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Biomedical subjects

D J Brenner

Publications and source records attributed to D J Brenner.

At least 307 records · Page 17Linked to original sources
PubMed1981

Kluyvera, a new (redefined) genus in the family Enterobacteriaceae: identification of Kluyvera ascorbata sp. nov. and Kluyvera cryocrescens sp. nov. in clinical specimens.

Kluyvera is proposed as a new genus for the group of organisms formerly known as Enteric Group 8 (synonym = API group 1). Strains of Kluyvera share the properties of most members of the family Enterobacteriaceae: they are gram-negative rods, motile with peritrichous flagella, catalase positive, and oxidase negative; they grow on MacConkey agar, ferment D-glucose with the production of acid and gas, and are susceptible to many antibiotics. Strains are usually indole positive, methyl red positive, Voges-Proskauer negative, citrate positive, H2S (triple sugar iron) negative, urea negative, phenylalanine deaminase negative, lysine decarboxylase positive, arginine dihydrolase negative, and ornithine decarboxylase positive. Kluyvera strains ferment many of the sugars and polyhydroxyl alcohols used in identification. By deoxyribonucleic acid-deoxyribonucleic acid hybridization, strains of Kluyvera were divided into three groups. Kluyvera ascorbata is proposed as the type species for the genus. Most strains of K. ascorbata have been isolated from clinical specimens. K. cryocrescens is proposed as the second species. It was occasionally isolated from clinical specimens, but it was isolated more commonly from the environment. Kluyvera species group 3 was heterogeneous, but was distinct from the two named species by deoxyribonucleic acid hybridization. This group was rare, so no species name will be proposed at this time. K. ascorbata can be differentiated from K. cryocrescens by its positive ascorbate test, inability to grow at 5 degrees C in a refrigerator, and smaller zones of inhibition around carbenicillin and cephalothin disks. The test normally used for identification does not clearly differentiate these two species. Kluyvera species are probably infrequent opportunistic pathogens. The most common source is sputum, where they are probably not clinically significant. Five strains have been from blood cultures. More information is needed about the incidence and clinical significance of the genus Kluyvera.

Base Composition↗
PubMed1981

Tatumella ptyseos gen. nov., sp. nov., a member of the family Enterobacteriaceae found in clinical specimens.

The name Tatumella ptyseos gen. nov., sp. nov., is proposed for a group of organisms (previously called group EF-9) isolated from clinical sources in the United States, Canada, and Puerto Rico. A total of 68% of these isolates were from sputum specimens. T. ptyseos strains are gram-negative, oxidase-negative, fermentative rods that grow on MacConkey agar. The distinctive biochemical characteristics of 44 T. ptyseos isolates were as follows: acid but no gas from D-glucose, sucrose, and, usually (71%), D-xylose (62% delayed); no acid from lactose, maltose, or D-mannitol; negative tests for indole, urea, methyl red, gelatin, L-lysine decarboxylase, and L-ornithine decarboxylase; L-arginine dihydrolase variable; phenylalanine deaminase positive; Voges-Proskauer positive by the Coblentz method but negative by the O'Meara method; nonmotile at 36 degrees C but 66% weakly motile (30% delayed) at 25 degrees C; Simmons citrate positive at 25 degrees C (89%) but Simmons citrate negative at 36 degrees C. Deoxyribonucleic acid-deoxyribonucleic acid relatedness studies on 26 T. ptyseos strains showed that they were 80 to 100% related at 60 degrees C, which indicated that they comprise a single species. The deoxyribonucleic acid relatedness to other species within the Enterobacteriaceae was 7 to 38%. This is evidence that this species belongs in this family, is distinct from all described species and is best placed in a new genus. The T. ptyseos isolates studied were susceptible to all of the antimicrobial agents tested by broth dilution; these antimicrobial agents were amikacin, ampicillin, cephalothin, chloramphenicol, gentamicin, kanamycin, tetracycline, and tobramycin. Three striking differences between T. ptyseos and other members of the Enterobacteriaceae were its large zone of inhibition around penicillin (mean diameter 24 mm), its tendency to die on some laboratory media (such as blood agar) within 7 days, and its small number (usually one) of flagella. Strain H36 (=ATCC 33301, =CDC D6168, =CDC 9591-78) is the type strain of this new species. T. ptyseos is the type species for the genus Tatumella.

DNA, Bacterial↗
PubMed1981

Characterization of biochemically atypical Vibrio cholerae strains and designation of a new pathogenic species, Vibrio mimicus.

