Bathing Water Samples Research Articles

Multiplexed paper test strip for quantitative bacterial detection

Rapid, sensitive, on-site detection of bacteria without a need for sophisticated equipment or skilled personnel is extremely important in clinical settings and rapid response scenarios, as well as in resource-limited settings. Here, we report a novel approach for selective and ultra-sensitive multiplexed detection of Escherichia coli (non-pathogenic or pathogenic) using a lab-on-paper test strip (bioactive paper) based on intracellular enzyme (β-galactosidase (B-GAL) or β-glucuronidase (GUS)) activity. The test strip is composed of a paper support (0.5 × 8 cm), onto which either 5-bromo-4-chloro-3-indolyl-β-D: -glucuronide sodium salt (XG), chlorophenol red β-galactopyranoside (CPRG) or both and FeCl(3) were entrapped using sol-gel-derived silica inks in different zones via an ink-jet printing technique. The sample was lysed and assayed via lateral flow through the FeCl(3) zone to the substrate area to initiate rapid enzyme hydrolysis of the substrate, causing a change from colorless-to-blue (XG hydrolyzed by GUS, indication of nonpathogenic E. coli) and/or yellow to red-magenta (CPRG hydrolyzed by B-GAL, indication of total coliforms). Using immunomagnetic nanoparticles for selective preconcentration, the limit of detection was ~5 colony-forming units (cfu) per milliliter for E. coli O157:H7 and ~20 cfu/mL for E. coli BL21, within 30 min without cell culturing. Thus, these paper test strips could be suitable for detection of viable total coliforms and pathogens in bathing water samples. Moreover, inclusion of a culturing step allows detection of less than 1 cfu in 100 mL within 8 h, making the paper tests strips relevant for detection of multiple pathogens and total coliform bacteria in beverage and food samples.

Rapid Enumeration of Active <i>Legionella pneumophila</i> in Freshwater Environments by the Microcolony Method Combined with Direct Fluorescent Antibody Staining

In this study, a microcolony technique was combined with direct fluorescent antibody staining for the specific detection and enumeration of Legionella pneumophila in freshwater samples with growth activity. This method allowed the detection of active L. pneumophila (within 48 h) in 91 bath water samples collected from 30 bathing facilities, with similar sensitivity of a conventional plate-counting method. These results suggest that the microcolony method combined with fluorescent antibody staining could be useful as a monitoring technique for the prevention of Legionnaires’ disease through the early detection of L. pneumophila in freshwater.

Viral and bacterial contamination in recreational waters: a case study in the Lisbon bay area

To assess the presence of viral pathogens in bathing water samples and to evaluate the interdependency of bacterial indicator counts and viral detection. Bathing water samples of 16 beaches collected along a Portuguese Coastal area were screened for the hepatitis A virus (HAV) and norovirus genogroup I (NVGI) using RT-PCR technique. Bacteriological water quality was also assessed, according to European regulations. HAV and NVGI were detected in 95% and 27% of the water samples, respectively, whereas bacteriological quality was good in all but one sample, according to current water quality regulations. All water samples would be considered of excellent quality according to the most recent European regulations. No relationship between viral detection and regulatory-based bacterial indicators was found. The current results reinforce the importance of increased surveillance for pathogenic viruses in bathing waters.

Evaluation of Duopath Legionella Kit for the Rapid Identification of Legionella Strains Isolated from Water Samples

Duopath Legionella (Merck KGaA, Darmstadt, Germany) is a rapid and simple immunochromatographic assay kit for the identification of Legionella species. We evaluated the precision of the kit in identifying 100 strains of Legionella and 35 strains of non-Legionella bacteria isolated from cooling tower and bath water samples. Consequently, of all the Legionella strains tested, 99 strains were judged to be Legionella, and only one strain (Legionella busanensis) was judged to be non-Legionella. All of the 35 non-Legionella strains were judged to be non-Legionella. We therefore conclude that Duopath Legionella is a useful method for the rapid identification of Legionella.

Construction of a Leftover Bath Water Model for Microbial Testing

In this study, in order to construct a model of leftover bath water, we analyzed one hundred samples of used bath water samples which were provided by twenty-eight volunteer families. It appeared that the number of detected bacteria from such bath water was correlated closely with the number of bathers. Moreover, the pH, acidity, chemical oxygen demand (COD), ion, protein content of the leftover bath water were measured. The number of bathers had no connection with the pH, acidity, COD, and ion content of the leftover bath water. However, the protein content of the bath water correlated with the number of detected bacteria. Based on these results, the model of leftover bath water was constructed. Achromobacter xylosoxidans, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa were incubated with the model bath water as indices of bath water contamination. The number of incubated viable cells in the model bath water increased with increasing concentrations of casamino acid. Consequently, it was suggested that varying the concentration of casamino acid based on family size or contamination would be necessary in the efficient use of the constructed model of leftover bath water for microbial testing.

