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Bacterial Contamination (bacterial + contamination)
Selected AbstractsSTATEWIDE EMPIRICAL MODELING OF BACTERIAL CONTAMINATION OF SURFACE WATERS,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2006James D. Wickham ABSTRACT: Bacterial contamination of surface waters is attributed to both urban and agricultural land use practices and is one of the most frequently cited reasons for failure to meet standards established under the Clean Water Act (CWA) (P.L. 92,500). Statewide modeling can be used to determine if bacterial contamination occurs predominantly in urban or agricultural settings. Such information is useful for directing future monitoring and allocating resources for protection and restoration activities. Logistic regression was used to model the likelihood of bacterial contamination using watershed factors for the state of Maryland. Watershed factors included land cover, soils, topography, hydrography, locations of septic systems, and animal feeding operations. Results indicated that bacterial contamination occurred predominantly in urban settings. Likelihood of bacterial contamination was highest for small watersheds with well drained and erodible soils and a high proportion of urban land adjacent to streams. The number of septic systems and animal feeding operations and the amount of agricultural land were not significant explanatory factors. The urban infrastructure tends to "connect" more of the watershed to the stream network through the creation of roads, storm sewers, and wastewater treatment plants. This may partly explain the relationship between urbanization and bacterial contamination found in this study. [source] Sensors for the Detection and Quantification of Bacterial Contamination in Water for Human Use,ADVANCED ENGINEERING MATERIALS, Issue 5 2010Raquel Barbosa Queirós The deterioration of water quality by Cyanobacteria cause outbreaks and epidemics associated with harmful diseases in Humans and animals because of the toxins that they release. Microcystin-LR is one of the hepatotoxins most widely studied and the World Health Organization, recommend a maximum value of 1,µg,L,1 in drinking water. Highly specific recognition molecules, such as molecular imprinted polymers are developed to quantify microcystins in waters for human use and shown to be of great potential in the analysis of these kinds of samples. The obtained results were auspicious, the detection limit found, 1.5,µg,L,1, being of the same order of magnitude as the guideline limit recommended by the WHO. This technology is very promising because the sensors are stable and specific, and the technology is inexpensive and allows for rapid on-site monitoring. [source] Micro-organisms and dust exposure in an Italian grain millJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2005C. Dacarro Abstract Aims:, In order to assess possible occupational risk for workers in a grain mill, we evaluated aerial microbiological contamination in different areas of the mill and at different points of the production line. We also measured the concentration of aerodispersed dust particles. Methods and Results:, An assessment of microbiological contamination levels based on a Global Index of Microbial Contamination per cubic metre (GIMC per m3), an Index of Mesophilic Bacterial Contamination, and an Amplification Index is proposed. The indices were obtained from total and fungal counts. The cleaning sector is the most contaminated area of the mill: the mean GIMC per m3 was 17 213·6. In this area, the average microbial contamination was 11·41 times higher than that in the external environment. The highest concentrations of aerodispersed dust (inhalable 2·763 mg m,3; respirable 1·400 mg m,3) were found in the cleaning area. Conclusions:, The proposed microbiological indices and the concentrations of aerodispersed dust particles show that the most hazardous section of the mill is the cleaning area. The large variation in the data does not depend on seasonal factors, but rather on not easily identifiable conditions of the internal environment which facilitate diffusion and/or proliferation of the micro-organisms. Significance and Impact of the Study:, The proposed microbiological contamination indices and the evaluation of the concentration of dust particles allow the identification of critical positions during the production cycle so that suitable measures to prevent the aerial contamination can be taken. [source] Bacterial contamination: effect and limit of initial flow diversionISBT SCIENCE SERIES: THE INTERNATIONAL JOURNAL OF INTRACELLULAR TRANSPORT, Issue n2 2009M. Satake First page of article [source] STATEWIDE EMPIRICAL MODELING OF BACTERIAL CONTAMINATION OF SURFACE WATERS,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2006James D. Wickham ABSTRACT: Bacterial contamination of surface waters is attributed to both urban and agricultural land use practices and is one of the most frequently cited reasons for failure to meet standards established under the Clean Water Act (CWA) (P.L. 92,500). Statewide modeling can be used to determine if bacterial contamination occurs predominantly in urban or agricultural settings. Such information is useful for directing future monitoring and allocating resources for protection and restoration activities. Logistic regression was used to model the likelihood of bacterial contamination using watershed factors for the state of Maryland. Watershed factors included land cover, soils, topography, hydrography, locations of septic systems, and animal feeding operations. Results indicated that bacterial contamination occurred predominantly in urban settings. Likelihood of bacterial contamination was highest for small watersheds with well