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PubMed1988

Water hygiene of two swimming pools: microbial indicators.

The microbiological quality of the water of two swimming pools was evaluated to determine which organisms might be the best indicators of pollution. Membrane filtration gave low numbers of the common indicators of faecal pollution but high counts of the indigenous skin bacteria. As illnesses normally contracted in a swimming pool are mostly those of the skin rather than intestinal, it is suggested that the best indicators of the hygienic condition of water in a swimming pool are staphylococci because of their resistance to disinfection, high numbers in the environment, and ease of recovery.

Bacteria↗
PubMed1993

Bacteriological analysis of high-speed handpiece turbines.

The microbial contamination of handpiece turbines was examined clinically. In 20 handpieces, no bacterial growth was found on any culture from an autoclaved or non-autoclaved handpiece group. But growth occurred in the positive control inoculated with fresh whole human saliva. An adjunctive investigation with saliva substitute showed that oral fluids can contaminate handpiece turbines during simulated clinical treatment.

Colony Count, Microbial↗
PubMed2005

Comparison of kinetic models to describe high pressure and gamma irradiation used to inactivate Vibrio vulnificus and Vibrio parahaemolyticus prepared in buffer solution and in whole oysters.

Comparisons of different models in inactivation kinetics were conducted on data obtained from high-pressure and gamma-irradiation processing. Vibrio vulnificus (MO-624) and Vibrio parahaemolyticus (O3:K6 TX-2103) suspended in phosphate-buffered saline (pH 7.4, 10(7) CFU/ml) were exposed to pressures from 207 to 379 MPa for 1 to 20 min. Inoculated whole oysters (106 CFU/g) were exposed to pressure from 276 to 379 MPa for 1 to 15 min. Pure cultures and inoculated oysters (10(6) CFU/g) also were irradiated (gamma irradiation) at doses of less than 3 kGy. Four mathematical models, the Bigelow model, Arrhenius equation, Fermi equation, and Weibull frequency distributions, were applied to microbial survival data, and performances of the different kinetic models were compared. Weibull frequency distributions can predict the high-pressure inactivation of Vibrio spp. with more accuracy in both pure cultures and inoculated oyster samples. The Fermi model provided a better description of gamma-irradiation inactivation kinetics compared with the traditional Bigelow model.

Animals↗
PubMed1993

[Microbial contamination of wash water in automatic washing and disinfection machines].

Samples were taken from the water containing tube system of 7 cleaning and disinfection machines located at the university clinics. The machines were used for the treatment of medical tools. The samples were bacteriologically examined. The results showed systemic contaminations of the tubes of all tested machines. The well known positive effect of common ion-exchangers on bacterial growth was not the only reason for the high degree of microbial contaminations. Partial bacterial growth on the inner sides of the water tubes was detected. The reason was the use of bacteriological objectionable tube materials. Recontamination of the post treated medical tools is possible at any time by the last washing water. Preceding sterile filtration showed as supposed no effect. Consequences for the use of cleaning and disinfection machines are discussed.

Bacteria↗
PubMed1998

Bacterial growth in ground beef patties made with meat from animals fed diets without or with supplemental vitamin E.

A study was designed to determine populations of aerobic bacteria, coliforms, sorbitol-negative bacteria, and Listeria monocytogenes during display at 4 and 12 degrees C of ground beef patties made with meat from animals fed diets supplemented daily (for 100 days) with 0, 1,000, or 2,000 IU of vitamin E. The patties (113.5 g) were either left uninoculated or were inoculated with Escherichia coli O157:H7 or L. monocytogenes and were tray-overwrapped and stored (at 4 or 12 degrees C for 8 to 10 or 4 to 6 days, respectively) while being continuously exposed to fluorescent light in a display setting. Patties were visually evaluated for overall appearance (based on color and/or discoloration) twice a day and analyzed for microbiological counts at 2-day intervals during display at 4 degrees C and at 0, 1, 2, 3, 4, and 6 days during display at 12 degrees C. Use of beef from animals fed supplemental vitamin E ("high-vitamin E beef") resulted in ground beef patties which, when stored at 4 degrees C, maintained visually acceptable color longer than did patties made from control beef (from animals not fed supplemental vitamin E), but effects on microbial growth were less pronounced. In general, use of high-vitamin E beef versus control beef in patty manufacture had no major effect on populations of aerobic bacteria, coliforms, sorbitol-negative bacteria, or L. monocytogenes in ground beef patties displayed at 4 or 12 degrees C. Listeria monocytogenes multiplied at 12 degrees C, but growth was similar among ground beef patties made from high-vitamin E beef versus control beef. Overall, changes in bacterial populations were similar in ground beef patties derived from meat from animals with or without added vitamin E in their diets, but control ground beef became visually unacceptable sooner.

