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Biomedical subjects

R E Weaver

Publications and source records attributed to R E Weaver.

At least 91 records · Page 5Linked to original sources

Non-cholera vibrio infections in the United States. Clinical, epidemiologic, and laboratory features.

Non-cholera vibrios are organisms that are biochemically indistinguishable from Vibrio cholerae but do not agglutinate in vibrio 0 group 1 antiserum. Since 1972 there has been a dramatic increase in the number of these organisms referred to the Center for Disease Control for identification. Clinical, epidemiologic, and laboratory data were analyzed for 26 of 28 patients with isolates identified between January 1972 and March 1975. Thirteen (50%) of the isolates were obtained from feces of patients who had an acute diarrheal illness; no other pathogens were isolated from their feces, and all patients survived. Four (15%) patients had non-cholera vibrios isolated from other gastrointestinal or biliary tract sites; none of these patients had acute illness definitely attributable to non-cholera vibrios. Nine (35%) patients had non-cholera vibrios isolated from other tissues and body fluids; four deaths occurred in this group. Patients with acute diarrhea frequently had a history of recent shellfish ingestion or foreign travel, whereas some patients with systemic non-cholera vibrio infection had a history of recent occupational or recreational exposure to salt water.

Adolescent↗

Wound infection by an indigenous Pseudomonas pseudomallei-like organism isolated from the soil: case report and epidemiologic study.

A 27-year-old farmer in the Oklahoma panhandle was pinned under his overturned tractor for 2 hr and received superficial and deep lacerations. He contracted an infection of a pelvic wound with an organism that had cultural and biochemical characteristics identical to those of Pseudomonas pseudomallei. Identical organisms were recovered from soil taken from the site of the accident. The organism isolated from the wound proved to be less virulent in guinea pigs than usual laboratory strains of P. pseudomallei; fatty acid analysis showed a distinctly different pattern from that of laboratory strains of P. pseudomallei. The infecting organism may be a variant of P. pseudomallei or a new species of Pseudomonas.

Adult↗

Comparison of thirty-seven strains of Vd-3 bacteria with Agrobacterium radiobacter: morphological and physiological observations.

Thirty-seven cultures of Vd-3 bacteria, isolated from clinical specimens, were characterized morphologically and physiologically. The cultures produced positive reactions when tested for oxidase, urease, nitrate reduction, phenylalanine deaminase, oxidative metabolism of carbohydrate substrates, and 3-ketolactose production. These peritrichously flagellated microorganisms were isolated primarily from the respiratory tract. When compared to authentic strains of Agrobacterium, they appeared to be most similar to A. radiobacter. Gas-liquid chromatography of trimethylsilyl derivatives of whole-cell hydrolysates of some of the Vd-3 strains and A. radiobacter yielded nearly identical elution patterns. The Vd-3 cultures were identified as probable strains of A. radiobacter. A method is presented for differentiating cultures of A. radiobacter from other similar bacteria encountered in clinical specimens. Although these bacteria rarely occur in clinical specimens, the clinical microbiologist should be familiar withe their outstanding characteristics.

Bacterial Infections↗

Cellular fatty acid composition of isolates from Legionnaires disease.

The cellular fatty acids of four isolates from Legionnaires disease and two antigenically related isolates were identified by gas chromatography, mass spectrometry, and associated techniques. The six isolates had essentially the same fatty acid composition, which was characterized by large amounts (greater than 80%) of branched-chain acids.

Bacteria↗

Unidentified gram-negative rod infection. A new disease of man.

A Gram-negative bacillus that defies identification was isolated from blood cultures of 17 patients with fever. Fifteen patients were male adults, and 14 patients had underlying diseases, including previous splenectomy in five, which impair host defenses against infection. Illnesses occurred in the summer and autumn in 14 cases and had been recently preceded by dog bites in 10 cases. Clincal syndromes included cellulitis in seven cases, primary bacteremia without localization in four, purulent meningitis in four, and endocarditis in three. Three patients died. The organism grows slowly on blood or chocolate agar in 10% CO, is oxidase- and catalase-positive, and is negative for nitrate reduction, indole production, and urease. It produces acid from glucose, lactose, and maltose. These features distinguish it from all previously described and classified bacteria. Furthermore, the epidemiologic features of the patients suggest that this organism is an opportunistic invader and may have an animal reservoir in nature.

Adolescent↗

Halophilic Vibrio species isolated from blood cultures.

