Healthy puppies and kittens as carriers of Campylobacter spp., with special reference to Campylobacter upsaliensis

Prevalence and antibacterial susceptibilities of Arcobacter spp. and Campylobacter spp. from fresh vegetables

This study was aimed at the isolation and identification of Arcobacter spp. and Campylobacter spp. from fresh vegetables sold at district markets in the Kayseri province, and at the determination of the antibacterial susceptibility of the recovered isolates. For this purpose, a total of 175 vegetable samples, including 35 spinach, 35 lettuce, 35 parsley, 35 arugula, and 35 radish samples, were collected. While the pre-enrichment and membrane filtration techniques were used for the isolation of Arcobacter spp., the pre-enrichment and direct inoculation methods were used for the isolation of Campylobacter spp. The isolates were identified by means of phenotypic tests and the polymerase chain reaction (PCR), using genus- and species-specific primers. In addition, the susceptibilities of the isolates to amoxicillin-clavulanic acid, enrofloxacin, erythromycin, gentamicin, neomycin, streptomycin, and tetracycline were determined by the disk diffusion method. Out of the 175 vegetable samples tested, 93 (53.14%) were found to be positive for Arcobacter spp., and 119 Arcobacter spp. isolates were recovered from these 93 positive samples. All of the samples examined were found to be negative for Campylobacter spp. One hundred one (86%) and 14 (10%) of the 119 Arcobacter isolates obtained were identified as A. butzleri and A. cryaerophilus, respectively, but four isolates could not be identified at the species level by mPCR. Mixed contamination with more than one species and/or genotypes of Arcobacter was detected in 24 of the positive samples. While all of the Arcobacter isolates were susceptible to erythromycin, gentamicin, streptomycin, and tetracycline, 2 (1.68%), 2 (1.68%), and 5 (4.20%) isolates were resistant to amoxicillin/clavulanic acid, enrofloxacin, and neomycin, respectively. Consequently, the determination of a high prevalence of arcobacters and mixed contamination with more than one species and/or genotypes of arcobacters in vegetables often consumed raw by humans demonstrated that the consumption of raw vegetables may be a risk to the public health.

Survival capability of Campylobacter upsaliensis under environmental stresses

Objective

Campylobacter upsaliensis has been recognized as an emerging pathogen. However, little is known about its survival in the environment. To evaluate its survival capability, we estimated the reduction in viable counts of C. upsaliensis after aerobic exposure to starvation in phosphate-buffered saline (PBS), acidity (pH = 4.3), high osmolarity (4% NaCl), and dryness in wet pulp disks at different temperatures. Also, survival in dog feces and dog food at variable temperate was assessed.

Results

Campylobacter upsaliensis remained culturable under starvation for 4 days at 25 °C and for 10 weeks at 4 °C. C. upsaliensis was also recoverable after exposure to high osmolality for 9 days, dryness for 5 days, and acidity for 2 days, respectively. Similarly, C. upsaliensis survived in dog feces and dog food for several days at 25 °C and weeks at 4 °C. The survival capability of the organism was dependent on the water content, and also temperature. Notably, the tested C. upsaliensis strain was less resilient under all tested conditions than a C. jejuni strain used as a control. The findings showed that C. upsaliensis is able to survive under various environmental stresses, suggesting that it could pose a potential threat to public health.

Evaluating the presence of human pathogens in commercially frozen, biologically appropriate raw pet food sold in Italy

BACKGROUND

Biologically appropriate raw food (BARF) diet is becoming more and more popular among pet owners in Europe. However, there are documented microbiological risks associated with raw feeding, and this study aimed to determine the presence of human pathogens in commercially frozen BARF products sold in Italy.

METHODS

Salmonella species, Escherichia coli O157:H7, Listeria monocytogenes and Campylobacter species were identified. The general microbiological quality of BARF products and hygiene were also evaluated. Sample size was limited and therefore the study may not be representative of a larger sample.

RESULTS

None of the tested samples showed total bacterial count (TBC) higher than the limit set to consider a sample unacceptable. However, 14 out of 21 samples showed TBC higher than the limit set to consider a sample marginally acceptable. A high percentage of samples were contaminated by the aforementioned pathogens, highlighting the need for pet owners to be aware of the risks of this feeding strategy both to themselves and to their pets.

CONCLUSIONS

Considering that BARF diet meals can be prepared at home using the hands, as well as tools and spaces that could be shared, guidelines on safer handling of these pet food products should be recommended by veterinarians and nutritionists.

The role of Campylobacter spp. in chronic enteropathy in dogs

The aim of the study was to identifyCampylobacterspecies in a group of patients with chronic gastrointestinal problems and to investigate the relationship between the presence ofCampylobacterspp. in stool samples and as well as the severity of chronic enteropathy. Twenty-six dogs with chronic gastrointestinal problems were included in the prospective study. Each research subject had their stomach, duodenum, ileum, and colon examined endoscopically. A histopathological examination of the obtained biopsy samples was then performed, excluding other potential diseases. Stool samples were collected and then examined for the presence ofCampylobacterspp. To evaluate the relationship betweenCampylobacterspp. occurrence and the intensity of chronic enteropathy, patients were divided into two groups; animals in the first group presented with no to mild inflammation whereas research subjects in the second group suffered from moderate to severe inflammation. Subsequently, the patients were divided based on positive or negative test results forCampylobacterspp. cultures. No significant relationship between the presence ofCampylobacterspp. in stool samples and chronic enteropathy was found. In contrast to other previously published papers, our study showed a lower occurrence ofCampylobacter upsaliensis.

Pathogenomics of Emerging Campylobacter Species

Campylobacter is among the four main causes of gastroenteritis worldwide and has increased in both developed and developing countries over the last 10 years. The vast majority of reported Campylobacter infections are caused by Campylobacter jejuni and, to a lesser extent, C. coli; however, the increasing recognition of other emerging Campylobacter pathogens is urgently demanding a better understanding of how these underestimated species cause disease, transmit, and evolve. In parallel to the enhanced clinical awareness of campylobacteriosis due to improved diagnostic protocols, the application of high-throughput sequencing has increased the number of whole-genome sequences available to dozens of strains of many emerging campylobacters. This has allowed for comprehensive comparative pathogenomic analyses for several species, such as C. fetus and C. concisus These studies have started to reveal the evolutionary forces shaping their genomes and have brought to light many genomic features related to pathogenicity in these neglected species, promoting the development of new tools and approaches relevant for clinical microbiology. Despite the need for additional characterization of genomic diversity in emerging campylobacters, the increasing body of literature describing pathogenomic studies on these species deserves to be discussed from an integrative perspective. This review compiles the current knowledge and highlights future work toward deepening our understanding about genome dynamics and the mechanisms governing the evolution of pathogenicity in emerging Campylobacter species, which is urgently needed to develop strategies to prevent or control the spread of these pathogens.

