RESUMO
During the 2021 European Food Safety Authority coordinated harmonized monitoring of antimicrobial resistance in Campylobacter species in Slovenia, five Campylobacter-like strains were cultured from caeca of a total of 104 domestic pigs that could not be identified using the standard-prescribed biochemical tests or MALDI-TOF MS. The isolates were obtained using the standard ISO 10272 procedure for the isolation of thermotolerant Campylobacter with prolonged cultivation time. Small Campylobacter-like colonies were observed on mCCDA and CASA agar plates after 2-4 days of incubation; dark-field microscopy revealed relatively big spirilli-shaped bacteria exhibiting characteristic Campylobacter-like motility. The cells were 1.5-3 µm long and 0.5-0.7 µm wide, Gram-negative, oxidase-positive and catalase-positive. MALDI-TOF mass spectra were distinctive and consistent, but with low MALDI-TOF MS log scores and the closest matches being those of Campylobacter hyointestinalis and Campylobacter fetus. All five strains underwent whole-genome sequencing. Analysis of 16S rRNA gene sequences revealed that the isolates were most similar (98.3-98.4â% identity) to Campylobacter lanienae. Pairwise average nucleotide identity (ANI) values revealed that the five studied strains shared pairwise ANI of 96.2-96.5â% but were clearly distinct from the previously described Campylobacter species (ANI ≤72.8â%). The core genome-based phylogeny confirmed that the new strains form a distinct and well-supported clade within the genus Campylobacter. The conducted polyphasic taxonomic analysis confirmed that the five strains represent a novel Campylobacter species for which the name Campylobacter magnus sp. nov. is suggested, with strain 46386T (=DSM 115534T=CCUG 76865T) as the type strain.
Assuntos
Campylobacter , Sus scrofa , Suínos , Animais , RNA Ribossômico 16S/genética , Filogenia , Análise de Sequência de DNA , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , Ácidos Graxos/química , Campylobacter/genética , NucleotídeosRESUMO
Seven Helicobacter-like isolates were cultured from caecal contents of 100 domestic pigs (Sus scrofa domesticus) sampled as part of the EFSA-coordinated harmonized monitoring of antimicrobial resistance in Campylobacter sp. in 2015. The bacteria were isolated using the standard ISO 10272 procedure for the isolation of thermotolerant Campylobacter with extended incubation time and formed small, grey, moist and flat colonies with a metallic sheen (small Campylobacter-like colonies) on modified Charcoal-Cefoperazone-Deoxycholate Agar (mCCDA) and Skirow agar plates. Morphologically, the bacterial cells were spirilli-shaped and highly motile, 1-2 µm long and ≤0.5 µm wide, Gram-negative, oxidase-positive and catalase-positive. They could not be identified using the standard-prescribed biochemical tests and had uniform, unique and reproducible MALDI-TOF mass spectra that most closely matched those of Helicobacter pullorum. Three strains (11154-15T, 14348-15 and 16470-15) underwent whole-genome sequencing. Analysis of 16S rRNA gene sequences revealed a high similarity (≥99.8â% identity) to Helicobacter canadensis. Pairwise average nucleotide identity (ANI) values revealed that the three studied strains were closely related (ANI ≥98.9â%), but distinct from the previously described Helicobacter species (ANI ≤90.6â%). The core genome-based phylogeny confirmed that the new strains form a distinct clade most closely related to H. canadensis. The conducted polyphasic taxonomic analysis confirmed that the three strains represent a novel Helicobacter species for which the name Helicobacter colisuis sp. nov. is suggested, with strain 11154-15T (= DSM 113688T = CCUG 76053T) as the type strain.
Assuntos
Campylobacter , Helicobacter , Animais , Suínos , RNA Ribossômico 16S/genética , Sus scrofa , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Ágar , Filogenia , Análise de Sequência de DNA , Composição de Bases , Ácidos Graxos/químicaRESUMO
This study describes the epidemiological characteristics of classical swine fever (CSF) outbreaks in Japan. The first case was confirmed in September 2018, 26 years after the last known case. Outbreaks occurred on 39 farms, 34 commercial farms, and 5 non-commercial farms, between September 2018 and August 2019. In this study, a descriptive analysis was conducted of the epidemiological data on the characteristics of the affected farms, clinical manifestations, intra-farm transmission, association with infected wild boars, and control measures implemented on the farms. Twenty-eight of the 34 affected commercial farms were farrow-to-finish farms. It was assumed that the major risk factors were frequent human-pig interactions and the movement of pigs between farms. Fever and leukopenia were commonly observed in infected pigs. In 12 out of 18 farms where clinical manifestations among fattening pigs was the reason for notification, death was the most frequent clinical manifestation, but the proportion of dead animals did not exceed 0.5% of the total number of animals at most of the affected farms. Therefore, the clinical form of CSF in Japan was considered to be sub-acute. Twenty-three of the 29 farms (79%) with pigs at multiple stages (i.e., piglets, fattening pigs, and sows), had infection across the multiple stages. Many of these farms were within 5 km of the site where the first infected wild boars had been discovered, suggesting that infected wild boars were the source of infection. Infections still occurred at farms that had implemented measures at their farm boundaries to prevent the introduction of the virus into their farms, such as disinfection of vehicles and people, changing boots of the workers, and installation of perimeter fences. It is necessary to continue to strengthen biosecurity measures for farms located in areas with infected wild boars and to continue monitoring the distribution of infected wild boars so that any abnormalities can be reported and inspected at an early stage.