57 Veterinaria Italiana 2022, 58 (1), 57-66. doi: 10.12834/VetIt.2299.15789.1 Accepted: 21.07.2021 | Available on line: 16.11.2022 1Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise ‘G. Caporale’, Teramo, Italy. 2ASL Teramo , Teramo, Italy. 3Clinica Veterinaria Valdinievole, Italy. *Corresponding author at: Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise ‘G. Caporale’, Campo Boario, Teramo, Italy. E‑mail: f.iannino@izs.it Filomena Iannino1*, Guido Di Donato1,2, Stefania Salucci1, Enzo Ruggieri1, Giacomo Vincifori1, Maria Luisa Danzetta1, Paolo Dalla Villa1, Elisabetta Di Giannatale1, Giulia Lotti3 and Fabrizio De Massis1 Keywords Campylobacter, Campylobacteriosis, Dog, Risk factors, Zoonosis, Shelter, Antimicrobial resistance. Summary Campylobacteriosis has been the most frequently reported zoonotic disease in humans in Europe. The scientific literature has reported that the role of dogs may be relevant. The objectives of this work are to improve the knowledge about Campylobacter spp. carriage, infection and antimicrobial resistance in household and shelter dogs in Italy, and to assess risk factors at the dog/human interface. During the 2015-2016 period, rectal swabs were collected from 431 household vet-visiting dogs and 173 dogs housed in shelters. A total of 3 veterinary clinics, located in three Italian regions (Abruzzo, Molise and Tuscany) and 10  shelters, five in Abruzzo and five in Molise, were included in the study. Relevant risk factors for the transmission of Campylobacter spp. from dogs to humans were assessed by means of a questionnaire administered to owners of household dogs. For Campylobacter spp. isolation, selective cultivation methods were used, followed by confirmation and species identification with the PCR method. Phenotypic antibiotic resistance profiles assayed using antimicrobial susceptibility testing were combined. Campylobacter spp. were isolated from 9 household dogs (2.1% CI 1.1% - 3.9%) and from 13  shelter dogs (7.5 % CI 4.5% - 12.4%). In household dogs C. jejuni was the most represented species (0.9%). In shelter dogs, the most common species was C. jejuni (5.2%). Campylobacter spp. isolates were resistant to ciprofloxacin (22.73%), nalidixic acid (22.73%), tetracyclines (27.27%), streptomycin (9.09%) and erythromycin (4.55%). The main C. jejuni Clonal Complex identified in dogs were CC21, CC45, CC206, CC403, CC42 and CC658. The risk of contracting Campylobacteriosis from dogs remains a concrete reality. This risk is increased in the presence of common habits, as shown by the data from the questionnaire. Prevalence control of Campylobacter spp. in household and shelter dogs would be important in order to reduce the transmission to humans. Campylobacter and risk factors associated with dog ownership: a retrospective study in household and shelter dogs farm animals, direct contact with pets and insect as flies (Adak et al. 2005, Mazick et al. 2005, Strother et al. 2005). The species most commonly associated with human infections are Campylobacter jejuni, followed by C. coli, C. lari, and C. upsaliensis (Kaakoush et  al. 2005, Ibrahim et al. 2019, Gahamanyi et al. 2020). In many symptomatic cases, campylobacteriosis occurs as mild and self-limiting gastroenteritis, but long-term effects such as reactive arthritis (ReA), post infectious irritable bowel syndrome (IBS), Guillain Barré syndrome (GBS), inflammatory bowel disease (IBD) and Reiter’s syndrome (RS) may be Introduction In recent years, campylobacteriosis has been the most frequently reported zoonotic disease in humans in Europe (EFSA 2017, Tam et al. 2003). The most common sources of human campylobacteriosis are the handling or consumption of contaminated/undercooked meat (especially poultry), the handling or consumption of contaminated or unpasteurized milk and dairy products, the consumption of contaminated water, person to person contact, direct contact with carrier 58 Veterinaria Italiana 2022, 58 (1), 57-66. doi: 10.12834/VetIt.2299.15789.1 Campylobacteriosis and role of dogs Iannino et al. Each questionnaire collected data on the risk factors for zoonotic transmission