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PubMed2002

Breath hydrogen concentrations of cats given commercial canned and extruded diets indicate gastrointestinal microbial activity vary with diet type.

Breath hydrogen (H(2)) concentration, an indicator of intestinal microbial abundance, was determined in cats given purified and commercial canned and dry-type diets. Before measurements, the cats were fed diets for more than 2 wk and habituated to a daily feeding interval of 4 hr. Breath H(2) concentrations were determined before a meal (approximately 25% daily MER) and then every 20 min for 8 hr or hourly for 10 hr. A clear rise above baseline breath H(2) concentrations, 1-2 ppm, was not observed in 6 males given a casein-based purified diet. A mean (+/- SEM) peak breath H(2) concentration of 22 +/- 4 ppm was observed in 6 other males, 6.3 hr after ingestion of a canned diet with protein, fat, and carbohydrate proportions similar to those of the purified diet. Area-under-the-curve (AUC) breath H(2) responses to the canned diet were substantially greater (p < 0.05) than responses observed in 5 males given a dry-type diet, but similar to responses observed in 12 males given an uncooked form of the canned diet. Gamma irradiation to inactivate microbes in the uncooked diet did not affect the breath H(2) response. Breath H(2) responses to 2 other canned and 2 other dry-type diets were evaluated in 8 adult females using a 4 x 4 Latin-square design. Peak and AUC responses to the canned diets were similar but approximately 2 times greater (p < 0.05) than responses to the dry diets. Relative to dry-type diets, canned diets induce a substantially greater breath H(2) production, and therefore appear to support a greater intestinal microbial population.

Animal Feed↗
PubMed1997

A clinical and microbiological evaluation of systemic and local metronidazole delivery in adult periodontitis patients.

The present study describes results on selected clinical and microbiological parameters obtained by treatment with local (Elyzol) and systemic (Flagyl) use of metronidazole alone and/or mechanical subgingival debridement in adult periodontitis. Patients were randomly divided into local and systemic treatment groups each comprising 5 individuals in each of whom 4 sites (one site/ quadrant) with a probing depth of > or = 5 mm were selected and treated with separate treatment modalities. The overall treatment design provided 6 different test groups. Groups of quadrants received: (1) scaling and root planing; (2) local metronidazole treatment; (3) systemic metronidazole treatment; (4) local metronidazole combined with scaling and root planing; (5) systemic metronidazole combined with scaling and root planing; (6) no treatment. The microbiological and clinical effects of treatment modalities were monitored over a period of 42 days. All treatments resulted in clinical improvements (gingivitis, probing pocket depth, attachment level) except for the untreated group. Parallel to the clinical changes, all treatments reduced the number of total bacteria and proportions of obligately anaerobic microorganisms. Although both of the combined treatment groups responded to therapy with better resolution of infection that the pure mechanical and pure metronidazole treatments, local metronidazole in combination with scaling and root planing seems to be more effective in terms of producing both clinical and microbial improvements.

Administration, Oral↗
PubMed2003

Survival of lactococci during passage through mouse digestive tract.

One of the important properties of probiotics is the ability to survive in the intestine. There have been few studies on the probiotic property of lactococci, since they are formally not considered to be natural inhabitants of the intestine. To evaluate lactococci as probiotic bacteria, we investigated their ability to survive during gastric transit by in vitro and in vivo tests. When exposed to an in vitro simulated gastrointestinal environment, such as low pH and bile, only Lactococcus lactis subsp. lactis bv. diacetylactis N7 showed a moderate survival rate among the four strains tested. The tested strains were orally administered to mice, and intestinal passage of the ingested strains was monitored by two methods: antibiotics and PCR. Viable cells of strain N7 were recovered from feces within 24-48 h after administration but not at 72 h. Lactococcus lactis subsp. cremoris ATCC 19257, which had a poor survival rate in vitro test, was also detected at 12 h but not at 24 h. These results indicate that lactococci can reach the mouse intestine alive, but not colonize it. If administered daily, viable strain N7 may exist continuously in the intestine. The effect of strain N7 on intestinal microbial balance and on animal health will be the subject of a further study.

