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Biomedical subjects

M S Favero

Publications and source records attributed to M S Favero.

At least 73 records · Page 4Linked to original sources
PubMed1985

Factors associated with Pseudomonas pickettii intrinsic contamination of commercial respiratory therapy solutions marketed as sterile.

Laboratory investigations were conducted to study the growth dynamics of Pseudomonas pickettii in commercial 0.9% sodium chloride solution under various environmental conditions and to determine the retention of these organisms after challenge through a 0.2-micron cartridge filter system. Low numbers of P. pickettii (1 to 10 CFU/ml of test solution) inoculated into commercial vials containing 5 ml of 0.9% sodium chloride solution and 500-ml volumes of 0.9% sodium chloride solution were shown to proliferate over a 168-h incubation period. These organisms demonstrated growth over a wide range of temperatures (15 to 42 degrees C) in this salt solution, and survival studies at 50, 55, and 60 degrees C indicated that this strain was not unusually resistant to heat (with the times required at a given temperature to reduce the surviving microbial population 10-fold [D-values] being 26.0, 1.9, and 0.7 min, respectively). A challenge test demonstrated that P. pickettii organisms were not completely retained by a 0.2-micron cartridge filter. The number of organisms detected increased from 1 CFU/liter of effluent at 1 to 2 min to a maximum of 176 CFU/liter at 4 to 5 min. Our results indicate that P. pickettii can penetrate a 0.2-micron filtration system and that the passage of organisms and subsequent microbial growth in the filter effluent probably are the mechanisms by which these organisms were recovered from "sterile" commercial 0.9% sodium chloride solution.

Drug Contamination↗
PubMed1984

Intrinsic bacterial contamination of a commercial iodophor solution: investigation of the implicated manufacturing plant.

After an outbreak of peritoneal infections attributed to intrinsic contamination of a poloxamer-iodine solution with Pseudomonas aeruginosa, the manufacturer of the contaminated solution permitted investigation and sampling of materials within the plant. Pseudomonas spp. were recovered from two different unopened lots of solution and from numerous water samples obtained at the plant. The isolates from water identical to those of an isolate recovered from Prepodyne solution (West-Agro Chemical Co., Inc., Westwood, Kans., manufactured for AMSCO Medical Products Div., Erie, Pa.) manufactured 1 month earlier at the same plant. P. aeruginosa was not recovered from incoming city water. P. aeruginosa was recovered from sterile water and poloxamer-iodine after 48 h of incubation in a plant polyvinyl chloride pipe. Scanning electron micrographs of polyvinyl chloride pipe used in the plant showed massive concentrations of rod-shaped and coccobacillary cells apparently embedded in interior deposits of the pipe. Manufacturers of iodophors should be aware that pipes or other surfaces colonized with bacteria may be a source of contamination of their products.

Journal Article↗
PubMed1983

Outbreak of pyrogenic reactions at a dialysis center. Association with infusion of heparinized saline solution.

Twenty-three pyrogenic reactions occurred in 16 patients undergoing hemodialysis at a private dialysis center in the south central United States between November 23 and December 2, 1978. No deaths were attributed to reactions; however, 10 patients were hospitalized for observation after experiencing a reaction. Cultures of all blood specimens obtained from the patients gave negative results. Chills (75 percent), nausea and/or vomiting (30 percent), and fever (90 percent) were the most common signs and symptoms, with mean times of onset after starting dialysis of 1.1, 1.6, and 3.6 hours, respectively. An epidemiologic and laboratory investigation documented that reactions occurred only in patients who had anticoagulation with a dilute solution of heparin. Analyses of heparinized saline solution used during the outbreak revealed a bacterial count of 7.4 X 10(5)/ml and a bacterial endotoxin level of 1,300 ng/ml. Acinetobacter calcoaceticus var. Iwoffi was isolated from the solution. Diluted heparin solution was prepared at the dialysis center by adding commercially supplied sodium heparin to 0.9 percent sodium chloride infusion fluid. Bacteria and endotoxin were not detected in vials of stock heparin and bags of unopened 0.9 percent sodium chloride infusion fluid. We concluded that contamination of the solution occurred at the dialysis center. After changes in the preparation and use of heparin were instituted on December 4, 1978, no pyrogenic reactions occurred in more than 400 subsequent dialyses.

