Fecal indicators and bacterial pathogens in bottled water from Dhaka, Bangladesh.

Forty-six bottled water samples representing 16 brands from Dhaka, Bangladesh were tested for the numbers of total coliforms, fecal indicator bacteria (i.e., thermotolerant Escherichia coli and Enterococcus spp.) and potential bacterial pathogens (i.e., Aeromonas hydrophila, Pseudomonas aeruginosa, Salmonella spp., and Shigella spp.). Among the 16 brands tested, 14 (86%), ten (63%) and seven (44%) were positive for total coliforms, E. coil and Enterococcus spp., respectively. Additionally, a further nine (56%), eight (50%), six (37%), and four (25%) brands were PCR positive for A. hydrophila lip, P. aeruginosa ETA, Salmonella spp. invA, and Shigella spp. ipaH genes, respectively. The numbers of bacterial pathogens in bottled water samples ranged from 28 ± 12 to 600 ± 45 (A. hydrophila lip gene), 180 ± 40 to 900 ± 200 (Salmonella spp. invA gene), 180 ± 40 to 1,300 ± 400 (P. aeruginosa ETA gene) genomic units per L of water. Shigella spp. ipaH gene was not quantifiable. Discrepancies were observed in terms of the occurrence of fecal indicators and bacterial pathogens. No correlations were observed between fecal indicators numbers and presence/absence of A. hydrophila lip (p = 0.245), Salmonella spp. invA (p = 0.433), Shigella spp. ipaH gene (p = 0.078), and P. aeruginosa ETA (p = 0.059) genes. Our results suggest that microbiological quality of bottled waters sold in Dhaka, Bangladesh is highly variable. To protect public health, stringent quality control is recommended for the bottled water industry in Bangladesh.

Impact of roof surface runoff on urban water quality.

The pollutant impacts of urban stormwater runoff on receiving waters are well documented in research literature. However, it is road surfaces that are commonly identified as the significant pollutant source. This paper presents the outcomes of an extensive program of research into the role of roof surfaces in urban water quality with particular focus on solids, nutrients and organic carbon. The outcomes confirmed that roof surfaces play an important role in influencing the pollutant characteristics of urban stormwater runoff. Pollutant build-up and wash-off characteristics for roads and roof surfaces were found to be appreciably different. The pollutant wash-off characteristics exhibited by roof surfaces show that it influences the first flush phenomenon more significantly than road surfaces. In most urban catchments, as roof surfaces constitute a higher fraction of impervious area compared with road surfaces, it is important that the pollutant generation role of roof surfaces is specifically taken into consideration in stormwater quality mitigation strategies.

Carotenoid and mineral content of different morphotypes of Centella asiatica L. (Gotukola).

Six morphotypes of Centella asiatica designated G(1), G(2), G(3), G(7), G(8) and G(12) were analyzed for carotenoid content, proximate components and selected dietary minerals. Potassium was found to be the major element present in C. asiatica and the content in G(1) and G(3) (6,165.0 ± 125.8 mg/100 g dry weight) was significantly (P < 0.05) higher than all other morphotypes. C. asiatica is more popular for its higher contents of iron and calcium. However, no significant (P>0.05) differences in calcium content among the morphotypes were observed. The imported variety G(7) had significantly higher (P < 0.05) mean content of iron (74.3 ± 34.1 mg/100 g dry weight). The morphotypes G(8) and G(12) contained significantly higher (P < 0.05) content of ß-carotene (77.2 ± 5.1 µg/g fresh weight) and lutein (133.5 ± 10.1 µg/g, fresh weight) respectively. Lutein and ß-carotene levels of these two types were also significantly higher (P < 0.05) than those in the other varieties. The study did not provide any evidence to believe that a given morphotype is superior to another in its overall nutritional value.

Health risk from the use of roof-harvested rainwater in Southeast Queensland, Australia, as potable or nonpotable water, determined using quantitative microbial risk assessment.

