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Biomedical subjects

G V Doern

Publications and source records attributed to G V Doern.

At least 163 records · Page 9Linked to original sources
PubMed1982

Comparison of the API 20S Streptococcus identification system with an immunorheophoresis procedure and two commercial latex agglutination tests for identifying beta-hemolytic streptococci.

The API 20S Streptococcus identification system and a new immunorheophoresis procedure were evaluated as means for determining the Lancefield serogroup of beta-hemolytic streptococci recovered from human clinical specimens. The serogroup of 96 strains was determined by these methods and by two commercially available latex agglutination tests. Streptex and SeroSTAT. The results of all four procedures were compared with the results of a classical precipitin test. The API 20S system correctly categorized 92.7% of the isolates; 94.8% were correctly identified by the immunorheophoresis procedure. The latex agglutination procedures were of comparable accuracy, yielding correct identifications with approximately 92% of the strains tested.

Bacteriological Techniques↗
PubMed1982

Neisseria sicca osteomyelitis.

Neisseria sicca was identified as the cause of vertebral osteomyelitis in a male patient who had previously suffered a nonpenetrating, traumatic back injury. The identifying characteristics and antimicrobial susceptibility patterns are presented for this rare human pathogen, which heretofore has not been reported as a cause of infection localized to bone.

Humans↗
PubMed1982

Quantitative microbiological monitoring of hemodialysis fluids: evaluation of methods and demonstration of lack of test relevance in single-pass hemodialysis machines with automatic dialysate proportioning with reverse osmosis-treated tap water.

Two methods for estimating the quantity of microorganisms present in hemodialysis fluid, a blood agar surface-spread plate method and a total-count water tester device impregnated with modified standard plate count agar (Millipore Corp., Bedford, Mass.), were evaluated. Both methods exhibited comparable precision; however, colony counts obtained with the total-count water tester were consistently and unacceptably low. The need for routine quantitative microbiological monitoring of hemodialysis fluids such as that recommended by the American Public Health Association was not supported by the results of this study. Such testing was not of value in predicting untoward reactions for patients undergoing hemodialysis, nor did quantitative testing of hemodialysis fluids identify the buildup of potentially hazardous levels of contamination within hemodialysis systems. Finally, the kinds of organisms found in hemodialysis systems, i.e., gram-negative water-borne bacilli, were elucidated.

Bacteriological Techniques↗
PubMed1982

Direct identification of Staphylococcus aureus in blood culture fluid with a commercial latex agglutination test.

A commercial latex agglutination slide test (SeroSTAT Staph, Scott Laboratories, Inc., Fiskeville, R.I.) accurately identified Staphylococcus aureus when applied directly to blood culture fluid containing staphylococci. This latex agglutination test exhibited 100% accuracy when 30 seeded aerobic and anaerobic radiometric blood cultures (15 strains of S. aureus, 15 strains of other staphylococcal species) were tested blindly. In 36 actual clinical specimens yielding 16 isolates of S. aureus and 20 isolates of Staphylococcus epidermidis, 94.4% accuracy was achieved. The latex agglutination test provided positive test results before objective criteria of blood culture positivity such as radiometric growth indices and Gram stains became positive.

Aerobiosis↗
PubMed1981

Evaluation of a new latex agglutination inhibition card test for determining serum gentamicin levels.

A new latex agglutination inhibition card test was compared with a microbiological method and radioimmunoassay for determining serum gentamicin levels. When 60 sera, each containing a known concentration of gentamicin, were analyzed by the microbiological method and by radioimmunoassay, both methods were found to yield accurate and precise results. Analysis of the same 60 sera with the latex agglutination inhibition card test revealed significant variability over a wide range of serum gentamicin concentrations.

Bacillus↗
PubMed1981

Evaluation of a direct blood culture disk diffusion antimicrobial susceptibility test.

A total of 556 unique blood culture isolates of nonfastidious aerobic and facultatively anaerobic bacteria were examined by direct and standardized disk susceptibility test methods (4,234 antibiotic-organism comparisons). When discrepancies which could be accounted for by the variability inherent in disk diffusion susceptibility tests were excluded, the direct method demonstrated 96.8% overall agreement with the standardized method. A total of 1.6% minor, 1.5% major, and 0.1% very major discrepancies were noted.

Bacteria↗
PubMed1981

Pseudomonas denitrificans meningitis.

An elderly male patient with Pseudomonas denitrificans bacteremia and meningitis is described. The antimicrobial susceptibility and minimum criteria necessary for the identification of this unusual and rare human pathogen are discussed.

Anti-Bacterial Agents↗
PubMed1980

Antibiotic susceptibility of beta-lactamase-producing strains of Branhamella (Neisseria) catarrhalis.

