Artemia Franciscana Nauplii Research Articles

An Electrolytically Prepared Colloidal Silver Preparation Protects against Citrate-induced Toxicity in Artemia franciscana Nauplii

An Electrolytically Prepared Colloidal Silver Preparation Protects against Citrate-induced Toxicity in Artemia franciscana Nauplii

Synergistic, antagonistic, and additive effects of naphthalene, phenanthrene, fluoranthene and benzo(k)fluoranthene on Artemia franciscana nauplii and adult

Polycyclic aromatic hydrocarbons (PAHs) are widespread across the globe and can be highly toxic for the marine environment. This research investigated the short-term (48 h of exposure) effects of PAHs mixtures on the nauplii and adult of crustacean Artemia franciscana considering the impact in term of toxicity and changes in gene expression. Results showed that all combinations caused additive or synergic effects with the exception of naphthalene + phenanthrene (NAP + PHE; Combination Index (CI) = 22.3), while naphthalene + benzo(k)fluoranthene (NAP + BkF; CI = 7.8) mixture evidenced an antagonistic effect. Real-time qPCR showed that all mixtures impacted the expression level of the five known genes involved in Artemia stress response. The effects of PAHs at environmental concentrations on both adult and nauplii suggested the need for further investigations about the impact of such contaminants on the marine biota considering that crustaceans can accumulate PAHs at concentrations comparable to those assessed in the present study.

Toxicity Evaluation of Iodine Disinfectant Inclusion on Mortality and Growth of Artemia franciscana Nauplii

Artemia franciscana nauplii is a source of nutrients and pathogen vectors due to the non-selective nature of the filter feeder. Prevention of pathogens is done by adding iodine disinfectant to suppress the emergence of bacteria. One way to find out if a substance is toxic is by testing the toxicity and lethal concentration (LC50) on A. franciscana nauplii. The aim of this study was to evaluate the disinfectant effect of iodine and determine the lethal concentration of iodine in 50% of A. franciscana nauplii (LC50). Brine Shrimp Lethality Test (BSLT) method using Artemia as test animal. The results of the toxicity test with several doses of iodine showed that the toxic threshold value for 96 hours was 20.31 ppm. The results were supported by the presence of stunted growth at a dose of 100 ppm by measuring the length and weight. The conclusion of this study is that the administration of iodine at several concentrations is toxic to A. franciscana nauplii if it exceeds 20.31 ppm and affects the growth of A. franciscana nauplii.

Calibration of an acute toxicity model for the marine crustacean, Artemia franciscana, nauplii to support oil spill effect assessments

Oil spill risk and impact assessments rely on time-dependent toxicity models to predict the hazard of the constituents that comprise crude oils and petroleum substances. Dissolved aromatic compounds (ACs) are recognized as a primary driver of aquatic toxicity in surface spill exposure scenarios. However, limited time-dependent toxicity data are available for different classes of ACs to calibrate such models. This study examined the acute toxicity of 14 ACs and 3 binary AC mixtures on Artemia franciscana nauplii at 25 °C. Toxicity tests for 3 ACs were also conducted at 15 °C to evaluate the role of temperature on toxicity. The ACs investigated represented parent and alkylated homocyclic and nitrogen-, sulfur- and oxygen-containing heterocyclic structures with octanol-water partition coefficients (log Kow) ranging from 3.2 to 6.6. Passive dosing was used to expose and maintain concentrations in toxicity tests which were confirmed using fluorometry, and independently validated for 6 ACs using GC–MS analysis. Mortality was assessed at 6, 24, and 48 h to characterize the time course of toxicity. No mortality was observed for the most hydrophobic AC tested, 7,12-dimethylbenz[a]anthracene, due to apparent water solubility constraints. Empirical log LC50 s for the remaining ACs were fit to a linear regression with log Kow to derive a critical target lipid body burden (CTLBB) based on the target lipid model. The calculated 48 h CTLBB of 47.1 ± 8.1 μmol/g octanol indicates that Artemia nauplii exhibited comparable sensitivity to other crustaceans. A steep concentration-response was found across all compounds as evidenced by a narrow range (1.0–3.1) in the observed LC50 /LC10 ratio. Differences in toxicokinetics were noted, and no impacts of temperature-dependence of AC toxicity were found. Toxicity data obtained for individual ACs yielded acceptable predictions of observed binary AC mixture toxicity. Results from this study advance toxicity models used in oil spill assessments.