drained and erodible soils and a high proportion of urban land adjacent to streams. The number of septic systems and animal feeding operations and the amount of agricultural land were not significant explanatory factors. The urban infrastructure tends to "connect" more of the watershed to the stream network through the creation of roads, storm sewers, and wastewater treatment plants. This may partly explain the relationship between urbanization and bacterial contamination found in this study. [source] Bacterial contamination on touch surfaces in the public transport system and in public areas of a hospital in LondonLETTERS IN APPLIED MICROBIOLOGY, Issue 6 2009J.A. Otter Abstract Aims:, To investigate bacterial contamination on hand-touch surfaces in the public transport system and in public areas of a hospital in central London. Methods and Results:, Dipslides were used to sample 118 hand-touch surfaces in buses, trains, stations, hotels and public areas of a hospital in central London. Total aerobic counts were determined, and Staphylococcus aureus isolates were identified and characterized. Bacteria were cultured from 112 (95%) of sites at a median concentration of 12 CFU cm,2. Methicillin-susceptible Staph. aureus (MSSA) was cultured from nine (8%) of sites; no sites grew methicillin-resistant Staph. aureus (MRSA). Conclusions:, Hand-touch sites in London are frequently contaminated with bacteria and can harbour MSSA, but none of the sites tested were contaminated with MRSA. Significance and Impact of the Study:, Hand-touch sites can become contaminated with staphylococci and may be fomites for the transmission of bacteria between humans. Such sites could provide a reservoir for community-associated MRSA (CA-MRSA) in high prevalence areas but were not present in London, a geographical area with a low incidence of CA-MRSA. [source] Bacterial contamination of PCA and epidural infusion devicesANAESTHESIA, Issue 7 2009M. Rothwell Summary We prospectively audited the bacterial contamination of re-useable analgesia infusion pumps. In a one-month period, 112 samples from the handset and keypads of our analgesia infusion pumps were cultured for bacterial contamination. Forty-five percent of handset swabs and 46% of keypad swabs grew bacteria; the commonest organism being coagulase-negative staphylococcus. An additional cleaning step using 70% isopropyl alcohol wipes was introduced and the contamination rate was re-audited in 100 samples. The contamination rate was reduced to 6% of handset swabs and 4% of keypad swabs. A high initial rate of bacterial contamination of re-useable analgesia infusion pumps was significantly reduced by the implementation of a simple, additional cleaning procedure. [source] Bacterial contamination of stethoscopes on the intensive care unitANAESTHESIA, Issue 6 2009A. M. Whittington Summary We assessed how often bedside stethoscopes in our intensive care unit were cleaned and whether they became colonised with potentially pathogenic bacteria. On two separate days the 12 nurses attending the bedspaces were questioned about frequency of stethoscope cleaning on the unit and the bedside stethoscopes were swabbed before and after cleaning to identify colonising organisms. Twenty-two health care providers entering the unit were asked the same questions and had their personal stethoscopes swabbed. All 32 non-medical staff cleaned their stethoscopes at least every day; however only three out of the 12 medical staff cleaned this often. Out of 24 intensive care unit bedside stethoscopes tested, two diaphragms and five earpieces were colonised with pathogenic bacteria. MRSA cultured from one earpiece persisted after cleaning. Three out of the 22 personal stethoscope diaphragms and five earpieces were colonised with pathogens. After cleaning, two diaphragms and two earpieces were still colonised, demonstrating the importance of regular cleaning. [source] Pulpal responses to bacterial contamination following dentin bridging beneath hard-setting calcium hydroxide and self-etching adhesive resin systemDENTAL TRAUMATOLOGY, Issue 2 2008Yuichi Kitasako Class V cavities were prepared on 30 monkey teeth, and the pulps were exposed with a carbide bur through the cavity floor. Each exposed pulp was capped with either DY or 2V. The cavities were restored with a hybrid resin composite. The resin composite was removed at 180 days after capping, and then cavities were left open to the oral environment for 2 weeks to obtain bacteria contamination DY (BDY) and 2V (B2V; n = 10). A non-bacterial-contaminated group capped with DY was used as control. After bacterial challenges, inflammatory cell infiltration, incidence and differentiation of dentin bridges were evaluated histologically. There were significant differences in the presence of inflammatory cell infiltration among all groups (P < 0.05). No moderate or severe inflammatory reaction was found in Group DY. Group BDY showed moderate or severe inflammatory cell infiltration in 50%, and showed four necrotic specimens. Although no statistically significant difference was found in the formation and differentiation of dentin bridges among all groups, tunnel defects in dentin bridges were detected in 70% (DY), 80% (BDY), and 50% (B2V). Group B2V showed a significantly lower presence of inflammatory cell infiltration than Group BDY (P < 0.05). Bonding agent is supposed to seal the exposure site, and the remaining bonding agent on the cavities was effective as the barrier in the dentin bridges after bacterial challenges. [source] Comparison of routine metabolic rates of the stygobite, Gammarus acherondytes (Amphipoda: Gammaridae) and the stygophile, Gammarus troglophilusFRESHWATER BIOLOGY, Issue 6 2006FRANK M. WILHELM Summary 1. Reduced metabolic rate among cave organisms compared with surface species has long been suggested as an adaptation to food shortage in cave environments. However, comparisons of metabolic rates between species have not often included closely related surface and cave species. By measuring metabolic rate across three seasons and over a range of body sizes, we examined the hypothesis that the routine metabolic rate of Gammarus acherondytes, a federally listed stygobitic amphipod, is lower than that of the closely related stygophilic Gammarus troglophilus. To determine if human activities increased the supply of organic matter to caves, we also examined the relationship between residential development and bacterial contamination in water wells. 