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

Pilot-Scale Evaluation of Poultryponics: Insights into Nitrogen Utilization and Food Pathogen Dynamics

Poultry processing wastewater (PPW) is a nutrient-rich effluent with the potential for reuse in crop irrigation. This study investigated transforming PPW into a hydroponic nutrient solution using a pilot scale "poultryponics" system operated continuously for 222 days. The system treated ∼57 L d-1 of real PPW and consisted of bioreactors (inoculated with a consortium of microalgae and nitrifying bacteria), clarifiers, membrane filters, a UV disinfection unit, and a deep-water hydroponic system. The system was evaluated in terms of nitrogen transformation, organic removal efficiency, and pathogen levels. Although soluble organic removal efficiencies (sCOD) were high (>80%) in all bioreactors, nitrification was limited due to high organic loading (350-800 mg sCOD L-1), relatively short retention time (24 h), and low dissolved oxygen levels (<3.5 mg O2 L-1). Grow beds showed significant nitrification, indicating the importance of upstream organic removal. CO2 supplementation (0.5% v/v) in bioreactors did not promote nitrification in the bioreactors but was beneficial for nitrification in grow beds due to pH-modulating effects. Microbiological analyses showed no Salmonella detection in bioreactors and substantial reductions in total coliform (∼40%) and aerobic plate counts (∼30%) after UV treatment. These findings demonstrate the sustainable and safe reuse of nutrient-rich industrial effluents in agriculture.

Wastewater-based epidemiology of Campylobacter spp.: A systematic review and meta-analysis of influent, effluent, and removal of wastewater treatment plants

Campylobacter spp. is one of the four leading causes of diarrhoeal diseases worldwide, which are generally mild but can be fatal in children, the elderly, and immunosuppressed persons. The existing disease surveillance for Campylobacter infections is usually based on untimely clinical reports. Wastewater surveillance or wastewater-based epidemiology (WBE) has been developed for the early warning of disease outbreaks and the detection of the emerging new variants of human pathogens, especially after the global pandemic of COVID-19. However, the WBE monitoring of Campylobacter infections in communities is rare due to a few large data gaps. This study is a meta-analysis and systematic review of the prevalence of Campylobacter spp. in various wastewater samples, primarily the influent of wastewater treatment plants. The results showed that the overall prevalence of Campylobacter spp. was 53.26 % in influent wastewater and 52.97 % in all types of wastewater samples. The mean concentration in the influent was 3.31 ± 0.39 log10 gene copies or most probable number (MPN) per 100 mL. The detection method combining culture and PCR yielded the highest positive rate of 90.86 %, while RT-qPCR and qPCR were the two most frequently used quantification methods. In addition, the Campylobacter concentration in influent wastewater showed a seasonal fluctuation, with the highest concentration in the autumn at 3.46 ± 0.41 log10 gene copies or MPN per 100 mL. Based on the isolates of all positive samples, Campylobacter jejuni (62.34 %) was identified as the most prevalent species in wastewater, followed by Campylobacter coli (30.85 %) and Campylobacter lari (4.4 %). These findings provided significant data to further develop and optimize the wastewater surveillance of Campylobacter spp. infections. In addition, large data gaps were found in the decay of Campylobacter spp. in wastewater, indicating insufficient research on the persistence of Campylobacter spp. in wastewater.

The role of environmental reservoirs in human campylobacteriosis

Campylobacteriosis is infection caused by the bacteria Campylobacter spp. and is considered a major public health concern. Campylobacter spp. have been identified as one of the most common causative agents of bacterial gastroenteritis. They are typically considered a foodborne pathogen and have been shown to colonise the intestinal mucosa of all food-producing animals. Much emphasis has been placed on controlling the foodborne pathway of exposure, particularly within the poultry industry, however, other environmental sources have been identified as important contributors to human infection. This paper aims to review the current literature on the sources of human exposure to Campylobacter spp. and will cover contaminated poultry, red meat, unpasteurised milk, unwashed fruit and vegetables, compost, wild bird faeces, sewage, surface water, ground water and drinking water. A comparison of current Campylobacter spp. identification methods from environmental samples is also presented. The review of literature suggests that there are multiple and diverse sources for Campylobacter infection. Many environmental sources result in direct human exposure but also in contamination of the food processing industry. This review provides useful information for risk assessment.