Biochemically atypical strains classified as Vibrio cholerae were characterized by biochemical reactions, serology, antibiotic susceptibility testing, and deoxyribonucleic acid relatedness. Strains with the following atypical reactions were shown to be V. cholerae: mannose negative, mannitol negative, lysine decarboxylase negative, no growth in the presence of 5% NaCl, salicin and cellobiose positive. Sucrose-negative strains were shown to constitute a new species, Vibrio mimicus, whose type strain is 1721-77 (ATCC 33653). In addition to its negative sucrose reaction, V mimicus was differentiated from V. cholerae by its negative Voges-Proskauer, corn oil, and Jordan tartrate reactions and by its sensitivity to polymyxin. V. mimicus was isolated from shellfish and water, as well as from human diarrheal stools and ear infections. Most strains were typable with antisera against V. cholerae. Strains from three serogroups produced either a heat-labile or a heat-stable enterotoxin.

Bacteriological Techniques↗
PubMed1981

Recognition of a second serogroup of Legionella longbeachae.

A strain of Legionella longbeachae (Tucker 1) that was isolated from the postmortem lung tissue of a pneumonia patient was serologically distinct from four other strains of L. longbeachae. The recognition of a second serogroup of L. longbeachae represents the first reported instance of serogroup diversity within a species of Legionella other than L. pneumophila. The disease caused by the Tucker 1 strain does not seem to be readily distinguishable from that of pneumonia caused by other legionellae.

Antigens, Bacterial↗
PubMed1981

Legionella longbeachae species nova, another etiologic agent of human pneumonia.

A new species of bacteria that is an etiologic agent of human pneumonia has been isolated and characterized. Clinical symptoms of infection with this organism are not readily distinguishable from those caused by Legionella pneumophila infection. The organism was isolated from respiratory tract specimens from four patients. Two cases of infection apparently originated in California and one in Georgia, and a fourth was of unknown geographic origin. The name Legionella longbeachae species nova is proposed for this organism. The type strain of L. longbeachae is Long Beach 4 (= American Type Culture Collection 33462).

Aged↗
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↗
PubMed1980

Salmonella typhi: the laboratory as a reservoir of infection.

As a part of educational and proficiency exercises thousands of students and laboratory personnel have been exposed to Salmonella typhi. In a retrospective study 24 cases of laboratory-acquired typhoid fever in the United states during a 33-month period were identified; laboratory-acquired cases represented only 2.4% of all typhoid cases but 11.2% of the sporadic cases. Twenty-one of the 24 cases occurred when S. typhi was voluntarily introduced into the laboratory for educational proficiency testing or research purposes. Twelve patients were exposed to S. typhi when working with it as an unknown organism; another five were merely present in the laboratory. Obvious breaks in technique were found to be the cause of infection for only seven of the 24 patients, although infection of the others implies that breaks in technique occurred. Laboratory-acquired typhoid fever may severe as a marker for other less severe laboratory-acquired infections; these data suggest that such infections could be common.

Adult↗
PubMed1980

Isolation of Vibrio-like group, EF-6, from patients with diarrhea.

The Vibrio-like organism EF-6 was isolated from more than 500 patients with diarrhea in Bangladesh between October 1976 and June 1977. Bacteriological studies indicate that EF-6 is a member of the family Vibrionaceae and that it should be provisionally placed in the genus Vibrio. EF-6 was isolated from patients who had diarrhea, but was not conclusively implicated as the etiological agent. Pending further study, EF-6 should be considered a potential enteropathogen.

Culture Media↗
PubMed1980

Unusual groups of Morganella ("Proteus") morganii isolated from clinical specimens: lysine-positive and ornithine-negative biogroups.

Morganella ("Proteus") morganii is the only species in the recently proposed genus Morganella, but we suspect there are yet undescribed species in the genus. Two candidates for new species were recently investigated. Nineteen strains isolated from clinical specimens resembled M. morganii but were lysine positive and nonmotile and fermented glycerol within 24 h. Typical M. morganii are lysine negative and motile and ferment glycerol slowly or not at all. The three-test variance from typical M. morganii suggested that this new group might be a new Morganella species; however, strains of the group were closely related to typical M. morganii by deoxyribonucleic acid (DNA)-DNA hybridization. A second group of 14 strains isolated from clinical specimens was ornithine negative but was otherwise very similar to M. morganii. This group was also closely related to M. morganii by DNA hybridization. Both sets of strains clearly belong in the species Morganella morganii as distinct biogroups; they are not separate species as originally suspected. Initially both biogroups posed a problem in identification until their true relationship to M. morganii was determined.

Anti-Bacterial Agents↗
PubMed1980

Legionella gormanii sp. nov.

A new species of Legionella was isolated from soil collected from a creek bank. The name Legionella gormanii sp. nov. is proposed.

DNA, Bacterial↗
PubMed1980

The rickettsia-like organisms TATLOCK (1943) and HEBA (1959): bacteria phenotypically similar to but genetically distinct from Legionella pneumophila and the WIGA bacterium.

