Survival ofCampylobacter jejuniandCampylobacter coliwater isolates in lake and well water

Prediction of edapho-climatic parameters in the incidence of Campylobacter spp. in northwestern Mexico

Campylobacter spp. is one of the main causes of enteric zoonotic infections worldwide. In Mexico, although a commonly detected pathogen in both children and adults, there is limited surveillance and few studies. The northern part of Mexico stands out for an unnoticed outbreak of Campylobacter jejuni due to contaminated drinking water, which caused an abrupt increase in Guillain-Barré syndrome in the local population. Although it is suggested that its distribution in nature is related to edaphic and climatic factors, this relationship is scarcely known. To understand abiotic factors driving the occurrence and prevalence of Campylobacter spp. in three municipalities from three states in northwestern Mexico (Chihuahua, Sonora, and Baja California), we used the kriging interpolation method of unsampled areas and the correspondence analysis of 23 environmental variables. Of the three municipalities evaluated, Janos in Chihuahua (CHIH), has the highest number of geographic areas classified as high and medium incidence, followed by Santa Cruz, Sonora (SON) and Mexicali, Baja California (BC). Mexicali (BC) edaphic variables limit the potential incidence of the bacterium, mainly due to the lack of soil moisture and its difficulty of surviving on dry surfaces, related to electrical conductivity and salinity. Janos (CHIH) presents limitations in terms of soil water availability, although its presence is more heterogeneous (2 to 8 months). Santa Cruz (SON) has the highest soil water availability (4 to 5 months), and presents pH, texture and low percentage of salinity conditions for the potential incidence of Campylobacter spp. Mexicali (BC) reports a temperature in the warmest month of up to 43°C, which could influence the presence of thermophilic species. The annual precipitation is another limiting factor for the potential incidence of Campylobacter spp. since it does not exceed 509.5 mm, contributing to Janos (CHIH) as the municipality with the highest potential incidence of this bacterium.

Role of Maternal Antibodies in the Protection of Broiler Chicks against Campylobacter Colonization in the First Weeks of Life

Thermophilic Campylobacter species are the most common cause of bacterium-mediated diarrheal disease in humans globally. Poultry is considered the most important reservoir of human campylobacteriosis, but so far, no effective countermeasures are in place to prevent the bacterium from colonizing broiler flocks. This study investigated maternal antibodies' potential to offer protection against Campylobacter in broiler chicks via a field trial and an immunization trial. In the field trial, breeder flocks with high and low anti-Campylobacter antibody levels in the yolk were selected based on serological screening. Offspring were subsequently monitored for maternal antibodies and Campylobacter prevalence during early life. Although maternal antibodies declined rapidly in the serum of broilers, offspring from flocks with lower anti-Campylobacter antibody levels seemed to be more susceptible to colonization. In the immunization trial, breeders from a seropositive breeder flock were vaccinated with an experimental bacterin or subunit vaccine. Immunization increased antibody levels in the yolk and consequently in the offspring. Elevated maternal antibody levels were significantly associated with reduced Campylobacter susceptibility in broilers at 2 weeks old but not at 1 and 3 weeks old. Overall, the protective effect of maternal immunity should be cautiously considered in the context of Campylobacter control in broilers. Immunization of breeders may enhance resistance but is not a comprehensive solution.

Virulence Profiling, Multidrug Resistance and Molecular Mechanisms of Campylobacter Strains from Chicken Carcasses in Tunisia