Effect of diet composition and temperature on the gastric evacuation rate of European sardine: implication for egg predation estimates

Cannibalism and intraguild predation of fish eggs are frequently observed for small and medium pelagic fish and can be an important cause of natural mortality. The European sardine Sardina pilchardus is the major predator of pelagic fish eggs in Atlantic Iberian waters. Estimates of egg mortality due to predation rely on a number of parameters that are frequently unknown for most species, such as gastric evacuation rate (GER) and feeding periodicity, and rates obtained for other fish species are generally used. These assumptions can severely affect egg mortality estimates. We conducted laboratory experiments to estimate the GER of European sardine that were fed diets composed of different proportions of fish eggs and other food types, such as Artemia franciscana nauplii, Brachionus plicatilis and microalgae, at different temperatures experienced by sardine in the wild (15, 17 and 21°C). Temperature, predator size and sex did not influence the gastric rates. Prey type significantly affected the GER of sardines, with slower evacuation when offered diets containing a higher concentration of fish eggs rather than microalgae, rotifers and Artemia nauplii. Fish eggs are more nutritionally rich compared to microalgae, rotifers and Artemia nauplii, and therefore more difficult to digest. GERs obtained here for S. pilchardus were similar to those obtained for Sardinops sagax in South Africa. This study provides important information that allows for improving estimates of daily feeding rates and egg mortality by predation, thus increasing our understanding of small pelagic fish population dynamics.

Genotoxicity Set Up in Artemia franciscana Nauplii and Adults Exposed to Phenanthrene, Naphthalene, Fluoranthene, and Benzo(k)fluoranthene

Polycyclic aromatic hydrocarbons (PAHs) consist of a group of over 100 different organic compounds mainly generated by anthropogenic activities. Because of their low water solubility, they tend to be accumulated in sediment, where their degradation rate is very low. Few studies have been carried out so far to investigate the effects of PAHs on Artemia franciscana. Artemia is easy to manage at laboratory scale, but it is not a sensitive biological model considering the traditional endpoints (i.e., mortality). In addition to evaluating the lethality on nauplii and adults of A. franciscana after 24 and 48 h, we focused on the genotoxicity to investigate the potential effects of phenanthrene (PHE), naphthalene (NAP), fluoranthene (FLT), and benzo(k)fluoranthene (BkF). Results showed that FLT was the most toxic both for nauplii and adults after 48 h of exposure. Real-time qPCR showed that all toxicants, including BkF, which had no negative effects on the survival of the crustacean, were able to switch the gene expression of all nine genes. This work has important ecological implications, especially on contaminated sediment assessment considering that PAHs represent the most abundant organic group of compounds in marine environment, opening new perspectives in understanding the molecular pathways activated by crustaceans.

RNA interference of Hsp70 in Artemia franciscana nauplii and its effect on morphology, growth, survival and immune response

