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Human enteroviruses have been found in water from a chalk well with history of excellent bacteriological and organoleptic quality. A proportion of these viruses survived disinfection treatment which consisted of a nominal 1 mg/ℓ of free chlorine maintained for a minimum contact period of 15 minutes at a pH value of 7.2. It is concluded that viruses may occur in underground sources which have consistently proved to be satisfactory in routine monitoring tests for bacterial indicators of faecal pollution. Possible mechanisms which these circumstances may arise are discussed.

SummaryThe microbiological quality of eight halogenated and two u.v.-treated hydrotherapy pools in hospitals was investigated. The microbiological quality of halogenated hydrotherapy pools was comparable to halogenated public swimming pools, although in somePseudomonas aeruginosaand faecal pollution indicators were more frequent due to bad management.On the other hand u.v.-treated hydrotherapy pools had very bad microbiological quality. Apart from faecal pollution indicators,P. aeruginosawas present in very high numbers.Halogenated hydrotherapy pools were not highly contaminated with amoebae, andNaegleriaspp. were never detected. On the other hand u.v.-treated pools contained very high numbers of thermophilicNaegleria. TheNaegleriaisolates were identified asN. lovaniensis, a species commonly found in association withN. fowleri.Isoenzyme analysis showed a different type ofN. lovaniensiswas present in each of two u.v.-treated pools.

This study has evaluated the removal of traditional biological indicators of faecal pollution and two new indicators: Pseudomonasaeruginosa and Clostridiumperfringens in waste stabilization ponds which were installed at the waste treatment plant of Loures, at Frielas, near Lisbon. The removal efficiency for indicator organisms was 10/100 ml in the anaerobic pond A1, except for one of them, and less in A2. In facultative ponds the removal was 10/100 ml while in maturation pond M2 the removal efficiency was higher for traditional indicators than for the new indicators; in pond Ml the removal was less than in M2.

The microbiological quality of the water of two swimming pools was evaluated to determine which organisms might be the best indicators of pollution. Membrane filtration gave low numbers of the common indicators of faecal pollution but high counts of the indigenous skin bacteria. As illnesses normally contracted in a swimming pool are mostly those of the skin rather than intestinal, it is suggested that the best indicators of the hygienic condition of water in a swimming pool are staphylococci because of their resistance to disinfection, high numbers in the environment, and ease of recovery.

The relationships existing between coprostanol (5β-cholestan-3β-ol), faecal indicator bacteria and various physico-chemical tracer and bacterial stress factors in an ice-covered Finnish lake were investigated. Field observations show that coprostanol lies below the theoretical mixing line, indicating a net removal, primarily by settling together with suspended sediments. Faecal indicator bacteria, however, are differently transported and are removed by various environmental factors e.g. industrial wastes. Thus, only faecal streptococci show a regional covariance to coprostanol. Principal component analyses reveal a strong correlation between coprostanol and faecal streptococci in water but not with coliforms and sulfite reducing sporing anaerobs. However, in sediments also coliforms are correlated significantly with coprostanol and faecal streptococci. Therefore it might be necessary to estimate the quality of those waters polluted by both industrial and faecal wastes by means of coprostanol, a principal sterol in sewage of man and higher animals, which is thus well suited as a chemical marker of faecal pollution.

This paper compares three different methods to determine faecal pollution in shellfish. Two of these are related to MPN (Most Probable Number) technique and the last one is a direct count. The different results which may be obtained using these different techniques are shown. The relevance that introduction of the intervalve water may have on the bacterial titres in shellfish is presented. The shellfish utilized in this work came from two locations situated in the same bay. Simultaneous analyses on flesh, intervalve water and shellfish growing water show the different microbial titre that these three elements may have at the same time.

SUMMARYMonthly bacteriological water testing of traditional water sources (ponds, rivers, unprotected springs and traditional wells) used by five villages in northeastern Imo State, Nigeria, was conducted during the period January 1983 to August 1985. The membrane-filtration technique was used to detect faecal coliforms (FC) and faecal streptococci (FS). Evidence of faecal pollution was seen throughout the year for all water sources. During the study period, the monthly geometric mean counts per 100 ml of water (all sources combined) ranged from 760 to 17877 for FC and from 678 to 17394 for FS. The peak period of faecal pollution occurred during the transition between the dry and wet seasons and in the early wet season. During this peak pollution season (February–May), the geometric mean counts were 2·5–7·2 times higher than in the remaining part of the year for all source types except rivers, with ponds being the most heavily polluted. Preliminary findings on the sensitivity and specificity, in this tropical environment, of the standard membrane-filtration technique for enumerating FC are presented. The implications of the findings of this study for the environmental control of waterborne and hygiene-related diseases are discussed.

