The impact of indoor air quality and contaminants on respiratory health of older people living in long-term care residences in Porto

Background: persons who are 65 years or older often spend an important part of their lives indoors thus adverse indoor climate might influence their health status. Objective: to evaluate the influence of indoor air quality and contaminants on older people’s respiratory health. Design: cross-sectional study. Setting: 21 long-term care residences (LTC) in the city of Porto, Portugal. Subjects: older people living in LTC with ≥65 years old. Methods: the Portuguese version of BOLD questionnaire was administered by an interviewer to older residents able to participate (n = 143). Indoor air contaminants (IAC) were measured twice, during winter and summer in 135 areas. Mixed effects logistic regression models were used to study the association between the health questionnaire results and the monitored IAC, adjusted for age, smoking habits, gender and number of years living in the LTC. Results: cough (23%) and sputum (12%) were the major respiratory symptoms, and allergic rhinitis (18%) the main selfreported illness. Overall particulate matter up to 2.5 micrometres in size median concentration was above the reference levels both in winter and summer seasons. Peak values of particulate matter up to 10 micrometres in size (PM10), total volatile organic compounds, carbon dioxide, bacteria and fungi exceeded the reference levels. Older people exposed to PM10 above the reference levels demonstrated higher odds of allergic rhinitis (OR = 2.9, 95% CI: 1.1–7.2). Conclusion: high levels of PM10 were associated with 3-fold odds of allergic rhinitis. No association was found between indoor air chemical and biological contaminants and respiratory symptoms.

Indoor air quality in Portuguese schools: levels and sources of pollutants

Indoor air quality (IAQ) parameters in 73 primary classrooms in Porto were examined for the purpose of assessing levels of volatile organic compounds (VOCs), aldehydes, particulate matter, ventilation rates and bioaerosols within and between schools, and potential sources. Levels of VOCs, aldehydes, PM2.5 , PM10 , bacteria and fungi, carbon dioxide (CO2 ), carbon monoxide, temperature and relative humidity were measured indoors and outdoors and a walkthrough survey was performed concurrently. Ventilation rates were derived from CO2 and occupancy data. Concentrations of CO2 exceeding 1000 ppm were often encountered, indicating poor ventilation. Most VOCs had low concentrations (median of individual species <5 μg/m(3) ) and were below the respective WHO guidelines. Concentrations of particulate matter and culturable bacteria were frequently higher than guidelines/reference values. The variability of VOCs, aldehydes, bioaerosol concentrations, and CO2 levels between schools exceeded the variability within schools. These findings indicate that IAQ problems may persist in classrooms where pollutant sources exist and classrooms are poorly ventilated; source control strategies (related to building location, occupant behavior, maintenance/cleaning activities) are deemed to be the most reliable for the prevention of adverse health consequences in children in schools.

Indoor air quality in schools and its relationship with children's respiratory symptoms

A cross-sectional survey was conducted to characterize the indoor air quality (IAQ) in schools and its relationship with children's respiratory symptoms. Concentrations of volatile organic compounds (VOC), aldehydes, PM2.5, PM10, carbon dioxide, bacteria and fungi were assessed in 73 classrooms from 20 public primary schools located in Porto, Portugal. Children who attended the selected classrooms (n = 1134) were evaluated by a standardised health questionnaire completed by the legal guardians; spirometry and exhaled nitric oxide tests. The results indicated that no classrooms presented individual VOC pollutant concentrations higher than the WHO IAQ guidelines or by INDEX recommendations; while PM2.5, PM10 and bacteria levels exceeded the WHO air quality guidelines or national limit values. High levels of total VOC, acetaldehyde, PM2.5 and PM10 were associated with higher odds of wheezing in children. Thus, indoor air pollutants, some even at low exposure levels, were related with the development of respiratory symptoms. The results pointed out that it is crucial to take into account the unique characteristics of the public primary schools, to develop appropriate control strategies in order to reduce the exposure to indoor air pollutants and, therefore, to minimize the adverse health effects.

