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Biomedical subjects

E Yourassowsky

Publications and source records attributed to E Yourassowsky.

At least 127 records · Page 7Linked to original sources
PubMed1979

Use and interpretation of Schlichter's test on Haemophilus influenzae: relation of in vitro to in vivo results for cefamandole.

When Haemophilus influenzae infections are treated by an antibiotic acting on the bacterial wall, the adequacy of antimicrobial therapy can be assessed by Schlichter's test. This test may be carried out using Mueller Hinton broth (or Mueller Hinton broth with 50% pooled serum and a supplement of Ca++ and Mg++) supplemented with Fildes' enrichment and an inoculum adjusted to the 0.5 McFarland turbidity standard diluted 200x. However, correct reading of end points can be obtained only by phase contrast microscopic examination, which allows the establishment of good correlation between the in vitro and in vivo findings. In patients with lung infections successfully treated with cefamandole, the presence of spheroplasts in samples derived from Schlichter's tests correlates well with clinical improvement and eradication of the pathogenic organism checked by transtracheal aspiration.

Blood Bactericidal Activity↗
PubMed1979

Clinical and pharmacological evaluation of different preparations of oral erythromycin.

The activity of erythromycin stearate in respiratory tract infections was evaluated. This study involved 269 out-patients. Of these, 76 satisfied the strict criteria for detailed bacteriological study with positive cultures of a known pathogen before treatment and bacteriological follow-up after treatment. The results of erythromycin stearate were good against the haemolytic streptococcal infections. The activity of this antibiotic was shown to be insufficient against Haemophilus influenzae. A second clinical trial with 20 patients with acute exacerbations of chronic bronchitis demonstrated quite good activity from erythromycin ethylsuccinate and no intolerance when administered in a dose of 1 g q.i.d. The administration of 1 g of the ethylsuccinate immediately after a meal gave a peak serum concentration after 60 min of 3.36 micrograms/ml. Blood levels on the fourth day of this treatment showed some accumulation, concentrations of greater than 4 micrograms/ml being found at 30, 60 and 90 min after the dose. With its good absorption, its lack of toxicity and its reputation for good diffusion into bronchial secretions, we consider that erythromycin ethylsuccinate should have a major place in the treatment of respiratory tract infections.

Administration, Oral↗
PubMed1979

[Ampicillin-resistant "Haemophilus": their detection and occurrence in Brussels area (author's transl)].

Three hundred and five strains of Haemophilus (129 H. influenzae, 55 H. parainfluenzae, 97 H. parahaemolyticus, 5 H. haemolyticus, 10 H. paraphrophilus and 9 H. paraphrohaemolyticus) isolated from pathological material over the year 1976, were systematically tested for beta-lactamase production. Only 2 strains of H. parainfluenzae produced this enzyme. Both were able to transfer ampicillin resistance to Escherichia coli K12. All strains but the two beta-lactamase producers were susceptible to penicillin G, ampicillin and cephalotin. However, the correct interpretation of the susceptibility tests needed the microscopic observation of prints of the inhibition zones surrounding the disks: all sensitive strains presented a hazy growth around the disks which corresponded to the presence of spheroplasts; this phenomenon was not observed with the 2 beta-lactamase producing strains of H. parainfluenzae which grew up to the disks but presented a typical bacillary form.

Ampicillin↗
PubMed1978

Indications, interpretation and applications of antibiotic assays.

Routine monitoring of serum levels is imperative when antibiotics are given to patients with impairment of renal function. Other desirable indications include: need for assessment of adequate aminoglycoside levels in the initial management of severe infection; chloramphenicol therapy; need for control of bioavailability of new drugs or of new derivatives of known compounds; specific clinical situations (unexplained therapeutic failure, assessment of the oral use of antibiotics as an adequate therapy in patient with severe infections; appraisal of the innocuity of topical antibiotics in burned patients or in patients with liver or renal insufficiency). The serum antibacterial test is highly recommended for assessing the adequency of antibiotic therapy in patients with bacterial endocarditis and in infected patients with impaired host resistance such as those with leukopenia. Control of initial treatment in any severe infection, osteomyelitis (particularly when combined antibiotics are used) and tuberculosis are other indications of this test. Any attempt to correlate the results yielded by antibiotic assays with in-vivo effectiveness must take into account the patient himself and the several unknown factors which, in each individual case, can affect the ultimate result of the antibiotic therapy, such as antibiotic delivery to tissues, drug binding to cellular debris, intracellular penetration of the antibiotic, etc.

Administration, Oral↗
PubMed1978

Amoxicillin entry into human cerebrospinal fluid: comparison with ampicillin.

