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Biomedical subjects

W L George

Publications and source records attributed to W L George.

At least 37 records · Page 2Linked to original sources
PubMed1986

In vitro activities of 17 antimicrobial agents against the formate/fumarate-requiring, anaerobic gram-negative bacilli.

The in vitro activities of 17 antimicrobial agents were evaluated against 46 clinical isolates of formate/fumarate-requiring anaerobic gram-negative bacilli. Strains of Bacteroides ureolyticus (23) were almost uniformly susceptible to the tested antimicrobials, whereas strains of Bacteroides gracilis (18) showed some striking resistance with penicillin active against only 67%, the cephalosporins active against 67%-89%, and clindamycin active against 67%. Although few strains of Wolinella species/C. concisus (5) were available for testing, these isolates tended to be more resistant than B. ureolyticus but less resistant than B. gracilis.

Anti-Bacterial Agents↗
PubMed1986

Phenotypic characteristics of Aeromonas species isolated from adult humans.

The phenotypic characteristics of 89 Aeromonas strains, most of which had been isolated from feces, were examined. Eighty-two percent of the isolates could be placed into one of four groups on the basis of five tests. The relationship of these groups to the three motile species of Aeromonas (Aeromonas caviae, A. hydrophila, and A. sobria) that have been isolated from humans is unclear. Because the means for identification of Aeromonas strains to the species level appear to be imprecise and because the role of each of these species in human diarrhea is unclear at this time, we recommend that identification of enteric Aeromonas isolates to the species level not be done routinely.

Acetoin↗
PubMed1986

Microbiological and biochemical characterization of spirochetes isolated from the feces of homosexual males.

Spirochetes were isolated from the feces of 11 homosexual males who had diarrhea. The anaerobic organisms were isolated from a selective medium that consisted of Trypticase soy agar supplemented with either 5% horse or human blood, 400 micrograms of spectinomycin per ml, and 5 micrograms of polymyxin B per ml. Nonselective media that permitted good growth of these fastidious organisms were developed, and selected biochemical tests were performed. The tests included carbohydrate utilization, detection of certain enzymes, and determination of volatile fatty-acid end products of metabolism. Two growth patterns were noted on solid media, a haze of growth and production of small colonies. Based on the results of biochemical tests, patterns of preformed enzymes, and volatile fatty-acid production, we believe that the 11 isolates represent a heterogeneous group of spirochetes. The data suggest that the human colon may harbor unique strains of cultivable spirochetes; additional study of the taxonomy of the organisms and assessment of their virulence for humans are needed.

Culture Media↗
PubMed1985

Safety and efficacy of ticarcillin plus clavulanic acid in the treatment of infections of soft tissue, bone, and joint.

The efficacy and safety of ticarcillin plus clavulanic acid in the treatment of patients with infections of soft tissue, bone, and joint were evaluated in this open study. Clinical diagnoses included osteomyelitis, soft tissue abscess or ulcer, cellulitis, bite wound, traumatic or postoperative cellulitis, necrotizing fasciitis, septic arthritis, septic bursitis, and septic thrombophlebitis. Trauma or underlying disease such as diabetes mellitus or vascular insufficiency was common (more than 50 percent) in the patient population. Clinical efficacy was evaluable in 66 patients who received 3 g of ticarcillin and 0.1 g of clavulanic acid every four or six hours for a mean of 23.4 days. A satisfactory clinical response was observed in 92 percent of the patients. Major pathogens isolated were Enterobacteriaceae, anaerobic cocci, Staphylococcus aureus, and beta-hemolytic Streptococcus. Of the 143 isolates recovered from 55 bacteriologically evaluable cases, 87 percent were eradicated by therapy. Overall, a satisfactory bacteriologic outcome occurred in 93 percent of the patients, and the pathogen(s) persisted in 7 percent. More than 98 percent of the isolates were susceptible to ticarcillin plus clavulanic acid in vitro. Emergence of resistance during therapy occurred with three strains of Pseudomonas aeruginosa. Adverse drug-related reactions required discontinuation of treatment in two patients, although other minor abnormal laboratory findings were common. These results indicate that ticarcillin plus clavulanic acid offers safe and effective therapy for infections of soft tissue, bone, and joint.

Adult↗
PubMed1985

Plesiomonas shigelloides-associated diarrhea.

Plesiomonas shigelloides was thought to be the cause of diarrhea in six patients seen in Los Angeles. Although this organism is considered to be a cause of diarrhea in the Orient, it has infrequently been noted to be associated with diarrhea in North America.

Adult↗
PubMed1985

Comparative in vitro activities of selected antimicrobial agents against Aeromonas species and Plesiomonas shigelloides.