Prevalence and risk factors associated with Campylobacter spp. occurrence in healthy dogs visiting four rural community veterinary clinics in South Africa

Reports on the occurrence of Campylobacter spp. in dogs in South Africa are non-existent. This study investigated the prevalence of Campylobacter spp. in 481 dogs visiting four rural community veterinary clinics in South Africa. Dogs were screened for Campylobacter spp. by culture and polymerase chain reaction (PCR), and logistic regression analysis was performed to assess the association between sex, clinic, breed and age and the occurrence of Campylobacter spp. in dogs. The prevalence of Campylobacter spp. was 41.50% (95% confidence interval [CI], 37.39% - 46.04%). Campylobacter jejuni, C. upsaliensis and C. coli were detected in 29.31% (95% CI, 25.42% - 33.54%), 13.10% (95% CI, 10.37% - 16.42%) and 5.41% (95% CI, 3.71% - 7.82%) of dogs, respectively. Dogs carrying more than one species of Campylobacter spp. accounted for 6.23% (95% CI, 4.40% - 8.78%). Campylobacter upsaliensis and C. jejuni were detected in 3.74% (95% CI, 2.37% - 5.86%), whereas C. coli and C. jejuni were found in 2.49% (95% CI, 1.42% - 4.34%) of dogs. Age and clinic were the risk factors significantly associated with Campylobacter spp. occurrence, while age, breed and clinic were predictors of C. jejuni carriage. Furthermore, age was the only risk factor associated with a higher likelihood of carrying C. upsaliensis. The prevalence of Campylobacter spp. C. jejuni and C. upsaliensis increased significantly as dogs grew older. In addition, the odds of carrying Campylobacter spp. were higher in the Staffordshire bull terrier breed compared to crossbreed dogs. In conclusion, this study shows that dogs visiting rural community veterinary clinics in South Africa are reservoirs of Campylobacter spp. and may be potential sources of Campylobacter spp. for humans living in close proximity of the dog populations under study.

Salmonella, Campylobacter, Clostridium difficile, and anti-microbial resistant Escherichia coli in the faeces of sympatric meso-mammals in southern Ontario, Canada

The role of free-ranging wildlife in the epidemiology of enteropathogens causing clinical illness in humans and domestic animals is unclear. Salmonella enterica and anti-microbial resistant bacteria have been detected in the faeces of raccoons (Procyon lotor), but little is known about the carriage of these bacteria in other sympatric meso-mammals. Our objectives were to: (a) report the prevalence of Salmonella and associated anti-microbial resistance, Campylobacter spp, Clostridium difficile, and anti-microbial resistant Escherichia coli in the faeces of striped skunks (Mephitis mephitis) and Virginia opossums (Didelphis virginiana) in southern Ontario; and (b) compare the prevalence of these bacteria in the faeces of these meso-mammal hosts with raccoons from a previously reported study. Faecal swabs were collected from striped skunks and Virginia opossums on five swine farms and five conservation areas from 2011 to 2013. Salmonella was detected in 41% (9/22) and 5% (5/95) of faecal swabs from Virginia opossums and striped skunks, respectively. None of the Salmonella serovars carried resistance to anti-microbials. The prevalence of Campylobacter spp., C. difficile, and anti-microbial resistant E. coli ranged from 6% to 22% in striped skunk and Virginia opossums. Using exact logistic regression, Salmonella was significantly more likely to be detected in faecal swabs of Virginia opossums than skunks and significantly less likely in faecal swabs from skunks than raccoons from a previously reported study. In addition, Campylobacter spp. was significantly more likely to be detected in raccoons than opossums. Salmonella Give was detected in 8/9 (89%) of Salmonella-positive Virginia opossum faecal swabs. Our results suggest that striped skunks and Virginia opossums have the potential to carry pathogenic enteric bacteria in their faeces. The high prevalence of Salmonella Give in Virginia opossum faecal swabs in this study as well as its common occurrence in other Virginia opossum studies throughout North America suggests Virginia opossums may be reservoirs of this serovar.

Isolation of emerging Campylobacter species in working farm dogs and their frozen home-killed raw meat diets

We applied 7 culture methods to 50 working farm dog fecal samples and 6 methods to 50 frozen home-killed raw meat diet samples to optimize recovery of a wide range of Campylobacter spp. Culture methods combined filtration, enrichment broths, and agars at 37°C and 42°C in conventional and hydrogen-enriched microaerobic atmospheres. Overall, a prevalence of 62% (31 of 50) and 6% (3 of 50) was detected in dog and meat samples, respectively, based on Campylobacter genus PCR. A total of 356 Campylobacter spp. isolates were recovered from dogs, with successful isolation by individual methods ranging from 2 to 25 dogs. The species detected most commonly were C. upsaliensis and C. jejuni, and less commonly C. coli and C. lari. Species isolated that are rarely reported from dogs included C. rectus, C. lari subsp. concheus, C. volucris, and Helicobacter winghamensis. Six isolates from dogs positive by Campylobacter genus PCR were confirmed, using 16S rRNA sequencing, as Arcobacter cryaerophilus (1) and Arcobacter butzleri (5). C. jejuni multi-locus sequence typing results revealed a diversity of sequence types in working dogs, with several uncommonly reported from other C. jejuni sources in New Zealand. Overall, 20 isolates from 3 meat samples were positive by Campylobacter genus PCR; 1 meat sample was positive for C. jejuni, 1 for C. rectus, and 1 isolate was subsequently identified as A. butzleri. The method using Campylobacter enrichment broth in a hydrogen-enriched environment on nonselective agar resulted in significantly reduced recovery of Campylobacter spp. from both sample types.

