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PubMed2006

Effects of environmental characteristics of aquaculture sites on the quality of cultivated Newfoundland blue mussels (Mytilus edulis).

This study examined (1) the effects of seasonal and annual environmental characteristics (temperature, chlorophyll content, salinity, microbial water quality, and algal lipid composition) in four aquaculture locations on the quality (meat content, shell size, and microbial and lipid compositions) of cultivated blue mussels and (2) the optimum harvest time for premium-quality mussels. Seasonal and annual temperature fluctuation of the seawater in the aquaculture sites significantly (P < 0.05) affected their salinity, microbial content, and algal fatty acid compositions, which in turn affected the quality attributes of cultivated mussels. The optimum growth period in terms of meat content (4-5 g) and shell size (50-60 mm) can be achieved within 1 year of cultivation. Because the cultivated mussels examined in this study never reached the maximum microbial load limits (10(5) or log 5 colony-forming units/g of meat), they can be harvested throughout the year. Meanwhile, no significant (P > 0.05) annual changes were observed in total omega-3 polyunsaturated fatty acids content of cultivated mussels. Nonetheless, the optimum harvest time may be April-June for eicosapentaenoic acid (EPA) rich mussels and September-October for docosahexaenoic acid (DHA) rich mussels in terms of fatty acid proportions; however, June may be the best month for the highest concentrations of both EPA and DHA.

Animals↗

PubMed2005

Long-term performance and microbial dynamics of an up-flow fixed bed reactor established for the biodegradation of fluorobenzene.

An up-flow fixed bed reactor (UFBR) was established to investigate the biodegradation of fluorobenzene (FB) under a number of operating conditions, which included variation in the concentration of FB in the feed stream (up to 180 mg l(-1)) and temporary suspension of feeding. Degradation of FB was followed for a period of 8 months under a continuous flow regime. During the operation of the UFBR, FB was never detected in the reactor effluent, being biodegraded by the microbial biofilm or adsorbed to the granular activated carbon (GAC). Biodegradation of FB was observed from the beginning of the reactor operation, and overall, it accounted for 50% of the total amount fed to the bioreactor. High organic loads of FB (210-260 mg d(-1) dm(-3)) were found to affect the biological removal efficiency, possibly due to an inhibitory effect caused by the higher FB concentrations fed to the bioreactor (149-179 mg l(-1)). When FB feeding was suspended for 1 month, biodegradation continued, indicating that the adsorbed FB became bioavailable. Biofilm bacterial dynamics were followed throughout the UFBR operation by denaturing gradient gel electrophoresis and plate-counting techniques, showing that a quite stable community was found in the bioreactor, and this was mainly attributed to the high selective pressure exerted by the presence of FB.

Biofilms↗

PubMed2000

Investigation of hygiene aspects during air chilling of poultry carcases using a model rig.

1. An experimental rig, designed and built to simulate conditions found in commercial poultry chilling systems, was used to investigate the effects of varying air temperature and chilling duration, and the effect of chlorinated water sprays, on the microbial load present on the skin and in the body cavity of freshly eviscerated poultry carcases; deep muscle and skin temperatures were monitored during chilling at three different temperatures. 2. During dry chilling for 2 h, total viable microbe counts (TVC) and counts of coliforms and pseudomonads from the body cavity fell by between half and one log unit; smaller reductions were observed in samples from the breast skin. 3. The situation changed when chlorinated water sprays (50, 100 or 250 ppm available chlorine) were applied for the first hour of chilling; spraying carcases enhanced the reduction in numbers on the skin; the effect was most pronounced with 250 ppm chlorine; conversely in the body cavity, the general effects of sprays was to increase contamination by up to one log unit. 4. There was no evidence that sprays increased the rate of chilling. 5. When carcases were held overnight in the rig at 11 degrees C after chilling, microbe counts on dry-chilled carcases remained stable, but increased on carcases that had been sprayed with chlorinated water.

Animals↗

PubMed1991

An activated sludge process to reduce the pollution load of a dye-industry waste.

