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At least 793 records · Page 44Linked to original sources
PubMed2003

Multivariate analyses of invertebrate community responses to a C12-15 AE-3S anionic surfactant in stream mesocosms.

The ecological effects of a C(12-15)AE-3S linear alkylethoxysulfate anionic surfactant on aquatic organisms were studied in stream mesocosms. Analyses of the experimental data have yielded multiple population-level no-observed effect concentrations (NOECs) but did not provide a measure of community-level response to surfactant exposure. In the present study, the invertebrate data from the mesocosm study were further examined for community-level effects using multivariate techniques. Two multivariate statistical methods were selected as representative of recommended methods and used to analyze invertebrate abundance. One method was similarity analysis using the Bray-Curtis index, and the second method was the canonical ordination technique principal response curves recently developed for analysis of mesocosm data. Both sets of techniques detected statistically significant changes in invertebrate community structure following surfactant exposure. Ordinations constructed from Bray-Curtis similarity matrices provided clearer two-dimensional representations of these changes than ordinations from redundancy analysis. Re-displaying treatment and temporal effects on community structure on separate axes as response curves provided a clearer method for interpreting community response to surfactant exposure. Both approaches detected treatment effects in low and high abundance taxa. The highest rank abundance taxa in the pretreatment streams contributed very little to the differences observed between the control and treated streams. The same set of taxa was identified as the dominant drivers for structural differences between control and treated communities despite underlying mathematical differences in these two methods. Invertebrate community-level NOECs estimated from these different multivariate methods (2.5-5.0 mg/l) were comparable and these NOECs were similar to invertebrate population NOECs determined for this surfactant.

Alkanesulfonic Acids↗
PubMed2005

Sea lice treatments on salmon farms have no adverse effects on zooplankton communities: a case study.

The long-term effects of the sea lice treatment products Excis and Slice on zooplankton communities in a Scottish sea loch were investigated at a commercially operating salmon farm over 31 months. Cypermethrin and emamectin benzoate are the active ingredients in Excis and Slice respectively, which are widely used to control ectoparasitic sea lice on farmed salmon. Excis and Slice treatments did not cause basin-wide effects on the zooplankton community. For both formulations, no adverse affects on zooplankton were detected, instead observed changes in zooplankton abundance and community composition displayed natural seasonal cycles of abundance. Water column concentrations of cypermethrin and emamectin benzoate following sea lice treatments at the fish farm were predicted using models. Cypermethrin concentrations of 3000 ng/l were predicted for short periods immediately after each cage treatment assuming no particle adhesion. The 3-h and 24-h Environmental Quality Standards (EQS) were exceeded for 10 h and 32 h respectively on the second day when five cages were treated. However, cypermethrin concentrations higher than 0.5 ng/l (24-h EQS) were predicted to occur over <2% of the total basin area on each treatment day. The 3-h EQS (16 ng/l) was exceeded in <0.3% of the basin on each treatment day. The concentration of soluble emamectin benzoate present in the water column was predicted from modelled deposition footprints and sediment concentrations to be of order 10(-3) ng/l. Predicted concentrations of both chemicals were generally lower than those causing toxicity to copepods in previous laboratory studies and further support the results of this field study that environmental concentrations of Excis and Slice do not adversely impact zooplankton communities.

Animals↗
PubMed2006

Acute bacterial meningitis in Qatar.