Pet-associated Campylobacteriosis: A persisting public health concern

Campylobacter is regarded as a leading cause of human bacterial gastroenteritis in the United States. We report on a case of laboratory-confirmed Campylobacter jejuni infection in the Commonwealth of Pennsylvania among members of a household living with a laboratory-confirmed but non-speciated Campylobacter-infected puppy. We describe an outbreak of likely dog-associated campylobacteriosis, the risk factors, potential routes of exposure and the clinical features in the exposed family members, which began shortly after exposure to the recently purchased dog. We also provide public health recommendations to prevent Campylobacter infections in veterinary care providers, pet owners and those planning to adopt pets in the future. Finally, this report underscores the importance of the One Health approach when public health responders, human and animal healthcare providers and clinical diagnostic laboratories are tasked with developing effective strategies when investigating, detecting and responding to zoonoses (diseases shared between animals and humans).

Campylobacter: from microbiology to prevention

In last years, Campylobacter spp has become one of the most important foodborne pathogens even in high-income countries. Particularly, in Europe, Campylobacteriosis is, since 2005, the foodborne disease most frequently notified and the second in USA, preceded by the infection due to Salmonella spp. Campylobacter spp is a commensal microorganism of the gastrointestinal tract of many wild animals (birds such as ducks and gulls), farm animals (cattle and pigs) and companion animals (such as dogs and cats) and it is responsible for zoonoses. The transmission occurs via the fecal-oral route through ingestion of contaminated food and water. The disease varied from a watery diarrhea to a severe inflammatory diarrhea with abdominal pain and fever and can be burdened by some complications. The main recognized sequelae are Guillain-Barré Syndrome (GBS), the Reactive Arthritis (REA) and irritable bowel syndrome (IBS). Recently, many cases of Campylobacter spp isolated from human infections, showed an important resistance to various antibiotics such as tetracyclines and fluoroquinolones. For these reasons, the prevention of this infection plays an essential role. Many preventive measures exist to limit the transmission of the pathogens and the subsequent disease such as the health surveillance, the vaccination of the poultry and the correct food hygiene throughout the entire production chain. A global surveillance of Campylobacteriosis is desirable and should include data from all countries, including notifications of cases and the microbiological data typing of strains isolated from both human and animal cases.

A Systematic Review and Meta-Analysis of the Campylobacter spp. Prevalence and Concentration in Household Pets and Petting Zoo Animals for Use in Exposure Assessments

Animal contact is a potential transmission route for campylobacteriosis, and both domestic household pet and petting zoo exposures have been identified as potential sources of exposure. Research has typically focussed on the prevalence, concentration, and transmission of zoonoses from farm animals to humans, yet there are gaps in our understanding of these factors among animals in contact with the public who don't live on or visit farms. This study aims to quantify, through a systematic review and meta-analysis, the prevalence and concentration of Campylobacter carriage in household pets and petting zoo animals. Four databases were accessed for the systematic review (PubMed, CAB direct, ProQuest, and Web of Science) for papers published in English from 1992-2012, and studies were included if they examined the animal population of interest, assessed prevalence or concentration with fecal, hair coat, oral, or urine exposure routes (although only articles that examined fecal routes were found), and if the research was based in Canada, USA, Europe, Australia, and New Zealand. Studies were reviewed for qualitative synthesis and meta-analysis by two reviewers, compiled into a database, and relevant studies were used to create a weighted mean prevalence value. There were insufficient data to run a meta-analysis of concentration values, a noted study limitation. The mean prevalence of Campylobacter in petting zoo animals is 6.5% based on 7 studies, and in household pets the mean is 24.7% based on 34 studies. Our estimated concentration values were: 7.65x103cfu/g for petting zoo animals, and 2.9x105cfu/g for household pets. These results indicate that Campylobacter prevalence and concentration are lower in petting zoo animals compared with household pets and that both of these animal sources have a lower prevalence compared with farm animals that do not come into contact with the public. There is a lack of studies on Campylobacter in petting zoos and/or fair animals in Canada and abroad. Within this literature, knowledge gaps were identified, and include: a lack of concentration data reported in the literature for Campylobacter spp. in animal feces, a distinction between ill and diarrheic pets in the reported studies, noted differences in shedding and concentrations for various subtypes of Campylobacter, and consistent reporting between studies.

Risk Factors for Sporadic Domestically Acquired Campylobacter Infections in Norway 2010-2011: A National Prospective Case-Control Study

Background

Campylobacteriosis is the most frequently reported food- and waterborne infection in Norway. We investigated the risk factors for sporadic Campylobacter infections in Norway in order to identify areas where control and prevention measures could be improved.

Methods

A national prospective case-control study of factors associated with Campylobacter infection was conducted from July 2010 to September 2011. Cases were recruited from the Norwegian Surveillance System of Communicable Diseases (MSIS). Controls were randomly selected from the Norwegian Population Registry. Cases and controls were mailed a paper questionnaire with a prepaid return envelope. Univariable analyses using logistic regression were conducted for all exposures. A final parsimonious multivariable model was developed using regularized/penalized logistic regression, and adjusted odds ratios were calculated.

Results

A total of 995 cases and 1501 controls were included in the study (response proportion 55% and 30%, respectively). Exposures that had significant increases in odds of Campylobacter infection in multivariable analysis were drinking water directly from river, stream, or lake (OR: 2.96), drinking purchased bottled water (OR: 1.78), eating chicken (1.69), eating meat that was undercooked (OR: 1.77), eating food made on a barbecue (OR: 1.55), living on a farm with livestock (OR: 1.74), having a dog in the household (OR: 1.39), and having household water supply serving fewer than 20 houses (OR: 1.92).

Conclusions

Consumption of poultry and untreated water remain important sources of Campylobacter infection in Norway, despite ongoing control efforts. The results justify the need for strengthening education for consumers and food handlers about the risks of cross-contamination when preparing poultry and with consuming raw or undercooked chicken. The public should also be reminded to take precautions when drinking untreated water in nature and ensure continued vigilance in order to protect and maintain the quality of water from small-scale water supply systems.

Faeco-prevalence of Campylobacter jejuni in urban wild birds and pets in New Zealand

Background

Greater attention has been given to Campylobacter jejuni (C. jejuni) prevalence in poultry and ruminants as they are regarded as the major contributing reservoirs of human campylobacteriosis. However, relatively little work has been done to assess the prevalence in urban wild birds and pets in New Zealand, a country with the highest campylobacteriosis notification rates. Therefore, the aim of the study was to assess the faeco-prevalence of C. jejuni in urban wild birds and pets and its temporal trend in the Manawatu region of New Zealand.