Brine shrimp Artemia franciscana release either encysted embryos via oviparous reproduction or motile nauplii via ovoviviparous reproduction. Artemia cysts contain an abundant amount of ArHsp21, ArHsp22, artemin, and p26, small heat shock proteins which regulate diapause and stress tolerance of this branchiopod crustacean. However, not much is known of the role of molecular chaperone, Hsp70 in this animal. In this study, the immunostimulatory role of Hsp70 in A. franciscana was investigated, work which included examining the function of this protein in embryo development, growth, survival and stress tolerance. Knockdown of Hsp70 was successfully performed by RNA interference (RNAi), with specific Hsp70 dsRNA construct delivered to female broods by microinjection to knockdown the protein in nauplii. The loss of Hsp70 neither affected the growth nor morphology as Artemia nauplii hatched normally and thereafter grew to adult within 28 days, observations similar to the control animals, the latter injected with GFP dsRNA. The survival of nauplii lacking Hsp70 appeared lower upon 28 days culture but the differences were insignificant when comparisons were made with the controls (P > .05). On other aspect, knockdown of Hsp70 reduced approximately 31% survival upon Vibrio campbellii challenge, indicating that Hsp70 assisted in the tolerance of Artemia nauplii during pathogen infection, perhaps through immune stimulation. Initial findings revealed that Hsp70 knockdown did not affect the expression of prophenoloxidase (proPO), a crucial immune protein of the shrimp innate immunity. By examining the morphology, growth, viability and molecular changes upon Hsp70 elimination, this study contributes to our understanding of the important roles of Hsp70 in A. franciscana, an important live food species used in aquaculture.

Effect of Streptomyces sp. RL8 on the survival of Artemia franciscana nauplii and resistance to Vibrio parahaemolyticus

Artemia franciscana nauplii were enriched with Streptomyces sp. RL8 in order to assess its effect on the survival rate of Artemia and its protective effects against Vibrio parahaemolyticus infection. Streptomyces sp. RL8 showed antagonistic activity against the opportunistic pathogenic Vibrio species of interest for aquaculture and decreased the growth of V. parahaemolyticus Collection of Aquatic Important Microorganisms (CAIM) 170 during in vitro co-culture experiments. Two experimental groups of nauplii, each replicated three times, were enriched with strain Streptomyces sp. RL8 at 106 and 108 colony-forming units (CFU)/ml; an unfed group served as the control. The experimental groups were challenged 24 h post-feeding with the strain V. parahaemolyticus CAIM 170 at 105 and 107 CFU/ml, and the survival of A. franciscana recorded at 24 and 48 h post-inoculation. Nauplii survival was significantly higher (88.75% and 86.25%) in the groups treated with Streptomyces sp. RL8 at 106 and 108 CFU/ml than in the control group (70.71%). These results confirm the probiotic properties of Streptomyces sp. RL8 and suggest that A. franciscana enriched with this strain can be fed to fish and shrimp larvae.

Efficacy assessment of commercially available natural products and antibiotics, commonly used for mitigation of pathogenic Vibrio outbreaks in Ecuadorian Penaeus (Litopenaeus) vannamei hatcheries

Bacterial diseases cause high mortality in Penaeus (Litopenaeus) vannamei postlarvae. Therefore, appropriate application of efficient therapeutic products is of vital importance for disease control. This study evaluated through in vitro analyses the antimicrobial effectiveness of commercial therapeutic products used for P. vannamei bacterial diseases and antibiotics against pathogenic Vibrio strains circulating in Ecuadorian hatcheries. Twenty strains were isolated from 31 larvae samples with high bacterial counts from 10 hatcheries collected during mortality events. The strains virulence was verified through challenge tests with Artemia franciscana nauplii and P. vannamei postlarvae. Through 16S rRNA sequence analysis, strains showed a great similarity to the Vibrio sequences reported as pathogens, with 95% belonging to the Harveyi clade. Through antibiograms and minimal inhibitory concentration (MIC) in vitro tests we found that furazolidone, ciprofloxacin, chloramphenicol, norfloxacin, nalidixic acid, florfenicol, fosfomycin and enrofloxacin inhibited the growth of all or most of the strains. Less efficient antibiotics were penicillin, oxytetracycline and tetracycline. A multiple antibiotic resistance (MAR) index of 0.23 showed some level of resistance to antibiotics, with two MAR prevalent patterns (Penicillin-Oxytetracycline and Penicillin-Oxytetracycline-Tetracycline). From a total of 16 natural products (five probiotics, nine organic acids and two essential oils), only three (one probiotic, one organic acid and one essential oil) were effective to control most of the strains. Shrimp producers can apply relatively simple in vitro analyses, such as those employed in this study, to help take adequate management decisions to reduce the impact of bacterial diseases and increase profit.