at the dog/human interface, such as habits and behaviors of the hosting families of the dog and/or other pets or domestic animals. The questionnaires included 28 questions grouped in different sections (Table I). The introductory questions referred to the owner’s data and the identification and description of the veterinarian and the dog. The first group of questions referred to the veterinary visit and the general conditions of the dog (purpose of the veterinary-visit, health conditions, and nutritional status). The second group of questions referred to the dog’s risk factors for carriage and infection (nutrition, travel abroad, origin, life habits, places frequented). The third group of questions referred to the human risk factors for infection (contact with humans, dog's life habits, presence of other animals, composition of the family unit). Collection of samples and laboratory examinations During the 2015-2016 period, rectal swabs were collected from 431 household dogs in veterinary clinics and 173 shelter dogs. A total of 3 veterinary clinics, located in the Abruzzo, Molise and Tuscany regions and 10 shelters, five in the Abruzzo and five in the Molise region, were included in the study. From each dog, 2 rectal swabs were collected. The rectal swabs were gathered from the rectum of the animals using culture swab transport system (Transystem™ Amies with charcoal, Copan, Brescia, Italy). All samples were transported at 4  °C in refrigerated boxes and processed immediately upon arrival to the laboratory and not later than 72 hours after sampling (at 4 °C). The isolation of Campylobacter spp. was performed according to the World Organisation of Animal Health (WOAH) (OIE 2008) in modified charcoal cefoperazone deoxycholate agar (mCCDA) (Thermo Scientific Oxoid, Milan, Italy) and Karmali agar (Italian Biolife, Milan, Italy). Both methods involved directly plating swabs and enriching in Preston broth (Italian Biolife, Milan, Italy) for 24 hours in a microaerophilic atmosphere. After enrichment, 100 microliters of the Preston broth were plated in duplicate on mCCDA and Karmali plates and all plates (directly and after enrichment) were incubated under a microaerobic atmosphere at 41.5 °C and 37 °C for 48 hours. After incubation, the plates were examined to detect the presence of suspected of Campylobacter  sp. colonies. The suspect Campylobacter  colonies were identified by a multiplex PCR method, as described by Wang and colleagues (Wang et  al. 2002) for thermotolerant Campylobacter  and by sequencing of the 16S  region associated with infection (Keithlin et  al. 2014, Esan et al. 2017, Brooks et al. 2017). The role of dogs as a source of infection could be relevant (Gras et al. 2013, Koene et al. 2004). Owning a pet, especially a puppy, has been identified as a risk factor for Campylobacter sp. infection (Doorduyn et al. 2010). In many cases, dogs are asymptomatic carriers of Campylobacter spp. Some studies found no significant relationship between diarrhoea and Campylobacter sp. infection status (Acke et  al. 2009), suggesting that the organism is commensal. Conversely, other studies reported an association between infection and clinical signs particularly in relatively young dogs (Guest 2007, Chaban 2010). Animals may be more susceptible to clinical disease when stressed by concurrent disease, hospitalization, shipment, pregnancy or surgery. Acute campylobacteriosis that develops in puppies and some adult dogs is characterized by mucus-laden, watery or bile-streaked diarrhoea (with or without blood and leukocytes) of five to 15 days duration, partial anorexia, and occasional vomiting. Elevated temperature and leukocytosis may also be present (Fox 1990, Brown et al. 1999). The close relationship between humans and dogs especially family pets, can play an important role in the transmission of zoonotic agents (Stull et al. 2010). The present study aimed to analyse three important aspects of campylobacteriosis: • prevalence and diversity of Campylobacter species in owned and shelter dogs; • their antimicrobial resistance; • identification of possible risk factors for zoonotic transmission at the dog/human interface. Materials and methods The study has been divided into three phases: • drawing up and administration of questionnaires to dog owners visiting veterinary clinics; • collection of samples and laboratory examinations; • data analysis. Questionnaire design and administration A total of 431 questionnaires were administered to different dog owners and compiled in case of the owner approval. The number of completed questionnaires was  412. 