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PubMed1980

[Qualitative and quantitative examination of bacteria found in aquatic habitats. 1. Communication: selective recording of bacteria during isolation on different solid media (author's transl)].

The quantity of bacteria taken from 8 watersamples and 46 slimesamples in the sphere of drinking water were examined using 15 different solid media. These media showed variations in total colony count and more or less selectivity against several bacterial groups. For the recording of as much bacteria as possible and as much different species as possible low nutrient containing media are necessary.

Agar↗

PubMed1996

[Cytolysins and homologous proteins produced by gram-negative bacteria. II. Hemolysins of Aeromonas, Serratia, Proteus and Morganella and proteins from gram-negative bacteria related to cytolysins].

This article presents the genetic determination, synthesis and activation of hemolysins produced by mentioned above bacteria, as well as the possible role of these toxins in the pathogenicity. All these cytolysins are related to RTX proteins presented to the previous paper. The short information about cytotoxic proteins from other Gram-negative bacteria (P. aeruginosa, K. pneumoniae, Vibrionaceae, G. vaginalis) and homologous proteins from E. chrysanthemi and R. leguminosarum biovar viciae are also included.

Aeromonas↗

PubMed1997

[Fungi and bacteria on air filters from heating, ventilation and air-conditioning systems: a method for determination of fungi and bacteria on air filters].

A method was developed for the determination of microorganism concentrations on air filters of HVAC systems, and the influence of different test parameters on the microbiological results was examined by considering various used air filters from several such systems. Microorganisms are detected by shaking air filter samples in fluid, where their concentration is then determined as surface cultures. Since varying the shaking time (30, 60, 90 min) had no influence on the quantitative microorganism determination, a shaking time of 60 minutes was chosen for detection of bacteria, yeasts and moulds. Incubation of blood agar plates either for 4 days at 20 degrees C +/- 2 degrees C or for 2 days at 36 degrees C +/- 1 degree C yielded identical concentrations of bacteria and yeasts. Since results obtained with malt extract agar and Czapek-Dox agar are comparable, one of the two culture media is sufficient for the quantitative determination of moulds on air filters. For statistical evaluation, the inoculation of three parallel agar plates per growth medium was found to be adequate, and the arithmetic mean and the median proved to be equivalent. Investigation on the detection rate showed that, on the average, the method developed demonstrated 80% of the microorganisms detectable on an air filter sample. Thus a simple method is available for quantitative determination of microorganisms on air filters.

Agar↗

PubMed1976

Aldolases of the lactic acid bacteria. Demonstration of immunological relationships among eight genera of Gram positive bacteria using an anti-pediococcal aldolase serum.

Reciprocal qualitative and quantitative immunological experiments employing an anti-Pediococcus cerevisiae aldolase serum confirmed many of the interspecific relationships demonstrated previously among lactic acid bacteria with antisera prepared against the Streptococcus faecalis fructose diphosphate aldolase. The extent of immunological relatedness observed between the Lactobacillus and Pediococcus aldolases was markedly gses indicating that the pediococci share closer phylogenetic ties with the rod-shaped lacotbacilli than with their spherical counterparts in the streptococci. In addition to confirming the existence of definitive, but distant, relationships between the lactic acid bacteria and certain gram positive nonsporeforming anaerobes, immunological cross-reactivity was also demonstrated between the pediococcal aldolases and those of Aerococcus viridans.

Biological Evolution↗

PubMed2004

Isolation, structural elucidation and in vitro activity of 2-acetyl-2-decarboxamido-oxytetracycline against environmental relevant bacteria, including tetracycline-resistant bacteria.

