Anti-luminous Vibrio factors associated with the ‘green water’ grow-out culture of the tiger shrimp Penaeus monodon

Lio-Po, Gilda D.; Leaño, Eduardo M.; Peñaranda, Ma. Michelle D.; Villa-Franco, Annie U.; Sombito, Christopher D.; Guanzon, Nicholas G., Jr.

doi:10.1016/j.aquaculture.2005.01.029

Mycoflora of the 'green water' culture system of tiger shrimp Penaeus monodon Fabricius

Leaño, Eduardo M.; Lio-Po, Gilda D.; Nadong, Lorena A.; Tirado, Analyn C.; Sadaba, Resurreccion B.; Guanzon, Nicolas G. (Blackwell Publishing Ltd, 2005)

This study was conducted to quantify and characterize the mycoflora associated with the ‘green water’ culture system of Penaeus monodon. Samples of water, tilapia gut and mucus, and shrimp hepatopancreas from three shrimp farms were collected during 15, 30, 45 and 60 days of culture (DOC). Results showed that high fungal loads were observed in tilapia gut (total: 117–1352 colony forming unit (CFU) 5 cm hind gut−1; yeasts: 0–136 CFU 5 cm hind gut−1) and mucus (total: 12–311 CFU (5 cm2)−1; yeasts: 0–88 CFU (5 cm2)−1), while minimal fungal populations were observed in water samples (total: 0–110CFU mL−1; yeasts: 0–5 CFU ml−1). Shrimp hepatopancreas harboured a very low number of filamentous fungi (0–27 CFU 0.1 g−1) and yeasts (0–7CFU 0.1 g−1) especially at 60 DOC. The filamentous fungal isolates were dominated by Penicillium and Aspergillus species, while the yeast populations were dominated by Rhodotorula and Saccharomyces species. The dominance of these fungi on tilapia mucus and gut and their presence in the rearing water might play an important role in the overall mechanisms involved in the control of luminous Vibrio in the ‘green water’ grow-out culture of P. monodon.

Antibacterial metabolites in the microbial and phytoplankton flora of the "green water" culture of shrimp (Penaeus monodon): Part I. Anti-luminous vibrio factors associated with the "green water" grow-out culture of shrimp (Penaeus monodon)

Lio-Po, Gilda D.; Leaño, Eduardo M.; Peñaranda, Ma. Michelle D.; Franco, Annie; Sombito, Christopher D.; Guanzon Jr., Nicholas G. (Aquaculture Department, Southeast Asian Fisheries Development Center, 2005-03)

The ability of the “green water” grow-out culture of black tiger shrimp (Penaeus monodon) to prevent outbreaks of luminous vibriosis was investigated by screening associated isolates of bacteria, fungi, phytoplankton and fish skin mucus for anti-luminous Vibrio metabolites. Among the 87 bacterial isolates tested, 62 (71%) caused inhibition (+~+++) of the pathogen after 24-48 hr co-cultivation. The variation in growth inhibition rates of +, ++, and +++ were demonstrated by 14 (16%), 13 (15%), and 28 (32%) isolates, respectively, 24 hr after treatment. Eight bacterial isolates showed consistently sustained maximum inhibition (+++/+++) of luminous Vibrio after 24-48 hr exposure. Majority of these luminous Vibrio inhibiting bacterial isolates were obtained from tilapia mucus and gut. In tests with fungi, 4 of 20 (20%) yeast isolates showed intracellular metabolites inhibitory to luminous Vibrio. Among filamentous fungi, 5 of 45 (11%) isolates yielded intracellular metabolites while 3 of 41 (7%) isolates had extracellular metabolites inhibitory to luminous Vibrio. These fungal isolates were identified as Rhodotorula sp., Saccharomyces sp., Candida sp., Penicillium sp., mycelia sterilia and two unidentified species. The microalgae, Chaetoceros calcitrans and Nitzchia sp. consistently demonstrated complete inhibition of luminous Vibrio from 24 and 48 hr post-exposure, respectively, and during the 7 day experiment. Leptolyngbia sp. caused a 94-100% reduction of the luminous Vibrio population from 10⁴ to 10¹ cfu/mL 24 hr post-exposure which was sustained throughout the 10-day observation period. In contrast, the inhibitory effects of Skeletonema costatum on luminous Vibrio was bacteriostatic throughout the 7 days exposure while Nannochlorum sp. did not significantly inhibit luminous Vibrio. The skin mucus of jewel tilapia Tilapia hornorum had no resident luminous bacteria and inhibited this bacterial pathogen in 6-48 hr proportionate to the 10³ and 10⁵ cfu/mL test concentrations of luminous Vibrio. This study provides scientific explanation that the effectivity of the “green water” culture of tiger shrimp in preventing outbreaks of luminous vibriosis among P. monodon juveniles in grow-out ponds can be attributed to the presence of anti-luminous Vibrio factors in the bacterial, fungal, phytoplankton flora and the skin mucus of tilapia associated with this novel technique of shrimp culture.

Studies on the efficacy of Sarafin® (sarafloxacin hydrochloride) on vibrios associated with vibriosis in black tiger shrimp (Penaeus monodon)

Pakingking, Rolando V., Jr.

; Lacierda, Erlinda; Torres, James L. (Fish Health Section, Asian Fisheries Society, 2002)

In vitro activity of Sarafin® (sarafloxacin hydrochloride) was determined against 7 luminous Vibrio harveyi isolates and 3 non-luminous Vibrio species (V. parahaemolyticus, V. alginolyticus and Vibrio species) isolated from diseased shrimp (Penaeus monodon) and rearing water, a strain of V. anguillarum from diseased marine fish, 1 strain each of V. alginolyticus, V. vulnificus, and V. mimicus from diseased grouper (Epinephelus coioides), and V. alginolyticus from diseased seabass (Lates calcarifer). Bacterial susceptibility was expressed as minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The MIC and MBC values obtained for all V. harveyi isolates ranged from <0.3 to 1.25 µg/ml. For the non-luminous Vibrio species, MIC and MBC values ranged from <0.08 to 1.25 µg/ml. In vivo tolerance levels (24 h static bioassay) of larval and postlarval stages of P. monodon for Sarafin® were <10 µg/ml for nauplii, mysis, and postlarvae and ≤1 µg/ml for zoeae. Morphological deformities in the carapace, rostrum, and setae were noted among larvae exposed to >50 µg/ml Sarafin®. These results indicate that Sarafin® is a potential candidate as a chemotherapeutic agent against luminous vibriosis in P. monodon.