Comparative analysis of Campylobacter populations within individual market-age broilers using Fla gene typing method

Campylobacter species is the most common human pathogen causing gastrointestinal infections in humans, and poultry is considered a major source of this pathogen. In this project, we aim to study the genetic diversity of Campylobacter populations within individual chickens using cecal samples to understand the nature of intestinal colonization in chickens by Campylobacter species. Genotyping was conducted based on the DNA sequence of short variable regions (SVR) in the flaA gene. Cecal samples were collected from 9 market-age broiler chickens and used for isolation of Campylobacter genomic DNA. The SVR fragments of 400 bp were amplified using SVR-specific primers, cloned, and sequenced. Sequencing results obtained from 86 clones (~10 clones/bird) showed that on an average 23.25% of clones had mutations within individuals. The mutations did not show any consistent pattern, suggesting a random nature of the mutations. When translated SVR sequences were analyzed, on average 20.57% of strains carried altered amino acid sequences in SVR within individuals. Four translated sequences had nonsense mutations to produce truncated proteins. These results suggest that there are multiple genotypes colonizing in a cecum and the occurrence of truncated FlaA protein may represent a novel mechanism for evasion of adaptive immune responses.

Campylobacter epidemiology: an aquatic perspective

Members of the genus Campylobacter have established themselves as the most common human gastro-enteric pathogens throughout much of the developed world. The ubiquitous distribution of Campylobacter spp. in animal reservoirs and food products derived thereof make such vehicles primary risk factors in contracting campylobacteriosis. The contamination rates, identification of common pathogenic serotypes and extended survival of Campylobacter in surface waters illustrates the potential, but yet to be quantified, campylobacteriosis risk associated with untreated water. The existence and potential pathogenicity of viable but nonculturable forms of Campylobacter remains a contentious subject. Furthermore, the role of such forms in the epidemiology of Campylobacter related disease and their involvement in the large number of waterborne gastroenteritis outbreaks from which a disease agent cannot be isolated remains to be fully clarified. This article presents a survey of current perspectives with regard to the survival and epidemiology of Campylobacter spp. in natural water systems.

Description and sources of contamination by Campylobacter spp. of river water destined for human consumption in Brittany, France

Presence or absence of Campylobacter spp. in water of five rivers upstream from an intake point for drinking water production was investigated, and isolates genetically compared with human, pig and poultry isolates in order to determine their source. River water and drinking water obtained from these rivers were sampled one time per month, over a period of one year, and tested for Campylobacter. Isolates were typed by PFGE. Campylobacter was not detected in treated drinking water, but 50% of the river samples were contaminated. Contamination was observed on the four seasons. In total, 297 Campylobacter isolates were collected and generated 46 PFGE profiles. Campylobacter jejuni was the most frequently detected species in samples (74.1% of the isolates), followed by Campylobacter coli (17.8%) and Campylobacter lari (8.1%). Forty-two of the 46 PFGE profiles were unique. Only one genotype was detected three times in a river during the year and four genotypes in two different rivers. When compared to animal and human Campylobacter PFGE profiles, 14, 11 and one Campylobacter genotypes from water were genetically closed to human, poultry, and pig Campylobacter genotypes, respectively. The Campylobacter population displayed a high level of genetic diversity, suggesting that contamination originated from various origins. Human, poultry and pig were sources of contamination of the river by Campylobacter. Finally, no Campylobacter were detected in drinking water, indicating that the risk of outbreaks due to consumption of drinking water is low.

Identification of hyperinvasive Campylobacter jejuni strains isolated from poultry and human clinical sources

Campylobacter jejuni causes gastroenteritis with a variety of symptoms in humans. In the absence of a suitable animal model, in vitro models have been used to study virulence traits such as invasion and toxin production. In this study, 113 C. jejuni isolates from poultry and poultry-related (n=74) environments as well as isolates from human cases (n=39) of campylobacteriosis and bacteraemia were tested for invasiveness using INT 407 cells. The method was sufficiently reproducible to observe a spectrum of invasiveness amongst strains. As a result, strains were classified as low, high and hyper-invasive. The majority of strains (poultry and human) were low invaders (82 % and 88 %, respectively). High invasion was found for 5 % of human strains and 11 % of poultry-related isolates. However, only 1 % of poultry strains were classified as hyperinvasive compared to 13 % of human isolates (P=0.0182). Of those isolates derived from the blood of bacteraemic patients, 20 % were hyperinvasive, though this correlation was not statistically significant. An attempt was made to correlate invasiveness with the presence of seven genes previously reported to be associated with virulence. Most of these genes did not correlate with invasiveness, but gene cj0486 was weakly over-represented, and a negative correlation was observed for the gene ciaB. This trend was stronger when the two genes were analysed together, thus ciaB(-) cj0486(+) was over-represented in high and hyperinvasive strains, with low invaders more commonly found to lack these genes (P=0.0064).