59Veterinaria Italiana 2022, 58 (1), 57-66. doi: 10.12834/VetIt.2299.15789.1 Iannino et al. Campylobacteriosis and role of dogs Table I. Questionnaire completed by dog owners visiting veterinary clinics. —cont’d Owner Name and surname Home address and telephone number Owner occupation Veterinarian Name and surname Name of veterinary clinic and address Animal Transponder (microchip) Name Breed Size Sex Date of birth Coat description Reason for clinical examination  1. Routine examination/vaccination  2. Fever  3. Diarrhoea  4. Vomiting  5. Trauma  6. Dermatitis  7. Other Antibiotic administration Have antibiotics been administered?  yes  no if you answered 'Yes' provide details:  In the last month  In the last 3 months  In the last year Trade name of the drug Feeding and body condition score Feeding regime Wet food (canned food) 70% to 80% of moisture content  Regularly (principal component of food)  Weekly (one or more times per week)  Monthly (occasionally)  Never Semi‑moist food (snacks) 15% to 40% of moisture content  Regularly (principal component of food)  Weekly (one or more times per week)  Monthly (occasionally)  Never Dry food (pellets) less than 10% of moisture content  Regularly (principal component of food)  Weekly (one or more times per week)  Monthly (occasionally)  Never Cooked food or food for human consumption  Regularly (principal component of food)  Weekly (one or more times per week)  Monthly (occasionally)  Never Raw meat  Regularly (principal component of food)  Weekly (one or more times per week)  Monthly (occasionally)  Never Body condition score  1 Ribs, lumbar vertebrae, pelvic bones and all bony, prominences evident from a distance. No discernible body fat. Obvious loss of muscle mass.  1.5 Ribs, lumbar vertebrae and pelvic bones easily visible. No palpable fat. Some evidence of other bony prominence. Minimal loss of muscle mass.  2 Ribs easily palpated and may be visible with no palpable fat. Tops of lumbar vertebrae visible. Pelvic bones becoming prominent. Obvious waist.  2.5 Ribs easily palpable, with minimal fat covering. Waist easily observed when viewed from above. Abdominal tuck evident.  3 Ribs palpable without excess fat covering. Waist observed behind ribs when viewed from above. Abdomen tucked when viewed from the side.  3.5 Ribs palpable with slight excess fat covering. Waist is discernible when viewed from above but is not prominent. Abdominal tuck apparent.  4 Ribs palpable with difficulty; heavy fat cover. Noticeable fat deposits over lumbar area and base of tail. Waist absent or barely visible. Abdominal tuck may be present.  4.5 Ribs not palpable under very heavy fat cover, or palpable only with significant pressure. Heavy fat deposits over lumbar area and base of tail. Waist absent. No abdominal tuck. Obvious abdominal distension may be present.  5 Massive fat deposits over thorax, spine and base of tail. Waist and abdominal tuck absent. Fat deposits on neck and limbs. Obvious abdominal distention Origin of the animal Breeding Stray dog Other family Shelter Other Travel abroad, life habits, places frequented Travel abroad in the last 3 months  yes  no How long has the dog been housed with the current family? Years Months Where does the dog live?  