SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Crystalline lithocholic (3alpha-hydroxycholanic) acid was isolated from a pooled sample of feces from healthy men for the first time. This acid, which occurs in small amounts in human bile, was obtained by alcohol extraction, followed by solvent partition and chromatography. Under these conditions most of the acid was recovered in the form of its methyl ester.
When incubated at room temperature (23 degrees C) for 3 to 14 days, feces from cats infected 4 to 8 days with Toxoplasma gondii, and free of Toxocara cati eggs, produced toxoplasmosis in mice. Results indicate that the nematode egg is not necessary for transmission of the parasite.
Multiply antibiotic-resistant strains of Clostridium perfringens were isolated from porcine feces. Strains that were resistant to tetracycline, erythromycin, clindamycin, and lincomycin were isolated, but no penicillin- or chloramphenicol-resistant strains were obtained. Typical minimal inhibitory concentrations for resistant strains were 16 to 64 mug of tetracycline per ml, 64 to >128 mug of erythromycin per ml, >/=128 mug of lincomycin per ml, and 16 to 128 mug of clindamycin per ml. Resistance to erythromycin was always associated with resistance to lincomycin and clindamycin. Minimal inhibitory concentrations were determined for 258 strains from six farms that used antibiotics in their feeds and 240 strains from five farms that did not use antibiotics. The results show that 77.9 and 22.7% of the strains from the former farms were resistant to tetracycline and erythromycin-clindamycin-lincomycin, respectively. The comparable data from the latter farms were 25.0 and 0.8%, respectively. Agarose gel electrophoresis failed to reveal a plasmid band that was common to the resistant strains but absent in the susceptible strains. Attempts to transfer tetracycline, erythromycin, and clindamycin resistance from one strain, CW459, were not successful. Antibiotic-susceptible mutants were not isolated from this strain, despite the use of a variety of curing agents.
Twelve healthy volunteers received single 400-mg oral doses of norfloxacin. During the ensuing 48 h, from 8.3 to 53.3% (mean, 28%) of this dose was recovered in the feces. Peak drug concentrations in fecal specimens ranged from 207 to 2,716 micrograms/g.
We report the in vitro antibiotic susceptibility of 1,220 strains belonging to the thermotolerant Campylobacter species, isolated from the feces of pediatric patients with diarrhea in the period from 1987 to 1993. The strains were identified as 1,148 C. jejuni isolates and 72 C. coli isolates. The overall results show that the strains showed drug resistance as follows: 51.8% to ampicillin, 4.4% to clindamycin, 2.6% to chloramphenicol, 21.2% to tetracycline, and 1% to gentamicin. Twenty-one strains (1.7%) displayed resistance to the combination of amoxicillin-clavulanic acid, and 3.2% of the strains were resistant to erythromycin (MIC of > or = 4 micrograms/ml), with a notable difference according to the species under consideration. While C. jejuni remained stable at 0.9 to 4% resistance to erythromycin, for C. coli the percentages detected ranged from 0 to 33%, with overall rates of 2.5 and 15.2% for the two species, respectively. Resistance to nalidixic acid (MIC of > or = 32 micrograms/ml) was found in 27.2% of the strains (27.8% for C. jejuni and 18% for C. coli), and resistance to ciprofloxacin (MIC of > or = 4 micrograms/ml) was found in 24.2% of the strains for C. jejuni and 15.2% for C. coli). Cross-resistance between nalidixic acid and ciprofloxacin was found in 89.1% of the strains (type 1 mutants), while 10.9% were resistant to nalidixic acid but susceptible to ciprofloxacin (type 2 mutants).
