Helicobacter ibis sp. nov., isolated from faecal droppings of black-faced ibis (Theristicus melanopis).

As part of a larger study on Epsilonproteobacteria carried by wild birds in the city of Valdivia (southern Chile), two curved rod-shaped Gram-stain-negative strains (A82T and WB-40) were recovered from faecal samples and subjected to a taxonomic study. Results of a genus-specific PCR showed that these isolates belonged to the genus Helicobacter. Further identification by 16S rRNA and hsp60 (60 kDa heat-shock protein) gene sequence analysis revealed that they formed a separate phylogenetic clade, different from other known Helicobacter species with 'Helicobacter burdigaliensis' CNRCH 2005/566HT and Helicobacter valdiviensis WBE14T being the most closely related species. This was confirmed by core-genome phylogeny as well as digital DNA-DNA hybridization and average nucleotide identity analyses between the genomes of strains A82T and WB-40 and all other Helicobacter species. The draft genome sequences of A82T and WB-40, obtained by Illumina NextSeq 2000 sequencing, consisted of 1.6 Mb with a G+C content of 31.9-32.0 mol%. The results obtained from the phylogenetic and genomic characterization, together with their different morphological and biochemical features, revealed that these two strains represent a novel species, for which we propose the name Helicobacter ibis sp. nov. with A82T (=LMG 32718T=CCCT 22.04T) as the type strain.

Fungal bioaerosol as an occupational hazard in the podiatrist's workplace.

Previous studies have reported the potential emission of nail dust to the indoor air of the podiatrist's workplace during nail drilling procedures. The main objective of this study was to analyse the fungal bioaerosol present in the indoor air of podiatry rooms, including during the nail drilling procedure. Seventeen private clinics were sampled in Madrid during spring and summer. The most prevalent filamentous fungi detected were Cladosporium spp. and Penicillium spp. in both seasons. The presence of Trichophyton rubrum and Trichophyton interdigitale was reported in samples during the drilling procedures, establishing a positive association with the clinical suspicion of onychomycosis (p = 0.002) and the utilization of aspiration systems (p=0.04). The present study concludes that airborne fungal concentrations in podiatrist's clinics are consistent with national and international guidance. Occupational exposure to dermatophytes may briefly occur during definite periods across the daily activity despite the use of dust aspiration systems.

Enterohepatic Helicobacter species - clinical importance, host range, and zoonotic potential.

The genus Helicobacter defined just over 30 years ago, is a highly diverse and fast-growing group of bacteria that are able to persistently colonize a wide range of animals. The members of this genus are subdivided into two groups with different ecological niches, associated pathologies, and phylogenetic relationships: the gastric Helicobacter (GH) and the enterohepatic Helicobacter (EHH) species. Although GH have been mostly studied, EHH species have become increasingly important as emerging human pathogens and potential zoonotic agents in the last years. This group of bacteria has been associated with the development of several diseases in humans from acute pathologies like gastroenteritis to chronic pathologies that include inflammatory bowel disease, and liver and gallbladder diseases. However, their reservoirs, as well as their routes of transmission, have not been well established yet. Therefore, this review summarizes the current knowledge of taxonomy, epidemiology, and clinical role of the EHH group.

Virulence assessment of enterohepatic Helicobacter species carried by dogs using the wax moth larvae Galleria mellonella as infection model.

