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Biomedical subjects

S D Allen

Publications and source records attributed to S D Allen.

At least 109 records · Page 6Linked to original sources
PubMed1986

Pasteurella multocida meningitis in infancy. An avoidable infection.

Pasteurella multocida is a common commensal in the upper respiratory tracts of cats and dogs. Infection with P multocida in humans usually follows infected bite wounds; however, infection in humans unrelated to animal bites is rare. We describe two infants with P multocida meningitis in whom infection was probably related to nontraumatic facial licking by household pet dogs. Both patients recovered fully. Although the risk is low, parents should be informed that mucous membrane exposure to household pets may expose an infant to the risk of systemic P multocida infection.

Ampicillin↗
PubMed1986

Clinical, pathogenetic, and laboratory features of Capnocytophaga infections.

Granulocytopenia and oral mucosal defects have been reported to be important predisposing factors to recently recognized cases of Capnocytophaga septicemia. The authors call attention to an apparent preponderance of these cases in the pediatric age group and emphasize laboratory features which they have found helpful in the diagnosis of Capnocytophaga infections. Thirteen patients with Capnocytophaga infections were seen during a seven-year period. Seven of these patients had Capnocytophaga bacteremia. Six of seven bacteremic patients were granulocytopenic, six had oral mucosal defects, and three died. Five of the seven bacteremic patients were younger than 20 years of age. This represents a disproportionate distribution of cases in the pediatric age group within the author's institution, because 43% of blood culture specimens submitted to their microbiology laboratory are obtained from pediatric patients. This observation is supported by a review of the reported cases of Capnocytophaga septicemia in which 7 of 12 patients were younger than 20 years of age. Because Capnocytophaga may superficially resemble the more commonly isolated Fusobacterium nucleatum, distinguishing features for laboratory identification are discussed.

Adolescent↗
PubMed1986

Volume of blood submitted for culture from neonates.

We prospectively examined 298 sets (298 aerobic, 299 anaerobic, and 73 resin cultures) of blood cultures from 161 critically ill newborns. The attending physicians were unaware of the study. The mean blood volume per patient (aerobic and anaerobic) was 1.05 (range, 0.11 to 3.04) ml. The mean blood volume per aerobic bottle was 0.53 (range, 0.01 to 1.90) ml. Among aerobic samples 2.7% were less than or equal to 0.1 ml, 16% were less than or equal to 0.3 ml, 33% were less than or equal to 0.4 ml, and 55% were less than or equal to 0.5 ml. For anaerobic cultures the mean blood volume was 0.52 (range, 0.01 to 1.79) ml. Among anaerobic samples 2.7% were less than or equal to 0.1 ml, 15% were less than or equal to 0.3 ml, 35% were less than or equal to 0.4 ml, and 58% were less than or equal to 0.5 ml. Blood volume did not correlate with gestational age, chronologic age, or weight. The mean volume of blood submitted in positive cultures was not significantly greater than that in negative cultures. The blood volume used for culture from ill newborns may be inadequate for detecting sepsis, and the adequacy of currently available culture methods needs to be assessed for the small samples submitted from critically ill newborns.

Aerobiosis↗
PubMed1986

Diabetic foot infections. Bacteriologic analysis.

Diabetic patients with foot infections were prospectively evaluated over a two-year period. Cultures from reliable specimens avoiding contamination with foot ulcers were obtained in 54 infectious episodes. Staphylococcus species, Enterococcus species, Corynebacterium species, and various species of Enterobacteriaceae were commonly isolated. Common anaerobic isolates included Peptostreptococcus magnus, Peptostreptococcus prevotii, and Bacteroides species. Results of cultures from 94 unreliable specimens were similar. Results of reliable and unreliable specimens obtained simultaneously in 26 patients agreed in seven (27%), but antibiotics selected for organisms isolated from unreliable specimens would have adequately covered pathogens found in the reliable culture in 24 (93%). Diabetic foot infections usually involve mixed bacterial flora, including aerobic, facultatively anaerobic, and anaerobic microorganisms. Specimens should be obtained from infected tissue that does not communicate directly with the foot ulcer if possible. If such specimens are not available, cultures of purulent exudate within the foot ulcer or soft-tissue sinuses may provide useful information on which to base decisions about antibiotic therapy. Broad-spectrum beta-lactam antibiotics or a combination of antibiotics active against facultatively anaerobic cocci and bacilli as well as anaerobes provide the best empirical antimicrobial coverage in these patients.

