https://hdl.handle.net/10259/4292 Mon, 20 Apr 2026 19:27:35 GMT 2026-04-20T19:27:35Z https://hdl.handle.net/10259/11287 Genome-Wide association study to identify genetic markers associated with Campylobacter jejuni motility Ortega Sanz, Irene; Rovira Carballido, Jordi; Megías, Gregoria; Rivero Pérez, Maria Dolores; Melero Gil, Beatriz The ability of Campylobacter jejuni to survive and persist under harsh conditions is linked to the presence of flagella. This structure promotes the motility of the bacteria towards their optimum environment. The aim of this study was to examine the genetic basis for motility within 136 C. jejuni isolates through two different Genome-Wide Association Studies, gene presence/absence and Single Nucleotide Polymorphisms (SNPs). The motility phenotype was widely distributed across the phylogeny with large intra-lineage swarming performance variabilities. Accessory genes significantly associated with motility were found in four key genomic regions. One of these regions affected the Cj0727-Cj0733 operon, that encodes a putative ABC transporter system for phosphate uptake, while other influenced the capsule biosynthesis locus. Multiple SNPs mostly linked to increased motility were also discovered in clusters of genes, with special relevance to transport and membrane proteins. Therefore, the capsule and membrane composition might influence nutrient transfer, further impacting the protonmotive force that drives flagellar motor rotation in C. jejuni. The study provides novel genetic markers with a potential role in the motility phenotype of the pathogen. Fri, 01 Aug 2025 00:00:00 GMT https://hdl.handle.net/10259/11287 2025-08-01T00:00:00Z https://hdl.handle.net/10259/11268 Genomic Characterization of Campylobacter jejuni Associated with Perimyocarditis: A Family Case Report Ortega Sanz, Irene; García, Marcial .; Bocigas, Carolina; Megías, Gregoria; Melero Gil, Beatriz; Rovira Carballido, Jordi Campylobacter spp. is the leading cause of foodborne gastrointestinal infections in humans worldwide. This study reports the first case of four family members who had contact with the same source of Campylobacter jejuni contamination with different results. Only the little siblings were infected by the same C. jejuni strain, but with different symptoms. Whereas the daughter was slightly affected with mild enteritis, the son suffered a longer campylobacteriosis followed with a perimyocarditis. This is the first case of the youngest patient affected by C. jejuni-related perimyocarditis published to date. The genomes of both strains were characterized by whole-genome sequencing and compared with the C. jejuni NCTC 11168 genome to gain insights into the molecular features that may be associated with perimyocarditis. Various comparison tools were used for the comparative genomics analysis, including the identification of virulence and antimicrobial resistance genes, phase variable (PV) genes, and single nucleotide polymorphisms (SNPs) identification. Comparisons of the strains identified 16 SNPs between them, which constituted small but significant changes mainly affecting the ON/OFF state of PV genes after passing through both hosts. These results suggest that PV occurs during human colonization, which modulates bacteria virulence through human host adaptation, which ultimately is related to complications after a campylobacteriosis episode depending on the host status. The findings highlight the importance of the relation between host and pathogen in severe complications of Campylobacter infections.; Campylobacter spp. is the leading cause of foodborne gastrointestinal infections in humans worldwide. This study reports the first case of four family members who had contact with the same source of Campylobacter jejuni contamination with different results. Only the little siblings were infected by the same C. jejuni strain, but with different symptoms. Whereas the daughter was slightly affected with mild enteritis, the son suffered a longer campylobacteriosis followed with a perimyocarditis. This is the first case of the youngest patient affected by C. jejuni-related perimyocarditis published to date. The genomes of both strains were characterized by whole-genome sequencing and compared with the C. jejuni NCTC 11168 genome to gain insights into the molecular features that may be associated with perimyocarditis. Various comparison tools were used for the comparative genomics analysis, including the identification of virulence and antimicrobial resistance genes, phase