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Declan J. Mckeever - One of the best experts on this subject based on the ideXlab platform.
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in vitro pharmacodynamics of gamithromycin against mycoplasma mycoides subspecies mycoides small colony
Veterinary Journal, 2013Co-Authors: John D. Mitchell, Quintin Mckellar, Declan J. MckeeverAbstract:Abstract Mycoplasma mycoides mycoides Small Colony ( Mmm SC) is the causative agent of contagious bovine pleuropneumonia (CBPP), which is responsible for major economic losses in sub-Saharan Africa. Current control relies on live attenuated vaccines, which are of limited efficacy, and antimicrobials are now being assessed as an alternative or adjunct to vaccination. The objective of this study was to determine the in vitro effector kinetics of the macrolide antimicrobial, gamithromycin, against Mmm SC in Artificial Medium and adult bovine serum. Furthermore, it was determined if any differences in gamithromycin activity between these two matrices were mirrored by the older macrolides, tylosin and tilmicosin. Minimum inhibitory concentrations (MICs) for gamithromycin, tylosin and tilmicosin against Mmm SC strains B237 and Tan8 were determined in Artificial Medium and serum. Time-kill curves were constructed at concentrations corresponding to multiples of the MIC for all three macrolides in Artificial Medium and for gamithromycin in serum. Data were fitted to sigmoid E max models. Post-antibiotic effects (PAE) were established by exposing strain B237 to antimicrobials at 10× MIC for 1 h and monitoring mycoplasma growth thereafter. MICs for gamithromycin, tylosin and tilmicosin were 64-, 8- and 64-fold lower, respectively, in serum than in Artificial Medium at an inoculum size of 10 6 cfu/mL B237. A similar pattern emerged for Tan8. All three antimicrobials were mycoplasmastatic with maximum effects of −0.44, −0.32 and −0.49 log 10 (cfu/mL) units for gamithromycin, tylosin and tilmicosin, respectively, against B237 in Artificial Medium. Tylosin and tilmicosin elicited longer PAEs than gamithromycin. In conclusion, gamithromycin, tylosin and tilmicosin all demonstrated in vitro efficacy against Mmm SC and represent potential candidates for clinical studies to assess their therapeutic effect against CBPP.
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evaluation of antimicrobial activity against mycoplasma mycoides subsp mycoides small colony using an in vitro dynamic dilution pharmacokinetic pharmacodynamic model
Journal of Medical Microbiology, 2013Co-Authors: John D. Mitchell, Quintin Mckellar, Declan J. MckeeverAbstract:The objectives of this study were to assess the activity of oxytetracycline (OTC), danofloxacin and tulathromycin against Mycoplasma mycoides subsp. mycoides Small Colony, the causative agent of contagious bovine pleuropneumonia, in an in vitro dynamic concentration model and to determine the concentration and/or time dependence of such activity. Time–kill assays that simulated elimination of antimicrobials from the body were performed. Initial antimicrobial concentrations corresponded to various multiples of the MIC and cultures were diluted in a stepwise fashion with either drug-free or drug-containing Artificial Medium to mimic administration by single-release bolus or infusion, respectively. Where appropriate, data were fitted to sigmoidal E max models. OTC produced no change in mycoplasma titre from the initial inoculum size, regardless of the concentration or means of drug exposure. Both danofloxacin and tulathromycin resulted in a decrease in mycoplasma titre but neither was bactericidal (99.9 % kill) over 12 h. A greater antimycoplasmal effect, defined as the change in log10 (c.f.u. ml−1) over 12 h, was achieved when danofloxacin was administered as a single-release bolus, suggesting concentration-dependent activity, whereas the antimycoplasmal effect of tulathromycin was comparable following administration by single-release bolus or infusion, owing to its long half-life.