The 9H-Fluoren Vinyl Ether Derivative SAM461 Inhibits Bacterial Luciferase Activity and Protects Artemia franciscana From Luminescent Vibriosis.

Vibrio campbellii is a major pathogen in aquaculture. It is a causative agent of the so-called “luminescent vibriosis,” a life-threatening condition caused by bioluminescent Vibrio spp. that often involves mass mortality of farmed shrimps. The emergence of multidrug resistant Vibrio strains raises a concern and poses a challenge for the treatment of this infection in the coming years. Inhibition of bacterial cell-to-cell communication or quorum sensing (QS) has been proposed as an alternative to antibiotic therapies. Aiming to identify novel QS disruptors, the 9H-fluroen-9yl vinyl ether derivative SAM461 was found to thwart V. campbellii bioluminescence, a QS-regulated phenotype. Phenotypic and gene expression analyses revealed, however, that the mode of action of SAM461 was unrelated to QS inhibition. Further evaluation with purified Vibrio fischeri and NanoLuc luciferases revealed enzymatic inhibition at micromolar concentrations. In silico analysis by molecular docking suggested binding of SAM461 in the active site cavities of both luciferase enzymes. Subsequent in vivo testing of SAM461 with gnotobiotic Artemia franciscana nauplii demonstrated naupliar protection against V. campbellii infection at low micromolar concentrations. Taken together, these findings suggest that suppression of luciferase activity could constitute a novel paradigm in the development of alternative anti-infective chemotherapies against luminescent vibriosis, and pave the ground for the chemical synthesis and biological characterization of derivatives with promising antimicrobial prospects.

Printable nanocomposites of polymers and silver nanoparticles for antibacterial devices produced by DoD technology.

Silver nanoparticles (Ag-NPs) are known for their efficient bactericidal activity and are widely used in industry. This study aims to produce printable antibacterial devices by drop-on-demand (DoD) inkjet technology, using Ag-NPs as the active part in complex printable fluids. The synthesis of this active part is described using two methods to obtain monodisperse NPs: chemical and microwave irradiation. The synthesized NPs were characterized by UV-VIS, STEM, TEM, DLS and XRD. Two printable fluids were produced based: one with Ag-NPs and a second one, a polymeric nanocomposite, using silver nanoparticles and polyvinyl butyral (Ag-NPs/PVB). Cellulose acetate was used as a flexible substrate. The ecotoxicity analysis of fluids and substrate was performed with Artemia franciscana nauplii. Optimized electric pulse waveforms for drop formation of the functional fluids were obtained for the piezoelectric-based DoD printing. Activity of printed antibacterial devices was evaluated using the Kirby-Bauer method with Staphylococcus aureus and Escherichia coli. The results show that the printed device with Ag-NP fluids evidenced a bacterial inhibition. An important advantage in using the DoD process is the possibility of printing, layer by layer or side by side, more than one active principle, allowing an interleaved or simultaneous release of silver NP and other molecules of interest as for example with a second functional fluid to ensure effectiveness of Ag activity.