OBJECTIVE: To study the changes in the epidemiology, clinical and bacteriological profiles of bacterial meningitis in the era of the Haemophilus influenzae type b (Hib)vaccine and pneumococcus resistance. METHODS: This is a retrospective study of children aged <12 years admitted to the Hamad Medical Corporation, Qatar between January 1998 through December 2002 with positive cerebrospinal fluid culture. RESULTS: We described 64 patients with culture proven bacterial meningitis. In infants <3 months (n=29 [45%]), the most common organism was Group B Streptococcus (GBS) (20%). Children >3 months (n=35 [55%]); Hib (25%) and Streptococcus pneumoniae (STP) (20%) were the most common organisms before introduction of Hib vaccination. A significant drop of Hib infections were noticed after introduction of the vaccine. Fever, neck stiffness, seizure, vomiting, and bulging fontanel were the most frequent presenting features. Group B Streptococcus were sensitive to ampicillin and cefotaxime with no resistance detected. Forty percent of STP isolates were resistant to penicillin and 12% were resistant to ceftriaxone. Fifty percent of Hib were resistant to ampicillin; while none of Hib were resistant to ceftriaxone. No case of Listeria monocytogenes meningitis was diagnosed. Morbidity was 28%, and one patient expired (2%) after Klebsiella pneumoniae meningitis. Streptococcus pneumoniae was associated with the highest morbidity (62%) while Hib had zero morbidity in our patients. CONCLUSION: Bacterial meningitis is a serious illness with a significant morbidity and mortality. Haemophilus influenzae type b infection decreased which indicated an effective vaccination. As there is 12% bacterial resistance of STP reported against ceftriaxone; We recommend Cefotaxime for infants <3 months while ceftriaxone plus vancomycin as empiric therapy for older patients with community acquired bacterial meningitis. A pneumococcal vaccination may further decrease the incidence of meningitis in our community. A continuos surveillance to detect changes in the microbiology of organisms causing bacterial meningitis or their sensitivity in our community is essential to update these recommendations.

Acute Disease↗
PubMedDate not supplied

Characterization of microbial communities from coastal waters using microarrays.

Molecular methods, including DNA probes, were used to identify and enumerate pathogenic Vibrio species in the Chesapeake Bay; our data indicated that Vibrio vulnificus exhibits seasonal fluctuations in number. Our work included a characterization of total microbial communities from the Bay; development of microarrays that identify and quantify the diversity of those communities; and observation of temporal changes in those communities. To identify members of the microbial community, we amplified the 16S rDNA gene from community DNA isolated from a biofilm sample collected from the Chesapeake Bay in February, 2000. The resultant 75 sequences were 95% or more similar to 7 species including two recently described Shewanella species, baltica and frigidimarina, that have not been previously isolated from the Chesapeake. When the genera of bacteria from biofilm after culturing are compared to those detected by subcloning amplified 16S fragments from community DNA, the cultured sample exhibited a strong bias. In oysters collected in February, the most common bacteria were previously unknown. Based on our 16S findings, we are developing microarrays to detect these and other microbial species in these estuarine communities. The microarrays will detect each species using four distinct loci, with the multiple loci serving as an internal control. The accuracy of the microarray will be measured using sentinel species such as Aeromonas species, Escherichia coli, and Vibrio vulnificus. Using microarrays, it should be possible to determine the annual fluctuations of bacterial species (culturable and non-culturable, pathogenic and non-pathogenic). The data may be applied to understanding patterns of environmental change; assessing the "health" of the Bay; and evaluating the risk of human illness associated with exposure to and ingestion of water and shellfish.

Animals↗
PubMed2000

Eradication of vancomycin resistant Enterococcus faecium from a paediatric oncology unit and prevalence of colonization in hospitalized and community-based children.

We previously reported an outbreak of vancomycin resistant enterococci (VRE) in a paediatric oncology unit in December 1995 which was associated with widespread environmental contamination of the unit with VRE. We undertook this study to evaluate the effectiveness of the infection control policy instituted subsequent to the outbreak and to investigate the underlying prevalence of VRE colonization in hospitalized, outpatient and community-based children. We sought to establish the molecular similarity of VRE isolates from the study. Stool specimens were obtained from outpatients at risk of VRE, hospital inpatients and from healthy community-based children. VRE colonization was eradicated from the inpatient unit within 11 months, but in outpatients, 16 months after the outbreak, 4 of 137 (2.9 %) attending oncology outpatients, 5 of 65 (7.7%) with cystic fibrosis and 1 of 12 (8.3 %) with liver disease were found to be colonized with VRE. The isolates were all Enterococcus faecium, Van A phenotype except one E. casseliflavus of the Van C phenotype. All were unique in SmaI DNA macrorestriction patterns with the exception of two isolates, which were similar to the original outbreak strain and three further isolates of a single strain but which differed from the outbreak strain. Of 315 hospital inpatients, 2.5 % were colonized with VRE of the Van C resistance phenotype but VRE was not detected in 116 healthy, community-based children. We conclude that effective strategies can successfully control spread of VRE but despite a low prevalence of VRE colonization in hospital patients and in community-based children, outbreaks can occur when infection control practices are not optimal. Continued vigilance to detect VRE and limit spread within hospitals is therefore necessary.