2-Acetyl-2-decarboxamido-oxytetracycline (ADOTC) is a major impurity of oxytetracycline (OTC) produced as a side product during fermentation. ADOTC was isolated from OTC and other impurities using preparative HPLC. The preparative column was an Xterra MS, C18 chromatographic column (100 mm x 19 mm i.d., 5 microm), and the mobile phase contained methanol-water (27:73 (v/v)) with 0.08 M formic acid added. The flow rate was 9.0 ml/min. It was possible to isolate few milligram ADOTC in a day. The compound was unambiguously identified using NMR and MS-MS. The anti-microbial activity against activated sludge bacteria was determined giving a potency of only 3% of that of OTC. With tetracycline-resistant bacteria, no anti-microbial activity was observed, indicating a mode of action similar to that of OTC.

Animals↗

PubMed2004

Antagonistic activity of lactic acid bacteria as probiotics against selected bacteria of the Enterobaceriacae family in the presence of polyols and their galactosyl derivatives.

Probiotic lactic acid bacteria were grown on erythritol, xylitol, sorbitol or lactitol and produced various derivatives: gal-erythritol, gal-xylitol, and gal-sorbitol as prebiotics. Galactosyl derivatives of erythritol, xylitol and sorbitol were metabolised by Lactobacillus spp. This resulted in their antagonistic activity against the test microflora. No activity was observed in the presence of xylitol and erythritol. Gal-sorbitol obtained by enzymatic transglycosylation from lactose had the same abilities of inducing the antagonistic activity of lactic acid bacteria that lactitol had.

Biotechnology↗

PubMed2003

Chloramphenicol and florfenicol susceptibility of fish-pathogenic bacteria isolated in France: comparison of minimum inhibitory concentration, using recommended provisory standards for fish bacteria.

AIM: To investigate the distribution of antimicrobial resistance to phenicols in the fish pathogenic bacteria Aeromonas salmonicida, motile Aeromonas, Yersinia ruckeri, lactic bacteria and the nutritionally fastidious Flavobacterium psychrophilum. The last species was screened on two media (diluted Mueller-Hinton and peptone-enriched Anacker and Ordal), both supplemented with horse serum. METHODS AND RESULTS: Minimal inhibitory concentration (MIC) assessment, using the agar dilution method according to proposed standards, confirmed that chloramphenicol resistance was more frequent and expressed at higher levels than florfenicol resistance. A significant resistant population, highlighted by the bimodal distribution of MICs, was detected only for chloramphenicol in A. salmonicida. No link could be found with the geographical origin of the isolates or fish species. Other cases of resistance appeared randomly distributed or related to the natural properties of the bacterial species. Although the two media used for testing F. psychrophilum resulted in comparable performances in dilution methods, Anacker and Ordal was more adapted to disc diffusion tests. CONCLUSION: Despite wide use, resistance to florfenicol does not seem to occur frequently in French fish farms. SIGNIFICANCE AND IMPACT OF THE STUDY: It is important to maintain a surveillance, as development of florfenicol resistance has occasionally been documented. For this purpose, and for the species studied in this work, the recently proposed standards appear generally well-adapted.

Animals↗

PubMedDate not supplied

hrp genes of Pseudomonas solanacearum are homologous to pathogenicity determinants of animal pathogenic bacteria and are conserved among plant pathogenic bacteria.

The majority of bacterial plant diseases are caused by members of three bacterial genera, Pseudomonas, Xanthomonas, and Erwinia. The identification and characterization of mutants that have lost the abilities to provoke disease symptoms on a compatible host and to induce a defensive hypersensitive reaction (HR) on an incompatible host have led to the discovery of clusters of hrp genes (hypersensitive reaction and pathogenicity) in phytopathogenic bacteria from each of these genera. Here, we report that predicted protein sequences of three hrp genes from Pseudomonas solanacearum show remarkable sequence similarity to key virulence determinants of animal pathogenic bacteria of the genus Yersinia. We also demonstrate DNA homologies between P. solanacearum hrp genes and hrp gene clusters of P. syringae pv. phaseolicola, Xanthomonas campestris pv. campestris, and Erwinia amylovora. By comparing the role of the Yersinia determinants in the control of the extracellular production of proteins required for pathogenicity, we propose that hrp genes code for an export system that might be conserved among many diverse bacterial pathogens of plants and animals but that is distinct from the general export pathway.