Only inside the household  Only outside the household  Inside and outside the household continued 60 Veterinaria Italiana 2022, 58 (1), 57-66. doi: 10.12834/VetIt.2299.15789.1 Campylobacteriosis and role of dogs Iannino et al. (CCs) were assigned by submitting the DNA sequence to the Campylobacter  MLST database website (http://pubmlst.org/campylobacter). Data analysis For the comparison of the prevalence rates between the two groups of data (household and shelter dogs), according to the literature (Berger 1985), it was decided to use a Bayesian approach, using a Beta distribution with the relative 95% confidence intervals (CIs). Results Questionnaire administration Table II shows the results of the questionnaires administered to the dog owners. Most owners prefer dry food, even though a not negligible percentage of owners (4.8%) more or less regularly feed their dog with raw meat. Most dogs live at home (37.4%), while 32.0% live outdoor, and 30.6% in both environments. In most cases, owners have contact with their dogs during meals (51.7%), and they have been licked by from their pets on their hands and face (72.8%). Most of the dogs participants in the study live in an urban environment (254 out of 412, 61.7%) and in 69.7% of cases the majority of owners do not have other pets or domestic animals. Sample and data analysis Campylobacter spp. were isolated from 9 out of 431 household dogs (2.1%, CI 1.1%-3.9%) and from 13 out of 173 shelter dogs tested (7.5%; CI 4.5%-12.4%) (Table  III). The 95% CIs of the prevalence rates calculated by the Beta distribution do not overlap, thus showing a significant difference between the two percentages. (AbiPrism 3500, Applied Biosystem) for other Campylobacter spp. Genomic DNA was extracted using an Ultraclean microbial DNA kit (Mo Bio Laboratories, Solana Beach, CA, USA) according to the manufacturer’s instructions and quantified using a NanodDrop Spectrophotometer (NanoDrop Technologies, Celbio Srl., Milan, Italy). Campylobacter  strain susceptibility to antibiotics was evaluated with the microbroth dilution method using Sensititre® custom susceptibility plates, EUCAMP 2 (Trek Diagnostic Systems, Biomedical Service, Venice, Italy). The colonies were harvested in Columbia agar for 24 hours then inoculated in Mueller Hinton Broth supplemented with blood and dispensed into Eucamp microtiter plates (TREK Diagnostic Systems, Biomedical Service, Italy), containing known scalar concentrations of the following antibiotics: gentamicin (Gm) (0.12-16 µg/ml), streptomycin (S) (0.25-16 µg/ml), ciprofloxacin (Cip) (0.12-16 µg/ml), tetracyclines (Te) (0.5-64 µg/ml), erythromycin (E) (1-128 µg/ml) and nalidixic acid (NA) (1-64 µg/ml). After inoculation, the plates were incubated at 42 °C under a microaerophilic atmosphere for 24 hours and then screened. C.  jejuni strain NCTC 11351 was used as a quality control. For the evaluation of the minimum inhibitory concentration (MIC), the Swin v3.3 software (TREK Diagnostic Systems, Biomedical Service, Italy) was used in accordance with the epidemiological cutoff values (ECOFFs) defined by the European Committee on Antimicrobial Susceptibility Testing (EUCAST, www.eucast.org) to interpret susceptibility. Multilocus sequence typing (MLST) was performed using standard protocols as previously described (Dingle et al. 2001). The DNA of the samples subjected to MLST was extracted from the strains using a Maxwell® 16  System automatic extractor (Promega, IT) according to the manufacturer's indications. Sequence types (OIE 2008), and clonal complexes Table I. Questionnaire completed by dog owners visiting veterinary clinics. —cont’d Do you take your dog to public area?  yes  no Does the dog lick family members’ hands and face?  yes  no What do you use to collect the dog’s feces?  Paper towels  Plastic bags  Shovel  I do not collect the feces Other Do you clean your hands after any food manipulation and administration?  yes  no Do you wash your hands after any contact with the dog?  yes  no Do you touch your dog while you consume food?  yes  no Do you allow the dog to get on the sofa/bed?  yes  no Living environment of the family  urban  rural Does the family have other animals?  