2. For G. acherondytes, the slope of the overall relationship between oxygen consumption and body dry mass did not differ from zero and did not vary seasonally, whereas for G. troglophilus it was positive and higher in summer than in winter and spring. These results provide insights into a potential novel metabolic adaptation among stygobites. Higher metabolic rate in young G. acherondytes would allow efficient use of typically transient energy sources and a low metabolic rate at larger body sizes would increase survival through periods of food scarcity. 3. The number of wells with faecal coliform contamination was weakly but positively correlated with the number of residential building permits, indicating that surface land-use changes probably increase the availability of energy in groundwater systems inhabited by G. acherondytes. This may give stygophilic animals, with higher metabolic rates, a competitive advantage in the caves, thus reducing the abundance of stygobites such as G. acherondytes. [source] Chemical and Bacterial Quality of Aeration-Type Waste Water Treatment System DischargeGROUND WATER MONITORING & REMEDIATION, Issue 2 2007Samuel V Panno On-site waste water treatment systems are a potential source of chemical and bacterial contamination to ground water in areas with highly susceptible aquifers such as the sinkhole plain of southwestern Illinois. Ground water from wells, cave streams, and water that discharges from the numerous springs in this area is typically contaminated with nitrate and enteric bacteria and thus may pose a health hazard to those who come into contact with it. In order to determine if the most popular type of on-site waste water treatment systems in the study area was a potential source, samples of effluents discharged at the land surface from 23 domestic aeration-type on-site waste water treatment systems were collected to characterize their water quality and bacterial contents. Most of the effluents contained relatively large concentrations of sodium (Na+), chloride (Cl,), nutrients (nitrogen [N], phosphate [PO43,], and potassium [K+]), and enteric bacteria. Ion concentration ranges (in mg/L) were Na+ (46 to 416), Cl, (21 to 618), N (4.7 to 67), PO4 -P (1.4 to 48), and K+ (6.0 to 257). The sources of elevated Na+ and Cl, were human waste and NaCl used in the water softening systems of the houses. Ammonium was usually the dominant inorganic N species, indicating incomplete oxidation of the waste water. Discharge of Na+, Cl,, and nutrients could also have negative impacts on ground water and surface water quality, subsurface and surface aquatic ecosystems, and vegetation. Our characterization of effluent from these waste water treatment systems revealed their generally poor quality and the likelihood that they can contaminate ground water in areas with highly vulnerable aquifers. [source] Recombinant factor IX (BeneFix®) by adjusted continuous infusion: a study of stability, sterility and clinical experienceHAEMOPHILIA, Issue 2 2001P. Chowdary The safety and efficacy of adjusted continuous infusion (CI) of recombinant factor IX (FIX; BeneFix®) was assessed in vitro and in a clinical study. BeneFix® was reconstituted at 100 IU mL,1 with or without unfractionated heparin (4 U mL,1) and stored at either 4 °C or room temperature. Reconstituted BeneFix® retained at least 90% activity over 14 days if stored at 4 °C but stability was reduced at room temperature. BeneFix® reconstituted in a sterile pharmacy was free of bacterial contamination. Six patients with haemophilia B received seven CIs of BeneFix® to cover routine surgery and severe bleeding episodes. The CIs lasted between 3 and 10 days. In all cases, haemostasis was excellent and the desired therapeutic FIX level was easily maintained. No thrombotic episodes or inhibitor development occurred but two patients developed thrombophlebitis at the infusion site when heparin was not added to the infusion. BeneFix® is not currently licensed for CI and we suggest that studies to enable licensing should be established as soon as possible. [source] A novel approach to controlling bacterial contamination on toothbrushes: chlorhexidine coatingINTERNATIONAL JOURNAL OF DENTAL HYGIENE, Issue 4 2009LA Turner Abstract:, Purpose:, This project was conducted to determine the effectiveness of chlorhexidine-coated toothbrush filaments in reducing quantities of bacteria. Materials and methods:, An Institutional Review Board (IRB)-approved, two-group, double-blind, randomized, post-test only study was conducted. Sixty-four individuals utilized control and experimental toothbrushes, for 30 days. At the end of the study toothbrushes were returned and transported to the laboratory for analysis. Microorganisms were detached from the filaments by sonification and vortexing then plated on Mitis Salivarius (MS) (selective) and trypticase soy agar (TSA) 5% Sheep Blood (non-selective) media. Inoculated plates were incubated aerobically for 24 h at 37°C. After incubation, bacterial colony-forming units (CFU) were determined. Data