A total of 214 rainwater samples from 82 tanks were collected in urban Southeast Queensland (SEQ) in Australia and analyzed for the presence and numbers of zoonotic bacterial and protozoal pathogens using binary PCR and quantitative PCR (qPCR). Quantitative microbial risk assessment (QMRA) analysis was used to quantify the risk of infection associated with the exposure to potential pathogens from roof-harvested rainwater used as potable or nonpotable water. Of the 214 samples tested, 10.7%, 9.8%, 5.6%, and 0.4% were positive for the Salmonella invA, Giardia lamblia ß-giardin, Legionella pneumophila mip, and Campylobacter jejuni mapA genes, respectively. Cryptosporidium parvum oocyst wall protein (COWP) could not be detected. The estimated numbers of Salmonella, G. lamblia, and L. pneumophila organisms ranged from 6.5 × 10¹ to 3.8 × 10² cells, 0.6 × 10° to 3.6 × 10° cysts, and 6.0 × 10¹ to 1.7 × 10² cells per 1,000 ml of water, respectively. Six risk scenarios were considered for exposure to Salmonella spp., G. lamblia, and L. pneumophila. For Salmonella spp. and G. lamblia, these scenarios were (i) liquid ingestion due to drinking of rainwater on a daily basis, (ii) accidental liquid ingestion due to hosing twice a week, (iii) aerosol ingestion due to showering on a daily basis, and (iv) aerosol ingestion due to hosing twice a week. For L. pneumophila, these scenarios were (i) aerosol inhalation due to showering on a daily basis and (ii) aerosol inhalation due to hosing twice a week. The risk of infection from Salmonella spp., G. lamblia, and L. pneumophila associated with the use of rainwater for showering and garden hosing was calculated to be well below the threshold value of one extra infection per 10,000 persons per year in urban SEQ. However, the risk of infection from ingesting Salmonella spp. and G. lamblia via drinking exceeded this threshold value and indicated that if undisinfected rainwater is ingested by drinking, then the incidences of the gastrointestinal diseases salmonellosis and giardiasis are expected to range from 9.8 × 10° to 5.4 × 10¹ (with a mean of 1.2 × 10¹ from Monte Carlo analysis) and from 1.0 × 10¹ to 6.5 × 10¹ cases (with a mean of 1.6 × 10¹ from Monte Carlo analysis) per 10,000 persons per year, respectively, in urban SEQ. Since this health risk seems higher than that expected from the reported incidences of gastroenteritis, the assumptions used to estimate these infection risks are critically examined. Nonetheless, it would seem prudent to disinfect rainwater for use as potable water.

Implications of faecal indicator bacteria for the microbiological assessment of roof-harvested rainwater quality in southeast Queensland, Australia.

The study aimed to evaluate the suitability of Escherichia coli, enterococci, and Clostridium perfringens for assessing the microbiological quality of roof-harvested rainwater and assessing whether the concentrations of these faecal indicators can be used to predict the presence or absence of specific zoonotic bacterial or protozoan pathogens. From a total of 100 samples tested, 58%, 83%, and 46% of samples were found to be positive for, respectively, E. coli, enterococci, and Clostridium perfringens spores, as determined by traditional culture-based methods. Additionally, in the samples tested, 7%, 19%, 1%, 8%, 17%, and 15% were PCR positive for Aeromonas hydrophila lip, Campylobacter coli ceuE, Campylobacter jejuni mapA, Legionella pneumophila mip, Salmonella invA, and Giardia lamblia beta-giardin genes, respectively. However, none of the samples was positive for E. coli O157 lipopolysaccharide, verocytotoxin 1, and verocytotoxin 2 and Cryptosporidium parvum oocyst wall protein genes. The presence or absence of these potential pathogens did not correlate with any of the faecal indicator bacterial concentrations as determined by a binary logistic regression model. The roof-harvested rainwater samples tested in this study appeared to be of poor microbiological quality, and no significant correlation was found between the concentration of faecal indicators and pathogenic microorganisms. The use of faecal indicator bacteria raises questions regarding their reliability in assessing the microbiological quality of water and particularly their poor correlation with pathogenic microorganisms. The presence of one or more zoonotic pathogens suggests that the microbiological analysis of water should be performed and that appropriate treatment measures should be undertaken, especially in tanks where the water is used for drinking.