BACKGROUND: Enterohepatic species of the genus Helicobacter (EHH) are emerging pathogens that have been associated with gastrointestinal and hepatobiliary diseases in humans. However, studies on their pathogenicity are scarce. Galleria mellonella is a recently proposed model for the study of virulence in different pathogens, such as Campylobacter spp. and Helicobacter pylori. Despite this, its usefulness in EHH has not yet been evaluated. Therefore, we determined the pathogenic potential of different EHH species isolated from dogs in this infection model. MATERIALS AND METHODS: Four species of EHH (H. bilis, H. canicola, H. canis, and 'H. winghamensis') isolated from fecal samples from domestic dogs were evaluated. Three strains of each species were inoculated in cohorts of G. mellonella at a concentration of 1 × 107  CFU/mL. Survival curves were determined by the Kaplan-Meier method. In addition, the quantification of melanin, bacterial load in hemolymph, and histopathology were evaluated daily post-infection (pi). RESULTS: G. mellonella larvae are susceptible to EHH infection, exhibiting intra- and inter-species variability. Melanin production became evident from 4 h pi and increased throughout the assay. All species were recovered from the hemolymph after 20 min pi; however, only H. canis could be recovered up to 48 h pi. Histopathology revealed cellular and humoral immune response, evidencing accumulation of hemocytes, nodulation, and melanin deposition in different tissues. CONCLUSION: EHH species carried by dogs have considerable pathogenic potential, being H. canicola the species with the highest degree of virulence. Thus, G. mellonella is a useful model to assess virulence in these emerging pathogens.

New insights on the infection of pathogenic Leptospira species in American mink (Neovison vison) in southern Chile.

Leptospirosis is a zoonosis of global distribution, caused by the infection of pathogenic Leptospira, a group of bacteria capable of infecting both domestic and wild animals. Mink (Neovison vison) in southern Chile is recognized as a wild and synanthropic rodent predator (among various other prey), and Leptospira infection in them can be acquired through contact with the pathogen in the environment or by eating infected prey. Thus, the aim of this study was to provide more specifics regarding the source of the infection for the American mink under the conditions of Southern Chile. Minks were captured in the Los Ríos region, southern Chile, in an area with well-developed dairy farming. Two areas were selected for mink trapping, one with a high degree of dairy farming and a second with a low degree of dairy farming. Within them, 16 study sites were visited, and 45 American mink were trapped and euthanized to obtain kidney tissue and blood serum samples for bacteria isolation and determination of antibodies titers, respectively. Molecular characterization of the isolated strains was performed. Three minks from sites of high-dairy farming industry and only one from sites with low-degree dairy farming were detected as infected through molecular confirmation. This study shows evidence that confirms previous findings made in southern Chile, regarding mink as host of Leptospira interrogans serovar Hardjo-prajitno associated to cattle-farming areas. However, typing information ( Leptospira interrogans Copenhageni and Icterohaemorrhagiae ) suggests that the consumption of rodents may also be a potential source of infection.

Concurrent progressive multifocal leukoencephalopathy and central nervous system infiltration by multiple myeloma: A case report.

Progressive multifocal leukoencephalopathy rarely occurs in patients with multiple myeloma. Intracranial central nervous system invasion is also an uncommon event in multiple myeloma, occurring in less than 1% of cases. We describe herein an exceptional case of coexisting progressive multifocal leukoencephalopathy and intraparenchymal central nervous system myeloma infiltration. A 73-year-old woman with relapsed multiple myeloma was treated with 15 cycles of lenalidomide and dexamethasone, but therapy had to be stopped because of a hip fracture after a fall. During hospitalization, the patient developed progressive multifocal leukoencephalopathy caused by John Cunningham virus, and a prominent intra-parenchymal CD138-positive infiltrate was detected. VDJ rearrangements of the immunoglobulin heavy chain gene and the mutational profile of plasma cells in bone marrow at the time of diagnosis and in brain biopsy after progression were analyzed by next generation sequencing, showing genetic differences between medullary and extramedullary myeloma cells. The role of long-term treatment with lenalidomide and dexamethasone in the development progressive multifocal leukoencephalopathy or intraparenchymal central nervous system myeloma infiltration remains unknown. However, our results suggest that both events may have arisen as a consequence of treatment-related immunosuppression. Thus, an appropriate clinical approach compatible with the simultaneous treatment of progressive multifocal leukoencephalopathy and multiple myeloma should be developed.

Campylobacter ornithocola sp. nov., a novel member of the Campylobacter lari group isolated from wild bird faecal samples.