Animals↗
PubMed1995

The diagnostic value of amniotic fluid Gram stain examination and limulus amebocyte lysate assay in patients with preterm birth.

The purpose of this study was to determine the value of Gram stain examination and Limulus amebocyte lysate (LAL) test in the detection of intraamniotic infection. Ninety women with preterm labor and intact membranes (n = 55) or preterm premature rupture of membranes (PROM) (n = 35) who delivered prematurely were included in the study. Amniotic fluid was cultured for aerobic and anaerobic bacteria as well as for mycoplasmas. Amniotic fluid analysis included Gram stain examination and limulus amebocyte lysate tests. The prevalence of positive amniotic culture was 32.2% (29/90) and the most common isolate was Ureaplasma urealyticum. Patients with preterm PROM group had a higher rate of infection than those with preterm labor and intact membranes 57.1% (20/35) vs. 16.4% (9/55), respectively (p = 0.0001). We found a lower gestational age at delivery and lower mean birth weight in neonates born to mothers with a positive amniotic fluid culture than those with negative amniotic fluid culture. The combined use of Gram stain examination and LAL test had a sensitivity and specificity of 51.7% (15/29) and 95.1% (58/61) respectively for the detection of positive amniotic fluid culture. We conclude that Gram stain examination and LAL test are rapid, simple and specific tests that can be used to detect microbial invasion of the amniotic cavity except in patients with mycoplasmas infections.

Adult↗
PubMedDate not supplied

[Diagnostic suspension for detection of the infective agent of tularemia].

The matrix for obtaining silica-based diagnosticum was selected, its activation with surfactant was optimized and its immobilization with tularemia immunoglobulins was carried out. In the glass suspension agglutination test (SAT) the sensitivity of the diagnosticum was 3.125 x 10(6) to 6.25 x 10(6) microbial cells per ml; the duration of SAT, including the evaluation of its results, was 1-5 minutes.

Agglutination Tests↗
PubMed2005

[Molecular analysis of the microbial communities of the Dagang Kongdian flooding bed oilfield].

Both PCR-TGGE (temperature gradient gel electrophoresis, TGGE) and 16S rRNA gene clone library construction were used to comparatively analyze the microbial communities of a water injection well (WW) and an oil well (OW) in Dagang oilfield. TGGE analysis of the PCR amplified 16S rDNA V3 region products showed great difference between these two microbial communities. Six major bands were detected in the TGGE profile of the WW sample, while only one predominant band in the OW sample was found. Two 16S rRNA gene clone libraries were also constructed, and 108 and 50 clones were selected from the WW and OW library respectively for amplified ribosomal DNA restriction analysis (ARDRA). 33 taxanomic operational units (OTUs) were found in the WW library with 6 major OTUs, while only 8 OTUs were found in the OW library with one OTU predominant. The results of TGGE and clone library profiling analysis both indicated that microbial community of the WW had higher diversity than the OW. Sequence analysis of the representative clone of each OTU showed that most bacteria of the WW were affiliated with alpha, beta, and gamma Proteobacteria and Actinobacteria, especially Rhodobacter (47%). Most bacteria of the OW were affiliated with alpha, beta, and gamma Proteobacteria, especially Pseudomonas (62%). Molecular analysis of the microbial diversity in oilfield provides foundation for better application of MEOR (Microbial Enhanced Oil Recovery).

Actinobacteria↗
PubMed2005

Survival and growth of Yersinia enterocolitica strains inoculated in skimmed milk treated with high hydrostatic pressure.

Four human pathogenic strains of Yersinia enterocolitica (serotypes O:1, O:3, O:8, and O:9) were inoculated (7-8 log CFU/ml) in UHT skimmed milk and treated at 300, 400, and 500 MPa for 10 min at 20 degrees C, and then kept at 8 degrees C to assess their evolution for 15 days. Treatments at 400 and 500 MPa caused the highest lethality, generally reaching counts below detection level (1 CFU/ml) in the culture media. At 300 MPa, the most baroresistant serotypes were O:3 and O:8. After 15 days of storage at 8 degrees C, Y. enterocolitica showed growth over 8 log (CFU/ml) in all treatments. Kinetic study of microbial inactivation in skimmed milk was performed with serotype O:8 at 300 MPa, showing a tailing after 35 min of pressure treatment.

