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W L Dibb

Publications and source records attributed to W L Dibb.

33 records · Page 2Linked to original sources
PubMed1983

The in vitro activity of gentamicin, tobramycin and netilmicin against 500 clinical isolates of bacteria. A comparative study using three different test media.

The in vitro activities of the three aminoglycoside antibiotics, gentamicin, and tobramycin have been compared against 500 isolates of Enterobacteriaceae, Pseudomonas aeruginosa and Staphylococcus aureus. An agar dilution method was employed with three sensitivity media: Iso-Sensitest Agar, Mueller-Hinton Agar and PDM-Antibiotic Sensitivity Medium. All three aminoglycosides were highly active against S. aureus (MIC less than or equal to 0.5 mg/l) and the majority of Enterobacteriaceae (MIC90 approx. 1 mg/l). Tobramycin showed the highest activity against P. aeruginosa (MIC less than or equal to 1 mg/l). No major difference in measured MIC were found on the three media. Gentamicin and netilmicin were somewhat less active against P. aeruginosa on Mueller-Hinton Agar. MICs for tobramycin against Enterobacteriaceae were a little higher on PDM than on the other two agars. Our results show that measured MIC varied very little on the three sensitivity media. All media are suitable for routine use, provided that control strains are employed.

Anti-Bacterial Agents↗
PubMed1983

N-formimidoyl thienamycin: in vitro comparison with cefoxitin and tobramycin against clinical, bacterial isolates.

The in vitro activity of the novel beta-lactam antibiotic, N-formimidoyl thienamycin (N-f thienamycin) has been compared with those of cefoxitin and tobramycin. An agar dilution method was employed. N-f thienamycin was active against all Enterobacteriaceae isolates (MIC less than or equal to 4 mg/l). All Pseudomonas aeruginosa isolates were inhibited by 2 mg/l. N-f thienamycin was also active against Acinetobacter calcoaceticus (96 per cent inhibited by 0.5 mg/l) and Gram-positive cocci. All enterococci were inhibited by 2 mg/l. The drug was active against Haemophilus influenzae (MIC less than or equal to 1 mg/l) and the Bacteroides fragilis group (MIC less than or equal to 0.5 mg/l). Cefoxitin was inactive against most Enterobacter and A. calcoaceticus isolates and all P. aeruginosa and enterococcal isolates. Tobramycin was virtually inactive against Gram-positive cocci other than Staphylococcus aureus. N-f thienamycin thus has a broad spectrum of in vitro activity, greater than that of cefoxitin and tobramycin, and may therefore be useful in the treatment of serious infection, particularly when the aetiology is unknown.

Acinetobacter↗
PubMed1983

Comparison of four methods for differentiation of Staphylococcus aureus from other Micrococcaceae in the routine laboratory.

Four methods for the identification of Staphylococcus aureus (tube coagulase test, thermostable nuclease test, indirect agglutination of fibrinogen coated erythrocytes and a commercial latex kit: SeroSTAT Staphylococcus Test) have been compared. Clinical isolates (698) and 40 reference strains of Micrococcaceae were included in the study together with control organisms. The coagulase test gave no false positive results but 39/406 clinical isolates of S. aureus were negative at 2h and one half were only weakly positive. At 18 h, all but 2 of 406 isolates gave a positive reaction. The thermostable nuclease test was very specific; no clinical isolates of S. aureus gave negative results and no "coagulase-negative" clinical isolates gave a definite positive reaction. The indirect haemagglutination method was sometimes difficult to interpret and frequently gave negative or doubtful results for S. aureus. The SeroSTAT test was easy to use and interpret and was specific; the method is suitable for routine laboratory use, particularly when a rapid result is desirable.

Bacteriological Techniques↗
PubMed1983

Evaluation of the Anaerobe-Tek system for the identification of Bacteroides and Fusobacterium species.

Reference strains and clinical isolates of Bacteroides and Fusobacterium species were examined by the Anaerobe-Tek System (A/T-system). Of 104 strain, only 57 (54.8%) were identified correctly to species level. 38 strains (36.5%) were incorrectly identified and for 9 strains (8.7%) there were no codes in the manufacturers' data base manual. The results indicate that, in our hands, the A/T-system in its present form, is not suitable for the identification of clinical isolates of Bacteroides and Fusobacterium species.

Bacteriological Techniques↗
PubMed1983

Pseudomonas aeruginosa and Acinetobacter calcoaceticus: in vitro susceptibility of 150 clinical isolates to five beta-lactam antibiotics and tobramycin.

