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Biomedical subjects

G Furness

Publications and source records attributed to G Furness.

At least 37 records · Page 2Linked to original sources
PubMed1978

A diagnostic key employing biological reactions for differentiating pathogenic Corynebacterium genitalium (NSU corynebacteria) from commensals of the urogenital tract.

More than 100 strains of Corynebacterium genitalium, probably responsible for coryneform urethritis and other infections, and 600 commensals of the male and female urogenital tracts have been studied and grouped into five pathogenic types numbered I to V and six saprophytic types designated C-1 to C-6 on the basis of eight biological reactions. This preliminary classification has been based on differences in requirements for oxygen, on the fermentation of fructose, dextrose, sucrose, and starch together with the production of the enzymes gelatinase, lipase, and urease. One criterion differentiated the pathogens from the commensals: All pathogens were nonfructose fermenters whereas every commensal fermented this sugar.

Bacteriological Techniques↗
PubMed1977

Differences in the growth requirements of some strains of Ureaplasma urealyticum of human origin.

The growth requirements of Ureaplasma urealyticum strains T-McA, T-Pi, T-27, and T-207 were studied. All strains grew in T-broth containing horse serum. Only strain T-McA grew in broth containing serum fraction A, a finding that confirmed that ureaplasmas are not homogeneous and suggested that they can be divided into two species on the basis of their requirement for horse serum. The growth factors required by T-McA are arginine, cystine, methionine, and unidentified metabolites in serum fraction A and trypticase soy broth. The vitamins in Eagle's minimal essential medium are not essential metabolites for T-McA but enhanced its growth. Therefore, we recommend that these vitamins be incorporated in ureaplasma media and that the effect of supplementing media with arginine, cystine, and methionine for the primary isolation of ureaplasmas be ascertained.

Arginine↗
PubMed1976

Morphology, ultrastructure, and mode of division of Mycoplasma fermentans, Mycoplasma hominis, Mycoplasma orale, and Mycoplasma salivarium.

The morphology of viable Mycoplasma fermentans, Mycoplasma hominis, Mycoplasma orale types 1 and 2, and Mycoplasma salivarium was studied in broth cultures by interference microscopy and in thin sections by electron microscopy. Only spherical cells were seen by interference microscopy. M. hominis had a capsule-like outer layer. Except for M. orale type 1, mycoplasmas in thin sections were 0.3-1 mum in diameter, with a bounding trilaminar membrane 7.5-10 nm thick. The mycoplasmas contained DNA fibrils and randomly distributed ribosomes. No polyribosomes were seen. Dividing mycoplasmas elongated slightly; the membrane invaginated, forming one bud. Sometimes M. hominis and M. salivarium produced one bud by elongation, and the bud was attached by a tube. This method of division is not considered as characteristic but rather as due to centrifugal force separating unfixed cells during preparation for electron microscopy. Cross-septa were never observed. In thin sections M. orale type 1 was elongated and without buds, an observation which suggested that preparation for electron microscopy distorted the mycoplasmas.

Cell Division↗
PubMed1976

A study of the amino acids and proteins of some human T-mycoplasma membranes.

Purified membranes were prepared from seven human T-mycoplasmas. Their amino acid composition was determined and was similar to that of other biological membranes. Their proteins were examined by isoelectric focusing and 7 to 10 protein bands were detected mostly in the pH 4 to 7 range of the gel. T-mycoplasma T-McA also had one distinctive band at pH 3 while T-mycoplasma T-213 had a prominent basic band at pH 9. The proteins were denatured by storage at -25 degrees. Five to seven Periodic Schiff-positive bands also were observed but were not identified.

Amino Acids↗
PubMed1976

Infection of a nonspecific urethritis patient and his consort with a pathogenic species of nonspecific urethritis Corynebacteria, Corynebacterium genitalium, N. SP.

A patient with nonspecific urethritis (NSU) and his consort were examined for infection with NSU corynebacteria, mycoplasmas, and gonococci. No classic and T-mycoplasmas or gonococci were cultured, but one species of NSU corynebacteria was isolated not only from the patient's urethral discharge during three episodes of NSU but also from his consort. It was not isolated after successful treatment of the patient with tetracycline and the use of condoms prevented reoccurrence of urethritis. This NSU corynebacterium was isolated previously from one epididymitis patient and two NSU patients but not from any of the normal male and female subjects examined. Therefore, this strain is considered to be one of the etiologic agents of NSU and female subjects are asymptomatic carriers. In consequence, it is suggested that NSU corynebacteria which are commensals and pathogens of the male and female urogenital tracts should be incorporated in a new species, of the Coryneform group, and that this strain should be the type species, Corynebacterium genitalium n. sp.

Adult↗
PubMed1975

T-mycoplasmas: Growth patterns and physical characteristics of some human strains.

Five T-mycoplasmas isolated from patients with nonspecific urethritis and five laboratory strains of T-mycoplasma were examined for differentiating biological properties. The strains differed by the presence or absence of a lag phase and the number of T-mycoplasmas constituting a colony-forming unit (cfu). Most T-mycoplasmas had no lag phase and a cfu consisting of single organisms. All had biphasic ultraviolet inactivation curves typical of suspensions containing both mononucleate and binucleate cells. Binucleate cells probably were in the process of division. They resisted sonication for 3 min. Sonication disrupted multicellular cfu in to single cells within 2 min. Stationary-phase organisms died more rapidly than exponential-phase cells. T-mycoplasmas replicated at 2 C; they grew more slowly in T-broth at 40 C and died in 2.5 min at 56 C. Inactivation curves at 45 C and 50 C differed but insufficiently to permit identification of individual strains. At pressures less than 5 psi, single-cell suspensions passed through filter membranes with 0.65-mum and 0.45-mum pores but were retained by membranes with 0.22-mum pores.

