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Hygienic monitoring of environmental surroundings in office-based ambulatory surgery units--an instrument for infection control.

Out-patient operations cause lower costs and they are a method the patients are less burdened with than it is the case with usual operating methods. Avoiding nosocomial infections is regarded as another advantage. The rate of infection can be given by a carefully kept nosocomial infection surveillance. Ambulatory surgery units have difficulties in keeping these statistics because they often do not take over the after-treatment of this patients. Out-patient operations in surgeries must guarantee the same standard of hygiene which can usually be found in hospitals. Hospital epidemiologists, health authorities and professional associations have published corresponding guidelines with organizational/functional and structural requirements. These requirements, however, are only met by few ambulatory practices. Surgery holders justify the non-observance of the guidelines by supposing that the spectrum of germs in their office differs from that in a hospital and that there aren't any pathogens. The standard of hygiene in ambulatory surgery units is not controlled regularly. Therefore the hygienic conditions and the microbial burden of five surgeries that carry out out-patient operations under general anaesthesia were determined within the scope of microbial monitoring of the surroundings. Only two surgeries achieved a standard of hygiene which is comparable with that of a hospital. Up to 42% of the taken samples were sterile. The other three surgeries did not meet the requirements. The microbial burden in these surgeries was distinctly higher. The spectrum of detected microorganisms was very wide and there were pathogens too. Hygienic controls and monitoring of the surroundings should be carried out regularly as a measure to guarantee the production and maintenance of quality. Thus the actually achieved hygienic standard in the surgeries can be controlled and improved if necessary. Ambulatory surgeries should be liable to similar hygienic controls as hospitals.

Ambulatory Surgical Procedures↗

The use of tetracycline fibres in the treatment of generalised aggressive periodontitis: clinical and microbiological findings.

The purpose of the present study was to evaluate the effects of tetracycline fibres (TCF) as an adjunct to scaling in the treatment of generalised aggressive periodontitis and to compare the effects with mechanical treatment only. Ten patients, 24-39 years old referred for treatment to the Department of Preventive Dentistry, Periodontology and Implant Biology, Aristotle University of Thessaloniki took part in the study. A split-mouth experimental design was used. Measurements referring to bleeding on probing (BOP), pocket depth (PD) and clinical attachment level (CAL) were performed at 12 sites randomly selected. Clinical recordings were made at baseline, 2 and 6 months, after treatment. Subgingival plaque samples were taken for microbiological analysis using the 'checkerboard' DNA-DNA hybridisation technique at baseline, immediately after treatment and at 2 and 6 months. Full-mouth scaling and root planing were performed, with the exception of 2 pre-selected sites, which served as controls. Tetracycline fibres were applied in 5 pockets located in the same half mouth. Analysis of clinical findings showed that mechanical instrumentation in combination with TCF application led to a greater improvement in clinical parameters than scaling and root planing only. Microbial analysis showed a statistically significant greater reduction in the percentages of detection for B. forsythus, P. nigrescens and A. naeslundii genospecies II in pockets where tetracycline fibres were applied. In conclusion, the clinical and microbiological data of the present study suggest that the adjunctive use of TCF improves the clinical response of scaling and root planing in aggressive periodontitis patients.

Actinomyces↗

Microbial biomass, community structure and metal tolerance of a naturally Pb-enriched forest soil.