The entry of amoxicillin and ampicillin into cerebrospinal fluid (CSF) of humans was studied in the absence of meningeal inflammation. Twelve volunteers received 33 mg of amoxicillin per kg intravenously over 30 min and nine volunteers received 33 mg of ampicillin per kg. The CSF specimens were sampled at 1, 2, and 4 h after the beginning of the infusion. Blood samples were obtained at the end of the infusion and at 45, 60, 90, 120, 180, and 240 min after the beginning of the infusion. Amoxicillin and ampicillin were both detected in the CSF. Ampicillin tended to give higher CSF levels than amoxicillin, although the difference was small. Serum concentrations of ampicillin equaled those of amoxicillin.

Adult↗
PubMed1978

Susceptibility of Campylobacter fetus subsp. jejuni to twenty-nine antimicrobial agents.

The activity of 29 antimicrobial agents was tested against 95 strains of Campylobacter fetus subsp. jejuni isolated from human stools. Furazolidone and gentamycin were the most active agents. The tetracyclines, erythromycin, and chloramphenicol were very active against most of the strains, but with each antibiotic a few resistant strains were found. The penicillins were relatively inactive, and the cephalosporins tested were only active against occasional strains.

Anti-Bacterial Agents↗
PubMed1978

In-vitro activity of antimicrobial agents against Neisseria gonorrhoeae in Brussels.

The minimum inhibitory concentrations (MICs) of 18 antimicrobial agents against 104 strains of Neisseria gonorrhoeae isolated in the Brussels area between January and October 1976 have been measured. The MICs for penicillin G, ampicillin, amoxycillin, carbenicillin, and cephalexin showed a bimodal distribution. The second modus strains of cephalexin (MIC = 6.25 microgram/ml) were relatively resistant to penicillin G (MIC greater than or equal to 0.08 microgram/ml). About 51% of all strains were relatively resistant to penicillin G, 40.5% to ampicillin (MIC greater than or equal to 0.16 microgram/ml), 46% to amoxycillin, and 47.5% to carbenicillin. For cephalexin and cephaloridine, 25% and 8.5% respectively of all strains were relatively resistant (MIC greater than 3.12 microgram/ml). For cefazolin all MICs fell into a range of 0.097--3.12 microgram/ml. Resistance to tetracycline, doxycycline, minocycline, erythromycin, and spiramycin (MIC greater than or equal to 1 microgram/ml) was found in 9.5%, 7%, 6%, 36.5%, and 71% respectively of all isolates. No strains were resistant to rifampicin. For chloramphenicol and thiamphenicol the MICs ranged from 0.39 to 12.5 microgram/ml and from 0.195 to 3.12 microgram/ml respectively. The results for sulphamethoxazole, trimethoprim, and the combination of sulphamethoxazole and trimethoprim in a 20:1 ratio are given and discussed. The fractional inhibitory concentration (FIC) indices have also been calculated. No beta-lactamase-producing strains were found, and a contingency coefficient C has been determined for all the pairs of antibiotics investigated.

Anti-Bacterial Agents↗
PubMed1978

Qualitative study of paradoxical zone phenomenon of penicillins against 17 bacterial species of clinical importance.

Using a triple agar layer technique and enzymatic inactivation of penicillin, the occurrence of a paradoxical zone phenomenon (illustrated by a typical 'target' image around the reservoir of antibiotic) was determined for several bacterial species specially chosen with regards to their taxonomic position, clinical importance and penicillin susceptibility. Among gram-positive bacteria, a paradoxical zone was obtained for approximately 43% of the strains studied here (all 10 strains of Staphylococcus aureus, all 10 strains of Streptococcus faecalis, 7 of 10 strains of group B beta-hemolytic streptococci, 1 of 10 group A strains, 3 of 10 strains of alpha-hemolytic streptococci, 3 of 10 strains of Clostridium perfringens but for none of 10 strains each of Streptococcus pneumoniae, and Listeria monocytogenes). Among gram-negative bacteria, a target image was regularly obtained with Haemophilus influenzae (all 10 strains tested) and Proteus species (9 of 10 strains) but with none of the following species: Escherichia coli, Salmonella, Shigella, Pseudomonas aeruginosa, Neisseria gonorrhoeae, Neisseria meningitidis and Bacteroides fragilis. Therapeutic implications of these observations are difficult to assess, and need further investigation.

Bacteria↗
PubMed1977

Usefulness of transtracheal puncture and aspiration in the bacteriological diagnosis of pulmonary tuberculosis.