Findings

A repeated cross-sectional study was conducted from April 2008 to July 2009, where faecal samples were collected from 906 ducks, 835 starlings, 23 Canadian goose, 2 swans, 2 pied stilts, 498 dogs and 82 cats. The faeco-prevalence of C. jejuni was 20% in ducks, 18% in starlings, 9% in Canadian goose, 5% in dogs and 7% in cats. The faeco-prevalence of C. jejuni was relatively higher during warmer months of the year in ducks, starlings and dogs while starlings showed increased winter prevalence. No such trend could be assessed in Canadian goose, swans, pied stilts and cats as samples could not be collected for the entire study period from these species.

Conclusions

This study estimated the faeco-prevalence of C. jejuni in different animal species where the prevalence was relatively high during warmer months in general. However, there was relative increase in winter prevalence in starlings. The urban wild bird species and pets may be considered potential risk factors for human campylobacteriosis in New Zealand, particularly in small children.

Genotypes and antibiotic resistance of canine Campylobacter jejuni isolates

Campylobacter jejuni is the most important cause of bacterial gastroenteritis in humans. It is a commensal in many wild and domestic animals, including dogs. Whereas genotypes of human and chicken C. jejuni isolates have been described in some detail, only little information on canine C. jejuni genotypes is available. To gain more information on genotypes of canine C. jejuni and their zoonotic potential, isolates from routine diagnostics of diarrheic dogs as well as isolates of a prevalence study in non-diarrheic dogs were analyzed. Prevalence of thermophilic Campylobacter among non-diarrheic dogs was 6.3% for C. jejuni, 5.9% for Campylobacter upsaliensis and 0.7% for Campylobacter coli. The C. jejuni isolates were genotyped by multi locus sequence typing (MLST) and flaB typing. Resistance to macrolides and quinolones was genetically determined in parallel. Within the 134 genotyped C. jejuni isolates 57 different sequence types (ST) were found. Five STs were previously unrecognized. The most common STs were ST-48 (11.2%), ST-45 (10.5%) and ST-21 (6.0%). Whereas no macrolide resistance was found, 28 isolates (20.9%) were resistant to quinolones. ST-45 was significantly more prevalent in diarrheic than in non-diarrheic dogs. Within the common time frame of isolation 94% of the canine isolates had a ST that was also found in human clinical isolates. In conclusion, prevalence of C. jejuni in Swiss dogs is low but there is a large genetic overlap between dog and human isolates. Given the close contact between human and dogs, the latter should not be ignored as a potential source of human campylobacteriosis.

Occurrence of virulence genes among Campylobacter jejuni and Campylobacter coli isolates from domestic animals and children

The presence of the flaA, cadF, cdtB and iam genes of Campylobacter spp. was determined with the PCR method. The materials to investigate were 56 C. jejuni and 23 C. coli strains isolated from clinical samples (children and domestic animals). It was found that all of the Campylobacter spp. isolates from children with diarrhoea and domestic animals had cadF gene, responsible for adherence. The flaA gene was present in all Campylobacter spp. isolates derived from children and cats. Occurrence of flaA gene was confirmed in 100% of C. jejuni strains obtained from dogs. The high prevalence of the cdtB gene associated with toxin production was observed in this study (100%-Campylobacter spp. isolates obtained from dogs and cats, 97.9%-Campylobacter spp. isolates from children). The isolates showed a wide variation for the presence of iam gene. The lowest prevalence (23.5%) was detected in Campylobacter spp. obtained from dogs. The highest rates of iam detection (91.6%) were revealed in C. coli isolates from children.

Bacterial enteritis in dogs and cats: diagnosis, therapy, and zoonotic potential

A variety of bacteria are known or suspected of being able to cause enteritis in dogs and cats. Campylobacter spp, Clostridium difficile, Clostridium perfringens, and Salmonella spp are most commonly implicated, but many other organisms are likely involved. Poor understanding of the intestinal microflora and the fact that many, if not all, of these microorganisms can also be found in healthy individuals complicates testing, thereby affecting the use of specific treatments and assessment of potential infection control and zoonotic disease risks. An understanding of the strengths and limitations of various diagnostic options is important for the management of canine and feline enteritis.

Prevalence and shedding patterns of Campylobacter spp. in longitudinal studies of kennelled dogs

Dog ownership is considered a risk factor for campylobacteriosis in humans. This study investigated the prevalence and shedding of Campylobacter spp. in kennelled dogs. Faecal samples (n=399) were collected in longitudinal studies from 52 dogs in two kennels. Campylobacter spp. were isolated using charcoal-based selective agars and direct PCR. The prevalence of Campylobacter spp. in dogs in boarding kennels ranged from 46% (95% CI 22, 72) on entry, to 50% (95% CI 30, 70) overall, and in dogs in 'rescue' kennels from 68% (95% CI 49, 84) on entry to 73% (95%, CI 56, 87) overall. C. upsaliensis was isolated from 62% (95% CI 48, 73) of the dogs, whilst C. jejuni was isolated from 15% (95% CI 7, 26) of animals. The majority of infected dogs entered the kennels already carrying Campylobacter spp., and remained infected throughout their stay. However, in some cases, shedding appeared to commence after kennelling. Given that the prevalence of C. upsaliensis and C. jejuni was relatively high in dogs from both boarding and rescue kennels, such animals may pose a zoonotic risk.

Risk factors for indigenousCampylobacter jejuniandCampylobacter coliinfections in The Netherlands: a case-control study

A case-control study comprising 1315Campylobacter jejunicases, 121Campylobacter colicases and 3409 frequency-matched controls was conducted in The Netherlands in 2002–2003. Risk factors for bothC. jejuniandC. colienteritis were consumption of undercooked meat and barbecued meat, ownership of cats and use of proton pump inhibitors. Consumption of chicken was a predominant risk factor forC. jejunienteritis, but many additional risk factors were identified. Unique risk factors forC. coliinfections were consumption of game and tripe, and swimming. Contact with farm animals and persons with gastroenteritis were predominant risk factors forC. jejunienteritis in young children (0–4 years). Important risk factors for the elderly (⩾60 years) were eating in a restaurant, use of proton pump inhibitors and having a chronic intestinal illness. Consumption of chicken in spring, steak tartare in autumn and winter and barbecued meat in rural areas showed strong associations withC. jejuniinfections. This study illustrates that important differences in risk factors exist for differentCampylobacterspp. and these may differ dependent on age, season or degree of urbanization.

