Environmental aspects of Campylobacter infections

Similarity of Campylobacter lari among human, animal, and water isolates in Norway

A total of 49 isolates of Campylobacter lari from human, poultry, ducks, pigs, and water were genetically characterized. The species were identified by biotyping and multiplex polymerase chain reaction (PCR). Automatic riboprints were performed with the PstI restriction enzyme and RiboPrinter. The identification of the isolates was predicted when the corresponding pattern matched one of the patterns of the DuPont identification (DUP-ID) library and was then assigned an identification number. Thirty-five (71.4%) of the isolates were given a DUP-ID number. The isolates from water and animals showed a high degree of similarity to the human strains represented by DUP-PST1-1010, DUP-PST1-1166, DUP-PST1-1178, and DUP-PST1-1081. Some profiles (i.e., DUP-PST1-2021 and DUP-PST1-1184) were found only among the human isolates. Dendrogram analysis using BioNumerics grouped isolates into three main clusters. One of those clusters contained DUP-PST1-2021, DUP-PST1-1184, and DUP-PST1-1081, which was found in both humans and ducks. A second cluster generated DUP-PST1-1010, found in both humans and poultry, and DUP-PST1-1079, found in water. The third cluster consisted of two strains, DUP-PST1-1066 and DUP-PST1-1078, originating in humans, animals, and water. Three human strains and two poultry strains were diverse and formed their own clusters and could not be assigned a DUP-ID number. Because of the similarity of C. lari isolated from humans, poultry, ducks, pigs, and water, as well as the limited knowledge of environmental survival and its virulence factors, special hygienic precautions should be taken to avoid the risk of transmitting Campylobacter.

Distribution and ecology of campylobacters in coastal plain streams (Georgia, United States of America)

Campylobacter is the leading cause of bacterium-associated diarrhea in the United States and most developed countries. While this disease is considered a food-borne disease, many clinical cases cannot be linked to a food source. In rural and agrarian areas environmental transmission may be an important factor contributing to case loads. Here we investigated the waterborne prevalence of campylobacters in a mixed-use rural watershed in the coastal plain of southern Georgia (United States). Six sites representing various degrees of agricultural and human influence were surveyed biweekly to monthly for 1 year for the presence of culturable thermophilic campylobacters and other measures of water quality. Campylobacters were frequently present in agriculture- and sewage-impacted stretches of streams. The mean campylobacter counts and overall prevalence were highest downstream from a wastewater treatment plant that handled both human and poultry slaughterhouse waste (<or=595 CFU ml-1; 100% positive); the concentrations were significantly higher than those for the four upstream sites (P<0.05). The counts were significantly correlated with the number of fecal coliform bacteria, conductivity, pH, and concentrations of nutrients (NO3-, PO(4)3-, and NH3). Campylobacters were isolated more frequently and larger numbers were present during the summer months, similar to the occurrence of clinical cases of campylobacteriosis in this region. A multivariate model showed that the levels were significantly influenced by increasing precipitation, which also peaked in the summer. The results indicate that loading from both human and domestic animal waste may be high in the watershed studied during the summer months. Mixed-use watersheds supporting agriculture production, human populations, and wildlife may be at risk for contamination by campylobacters and may be an important route for human exposure.

Temperature-driven Campylobacter seasonality in England and Wales

Campylobacter incidence in England and Wales between 1990 and 1999 was examined in conjunction with weather conditions. Over the 10-year interval, the average annual rate was determined to be 78.4 +/- 15.0 cases per 100,000, with an upward trend. Rates were higher in males than in females, regardless of age, and highest in children less than 5 years old. Major regional differences were detected, with the highest rates in Wales and the southwest and the lowest in the southeast. The disease displayed a seasonal pattern, and increased campylobacter rates were found to be correlated with temperature. The most marked seasonal effect was observed for children under the age of 5. The seasonal pattern of campylobacter infections indicated a linkage with environmental factors rather than food sources. Therefore, public health interventions should not be restricted to food-borne approaches, and the epidemiology of the seasonal peak in human campylobacter infections may best be understood through studies in young children.

Specific detection of Arcobacter and Campylobacter strains in water and sewage by PCR and fluorescent in situ hybridization

The aim of this study was to evaluate PCR and fluorescent in situ hybridization (FISH) techniques for detecting Arcobacter and Campylobacter strains in river water and wastewater samples. Both 16S and 23S rRNA sequence data were used to design specific primers and oligonucleotide probes for PCR and FISH analyses, respectively. In order to assess the suitability of the methods, the assays were performed on naturally and artificially contaminated samples and compared with the isolation of cells on selective media. The detection range of PCR and FISH assays varied between 1 cell/ml (after enrichment) to 10(3) cells/ml (without enrichment). According to our results, both rRNA-based techniques have the potential to be used as quick and sensitive methods for detection of campylobacters in environmental samples.