Information and the evolution of codon bias

The informational properties of biological systems are the subject of much debate and research. I present a general argument in favor of the existence and central importance of information in organisms, followed by a case study of the genetic code (specifically, codon bias) and the translation system from the perspective of information. The codon biases of 831 Bacteria and Archeae are analyzed and modeled as points in a 64-dimensional statistical space. The major results are that (1) codon bias evolution does not follow canonical patterns, and (2) the use of coding space in organsims is a subset of the total possible coding space. These findings imply that codon bias is a unique adaptive mechanism that owes its existence to organisms' use of information in representing genes, and that there is a particularly biological character to the resulting biased coding and information use.

Role of Aeromonas hydrophila in bacterial septicemia of cultured carps in Khouzestan Province and investigation on protectivity of bacterin (s) prepared from acute isolate(s) of it

Motile Aeromonas are the most common bacteria of freshwater in the world that cause disease in fish and other cold-blooded and warm-blooded hosts. Among this group of bacteria, Aeromonas hydrophila is important in causing complications such as fin rot, skin ulcers and lethal hemorrhagic septicemia in fish. Several virulence factors involved in the pathogenesis of Aeromonas hydrophila, including extracellular enzymes (protease, lipase, elastase, gelatinase and nuclease) and toxins. From the exotoxins, hemolysin, aerolysin and cytolytic enterotoxin play an important role in pathogenesis. Detection of virulence markers by PCR as a key component of determining the pathogenesis of the bacteria and using indigenous vaccines for better immunization against this disease is important. In this study, a total of 200 fanned carps (126 common carp. 39 silver carp and 35 of grass carp) with symptoms suspected aeromonas septicemia were isolated from Khouzestan province farms. 125 bacteria belong to Aeromonas genus detected by biochemical and PCR methods. 31 of all isolates recognized as Aeromonas hydrophila with biochemical methods, I6srRNA detection and Lipase genes. Results showed that the role of Aeromonas sp. and Aeromonas hydrophila in fish with disease symptoms were 62.5% and 15.5% respectively. By using specific primers, three virulence genes including hemolysin, aerolysine and cytolytic enterotoxin were detected in these confirmed isolates, that 18 isolates (58/06%) hemolysin positive (hlyA +), 16 isolates (51/61%) aerolysine positive (aerA+) and 23 isolates (74/19%) for cytolytic enterotoxin gene (act+) were positive. The result of present study showed that most of the confirmed isolates genotype was hlyA+ act- with frequency equal to 51/61%. For investigating the protection effect of acut strain of bacteria, UV inactivated bacterin was used.

Co-occurrence of Helicobacter pylori with faecal bacteria in Nairobi river basin: public health implications.

Introduction: Overwhelming evidence implicates Helicobacter pylori (H. pylori) as an etiologic agent of gastrointestinal diseases including gastric cancer. The mode of transmission of this pathogen remains poorly understood. Objective: This investigation is to establish the presence of H. pylori in the waters of the Nairobi river basin and the predictive value the presence of fecal indicator bacteria would have for H. pylori. Methodology: Physical, chemical and biological assessment of water quality of rivers in Nairobi were carried out using standard methods. H. pylori DNA in water was detected using highly specific primers of glmM gene (294pb). Results: There was high presence of faecal bacteria in the waters sampled. H. pylori DNA was detected in two domestic wells and one river. The wells were located in two different regions of the water basin but influenced by similar human activities. Conclusion: The high presence of faecal bacteria in the waters sampled did not parallel the H. pylori detection in the same waters. H. pylori was detected in the Nairobi river basin, but there was no relationship between the numerical levels of fecal bacteria and H. pylori.