Typing of Campylobacter jejuni isolates from dogs by use of multilocus sequence typing and pulsed-field gel electrophoresis

Campylobacter is a major cause of human gastroenteritis worldwide. Risk of Campylobacter infection in humans has been associated with many sources, including dogs. This study aimed to investigate whether C. jejuni carried by dogs could potentially be a zoonotic risk for humans and if there were common sources of C. jejuni infection for both humans and dogs. Multilocus sequence typing (MLST) together with macrorestriction analysis of genomic DNA using SmaI and pulsed-field gel electrophoresis (PFGE) were both used to analyze 33 C. jejuni isolates obtained from various dog populations, including those visiting veterinary practices and from different types of kennels. MLST data suggested that there was a large amount of genetic diversity between dog isolates and that the majority of sequence types found in isolates from these dogs were the same as those found in isolates from humans. The main exception was ST-2772, which was isolated from four samples and could not be assigned to a clonal complex. The most commonly identified clonal complex was ST-45 (11 isolates), followed by ST-21 (4 isolates), ST-508 (4 isolates), and ST-403 (3 isolates). The profiles obtained by macrorestriction PFGE were largely in concordance with the MLST results, with a similar amount of genetic diversity found. The diversity of sequence types found within dogs suggests they are exposed to various sources of C. jejuni infection. The similarity of these sequence types to C. jejuni isolates from humans suggests there may be common sources of infection for both dogs and humans. Although only a small number of household dogs may carry C. jejuni, infected dogs should still be considered a potential zoonotic risk to humans, particularly if the dogs originate from kennelled or hunt kennel dog populations, where the prevalence may be higher.

Prevalence of potentially pathogenic enteric organisms in clinically healthy kittens in the UK

Faecal samples were collected from 57 clinically healthy kittens presented for initial vaccination, in the UK. Routine bacteriological examination identified Salmonella species in one and Campylobacter species in five samples. Polymerase chain reaction (PCR) detected the presence of Campylobacter species in a further four samples. Routine parasitological examination revealed Toxocara species ova in nine (including four kittens stated to have been administered an anthelmintic) and Isospora species in four samples. No Giardia or Cryptosporidium species were detected by routine methods. A Giardia species enzyme-linked immunosorbent assay (ELISA) test kit designed for use in cats was positive in three kittens. A similar test kit designed for use in humans was negative in all samples and produced negative results even when known positive samples were tested. Potentially pathogenic enteric organisms were detected in 19 kittens by routine methods and 26 (prevalence 45%) by all methods. The high prevalence in asymptomatic kittens highlights the possibility that the detection of these organisms in kittens with gastrointestinal disease may be an incidental finding.

Perceptions, practices, and consequences associated with foodborne pathogens and the feeding of raw meat to dogs

This study explored the impact of feeding raw meat to dogs on the fecal prevalence of several enteric bacterial zoonotic pathogens. Campylobacter jejuni was isolated from 1/42 (2.6%) raw meat-fed dogs. Salmonella enterica was isolated from 2/40 (5%) of the raw meat feeds, 6/42 (14%) raw meat-fed dog feces, none of the dogs that did not receive raw meat (P = 0.001), 4/38 (10.5%) of the vacuum cleaner waste samples from households where raw meat was fed, and 2/44 (4.5%) of vacuum cleaner waste samples from households where raw meat was not fed to dogs (P = 0.41). Responses to a questionnaire probing practices and beliefs regarding raw meat feeding that was administered to dog owners demonstrated that dog owners may either not be aware or refuse to acknowledge the risks associated with raw meat-feeding; thus, they may neglect to conduct adequate intervention strategies to prevent zoonoses among themselves and their families.

Prevalence of Campylobacter spp. in a cross-sectional study of dogs attending veterinary practices in the UK and risk indicators associated with shedding

Campylobacteriosis is a major cause of gastroenteritis in humans and some studies have suggested that dog ownership is a risk factor for the condition. To determine the prevalence, species distribution, and risk indicators for Campylobacter spp. infecting dogs attending veterinary practices in UK, faecal samples were collected in a cross-sectional study from 249 dogs with and without clinical signs. The prevalence of Campylobacter spp. was 38% (95% CI 32, 44), with Campylobacter upsaliensis accounting for 94 (98%) of the isolates and Campylobacter jejuni for the remainder. Multivariable analysis indicated that younger dogs were more likely to carry C. upsaliensis and the high prevalence of this pathogen supports the hypothesis that dogs, particularly younger animals, may be an important source of C. upsaliensis infection for humans. However the prevalence of C. jejuni, the most common Campylobacter spp. associated with disease in humans, was low (1.2%, 95% CI 0.3, 3).

The transmission of thermotolerant Campylobacter spp. to people living or working on dairy farms in New Zealand

New Zealand has one of the highest rates of campylobacteriosis in the developed world with an incidence rate of 383.5 cases per 100,000 in 2006. Dairy farming has been suggested as a potential source of campylobacteriosis. To explore this connection, seven farm investigations were undertaken at dairy farms on which a campylobacteriosis case had been notified. Campylobacter spp. were isolated from a range of sources on the farm (including 66% of bovine faecal samples) and genotypes compared with that of the clinical isolate of the index case. In depth, epidemiological questionnaires were also administered to determine exposure risks from a wide range of possible sources. Contact with dairy cow faeces was the most likely source of infection in four of the seven cases investigated, and occurred exclusively in new farm workers and children. In one of the cases investigated, infection was likely to have been acquired from non-dairy related sources, and in two cases the source could not be determined. The relative risk of dairy farm worker being notified with campylobacteriosis was estimated to be 1.88 (95% confidence interval=1.6-2.2).

Prevalence ofCampylobacterand four endoparasites in dog populations associated with Hearing Dogs

OBJECTIVES

This study established the prevalence of four gastrointestinal parasites (Isopora species, Giardia species, Uncinaria stenocephala, Toxocara canis) and one bacterial infection (Campylobacter jejuni/coli) in dogs associated with the charity Hearing Dogs for Deaf People.

