Estuarine crustaceans are often exposed to low dissolved O2 (hypoxia) accompanied by elevated CO2... more Estuarine crustaceans are often exposed to low dissolved O2 (hypoxia) accompanied by elevated CO2 (hypercapnia), which lowers water pH. Acclimatory responses to hypoxia have been widely characterized; responses to hypercapnia in combination with hypoxia (hypercapnic hypoxia) are less well known. Here we used oligonucleotide microarrays to characterize changes in global gene expression in the hepatopancreas of Pacific whiteleg shrimp, Litopenaeus vannamei, exposed to hypoxia or hypercapnic hypoxia for 4 or 24 h, compared with time-matched animals held in air-saturated water (normoxia). Unigenes whose expressions were significantly impacted by treatment and/or time were used to build artificial neural networks (ANNs) to identify genes with the greatest sensitivity in pairwise discriminations between treatments at each time point and between times for each treatment. ANN gene sets that discriminated hypoxia or hypercapnic hypoxia from normoxia shared functions of translation, mitochond...
New Zealand Journal of Marine and Freshwater Research, 2003
The prevalence and intensity of metazoan ectoparasites on the skin and gills of kingfish, Seriola... more The prevalence and intensity of metazoan ectoparasites on the skin and gills of kingfish, Seriola lalandi lalandi (Carangidae), collected from White Island (n = 32), Ranfurly Banks (n = 7), and Three Kings Islands (n = 7), is reported. Kingfish were host to two monogenean and four copepod ectoparasite species, Benedenia seriolae, Zeuxapta seriolae, Caligus lalandei, Caligus aesopus, Neobrachiella spp., and Lernanthropus spp., respectively. B. seriolae and C. lalandei infect the skin, whereas the remaining parasites were located on the gills. All parasites exhibited considerable variability in the prevalence and intensity of infection. A few kingfish were completely devoid of C. aesopus, Neobrachiella spp., and/or Lernanthropus spp., whereas others were infected by moderate numbers of these species. However, all kingfish were infected by B. seriolae and Z. seriolae. Therefore, it appears that acclimation of wild kingfish from the east coast of New Zealand's North Island into captivity will lead to the transfer of both B. seriolae and Z. seriolae, and that effective quarantine measures will be required to avoid introducing these parasites into broodstock systems. The site preferences of B. seriolae, Z. seriolae, and C. aesopus were also investigated. B. seriolae exhibited a preference for attachment on the lateral surfaces of the skin behind the dorsal fin, but forward of the anal fin. Z. seriolae displayed a preference for attachment on gill arches 2 and 3, particularly in gill filaments located in the upper regions of the buccal cavity. C. aesopus most commonly occurred on the gill arch.
This study assessed the efficacy of bath administrations of Aqui-S, formalin and praziquantel aga... more This study assessed the efficacy of bath administrations of Aqui-S, formalin and praziquantel against adults and eggs of Benedenia seriolae and Zeuxapta seriolae, two monogenean ectoparasites of kingfish (Seriola lalandi lalandi). Our results showed that 2.5 ppm praziquantel administered for either 24 or 48 h was the most effective treatment for removing B. seriolae (>99%). However, B. seriolae treated with praziquantel for 24 h deposited viable eggs. Formalin at 250 and 400 ppm for 1 h followed by a 5 min freshwater dip was less effective for removing B. seriolae (ca. 80%), but both treatments inhibited the production of eggs by treated parasites. However, a large proportion of B. seriolae eggs exposed to either formalin treatment remained viable. Praziquantel (2.5 ppm for either 24 or 48 h) and formalin (400 ppm for 1 h + 5 min f/w dip) were the most effective treatments for removing Z. seriolae from the gills of kingfish (>99%) but the parasites thus removed continued to deposit viable eggs. Exposure to the anaesthetic Aqui-S did not significantly increase numbers of B. seriolae or Z. seriolae removed from the host above those of the control, but it was ineffective in preventing the production of eggs by treated parasites, and did not reduce egg viability. Eggs of B. seriolae were not prevented from hatching unless exposed to air for a period greater than 3 h, and Z. seriolae eggs were only prevented from hatching if exposed to air for periods greater than 5 h prior to the development of eyespots. These results 0044-8486/$ -see front matter D Aquaculture 236 indicate that both primary and secondary treatments will be required to successfully control B. seriolae and Z. seriolae infections in captive kingfish. D
Bacteriophages (phages) have been utilized for decades as a means for uniquely identifying their ... more Bacteriophages (phages) have been utilized for decades as a means for uniquely identifying their target bacteria. Due to their inherent natural specificity, ease of use, and straightforward production, phage possess a number of desirable attributes which makes them particularly suited as bacterial detectors. As a result, extensive research has been conducted into the development of phage, or phage-derived products to expedite the detection of human pathogens. However, very few phage-based diagnostics have transitioned from the research lab into a clinical diagnostic tool. Herein we review the phage-based platforms that are currently used for the detection of Mycobacterium tuberculosis, Yersinia pestis, Bacillus anthracis and Staphylococcus aureus in the clinical field. We briefly describe the disease, the current diagnostic options, and the role phage diagnostics play in identifying the cause of infection, and determining antibiotic susceptibility.