The population dynamics of bifidobacteria in human feces during raffinose administration were investigated at the species level by using fluorescence in situ hybridization (FISH) coupled with flow cytometry (FCM) analysis. Although double-staining FISH-FCM using both fluorescein isothiocyanate (FITC) and indodicarbocyanine (Cy5) as labeling dyes for fecal samples has been reported, the analysis was interfered with by strong autofluorescence at the FITC fluorescence region because of the presence of autofluorescence particles/debris in the fecal samples. We circumvented this problem by using only Cy5 fluorescent dye in the FISH-FCM analysis. Thirteen subjects received 2 g of raffinose twice a day for 4 weeks. Fecal samples were collected, and the bifidobacterial populations were monitored using the established FISH-FCM method. The results showed an increase in bifidobacteria from about 12.5% of total bacteria in the prefeeding period to about 28.7 and 37.2% after the 2-week and 4-week feeding periods, respectively. Bifidobacterium adolescentis, the Bifidobacterium catenulatum group, and Bifidobacterium longum were the major species, in that order, at the prefeeding period, and these bacteria were found to increase nearly in parallel during the raffinose administration. During the feeding periods, indigenous bifidobacterial populations became more diverse, such that minor species in human adults, such as Bifidobacterium breve, Bifidobacterium bifidum, Bifidobacterium dentium, and Bifidobacterium angulatum, proliferated. Four weeks after raffinose administration was stopped, the proportion of each major bifidobacterial species, as well as that of total bifidobacteria, returned to approximately the original values for the prefeeding period, whereas that of each minor species appeared to differ considerably from its original value. To the best of our knowledge, these results provide the first clear demonstration of the population dynamics of indigenous bifidobacteria at the species level in response to raffinose administration.
The sensitivity of a test for cattle shedding Escherichia coli serogroup O26 was estimated using several fecal pats artificially inoculated at a range of concentrations with different E. coli O26 strains. The test involves the enrichment of fecal microflora in buffered peptone water, the selective concentration of E. coli O26 using antibody-coated immunomagnetic-separation beads, the identification of E. coli colonies on Chromocult tryptone bile X-glucuronide agar, and confirmation of the serogroup with E. coli serogroup O26-specific antisera using slide agglutination. The effective dose of E. coli O26 for an 80% test sensitivity (ED(80)) was 1.0 x 10(4) CFU g(-1) feces (95% confidence interval, 4.7 x 10(3) to 2.4 x 10(4)). Differences in test sensitivity between different E. coli O26 strains and fecal pats were also observed. Individual estimates of ED(80) for each strain and fecal pat combination ranged from 4.2 x 10(2) to 4.8 x 10(5) CFU g(-1). These results suggest that the test is useful for identifying individuals shedding a large number of E. coli O26 organisms or, if an appropriate number of individuals in a herd are sampled, for identifying affected herds. The study also provides a benchmark estimate of sensitivity that can be used to compare alternative tests for E. coli O26 and a methodological approach that can be applied to tests for other pathogenic members of the Enterobacteriaceae and other sample types.
An anaerobic cellulolytic bacterium, identified as a Bacteroides sp., was present in 10(-8) g of feces from only one of five human subjects.
A growth medium and test were developed for rapid detection of urease in fermentative anaerobic bacteria. Using nonselective rumen fluid roll-tube agar medium and the new test, it was confirmed that Peptostreptococcus productus is often the most numerous urease-forming species in human feces. Also, some fecal strains of Ruminococcus albus, Clostridium innocuum, and Clostridium beijerinckii produced urease. Single strains of Fusobacterium prausnitzii, Coprococcus catus, and Streptococcus mitis that were strongly ureolytic on isolation later lost this ability. Urease activity was also detected in many strains of nonselectively isolated rumen species. They include Succinivibrio dextrinosolvens, Treponema sp., Ruminococcus bromii (not previously known to be present in the rumen), Butyrivibrio sp., Bifidobacterium sp., Bacteroides ruminicola, and P. productus. Most P. productus strains contain urease; however, the uniformity of this feature in the other species noted above is not known. The urease in many of these species was not detected if the growth medium contained 0.2% or more (each) yeast extract and Trypticase.
Organisms able to grow on arabinogalactan, pectin, xylan, wheat bran, guar, apple cell walls, and mucin were isolated by enrichment from human feces. The number of polysaccharide fermenters and the properties of the predominant bacteria varied between subjects. The ability to use one polysaccharide was not related to the ability to use others. Some organisms (e.g., Bacteroides spp.) isolated on other substrates also utilized mucin, but were not isolated in the mucin enrichment. The mucin fermenters isolated by enrichment had a very restricted ability to utilize complex polysaccharides and their constituent monosaccharides, suggesting that the presence of plant polysaccharides in the human colon is unlikely to prevent the use of colonic mucin as an energy source by bacteria. Characterization with a range of biochemical tests showed that many of the isolates, but especially the mucin fermenters, did not resemble organisms described previously.