yes  no Family members ID member Sex  F  M Kinship Profession Date of birth 61Veterinaria Italiana 2022, 58 (1), 57-66. doi: 10.12834/VetIt.2299.15789.1 Iannino et al. Campylobacteriosis and role of dogs Our finding showed that the principal C. jejuni Clonal Complex identified in dogs were CC21, CC45, CC206, CC403, CC42 and CC658 (Table IV). Campylobacter  sp. isolates have demonstrated resistance mainly to tetracyclines, ciprofloxacin, nalidixic acid, and streptomycin. The resistance to Four out of the 9 isolates in household dogs were identified as C.  jejuni, 2 as C.  upsaliensis, 1 was identified as C. coli, 1 as C. lari and 1 as C. vulpis. In shelter dogs, nine isolates were identified as C. jejuni, 3 as C. lari and 1 as C. coli (Table III). Table II. Results of the questionnaires compiled by 412 owners of dogs visiting a veterinary clinic. —cont’d Description of the sample Age average age: 5.60 (+/‑3.602 Standard Deviation) Sex Breed Sex No. of sampled dogs % Female 137 33.3% Male 275 66.7% Total 412 100.0% Breed No. of sampled dogs % Mongrel 105 25.5% Purebred dogs 307 74,5% Total 412 100.0% Dog Size Body condition Score Size Number % Large sized dog (adult weight more than 25 kg) 133 32.3% Medium sized dog (adult weight between 10 kg and 25 kg) 137 33.3% Small‑sized dog (adult weight between 1 kg and 10 kg) 142 34.5% Total 412 100.0% Score Number % 1 0% 2 0% 3 5 1.5% 4 22 6.4% 5 62 18.1% 6 108 31.6% 7 105 30.7% 8 37 10,8% 9 3 0.9% Total 342 100.0% Presence of diarrhoea in the previsit period and antibiotic administration Diarrhoea Antibiotic administration Onset time Number % In the last three months 80 64.0% In the last 6 months 21 16.8% In the last year 24 19.2% Total 125 100.0% Administration Number % In the last month 56 77.8% In the last 3 months 8 11.1% In the last year 8 11.1% Total 72 100.0% Antibiotic active Active ingredient Frequency of use for each antibiotic % Amoxicillin 28 38.9% Cephalosporin 16 22.2% Metronidazole 6 8.3 Amoxicillin, Cephalosporin 4 5.6 Cephalosporin, Metronidazole 4 5.6% Amoxicillin, Metronidazole 2 2.8% Enrofloxacin 2 2.8% Marbofloxacin 2 2.8% Metronidazole, Spiramycin 2 2.8% Tylosin, Metronidazole 2 2.8% Amoxicillin, Cephalosporin, Metronidazole 1 1.4% Amoxicillin, Itraconazole 1 1.4% Amoxicillin, Metronidazole, Tylosin 1 1.4% Enrofloxacin, Cephalosporin 1 1.4% 72 100% continued 62 Veterinaria Italiana 2022, 58 (1), 57-66. doi: 10.12834/VetIt.2299.15789.1 Campylobacteriosis and role of dogs Iannino et al. Table II. Results of the questionnaires compiled by 412 owners of dogs visiting a veterinary clinic. —cont’d Feeding regime Administered monthly (occasionally) Administered regularly (main component of food) Administered weekly (one or more times per week) Number % Number % Number % Wet food 7 1.7% 71 17.2% 14 3.4% Semi‑moist food 19 4.6% 7 1.7% 56 13.6% Dry food 10 2.4% 316 76.7% 7 1.7% Homemade food 46 11.2% 69 16.7% 52 12.6% Raw meat 12 2.9% 5 1.2% 3 0.7% Origin and living place Origin Where does the dog live? Number % Breeding 189 45.9% Other family 140 34.0% Shelter 40 9.7% Stray dog 36 8.7% Born at home 3 0.7% Pet Shop 1 0.2% Other 3 0.7% Total 412 100.0% Total % Only inside the household 154 37.4% Only outside the household 132 32.0% Inside and outside 126 30.6% Total 412 100.0% Habits Yes No Number % Number % Does the dog licks your hands and face? 300 72.8% 112 27.2% Do you clean the hands after any food manipulation and administration? 340 82.5% 72 17.5% Do you wash your hands after any contact with the dog? 186 45.1% 226 54.9% Do you touch your dog while consuming your food? 213 51.7% 199 48.3% Do you allow the dog to get on the sofa/bed? 184 44.7% 228 55.3% What do you use to pick up dog's feces? Number % Plastic bags 168 48.8% Paper towels 37 10,8% Shovel 106 30,8 I don't take the feces 28 8.1% Other 5 1.5% Total 344 100% Table III. Campylobacter species in household and shelter dogs. Type of dog lifestyle Campylobacter species isolated No. of positive samples % Household dogs Campylobacter jejuni 4 0.9% Campylobacter upsaliensis 2 0.5% Campylobacter vulpis 1 0.2% Campylobacter lari 1 0.2% Campylobacter coli 1 0.2% Total 9 2.1% Shelter dogs Campylobacter jejuni 9 5.2% Campylobacter lari 3 1.7% Campylobacter coli 1 0.6% Total 13 7.5% Table IV. C. jejuni Clonal Complex (CC). Clonal Complex (CC) Sequence type (ST) N°strains 21 50 2 45 538 1 2,854 1 206 3,335 1 122 1 403 403 2 177 1 42 6,532 1 658 1,044 3 63Veterinaria Italiana 2022, 58 (1), 57-66. doi: 