Thermophilic campylobacters in surface waters around Lancaster, UK: negative correlation with Campylobacter infections in the community

The incidence of campylobacter enteritis in Lancaster City Health Authority is three times the UK average for similar sizes of population and has marked seasonal peaks in May and June. Environmental monitoring of surface waters around Lancaster showed that thermophilic campylobacters were absent from drinking water from the fells and from the clean upper reaches of the River Conder but were present in the main rivers entering Morecambe Bay, the lower reaches of the River Conder, the Lancaster canal, and seawater from the Lune estuary and Morecambe Bay. All the surface waters tested showed the same seasonality, namely, higher numbers in the winter months and low numbers or none in May, June and July. The absence of thermophilic campylobacters in the summer months may be due to high sunshine levels because experiments on the effects of light showed that campylobacters in sewage effluent and seawater were eliminated within 60 and 30 min of daylight respectively but survived for 24 h in darkness. As the concentrations of campylobacters in surface waters were at their lowest precisely at the time of peak infections in the community it is unlikely that surface waters form Lancaster's reservoir of campylobacter infection for the community.     

The effects of UVB and temperature on the survival of natural populations and pure cultures of Campylobacter jejuni, Camp. coli, Camp. lari and urease-positive thermophilic campylobacters (UPTC) in surface waters

AIMS: To determine whether diurnal and seasonal variations in campylobacters in surface waters result from the effects of temperature and u.v. radiation, and whether natural populations of Campylobacter lari and urease-positive thermophilic campylobacters (UPTC) from birds survive better in surface waters than Camp. jejuni from sewage. METHODS AND RESULTS: Natural populations of Camp. lari and UPTC in sea water, and Camp. jejuni in river water, were exposed to artificial sunlight (equivalent to a sunny day in June). Both populations became non-culturable within 30 min, with T90s of 15 min and 25 min, respectively. Cultures of Camp. jejuni became non-culturable within 40 min and those of Camp. coli, Camp. lari and UPTC, within 60 min. In darkness, survival was temperature-dependent. Natural populations took 12 h at 37 degrees C and 5 days at 4 degrees C to become non-culturable in sea water, and slightly less in river water. Cultures of Camp. lari and UPTCs survived for significantly longer than Camp. jejuni and Camp. coli. Loss of culturability for all isolates was most rapid at 37 degrees C and slowest at 4 degrees C. Newly isolated strains from sea water and river water behaved in an almost identical manner to NCTC strains. CONCLUSION: Campylobacter lari and UPTCs survive for longer in surface waters than Camp. jejuni and Camp. coli, particularly in the dark. Low Campylobacter numbers in coastal waters in the summer, especially in the afternoon, are due to the combined effects of higher temperatures and higher levels of u.v. radiation. SIGNIFICANCE AND IMPACT OF THE STUDY: Campylobacter lari and UPTCs from birds predominate in bathing waters in Morecambe Bay because they are better able to survive; they also originate from closer to the shore than Camp. jejuni and Camp. coli in sewage effluent, which survive poorly and die before the incoming tide reaches the shore. The predominance of Camp. jejuni in river water results from its dominance of the inputs and not from its ability to survive.     

Thermophilic campylobacters in surface waters around Lancaster, UK: negative correlation with campylobacter infections in the community

J ones , K., B etaieb , M. & T elford , D.R. 1990. Thermophilic campylobacters in surface waters around Lancaster, UK: negative correlation with campylobacter infections in the community. Journal of Applied Bacteriology 69 , 758–764.
The incidence of campylobacter enteritis in Lancaster City Health Authority is three times the UK average for similar sizes of population and has marked seasonal peaks in May and June.
Environmental monitoring of surface waters around Lancaster showed that ther-mophilic campylobacters were absent from drinking water from the fells and from the clean upper reaches of the River Conder but were present in the main rivers entering Morecambe Bay, the lower reaches of the River Conder, the Lancaster canal, and seawater from the Lune estuary and Morecambe Bay. AH the surface waters tested showed the same seasonality, namely, higher numbers in the winter months and low numbers or none in May, June and July. The absence of thermo-philic campylobacters in the summer months may be due to high sunshine levels because experiments on the effects of light showed that campylobacters in sewage effluent and seawater were eliminated within 60 and 30 min of daylight respectively but survived for 24 h in darkness.
As the concentrations of campylobacters in surface waters were at their lowest precisely at the time of peak infections in the community it is unlikely that surface waters form Lancaster's reservoir of campyiobacter infection for the community.     

