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Biomedical subjects

R H Eng

Publications and source records attributed to R H Eng.

At least 91 records · Page 5Linked to original sources
PubMed1984

Examination of gram-negative bacilli from meningitis patients who failed or relapsed on moxalactam therapy.

One Salmonella and four Escherichia coli isolates from patients with bacterial meningitis who had responded slowly, relapsed, or failed to respond to monotherapy with moxalactam were examined. For purposes of comparison, an E. coli isolate from one patient who had responded promptly to therapy was also studied. On testing, moxalactam had higher MICs and MBCs (two to four times) than cefotaxime or ceftriaxone for all isolates; the rates of killing of the isolates were dependent on the antibiotic concentrations used. At comparable multiples of the MIC, these isolates were generally killed more slowly by moxalactam than by cefotaxime or ceftriaxone. In addition, a reduction of 3 in the logarithm of the number of CFU per milliliter could be attained at far lower concentrations with cefotaxime or ceftriaxone than with moxalactam. The degree of concentration-related killing of bacteria produced by the beta-lactams appeared to correlate with the clinical responses of the patients. Furthermore, real differences appeared to exist among the third-generation cephalosporins, which were not evident by the MIC and MBC points alone but were evident in the concentration-related killing curves: Determination of a reduction of 3 in the logarithm of the number of CFU per milliliter after a 6-h incubation is suggested as the criterion for the screening of antibiotics for the therapy for gram-negative bacillary meningitis.

Aged↗
PubMed1984

Mycobacterium xenopi infection in a patient with acquired immunodeficiency syndrome.

A case of Mycobacterium xenopi infection in a patient with acquired immunodeficiency syndrome (AIDS) is described and the clinical experience of others in the United States with this organism is reviewed. Disseminated infection by this organism appears to occur only in the immunocompromised host. Because M xenopi has been found in hot water systems by others and is an organism more susceptible to the traditional antituberculosis antibiotics, recognition and distinction of this organism from the more resistant and difficult to treat Mycobacterium avium-intracellulare in the patients with AIDS may be important.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Saccharomyces cerevisiae infections in man.

Saccharomyces cerevisiae is a yeast commonly used to make food products such as bread, beer and wine, or ingested whole as a 'health' food. We report five cases of infections involving S. cerevisiae, including one in which S. cerevisiae alone was implicated, and review the literature on its pathogenicity.

Aged↗
PubMed1983

Antifungal activity in human urine and serum after ingestion of garlic (Allium sativum).

A fresh extract of garlic (Allium sativum) was administered orally to human volunteers. At intervals, serum and urine were collected and assayed for antifungal activity. The maximum tolerable dose was determined to be 25 ml of garlic extract. Larger amounts caused severe burning sensations in the esophagus and the stomach and vomiting. After oral ingestion of 25 ml of the extract, anticandidal and anticryptococcal activities were detected in undiluted serum 0.5 and 1 h after ingestion. No detectable antifungal activity was found in the excreted urine at any time after oral ingestion. Oral garlic is of limited value in the therapy of human fungal infections.

Antifungal Agents↗
PubMed1983

In vitro evaluation of the BACTEC resin-containing blood culture bottle.

The BACTEC resin-containing blood culture bottle (16B; Johnston Laboratories) was designed to bind antibiotics and to support bacterial growth. However, only modest increases in the recovery rates of pathogens have been found in clinical studies. This in vitro study evaluated the ability of the 16B to recover organisms from human serum containing clinically achievable concentrations of antibiotics. Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Haemophilus influenzae, Staphylococcus aureus, Streptococcus faecalis, and a viridans streptococcus were added to serum containing antibiotic(s), and at various time intervals of antibiotic exposure, portions were removed and inoculated into both the 16B and the 6B (conventional aerobic) bottles. The studies of the kinetics of killing of the bacterial strains by the various antibiotics showed a good correlation between those combinations of bacteria-antibiotic(s) which produced slow killing and the combinations of bacteria-antibiotic(s) which were recovered preferentially in the 16B bottles. Low recovery rates were noted when the antibiotics killed the organisms rapidly. The indications for use of the resin-containing blood culture bottle should be limited to those situations in which the patient is receiving antibiotics and the bacteremia is suspected to involve a pathogen which is killed slowly by the administered drug(s) or when the bacteremia is continuous. The failure of the BACTEC 16B blood culture bottle to recover organisms may in part reflect the bactericidal activity of the antibiotics administered.