Amino Acid Sequence↗

PubMed1977

Isolation of bacteria, transforming bacteria, and bacteroids from soybean nodules.

Postnuclei supernatant of soybean (Glycine max cv. Chippewa 64) nodule homogenate was fractionated by stepwise sucrose density gradient centrifugation into supernatant, endoplasmic reticulum and mitochondria, and three distinct bands with 1.22, 1.25, and 1.27 g/cm(3) of peak density. Based on their enzymic activities, composition of electron transport components, and ultrastructural characteristics, the lightest band appears to be the mature bacteroids; the intermediate band the transforming bacteria; and the heaviest, the bacteria. The isolation procedure separates nodule symbionts into different functional and developmental fractions, and it may be a valuable tool for studies involving development, regulation, and senescence of bacteroids in the nodule.

Journal Article↗

PubMed1988

Competition for hydrogen between sulphate-reducing bacteria and methanogenic bacteria from the human large intestine.

Sulphate-reducing activity in human faecal slurries was followed by measuring sulphide production. Sulphate-reducing bacteria (SRB) were found to outcompete methanogenic bacteria (MB) for the mutual substrate hydrogen in faecal slurries from methane- and non-methane-producing individuals mixed together. When molybdate (20 mmol/l) was added to these slurries, sulphate reduction was inhibited and methanogenesis became the major route of electron disposal. Sulphide production was stimulated by the addition of 20 mmol/l sulphate in non-methanogenic but not in methanogenic slurries. In methanogenic slurries that contained the methanogen inhibitor 2-bromoethanesulphonic acid (BES), hydrogen accumulated whilst sulphide levels were unaffected, confirming the absence of SRB in methanogenic faeces. The addition of nitrate (10 mmol/l) to faecal slurries completely inhibited methanogenesis but only slightly reduced sulphate reduction. The sulphated mucopolysaccharides, chondroitin sulphate and mucin, strongly stimulated sulphide production in non-methanogenic faecal slurries only, suggesting that these substances may be a potential source of sulphate in the large gut.

Alkanesulfonates↗

PubMed1990

Influenza A virus potentiates bacteria-induced histamine release. Examination of normal individuals and patients allergic to bacteria.

Influenza A virus was found to enhance basophil histamine release induced by Escherichia coli, Salmonella enteritidis, Staphylococcus aureus, Streptococcus pneumoniae and Streptococcus sanguis, but did not per se release histamine. This potentiating effect of the virus was seen both when the bacteria-induced mediator release was IgE-dependent (i.e. patient allergic to bacterium) and when the bacterium caused histamine release by a non-immunological mechanism independent of IgE (putative sugar-lectin mediated). Also histamine release induced by other immunological and non-immunological stimuli, such as anti-IgE, calcium ionophore or agarose beads was enhanced in the presence of the virus. The potentiating effect of the virus on bacteria-induced mediator release might be of importance for the conversion from latent to manifest asthma in upper respiratory tract infections.

Adult↗

PubMed1993

Growth of syntrophic propionate-oxidizing bacteria with fumarate in the absence of methanogenic bacteria.

Oxidation of succinate to fumarate is an energetically difficult step in the biochemical pathway of propionate oxidation by syntrophic methanogenic cultures. Therefore, the effect of fumarate on propionate oxidation by two different propionate-oxidizing cultures was investigated. When the methanogens in a newly enriched propionate-oxidizing methanogenic culture were inhibited by bromoethanesulfonate, fumarate could act as an apparent terminal electron acceptor in propionate oxidation. C-nuclear magnetic resonance experiments showed that propionate was carboxylated to succinate while fumarate was partly oxidized to acetate and partly reduced to succinate. Fumarate alone was fermented to succinate and CO(2). Bacteria growing on fumarate were enriched and obtained free of methanogens. Propionate was metabolized by these bacteria when either fumarate or Methanospirillum hungatii was added. In cocultures with Syntrophobacter wolinii, such effects were not observed upon addition of fumarate. Possible slow growth of S. wolinii on fumarate could not be demonstrated because of the presence of a Desulfovibrio strain which grew rapidly on fumarate in both the absence and presence of sulfate.

