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Results for “Total Microbial Load”

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At least 19 recordsLinked to original sources

PubMed2006

Microbial load, acidity, lipid oxidation and volatile basic nitrogen of irradiated fish and meat-bone meals.

Experiments were carried out to study the effect of different doses of gamma irradiation (0, 5, 10, 15 and 20 kilo gray; kGy) on some nutritive components and chemical aspects pertaining to quality of fish meal and meat-bone meal. The radiation doses required to reduce the total microbial load and Salmonella sp. one log cycle (D(10)) in fish meal and meat-bone meal were determined. Results indicated that gamma irradiation of fish meal and meat-bone meal with 5-20 kGy doses had no effects on the total acidity values but increased the values of lipid oxidation and total volatile basic nitrogen. D(10) of total microbial load and Salmonella sp. were 833 and 313 Gy for fish meal and 526 Gy and 278 Gy for meat-bone meal, respectively. It can be concluded that radiation processing could be employed in the recycling of fish and meat-bone meals by using them as feedstuffs in poultry diets with no fear of losing their nutritive components.

Animal Feed↗

PubMedDate not supplied

A comparative, qualitative and quantitative antimicrobial efficacies of mouthrinses containing chlorhexidine gluconate and essential oils.

A project was launched to evaluate and compare antimicrobial efficacy of Hexidine and Listerine over placebo in 10 day human experimental gingivitis study. A rigid study schedule for subject compliance spanning well over 3 months was sorted out and volunteers recruited for study rinsed all the 3 assigned mouthrinses containing (a) chlorhexidine gluconate, (b) "essential oils" and (c) flavoured distilled water one after the other at certain prefixed intervals. After 10 days of assigned mouthrinse regimen, where the assigned mouthrinse was the only method practiced by the volunteers for oral hygiene, Supragingival Plaque was quantitatively and qualitatively assayed. Qualitatively supragingival plaque was assayed by Gram staining (Direct smear and Thioglycollate Broth) and growth characteristics i.e; Aerobic, Microaerophilic and Anaerobic growth was noted. Quantitatively plaque was assayed by calculating total microbial load per tooth by preparing Mafarland Nephelometer standard and Spectrophotometric analysis. It is concluded that Hexidine and Listerine exert similar antimicrobial efficacy in 10 days experimental gingivitis study. Hexidine and Listerine exert their antimicrobial influence through reduction of total Aerobes and Anaerobes reducing total microbial load per tooth by 58% and 53% respectively as compared to placebo.

Adult↗

PubMed2025

Uncertainty Modeling Outperforms Machine Learning for Microbiome Data Analysis.

Microbiome sequencing measures relative rather than absolute abundances, providing no direct information about total microbial load. Normalization methods attempt to compensate, but rely on strong, often untestable assumptions that can bias inference. Experimental measurements of load (e.g., qPCR, flow cytometry) offer a solution, but remain costly and uncommon. A recent high-profile study proposed that machine learning could bypass this limitation by predicting microbial load from sequencing data alone. To evaluate this claim, we assembled mutt, the largest public database of paired sequencing and load measurements, spanning 35 studies and over 15,000 samples. Using mutt, we show that published machine learning models fail to generalize: on average they perform worse than a naive baseline that always predicted the training set mean. These failures stem from covariate shift-limited shared taxa between studies, differences in community composition, and differences in preprocessing pipelines-that silently derail model inputs. In contrast, Bayesian partially identified models do not attempt to impute microbial load, but instead propagate scale uncertainty through downstream analyses. Across 30 benchmark datasets, Bayesian partially identified models consistently outperformed normalization and machine learning approaches, providing a principled and reproducible foundation for microbiome inference.

16S rRNA-seq↗

PubMedDate not supplied

Combined host and specific anti-Pseudomonas-directed therapy for Pseudomonas aeruginosa infections in burned mice: experimental results and theoretic considerations.

Four strains of Pseudomonas aeruginosa showed significant variation in the elaboration of the virulence-associated exoproducts, exotoxin A and proteases. These variations appeared to affect the mortality observed when these strains were used to infect burned mice. Further, these variations seemed to influence the efficacy of individual after sepsis treatments designed to (1) reduce total microbial load in the host (HIg treatment), (2) reduce total circulating protease load in the host (alpha 1-PI treatment), or (3) neutralize the specific effects of exotoxin A (antitoxin treatment). Combined treatment, using all of these approaches, was significantly better than individual treatment.

