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At least 19 recordsLinked to original sources
PubMed1992

Intestinal, segmented, filamentous bacteria.

Segmented, filamentous bacteria (SFBs) are autochthonous, apathogenic bacteria, occurring in the ileum of mice and rats. Although the application of formal taxonomic criteria is impossible due to the lack of an in vitro technique to culture SFBs, microbes with a similar morphology, found in the intestine of a wide range of vertebrate and invertebrate host species, are considered to be related. SFBs are firmly attached to the epithelial cells of the distal ileal mucosa, their preferential ecological niche being the epithelium covering the Peyer's patches. Electron microscopic studies have demonstrated a considerable morphological diversity of SFBs, which may relate to different stages of a life cycle. Determinants of SFB colonization in vivo are host species, genotypical and phenotypical characteristics of the host, diet composition, environmental stress and antimicrobial drugs. SFBs can survive in vitro incubation, but do not multiply. On the basis of their apathogenic character and intimate relationship with the host, it is suggested that SFBs contribute to development and/or maintenance of host resistance to enteropathogens.

Animals↗
PubMed1992

Research note: isolation of two filamentous bacteria associated with enteritis in turkey poults.

Two microaerophilic filamentous bacteria have been isolated from the intestines of turkey poults exhibiting signs of enteritis. These two filamentous bacteria, denoted as F-1 and F-2, were reinoculated into 4-day-old poults and those poults have shown a reduction in rate of gain when compared with aged-matched controls. Weight reduction was 14% for F-1 and 11% for F-2, respectively, at 21 days of age.

Animals↗
PubMed1992

Different degree of ileal colonization by segmented, filamentous bacteria in two strains of mice.

Segmented, filamentous bacteria (SFBs) are autochthonous, apathogenic inhabitants of the ileum of various animal species. Outbred Swiss (Cpb:SE) mice have significantly higher degrees of SFB colonization than do inbred BALB/c mice. The present studies were carried out to identify determinants of this strain difference. In a cross-fostering experiment it was shown that SFB colonization of the pups is determined by the strain of the pups themselves rather than by the strain of the nursing dam. Thus, maternal effects may not be involved in SFB colonization. In a cross-infecting experiment using germ-free and SFB-positive animals of the two mouse strains, it was found that ileal SFB colonization is determined by host characteristics rather than by origin of the SFBs. Thus, SFBs that are specific for a given mouse strain may not exist in the two strains of mice. It is concluded that the mouse strain difference in SFB colonization is determined by host characteristics, which probably have a genetic basis.

Animals↗
PubMedDate not supplied

Visceral granulomas in chickens infected with a filamentous bacteria.

Visceral granulomas containing gram-positive filamentous bacteria were diagnosed in eight chickens collected from processing plants over a period of 4 years. Formalin-fixed tissues were submitted from the chickens after slaughter, but no specimens suitable for bacterial culture were received. The bacteria lacked similar tinctorial, morphologic, and ultrastructural features of other gram-positive bacteria that have been identified in chickens. The bacteria were visible with hematoxylin and eosin and faintly visible with Gomori methenamine-silver, but negative with periodic acid-Schiff and Fite-Faraco acid-fast stains. Granulomas were found in the liver, spleen, and peritoneum.

Animals↗
PubMed1992

Influence of a natural-ingredient diet containing Phaseolus vulgaris on the colonization by segmented, filamentous bacteria of the small bowel of mice.

The appearance of segmented, filamentous bacteria (SFBs) in the small bowel of mice is influenced by the composition of the diet, but the dietary components responsible are not known. The addition of ground, whole Phaseolus vulgaris to a natural-ingredient diet at the expense of part of the skim milk powder, ground barley and wheat middlings components, caused an increase of the colonization of the mouse small bowel by SFBs. This effect was not seen when whole Phaseolus was added to a purified diet at the expense of part of the casein, corn oil, coconut fat, corn starch, dextrose and cellulose components. In an attempt to identify the fraction of Phaseolus that might contain SFB-inducing substances, the skin and kernel fraction of the bean were added to the natural-ingredient diet. The skin and kernel fraction were found to be as effective in inducing SFB appearance as was whole Phaseolus.