Genetically modified phages have the potential to detect pathogenic bacteria from clinical, envir... more Genetically modified phages have the potential to detect pathogenic bacteria from clinical, environmental, or food-related sources. Herein we assess an engineered 'bioluminescent' reporter phage (Wß::luxAB) as a clinical diagnostic tool for Bacillus anthracis, the etiological agent of anthrax. Wß::luxAB is able to rapidly (within minutes) detect a panel of B. anthracis strains by transducing a bioluminescent phenotype. The reporter phage displays species specificity by its inability, or significantly reduced ability, to detect members of the closely related Bacillus cereus group and other common bacterial pathogens. Using spiked clinical specimens, Wß::luxAB detects B. anthracis within 5 h at clinically relevant concentrations, and provides antibiotic susceptibility information that mirrors the CLSI method, except that data are obtained at least 5-fold faster. Although anthrax is a treatable disease, a positive patient prognosis is dependent on timely diagnosis and appropriate therapy. Wß::luxAB rapidly detects B. anthracis and determines antibiotic efficacy, properties that will help patient outcome.
Estuarine crustaceans are often exposed to low dissolved O2 (hypoxia) accompanied by elevated CO2... more Estuarine crustaceans are often exposed to low dissolved O2 (hypoxia) accompanied by elevated CO2 (hypercapnia), which lowers water pH. Acclimatory responses to hypoxia have been widely characterized; responses to hypercapnia in combination with hypoxia (hypercapnic hypoxia) are less well known. Here we used oligonucleotide microarrays to characterize changes in global gene expression in the hepatopancreas of Pacific whiteleg shrimp, Litopenaeus vannamei, exposed to hypoxia or hypercapnic hypoxia for 4 or 24 h, compared with time-matched animals held in air-saturated water (normoxia). Unigenes whose expressions were significantly impacted by treatment and/or time were used to build artificial neural networks (ANNs) to identify genes with the greatest sensitivity in pairwise discriminations between treatments at each time point and between times for each treatment. ANN gene sets that discriminated hypoxia or hypercapnic hypoxia from normoxia shared functions of translation, mitochond...
New Zealand Journal of Marine and Freshwater Research, 2003
The prevalence and intensity of metazoan ectoparasites on the skin and gills of kingfish, Seriola... more The prevalence and intensity of metazoan ectoparasites on the skin and gills of kingfish, Seriola lalandi lalandi (Carangidae), collected from White Island (n = 32), Ranfurly Banks (n = 7), and Three Kings Islands (n = 7), is reported. Kingfish were host to two monogenean and four copepod ectoparasite species, Benedenia seriolae, Zeuxapta seriolae, Caligus lalandei, Caligus aesopus, Neobrachiella spp., and Lernanthropus spp., respectively. B. seriolae and C. lalandei infect the skin, whereas the remaining parasites were located on the gills. All parasites exhibited considerable variability in the prevalence and intensity of infection. A few kingfish were completely devoid of C. aesopus, Neobrachiella spp., and/or Lernanthropus spp., whereas others were infected by moderate numbers of these species. However, all kingfish were infected by B. seriolae and Z. seriolae. Therefore, it appears that acclimation of wild kingfish from the east coast of New Zealand's North Island into captivity will lead to the transfer of both B. seriolae and Z. seriolae, and that effective quarantine measures will be required to avoid introducing these parasites into broodstock systems. The site preferences of B. seriolae, Z. seriolae, and C. aesopus were also investigated. B. seriolae exhibited a preference for attachment on the lateral surfaces of the skin behind the dorsal fin, but forward of the anal fin. Z. seriolae displayed a preference for attachment on gill arches 2 and 3, particularly in gill filaments located in the upper regions of the buccal cavity. C. aesopus most commonly occurred on the gill arch.