ADP Ribose Transferases↗

PubMed2005

Molecular analysis of microbial diversity in advanced caries.

Real-time PCR analysis of the total bacterial load in advanced carious lesions has shown that the total load exceeds the number of cultivable bacteria. This suggests that an unresolved complexity exists in bacteria associated with advanced caries. In this report, the profile of the microflora of carious dentine was explored by using DNA extracted from 10 lesions selected on the basis of comparable total microbial load and on the relative abundance of Prevotella spp. Using universal primers for the 16S rRNA gene, PCR amplicons were cloned, and approximately 100 transformants were processed for each lesion. Phylogenetic analysis of 942 edited sequences demonstrated the presence of 75 species or phylotypes in the 10 carious lesions. Up to 31 taxa were represented in each sample. A diverse array of lactobacilli were found to comprise 50% of the species, with prevotellae also abundant, comprising 15% of the species. Other taxa present in a number of lesions or occurring with high abundance included Selenomonas spp., Dialister spp., Fusobacterium nucleatum, Eubacterium spp., members of the Lachnospiraceae family, Olsenella spp., Bifidobacterium spp., Propionibacterium sp., and Pseudoramibacter alactolyticus. The mechanisms by which such diverse patterns of bacteria extend carious lesions, including the aspect of infection of the vital dental pulp, remain unclear.

Adult↗

PubMed2002

Microbial load of drinking water reservoir tributaries during extreme rainfall and runoff.

Hygienic and microbiological examinations of watercourses are usually not carried out during heavy rainfall and runoff events. After rainfall or snowmelt, there are often massive increases in turbidity in flooding creeks in mountain ranges, which are frequently interpreted as an indication of microbial contamination. The aim of this study was to quantify the microbial loads of watercourses during such runoff events and to compare these loads with loads occurring during regular conditions. In a 14-month monitoring period we investigated the microbial loads of three tributaries of different drinking water reservoirs. A total of 99 water samples were taken under different runoff conditions and analyzed to determine physical, chemical, bacterial, and parasitic parameters. Thirty-two water samples were considered event samples during nine measuring series. The criteria for events, based on duration and intensity of precipitation, water depth gauge measurements, and dynamics, had been fixed before the investigation for each creek individually. Of the physical and chemical parameters examined, only the turbidity, pH, and nitrate values differed clearly from the values obtained for regular samples. Most of the bacteriological parameters investigated (colony, Escherichia coli, coliform, fecal streptococcal, and Clostridium perfringens counts) increased considerably during extreme runoff events. If relevant sources of parasitic contamination occurred in catchment areas, the concentrations of Giardia and Cryptosporidium rose significantly during events. The results show that substantial shares of the total microbial loads in watercourses and in drinking water reservoirs result from rainfall and extreme runoff events. Consequently, regular samples are considered inadequate for representing the microbial contamination of watercourse systems. The procedures for raw water surveillance in the context of multiple-barrier protection and risk assessment ought to include sampling during extreme runoff situations.

Rain↗

PubMed1971

Resistance to infections in extended space flight.

Although much can be done to minimize the spread of micro-organisms from one individual to another, it is inevitable that an exchange of microflora will occur among individuals in an enclosed space. The chief sources of the microflora will be the respiratory tract, the gastrointestinal tract and the skin. Local care can deal with most problems of the skin, but potential problems in the respiratory and gastrointestinal tract cannot be dealt with as readily. Although many of the common pathogens can be eliminated by pre-flight procedures, the building up of normal flora represents potential hazards of substantial magnitude. The chief limitations of the effects of high concentrations of normal microbial flora are in the variety of host defensive mechanisms. Some of these have been reviewed, and it has been indicated that with respect to the bronchopulmonary defense mechanisms, the major defenses rest in the pulmonary alveolar macrophage system. This system has been shown to be adversely affected by a large variety of environmental circumstances, many of which will be operative in prolonged spaceflight. Similarly in the gastrointestinal tract, the large microbial load represents a source of micro-organisms and of waste products, which represent potential hazards. Methods for minimizing the latter effects include reducing the total microbial load or implanting a monoculture of a desired micro-organism which produces a minimum of the undesirable side effects. The solution to these problems requires sustained effort, and it is likely that solutions when found will have substantial application to medicine and public health in ground-based communities.