The quality of the drinking-water produced by an indirect reuse system and a direct reuse system was evaluated with respect to organic micropollutants. The quality of the water produced by the direct system was superior to that produced by the indirect system. No adequate multiple barriers against organic and bacteriological contaminants were found in the indirect reuse system, as opposed to the direct reuse system where these barriers are provided. Coprostanol, a faecal sterol, was found to be a useful qualitative indicator of faecal pollution in water. Several indicators for organic macropollution, as well as organic pollution indices as indicators for organic micropollutants, were evaluated.

This study was designed to compare the levels of bacteriophages specific to Escherichia coli to the levels of bacterial indicators in the water at three recreational beaches on the Firth of Forth. Beaches were chosen on the basis that they were known to suffer widely different degrees of faecal contamination. A direct plaque assay using 100 ml water samples was used to enumerate coliphages, and total coliforms and faecal coliforms were enumerated by membrane filtration. There was a high degree of correlation between the levels of coliphages and coliforms between the three sites studied. Within sites, levels of coliphages and coliforms showed a high degree of correlation on the two highly-polluted beaches, whereas correlation was low on the less-polluted beach. At the less-polluted beach coliphages were detected in the absence of faecal coliforms on two occasions, whereas faecal coliforms were detected in the absence of coliphages on one occasion. The results suggest that coliphages are as adequate indicators of faecal pollution at the sites studied as are coliform bacteria.

In order to examine the temporal relationship between bather load and water quality indicator levels, faecal pollution indicator (faecal coliforms and faecal streptococci) and opportunistic pathogen (Candida albicans and Pseudomonas aeruginosa) levels were monitored hourly in the nearshore waters of a shallow Lake Ontario bathing beach on a hot August day when the bather load was high, and on two overcast August days when the bather load was negligible. On the high bather load day, an increase occurred in the numbers of faecal coliforms and faecal streptococci in the beach water in conjunction with an increase in the bather load; P. aeruginosa levels increased later in the day. There was little apparent relationship between C. albicans levels and the other parameters on the high bather load day. No corresponding increases were observed for any of the monitored parameters on the low bather load days. The results indicate that bather load and sample collection time may influence estimations of recreational water quality based on faecal pollution indicator and P. aeruginosa levels.

Domestic dog defecations, potential carriers of toxocariasis, were mapped in comparable areas of public recreation grounds in Brighton, UK. A strong linear relationship was found between soil phosphorus content and defecation density, such that two distinct areas showed very similar regression lines generalised as y = 21 + 3·25x, where y ii soil phosphorus in mg kg−1 and x is the number of faecal deposits within the surrounding 5 × 5 m area of turf. In one area there were residually high phosphorus levels three years after dogs had been banned and it is suggested that soil phosphorus analysis may be a useful assay tool in investigations of canine pollution.

5β-Stanols, and in particular coprostanol, which is one of the principal sterols of human sewage, show promise as chemical tracers of faecal pollution in estuaries. In the present survey, coprostanol has been measured gas chromatographically in the waters and sediments of the Clyde Estuary. Thus, the bottom sediments contained 0.1–14 ppm of coprostanol (5β-cholestan-3β-ol) together with the corresponding 24-methyl- and 24-ethyl-5β-stanols, while in the seawater samples, the coprostanol concentrations closely paralled the faecal coliform counts. Overall, the amounts of coprostanol correlate well with the location and amounts of the known inputs of sewage from outfalls and dumping.

Bifidobacteria were consistently present in the faeces of both man and pigs but only occasionally in the faeces of cattle and sheep, and they were not isolated from faecal samples from other animals; total counts of bifidobacteria were obtained by membrane filtration with YN-17 medium, a modification of Resnick and Levin's YN-6 medium. Mannitol-fermenting strains of bifidobacteria were isolated from both human and animal faeces, but sorbitol-fermenting strains were obtained only from human samples. These sorbitol-fermenting strains were identified as either Bifidobacterium adolescentis or B. breve and their numbers were obtained by membrane filtration of Human Bifid Sorbitol agar (HBSA). Sorbitol-fermenting bifidobacteria are specific indicators of human faecal pollution of waters and wastewaters.