A laboratory-scale activated sludge process was developed to reduce the pollution load of a dye-industry waste, containing aniline, phenol, methyl violet and rhodamine B as its major components. The waste exerted an organic load of 5576 mg litre(-1) as the chemical oxygen demand (COD), of 896 mg litre(-1) as total organic carbon (TOC), and had a 31.5 mg litre(-1) phenol content. A microbial sludge, capable of growing on the waste, was developed from cattle dung, adapted to the waste and used as a bioinoculum for the process. This resulted in reductions of 60% in COD, 37% in TOC, and 92% in phenol content, and a decrease in optical density of the colour of the waste from an initial 0.915 to 0.360 at 580 nm. Microorganisms isolated from sludge were identified as Pseudomonas alcaligenes and P. mendocina.

Journal Article↗

PubMed2001

Heterotrophic bacteria community and pollution indicators of mussel--farm impact in the Gulf of Gaeta (Tyrrhenian Sea).

Field studies were carried out to determine and compare the impact of organic loads due to the biodeposition of a mussel farm on the water quality and sediment in a coastal area of the Tyrrhenian Sea (Western Mediterranean). A total of five environmental and five microbial parameters were examined from March, 1997 to February, 1998 on a monthly basis at three stations: the first was located under the mussel farm, the second located at about 40 m away from the mussel farm, while the third designed as a control was at about 1-km. No clear changes in the physical characteristics of the water masses were observed, comparing the three sampling sites and the water column generally showed homogeneous conditions (in terms of temperature and salinity). Changes in density of aerobic heterotrophic bacteria, Escherichia coli and Enterococci in the water column are apparently independent from changes in environmental parameters. At all stations a constant significant correlation between temperature and presumptive Vibrio parahaemolyticus was reported suggesting that this abiotic factor exerted a major control on this bacterial group and its distribution in the water column is not related to the biodeposition of the mussel farm. The major impact identified was on the sediment where variations in bacterial abundance was observed. In the Mussel station sediment enrichment of organic compounds, and the consequent modification of the characteristics of the benthic environment, determined an increase in aerobic heterotrophic bacteria, and particularly of vibrios density (on average about 60%), suggesting that these bacteria are good indicators of organic enrichment.

Animals↗

PubMedDate not supplied

Dental disease, caries related microflora and salivary IgA of children with severe congenital cardiac disease: an epidemiological and oral microbial survey.

The objectives were to determine levels of dental caries, plaque accumulation, gingival inflammation, knowledge of dental health practices, and oral bacterial loading of S. mutans, Lactobacillus sp., Candida sp., and salivary IgA in the mouths of children afflicted with severe congenital heart disease. A total of 60 children from the cardiac units of the Hospital for Sick Children and Guys Hospital Paediatric Department were compared with 60 case-matched control children from the Department of Orthodontics and Paediatric Dentistry, UMDS (Guys Dental School), London. Using the methodology of the World Health Organization, the decayed, missing and filled surfaces and teeth of primary (dmft) and permanent (DMFT) were compared. There were similar levels of caries in the cardiac (dmft 3.9 and DMFT 2.7) and the control (dmft 3.7 and DMFT 2.0). A significant difference was the proportion of untreated carious lesions in the cardiac group (52%) compared to the control group (32%; P < 0.001). Standard oral microbiological techniques were used to isolate S. mutans, Lactobacillus sp., Candida sp., and conventional methods for estimating salivary IgA. There was no difference between the cardiac and the control group. Children with severe congenital cardiac disease have moderately high levels of dental caries with a significantly greater amount of untreated disease. The high bacterial loading associated with high levels of bacterial dental plaque and gingivitis may put cardiac patients at unnecessary risk of developing bacterial endocarditis.

Adolescent↗

PubMed2006

Effect of vaginal douching and different semen extenders on bacterial load and fertility in turkeys.

1. A study on artificial insemination of Beltsville Small White turkeys investigated the effect on bacterial load and fertility of vaginal douching with diluents containing Gentamicin 400 microg/ml and different semen extenders. 2. Irrespective of the extenders used, vaginal douching with Gentamicin reduced the microbial load of the vagina with resultant improvement in fertility and hatchability and corresponding reduction in embryonic mortality. 3. Eggs from hens inseminated with semen extended with Beltsville Poultry Semen Extender (BPSE) diluent along with vaginal douching showed a trend towards higher per cent fertility and per cent hatchability of total and fertile eggs set compared to other extenders, though this was non-significant.