Abscess↗
PubMed1985

Isolation of a novel transposon which carries the Escherichia coli enterotoxin STII gene.

The Escherichia coli heat-stable enterotoxin STII gene in P307 is flanked by inverted repeat sequences, suggesting that the STII gene is part of a transposon. To study the transposability, a DNA fragment containing the putative STII transposon has been cloned. Results of transposition assays indicated that the STII gene can transpose from one plasmid to another. The size of the transposon has been determined to be approximately 9 kilobases. The structure and the location of the STII gene in clinical isolates of Escherichia coli have been investigated by restriction enzyme analyses. The structural genes of STII from different clinical isolates appear to be uniform in size, but the flanking sequences are heterogeneous. This result suggests that the STII genes in different isolates are not on the same transposon as observed in P307.

Bacterial Toxins↗
PubMed1985

Automated reading of MIC microdilution trays containing fluorogenic enzyme substrates with the Sensititre Autoreader.

The Sensititre Autoreader is a microcomputer-driven instrument capable of automatically reading antimicrobial susceptibility microdilution trays. The instrument measures the fluorescence liberated by bacterial enzymatic activity on fluorogenic substrates as an indicator of growth in each well. A mathematical algorithm converts the fluorescent signals from an antimicrobial dilution series to an MIC endpoint. A three-center study evaluated the performance of the Autoreader in comparison with MIC determined visually in a duplicate set of control plates lacking fluorogenic substrate. Among 828 isolates of gram-negative bacilli tested against 17 antimicrobial agents, Autoreader 18-h MIC were within +/- 1 twofold dilution of control MIC values (agreement) in 95.3% of instances. In 3.5% of the instances, Autoreader values occurred +/- 2 half-step dilutions from control values (minor discrepancy), and in only 1.2% of instances did Autoreader values deviate from control values by greater than +/- 2 dilution steps (major discrepancy). Agreement, minor discrepancies, and major discrepancies were noted among 148 gram-positive cocci tested against 11 antimicrobial agents in 93.5, 4.8, and 1.7% of the instances, respectively. Over half of the major discrepancies noted with gram-negative bacilli occurred with Proteus mirabilis-beta-lactam combinations, a problem that was resolved when a lower initial inoculum was used. Inter-and intralaboratory reproducibility was excellent. Standard Sensititre susceptibility trays may be instrument read at 18 h reproducibly and accurately with only slight modification of conventional procedures to include fluorogenic enzyme substrates in the incubation broth.

Anti-Bacterial Agents↗
PubMed1984

Control of glycoprotein synthesis. The in vitro synthesis by hen oviduct membrane preparations of hybrid asparagine-linked oligosaccharides containing 5 mannose residues.