Antibiotic resistance in foodborne pathogens is an emergent global health concern. The objectives of this study were to assess antimicrobial resistance (AMR) in Campylobacter isolates from chicken carcasses and to investigate the AMR molecular mechanisms as well as the presence of virulence determinants. The study was performed on 257 samples collected from abattoirs and retail shops in northeastern Tunisia. Forty-eight Campylobacter isolates were recovered and identified as C. jejuni (n = 33) and C. coli (n = 15). Antibiotic resistance was tested against eight antibiotics and high resistance rates were observed against tetracycline (100%), erythromycin (97.9%), ciprofloxacin (73%), nalidixic acid (85.4%), ampicillin (83.3%), amoxicillin/clavulanic acid (22.9%), chloramphenicol (75%), and gentamicin (27.1%). All isolates were multidrug-resistant, and 22 resistance patterns were found. All isolates were screened for AMR genes (tet(O), tet(A), tet(B), tet(L), cmeB, ermB, bla_OXA-61, and aphA-3), and for point mutations in gyrA (C257T substitution) and 23SrRNA (A2075G/A2074C) genes. All screened AMR genes, as well as the C257T and the A2075G mutations, were detected. The virulence genotypes were also determined, and all isolates carried the motility (flaA) and invasion (cadF) genes. Most of them also harbored the cdtA, cdtB, and cdtC genes, encoding the Campylobacter toxin. The screening of the cgtB and the wlaN genes, involved in Guillain-Barré Syndrome expression, revealed the presence of the cgtB in 21.2% of C. jejuni strains, whereas none of them carried the wlaN gene. Our findings highlight the emergence of Campylobacter strains simultaneously harboring several virulence and AMR determinants, which emphasizes the risk of transmission of MDR strains to humans via the food chain. Hence, controlling the dissemination of foodborne pathogens “from the farm to the fork” as well as restricting the use of antimicrobials in husbandry are mandatory to prevent the risk for consumers and to mitigate the dissemination of MDR pathogens.

Decay of four enteric pathogens and implications to wastewater-based epidemiology: Effects of temperature and wastewater dilutions

Measurement of pathogens in raw wastewater from a population within certain sewer catchments can provide quantitative information on public health status within the sampled urban area. This so-called wastewater-based epidemiology (WBE) approach has the potential of becoming a powerful tool to monitor pathogen circulation and support timely intervention during outbreaks. However, many WBE studies failed to account for the pathogen decay during wastewater transportation in back calculating the disease prevalence. Various sewer process factors, including water temperature and infiltration/inflow, can lead to the variation of pathogen decay rates. This paper firstly reviewed the effects of temperature and types of water, i.e., wastewater, freshwater, and saline water, on the decay of four selected enteric pathogens, i.e., Campylobacter, Salmonella, Norovirus, and Adenovirus. To elucidate the importance of the pathogen decay rates (measured by culture and molecular methods) to WBE, a sensitivity analysis was conducted on the back-calculation equation for infection prevalence with decay rates collected from published literature. It was found that WBE back-calculation is more sensitive to decay rates under the condition of high wastewater temperature (i.e., over 25 °C) or if wastewater is diluted by saline water (i.e., sewer infiltration or use of seawater as an alternative source of freshwater constituting around 1/3 household water demand in some cities). Stormwater dilution of domestic wastewater (i.e., sewer inflow might achieve 10 times volumetric dilution) was shown to play a role in increasing the sensitivity of WBE back-calculation to bacterial pathogens, but not viral pathogens. Hence, WBE back-calculation in real sewers should account for in-sewer decay of specific pathogen species under different wastewater temperatures and dilutions. Overall, this review contributes to a better understanding of pathogen decay in wastewater which can lead to improved accuracy of WBE back-calculation.

Identification and Characterization of Campylobacter Species in Livestock, Humans, and Water in Livestock Owning Households of Peri-urban Addis Ababa, Ethiopia: A One Health Approach