The Special Bacteriology Section of the Center for Disease Control has received 38 cultures of a halophilic bacterium which apparently unnamed. On the basis of the minimal characteristics of Vibrio species proposed by Hugh and Sakazaki, this bacterium belongs to the genus Vibrio. The unnamed species can be differentiated from Vibro parahaemolyticus by a lower tolerance for sodium chloride (NaC1) and the fermentation of lactose. The failure to ferment sucrose is an additional characteristic which differentiates these organisms from V. alginolyticus. Of 33 unnamed species strains tested, all were sensitive to penicillin, ampicillin, carbenicillin, cephalothin, chlorapmphenicol, gentamicin, tetracycline, rifampin, nitrofurantoin, and sulfisoxazole by agar diffusion and agar dilution tests. The sources of isolation of the cultures of the unnamed species suggest that it is a clinically important organism. Twenty strains were isolated remaining cultures were isolated from localized infections of the extremities. In contrast, only 2 of 60 cultures of V. parahaemolyticus and V. alginolyticus received in our laboratory as human isolates from extra-intestinal sources were isolated from blood.

Anti-Bacterial Agents↗

Isolation of Langat virus from Haemaphysalis papuana Thorell in Thailand.

A strain of Langat virus (LGT), T-1674, was isolated from a pool of Haemaphysalis papuana Thorell collected in the forest of Khao Yai National Park in Central Thailand. The isolated virus was found to have growth and antigenic similarity to the prototype Langat strain (TP-21). This is the first report of a natural infection of Haemaphysalis ticks with LGT and of the isolation of this arbovirus in Thailand. The wide distribution of known vectors of LGT in Thailand suggests that the virus may be present in other areas of the country.

Animals↗

Human disease caused by Brucella canis. A clinical and epidemiologic study of two cases.

Nonlaboratory-associated human illness caused by Brucella canis occurred in two persons. Fever, chills, malaise, and weight loss were prominent symptoms in both patients. Epidemiologic investigation identified a household dog as the likely source of one patient's infection, and serologic studies and blood cultures on neighborhood dogs showed that approximately 30% were positive for B canis. Persons exposed to infected dogs appeared to have a low risk of disease. Although routine Brucella agglutinin tests do not detect antibodies to B canis, available methods for diagnosis include a specific B canis serologic test and culture techniques.

Adolescent↗

Recognition of Pseudomonas pickettii in the clinical laboratory: biochemical characterization of 62 strains.

Pseudomonas pickettii strains were studied to determine the characteristics essential for their identification in the clinical microbiology laboratory. Preliminary investigations indicated that these glucose-oxidizing, denitrifying, gram-negative rods were quite similar to an unclassified group of clinical isolates designated VA-2. Gas liquid chromatography of trimethylsilyl derivatives of whole cell hydrolysates of P. pickettii and VA-2 strains yielded nearly identical elution profiles. The VA-2 cultures were concluded to be probable strains of P. pickettii. A method is presented for differentiating cultures of P. pickettii from other similar bacteria encountered in clinical specimens.

Classification↗

Cultural and biochemical characteristics and fatty acid composition of Pseudomonas diminuta and Pseudomonas vesiculare.

The cultural characteristics, biochemical activity, and cellular fatty acid composition of Pseudomonas diminuta and Pseudomonas vesiculare provided means for differentiation of these closely related species. Broth cultures of P. diminuta showed turbid growth and a distinct surface pellicle after 24 h at 35 C. P. vesiculare had no pellicle, and only light, diffuse growth was observed. All strains of P. vesiculare oxidized maltose and hydrolyzed esculin to varying degrees; P. diminuta was negative in these tests. The cellular fatty acids of these two species were similar, except that P. diminuta possessed a C19 cyclopropane acid which was not detected in P. vesiculare.

Esculin↗

Characterization and differentiation of 59 strains of Moraxella urethralis from clinical specimens.

The biochemical characteristics of 59 strains of Moraxella urethralis from clinical specimens, primarily from urine and the female genital tract, were studied. The characteristics included (i) the inability to acidify carbohydrate substrates, (ii) the ability to produce phenylalanine deaminase, (iii) the ability to reduce nitrite, (iv) the lack of urease activity, and (v) the ability of most strains to alkalinize citrate. A means of differentiating M. urethralis from Moraxella osloensis and Moraxella phenylpyruvica was determined.

Aminohydrolases↗

Deoxyribonucleic acid hybridization studies on Flavobacterium meningosepticum.

Seventeen flavobacteria, including 12 strains of Flavobacterium meningosepticum, were investigated to determine their genetic relationships by deoxyribonucleic acid (DNA)-DNA hybridization and guanine plus cytosine content. The percentage of binding among the strains tested ranged from 6 to 87%. There was no correlation between the serotype and DNA-duplex formation. The guanine plux cytosine content of the representative strains of the five serotypes ranged from 31 to 50%.

Agar↗