Thermophilic campylobacters in surface water: a potential risk of campylobacteriosis

Campylobacteriosis caused by Campylobacter jejuni, Campylobacter coli and Campylobacter lari is one of the most frequently occurring acute gastroenteritis diseases in humans. An important risk factor is untreated drinking water. Thermotolerant campylobacters were isolated from Bø River water using 100-ml filtrate samples. Campylobacters were isolated from 32 of 60 samples (53.3%). Of the 75 strains isolated, 47 (62.7%) were detected using the enrichment procedure and 28 (37.2%) by direct plating of the filter. Campylobacter coli was the dominating species (44%) followed by Campylobacter jejuni (34.6%) and Campylobacter lari (14.7%). Five isolates (6.7%) could not be classified. Campylobacter were isolated without the occurrence of fecal coliforms indicating that fecal coliforms cannot be used as index bacteria to predict the occurrence of campylobacters. Case-control studies have indicated untreated drinking water and barbecuing as important risk factors, and waterborne campylobacteriosis has been caused by the three species isolated. The virulence factors of isolated environmental strains are not fully known. It was concluded that it is hazardous to use untreated surface water for drinking. Special efforts should be taken to avoid contamination of agricultural products from irrigation.

Diversity of Campylobacter isolates from three activated sludge systems

Thermophilic campylobacters were isolated from three sewage plants in Rio de Janeiro, RJ, Brazil and identified. Laboratory analysis of 390 sewage samples showed the presence of 169 thermophilic strains. The results demonstrated that human and animal pathogenic biotypes could be isolated from activated sludge during the initial processing steps. The aeration tank could be considered a barrier to Campylobacter survival. C. jejuni was the prevalent species isolated (40.8%). The most common biotypes were C. jejuni biotype I (21.3%), C. coli biotype I (16%) and C. jejuni biotype II (14.8%).

The speciation and subtyping of campylobacter isolates from sewage plants and waste water from a connected poultry abattoir using molecular techniques

In this study the distribution of phenotypes of campylobacter strains in sewage and surface waters was investigated by subtyping and by speciation of isolates from various aquatic environments. These environments included two municipal sewage plants (SPA and SPB) and waste water from a poultry abattoir (WWA). Both the sewage plants SPA and SPB collected domestic and industrial waste, and SPA received drain water from WWA. SPB received no waste water from any meat-processing plant. The isolates were speciated by PCR and subtyped by PCR/RFLP based on the flagellin PCR products. From all three reservoirs, no Campylobacter lari was isolated, and approximately 80% of the isolates could be identified as C. jejuni and the rest belonged to the C. coli species. The PCR/RFLP typing technique has a high discrimination level and was reproducible between two separate laboratories. The 182 isolates tested yielded 22 distinct Dde I profiles. The results indicate that strains with profiles found in poultry are also detectable in waste water presumed to be solely from domestic and human sources. In addition some strains were unique to the known poultry-related sources, suggesting that avian-specific strains, non-pathogenic to man, may exist in the environment. In contrast some strains were unique to human waste indicating the potential importance of non-poultry sources of infection. No seasonality was observed in the profile distribution. So, at least in the Netherlands, it is unlikely that infections caused by contaminated surface waters contribute to the seasonality of human campylobacteriosis.

The occurrence of Salmonella, Campylobacter and Yersinia spp. in river and lake waters

In order to assess Salmonella, Campylobacter and Yersinia spp. occurrence in surface waters and to compare it with the standard faecal indicator bacteria, 86 river and lake samples, from eight sampling sites in Northern Greece were examined for the presence of these pathogens in parallel to total and faecal coliforms and faecal streptococci. A total of 17 Salmonellae, 14 Campylobacters and 9 Yersiniae were isolated. Only in Salmonella positive samples the geometric means of total and faecal coliforms were found significantly higher (p < 0.01) than in the negative samples, whereas the presence of Campylobacters and Yersiniae may not be predicted by the standard indicator bacteria.

Isolation of Campylobacter and Yersinia spp. from Drinking Waters

Recently it has become apparent that drinking water may be a reservoir for Campylobacter and Yersinia spp. and that transmission of infection occurs by the fecal-oral route. In order to assess Campylobacter and Yersinia spp. occurrence in drinking water, 500 samples were examined for the presence of these pathogens in parallel to coliforms-fecal indicator bacteria set by E. coli. Five strains of C. jejuni (1.0%) and 20 of Yersinia spp. (4.0%) were isolated. The occurrence of C. jejuni and Yersinia spp. was statistically higher (p <.001, p <.05 respectively), in the presence of coliform bacteria. The frequency of Yersinia spp. in chlorinated and nonchlorinated samples differed significantly (p <.05), whereas C. jejuni frequency did not (p >.05).