Demonstration of the interactions between aromatic compound-loaded lipid nanocapsules and Acinetobacter baumannii bacterial membrane

International audience

ATTACHMENT, GROWTH AND PERSISTENCE OF CRONOBACTER ON GRANULAR ACTIVATED CARBON FILTERS

Several Cronobacter outbreaks have implicated contaminated drinking water. This study assessed the impact of granular activated carbon (GAC) on the microbial quality of the water produced. A simulated water filter system was installed by filling plastic columns with sterile GAC, followed by sterile water with a dilute nutrient flowing through the column at a steady rate. Carbon columns were inoculated with Cronobacter on the surface, and the effluent monitored for Cronobacter levels. During a second phase, commercial faucet filters were distributed to households for 4-month use. Used filters were backwashed with sterile peptone water, and analyzed for Cronobacter, total aerobic plate count, coliform bacteria and Enterobacteriaceae. Cronobacter colonized the simulated GAC and grew when provided minimal levels of nutrients. Backwashed used filters used in home settings yielded presumptive Escherichia coli, Pseudomonas and other waterborne bacteria. Presumptive Cronobacter strains were identified as negative through biochemical and genetic test.

Renal and antibacterial effects induced by myotoxin I and II isolated from Bothrops jararacussu venom

Bothrops jararacussu myotoxin I (BthTx-I; Lys 49) and II (BthTX-II; Asp 49) were purified by ion-exchange chromatography and reverse phase HPLC. In this work we used the isolated perfused rat kidney method to evaluate the renal effects of B. jararacussu myotoxins I (Lys49 PLA(2)) and II (Asp49 PLA(2)) and their possible blockage by indomethacin. BthTX-1 (5 mu g/ml) and BthTX-II (5 mu g/ml) increased perfusion pressure (PP; ct(120) = 110.28+/-3.70 mmHg; BthTX I = 171.28+/-6.30* mmHg; BthTX II = 175.50+/-7.20* mmHg), renal vascular resistance (RVR; ct(120) = 5.49+/-0.54 mmHg/ml.g(-1) min(-1); BthTX I = 8.62+/-0.37* mmHg/ml g(-1) min(-1); BthTX II=8.9+/-0.36* mmHg/ml g(-1) min(-1)), urinary flow (UF; ct(120)= 0.14+/-0.01 ml g(-1) min(-1); BthTX I=0.32+/-0.05* ml g(-1) min(-1); BthTX II=0.37+/-0.01* ml g(-1) min(-1)) and glomerular filtration rate (GFR; ct(120)=0.72+/-0.10 ml g(-1) min(-1); BthTX I=0.85+/-0.13* ml g(-1) min(-1); BthTX II=1.22+/-0.28* ml g(-1) min(-1)). In contrast decreased the percent of sodium tubular transport (%TNa+; ct(120)=79,76+/-0.56; BthTX I=62.23+/-4.12*; BthTX II=70.96+/-2.93*) and percent of potassium tubular transport (%TK+;ct(120)=66.80+/-3.69; BthTX I=55.76+/-5.57*; BthTX II=50.86+/-6.16*). Indomethacin antagonized the vascular, glomerular and tubular effects promoted by BthTX I and it's partially blocked the effects of BthTX II. In this work also evaluated the antibacterial effects of BthTx-I and BthTx-II against Xanthomonas axonopodis. pv. passiflorae (Gram-negative bacteria) and we observed that both PLA2 showed antibacterial activity. Also we observed that proteins Also we observed that proteins chemically modified with 4-bromophenacyl bromide (rho-BPB) decrease significantly the antibacterial effect of both PLA(2). In conclusion, BthTx I and BthTX II caused renal alteration and presented activity antimicrobial. The indomethacin was able to antagonize totally the renal effects induced by BthTx I and partially the effects promoted by BthTx II, suggesting involvement of inflammatory mediators in the renal effects caused by myotoxins. In the other hand, other effects could be independently of the enzymatic activity of the BthTX II and the C-terminal domain could be involved in both effects promoted for PLA(2). (C) 2005 Elsevier Ltd. All rights reserved.

