CONDITIONS OF CLINICAL SYMPTOMS AND LIFE OF VANAME SHRIMP IN PREVENTION OF Vibrio alginolyticus INFECTION USING MIANA LEAF EXTRACT

This study aims to determine the clinical symptoms and survival of white vaname shrimp in the prevention of Vibrio alginolyticus infection using miana leaf extract. The study consisted of 4 treatments and 3 replications. The treatments in this study were 1 treatment and 3 treatments using different concentrations of bacteria, namely 103 CFU/ml, 105 CFU/ml, and 107 CFU/ml. The research was carried out in June-July 2020 at the Hatchery Laboratory of the Faculty of Marine and Fisheries Sciences, Hasanuddin University. Data analysis used descriptive analysis and analysis of variance (ANOVA). The results showed that A (control) shrimp was under normal conditions, treatment B (103 CFU/ml) was red, treated C (105 CFU/ml) was red and had necrosis of the body, and treatment D (107 CFU/ml) was shrimp. reddening, necrosis of tail and body segments. The results of data analysis showed that the use of miana leaf extract had a significant effect (p<0.05) on the use of live vaname shrimp. The highest vaname shrimp survival was treatment A (control) at 100%, treatment B (103 CFU/ml) at 90%, treatment C (105 CFU/ml) at 63.33% and treatment D (107 CFU/ml) by 40%.

Characteristic and Otopathogenic Analysis of a Vibrio alginolyticus Strain Responsible for Chronic Otitis Externa in China

Vibrio alginolyticus, a Gram-negative rod bacterium found in marine environments, is known to cause opportunistic infections in humans, including ear infections, which can be difficult to diagnose. We investigated the microbiological and otopathogenic characteristics of a V. alginolyticus strain isolated from an ear exudate specimen obtained from a patient with chronic otitis externa to provide a basis for the future diagnosis of V. alginolyticus-associated infections. The identification of V. alginolyticus was accomplished using a combination of matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS), classical biochemical identification methods, and the use of Vibrio-selective media and advanced molecular identification methodologies. Antimicrobial susceptibility testing revealed that the strain was resistant to ampicillin and sensitive to β-lactam, aminoglycosides, fluoroquinolones, and sulfonamide antibiotics. The potential otopathogenic effects of V. alginolyticus were determined through the performance of cell viability, cell apoptosis, and cell death assays in tympanic membrane (TM) keratinocytes and HEI-OC1 cells treated with V. alginolyticus-conditioned medium using cell-counting kit (CCK)-8 assay, a wound-healing migration assay, Annexin V/propidium iodide (PI) flow cytometric analysis, and terminal deoxynucleotidyl transferase deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL staining). The results indicated that the identified V. alginolyticus strain exerts cytotoxic effects on keratinocytes and HEI-OC1 cells by inhibiting cell proliferation and migration and inducing apoptosis and cell death. To evaluate the ototoxicity of V. alginolyticus, the cell density and morphological integrity of hair cells (HCs) and spiral ganglion neurons (SGNs) were analyzed after exposing cochlear organotypic explants to the bacterial supernatant, which revealed the pre-dominant susceptibility and vulnerability of HCs and SGNs in the basal cochlear region to the ototoxic insults exerted by V. alginolyticus. Our investigation highlights the challenges associated with the identification and characteristic analysis of the Vibrio strain isolated in this case and ultimately aims to increase the understanding and awareness of clinicians and microbiologists for the improved diagnosis of V. alginolyticus-associated ear infections and the recognition of its potential otopathogenic and ototoxic effects.

CsrA Regulates Swarming Motility and Carbohydrate and Amino Acid Metabolism in Vibrio alginolyticus

Vibrio alginolyticus, like other vibrio species, is a widely distributed marine bacterium that is able to outcompete other species in variable niches where diverse organic matters are supplied. However, it remains unclear how these cells sense and adjust metabolic flux in response to the changing environment. CsrA is a conserved RNA-binding protein that modulates critical cellular processes such as growth ability, central metabolism, virulence, and the stress response in gamma-proteobacteria. Here, we first characterize the csrA homolog in V. alginolyticus. The results show that CsrA activates swarming but not swimming motility, possibly by enhancing the expression of lateral flagellar associated genes. It is also revealed that CsrA modulates the carbon and nitrogen metabolism of V. alginolyticus, as evidenced by a change in the growth kinetics of various carbon and nitrogen sources when CsrA is altered. Quantitative RT-PCR shows that the transcripts of the genes encoding key enzymes involved in the TCA cycle and amino acid metabolism change significantly, which is probably due to the variation in mRNA stability given by CsrA binding. This may suggest that CsrA plays an important role in sensing and responding to environmental changes.

Vibrio alginolyticus in marine foods of animal origin from establishments in the port of Chabihau, Yucatan, Mexico

To determine if the marine foods of animal origin that are sold in establishments in the port of Chabihau, Yucatan, Mexico, represent potential risk factors for the Vibrio alginolyticus species for the development of acute gastroenteritis, wound infection, ear infection and primary septicemia. Three hundred and ninety seafood samples were studied: [298 (76.41%) raw, 8 (2.05%) marinated without heat, 77 (19.74%) partially cooked with heat and 7 (1.79%) completely cooked with heat]. For the homogenization and enrichment of the samples, as well as for the isolation and identification of the Vibrio alginolyticus species, we proceeded according to the methodology described in the eighth edition of the Bacteriological Analytical Manual (FDA). The criteria used in conducting the hypothesis tests for the difference between two percentages was based on the recommendations made by Cochran. The prevalences obtained in raw seafood, marinated without heat, partially cooked with heat and completely cooked with heat were, respectively, 7.72% (23/298), 0.00% (0/8), 7.79% (6/77) and 0.00% (0/7). In 29 (7.44%) samples an equal number of strains were isolated whose biochemical characteristics corresponded to the Vibrio alginolyticus species. It is concluded that raw seafood and partially cooked seafood represent potential risk factors for the Vibrio alginolyticus species for the development of acute gastroenteritis, wound infection, ear infection and primary septicemia.