Campylobacter is the most common cause of bacterial infectious diarrhea and acute gastroenteritis globally, and is recognized as a significant zoonotic pathogen. Antimicrobial resistance amongst Campylobacter isolates is a significant global concern. A cross-sectional study was conducted to identify and characterize Campylobacter species in humans, animals and water sources in livestock owning households of peri-urban Addis Ababa, Ethiopia; and to characterize antimicrobial resistance. A total of 519 fecal samples from humans (n = 99), livestock (n = 179), poultry (n = 69), and water (n = 172) were collected. Samples were cultured for viable Campylobacter spp. and multiplex PCR utilized for the identification and confirmation. Antimicrobial susceptibility of the isolates was assessed using the Kirby-Bauer disc diffusion method. Campylobacter spp. was detected in 67/519 (13.0%) of the total tested samples, and the household level prevalence of Campylobacter was 42.4%. The prevalence of Campylobacter spp. was: humans (10.1%), cattle (18.5%), poultry (13.0%), sheep (13.3%), goats (7.1%), and water (10.5%). Campylobacter jejuni and C. fetus were the most frequently isolated species, followed by C. coli. The majority of isolates obtained from human samples had co-occurrence with isolates from cattle, poultry or water samples from the same household. The use of stored water, the practice of indoor and outdoor manure collecting, and animal species Campylobacter positivity were significantly associated with greater odds of human Campylobacter spp. positivity. All Campylobacter isolates from humans, poultry, sheep, goats and water, and 96.0% of isolates from cattle were resistant to at least one or more of the tested antimicrobials, with 95.5% of isolates resistant to three or more classes of antimicrobials. A One Health approach is recommended to further investigate Campylobacter species infections, and other zoonotic infectious diseases, in the livestock owning populations in Ethiopia, where there is close interaction between humans, animals and the environment.

Draft Genome Sequences of Eight Campylobacter volucris Isolates from Freshwater Sources in Victoria, Australia

Campylobacter spp. can survive and be transmitted from a range of environments. Here, we examine eight draft genome sequences of Campylobacter volucris, identified as part of an examination of waterborne Campylobacter species. This is the first report of environmental survival of C. volucris outside gull species.

Campylobacter spp. can survive and be transmitted from a range of environments. Here, we examine eight draft genome sequences of Campylobacter volucris, identified as part of an examination of waterborne Campylobacter species. This is the first report of environmental survival of C. volucris outside gull species.

Genomic and Phenotypic Characterisation of Campylobacter jejuni Isolates From a Waterborne Outbreak

Campylobacter infections are the leading cause of bacterial gastroenteritis. In Europe, over 246,000 cases are confirmed annually. Infections are often transmitted via contaminated food, such as poultry products, but water may be the source of infection as well. The aim of this study was to characterise a selection of Campylobacter jejuni human isolates, together with a water isolate, from a waterborne outbreak in Norway in 2019, including human isolates from early, mid-, and late epidemic. The isolates were characterised with whole-genome sequencing, analysing the expression of putative virulence genes and demonstrating the pathogenic potential in an in vitro adhesion model using HT-29 cells. All isolates belonged to the multilocus sequence type 1701 and ST45 clonal complex. In the genomic analysis, the water isolate clustered somewhat separately from the human isolates. There was some variation between the human isolates, but the water isolate seemed to display the greatest pathogenic potential, demonstrated by the highest levels of virulence gene expression, adhesion to epithelial cells and IL-8 induction. These results suggest that the water isolate of the study has potential to cause human infections, and that some bacterial changes due to host or environmental adaptation, may occur during a waterborne Campylobacter epidemic. This is, to the best of our knowledge, the first study on C. jejuni isolates from a waterborne outbreak, including both human isolates and a water isolate, characterised with genomic and phenotypic approaches.

Identification and differentiation of Campylobacter isolated from chicken meat using real-time polymerase chain reaction and high resolution melting analysis of hipO and glyA genes

Background and Aim:

Campylobacter species have been recognized as the most frequently identified bacterial cause of human gastroenteritis. The aims of this study were to identify Campylobacter jejuni and Campylobacter coli species isolated from chicken meat and to analyze the differences in the melting curve patterns of both species.

Materials and Methods:

A total of 105 chicken meat samples collected from slaughterhouses and retailers in six provinces in Indonesia were examined for the isolation and identification of Campylobacter spp. A total of 56 positive isolates of Campylobacter spp. were analyzed using the quantitative real-time polymerase chain reaction and high resolution melting method.

Results:

The prevalence of Campylobacter spp. in chicken meat was found to be 61.9%. Regarding the identification, 23 isolates (41.07%) were C. jejuni, 22 (39.29%) were C. coli, six (10.71%) were a mix between C. jejuni and C. coli, and five isolates (8.93%) were Campylobacter spp. All the C. jejuni and C. coli isolates produced varied melting curve patterns.

Conclusion:

The high prevalence of C. jejuni and C. coli in chicken meat in Indonesia indicates a high risk of the incidence of campylobacteriosis in humans.