In vitro antimicrobial susceptibility, genetic diversity and prevalence of UDP-glucose 4-epimerase (galE) gene in Campylobacter coli and Campylobacter jejuni from Turkey production facilities

This study evaluated the genetic diversity of multi-drug resistant Campylobacter jejuni (n=44) and C. coli (n=30) isolated from 18 turkey houses. Antimicrobial resistances to ampicillin, ciprofloxacin and nalidixic acid were higher (P<0.05) in C. coli than in C. jejuni strains. PCR analysis indicated that 82% of total isolates tested, including 91% of C. jejuni and 70% of C. coli tested positive for a 496-bp UDP-glucose 4-epimerase (galE) gene. The diversity of isolates was mapped by antibiogram, SmaI-PFGE and flaA-RFLP typing methods using the discriminatory index (DI). RFLP was more suitable in discriminating C. coli (DI=0.895) than PFGE (DI=0.816) or antibiogram profile (DI=0.552), while either PFGE (DI=0.941) or RFLP (DI=0.942) could be used in discriminating C. jejuni strains. The combined PFGE and antibiogram dendrogram had the highest DI for both C. coli (0.910) and C. jejuni (0.968), suggesting that a combination of typing methods is more useful in examining the diverse Campylobacter population on turkey farms.

Genotyping of Campylobacter spp. from retail meats by pulsed-field gel electrophoresis and ribotyping

AIMS

To determine the genetic relatedness of Campylobacter spp. from retail meat products, and compare the discriminatory power of pulsed-field gel electrophoresis (PFGE) and automatic ribotyping.

METHODS AND RESULTS

A total of 378 Campylobacter isolates recovered from 159 raw meats (130 chicken, 25 turkey, three pork and one beef) sampled from 50 retail grocery stores of four supermarket chains in the Maryland suburban area from August 1999 to July 2000 were analysed by PFGE with SmaI, 120 isolates of which were also characterized by ribotyping with PstI using RiboPrinter system. A total of 148 unique PFGE patterns were identified, 91 of which were present in multiple Campylobacter isolates and 24 in multiple meat samples. Nineteen Campylobacter clones with identical PFGE patterns recurred frequently (up to nine times) throughout the sampling period. Comparing ribotyping with PFGE, we identified 44 PFGE patterns and 22 RiboGroups among the 120 isolates tested. Multiple PFGE patterns within one RiboGroup were commonly observed, as well as multiple RiboGroups within one PFGE pattern.

CONCLUSIONS

Although Campylobacter present in retail meats were genetically diverse, certain clones persisted in poultry meats. PFGE had a greater discriminatory power than ribotyping, and the two methods were complementary in genotyping Campylobacter.

SIGNIFICANCE AND IMPACT OF THE STUDY

Genomic DNA fingerprinting of Campylobacter confirmed diverse and recurrent Campylobacter clones in the retail meats, which provides additional data for a better understanding of the epidemiological aspect of Campylobacter infection.

Inter-laboratory evaluation of three flagellin PCR/RFLP methods for typing Campylobacter jejuni and C. coli: the CAMPYNET experience

AIMS

To compare typeability, discriminatory ability, and inter-laboratory reproducibility of three flagellin PCR/RFLP (fla typing) methods previously described for Campylobacter.

METHODS AND RESULTS

The sample set (n = 100) was diverse, including both C. jejuni (n = 85) and C. coli (n = 15). Two of the three flaA typing methods amplified flaA alone, whereas one, a multiplex assay, amplified flaB in addition to flaA. DdeI restriction enzyme was employed for all methods, but HinfI was also investigated. 98-100% typeability was obtained for flaA-based methods, but only 93% for the multiplex assay, due to inconsistent amplification of a non-specific product. In addition, there appeared to be selective amplification of flaA over flaB. More DdeI types were generated using a longer flaA PCR amplicon, whilst additional use of HinfI increased the number of types by ca 25%. Inter-laboratory reproducibility for both flaA-based methods was defined at 100%.