The in vitro antimicrobial susceptibilities of fecal isolates of Aeromonas caviae, Aeromonas hydrophila, Aeromonas sobria, and Plesiomonas shigelloides were tested by agar dilution. This in vitro study suggested that ciprofloxacin, enoxacin, norfloxacin, tetracycline, and trimethoprim-sulfamethoxazole might be effective oral agents for treatment of diarrhea involving Aeromonas spp. or P. shigelloides.

Aeromonas↗
PubMed1985

Comparative in vitro activities of selected antimicrobial agents against Edwardsiella tarda.

MICs of 14 antimicrobial agents for 29 strains of Edwardsiella tarda were determined by an agar dilution method. Of the agents tested, ciprofloxacin, enoxacin, and norfloxacin were the most active on a weight basis. All strains were also susceptible to clinically achievable concentrations of ampicillin, chloramphenicol, tetracycline, trimethoprim, sulfamethoxazole, trimethoprim plus sulfamethoxazole, cefotaxime, and gentamicin. Ninety percent of the strains demonstrated high-level resistance to polymyxin B and colistin.

Anti-Bacterial Agents↗
PubMed1985

Bacteroides gracilis, an important anaerobic bacterial pathogen.

Clinical isolates of agar-pitting, formate-fumarate-requiring, anaerobic gram-negative bacilli were recharacterized in consideration of the species descriptions of Bacteroides ureolyticus and the newly described B. gracilis, Campylobacter concisus, and Wolinella sp. During an 11-year period, 7.5% (101 of 1,341) of all specimens yielding anaerobes were found to contain an organism in this group. Of the 71 isolates that were available for study, 43 were B. ureolyticus, 23 were B. gracilis, and 5 were in the Wolinella-C. concisus group. The role in infection and patterns of antimicrobial susceptibility for B. ureolyticus and B. gracilis were studied. Review of the clinical data indicated that 83% of B. gracilis strains were recovered from patients with serious visceral or head and neck infection, whereas 73% of B. ureolyticus isolates were recovered from superficial soft-tissue or bone infections. The strains of B. ureolyticus were uniformly susceptible to the tested antimicrobial agents. B. gracilis, however, showed some striking resistance, with penicillin active against only 67% and the cephalosporins active against 67 to 84% of the isolates tested. The association of B. gracilis with serious deep-tissue infection, coupled with the relatively high frequency of antibiotic resistance, indicates that it is an important, previously unrecognized, pathogen.

Bacillus↗
PubMed1985

Intravenous catheter-associated fungemia due to Candida rugosa.

We report a case of intravenous catheter-associated fungemia caused by Candida rugosa; this is the first report of such an infection in a human. Multiple cultures of blood taken over a 24-h period and of the intravenous catheter tip were positive for this unusual isolate. The patient was treated with intravenous amphotericin B and made an uneventful recovery. Intravenous cannulae and other intravascular devices are well recognized as potential sites of intravascular infection by a variety of microorganisms, including several Candida species; however, fungemia caused by C. rugosa has not been reported.

Amphotericin B↗
PubMed1985

Aeromonas-related diarrhea in adults.

We have reviewed the incidence of Aeromonas in patients with enteric disease at our hospital and found it to be the highest of any potential enteric pathogen. Eighty adult patients with diarrhea had Aeromonas isolated from feces, and in 73 Aeromonas was the only potential bacterial or parasitic pathogen detected. The spectrum of illness in patients with Aeromonas-related diarrhea ranged from acute, self-limited diarrhea to a chronic, indolent diarrheal illness. Sixteen percent (13/80) of the patients had evidence of colitis noted during sigmoidoscopy or colonoscopy. Our data (and those from other studies) indicate that Aeromonas is relatively common in the feces of adults with diarrhea; they also indicate the need for prospective, controlled clinical and bacteriological studies to determine whether or not Aeromonas is an important enteric pathogen in adults.

Adult↗
PubMed1984

In vitro antibacterial activity of the combination of clindamycin and ceftazidime.

A total of 49 anaerobic and 52 aerobic or facultative bacteria were tested for their susceptibilities to clindamycin and ceftazidime alone and in combination. Synergy was noted for 11 strains, whereas antagonism was not detected. The combination of clindamycin and ceftazidime may prove to be useful for the treatment of severe mixed infections caused by anaerobes and aerobes or facultative bacteria.

Bacteria↗
PubMed1984

Alterations in human fecal flora, including ingrowth of Clostridium difficile, related to cefoxitin therapy.

