Detection of penicillin tolerance in Streptococcus pyogenes.

Three traditional assays were used to determine the minimal bactericidal concentration (MBC) and minimal inhibitory concentration (MIC) for Streptococcus pyogenes (group A streptococci) in two phases of growth and the time taken to kill the organisms. Three other methods were used for the determination of penicillin tolerance: a cell-lysis assay, the beta-lactamase disk method and the replication method. Twenty strains, comprising penicillin-tolerant clinical isolates and two laboratory mutants, were used to evaluate the six tests. Results indicated that two groups of S. pyogenes can be distinguished--four highly tolerant and three moderately tolerant strains. The moderately tolerant strains were not recognised when rapidly growing instead of stationary cultures were used for the MBC and MIC determinations. The MBC/MIC ratio for tolerant strains was > 100. Tolerance percentage ranged from 0.30 to 1.07 and 0.29 to 3.96 for cultures in the mid-logarithmic and stationary phases of growth, respectively. The cell-lysis assay, the beta-lactamase disk method and the replication method may be used to screen for tolerance. Detection of high or moderate tolerance by determining the MBC/MIC ratio for mid-logarithmic or stationary cultures is recommended.

Susceptibility of Streptococcus pyogenes to azithromycin, clarithromycin, erythromycin and roxithromycin in vitro.

The susceptibility of 180 clinical isolates of Streptococcus pyrogenes from six regions of The Netherlands to the macrolide antibiotics azithromycin, clarithromycin, erythromycin and roxithromycin was analysed. The results of a microbroth MIC method, the E-test method and a disk diffusion assay were compared, and the MBC determined. In addition, the susceptibility to erythromycin of 436 clinical isolates of S. pyogenes from the Leiden region was determined. The microbroth MIC90s of azithromycin, clarithromycin, erythromycin and roxithromycin for group A streptococci were < or = 0.5 mg/L. Erythromycin had the lowest MIC90 (0.09 mg/L). The MIC data obtained with the E-test method suggested that clarithromycin and erythromycin had slightly higher anti-streptococcal activity than azithromycin and roxithromycin in vitro. MICs obtained with the E-test were lower than those found with the microbroth method. Only minor discrepancies were observed among the three methods. The MBC50 for both clarithromycin and erythromycin was 0.75 mg/L and 5.0 mg/L for azithromycin and roxithromycin. None of the 180 strains and two of the collection of 436 strains (0.5%) were resistant to erythromycin and the other macrolides tested; MICs ranged from 1 to 16 mg/L. The erythromycin-resistant strains showed an inducible type of macrolide-lincosamide-streptogramin B (MLS) resistance.

Bacterial contamination and the effect of filters in anaesthetic circuits in a simulated patient model.

In order to investigate bacterial contamination of anaesthetic breathing circuits and means of prevention of this, six different laboratory experiments were performed. These experiments involved the bacterial contamination of Dräger Narkose Spiromat 650 and Dräger AV-1 circle system circuits and of an isolated soda lime carbon dioxide absorber. The effects of anaesthetic gas, gas flow rate and the incorporation of a hydrophobic membrane heat and moisture exchanging bacterial/viral filter (HMEF) at the patient end of these circuits were investigated. It was found that without a HMEF the whole interior of the anaesthetic circuits became contaminated with bacteria. Components closest to the simulated patient showed the highest levels of contamination. Higher gas flows were associated with decreased levels of circuit contamination, presumably because more bacteria were expelled from the system. Halothane (1 volume %) and soda lime were not found to have any demonstrable bactericidal action. The presence of a HMEF between the simulated patient and the Y-piece prevented any detectable contamination from reaching the circuit. Consequently, the presence of a HMEF provides protection of the anaesthetic circuit as well as other patients, healthcare workers and the environment.

Hygiene, skin infections and types of water supply in Venda, South Africa.

The impact of the installation of a system to supply chlorinated drinking water in Venda, South Africa, on water quality, water use and health status was evaluated by means of questionnaires, examination for skin infections, and microbiological analysis of water samples. Although the water collection journey became shorter in comparison with use of traditional water supplies such as boreholes and unprotected springs, water use per caput showed no increase. The improved water supply showed no contamination with coliforms even after storage. Borehole water exhibited low coliform counts at the source, but after storage a 10- to 15-fold increase took place. Water samples from unprotected springs exhibited high coliform counts, which declined during storage. The prevalence of infectious skin diseases (27.5%) and diarrhoea (3.7%) among pre-schoolchildren showed no correlation with the quality of drinking water or the use of water per caput. Although the prevalence of infectious skin diseases did exhibit a negative correlation with the frequency of washing, no significant health benefit of the improved water supply could be demonstrated in this limited study.

Campylobacter jejuni bacteraemia as a cause of recurrent fever in a patient with hypogammaglobulinaemia.

In a hypogammaglobulinaemic patient with faecal cultures persistently positive for Campylobacter jejuni it was shown that C. jejuni bacteraemia was responsible for a long history of self-limiting attacks of fever. A focus of infection outside the gastro-intestinal tract was not found. Antimicrobial treatment failed to eradicate C. jejuni. Antibodies against C. jejuni were not detectable and there was also a defect in serum bactericidal activity. In contrast with normal serum, it was shown that, when patient's serum was used in tests, IgG and the components of complement C3 and C4 did not bind to C. jejuni.

A comparison of pefloxacin/metronidazole and doxycycline/metronidazole in the treatment of laparoscopically confirmed acute pelvic inflammatory disease.