were analysed using Wilcoxon and Kruskal,Wallis tests. Results:, Fifty-nine toothbrushes were returned for analysis; experimental (n = 31) and control (n = 28). Data from TSA media revealed a mean CFU for the control group of 5.41 × 105 compared with 6.28 × 105 for the experimental group. Data from MS agar resulted in a mean CFU for the control group of 4.32 × 105 compared with 4.20 × 105 for the experimental group. Conclusion:, Results revealed no statistically significant difference in the quantity of bacteria surviving on toothbrush filaments between control and experimental groups, on both selective and non-selective media, after 30 days. [source] Prevention of bacterial contamination, including initial flow diversionISBT SCIENCE SERIES: THE INTERNATIONAL JOURNAL OF INTRACELLULAR TRANSPORT, Issue n2 2009E. Wood First page of article [source] Comparison of different methods of bacterial detection in blood componentsISBT SCIENCE SERIES: THE INTERNATIONAL JOURNAL OF INTRACELLULAR TRANSPORT, Issue 1 2009M. Schmidt Background, Over the last two decades, the residual risk of acquiring a transfusion-transmitted viral infection has been reduced to less than 1 : 1 000 000 via improvements in different techniques (e.g. donor selection, leuco-depletion, introduction of 3rd or 4th generation enzyme-linked immunosorbent assays and mini-pool nucleic acid testing (MP-NAT). In contrast, the risk for transfusion-associated bacterial infections has remained fairly stable, and is estimated to be in a range between 1 : 2000 and 1 : 3000. Platelets are at an especially higher risk for bacterial contamination, because they are stored at room temperature, which provides good culture conditions for a broad range of bacterial strains. To improve bacterial safety of blood products, different detection systems have been developed that can be divided into culture systems like BacT/ALERT or Pall eBDS, rapid detection systems like NAT systems, immunoassays and systems based on the FACS technique. Culture systems are used for routine bacterial screening of platelets in many countries, whereas rapid detection systems so far are mainly used in experimental spiking studies. Nevertheless, pathogen-reduction systems are currently available for platelet concentrates and plasma, and are under investigation for erythrocytes. Methods, In this review, the functional principles of the different assays are described and discussed with regard to their analytical sensitivity, analytical specificity, diagnostic sensitivity, diagnostic specificity and clinical efficiency. The detection methods were clustered into three groups: (i) detection systems currently used for routine screening of blood products, (ii) experimental detection systems ready to use for routine screening of blood products, and (iii) new experimental detection systems that need to be investigated in additional spiking studies and clinical trials. Results, A recent International Society of Blood Transfusion international forum reported on bacterial detection methods in 12 countries. Eight countries have implemented BacT/ALERT into blood donor screening, whereas in three countries only quality controls were done by culture methods. In one country, shelf-life was reduced to 3 days, so no bacterial screening was implemented. Screening data with culture methods can be used to investigate the prevalence of bacterial contamination in platelets. Differing results between the countries could be explained by different test definitions and different test strategies. Nevertheless, false-negative results causing severe transfusion-related septic reactions have been reported all over the world due to a residual risk of sample errors. Rapid screening systems NAT and FACS assays have improved over the last few years and are now ready to be implemented in routine screening. Non-specific amplification in NAT can be prevented by pre-treatment with Sau3AI, filtration of NAT reagents, or reduction of the number of polymerase chain reaction cycles. FACS systems offer easy fully automated handling and a handling time of only 5 min, which could be an option for re-testing day-5 platelets. New screening approaches like immunoassays, detection of bacterial adenosine triphosphate, or detection of esterase activity need to be investigated in additional studies. Conclusion, Bacterial screening of blood products, especially platelets, can be done with a broad range of technologies. The ideal system should be able to detect one colony-forming unit per blood bag without a delay in the release process. Currently, we are far away from such an ideal screening system. Nevertheless, pathogen-inactivation systems are available, but a system for all blood components will not be expected in the next few years. Therefore, existing culture systems should be complemented by rapid systems like NAT or FACS especially for day-5 platelets. [source] Features of Saccharomyces cerevisiae as a culture starter for the production of the distilled sugar cane beverage, cachaça in BrazilJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2010C.R. Campos Abstract Aims:, To evaluate the dominance and persistence of strains of Saccharomyces cerevisiae during the process of sugar cane fermentation for the production of cachaça and to analyse the microbial compounds produced in each fermentative process. Methods and Results:, Three S. cerevisiae strains were evaluated during seven consecutive 24-h fermentation batches using recycled inocula. The UFLA CA 116 strain had the largest population of viable organisms, and the maximum population was achieved in the fourth batch after 96 h of fermentation. The UFLA CA 1162 and UFLA CA 1183 strains grew more slowly, and the maximum population was reached in the seventh batch. Molecular