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J S Redding

Publications and source records attributed to J S Redding.

At least 19 recordsLinked to original sources

Antimicrobial resistance among respiratory isolates of Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae in the United States.

A national surveillance study was conducted to determine trends in antimicrobial resistance patterns among three common causes of community-acquired respiratory tract infections. Fifteen participating U.S. medical centers submitted clinically significant isolates of Haemophilus influenzae, Moraxella (Branhamella) catarrhalis, and Streptococcus pneumoniae to two central laboratories for testing with a group of 12 antimicrobial agents. The majority of isolates were recovered from adult males greater than 50 years old. Overall, 84.1% of 378 M. catarrhalis and 16.5% of 564 H. influenzae (29.5% of type b strains; 15.0% of non-type b strains) produced beta-lactamase and were thus resistant to penicillin, ampicillin, and amoxicillin. Resistance in H. influenzae to other agents was 2.1% to tetracycline, 0.7% to trimethoprim-sulfamethoxazole, 1.1% to cefaclor, and 0.2% to cefuroxime and amoxicillin-clavulanate, while the M. catarrhalis isolates yielded very low MICs of these latter drugs. As demonstrated in prior studies, erythromycin showed little activity against H. influenzae. Of 487 S. pneumoniae isolates, 1 (0.2%) was penicillin resistant, while 3.8% were relatively resistant to penicillin, 4.5% were resistant to trimethoprim-sulfamethoxazole, 2.3% were resistant to tetracycline, 1.2% were resistant to chloramphenicol, and 0.2% were resistant to erythromycin. Overall, the lowest resistance rates for these common bacterial respiratory pathogens were noted with amoxicillin-clavulanate, cefuroxime, and cefaclor.

Adolescent↗

Antibacterial activity of the new glycopeptide antibiotic SKF104662.

The inhibitory activity of the new glycopeptide antibiotic SKF104662 was generally equivalent (+/- 1 concentration increment) to the activities of vancomycin, teicoplanin, and daptomycin against selected gram-positive bacteria. However, SKF104662 demonstrated greater activity against Staphylococcus epidermidis and S. haemolyticus than did teicoplanin and was more active than the other drugs against Clostridium difficile isolates. SKF104662 possessed bactericidal activity quite similar to that of vancomycin against selected isolates of Staphylococcus, Streptococcus, and Enterococcus species.

Anti-Bacterial Agents↗

Susceptibility of multiply resistant Haemophilus influenzae to newer antimicrobial agents.

One hundred and six isolates of Haemophilus influenzae from a national antimicrobial surveillance study demonstrated resistance to two or more of 10 primary antimicrobial agents by mechanisms other than or in addition to beta-lactamase. Of particular note were strains multiply resistant to ampicillin (by beta-lactamase production), chloramphenicol, trimethoprim/sulfamethoxazole, and tetracycline in various combinations. All of the aforementioned strains were shown to be highly susceptible to amoxicillin/clavulanate, the second generation cephalosporins cefuroxime and cefonicid, and the third generation cephalosporins cefotaxime, ceftizoxime, ceftriaxone, ceftazidime, moxalactam, and cefixime. However, 68 strains that demonstrated resistance or marginal susceptibility (MIC greater than or equal to 2 micrograms/ml) to ampicillin by mechanisms other than beta-lactamase, also demonstrated reduced susceptibility to amoxicillin/clavulanate (MICs up to 8 micrograms/ml) and the second generation cephalosporins (MICs up to 32 micrograms/ml). While the latter strains were susceptible to the third generation cephalosporins, MICs were often 10-fold higher than MICs of ampicillin susceptible isolates or of beta-lactamase producing isolates. All of the multiply antimicrobial-resistant strains were highly susceptible (MIC less than or equal to 0.25 micrograms/ml) to the two quinolones ciprofloxacin and pefloxacin.

Ampicillin Resistance↗

Influence of storage and susceptibility test conditions on stability and activity of LY163892 and four other cephalosporins.