Distribution and seasonality of microbial indicators and thermophilic campylobacters in two freshwater bathing sites on the River Lune in northwest England

Two freshwater bathing sites, the Crook O'Lune and the University Boathouse, on the River Lune in the north-west of England, were monitored over a 2 year period for the faecal indicators, faecal coliforms and faecal streptococci, the pathogens, Salmonella and Campylobacter, and compliance with the EU Directive on Bathing Water Quality. Faecal indicator numbers showed no seasonal variation, with numbers in the bathing season similar to those in the non-bathing season. They were consistently above the EU Guideline and Imperative standards so that if the EU Bathing Water Quality Directive (76/160/EEC) were applied, neither site would comply. Faecal indicator numbers in the sediments were an order of magnitude higher than in the overlying water. Campylobacter numbers showed seasonal variation in the water with higher counts in winter than in the summer, although numbers were low. Higher numbers were found in the sediments but there was no seasonal variation. Analysis of various inputs showed that indicators and campylobacters came from a mixture of sources, namely a sewage treatment works, agricultural run-off, streams and mallards. Microbial numbers in the water at the Crook O'Lune, which is closer to the sources of pollution, were twice those at the Boathouse. In the sediments they were six to eight times higher. Faecal coliforms were all identified as Escherichia coli of which 80% were a single biotype. Faecal streptococci were all enterococci of which 55% were E. avium, 38% E. faecalis and 7% E. durans. Salmonella was not isolated from either the water column or the sediments. Campylobacters were mainly Camp. jejuni, followed by Camp. coli, UPTC and Camp. lari.     

Non-compliance of beaches with the EU directives of bathing water quality: evidence of non-point sources of pollution in Morecambe Bay

Morecambe's three EU designated bathing beaches frequently fail the EU directives, even after a state of the art sewage treatment plant has become operational. We have been using conventional microbiology to look at the seasonality and distribution of indicator and pathogenic bacteria in Morcambe Bay and using molecular methods (polymerase chain reaction (PCR) and pulse field gel electrophoresis (PFGE)) to investigate the pathways by which pathogens reach the bathing waters. We will present data for Morecambe Bay which show that: 1. Failures and passes appear to be associated with the prevailing climatic conditions. 2. Indicator bacteria may not always be derived from sewage effluents. 3. Not all pathogens are distributed in the same way as indicator bacteria. 4. Pathogens such as Campylobacter are as likely to come from birds as from sewage.     

Potential sources of bacteriological pollution for two bays with marinas in Trinidad

Welcome Bay and Chaguaramas Bay in the northwest peninsula of Trinidad contain large marinas and smaller sections of bathing beaches. Bacteriological surveys were conducted at both bays to assess water quality and to determine potential sources of pollution. These surveys were conducted during the wet season of 1996 and the dry season of 1997. Eleven sample stations were established at Welcome Bay and 12 at Chaguaramas Bay. Freshwater samples were collected from rivers and drains within the survey area. Marine water samples were collected from marinas, bathing beaches and inshore and outer areas at both bays. Five water samples were collected from each sampling station during the wet season of 1996 and six during the dry season of 1997. The membrane filter technique was used to determine faecal coliform and Escherichia coli levels in all samples. There was a seasonal effect on water quality, with significantly higher faecal coliform levels in the wet season, when water quality was not in compliance with international standards. This represents a potential health risk in bathing areas. Water quality was better at the outer area of both bays. Water quality at the inner bay areas was most likely adversely affected by land-based sources of pollution identified in this study. These sources include three drains and two rivers, which discharged into the bays. Yachts were apparently not a source of sewage pollution: there was no significant relationship between yacht number and faecal coliform levels.     

Correlation between environmental monitoring of thermophilic campylobacters in sewage effluent and the incidence of Campylobacter infection in the community

Environmental monitoring of thermophilic campylobacters in liquid sewage effluent (primary settlement only) during 1988 and 1989 showed a prominent seasonablity with distinct peaks in May and June (the average number of bacteria per 100 ml of effluent in months other than May and June was 2244 and the average for the peak months was 50 778). Apart from September 1989, this seasonality coincided precisely with the seasonal variation of Campylobacter enteritis in the community with similar distinct peaks in May and June (the incidence of infection in May and June was twice or three times that in the other months).
Sampling of sewers showed that the campylobacters in the sewage effluent came mainly from abbatoir and animal processing plants with only a minor input from the community. Therefore, the seasonal peaks in the sewage effluent and in the community may not be dependent on human infections but on zoonotic infections which may also peak in May and June.     