Acinetobacter↗
PubMed1983

Dialysis encephalopathy and aluminum exposure: an epidemiologic analysis.

We identified 55 patients with dialysis encephalopathy in six dialysis centers studied by means of a uniform clinical classification. Dialysis encephalopathy was the direct cause of death in most cases, and the disease appeared to significantly shorten survival. The overall attack rate of dialysis encephalopathy was 4% and varied among dialysis centers from 2.2% to 14.7%. In two centers with adequate data, the attack rate for dialysis encephalopathy rose significantly with increasing cumulative aluminum exposure via dialysate, and the mean cumulative aluminum exposure for patients with the disease was significantly higher than that for all other patients at risk. We further demonstrated that the cumulative level of aluminum tolerated by the patient before onset of symptoms was inversely related to the average aluminum concentration of dialysate water.

Aluminum↗
PubMed1983

Inactivation of hepatitis B virus by intermediate-to-high-level disinfectant chemicals.

In five separate tests, hepatitis B virus in dried human plasma was exposed for 10 min at 20 degrees C to disinfectant chemicals having activity levels ranging from intermediate (e.g., 70% isopropyl alcohol) to high (e.g., 2% aqueous glutaraldehyde at pH 8.6). Five chimpanzees (one animal per disinfectant chemical) received treated material intravenously, and none showed signs of infection after post-inoculation periods of 9 months. Two animals were rechallenged with inoculum treated in the same manner, except that saline was used instead of a disinfectant chemical; both were infected within 4 weeks. Our results showed that hepatitis B virus was not as resistant to disinfectant chemicals as once thought and suggested that chemicals with similar activity levels (intermediate to high) might possibly be used on hepatitis B virus contamination with a margin of safety.

Animals↗
PubMed1982

Transmission of type B viral hepatitis via eye inoculation of a chimpanzee.

To simulate a splash of infectious material in the eyes, plasma from a hepatitis B patient was placed on the corneal surfaces of a chimpanzee. The animal became infected 9 weeks later. This result indicates a need for the use of eye protection in high-risk areas, such as clinical laboratories, hemodialysis units, and dental operatories.

Animals↗
PubMed1981

Effect of multiple use of dialyzers on hepatitis B incidence in patients and staff.

Data pertaining to incidence of hepatitis B from a 1976 Center for Disease Control Study were matched with responses from a Renal Physicians Association survey on dialyzer reuse in the United States. Of 6,079 patients, 166 (2.7%) became positive for hepatitis B surface antigen (HBsAg) in 96 centers practicing reuse, whereas 495 (2.6%) of 18,947 became HBsAg positive in 439 centers practicing single use. Among staff, 75 (2.5%) of 3,049 became positive for HBsAg in centers practicing reuse vs 200 (2.3%) of 8,696 in centers not reusing dialyzers. Incidence of infection among staff associated with a center having at least one HBsAg-positive patient was 2.9% in centers practicing reuse vs 3.6% in centers practicing single use. Nearly all (95%) staff who became HBsAg positive were associated with centers having at least one HBsAg-positive patient. The practice of reusing dialyzers does not appear to be associated with increased risk of hepatitis B infection among patients and staff.

Cross Infection↗
PubMed1981

In vivo studies of dialysis-related endotoxemia and bacteremia.

The transfer of bacteria and endotoxin and the development of fever was monitored during hemodialysis of dogs. Bacterial and endotoxin levels in dialysis fluids exceeded those reportedly associated with pyrogenic reactions, and bacteria-free dialysate filtrates administered intravenously were shown to be pyrogenic in 2 of 2 dogs. During 18 hollow-fiber dialyses, neither bacteria nor endotoxin, as measured in the Limulus lysate assay (LLA), was detected in venous and arterial blood samples. Body temperatures did not increase during or within 1/2 h after dialysis. In experiments with parallel dialyzers, contaminated dialysate was simultaneously ultrafiltered into the second blood compartment. Ultrafiltrates were unreactive in the LLA and the absence of pyrogens was confirmed with the pyrogen test, USP, in five of five experiments. This investigation suggests that the intact cellophane membrane of the hollow-fiber dialyzer is an effective barrier to endotoxin and bacteria.

Animals↗