Aerospace Medicine↗

PubMed2006

Inactivation of Saccharomyces cerevisiae and polyphenoloxidase in mango nectar treated with UV light.

Fresh mango nectar was processed by UV light at five flow rates (0.073 to 0.451 liter/min) and five UV light doses (75 to 450 kJ/m2) to evaluate total microbial load, Saccharomyces cerevisiae survival, and polyphenoloxidase activity. UV systems containing an inner mercury lamp (254 nm) each with intensity of 25 mW/cm2 were used as germicidal sources. In addition, mango nectar was treated for 15 min at 0.073 and 0.451 liter/min, stored at 3 degrees C, and evaluated periodically for total microbial count, yeast count, color, and polyphenoloxidase activity. The first-order kinetics modeling found that DUV-values in mango nectar ranged from 27.9 to 10.9 min (R2 > 0.950) and 26.0 to 11.8 min (R2 > 0.962) for total microbial count and yeast count, respectively. The maximum log reduction (CFU per milliliter) was 2.71 and 2.94 for total microbial count and yeast count, respectively, after 30 min of UV treatment at 0.451 liter/min. DUV-values ranging from 156 to 204 min were observed for polyphenoloxidase activity. The remaining polyphenoloxidase activity after 30 min of UV treatment at 0.451 liter/min was 19 +/- 4%. Initial microbial load and yeast in stored mango nectar were reduced in the range 2.86 to 3.41 and 1.82 to 1.97 log (CFU/ml) cycles, respectively. No substantial microbial growth was observed prior to 20 days of storage. Averages of 1,055 +/- 32, 803 +/- 32, and 710 +/- 37 enzyme activity units were observed in mango nectar UV processed at 0, 0.073, and 0.451 liter/min, respectively, during the entire storage period. However, mango nectar treated at 0.073 and 0.451 liter/min maintained a yellow and yellow-orange color, respectively, after 26 days of storage.

Catechol Oxidase↗

PubMed1998

Changes in microbiological and physicochemical properties of bee pollen by application of gamma irradiation and ozone treatment.

The effects of gamma irradiation and ozone treatment on microbiological and physicochemical properties of bee pollen were investigated. Gamma irradiation at 7.5 kGy reduced the total microbial loads below detection levels (>10(2) CFU g(-1)), but after ozone treatment of up to 18 ppm for 8 h the total aerobic bacteria were found in concentrations of more than 10(3) CFU g(-1). Physicochemical properties such as amino acid and fatty acid composition, thiobarbituric acid value, mineral content, and pigment were not significantly changed by gamma irradiation, whereas ozone treatment caused significant changes in fatty acid composition, thiobarbituric acid value, and pigment by lipid oxidation and decoloration (P < 0.05).

Amino Acids↗

PubMed1999

The presterilization microbial load on used medical devices and the effectiveness of hydrogen peroxide gas plasma against Bacillus subtilis spores.

OBJECTIVES: To determine the microbial load found on used critical medical devices (5 spinal anesthesia needles, 21 catheters, and 28 sheaths) prior to sterilization and to evaluate the effectiveness of hydrogen peroxide gas plasma against inoculated Bacillus subtilis var globigii (American Type Culture Collection 9372) spores. METHODS: Membrane filter and pour-plate methods were applied to estimate total microbial loads (aerobic and anaerobic, mesophilic and thermophilic, vegetative and spore forms). Spinal anesthesia needles (102 units) and sheath components (61 units) were inoculated with a suspension of B. subtilis spores. After drying, the devices were sterilized with hydrogen peroxide gas plasma. RESULTS: Higher counts of aerobic, mesophilic, and fungal organisms were recovered when the drying period was insufficient. Anaerobic spores were not found in any analyzed presterilization items. The hydrogen peroxide gas plasma effected a 5 to 7 log10-fold reduction in B. subtilis spore counts in well-dried needles and sheath components. CONCLUSIONS: The success of hydrogen peroxide gas plasma sterilization depends mostly on educating the staff to assure well-cleaned and dried reusable medical devices, allowing penetration of the hydrogen peroxide gas plasma into the critical points of the items and providing a reduction in organisms.