To evaluate the effects of parenteral cefoxitin therapy on human fecal flora, we cultured fecal specimens obtained from six patients before, during, and after therapy and used standard methods to identify and quantify all microorganisms. The major changes (observed in at least three patients) included the acquisition or proliferation of group D Streptococcus species, coagulase-negative Staphylococcus species, cefoxitin-resistant members of the family Enterobacteriaceae, Pseudomonas species, and various species of the Bacteroides fragilis group. The most striking finding was ingrowth of Clostridium difficile, noted in five of the six patients. There was concomitant eradication or decrease of cefoxitin-susceptible Enterobacteriaceae family members, Bacteroides species other than the B. fragilis group, Clostridium species other than C. difficile, and Lactobacillus species. These marked alterations of fecal flora may have important clinical consequences.

Adult↗
PubMed1983

Group G streptococcal arthritis.

Five patients were seen in the UCLA hospital system with septic arthritis due to group G Streptococcus. All had prior joint disease or surgery on the affected joint. Findings from physical examination and laboratory evaluation were typical for pyogenic arthritis. Response to antimicrobial therapy was slow and marked by recurrent sterile joint effusions. Group G streptococcal arthritis may be diagnosed more frequently if routine serologic grouping of streptococcal isolates from joint fluid samples is performed. Such identification may also have prognostic significance.

Aged↗
PubMed1982

Clostridium difficile and cytotoxin in feces of patients with antimicrobial agent-associated pseudomembranous colitis.

Thirty patients with antimicrobial agent-associated pseudomembranous colitis (PMC) were studied for the presence of Clostridium difficile and its cytotoxin in feces. Either colonoscopy or barium enema radiography was required in three patients for the diagnosis of PMC because of nondiagnostic findings at sigmoidoscopy. Both the organism and cytotoxin were detected in 27 of the 30 patients; Staphylococcus aureus was excluded as the cause of PMC in two of the remaining patients. Eighteen of 19 patients with C. difficile-induced PMC who were treated with oral vancomycin had a salutary response; seven patients, however, had a relapse of colitis following the discontinuation of vancomycin. In general, relapses of colitis responded to retreatment with vancomycin. The implication of C. difficile as a cause of diarrhea is best achieved by the demonstration of colonic mucosal plaques or of a pseudomembrane. The value of fecal culture for C. difficile and cytotoxin assay is limited by the existence of asymptomatic carriers.

Adult↗
PubMed1982

Intravenous metronidazole for treatment of infections involving anaerobic bacteria.

Intravenous metronidazole was administered, either by continuous or intermittent infusion, to 20 patients with infections involving anaerobic bacteria; 14 of the 20 patients were changed to oral administration of metronidazole for completion of therapy. Six of eight patients with infections derived from oropharyngeal bacterial flora were cured; the addition of ampicillin was required in one patient, however, because of an incomplete response to metronidazole. Eight of eleven evaluable patients with infections derived from bowel flora were also cured by metronidazole or metronidazole plus an aminoglycoside. Of 93 anaerobic bacteria isolated before therapy, 89 were susceptible to 16 micrograms or less of metronidazole per ml. Mean plasma levels of metronidazole were 27.6 +/- 11.4 micrograms/ml in patients receiving continuous infusions of drug and 19.9 +/- 10.7 micrograms/ml (trough) in patients receiving intermittent infusions. Two patients developed peripheral neuropathy during therapy. Metronidazole is an effective agent for the treatment of anaerobic infections. Because metronidazole is not active against facultative and aerobic bacteria, the addition of a second antimicrobial agent may be required for the treatment of mixed anaerobic-aerobic infections.

Adult↗
PubMed1982

Clostridium difficile and its cytotoxin in feces of patients with antimicrobial agent-associated diarrhea and miscellaneous conditions.

Fecal specimens from 223 subjects were evaluated for the presence of Clostridium difficile by use of a selective medium developed in our laboratory and for the presence of C. difficile cytotoxin. C. difficile and cytotoxin were detected in 89 and 83%, respectively, of patients with antimicrobial agent-associated pseudomembranous colitis (PMC). In patients in whom PMC was not documented, C. difficile and cytotoxin were present in only 37 and 21%, respectively. C. difficile and cytotoxin were also recovered from the feces of 6 and 3, respectively, of 13 antimicrobial recipients who did not have diarrhea. Although C. difficile appears to be a major cause of PMC, it is not responsible for at least some two-thirds of cases of antimicrobial agent-associated diarrhea in which PMC is not documented. Neither the recovery of C. difficile nor the detection of its cytotoxin should be considered diagnostic for C. difficile-induced disease.

Anti-Bacterial Agents↗