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pharmacodynamics of antimicrobials against mycoplasma mycoides mycoides small colony the causative agent of contagious bovine pleuropneumonia
PLOS ONE, 2012Co-Authors: John D. Mitchell, Quintin Mckellar, Declan J. MckeeverAbstract:Background Mycoplasma mycoides subspecies mycoides Small Colony (MmmSC) is the causative agent of Contagious Bovine Pleuropneumonia (CBPP), a disease of substantial economic importance in sub-Saharan Africa. Failure of vaccination to curtail spread of this disease has led to calls for evaluation of the role of antimicrobials in CBPP control. Three major classes of antimicrobial are effective against mycoplasmas, namely tetracyclines, fluoroquinolones and macrolides. Therefore, the objectives of this study were to determine the effector kinetics of oxytetracycline, danofloxacin and tulathromycin against two MmmSC field strains in Artificial Medium and adult bovine serum. Methods Minimum inhibitory concentrations (MIC) were determined for oxytetracycline, danofloxacin and tulathromycin against MmmSC strains B237 and Tan8 using a macrodilution technique, and time-kill curves were constructed for various multiples of the MIC over a 24 hour period in Artificial Medium and serum. Data were fitted to sigmoid Emax models to obtain 24 hour-area under curve/MIC ratios for mycoplasmastasis and, where appropriate, for mycoplasmacidal activity and virtual mycoplasmal elimination. Results Minimum inhibitory concentrations against B237 were 20-fold higher, 2-fold higher and approximately 330-fold lower in serum than in Artificial Medium for oxytetracycline, danofloxacin and tulathromycin, respectively. Such differences were mirrored in experiments using Tan8. Oxytetracycline was mycoplasmastatic against both strains in both matrices. Danofloxacin elicited mycoplasmacidal activity against B237 and virtual elimination of Tan8; similar maximum antimycoplasmal effects were observed in Artificial Medium and serum. Tulathromycin effected virtual elimination of B237 but was mycoplasmastatic against Tan8 in Artificial Medium. However, this drug was mycoplasmastatic against both strains in the more physiologically relevant matrix of serum. Conclusions Oxytetracycline, danofloxacin and tulathromycin are all suitable candidates for further investigation as potential treatments for CBPP. This study also highlights the importance of testing drug activity in biological matrices as well as Artificial media.
Shinya Yokoyama - One of the best experts on this subject based on the ideXlab platform.
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co2 fixation and oil production through microalga
Energy Conversion and Management, 1995Co-Authors: Shigeki Sawayama, Seiichi Inoue, Yutaka Dote, Shinya YokoyamaAbstract:Abstract As one way to prevent global warming due to carbon dioxide, microalgal oil production with secondarily treated sewage (STS) and thermochemical oil recovery from algal cells were studied. A hydrocarbon-rich microalga, Botryococcus braunii , produced hydrocarbons and consumed nitrate and phosphate in STS. Removal effects of the alga regarding As, Cd and Cr were observed during these experiments with an Artificial Medium. As for oil recovery from algal cells, the maximum yield of oil obtained by liquefaction was 64 wt% on a dry basis at 300°C with a catalyst of sodium carbonate.
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growth of the hydrocarbon rich microalga botryococcus braunii in secondarily treated sewage
Applied Microbiology and Biotechnology, 1992Co-Authors: Shigeki Sawayama, Yutaka Dote, Tomoaki Minowa, Shinya YokoyamaAbstract:A hydrocarbon-rich green microalga, Botryococcus braunii, was able to grow well in secondarily treated sewage (STS) from domestic waste-water in a batch system. The growth in STS from domestic waste-water was as good as in the common Artificial Medium of modified Chu 13 and its hydrocarbon contents were high enough at 53% and 40% compared with 58% in the case of the modified Chu 13 Medium. B. braunii utilized nitrate from 7.67 or 4.48 mg/l to a level below detection of < 0.01 mg/l in STS. After this consumption of nitrate, nitrite was consumed, and ammonium was not. Phosphate, even at an extremely low concentration, was also consumed by B. braunii. These results show the possibility of using STS as a Medium to grow B. braunii and for removal of nitrogen and phosphorus by algal consumption in STS.
Elisa Marchetti - One of the best experts on this subject based on the ideXlab platform.
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Supplementation of an Artificial Medium for the Parasitoid Exorista larvarum (Diptera: Tachnidae) With Hemolymph of Hermetia illucens (Diptera: Stratiomyidae) or Antheraea pernyi (Lepidoptera: Saturniidae).
