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C V Sanders

Publications and source records attributed to C V Sanders.

At least 37 records · Page 2Linked to original sources
PubMed1991

Role of newer antimicrobial agents in the treatment of mixed aerobic and anaerobic infections.

Mixed infections with aerobic and anaerobic bacteria are being recognized with increasing frequency in clinical practice. Several concepts regarding such infections are clinically significant for the physician. These include the presence and significance of species in the Bacteroides fragilis group at clinical sites of infection, the facilitation of B. fragilis virulence by beta-lactamase producing aerobic bacteria and the role of enterococci in such infections. In response to the need for new forms of therapy for mixed aerobic and anaerobic infections, several new classes of antimicrobial agents have been introduced. Some of these allow for the potential option of monotherapy in certain clinical settings. In addition to clinical and microbiologic efficacy, safety and cost-effectiveness are factors that must be addressed with regard to these agents.

Anti-Bacterial Agents↗
PubMed1991

Antimicrobial therapy of anaerobic infections, 1991.

Most anaerobic infections are polymicrobial and must be treated with agents active against a variety of both aerobic and anaerobic bacteria. Antimicrobial therapy is used both to contain infections and to treat those that have not been contained (bacteremia). Bacterial resistance, especially to penicillins and tetracyclines, but also to newer agents of other classes, continues to increase and often requires treatment with more than one drug. Combination therapy is also frequently necessary in serious infections, and is indicated for empiric management before receiving results of in vitro microbiology laboratory tests. However, recent results suggest that monotherapy for anaerobic infections may dominate in the future, although combination therapy has been the mainstay of antimicrobial therapy. Selection of an agent must take into account the site of infection and thus the bacteria most likely to be found. It should be kept in mind that in vitro susceptibility is not the only determinant of antimicrobial effectiveness. The pharmacology of the drug--absorption, distribution, concentration in body fluids and tissues, and metabolism--also plays an important role. Finally, the nature and severity of the underlying illness, the toxicity of the agent, and costs must be considered.

Anti-Bacterial Agents↗
PubMed1990

In-vitro study of the susceptibility of cefoxitin/cefotetan resistant Bacteroides fragilis group strains to various other antimicrobial agents.

The in-vitro activity of various beta-lactam antibiotics, beta-lactam/beta-lactamase inhibitor combinations, clindamycin, and metronidazole was determined against Bacteroides fragilis group isolates that were resistant to both cefoxitin and cefotetan. Among the cephalosporins tested ceftizoxime was the most active with 80% of the strains susceptible, followed by cefotaxime (65% susceptible), and cefoperazone (47% susceptible). Piperacillin and clindamycin showed comparable activity to ceftizoxime with 80% and 81% susceptible, respectively. The addition of a beta-lactamase inhibitor (sulbactam, clavulanate, or tazobactam) enhanced the activity of the various beta-lactam agents from 4-fold to 16-fold overall. One strain of B. fragilis was found that was resistant to all beta-lactam agents either alone or in combination. All strains in this study were susceptible to less than or equal to 4 mg/l of metronidazole.

Aminoglycosides↗
PubMed1990

Comparison of in vitro antibiograms of Bacteroides fragilis group isolates: differences in resistance rates in two institutions because of differences in susceptibility testing methodology.

With 120 clinical isolates of the Bacteroides fragilis group, a comparison of rates of resistance to selected antimicrobial agents by using two susceptibility tests was performed in two medical institutions. The broth microdilution method produced MICs significantly lower than those determined by the agar dilution method. With ceftizoxime and cefoxitin, 88 and 18%, respectively, of the MICs were greater than or equal to 2 twofold dilutions apart. These differences in MIC results produced major interpretive discrepancies for ceftizoxime and cefoxitin, whereas no significant differences in resistance rates were noted for clindamycin and metronidazole.

Anti-Bacterial Agents↗
PubMed1990

Activities of ciprofloxacin and ofloxacin against rapidly growing mycobacteria with demonstration of acquired resistance following single-drug therapy.

The susceptibility to ciprofloxacin of 548 clinical isolates of rapidly growing mycobacteria belonging to eight subgroups or species was determined. The 170 isolates of Mycobacterium fortuitum biovar.fortuitum were most susceptible; the MIC for 90% of the organisms was 0.125 micrograms/ml. The other biovariants of M. fortuitum, M. smegmatis, and the M. chelonae-like organisms were less susceptible; the modal MIC was 0.5 micrograms/ml, and the MIC for 90% of organisms was 1.0 micrograms/ml. The two subspecies of M. chelonae were generally resistant, with only 8% of 206 isolates falling in the moderately susceptible category (MIC, 2 micrograms/ml) and only 2% falling in the susceptible category (MIC, less than or equal to 1 micrograms/ml). MICs of ofloxacin averaged 1 to 2 dilutions higher than those of ciprofloxacin for all subgroups tested. Three patients with M. fortuitum cutaneous disease relapsed after an initial response to therapy with ciprofloxacin, and their isolate was shown to have acquired drug resistance. Mutational frequencies for M. fortuitum with ciprofloxacin were relatively high (10(-5) to 10(-7), and MICs for single-step mutants were similar to those for the clinically resistant strains. Thus, despite the excellent activity of ciprofloxacin against rapidly growing mycobacterial groups other than M. chelonae, single-drug therapy should be used with caution because of the risk of development of mutational resistance.

