PubMed Health⌕ Search

Biomedical subjects

D Furtado

Publications and source records attributed to D Furtado.

At least 19 recordsLinked to original sources
PubMed1990

In vitro and in vivo bactericidal activities of 10%, 2.5%, and 1% povidone-iodine solution.

The bactericidal action of three formulations of a povidone-iodine (PVI) complex in vitro, in vivo, and in the presence of competing organic matter was evaluated. Bacterial organisms included Staphylococcus aureus ATCC 25923 and 25 clinical isolates of Staph. aureus, designated KU 1-25. For the in vitro studies, 1.0 mL of bacterial inoculum containing 10(7) organisms was introduced into 9.0 mL of chemically stable 10% and 1% PVI formulations in sterile culture tubes, and 1.0-mL samples were withdrawn at set intervals. Samples were plated by using standard techniques and incubated for 24 hours, after which colony-forming units were counted. For in vivo studies, 0.1 mL of 10(6) Staph. aureus ATCC 25923 or KU inoculum was deposited on the dorsum of the hand of healthy human subjects. This area was wiped with a cotton swab saturated with 1%, 2.5%, or 10% PVI formulations. Samples were taken at 15 and 30 seconds after application of the iodophor. To test the bactericidal activity of the three formulations in the presence of a competing substrate, a swab soaked with sterile sheep's blood was applied to the skin and allowed to dry. The percentage of 10(4) Staph. aureus inoculum recovered allowed for comparison of the three products. In vitro, the 1% PVI formulation was bactericidal for 10(7) Staph. aureus within two minutes, as compared with the four minutes required by 10% PVI. On the skin contaminated with 10(6) organisms, the rates of killing within 30 seconds were comparable for both solutions.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1984

Hydrogen peroxide: potential for prophylaxis against bacteriuria.

The effect of dilute solutions of hydrogen peroxide, povidone-iodine, and acetic acid on a chronic Staphylococcus epidermidis bacteriuria was studied to determine whether direct bladder instillation of the antimicrobial solutions would reduce or eliminate the bacterial count. In vivo instillation of volumes ranging from 50 to 400ml and retained for 30 seconds to 48 hours was evaluated. The effect of the antimicrobial solution on bacterial survival in urine was also measured in vitro through quantitative analysis of the mixture at various times over 24 hours. Instillation of the antimicrobial solutions into the bladder had no measurable effect on the established bacteriuria. Symptoms of discomfort related to such a manipulation were least evident with hydrogen peroxide. In vitro, hydrogen peroxide had an antimicrobial effect as reflected by the reduction of the number of surviving organisms. Despite inefficacy in a case of already established bacteriuria, hydrogen peroxide appears worthy of study as a prophylactic agent against a variety of organisms because it exhibits in vitro efficacy and minimal in vivo symptoms.

Acetates↗
PubMed1982

Rate of penicillin killing of Staphylococcus aureus and Autobac 1 susceptibility test results.

A clinical isolate of Staphylococcus aureus interpreted as resistant to penicillin by the Autobac 1 susceptibility testing method (i.e., light-scattering index of 0.77) was found to be susceptible to penicillin by both the disk diffusion and broth dilution techniques. The growth rate of the clinical isolate during a 4-h incubation interval was similar to that of a known sensitive reference strain (S. aureus ATCC 25923) used as a control organism for the Autobac test. The bactericidal effect of penicillin was evaluated by measuring the rate of killing over a 4-h interval. The percentages of organisms surviving exposure to 5.0 or 2.5 U of penicillin G per ml (number of organisms recovered at 3 h/number of organisms introduced as inoculum) were 68 and 76%, respectively, for the clinical isolate and 15 and 21%, respectively, for the reference strain. After 24 h of incubation, penicillin was bactericidal for both strains. The need to increase the time of incubation for those S. aureus isolates resistant to penicillin after 3 h of standard incubation time in the Autobac system is discussed.

Animals↗
PubMed1982

Evaluation of three methods for detecting bacterial contamination in intravenous solutions.

