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Biomedical subjects

I I Washington JA

Publications and source records attributed to I I Washington JA.

8 recordsLinked to original sources
PubMed1978

Differences between cephalothin and newer parenterally absorbed cephalosporins in vitro: a justification for separate disks.

The activities of cefamandole and cefoxitin in vitro were compared with that of cephalothin against staphylococci and gram-negative bacilli. Cephalothin was the most active agent against staphylococci. Cefamandole exhibited the greatest activity against the Enterobacteriaceae, with the exceptions of Serratia marcescens and indole-positive Proteeae, against which cefoxitin was the most active antibiotic. The activity of newer cephalosporins that are resistant to the beta-lactamases of gram-negative bacteria renders untenable the status of cephalothin as the class representative of the cephalosporins for susceptibility testing.

Acinetobacter↗
PubMed1976

Effects of selective media and atmosphere of incubation on the isolation of group A streptococci.

The effects of selective media and atmosphere of incubation on the isolation of group A beta-hemolytic streptococci were evaluated. Sheep blood agar medium with gentamicin (2.5 or 5.0 mug/ml) was inferior to antibiotic-free sheep blood agar medium. This resulted from the partial restriction of group A streptococcal growth on gentamicin medium. Recovery of beta-hemolytic streptococci from specimens in air, CO2, or anaerobic incubation was evaluated. The isolation of group A streptococci was equivalent in the three incubation atmospheres; however, non-group A beta- hemolytic streptococci were isolated significantly more often from specimens incubated in an anaerobic or CO2 atmosphere than from those incubated in air. Therefore, sheep blood agar medium, stabbed with a wire loop and incubated in air, is recommended for the isolation of group A streptococci from throat swabs.

Agar↗
PubMed1976

Comparison of isolation of Haemophilus vaginalis (Corynebacterium vaginale) from peptone-starch-dextrose agar and Columbia colistin-nalidoxic acid agar.

A total of 447 cervical or vaginal specimens were inoculated in parallel onto peptone-starch-dextrose (PSD) and Columbia colistin (10 mg/ml)-nalidixic acid (15 mug/ml) (CNA) agar and were incubated for 48 h at 35 degrees C in an atmosphere with 2 to 10% CO2. One hundred (22.4%) of the cultures were positive for Haemophilus vaginalis. Forty-eight of the isolates were recovered from both PSD and Columbia CNA agar, five from PSD only, and 47 from Columbia CNA agar only (P less than 0.001). On Columbia CNA agar, 76 of the isolates were detected after 24 h of incubation, and the remainder were detected within 4 days of incubation.

Agar↗
PubMed1975

Prosthetic valve endocarditis.

From January 1963 until January 1974, 45 patients had prosthetic valve endocarditis. Symptoms of prosthetic valve endocarditis developed within 2 months after operation (early onset) in 16 patients (36%) and more than 2 months after operation (late onset) in 29 patients (64%). Overall mortality among the 45 patients was 56% (88% among those with early onset and 40% among those with late onset). Medical therapy alone was curative in 60% of the surviving patients. Combined medical and surgical therapy was curative in 40% of the survivors. The most frequent isolates in the early-onset group were Staphylococcus aureus (44%) and Gram-negative bacilli (38%); associated mortality was 86% and 83%, respectively. The most frequent isolates in the late-onset group were viridans streptococci (41%) and Gram-negative bacilli (31%); the mortality was 25% and 22% respectively. Suggestions are offered for operative antimicrobial prophylaxis and for medical and surgical treatment of prosthetic valve endocarditis. Prompt surgical replacement of an infected prosthesis is necessary when medical therapy fails.

Bacteria↗
PubMed1975

Isolation of Chlamydia from patients with urethritis.

From October 1973 through August 1974, 335 genitourinary tract specimens from patients with urethritis were inoculated into McCoy's cell cultures for the diagnosis of Chlamydia infections. Of the 45 Chlamydia isolates, 42 were recovered when glass vials rather than plastic microtiter plates were used as cell culture vessels. Herpes simplex virus was isolated 15 times. Bacterial overgrowth occurred 42 times; however, in 20 specimens the contamination was not apparent until after the first subculture. This is the first report of the frequency of Chlamydia infections in patients with urethritis in the Midwest and indicates that these organisms have a significant etiologic role in nongonococcal urethritis in this community.

Bacteriological Techniques↗
PubMed1972

Four-hour microbiological assay of gentamicin in serum.

Since the microbiological assay of the antibiotic content of serum generally requires 18 to 24 hr of incubation, results of such procedures may not become available in time to make appropriate adjustments in subsequent dosages of antibiotic. A 4-hr bioassay for determining concentrations of gentamicin in serum has been developed in which Staphylococcus aureus ATCC 6538P is used as the test organism. Poured plates have yielded satisfactory results after storage at 4 C for 5 days. Results of the 4-hr procedure agree closely with those of a conventional 18-hr disc-plate assay performed with the same test organism.

Biological Assay↗
PubMed1972

In vitro antibacterial activity of spectinomycin.

The in vitro inhibitory and bactericidal activities of spectinomycin hydrochloride were tested against a variety of bacteria. The antibiotic was inhibitory at 31.2 mug/ml to most strains of Escherichia coli, Klebsiella, Enterobacter, and Staphylococcus epidermidis. Concentrations of antibiotic exhibiting bactericidal activity exceeded the inhibitory concentration by at least fourfold. Regression graphs were plotted for results obtained with 30-, 100-, 200-, and 300-mug spectinomycin discs; tentative interpretative standards are proposed.

Bacteria↗