A new carbacephem analog of cefaclor, LY163892, was examined along with four other cephalosporins for chemical stability and for antibacterial activity under a variety of susceptibility test conditions. LY163892 was found to be markedly more stable than cefaclor during storage at 4 and 35 degrees C in human serum, human urine, and various bacteriological media. Under these conditions, LY163892 demonstrated stability equal or superior to the stabilities of cephalexin, cephalothin, and cefuroxime. Broth and agar dilution susceptibility tests did not reveal significant differences in LY163892 activity in a variety of test media, although LY163892 MICs were somewhat higher in Mueller-Hinton chocolate agar or Trypticase soy broth (BBL Microbiology Systems, Cockeysville, Md.) than in other media. The activity of LY163892 against selected pathogens was only slightly influenced by the increased or decreased pH of the test medium, in a manner similar to that of the other cephalosporins tested. Thus, the carbacephem structure of LY163892 appears to represent a more stable cephalosporin than cefaclor, while retaining a similar antimicrobial spectrum.

Bacteria↗

National collaborative study of the prevalence of antimicrobial resistance among clinical isolates of Haemophilus influenzae.

A total of 2,811 clinical isolates of Haemophilus influenzae were obtained during 1986 from 30 medical centers and one nationwide private independent laboratory in the United States. Among these, 757 (26.9%) were type b strains. The overall rate of beta-lactamase-mediated ampicillin resistance was 20.0%. Type b strains were approximately twice as likely as non-type b strains to produce beta-lactamase (31.7 versus 15.6%). The MICs of 12 antimicrobial agents were determined for all isolates. Ampicillin resistance among strains that lacked beta-lactamase activity was extremely uncommon (0.1%). Percentages of study isolates susceptible to cefamandole, cefaclor, cephalothin, and cephalexin were 98.7, 94.5, 87.3, and 43.3%, respectively. For 14 strains (0.5% of the total), chloramphenicol MICs were greater than or equal to 8.0 micrograms, and thus the strains were considered resistant. All of these resistant strains produced chloramphenicol acetyltransferase. In addition, all 14 strains were resistant to tetracycline; 11 produced beta-lactamase. The percentage of isolates susceptible to tetracycline was 97.7%. In contrast, erythromycin and sulfisoxazole were relatively inactive. The combination of erythromycin-sulfisoxazole (1/64) was more active than erythromycin alone but essentially equivalent in activity to sulfisoxazole alone. Finally, small numbers of clinical isolates of H. influenzae were resistant to trimethoprim-sulfamethoxazole and rifampin.

Ampicillin Resistance↗

Salt-supplemented medium for testing methicillin-resistant staphylococci with newer beta-lactams.

The addition of 2% NaCl to cation-supplemented Mueller-Hinton broth (CSMHB) was evaluated for microdilution testing of the susceptibility of staphylococci to five cephalosporins, imipenem, amoxicillin-clavulanate, and ticarcillin-clavulanate. With Staphylococcus aureus, NaCl improved the recognition of methicillin (oxacillin) resistance to cefamandole, imipenem, or ticarcillin-clavulanate. Resistance to amoxicillin-clavulanate was readily determined, irrespective of the presence of added salt. The addition of 2% NaCl to CSMHB did not significantly improve detection of resistance to any of the beta-lactams among coagulase-negative staphylococci. Since the addition of NaCl did not have significant adverse effects on tests with coagulase-negative staphylococci, the routine addition of 2% NaCl to oxacillin or methicillin tests with staphylococci may be justifiable on the basis of convenience or standardization. However, addition of NaCl to susceptibility tests of other beta-lactams does not consistently improve recognition of resistance among staphylococci and thus cannot be recommended for routine use.

Amoxicillin↗

Disk diffusion interpretive criteria for extended-spectrum cephalosporins with Haemophilus influenzae.