Animals↗
PubMed2001

Adequacy of in situ glass slides and direct sand extractions to assess the microbiota within sand columns used for drinking water treatment.

Historically, Cholodny-Rossi buried glass slide techniques have been used to study the microbiota of subsurface environments, yet the bias of such a technique has not been compared against direct sand extraction using modern in situ probing. Over a period of 34 wk, four separate 4-m-deep sand columns receiving raw lake water were examined to compare direct extraction of sand filter biofilm material against in situ glass slide biofilms. Significantly different DAPI direct counts and fluorescent in situ hybridization signals for major phylogenetic groups were observed. Not only were lower proportions (P < 0.001) of EUB338-probed DAPI cells observed on in situ glass slides, but also fewer gamma-Proteobacteria (12%-21%) and more alpha-Proteobacteria (16%-33%) when compared to direct sand extracts. Hence, investigators of the microbial ecology of even simple sand biofilms must consider the inherent biases from "accepted" methods and seek further independent methods to identify those which may be most accurate.

Bacteria↗
PubMed2000

Effects of 0.12% chlorhexidine gluconate on experimental gingivitis in non-human primates: clinical and microbiological alterations.

OBJECTIVE: This study examined the efficacy of 0.12% chlorhexidine gluconate (Peridex) to reduce gingival inflammation in the absence of mechanical hygiene and its effect on the oral microbial ecology in a non-human primate (NhP) model of gingivitis. DESIGN: Twelve NhP were stratified based on existing inflammation into two groups of six NhP per group. Oral hygiene was performed on both groups so as to reach a level of gingival health (BOP < or = 0.3) at the conclusion of the hygiene phase. One group received 30 ml of 0.12% chlorhexidine gluconate twice daily 7 days/week, and a second group received 30 ml of placebo (distilled water colored to match the active) using the same regimen for 10 weeks. MEASUREMENT OUTCOMES: Clinical parameters including plaque (PLI), pocket depth (PD), attachment level (AL), and bleeding on probing (BOP) were evaluated at 2-week intervals. Subgingival plaque samples were collected by paper point at 2-week intervals and cultured for predominant cultivable bacteria. RESULTS: By week 2, there was a difference in BOP between the groups, which reached statistical significance by week 4. This difference in BOP was maintained throughout the course of the study. Chlorhexidine gluconate (0.12%) had no significant effect on PLI, PD, or AL; although PD was greater in the placebo group after week 2 and throughout the study. Microbiologically, at week 4, the treatment group had a reduction in total bacterial counts, as well as Gram positive bacteria, and total black pigmented bacteria, compared to the placebo group. However, only the differences in Actinomyces spp. reached significance. Interestingly, when both groups received only one treatment/day on the weekends (i.e., day 6 and 7), an associated loss of statistically significant differences between the two groups was observed. Additional experiments dosing the non-human primates once daily, 5 days/week yielded no significant differences in clinical parameters, including bleeding, when compared with the placebo group. CONCLUSION: Non-human primates provided a model system of gingivitis for testing antimicrobial agent effects on the subgingival ecology and accompanying inflammatory responses. Chlorhexidine gluconate (0.12%), even in the absence of mechanical hygiene, was effective in inhibiting clinical signs of inflammation, associated with alterations in the subgingival microbial ecology, most notably Actinomyces spp.

Actinomyces↗
PubMed2000

Efficacy of an herbal extract on the microbiological quality of broiler carcasses during a simulated chill.