Anti-Bacterial Agents↗
PubMed1983

The significance of eubacterium bacteremia.

Eubacterium is a commensal of the human gastrointestinal tract. In rare instances this organism can become blood-borne. Nine cases of bacteremia were described and eight cases were found in the medical literature. Thirteen of the 17 cases (76%) had active gastrointestinal disease leading to the Eubacterium bacteremia. It is suggested that recovery of Eubacterium in blood culture should alert the clinician to the possibility of active gastrointestinal disease including occult neoplasms.

Adolescent↗
PubMed1982

Susceptibility of dermatiaceous fungi to amphotericin B, miconazole, ketoconazole, flucytosine and rifampin alone and in combination.

The dematiaceous fungi comprise a group of organisms that are deeply pigmented and found in soil or on decaying organic material, such as wood. The majority of infections with these fungi presumably results from traumatic inoculation. Although various forms of infection have been appreciated for some time, none of the presently available antifungal drugs have been shown to have predictable activity against these organisms. We report on the activity in vitro of various antifungal agents alone and in combination against various dematiaceous fungi.

Amphotericin B↗
PubMed1982

Effect of rifampin on ampicillin killing of group B streptococci.

The activity of rifampin against group B streptococci as a single agent and in combination with ampicillin was examined. The minimum concentration of rifampin required to inhibit 90% of the isolates of group B streptococci (18 of 20 isolates) was 0.6 microgram/ml. The checkerboard double-dilution studies of these two antibiotics and the time-killing studies both indicate that rifampin inhibits the bactericidal activity of ampicillin for group B streptococci.

Ampicillin↗
PubMed1982

Species identification of coagulase-negative staphylococcal isolates from blood cultures.

Coagulase-negative staphylococci generally are not fully identified, are called Staphylococcus epidermidis, and are considered contaminants when isolated from blood cultures. In a cancer hospital during 6 months, 46 patients had multiple blood cultures (mean, 3.1) which yielded coagulase-negative staphylococci. Species identification of these showed that 10 of the 46 (22%) were not S. epidermidis. Similarly, 96 coagulase-negative staphylococci isolated from only one of multiple blood cultures from patients and thought to be skin contaminants were identified. Of 96 of the staphylococci, 14 (16%) of the latter group were not S. epidermidis. Species found included S. haemolyticus, S. hominis, S. warneri, S. simulans, and S. xylosus. Eight isolates of these species were methicillin resistant, and all eight were mannitol fermenters. The results suggest that these species invasively infect cancer patients with the same frequency at which the species colonize. No one species was identified as being more pathogenic than the others. Routine species identification of coagulase-negative staphylococci from blood cultures of cancer patients contributed little to management except to occasionally distinguish multiple-episode culture contamination by different species from sustained bacteremia with the same species.

Adult↗
PubMed1982

Epidemiology of Klebsiella antibiotic resistance and serotypes.

Because of the emergence of drug-resistant Klebsiella strains in many hospitals, the distribution of the serotypes was reexamined to determine whether there was any correlation between the serotype and the site of isolation from the body, the antimicrobial susceptibility pattern, or the place of acquisition of the organism (hospital or community). One hundred consecutive isolates of Klebsiella pneumoniae from different patients were typed as 1, 2, 3, 4, 5, 6, or greater than 6. Of these, 8 of 28 strains isolated from respiratory secretions were serotype 2 (9 typable strains), 6 of 24 wound isolates were serotype 3 (8 typable strains), and the urine isolates varied in their serotypes. Regardless of serotype, most strains appeared mucoid on blood and MacConkey agars. Twenty-six percent of the isolates were resistant to at least one antimicrobial agent. No correlation was found between the serotypes and the antibiotic resistance; however, strains isolated within 25 days of admission to the hospital from the community were all susceptible. It appears that although there may be a correlation between the serotype and isolation from some sites of the body, knowledge of the serotype of the organism cannot predict the antimicrobial susceptibility pattern. The clinician's choice of antibiotic therapy should depend largely on whether the Klebsiella strain was acquired by the patient in the community (0% resistant) or in the hospital (31% resistant).