Animal Feed↗
PubMed1991

Mono-association of mice with non-cultivable, intestinal, segmented, filamentous bacteria.

A technique is described so that mice mono-associated with non-cultivable, segmented filamentous bacteria (SFB's) can be produced for the first time. As SFB donors, mice were used which had an intestinal microflora consisting of both SFB's and bacteria of the genus Clostridium. Recipients were germ-free mice. It was demonstrated that the intraileal inoculation method was more effective than the orogastric route. Therefore, intestinal homogenates of donor mice were treated with filtered ethanol, diluted and administered intraileally to recipient mice. Evidence is presented that cage mates of the recipient mice were mono-associated with SFB's. The availability of these animals, i.e. in vivo monocultures of SFB's, allows taxonomic and functional characterization of SFB's, which was as yet not possible.

Animals↗
PubMed1979

Colonization of a portion of the bovine tongue by unusual filamentous bacteria.

Tongue samples from cattle on varied diets and ranging in age from 2 months to adult were studied by transmission and scanning electron microscopy to observe the in situ distribution and adhesion patterns of two readily identifiable genera of filamentous bacterial. The two, both members of the Simonsiellaceae, adhere to the epithelium by means of fibers which are produced on one side of the bacterial filaments and subsequently display a sidedness in their manner of adhesion to epithelial surfaces. Other bacterial populations found on the tongue were normally members of chains and seldom present as single cells. This suggests that filamentous or chain-forming bacteria may have a selective advantage over single bacteria in their ability to colonize and remain attached to the epithelium of the tongue.

Animals↗
PubMed2024

Filamentous bacteria-induced sludge bulking can alter antibiotic resistance gene profiles and increase potential risks in wastewater treatment systems.

Sludge bulking caused by filamentous bacteria is a prevalent issue in wastewater treatment systems. While previous studies have primarily concentrated on controlling sludge bulking, the biological risks associated with it have been overlooked. This study demonstrates that excessive growth of filamentous bacteria during sludge bulking can significantly increase the abundance of antibiotic resistance genes (ARGs) in activated sludge. Through metagenomic analysis, we identified specific ARGs carried by filamentous bacteria, such as Sphaerotilus and Thiothrix, which are responsible for bulking. Additionally, by examining over 1,000 filamentous bacterial genomes, we discovered a diverse array of ARGs across different filamentous bacteria derived from wastewater treatment systems. Our findings indicate that 74.84% of the filamentous bacteria harbor at least one ARG, with the occurrence frequency of ARGs in these bacteria being approximately 1.5 times higher than that in the overall bacterial population in activated sludge. Furthermore, genomic and metagenomic analyses have shown that the ARGs in filamentous bacteria are closely linked to mobile genetic elements and are frequently found in potentially pathogenic bacteria, highlighting potential risks posed by these filamentous bacteria. These insights enhance our understanding of ARGs in activated sludge and underscore the importance of risk management in wastewater treatment systems.

Sewage↗
PubMedDate not supplied

[Characteristics of filamentous phototrophic bacteria from freshwater lakes].

Filamentous phototrophic bacteria were isolated in pure cultures from fresh-water stratified lakes, and identified as chlorobacteria. The photosynthesizing apparatus of these bacteria is chlorobium-vesicules, the main pigment is bacteriochlorophyll c. The bacteria do not require reduced compounds of sulphur; they are capable of anaerobic photosynthesis on organic compounds or grow under aerobic conditions in the light or in the darkness. They are mesophilic (optimum temperature is 25 degrees C); the optimum of pH is 7.0. A possibility to class these microorganisms as a new species of the genus Chloroflexus is discussed.