Membrane filtration, small-aliquot inoculation, and double-strength broth methods of sterility testing were evaluated for detection of small numbers of bacteria in 5% dextrose injection (D5W). Each of 240 bags of D5W 50 ml were inoculated with approximately 10 2 Staphylococcus epidermidis and subjected to one of the three test methods at 1, 3, 6, 9, 12, 18, 24, or 48 hours after inoculation. After incubating at 25 degrees C for seven days, the test units were examined for turbidity, indicating growth of bacterial contaminants. Double-strength broth was shown to be more reliable than the other two test methods, detecting the bacterial contaminants in 30 of 30 samples through six hours. Successful recovery of low-level Staph. epidermidis in D5W decreased significantly after a nine-hour delay in processing. Membrane filtration and aliquot-sampling methods were comparable, each detecting contamination in 3-4 of 10 bags at one hour after inoculation. The number of false negatives increased with time, with no contaminants detected in any of the bags tested with these two methods nine hours after inoculation. It is concluded that the testing method selected to monitor for sterility and the amount of time elapsed before processing the sample are critical to the accuracy of results.

Bacteriological Techniques↗
PubMed1982

Determining a time frame for sterility testing of intravenous admixtures.

Defining an optimal time of analysis for detecting bacterial contaminants in intravenous admixtures was studied. Three different intravenous solutions were inoculated with low-level numbers (10(1)) of Staphylococcus epidermidis and tested for sterility using the Ivex-2 Filterset method at six time intervals after inoculation: less than 1, 20, 40, 60, 120, and 240 minutes. Solutions used were 5% dextrose injection 1000 ml, 0.9% sodium chloride injection 1000 ml, and 5% dextrose injection 50 ml. At each interval, 10 solutions of each type were tested. An additional 20 controls were employed to monitor technique, facilities, and environmental conditions. Successful recovery of Staph. epidermis decreased significantly when sample processing was delayed for longer than 40-60 minutes after inoculation. Furthermore, the number of false negatives was greater for dextrose solutions than for sodium chloride solutions after this time period. Volume of admixtures had no effect on contamination detection. This study suggests that sterility testing should be completed within 40-60 minutes after preparation of intravenous admixtures.

Bacteriological Techniques↗
PubMed1982

Evaluation of three methods for detecting low-level bacterial contamination in intravenous solutions.

The accuracy of three sterility-testing methods in detecting low-level contamination in deliberately contaminated intravenous solutions was studied. One-liter bags of 5% dextrose (D5W) and 0.9% sodium chloride (saline injections were contaminated with Staphylococcus epidermidis and Pseudomonas aeruginosa; approximately 10(1) viable bacteria were injected into each bag. Two membrane-filtration methods (Ivex-2 and Addi-Chek) and one aliquot method [twice concentrated trypic soy broth (2X-TSB)] were used to test each of 10 diliberately contaminated solutions for both D5W and saline; 500 ml of each liter bag was filtered or added to 2X-TSB. Incubation containers were stored at 37 degrees C and inspected at 24, 48, and 72 hours for turbidity. There was no significant difference among the three methods in the detection of contaminated saline solutions. The Addi-Chek system was significantly less effective in detecting contamination in D5W than either of the other methods. It is concluded that the Ivex-2 system is accurate and the easiest-to-use system of the three tested.

Bacteriological Techniques↗
PubMed1982

Method for testing aseptic technique of intravenous admixture personnel.

A method of checking the aseptic technique of personnel that prepare i.v. admixtures is described. The following sterile dosage forms of trypticase soy broth (TSB) were prepared: (1) single-strength ampuls 5 ml, (2) six-times (6X) concentrated broth ampuls 10 ml, (3) lyophilized broth sufficient to make 5 ml single-strength broth in 10-ml vials, and lyophilized broth sufficient to make 10.6 ml 6X concentrated broth in 20-ml vials. Admixture personnel were told these were investigational products, and they were given simulated orders to prepare syringes and 50-ml piggyback admixtures of the products. The specimens containing the broth were intercepted by an investigator, incubated for seven days at 37 degree C, and observed for turbidity on days 2 and 7. To verify that the broth supported the growth of bacteria, two common contaminants were inoculated into the broth in the syringes and admixtures to serve as positive controls. At least 100 samples from each of four procedures were processed during the three-month study period. A total of 405 samples prepared by 13 individuals were tested. None of the samples became turbid; hence, the bacterial contamination rate was 0%. Among the positive controls, 98% inoculated with one species and 100% inoculated with the other became turbid. This method is now used for monitoring the aseptic technique of new admixture personnel. This unique method of checking the aseptic technique of personnel is accurate and cost effective, and it avoids the risk of adventitious contamination.