Animal Feed↗
PubMed2004

Microbial screening of UC blood units by an automated culture system: effect of delayed testing on bacterial detection.

BACKGROUND: Microbial screening is a mandatory test for banked UC blood (UCB) to comply with the code of good manufacturing practice (GMP). Cord blood banks (CBBs) are not always closely located to a GMP-licensed microbiology laboratory, resulting in time delays for transport of specimens prior to microbiological testing. This study investigated the influence of >/=24 h delays in initiating automated microbial screening on the detection of bacteria in UCB, by analysis of specimens deliberately spiked with bacteria and the recovery of bacteria from cryopreserved spiked-UCB. MATERIALS AND METHODS: UCB was processed according to standard CBB procedures and spiked with Staphylococcus epidermidis or Escherichia coli [2-2000 colony forming units (CFU)/mL]. Spiked-UCB (0.5 mL) was (1) held at room temperature (RT) and inoculated into pediatric BacT/Alert bottles (bioMérieux) at Days 1, 4 and 7 (delayed inoculation); and (2) inoculated directly (Day 0) into replicate BacT/Alert bottles and held at RT for 1, 4 or 7 days before loading onto the BacT/ALERT system (delayed loading). Spiked-UCB samples were cryopreserved. Bacterial counts were quantitated on horse blood agar plates. RESULTS: Bacterial growth in UCB spiked with a single bacterium was capable of detection by the BacT/ALERT system. S. epidermidis grew in all conditions of delayed testing (ie. delayed inoculation and delayed loading). E. coli failed to grow under conditions of delayed inoculation but grew at all time points of delayed loading. S. epidermidis and E. coli were recovered from cryopreserved spiked-UCB. DISCUSSION: Inoculation of culture bottles as soon as possible after sample preparation is preferable. Bacteria can maintain viability in BacT/ALERT bottles inoculated and held at RT for up to 7 days prior to automated culture testing. Bacteria can be successfully recovered from cryopreserved UCB.

Bacteria↗
PubMed1999

Environmental factors affecting the occurrence of mycobacteria in brook sediments.

The occurrence of mycobacteria was studied in aerobic brook sediments from 39 drainage areas in Finland. The culturable counts of mycobacteria were related to climatic conditions, characteristics of the drainage area, chemical characteristics of the sediment and water, culturable counts of other heterotrophic bacteria, and microbial respiration rate in the sediment. The counts of mycobacteria varied from 1.1 x 10(2) to 1.5 x 10(4) cfu g-1 dry weight of sediment. They correlated positively with the proportion of the drainage area consisting of peatland, total content of C, content of Pb, microbial respiration rate in the sediment, and chemical oxygen demand of the water. The correlations of the mycobacterial counts with pH of sediment and alkalinity of water were negative. The results of the present sediment study and of the forest soil study published earlier strongly suggest that an increase in acidity increases the counts of mycobacteria and decreases the counts and activity of other heterotrophic bacteria. Mycobacterial counts were more than 100 times higher (per dry weight) in forest soils with pH 3.5-4.3 than in sediments with pH 4.5-6.3.

Climate↗
PubMedDate not supplied

Conjunctival microbial flora in leprosy.