Bacillus subtilis↗

PubMed1985

[Rapid method for indirect bacterial determination in minced meat and spices by measurement of carbon dioxide production rates].

A rapid method has been developed for the determination of total microbial count in foods within one hour in the range between 10(5) and 10(9) microorganisms per ml resp. g. This method was developed for microbial analysis of highly contaminated food stuffs, e.g. of minced meat and spices, which are not suitable for indirect determination of total microbial counts by measurement of oxygen consumption rates. The method is based on the measurement of microbially produced CO2 by means of a selective electrode. For that purpose a sample is diluted with a glucose containing suitable nutrient broth and placed into a tightly closable measuring vessel. Substrate-specific correlations between microbial loads (total plate count) and CO2-production rates were determined.

Animals↗

PubMed1996

Number of mutans streptococci or lactobacilli in a total dental plaque sample does not explain the variation in caries better than the numbers in stimulated whole saliva.

For practical reasons the numbers of mutans streptococci (MS) and lactobacilli (LB) in plaque are commonly estimated from saliva samples. The saliva counts are considered to be a reasonable indicator of the entire dentition's total microbial load. However, the value of salivary counts for explaining and predicting caries have been found to be low. There was therefore reason to compare the relationships between caries on the one hand and, on the other, the number of MS or LB in plaque and in saliva, respectively, in order to assess their relative merits for explaining the variation in caries, both in a total material and in subgroups with less favourable oral hygiene. Sixty children aged 14-15 years participated in the study. Caries and plaque were registered and the number of MS and LB was estimated in total plaque and in stimulated saliva samples. The results showed that the number of MS or LB in plaque did not explain the variation in caries to a greater degree than did the salivary counts. For both bacteria the explanatory values increased, as expected, in subgroups with less favourable oral hygiene, but not even at this higher level of explanation was there any difference between plaque and saliva. The LB count was a stronger explanatory variable than the MS count. It was concluded that the number of MS and LB, estimated in total plaque as well as in saliva samples, is not a useful tool in prediction.

Adolescent↗

PubMed1976

Effect of nisin in saturated brine and storage on the quality of dried bolti fish (Tilapia nilotica).

Bolti fish which had been eviscerated and brined in a saturated brine containing 0.5 mg nisin/g of fish for 10, 15 and 20 min, were divided into two parts, one for dehydration and the second for sun-drying. The dried products were packed in polyethylene bags and stored at room temperature for 3 months. The quality attributes were estimated during processing and monthly during storage. Total volatile bases showed a certain increase after salting, drying and throughout storage periods; thiobarbituric acid value gave the same trend, total microbial load showed a slight increase during storage, but coliform bacteria were not present after salting.

Animals↗

PubMed1997

The determination of efficacy of antimicrobial rinses on turkey carcasses using response surface designs.

Chlorine, lactic acid. TSP (trisodium phosphate) and a commercial phosphate blend (Avgard) were evaluated for their potential bactericidal effects on faecally contaminated turkey carcasses. Carcasses were sprayed for 10 s with each bactericide, at various concentrations and pressure combinations, derived from a response surface central composite design. For all the bactericides, variation in pressure had no significant (P > 0.05) effect in reducing either total or coliform counts. Lactic acid at various concentrations showed a significant effect (P < 0.20) in reducing total and coliform counts. The results indicate that lactic acid at 4.25% (w/w) has the potential for reducing the total microbial load and coliforms by more than 95%. Chlorine, TSP and Avgard concentration did not significantly (P > 0.20) affect the microbial load when compared with a water spray, i.e. no bactericide. Preliminary presumptive testing indicated that lactic acid and Avgard had some effect against Salmonella spp. Chlorine and TSP, irrespective of concentration and pressure, were not effective against Salmonella spp. Overall, these findings suggest that lactic acid was the most effective bactericide for reducing microbial contamination and improving the safety of poultry meat.

Animals↗

PubMed2003

A study on microbial diversity in different cultivars of Brassica napus in relation to its wilt pathogen, Verticillium longisporum.

