceptible (MICs, greater than or equal to 0.12 and less than or equal to 1.0 microgram/ml) to penicillin; none was resistant. Temafloxacin, ciprofloxacin, and ofloxacin (MICs for 90% of strains tested, between 1 and 2 micrograms/ml) were the most active fluoroquinolones tested, and BMY-28100 (MIC for 90% of strains tested, 0.25 microgram/ml) was the most active of the new beta-lactams tested.

4-Quinolones↗

Use of molecular typing to study the epidemiology of Serratia marcescens.

Although Serratia marcescens is a well-known nosocomial pathogen, investigation of its hospital ecology has been limited by the lack of available typing techniques. During an investigation of the occurrence of this organism in a neonatal intensive care unit, we evaluated a number of such techniques. Using a selective medium, we conducted prospective surveillance of neonatal rectal colonization and environmental contamination with S. marcescens. In 8 months of surveillance, 5.1% (20 of 394) of the infants admitted to the unit became colonized. Most sink surfaces and drains were also culture positive. Differences between isolates could not be detected in biotypes from a commercial identification system (MicroScan) or by antibiograms, total protein fingerprints, or plasmid profiles. Serogrouping and genomic DNA restriction endonuclease analysis revealed the presence of six strains that colonized infants and a similar number of environmental strains. These two methods were concordant, with the exception that genomic DNA analysis demonstrated lack of relatedness between some strains within the same serogroup. DNA restriction endonuclease analysis was practical and reliable. The differences this method detected between environmental and neonatal strains provided strong evidence that the environment was not an important reservoir for S. marcescens in our neonatal intensive care unit.

Cross Infection↗

Typing of Campylobacter pylori by bacterial DNA restriction endonuclease analysis and determination of plasmid profile.

Campylobacter pylori isolates from 37 symptomatic patients and 3 asymptomatic volunteers were examined by chromosomal DNA restriction endonuclease analysis and determination of plasmid profile. Restriction digests with HindIII, HaeIII, PvuII, and BglII produced clear and reproducible results that permitted discrimination between different strains. Only 35% of C. pylori isolates were found to have plasmid DNA. Isolates from different patients, including those from two pairs of siblings, had unique restriction patterns and plasmid profiles. Consecutive isolates obtained 1 year apart from each of two asymptomatic volunteers had identical restriction patterns and plasmid profiles, suggesting persistence of the same strain. A pair of isolates obtained one year apart from the third volunteer differed in plasmid DNA content but had similar chromosomal DNA restriction patterns. Plasmid profile determination and bacterial DNA restriction endonuclease analysis provide a reliable means of discriminating between different strains of C. pylori and may be useful for typing these organisms in epidemiologic studies.

Campylobacter↗

Evaluation of a commercial microtiter system (MicroScan) using both frozen and freeze-dried panels for detection of high-level aminoglycoside resistance in Enterococcus spp.

The MicroScan system was compared with agar dilution screen plates for the detection of high-level aminoglycoside resistance in 182 enterococcal isolates. Both the frozen Gram-Positive Combo Type 2 and the freeze-dried Type 5 panels were evaluated. The specificity of both panels for the detection of streptomycin and gentamicin resistance was 100%. However, the sensitivities for the detection of gentamicin and streptomycin resistance were 84 and 31%, respectively, for the Type 2 panels and 90 and 41%, respectively, for the Type 5 panels. The sensitivities of these panels for the detection of enterococcal high-level aminoglycoside resistance are inadequate for routine use.

Anti-Bacterial Agents↗

Antibody to cytotoxin in infection by Helicobacter pylori.

Gastrointestinal disease and colonization by Helicobacter pylori were determined in 36 asymptomatic volunteers and 30 symptomatic individuals undergoing endoscopy and biopsy. Serum antibody immunoglobulin G (IgG) and IgA to H. pylori were measured by enzyme-linked immunosorbent assay. Serum antibody to a cytotoxin produced by H. pylori was detected with a neutralization assay. Serum IgG was 95% predictive of infection by H. pylori, and serum IgA was 88% predictive. Antibody to the cytotoxin was detected in 12 of 18 infected individuals. Antibody to the cytotoxin was a highly specific (96%), but not a very sensitive (67%), indicator of infection by H. pylori. The neutralization assay was 87% predictive of infection. These data confirm the diagnostic value of serum antibody to H. pylori for the detection of infection. The toxin-neutralizing activity of sera from individuals infected with H. pylori suggests that the cytotoxin is produced in vivo. It may therefore contribute to disease associated with H. pylori.

Adult↗

Reproducibility of interpretation of Gram-stained vaginal smears for the diagnosis of bacterial vaginosis.

In the diagnostic microbiology laboratory, interpretation of Gram-stained slides of vaginal swab specimens is used to support the clinical diagnosis of bacterial vaginosis. The reproducibility with which technologists interpret these Gram-stained slides was evaluated by presenting, in coded fashion, 80 original slides and 80 duplicate slides of vaginal swab specimens to three technologists. They each interpreted the original slide twice and the duplicate slide from the same specimen once. Intraobserver and interobserver agreement was assessed by use of the weighted kappa statistic. Semiquantitation of Lactobacillus and Gardnerella morphotypes and a diagnosis of bacterial vaginosis showed the greatest intraobserver agreement, with kappa values ranging from 0.772 to 1.000. Interobserver agreement was also high for rating Lactobacillus morphotypes and clue cells (kappa values between 0.735 and 0.869) but decreased slightly for Gardnerella morphotypes and a diagnosis of bacterial vaginosis (kappa values between 0.656 and 0.800). These results indicate that there is good agreement for the interpretation of Gram-stained slides of vaginal swab specimens and that this method alone, without culture, can be used reliably to support the clinical diagnosis of bacterial vaginosis.

