Cross infection on a combined paediatric plastic surgery and burns unit: a clinical and microbiological audit.

To try and determine any presence of cross-infection between patients, prospective screening of 226 consecutive admissions on our burns unit was performed by taking nose, throat and wound swabs. Infected wounds were also swabbed and a correlation was sought between the organisms cultured on screening swabs and those responsible for infection. We did not find any evidence of cross- infection occurring between the burns patients and the other categories of patients on the ward. Screening swabs were useful in detecting carriers, who were found to be more of a risk to themselves than to other patients on the unit.

Non-tuberculous mycobacterial infection in children with cancer.

Reported here is the clinical presentation and management of patients with rapidly growing non-tuberculous mycobacterial infection diagnosed in a paediatric oncology unit. A retrospective analysis that correlated patient isolates with the children's cancer registry revealed two cases of non-tuberculous mycobacterial infection; both had been observed within the last 6 years and were due to Mycobacterium chelonae. The first case was line-associated and the second was a disseminated infection. In both cases the patients were lymphopenic and had had indwelling vascular catheters. Neither patient was neutropenic. The literature on mycobacterial infection in children with cancer is also reviewed.

Investigation of gaseous ozone for MRSA decontamination of hospital side-rooms.

A domestic, gaseous ozone generator was investigated for use in the decontamination of hospital side-rooms that have housed patients colonized with methicillin-resistant Staphylococcus aureus (MRSA). Three models of bacterial contamination were used. These were exposed to ozone generation in a standard hospital side-room for 4 and 7 h. A methicillin-sensitive and a methicillin-resistant strain of S. aureus were compared. Ozone concentrations of 0.14 ppm were reached, levels which are sufficient to cause mild pulmonary toxicity. Bacterial counts were reduced in the vicinity of the gas generator in most instances, but the effect elsewhere in the room was, at best, limited. MRSA appeared more resistant to the effects of ozone than methicillin-sensitive S. aureus. We conclude that the device tested would be inadequate for the decontamination of such hospital side-rooms.

Ecthyma gangrenosum occurring at sites of iatrogenic trauma in pediatric oncology patients.

We report two cases of ecthyma gangrenosum which occurred at sites of iatrogenic trauma. The first case developed due to metastatic seeding with Pseudomonas aeruginosa during an episode of septicaemia and the second case occurred as a primary skin lesion. Both required prolonged courses of antibiotics and one patient died. The different pathogenic mechanisms and outcomes associated with this condition are discussed.

Non-enteritic aeromonas infections in hospitalized patients.

Aeromonas species were isolated from specimens other than faeces from 59 hospital inpatients over a 15 year period. Of the isolates, 79.7% were regarded as clinically significant, with skin and soft tissues and blood cultures as the commonest sites of infection. Of the isolates, 52.5% were hospital-acquired, and 55.9% of patients had serious underlying disease. Community-acquired infections in previously healthy individuals accounted for only 13.6% of isolates. However unlike many other opportunistic infections, aeromonas infection was not closely associated with prior antibiotic therapy, nor was there a significant increase in the frequency of infection over the study period.

A multicentre study of the in-vitro activity of cefotaxime, cefuroxime, ceftazidime, ofloxacin and ciprofloxacin against blood and urinary pathogens.

The in-vitro susceptibilities of aerobic bacteria isolated from 1804 blood and 4529 urine specimens collected at nine hospitals in the UK were examined. An agar dilution method was used to determine the MICs of each isolate to three cephalosporins, cefotaxime, cefuroxime and ceftazidime, and to two fluoroquinolones, ofloxacin and ciprofloxacin. Sensitivities were then calculated using British Society for Antimicrobial Chemotherapy recommended breakpoints. Of the cephalosporins tested cefotaxime was the most active against the Enterobacteriaceae. All the systemic staphylococcus isolates collected were sensitive to both cefotaxime and cefuroxime. As expected, ceftazidime was the only cephalosporin active against the Pseudomonas isolates. Both quinolones were highly active against the Enterobacteriaceae and Pseudomonas spp. They also demonstrated good Gram-positive activity, particularly against Staphylococcus aureus and Enterococcus spp.

Enterococcal bacteraemia: a prospective study of 125 episodes.

One hundred and twenty-five episodes of enterococcal bacteraemia occurring over a 50-month period were studied prospectively. Enterococcus faecium was the commonest species, accounting for 76 (59.8%) of the 127 isolates. Overall, 33.1% of isolates were resistant to ampicillin and one isolate (0.8%) to vancomycin; high-level gentamicin resistance was detected in 4.3% of 93 isolates tested. The percentage of nosocomial episodes was 70.4, and 95.2% of the patients had significant underlying illness. Central venous catheters (CVCs) were the commonest source of infection. Eighty-four per cent of episodes were ultimately treated with appropriate antibiotics. The overall mortality rate was 17.6%, and that directly attributable to infection was 8.0%. An increased mortality rate was observed in intensive care and neonatal unit patients, and in patients who had received antimicrobial therapy in the 2 weeks prior to enterococcemia. CVC-related infections were associated with a reduced mortality. No other clinical or microbiological factors were found to influence outcome.

Changing causes of septicaemia in paediatric oncology patients: effect of imipenem use.

One hundred and fifty-four episodes of septicaemia occurred in 78 patients on a Paediatric Oncology Unit over 2 years. Septicaemias with Gram-positive bacteria were more common than with Gram-negative organisms, coagulase-negative staphylococci (CNS) being the commonest pathogens. The mortality rate in patients with septicaemia was 1.9%. Azlocillin and gentamicin comprised the first-line of empirical antibiotic therapy for suspected infection for the first 10 months of the study; imipenem with cilastatin, as monotherapy, was used subsequently. More isolates of enterococci, and fewer isolates of Enterobacter, were seen after the introduction of imipenem. The use of imipenem was associated with an increased frequency of resistance to flucloxacillin in CNS. Such strains have been shown to contain sub-populations of cells that are resistant to imipenem. A clinical response was achieved in 82.9% of septicaemic episodes treated with imipenem, compared with 62.7% for azlocillin and gentamicin. However, imipenem as monotherapy may not be appropriate in central venous catheter related infections, owing to the frequent occurrence of imipenem-resistant organisms, CNS and Pseudomonas spp., in this situation.

Antibiotic-resistant enterococci.

Enterococci have emerged as an important cause of nosocomial infection. Successful antibiotic treatment of serious enterococcal infection usually depends on the synergistic bactericidal effect achieved by the combination of a cell wall-active agent, such as ampicillin or a glycopeptide, and an aminoglycoside. However, the prevalence of enterococci resistant to one or more of these antibiotics is increasing, and has resulted in serious therapeutic difficulties. The mechanisms of antibiotic resistance, and the epidemiology, laboratory diagnosis and management of infection with antibiotic-resistant enterococci are discussed.