Adolescent↗
PubMed2002

Detection of Chlamydia trachomatis infection in early pregnancy using self-administered vaginal swabs and first pass urines: a cross-sectional community-based survey.

A cross-sectional survey of 1216 newly pregnant women (mean age = 31 years) from 32 general practices and five family planning clinics was conducted to find the prevalence of chlamydial infection and to evaluate self-administered vaginal swabs and first-pass urines for detection of Chlamydia trachomatis by ligase chain reaction assay. Overall prevalence of infection was 2.4% (95% CI = 1.5 to 3.3) but in women aged less than 25 years it was 8.6% (95% CI = 4.1 to 12.9) and in pregnant teenagers it was 14.3% (95% CI = 3.7 to 24.9). In 1161 women with both swab and urine results, 25 women were positive on both specimens three on swab alone, and one on urine alone. When asked which they preferred to provide, 47% said urine, 59 swab and 48% preferred both equally. This is the first study to show that non-invasive screening in early pregnancy is feasible in the community. Although swabs detected 10% more infections, nearly half the women preferred providing urine specimens.

Adolescent↗
PubMed2005

Contact screening and latent TB infection treatment in Singapore correctional facilities.

SETTING: Singapore, a city-state with a tuberculosis (TB) incidence rate of 47 per 100000 population in 2000. OBJECTIVES: 1) To report our experience with contact investigation and latent TB infection (LTBI) treatment in high-risk contacts with unknown human immunodeficiency virus (HIV) status in correctional facilities (CFs) (prisons/drug rehabilitation centres); and 2) to compare the yield of contact screening in this setting with that in the community (household/family) setting. METHODS: The tuberculin skin test (TST) readings of 704 CF contacts screened from 1999 to 2001 were compared with those of 2729 household/family contacts who underwent screening in 2000. RESULTS: Respectively eight (1.1%) and 20 (0.7%) active TB cases were detected among the CF and community contacts. A significantly higher proportion of CF contacts had first (non-conversion) TST readings > or =15 mm (39% vs. 22%, OR 2.3; 95%CI 1.9-2.7; P < 0.001), and 10-14 mm (26% vs. 18%, OR 1.6; 95%CI 1.3-2.0; P < 0.001) and TST conversion (43% vs. 20%, OR 2.9; 95%CI 1.7-4.9; P < 0.001). LTBI treatment was started in 65% of the CF contacts screened; 87% completed treatment. CONCLUSION: We found a high LTBI rate among CF contacts, presenting an opportunity for intervention.

Adult↗
PubMed2006

Molecular epidemiology of group A rotaviruses in water sources and selected raw vegetables in southern Africa.

Group A rotaviruses (RVs) are the most important cause of acute viral gastroenteritis in infants and young children. In this study raw and treated drinking water supplies at plants in two geographic areas, as well as selected irrigation water and corresponding raw vegetables in three regions of southern Africa, were screened for the presence of RVs using molecular techniques. Group A RVs were detected in 11.8% of partially treated and 1.7% of finally treated drinking water samples and in 14% of irrigation water samples and 1.7% of corresponding raw vegetable samples. Type-specific reverse transcriptase-PCR and sequence analysis revealed the presence of multiple types (G1, G2, G8, and G9) in irrigation water and single types (G1 or G3) in raw and treated drinking water. Group A RVs detected in all samples consisted of mixed P types (P[4], P[6], P[8], and P[9]), with P[6] predominating. The detection of types G8, G9, and P[6] reflects the emergence of these types in clinical infections. The similarity of environmental types to those in patients with clinical RV infections confirms the value of wastewater screening as a tool for assessing RVs circulating in communities, with the benefit of detecting types that cause both clinical and subclinical infections. The results provide new information on RV types in water and related environments and identify the potential risk of waterborne transmission. In addition, the presence of RVs in drinking water underlines shortcomings in quality specifications. These data provide valuable information regarding the prevalence of RVs in environmental sources, with important implications for vaccine development.