Bacteria↗
PubMedDate not supplied

Clinical, pathological, and epizootiological features of long-segmented filamentous organisms (bacteria, LSFOs) in the small intestines of chickens, turkeys, and quails.

Long-segmented filamentous organisms (LSFOs) are easily recognized gram-positive bacteria that infect several species of animals. The present study describes the epizootiological, clinical, and pathological characteristics of LSFOs in chicks, turkey poults, and quails in Georgia and California. LSFOs are most likely to be seen in young poultry that have gastrointestinal illnesses during winter. Concomitant infections with other bacteria and protozoans are common. Although inflammation and displacement of microvilli are characteristics of LSFO infections in these birds, LSFOs are not necessarily pathogens. They may be normal intestinal flora or commensal organisms that overgrow when certain unknown gastrointestinal conditions are correct or certain unknown events occur.

Animals↗
PubMed1992

Effect of temperature and medium composition on mycelial growth of Streptomyces tendae in submerged culture.

To investigate the influence of culture conditions on growth of filamentous bacteria in submerged culture, S. tendae was cultivated at various temperatures and in various media. For this purpose, a temperature-controlled growth chamber was constructed, which allows the cultivation of filamentous bacteria and fungi oxygen saturated medium. To observe the development of mycelia emerging from spores, this growth chamber was mounted on a microscope stage and series of images were analyzed by an image processing system. Growth kinetics obtained in liquid culture were identical to those determined on solid media. Specific growth rate and apical extension rates of individual hyphae seemed to be higher than those observed on solid media, due to a better supply of medium in submerged culture. A two-fold increase in specific growth rate, mean apical extension rate and branching rate was observed when the temperature was increased from 27 degrees C to 37 degrees C, therefore, the length of the hyphal growth unit was not changed. Growth in synthetic media used here was considerably slower compared with complex medium. A decrease in glucose concentration from 40.0 g l-1 to 1.0 g l-1 resulted in an increase in branching rate and specific growth rate, while apical extension rate of individual hyphae was unchanged.

Bacteriological Techniques↗
PubMed1978

Ultrastructure of the subgingival microflora in juvenile periodontitis.

The ultrastructure of the subgingival deposits on the root surfaces of teeth affected by juvenile periodontitis was studied on 12 teeth from nine individuals, 15--30 years of age. The deposits consisted of either microbial masses associated with a pellicle, or of a cuticular material almost free of bacteria. Gram-negative rods and filaments were the predominant microorganisms. "Corncob" configurations consisting of filamentous bacteria surrounded by Gram-positive cocci, and "bristle brush" formations comprising corncobs surrounded by long rods were observed in the superficial layer of the plaque. Spirochetes and flagellated rods constituted a major segment of the microflora. The present data indicated that the deep pockets in juvenile periodontitis harbor a sparse but relatively characteristic microbial population.

Adolescent↗
PubMed1991

Light and electron microscopic observations of a segmented filamentous bacterium attached to the mucosa of the terminal ileum of pigs.

Segmented filamentous bacteria were seen attached to apical villous enterocytes of the terminal ileum in 15 of 2,766 live pigs submitted for necropsy over a 6-year period. Infected pigs ranged in age from 2 to 13 weeks. All pigs except 2, however, were greater than 4 weeks old and had been weaned. All infected pigs came from conventional commercial herds with intensive, all-indoor, confinement rearing management systems. The bacteria were gram negative or gram variable and were not associated with any clinical disease. Bacteria were more commonly attached to epithelium on the dome villi in the ileum. Electron microscopic examination revealed organisms composed of a cranial segment with a nipple-like appendage and several other segments making up elongated filaments of various lengths. Each filament was divided into segments by transverse septa. The nipple-like appendage served as an attachment apparatus by indenting the enterocyte surface without physically penetrating it. Occasionally, the colonizing bacterium was itself colonized by small rod-shaped bacteria that completely surrounded the filament.