variable (PV) genes, and single nucleotide polymorphisms (SNPs) identification. Comparisons of the strains identified 16 SNPs between them, which constituted small but significant changes mainly affecting the ON/OFF state of PV genes after passing through both hosts. These results suggest that PV occurs during human colonization, which modulates bacteria virulence through human host adaptation, which ultimately is related to complications after a campylobacteriosis episode depending on the host status. The findings highlight the importance of the relation between host and pathogen in severe complications of Campylobacter infections. Tue, 01 Aug 2023 00:00:00 GMT https://hdl.handle.net/10259/11268 2023-08-01T00:00:00Z https://hdl.handle.net/10259/11267 Effects of Strawberry Leaf Extract on the Quality Characteristics and Oxidation Stability of Dry Fermented Sausage During Ripening and Storage Račkauskienė, Ieva; Rovira Carballido, Jordi; Jaime Moreno, Isabel; González San José, Mª Luisa; Venskutonis, Petras Rimantas Strawberry leaf extract (SLE) was used in dry fermented sausages, “Salchichón”, to enrich them with antioxidants. The effect of SLE on various characteristics was monitored during ripening and storage. SLE had a slight effect on microbiological characteristics; however, the pH after 3, 14, and 21 days was slightly lower (4.51–4.55) in the samples with higher SLE concentration (0.5% + 1% dextrose). Peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) values of sausages with SLE and with ascorbic acid (reference antioxidant), at the end of ripening, were similar. SLE acted as a pro-oxidant when the sausage was stored in the light; however, it showed antioxidant activity in the dark and at 50 °C storage conditions. Higher extract concentration reduced redness a* value and increased yellowness b* value in the CIELab colour system. Addition of SLE to dry fermented sausages has no negative effect on the ripening process; however, storage conditions of the final product should be carefully controlled. Sensory analysis of the final product showed that SLE imparts a recognisable herbal odour; however, it did not reduce the overall product acceptability. It may be concluded that SLE may be a promising ingredient for increasing the nutritional quality of fermented sausages. Mon, 01 Sep 2025 00:00:00 GMT https://hdl.handle.net/10259/11267 2025-09-01T00:00:00Z https://hdl.handle.net/10259/11265 Genotyping, virulence genes and antimicrobial resistance of Campylobacter spp.isolated during two seasonal periods in Spanish poultry farms García Sánchez, Lourdes; Melero Gil, Beatriz; Diez Mate, Ana Mª; Jaime Moreno, Isabel; Canepa Oneto, Antonio Jesús; Rovira Carballido, Jordi Campylobacter spp. are the leading causes of bacterial human gastroenteritis worldwide; being poultry farms the main source of infections. In order to obtain information on prevalence and diversity of Campylobacter-infected flocks in the North of Spain, fourteen farms were studied between autumn and spring in 2014 and 2015, respectively. Moreover, virulence genes involved in pathogenicity and antimicrobial resistance were investigated. A survey about preventive hygiene practices at farms was performed to determine the risky practices that could contribute to the presence of Campylobacter in this step of the poultry food chain. Testing the presence of Campylobacter spp. showed 43 % of the farms were positive during autumn, whereas only 31 % were positive in spring. A very high prevalence within-flock was observed (43.1 % to 88.6 %) and C. jejuni was the most prevalent species in both periods. Genotyping by pulsed field gel electrophoresis (PFGE) showed a high heterogeneity among farms (309 isolates clustered into 21 pulsotypes). Virulence genes were present in all C. jejuni isolates while cdtA and cdtC were absent in C. coli. On the contrary, the latter showed higher antimicrobial resistance than C. jejuni. This study suggests that environment might be one of the main sources for Campylobacter transmission, as water supply seemed to be a clear cause of the contamination in a specific farm. However, in other farms other environmental factors contributed to the contamination, confirming the multifactorial origin of Campylobacter colonization in broilers. Therefore, biosecurity measures in farms are crucial to reduce Campylobacter contamination, which may have important implications for human and animal health. Sun, 01 Mar 2020 00:00:00 GMT https://hdl.handle.net/10259/11265 2020-03-01T00:00:00Z