Hen oviduct membranes were incubated with UDP-N-acetyl-D-[14C]glucosamine and [3H]GlcNAc beta 1-2Man alpha 1-3[Man alpha 1-6(Man alpha 1-3)Man alpha 1-6]Man beta 1-4GlcNAc beta 1-4GlcNAc-Asn (glycopeptide Gn(I)M5). Two double labeled products were obtained, both containing 5 Man and 4 GlcNAc residues. In order to separate these isomeric components, the mixture was treated with rat liver Golgi-rich membranes as a source of mannosidase II. One of the isomers was degraded by mannosidase action while the other was not, thereby allowing separation of two products (A and B). Product A was shown to be [3H]GlcNAc beta 1-2[( 14C] GlcNAc beta 1-3,4, or 6)Man alpha 1- 3Man beta 1-4GlcNAc beta 1-4GlcNAc, proving that hen oviduct membranes were capable of incorporating GlcNAc in beta-linkage into the Man alpha 1-3- residue of Gn(I)M5. Product B was identified as [3H]GlcNAc beta 1-2Man alpha 1-3[( 14C]GlcNAc beta 1-4)-[Man alpha 1-3)Man alpha 1-6]Man beta 1-4GlcNAc beta 1- f4GlcNAc , showing that hen oviduct membranes could incorporate a bisecting GlcNAc residue (linked beta 1-4 to the beta-linked Man) into Gn(I)M5. The ability of hen oviduct to carry out these two reactions in vitro supports the hypothesis first suggested by Harpaz and Schachter ( Harpaz , N., and Schachter , H. (1980) J. Biol. Chem. 255, 4894-4902) that the synthesis of bisected hybrid oligosaccharides is controlled by the insertion of a bisecting GlcNAc residue into Gn(I)M5. The presence of a bisecting GlcNAc residue prevents mannosidase II action and the synthetic pathway is therefore committed to hybrid oligosaccharide synthesis.

Animals↗
PubMed1984

Enzyme-linked immunosorbent assay, using monoclonal antibody, to detect enterotoxic Escherichia coli K99 antigen in feces of dairy calves.

A modified, double-antibody, enzyme-linked immunosorbent assay (ELISA) was developed to detect the K99 pilus antigen of enterotoxic Escherichia coli (ETEC) in feces of calves. Extremely high positive to negative ratios (greater than 200) were obtained by using monoclonal antisera as the primary antibody. Strong positive reactions were obtained with strains of E coli known to produce the K99 antigen; however, non-enteropathogenic E coli (strains not producing the K99 antigen), Salmonella, Proteus, Klebsiella, Pseudomonas, Staphylococcus, Streptococcus, and rotavirus produced negative results. Seventy-five fecal samples, 8 from healthy calves and 67 from calves with neonatal calf diarrhea were examined with the K99 ELISA for the presence of ETEC. Rotavirus test and fecal culture results were available on feces from calves with diarrhea and were used with the K99 ELISA results to determine the specific cause of the disease. Enterotoxic E coli was the predominant agent detected in the feces of 29 diarrheal calves less than 5 days of age. Mixed infections of rotavirus and ETEC were also common in these calves, but rotavirus infections alone were not detected. In 38 calves greater than or equal to 5 days, rotavirus was detected without ETEC. Of these calves, only 2 produced positive tests with the K99 ELISA. Salmonella sp and Proteus sp were detected from 5 of 67 calves with diarrhea.

Agglutination Tests↗
PubMed1983

Delay in the onset of parturition in the rat following prenatal administration of developmental toxicants.

The duration of gestation was determined in Sprague-Dawley albino rats exposed during days 6-18 of pregnancy to diethylstilbestrol (DES) or 3,4,3',4'-tetrachlorobiphenyl (4CB). Each compound produced a delay in the onset of parturition compared to corn-oil-treated controls. The incidence of perinatal mortality was significantly elevated in animals born after 22 days of gestation in both control and treated litters.

Animals↗
PubMed1982

Indicators of developmental toxicity following prenatal administration of hormonally active compounds in the rat. I. Gestational length.

Prenatal administration of 3,4,3',4'-tetrachlorobiphenyl, zeranol, or diethylstilbestrol was observed to delay parturition in the rat and result in a concomitant increase in perinatal mortality. Even among control animals, those litters in which birth occurred after the beginning of day 22 of pregnancy contained significantly fewer survivors one day after birth. Increases in the length of gestation were correlated with increased weight of newborn control pups independent of litter size. The relationship between weight and litter size was anomalous, however, in treated animals. Gestational length is a sensitive indicator of a developmental effect even in the absence of overt teratogenicity.

Animals↗
PubMed1982

Atypical biogroups of Escherichia coli found in clinical specimens and description of Escherichia hermannii sp. nov.