characterization of isolated yeast cells using PFGE (pulse field gel electrophoresis) revealed that more than 86% of the isolates corresponded to the initially inoculated yeast strain. The concentration of aldehydes, esters, methanol, alcohol and volatile acids in the final-aged beverages were within the legal limits. Conclusions:, Cachaça produced by select yeast strains exhibits analytical differences. UFLA CA 1162 and UFLA CA 116 S. cerevisiae isolates can be considered the ideal strains for the artisanal production of cachaça in Brazil. Significance and Impact of the Study:, The use of select yeast strains can improve the quality and productivity of cachaça production. Our findings are important for the appropriate monitoring of yeast during sugar cane fermentation. In addition, we demonstrate that UFLA CA 116 and UFLA CA 1162, the ideal yeast strains for cachaça production, are maintained at a high population density. The persistence of these yeast strains in the fermentation of sugar cane juice promotes environmental conditions that prevent or decrease bacterial contamination. Thus, the use of select yeast strains for the production of cachaça is a viable economic alternative to standardize the production of this beverage. [source] Determination of aerial microbiological contamination in scholastic sports environmentsJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2003C. Dacarro Abstract Aims: To assess the microbiological indoor air quality (IAQ) of high school and college gyms during physical training lessons and to evaluate the effective microbiological exposure of students. Methods and Results: Air samples from 11 high school and college gyms of Pavia, Italy were collected. Total bacterial counts, total fungal counts and characterization of fungal taxa were determined. Air quality was evaluated using three microbiological contamination indices: the global index of microbiological contamination per m3 (GIMC per m3), the index of mesophilic bacterial contamination (IMC) and the amplification index (AI). Conclusions: This work testifies that air contamination in indoor gyms is always superior to that of the outdoor environment. Nevertheless, students are exposed to relatively low concentrations of airborne micro-organisms. The highest values of fungal counts and GIMC per m3 (>14 661) were observed between April and October when the central heating systems were switched off. The lowest fungal counts were detected in modern buildings equipped with forced ventilation systems. From qualitative aeromycological studies, 45 fungal taxa were identified, and different potentially allergenic species were isolated. Significance and Impact of the Study: The standardization of air sampling methods and the correct evaluation of aeromicrobiological results allow the classification of indoor air healthiness. The proposed microbiological contamination indices together with the characterization of airborne fungal taxa are useful tools for detailed description of IAQ. [source] Hygiene measures considering actual distributions of microorganisms in Japanese householdsJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2002M. Ojima Aims: Effective household hygiene measures require that sources of bacterial contamination and the places to which contamination spreads be carefully identified. Therefore, a study was performed to examine the distribution of microorganisms throughout ordinary households in Japan, which has its own unique customs of daily life and food preparation. Methods and Results: Using the stamping method, samples were taken from 100 different places and items in each of 86 households. This study found kitchens/dining rooms to have the greatest level of microbial contamination and bathrooms, the next highest level. Toilets (water closets) were found to have an unexpectedly low level of bacterial contamination. The largest bacterial counts were found on items such as drain traps, dish-washing sponges, counter towels, sinks, dish-washing tubs, and bathroom sponges. Conclusions: It is necessary to carefully identify both the items that can become instruments for spreading bacterial contamination and the places that easily become subject to secondary contamination, and then to take timely and effective disinfection/sanitizing measures. Significance and Impact of the Study: The data gathered in this study will be very valuable for anticipating the pathways over which bacteria are transported and prioritizing disinfection targets, to make effective disinfection possible. [source] Bacteriological quality of skin-moisturizing creams and lotions distributed in a tropical developing countryJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2001I.N. Okeke Aims: To evaluate the bacteriological quality of skin moisturizing products in the South-west part of Nigeria and study factors predisposing their bacterial contamination under tropical conditions. Methods and Results: Viable counts for bacteria exceeded 103 cfu ml,1or cfu g,1 in 8 (16·3%) commercially available creams and lotions at time of purchase. Escherichia coli (8), Pseudomonas spp. (7), Staphylococcus spp. (9) and Bacillus spp. (6) were the most commonly recovered bacteria. Following use by volunteers, the proportion of E. coli and other Gram-negative organisms recovered increased. Organic matter, particularly in the absence of preservatives, enhanced survival and growth of bacteria in creams stored under ambient tropical conditions during challenge experiments. Conclusions: Contaminated products are relatively uncommon but some products present a potential health hazard because they are unable to suppress the growth of organisms of likely faecal origin during use. Significance and Impact of the Study: Quality assurance