Animals↗

PubMed2005

Evaluation of consumable household products for decontaminating retail skinless, boneless chicken breasts.

The effect of 15 consumable products, including juices, wines, and vinegar, used as rinsing agents on microbial loads of retail skinless, boneless chicken breasts was evaluated in two studies. Ten breasts were rinsed for 1 min with each solution. Samples were swabbed before and after rinsing with a cellulose sponge and evaluated for total aerobic (APC), total coliform (TCC), and generic Escherichia coli counts by Petrifilm methods. No differences were found in initial APC or TCC in either study, with initial mean APC ranging from 5.30 to 7.05 log CFU/cm2 and initial mean TCC ranging from 2.21 to 3.36 log CFU/cm2. In study 1, the APC for breasts rinsed with distilled white vinegar (3.22 log CFU/cm2) was lower than for those rinsed with all other solutions except cranberry juice cocktail (3.86 log CFU/cm2). The TCC for breasts rinsed with distilled white vinegar (0.00 log CFU/cm2) and cranberry juice cocktail (0.20 log CFU/cm2) were lower than those for all other solutions except 10% NaCl (0.43 log CFU/cm2) and 10% NaHCO3 (0.48 log CFU/cm2). In study 2, APC values for breasts rinsed with red wine (5.29 log CFU/cm2) and white wine (5.32 log CFU/cm2) were lower than for breasts rinsed with the other three solutions. The TCC after rinsing with chicken broth (4.48 log CFU/cm2) was higher than for all other solutions except Italian dressing. Although distilled white vinegar was the most effective rinsing agent, all solutions produced lower counts after rinsing, indicating that consumers could use rinsing to remove microorganisms from chicken breast surfaces prior to cooking.

Animals↗

PubMed2004

Application of antimicrobial ice for reduction of foodborne pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes) on the surface of fish.

AIMS: The efficacy of antimicrobial ice was evaluated for the reduction of foodborne pathogens on the surface of fish. METHODS AND RESULTS: Antimicrobial ice containing chlorine dioxide (ClO2) was utilized to control foodborne pathogens in laboratory media and on fish skin. Escherichia coli O157:H7, Salmonella serotype Typhimurium and Listeria monocytogenes strains were treated with antimicrobial ice for 30 min on plates of selective agar and for 120 min on fish skin at room temperature, and then incubated for enumeration. After treatment with 100 ppm ClO2 for 30 min, 5.4, 4.4 and 3.2 log10 reduction was obtained with E. coli O157:H7, Salm. Typhimurium and L. monocytogenes on laboratory media, respectively. When antimicrobial ice (100 ppm ClO2) was applied to fish skin for 120 min, total reduction of E. coli O157:H7, Salm. Typhimurium and L. monocytogenes was 4.8, 2.6 and 3.3 log10, respectively. CONCLUSION: The initial load of foodborne pathogens was reduced by antimicrobial ice and the lowered microbial level was maintained during treatment. SIGNIFICANCE AND IMPACT OF THE STUDY: The application of antimicrobial ice is a simple and effective method for the safe preservation of fish.

Animals↗

PubMedDate not supplied

Maximizing total nitrogen removal from onsite-generated wastewater.