Agriculture↗
PubMed2000

Community-based validation of the McCormick Toy Test.

The aim of the present study was to investigate the validity of a community-based hearing test to detect conductive hearing loss in 3-year-old children. Sixty-five children had their hearing tested using standard audiological tests at the same time as they underwent their 3-year-old health checks. The checks were performed by health visitors at community health clinics, and included the McCormick Toy Test (MCTT) for hearing. Fourteen children failed both tests and none passed the MCTT and failed the standard tests, giving a sensitivity of 100%. Forty-eight children passed both tests and three children failed the MCTT but passed the standard tests, giving a specificity of 94%. Positive predictive value was 82%. The results from this sample indicate that the MCTT may be used as a valid test for conductive hearing loss for 3-year-old children in the community setting.

Acoustic Impedance Tests↗
PubMed2003

Detection of Clostridium difficile cytotoxin and Clostridium perfringens enterotoxin in cases of diarrhoea in the community.

Faecal specimens from 843 cases of diarrhoea in the community were tested for the presence of Clostridium difficile cytotoxin and Clostridium perfringens enterotoxin. C. difficile cytotoxin was detected in faecal specimens from 0.6 % of cases aged at least 2 years by using a Vero cell assay. Factors associated with detection of C. difficile cytotoxin were antibiotic therapy, age over 60 years and living in a home with other elderly people. Three methods were used for the detection of C. perfringens enterotoxin: a Vero cell assay, a commercial (TechLab) enzyme immunoassay (EIA) and an in-house EIA. The lower level of detection of pure C. perfringens enterotoxin in buffer was 0.01 micro g ml(-1) by the TechLab EIA and 1.0 micro g ml(-1) by the Vero cell assay. C. perfringens enterotoxin was detected by using the TechLab EIA in faecal specimens from 2.5 % of cases. This commercial EIA was less sensitive than the in-house EIA, detecting only 31 % of positive cases, but was specific and could be used for outbreak investigation by routine diagnostic laboratories. Age over 60 years was a factor associated with C. perfringens enterotoxin detection; this age group may be targeted for testing.

Adolescent↗
PubMed2006

Population-based survey on prevalence of adult patients with epilepsy in Taiwan (Keelung community-based integrated screening no. 12).

PURPOSE: To determine the prevalence rate and patterns of adult patients with epilepsy in Taiwan, we conducted a community-based neuroepidemiological survey. METHODS: Epilepsy was detected by neurologists using one-stage method. It was integrated into a community health screening service and performed from 1 January 2001 to 31 December 2001 in Keelung, a northern city in Taiwan. A total of 13,663 subjects aged 30 years or older participated in this survey. RESULTS: There were 52 patients with epilepsy in this study. Among them, 37 were patients with active epilepsy. The age-adjusted prevalence rate of active epilepsy above 30 years old was 2.77/1000 (to the 1980 US population) with the highest rate in subjects aged 40-49 years (4.0/1000). There was a trend of higher prevalence rate in male than in female. The most common seizure type was complex partial seizure (46.0%). Using one-stage detection method, we found nine (24.3%) patients with active epilepsy who had never been diagnosed before. Among the patients with active epilepsy, 35.1% were symptomatic cases. Head injury (13.5%) is the leading cause, followed by CNS infection (8.1%), stroke (5.4%) and perinatal insult (5.4%). The lifetime prevalence rate of epilepsy (including active epilepsy and epilepsy in remission) was 3.14/1000 for age above 30 years. CONCLUSIONS: Comparing to previous epilepsy survey in 1993, our results showed that the prevalence rate of epilepsy was rather stable over the past decade in northern Taiwan. Head injury is the leading cause responsible for active epilepsy. Improving public safety is an important public health issue which may help to reduce occurrence of epilepsy.

Adult↗
PubMed1995

Evaluation of the Mycobacterium leprae particle agglutination (MLPA) test as a tool in the epidemiology of leprosy in high prevalence village in South Sulawesi, Indonesia.