Toxicity Assessment of Nephrolepis exaltata (L.) Schott, Fam. Nephrolepidaceae

Abstract The fern Nephrolepis exaltata (L.) Schott, fam. Nephrolepidaceae, has little traditional medicinal use. In order to estimate its potential safety, in the present study we have investigated the phytotoxicity (on Triticum aestivum L.) and toxicity on brine shrimp of extracts from plants grown hydroponically. The species identity was confirmed by macroscopic and microscopic examinations on rhizomes, rachises, pinnae and runners, using bright field and fluorescent microscopy. Biological assays were performed on aqueous and ethanol solutions of the fronds. The brine shrimp lethality assay was performed on Artemia franciscana Kellog and a phytobiological bioassay on Triticum aestivum L. Lethality, root elongation and karyokinetic film modifications were evaluated, and LC50 and IC50 values were calculated. The microscopic analysis revealed the main histo-anatomic elements: polystelic structure and hypodermis (rhizome, rachis, runners), trichomes (rachis), homogenous structure, trichomes and diacytic/anisocytic stomata (leaves). The ethanol and aqueous extracts showed low cytotoxic effects on both Triticum aestivum roots and Artemia franciscana nauplii.

Effect of Food Enrichment on the Survival of Hippocampus Ingens Girard, 1858 Alevine under Semicontroled Conditions

Due to the decline in seahorse populations generated by exploitation and degradation of their habitat, an attempt has been made to obtain the closed cycle of cultivation of different species of the genus, includingH. ingens, the unique specie located in the Eastern Pacific. In the majority of the studies carried out, the mainlimitation has been the provision of a diet that supplies an adequate growth and survival of the organisms. The objective of this research was to determine the effect of nutritional enrichment of Brachionus plicatilis and Artemiafranciscana, used as food in the survival of H. ingens. Fifteen specimens of wild adult seahorses were capturedin Bahía de La Paz, and generated four couples and 17 successful batches. To assess the enrichment from thethird to the seventh day, each batch was divided into six groups and placed in 60-liter aquaria, feeding on rotifersmaintained with six different treatments. Three Artemia franciscana nauplii enrichment treatments were thentested to evaluate the effect on the survival of the juveniles in the period from day eight to day 60. From day 61and on seahorses were fed with adult Artemia franciscana also enriched with the three different treatments. Theseresults show that the enrichment of the food offered in the first months of life of seahorses has a significant effecton their survival.

Alternative mitochondrial respiratory chains from two crustaceans: Artemia franciscana nauplii and the white shrimp, Litopenaeus vannamei

Mitochondrial ATP is synthesized by coupling between the electron transport chain and complex V. In contrast, physiological uncoupling of these processes allows mitochondria to consume oxygen at high rates without ATP synthesis. Such uncoupling mechanisms prevent reactive oxygen species overproduction. One of these mechanisms are the alternative redox enzymes from the mitochondrial respiratory chain, which may help cells to maintain homeostasis under stress independently of ATP synthesis. To date, no reports have been published on alternative redox enzymes in crustaceans mitochondria. Specific inhibitors were used to identify alternative redox enzymes in mitochondria isolated from Artemia franciscana nauplii, and the white shrimp, Litopenaeus vannamei. We report the presence of two alternative redox enzymes in the respiratory chain of A. franciscana nauplii, whose isolated mitochondria used glycerol-3-phosphate as a substrate, suggesting the existence of a glycerol-3-phosphate dehydrogenase. In addition, cyanide and octyl-gallate were necessary to fully inhibit this species' mitochondrial oxygen consumption, suggesting an alternative oxidase is present. The in-gel activity analysis confirmed that additional mitochondrial redox proteins exist in A. franciscana. A mitochondrial glycerol-3-phosphate dehydrogenase oxidase was identified by protein sequencing as part of a branched respiratory chain, and an alternative oxidase was also identified in this species by western blot. These results indicate different adaptive mechanisms from artemia to face environmental challenges related to the changing levels of oxygen concentration in seawater through their life cycles. No alternative redox enzymes were found in shrimp mitochondria, further efforts will determine the existence of an uncoupling mechanism such as uncoupling proteins.