Adult↗
PubMed1990

Discordant results between the broth disk elution and broth microdilution susceptibility tests with Bacteroides fragilis group isolates.

Susceptibility testing of 161 clinical isolates of the Bacteroides fragilis group was performed to compare interpretive results generated by the broth disk elution and broth microdilution methods recommended by the National Committee for Clinical Laboratory Standards. Among the cephalosporin-cephamycin compounds tested, correlation was poorest for ceftizoxime (71%), ceftriaxone (57%), and cefotaxime (47%); when the tests did not correlate, false resistance was seen 92, 95, and 93% of the time, respectively. Cefotetan and cefoperazone showed lack of correlation in 19 and 20% of the tests, respectively. For cefotetan, false resistance was more frequent, while with cefoperazone, false susceptibility occurred more often. Cefoxitin produced the fewest discrepancies; 10% of the disk elution tests produced either false-resistance or false-susceptibility results. Mezlocillin and piperacillin showed lack of correlation in 8 and 14% of the tests, respectively, and discrepancies were due primarily to false-resistance results. Overall with the beta-lactams, 84% of the discordant interpretive results were false resistance by the broth disk elution test. Clindamycin had a discrepancy rate of 10%, with the majority of discrepancies being false susceptibility disk elution results. Because of the high number of discrepancies noted with ceftizoxime, ceftriaxone, and cefotaxime, we recommend that these drugs not be tested by the disk elution method and that they be tested by a quantitative MIC method such as the broth microdilution test. Furthermore, caution should be exercised when interpreting broth disk elution results with all the beta-lactams included in this study except imipenem. These data indicate the lack of correlation of results between these two tests for many beta-lactams and suggest the need for a reexamination of the disk elution method to provide a more accurately standardized test.

Bacteroides fragilis↗
PubMed1990

In vitro anaerobic data on ticarcillin/clavulanate. A review of an ongoing survey.

Although a number of new antimicrobial agents described as "broad spectrum" have been introduced during the past several years, it should be recognized that each of them has its own unique spectrum of activity, strengths and weaknesses that define its appropriate clinical use. This report reviews the comparative susceptibility data on 495 bacterial isolates obtained from obstetric and gynecologic patients and on 522 Bacteroides fragilis group isolates. Susceptibility testing was conducted with broth microdilution using twofold dilutions of antimicrobials. The overall minimal inhibitory concentrations-90 (MIC90) for the 495 isolates were very low, and few resistant isolates were found. The MIC90 for cefotetan was 16 times greater than that for ticarcillin/clavulanate and ampicillin/sulbactam. Cephalosporins showed good activity against anaerobic cocci but variable activity against anaerobic gram-negative rods. A relatively high percentage of B fragilis group isolates were also resistant to clindamycin. The addition of 2 mg/mL of clavulanate to ticarcillin caused a 4- to 32-fold decrease in the MIC90 for various Bacteroides species. Less than 2% of the strains tested were resistant to clavulanate plus ticarcillin or amoxicillin. These results suggest that monotherapy with such agents could replace combination antibiotic therapy for mixed obstetric and gynecologic infections.

Ampicillin↗
PubMed1989

Fusobacterium necrophorum sepsis with cerebral infarction.

We have described the case of a 23-month-old female child in whom Fusobacterium sepsis progressed to cerebral infarction despite therapy with intravenous chloramphenicol and ampicillin. Some clinical improvement was noted upon addition of metronidazole to the treatment regimen. The child survived, but has severe neurologic sequelae. Physicians should suspect anaerobic infection in children who have signs of severe neurologic infection and in whom cultures are negative for aerobes. In selected cases, early treatment with metronidazole may be helpful.

Cerebral Infarction↗
PubMed1989

Listeriosis as an obstetric complication in an immunocompromised patient.

We have reported a case of maternal death associated with Listeria monocytogenes septicemia in a woman who was being treated with immunosuppressive drugs for lupus nephritis. This report, coupled with a previous case of L monocytogenes sepsis in a pregnant patient with AIDS, emphasizes that L monocytogenes infection may be an important, unrecognized pathogen in pregnant women with impaired immunity.

Adult↗
PubMed1989

The genital mycoplasmas.

The smallest free-living, self-replicating organisms known, the mycoplasmas have been the subject of intense research. Of the 12 species that have been found in association with humans, Mycoplasma pneumoniae, M. hominis, and Ureaplasma urealyticum have been clearly shown to have pathogenic properties. The newly described M. genitalium may also have the ability to cause disease. The syndromes with which these organisms have been associated in the genital tract are reviewed, as well as methods of diagnosis and therapy.

Animals↗
PubMed1989

Human immunodeficiency virus: risk of exposure among health care workers at a southern urban hospital.