Oilseed rape (Brassica napus) is one of the major oilseed crops in the world but is vulnerable to attack by many pathogens and insect pests. In addition to the host plant genotype, micro-organisms present in the rhizosphere and within plant tissues affect the susceptibility to plant pathogens. While rapid progress has been achieved concerning the concept of plant resistance genes, information on the role of the microbial community in plant protection is less apparent. We have studied the endophytic bacterial populations present in different tissues of oilseed rape and also analysed several cultivars (Express, Libraska, Maluka and Westar), which differ in their susceptibility to the wilt pathogen Verticillium longisporum. The population diversity was studied using agar plating assay, fatty acid methyl ester analysis and functional characterisation of isolated strains. Our work shows that already in the seeds there exists diversity in populations as well as in the total microbial load between two of the four tested cultivars. About 50% of the strains isolated from cultivars Express and Libraska showed moderate to strong direct inhibition of V. longisporum. The diversity of the endophytic flora isolated from oilseed rape and its implications in crop protection are discussed.

Alcaligenes↗

PubMed1973

Studies on the microbial flora in the air of submarines and the nasopharyngeal flora of the crew.

Airborne bacteria surveys in nuclear submarines show that the total microbial load was maintained at satisfactorily low levels during prolonged patrols despite factors which were expected to increase this form of pollution.The isolation rates of Staphylococcus aureus and Neisseria meningitidis from nasal and nasopharyngeal swabs respectively, together with the serum antibody titres to Mycoplasma pneumoniae, before and after patrols suggested that the transmission of these organisms between individuals was not much increased by patrol conditions. The finding of higher numbers of airborne gram-negative rods and bodily contamination by enterobacteria is frequently reported in submersibles but does not appear to cause major outbreaks of illness in nuclear submarine crews.

Actinobacillus↗

PubMed2003

Investigation of single-use versus reusable infectious waste containers as potential sources of microbial contamination.

BACKGROUND: Laws require that infectious waste be segregated from noninfectious waste. Companies certified to dispose of infectious waste offer both reusable and single-use containers. The focus of this study was to determine if there would be a microbiologic advantage to the use of one type of container over another in a burn hospital. METHODS: Monthly swab cultures were taken from the tops of >250 infectious waste containers during 2 years. Bacteria and fungi were identified. In a substudy swab cultures were taken from an area of reusable tops before and after cleaning to evaluate the efficacy of cleaning on both the number and type of microbes present. Infection rates for acute patients were compared before and after control measures were instituted to decrease microbial transfer from infectious waste containers to patients. RESULTS: Cultures taken from reusable boxes when received from the container company showed that >99% were contaminated with bacteria or fungi; most were normal environmental or skin flora, but some cultures showed microorganisms that can be potentially harmful to patients with compromised immunity. Wiping the lids with a phenolic disinfectant decreased both the total microbial load (P <.001) and the variety of microbes present (P <.001). In contrast, only 10% of the incoming single-use boxes showed any contamination. Infection rates dropped from 5.8 to 3.2 per 100 burn patients (P <.05) after the institution of cleaning and other changes made to decrease the possibility of microbial transfer from the infectious waste boxes to the patients. CONCLUSIONS: Upon delivery, significantly fewer single-use infectious waste boxes were contaminated than reusable ones (P <.001). Extra infection control measures were needed when reusable infectious waste boxes were used in areas housing patients with compromised immunity. Facilities need be aware of the possible contamination of reusable infectious waste containers with microorganisms capable of causing nosocomial infections in patients who are compromised.

Burn Units↗

PubMed1993

The association of carious dentin microflora with tissue changes in human pulpitis.

Correlations were sought between the number and type of microorganisms recovered from sampled carious dentin and the cellular responses observed in dental pulpal tissues from a sample of 65 vital, carious teeth extracted from adult humans who had declined the option of tooth restoration. Standardized homogenates of carious dentin were plated using selective and nonselective media under anaerobic and microaerophilic conditions. Pulpal responses were characterized histopathologically on the basis of the nature of the cellular infiltrate and the extent of degenerative changes. A significant association between the number of Prevotella intermedia and Prevotella melaninogenica in carious dentin and extensive, principally mononuclear, inflammatory infiltration was evident despite a high degree of complexity and intersubject variability in the microbial flora. There was no apparent association between other microorganisms or total microbial load and the histopathological category.

Actinomyces↗