Anti-Bacterial Agents↗
PubMed1982

Penetration of antibiotics into vegetation of heart valves: a mathematical model.

The effect of vegetation size upon the concentration of antibiotic within various points of a fibrin-clot heart valve vegetation such as ones found in bacterial endocarditis was examined. A mathematical model based upon Fick's second law of diffusion was developed and solved on a PDP-II computer. The antibiotic was assumed to have a half-life of 30 min and intermittently injected intravenously every 4 h. After 5 simulated antibiotic doses, peak and trough levels of the antibiotic near the center of the vegetations of sizes 0.5, 1.0, 2.0 cm were, respectively, 37 and 3%, 22 and 15%, and 18 and 18% of the free serum antibiotic concentration. This model can be used to estimate antibiotic levels in different areas of a valvular vegetation.

Absorption↗
PubMed1982

Failure of erythromycin in preventing bacterial endocarditis.

Use of oral erythromycin to prevent bacterial endocarditis has been accepted in the treatment of penicillin-allergic patients who required oral or sinusal surgery. A case of Streptococcus sanguis endocarditis, however, developed in a patient following intravenous erythromycin administration during surgery on the maxillary sinus. The organism isolated proved resistant to erythromycin. This isolation of an erythromycin-resistant organism, together with previous reports of the drug's failure in preventing endocarditis in animal models, and recognition of the bacteriostatic action of erythromycin, argue for caution in our current practice of using erythromycin as a single drug therapy to prevent endocarditis in the patient who is allergic to penicillin.

Adult↗
PubMed1981

Lumbar puncture-induced meningitis.

A retrospective study was done to evaluate the risk of lumbar puncture-induced meningitis. Fourteen percent (23/165) of patients with bacteremia caused by Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitis, and groups A and B streptococci had spontaneous meningitis (without a preceding lumbar puncture). In contrast, only 0.8% (7/924) of patients with blood culture containing other organisms had spontaneous meningitis and 2.1% (3/140) of these patients had clinical courses consistent with lumbar puncture-induced meningitis. However, the 2.1% incidence in the latter group is not significantly different from 0.8%, the expected incidence of spontaneous meningitis. It is suggested that if lumbar puncture-induced meningitis does occur, it is rare enough to be clinically insignificant.

Adult↗
PubMed1981

Candida pericarditis.

Purulent pericarditis due to species of Candida is rare. Only seven cases were found in the literature. Described here is a man with Candida tropicalis colonization of the urinary bladder in whom C. tropicalis pericarditis later developed. Amphotericin B was given intravenously. The amphotericin B level in pericardial fluid was approximately 50 percent of the concentration in serum. Although microbiologic cure was achieved with amphotericin B, the patient died of other causes. Autopsy showed sterile constrictive pericarditis.

Adult↗
PubMed1981

Susceptibility of Zygomycetes to human serum.

Seven members of the class Zygomycetes were tested for serum susceptibility. Five of the isolates were inhibited to different degrees by pooled fresh human serum. Heating the serum at 56 degrees C for 30 min to inactivate complement did not abolish the inhibitory activity in the serum. Members of the genera Cunninghamella and Absidia appeared most susceptable to the inhibitory effects of serum while members of the genus Rhizopus were most resistant. One isolate of R. arrhizus appeared to have enhanced growth in the presence of human serum. Our findings suggest certain species of the class Zygomycetes are strongly inhibited by serum, and this may account for the rarity of human infections by these species.

Blood Physiological Phenomena↗