Evaluating sewage-associated JCV and BKV polyomaviruses for sourcing human fecal pollution in a coastal river in Southeast Queensland, Australia.

In this study, the host-sensitivity and host-specificity of JC virus (JCV) and BK virus (BKV) polyomaviruses were evaluated by testing wastewater and fecal samples from nine host groups in Southeast Queensland, Australia. The JCV and BKV polyomaviruses were detected in 63 human wastewater samples collected from primary and secondary effluent, suggesting high sensitivity of these viruses in human wastewater. In the 81 animal wastewater and fecal samples tested, 80 were polymerase chain reaction (PCR) negative for the JCV and BKV markers. Only one sample (out of 81 animal wastewater and fecal samples) from pig wastewater was positive. Nonetheless, the overall host-specificity of these viruses to differentiate between human and animal wastewater and fecal samples was 0.99. To our knowledge, this is the first study in Australia that reports on the high specificity of JCV and BKV polyomaviruses. To evaluate the field application of these viral markers for detecting human fecal pollution, 20 environmental samples were collected from a coastal river. In the 20 samples tested, 15% (3/20) and 70% (14/20) samples exceeded the regulatory guidelines for Escherichia coli and enterococci levels for marine waters. In all, five (25%) samples were PCR positive for JCV and BKV, indicating the presence of human fecal pollution in the coastal river investigated. The results suggest that JCV and BKV detection using PCR could be a useful tool for identifying human-sourced fecal pollution in coastal waters.

Faecal pollution source identification in an urbanizing catchment using antibiotic resistance profiling, discriminant analysis and partial least squares regression.

Increasing urbanisation and changes in land use lead to adverse impacts on the quality of natural water resources. The specific sources of contamination are often difficult to identify using conventional water quality monitoring techniques. This acts as a significant constraint to the development of appropriate management techniques to protect natural water resources. Consequently, alternative means of identifying pollutant sources and their locality are necessary. In this study, Antibiotic Resistance Patterns (ARP) were established for a library of 1005 known Escherichia coli source isolates obtained from human and non-human (domesticated animals, livestock and wild) sources in an urbanizing catchment in Queensland State, Australia. Discriminant Analysis (DA) was used to differentiate between the ARP of source isolates and to identify the sources of faecal contamination. Partial Least Square (PLS) regression was then utilised on identified human source isolates to correlate their locality with specified sampling locations within the catchment. The resulting ARP DA indicated that a majority of the faecal contamination in the rural areas was non-human. However, the percentage of human isolates increased significantly in urbanized areas using on site systems for wastewater treatment. The PLS regression was able to develop predictive models which indicated a high correlation of human source isolates from the urban area. The study results confirm the feasibility of using ARP for source tracking faecal contamination in surface waters, as well as predicting their point of origin.

Real-time PCR detection of pathogenic microorganisms in roof-harvested rainwater in Southeast Queensland, Australia.

In this study, the microbiological quality of roof-harvested rainwater was assessed by monitoring the concentrations of Escherichia coli, enterococci, Clostridium perfringens, and Bacteroides spp. in rainwater obtained from tanks in Southeast Queensland, Australia. Samples were also tested using real-time PCR (with SYBR Green I dye) for the presence of potential pathogenic microorganisms. Of the 27 rainwater samples tested, 17 (63%), 21 (78%), 13 (48%), and 24 (89%) were positive for E. coli, enterococci, C. perfringens, and Bacteroides spp., respectively. Of the 27 samples, 11 (41%), 7 (26%), 4 (15%), 3 (11%), and 1 (4%) were PCR positive for the Campylobacter coli ceuE gene, the Legionella pneumophila mip gene, the Aeromonas hydrophila lip gene, the Salmonella invA gene, and the Campylobacter jejuni mapA gene. Of the 21 samples tested, 4 (19%) were positive for the Giardia lamblia beta-giardin gene. The binary logistic regression model indicated a positive correlation (P < 0.02) between the presence/absence of enterococci and A. hydrophila. In contrast, the presence/absence of the remaining potential pathogens did not correlate with traditional fecal indicators. The poor correlation between fecal indicators and potential pathogens suggested that fecal indicators may not be adequate to assess the microbiological quality of rainwater and consequent health risk.