Occurrence and strain diversity of thermophilic campylobacters in cattle of different age groups in dairy herds

AIMS: To investigate the occurrence and numbers of thermophilic campylobacters excreted by cattle in dairy herds, and to assess the strain diversity within herds. METHODS AND RESULTS: Faecal samples from 15 animals at each of 24 cattle farms were cultured quantitatively for thermophilic campylobacters and 23% of animals and 83% of farms were positive for Campylobacter jejuni. Young animals had a higher prevalence and higher faecal concentration than older animals. Serotyping and pulsed field gel electrophoresis (PFGE) of isolates showed that the most common serotypes were 2, 4-complex and 11. Serotype 2 was especially prevalent among calves (68% of the positive calves). In eight of the 20 positive herds, all isolates had the same sero- and PFGE type while, in the other herds, two to five different types were isolated. CONCLUSIONS: Significant differences were found between age groups in relation to the prevalence and numbers of excreted campylobacters, serotype distribution and strain diversity. The relatively few different strains in each herd indicate that transmission between animals is common. SIGNIFICANCE AND IMPACT OF THE STUDY: The high prevalence on cattle farms of the human pathogen C. jejuni and the wide distribution of serotype 2, the most common serotype among Danish patients, indicate that cattle might be an important reservoir for human infections. The ability of this serotype to colonize calves in high numbers further indicates that serotype 2 strains may have an advantage over other serotypes.     

Anti-microbial activity of smoke from different woods

Monitoring of thermophilic campylobacters in two Libyan seawage treatment plants has shown that the communities of Tripoli and Sabratha almost certainly harbour campylobacters capable of producing enteritis. The plant in Tripoli eradicated the campylobacters from effuent by secondary treatment with trikling filtration followed by chlorination. The plant ant Sabratha, which was not working well at the time of sampling, reduced campylobacter numbers by only 53% and 74% during secondary teatment in a stabilization pond, and a reservoir in Sabratha, which received effluent from the stabilization pond and which supplies water for irrigation, also contained thermophilic campylobacters. In both treatment plants campylobacters were eradicated from sewage sludge by digestion and drying.     

The colonization of turkeys by thermophilic campylobacters

The rate at which five broods of turkey chicks became colonized by thermophilic campylobacters was investigated. Day-old chicks were normally free of campylobacters on arrival on the farm with colonization beginning within 7 d. The carriage rate was 100% by day 14 in three of the broods and by day 21 in the other two. Higher carriage rates were obtained with enrichment procedures than with direct plating. Two broods were investigated over an extended interval for the number of campylobacters shed in their faeces. In brood A, campylobacters increased from day 1 to day 14 concomitant with increases in the carriage rate and in the number of chicks with diarrhoea. By day 39, when the birds were sold to other farms, the excretion rate had reached 6 × 10⁷ campylobacters g⁻¹ fresh faeces. Brood B was monitored over 91 d and showed peaks in Campylobacter numbers on days 19 and 75, corresponding to peaks in the number of diarrhoeic samples. The introduction of new birds into the brood resulted in an increase in the Campylobacter population and in the number of birds with diarrhoea. Campylobacter jejuni was the only species isolated but comprised several different biotypes. Analysis of the number of campylobacters at different sites along the gastrointestinal tract of mature turkeys at slaughter showed that numbers increased with distance from the beak and were highest in the caeca.     

The detection of genetic variation in Leptospira interrogans serogroup ICTEROHAMORRHAGIAE by ribosomal RNA gene restriction fragment patterns

Twenty-eight isolates of catalase-negative/weak (CNW) thermophilic campylobacters from human blood and faecal cultures were characterized by one-dimensional (1-D) high-resolution SDS-PAGE of cellular proteins. A further 11 Campylobacter strains were included for reference purposes. Partial protein patterns were used as the basis for numerical analysis, which showed that all of the hippurate-positive strains had a high similarity to C. jejuni. Two subclusters were formed within C. jejuni corresponding to C. jejuni subsp. doylei (15 strains) and C. jejuni subsp. jejuni (4 strains). Most of the paediatric strains from South Africa were members of C. jejuni subsp. doylei. Hippurate-negative CNW thermophilic strains were identified as "C. upsaliensis". The analysis demonstrated that the catalase-negative C. jejuni strains were quite distinct from "C. upsaliensis" and that electrophoretic protein patterns provide an excellent criterion for the identification of subspecies within C. jejuni.     

Campylobacter enteritis associated with consumption of unpasteurised milk.