METHODS

Dogs' faeces were routinely sampled from dogs according to whether they were in Socialising, Kennelling or Visiting the Hearing Dogs site. A further group consisted of dogs with diarrhoea.

RESULTS

Prevalence rates for dogs in Socialising (n=326), Kennelling (n=117), Visiting (n=106) and Diarrhoea (n=59) groups, respectively, were as follows: Campylobacter- 26, 21, 15 and 31 per cent; Coccidia - 3, 0, 0 and 2 per cent; Giardia- 13, 3, 2 and 10 per cent; hookworm - 1, 1, 4 and 5 per cent; and Toxocara- 4, 2, 3 and 2 per cent. There were significant differences in the levels of Giardia and hookworm found between the four different groups of dogs. No significant gender differences were found, and dogs that were positive for Campylobacter in the Visiting group were significantly younger.

CLINICAL SIGNIFICANCE

This study provides current information on the infection rates in specific dog populations in the UK. This is relevant to the veterinary health of dogs and the possible risk of zoonotic infection to humans.

Salmonellae and campylobacters in household and stray dogs in northern Taiwan

Rectal swabs were collected from 437 household and 491 stray dogs in northern Taiwan from May 2003 to June 2005 to investigate the prevalence and antimicrobial susceptibilities of salmonellae and campylobacters. The results revealed that 2.1% of household dogs and 6.3% of stray dogs were positive for salmonellae, with Salmonella Duesseldorf being the most dominant serotype in both. Additionally, 2.7% of the household dogs and 23.8% of the stray dogs were positive for campylobacters. Campylobacter jejuni was the most prevalent species (86.8%), followed by C. upsaliensis (9.3%) and C. coli (3.9%). Both salmonella and campylobacter isolation rates from the stray dogs were significantly higher than those from the household dogs (p < 0.01). The susceptibility of 33 C. jejuni isolates to eight antimicrobials was studied by the E-test. A high rate of resistance was observed to azithromycin (93.9%), clindamycin (87.9%), erythromycin (81.8%), tetracycline (78.8%), chloramphenicol (69.7%), nalidixic acid (51.5%), gentamicin (33.3%), and ciprofloxacin (18.2%). The susceptibility of 40 Salmonella isolates to 15 antimicrobials was also studied by the disc-diffusion method. All the Salmonella isolates were susceptible to ciprofloxacin and ceftriaxone. Resistance was observed most frequently to tetracycline (77.5%), chloramphenicol (52.5%), and ampicillin (50%).

Genotyping of Campylobacter jejuni strains from Danish broiler chickens by restriction fragment length polymorphism of the LPS gene cluster

AIMS

To apply and evaluate LG (LPS genes) genotyping, which is a genotyping method based on a cluster of genes involved in the synthesis of surface lipopolysaccharides (LPS) in Campylobacter species, for typing of Campylobacter jejuni isolates obtained from Danish broiler chickens. Furthermore, the LG genotyping method was used to study the genetic stability of four C. jejuni strains after gastrointestinal passage through experimentally infected chickens.

METHODS AND RESULTS

In the present study, the LG genotyping method was modified with respect to the restriction enzymes used. To validate the method, 63 Penner serotype reference strains and 107 C. jejuni chicken isolates, representing the most common Penner serotypes of C. jejuni in Danish poultry, were selected for typing. The method was successfully used for typing all isolates and the LG genotype profiles were reproducible. There were no changes in the LG genotype of the C. jejuni strains obtained after experimental passage through chickens.

CONCLUSIONS

All C. jejuni strains obtained from broiler chickens were typeable by the LG genotyping method. Application of the RsaI restriction enzyme improved the method in terms of ease and consistency of analyses and increase of discriminatory power.

SIGNIFICANCE AND IMPACT OF THE STUDY

The LG genotyping method is a valuable tool for typing C. jejuni isolates obtained from poultry. However, the association between Penner serotyping based on passive haemagglutination of heat-stable antigens and LG genotyping was low when applied to poultry isolates. This is in contrast to previous studies on isolates of human origin that reported a high correlation between results obtained by the two typing methods (Shi et al. 2002).

Pet dogs and chicken meat as reservoirs of Campylobacter spp. in Barbados

Campylobacter spp. are the second most common pathogen isolated from stools of patients with gastroenteritis in Barbados. The aim of this study was to identify reservoirs of Campylobacter and the likely source(s) of human infection. Fecal specimens from 596 animals and 311 samples of animal food products were analyzed for the presence of Campylobacter spp. by standard culture techniques. Isolates were characterized by conventional phenotypic tests, confirmed by latex agglutination and PCR with genus-specific primers, and identified by the use of species-specific primers. High isolation rates were obtained for chickens (94.2%), pigs (90.5%), dogs (46.9%), cats (37.3%), and wild birds (39.3%). Campylobacter was also recovered from monkeys (17.1%) and sheep (4.2%) but not from cows. Chicken meat was frequently contaminated with Campylobacter (58.4%), but its recovery from other animal food products was rare. Campylobacter jejuni was the most commonly identified species in humans (63.6%), chickens (86.6%), dogs (51.5%), and chicken meat (79.8%). Porcine isolates were predominantly C. coli (98.4%), while cats harbored mainly C. upsaliensis and C. helveticus. Wild birds alone carried urease-positive thermophilic campylobacters. C. jejuni and C. coli isolates from different sources were compared with isolates from humans by randomly amplified polymorphic DNA typing with the primers OPA 11 and HLWL 85. Genotyping revealed similarities between isolates from chicken meat and those from humans and could not distinguish between two clinical isolates and four canine strains. Our results suggest that dogs are significant reservoirs of Campylobacter and contribute to human enteric infections and that chicken meat is a likely vehicle for the transmission of campylobacters to humans.