10.12834/VetIt.2299.15789.1 Iannino et al. Campylobacteriosis and role of dogs encourage dog owners to carry out an appropriate collection of feces. With regard to the second point, the prevalence of Campylobacter spp. recorded in shelter dogs (13 out of 173, 7.5%, CI 4.5%-12.4%) has been significantly higher than the prevalence recorded in household dogs (9 positive out of 431, 2.1%, CI 1.1%-3.9%). Among dogs resulted positive for Campylobacter spp., no one had diarrhoea at the time of sampling, one had diarrhoea in the previous three months, one in the previous six months and one in the last year, confirming what is reported in the literature, i.e. that infected dogs usually do not show clear symptoms. In the literature reports, Campylobacter  sp. prevalence in dogs varies greatly between authors (Leonard et  al. 2011, Acke et  al. 2009, Giacomelli et  al. 2005, Holmberg et  al. 2015) depending on the sampled population, the study design, and the analysis method. However, a higher prevalence is generally reported in shelter dogs, probably due to different hygiene and life conditions, increased stress factors, cohabitation with other dogs and contact with other animals, such as mice and rats. The majority of investigated household dogs have home habits, which means a reduced risk of contracting the pathogens investigated in the present study. Life conditions of shelter dogs, on the contrary, are characterized by the housing in boxes which may include a different number of dogs and the presence of open common areas, delimited by fences, allowing more frequent contacts between animal and zoonotic agent’s carriers. In both cases, however, the prevalence recorded suggests the need to adopt precise hygiene protocols in the man/ dog relationship. The prevalence of Campylobacter spp. was lower than that generally found in the literature. The presence of 13.6% of household dogs treated with antibiotics in the month preceding the veterinary visit could have influenced the results of the diagnostic tests. It was not possible to obtain information on the use of antibiotics in the shelters, but it would be appropriate to investigate this circumstance with further studies. This record of Campylobacter  spp. in Italian dogs, and of Campylobacter  jejuni in particular, further highlights the risk related to the zoonotic potential of the pathogen. Its diffusion may be favored by the lifestyle in man/animal relationship and by the close contact that many companion animals have with their owners. The third aspect of this study concerns the antibiotic resistance of Campylobacter spp. In veterinary practice, in the daily clinics, the antibiotics administered to pets may represent a source of molecular pressure on the microorganisms, tetracyclines was the highest, while the resistance to erythromycin was the lowest (Table V). There was a high number of strains with intermediate sensitivity (10 isolates, 76.9%). Discussion This study obtained information on: • the assessment of behaviors in household dogs, which can be considered risk factors for the transmission of Campylobacter  and other zoonotic agents • the prevalence of Campylobacter  spp. in household and shelter dogs and its characterization, including the C.  jejuni Clonal Complex • the antibiotic resistance of the Campylobacter spp. With regard to the first point, there are few data in the literature on the living habits of households’ dogs, especially based on market studies (Boya et al. 2012) or sociological studies (Charles 2016). The present study evaluated some behaviors and habits as possible risk factors for the transmission of zoonotic agents. Notably, among these, the “Habits” section of Table II shows very high percentages associated with habits that could be considered risky in the presence of infected dogs. Moreover, the habit of feeding dogs with raw meat, as reported in the “Feeding regime” section of the Table II, is carried out in a non-negligible percentage of cases (4.8%), therefore representing an additional risk factor (Hellgren et al. 2019). Data belonging to the section “Origin and living place” especially with regard