DNA relatedness was used to define the biochemical boundaries of Escherichia coli. A large number of biochemically atypical strains were shown to belong to biogroups of E. coli. These included strains negative in reactions for indole, all three decarboxylases, D-mannitol, lactose, or methyl red and strains positive in reactions for H2S, urea, citrate, KCN, adonitol, myo-inositol, or phenylalanine deaminase. Frequency and source data are presented for these atypical E. coli biogroups. One group of KCN-positive, cellobiose-positive, yellow-pigmented strains was 84 to 91% interrelated but only 35 to 45% related to E. coli. The name Escherichia hermannii sp. nov. is proposed for this group of organisms that was formerly called Enteric Group 11 by the Enteric Section, Centers for Disease Control, Atlanta, GA. Twenty-nine strains of E. hermannii have been isolated in the United States from a variety of clinical sources, principally wounds, sputum, and stools. Three additional strains were isolated from food. E. hermannii strains are gram-negative, oxidase-negative, fermentative, motile rods. In addition to yellow pigment and positive KCN and cellobiose tests, the biochemical reactions characteristic of 32 strains of E. hermannii were as follows: gas from D-glucose, acid from D-glucose, maltose, D-xylose, L-arabinose, L-rhamnose, and D-mannitol; no acid from adonitol or inositol; variable acid production from lactose and sucrose; positive tests for indole, methyl red, and mucate; negative tests for Voges-Proskauer. Simmons citrate, H2S, urea, phenylalanine deaminase, and gelatin hydrolysis; negative or delayed test for L-lysine decarboxylase and negative test for L-arginine dihydrolase; and positive test for ornithine decarboxylase. E. hermannii strains were resistant to penicillin, ampicillin, and carbenicillin and sensitive to other commonly used antibiotics. Wounds account for almost 50% of human isolates of E. hermannii, followed by sputum or lung isolates (ca. 25%) and stool isolates (20%).

Anti-Bacterial Agents↗
PubMed1982

Immunoglobulin M antibody titers in the diagnosis of Legionnaires disease.

The purpose of this study was to determine whether measurement of immunoglobulin M (IgM) antibodies against Legionella pneumophila serogroup 1 can aid in the diagnosis of Legionnaires disease. On the basis of measurements of antibody levels in 1,942 control sera, we used an IgM titer of 1:256, observed in 2.3% of the controls, as presumptive evidence of Legionnaires disease. Measurement of IgM titers permitted us to presumptively or definitively diagnose Legionnaires disease in 13 of 34 patients earlier than we would have if only IgG titers had been measured. Of the 13 patients, 5 were diagnosed serologically only by IgM antibody determination. IgM titers were presumptively diagnostic in week 1 of clinical symptoms in 4 of the 13 patients. We conclude that conjugates used for antilegionella indirect fluorescent-antibody tests should be capable of detecting IgM antibodies so that the value of serological results in diagnosing and managing Legionnaires disease will be maximized.

Fluorescent Antibody Technique↗
PubMed1981

Survey of chronic sinusitis-induced skull anomalies in desert bighorn sheep.

Bone anomalies were found in 20% of 630 skulls from desert bighorn sheep (Ovis canadensis) representing populations of california bighorn (O canadensis californiana), lower California bighorn (O canadensis cremnobates), Mexican bighorn (O canadensis mexicana), and Nelson bighorn (O canadensis nelsoni) that are native to Arizona, California, Nevada, New Mexico, and Utah. The anomalies were extremely diverse, ranging from osteonecrosis within the matrix of the paranasal sinuses to extensive lysis of the frontal bone, horn core, and sheath. In rams, the necrosis most often occurred in the mid- to posterior region of the cornual sinus and resulted in blistering of the sheath and sometimes a breaking away of the horn. In ewe skulls, the anomalies were generally at the base of the cornual sinus or within the frontal sinus. Osteonecrosis in the ewe skulls had generally invaded the region of the orbit or penetrated the cribriform plate. The skull lesions were most often observed in desert bighorn rams greater than or equal to 5 years old. The age of ewes could not be accurately determined. The skull anomalies were believed to result from pyogenic osteomyelitis.

Animals↗