To assess the bacteriological quality 768 drinking water samples were collected from different locations in Khairpur City, Sindh, Pakistan over a period of two years from January 2006 to December 2007. The study reveals that out of 768 drinking water samples 567 (73.83%) samples were found to be contaminated with total coliform among them 85 (11.06%) found in the January-March period, 182 (23.70%) in April-June period, 188 (24.47%) in July-September, 112 (14.58%) in October-December period. Faecal coliform was found in 351 (45.70%) water sample, in which 49 (15.80%) occurred during January-March, 137 (17.83%) during April-June, 136 (17.71%) during July-September and 69 (8.98%) during September-December. It can be concluded from the results of the present study that bacteriological quality of two-third drinking water in Khairpur City is not safe as the water is the potential source of diarrhoeal disease agents. Keywords: Drinking water; Khairpur City; Faecal pollution; DiarrhoeaDOI: http://dx.doi.org/10.3329/bjm.v25i1.4862 Bangladesh J Microbiol, Volume 25, Number 1, June 2008, pp 69-72

Summary The New Zealand Waters Pollution Regulations 1963, referring to recreational water to which the public can gain access, states that the “coliform bacteria content shall not consistently exceed 1,000/100 ml”. This standard is now under revision, and the suggested new standard is a median faecal coliform index of 200/100 ml with a maximum value not exceeding 400/100 ml. Recent literature supports the use of faecal coliform sub‐group bacteria as the best indicator of faecal pollution and reference is made to the membership of this sub‐group. Inherent inaccuracies of the Most Probable Number (MPN) method of assessing bacterial populations are pointed out, such as experimental variations with different cultural media, and possible errors in interpretation of results. In North America, there is evidence that an MPN for the total coliform group of 1000/100 ml indicates a faecal coliform sub‐group MPN of 200/100 ml, and epidemiological experience supports these values as standards. We tabulate and discuss...

In an important percentage of stools of healthy persons Shiga bacteriophage occurs. The Shiga bacteriophage occurs during some lapse of time in water which has been polluted by human faeces. The Shiga bacteriophage could be ascertained in water by means of the enrichment method ofNyberg. The Shiga bacteriophage method for indicating the pollution of strongly polluted water is as sensitive or sometimes less so than the methods ofEijkman and ofClemesha. For the examination of water in several stages of purification in water works the Shiga bacteriophage method is as sensitive or even more so than the other methods. The Shiga bacteriophage does not act strongly in the self-purification of polluted water. The Shiga bacteriophage may be used as indicator for a faecal pollution of water and this method may be applied along with the other bacteriological methods in water control. It may be advantageous to study more closely its limits and its benefits in the practice of water control

A treated city water supply and most waters tested from several tourist hotels in a popular international resort were found to be microbiologically safe for drinking, but untreated domestic water supplies and locally prepared soft drinks frequently had high levels of bacterial contamination and faecal pollution. A novel oral rehydration mixture, based on fruit juice cordial which kills intestinal bacteria in vitro, was effective for treating young children with diarrhoea and mild to moderate dehydration in the same environment.

In 1978 faecal pollution of Belgian coastal waters was investigated. The degree of pollution is maximal on the coastline and decreases quickly offshore. At 5 km from the coastline, pollution indicators are still detectable. No significant difference was seen between the values of surface and deep-sea samples.

The bacteriological examination constitutes an important part of the control of water, but in view of the inherent difficulties, the methods available are far from satisfactory. A final judgment of the potability of water should never be given from the bacteriological examination alone. The detection of the important pathogenic organisms is difficult and impossible, and this does not form part of the routine test, which is devised to determine (1) the total number of living bacteria and (2) the presence of coliform organisms. Presence of the members of the Bact . coli group or faecal coliforms is of the greatest significance, as this is considered to be indicative of recent faecal pollution. Milk is an excellent medium for bacterial growth, and as the possibilities of introducing bacteria into milk are great, they are numerous and varied. The bacterial content of milk is varied and might be divided into two main groups: (1) normal flora containing the saprophytic organisms naturally occurring in milk and (2) organisms pathogenic to man. Shellfish, such as oysters and mussels, are sometimes cultivated in polluted streams or estuaries and might become contaminated with certain human pathogenic bacteria; in view of this, care is taken in the selection of a suitable layering ground.