CONCLUSIONS

Fla typing requires standardization with respect to PCR primers and restriction enzymes. This study identified an assay, employing the full flaA gene and DdeI digestion, as an appropriate method on which to standardize. 100% inter-laboratory reproducibility was demonstrated using that method.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work should facilitate progress towards inter-laboratory standardization of fla typing.

Multilocus sequence typing for comparison of veterinary and human isolates of Campylobacter jejuni

Multilocus sequence typing (MLST) has been applied to 266 Campylobacter jejuni isolates, mainly from veterinary sources, including cattle, sheep, poultry, pigs, pets, and the environment, as well as isolates from human cases of campylobacteriosis. The populations of veterinary and human isolates overlap, suggesting that most veterinary sources should be considered reservoirs of pathogenic campylobacters. There were some associations between source and sequence type complex, indicating that host or source adaptation may exist. The pig isolates formed a distinct group by MLST and may well represent a potential pig-adapted clone of C. jejuni. A subset (n = 82) of isolates was reanalyzed with a second MLST scheme which provided a unique set of isolates that had been analyzed at a total of 12 loci. The distribution of isolates among the complexes in each of the two schemes was similar but not identical. In addition to isolates from human outbreaks, one group of isolates that were not epidemiologically linked was also identical at all 12 loci. This group of isolates is believed to represent another stable strain of C. jejuni.

PCR/restriction fragment length polymorphism (RFLP) typing of human and poultry Campylobacter jejuni strains

AIMS

The PCR/RFLP typing of 156 isolates Campylobacter jejuni originating from poultry and humans was performed (101 human and 55 poultry strains).

METHODS AND RESULTS

On the basis of restrictive digest, six types were identified with AfaI, seven types with MboI and five types with HaeIII. With a combination of these three enzymes, 22 types were found. In human strains, the most frequently occurring types were Cj.4 (28%), Cj.1 (19%), Cj. 13 (13%) and Cj. 2 (5%). In the case of poultry strains, the most frequent types were Cj. 1 (34%), Cj. 11 (22%), C.j. 21 (16%) and Cj. 15 (11%).

CONCLUSIONS

The findings support the hypothesis that poultry is a significant source but not sole source of Campylobacter sp. in relation to humans.

SIGNIFICANCE AND IMPACT OF THE STUDY

The typing of Campylobacter sp. forms the basis for an evaluation of the current state and risk assessment of various Campylobacter sp. sources in relation to humans.

In vitro study on the effect of organic acids on Campylobacter jejuni/coli populations in mixtures of water and feed

Gastroenteritis caused by Campylobacter spp. infection has been recognized as one of the important public health problems in the developed countries. Outbreaks mostly originate from the consumption of contaminated poultry or infected water. The aim of this study was to determine the bactericidal activity on Campylobacter spp. of organic acids individually and in combinations at different pH levels and times and to compare bactericidal activities with activities of commercially available products. Ten strains of Campylobacter spp. were added in a mixture of water with commercial broiler feed, separately adjusted by four acids: formic, acetic, propionic, and hydrochloric acids, into pH 4.0, 4.5, 5.0, and 5.5. A combination of three organic acids was used in two different formulation ratios: formic:acetic:propionic at 1:2:3 and 1:2:5, at pH 4.0, 4.5, 5.0, and 5.5. All organic acids showed the strongest bactericidal effect on Campylobacter at pH 4.0. In contrast, at pH 5.0 and 5.5, the bactericidal activity of the four acids was low. The combination of organic acids showed a synergistic bactericidal activity at pH 4.5. Interestingly, the effect of the combined organic acids was stronger than the commercial products. Morphological cell changes were studied by transmission electron microscopy to determine the effect of the organic acids on the cell structure of Campylobacter. Some loss of outer membranes of the bacteria could be found in treated groups. Therefore, it can be concluded that organic acids, individually or in combination, have a strong bactericidal effect on Campylobacter spp. Routine application of organic acids to the water supply on poultry farms could prevent or diminish Campylobacter transmission.

The ability of Fla-typing schemes to discriminate between strains of Campylobacter jejuni

AIMS

The aim of this investigation was to compare the usefulness of two previously published flagellin PCR-RFLP typing (Fla-typing) techniques for the subtyping of Campylobacter jejuni strains, in terms of ease of use and discriminatory power.