Protecta II, an herbal extract on an NaCl carrier, was evaluated in a 30-min, 1 C simulated chill for its effectiveness of lowering microbial counts on broiler carcasses. Eighteen broiler carcasses were obtained from a local processing plant after final wash but before chill, placed into an insulated container, and transported to the research facility for treatment. Six plant run controls (PRC) were immediately bagged on return to the pilot plant, and a whole-carcass rinse was performed. The remaining carcasses were subjected to a 30-min chill (1 C) in tap water or a 2% solution of Protecta II, (n = 6 per treatment). After treatment, carcasses were rinsed with tap water and subjected to the whole-carcass rinse procedure. All rinse diluents were microbiologically analyzed for total aerobes, coliforms, generic Escherichia coli, and Campylobacter. Six replications were analyzed on 6 different d for a total 36 carcasses per treatment and 36 PRC. The PRC carcasses had 3.7, 2.5, 2.1, and 2.0 log10 cfu/mL for total aerobes, coliforms, generic E. coli, and Campylobacter. Water treatment significantly reduced counts (2.6, 1.4, 0.7, and 0.9 log10 cfu/mL, respectively) when compared with the PRC. Protecta II treatment significantly reduced counts (P < 0.01) even further to counts of 0.06, 0.04, 0.01, and 0.00 log10 cfu/mL for total aerobes, coliforms, Campylobacter, and E. coli, respectively. Detectable levels of the monitored organisms were 1 cell/mL (log10 0) for the E. coli, coliforms, and total counts and 10 cells/mL (log10 1) for the Campylobacter. Microbial counts for carcasses treated with Protecta II would be considered too low to be detected (<1 cell/mL).

Animals↗
PubMed2003

[Effects of topical application of immunoglobulin yolk on mutans streptococci in dental plaque].

OBJECTIVE: To evaluate the inhibitory effects of topical application of specific immunoglobulin yolk antibodies (IgY) to mutans streptococci on composition of human dental plaque. METHODS: A total of 24 healthy adult volunteers were selected and randomly distributed into three experimental groups. After a supragingival scaling, the subjects were treated with an application of IgY containing spray (test group, n = 9), a 0.15% chlorhexidine(CH) spray(positive control group, n = 9) or a placebo phosphate buffered saline(PBS) spray without any active ingredients(negative control group, n = 6) three times daily for three weeks. Pooled plaque samples from the smooth surfaces of teeth were collected for microbiologic analysis before administration (baseline, day 0), during treatment(days 7, 14 and 21) and after withdrawal of the agents(days 28, 42 and 56) and plaque index were recorded. Microbial cultivation were performed by serially diluting the samples with PBS solution an cultivating the aliquots on mitis salivarius agar(MS) and MS supplemented with bacitracin (MSB) for oral streptococci and mutans streptococci respectively. The number of colony-forming unit (CFU) per plate was counted and the percentage of mutans streptococci per oral streptococci in dental plaque were determined. The effect of IgY on colonization of mutans streptococci were analyzed by an analysis of variance (ANOVA). RESULTS: The plaque indexes remained unchanged, but mutans streptococci in dental plaque was suppressed significantly following a short term(three weeks) application of IgY, and low level of mutans streptococci persisted for at least 5 weeks after withdrawal of IgY. CONCLUSION: The results suggest that the immunization with specific immunoglobulin yolk against mutans streptococci could be useful for long term suppression of mutans streptococci colonization in human dental plaque.

Adult↗
PubMed2005

Resistance of Yersinia enterocolitica, Escherichia coli O157:H7 and natural microflora against acidic conditions and freezing-thawing in fresh sausages.

The resistance of Yersinia enterocolitica O:9, Escherichia coli O157:H7 and natural microflora against lactic acid (LA), ascorbic acid (AA), and freezing-thawing in noninoculated and inoculated fresh sausages was studied. Samples were stored at -18 degrees C for 28 days and thawed in microwave (MW), at room temperature (RT), in refrigerator (R) and under flowing of tap water (F) on days 7, 14, 21 and 28. Plate Count Agar (PCA), Sorbitol Mac Conkey agar (SMC) and Mac Conkey agar (MC) were used for microbial counts. A maximal reduction of 1.57 log in mesophilic aerobes and no significant changes in total and fecal coliform levels with respect to the initial counts in natural microflora were observed along storage. In inoculated fresh sausages, reductions of 1.37 log on PCA and 2.17 log on SMC were obtained in E. coli O157:H7 populations as compared to the control groups on day 0. Similarly, reductions of 1.69 log on PCA and 2.79 log on MC as compared to the initial level were observed in counts of Y. enterocolitica inoculated samples. Salmonella Anatum, P. aeruginosa, Y. enterocolitica B1A O:7,8-8-8,19 and E. coli non O157:H7 strains were recovered from the natural microflora by enrichment techniques. Thawing in refrigerator was more frequently related to the best reductions of total mesophilic aerobe, E. coli O157:H7 and Y. enterocolitica O:9 counts than the other thawing methods. Reductions of microbial populations observed in LA treated samples were similar to those observed in AA treated samples. Although the acidic and freezing treatments might reduce the microbial levels in natural microflora of fresh sausages, they appeared to be ineffective in the total elimination of high inocula of pathogens like E. coli O157:H7 and Y. enterocolitica O:9.

