Outbreak of nosocomial Burkholderia cepacia infection and colonization associated with intrinsically contaminated mouthwash.

From August 1996 through June 1998, 69 ventilated, intensive care unit patients at two Arizona hospitals had nosocomial respiratory tract cultures positive for Burkholderia cepacia. Intrinsically contaminated alcohol-free mouthwash was identified by pulsed-field gel electrophoresis as the source of the outbreak.

Antimicrobial and cancer cell growth inhibitory activities of 3beta-acetoxy-17beta-(L-prolyl)amino-5alpha-androstane in vitro.

The in vitro activity of the steroidal amide 3beta-acetoxy-17beta-(L-prolyl)amino-5alpha-androstane against 179 gram-positive clinical isolates was examined. The minimum bactericidal concentration (MBC)/MIC ratios were < or = 2 for 73% of methicillin-resistant Staphyllococcus aureus, 59% of vancomycin-resistant Enterococcus spp. and 88% of penicillin-resistant Streptococcus pneumoniae. The androstane derivative was bactericidal for a variety of other gram-positive genera, including Nocardia, Corynebacterium and Listeria. Variation in MICs is pH 6-8 media was slight. The frequency of occurrence of bacterial spontaneous mutations to resistance ranged from 10(-6) to 10(-9). Kill curve analysis confirmed the bactericidal nature of the steroidal amide, and demonstrated that killing was time dependent but not concentration dependent for all organisms. The ability of 3beta-acetoxy-17beta-(L-prolyl)amino-5alpha-androstane to inhibit human cancer cell growth was also evaluated. The concentration required to inhibit 50% of cell growth (GI50) was < 2.5 mg/l for all cell lines examined. In single-dose murine toxicity evaluations, the androstane derivative was non-toxic at doses up to 400 mg/kg.

Outbreak of Pseudomonas aeruginosa ventriculitis among patients in a neurosurgical intensive care unit.

OBJECTIVE: To determine the cause of an outbreak of Pseudomonas aeruginosa cerebral ventriculitis among eight patients at a community hospital neurosurgical intensive care unit. All had percutaneous external ventricular catheters (EVCs) to monitor cerebrospinal fluid (CSF) pressure. METHODS: Cohort study of all patients who had EVCs placed during the epidemic period (August 8-October 22, 1997). A case-patient was any patient with P aeruginosa ventriculitis during the epidemic period. Pulsed-field gel electrophoresis (PFGE) was performed on all isolates. RESULTS: P aeruginosa was significantly more likely to be isolated from CSF per EVC placed in the epidemic than pre-epidemic (January 1-August 7, 1997) periods (8/61 [13%] vs 2/131 [1.5%], P=.002). During the epidemic period, ventriculitis was significantly more likely after EVC placement in the operating room than in other units (8/24 vs 0/22, P=.004). EVC placement technique differed for EVCs placed in the operating room (little hair was removed, preventing application of an occlusive dressing) versus other hospital units (more hair was removed, and an occlusive dressing was applied). Among patients who had operating room EVC placement, contact with one healthcare worker was statistically significant (7/13 vs 0/8, P=.02). Hand cultures of this worker were negative. All isolates had closely related PFGE patterns. CONCLUSIONS: These data suggest that a single healthcare worker may have contaminated EVC insertion sites, resulting in an outbreak of P aeruginosa ventriculitis. Affected patients were unlikely to have had an occlusive dressing at the EVC insertion site. Application of a sterile occlusive dressing may decrease the risk of ventriculitis in patients with EVCs.

Clinical and microbiological assessment of Mycobacterium simiae isolates from a single laboratory in southern Arizona.

Mycobacterium simiae was the third most common mycobacterium identified over a 2-year period from a single clinical laboratory in southern Arizona. Thirty-three isolates from 25 patients were identified over 1 year. The isolation of M. simiae was considered clinically significant for only two of 23 evaluable patients. None of five patients with human immunodeficiency virus infection had clinical disease associated with M. simiae. Twenty isolates were available for detailed study. All but one of the 20 isolates were niacin-negative, and 11 were nonphotochromogenic. All 20 isolates had a triple-cluster pattern consistent with M. simiae by high-performance liquid chromatography, and restriction fragment patterns were identical for 16 isolates. Analysis of 16S rDNA confirmed the identity of all the tested isolates as M. simiae. In this study, M. simiae was a frequent clinical isolate but was rarely associated with disease. The organisms isolated were confirmed to be M. simiae but appeared to be phenotypically distinct strains of low virulence.

More than 10 years of unrecognized nosocomial transmission of legionnaires' disease among transplant patients.

OBJECTIVE: To investigate a cluster of cases of legionnaires' disease among patients at a hospital. SETTING: A university hospital that is a regional transplant center. DESIGN: Retrospective review of microbiology and serology data from the hospital laboratories and prospective surveillance via the radiology department; a case-control study and environmental sampling within the hospital and from nearby cooling towers. RESULTS: Diagnosis of seven cases of legionnaires' disease in the first 9 months of 1996 led to recognition of a nosocomial outbreak that may have begun as early as 1979. Review of charts from 1987 through September 1996 identified 25 culture-confirmed cases of nosocomial or possibly nosocomial legionnaires' disease, including 18 in bone marrow and heart transplant patients. Twelve patients (48%) died. During the first 9 months of 1996, the attack rate was 6% among cardiac and bone marrow transplant patients. For cases that occurred before 1996, intubation was associated with increased risk for disease. High-dose corticosteroid medication was strongly associated with the risk for disease, but other immunosuppressive therapy or cancer chemotherapy was not. Several species and serogroups of Legionella were isolated from numerous sites in the hospital's potable water system. Six of seven available clinical isolates were identical and were indistinguishable from environmental isolates by pulsed-field gel electrophoresis. Initial infection control measures failed to interrupt nosocomial acquisition of infection. After extensive modifications to the water system, closely monitored repeated hyperchlorinations, and reduction of patient exposures to aerosols, transmission was interrupted. No cases have been identified since September 1996. CONCLUSIONS: Legionella can colonize hospital potable water systems for long periods of time, resulting in an ongoing risk for patients, especially those who are immunocompromised. In this hospital, nosocomial transmission possibly occurred for more than 17 years and was interrupted in 1996, after a sudden increase in incidence led to its recognition. Hospitals specializing in the care of immunocompromised patients (eg, transplant centers) should prioritize surveillance for cases of legionnaires' disease. Aggressive control measures can interrupt transmission of this disease successfully.