This study assessed the efficacy of bath administrations of Aqui-S, formalin and praziquantel aga... more This study assessed the efficacy of bath administrations of Aqui-S, formalin and praziquantel against adults and eggs of Benedenia seriolae and Zeuxapta seriolae, two monogenean ectoparasites of kingfish (Seriola lalandi lalandi). Our results showed that 2.5 ppm praziquantel administered for either 24 or 48 h was the most effective treatment for removing B. seriolae (>99%). However, B. seriolae treated with praziquantel for 24 h deposited viable eggs. Formalin at 250 and 400 ppm for 1 h followed by a 5 min freshwater dip was less effective for removing B. seriolae (ca. 80%), but both treatments inhibited the production of eggs by treated parasites. However, a large proportion of B. seriolae eggs exposed to either formalin treatment remained viable. Praziquantel (2.5 ppm for either 24 or 48 h) and formalin (400 ppm for 1 h + 5 min f/w dip) were the most effective treatments for removing Z. seriolae from the gills of kingfish (>99%) but the parasites thus removed continued to deposit viable eggs. Exposure to the anaesthetic Aqui-S did not significantly increase numbers of B. seriolae or Z. seriolae removed from the host above those of the control, but it was ineffective in preventing the production of eggs by treated parasites, and did not reduce egg viability. Eggs of B. seriolae were not prevented from hatching unless exposed to air for a period greater than 3 h, and Z. seriolae eggs were only prevented from hatching if exposed to air for periods greater than 5 h prior to the development of eyespots. These results 0044-8486/$ -see front matter D Aquaculture 236 indicate that both primary and secondary treatments will be required to successfully control B. seriolae and Z. seriolae infections in captive kingfish. D
Bacteriophages (phages) have been utilized for decades as a means for uniquely identifying their ... more Bacteriophages (phages) have been utilized for decades as a means for uniquely identifying their target bacteria. Due to their inherent natural specificity, ease of use, and straightforward production, phage possess a number of desirable attributes which makes them particularly suited as bacterial detectors. As a result, extensive research has been conducted into the development of phage, or phage-derived products to expedite the detection of human pathogens. However, very few phage-based diagnostics have transitioned from the research lab into a clinical diagnostic tool. Herein we review the phage-based platforms that are currently used for the detection of Mycobacterium tuberculosis, Yersinia pestis, Bacillus anthracis and Staphylococcus aureus in the clinical field. We briefly describe the disease, the current diagnostic options, and the role phage diagnostics play in identifying the cause of infection, and determining antibiotic susceptibility.
Genetically modified phages have the potential to detect pathogenic bacteria from clinical, envir... more Genetically modified phages have the potential to detect pathogenic bacteria from clinical, environmental, or food-related sources. Herein we assess an engineered 'bioluminescent' reporter phage (Wß::luxAB) as a clinical diagnostic tool for Bacillus anthracis, the etiological agent of anthrax. Wß::luxAB is able to rapidly (within minutes) detect a panel of B. anthracis strains by transducing a bioluminescent phenotype. The reporter phage displays species specificity by its inability, or significantly reduced ability, to detect members of the closely related Bacillus cereus group and other common bacterial pathogens. Using spiked clinical specimens, Wß::luxAB detects B. anthracis within 5 h at clinically relevant concentrations, and provides antibiotic susceptibility information that mirrors the CLSI method, except that data are obtained at least 5-fold faster. Although anthrax is a treatable disease, a positive patient prognosis is dependent on timely diagnosis and appropriate therapy. Wß::luxAB rapidly detects B. anthracis and determines antibiotic efficacy, properties that will help patient outcome.
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Papers by Natasha Sharp