During a study on the prevalence and diversity of campylobacteria in wild birds faecal samples from the city of Valdivia (southern Chile) 17 Gram-stain-negative, curved-rod-shaped isolates, were initially identified as Campylobacter lari by PCR-RFLP. Further identification by 16S rRNA sequence analysis revealed that they formed a distinct group in the genus Campylobacter. This unique position was confirmed by the results of analysis of rpoB, atpA and cpn60 gene sequences. The average nucleotide identity between the representative strain WBE38T and the type strain of the most closely related taxon C. larisubsp.concheus (LMG 11760) was 90.8 %. The oxidase and urease activity of the novel isolates enabled them to be phenotypically differentiated from species of the genus Campylobacter with validly published names. Therefore, on the basis of phenotypic, genetic and genomic characterizations, the results of this study clearly indicate that these strains represent a novel species within the genus Campylobacter, for which the name Campylobacter ornithocola sp. nov. is proposed, with the type strain WBE38T (=CECT 9147T=LMG 29815T).

Genomic and clinical evidence uncovers the enterohepatic species Helicobacter valdiviensis as a potential human intestinal pathogen.

BACKGROUND: Helicobacter valdiviensis is a recently described enterohepatic species isolated from wild bird's fecal samples. Currently, its pathogenic potential and clinical significance are unknown mainly due to the lack of whole-genome sequences to compare with other helicobacters and the absence of specific screenings to determine its prevalence in humans. MATERIALS AND METHODS: The species type strain (WBE14T ) was whole-genome-sequenced, and comparative analyses were carried out including the genomes from other Helicobacter species to determine the exact phylogenetic position of H. valdiviensis and to study the presence and evolution of virulence determinants. In parallel, stools from diarrheic patients and healthy individuals were screened by PCR to assess the clinical incidence of H. valdiviensis. RESULTS: Helicobacter valdiviensis belongs to a monophyletic clade conformed by H. canadensis, H. pullorum, H. winghamensis, H. rodentium, and H. apodemus. Its predicted genome size is 2 176 246 bp., with 30% of G+C content and 2064 annotated protein-coding genes. The patterns of virulence factors in H. valdiviensis were similar to other enterohepatic species, but evidence of horizontal gene transfer from Campylobacter species was detected for key genes like those coding for the CDT subunits. Positive PCR results confirmed the presence of H. valdiviensis in 2 of 254 (0.78%) stools of patients with acute diarrhea while not a single sample was positive in healthy individuals. CONCLUSIONS: Horizontal gene transfer has contributed to shape the gene repertory of H. valdiviensis, which codes for virulence factors conserved in other pathogens that are well-known human pathogens. Additionally, the detection of H. valdiviensisDNA in diarrheic patients supports its role as a potential emergent intestinal pathogen. Further, sampling efforts are needed to uncover the clinical relevance of this species, which should be accomplished by the isolation of H. valdiviensis from ill humans and the obtention of whole genomes from clinical isolates.

Higher water temperature and incubation under aerobic and microaerobic conditions increase the recovery and diversity of Arcobacter spp. from shellfish.

Some Arcobacter species are considered emerging food-borne and waterborne pathogens, and shellfish have been suggested as one of their reservoirs. However, only a few studies have investigated the presence of Arcobacter in this kind of food. This study assesses the prevalence and diversity of Arcobacter spp. in shellfish by multiplex PCR (m-PCR) and culturing methods (under different atmospheric conditions) and evaluates the possible influence of environmental parameters (temperature, salinity, and harvesting bay). Arcobacter was detected by m-PCR and/or culturing in 61 (29.9%) of 204 shellfish samples. Of the positive samples by culturing, 41.1% were obtained under only aerobic incubation conditions, while 23.2% were obtained under only microaerobic conditions. Of 476 investigated isolates, 118 belonged to different enterobacterial repetitive intergenic consensus (ERIC)-PCR genotypes (strains) and to 11 different species. This study shows the highest diversity of Arcobacter species ever observed in samples from any origin. The most prevalent species was Arcobacter butzleri (60.2%), followed by Arcobacter molluscorum (21.2%). The prevalence of Arcobacter was significantly higher during the summer than in other seasons, being associated with an increase in water temperature. Results confirm that shellfish are a reservoir for a remarkable diversity of Arcobacter spp.