Identification of Transmission Routes of Campylobacter and On-Farm Measures to Reduce Campylobacter in Chicken

An in-depth analysis was performed on Swedish broiler producers that had delivered chickens with Campylobacter to slaughter over several years, in order to identify possible transmission routes and formulate effective measures to prevent chickens being colonized with Campylobacter. Between 2017 and 2019, 626 samples were collected at farm level and Campylobacter was isolated from 133 (21.2%). All C. jejuni and C. coli isolated from these samples were whole-genome sequenced, together with isolates from the corresponding cecum samples at slaughter (n = 256). Core genome multi-locus sequence typing (cgMLST) analysis, using schemes consisting of 1140 and 529 genes for C. jejuni and C. coli, respectively, revealed that nearby cattle, contaminated drinking water, water ponds, transport crates, and parent flocks were potential reservoirs of Campylobacter. A novel feature compared with previous studies is that measures were implemented and tested during the work. These contributed to a nationwide decrease in Campylobacter-positive flocks from 15.4% in 2016 to 4.6% in 2019, which is the lowest ever rate in Sweden. To conclude, there are different sources and routes of Campylobacter transmission to chickens from different broiler producers, and individual measures must be taken by each producer to prevent Campylobacter colonization of chickens.

Prevalence, genotypic diversity and detection of virulence genes in thermotolerant Campylobacter at different stages of the poultry meat supply chain

Thermotolerant Campylobacter is the leading bacterial cause of foodborne illness in humans worldwide. The objectives of this study were to estimate prevalence and to identify and characterize potential sources of thermotolerant Campylobacter contamination in broilers on farms and at the slaughterhouse; to evaluate the clonal relationship among thermotolerant Campylobacter isolates from different stages of the broiler meat supply chain, and to analyze the presence of virulence genes in different sources of thermotolerant Campylobacter. A total of 1210 samples were collected from three broiler meat supply chains in Santa Fe, Argentina. At the farms, the sampling collection included broilers one week prior to slaughter, wild-living birds, domestic dogs, wild rodents, farm workers' boots, litter, feed, drinking water, flies, and darkling beetles (Alphitobius diaperinus). At the slaughtering line, the samples taken were from the evisceration zone (broiler cecum, working surfaces, evisceration knives and workers' hands), from the chiller zone (surfaces and direct supply water) and from the packing zone (work surfaces, workers' hands and broiler carcasses). The samples taken along each supply chain were in the same batch. The isolates obtained were identified to the species level (C. jejuni and C. coli) by multiplex PCR and were analyzed using pulsed-field gel electrophoresis to compare different profiles according to the source. Finally, the presence of 11 virulence genes was examined (cadF, cdtA, cdtB, cdtC, ciaB, flaA, flhA, iam, wlaN, virB11, racR). From 254 isolates, 128 (50.4%) were Campylobacter jejuni and 126 (49.6%) Campylobacter coli. C. jejuni was the species most prevalent in farm and C. coli the species most prevalent at the slaughterhouse. We detected thermotolerant Campylobacter in samples of wild birds, darkling beetles, farm workers' boots, flies and litter. At the slaughterhouse, the prevalence varied along the process line. By analyzing PFGE results, C. jejuni showed 21 profiles with three predominant genotypes, while C. coli showed 14 profiles with four predominant genotypes. A high genotype diversity was found; however, relationships between isolates from different stages of the broiler meat chain, between broiler and potential sources of thermotolerant Campylobacter contamination and between strains in the farm and in the slaughterhouse were detected. Furthermore, there was evidence of cross-contamination at the slaughterhouse. FlaA, flhA genes were detected in all strains, and the third most prevalent virulence gene was cadF. Only those strains obtained from flies, wild-living birds and broiler carcass samples harbored 10 of 11 pathogenic genes. The prevalence of some pathogenic genes between C. jejuni and C. coli was different. This evidence should contribute the scientific basis to implement risk management measures in public health.

