Xanthomonas maltophilia is increasingly a cause of nosocomial infections. The mode of transmission of this organism is not well known.

To investigate clonality of X maltophilia isolates in epidemic and endemic settings.

An outbreak of X maltophilia was noted in the Intensive Care Nursery (ICN). Over the ensuing 9 months, hospitalwide isolates of X maltophilia were analyzed using contour-clamped homogeneous electric field (CHEF) gel electrophoresis of chromosomal DNA. This method was compared with the antibiogram for detecting differences and similarities among strains.

X maltophilia was recovered from 76 sites in 72 patients; 65 isolates from 61 patients and the hands of one nurse were available for analysis. CHEF demonstrated differences between most epidemiologically unrelated strains and similarity between most epidemiologically related strains. Several strains, initially presumed to be related because of temporal and spatial proximity of the patients involved, were determined by CHEF analysis to be independent infections. One pair of isolates whose Xbal CHEF patterns differed by a single band were differentiated clearly by Sspl. There was enough variation in the minimum inhibitory concentrations of selected antibiotics to allow typing of some strains. The antibiogram, however, did not group all of the ICN outbreak isolates with others found to be genetically identical by CHEF and it grouped 39 of 56 isolates with others not genetically the same.

Although it is a convenient and economical tool, the antibiogram has limitations. Analysis by CHEF should help to elucidate the epidemiological spread of X maltophilia in the hospital.

To compare liquid soap versus 4% chlorhexidine gluconate in 4% alcohol for the decontamination of bare or gloved hands inoculated with an epidemic strain of Clostridium difficile.

C difficile (6.7 log10 colony-forming units [CFU], 47% spores), was seeded onto bare or latex gloved hands of ten volunteers and allowed to dry. Half the volunteers initially washed with soap and half with chlorhexidine, followed by the other agent 1 week later. Cultures were done with Rodac plates at three sites on the hand: finger/thumbtips, the palmar surfaces of the fingers, and the palm. Statistical comparison was by paired Student’s t test.

On bare hands, soap and chlorhexidine did not differ in residual bacterial counts on the finger/thumbtips (log10 CFU, 2.0 and 2.1, P= NS) and fingers (log10 CFU, 2.4 and 2.5, P=NS). Counts were too high on bare palms to quantitate. On gloved hands, soap was more effective than chlorhexidine on fingers (log10 CFU 1.3 and 1.7, P<.01) and palms (log10 CFU 1.5 and 2.0, P<.01), but not finger/thumbtips (log10 CFU 1.6 with each, P=NS). Residual C difficile counts were lower on gloved hands than bare hands (P<0.01 to <0.0001).

The two agents did not differ significantly in residual counts of C difficile on bare hands, but on gloved hands residual counts were lower following soap wash than following chlorhexidine wash. These observations support the use of either soap or chlorhexidine as a handwash for removal of C difficile, but efficacy in the prevention of C difficile transmission must be determined by prospective clinical trials.

To assess the prevalence of high-level gentamicin-resistant enterococcus (HGRE) colonization, transmission patterns, and spectrum of illness among residents of a long-term care facility.

Monthly surveillance for HGRE colonization of wounds, rectum, and perineum over a 1-year period.

A Veterans Affairs long-term care facility attached to an acute-care facility.

All 341 patients in the facility during the observation period.

Over the 1-year period, 120 patients (35.2%) were colonized with HGRE at least once, with an overall monthly colonization rate of 20± 1.5%. HGRE were isolated from rectum (12.8%), wounds (11.7%), and perineum (9.3%). Patients with the poorest functional status had the highest rate of colonization (P<0.0005). HGRE-colonized patients were more likely to be colonized with methicillin-resistant Staphylococcus aureus (51% versus 25%; P<0.0005). Seventy-four patients (21.7%) were colonized at admission or at the start of the study. Another 46 patients (13.5%) acquired HGRE during the study, including 36 who acquired HGRE while in the long-term care facility and 10 who were positive when transferred back from the acute-care hospital. Based on plasmid profiles, only two patients appeared to have isolates similar to those of current or previous roommates. Carriage of HGRE was transient in most cases. Only 20 patients were colonized for 4 or more months, and those patients usually carried different strains intermittently. Infections were infrequent, occurring in only 4.1% of total patients.

In our long-term care facility, HGRE were endemic, and new acquisition of HGRE occurred frequently. However, only two patients had evidence of acquisition from a roommate, suggesting that cross-infection from a roommate was not a major route of spread of HGRE.

To determine the incidence and type of antibiotic use variances at our institution.

Inpatient bacterial culture and susceptibility results were reviewed for 1 week per month. Medication administration records were evaluated to determine whether antibiotic selection was appropriate, given the susceptibility of the organism. Process indicators included use of the least costly antibiotic. as well as appropriate dose, interval, and route of administration. The complete medical record was reviewed for all patients if management did not appear to meet criteria.

A 225-bed. tertiary-care children’s teaching hospital.

Thirty-five (8.2%) of 428 patients reviewed over 12 months had a total of 49 variances: failure to treat (3), treatment of contaminant/colonizer (2), use of more costly agent (10), failure to revise therapy (8), inappropriate route (2), inappropriate empiric antibiotic (4), incorrect dose (3), unnecessary multiple antibiotics (6), inappropriate drug (8), and prolonged prophylaxis (3).

Thirty-five patients with 10 types of variances were identified during the study. Follow-up monitoring will assess the impact of educational efforts on the incidence of variances. Specific problem antibiotics have been identified for further audits.