Disk diffusion interpretive zone size criteria for use with Haemophilus test medium are proposed for five extended-spectrum cephalosporins. With cefuroxime, zones greater than or equal to 24 mm in diameter indicated susceptibility, while zones less than or equal to 20 mm implied resistance. With cefotaxime, ceftizoxime, and ceftriaxone, a single susceptible-zone size, greater than or equal to 26 mm, is proposed.

Cephalosporins↗

In vitro activity of LY146032 (daptomycin) against selected aerobic bacteria.

The in vitro activity of the new lipopeptide antibiotic LY146032 was generally four-fold greater (MIC 90 less than or equal to 0.5 microgram/ml) than that of vancomycin against methicillin-susceptible or methicillin-resistant Staphylococcus aureus and coagulase-negative species of Staphylococcus. Enterococci, Streptococcus bovis, group B and viridans streptococci, and Corynebacterium group J-K isolates were inhibited by less than or equal to 4 micrograms/ml of LY146032, which represented activity equivalent to or greater than that of vancomycin. Unlike vancomycin, LY146032 was bactericidal for Enterococcus faecalis, Enterococcus faecium and Listeria monocytogenes. Due to its bactericidal properties LY146032 appeared to represent an improvement over vancomycin and teicoplanin.

Anti-Bacterial Agents↗

Improved medium for antimicrobial susceptibility testing of Haemophilus influenzae.

The need for complex growth media has complicated routine susceptibility testing of Haemophilus influenzae because of antagonism of certain antimicrobial agents by the medium or because of difficulties in interpretation of growth endpoints. Haemophilus test medium (HTM) is a simple, transparent medium for broth- or agar-based tests with H. influenzae. HTM incorporates Mueller-Hinton medium with additions of 15 micrograms of hematin per ml, 15 micrograms of NAD per ml, and 5 mg of yeast extract per ml as growth-promoting additives. Agar or broth microdilution MICs of 10 antimicrobial agents for a collection of 179 H. influenzae isolates determined by using HTM compared favorably with MICs determined by the conventional agar or broth dilution methods recommended by the National Committee for Clinical Laboratory Standards. Disk diffusion tests performed with HTM allowed accurate categorization of susceptible and resistant strains and were easier to interpret than tests performed with Mueller-Hinton chocolate agar. A particular advantage of HTM was the reliability of broth- or agar-based test results with trimethoprim-sulfamethoxazole. The results of the study suggest modification of current National Committee for Clinical Laboratory Standards MIC-interpretive criteria for H. influenzae with amoxicillin-clavulanate, chloramphenicol, and trimethoprim-sulfamethoxazole. Error rate-bounded analysis of MICs and disk diffusion zone sizes also suggest modified zone-interpretive criteria for ampicillin, amoxicillin-clavulanate, chloramphenicol, and tetracycline with HTM or conventional media. Interpretive zone sizes are newly proposed for cefaclor and rifampin disk diffusion tests.

Anti-Bacterial Agents↗

In vitro activity of the new macrolide antibiotic roxithromycin (RU 28965) against clinical isolates of Haemophilus influenzae.

The in vitro activity of the new macrolide antibiotic roxithromycin (RU 28965) was compared with the activities of five other orally absorbable antimicrobial agents against 100 clinical isolates of Haemophilus influenzae. Roxithromycin MICs were generally twofold to fourfold higher than those of erythromycin; the MIC for 90% of the strains for roxithromycin was 8 micrograms/ml.

Anti-Bacterial Agents↗

Evaluation of broth disk elution methods for susceptibility testing of anaerobic bacteria with the newer beta-lactam antibiotics.