A double-blind, randomised study was conducted to compare the efficacy and safety of a combination of pefloxacin and metronidazole versus doxycycline and metronidazole in patients with pelvic inflammatory disease (PID). The clinical diagnosis had to be confirmed by laparoscopy before patients were included. Of the 74 patients who fulfilled the clinical criteria for PID, laparoscopy confirmed the diagnosis in only 40 patients (54%). The microorganism most frequently found as causative pathogen was Chlamydia trachomatis. Both treatment groups showed a good response to the study-medication. At discharge 9 patients in the pefloxacin group (45%) were cured and 10 patients (50%) had improved. In the doxycycline group 7 patients (35%) were cured and 10 patients (50%) had improved. Obviously pefloxacin/metronidazole and doxycycline/metronidazole are equally effective in the treatment of PID.

Prevalence of resistance of N. gonorrhoeae to penicillin and three other antibiotics in a rural area in Kenya.

Of 90 isolates of Neisseria gonorrhoeae in a rural area in Kenya, 44 (48.9%) produced beta-lactamase (penicillinase). Testing for susceptibility of 35 penicillinase producing N. gonorrhoeae (PPNG) strains to four antibiotics yielded the following results: 16 (45.7%) showed a decreased susceptibility to tetracycline; six (17.1%) showed resistance, probably plasmid mediated; 10 (28.6%) had intermediate susceptibility to gentamicin; one (2.9%) was resistant; and two (5.7%) isolates were resistant to cefotaxime. 16 (57.1%) of 28 non PPNG strains showed a decreased susceptibility to penicillin; 10 (35.7%) were resistant. Nine (32.1%) of 28 non-PPNG isolates showed intermediate susceptibility to tetracycline; one (3.6%) was resistant. Eight of non PPNG isolates (28.6%) showed decreased susceptibility to gentamicin. These results imply that penicillin and tetracycline should be abandoned as primary therapy. For the time being, thiamphenicol and spectinomycin seem to be good alternatives. The observation of cefotaxime resistance in N. gonorrhoeae in a rural area implies a warning concerning future possibilities for use of third generation cephalosporins.

[Consensus prevention of hospital infections]. / Consensus preventie ziekenhuisinfecties.

Purpose of this consensus development conference held in Utrecht on 19th May, 1989 was to reach agreement on hygienic hand washing and disinfection procedures, preoperative hand disinfection, isolation procedures, implementation of rules and regulations. A working party had prepared 18 statements on these four subjects, with added explanations. The audience which had received this information in advance, was invited to discuss and possibly modify or reject the statements. Agreement was reached about the following: regular washing of the hands of personnel on the wards is useful to prevent hospital infections; this should be done according to an agreed and feasible protocol defining when and how. Disinfection of the hands of care personnel on the wards should be done with 70-80% alcohol with cetiol; for non-infected patients with normal resistance hand washing and hand disinfection are judged equivalent. Hand disinfection procedures are advocated for personnel caring for immuno-compromised or infected patients. Alcohol (70-80%) with added chlorhexidine (0.5%) and cetiol was chosen for preoperative hand disinfection to be applied after a washing session; brushes should be used sparingly. A category specific isolation system was preferred to a disease specific system. Except for air transmitted infections, barrier nursing is usually adequate. It was deemed important to register practical problems before trying to implement the regulations.

[Clinical, bacteriological and cost-saving effects of antibiotic prophylaxis in craniotomy]. / Klinische, bacteriologische en kostenbesparende effecten van antibiotische profylaxe bij craniotomie.

Objective of the study. To investigate the effect of antibiotic prophylaxis on the incidence of infections, on the bacterial flora of wounds and on the health-care costs. A retrospective study disclosed an incidence of infection of 8.1% in patients who underwent craniotomy. Methods. Double-blind, placebo-controlled study of the effects of cloxacillin (4 x 1 gr intravenously during 24 h, perioperatively) in 310 patients who had to undergo a craniotomy. Results. In the cloxacillin group significantly fewer infections occurred than in the placebo group, 6 infections in 156 and 20 infections in 154, respectively. In the cloxacillin group significantly fewer samples contained micro-organisms than in the placebo group. Cloxacillin prophylaxis reduces the cost of patient care by about 20%. Conclusion. Cloxacillin prophylaxis in craniotomy cases reduces the percentage of infections, the percentage of positive cultures of the wound, and the costs of patient care.

[Inventory and comparison of guidelines for antibiotic utilization in Dutch hospitals]. / Inventarisatie en vergelijking van richtlijnen voor antibioticagebruik in Nederlandse ziekenhuizen.

In 1976 the Dutch Health Council advised hospitals to formulate guidelines for use of antibiotics. These guidelines and their use should improve the quality of care in terms of medical effectiveness and cost-effectiveness. In 1988 the Peer Review Council held a survey among all (140) Dutch hospitals to collect data about these guidelines. Thirty-seven sets of guidelines used in 71 hospitals were obtained. We analysed these sets of guidelines as to the following general aspects: the status of the guidelines in the hospitals, the problem-oriented approach, the topics dealt with in the guidelines and the authors of the guidelines. Four specific aspects related to rational use of antibiotics were analysed as well: the use of cephalosporin, the use of different antibiotics for prophylaxis and therapy and the cost-effectiveness of antibiotic treatment in relation to urosepsis. Results of these analyses show that guidelines are too often formulated in a noncommittal way and that there is a need for a more functional registration system to link information about the clinical working diagnoses, the bacteria isolated and the sensitivity to the antibiotics used. These linkages are essential for feedback to clinicians, microbiologists and pharmacists and a prerequisite for management of the quality of care with respect to use of antibiotics.