THE subject of bacterial standards in water examinations is one about which the experience of different workers in India appears to be distinctly at variance. The first elaborate work on the subject seems to have been carried out by Col. Clemesha at the King Institute of Preventive Medicine, Madras. As a result of these researches he put forward a defence of the B. coli method, especially when combined with the separate species method. Dr Hirst, working in Ceylon, obtained results that agreed in many respects with Clemesha's conclusions. The next important work in India is that of Major Morison, in Poona. He found the method to be of value not only in detecting faecal pollution but also took a great step in advance by demonstrating that the amount of faecal pollution, as estimated by this method, bears some ratio to the pathogenicity of the water. While the experience of the above workers has on the whole been favourable to the method, that of some others has been distinctly unfavourable. Col. Liston, working in the Bombay Bacteriological Laboratory, found that the numerical presence of B. coli in Bombay water is not proportional to the amount of faecal pollution and that often the organisms thus found in water could not be referred to recent or objectionable faecal pollution. Major MacCombie Young, working in Assam, had a similar experience. He found these organisms to be normal inhabitants of a water which on topographical considerations he believes to be totally free from pollution. He reports that

In recent decades, considerable effort has been devoted to finding microbial source-tracking (MST) markers that are suitable to assess the health risks of faecally polluted waters, with no universal marker reported so far. In this study, the abundance and prevalence of a crAssphage-derived DNA marker in wastewaters of human and animal origins were studied by a new qPCR assay with the ultimate aim of assessing its potential as an MST marker. crAssphage showed up to 106 GC/ml in the sewage samples of human origin, in both the total DNA and the viral DNA fraction. In wastewaters containing animal faecal remains, 39% of the samples were negative for the presence of the crAssphage sequence, while those showing positive results (41% of the samples) were at least 1 log10 unit lower than the samples of human origin. Noteworthy, the log10 values of the ratio (R) crAssphage (GC/ml)/Escherichia coli (CFU/ml) varied significantly depending on the human or animal origin (R > 1.5 for human samples and R

Two important epidemiological characteristics (serotype and pyocin type) of Pseudomonas aeruginosa strains isolated from freshwater and seawater were investigated. Serotype I predominated, followed by serotype 6, whereas serotypes 11 and 9 were only occasionally isolated. The most frequent pyocin types from seawater and freshwater were 13B and 16B, respectively. The distribution of the different types in relation to the degree of faecal pollution was also studied. Pyocin types 12A and 13B were the best adapted to the marine environment, and serotype 10 and the pyocin type 17B were worst adapted to these aquatic environments

Detection of enzymatic activities has been proposed as a rapid surrogate for the culture-based microbiological pollution monitoring of water resources. This paper presents the results of tests on four fully automated prototype instruments for the on-site monitoring of beta-d-glucuronidase (GLUC) activity. The tests were performed on sediment-laden stream water in the Hydrological Open Air Laboratory (HOAL) during the period of March 2014 to March 2015. The dominant source of faecal pollution in the stream was swine manure applied to the fields within the catchment. The experiments indicated that instrument pairs with the same construction design yielded highly consistent results (R(2) = 0.96 and R(2) = 0.94), whereas the results between different designs were less consistent (R(2) = 0.71). Correlations between the GLUC activity measured on-site and culture-based Escherichia coli analyses over the entire study period yielded R(2) = 0.52 and R(2) = 0.47 for the two designs, respectively. The correlations tended to be higher at the event scale. The GLUC activity was less correlated with suspended sediment concentrations than with E. coli, which is interpreted in terms of indicator applicability and the time since manure application. The study shows that this rapid assay can yield consistent results over a long period of on-site operation in technically challenging habitats. Although the use of GLUC activity as a proxy for culture-based assays could not be proven for the observed habitat, the study results suggest that this biochemical indicator has high potential for implementation in early warning systems.

Antibiotic resistance profiling (ARP) is a potentially useful method for distinguishing faecal bacteria according to host source. This phenotypic approach has cost benefits over genotypic methods, but existing protocols are time-consuming and manual data handling is open to human error. A simplified, low-cost approach to the ARP technique was developed that used automated data recording techniques combined with simple statistical analyses to compare isolates of the genus Enterococcus from various faecal sources. An initial battery of 21 antibiotics (at up to four concentrations) was chosen for source discrimination. Images of growth or non-growth in microplate wells were stored as bitmaps and converted to binary data to form a database of known antibiotic resistance profiles. Discriminant function analysis (DFA) showed that the average rate of isolates correctly classified by the database (wastewater vs non-wastewater) was 86%. Once the more discriminating antibiotics and their concentrations had been identified, it was possible to reduce the number of tests from 80 to 18 whilst increasing the number of correctly classified human isolates. ARP could offer a low-cost and rapid means of identifying sources of faecal pollution. As such, the technique may be of particular benefit to developing countries, where water quality may have a significant impact on health and where cost is a major factor when choosing environmental management technology.