Description of Helicobacter valdiviensis sp. nov., an Epsilonproteobacteria isolated from wild bird faecal samples.

Two Gram-stain-negative, gently curved rod-shaped isolates (WBE14(T) and WBE19), recovered from wild bird faecal samples in the city of Valdivia (Southern Chile) were subjected to a polyphasic taxonomic study. Results of a genus-specific PCR indicated that these isolates belonged to the genus Helicobacter. This was further confirmed by a phylogenetic analyses based on the 16S rRNA, 60 kDa heat-shock protein (cpn60) and gyrase subunit B (gyrB) genes, where both strains formed a novel phylogenetic line within this genus. The 16S rRNA gene sequence similarity of strain WBE14(T) to the type strains of all other species of the genus Helicobacter examined ranged from 89.4 to 97.0%; Helicobacter brantae and Helicobacter pametensis were the most closely related species. However, on the basis of the protein-coding genes Helicobacter pullorum and Helicobacter canadensis are the most closely related species. These data, together with their different morphological and biochemical characteristics, revealed that these strains represent a novel species, for which the name Helicobacter valdiviensis sp. nov. is proposed, with the type strain WBE14(T) ( = CECT 8410(T) = LMG 27920(T)).

Use of probiotics in preventing and treating excess weight and obesity. A systematic review.

Background: The prevalence of excess weight and obesity is increasing in an extremely concerning manner worldwide, with highly diverse therapies for current treatment. This review evaluated the scientific evidence of the past 10 years on the use of probiotics in treating excess weight and obesity in the absence of dieting. Materials: A systematic review was conducted by searching for clinical trials on humans published in English in the PubMed, Scopus and Cochrane Central databases, using the combination of keywords "Overweight", "Probiotics" and "Obesity", and published between 2012 and 2022. Results: Six published studies met the inclusion criteria. The review showed that, although there is a lack of consensus in the literature, the use of probiotics in the absence of dieting produced a significant reduction in body weight and body mass index in 66.6% of the reviewed studies, a significant reduction in waist circumference in 80.0% of the reviewed studies, and an improvement in total body fat mass and waist circumference. Conclusions: This review showed evidence of a trend in preventing body weight gain and reducing weight through the use of probiotics in individuals with excess weight or obesity. A combination of various strains of the genera Bifidobacterium and Lactobacillus was the most effective.

Self-perception of the acquisition of transferable competencies by the participants in a research congress for undergraduate students: A cross-sectional study.

Context: Several curricular initiatives have been developed to improve the acquisition of research competencies by Health Science students. Objectives: To know how students self-perceived of whether their participation in the XIV National Research Congress for Undergraduate Students of Health Sciences had helped them in the acquisition of 36 research-related transferable competencies (TCs) common to Health Science degrees. Methods: A survey design (Cronbach's alpha = 0.924), using a self-administered questionnaire, was conducted among undergraduate students who voluntarily participated in the Congress. Data analysis was performed using SPSS 25 and Statgraphics 19. Statistical significance was considered for P < 0.05. Results: Eighty-one students from 12 Health Science degree programs responded. Key findings are presented in a structured manner, using a Likert-5 scale. Twenty-five of the competencies surveyed obtained an average ≥ 4 highlighting: "Critically evaluate and know how to use sources of clinical and biomedical information to obtain, organize, interpret, and communicate scientific and health information"; "To be able to formulate hypotheses, collect and critically evaluate information for problem solving, following the scientific method", "Critical analysis and research" and "Communicate effectively and clearly, orally and in writing with other professionals". Significance was found in 15 competencies. The development of the competencies "Teamwork", "Critical reasoning" and "Analysis and synthesis abilities" was considered to be of greater "personal utility" by the respondents. Conclusion: Participation in this event contributed to the development of research-related TCs, critical analysis and information management and communication, especially in relation to learning the sources of clinical and biomedical information, to know, following the scientific method, how to formulate hypotheses that allow students to solve problems in their professional activity. The experience was significantly influenced by the respondents' year, the type of participation in the event and the gender of the students. Limitations and suggestions regarding future research are discussed to encourage further exploration of the topic.