The in vitro activities of azlocillin, carbenicillin, ceftriaxone, piperacillin, N-formimidoyl thienamycin (N-f thienamycin) and tobramycin have been compared against clinical isolates of Pseudomonas aeruginosa (n = 100) and Acinetobacter calcoaceticus (n = 50). An agar dilution method was employed for measurement of minimal inhibitory concentration (MIC). Tobramycin was the most active drug against P. aeruginosa (MIC less than or equal to 2 mg/l). Of the beta-lactam antibiotics, N-f thienamycin and tobramycin were highly active against A. calcoaceticus (MIC less than or equal to 2 mg/l), although one isolate was resistant to tobramycin (MIC greater than 16 mg/l). The other drugs were only moderately active against A. calcoaceticus.

Acinetobacter↗
PubMed1982

The in vitro activity of moxalactam against 430 clinical, bacterial isolates.

The in vitro activity of the novel beta-lactam antibiotic moxalactam against 430 bacterial isolates was determined by an agar dilution method. Moxalactam was highly active against Enterobacteriaceae including indole-positive Proteus and Providencia, all isolates being susceptible to 1.0 microgram/ml or less. The drug was somewhat less active against Gram-positive cocci and Pseudomonas aeruginosa, and enterococci were highly resistant. All Haemophilus influenzae isolates were inhibited by 0.06 microgram/ml or less. Activity against Bacteroides fragilis was good but wide variations of minimal inhibitory concentrations were noted. Moxalactam may become a useful alternative to the aminoglycosides in the treatment of serious infections caused by Gram-negative bacteria.

Anti-Bacterial Agents↗
PubMed1982

The N/F and Oxi/Ferm systems for identification of oxidative-fermentative Gram-negative rods: a comparative study.

Two commercial systems, the Flow N/F System and the Roche Oxi/Ferm Tube for identification of oxidative-fermentative Gram-negative rods were compared. Both systems were easy to use, but several reactions in both kits were sometimes difficult to interpret. Of 53 reference strains, 70 per cent were identified correctly by the N/F System, whereas the Oxi/Ferm Tube identified 43 per cent. Incorrect identities were obtained in 9 per cent and 26 per cent of cases by the N/F and Oxi/Ferm kits respectively. The remaining isolates required additional tests for definite identification. Of 67 clinical isolates, 27 per cent were identified differently by the 2 systems and only 30 per cent were in complete agreement. The N/F System should be of considerable use to the routine clinical laboratory for the identification of this group of organisms. The Oxi/Ferm Tube requires additional tests frequently and seems to be less accurate in our hands than the N/F System.

Acinetobacter↗
PubMed1981

Characteristics of 20 human Pasteurella isolates from animal bite wounds.

The bacteriological characteristics of 18 isolates of Pasteurella multocida and two isolates of Pasteurella pneumotropica from infected animal bite wounds have been studied. A high proportion (8/18) of the P. multocida isolates fermented lactose and five fermented maltose. Two failed to ferment sorbitol. Neither of the P. pneumotropica strains showed ornithine decarboxylase activity. Other biochemical characteristics were mainly in agreement with previous reports. The susceptibility of the isolates to 10 antibacterial agents has been determined by the disc diffusion method. Ampicillin, cephalothin and cotrimoxazole showed uniformly good activity whereas penicillin G and doxycycline were slightly less active. Apart from one horse bite, all bites were inflicted by cats and dogs. Two cases were serious. P. multocida seems to be a commoner occurrence in infected animal bite wounds than reports suggest. P. pneumotropica bite infections are seemingly uncommon.

Animals↗
PubMedDate not supplied

Ceftriaxone: in vitro activity against 410 bacterial isolates compared with cefotaxime.

The in vitro activity of the two new cephalosporins, cefotaxime and ceftriaxone, against 410 bacterial isolates was compared using an agar dilution method. Both compounds were highly active against Enterobacteriaceae, including indole-positive Proteus and Providencia; the great majority of the isolates were inhibited by 0.06 mg/l of either drug. Activity against Pseudomonas aeruginosa and Staphylococcus aureus was moderate, and enterococci were resistant. All Streptococcus pneumoniae, Streptococcus pyogenes and Haemophilus influenzae isolates were susceptible to 0.03 mg/l of either drug. The isolates belonging to the Bacteroides fragilis group were inhibited over a wide range of concentrations and some were highly resistant (MIC greater than or equal to 64 mg/l). There were no significant differences in the antibacterial activity of the two drugs against our isolates. Both drugs may be of potential use in the treatment of serious infections caused by Enterobacteriaceae; they may prove to be a useful alternative to the aminoglycosides.

Bacteria↗