Journal of economic entomology, 2016Co-Authors: Jonas Vandicke, Elisa Marchetti, Thomas Spranghers, Jochem Bonte, Patrick De ClercqAbstract:The effect of supplementing hemolymph of the black soldier fly, Hermetia illucens (L.), or the Chinese oak silkworm, Antheraea pernyi (Guerin-Meneville), to a basic insect-free Artificial Medium for the tachinid Exorista larvarum (L.) was investigated. The supplementation (20% w/w) was based on the assumption that insect additives may optimize the media for this parasitoid. Egg hatch, pupal and adult yields, and sex ratio did not differ among the enriched and basic media. Preimaginal development was faster on both hemolymph-enriched media than on the basic Medium. Despite the shorter development on the Medium supplemented with H. illucens hemolymph than on the basic Medium, on the two media puparium weights were comparable. The female flies reared on the Medium enriched with H. illucens hemolymph did not lay more eggs, but the latter yielded significantly more puparia compared with the control females. Conversely, the Medium enriched with A. pernyi hemolymph yielded lower female puparium weights than the basic Medium and produced only one ovipositing female out of the five obtained female adults. These results indicate that the in vitro development of E. larvarum improved when the basic Artificial Medium was enriched with H. illucens hemolymph, whereas the supplementation with A. pernyi hemolymph negatively affected the quality of the in vitro-reared females.
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a simplified Artificial Medium for the in vitro rearing of exorista larvarum diptera tachinidae
Biocontrol Science and Technology, 2010Co-Authors: Lucia Stangolini, Elisa MarchettiAbstract:Abstract The standard Artificial Medium for the parasitoid Exorista larvarum, composed of skimmed milk, yeast extract, egg yolk, sucrose and gentamicin, was simplified by deleting sucrose. Fecund adults were obtained on both the standard and the simplified Medium. No difference was found between them for any of the developmental parameters examined.
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In vitro rearing of the tachinid parasitoid Exorista larvarum with exclusion of the host insect for more than one generation
2008Co-Authors: Elisa Marchetti, Piero Baronio, Maria Luisa DindoAbstract:We tested the possibility to eliminate the host insect from the line of production of Exorista larvarum (L.), a larval parasitoid of Lepidoptera, for more than one generation. Galleria mellonella (L.) larvae or a plastic sheet were provided as oviposition substrates either to parental or 1 st generation females. The eggs/female laid in 45 min were dramatically fewer on the plastic sheet compared to host larvae and decreased from the parental to the 1 st generation. Both the 1 st and 2 nd generation eggs (respectively laid by parental and 1 st generation females) were removed from the oviposition substrates (host larvae or plastic sheet) and placed on a skimmed milk-based Artificial Medium. The percentages of hatched eggs were not significantly affected by the oviposition substrate, but the generation effect was significant and fewer eggs hatched in the 2 nd than in the 1 st generation. The percentages of puparia and adults were not significantly influenced either by the oviposition substrate or generation. All the 2 nd generation adults obtained from eggs laid on the plastic sheet died 1-2 days after emergence, before the females oviposited, whereas the 2 nd generation adults obtained from eggs removed from the host integument survived. After mating, the females laid eggs on G. mellonella larvae. The results confirmed that, for one generation, the out-of-host eggs are competitive with those removed from G. mellonella larvae to rear E. larvarum on an Artificial Medium. The quality of the in vitro-cultured tachinids however decreases over generations, especially if the host is completely excluded from their line of production, i.e. not even used for collecting eggs. Moreover, several factors need to be investigated for E. larvarum to be stimulated to lay more eggs on Artificial substrates.
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In Vitro Rearing of the Parasitoid Exorista larvarum (Diptera: Tachinidae) from Eggs Laid Out of Host
Journal of Economic Entomology, 2007Co-Authors: Maria Luisa Dindo, Elisa Marchetti, Piero BaronioAbstract:We evaluated the possibility of using the eggs laid out of host to rear Exorista larvarum (L.) (Diptera: Tachinidae), a larval parasitoid of Lepidoptera, on Artificial media. In a first experiment, eggs oviposited on a plastic sheet (either by inexperienced or experienced females) showed the same in vitro hatching capability as those removed from the larvae of the factitious host Galleria mellonella L. Subsequently, eggs laid on the host integument or out of host, either by inexperienced or experienced females, were removed from the oviposition substrate and placed on a skimmed milkbased Artificial Medium. The percentages of hatched eggs, of puparia and adults, as well as the puparial weights did not differ significantly among the three treatments. These findings suggested that E. larvarum may be successfully reared in vitro with a total exclusion of the host insect. In a further test, no difference for the in vitro hatching time was found between the eggs oviposited either on a plastic sheet or on G. mellonella larvae in the same length of time (60 min). This result suggested that at oviposition the out-of-host eggs were unincubated, similarly to those that had been laid on the host larvae.