The research reported here examined the use of hydraulic loading strategies to maximize nitrogen removal from onsite-generated wastewater. These strategies are made practical by the inherently intermittent flow of onsite-generated wastewater. Experimentation was conducted at the Western Regional Wastewater Pretreatment Facility in Montgomery County, Ohio, with an established, full-scale onsite wastewater treatment system rated at 500 gallons per day. The onsite wastewater treatment unit was fed primarily with domestic wastewater that had passed through fine screens and grit removal. The dosing schedule was intermittent, representing what would be expected from onsite-generated wastewater. Oxidation occurred in the aeration tank and potentially on the solid-liquid filtration socks within the aeration tank. All major wastewater characterization parameters were monitored during the approximately one-year study, including five-day biochemical oxygen demand (BOD;), total suspended solids (TSS), nitrate, total nitrogen, pH, and alkalinity. Excellent removal of BOD5 and TSS resulted, with the effluent concentration of each parameter substantially and consistently below 10 mg/L for all operating conditions. Excellent total nitrogen removal occurred, typically to below 10 mg/L of nitrogen when the instantaneous flow of wastewater was low, even when the daily hydraulic loading was high. The removal of nitrogen was attributed to microbial biodegradation. This result indicates that the onsite wastewater treatment unit has an inherent denitrification capacity that can be matched with an equalized-hydraulic-loading strategy. The practical ability to equalize and reduce instantaneous loading results from the inherently intermittent nature of the flow associated with onsite wastewater treatment.

Filtration↗

PubMed2006

Quantitative evaluation of bacteria released by bathers in a marine water.

Enterococci, a common fecal indicator, and Staphylococcus aureus, a common skin pathogen, can be shed by bathers affecting the quality of recreational waters and resulting in possible human health impacts. Due to limited information available concerning human shedding of these microbes, this study focused on estimating the amounts of enterococci and S. aureus shed by bathers directly off their skin and indirectly via sand adhered to skin. Two sets of experiments were conducted at a marine beach located in Miami-Dade County, Florida. The first study, referred to as the "large pool" study, involved 10 volunteers who immersed their bodies in 4700L during four 15min cycles with exposure to beach sand in cycles 3 and 4. The "small pool" study involved 10 volunteers who were exposed to beach sand for 30min before they individually entered a small tub. After each individual was rinsed with off-shore marine water, sand and rinse water were collected and analyzed for enterococci. Results from the "large pool" study showed that bathers shed concentrations of enterococci and S. aureus on the order of 6x10(5) and 6x10(6) colony forming units (CFU) per person in the first 15min exposure period, respectively. Significant reductions in the bacteria shed per bather (50% reductions for S. aureus and 40% for enterococci) were observed in the subsequent bathing cycles. The "small pool" study results indicated that the enterococci contribution from sand adhered to skin was small (about 2% of the total) in comparison with the amount shed directly from the bodies of the volunteers. Results indicated that bathers transport significant amounts of enterococci and S. aureus to the water column, and thus human microbial bathing load should be considered as a non-point source when designing recreational water quality models.

Bacteria↗

PubMed1998

Structure of a microbial community in soil after prolonged addition of low levels of simulated acid rain

Humus samples were collected 12 growing seasons after the start of a simulated acid rain experiment situated in the subarctic environment. The acid rain was simulated with H2SO4, a combination of H2SO4 and HNO3, and HNO3 at two levels of moderate acidic loads close to the natural anthropogenic pollution levels of southern Scandinavia. The higher levels of acid applications resulted in acidification, as defined by humus chemistry. The concentrations of base cations decreased, while the concentrations of exchangeable H+, Al, and Fe increased. Humus pH decreased from 3.83 to 3.65. Basal respiration decreased with decreasing humus pH, and total microbial biomass, measured by substrate-induced respiration and total amount of phospholipid fatty acids (PLFA), decreased slightly. An altered PLFA pattern indicated a change in the microbial community structure at the higher levels of acid applications. In general, branched fatty acids, typical of gram-positive bacteria, increased in the acid plots. PLFA analysis performed on the bacterial community growing on agar plates also showed that the relative amount of PLFA specific for gram-positive bacteria increased due to the acidification. The changed bacterial community was adapted to the more acidic environment in the acid-treated plots, even though bacterial growth rates, estimated by thymidine and leucine incorporation, decreased with pH. Fungal activity (measured as acetate incorporation into ergosterol) was not affected. This result indicates that bacteria were more affected than fungi by the acidification. The capacity of the bacterial community to utilize 95 different carbon sources was variable and only showed weak correlations to pH. Differences in the toxicities of H2SO4 and HNO3 for the microbial community were not found.

Journal Article↗

PubMed2003

Five-year maintenance follow-up of early-onset periodontitis patients.