Selective toxicity of hydroxyl-rich carbon nanodots for cancer research

The toxicity of nanoparticles in a biological system is an integration of effects arising from surface functionality, particle size, ionic dissolution, etc. This complexity suggests that generalization of a material’s toxicity may be inappropriate. Moreover, from a medicinal point of view, toxicity can be used for treatment of malignant cells, such as cancer. In this study, highly biocompatible carbon nanodots (gCDs) were synthesized by reacting citric acid and urea in glycerol, which resulted in abundant hydroxyl functional groups on the particle surface. gCDs show excitation-dependent photoluminescence but with bright green to yellow emission. Importantly, a series of toxicity assessments showed that as-synthesized gCDs possessed exceptional biocompatibilities to various biological entities including 18 bacteria species, Petunia axillaris seedlings, and Artemia franciscana nauplii. Furthermore, the particles were shown to have low to no toxic effects on human embryonic kidney (HEK-293), breast (MCF-7), and oral squamous (CAL-27) carcinoma cell lines. Of particular interest, the gCDs displayed antiproliferative activities against ovarian choriocarcinoma cells (JAr/Jeg-3 cell lines), which may be further explored for cancer drug discovery.

Acute toxicity, uptake, and elimination of zinc oxide nanoparticles (ZnO NPs) using saltwater microcrustacean, Artemia franciscana

This study aims to evaluate the potential toxic effects of ZnO nanoparticles on Artemia franciscana nauplii. The ZnO NPs suspension was characterized by TEM, EDS and DLS techniques. Acute toxicity was investigated by exposure of nauplii to concentrations of 1, 5, 7.5, 10, 15, 20, 25 and 30 mg/L of ZnO NPs for 48 h and 96 h. The 96-h EC10 and EC50 values of ZnO NPs were found to be 1.39 mg/L and 4.86 mg/L respectively. The ZnO NPs suspensions did not cause any significant acute toxicity after 48 h of exposure, but the immobilization rate increase significantly compare to control group after 96 h (P < 0.05). The results showed that the uptake, accumulation, and elimination of NPs in nauplii depends on the concentration of NPs and time. The elimination rates of 46.66% and 83.85% were recorded at 1 and 10 mg/L of NPs after 24 h of depuration period, respectively.

First feeding of diploid and triploid yellowtail tetra Astyanax altiparanae: An initial stage for application in laboratory studies

In this study, the aim was to establish a protocol for first feeding of diploid and triploid yellowtail tetra Astyanax altiparanae in laboratory conditions. The fry were fed with five different diets: (i) Artemia franciscana nauplii, (ii) plankton, (iii) dry food, (iv) Artemia franciscana nauplii + plankton, and (v) Artemia nauplii + plankton + dry food. Additionally, the growth and survival rates of diploid and triploid individuals were also evaluated. On day 10, the length of the fish between the treatments differed significantly (p = .0001) and ranged from 4.07 ± 0.06 mm (dry food) to 8.50 ± 0.64 mm (plankton + Artemia). The sizes of the fish increased with time, except for the fish fed with dry food. The survival rates were similar for the fish fed with the four diets and ranged from 80.7 ± 5.4% (dry food + plankton + Artemia to 92.0 ± 1.6% (plankton + Artemia), but differed from the fish fed with dry food (17.7 ± 5.8%, p = .0017). Diploids and triploids did not present differences on day 0 (p = .2252) and on day 10 (p = .4844) when the fish presented 6.77 ± 0.25 mm and 6.54 ± 0.15 mm respectively. Survival of diploids (87.3 ± 5.13%) and triploids (74.67 ± 2.30%) were also similar (p = .0285). These data are innovative and useful for establishing protocols for this species in both academic and applied sciences.

