ABSTRACT
Aims@#The occurrence of bacterial disease in shrimp ponds is a major problem faced in shrimp farming. Thus, the aims of this study were to isolate and evaluate antibiotic resistant profile of Vibrio harveyi strain isolated from shrimp pond water, as well as to study the potential anti-Vibrio activity of Combretum quadrangulare Kurz. (CQ) and Mimosa pudica (MP) leaves extracts.@*Methodology and results@#Vibrio harveyi WSC103 was isolated from water in white shrimp (Litopenaeus vannamei) culture pond and identified using 16S rRNA gene sequencing analysis. This strain showed characteristics of multidrug-resistant (7 antibiotics). It had become more sensitive to antibiotics (9 out of 10 antibiotics) after plasmid curing. It is showed CQ and MP leaves extracts contain potent bioactive compounds (tannins, flavonoids, steroids, cardiac glycosides and alkaloids) against V. harveyi WSC103. The aqueous, 95% ethanolic and 75% acetone extracts of CQ (MIC value of 3.13-12.50 mg/mL) and MP (MIC value of 3.13-25.00 mg/mL) leaves revealed strong vibriostatic activity, but aqueous and 95% ethanolic extracts in both plants showed vibriocidal activity. The 95% ethanolic extract of both CQ and MP leaves displayed the excellent vibriocidal property with MBC value of 100 mg/mL with zone of inhibition at 11.44 ± 1.01 and 11.78 ± 1.01 mm by agar disc diffusion.@*Conclusion, significance and impact of study@#The isolated Vibrio harveyi WSC103 was successfully characterized as a novel multidrug-resistant strain. The ethanolic C. quadrangulare Kurz. and M. pudica extracts exhibited prominent vibriostatic and vibriocidal capacities. These finding is proven that C. quadrangulare Kurz. and M. pudica extracts would be an alternative anti-Vibrio agent for aquaculture infectious treatment.
Subject(s)
Vibrionaceae , Gram-Negative Bacteria , Combretum , MimosaABSTRACT
Objective: This study was aimed to isolate and screen marine sponge-associated bacteria producing anti-Vibrio compounds and to identify their compounds from the bacterial extract. Methods: Sponge-associated bacteria were isolated by spread plate method. Their anti-Vibrio activity against Vibrio parahaemolyticus, V. harveyi, and V. vulnificus was determined by dual culture test. Three potential isolates were identified based on 16S-rRNA gene analysis. All isolates producing anti-Vibrio compounds was tested for their haemolytic characters in blood agar medium. Anti-Vibrio activity of the most potential isolate was also tested by using its supernatant, extract, and concentrated culture. Chemical composition of crude extract derived from that isolate was identified by GC-MS analysis. Results: 68 bacterial isolates have been isolated from the marine sponge, Spongia sp., Svenzea sp., Ircinia sp., and Igernella sp. Of 68 isolates, 15 (22%) isolates had anti-Vibrio activities in various spectra against three Vibrio species, including V. harveyi, V. parahaemolyticus, and V. vulnificus. All isolates producing anti-Vibrio compounds were non-haemolytic. Bacterial isolates coded as D6.6, D6.19, and P4.17 have broad spectra. They could inhibit at least two Vibrio species as indicated by the clear zone formed around bacterial colonies. Based on 16S-rRNA, these isolates were closely related (similarity ≥ 99%) to Brevibacterium casei strain M Sw oHS, Bacillus altitudinis strain FJAT 47750, and Bacillus altitudinis strain PgBe190, respectively. D6.6 isolate was the most potential isolate, which could inhibit three Vibrio species. Consistently, its anti-Vibrio activity also confirmed by their supernatant, concentrated culture, and crude extract of that isolate. The crude extract derived from this isolate contained 10 major compounds that are biologically active. Conclusion: This study suggests that 15 bacteria strains isolated from marine sponges were potentially could inhibit Vibrio’s growth in vitro. These isolate could be further explored as anti-Vibrio agent.
ABSTRACT
Se determino la frecuencia de anticuerpos anti Vibrio parahaemolyticus en diversas poblaciones de sujetos asintomaticos seleccionados basandose en la ocupacion que desempenaban. Se emplearon para tal efecto dos metodos de aglutinacion que difieren solamente la forma de preparar el antigeno el metodo del antigeno "vivo" y el antigeno "muerto". La especificidad de la prueba se demostro al descartar la reactividad de cruzada de Vibrio parahaemolyticus con las enterobacterias mas comunes. De 100 personas encargadas de expender alimentos al publico se encontro que 17 tenian anticuerpos sericos para el germen. Diez personas de esta poblacion tenian mayor contacto con productos derivados del mar, demostrandose anticuerpos en cinco de ellas; asociacion que es significativa desde el punto de vista estadistico. Finalmente, se encontro en la poblacion general una frecuencia de 16.5% de sujetos con anticuerposnti Vibrio parahaemolyticus.Estos datos indican que las infecciones por Vibrio parahaemolyticus en nuestro medio mas aun entre personas manejadoras de alimentos procedentes del mar