Water quality degradation can be caused by excessive agricultural nutrient transfers from fertilised soils exposed to wet weather. Mitigation measures within the EU Nitrates Directive aim to reduce this pressure by including 'closed' fertiliser spreading periods during wet months. For organic fertilisers such as slurry and manure, this closed period requires sufficient on-farm winter storage and good weather conditions to relieve storage at the end of the period. Therefore, robust scientific evidence is needed to support the measure. Incidental nutrient transfers of recently applied organic fertilisers in wet weather can also be complicated by synchronous transfers from residual soil stores and tracing is required for risk assessments. The combination of nutrient monitoring and biomarker analyses may aid this and one such biomarker suite is faecal steroids. Accordingly, this study investigated the persistence of steroids and their association with phosphorus during leaching episodes. The focus was on the coupled behaviour of steroids and total phosphorus (TP) concentrations in sub-surface hydrological pathways. Cattle slurry was applied to monolith lysimeters either side of a closed period and concentrations of both steroids and TP were monitored in the leachate. The study showed no significant effect of the treatment (average p = 0.17), though tracer concentrations did significantly change over time (average p = 0.001). While the steroidal concentration ratio was validated for herbivorous faecal pollution in the leachate, there was a weak positive correlation between the steroids and TP. Further investigation at more natural scales (hillslope/catchment) is required to confirm tracer behaviours/correlations and to compliment this sub-surface pathway study.

The use of faecal coliform to faecal streptococci ratios as indicators of the source of faecal pollution has become popular. However, this methodology has been attacked on the grounds that the differential die-away rates of FC and FS invalidate the use of the ratio. Data is presented here to show that this differential die-away can in fact strengthen the value of the FC:FS ratio as a means of distinguishing human from non-human pollution. It is concluded that initially high FC:FS values which fall indicate human contamination, whereas initially low ratios which subsequently rise suggest a non-human faecal source.

DURING the course of an ecological survey of the faecal streptococci, the need has arisen for a medium which is more highly selective for Streptococcus faecalis than media devised for the enumeration of enterococci in general. A number of workers1–4 have indicated that Strep. faecalis is the predominant streptococcus (Lancefield group D) of the gut of man, and that this species is relatively rare in the gut of animals. Hence a specific means of demonstrating this organism would be of some value to sanitarians as a means of assessing human faecal pollution, at least in certain climatic regions5.

Background Urban water sources of Khamis Mushait Governorate, southwestern Saudi Arabia, were studied to assess their bacteriological characteristics and suitability for potable purposes. A cross-sectional epidemiological method was adopted to investigate the four main urban water sources (i.e. bottled, desalinated, surface, and well water). These were sampled and examined between February and June 2007. Results A total of 95 water samples from bottled, desalinated, surface, and well water were collected randomly from the study area using different gathering and analysing techniques. The bacteriological examination of water samples included the most probable number of presumptive coliforms, faecal coliforms, and faecal streptococci (MPN/100 ml). The results showed that the total coliform count (MPN/100 ml) was not detected in any samples taken from bottled water, while it was detected in those taken from desalinated, surface, and well water: percentages were 12.9, 80.0, and 100.0, respectively. Faecal coliforms were detected in desalinated, surface, and well water, with percentages of 3.23, 60.0 and 87.88, respectively. About 6.45% of desalinated water, 53.33% of surface water, and 57.58% of well water was found positive for faecal streptococci. Colonies of coliforms were identified in different micro-organisms with various percentages. Conclusion Water derived from traditional sources (wells) showed increases in most of the investigated bacteriological parameters, followed by surface water as compared to bottled or desalinated water. This may be attributed to the fact that well and surface water are at risk of contamination as indicated by the higher levels of most bacteriological parameters. Moreover, well water is exposed to point sources of pollution such as septic wells and domestic and farming effluents, as well as to soil with a high humus content. The lower bacteriological characteristics in samples from bottled water indicate that it is satisfactory for human drinking purposes. Contamination of desalinated water that is the main urban water source may occur during transportation from the desalination plant or in the house reservoir of the consumer. Improving and expanding the existing water treatment and sanitation systems is more likely to provide safe and sustainable sources of water over the long term. Strict hygienic measures should be applied to improve water quality and to avoid deleterious effects on public health, by using periodical monitoring programmes to detect sewage pollution running over local hydrological networks and valleys.