Detection of Legionella pneumophila serogroup 7 strain from bathwater samples in a Japanese hospital

Hospital-acquired legionellosis is one of the serious problems in nosocomial infection. For risk assessment of nosocomial Legionella infection, we surveyed samples from bathrooms for public use in three hospitals and two nursing homes to determine whether Legionella pneumophila was present. A total of 70 hot bathwater samples and samples wiped from bathtubs were collected at 1-h intervals. Fifteen shower-water and 15 inner-head samples were obtained at the start of a bath. Water samples were cultured using the Legionella spp. selective medium, and discrimination between L. pneumophila and other Legionella spp. was performed by PCR analysis. L. pneumophila serogroup 7 was detected in 1 bathwater and 1 wiped sample, both of which were collected 1 h after daily use from the same bathtub in a hospital. However, L. pneumophila SG7 was not detected in any other samples. Furthermore, the concentrations of free residual chlorine in most bath- and shower-water samples were lower than 0.1 mg/l. These results suggest that L. pneumophila has become a potential pathogen for nosocomial infections in public-type hospital baths. From the point of view of an infection-control program, it might be advisable to hold the concentration of free residual chlorine at 0.2-0.4 mg/l, which is generally required for public baths in Japan.

Delayed incubation as an alternative method to sample storage for enumeration of E. coli and culturable bacteria in water

The effects of sample storage on enumeration of Escherichia coli in marine bathing water and culturable bacteria in drinking water were evaluated. Results showed that overnight storage at 0−5°C significantly reduced the counts of E. coli in bathing water ( p=0.0001) with a mean reduction of 25%. A similar effect of sample storage was observed for the enumeration of culturable bacteria in drinking water at 22±2°C for 66±4 h ( p=0.0074; mean reduction=25%) or at 36±2°C for 44±4 h ( p=0.0353; mean reduction=6%). The use of a delayed incubation method, i.e. overnight storage at 0−5°C of inoculated agar plates prior to incubation, did not significantly affect the counts of culturable bacteria when plates were incubated at 22±2°C for 66±4 h, whereas it resulted in a significant increase of the bacterial numbers when plates were incubated at 36±2°C for 44±4 h ( p=0.0002; mean increase=32%). Based on these results, it is suggested to avoid the use of overnight or longer sample storage for the enumeration of E. coli in bathing water samples, as well as for the enumeration of culturable bacteria in drinking water. The delayed incubation method appears to be a reliable procedure for the enumeration of culturable bacteria and could represent a valid alternative to sample storage in order to overcome problems associated with the performance of bacteriological counts during weekends or statutory holidays. However, a multi-laboratory study is needed to evaluate the reproducibility of the delayed incubation method for the enumeration of culturable bacteria and its possible use for the enumeration of E. coli by membrane filtration.

Antibiotic resistance patterns of enterococci isolated from coastal bathing waters.

Recreational water should be considered a risk for enterococcal infections in regions with high utilisation and long exposure periods. A total of 1113 enterococcal isolates was obtained from 1670 bathing water samples from 120 bathing areas of seven prefectures in northern Greece. Enterococcus avium, E. raffinosus and E. faecium were the most prevalent species. Single, double and multiple antibiotic resistance patterns were observed in 33.5% 31.0% and 22.8% of the isolates, respectively. Resistance to erythromycin occurred most frequently, in 57.3% isolates, many of which also exhibited resistance to ciprofloxacin and rifampicin as well as high-level resistance to kanamycin and streptomycin. The results suggest that bathing water may contribute to the dissemination of uncommon enterococcal species that exhibit resistance to several antibiotics which are used to treat community-acquired infections.

Hygiene of bathing waters

Bathing is possible without any epidemic risk in Southbavarian lakes. Limit values according to the water monitoring by the EC-Directive 76/160/EC were rarely exceeded and occurred only in 0.3 to 2.1 % of the samples from 1990 to 1998. In river waters, however, limit values occurred in 17 to 35.3 % of the samples and one should beware of bathing there. In 1999 some lakes became fecally polluted by overflows which could be documented by high numbers of total coliforms but not by Escherichia coli. Subsequently total coliforms functioned as an important hygienic parameter. Therefore, total coliforms should not be abolished in the revision of the EC-Directive. Water monitoring of little lakes further revealed that the future limit value of 100 fecal streptococci in 100 ml was exceeded in more than 50 % of the samples. Enterohaemorrhagic E. coli were demonstrated in 2 % of the surface water samples. Thermophilic campylobacters could be isolated from 17.4 % of bathing water samples which were faultless according to the hygienic parameters of the EC-Directive. In this respect all possibilities should be utilized to minimize fecal pollutions at bathing places.

