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Biomedical subjects

S D Allen

Publications and source records attributed to S D Allen.

At least 127 records · Page 7Linked to original sources
PubMed1981

Rapid radioimmunoassay diagnosis of Legionnaires' disease: detection and partial characterization of urinary antigen.

Urine from nine patients with serogroup 1 Legionnaires' disease, 100 with infected or contaminated urine, 50 with bacteremic infections, 26 with infectious or infiltrative pulmonary diseases, and 65 with miscellaneous infectious or noninfectious illnesses, was examined by radioimmunoassay for the presence of Legionella pneumophila antigen(s). Urine of all nine Legionnaires' disease patients was clearly differentiated from that of the 241 control subjects by the assay. The antigen was detected from 2 to at least 10 days after the initiation of erythromycin therapy. A probable false-positive results occurred in a patient with necrotizing nosocomial pneumonia who died before definitive serologic evaluation for Legionnaires' disease could be completed. The antigen was stable at 100 degrees C for 30 minutes and was not degraded by trypsin. Its elution behavior suggested that its molecular weight is approximately 10 000. The radioimmunoassay appears to be a useful method for rapidly diagnosing serogroup 1 Legionnaires' disease.

Antigens, Bacterial↗
PubMed1980

The microbiology and therapy of acute pelvic inflammatory disease in hospitalized patients.

We examined microbial isolates from the endocervical and peritoneal cavity of 30 women hospitalized with acute PID. Patients were randomly assigned to one of two antibiotic regimens: amoxicillin, 6 gm by mouth every 24 hours, or aqueous penicillin G, 30 million units and gentamicin, 180 to 240 mg intravenously every 24 hours. We measured response by quantifying physical examination findings. Neisseria gonorrhoeae was isolated from the cervix of 24 patients (80%) and from the peritoneal cavity of 10 (33%). Other peritoneal isolates included Enterobacteriaceae in five patients, Ureaplasma urealyticum in five, Mycoplasma hominis in six, and Chlamydia trachomatis in three. Bacteroides melaninogenicus, the most frequent anaerobe, was isolated in 11 cases. Bacteroides fragillis was not isolated from any specimen. The cure rates were the same for both regimens: three patients failed on each. Four women required total abdominal hysterectomy and unilateral or bilateral salpingo-oophorectomy.

Adolescent↗
PubMed1980

Increase in antibiotic resistance among isolates of Salmonella in the United States, 1967-1975.

To study temporal changes in the antibiotic resistance of Salmonella in the United States, a study design similar to that of a 1967 study was used to determine the antibiotic sensitivity of 754 human nontyphoid Salmonella isolates sent to the Center for Disease Control, Atlanta, Georgia, in 1975. The frequency of resistance to one or more of the same nine antibiotics used in both studies increased significantly during the eight years in Salmonella typhimurium (40%-59%; P = 0.004), other serotypes (14%-23%; P = 0.001), and all serotypes combined (21%-31%; P < 0.001). The increase in frequency of resistance was significant for streptomycin (P = 0.022), sulfonamides (P < 0.001), ampicillin (P < 0.001), and kanamycin (P < 0.001). No chloramphenicol-resistant isolates were found in the 1967 study, whereas six isolates (0.8%) were resistant in 1975. The frequency of strains resistant to six or more antibiotics increased greatly (0.8%-5.0%; P < 0.001). These data document a continuing increase in antimicrobial resistance among Salmonella isolates.

Ampicillin↗
PubMed1979

Ureolytic Escherichia coli of human origin: serological, epidemiological, and genetic analysis.

Forty-five strains of ureolytic Escherichia coli of human origin, isolated in the United States between 1956 and 1977, were characterized by geographical distribution, site of infection, serotype, resistance to antibiotics, and biochemical reactions. All strains were studied for the ability to generate clones of nonureolytic E. coli (segregants), and a subset of these were selected for plasmid analysis and a variety of bacterial matings. There did not appear to be a common geographical distribution, serotype, antibiogram, or other aberrant biochemical reactions other than the hydrolysis of urea among these strains. The predominance of urinary tract isolates (46.7% total) may reflect a relationship between urea hydrolysis and pathogenesis at this site. Ten of the strains (22.2%) did segregate nonureolytic E. coli colonies, and all possessed at least one common plasmid species with a molecular weight of about 65 X 10(6). Only strain 1138-77 serotype O16:H6 conjugally transfered the ability to hydrolyze urea, ferment sucrose, and resist inhibition by sulfadiazide simultaneously. The resulting, recombination-deficient E. coli K-12 tranconjugant was found to possess a plasmid with a molecular weight of about 80 X 10(6) to 90 X 10(6).

Anti-Bacterial Agents↗
PubMed1979

Comparison of capillary ear blood and arterial blood to validate capillary sampling as an accurate assay of blood gas in swine.