OBJECTIVES: The purpose of this study was to evaluate the clinical and microbiological status of patients with early-onset or aggressive periodontitis (EOP) who had received supportive periodontal care (SPC) every 3-6 months for a period of 5 years, following active periodontal treatment. MATERIAL AND METHODS: The study population consisted of 25 individuals with early-onset periodontitis. Clinical examination and recordings of probing pocket depth (PPD) and clinical attachment level (CAL) were performed at baseline prior to treatment (T0), 3 months following the termination of active periodontal treatment (T1) and annually at the SPC appointments (T2,T3,T4,T5). Microbiological samples were obtained at the 5-year SPC (T5). Subgingival plaque samples for each individual were collected from one deep pocket (>5 mm), based on pretreatment measurements, randomly selected in each quadrant. The levels of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis and Treponema denticola were determined using oligonucleotide probe hybridization. RESULTS: During the 5-year period, the mean of SPC/patient was 12.7 sessions. A significant improvement was observed in PPD, CAL, gingival bleeding index and suppuration following treatment. However, between T1 and T5, 134 sites in 20 patients deteriorated with a CAL loss of> or =2 mm. Out of these 134 sites showing disease progression, microbial samples were randomly obtained in 13 sites (9.7%) from 8 patients. Among other factors, smoking and stress were found to have significant predictive value on the future attachment loss. P. gingivalis, T. denticola and total bacterial load were statistically significantly higher in patients who experienced disease progression during the 5-year maintenance period. CONCLUSIONS: For most EOP patients, regular SPC was effective in maintaining clinical and microbiological improvements attained after active periodontal therapy. However, a small percentage of sites was identified as progressive in 20 patients. Variables found to be related to periodontal progression were the presence of as well as the high bacterial counts of P. gingivalis, T. denticola and total bacterial load, number of acute episodes, number of teeth lost, smoking and stress.

Adult↗

PubMed1969

Microbiological evaluation of Pacific shrimp processing.

Microbiological evaluation of Pacific shrimp (Pandalus jordani) processing was made from samples obtained at five key processing points. The microbial count of raw shrimp ranged from 1.3 x 10(6) to 3.0 x 10(6). The initial microbial flora, in order of predominance, was Acinetobacter-Moraxella, Flavobacterium, Pseudomonas, gram-positive cocci, and Bacillus species. No yeasts were isolated. Differences in processing practices influenced both microbial count and the shrimp flora. The microbial load, however, always increased after peeling and sorting operations and decreased after cooking, washing, and brining steps. Significantly, the gram-positive cocci were recovered with increasing frequency after each processing step, reaching 76% of the total load in a final product. Most of them, however, were coagulase-negative.

Alcaligenes↗

PubMedDate not supplied

Microbial contamination of "in use" bar soap in dental clinics.

Bar soap from 18 different dental clinics were investigated for microbial contamination, while it was "in-use". Of the 32 samples obtained from the bar soap, 100% yielded positive culture. A total of 8 different genera of organisms were isolated. Each bar soap was found to harbor 2-5 different genera of micro organisms. Heavily used soap had more micro organisms compared to less used soap. The microbial load of the "in-use" bar soap constituted a mixed flora of gram positive, gram negative, aerobes, anaerobes, and fungi. The results indicate that the bar soap under "in-use" condition is a reservoir of microorganisms and handwashing with such a soap may lead to spread of infection.

Aspergillus niger↗

PubMed2004

Microbial loads, mycotoxins, and quality of durum wheat from the 2001 harvest of the northern plains region of the United States.

The 2001 durum wheat crop grown in the Northern Plains was surveyed for microbial loads, mycotoxins, and quality. Correlations among these factors were identified. Effects of cleaning, milling, and pasta processing on microbial loads and deoxynivalenol (DON) concentrations were determined. Aerobic plate counts (APCs), mold and yeast counts (MYCs), internal mold infection (IMI), and internal Fusarium infection (IFI) were lowest in grain samples from Montana and highest in grain from northeastern North Dakota. DON and 15-acetyldeoxynivalenol (15-ADON) were not detected in samples from Montana. Nivalenol was not detected in any samples. DON in North Dakota samples ranged from none detected to 23 micrograms/g. 15-ADON was detected in a few North Dakota samples, with a maximum of 0.8 microgram/g. DON positively correlated with APCs, MYCs, IFI, damaged kernels, total defects, U.S. grade number, and tombstone kernel content and negatively correlated with test weight, vitreous kernel content, and kernel weight. APCs, MYCs, and DON concentrations were lower in semolina than whole grain. Processing semolina into spaghetti did not change DON concentrations. APCs for spaghetti were reduced 2.2 to 4.1 logs from those for semolina, whereas MYCs were reduced 0.1 to 1.7 log. Some APCs in durum flour and semolina were higher than certain industry specifications would allow, although other factors were acceptable. However, microbial loads in the spaghetti were all within specifications found in the available literature.

