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Vibrio alginolyticus is one of the most serious causative agents of diseases in cultured marine fish and shellfish. However, the characteristics of virulence factors in pathogenic V. alginolyticus are poorly known. To gain insight into fish diseases caused by V. alginolyticus, we carried out two‐dimensional gel electrophoresis (2‐DE) combined with MALDI‐TOF mass spectrometry to identify uniquely expressed proteins in the disease‐causing V. alginolyticus. V. alginolyticus strains were isolated from marine environments and diseased fish obtained from southern Thailand. We identified seven unique proteins in the disease‐causing V. alginolyticus strain. Among those, the outer membrane protein A (OmpA) had the strongest expression. Therefore, the function of this protein was further analysed. To investigate the role of OmpA protein, an in‐frame deletion mutant of ompA was constructed using the homologous recombination method. Although the ompA mutant V. alginolyticus strain (ΔompA) grew normally, the mutant exhibited a significant defect in the swarming ability and the biofilm formation. Furthermore, Galleria mellonella larvae injected with the mutant bacteria had a significantly greater survival percentage than those injected with the wild‐type strain, demonstrating that OmpA protein is required for the pathogenicity of V. alginolyticus. Together, this study suggests a potential target for vaccine development against pathogenic V. alginolyticus strain. [ABSTRACT FROM AUTHOR]

Canine mammary tumours (CMTs) are regarded as invasive with a high rate of recurrent and metastasis in intact female dogs. Tumour diagnosis, therefore, is an important step in predicting and monitoring tumour progression. This study was designed to identify protein expression on CMTs by employing a proteomic approach. The primary cell culture from benign mixed tumour, simple carcinoma, complex carcinoma and normal mammary gland were established, and two-dimensional electrophoresis (2DE) was subsequently performed. The different spots on each sample type were collected for identification using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results indicated that cytokeratin 5 (CK5) and transketolase (TKT) were identified in benign mixed tumour cells and complex carcinoma cells. In contrast, cytokeratin 18 (CK18) and pyruvate kinase PKM were identified in simple carcinoma cells. Moreover, alpha-2-HS-glycoprotein tumour antigen was identified specifically in complex carcinoma cells. In addition, ATP-dependent 6-phosphofructokinase platelet type and elongation factor 2 proteins were observed in benign cells. In conclusion, all expressed proteins in this study have been recognized for acting as their expression that differs from healthy mammary epithelial cells. Expectantly, this study identified the expressed proteins that might be useful in further diagnostic biomarker studies on CMTs., (© 2020 John Wiley & Sons Ltd.)