Campylobacter spp. in Dogs and Cats in Switzerland: Risk Factor Analysis and Molecular Characterization with AFLP

A 1-year cross-sectional study was carried out to determine the prevalence, risk factors for carriage, and genetic diversity of Campylobacter spp. in healthy dogs and cats in Switzerland. Veterinary practitioners collected samples from 1268 animals (all ages) presented for vaccination. The prevalence of Campylobacter spp. in 634 dogs and 596 cats that were eligible for the study was 41.2% (confidence interval 95%: 37.3-45.1%) and 41.9% (CI 95%: 37.9-46%), respectively. Risk factors identified for carriage of Campylobacter jejuni were found to be different from risk factors for C. upsaliensis/C. helveticus. Young animals (< or =3 years) had significantly higher odds of carrying C. upsaliensis/C. helveticus than older animals (OR 1.8-3.3), whereas for C. jejuni carriage, the age was not a risk factor. Amplified fragment length polymorphism (AFLP) genotyping revealed heterogeneity among C. jejuni strains and was found to clearly separate C. helveticus from C. upsaliensis. It was shown that cats more often carry C. helveticus with an estimated prevalence of 28.2%, whereas dogs mainly are carrying C. upsaliensis.

The Microbial Rosetta Stone Database: a compilation of global and emerging infectious microorganisms and bioterrorist threat agents

BACKGROUND

Thousands of different microorganisms affect the health, safety, and economic stability of populations. Many different medical and governmental organizations have created lists of the pathogenic microorganisms relevant to their missions; however, the nomenclature for biological agents on these lists and pathogens described in the literature is inexact. This ambiguity can be a significant block to effective communication among the diverse communities that must deal with epidemics or bioterrorist attacks.

RESULTS

We have developed a database known as the Microbial Rosetta Stone. The database relates microorganism names, taxonomic classifications, diseases, specific detection and treatment protocols, and relevant literature. The database structure facilitates linkage to public genomic databases. This paper focuses on the information in the database for pathogens that impact global public health, emerging infectious organisms, and bioterrorist threat agents.

CONCLUSION

The Microbial Rosetta Stone is available at http://www.microbialrosettastone.com/. The database provides public access to up-to-date taxonomic classifications of organisms that cause human diseases, improves the consistency of nomenclature in disease reporting, and provides useful links between different public genomic and public health databases.

Effects of climate on incidence of Campylobacter spp. in humans and prevalence in broiler flocks in Denmark

Campylobacter infections are increasing and pose a serious public health problem in Denmark. Infections in humans and broiler flocks show similar seasonality, suggesting that climate may play a role in infection. We examined the effects of temperature, precipitation, relative humidity, and hours of sunlight on Campylobacter incidence in humans and broiler flocks by using lag dependence functions, locally fitted linear models, and cross validation methods. For humans, the best model included average temperature and sunlight 4 weeks prior to infection; the maximum temperature lagged at 4 weeks was the best single predictor. For broilers, the average and maximum temperatures 3 weeks prior to slaughter gave the best estimate; the average temperature lagged at 3 weeks was the best single predictor. The combined effects of temperature and sunlight or the combined effects of temperature and relative humidity predicted the incidence in humans equally well. For broiler flock incidence these factors explained considerably less. Future research should focus on elements within the broiler environment that may be affected by climate, as well as the interaction of microclimatic factors on and around broiler farms. There is a need to quantify the contribution of broilers as a source of campylobacteriosis in humans and to further examine the effect of temperature on human incidence after this contribution is accounted for. Investigations should be conducted into food consumption and preparation practices and poultry sales that may vary by season.

Epidemiologic features of Campylobacter infection among cats in the upper midwestern United States

OBJECTIVE

To describe the epidemiologic features of Campylobacter infection among cats in the Minneapolis-Saint Paul metropolitan area.

DESIGN

Prevalence survey.

ANIMALS

152 cats examined at 3 private veterinary clinics and an animal humane society.

PROCEDURES

Fecal samples were submitted for bacterial culture for Campylobacter spp. To determine the duration of Campylobacter carriage, follow-up fecal samples were collected from cats with positive Campylobacter culture results.

RESULTS

Campylobacter organisms were cultured from 37 of the 152 (24%) fecal samples. Campylobacter isolates were identified as Campylobacter upsaliensis (29 cats), Campylobacter jejuni (2), and Campylobacter coli (1); species of the remaining 5 isolates could not be determined. Campylobacter organisms were isolated from 36 of the 122 (30%) cats that were < or = 1 year old but from only 1 of the 30 (3%) cats that were > 1 year old, and shedding was more common during the summer and fall months. No association between Campylobacter shedding and clinical signs of disease was identified. For 4 of 13 cats from which follow-up fecal samples were obtained, duration of Campylobacter carriage could not be determined because Campylobacter organisms were isolated from all follow-up samples. For the remaining 9 cats, median duration of Campylobacter carriage was 44 days.

CONCLUSIONS AND CLINICAL RELEVANCE

C. upsaliensis can commonly be isolated from the feces of overtly healthy kittens in the Midwest United States. Because carriage may be prolonged, veterinarians should encourage good hand hygiene among owners of cats, especially among owners with new kittens in their household.

Major structural differences and novel potential virulence mechanisms from the genomes of multiple campylobacter species

Sequencing and comparative genome analysis of four strains of Campylobacter including C. lari RM2100, C. upsaliensis RM3195, and C. coli RM2228 has revealed major structural differences that are associated with the insertion of phage- and plasmid-like genomic islands, as well as major variations in the lipooligosaccharide complex. Poly G tracts are longer, are greater in number, and show greater variability in C. upsaliensis than in the other species. Many genes involved in host colonization, including racR/S, cadF, cdt, ciaB, and flagellin genes, are conserved across the species, but variations that appear to be species specific are evident for a lipooligosaccharide locus, a capsular (extracellular) polysaccharide locus, and a novel Campylobacter putative licABCD virulence locus. The strains also vary in their metabolic profiles, as well as their resistance profiles to a range of antibiotics. It is evident that the newly identified hypothetical and conserved hypothetical proteins, as well as uncharacterized two-component regulatory systems and membrane proteins, may hold additional significant information on the major differences in virulence among the species, as well as the specificity of the strains for particular hosts.