Antisepsis↗
PubMed1981

Type III group B streptococcal infections in mice: bacteremia and meningitis following oral inoculation.

The successful production of disease in mice by a type III group B streptococcus is described in this report. When injected intravenously, 106 organisms produced a fulminating sepsis and resulted in 100% mortality within 48 h. Inoculation of 108 - 109 organisms directly onto the surface of the oropharynx progressed to bacteremia and meningitis in greater than 50% of animals. In a group of mice treated with penicillin immediately after oropharyngeal inoculation, the incidence of invasive bacteremia was reduced to 30%. The use of this animal model for studying the pathogenesis and treatment of experimentally produced meningitis and eradication of oropharyngeal colonization is discussed.

Animals↗
PubMed1979

Phase separations in membranes of Anacystis nidulans grown at different temperatures.

Freeze fracture electron microscopy studies were performed on samples of Anacystis nidulans quenched from different temperatures. Membrane lipid phase separations were observed to take place over the ranges 15--30 degrees C, 5--25 degrees C and -5--15 degrees C for cultures grown at 38, 28 and 18 degrees C, respectively. Differential scanning calorimetry heating curves showed endotherms which coincided with these temperature ranges. Variations of phase separation temperatures with growth temperature, and hysteresis effects in the calorimetric measurements, were related to changes in the fatty acid composition of membrane lipids.

Cell Fractionation↗
PubMed1977

Effect of prolonged bacteremia on leukocyte bactericidal function.

Neutrophil bactericidal function (NBF) was studied in dogs during intravenous infusions of Pseudomonas aeruginosa. Administration of 10(6) bacteria per minute over 3 hours was associated with a bacteremia level of about 10(3) organisms per milliliter of blood without adverse effects on NBF. Infusion of 10(7) organisms per minute resulted in blood bacterial counts in the upper 10(4) range and significantly impaired NBF. To determine the relative contribution of the spleen in bacterial phagocytosis, splenectomies were performed in additional dogs immediately prior to 5 hour infusions of 10(6) Pseudomonas aeruginosa per minute. Results revealed that splenectomy did not influence the blood bacterial clearance. These experimental findings emphasize the dominant role of polymorphonuclear leukocytes in bacterial defense.

Animals↗
PubMed1977

Secondary effects of aganglionosis in the piebald-lethal mouse model of Hirschsprung's disease.

An attempt was made to identify the factors secondary to fecal stasis and megacolon that are related to overall debilitation and eventual death of the piebald mouse. The piebald mouse showed periodic leukocytosis and bacteremia that were associated with lesions in the mucosal surface of the megacolon. Defective growth, loss of weight, and retardation of development with megacolon were documented by systematic study of body weight and of the relationship between body weight and organ weights. Alterations in body weight and in organ weight to body weight ratios were parallel in the piebald mouse, in mice with imperforate anus, and in mice with surgically-induced megacolon. Histologic studies confirmed a pattern of hypertrophy of the muscularis externa in the piebald mouse. The body temperature was lower than for normal siblings, but the sodium, potassium, and water content of the feces, the general blood chemistry profiles, and the intestinal microflora did not differ from those of the normal mouse. There was no evidence of bacterial overgrowth in the small intestine of the piebald mouse with fecal stasis and megacolon.

Animals↗
PubMed1976

Experimental group B streptococcal infections in mice: hematogenous virulence and mucosal colonization.