The effect of long-term elevated soil Pb levels on soil microbiota was studied at a forest site in Norway, where the soil has been severely contaminated with Pb since the last period of glaciation (several thousand years). Up to 10% Pb (total amount, w/w) has been found in the top layer. The microbial community was drastically affected, as judged from changes in the phospholipid fatty acid (PLFA) pattern. Specific PLFAs that were high in Pb-enriched soil were branched (especially br17:0 and br18:0), whereas PLFAs common in eukaryotic organisms such as fungi (18:2omega6,9 and 20:4) were low compared with levels at adjacent, uncontaminated sites. Congruent changes in the PLFA pattern were found upon analyzing the culturable part of the bacterial community. The high Pb concentrations in the soil resulted in increased tolerance to Pb of the bacterial community, measured using both thymidine incorporation and plate counts. Furthermore, changes in tolerance were correlated to changes in the community structure. The bacterial community of the most contaminated soils showed higher specific activity (thymidine and leucine incorporation rates) and higher culturability than that of control soils. Fungal colony forming units (CFUs) were 10 times lower in the most Pb-enriched soils, the species composition was widely different from that in control soils, and the isolated fungi had high Pb tolerance. The most commonly isolated fungus in Pb-enriched soils was Tolypocladium inflatum. Comparison of isolates from Pb-enriched soil and isolates from unpolluted soils showed that T. inflatum was intrinsically Pb-tolerant, and that the prolonged conditions with high Pb had not selected for any increased tolerance.

Bacteria↗

Effect of dehairing operations on microbiological quality of swine carcasses.

To develop a hazard analysis and critical control point plan for food processing operations, critical control points must be determined. Swine slaughtering and dressing operations were investigated to establish their critical control points. We monitored the microbiology of swine carcasses by surface swabbing carcass bellies at various steps during the process and by quantitating total aerobic plate count (APC) and coliforms. Starting with a dehaired carcass, the sequential steps monitored included presingeing, postsingeing, polishing, and chilling. Initial results indicate that singeing and chilling substantially reduced the levels of APC and coliforms, whereas polishing increased their levels. The hygienic characteristics of individual operations involved in dressing swine carcasses were then evaluated in the second experiment. A set of 40 randomly selected carcasses leaving singeer, polisher, shaver, and washer were sampled. Carcasses were heavily contaminated during the final polishing procedure, and the APC increased threefold compared with prepolishing levels. Washing reduced the bacterial numbers by 69%. To reduce the microbial load on swine carcasses, final polishing and manual shaving steps were not used during the dressing operation on a set of 90 carcasses. APCs on singed carcasses were reduced from 1.34 to -0.15 log10 CFU/cm2 when the final polisher and manual shavers were not used. However, carcasses were subsequently recontaminated with bacteria after evisceration, and the APCs were similar (P > 0.05) regardless of whether the final polishing and manual shaving steps were used, averaging 1.30 and 1.46 log10 CFU/cm2. These results indicated that individual operations can be identified as critical control points, appropriate limits can be set and monitored in a hazard analysis and critical control point system, and steps where further changes to reduce bacterial levels may be needed for swine slaughtering plants.

Abattoirs↗

Performance of calorimetric methods for the investigation of microbial systems in combination with additional sensors.

Calorimetric methods are used in combination with online oxygen measurement (using an amperometric sensor) and determination of the optical density (using a fibre optic sensor) to investigate microbial growth behaviour. The calorimetric curves of different batch experiments show a characteristic and reproducible course. Changes in the slope of the DeltaT-time curves indicate the effects of limiting factors on the microbial activity during the cultivation. A first limitation could be correlated with the depletion of oxygen in the medium; a second correlates with the depletion of the carbon source. Measurements of optical density in some cases provide reliable information about the growth of a microorganism culture. Our measurements show a good correlation of the universal calorimetric signal (heat-time curve) to the signal of the miniaturised photometric (OD) sensor.

Calorimetry↗

Changes in subgingival microflora and humoral immune response following periodontal therapy.