All 11 clinically significant isolates of Branhamella catarrhalis examined in this study were found to produce beta-lactamase. The enzyme was apparently not plasmid associated since extrachromosomal deoxyribonucleic acid was not detected in any of the strains. The beta-lactamase activity of all strains was significantly depressed by the beta-lactamase inhibitors clavulanic acid and CP 45899. Based on comparisons of relative susceptibility to various beta-lactam antibiotics, it was inferred that the beta-lactamase of B. catarrhalis was significantly more active against penicillin congeners than against cephalosporin congeners. Most strains were not inhibited by readily achievable serum concentrations of the pencillinase-sensitive penicillins, penicillin G, ampicillin, and amoxicillin. Methicillin was equally ineffective. With rare exceptions, most strains of B. catarrhalis were inhibited by achievable serum concentrations of seven cephalosporins (cephalothin, cephapirin, cephaloridine, cephalexin, cephamandole, cefaclor, and cefuroxin) and one cephamycin (cefoxitin). All strains were uniformly resistant to clindamycin but were inhibited by achievable serum concentrations of erythromycin, tetracycline, chloramphenicol, and trimethoprim-sulfamethoxazole. Comparison of geometric mean minimum inhibitory concentrations of all antimicrobial agents tested suggested that B. catarrhalis was most susceptible to cefoxitin, erythromycin, and tetracycline.

Anti-Bacterial Agents↗
PubMed1980

Branhamella (Neisseria) catarrhalis: criteria for laboratory identification.

Eleven clinically significant isolates of Branhamella catarrhalis grew well on modified Thayer-Martin medium and produced beta-lactamase, but did not grow on nutrient agar at 22 degrees C. Minimum inhibitory concentrations of vancomycin, colistin, and trimethoprim were found to be higher than the concentrations of these antibiotics in modified Thayer-Martin medium. The criteria necessary for laboratory identification of B. catarrhalis are discussed.

Colistin↗
PubMed1976

Ultrastructural characterization of capsulated Haemophilus influenzae type b and two spontaneous nontypable mutants.

Capsulated Haemophilus influenzae type b and two spontaneous mutants (classes I and II variants) were characterized by transmission and scanning electron microscopy. When cells were treated with type b-specific antiserum prior to manipulations for electron microscopy, sectioned capsulated cells had electron-dense, fibrous capsular antigen-antibody complexes around them. In negatively stained preparations, the complexes appeared as electron-transparent zones surrounding cells. In contrast, only residual electron-dense, extracellular material was seen in sectioned, untreated, capsulated cells, and electron-dense "bridges" connected adjacent cells in negatively stained preparations. No extracellular capsular material was seen around the class I and II variants. Characteristic electron-translucent regions were always observed within the cytosol of the class I cells, both in thin sections and by negative staining. These areas were located adjacent to the cell envelope separating the plasma membrane from the dense cytoplasmic matrix. At times, electron-dense, thread-like material extended from the dense cytoplasmic matrix to the plasma membrane. No such regions were seen in the capsulated and class II cells. Class I cells fixed with methanol or suspended in NaCl or phosphate-buffered saline prior to treatment with fluorescein-tagged type b-specific antiserum (FTA reagent) exhibited, by immunofluorescence, patches of capsular antigen along their sides. However, when fixed with glutaraldehyde or OsO4 or suspended in tris-(hydroxymethyl)aminomethane plus Ca2+ buffer prior to treatment with FTA reagent, no patches of capsular antigen were seen. Subsequent exposure of the latter cells to methanol followed by treatment with FTA reagent resulted in the reappearance of the patches of capsular antigen. Thus, in the class I variant the capsular antigen is unlikely to be surface located. Scanning electron microscopy revealed that class I and II variant cells within undisturbed colonies were regularly aligned side-by-side, whereas cells within colonies of the capsulated strain were randomly distributed.

Antigen-Antibody Complex↗
PubMedDate not supplied

In vitro activity of BAY v 3522, a new oral cephalosporin tested against Haemophilus influenzae and Branhamella catarrhalis.

The in vitro activity of BAY v 3522, a new orally absorbed cephalosporin, was assessed against 150 clinical isolates each of Haemophilus influenzae and Branhamella catarrhalis. The MIC90S for beta-lactamase-positive and -negative strains of H. influenzae were 8 and 2 micrograms/ml, respectively. For beta-lactamase-positive and -negative strains of B. catarrhalis, the BAY v 3522 MIC90S were 4 and 0.25 micrograms/ml, respectively. In general, BAY v 3522 was less active against H. influenzae than amoxicillin/clavulanic acid and cefixime, equivalent in activity to cefuroxime, and more active than cefaclor. BAY v 3522 had activity most similar to cefuroxime and cefaclor for B. catarrhalis but was less active than amoxicillin/clavulanic acid and cefixime.

Administration, Oral↗
PubMedDate not supplied

In vitro activity of cefprozil (BMY 28100) and cefepime (BMY 28142) against Streptococcus pneumoniae, Branhamella catarrhalis, and Haemophilus influenzae, and provisional interpretive criteria for disk diffusion and dilution susceptibility tests with Haemophilus influenzae.