Mixed Aetiology of Diarrhoea in Infants Attending Clinics in the North-West Province of South Africa: Potential for Sub-Optimal Treatment

Routine diagnostic methods for the aetiologic agents of diarrhoea in most developing countries are usually not sensitive enough, leading to under-diagnosis. Thus, this study investigated possible mixed diarrhoeal aetiology by using cultures and real-time polymerase chain reactions (PCR) in children younger than four years old in the Northwest Province, South Africa. In total, 505 stool samples were collected from symptomatic and asymptomatic children who were attending three clinics and the Brits hospital in Madibeng District, between September 2016 and December 2017. Rotavirus, norovirus, Campylobacter, Arcobacter, and diarrhoeagenic Escherichia coli (DEC) were targeted. Campylobacter spp. (24.6%), Arcobacter (15.8%) and DEC (19.6%) were detected using PCR; only Campylobacter spp. (29.7%) and DEC (26.9%) were detected through the culture. Campylobacter jejuni (36%), Campylobacter coli (28%), Campylobacter upsalensis (12%), and Arcobacter butzleri (15.8%) were the only spp. of Campylobacter and Arcobacter identified. The eaeA gene (31.4%) of enteropathogenic E. coli/enterohaemorrhagic E. coli (EPEC/EHEC) was the most prevalent DEC virulence gene (VG) identified. Rotavirus and norovirus were detected at 23.4% and 20%, respectively. Mixed viral aetiology (7.3%) and the co-infection of A. butzleri and Campylobacter (49%) were recorded. A mixed bacterial-viral aetiology was observed in 0.6% of the specimens. Sensitive diagnostic procedures like PCR should be considered to provide the best treatment to children experiencing diarrhoea.

Detection of Campylobacter spp. in water by dead-end ultrafiltration and application at farm level

AIMS

The purposes were to evaluate the detection of low levels of Campylobacter in water by dead-end ultrafiltration (DEUF) to determine the sensitivity and suitability for use under field condition.

METHODS AND RESULTS

The DEUF technique followed by detection according to ISO 10272 was tested on artificially and naturally contaminated water. Campylobacter were detected in all samples spiked with more than 10 CFU 60 l-1 and in four of nine samples with a concentration below 10 CFU 60 l-1 water. Naturally contaminated water from five different broiler producers was analysed. Campylobacter were detected in four of 12 samples from ponds near the houses and in three of 24 samples from water pipes inside the broiler houses, but not in tap water sampled at the entrance of the broiler houses.

CONCLUSIONS

The results indicate that DEUF is useful for detection of low numbers of Campylobacter in large volumes of water.

SIGNIFICANCE AND IMPACT OF THE STUDY

Contaminated water is an important source for transmission of Campylobacter to broilers and humans. The concentration of Campylobacter is usually low with a high level of background microbiota. This study shows the advantages of DEUF both in the laboratory and under field conditions.

Characterization and Phylogenetic Analysis of Campylobacter Species Isolated from Paediatric Stool and Water Samples in the Northwest Province, South Africa

Antibiotic-resistant Campylobacter could adversely affect treatment outcomes, especially in children. We investigated the antibiotic susceptibility profiles, virulence potentials and genetic relatedness of Campylobacter spp. from paediatric and water samples in the North West Province, South Africa. Overall, 237 human and 20 water isolates were identified using culture and real-time polymerase chain reaction (PCR). The antibiotic susceptibility profiles were determined using the disk diffusion method. Gradient strips were used to determine the minimum inhibitory concentration of each antibiotic. Antibiotic resistance (gryA, tetO and 23S rRNA 2075G and 2074C) and virulence (cadF and ciaB) genes were also investigated using PCR. A phylogenetic tree to ascertain the clonality between water and clinical isolates was constructed using MEGA 7. Overall, 95% (water) and 64.7% (human) of the isolates were resistant to at least one antibiotic tested. The highest resistance was against clarithromycin (95%) for water and ampicillin (60.7%) for human isolates. The 23S rRNA 2075G/2074C mutation was the most expressed resistance gene. Phylogenetic reconstruction revealed eight intermixed clades within water and human Campylobacter isolates. This study suggests the possible circulation of potentially pathogenic antibiotic-resistant Campylobacter in the Northwest Province, South Africa with drinking water being a possible vector for disease transmission in this area.