Population similarity analysis of indicator bacteria for source prediction of faecal pollution in a coastal lake.

Biochemical fingerprinting (BF) databases of 524 enterococci and 571 Escherichia coli isolates and an antibiotic resistance analysis (ARA) database comprising of 380 E. coli isolates from four suspected sources (i.e. dogs, chickens, waterfowls, and human sewage) were developed to predict the sources of faecal pollution in a recreational coastal lake. Twenty water samples representing four sampling episodes were collected from five sites and the enterococci and E. coli population from each site were compared with those of the databases. The degree of similarity between bacterial populations was measured as population similarity (Sp) coefficient. Using the BF-database, bacterial populations of waterfowls showed the highest similarity with the water samples followed by a sewage treatment plant (STP). Higher population similarities were found between samples from STP and water samples especially at two sites (T2 and T3) which were located near the sewerage pipes collecting wastewater from the study area. When using the ARA-database, the highest similarity was found between E. coli populations from STP and water samples at sites T2 and T4. Both faecal indicators and as well as methods predicted human faecal pollution, possibly through leakage from submerged sewerage pipes. The results indicated that the Sp-analysis of faecal indicator bacterial populations from suspected sources and water samples can be used as a simple tool to predict the source(s) of faecal pollution in surface waters.

Detection and source identification of faecal pollution in non-sewered catchment by means of host-specific molecular markers.

Multiple host-specific molecular markers were used to detect the sources of faecal pollution in a mixed land use non-sewered catchment in Southeast Queensland, Australia. These markers included human-specific Bacteroides (HF183 and HF134), cattle-specific Bacteroides (CF128), dog-specific Bacteroides (BacCan) and human-specific enterococci surface protein (esp) markers. The sensitivity and specificity of these markers were determined by testing 197 faecal samples from 13 host groups. The overall sensitivity and specificity of these markers was high (sensitivity>/=85% and specificity>/=93%) indicating their suitability for detecting the sources of faecal pollution. Of the 16 samples collected from the study area, 14 (87%) were positive for at least one of the molecular marker tested. Amongst all the markers, cattle-specific CF128 was more prevalent than others, followed by human-specific HF183 which was consistently detected in samples collected from sites within close proximity to urban development. Significant correlations were found between E. coli and enterococci concentrations with the positive/negative results of human-specific Bacteroides HF183 (p<0.001, p<0.0001) and HF134 (p<0.001, p<0.004) markers. No correlations were found between faecal indicators (E. coli or enterococci) with the CF128 or BacCan markers. A significant correlation was also found between enterococci concentrations and the presence/absence of the esp marker (p<0.02). Based on the results, it appears that the host-specific markers such as HF183 and esp are a sensitive measure of sources of human faecal pollution in surface waters in Southeast Queensland, Australia.

Role of organic matter in framboidal pyrite oxidation.

An experimental system has been set up to investigate the reaction kinetics of framboidal pyrite oxidation in real, reactive acid sulfate soil assemblages. This study was undertaken to determine the degree to which pyrite oxidation rates are reduced by bacteriological reactions and organic matter, which both modify the net reaction mechanisms and compete for available oxygen. The results from these experimental runs not only confirm the role of organic matter in mitigating pyrite oxidation but indicate that at least initially, the acidity produced is consumed or otherwise ameliorated by parallel reactions. Tracking pH or [H+] in both a reactor and in soil does not accurately reflect reaction progress and may not correctly indicate the true level of risk. In comparison, the tracking of pyrite oxidation with the concentration of sulfate in solution is not affected by side reactions or precipitation and is therefore a better indicator for the rate of pyrite destruction.