In October and November 1978 two outbreaks of enteritis occurred in the north of England. Symptoms lasted two to over eight days but in no case necessitated admission to hospital. Faecal specimens from most of the patients were found to contain thermophilic Campylobacter sp. Inquiry disclosed that all patients had consumed unpasteurised milk from local farms. Examination of rectal swabs from the cattle concerned and milk socks yielded strains of Campylobacter sp indistinguishable from those isolated from the patients. It was therefore concluded that, since campylobacters are not known to be excreted in milk, faecal contamination of the milk had probably occurred and had led to these outbreaks. Evidence suggests that thermophilic Campylobacter sp is an occasional contaminant of milk. So long as unpasteurised milk continues to be distributed further outbreaks will probably occur.     

Coliforms as a measure of sewage contamination of the River Zambezi

The effect of releasing untreated sewage from Victoria Falls Town into the Zambezi river was determined by bacteriological examination of water samples collected upstream of Victoria Falls and for 22 km downstream. Most probable numbers of faecal coliforms and Escherichia coli were estimated. Water upstream of the falls, on the Zimbabwe side of the river, contained between seven and 130 E. coli per 100 ml. This section of the river was free from major sources of faecal pollution. Below the falls, but before the Victoria Falls Town sewage outfall, numbers of E. coli were between 1.8 X 10(2) and 1.4 X 10(4)/100 ml, indicating the existence of a sewage discharge other than that from Victoria Falls Town. The river was also highly polluted from the Victoria Falls Town sewage outfall to a point 18.6 km downstream. The highest E. coli count was 3.3 X 10(4)/100 ml and declined slowly to 1.4 X 10(3)/100 ml 18.6 km downstream of the outfall.     

Biotypes and DNA ribopatterns of thermophilic campylobacters from faeces and seawater in Eastern Spain

Twelve strains of thermophilic campylobacters isolated in Valencia from faeces of infants and young children with diarrhoea, and from seawater, were biotyped and examined by analysis of chromosomal DNA Hae III ribopatterns. The strains were identified as Campylobacter jejuni and C. coli , and all had different ribopatterns except for three identical faecal isolates of C. jejuni biotype I. No correlation was found between Lior biotype and Hae III ribopattern but several bands within ribopatterns were identified as possible species markers for use in diagnostic and epidemiological studies.     

Coliforms as a measure of sewage contamination of the River Zambezi

The effect of releasing untreated sewage from Victoria Falls Town into the Zambezi river was determined by bacteriological examination of water samples collected upstream of Victoria Falls and for 22 km downstream. Most probable numbers of faecal coliforms and Escherichia coli were estimated. Water upstream of the falls, on the Zimbabwe side of the river, contained between seven and 130 E. coli per 100 ml. This section of the river was free from major sources of faecal pollution. Below the falls, but before the Victoria Falls Town sewage outfall, numbers of E. coli were between 1.8 × 10² and 1.4 × 10⁴/100 ml, indicating the existence of a sewage discharge other than that from Victoria Falls Town. The river was also highly polluted from the Victoria Falls Town sewage outfall to a point 18.6 km downstream. The highest E. coli count was 3.3 × 10⁴/100 ml and declined slowly to 1.4 × 10³/100 ml 18.6 km downstream of the outfall.     

A METHOD FOR ISOLATION OF CAMPYLOBACTER SPP. (JEJUNI, COLI AND LARI) FROM SHELLFISH AND THE MARINE ENVIRONMENT

A method has been developed to detect thermophilic species of Campylobacter in shellfish, marine and tributary waters, sediment and farm runoff by-products such as manure and silage. The method consists of a 48 h enrichment incubation and subcultured to selective agars. Presumptive colonies confirmed with a latex agglutination (antibodies) to common flagellar antigens of C. jejuni, C. coli and C. lardi. Over an 8 year period, West Coast estuaries (Washington, Oregon, and California) were sampled, resulting in analysis of a total of 512 samples. Results suggest that Campylobacter spp. are well distributed in the marine environment. Two enrichment broths were compared for the recovery of campylobacters from environmental samples. The method described in the Food and Drug Administration Bacteriological Analytical Manual (FDA/BAM) (1984), was compared to a modified method. Use of the modified method described here resulted in higher recovery rates of Campylobacter spp. Recoveries of campylobacters from sediment, shellfish, and water were 10,13, and 28% higher for the modified method, respectively.     