The in vitro activities of two new cephalosporins, an oral agent, cefprozil and a parenteral compound, cefepime, were assessed against recent clinical isolates of Streptococcus pneumoniae, Moraxella (Branhamella) catarrhalis, and Haemophilus influenzae. In general, both cefprozil and cefepime MICs were higher for beta-lactamase-producing strains of M. catarrhalis in comparison to strains that lacked beta-lactamase. By contrast, beta-lactamase-positive and -negative strains of H. influenzae had similar cefprozil and cefepime minimum inhibitory concentrations (MICs). The MIC90 values for cefprozil were 0.12, 32, 4.0, and 0.5 micrograms/ml versus S. pneumoniae, H. influenzae, and beta-lactamase-positive and negative strains of M. catarrhalis, respectively. In comparison to three other oral cephalosporins included in this study, cefaclor, cefuroxime axetil, and cefixime, cefprozil was the most active agent against S. pneumoniae, the least active against B. catarrhalis, and equivalent in activity to cefaclor against H. influenzae. The cefepime MIC values against S. pneumoniae, H. influenzae, and beta-lactamase-positive and negative strains of M. catarrhalis were 0.03, 0.25, 2.0, and 0.5 micrograms/ml, respectively. Cefepime was less active than ceftriaxone for all three organism groups, however, was in all cases more active than cefixime, cefuroxime, cefaclor, and cefprozil.(ABSTRACT TRUNCATED AT 250 WORDS)

Cefepime↗
PubMedDate not supplied

Quality control limits for disk diffusion and broth microdilution susceptibility tests with Haemophilus test medium.

A six-center collaborative study was performed with the aim of developing quality control test limits for both disk diffusion and broth microdilution susceptibility tests with Haemophilus influenzae ATCC 49247 using Haemophilus test medium. Quality control ranges are presented for 18 antimicrobials: ampicillin, amoxicillin-clavulanate, ampicillin-sulbactam, cefuroxime, cefamandole, cefonicid, cefotaxime, ceftriaxone, ceftizoxime, ceftazidime, cefixime, chloramphenicol, tetracycline, trimethoprim-sulfamethoxazole, rifampin, imipenem, aztreonam, and ciprofloxacin.

Anti-Bacterial Agents↗
PubMedDate not supplied

In vitro activity of ceftibuten against Haemophilus influenzae and Branhamella catarhallis.

The in vitro activity of ceftibuten, a new orally administered cephalosporin, was assessed against clinical isolates of Haemophilus influenzae and Branhamella catarrhalis. The activity of ceftibuten was compared to that of ampicillin, amoxicillin-clavulanic acid, and three oral cephalosporins, cefaclor, cefuroxime, and cefixime. With the exception of rare beta-lactamase-negative ampicillin-resistant strains of H. influenzae, resistance to ceftibuten was not observed with any of the study isolates. Ceftibuten was more active than amoxicillin/clavulanic acid for beta-lactamase-positive and -negative strains of H. influenzae; it was less active than this combination for B. catarrhalis. Ceftibuten was essentially equivalent in activity to cefixime against both Haemophilus and Branhamella but more active than cefaclor and cefuroxime against these two organisms.

Amoxicillin↗
PubMedDate not supplied

A comparison of commercially available monoclonal antibodies for direct and indirect immunofluorescence culture confirmation and direct detection of parainfluenza viruses.

Two commercially available immunofluorescence monoclonal antibody (MAB) reagents (Bartels, Baxter Healthcare, Issaquah, WA; and Symex, Broken Arrow, OK) were evaluated as a means for detecting parainfluenza virus (PIV) both in shell-vial cultures and directly in clinical specimens. Bartels reagents are used in an indirect immunofluorescence assay (IFA) format and exist as MABs reactive with all three PIV serotypes, individually and in a pool. Symex reagents, also available individually and in a trivalent pool, are used in a direct immunofluorescence assay (DFA) format. Among a total of 299 respiratory specimens, 24 yielded PIV. In a shell-vial culture confirmation test, both the individual and pooled monoclonal antibody reagents from both Bartels and Symex detected all 24 PIV isolates. There were three apparent false-positive results with the Bartels pooled IFA reagents. Of the 299 specimens, 160 were also tested directly for the presence of PIV. There were 13 positive specimens among these 160. The Bartels and Symex monoclonal antibody reagents detected similar percentages of positive samples when used for direct detection (that is, 78.6-85.7). No false-positive results were obtained with any of the reagents in the direct-detection format.

Antibodies, Monoclonal↗
PubMedDate not supplied

RP 59500, a new streptogramin highly active against recent isolates of North American staphylococci.

To assess the potential clinical utility of RP 59500, 10 investigators from separate locations in the United States and Canada each tested approximately 200 current isolates of staphylococci (Staphylococcus aureus and coagulase-negative staphylococci) by a standard protocol. RP 59500 was highly active (MIC90 < or = 2 micrograms/ml) against all strains, including those that were resistant to oxacillin, ciprofloxacin, erythromycin, and spiramycin.

Coagulase↗