Two "rickettsia-like organisms," TATLOCK and HEBA, isolated from human blood via guinea pigs and embryonated eggs in 1943 and 1959, respectively, have been cultured on artificial media (charcoal yeast extract agar) for the first time and characterized. TATLOCK and HEBA have identical cultural, biochemical, and antigenic characteristics, as well as identical cellular fatty-acid composition and antimicrobial susceptibilities. These two bacteria have most of the cultural and biochemical characteristics of Legionella pneumophilia, and their gas-liquid chromatography cellular fatty-acid profile is similar to that of WIGA, another bacterium similar to L. pneumophila. Direct fluorescent-antibody reagents prepared for HEBA and TATLOCK gave equal high-titered reciprocal staining and were negative on 220 other bacteria, including L. pneumophila. Deoxyribonucleic acid relatedness studies, however, showed that these bacteria are not genetically related to either L. pneumophila or the WIGA bacterium.

Anti-Bacterial Agents↗
PubMed1979

Classification of the Legionnaires' disease bacterium: Legionella pneumophila, genus novum, species nova, of the family Legionellaceae, familia nova.

Deoxyribonucleic acid (DNA) relatedness was used to classify strains of the Legionnaires' disease (LD) bacterium. These DNA comparisons showed that all strains of the LD bacterium were members of the same species. Included were strains isolated from the environment and strains with three different O-antigens. The DNA from the LD bacterium was not significantly related to DNA from any other group of bacteria that was tested. Biochemical data, growth characteristics, and guanine-plus-cytosine ratios were used to rule out the possibility that the LD bacterium was significantly related to members of genera whose DNA was not tested. In view of these data we propose that the LD bacterium be named Legionella pneumophila species nova, the type species of Legionella, genus novum. The type strain of L. pneumophila is Philadelphia 1.

Antigens, Bacterial↗
PubMed1979

Legionnaires' disease bacterium isolated in 1947.

The results of serologic, cultural, and DNA relatedness studies have shown that the Legionnaires' disease (LD) bacterium and an unclassified agent isolated in 1947 are the same species. Both organisms grew on charcoal-yeast extract agar, enriched Mueller-Hinton agar, and F-G agar, but neither grew on blood agar, trypticase soy agar, or in thioglycollate broth. Both agents reacted with convalescent sera from patients with Legionnaires' disease and convalescent sera from guinea pigs infected experimentally with the LD bacterium. The percentage of guanine plus cytosine in DNA preparations from each organism was ascertained by thermal denaturation to be 39%. In DNA hybridization reactions the 1947 isolate showed the same degree of relatedness to Philadelphia 1 strain of the LD bacterium as did three recent isolates of the bacterium. The LD bacterium was also shown to be antigenically related to another unclassified organism isolated in 1959.

Animals↗
PubMed1979

A newly identified bacterium phenotypically resembling, but genetically distinct from, Legionella pneumophila: an isolate in a case of pneumonia.

A bacterium with growth characteristics similar to, but genetically distinct from, either Legionella pneumophila or WIGA (a "rickettsia-like agent") was obtained from a postmortem lung specimen of a patient with fatal atypical pneumonia at the M. D. Anderson Hospital and Tumor Institute in Houston, Texas. This bacterium and WIGA have essentially the same cellular fatty acid composition, which is distinct from that of L. pneumophila. Deoxyribonucleic acid-reletadness studies show that the isolate from Texas is only about 10% related to both L. pneumophila and WIGA and there fore may represent a new species. This new bacterium should be considered in selecting laboratory procedures in the diagnosis of atypical pneumonia.

Bacteria↗
PubMed1979

Speciation in Yersinia.

Deoxyribonucleic acid (DNA) relatedness among members of the genus Yersinia and the biochemical reactions of these organisms were compared. These data were used to reassess speciation within the genus Yersinia, and three new species were proposed. These are Yersinia ruckeri sp. n., formerly called the redmouth bacterium; Yersinia intermedia, sp. n., formerly a rhamnose-positive, raffinose-positive, melibiose-positive biogroup within Yersinia enterocolitica; and Yersinia frederiksenii sp. n., formerly a rhamnose-positive, raffinose-negative, melibiose-negative biogroup within Y. enterocolitica.

DNA, Bacterial↗
PubMed1977

Dose and LET distributions due to neutrons and photons emitted from stopped negative pions.

Computer calculations are made of the dose and LET distributions due to neutrons and photons produced when negative pions are stopped in a phantom. When negative pions are stopped in a material they undergo nuclear capture, resulting in the disintegration of the nucleus and the emission of short range charged particles and longer range neutrons and photons. The uncharged radiation constitutes a potentially large source of dose outside the treatment volume. A simple phantom consisting of a 0-25 m cube of either tissue or bone-equivalent material is set up with a 0-05 m cube in the centre to represent the treatment volume. Neutrons and photons are started in this central volume and transported across the phantom using Monte Carlo transport codes. Several different initial energy spectra for the neutrons are used, taken from experimental and theoretical data. These different spectra are found to give significant differences in dose, though the distance to the 80% dose level is always about 0-015 m. Order of magnitude differences in some LET regions are also found. The dose deposited by neutrons in bone is about 24% less than in soft tissue, the photon dose being small compared with the neutron dose.

Elementary Particles↗