This study reports on the usefulness of an IgM phenolic glycolipid-1 (PGL-1) Mycobacterium leprae particle agglutination (MLPA) test for serodiagnosis of leprosy in a prospective longitudinal community survey in a high prevalence village in South Sulawesi, Indonesia, IgM PGL-1 MLPA has simple and limited value as a screening method for detection of transmission of leprosy in the community. Many normal persons in the community in a high prevalence area had increased IgM anti PGL-1 antibodies, presumably as a consequence of early subclinical infection. In conclusion, this study demonstrated that the MLPA test can only reliably detect anti-PGL-1 antibodies in the community and may be useful for follow-up study of subclinical infection of leprosy among individuals living the an endemic area.

Adolescent↗
PubMed2002

Microbial diversity of a heavily polluted microbial mat and its community changes following degradation of petroleum compounds.

We studied the microbial diversity of benthic cyanobacterial mats inhabiting a heavily polluted site in a coastal stream (Wadi Gaza) and monitored the microbial community response induced by exposure to and degradation of four model petroleum compounds in the laboratory. Phormidium- and Oscillatoria-like cyanobacterial morphotypes were dominant in the field. Bacteria belonging to different groups, mainly the Cytophaga-Flavobacterium-Bacteriodes group, the gamma and beta subclasses of the class Proteobacteria, and the green nonsulfur bacteria, were also detected. In slurry experiments, these communities efficiently degraded phenanthrene and dibenzothiophene completely in 7 days both in the light and in the dark. n-Octadecane and pristane were degraded to 25 and 34% of their original levels, respectively, within 7 days, but there was no further degradation until 40 days. Both cyanobacterial and bacterial communities exhibited noticeable changes concomitant with degradation of the compounds. The populations enriched by exposure to petroleum compounds included a cyanobacterium affiliated phylogenetically with Halomicronema. Bacteria enriched both in the light and in the dark, but not bacteria enriched in any of the controls, belonged to the newly described Holophaga-Geothrix-Acidobacterium phylum. In addition, another bacterial population, found to be a member of green nonsulfur bacteria, was detected only in the bacteria treated in the light. All or some of the populations may play a significant role in metabolizing the petroleum compounds. We concluded that the microbial mats from Wadi Gaza are rich in microorganisms with high biodegradative potential.

Alkanes↗
PubMed2000

Assessment of microbial community structure changes by amplified ribosomal DNA restriction analysis (ARDRA).

Amplified ribosomal DNA restriction analysis (ARDRA) is a simple method based on restriction endonuclease digestion of the amplified bacterial 16S rDNA. In this study we have evaluated the suitability of this method to detect differences in activated sludge bacterial communities fed on domestic or industrial wastewater, and subject to different operational conditions. The ability of ARDRA to detect these differences has been tested in modified Ludzack-Ettinger (MLE) configurations. Samples from three activated sludge wastewater treatment plants (WWTPs) with the MLE configuration were collected for both oxic and anoxic reactors, and ARDRA patterns using double enzyme digestions AluI+MspI were obtained. A matrix of Dice similarity coefficients was calculated and used to compare these restriction patterns. Differences in the community structure due to influent characteristics and temperature could be observed, but not between the oxic and anoxic reactors of each of the three MLE configurations. Other possible applications of ARDRA for detecting and monitoring changes in activated sludge systems are also discussed.

Aerobiosis↗
PubMed1989

Prevention of blindness by screening for diabetic retinopathy: a quantitative assessment.

Diabetic retinopathy is an important cause of blindness in the Western World. A review of the randomised trials of laser photocoagulation of the retina as a method of preventing blindness from this disorder showed that this treatment is very effective, reducing the risk of blindness by 61% in a treated eye. As only one eye is needed for sight the reduction in blindness in a population will be greater than 61% because the effect of treatment in one eye is not always identical with the effect in the other eye. For analysis this reduction was taken as 73%, representing the average of the minimum and maximum estimates (61% and 85%). The effectiveness of this treatment suggests that there is the potential for a national screening programme to bring about a major reduction in blindness from this cause. A quantitative assessment of the effect of screening indicated that a programme in which patients with diabetes mellitus are systematically referred to ophthalmic opticians for a retinal examination could detect 88% of all diabetics with serious retinopathy and that 87% of these cases would be treatable. Screening and early treatment of retinopathy would prevent deterioration of visual acuity and could reduce the risk of blindness due to diabetic retinopathy by an estimated 56% (0.73 X 0.88 X 0.87). The findings suggest that an effectively managed community based screening programme encompassing detection, referral, treatment, and follow up would prevent about 260 new cases of blindness in diabetics under the age of 70 each year in England and Wales. This would represent over 10% of all cases of blindness in adults in this age group.