METHODS AND RESULTS

Six groups of isolates, which were epidemiologically unrelated but with similar Fla-types, and five groups of epidemiologically related poultry isolates, with similar PFGE profiles, were used in the comparison. The Fla-typing methods used varied in the number and length of fla-genes amplified and the restriction enzymes used. In addition, the use of separately amplified PCR fragments of both the flaA and flaB genes to generate RFLP profiles was investigated.

CONCLUSION

The results clearly demonstrated that both previously published methods exhibit some advantages over the other. However, optimal discrimination was obtained by the use of separately amplified PCR fragments of both fla-genes.

SIGNIFICANCE AND IMPACT OF THE STUDY

The subtyping of Camp. jejuni isolates is considered essential for epidemiological purposes. Genotyping methods are now more frequently used but have yet to be standardized. Fla-typing is a rapid and easy to use method with acceptable discriminatory power. However, the discriminatory power of the currently published Fla-typing techniques may be further improved by incorporating RFLP profiles of both fla-genes.

Antibodies, directed towards Campylobacter jejuni antigens, in sera from poultry abattoir workers

Occupational exposure of susceptible humans to Campylobacter jejuni appears to result in resistance to disease. This is believed to be due to acquired protective immunity. To support this hypothesis the levels of C. jejuni-specific IgG and IgM antibodies were determined in sera from poultry abattoir workers. Such individuals are persistently exposed to C. jejuni, but apparently rarely acquire campylobacteriosis. Sera from 43 short-term workers (employed < or = 1 month), 78 long-term workers and 40 blood donors were investigated by ELISA. In 51 individuals a second serum sample, taken at least 1 month after the first, was also investigated. Eight workers had C. jejuni-positive faecal cultures and only one, a short-term worker, had symptoms of campylobacteriosis. There were significantly higher levels of specific IgG antibodies in long-term workers than in either of the other groups. There was no significant difference detectable in specific IgM antibody levels between any of the groups. The results provide supporting evidence that long-term exposure to C. jejuni induces circulating antibodies which reflect apparent reduced susceptibility to disease. Western blotting showed flagellin and polypeptides of 45, 40, 32 and 30 kD bound antibodies significantly more frequently by sera from long-term workers than short-term workers and blood donors. The most commonly detected antigens were the 40-kD (80%) and flagellin (55%). The results indicate that specific serum IgG responses induced by endemic exposure to C. jejuni might be directed towards a small number of protein antigens with apparently conserved epitopes.

Restriction fragment length polymorphism analysis of the flaA gene of Campylobacter jejuni for subtyping human, animal and poultry isolates

233 strains of Campylobacter jejuni were subtyped by PCR-RFLP analysis of the flagellin (flaA) gene by double digestion with EcoRI and PstI (EP flaA-profiling). The strains represented a variety of common Penner heat stable (HS) serotypes and comprised isolates of human, bovine, ovine, chicken and canine origin. FlaA amplicons were obtained directly from DNA in cell lysates of most strains. RFLP analysis showed considerable allelic variation and nine EP flaA-types were identified of which the most common were type 2 (32%), type 3 (20%), type 4 (12%) and type 6 (12%). Other flaA-profiles each represented less than 10% of strains. C. jejuni strains of each serotype generally had one or two specifically associated flaA-types although some were features of several serotypes. Strains with the same flaA-type were found in different hosts. EP flaA-profiles were reproducible, clear and simple to record, and laboratory protocols were rapid and low cost with high throughput capacity. The EP flaA-profiling scheme provided an excellent molecular subtyping method to supplement HS serotyping, and reference strains are recommended to facilitate its use in future epidemiological investigations.

A novel Campylobacter jejuni two-component regulatory system important for temperature-dependent growth and colonization

Campylobacter jejuni colonizes the intestines of domestic and wild animals and is a common cause of human diarrheal disease. We identified a two-component regulatory system, designated the RacR-RacS (reduced ability to colonize) system, that is involved in a temperature-dependent signalling pathway. A mutation of the response regulator gene racR reduced the organism's ability to colonize the chicken intestinal tract and resulted in temperature-dependent changes in its protein profile and growth characteristics.