Bacterial Infections↗

Parotid gland enlargement in HIV infection: clinical/imaging findings.

Parotid gland enlargement with or without facial paralysis may be the presenting clinical manifestation of AIDS. Submandibular involvement may occur as well. Failure to recognize this association may lead to inappropriate or unnecessary intervention in the investigation and treatment of the salivary gland enlargement. In this paper, we discuss the role of imaging techniques in the investigation of salivary gland enlargement, and identify the specific radiologic signs found in HIV infection. Demonstration of intraparotid or submandibular gland cysts with focal intraparotid mass lesion(s) on imaging may help to differentiate parotid gland enlargement due to HIV infection from the many other causes of parotid enlargement.

Adult↗

The prevalence of Campylobacter pylori gastritis among asymptomatic adults.

To determine the prevalence of Campylobacter pylori colonization in the healthy population we studied 54 asymptomatic volunteers and 65 patients referred because of gastrointestinal symptoms. All subjects underwent gastroscopy and gastric biopsy. C. pylori was isolated from 6 volunteers (11%) and 36 patients (55%). Histologic evidence of inflammation was present in 98% of the culture-positive subjects. Linear regression analysis revealed that the prevalence of C. pylori colonization increased with age. There was no difference in the isolation rate between the two groups when adjusted for age. Four of the six culture-positive volunteers underwent repeat endoscopy and gastric biopsy 1 year later; despite remaining asymptomatic, all still had positive culture results and histologic evidence of gastritis. We conclude that the prevalence of C. pylori-associated gastritis among symptomatic patients increases with age and that the organism may be present in the gastrointestinal tract for prolonged periods without symptoms or evidence of disease progression.

Adult↗

Comparative in vitro activities of six new fluoroquinolones and other oral antimicrobial agents against Campylobacter pylori.

The in vitro susceptibilities of 56 clinical isolates of Campylobacter pylori to six new fluoroquinolones and other oral antimicrobial agents were determined by an agar dilution technique. Ciprofloxacin was the most active of the fluoroquinolones (MIC for 90% of strains tested [MIC90], 0.05 microgram/ml). Other fluoroquinolones had variable activities, although most isolates were moderately susceptible to fleroxacin (MIC90, 4 micrograms/ml) and lomefloxacin (MIC90, 4 micrograms/ml).

Ampicillin↗

Chronic Shigella flexneri infection preceding development of acquired immunodeficiency syndrome.

Shigella sp. is known to be an important cause of diarrhea in homosexual men, although chronic infection is infrequently recognized. We describe recurrent and relapsing symptomatic infection due to Shigella flexneri in a human immunodeficiency virus-infected homosexual man subsequently developed acquired immunodeficiency syndrome. Patients with acquired immunodeficiency syndrome may be prone to developing chronic shigellosis because of impaired intestinal cell-mediated immunity.

Acquired Immunodeficiency Syndrome↗

Problems with rapid agglutination methods for identification of Staphylococcus aureus when Staphylococcus saprophyticus is being tested.

Six rapid agglutination tests for identification of Staphylococcus aureus were evaluated by using 62 strains of S. aureus, 63 strains of S. saprophyticus, and 67 strains of other coagulase-negative staphylococci. S. saprophyticus was responsible for 19 of 26 false-positive results and 20 uninterpretable reactions. Thus, urinary staphylococcal isolates that are positive by rapid agglutination tests may require other confirmatory tests for the identification of possible S. saprophyticus.

Hemagglutination Tests↗

Evaluation of a new latex test and a new enzyme immunoassay for determination of rubella immunity.

A new enzyme immunoassay (Rubenostika; Organon Teknika, Turnhout, Belgium), a new latex agglutination test (Rubalex; Orion Diagnostica, Espoo, Finland), and three other accepted methods for the determination of rubella immunity were compared with a standard hemagglutination inhibition assay. Of 224 serum samples tested, 54 (24%) were nonreactive and 24 (11%) were low titered. All procedures were very specific (94 to 100%). Rubenostika was the least sensitive method (88%), and Rubalex was the most sensitive (98%).

Antibodies, Viral↗

Molecular and epidemiologic study of multiresistant Serratia marcescens infections in a spinal cord injury rehabilitation unit.

Between March 1984 and February 1986, ten patients admitted to a spinal cord injury/stroke rehabilitation unit became bacteriuric with a strain of Serratia marcescens resistant to ampicillin, cephalothin, cefoxitin, ticarcillin, cotrimoxazole, gentamicin, and tobramycin. All the patients were catheterized, and in most, bacteriuria was asymptomatic. The organism was also recovered from their hospital environment (sinks, toilets, urine-collecting basins). Analysis of total plasmid content of multiresistant isolates revealed the presence of two plasmids (7 kilobase, 25.5 kilobase), not found in aminoglycoside susceptible strains of Serratia marcescens. Restriction endonuclease analysis and Southern hybridization (DNA probe: 25.5 kilobase plasmid) verified that these plasmids were identical. The 25.5 kilobase plasmid was purified, introduced by transformation into an Escherichia coli strain C recipient, and was found to mediate resistance to gentamicin and tobramycin. The emergence of multiresistant Serratia marcescens coincided with an increase in antibiotic usage on the ward. The reservoir seemed to be the urinary tracts of asymptomatic catheterized patients and their contaminated hospital environment.

Adult↗