Taxonomy, epidemiology, and clinical relevance of the genus Arcobacter.

The genus Arcobacter, defined almost 20 years ago from members of the genus Campylobacter, has become increasingly important because its members are being considered emergent enteropathogens and/or potential zoonotic agents. Over recent years information that is relevant for microbiologists, especially those working in the medical and veterinary fields and in the food safety sector, has accumulated. Recently, the genus has been enlarged with several new species. The complete genomes of Arcobacter butzleri and Arcobacter nitrofigilis are available, with the former revealing diverse pathways characteristic of free-living microbes and virulence genes homologous to those of Campylobacter. The first multilocus sequence typing analysis showed a great diversity of sequence types, with no association with specific hosts or geographical regions. Advances in detection and identification techniques, mostly based on molecular methods, have been made. These microbes have been associated with water outbreaks and with indicators of fecal pollution, with food products and water as the suspected routes of transmission. This review updates this knowledge and provides the most recent data on the taxonomy, species diversity, methods of detection, and identification of these microbes as well as on their virulence potential and implication in human and animal diseases.

Genomic Characterization of Antibiotic-Resistant Campylobacterales Isolated from Chilean Poultry Meat.

Due to the lack of knowledge about Campylobacterales in the Chilean poultry industry, the objective of this research was to know the prevalence, resistance, and genotypes of Campylobacter, Arcobacter and Helicobacter in 382 samples of chicken meat purchased in Valdivia, Chile. The samples were analyzed using three isolation protocols. Resistance to four antibiotics was evaluated by phenotypic methods. Genomic analyses were performed on selected resistant strains to detect resistance determinants and their genotypes. A total of 59.2% of the samples were positive. Arcobacter butzleri (37.4%) was the most prevalent species, followed by Campylobacter jejuni (19.6%), C. coli (11.3%), A. cryaerophilus (3.7%) and A. skirrowii (1.3%). Helicobacter pullorum (14%) was detected by PCR in a subset of samples. Campylobacter jejuni was resistant to ciprofloxacin (37.3%) and tetracycline (20%), while C. coli and A. butzleri were resistant to ciprofloxacin (55.8% and 2.8%), erythromycin (16.3% and 0.7%) and tetracycline (4.7% and 2.8%), respectively. Molecular determinants were consistent with phenotypic resistance. The genotypes of C. jejuni (CC-21, CC-48, CC-49, CC-257, CC-353, CC-443, CC-446 and CC-658) and C. coli (CC-828) coincided with genotypes of Chilean clinical strains. These findings suggest that besides C. jejuni and C. coli, chicken meat could play a role in the transmission of other pathogenic and antibiotic-resistant Campylobacterales.

Evidence of the Beneficial Impact of Three Probiotic-Based Food Supplements on the Composition and Metabolic Activity of the Intestinal Microbiota in Healthy Individuals: An Ex Vivo Study.