Broth disk elution procedures represent one of the most practical means for clinical laboratories to perform routine antibiotic susceptibility tests on anaerobic bacteria. The accuracy of five disk elution test methods and media (including the one to be proposed by the National Committee for Clinical Laboratory Standards) was evaluated for the testing of newer beta-lactam antibiotics, including cefoperazone, cefotaxime, cefoxitin, ceftazidime, ceftizoxime, moxalactam, and piperacillin. Various numbers of antibiotic disks were used to achieve disk elution test concentrations which approximated the highest MIC termed susceptible by the Food and Drug Administration. A group of 88 anaerobes representing many different species was tested in parallel by the five disk elution methods and the National Committee for Clinical Laboratory Standards reference agar dilution procedure. Overall, full agreement between the reference agar dilution MICs and the disk elution category results was 88.3% for PRAS BHI, 84.5% for Schaedler, 85.7% for thioglycolate, and 87.4% for Wilkins-Chalgren broth. Essential agreement (+/- 1 twofold MIC increment from the disk elution concentration) was achieved with 94.6% of PRAS BHI tests, 94.3% of Schaedler tests, 93.6% of thioglycolate tests, and 95.7% of Wilkins-Chalgren tests. Due to growth failures with a number of isolates and difficulties in interpreting results, the use of Wilkins-West broth was discontinued after approximately one-half of the isolates had been tested. The majority of errors with all of the disk elution methods occurred with isolates (most notably members of the Bacteroides fragilis group) having MICs near the single test concentrations used in the disk methods. With the notable exception of tests for the B. fragilis group, the disk elution methods offered acceptable accuracy with the newer beta-lactam antibiotics tested in this study.

Anti-Bacterial Agents↗

Cardiopulmonary resuscitation. The essentials.

Cardiopulmonary resuscitation (CPR) techniques are intended to revive those who experience an unexpected respiratory or circulatory catastrophe. The skills of CPR are reviewed for the surgeon, whose patients may need this assistance. Advances in the basic understanding, techniques, teaching, and practice of CPR have led to the saving of countless lives.

Acidosis↗

Collaborative evaluation of the Abbott Avantage system for identification of frequently isolated nonfermentative or oxidase-positive gram-negative bacilli.

The capability of the Abbott Avantage system to identify 10 species of commonly isolated glucose nonfermentative or oxidase-positive gram-negative bacilli in a 5-h test period was evaluated in a collaborative study. The Avantage nonenteric data base uses 20 biochemical test reactions performed in an expanded Abbott bacterial identification cartridge plus the results of a manual oxidase test. The species included in the Avantage data base are Acinetobacter anitratus, Acinetobacter Iwoffi, Aeromonas hydrophila, Flavobacterium meningosepticum-IIb group, Pseudomonas aeruginosa, Pseudomonas cepacia, Pseudomonas fluorescens-putida group, Pseudomonas maltophilia, Pasteurella multocida, and Plesiomonas shigelloides. The collaborative study included the testing of 200 coded challenge strains in all three laboratories and the subsequent testing of an additional group of 100 to 200 clinical isolates recovered independently by each laboratory. Reference identifications for all isolates were determined by conventional biochemical test reactions. The overall accuracy of identification of the coded challenge strains for the three laboratories was 97%, whereas 95% of 437 clinical isolates and selected stock cultures of clinical derivation were identified correctly.

Bacteria↗

Drug therapy in resuscitation from electromechanical dissociation.

Electromechanical dissociation (EMD) (organized ECG activity without myocardial contractions) is thought to be rare and associated with poor prognosis. Epinephrine, calcium chloride, and atropine are recommended during attempted resuscitation. Epinephrine's effectiveness in other forms of cardiac arrest is due to its alpha-adrenergic action. Its beta-adrenergic effect may be a disadvantage which is not characteristic of methoxamine, a pure alpha-agonist. Forty anesthetized dogs were asphyxiated until asystolic. Five min later each had slow organized ECG activity. Ventilation with air and sternal compressions were started; 10 dogs each received saline, atropine, calcium chloride, or methoxamine iv. Resuscitation was discontinued after 10 min. Two dogs were resuscitated after saline. Results were not significantly better after atropine or calcium chloride. All 10 which received methoxamine were resuscitated; methoxamine, given at the end of the protocol to all dogs not resuscitated with atropine or calcium chloride, promptly restored spontaneous circulation.

Animals↗