In vitro activity of meropenem and imipenem against mycobacteria: development of a daily antibiotic dosing schedule

The activity of two carbapenem antibiotics, meropenem and imipenem, against Mycobacterium species was assessed by means of the Bactec 460 radiometric apparatus. This system allowed a result to be read in 4-10 days. The instability of imipenem, particularly, in the test system necessitated the development of a regimen of daily addition of antibiotic to permit a more accurate assessment of antibiotic activity to be made. When antibiotic-containing media are incubated for long periods, as is the case when determining antimycobacterial activity, the stability of test antibiotics is an important factor that must be considered.

Use of a Radiometric Technique for Rapid Sensitivity Testing of Mycobacteria in Scotland: The First Year's Experience

We report the first year's experience of the use of a radiometric technique for sensitivity testing of mycobacterial isolates in Scotland. The techniques (using the Bactec 460 instrument) was much quicker than conventional methods (for example the mean time to obtain results for 60 strains of M.tuberculosis was 14.4 days, compared with 44.9 days for conventional methods). There was good agreement between results obtained by the two methods. Preliminary results also indicated the value of the radiometric technique for rapid isolation of mycobacteria from clinical samples (mean of 10.6 days with the radiometric technique compared with 26.7 days using egg media) although for optimal recovery, both techniques should be used in parallel.

Susceptibility of bacterial isolates from AIDS patients to six fluoroquinolones

The susceptibilities to ciprofloxacin, DR-3355 (S-(-)-ofloxacin), enoxacin, lomefloxacin, ofloxacin and PD127,391 of 69 significant bacterial isolates from HIV-positive patients at the City Hospital, Edinburgh have been determined. With the exception of the enterococci, most of the strains tested (including staphylococci, Escherichia coli and Pseudomonas aeruginosa) were susceptible to the fluoroquinolones. Ciprofloxacin was the most active of the clinically available drugs followed by ofloxacin, lomefloxacin and enoxacin. PD127,391 and DR-3355, the new fluoroquinolones tested, were at least as active as ciprofloxacin. Hence bacterial infections in AIDS patients should respond to fluoroquinolone therapy.

Use of a radiometric technique for rapid sensitivity testing of mycobacteria in Scotland: the first year's experience

We report the first year's experience of the use of a radiometric technique for sensitivity testing of mycobacterial isolates in Scotland. The techniques (using the Bactec 460 instrument) was much quicker than conventional methods (for example the mean time to obtain results for 60 strains of M.tuberculosis was 14.4 days, compared with 44.9 days for conventional methods). There was good agreement between results obtained by the two methods. Preliminary results also indicated the value of the radiometric technique for rapid isolation of mycobacteria from clinical samples (mean of 10.6 days with the radiometric technique compared with 26.7 days using egg media) although for optimal recovery, both techniques should be used in parallel.

An outbreak of isoniazid resistant tuberculosis in Glasgow 1981-1988

An increase in the number of patients attending the Victoria Infirmary, Glasgow with isoniazid resistant tuberculosis, prompted a survey of the incidence of the condition in Glasgow. There was a clustering of cases among the homeless and/or alcoholic population of the city, particularly between the years 1982 and 1986. This suggests an outbreak of isoniazid resistance among that population, probably spread from a single, but unidentified source.

Isolation of zidovudine resistant Escherichia coli from AIDS patients

Zidovudine-resistant Escherichia coli were isolated from faecal samples from 6 out of 11 AIDS patients receiving zidovudine. Resistance appeared to be due to the loss of thymidine kinase activity which is required for the phosphorylation of zidovudine to its active form. No zidovudine resistant enterobacteria were isolated from 30 control faecal samples. Hence, clinically, there appeared to be a high correlation between the development of zidovudine-resistance in E. coli and exposure to zidovudine (chi 2: 11.77, P less than 0.001). However the development of zidovudine resistance does not appear to be associated with cross-resistance to other antimicrobial agents as the zidovudine-resistant E. coli did not display a high degree of resistance to other antibacterials.

The growth-inhibitory properties of meropenem against anaerobes of clinical importance

The in-vitro activity of meropenem against anaerobic bacteria was assessed by an agar dilution procedure. MICs were measured for 449 clinical isolates and reference strains. Meropenem showed excellent activity against both Gram-negative anaerobes, including Bacteroides fragilis (MIC90 0.25 mg/l), and Gram-positive anaerobes. The MIC90 for Clostridium perfringens was 0.01 mg/l. Meropenem had comparable activity to imipenem against Gram-negative anaerobes but was more active than imipenem against clostridia, including C. difficile (MIC90 2 mg/l compared with 8 mg/l). Meropenem was more active against anaerobes than was cefoxitin, metronidazole or clindamycin.

Evaluation of a community treatment program for young adult schizophrenics

To evaluate a program of intensive case management for young adult chronic schizophrenics released from a large urban state mental health facility, several interrupted time series analyses were conducted over an 18-month period on 64 patients. Findings indicate that the intensive, active, and reactive role of case managers contributes significantly to the effectiveness of an aftercare, community-based treatment program.

The in-vitro activity of three long-acting cephalosporins against Bacteroides fragilis, Peptostreptococcus species and Clostridium perfringens

The in-vitro activity of three long-acting cephalosporins (cefotetan, cefonicid and ceftriaxone) was compared against 206 clinical isolates of Bacteroides fragilis, Peptostreptococcus species and Clostridium perfringens, using an agar dilution procedure to determine minimum inhibitory concentrations (MICs). Clindamycin was included as a comparator. Cefotetan was much more active than the two other cephalosporins against strains of Bacteroides fragilis (MIC90 16 mg/l compared with greater than 128 mg/l for the other two agents). Cefotetan also demonstrated superior activity against anaerobic cocci. All three compounds showed good activity against strains of Clostridium perfringens. Clindamycin was active against all of the test strains.