Conjunctival sacs of seventy one leprosy patients, paramedical and medical personnel working in a leprosy home were cultured. None of these eyes had any pathology in the outer eye. Surprisingly, 46.2% of the eyes which showed a positive culture carried accepted pathogens; Staphylococcus aureus being the commonest. Determining the preoperative bacterial flora and their elimination before undertaking intraocular surgery is recommended.

Anti-Bacterial Agents↗
PubMed1994

The structure and function of microbial communities in recirculating hydroponic systems.

Strategies to control the microbial community associated with plant growth systems need to be based on a fundamental understanding of the factors which structure and regulate the community. Spatial and temporal patterns in the abundance and production rate of microorganisms in hydroponic systems containing wheat were examined to evaluate how root-derived carbon is processed. The relevance of results to monitoring and control strategies is discussed.

Bacteria↗
PubMed2003

Rhizosphere microflora of plants used for the phytoremediation of bitumen-contaminated soil.

The microbial communities and their degradative potential in rhizospheres of alfalfa (Medicago sativa) and reed (Phragmites australis) and in unplanted soil in response to bitumen contamination of soil were studied in pot experiments. According to the results of fluorescence microscopy, over a period of 27 months, bitumen contamination of soil reduced the total number of microorganisms more significantly (by 75%) in unplanted than in rhizosphere soil (by 42% and 7% for reed and alfalfa, respectively) and had various effects on some important physiological groups of microorganisms such as actinomycetes as well as nitrogen-fixing, nitrifying, denitrifying, ammonifying, phosphate-solubilizing, sulphur-oxidizing, cellulolytic and hydrocarbon-degrading microorganisms. The changes in the physiological structure of the microbial community under bitumen contamination were found to hinge on not merely the presence of plants but also their type. It was noted that the rhizosphere microflora of alfalfa was less inhibited by hydrocarbon pollution and had a higher degradative potential than the rhizosphere microflora of reed.

Actinobacteria↗
PubMed1990

Investigations of the effectiveness of detergent washing, drying and chemical disinfection on contamination of cleaning cloths.

Detergent washing, drying and chemical disinfection for decontamination of cleaning cloths was investigated with cloths contaminated by use in the domestic environment. Detergent washing produced only limited reductions in microbial contamination and cloths then stored at room temperature for 24 h showed increases in contamination due to multiplication of residual survivors. For effective and consistent decontamination of cloths, detergent washing followed by drying at 80 degrees C for 2 h was required. Hypochlorite and phenolic disinfectants produced significant reductions in contamination, but chemical disinfection may be unreliable where cloths are heavily contaminated.

Bacteria↗
PubMed1993

Comparative study of procedures for isolation and cultivation of Legionella pneumophila from tap water in hospitals.

For the isolation and cultivation of Legionella pneumophila from tap water in hospitals, we compared different media and selection techniques. A second part of the study compared the L. pneumophila yields from different water samples at identical sites. A total of 210 water samples (500 ml each) were collected from two selected sites in each of 21 hospitals. Warm water samples were collected after flow times of 0, 5, 10, and 15 min; in addition, one cold water sample was collected. Filtration was used to concentrate all samples. Following filtration, 0.1 and 1 ml each of untreated samples, heat-treated samples (3 min, 59 degrees C), and acid-treated samples (pH 2.2, 15 min) were spread onto the selective media MWY (SR 118; Oxoid) and BMPA alpha (SR 111; Oxoid), and samples from 12 hospitals were also spread onto GVPC medium (SR 152; Oxoid). A total of 72 (34%) of the 210 samples from 12 hospitals were positive. With respect to the positive Legionella cultures, there was no significant difference between the selective media MWY, BMPA alpha, and GVPC. With the BMPA alpha supplement, more samples were positive following heat treatment (P < 0.05) or acid treatment (P < 0.05) than without any further treatment. For the maximum yield of Legionella colonies with minimum additional microbial flora, acid treatment was the most effective, and by all methods, the GVPC supplement was the most selective. For routine water tests in hospitals for differentiating between systemic and local contamination, acid treatment of the concentrated samples, the use of different selective media, and the correct selection of sampling sites are recommended.