to attendance in outdoor spaces, cannot be directly related to Campylobacter  infection, even if they can be considered as particularly significant risk factors. Again, in the section “habits”, data show that the percentage of people who declare that they do not collect feces (8.1%) is still very high, thus contributing to increase the risk of pathogen’s transmission due to environmental contamination. Collection with plastic bags, which is the most valid method for a thorough removal of feces, accounts for 48%. This indicates that much still needs to be done to Table V. Antimicrobial resistance of the isolated Campylobacter spp. No. of resistant isolates % on total isolates Tetracyclines 6 27.27% Ciprofloxacin 5 22.73% Nalidixic acid 5 22.73% Streptomycin 2 9.09% Erythromycin 1 4.55% 64 Veterinaria Italiana 2022, 58 (1), 57-66. doi: 10.12834/VetIt.2299.15789.1 Campylobacteriosis and role of dogs Iannino et al. of particular common habits, as shown by the data from the questionnaire. The very high percentages of people who do not wash their hands after contact with their dogs, allow their dogs to lick their face and hands and allow their dogs to sleep on the bed and sofa or eat raw meat increase the risk of zoonotic disease transmission. The higher prevalence of infection recorded among shelter dogs suggests that particular commitment should be devoted to staff training from people managing these premises, especially for people who is used to direct manage dogs and for this reason are more exposed to the risk of being in contact with Campylobacter spp. The risk of contracting Campylobacteriosis from dogs thus remains a concrete reality. Prevalence control of Campylobacter  spp. in household and shelter dogs would be considered important in order to reduce the transmission to humans. Funding This study is part of a project (IZSAM 04/13 RC) financed by the Italian Ministry of Health, co-ordinated by the Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise ‘G. Caporale’ (Teramo, ltaly). The study design was approved by the Italian Ministry of Health. which, if put in favorable conditions, may acquire resistance to these molecules and transmit it to their offspring. However, restriction of the use of antimicrobials due to introduction of electronic prescription (Ministero della Salute 2019) should further improve this condition. The prevalence of antimicrobial resistance in ciprofloxacin (22.73%), nalidixic acid (22.73%), tetracyclines (27.27%), streptomycin (9.09%) and erythromycin (4.55%) found in this study was confirmed by other studies (Andrzejewska et  al. 2013). This issue is worrying as these antibiotics are also commonly used in humans. Antimicrobial resistance genes can be transferred to the intestinal microbial flora, and resistant commensal bacteria can constitute a reserve of resistant genes for potential pathogens (Amar et al. 2014). The principal C. jejuni CCs in dogs were CC21, CC45, CC206, CC403, CC42 and CC 658. C.  jejuni CCs CC21 and CC45 are regularly isolated from multiple animal species, hindering a human source attribution. Conclusions Data regarding the prevalence of Campylobacter infection in household and shelter dogs confirms a real risk of transmission to humans by dogs, even though the prevalence was not very high compared to other studies. This risk is higher in the presence 65Veterinaria Italiana 2022, 58 (1), 57-66. doi: 10.12834/VetIt.2299.15789.1 Iannino et al. Campylobacteriosis and role of dogs Acke E., McGill K., Golden O., Jones B.R., Fanning S. & Whyte P. 2009. Prevalence of thermophilic Campylobacter species in household cats and dogs in Ireland. Vet Rec, 164, 44-47. Adak G.K., Meakins S.M., Yip H., Lopman B.A. & O'Brien S.J. 2005. Disease risks from foods, England and Wales, 1996-2000. Emerg Infect Dis, 11, 365-372. Amar C., Kittl S., Spreng D., Thomann A., Korczak B.M., Burnens A.P. & Kuhnert P. 2014. Genotypes and antibiotic resistance of canine Campylobacter jejuni isolates. Vet Microbiol, 168, 124-130. Andrzejewska M., Szczepańska B., Klawe J.J., Spica D. & Chudzińska M. 2013. 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