OBJECTIVES: To investigate the effect of scaling and root planing (SRP) on the microflora and humoral immune response in adult periodontitis. MATERIALS & METHODS: Clinical measurements, subgingival plaque samples, gingival crevicular fluid and sera were taken from 4 sites in 28 adult periodontitis patients before and after SRP. Polymerase chain reaction was used to determine the presence of A. actinomycetemcomitans, P. gingivalis, B. forsythus, P. intermedia, and T. denticola. ELISA was used to investigate the systemic and local antibody titres to these organisms, and thiocyanate dissociation for the determination of serum antibody avidity. RESULTS: SRP produced a good clinical improvement. On a subject basis there was little significant change in the microflora. However, on a site basis, there were significant reductions in P. intermedia, B. forsythus and T. denticola. There was little change in systemic and local antibody titres following SRP, although there was a significant reduction in antibody avidity to P. gingivalis and P. intermedia CONCLUSION: Post-therapy clinical improvement was associated with a reduction in bacterial prevalence, but statistical significance was only reached at a site level and this microbial reduction was not significant for all organisms. No significant post-therapy effects on the humoral immune response were noted other than a reduced antibody avidity to P. gingivalis and P. intermedia. The lack of a clear pattern in the humoral immune response may reflect a failure of the host response to produce adequate levels of biologically functional antibodies, and complex interactions between the subgingival flora and the host response.

Adult↗

Viable heterotrophic bacteria in water and sediment in 'Mar Piccolo' of Taranto (Ionian Sea, Italy).

Samples of water and sediment were collected from October 1996 to September 1997 in 'Mar Piccolo' of Taranto (Ionian Sea, Italy). Mar Piccolo is a semi-enclosed basin subject to pollution and receives a considerable amount of sewage and industrial waste. Qualitative and quantitative analyses of the composition of the microbial flora were conducted on samples from six stations. The highest bacterial densities, in water and in sediment samples, were found in summer and the lowest, in autumn. Among Gram-negative bacteria, the predominant genus was Aeromonas; Photobacterium and Pseudomonas were also found. Gram-positive bacilli were abundant at all sampling points. Faecal contamination indicators demonstrated that all the stations examined in Mar Piccolo are influenced by anthropogenic pollution throughout the year.

Colony Count, Microbial↗

Efficacy of a one-step hydrogen peroxide system for disinfection of soft contact lenses.

We investigated the efficacy of a one-step hydrogen peroxide system by culturing soft contact lenses before and after exposure to the AOSEPT disinfection system. Sixteen of 38 soft contact lenses obtained from asymptomatic wearers showed microbial growth. Nine cultures were positive for Pseudomonas sp., four showed growth of Staphylococcus sp., two were positive for beta-hemolytic streptococci, and one culture was positive for Alcaligenes faecalis. A second culture of the contact lenses after hydrogen peroxide disinfection showed no growth in 12 of the 16 previous positive cultures. The rate of disinfection was 55% for Pseudomonas sp. and 100% for other bacteria.

Adolescent↗

Distribution of microorganisms in the subsurface of the manus basin hydrothermal vent field in Papua New Guinea.

The distribution of microorganisms in the subsurfaces of hydrothermal vents was investigated by using subvent rock core samples. Microbial cells and ATP were detected from cores taken at depths of less than 99.4 and 44.8 m below the seafloor (mbsf), respectively. Cores from various depths were incubated anaerobically with a heterotrophic medium. Growth at 60 and 90 degrees C was ascribed to a Geobacillus sp. in the 448.6- to 99.4-mbsf cores and a Deinococcus sp. in the 64.8- to 128.9-mbsf cores, respectively, based on the 16S ribosomal DNA analysis.

Anaerobiosis↗

DNA as a nutrient: novel role for bacterial competence gene homologs.

The uptake and stable maintenance of extracellular DNA, genetic transformation, is universally recognized as a major force in microbial evolution. We show here that extracellular DNA, both homospecific and heterospecific, can also serve as the sole source of carbon and energy supporting microbial growth. Mutants unable to consume DNA suffer a significant loss of fitness during stationary-phase competition. In Escherichia coli, the use of DNA as a nutrient depends on homologs of proteins involved in natural genetic competence and transformation in Haemophilus influenzae and Neisseria gonorrhoeae. Homologs of these E. coli genes are present in many members of the gamma subclass of Proteobacteria, suggesting that the mechanisms for consumption of DNA may have been widely conserved during evolution.

Colony Count, Microbial↗

Archiving of food samples from restaurants and caterers--quantitative profiling of outbreaks of foodborne salmonellosis in Japan.