Austria↗
PubMed1998

Treatment considerations in rapidly progressive periodontitis: a case report.

This article presents a concept for the control of periodontal pathogens in early-onset periodontitis and demonstrates the reparative potential of periodontal tissue when the infection is under control. The patient discussed here was diagnosed with rapidly progressive periodontitis. We were able to reduce the bacterial mass with scaling and root planing and, in conjunction with systemic antibiotics, return the microbial profile to the normal range. Microbiological testing was used to monitor the microbiota and to adjust antimicrobial treatment. Improvements in probing depths and attachment levels were monitored for more than 1 year. Tissue response to this treatment made surgical intervention unnecessary. Although not essential, orthodontic treatment enhanced cleansability and improved esthetics.

Adult↗
PubMed2000

Presence of microorganisms on the fitting denture complete surface: study 'in vivo'.

It was the intention to study if glazing the fitting surface of maxillary dentures with a light-curing acrylic resin would diminish the bacterial counts. The study included the application of a photopolymerizing glaze to one half of the fitting denture surface; after 15 days microbial plaque was collected from a 1 cm2 area of the glazed and the untreated resin, respectively. At the same time bacteria were collected from a 1 cm2 area of the corresponding sites on the palatal mucosa. The application of the glaze had modified the number of bacteria cultured from the glazed surface versus the untreated surface. Denture surface: total aerobic bacteria, 1:4; aerobic streptococci, 1:4; aerobic staphylococci, 1:5; anaerobic bacteria, 1:3.5; mucosal surface aerobic bacteria, 1:4; streptococcal, 1:4. The differences were statistically significant at P<0.002. However, from a quantitative and qualitative point of view these differences were minor compared with the actual concentrations of the microorganisms of 104-106/cm2 observed on the fitting denture surface and the palatal mucosa.

Acrylic Resins↗
PubMed1998

Effect of soybean hulls, soy lecithin, and soapstock mixtures on ruminal fermentation and milk composition in dairy cows.

Two experiments were conducted to determine effects of soybean hulls, soy lecithin, and soapstock mixtures on ruminal fermentation, milk composition, and ruminal microbial populations. In Experiment 1, 20 Holstein dairy cows were assigned to one of five total mixed rations (TMR) in replicated 5 x 5 Latin squares to measure the effect of TMR on intake and milk composition. Four ruminally fistulated cows were used in a 4 x 5 Youden square to measure the effect of TMR on ruminal fermentation. The TMR consisted of 40 or 50% alfalfa and corn silages, 13% soybean hulls, and 47 or 37% of a concentrate containing either 2.25% soybean oil; 2.25% lipid from a mixture of soybean hulls, soy lecithin, and soapstock; or no added lipid. The ratios of soy lecithin to soapstock evaluated were 1:1, 2.5:1, and 4:1 (dry basis). The TMR containing soy lecithin and soapstock at ratios of 1:1 and 2.5:1 resulted in higher milk C18:2 than did the soybean oil TMR. Rate of ruminal NDF digestion of soybean hulls was reduced for the soybean oil TMR. In Experiment 2, a semi-continuous culture system was used to determine effects of soybean oil or an optimal mixture of soy lecithin and soapstock (1:1, wt/wt) on fermentation of soybean hulls and microbial populations. The TMR containing the lipid mixture increased the ratio of acetate to propionate compared with the TMR containing soybean oil and resulted in higher total protozoal counts than did the control TMR. The TMR containing mixtures of soy lecithin and soapstock at ratios of 1:1 and 2.5:1 elevated milk C18:2, and no negative effect on NDF digestion was detected, indicating some degree of ruminal protection.

Animal Feed↗
PubMedDate not supplied

Performance of Air-O-Cell, Burkard, and Button Samplers for total enumeration of airborne spores.