Multilocus enzyme electrophoresis: a valuable technique for providing answers to problems in parasite systematics

The aim of this review is to highlight the effectiveness of the technique of multilocus enzyme electrophoresis in answering questions relating to the systematics of parasites and to highlight errors in the way the technique has been used and the results interpreted. We have approached this topic by answering specific questions that we have been asked by colleagues and students not necessarily familiar with the technique, the method of data analysis and its application. Although the technique has been applied to provide answers for taxonomic and population genetics studies, it remains under-utilised, perhaps because of recent advances in newer molecular technology. Rather than not acknowledge or dismiss the value of more traditional technology, we suggest that researchers examine problems in the systematics of parasites by the comparison of data derived from morphological, biochemical and molecular techniques.

Evidence of genomic instability in Campylobacter jejuni isolated from poultry

Poultry isolates of Campylobacter jejuni derived from a survey of meat processing batches were genotyped by pulsed-field gel electrophoresis (PFGE) of chromosomal DNA to establish the clonal relationships between single-colony isolates. In the majority of batches studied, one or two genotype patterns predominated. However, in one batch (batch A), 21 single-colony isolates gave 14 different PFGE genotypes. The banding patterns obtained with SmaI were sufficiently different to distinguish between genotypes, although the patterns also produced many common bands. The question of whether these isolates represented different clones or had a common clonal ancestry was addressed by additional genotypic and phenotypic methods. Restriction length polymorphism of PCR products obtained from the flagellin genes showed an identical flagellin genotype for all of these isolates. In contrast, unrelated control isolates resulted in different flagellin genotypes. Moreover, all 14 different PFGE genotypes of batch A had identical Penner serotypes and identical or similar biotypes and phage types. It was concluded that the isolates were of clonal origin and that the diversity in the PFGE banding patterns had most likely originated from genomic rearrangements. However, the PFGE genotypes were shown to be stable upon subculturing in vitro and after in vivo passage in chickens, and natural transformation between isogenic mutants carrying antibiotic markers did not occur in vivo in a chick colonization model. The possible mechanisms for the hypothesized genomic recombinations and the conditions that allow, induce, or select for such events are discussed.

Genotypic Diversity among Campylobacter jejuni Isolates in a Commercial Broiler Flock

Analysis of nucleic acid polymorphism in the flagellin genes of Campylobacter jejuni was used to investigate genetic diversity among Campylobacter spp. in a commercial broiler flock. Three hundred single colonies of C. jejuni were isolated from fecal samples collected weekly for 3 weeks immediately before slaughter. Both the flaA and flaB genes were amplified by PCR, and the PCR product was digested with the restriction enzyme AluI. The fragments generated were then analyzed by agarose gel electrophoresis. Among the 300 recovered isolates, five different restriction fragment length polymorphism profiles were observed. Three of these profiles were dominant during the course of the study, and the other two profiles were detected at low frequency. Analysis of genetic variation in C. jejuni over the course of an experimental infection lasting 7 weeks indicated that there was no obvious drift in the flagellin gene type. These findings demonstrate that a range of bacterial genotypes can constitute the bacterial population within a commercial poultry flock, with the most likely sources of these types being multiple environmental exposure and/or genetic drift within the population. This degree of diversity must be considered in epidemiological analyses which utilize genetic typing methods that investigate Campylobacter contamination of any food source, including poultry, to ensure that the total gene pool for C. jejuni is evaluated.

Antibiotic susceptibility of campylobacter isolates from sewage and poultry abattoir drain water

In this study, the in vitro susceptibility of 209 campylobacter strains to the quinolones nalidixic acid, flumequine, ciprofloxacin, enrofloxacin, and to ampicillin, tetracycline and erythromycin was tested by the disk diffusion method. The strains were isolated from poultry abattoir effluent (DWA) and two sewage purification plants (SPA and SPB). Sewage purification plant SPA received mixed sewage, including that from a poultry abattoir, whereas SPB did not receive sewage from any meat-processing industry. The quinolone resistance of the DWA isolates ranged from 28% for enrofloxacin to 50% for nalidixic acid. The strains isolated from the sewage purification plants were more susceptible to the quinolones with a range of 11-18% quinolone resistance for SPB isolates to 17-33% quinolone resistance for SPA isolates. The susceptibility criteria as recommended by National Committee Clinical Laboratory Standards (USA) cannot readily be employed for campylobacter isolates. This investigation shows that the resistance of campylobacter bacteria is highest in the plant receiving sewage from a poultry slaughterhouse. Monitoring of antibiotic resistance of aquatic Campylobacter spp. is important, as surface waters are recognized as possible sources of infection.