The Ministry of Health, Labor and Welfare (former MHW) of Japan issued a Directive in 1997 advising restaurants and caterers to freeze portions of both raw food and cooked dishes for at least 2 weeks. This system has been useful for determining vehicle foods at outbreaks. Enumeration of bacteria in samples of stored food provide data about pathogen concentrations in the implicated food. Data on Salmonella concentrations in vehicle foods associated with salmonellosis outbreaks were collected in Japan between 1989 and 1998. The 39 outbreaks that occurred during this period were categorized by the settings where the outbreaks took place, and epidemiological data from each outbreak were summarized. Characteristics of outbreak groups were analyzed and compared. The effect of new food-storage system on determination of bacterial concentration was evaluated. Freezing and nonfreezing conditions prior to microbial examination were compared in the dose-response relationship. Data from outbreaks in which implicated foods had been kept frozen suggested apparent correlation between the Salmonella dose ingested and the disease rate. Combined with results of epidemiological investigation, quantitative data from the ingested pathogen could provide complete dose-response data sets.

Adolescent↗

Predominant microflora of downgraded Danish bulk tank milk.

The microflora of downgraded Danish bulk tank milk was examined to identify the main causes of increased microbial counts. Seventy-five representative samples with a microbial count exceeding 3.0 x 10(4) cfu/mL were selected for a more detailed microbial examination. A total of 1237 isolates from these samples were identified. Gram-negative, oxidase-positive bacteria were found in 72% of the samples. Coliforms were found in 20% of the samples, and non-coliforms were found in 49% of the samples. Coryneforms, other gram-positive rods, Lactococcus spp., Micrococcus spp., and coagulase-negative Staphylococcus spp. were found in 28 to 53% of the samples. Bacillus spp., Enterococcus spp., Staphylococcus aureus, Streptococcus dysgalactiae, Streptococcus uberis, and yeasts were found in <25% of the samples. Additionally, the isolates were divided into 3 groups, based on the main cause of an elevated microbial count. Microorganisms primarily associated with poor hygiene dominated the microflora in 64% of the samples; bacteria also related to poor hygiene, but in addition associated with growth at low temperatures (psychrotrophic bacteria) dominated the microflora in 28% of the samples; and bacteria mainly associated with mastitis dominated the microflora in 8% of the samples. A bulk tank milk storage period of 48 h instead of 24 h did not affect the proportion of downgraded milk samples and could not be associated with a specific group of microorganisms. Further, no relationship was found between somatic cell counts and the presence of mastitis bacteria.

Actinomycetales↗

Preservative effect of combined treatment with electrolyzed NaCl solutions and essential oil compounds on carp fillets during convectional air-drying.

The antimicrobial and antioxidant effects on carp fillet samples of treatments with alkaline electrolyzed NaCl solution EW (-) prior to treatment with acidic electrolyzed NaCl solution EW (+) and 1% solutions of the essential oils consisting of 0.5% carvacrol and 0.5% thymol (1% Cv+Ty) were tested. First carp fillet samples were treated with EW (-), then EW (+), followed by 1% (C+T), represented as [EW (-)/EW (+)/1% (Cv+Ty)] for 15 min, during drying at 45 degrees C. Samples were subsequently evaluated by microbiological, chemical and sensory analyses. Microbiological analyses indicated that the initial total microbial counts of samples treated with EW (-)/EW (+), 1% (Cv+Ty) or EW (-)/EW (+)/1% (Cv+Ty) were significantly (p< or =0.05) reduced, compared with the control sample. Treatment with EW (-)/EW (+)/1% (Cv+Ty) gave the strongest overall inhibition of microbial growth when compared to all of the other treatments. The volatile basic nitrogen (VBN) value of samples treated with EW (-)/EW (+)/1% (Cv+Ty) was kept at low level (18.46+/-0.45) until the end of drying period (5 days), compared with control samples (40.33+/-0.58). Treatment with EW (-)/EW (+)/1% (Cv+Ty) during drying significantly reduced the peroxide values (PV) and thiobarbituric acid values (TBA). Sensory evaluation indicated that there were significant differences (p< or =0.05) in the color, odor, taste, flavor and texture, on the end of the 5-day drying period between samples treated with EW (-)/EW (+)/1% (Cv+Ty), as compared to all of the other treatments. We conclude that treatment with EW (-)/EW (+)/1% (Cv+Ty) had stronger antimicrobial and antioxidant effects than all of the other treatments on carp fillets during drying, and could be a good alternative to artificial preservatives in food industry.