Performance of three devices used for the total enumeration of airborne spores-the Air-O-Cell sampling cassette, the Burkard personal volumetric air sampler, and the Button Aerosol Sampler--was evaluated under controlled laboratory conditions. The first two are glass-slide impactors; the third collects spores on a filter. The samplers were challenged with 0.44-5.10 microm polystyrene latex particles and five microorganisms of 0.84-3.07 microm mean aerodynamic diameter: Streptomyces albus, Bacillus subtilis, Cladosporium cladosporioides, Penicillium brevicompactum, and Penicillium melinii. An optical particle counter measured the particle concentrations upstream and downstream of each sampler, and thus determined the physical collection efficiency of the three samplers. Collection efficiency of the Button Aerosol Sampler was close to 100% for the entire particle size range studied. The cut-off size of each impactor was 2.3-2.4 microm. Acridine orange (with epifluorescent microscopy) and lactophenol cotton blue (with bright light microscopy) staining techniques were used for the microscopic enumeration of spores. No significant difference in microscopic counts was found (at the 95% significance level) when using these two techniques with the Button Aerosol Sampler filters. When the lactophenol cotton blue staining was used to compare total microbial counts yielded by all three samplers, the Button Sampler showed significantly higher counts for the smaller size microorganisms (B. subtilis and C. cladosporioides). For the larger microorganisms (P. brevicompactum and P. melinii) all three samplers yielded similar results. Uniformity of particle deposition on the collection surface was highest for the Button Aerosol Sampler due to the design of its inlet. Thus, the filter collection method used with the Button Aerosol Sampler is suitable and can be advantageous for the enumeration of total airborne spores.

Aerosols↗
PubMedDate not supplied

Rapid detection of single cell bacteria as a novel approach in food microbiology.

Solid-phase cytometry (SPC) is a novel technique that allows rapid detection of bacteria at the single cell level, without the need for a growth phase. After filtration of the sample, the retained microorganisms are fluorescently labeled on the membrane filter and automatically counted by a laser scanning device. Each fluorescent spot can be visually inspected with an epifluorescence microscope connected to the ChemScan by a computer-driven moving stage. Depending on the fluorogenic labels used, information on the identity and the physiological status of the microorganisms can be obtained within a few hours. Although SPC was originally recommended for the determination of the total viable microbial count in water and other liquid samples, it may also be a promising technique for the detection and enumeration of bacteria in food samples, provided they can be isolated from the unfilterable matrix. The short detection time inherent in this approach is a considerable advantage over conventional plate counting, especially for slow-growing microorganisms. The basic principles of SPC are discussed as well as its potential for the detection of Mycobacterium paratuberculosis, a model example of a slow-growing bacterium in milk.

Animals↗
PubMed2000

Increased salivary acetaldehyde levels in heavy drinkers and smokers: a microbiological approach to oral cavity cancer.

The pathogenetic mechanisms behind alcohol-associated carcinogenesis in the upper digestive tract remain unclear, as alcohol is not carcinogenic. However, there is increasing evidence that a major part of the tumour-promoting action of alcohol might be mediated via its first, toxic and carcinogenic metabolite acetaldehyde. Acetaldehyde is produced from ethanol in the epithelia by mucosal alcohol dehydrogenases, but much higher levels derive from microbial oxidation of ethanol by the oral microflora. In this study we investigated factors that might alter the composition and quantities of the oral microflora and, consequently, influence microbial acetaldehyde production. Information about dental health, smoking habits, alcohol consumption and other factors was obtained by a questionnaire from 326 volunteers with varying social backgrounds and health status, e.g. oral cavity malignancy. Paraffin-induced saliva was collected and the microbial production of acetaldehyde from ethanol was measured. Smoking and heavy drinking were the strongest factors increasing microbial acetaldehyde production. Whether poor dental status may alter local acetaldehyde production from ethanol remained unanswered. Bacterial analysis revealed that mainly gram-positive aerobic bacteria and yeasts were associated with higher acetaldehyde production. Increased local microbial salivary acetaldehyde production due to ethanol among smokers and heavy drinkers could be a biological explanation for the observed synergistic carcinogenic action of alcohol and smoking on upper gastrointestinal tract cancer. It offers a new microbiological approach to ethanol-associated carcinogenesis at these anatomic sites.

Acetaldehyde↗