Journal Article↗

PubMed1999

Sulfonates as terminal electron acceptors for growth of sulfite-reducing bacteria (Desulfitobacterium spp.) and sulfate-reducing bacteria: effects of inhibitors of sulfidogenesis.

This study demonstrates the ability of Desulfitobacterium spp. to utilize aliphatic sulfonates as terminal electron acceptors (TEA) for growth. Isethionate (2-hydroxyethanesulfonate) reduction by Desulfitobacterium hafniense resulted in acetate as well as sulfide accumulation in accordance with the expectation that the carbon portion of isethionate was oxidized to acetate and the sulfur was reduced to sulfide. The presence of a polypeptide, approximately 97 kDa, was evident in isethionate-grown cells of Desulfitobacterium hafniense, Desulfitobacterium sp. strain PCE 1, and the two sulfate-reducing bacteria (SRB)-Desulfovibrio desulfuricans IC1 (T. J. Lie, J. R. Leadbetter, and E. R. Leadbetter, Geomicrobiol. J. 15:135-149, 1998) and Desulfomicrobium norvegicum; this polypeptide was not detected when these bacteria were grown on TEA other than isethionate, suggesting involvement in its metabolism. The sulfate analogs molybdate and tungstate, effective in inhibiting sulfate reduction by SRB, were examined for their effects on sulfonate reduction. Molybdate effectively inhibited sulfonate reduction by strain IC1 and selectively inhibited isethionate (but not cysteate) reduction by Desulfitobacterium dehalogenans and Desulfitobacterium sp. strain PCE 1. Desulfitobacterium hafniense, however, grew with both isethionate and cysteate in the presence of molybdate. In contrast, tungstate only partially inhibited sulfonate reduction by both SRB and Desulfitobacterium spp. Similarly, another inhibitor of sulfate reduction, 1,8-dihydroxyanthraquinone, effectively inhibited sulfate reduction by SRB but only partially inhibited sulfonate reduction by both SRB and Desulfitobacterium hafniense.

Adenosine Triphosphate↗

PubMed1967

Drug resistance of enteric bacteria. IX. Distribution of R factors in gram-negative bacteria from clinical sources.

Many isolates belonging to the Enterobacteriaceae were collected in 1965 from the inpatients at geographically scattered hospitals in Japan. Among 2,650 Shigella strains examined, 58.4% were found to be drug-resistant; 95.0% of these resistant strains were multiply resistant. Among 434 resistant strains examined, 81% carried R factors that were transferable by cell-to-cell contact. Of 160 isolates of other enteric bacteria, drug-resistant strains included 84.2% of the Escherichia coli, 93.0% of the Klebsiella, and 90.0% of the Proteus cultures. Among these resistant strains, 70.3% of the E. coli, 66.7% of the Klebsiella, and 52.0% of the Proteus were multiply resistant. Of these resistant strains, 84.0% of the E. coli, 88.0% of the Klebsiella, and 50.0% of the Proteus strains carried R factors. These results indicate that R factors are widespread among gram-negative bacteria of clinical significance.

Anti-Bacterial Agents↗

PubMed1986

Incidence of methanogenic bacteria in a sigmoidoscopy population: an association of methanogenic bacteria and diverticulosis.