High-resolution genotyping of Campylobacter upsaliensis strains originating from three continents

Ninety-six Campylobacter upsaliensis strains that originated from Australia, Canada, and Europe (Germany) and that were isolated from humans, dogs, and cats were serotyped for their heat-stable surface antigens. All of them were genotyped by enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) profiling, and 83 strains were genotyped by macrorestriction analysis with the endonuclease XhoI. Eighty-four percent of the strains belonged to five different serotypes (serotypes OI, OII, OIII, OIV, and OVI), with the proportions of strains in each serotype being comparable among the groups of strains from all three continents. Two serotypes, OIII and OIV, were prevalent at rates of 35 to 40%. Serotypes OI, OII, and OVI were detected at rates of 1.5 to 15%. Between 10 and 17.7% of the strains did not react with the available antisera. Analysis of the ERIC-PCR profiles revealed two distinct genotypic clusters, which represented the German and the non-European strains, respectively. XhoI macrorestriction yielded two genotypic clusters; one of them contained 80.2% of the German strains and 34.6% of the non-European strains, and the second cluster consisted of 65.4% of the non-European strains and 19.8% of the German strains. Fourteen strains from all three continents were analyzed for their 16S rRNA gene sequences. Only two minor variations were detected in four of the strains. In conclusion, C. upsaliensis has undergone diverging processes of genome arrangement on different continents during evolution without segregating into different subspecies.

Longitudinal study of the excretion patterns of thermophilic Campylobacter spp. in young pet dogs in Denmark

The Campylobacter excretion patterns of 26 domestic pet dogs were described in a longitudinal study. The dogs entered the study between 3 and 8 months of age and were monitored until 2 years of age. They were tested monthly for Campylobacter carriage in stool samples that were cultured on the Campylobacter-selective media CAT and modified CCDA agar at 37 and 42 degrees C. This study comprised 366 fecal swab samples, of which 278 (76.2%) were found to be Campylobacter positive, with the following distribution of species: 75.0% Campylobacter upsaliensis, 19.4% Campylobacter jejuni, 2.1% Campylobacter lari, 0.7% Campylobacter coli, and 2.8% Campylobacter spp. Isolates were typed by pulsed-field gel electrophoresis (PFGE) to elucidate the strain excretion pattern. All study dogs excreted Campylobacter spp. during the study period. At 3 months of age, 60% of the dogs carried Campylobacter, increasing to nearly 100% carriers at 1 year of age, whereafter the carriage rate decreased to 67% at 24 months of age. The PFGE types showed that individual dogs were often colonized by unique strains of C. upsaliensis for several months, up to 21 months or longer. These C. upsaliensis strains were either clonal (or underwent concurrent minor mutative changes) or independent strains. In contrast, the excreted C. jejuni isolates were much more diverse and, in most cases, only seen in one sample from each dog. A high degree of diversity among different dogs was seen. We conclude that young domestic pet dogs excreted Campylobacter spp. during the majority of their puppyhood and adolescent period. In general C. upsaliensis strains were excreted for months, with short-term interruptions by or cocolonization with other transitory Campylobacter spp., predominantly C. jejuni. C. jejuni was more prevalent in dogs between 3 months and 1 year of age than in dogs between 1 and 2 years of age.

Genetic relatedness among Campylobacter jejuni serotyped isolates of diverse origin as determined by numerical analysis of amplified fragment length polymorphism (AFLP) profiles

AIMS

To use amplified fragment length polymorphism (AFLP) analysis to evaluate the genetic relatedness among 254 Campylobacter jejuni reference and field strains of diverse origin representing all defined 'Penner' serotypes for this species.

METHODS AND RESULTS

Field strains (n = 207) from human diarrhoea and diverse animal and environmental sources were collected mainly through a National surveillance programme in Denmark and serotyped by use of the established 'Penner' scheme. Genetic relationships among these isolates, and the archetypal serotype reference strains, were assessed by numerical analysis of AFLP profiles derived from genomic DNA. Extensive genetic diversity was seen among the strains examined; however, 43 groups of isolates were identified at the 92% similarity (S-) level. Thirteen groups contained isolates from a single host, possibly representing genotypes of 'low risk' to human health. The remaining 30 groups contained isolates from humans, chickens and associated food products, cattle, sheep, turkeys, ostriches and/or dogs. Strains assigned to serotypes 2, 6/7, 11 and 12 formed major clusters at the 77.6% S-level. Most other serotypes did not form homogeneous clusters.

CONCLUSIONS

High-resolution genotyping applied to strains from a comprehensive range of sources provides evidence for multiple sources of sporadic C. jejuni infection. The results suggest that public health protection measures should be directed at all foods of animal origin.

SIGNIFICANCE AND IMPACT OF THE STUDY

The genetic relatedness among all 'Penner' serotypes of C. jejuni is assessed by AFLP analysis. In addition, further evidence of epidemic and host-specific clones of C. jejuni is provided.

Simultaneous presence of multiple Campylobacter species in dogs

The prevalence of coinfection of Campylobacter species in dogs was determined using four isolation methods. In 26% of the positive-testing stools, multiple Campylobacter species were identified. The use of multiple isolation methods as well as the time lapse between sampling and processing are important for detection of coinfection.

Invasion of human epithelial cells by Campylobacter upsaliensis

Few data exist on the interaction of Campylobacter upsaliensis with host cells, and the potential for this emerging enteropathogen to invade epithelial cells has not been explored. We have characterized the ability of C. upsaliensis to invade both cultured epithelial cell lines and primary human small intestinal cells. Epithelial cell lines of intestinal origin appeared to be more susceptible to invasion than non-intestinal-derived cells. Of three bacterial isolates studied, a human clinical isolate, CU1887, entered cells most efficiently. Although there was a trend towards more efficient invasion of Caco-2 cells by C. upsaliensis CU1887 at lower initial inocula, actual numbers of intracellular organisms increased with increasing multiplicity of infection and with prolonged incubation period. Confocal microscopy revealed C. upsaliensis within primary human small intestinal cells. Both Caco-2 and primary cells in non-confluent areas of the infected monolayers were substantially more susceptible to infection than confluent cells. The specific cytoskeletal inhibitors cytochalasin B, cytochalasin D and vinblastine attenuated invasion of Caco-2 cells in a concentration-dependent manner, providing evidence for both microtubule- and microfilament-dependent uptake of C. upsaliensis. Electron microscopy revealed the presence of organisms within Caco-2 cell cytoplasmic vacuoles. C. upsaliensis is capable of invading epithelial cells and appears to interact with host cell cytoskeletal structures in order to gain entry to the intracellular environment. Entry into cultured primary intestinal cells ex vivo provides strong support for the role of host cell invasion during human enteric C. upsaliensis infection.