To assess the risk of exposure to the human immunodeficiency virus (HIV) among health care workers in a southern urban setting, random screening for antibodies to HIV was undertaken. Patients who were admitted for major trauma, for medical emergencies, or in labor were screened. Of 534 sera screened, 11 (2%) were seropositive. All but two of the seropositive patients were men. Rates were similar among black and white patients. Seven patients could be placed into an established risk group, but only one patient was known to have AIDS upon presentation to the emergency room. The mean age of seropositive individuals was 30.9 years; there were similar seroprevalence rates in each of four age groups among men. We conclude that there is a substantial risk of exposure to HIV in trauma and medical emergency centers; therefore all health care workers should practice universal barrier precautions whenever exposure to a patient's blood or body fluids is likely.

Adolescent↗
PubMed1988

Comparison of the in vitro activity of ciprofloxacin and 24 other antimicrobial agents against clinical strains of Chromobacterium violaceum.

Eleven clinical strains of Chromobacterium violaceum were tested for their susceptibility to 25 antimicrobial agents. Ciprofloxacin was the most active of the compounds tested although norfloxacin and pefloxacin were highly active. No resistance was detected to mezlocillin, piperacillin, apalcillin, imipenem, and aztreonam while a single strain was resistant to ticarcillin. Among the cephalosporin/cephamycin group only cefotetan showed good in vitro activity. Gentamicin was more active than amikacin and tobramycin. Good in vitro activity was also noted for chloramphenicol, doxycycline, and trimethoprim-sulfamethoxazole while C. violaceum strains were highly resistant to rifampin and vancomycin. The bactericidal activity of selected agents was shown to be concentration dependent using time-kill kinetic studies. Addition of clavulanic acid did not increase the activity of ticarcillin and in one case was shown to induce beta-lactamase. High correlation was noted between the broth microdilution and disk diffusion susceptibility tests in predicting the susceptibility patterns of C. violaceum.

Chromobacterium↗
PubMed1988

Principles of antimicrobial therapy for head and neck infections.

The physician should take a logical, systematic approach when choosing antimicrobial therapy. The recent proliferation of antimicrobial agents and changing susceptibility patterns amongst bacterial pathogens have made this a more arduous task. Classifying antibiotics according to their spectrum of activity, tissue penetration and potential side effects will aid in choosing empiric therapy for serious head and neck infections.

Anti-Bacterial Agents↗
PubMed1988

Ticarcillin disodium and clavulanate potassium in the treatment of post-cesarean-section endomyometritis.

The combination of ticarcillin disodium/clavulanate potassium is a potent, irreversible inhibitor of beta-lactamase that is active against a broad spectrum of gram-positive and -negative bacteria, which often are found in the polymicrobial infection of postcesarean endomyometritis. Eighty-four randomly chosen women with postcesarean endomyometritis received 3 g ticarcillin disodium plus 100 mg clavulanate potassium intravenously every six hours. The drug was discontinued after patients were afebrile and asymptomatic for 72 hours. The mean duration of therapy was 4.7 days. A clinical cure was achieved in 56 of the 70 evaluable patients (80%); 14 were clinical failures. Six of the 70 patients (9%) were bacteremic. One hundred eighty-five aerobic bacteria and 109 anaerobic bacteria were isolated. Of the 96 aerobic isolates tested, 75 (78%) were beta-lactamase positive, as were 68 of the 78 anaerobic isolates (87%).

Adult↗
PubMed1987

Comparative in vitro activity of the two new oral cephalosporin metabolites RO 19-5247 and RO 15-8074.

A total of 629 clinical strains of gram positive and gram negative bacteria were tested for their susceptibility to RO 19-5247, RO 15-8074, and other antimicrobial agents. Both RO 19-5247 and RO 15-8074 had good activity against strains of Enterobacteriaceae; however, resistance was found among some strains of Enterobacter, Citrobacter, Klebsiella and Morganella spp. Both compounds showed moderate to poor active against Acinetobacter spp., Pseudomonas aeruginosa, staphylococci and Streptococcus faecalis. Against strains of Haemophilus influenzae, Neisseria gonorrhoeae, Gardnerella vaginalis, Streptococcus pneumoniae and streptococci (not enterococci), each compound was highly active in vitro. RO 19-5247 and RO 15-8074 had comparable activity to cotrimoxazole, ceftazidime and ceftizoxime. Each new compound had considerably better activity then did cefaclor and amoxicillin/potassium clavulanate.

Cefmenoxime↗
PubMed1987

Comparative in vitro activity of the new oral cephalosporin BMY-28100.

Using a broth microdilution method, the in vitro activity of BMY-28100 against 365 clinical strains of commonly isolated bacteria was determined. BMY-28100 showed good activity against streptococci, methicillin-susceptible staphylococci, Salmonella spp., Shigella spp., and beta-lactamase producing Branhamella catarrhalis and Haemophilus influenzae. Against susceptible strains of these organisms, BMY-28100 showed activity comparable to that of penicillin G, ampicillin, co-trimoxazole, erythromycin, cefaclor, doxycycline and amoxicillin/potassium clavulanate. BMY-28100 had moderate activity against Arizona hinshawii and poor activity against Campylobacter jejuni and Yersinia enterocolitica.

Anti-Bacterial Agents↗