A methanogenic bacterium with the morphological and physiological properties of the genus Methanobrevibacter was isolated from the feces of a Japanese man who excreted methane in his breath. Indirect immunofluorescence staining revealed that the isolate had an antigenicity unrelated to that of any known members of the genus Methanobrevibacter.
An obligate anaerobe has been isolated from swine feces which decarboxylates p-hydroxyphenylacetic acid to 4-methylphenol (p-cresol). The bacterium was an ovoid rod, gram positive, nonsporeforming, and nonmotile. Lactate and acetate were major end products of glucose fermentation. Based on its characteristics, the bacterium is tentatively assigned to the genus Lactobacillus.
A technique combining enrichment in Preston enrichment broth and direct filtration onto chocolate agar was used to isolate Campylobacter species from pigeon feces. Campylobacter jejuni was isolated from 106 of 200 samples tested; 105 strains were isolated by enrichment-filtration, and 84 strains were isolated by direct plating. Most of the strains grew after 48 h at 37 degrees C.
Several strains of Escherichia coli O157:H7 artificially inoculated into vegetables and dairy products were recovered on hydrophobic grid membrane filters and enumerated by an enzyme-labeled antibody assay. The mean of the recoveries from 12 fresh vegetables was 108.8%, whereas that from 10 dairy products was 93.2%. Modified tryptic soy broth at 43 degrees C with shaking at 100 rpm provided optimum recovery of the organism from meat, with a sensitivity of less than or equal to 1 CFU/g, which is 10 times more sensitive than direct plating. The method performed equally well with vegetable and dairy products. Tryptic soy broth, however, under the same conditions gave the best results for fecal samples. Of 22 asymptomatic dairy cattle, reported as having positive Brucella titers when assayed with polyclonal antibodies, eight were found to contain E. coli O157 in their feces as demonstrated by the enzyme-labeled antibody assay by using monoclonal antibodies. This finding may explain some of the false-positive Brucella tests.
Gram-positive cocci, isolated from the feces of koalas and identified as Streptococcus bovis biotype I, formed a distinct clear zone on tannin-treated brain heart infusion agar, suggesting that this isolate has the unique characteristic of degrading the tannin-protein complex.
We report the first isolations of Helicobacter strains from wild birds and swine. Genus-specific oligonucleotide probes identified nine Cape Cod isolates from gull, tern, house sparrow, and pig feces as Helicobacter spp. and not Campylobacter spp. Antibiotic sensitivity and urease tests distinguished three phenotypes. Strains examined rapidly lost culturability under simulated natural conditions.
To evaluate the persistence of PCR-detectable Bacteroides distasonis in surface water, whole human feces were dispersed into water from the Ohio River and incubated in flasks in the laboratory or in diffusion chambers in situ. Duplicate samples were taken daily, and material that pelleted at 16,000 x g was assayed by PCR. Persistence of PCR-detectable DNA from this anaerobe depended upon temperature and predation, two of the factors shown by others to influence the survival of aerobic bacteria detected by culture. B. distasonis was detected by PCR for at least 2 weeks at 4 degrees C but for only 4 to 5 days at 14 degrees C, 1 to 2 days at 24 degrees C, and 1 day at 30 degrees C. In filtered water or in the presence of cycloheximide, a eukaryotic inhibitor, persistence at 24 degrees C was extended by at least a week.
Fecal droppings of migratory Canada geese, Branta canadensis, collected from nine sites near the Chesapeake Bay (Maryland), were examined for the presence of Cryptosporidium parvum and Giardia spp. Cryptosporidium sp. oocysts were found in feces at seven of nine sites, and Giardia cysts were found at all nine sites. The oocysts from three sites were infectious for mice and molecularly identified as the zoonotic genotype of Cryptosporidium parvum. Waterfowl can disseminate infectious C. parvum oocysts in the environment.