Rhodococcus sp. as probiotic bacteria for increase the survival, growth and coloration of fish Puntius conchonius

An The aim of this study was to evaluate the effect of bacteria Rhodococcus sp. in growth, survival, and coloration of Puntius conchonius. It was obtained a batch of 300 larvae of seven days after hatching and were divided in six aquariums of 60 litters (50 org per aquarium) and fed with Artemia franciscana nauplii, enriched with Rhodococcus sp. at a concentration of 1 x 10 7 cells per milliliter. There was also a control treatment where larvae were only fed with Artemia nauplii without probiotic. Every fifteen days, biometric parameters were obtained such as weight, total length, high, wide. Also, physicochemical parameters were measured like pH, dissolved oxygen, nitrates, nitrites, and ammonium, and it was evaluated the increase in fish coloration following the method for pigment extraction. Feeding period was carried out for 60 days. Survival was 100% in both treatments, but in fish fed with Rhodococcus sp. presented better growth results in total length, wide and weight, than control group. Regarding to fish coloration, variance analysis showed significant differences between treatments (P=0.035), having a better coloration in tissue of fish fed with probiotic, proving that this genus present enormous benefits as it not only improves productive parameters, but also increases coloration of fish; fundamental aspect for ornamental species commercialization.

Yellow-Emitting Carbon Nanodots and Their Flexible and Transparent Films for White LEDs.

We report carbon nanodots that can be utilized as effective color converting phosphors for the production of white light-emitting diodes (LEDs). Blue-excitable and yellow-emitting carbon nanodots, functionalized with 3-(imidazolidin-2-on-1-yl)propylmethyldimethoxysilane (IPMDS)-derived moieties (IS-CDs), are synthesized by a novel one-pot reaction in which the products from the initial reaction occurring between urea and 3-(2-aminoethylamino)propylmethyl-dimethoxysilane (AEPMDS) are further treated with citric acid. Distinctive from the majority of carbon nanodots reported previously, IS-CDs emit at 560 nm, under 460 nm excitation, with a quantum yield of 44%. Preliminary toxicity studies, assessed by the Artemia franciscana nauplii (brine shrimp larvae) bioassay, indicate that IS-CDs are largely nontoxic. Furthermore, the IS-CDs form flexible and transparent films without the need of encapsulating agents, and the solid films retain the optical properties of solvated IS-CDs. These features indicate an immense potential for the IS-CDs as an environmental-friendly, blue-excitable carbon nanodot-based phosphor in solid-state lighting devices.

An examination of the medicinal potential ofPlanchonella queenslandica: toxicity, antibacterial, and antiviral activities

Planchonella queenslandica (family Sapotaceae) is an Australian native plant with a history of indigenous Australian medicinal usage. Its antimicrobial activity was investigated by disc diffusion assays against a bacterial panel. Antiviral activity was determined using an MS2 bacteriophage plaque reduction model system. Toxicity was determined using the Artemia franciscana nauplii bioassay. Methanol, water and ethyl acetate leaf extracts displayed antibacterial activity. The methanol and ethyl acetate extracts had the broadest specificity, inhibiting the growth of 9 of the 14 bacteria tested (64 %) respectively. The water extract inhibited the growth of 6 of the 14 bacteria tested (43 %). All extracts were more effective against Gram-positive than Gram-negative bacteria. The methanol and ethyl acetate extracts each inhibited the growth of 100 % of the Gram-positive species tested and 5 of the 9 (56 %) Gram-negative bacteria. The water extract inhibited 3 of the 4 (75 %) Gram-positive bacteria and 3 of the 9 (33 %) of the Gram-negative bacteria tested. The methanol, water and ethyl acetate extracts also displayed antiviral activity in the MS2 plaque reduction assay, inhibiting 90.8 ± 2.4 %, 50.7 ± 5.8 and 71.7 ± 4.4 % of MS2 plaque formation respectively. All extracts were also shown to be non-toxic or of low toxicity in the Artemia fransiscana bioassay. The low toxicity of the P. queenslandica extracts and their inhibitory bioactivity in the MS2 bacteriophage reduction bioassay and against a panel of bacteria validate Australian Aboriginal usage as an antiseptic agent and confirms their medicinal potential.