Animals↗
PubMed1992

Comparison of techniques for culturing corneal ulcers.

All consecutive cases of presumed microbial keratitis were cultured with both a platinum spatula and calcium alginate swab moistened with trypticase soy broth. Ten (77%) of the 13 culture-proven ulcers in this series showed a greater number of colonies and more confluent growth on the agar plates inoculated with a moistened swab compared with a much lower yield obtained using a platinum spatula. All culture-positive bacterial ulcers showed growth when cultured with a swab. Two ulcers that were partially treated before culturing yielded very light growth from those rows inoculated with a swab and no growth from those rows inoculated with a spatula. Two ulcers showed equal growth between the two methods. One ulcer (Actinomycetes-Streptomyces/Nocardia) had greater growth obtained with a spatula compared with a swab. This series demonstrated a significantly greater retrieval of organisms from bacterial keratitis when a calcium alginate swab moistened with trypticase soy broth was used to rub the ulcer and directly inoculate the solid agar media. The single case of filamentous bacteria suggests that a spatula may yield better organism retrieval from ulcers caused by filamentous organisms.

Bacteria↗
PubMed1989

Elimination of murine viral pathogens from the caecal contents of mice by anaerobic preparation.

The aim of this study was to investigate methods to eliminate pathogenic viral agents while preserving the 'normalizing' properties of the gut microflora of mice. Mouse hepatitis virus A59 (MHV), Reo 3 virus and Theiler GD VII virus were added to the caecal contents of 'normal' mice and following dilution, with or without subsequent culturing, given to germ-free mice. Four weeks later antibody titres against these and other viruses were determined. MHV and Theiler CD VII virus survived dilution but were eliminated during culturing. Reo-virus survived the 10(-1) dilution-culture step. All dilutions and dilution-cultures of caecal contents resulted in 'normalization' in germ-free recipients of the relative caecal weight, percentage faecal fusiform-shaped bacteria, faecal bile acids and colonization of small intestine by segmented filamentous bacteria.

Animals↗
PubMed1976

In situ morphologies of deep-sea and sediment bacteria.

Deep-sea and sediment bacteria at the bottom of an approximately 1200-m water column were sampled by means of pressure vessels attached to a remote underwater manipulator. Cells were immediately fixed in situ with glutaraldehyde, and after processing in the laboratory their morphologies were observed with the scanning electron microscope. Most bacteria were coccoid or rod-lide and less than 0.4 mum in diameter or width. Few filamentous bacteria were observed. Bacteria were in aggregates or free-living. It is concluded that morphologies of deep-sea bacteria collected and fixed at the hydrostatic pressure of their environment are, in general, similar to the observed morphologies of deep-sea bacteria determined at 1 atm pressure after collection and decompression during ascent through the water column.

Bacteria↗
PubMed1977

Dorsal-ventral differentiation in Simonsiella and other aspects of its morphology and ultrastructure.

The morphology and ultrastructure of the aerobic, Gram-negative multicellular-filamentous bacteria of the genus simonsiella were investigated by scanning and transmission electron microscopy. The flat, ribbon-shaped, multicellular filaments show dorsal-ventral differentiation with respect to their orientations to solid substrata. The dorsal surface, orientated away from the substrate, is convex and possesses an unstructured capsule. The ventral surface, on which the organisms adhere and glide, is concave and has an extracellular layer with fibrils extending at right angles from the cell wall. The cytoplasm in the ventral region contains a proliferation of intracytoplasmic membranes and few ribosomes in comparison to the cytoplasm in other parts of the cell. Centripetal cell wall formation is asymmetrical and commences preferentially in the ventral region. Quantitative differences in morphology and cytology exist among selected Simonsiella strains. Functional aspects of this dorsal-ventral differentiation are discussed with respect to the colonization and adherence of Simonsiella to mucosal squamous epithelial cells in its ecological habitat, the oral cavities of warm-blooded vertebrates.

Animals↗