Blindness↗
PubMedDate not supplied

Abuse of prescription medicines in southwestern France.

BACKGROUND: Few quantitative data are available concerning abuse of medicine in the general population, although dependence on prescription medicines involves a significant proportion of the population. Falsified prescription forms can be used as an indicator of abuse. METHODS: Community pharmacists in a representative network were asked to report any falsified prescription form presented over a 1-year period. Sales data were used to express results as abuse rate and abuse rate ratio. RESULTS: Two-thirds of the 130 pharmacies in the network reported at least 1 falsified prescription. The reported incidence of falsified prescriptions was 2.3 per 10 000 inhabitants. A total of 392 falsified prescription forms was collected. The abuse rate ratios were 171 (95% CI 140 to 210) for dextroamphetamine-phenobarbital in combination, 168 (95% CI 131 to 216) for fenozolone, 67 (95% CI 53 to 84) for buprenorphine, and 40.5 (95% CI 33 to 50) for clobenzorex. CONCLUSIONS: These results show the efficiency of a method for detecting falsified prescriptions forms using community pharmacists. The abuse of medicines already known for their addictive potential can be estimated and alerts can also be detected.

Crime↗
PubMed1994

[Detection of virulence factors using DNA probes in uropathogenic strains of Escherichia coli].

BACKGROUND: There are several bacterial determinants that contribute to the onset of urinary tract infection by E. coli. The present study focuses on some of the virulence factors considered to be most important, as P fimbriae, the siderophore aerobactin and bacterial capsule, which were studied among 123 uropathogenic E. coli strains isolated from outpatients from the Basque Community. METHODS: Virulence factors were detected using Molecular Biology techniques, namely DNA hybridization to specific probes prepared in our laboratory. RESULTS: When probe pap2, specific for fimbrial adherence was used, 36.5% of the strains showed positive hybridization, and 66 and 73% of the strains hybridized to probes for aerobactin and common capsule region, respectively. CONCLUSIONS: We believe that this technology provides a very useful tool for rapid and easy screening of strains harbouring different virulence factors. Nevertheless, the fact that these methods detect genetic determinants that are not always being expressed must be borne in mind.

Bacterial Adhesion↗
PubMed2007

Soil fungal communities underneath willow canopies on a primary successional glacier forefront: rDNA sequence results can be affected by primer selection and chimeric data.

Soil fungal communities underneath willow canopies that had established on the forefront of a receding glacier were analyzed by cloning the polymerase chain reaction (PCR)-amplified partial small subunit (18S) of the ribosomal (rRNA) genes. Congruence between two sets of fungus-specific primers targeting the same gene region was analyzed by comparisons of inferred neighbor-joining topologies. The importance of chimeric sequences was evaluated by Chimera Check (Ribosomal Database Project) and by data reanalyses after omission of potentially chimeric regions at the 5'- and 3'-ends of the cloned amplicons. Diverse communities of fungi representing Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota were detected. Ectomycorrhizal fungi comprised a major component in the early plant communities in primary successional ecosystems, as both primer sets frequently detected basidiomycetes (Russulaceae and Thelephoraceae) forming mycorrhizal symbioses. Various ascomycetes (Ophiostomatales, Pezizales, and Sordariales) of uncertain function dominated the clone libraries amplified from the willow canopy soil with one set of primers, whereas the clone libraries of the amplicons generated with the second primer set were dominated by basidiomycetes. Accordingly, primer bias is an important factor in fungal community analyses using DNA extracted from environmental samples. A large proportion (>30%) of the cloned sequences were concluded to be chimeric based on their changing positions in inferred phylogenies after omission of possibly chimeric data. Many chimeric sequences were positioned basal to existing classes of fungi, suggesting that PCR artifacts may cause frequent discovery of new, higher level taxa (order, class) in direct PCR analyses. Longer extension times during the PCR amplification and a smaller number of PCR cycles are necessary precautions to allow collection of reliable environmental sequence data.

Artifacts↗