IRTA, Centre de Recerca en Sanitat Animal (CReSA, IRTA-UAB), Campus de la Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain.
OIE Collaborating Centre for the Research and Control of Emerging and Re-emerging Swine Diseases in Europe (IRTA-CReSA), Bellaterra, Barcelona, Spain.
BMC Vet Res. 2020 Jan 30;16(1):28. doi: 10.1186/s12917-020-2250-9.
Previous studies have shown that the genus Moraxella is commonly present in the nasal microbiota of swine.
In this study, 51 isolates of Moraxella were obtained from nasal swabs from 3 to 4 week old piglets, which represented 26 different fingerprintings by enterobacterial repetitive intergenic consensus (ERIC)-PCR. Whole 16S rRNA gene sequencing allowed the identification at species level of the Moraxella spp. isolates. The majority of the field strains were identified as Moraxella pluranimalium, but Moraxella porci was also detected. In addition, a cluster of 7 strains did not group with any described Moraxella species, probably representing a new species. Subsequent phenotypic characterization indicated that strains of Moraxella pluranimalium were mainly sensitive to serum complement, while the cluster representing the putative new species was highly resistant. Biofilm formation capacity was very variable among the Moraxella spp. isolates, while adherence to epithelial cell lines was similar among selected strains. Additionally, variability was also observed in the association of selected strains to porcine alveolar macrophages. Antimicrobial tests evidenced the existence of multidrug-resistance in the strains.
In summary, phenotypic characterization revealed heterogeneity among Moraxella strains from the nasal cavity of piglets. Strains with pathogenic potential were detected as well as those that may be commensal members of the nasal microbiota. However, the role of Moraxella in porcine diseases and health should be further evaluated.
先前的研究表明，莫拉氏菌属通常存在于猪的鼻腔微生物群中。
在这项研究中，从 3 至 4 周龄仔猪的鼻腔拭子中获得了 51 株莫拉氏菌分离株，这些分离株通过肠杆菌重复基因间一致性（ERIC）-PCR 呈现 26 种不同的指纹图谱。全 16S rRNA 基因测序可鉴定莫拉氏菌属分离株的种水平。大多数田间菌株被鉴定为多动物莫拉氏菌，但也检测到猪莫拉氏菌。此外，有 7 株菌簇未与任何描述的莫拉氏菌种聚类，可能代表一个新种。随后的表型特征表明，多动物莫拉氏菌的菌株主要对血清补体敏感，而代表假定新种的菌簇则高度耐药。生物膜形成能力在莫拉氏菌属分离株中差异很大，而选定菌株对上皮细胞系的粘附能力相似。此外，还观察到选定菌株与猪肺泡巨噬细胞的关联存在差异。抗菌试验证明了这些菌株存在多药耐药性。
综上所述，表型特征揭示了仔猪鼻腔莫拉氏菌菌株的异质性。检测到了具有潜在致病性的菌株以及可能是鼻腔微生物群共生成员的菌株。然而，莫拉氏菌在猪病和健康中的作用仍需进一步评估。