Motor neurone disease.

Motor neurone disease, or amyotrophic lateral sclerosis, is a serious progressive neurological disorder, characterized by loss of UMN and LMN. Pathological features include characteristic intracytoplasmic MN inclusion bodies and appearances on ubiquitin staining. The aetiopathogenesis of the disease remains unknown and there is, to date, no effective treatment. Several abnormalities have been demonstrated in neurotransmitter, neuropeptide and gene expression studies. Abnormalities in glutamate metabolism have led to the excitotoxin hypothesis of MN destruction. Other theories include deficits in MN trophic factors, trans-synaptic degeneration, impaired ability to detoxify putative toxic agents and impaired DNA/RNA metabolism. The existence of familial forms, some of which show linkage to markers in chromosome 21, allows a genetic approach to the mechanisms of disease. Recent studies suggest that mutations in the Cu/Zn SOD gene may be important in some of the familial forms. The atypical forms seen in the Western Pacific have stimulated a search for environmental agents. Agents undergoing therapeutic trials at present include CNTF, IGF1 glutamate antagonists, branched-chain amino acids and TRH analogue.

Accuracy, reproducibility and variability of quantitative assessments of bulbar and respiratory function in motor neurone disease.

The validity of quantitative tests to assess bulbar and respiratory function used in therapeutic trials in motor neurone disease (MND) is studied in 26 MND and 21 age- and sex-matched control subjects. Five raters timed repeated visual and auditory stimuli generated by a metronome simulating bulbar tests. For all raters, mean error rate was 5.07%, correlation coefficient was 0.89 (and %difference of 1.53), and coefficient of variation (CV) was 3.18%. The experienced rater obtained significantly better %differences and CV. For all subjects and tests, mean correlation coefficient was 0.98, and mean CV was 8.8%. There were no significant differences in reproducibility or variability in readings obtained in MND and control subjects assessed by the experienced rater. The use of composite bulbar, but not respiratory, scores resulted in significant improvements in reproducibility and variability.

Cerebral venous sinus thrombosis: a late sequel of invasive fibrous thyroiditis.

Riedel's invasive fibrous thyroiditis (IFT) is a rare disease of unknown etiology characterized by a dense fibrosis involving the thyroid gland and its surrounding tissues. Clinically, patients present with a stony hard goiter frequently associated with compressive symptoms. Involvement of the surrounding neck structures by IFT can lead to various clinical sequelae. We report the case of a 55-year-old woman with known IFT who developed thrombosis in the right internal jugular vein that progressed to the right sigmoid, transverse, and superior sagittal sinuses. IFT could have predisposed to cerebral venous sinus thrombosis by causing venous stasis, vascular damage and possibly a hypercoagulable state. To our knowledge, this is the first report of cerebral venous sinus thrombosis that developed as a complication of IFT.

Natural history of amyotrophic lateral sclerosis. Observations with the Charing Cross Amyotrophic Lateral Sclerosis Rating Scales.

Natural history data increase the descriptive knowledge about amyotrophic lateral sclerosis (ALS), help define primary outcome variables and numbers of patients needed on clinical trials, and may give valuable predictive information. Global scores do not adequately represent the clinical variability of ALS. The Charing Cross Quantitative and Qualitative ALS Rating Scales assess disease severity and progression by validated regional scores (bulbar, respiration, upper limb, lower limb) and activities of daily living. The main stages in the development of these scales are summarized. Interval, or quantitative, scales provide accurate and sensitive measurements of the evolution of the disease and are useful for phase II therapeutic trials. The deterioration rates of regional scores in individual patients may not be linear. Rates of disease progression in ALS vary (1) among patients, (2) among topographical regions within a single patient, and (3) at different stages of the disease in a single region in the same patient. The deterioration rates of the regional scores of an ALS population depend critically on whether deaths are included or excluded from the population mean scores. Qualitative scales with simple scores are best suited for large-scale, phase III trials and for life table analysis of times to failure.