Animals↗

Root canal microbiota of dogs' teeth with periapical lesions induced by two different methods.

OBJECTIVE: The microbial composition was investigated in root canals of dogs' teeth with periapical lesions induced by 2 different methods: open versus sealed canals. STUDY DESIGN: Teeth from Group I (n = 16) were left open for a week, then sealed with composite resin for 120 days. The teeth from Group II (n = 16) were left open for the same period. Microbiological samples from the root canals were collected and processed by the anaerobic technique for identification and counting of microorganisms after establishment of periapical reactions. RESULTS: Seventy-four cultivable isolates were recovered in sealed canals (Group I). Strict anaerobes accounted for 64.9% of all species isolated, and gram-negative microorganisms accounted for 55.4%. Microbial genera most frequently isolated were Prevotella, Fusobacterium, Peptostreptococcus, Streptococcus, Enterococcus, Clostridium, and Porphyromonas. Statistical analysis by Pearson chi-square or Fisher's test revealed positive association between sealed teeth and strict anaerobes (P < .05). In open canals (Group II), from a total of 58 cultivable isolates, 19% were strict anaerobes and 81% facultative anaerobes, with predominance of gram-positive species (75.8%). Genera most frequently isolated were Streptococcus, Propionibacterium, Staphylococcus, Neisseria, and Prevotella. CONCLUSION: Strict anaerobes were most frequently found in sealed teeth rather than in the teeth with canals left exposed to the oral cavity for 4 months. Therefore, the method that induced periapical inflammatory lesions by intentional oral exposure, followed by tooth sealing, produced root canal microbiota similar to the same found in humans.

Animals↗

The microbiological quality of drinking water sold on the streets in Kumasi, Ghana.

AIM: The aim of this study was to assess the microbiological quality of Ghanaian bottled and plastic-bagged drinking water sold on the streets of Metropolitan Kumasi, Ghana. METHODS AND RESULTS: Eight bottled, 88 factory-filled plastic sachet and 40 hand-filled hand-tied polythene-bagged drinking waters were examined for the presence of heterotrophic bacteria total viable counts (TVCs), indicators of faecal contamination (total coliforms, faecal coliforms and enterococci) and for lead, manganese and iron. Heterotrophic bacteria were found in all three types of water with TVCs per millilitre ranging from 1 to 460 for bottled water, 2-6.33 x 10(5) for factory-bagged sachet water and 2.33 x 10(3)-7.33 x 10(12) for hand-filled hand-tied bagged water. None of the microbial indicators of faecal contamination were detected in bottled water, whereas 4.5% of the factory-bagged sachets contained total coliforms and 2.3% faecal coliforms, and 42.5% of the hand-filled hand-tied bags contained total coliforms, 22.5% faecal coliforms and 5% enterococci. Iron was found in all three types of drinking water but at concentrations well within the WHO recommendations. Lead and manganese were not detected. CONCLUSION: Ghanaian bottled water is of good microbiological quality but some factory-bagged sachet and hand-filled hand-tied polythene-bagged drinking water are of doubtful quality. SIGNIFICANCE AND IMPACT OF THE STUDY: Factory-bagged sachets and hand-filled hand-tied bags of drinking water sold in Ghana should be monitored for microbiological contamination, with the aim of raising standards in the industry and re-assuring the public.