Ascorbic Acid↗
PubMed2005

Microbial diversity in production waters of a low-temperature biodegraded oil reservoir.

Microbial communities in two production waters of a low-temperature and low-salinity petroleum reservoir in Canada were examined using cultural and molecular approaches. The predominant cultivated microorganisms were homoacetogens but sulfate-reducers, acetoclastic methanogens and denitrifiers also gave significant counts. The dominant members of the culturable population were affiliated with the Firmicutes, the "Deltaproteobacteria", the "Epsilonproteobacteria", the Spirochaetes and the Euryarchaeota. 16S rRNA gene clone libraries were also constructed from the total DNA collected from production waters. The bacterial library was entirely composed by a single phylotype related to Arcobacter. The archaeal phylotypes were generally very closely related to members of the orders Methanosarcinales and Methanomicrobiales. Consistent with earlier observations, our data suggest that methanogenesis is a dominant terminal process in the reservoir. Moreover, the cross-evaluation of culture-dependent and -independent techniques also indicates that, contrary to most studies, both acetoclastic and lithotrophic methanogens may be involved in this process. This first investigation of the microbial diversity in a non water-flooded low-temperature and low-salinity petroleum reservoir expands substantially our knowledge of the extent of microbial diversity and highlights the complexity of microbial communities involved in the oil field food chain.

Alberta↗
PubMed2005

Effect of inoculum size on the combined temperature, pH and aw limits for growth of Listeria monocytogenes.

The growth/no growth responses of Listeria monocytogenes inoculated at four levels (0.90, 2.58, 4.20 and 6.81 log cfu/well; 300 microl medium/well) into tryptic soy broth (TSB) were monitored at different combinations of temperature (4 to 30 degrees C), pH (3.76 to 6.44) and aw (0.888 to 0.997) for 60 days. The study was conducted in 96-well microtiter plates and growth was monitored visually and by recording the turbidity of the medium with an automated microplate reader. The growth limits of the pathogen and hence the position of the growth boundary were found to be affected by the size of the inoculum. For example, at 25 degrees C and aw 0.997 the minimum pH values that allowed growth were 4.45 and 3.94 for inoculum levels of 0.90 and 6.81 log cfu/well, respectively. Similarly, at 25 degrees C and pH 6.44 the minimum aw values where growth was observed ranged from 0.900 to 0.928 depending on the inoculum level. The results showed that at temperatures from 10 to 30 degrees C the difference in the growth limits between the tested inoculum levels was higher in environments where a single factor (pH or aw) was inhibitory than in environments where pH and aw together were inhibitory. The data were used to develop a growth/no growth interface model for each inoculum level tested, using logistic polynomial regression. The concordance indices of the models ranged from 99.8% to 99.9% and showed a good fit to the observed data in all models. This study indicates the importance of inoculum size for microbial growth initiation and provides quantitative data that show how the combinations of hurdles which prevent growth vary with inoculum size.

Colony Count, Microbial↗
PubMed2005

Trichloroethylene (TCE) removal in a single pulse suspension bioreactor.