Capillary sampling in swine can be performed as an accurate assay of arterial blood gases. Studies with swine provided results similar to, or slightly more favorable than, those reported for human beings, depending upon which cutaneous technique was used on human beings. On the basis of free flow or arterilization of the cutaneous sample and of the correlation between capillary and arterial pH, CO2 partial pressure (PCO2), and O2 partial pressure (PO2) values, the capillary sampling technique of complete incisement of a 2-mm section from the tip of the warmed porcine ear could be a substitution technique for arterial blood sampling. Free flow with this technique was maximized and high correlation coefficients (r) for pH (r = 0.96), PCO2 (r = 0.82), and PO2 (r = 0.90) capillary-arterial values (n = 37) were obtained.

Animals↗
PubMed1978

Anaerobic flora of the normal human conjunctival sac.

Specimens from the conjunctival sacs of 92 healthy eyes were cultured on two separate occasions to determine the presence or absence of a persistent anaerobic flora. Aerobic bacteria and fungi were also studied for comparison. Of the 184 eye cultures, 112 (60.9%) contained at least one microorganism. Obligate anaerobes were recovered from 51.6% (95/184) of the cultures. Propionibacterium acnes, the predominant anaerobe encountered, was present in 49.5% (91/184) of the eyes. Aerobic and facultatively anaerobic bacteria, present in 32.6% of the total eye cultures, were less common than obligate anaerobes. Staphylococcus epidermidis was the most common of these. Fungi were rarely found. Our findings suggest that the conjunctival sac is either sterile or normally contains small numbers of anaerobic, aerobic, or facultatively anaerobic bacteria. As other workers have suggested, the origin of the bacteria in the eyes may be the skin of the eyelids.

Adult↗
PubMed1978

Diagnosis and etiology of nongonococcal urethritis.

The observation of more than four polymorphonuclear cells (PMN) per high-power field (hpf) in gram-stained smears of urethral secretions was found to differentiate patients with urethritis from patients without urethritis. A urethral discharge was present in 78% of patients with nongonococcal urethritis (NGU). Dysuria without demonstrable urethral discharge and with fewer than four PMN/hpf did not appear to fit into the NGU spectrum. NGU is now defined to include men who have negative urethral cultures for Neisseria gonorrhoeae with a urethral discharge and/or more than four PMN/hpf in their urethral smears. The findings of more than four PMN/hpf in the urethral smears of 22%of asymptomatic sexually active men with more than one sexual partner (polygamous controls) suggests that asymptomatic NGU is not uncommon. Chlamydia trachomatis was isolated significantly more frequently from the NGU study group than from the control group (P less than 0.001). This study adds Corynebacterium vaginale (Haemophilus vaginalis), group B streptococci, and yeasts to the list of sexually transmitted microorganisms that are not etiologic determinants of NGU.

Chlamydia trachomatis↗
PubMed1978

Use of ethanol for selective isolation of sporeforming microorganisms.

When mixed cultures containing sporeforming bacteria were treated with heat or with ethanol, the latter consistently resulted in better recovery of Clostridium and Bacillus species. Both techniques were effective in eliminating vegetative cells. An ethanol concentration greater than 25% and exposure for 45 min or longer were necessary to kill all vegetative cells in mixed-culture samples. Ethanol treatment (50% ethanol for 1 h) was effective for isolating sporeforming bacteria from intestinal specimens. Seven different species of Clostridium were the only bacteria isolated from the ethanol-treated specimen of intestinal contents from the large bowel of a patient. It was concluded that treatment with ethanol for 1 h is an effective technique for selective isolation of sporeforming bacteria from mixed cultures and certain types of clinical specimens.

Bacillus↗
PubMed1977

Bacteriological studies in a patient with antibiotic-associated pseudomembranous colitis.

Detailed aerobic and anaerobic bacteriological studies on the operative specimen from a patient with antibiotic-associated pseudomembranous colitis revealed approximately 10(11) facultatively anaerobic bacteria, but less than 10(5) obligate anaerobes per g of involved colonic tissue. Fourteen isolates of Escherichia coli, three isolates of Pseudomonas aeruginosa, and two isolates of Streptococcus fecalis were identified. The majority of the organisms were resistant to most of the antibiotics that the patient had received. Examinations of E. coli for heat-labile and heat-stable enterotoxins and tissue invasiveness were negative, and enterotoxin tests on the P. aeruginosa isolates were negative. Inoculation of mice with the bacterial isolates revealed no unusual pathogenicity. These findings suggest that antibiotic-associated colitis is associated with a marked loss in anaerobic colonic flora, but the colitis could not be explained by the presence of enterotoxins, tissue invasiveness, and pathogenicity of remaining microorganisms.

Aged↗
PubMed1975

Bacteremia with upper gastrointestinal endoscopy.

Fifty patients undergoing upper gastrointestinal fiberoptic endoscopy were studied prospectively for the development of bacteremia by aerobic and anerobic blood cultures obtained before, during, and at 5 and 30 minutes after the procedure. Forty-six patients were culture negative; four had positive cultures at 5 or 30 minutes after the procedure, or at both times. The level of bacteremia as estimated by pour plates was very low. Bacteremia did not correlate with the performance of biopsy or the type of mucosal abnormality found. It is concluded that only very high-risk patients should receive antimicrobial prophylaxis before this procedure. The minor risk of this low-level bacteremia should not be considered a contraindication to the performance of upper gastrointestinal endoscopy.

Duodenal Diseases↗