Scientific evidence has increasingly supported the beneficial effects of probiotic-based food supplements on human intestinal health. This ex vivo study investigated the effects on the composition and metabolic activity of the intestinal microbiota of three probiotic-based food supplements, containing, respectively, (1) Bifidobacterium longum ES1, (2) Lactobacillus acidophilus NCFM®, and (3) a combination of L. acidophilus NCFM®, Lactobacillus paracasei Lpc-37™, Bifidobacterium lactis Bi-07™, and Bifidobacterium lactis Bl-04™. This study employed fecal samples from six healthy donors, inoculated in a Colon-on-a-plate® system. After 48 h of exposure or non-exposure to the food supplements, the effects were measured on the overall microbial fermentation (pH), changes in microbial metabolic activity through the production of short-chain and branched-chain fatty acids (SCFAs and BCFAs), ammonium, lactate, and microbial composition. The strongest effect on the fermentation process was observed for the combined formulation probiotics, characterized by the significant stimulation of butyrate production, a significant reduction in BCFAs and ammonium in all donors, and a significant stimulatory effect on bifidobacteria and lactobacilli growth. Our findings suggest that the combined formulation probiotics significantly impact the intestinal microbiome of the healthy individuals, showing changes in metabolic activity and microbial abundance as the health benefit endpoint.

Updated 16S rRNA-RFLP method for the identification of all currently characterised Arcobacter spp.

BACKGROUND: Arcobacter spp. (family Campylobacteraceae) are ubiquitous zoonotic bacteria that are being increasingly recognised as a threat to human health. A previously published 16S rRNA-RFLP Arcobacter spp. identification method produced specific RFLP patterns for the six species described at that time, using a single endonuclease (MseI). The number of characterised Arcobacter species has since risen to 17. The aim of the present study was to update the 16S rRNA-RFLP identification method to include all currently characterised species of Arcobacter. RESULTS: Digestion of the 16S rRNA gene with the endonuclease MseI produced clear, distinctive patterns for 10 of the 17 species, while the remaining species shared a common or very similar RFLP pattern. Subsequent digestion of the 16S rRNA gene from these species with the endonucleases MnlI and/or BfaI generated species-specific RFLP patterns. CONCLUSIONS: 16S rRNA-RFLP analysis identified 17 Arcobacter spp. using either polyacrylamide or agarose gel electrophoresis. Microheterogeneities within the 16S rRNA gene, which interfered with the RFLP identification, were also documented for the first time in this genus, particularly in strains of Arcobacter cryaerophilus isolated from animal faeces and aborted foetuses.

Strategies to Combat Caries by Maintaining the Integrity of Biofilm and Homeostasis during the Rapid Phase of Supragingival Plaque Formation.

Bacteria in the oral cavity, including commensals and opportunistic pathogens, are organized into highly specialized sessile communities, coexisting in homeostasis with the host under healthy conditions. A dysbiotic environment during biofilm evolution, however, allows opportunistic pathogens to become the dominant species at caries-affected sites at the expense of health-associated taxa. Combining tooth brushing with dentifrices or rinses combat the onset of caries by partially removes plaque, but resulting in the biofilm remaining in an immature state with undesirables' consequences on homeostasis and oral ecosystem. This leads to the need for therapeutic pathways that focus on preserving balance in the oral microbiota and applying strategies to combat caries by maintaining biofilm integrity and homeostasis during the rapid phase of supragingival plaque formation. Adhesion, nutrition, and communication are fundamental in this phase in which the bacteria that have survived these adverse conditions rebuild and reorganize the biofilm, and are considered targets for designing preventive strategies to guide the biofilm towards a composition compatible with health. The present review summarizes the most important advances and future prospects for therapies based on the maintenance of biofilm integrity and homeostasis as a preventive measure of dysbiosis focused on these three key factors during the rapid phase of plaque formation.

Metataxonomic and metabolomic evidence of biofilm homeostasis disruption related to caries: An in vitro study.