This work describes TCE biotic removal in a single-pulse bioreactor under aerobic conditions. Activated sludge from a wastewater-treatment plant was used for inoculation of the cultivator. The experiment focused on a more detailed verification of microbial composition of mixed heterotrophic culture during pulsed phenol dosage. Attention was given to suppressing eucaryotic organisms, particularly yeasts and fungi, by the addition of cycloheximide. The TCE-removal capacity of the heterotrophic culture, described by kinetic tests, was dependent on pulsed phenol injection and on cyclic addition of phenol and TCE. Maximum TCE degradation was determined in a batch test. It was found that the addition of cycloheximide (an antibiotic against propagation and growth of fungi and yeast) increased the TCE degradation activity of the mixed microbial suspension. A certain residual amount of TCE remained in some of the experiments.

Antifungal Agents↗
PubMed2001

Campylobacter, Salmonella, Shigella and Escherichia coli in live and dressed poultry from metropolitan accra.

This study on the microbiology of chicken assessed a total of 97 live birds from three selected farms and 87 carcasses/chicken parts from two supermarkets, two open markets and one wholesale outlet (cold store) in the Accra metropolis. Campylobacter spp. were isolated from 14 (14.4%) gut contents of live birds from three farms. None of the frozen birds were positive for Campylobacter spp. These isolates were sensitive to most common antibiotics but not to ampicillin and tetracyclines. Salmonella spp. were isolated from 7 (7.2%) gut contents and 13 (6.8%) carcasses and were resistant to erythromycin. cefotiam, penicillin, ampicillin and cefadroxil. Samonella spp. had varied susceptibilities to nalidixic acid, chloramphenicol and minocyclin. No Shigella spp. was isolated from any of the live birds but 6 (6.9%) of imported chicken samples from the cold store and two markets were positive. Fosfomycin and chloramphenicol were the only antibiotics effective against these isolates. Twelve different Escherichia coli serovars were identified from the total of 21 positive samples. These, in order of magnitude isolated, are E. coli 0158 (14.3%), 0125 (14.3%), 025 (9.5%), 028ac (9.5%), 0159 (9.5%). 015 (9.5%), 0126 (9.5%), 063 (4.8%), 0143 (4.8%), 026 (4.8%), 078 (4.8%), 0164 (4.8%). Cefadroxil, ampicillin, penicillin, cefotiam, tetracycline and erythromycin were ineffective against all strains of E. coli isolated. Minocyclin was effective against all strains with the exception of E. coli 0159, 025, 0164 and 063, which were moderately susceptible. All strains with exception of E. coli 0164 were susceptible to fosfomycin. Nalidixic acid, chloramphenicol, kanamaycin, ceftrioxone and amoxycillin all showed varied effectiveness against the strains isolated. It is concluded that imported and locally produced chicken is a potential source of multiple-antibiotic-resistant enteropathogenic bacteria. Measures to improve the microbial quality of chicken are discussed.

Animals↗
PubMed2001

A new in vitro model for the study of microbial microleakage around dental restorations: a preliminary qualitative evaluation.

AIM: The aim of this study was to develop an in vitro model to replicate microbial microleakage at a tooth/ restoration interface using a constant depth film fermentor (CDFF). METHODOLOGY: Amalgam restorations were placed in machined bovine dentine cylinders and sealed externally with varnish, leaving a 1-mm perimeter exposed around the tooth/restoration interface. The dentine cylinders were housed in a CDFF and 300-microm thick microcosm dental plaques were grown over their exposed surfaces. The biofilms were maintained with a mucin-containing artificial saliva for up to 8 weeks. Cylinders were aseptically removed from the CDFF (at 1, 2, 4, & 8 weeks) and surface-decontaminated with validated protocols prior to splitting and sampling of apposing amalgam and dentine surfaces. Scanning electron microscopy (SEM) was used to ascertain the position and structure of the bacterial aggregates. Bacterial viability was determined by vital staining of the bacteria in situ. RESULTS: At all sampling times, SEM showed cocci, rods and filaments on both amalgam and dentine surfaces; some originated as cascades from the surface biofilm and extended into the tooth/restoration microspace. Vital staining showed the majority of bacteria from both dentine and amalgam surfaces to be viable. CONCLUSION: This preliminary investigation showed that the CDFF may be a valuable tool for the in vitro study of the dynamics of microbial microleakage around dental restorations.

Animals↗