VIVALDI, A H2020 European Project aiming at preventing and mitigating farmed bivalve diseases

The European shellfish industry enjoys a privileged position on the global scene. Its social dimension is essential, as it employs a high number of people in more than 8000 companies, mostly micro-companies. Shellfish production in Europe is little diversified and mainly relies on the industrially produced mussels, oysters and clams. Over the recent years, this sector has grown more slowly than other fish farming sectors, notably because it depends a great deal on the environmental quality and the emergence of diseases. Mortality events, linked to pathogen organisms such as viruses, bacteria and parasites (protozoa), tend to weaken the production’s sustainability. In this context, the European project VIVALDI (PreVenting and mItigating farmed biVALve DIseases) aims at increasing the sustainability and competitiveness of the shellfish industry in Europe, developing tools and approaches with a view to better preventing and controlling marine bivalve diseases. VIVALDI is a 4-years European Horizon 2020 project coordinated by Ifremer (2016-2020): 21 mostly European, public and private partners are involved, representing the diversity of the European shellfish industry landscape

Antimicrobial and bond strength properties of a dental adhesive containing zinc oxide nanoparticles

Aim: To assess the effect of adding zinc oxide nanoparticles to dental adhesives on their anti-microbial and bond strength properties. Methods: 45 human premolars were cut at the cement enamel junction (CEJ) and the crowns were sliced into buccal and lingual halves. The specimens were classified into three groups, etched with 37% phosphoric acid for 15 s and rinsed for 30 s. Single Bond, Single Bond+5% zinc oxide and Single Bond+10% zinc oxide were used in the first, second and third groups. A cylinder of Z250 composite was bonded and cured for 40 s. For anti-bacterial testing, 10 samples of each group were assessed by direct contact test; 10 μL of bacterial suspension was transferred into tubes containing adhesives and incubated for one hour; 300 μL of brain heart infusion (BHI) broth was added to each tube and after 12 h, 50 μL of bacteria and broth were spread on blood agar plates and incubated for 24 h. Results: The colony count decreased significantly in the second and third groups compared to the first. Conclusions: Incorporation of zinc oxide nanoparticles into dental adhesives increases their anti-microbial properties without affecting their bond strength.

Characterization of silver nanoparticles prepared by wet chemical method and their antibacterial and cytotoxicity activities

Purpose: To investigate the efficiency of silver nanoparticles synthesized by wet chemical method, and evaluate their antibacterial and anti-cancer activities. Methods: Wet chemical method was used to synthesize silver nanoparticles (AgNPs) from silver nitrate, trisodium citrate dehydrate (C6H5O7Na3.2H2O) and sodium borohydride (NaBH4) as reducing agent. The AgNPs and the reaction process were characterized by UV–visible spectrometry, zetasizer, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). The antibacterial and cytotoxic effects of the synthesized nanoparticles were investigated by agar diffusion method and MTT assay respectively. Results: The silver nanoparticles formed were spherical in shape with mean size of 10.3 nm. The results showed good antibacterial properties, killing both Gram-positive and Gram-negative bacteria, and its aqueous suspension displayed cytotoxic activity against colon adenocarcinoma (HCT-116) cell line. Conclusion: The findings indicate that silver nanoparticles synthesized by wet chemical method demonstrate good cytotoxic activity in colon adenocarcinoma (HCT-116) cell lines and strong antibacterial activity against various strains of bacteria.

Green synthesis of silver nanoparticles using Arbutus andrachne leaf extract and its antimicrobial activity

Purpose: To synthesize silver nanoparticles (AgNPs) of Arbutus andrachne leaf water extract (LE) and to evaluate the antimicrobial activity of both LE and AgNPs. Methods: The synthesized AgNPs were characterized using the following techniques: ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), X-ray diffraction (XRD) analysis, and analysis of particle size (PS) and zeta potential (ZP). The antimicrobial activities of LE and NPs were assessed by Kirby-Bauer disc diffusion (DD) and broth microdilution (MD) methods according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI). LE and AgNPs were examined against fresh cultures of four Gram-positive and five Gram-negative bacteria, and three yeast strains. Results: AgNPs were successfully synthesized and characterized using Arbutus andrachne LE. The AgNPs showed moderate antibacterial activity against Staphylococcus aureus ATCC 6538p, S. epidermidis ATCC 12228, Escherichia coli ATCC 29998, Klebsiella pnemoniae ATCC 13883 and Pseudomonas aeruginosa ATCC 27853, and also antifungal activity against Candida albicans ATCC 10239 and C. krusei ATCC 6258. Conclusions: Due to the potent activity of AgNPs against Gram-positive and Gram-negative bacteria, and yeast strains, it is suggested that AgNPs are potential broad spectrum antimicrobial agents.