A group B streptococcus recovered from a blood specimen from a neonate with sepsis was used to evaluate the use of mice for studies characterizing the hematogenous virulence and the asymptomatic mucosal colonization of the vagina or of the respiratory tract by these bacteria. When injected intravenously, the 50% lethal dose for mice was 10(6); however, as few as 10(2) organisms produced septic deaths. In mice undergoing water diuresis, bacteriuria and pyelonephritis were not produced after direct bladder inoculation of the streptococci. Asymptomatic vaginal colonizations that persisted for 12 days were produced in both pregnant and virgin mice. Vaginal colonization before delivery did not result in transmission of infection to litters or in protection against subsequent oropharyngeal colonization in the suckling mice. In mice born of nonexposed mothers, oropharyngeal colonization was produced in both suckling and 3-week-old weaned mice. Whereas infection persisted for 14 days in all suckling mice, clearance occurred in over 50% of the weaned mice by day 14. The use of mice for studies on the virulence of the group B streptococci as well as for studies on the pathogenesis of disease by virulent strains is discussed.

Animals↗
PubMed1976

Effect of chlorothiazide and furosemide diuresis on in vivo growth of Staphylococcus aureus in kidneys of mice.

In mice subcutaneous administration of the diuretics chlorothiazide or furosemide resulted in a prompt diuresis characterized by production of dilute urine within 30 min and lasting for 6 hr. In vivo proliferation or clearance of Staphylococcus aureus from the kidneys was only temporarily impaired during the time of maximum diuresis. When treatment was delayed until after phagocytosis was initiated, there was no effect on clearance. Clinically it would appear that bacterial proliferations in the renal parenchyma would not be promoted as a consequence of diuretic treatment.

Animals↗
PubMed1975

The effects of endotoxemia and bacteremia on gastrointestinal drug absorption in mice and rats.

Endotoxin [lipopolysaccharide (LPS)] from four Gram-negative bacteria injected i.v. delayed absorption of drugs administered in solution by gastric tube to mice and rats. Salicylate and guinine absorption was delayed at LPS doses from 50 to 400 mug/kg. Salicylate absorption was delayed by LPS when drug was given by gastric tube, while LPS did not affect drug levels when salicylate was given i.p. or intraduodenally. Bethanechol prevented the LPS effect and LPS pretreatment also protected against delayed absorption. LPS- treated rats retained more drugs in their stomachs after 30 minutes and their plasma salicylate levels were lowered. Everted intestinal sacs from LPS-treated rats transferred salicylate as well as controls. Thus, LPS delays gastrointestinal drug absorption solely by retarding gastric emptying. Escherichia coli urinary tract infection did not reproduce LPS delay of drug absorption, but the effects of systemic bacteria were similar to those of endotoxemia.

Animals↗
PubMed1975

Pathophysiologic alterations during bacterial infusions for the study of bacteremic shock.

Clearance of Pseudomonas aeruginosa from the blood stream in normal dogs was measured. An intravenous infusion of bacteria at a dose of 10(6) per milliliter per minute for two or five hours resulted in reproducible bacteremia in the 10(2) range per milliliter of blood without systemic side-effects. An identical bacterial infusion 24 hours later was characterized by enhanced clearance of bacteria and partial pyrogenic tolerance. A lethal bacterial dose of 4 X 10(7) per milliliter per minute infused for five hours exhibited an eightyfold higher bacteremia, shock and death within 24 hours. These events were characterized by leukopenia, hypothermia and hypoglycemia. Experimental results indicated that intact leukocyte bactericidal activity is the most important defense mechanism of the host in bacterial systemic infections.

Animals↗
PubMed1971

Effect of diuresis on Staphylococcus aureus kidney infections in mice.

In the Cornett strain of mice, water diuresis did not prevent hematogenous production of pyelonephritis by Staphylococcus aureus. Increased fluid intake did not affect the numbers of organisms deposited in the kidneys or the rate of growth during the first 4 hr after inoculation. Drinking the glucose solution did not enhance bacterial proliferation within the renal parenchyma. Subcutaneous injection of saline to supplement for interruption of drinking after inoculation reduced the numbers of organisms recovered in the kidneys but not sufficiently to prevent production of pyelonephritis. Incorporating penicillin as a marker indicated that fluids administered by subcutaneous injections were rapidly delivered to the kidneys. Combining diuresis with treatment did not influence the rapidity of delivery of antimicrobial to the kidneys or the length of time that it was present in the renal homogenate.

Animals↗