Theophylline blood levels in Sri Lankan asthmatics: comparison of two methods of assay.

OBJECTIVES: To assay theophylline blood levels in a sample of Sri Lankan chronic asthmatics taking oral theophylline, and to evaluate a simple and cost effective ultraviolet spectrophotometric assay for theophylline levels in blood. SETTING: Chronic asthmatics taking oral theophylline attending medical clinics at the National Hospital of Sri Lanka (NHSL) were recruited for the study. Blood samples were collected from recruited patients on their subsequent clinic visit. DESIGN AND METHODS: A cross-sectional study of theophylline blood levels. Blood samples were assayed for trough theophylline levels using two methods: an automated homogeneous enzyme immunoassay (EMIT), and a low cost ultraviolet spectrophotometric method. RESULTS: Only 2 patients of the 24 had theophylline blood levels in the accepted therapeutic range (10 to 20 micrograms/ml) (3.4); 19 patients had levels under 5 micrograms/ml. A correlation coefficient of 0.99 was obtained in the statistical comparison of the two methods, indicating that the spectrophotometric method has similar accuracy as the reference EMIT assay. CONCLUSIONS: The results signal a need for monitoring of theophylline in asthmatics when accepted clinical indications are present. The ultraviolet spectrophotometric method is ideal to initiate therapeutic drug monitoring (TDM) in the country because of its low cost (about Rs. 55 per assay), requiring only a UV recording spectrophotometer.

Plasma pharmacokinetics of a generic amoxycillin and the innovator brand: a comparison.

OBJECTIVE: To compare the bioavailability and plasma pharmacokinetics of a generic brand of amoxycillin (State Pharmaceutical Manufacturing Coporation) selected from the lower price range, with that of the innovation brand (Amoxil, Beecham). DESIGN: Sixteen healthy adult volunteers were allotted to two groups and each group was given a test dose of amoxycillin from each brand. Blood samples were collected at 0, 2, 3 and 4 hours thereafter plasma levels were assayed using high performance liquid chromatography. RESULTS: Analysis of results show that the generic product had similar bioavailability and pharmacokinetics when compared with the innovator product. CONCLUSION: The quality assured generic amoxycillin tested had similar bioavailability as a more costly branded version.

Human and bovine adenoviruses for the detection of source-specific fecal pollution in coastal waters in Australia.

In this study, the host-specificity and -sensitivity of human- and bovine-specific adenoviruses (HS-AVs and BS-AVs) were evaluated by testing wastewater/fecal samples from various animal species in Southeast, Queensland, Australia. The overall specificity and sensitivity of the HS-AVs marker were 1.0 and 0.78, respectively. These figures for the BS-AVs were 1.0 and 0.73, respectively. Twenty environmental water samples were collected during wet conditions and 20 samples were colleted during dry conditions from the Maroochy Coastal River and tested for the presence of fecal indicator bacteria (FIB), host-specific viral markers, zoonotic bacterial and protozoan pathogens using PCR/qPCR. The concentrations of FIB in water samples collected after wet conditions were generally higher compared to dry conditions. HS-AVs was detected in 20% water samples collected during wet conditions and whereas BS-AVs was detected in both wet (i.e., 10%) and dry (i.e., 10%) conditions. Both Campylobacter jejuni mapA and Salmonella invA genes detected in 10% samples collected during dry conditions. The concentrations of Salmonella invA ranged between 3.5 × 10(2) and 4.3 × 10(2) genomic copies per 500 ml of water Giardia lamblia ß-giardin gene was detected only in one sample (5%) collected during the dry conditions. Weak or significant correlations were observed between FIB with viral markers and zoonotic pathogens. However, during dry conditions, no significant correlations were observed between FIB concentrations with viral markers and zoonotic pathogens. The prevalence of HS-AVs in samples collected from the study river suggests that the quality of water is affected by human fecal pollution and as well as bovine fecal pollution. The results suggest that HS-AVs and BS-AVs detection using PCR could be a useful tool for the identification of human sourced fecal pollution in coastal waters.