Synthesis and antimicrobial activity of some 2- Piperidinomethylamino-4-(7-H/substituted coumarin-3-yl)- 6-chlorosubstitutedphenyl pyrimidines

Purpose: To prepare and evaluate some 2-piperidinomethylamino-4-(7-H/substitutedcoumarin-3-yl)-6- chlorosubstitutedphenyl pyrimidines as antimicrobial agents. Methods: Some 2-piperidinomethylamino-4-(7-H/substitutedcoumarin-3-yl)-6-chlorosubstitutedphenyl pyrimidines were prepared by reacting 2-amino-4-(7-H/substitutedcoumarin-3-yl)-6- (chlorosubstitutedphenyl) pyrimidines with piperidine and formaldehyde. The chemical structures of the synthesized compounds were elucidated by Fourier transform infrared (FTIR), 1H-nuclear magnetic resonance (1H-NMR), mass spectrometry and elemental analysis. These compounds were investigated for their antimicrobial activity against ten bacteria and five fungi by serial plate dilution method using standard drugs, namely, ofloxacin and ketoconazole, respectively, and their minimum inhibitory concentrations (MICs) were also determined. Results: A total of eighteen new compounds (1a-18a) were synthesized. Compound 6a (MIC = 50 μg/mL; p < 0.05 or less) displayed the highest activity against S. aureus , E. faecalis , Staphylococcus epidermidis , B. subtilis , and B. cereus . Compound 6a further showed good activity (MIC = 25 μg/mL; p < 0.05 or less) against E. coli ; P. aeruginosa K. pneumonia , B. bronchiseptica , and P. vulgaris . Compounds 6a (MIC = 25 μg/mL; p < 0.0001) and 17a (MIC = 25 μg/mL; p < 0.0001) displayed very good activity against C. albicans , A. niger , A. flavus , M. purpureous , and P. citrinum , respectively. Analysis of structure-activity relationship revealed that the presence of bromo group at 7-postion of the coumarin moiety along with the 4-chlorophenyl group at position-6 of the pyrimidine ring is critical for antimicrobial activity against Gram-positive bacteria, Gram negative bacteria and fungi. Conclusion: The synthesized 2-piperidino derivatives are better antifungal and antibacterial agents than the earlier reported 2-morpholino derivatives, but require further investigations against other microbial strains to ascertain their broad spectrum antimicrobial activity.

Toxicity of the therapeutic potassium permanganate to tilapia Oreochromis niloticus and to non-target organisms Ceriodaphnia dubia (microcrustacean cladocera) and Pseudokirchneriella subcapitata (green microalgae)

Potassium permanganate is a chemical compound widely used in aquaculture for the control and removal of parasites, and in the prevention of diseases caused by bacteria and fungi. However, this compound can be toxic to fish, being a strong oxidant. Moreover, there is no consistent information in the literature about its toxicity to non-target organisms. The purpose of this study was to evaluate the acute toxicity (LC50;96h) of potassium permanganate for tilapia, Oreochromis niloticus, and to determine its toxic effects on nontarget organisms using ecotoxicological assays performed with the microcrustacean Ceriodaphnia dubia and with the green microalgae Pseudokirchneriella subcapitata. The results showed that the concentration of 1.81 mg L-1 of potassium permanganate caused acute toxic effect in tilapia fingerlings. The ecotoxicological assays demonstrated that concentrations above 0.12 mg L-1 can cause chronic toxic effects on non-target organisms, indicating possible deleterious effects on the food chain of the aquatic ecosystem that may receive the discharge of effluents released by fish cultures treated with this chemotherapy. All toxic concentrations determined in this study were below those recommended in the literature for the use of this chemotherapy in fish cultures, demonstrating that this type of therapy should be more carefully considered in order to avoid damage to the treated fish and to the environment. (C) 2011 Elsevier B.V. All rights reserved.