during manufacture, pack size, preservative evaluation, organic matter and water content were identified as factors to be considered during the development of creams and lotions for use in tropical developing countries. [source] The demand impacts of chicken contamination publicity,a case studyAGRIBUSINESS : AN INTERNATIONAL JOURNAL, Issue 4 2002Roger A. Dahlgran Adverse publicity regarding food contamination can depress demand, causing lost producer revenue. This study addresses the magnitude of those losses through the analysis of the impact of TV and print news coverage of bacterial contamination of chicken in the United States. An inverse demand model for chicken is estimated using weekly data from 1982 through 1991. Our findings indicate adverse publicity about salmonella contamination of chicken depressed the demand for chicken, but that the effect was small, less than 1% during the period of maximum exposure. Further, consumers soon forget this news as they reverted to prior consumption patterns in a matter of weeks. [EconLit citation: D120] © 2002 Wiley Periodicals, Inc. [source] Pathogen inactivation technology: cleansing the blood supplyJOURNAL OF INTERNAL MEDICINE, Issue 3 2005H. G. KLEIN Abstract., Klein HG (The Johns Hopkins School of Medicine and Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, MD, USA). Pathogen inactivation technology: cleansing the blood supply (Review). J Intern Med 2005; 257: 224,237. The calculated residual infectious risk of HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) from blood transfusion is extremely low. However, the risk of bacterial contamination remains and a variety of other agents including emerging viruses, protozoa and tick-borne agents threaten blood supplies and undermine public confidence in blood safety. Traditional methods of donor screening and testing have limited ability to further reduce disease transmission and cannot prevent an emerging infectious agent from entering the blood supply. Pathogen inactivation technologies have all but eliminated the infectious risks of plasma-derived protein fractions, but as yet no technique has proved sufficiently safe and effective for traditional blood components. Half-way technologies can reduce the risk of pathogen transmission from fresh frozen plasma and cryoprecipitate. Traditional methods of mechanical removal such as washing and filtration have limited success in reducing the risk of cell-associated agents, but methods aimed at sterilizing blood have either proved toxic to the cells or to the recipients of blood components. Several promising methods that target pathogen nucleic acid have recently entered clinical testing. [source] Influence of a standardized closed soft tissue trauma on resistance to local infection.JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2003An experimental study in rats Abstract Purpose: The etiology of local posttraumatic infection in the locomotor system depends on the amount, virulence and pathogenicity of the inoculated microorganisms and the local/systemic host damage due to the type and extent of the accident or iatrogenic trauma. The relative effect of these factors remains unclear. In particular, it is still unclear today whether,in presence of microorganisms,soft tissue damage and its pathophysiological consequences lead to infection after soft tissue trauma, or whether the bacterial contamination is the primarily cause for posttraumatic infection. The aim of the project was to gain information on the consequences of a soft tissue injury in terms of resistance to local infection. Since clinical populations are too heterogeneous, the problem was investigated in a standardized, reduced (no surgery or implants) experimental in vivo model. Method: In female Sprague-Dawley-rats with a standardized closed soft tissue trauma to the tibialis anterior muscle (group I: n = 13) or without (group II: n = 13), we compared the incidence of local infection after a pairwise local, percutaneously injected bacterial challenge with various concentrations of Staphylococcus aureus (2 × 104 -2 × 106 colony forming units, CFU). The standardized closed soft tissue trauma was created by application of a specially designed, computer controlled impact device. The contaminated soft tissue and the underlying bone were removed under sterile conditions after five days and quantitatively evaluated for bacterial growths. Infection was defined as positive bacterial growth at the soft tissue and/or bone. A stepwise experimental design with an ,up-and-down" dosage technique was used to adjust the bacterial challenge in the area of the ID50 (50% infection dose). Statistical evaluation of the difference between the infection rates of both groups was performed by two-sided fisher exact test (p<0.05). Results: The overall infection rate was 46%. For the group with soft tissue trauma the ID50 was 1.32 × 105 CFU and 1.05 × 106 CFU for the group without soft tissue trauma. The infection rate was 69% (9 of 13 animals) for the group with soft tissue trauma and 23% (3 of 13 animals) for the group without soft tissue trauma. This difference is statistically significant (p = 0.047). Conclusions: The infection rate after a standardized closed soft tissue injury was significantly higher and the ID50 lower than without soft tissue trauma. Our results demonstrate that in presence of microorganisms it is not primarily the bacterial contamination but rather the soft tissue damage and its pathophysiological consequences resulting in decreased infection resistance that secondarily lead to infection. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] STATEWIDE EMPIRICAL MODELING OF BACTERIAL CONTAMINATION OF SURFACE WATERS,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 3 2006James D. Wickham ABSTRACT: Bacterial contamination of surface waters is attributed to both urban and agricultural land use practices and is one of the most frequently cited reasons for failure to meet standards established under the Clean Water Act (CWA) (P.L. 92,500). Statewide modeling can be used to determine if bacterial contamination occurs predominantly in urban or agricultural settings. Such information is useful for directing future monitoring and allocating resources for protection and restoration activities. Logistic regression was used to model the likelihood of bacterial contamination using watershed factors for the state of Maryland. Watershed factors included land cover, soils, topography, hydrography, locations of septic systems, and animal feeding operations. Results indicated that bacterial contamination occurred predominantly in urban settings. Likelihood of bacterial contamination was highest for small watersheds with well drained and erodible soils and a high proportion of urban land adjacent to streams. The number of septic systems and animal feeding operations and the amount of agricultural land were not significant explanatory factors. The urban infrastructure tends to "connect" more of the watershed to the stream network through the creation of roads, storm sewers, and wastewater treatment plants. This may partly explain the relationship between urbanization and bacterial contamination found in this study. [source] Bacterial contamination on touch surfaces in the public transport system and in public areas of a hospital in LondonLETTERS IN APPLIED MICROBIOLOGY, Issue 6 2009J.A. Otter Abstract Aims:, To investigate bacterial contamination on hand-touch surfaces in the public transport system and in public areas of a hospital in central London. Methods and Results:, Dipslides were used to sample 118 hand-touch surfaces in buses, trains, stations, hotels and public areas of a hospital in central London. Total aerobic counts were determined, and Staphylococcus aureus isolates were identified and characterized. Bacteria were cultured from 112 (95%) of sites at a median concentration of 12 CFU cm,2. Methicillin-susceptible Staph. aureus (MSSA) was cultured from nine (8%) of sites; no sites grew methicillin-resistant Staph. aureus (MRSA). Conclusions:, Hand-touch sites in London are frequently contaminated with bacteria and can harbour MSSA, but none of the sites tested were contaminated with MRSA. Significance and Impact of the Study:, Hand-touch sites can become contaminated with staphylococci and may be fomites for the transmission of bacteria between humans. Such sites could provide a reservoir for community-associated MRSA (CA-MRSA) in high prevalence areas but were not present in London, a geographical area with a low incidence of CA-MRSA. [source] The effect of a commercial UV disinfection system on the bacterial load of shell eggsLETTERS IN APPLIED MICROBIOLOGY, Issue 2 2006K. De Reu Abstract Aims:, To study the effect of UV irradiation on the bacterial load of shell eggs and of a roller conveyor belt. Methods and Results:, The natural bacterial load on the eggshell of clean eggs was significantly reduced by a standard UV treatment of 4·7 s; from 4·47 to 3·57 log CFU per eggshell. For very dirty eggs no significant reduction was observed. Eggs inoculated with Escherichia coli and Staphylococcus aureus (4·74 and 4·64 log CFU per eggshell respectively) passed the conveyor belt and were exposed to UV for 4·7 and 18·8 s. The reduction of both inoculated bacteria on the eggshell was comparable and significant for both exposure times (3 and 4 log CFU per eggshell). Escherichia coli was reduced but still detectable on the conveyor rollers. The internal bacterial contamination of eggs filled up with diluent containing E. coli or S. aureus was not influenced by UV irradiation. Conclusions:, There is a significant lethal effect of UV irradiation on the bacterial contamination of clean eggshells and recent shell contamination, contamination of rollers can be controlled and the internal contamination of eggs is not reduced. Significance and Impact of the Study:, The penetration of UV into organic material appears to be poor and UV disinfection can be used as an alternative for egg washing. [source] Subtyping of Bacterial Foodborne PathogensNUTRITION REVIEWS, Issue 7 2002Martin Wiedmann D.V.M. Ph.D. Phenotype-based and DNA-based subtyping methods allow for differentiation of bacterial isolates beyond the species and subspecies level. Bacterial subtyping methods not only have improved our ability to detect and track foodborne disease outbreaks, but also represent tools to track sources of bacterial contamination throughout the food system. The use of subtyping methods furthermore provides an opportunity to better understand the population genetics, epidemiology, and ecology of different foodborne pathogens. The last 5 years have seen tremendous advancement in the development of sensitive, rapid, automated, and increasingly easy-to-use molecular subtyping methods for a variety of different bacterial foodborne pathogens. This review will highlight key aspects of different subtyping methods for bacterial foodborne pathogens and provide examples of their applications in public health, food safety, epidemiology, and population genetics. Molecular subtyping and characterization methods may also facilitate the development of a novel framework for tracking, preventing, and regulating foodborne bacterial diseases, which is based on evolutionary relationships and genetic characteristics rather than traditional species definitions. [source] Bacteriological Findings and Hormonal Profiles in the Postpartum Balady GoatsREPRODUCTION IN DOMESTIC ANIMALS, Issue 1 2006M M Ababneh Contents Twenty-six Balady