Genetic relatedness of Burkholderia (Pseudomonas) cepacia isolates from five cystic fibrosis centers in Michigan.

Burkholderia cepacia isolates from patients with cystic fibrosis (CF) attending five CF centers were studied for relatedness by cellular fatty acid methyl esters (FAME) and by chromosomal DNA restriction analysis. Twenty-eight of 32 (87.5%) isolates tested were grouped in cluster group 1 based on their FAME profiles. DNA analysis revealed that 29 of 32 (90.6%) B. cepacia isolates from five CF centers had one closely related DNA pattern. To examine strain variation over a time period, FAME profiles and DNA patterns of isolates from serial cultures on seven patients from center D were studied. For four patients, all serial B. cepacia isolates belonged to a single FAME cluster group; for the remaining three patients, all serial isolates belonged to any two of the four cluster groups. On serial culture isolates, a single DNA pattern (pattern A) was found in 31 of 32 isolates demonstrating a close genetic relatedness. These data corroborate the observations that the majority of patients colonised with B. cepacia in a CF center harbor strains genetically closely related as determined by FAME profiles and DNA patterns.

Antibacterial properties of investigational, new, and commonly used antibiotics against isolates of Pseudomonas cepacia in Michigan.

Microdilution antimicrobial susceptibility testing was performed with 73 isolates of Pseudomonas cepacia collected from the sputum of patients throughout Michigan with cystic fibrosis. Susceptibility testing was done using new and investigational antibiotics (loracarbef, cefixime, cefpirome, desacetyl-cefotaxime, cefpodoxime, cefmetazole, cefepime, cefprozil, and fleroxacin) and commonly used antibiotics (ceftazidime, mezlocillin, piperacillin, ciprofloxacin, tobramycin, and amikacin). Ceftazidime was the most active antibiotic, and 91.8% of isolates were susceptible to it with MIC50 and MIC90 values of < or = 4 and 16 micrograms/ml, respectively. For mezlocillin, piperacillin, and ciprofloxacin 84.9, 89 and 39.7% of the isolates, respectively, were mostly moderately susceptible. Loracarbef, cefixime, cefprozil, cefmetazole, cefepime, fleroxacin, cefpodoxime, tobramycin, and amikacin did not show activity against P. cepacia. For cefpirome and desacetylcefotaxime 24.7 and 60.3% of the isolates, respectively, were moderately susceptible. Both MIC50 and MIC90 were > 32 micrograms/ml for cefpirome and 32 and > 64 micrograms/ml for desacetylcefotaxime.

Respiratory effects of wood heat: clinical observations and epidemiologic assessment.

An increasing number of families in the United States are converting to woodburning stoves in an effort to reduce winter heating bills. Woodburning stoves operate as a contained combuster of wood and produce a variety of pollutants as byproducts of combustion. Although technological advances have reduced emissions to some degree, even the most efficient woodburning stoves emit hazardous pollutants directly into the home when the stove is operating and the door is opened to add wood. The question arises as to whether pollutants are accumulating in homes where woodburning stoves are used as a source of heat. This issue is especially important considering the trend to increase home insulation and overall airtightness in an effort to conserve energy and reduce heat loss. This paper reviews the clinical case report that first postulated an association of recurrent chest illness with woodburning stove exposure and summarizes the findings to date on respiratory effects of wood heat for young children.

Symptoms of respiratory illness in young children and the use of wood-burning stoves for indoor heating.

The occurrence of symptoms of respiratory illness among preschool children living in homes heated by wood-burning stoves was examined by conducting an historical prospective study (n = 62) with an internal control group (matched for age, sex, and town of residence). Exposures of subjects were not significantly different (P greater than .05) with respect to parental smoking, urea-formaldehyde foam insulation, and use of humidifiers. The control group made significantly greater use of gas stoves for cooking whereas the study group made greater use of electric stoves for cooking and of air filters (P less than .05). Only one home used a kerosene space heater. During the winter of 1982, moderate and severe symptoms in all categories were significantly greater for the study group compared with the control group (P less than .001). These differences could not be accounted for by medical histories (eg, allergies, asthma), demographic or socioeconomic characteristics, or by exposure to sources of indoor air pollution other than wood-burning stoves. Present findings suggest that indoor heating with wood-burning stoves may be a significant etiologic factor in the occurrence of symptoms of respiratory illness in young children.

Cystic fibrosis.

Cystic fibrosis has been regarded as a disease of infants. Yet, with improved management, a high percentage of patients how survive into young adulthood. In addition, mild cases may not be detected until long after infance. The older patient often has minimal symptoms, and the majority are socially active and productive.