Colony Count, Microbial↗

Periodontal disease, oral microbial flora and salivary antibacterial factors in diabetes mellitus type 1 patients.

One hundred and thirty-one patients with diabetes mellitus type 1 (IDDM) and 20 healthy controls were checked for the presence of periodontal diseases and for some oral microbiological parameters. Results demonstrated that IDDM patients, who were well compensated from both the metabolic and clinical point of view, showed a prevalence for periodontopathies, which only differed slightly from controls. Only the presence of gingivitis was significantly higher in IDDM patients than in healthy subjects. Both anaerobic and aerobic microbial flora did not show substantial differences for either group. Among the salivary antibacterial factors studied, lysozyme was significantly decreased in diabetic patients compared to controls. It is concluded that IDDM patients undergo periodontal complications with a frequency quite close to that of non-diabetic healthy subjects, when the disease is under strict metabolic and clinical control.

Acetylglucosaminidase↗

Efficacy of some nupe medicinal plants against Salmonella typhi: an in vitro study.

Different medicinal plants: Euphobia hirta (Eh); Citrus aurantifolia (Ca), Cassia occidentalis (Co), and Cassia eucalyptus (Ce), which are claimed by the Nupes of Bida in Niger State of Nigeria to be effective in the treatment of typhoid fever were collected. Ethanolic and water extracts were obtained by standard procedures. Preliminary phytochemical screening showed that alkaloids were absent in all the parts of Eh, Co, and Ca studied, but present in all the parts of Ce studied. Saponins were absent in the leaves and florescence of Eh, Ca fruits, but present in little amounts in Eh and Co roots. Saponins were present in large amounts in all the parts of Ce studied. Tannins were in little amount in all the medicinal plants studied, except in Ca. Glycosides were not present in any of the medicinal plants studied. The in vitro and microbial analysis showed that only Ce showed inhibition to Salmonella typhi growth. Ca plus 'Kanwa' (a locally mined, alkaline salt) showed inhibition only at a high concentration of 'Kanwa'. The MIC and MBC of Ce are 1 and 2 mg/ml, respectively. The paper concludes that, of all the medicinal plants claimed by the Nupes to be effective against S. typhi, only Ce contains the natural compound that can be used in the treatment of typhoid fever.

Colony Count, Microbial↗

Nonstarter lactic acid bacteria biofilms and calcium lactate crystals in Cheddar cheese.

A sanitized cheese plant was swabbed for the presence of nonstarter lactic acid bacteria (NSLAB) biofilms. Swabs were analyzed to determine the sources and microorganisms responsible for contamination. In pilot plant experiments, cheese vats filled with standard cheese milk (lactose:protein = 1.47) and ultrafiltered cheese milk (lactose:protein = 1.23) were inoculated with Lactococcus lactis ssp. cremoris starter culture (8 log cfu/mL) with or without Lactobacillus curvatus or Pediococci acidilactici as adjunct cultures (2 log cfu/mL). Cheddar cheeses were aged at 7.2 or 10 degrees C for 168 d. The raw milk silo, ultrafiltration unit, cheddaring belt, and cheese tower had NSLAB biofilms ranging from 2 to 4 log cfu/100 cm2. The population of Lb. curvatus reached 8 log cfu/g, whereas P. acidilactici reached 7 log cfu/g of experimental Cheddar cheese in 14 d. Higher NSLAB counts were observed in the first 14 d of aging in cheese stored at 10 degrees C compared with that stored at 7.2 degrees C. However, microbial counts decreased more quickly in Cheddar cheeses aged at 10 degrees C compared with 7.2 degrees C after 28 d. In cheeses without specific adjunct cultures (Lb. curvatus or P. acidilactici), calcium lactate crystals were not observed within 168 d. However, crystals were observed after only 56 d in cheeses containing Lb. curvatus, which also had increased concentration of D(-)-lactic acid compared with control cheeses. Our research shows that low levels of contamination with certain NSLAB can result in calcium lactate crystals, regardless of lactose:protein ratio.

Animals↗