The ecological dysbiosis of a biofilm includes not only bacterial changes but also changes in their metabolism. Related to oral biofilms, changes in metabolic activity are crucial endpoint, linked directly to the pathogenicity of oral diseases. Despite the advances in caries research, detailed microbial and metabolomic etiology is yet to be fully clarified. To advance this knowledge, a meta-taxonomic approach based on 16S rRNA gene sequencing and an untargeted metabolomic approach based on an ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry analysis (UHPLC/Q-TOF-MS) were conducted. To this end, an in vitro biofilm model derived from the saliva of healthy participants were developed, under commensal and cariogenic conditions by adding sucrose as the disease trigger. The cariogenic biofilms showed a significant increase of Firmicutes phyla (p = 0.019), due to the significant increase in the genus Streptococcus (p = 0.010), and Fusobacter (p < 0.001), by increase Fusobacterium (p < 0.001) and Sphingomonas (p = 0.024), while suffered a decrease in Actinobacteria (p < 0.001). As a consequence of the shift in microbiota composition, significant extracellular metabolomics changes were detected, showed 59 metabolites of the 120 identified significantly different in terms of relative abundance between the cariogenic/commensal biofilms (Rate of change > 2 and FDR < 0.05). Forty-two metabolites were significantly higher in abundance in the cariogenic biofilms, whereas 17 metabolites were associated significantly with the commensal biofilms, principally related protein metabolism, with peptides and amino acids as protagonists, latter represented by histidine, arginine, l-methionine, glutamic acid, and phenylalanine derivatives.

Arcobacter defluvii sp. nov., isolated from sewage samples.

A study employing a polyphasic taxonomic approach was undertaken to clarify the position of 12 isolates recovered from sewage samples. These isolates were recognized as a potential novel species because a new and specific pattern was produced with the 16S rRNA-RFLP Arcobacter identification method. The sequences of the 16S rRNA gene not only supported the classification of these novel strains as members of the genus Arcobacter, but also showed that they formed a separate phylogenetic line. Strain SW28-11(T), chosen as the representative of these strains, showed 16S rRNA gene sequence similarity of 95.6 % with the closest related species Arcobacter nitrofigilis. The phylogenetic position of the novel strains was further confirmed by analysis of the housekeeping genes hsp60, rpoB and, for the first time, gyrB. The latter proved to be an excellent additional gene for establishing the phylogeny of this genus. These data, together with phenotypic characterization, revealed that this group of isolates represent a novel species of the genus Arcobacter. The name Arcobacter defluvii sp. nov., is proposed, with the type strain SW28-11(T) ( = CECT 7697(T) = LMG 25694(T)).

Exploring the role of healthy dogs as hosts of enterohepatic Helicobacter species using cultivation-dependent and -independent approaches.

Enterohepatic Helicobacter (EHH) species have been increasingly associated with acute gastroenteritis, inflammatory bowel disease and hepatobiliary diseases in humans. However, their host range and transmission routes are poorly understood. Therefore, the aim of this study was to determine the presence of EHH in healthy dogs using both cultivation-dependent and -independent methods. Three hundred and ninety faecal samples from domestic dogs without gastrointestinal symptoms were analysed between June 2018 and July 2019 in Valdivia (South of Chile). Samples were inoculated on selective medium and in parallel were filtrated over an antibiotic-free blood agar. Both media were incubated in a microaerobic atmosphere at 37°C for 7 days. Colonies were identified by PCR and phylogenetic analysis. A subset of 50 samples (half of them positive for EHH by cultivation and the remaining half negative) was analysed by PCR-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) for direct detection. Cultivation method detected EHH in 15.4% (60/390) of the samples, being the most prevalent species H. canis (5.8%, 23/390) and H. canicola (5.1%, 20/390), followed by H. bilis (3.6%, 14/390) and 'H. winghamensis' (1.3%, 5/390). In contrast, PCR-DGGE method detected Helicobacter DNA in almost all (96%, 48/50) tested samples. On the other hand, the method used also allowed to isolate other Campylobacterales, in fact 44.3% (173/390) of the samples were positive for Campylobacter upsaliensis (43.3%, 169/390) followed by C. jejuni (2.0%, 8/390). Moreover, two strains that presented Campylobacter-like morphology were finally identified as Anaerobiospirillum succiniciproducens. Our results indicate that healthy domestic dogs commonly carry EHH and other Campylobacter species. However, further studies are needed to determine whether and how these Helicobacter and Campylobacter species can be transmitted to humans.