An international outbreak of Salmonella infections caused by alfalfa sprouts grown from contaminated seeds.

An outbreak of Salmonella serotype stanley infections occurred in the United States and Finland in 1995. The outbreak was investigated through case-control studies in Arizona, Michigan, and Finland; by isolate subtyping; and by tracing and culturing of the implicated food. Alfalfa sprout consumption was the only exposure associated with S. stanley infections in Arizona (matched odds ratio [MOR] = 11.1; 95% confidence interval [CI], 1.4-513), Michigan (MOR = 5.5; CI, 1.6-23), and Finland (MOR undefined; CI, 4.9-infinity). US and Finnish patient isolates were a unique outbreak strain distinct from S. stanley isolates not linked to the outbreak. Alfalfa sprouts eaten by patients in 6 US states and Finland were traced to seed shipped by a Dutch shipper. Thus, it was concluded that alfalfa sprouts grown from contaminated seed caused an international outbreak of > or =242 S. stanley infections in > or =17 US states and Finland. This outbreak illustrates a new mechanism through which contamination of fresh produce can cause large, widely dispersed outbreaks.

Pneumonia and bacteremia due to Mycobacterium celatum masquerading as Mycobacterium xenopi in patients with AIDS: an underdiagnosed problem?

A newly described species of mycobacteria, Mycobacterium celatum, has rarely been reported as a cause of localized and disseminated human disease and can easily be misidentified as Mycobacterium xenopi when identification is based on biochemical testing alone. We report two cases of pneumonia and bacteremia due to M. celatum in patients with AIDS. In one case, diagnosis and initiation of therapy were delayed by misidentification of the infecting organism as M. xenopi. Genomic analysis or high-performance liquid chromatography is necessary to distinguish the two species. The finding in our two cases and a review of existing literature indicate that pulmonary disease may be an important manifestation of infection with M. celatum, especially in patients with AIDS. Further studies are needed to determine the incidence and clinical relevance of this organism in patients with AIDS and the optimal treatment regimens.

Direct identification of Mycobacterium species in BACTEC 7H12B medium by high-performance liquid chromatography.

Primary cultures of mycobacteria grown in BACTEC 7H12B medium (Becton Dickinson and Co., Paramus, N.J.), with and without the addition of oleic acid-albumin-dextrose-catalase (OADC) enrichment (Becton Dickinson and Co., Cockeysville, Md.), were analyzed for their mycolic acid patterns by high-performance liquid chromatography. Of the 126 isolates grown in medium to which OADC was added, 117 (93%) were successfully identified to the species level. The time to identification of Mycobacterium tuberculosis (n = 65) averaged 19 days, and the average time was 21 days for nontuberculosis mycobacteria (n = 52) from initial specimen processing. None of the 10 isolates cultured without OADC were identified. The mycolic acid patterns were considered reliable for identification if the height of the tallest peak in the chromatogram was at least 50% of the internal standard peak height.

High-performance liquid chromatography patterns of Mycobacterium gordonae mycolic acids.

An important class of fatty acids contained in the cell envelopes of Mycobacterium organisms is the group of high-molecular-weight, long-chain, alpha-branched, beta-hydroxylated mycolic acids. By using standard saponification techniques and derivatization of the acids to their p-bromophenacyl esters, it is possible to differentiate them by high-performance liquid chromatography. Mycolic acid chromatograms of 63 clinical isolates of Mycobacterium gordonae were compared with conventional biochemical methods for identification. The data show two distinct pattern types for this species, only one of which has been elaborated in the literature by using this protocol. Laboratory workers who intend to use this method as a clinical tool need to be aware that these two pattern types exist.

Computer hardware.

Computer hardware refers to the physical electronic and mechanical components of a computer system. These components can be broken down into the central processing unit, memory, storage, terminals, and printers. The function of each of these is described and variations discussed. The hardware needed for communications between computers is defined.

Metabolic studies of isolated human eccrine sweat glands.

This paper describes a method for isolating and studying the metabolism of human eccrine sweat glands. (a) Electron microscopy of glands which had been isolated and then incubated for an hour revealed no apparent alteration in morphology. (b) Known variation in gland size (male > female > children) was reflected in the relative rates of lactate production. (c) Lactate production was approximately 1.5 nmoles/gland per hr in the absence of glucose and rose to 2.7 at physiological concentrations of glucose (5.6 mmoles/liter). This amount of lactate production agrees well with the amounts found in sweat. (d) Both adrenergic (epinephrine) and cholinergic (methacholine) stimuli increased lactate production. (e) Glycogen depletion was demonstrated during incubation. (f) O(2) consumption was measured and aerobic metabolism was found to account for less than 1% of the energy derived from anaerobic pathways. These studies demonstrate that the large amounts of lactate appearing in human eccrine sweat can be accounted for by glandular metabolism and that both glycogen and glucose can be used as substrates.