Transtracheal puncture enables two samples of bronchial secretions to be taken-the product of transtracheal aspiration and simultaneously expectorated sputum (obtained in 71% of the cases)-for the purpose of testing for Mycobacterium tuberculosis in cases of suspected pulmonary tuberculosis. Two groups of patients were studied: Group I: 100 patients who were poor expectorators and who all underwent transtracheal puncture; Group II (Control): 100 patients who expectorated well or who had been given gastric lavages immediately on admission. Laboratroy analyses revealed M. tuberculosis in at least one of the samples obtained from each of the 200 patients. The authors compare the efficiency of the methods used within each group and between the two groups. Samples obtained by transtracheal aspiration and simultaneous expectoration (75% of positive results) more often contained M. tuberculosis than the other Group I samples (64% of total positive results; 64% of positive results for spontaneous sputa, 65% for gastric fluids), and as often as the Group II samples (76% of total positive results), particularly the expectoration samples (78% of positive results). Simultaneously expectorated sputum more frequently contained M. tuberculosis (82% of positive results) than transtracheal aspiration (69% of positive results). Transtracheal puncture and/or simultaneous expectoration were the only examinations revealing M. tuberculosis in 34 patients in Group I. Non-specific bacteriological findings are not relevant. However, the authors point out that this technique is not always innocuous (although no serious complications were observed in this series), and that transtracheal puncture must always be carried out by physicians trained in the technique.

Adult↗
PubMed1977

Isolation of Bacteroides corrodens and Eikenella corrodens from human clinical specimens. Comparative study of incidence and methods of identification.

In the course of a systematic search for Bacteroides corrodents and Eikenella corrodens in clinical specimens submitted for microbiological analysis, 61% of the specimens from anal abscesses, 6% of the vaginal specimens and none of the pharyngeal specimens yielded B. corrodens, whereas E. corrodens was recovered from only 9% of the pharyngeal specimens. Some characteristics were found to be useful in differentiating between the two species: B. corrodens strains were strictly anaerobic, cytochrome-oxidase-negative, urease-positive and gelatinase-positive; they were sensitive to lincomycin but resistant to vancomycin. E. corrodens strains on the other hand were facultatively anaerobic, oxidase-positive, urease-negative and gelatinase-negative; they were resistant to lincomycin but sensitive to vancomycin. The pathogenicity of the two species was difficult to assess as in most cases they were recovered from mixed cultures.

Anti-Bacterial Agents↗
PubMed1977

Taxonomy of Acinetobacter: the usefulness of beta-D-xyloside xylohydrolase for strain differentiation.

One hundred and twenty-two clinical isolates of Acinetobacter were studied for the presence of beta-galactosidase and of beta-xylosidase, for biochemical characteristics, and for genetic interspecies transformation tests. All strains lacked beta-galactosidase; in contrast, beta-xylosidase was always present in the oxidative strains. This test proved to be of value for separating strains able to form acid from carbohydrates (A. anitratum and A. haemolyticus spp haemolyticus) from the non-oxidative strains (A. lwoffi and A. haemolyticus spp alcaligenes). However, the genetic relationship of all strains tested warrants further study before Acinetobacters are grouped into clearly defined species.

Acinetobacter↗
PubMed1976

Clinical and bacteriological evaluation of amikacin in severe gram-negative infections.

Amikacin was administered to 51 patients with serious Gram-negative infections. A favorable clinical outcome was observed in 32 patients (62 per cent). No major untoward effects were noted. The severity of the underlying disease and the site of the infection were important for the outcome. Urinary tract infections responded in 21 (78 per cent) out of 27 patients, but bronchopulmonary infections responded in only 3 out of 10 patients (30 per cent). The degree of antibacterial activity of the serum of the patients receiving amikacin was found to be related to the outcome. An activity greater than or equal to 1/8 was associated with 78 per cent of favorable responses and was found more often in patients receiving 1500 mg daily.

Adult↗
PubMed1976

[Ticarcillin].

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Carbenicillin↗
PubMed1976

[Tobramycin].

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Anti-Bacterial Agents↗
PubMed1976

A Rapid, simple method for demonstrating synergy of amikacin and penicillin against various microorganisms.

A simple disk diffusion technique with use of triple-layer agar and enzymatic inactivation of penicillin demonstrated synergy between penicillins and aminoglycosides. The method was applied to measurement of the synergistic activity of amikacin and penicillin G against a strain of Streptococcus faecalis sensitive to both drugs, amikacin and ampicillin against a strain of S. faecalis sensitive to amplicillin but resistant to amikacin, and amikacin and carbenicillin against a strain of Proteus mirabilis sensitive to both drugs. The degree of synergy was related to the specific organism tested. For example, syngery of penicillin G and amikacin for S. faecalis could be demonstrated only when the organism was subjected first to the action of penicillin G alone. In addition to providing useful clinical information, the triple-layer technique appears to be a promising tool for the study and understanding of synergy between antimicrobial agents.

Amikacin↗