goats categorized according to parity into primiparous and pluriparous goats were used to investigate bacterial flora of the genital tract and hormonal profiles during the postpartum (PP) period. Escherichia coli and Staphylococcus aureus were isolated in pure or mixed culture from the uterus. Arcanobacterium pyogenes was isolated from swabs obtained from the vagina and cervix of one primiparous goat. Uteri and cervices but not vaginas were free of bacterial contamination by day 10 PP except for one pluriparous goat with scanty E. coli contamination on day 25 PP. Fluctuating oestradiol 17, (E2) levels demonstrated resumption of follicular activity as early as day 13 PP in both parity groups. Progesterone (P4) levels remained low at basal levels throughout the study period. Higher concentrations of 15-keto-13,14-dihydroprostaglandin F2, (PGFM) were observed during the first week PP compared with the rest of the PP period. PGFM concentrations dropped to low basal level by day 10 PP and remained constantly low throughout the study period. P4, E2 and PGFM profiles were not different between the different parity groups. In conclusion, intrauterine infection is not common in goats with normal kidding. E. coli was the most common intrauterine bacterial isolate. E2 and P4 profiles were consistent with resumption of follicular growth but not ovulation. High PGFM concentrations coincided with the fast regression phase of uterine involution. Hormonal profile and bacterial contamination and clearance were similar to those reported in other related species and not related to parity. [source] Bacterial contamination of PCA and epidural infusion devicesANAESTHESIA, Issue 7 2009M. Rothwell Summary We prospectively audited the bacterial contamination of re-useable analgesia infusion pumps. In a one-month period, 112 samples from the handset and keypads of our analgesia infusion pumps were cultured for bacterial contamination. Forty-five percent of handset swabs and 46% of keypad swabs grew bacteria; the commonest organism being coagulase-negative staphylococcus. An additional cleaning step using 70% isopropyl alcohol wipes was introduced and the contamination rate was re-audited in 100 samples. The contamination rate was reduced to 6% of handset swabs and 4% of keypad swabs. A high initial rate of bacterial contamination of re-useable analgesia infusion pumps was significantly reduced by the implementation of a simple, additional cleaning procedure. [source] AMERICAN SOCIETY OF ANESTHESIOLOGISTS CLASSIFICATION OF PHYSICAL STATUS AS A PREDICTOR OF WOUND INFECTIONANZ JOURNAL OF SURGERY, Issue 9 2007John C. Woodfield Background: Wound infection occurs when bacterial contamination overcomes the hosts' defences against bacterial growth. Wound categories are a measurement of wound contamination. The American Society of Anesthesiologists (ASA) classification of physical status may be an effective indirect measurement of the hosts' defence against infection. This study examines the association between the ASA score of physical status and wound infection. Methods: A retrospective review of a prospective study of antibiotic prophylaxis was carried out. Patients with a documented ASA score who received optimal prophylactic antibiotics were included. The anaesthetist scored the ASA classification of physical status in theatre. Other risk factors for wound infection were also documented. Patients were assessed up to 30 days postoperatively. Results: Of 1013 patients there were 483 with a documented ASA score. One hundred and one may not have received optimal prophylaxis, leaving a database of 382 patients. There were 36 wound infections (9.4%). Both the ASA classification of physical status (P = 0.002) and the wound categories (P = 0.034) significantly predicted wound infection. The duration of surgery, patient's age, acuteness of surgery and the organ system being operated on did not predict wound infection. On logistic regression analysis the ASA score was the strongest predictor of wound infection. Conclusion: When effective prophylactic antibiotics were used the ASA classification of physical status was the most significant predictor of wound infection. [source] Postoperative surgical site infections in cardiac surgery ,an overview of preventive measuresAPMIS, Issue 9 2007BENGT GÅRDLUND Postoperative surgical site infections are a major cause of postoperative morbidity and mortality in cardiac surgery. A surgical site infection occurs when the contaminating pathogens overcome the host defense systems and an infectious process begins. Bacteria may enter the operating site either by direct contamination from the patient's skin or internal organs, through the hands and instruments of the surgical staff or by bacteria-carrying particles that float around in the operating theatre and may land in the wound. The ability to withstand the contaminating bacteria depends on both local and systemic host defense. Successful preventive strategies are multiple and must include: 1) Minimizing the bacterial contamination of the surgical site (skin preparation, operating room ventilation, scrubbing, double gloving, etc.), 2) Minimizing the consequences of virulent contaminating bacteria by antibiotic prophylaxis (adequate dose, sort, timing, duration), 3) Minimizing injury to local host defense (atraumatic surgery, no excessive electrocautery, meticulous hemostasis, etc.), and 4) Optimizing general host defense (nutrition, tobacco smoking, weight loss, etc.). Compliance with these preventive procedures must be enforced through regular reviews of performance. Non-compliance with hygiene routines is often due to ignorance and poor planning. Education of personnel in these issues is a continuous process. [source] | |||||||||||||||||||