Consumer Product Safety↗

PubMed2003

The microflora recovered from the outer-surfaces of the Frialit-2 implanto-prosthetic connector.

The aim of the present investigation was to examine the outer-surface microbiota of the prosthetic connector of Frialit-2 implants, and to compare the microbial findings with the peri-implant parameters 2 years after functional loading. In 16 implant-treated patients (55.8 +/- 9.5 years) the outer-surface micro-organisms of the prosthetic connectors were determined in 32 Frialit-2 implants. The functional loading time of the prosthetic suprastructures was 24.1 +/- 13.8 months on average. After removal of the implant-supported restoration, microbial samples were obtained from the outer-surfaces of the Frialit-2 prosthetic connector. The microbial plaque samples were specified on CDC-blood agar as percentages of the total cultivable flora. Actinobacillus actinomycetemcomitans was semiquantitively determined on TSBV-agar in CFU/ml. The microbial plaque samples were dominated by Actinomyces israelii (68.8%), Eubacterium lentum (56.3%) and Veillonella parvula (43.8%) with proportions ranking between 3.9% (V. parvula) and 11.1% (A. israelii). The most frequently detected gram-negative microorganisms were Fusobacterium nucleatum (87.5%), Porphyromonas gingivalis (81.3%), and Peptostreptococcus micros (68.8%) with enhanced proportions for P. gingivalis (11.4%) and P. micros (11.4%). No statistical significant correlation could be established between the microbiota present on the outer-surfaces of the F2-connector and the peri-implant parameters examined. The outer-surface microflora recovered from the implanto-prosthetic-connector of Frialit-2 implants reveals a colonization with gram-positive bacteria and potentially harmful gram-negative micro-organisms that were frequently detected, but present at low levels. After 2 years of restorative loading, the outer-surface microbial colonization is compatible with peri-implant soft tissue health.

Actinomyces↗

PubMed2003

Shifts in archaeal communities associated with lithological and geochemical variations in subsurface Cretaceous rock.

Subsurface microbial community structure in relation to geochemical gradients and lithology was investigated using a combination of molecular phylogenetic and geochemical analyses. Discreet groundwater and substratum samples were obtained from depths ranging from 182 to 190 m beneath the surface at approximately 10-cm intervals using a multilevel sampler (MLS) that straddled Cretaceous shale and sandstone formations at a site in the southern San Juan Basin in New Mexico. DNA and RNA were extracted directly from quartzite sand substratum loaded into individual cells of the MLS and colonized in situ. Polymerase chain reaction (PCR)-mediated T-RFLP analysis of archaeal rRNA genes (rDNA) in conjunction with partial sequencing analysis of archaeal rDNA libraries and quantitative RNA hybridization with oligonucleotide probes were used to probe community structure and function. Although total microbial populations remained relatively constant over the entire depth interval sampled, significant shifts in archaeal populations, predominantly methanogens, were observed. These shifts coincided with the geochemical transition from relatively high methane (26 mM), low sulphate (< 3 mg l(-1)) conditions in the region adjacent to the organic matter-rich shale to relatively low-methane (< 0.5 mM), high-sulphate (48 mg l(-1)) conditions in the organic-poor sandstone beneath the shale. These results indicated that active, phylogenetically diverse archaeal communities were present in the subsurface Cretaceous rock environment at this site and that major archaeal clades shifted dramatically over scales of tens of centimetres, corresponding to changes in the lithology and geochemical gradients.

Archaea↗