Cell Division↗
PubMed1975

T-mycoplasmas: a study of the morphology, ultrastructure and mode of division of some human strains.

The morphology of 10 strains of T-mycoplasma was studied in wet preparations of viable cells by darkfield, phase-contrast and interference microscopy, and in fixed preparations by various techniques of electron microscopy. Mycoplasma-like artefacts in the horse-serum component of the medium were eliminated by filtration. All 10 strains were similar. Individual cells were spherical, 0-25-1-0 mum in size, with a bounding trilaminar membrane, 10 nm thick and containing 7-5-12-5-nm particles, and a layer of pilus-like projections, 5-8 nm long, on the outer surface. A possible capsular matrix was observed only by the pseudoreplica technique. The cells contained 12-15-nm ribosomes, nuclear fibroids 7-5-9 nm wide, and vacuoles. During replication, the cell elongated slightly and the ribsomes migrated to the ends of the cell leaving a ribosome-free area into which the bounding membrane invaginated to form a bud. The bud eventually separated by completion of the process of invagination; a cross-septum did not form. Usually only a single bud developed but sometimes two appeared simultaneously.

Cell Membrane↗
PubMed1975

Adaptation of Mycoplasma hominis to an obligate parasitic existence in monkey kidney cell culture (BSC-1).

During attempts to eliminate Mycoplasma hominis from a monkey kidney BSC-1 cell line with antibiotics, the mycoplasmas were isolated repeatedly. However, the organisms ultimately failed to grow on medium although electron microscopy confirmed that the cell culture still contained mycoplasmas. Thus, the mycoplasma had adapted to an environment in which viable cells were required for growth. Budding mycoplasmas which are indicative of replication were seen associated with viable cells extracellularly. Moreover, structures resembling cycoplasmas were observed budding from the cells which suggests that the mycoplasmas replicate within the cells and are similar to many viruses in their manner of release from the cells.

Adaptation, Biological↗
PubMed1975

The preparation of membranes of some human T-mycoplasmas and the analysis of their carbohydrate content.

Purified membranes were prepared from seven human T-mycoplasmas of which four are laboratory strains and three isolates from patients with nonspecific urethritis. The T-mycoplasmas were resistant to osmotic shock and sonication. Membranes were obtained only after lysing most of the T-mycoplasmas by four passes through a cell fractionator at 40,000 psi and separating the membranes from the unlysed cells by differential centrifugation. The membranes contained between 1 and 7% carbohydrates by dry weight. Mannose, galactose, and glucose were identified with glucose in the largest concentration.

Carbohydrates↗
PubMed1975

The urea requirement and urease production of some human species of T-mycoplasmas.

Seven species of human T-mycoplasmas that grow in Fraction A and 20 mug urea/ml died when the urea was omitted. Two species would not grow in Fraction A broth containing 10 mug/urea/ml. The other five strains grew in broth containing 10 mug urea/ml and were adapted by serial passage in broth containing decreasing concentrations of urea to grow in broth containing 2.5 mug/ml urea, but not in broth containing 1.25 mug/ml. Therefore the minimal urea requirement is not the same for the growth of all strains of T-mycoplasmas. In exponential phase broth cultures, urease was detected only intracellularly, none being found in the medium.

Humans↗
PubMed1975

Asymptomatic bacteriuria, bacteremia, and other infections due to NSU corynebacteria.

By means of the new medium, nonspecific urethritis (NSU) chocolate agar, NSU corymebacteria were isolated from patients with asymptomatic bacteriuria, bacteremia, cervicitis, conjuctivitis, and pericarditis, and also with bone marrow, wound, and cul-de-sac infections. The NSU corynebacteria were considered the etiologic agents. On the basis of biochemical reactions, antibiotic sensitivity, and complement fixation tests some isolates were the same microorganisms. Both patients with conjunctivitis were infected with the same NSU corynebacteria. A second isolate was cultured from patients with osteomyelitis and cervicitis, while a third was recovered from an infected leg wound and from a patient with pericarditis. Seven of the isolates, when injected into rabbits hypersensitive to four NSU corynebacteria isolated from the inflamed epididymis of patients with epididymitis, elicited delayed hypersensitivity reactions, which indicated that they also were related antigenically. It is suggested that nonspecific urethritis and eididymitis may represent an infection with NSU corynebacteria, or may be an extension of bacteriuria due to these microorganisms, with a delayed hypersensitivity reaction as a possible additional complication. Colony counts on NSU chocolate agar of the bacteria in urines from male and female patients were higher than those obtained on conventional agar media. NSU chocolate agar is superior to other agar media for the isolation of pathogenic and saprophytic bacteria not only from the urogenital tract but also from other foci of infection. It is easily prepared from commercial blood agar plates and its use should be considered when a selective medium is not required.

Adult↗
PubMed1975

Morphological changes induced during fixation of Mycoplasma mycoides for electron microscopy.

Only spherical mycoplasmas 0.6-0.9 mum diam were observed by darkfield microscopy in single cell suspensions prepared from exponential broth cultures of Mycoplasma mycoides var mycoides and Mycoplasma mycoides var capri. Similar cells were seen in pseudoreplicas by electron microscopy and they are considered characteristic of the morphology of M. mycoides. When the mycoplasmas were fixed by the addition of 10% formalin to the suspensions or washed, centrifuged cells were fixed by glutaraldehyde, filamentous and ring forms were observed in electron micrographs. These are not considered typical of the morphology of M. mycoides but are artifacts produced during the preparation of the mycoplasmas for electron microscopy.

Bacteriological Techniques↗