This study determined the incidence and concentration of methane-producing bacteria in tap water enema samples of 130 individuals taken before sigmoidoscopy. The number of subjects classified in five major colonic groups were as follows: normal colon 36, diverticulosis 57, inflammatory bowel disease 11, colon polyps 34, and colon cancer 11. Some patients were placed in more than one category. Ninety four of the subjects or 72% had methanogenic bacteria ranging in concentration from 6 to about 3 X 10(10)/g dry weight of faeces. The predominant methanogen in all groups was Methanobrevibacter smithii. Chi-square analysis showed that the incidence of methanogens in concentrations of 10(7)/g dry weight of faeces or greater in patients with diverticulosis (58%) was significantly greater than in normal patients (25%). High methanogen concentrations are associated with excretion of methane in the breath.

Adult↗

PubMed2000

Volatile sulfur production by pig cecal bacteria in batch culture and screening inhibitors of sulfate reducing bacteria.

We studied the effects of specific inhibitors of methanogenesis (2-bromoethane sulfonate, BES) and sulfate reduction (sodium molybdate) on volatile sulfur production in batch cultures of pig cecal bacteria. The volatile sulfur concentration in headspace gas was determined by flame-photometric detector gas chromatography. BES stimulated production of hydrogen sulfide (H2S) and methanethiol, and sodium molybdate completely inhibited the production of these volatile sulfur compounds. The results indicated that dissimilate sulfate reduction is mainly responsible for volatile sulfur production in the hindgut. Therefore the extracts of herbs, food colors, and aroma chemicals were tested for their inhibitory effects on H2S production by a dissimilatory sulfate-reducing bacteria. Desulfovibrio desulfuricans DSM642. H2S was measured by the chromatography of the headspace gas, using a flame photometric detector. Of 306 herbal extracts tested, 69 extracts from 38 herbs inhibited H2S production at 1.0 mg/mL. Sisymbrium officinale (hedge mustard) was the most potent inhibitor. Six pigments inhibited H2S release. Erythrosine and rose bengal showed inhibitory effects at 0.01 mg/mL. Peppermint oil and 96 aroma chemicals were assayed for their effects on H2S release. Thirty-two aroma chemicals suppressed H2S production at 0.1 mg/mL, and camphene, 1-decanol, and 2-nonanone were effective at 0.01 mg/mL.

Alkanesulfonic Acids↗

PubMed1978

Effects of anaerobic bacteria on Eimeria tenella infection in bacteria-free, monofloral, and conventional chickens.

Bacteria-free, monofloral, and conventional chicks were infected with Eimeria tenella. Monofloral chicks were established by inoculating birds in several gnotobiotic isolators with a single species of Escherichia coli or with one of three Bacteroides sp. isolates (No. 157, No. 202, or No. 366). Daily weights of individual birds were recorded for six days post-infection (PI). On Day 6 PI all birds were sacrificed and cecal lesions were scored. Conventional, infected birds lost weight on days 5 and 6 PI and showed severe lesions. Birds maintained as monofloral groups with isolates of Bacteroides sp. No. 157, No. 202 or E. coli showed equally severe lesions, but lost weight only on day 6 PI. Conventional, uninfected birds with no lesions, birds infected with Bacteroides sp. isolate No. 366 with mild lesions, and bacteria-free birds with mild to severe coccidial lesions all continued to gain weight on each day post-infection.

Animals↗

PubMed1977

[Equipment to find odour compounds, produced by bacteria in drinking water. I. Comparison of a bacteria produced odour compound with a chemical reference substance and a simple method for getting and concentrating biogenic odour compounds (author's transl)].

An increase in using surface water and bank filtration processes as raw water for drinking water production sometimes gave rise to problems of bad taste and odour. Some of these odourous compounds may be produced by bacteria, especially Streptomyces species. They are able to pass active carbon filters and therefore are a problem as well in raw water as in treated water. Biogenic odourous compounds often are soluble in water, that means they are present without being fixed to the bacteria cell. Human nose is able to percieve even dilutions of about 10(-9). If a bacterial produced substance is compared with an equal smelling chemical substance such as Isoborneol, also diltuions of 10(-9) may be smelt. Gas-chromatography only detects concentrations up to 10(-5), so the nose is much more efficient.

Filtration↗