Capillary electrophoresis in metal analysis: Investigations of multi-elemental separation of metal chelates with aminopolycarboxylic acids

Capillary zone electrophoresis was applied to the separation of Co(III), Bi(III), Fe(III), Cr(III), V(IV), Pb(II), Hg(II), Co(II), Cu(II) and Ni(II) metal ions complexed with common aminopolycarboxylic acids. Ethylenediaminetetraacetic (EDTA), cyclohexane-1,2-diaminetetraacetic (CDTA) and diethylenetriaminepentaacetic (DTPA) acids were investigated and compared in order to optimize the separation resolution. The influence of carrier electrolyte parameters such as electrolyte nature, pH and concentration upon the electrophoretic behaviour of chelates was investigated and discussed. Two migration modes – counterelectroosmotic and coelectroosmotic – were compared. Better resolution was achieved using counterelectroosmotic conditions (25 kV) with 5 mmol/l DTPA electrolyte at pH 8.5 and direct UV detection at 214 nm. The separation time was less than 8 min, but the resolution of Co(II), Cu(II) and Ni(II) chelates was poor. For all metals studied the calibration graphs were linear over at least two orders of magnitude of concentration. The detection limits were in the range 2·10−6–8·10−6 mol/l. A possibility of simultaneous determination of metal ions with different oxidation states such as V(IV)/V(V) and Cr(III)/Cr(VI) is demonstrated. Examples of electropherograms are presented for different samples. Application of the method to the analysis of metal ions in electroplating bath and waste water samples is also demonstrated.

Isolation of Legionella pneumophila from 24 hr-home bath water and an eradication trial of the bacteria from the bath

Contamination of 24 hr home bath with Legionella pneumophila is recently well recognized. Eradication of the water-bath contamination from L. pneumophila and other bacteria is an important matter to prevent the infection because the 24 hr-bathing facility is widely accepted in Japanese houses. Among the 16 bathing water samples we tested, Legionella pneumophia was isolated from 6 cases (37.5%) when the bathing water was not treated with disinfectants. Number of L. pneumophila increased up to 10(3) cfu/ml and total culturable bacterial counts reached to 10(5) cfu/ml within 5 days when the water was not treated. We selected 5 water baths among 6 positive cases to study the bactericidal effect of chlorine. As a result we concluded that the growth of L. pneumophila in 24 hr-water bath could be stopped by the 2 ppm chlorination program every day.

Filtering effects to bacteria and improvement of water quality by granite porphyry materials

The authors have investigated the filtering effects to bacteria and E. coli and the elution/adsorption for minerals, residual chlorine, COD, and organochlorine compounds by using granite prophyry, Bakuhanseki. The filtering effects of Bakuhanseki to bacteria were appeared, particularly the reduction rates of E. coli were 24.5 ± 8.32 and 84.4 ± 1.50% for Taihei river water samples and more than 50% for bath water samples, and the effects were accelerated by silver-coated Bakuhanseki materials. Residual chlorine and COD components in tap water reduced rapidly by one-pass flow through Bakuhanseki layer, and in the cyclic treatment system with the layer, the increases in concentrations of essential elements of Na, K, Fe and Ca were particularly shown, as well as the decreased concentrations of trihalomethanes and related compounds.

Detection of enterotoxigenic Escherichia coli in water by filter hybridization with three enterotoxin gene probes.

The DNA hybridization assay for genes encoding for Escherichia coli enterotoxins was used to examine water specimens in Thailand. In a reconstruction experiment, the DNA hybridization assay was 10(4) times more sensitive than testing random E. coli in the Y-1 adrenal and suckling mouse assays in identifying enterotoxigenic E. coli (ETEC) in water. Drinking and bathing water collected from 2 of 10 different homes of individuals with ETEC-associated diarrhea and 6% (5 of 78) and 11% (11 of 78) of drinking and bathing water samples collected from homes of individuals with diarrhea without ETEC infections, as well as 6% (5 of 77) and 8% (6 of 77) of drinking and bathing water collected from homes in which no inhabitants had diarrhea, were homologous with the DNA probes. Ten E. coli from each of the 31 water specimens which contained bacteria which were homologous with the DNA probes were tested in the Y-1 adrenal and suckling mouse assay. In only 2 of these 31 specimens could ETEC be identified with the standard assays. The DNA hybridization assay is a much more sensitive means of detecting organisms carrying genes coding for enterotoxin production than testing 10 individual colonies in the Y-1 adrenal and suckling mouse assays. This novel application of recombinant DNA technology provides a sensitive method of detecting organisms carrying genes coding for enterotoxin, and this method will be useful in defining the epidemiology of ETEC.