Validation of a polymerase chain reaction/restriction enzyme analysis method for species identification of thermophilic campylobacters isolated from domestic and wild animals

AIMS: To compare and evaluate a polymerase chain reaction/restriction enzyme analysis (PCR/REA) method with standard phenotypic tests for the identification and differentiation of the thermophilic campylobacters Campylobacter jejuni, C. coli, C. lari and C. upsaliensis. METHODS AND RESULTS: One hundred and eighty-two presumptive thermophilic campylobacters from 12 different animal species were tested by a recently published PCR/REA and standard phenotypic tests. By PCR/REA, 95% of the isolates were clearly identified as either one of the four thermophilic Campylobacter species or as not belonging to this group of organisms at all. By standard phenotyping, 174 of the 182 isolates were initially identified as either C. jejuni, C. coli, C. lari or C. upsaliensis. Additional genotypic tests and phenotyping showed that 52 of these identifications were either incorrect or unreliable. Of the C. jejuni isolates, 19% were identified as C. coli by initial phenotyping and 27 sheep isolates phenotyped as C. coli or C. lari were, in fact, arcobacters. CONCLUSIONS: The PCR/REA was more reliable than standard phenotyping for the identification of thermophilic campylobacters from different animals. SIGNIFICANCE AND IMPACT OF THE STUDY: Routinely used phenotypic tests often resulted in unreliable identifications, requiring additional testing. The PCR/REA, however, gave unequivocal results and was considered useful for the routine identification of thermophilic campylobacters from different animals.     

Seasonality of thermophilic Campylobacter populations in chickens

The small intestines and caeca of chickens were monitored for seasonal variation of thermophilic campylobacters over a 12-month period. There was a significant seasonal fluctuation in the carriage rate which correlated with the following environmental parameters: sunshine hours (P = 0.0003) and minimum (P = 0.007) and maximum temperatures (P = 0.003). The number of campylobacters in the small intestine and caeca also showed significant seasonal variation (P = 0.0008); however, the periodicity in the caeca was significantly different from that in the small intestine (P = 0.007). The numbers of Campylobacter in the caeca were significantly higher than those in the small intestine (P = 0.001). No significant correlation was found between the numbers of campylobacters in the caeca and small intestines and the environmental parameters monitored.     

Seasonal variation of thermophilic campylobacters in lambs at slaughter

A survey of the isolation rate and population size of thermophilic campylobacters in lambs at slaughter was carried out to determine the seasonal variation of thermophilic campylobacters in ovine hosts. Isolation rates determined by enrichment methods were always higher than those using direct plating onto selective agar and showed that Campylobacter could be isolated from 91·7% ( n = 360) of samples from the small intestine of the lambs. Enumerations (MPN), done monthly over a 2-year period, averaged 4·00 log 10 ( n = 1080, S.D . 0·16) campylobacters g⁻¹ fresh weight (fw) intestinal contents with some samples giving values higher than 7 log MPN gfw⁻¹. These results show that the prevalence of thermophilic campylobacters in sheep intended for slaughter is much higher than previously reported. Statistical analyses showed that there was a significant seasonal periodicity in the Campylobacter populations in the small intestines of lambs at slaughter ( P = 0·004) but that there was no statistical relationship with environmental parameters such as minimum and maximum temperature, rainfall or hours of sunshine. In an analysis along the length of the intestinal tract of lambs, campylobacters were isolated from 80% of small intestine and 30% of rumen samples, but not from the true stomach, large intestine or caecal samples. A survey of sheep grazing on salt marsh, fell (upland) and farm pasture showed that the isolation rate of thermophilic campylobacters in fresh faeces was substantially lower (29·3% ( n = 420)) than that from the small intestine of lambs at slaughter. No significant difference (>0·05) was found between the isolation rate of campylobacters from faeces sampled in late spring/early summer and autumn, nor between the different types of grazing.     

达标污水离岸排海末端处置技术研究综述

达标污水离岸排海处置具有低成本、高处理率等优点,是国内外沿海港口和临港工业园区进行污水处置的重要选择。介绍了国内外达标污水离岸排海末端处置技术的发展情况,分析了排污口位置选划、扩散器射流参数及水力结构优化等研究技术上存在的问题。认为排污口位置选划应在水动力、污染物扩散、泥沙冲淤及工程经济因素分析的基础上,还需要重点考虑污水排放对区域生态要素长期的影响;排海末端扩散器射流参数及水力结构优化也尤为关键,不仅直接影响稀释扩散效果,而且涉及到主管、上升管、喷口等多个可控因子,可以采用建立物理模型、数值模型及量纲分析等方法,合理优化扩散器的结构参数和扩散器的型式,对提高达标污水离岸处置的效果具有重要意义。