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In Vitro Rearing of the Parasitoid Exorista larvarum (Diptera: Tachinidae) from Eggs Laid Out of Host
2007Co-Authors: Maria Luisa Dindo, Elisa Marchetti, Piero BaronioAbstract:We evaluated the possibility of using the eggs laid out of host to rear Exorista larvarum (L.), a larval parasitoid of Lepidoptera, on Artificial media. In a first experiment, eggs oviposited on a plastic sheet (either by inexperienced or experienced females) showed the same in vitro hatching capability as those removed from the larvae of the factitious host Galleria mellonella L. Subsequently, eggs laid on the host integument (1) or out of host, either by inexperienced (2) or experienced (3) females, were removed from the oviposition substrate and placed on a skimmed milk-based Artificial Medium. The percentages of hatched eggs, of puparia and adults, as well as the puparial weights did not differ significantly among the three treatments. These findings suggested that E. larvarum may be successfully reared in vitro with a total exclusion of the host insect. In a further test, no difference for the in vitro hatching time was found between the eggs oviposited either on a plastic sheet or on G. mellonella larvae in the same lenght of time (60 mins) . This result suggested that at oviposition the out-of-host eggs were unincubated, similarly to those that had been laid on the host larvae
Joop C Van Lenteren - One of the best experts on this subject based on the ideXlab platform.
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pathogenicity of aschersonia spp against whiteflies bemisia argentifolii and trialeurodes vaporariorum
Journal of Invertebrate Pathology, 2002Co-Authors: E T M Meekes, Joop C Van LenterenAbstract:Abstract Entomopathogenic fungi of the genus Aschersonia are specific for whitefly and scale insects. They can be used as biological control agents against silverleaf whitefly, Bemisia argentifolii and greenhouse whitefly, Trialeurodes vaporariorum. Forty-four isolates of Aschersonia spp. were tested for their ability to sporulate and germinate on semi-Artificial media and to infect insect hosts. Seven isolates sporulated poorly (less than 1×107 conidia/dry weight) and 10 were not able to infect either of the whitefly species. Several isolates were able to produce capilliconidia. Infection level was not correlated with germination on water agar. After a selection based on spore production and infection, virulence of 31 isolates was evaluated on third instar nymphs of both whitefly species on poinsettia (Euphorbia pulcherrima). Whitefly infection levels varied between 2 and 70%, and infection percentages of B. argentifolii correlated with that of T. vaporariorum. However, mortality was higher for T. vaporariorum than for B. argentifolii, as a result of a higher ‘mortality due to unknown causes.’ Several isolates, among which unidentified species of Aschersonia originating from Thailand and Malaysia, A. aleyrodis from Colombia, and A. placenta from India showed high spore production on semi-Artificial Medium and high infection levels of both whitefly species.
Maria Luisa Dindo - One of the best experts on this subject based on the ideXlab platform.
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monarda fistulosa hydrolate as antimicrobial agent in Artificial media for the in vitro rearing of the tachinid parasitoid exorista larvarum
Entomologia Experimentalis Et Applicata, 2021Co-Authors: Maria Luisa Dindo, Chiara Rossi, Maura Di Vito, Lorenzo Barbanti, Monica Marianna Modesto, Giovanni Burgio, Paola MattarelliAbstract:Exorista larvarum (L.) (Diptera: Tachinidae), a larval parasitoid of Lepidoptera, can be reared from egg to fecund adult on Artificial media composed of crude components. The standard in vitro culture is performed in 24‐well plastic rearing plates. Exorista larvarum eggs, removed from superparasitized larvae of Galleria mellonella (L.) (Lepidoptera: Pyralidae), are individually placed in the wells, each containing a cotton swab soaked in liquid Medium. The plates are then sealed until parasitoid puparium formation. To avoid contamination by microorganisms, the Artificial Medium is routinely supplemented with 0.01% solution of gentamicin. Experiments were carried out to assess whether this broad‐spectrum antibiotic may be replaced with hydrolate of Monarda fistulosa L. (Lamiaceae), which was selected due to its high in vitro activity against pathogenic microorganisms for humans and plants. The hydrolate was either supplemented to the Artificial Medium (0.5% wt/wt) (first experiment) or placed in an empty well (200 μl) of the rearing plate, to be supplied as saturated air due to evaporation (second experiment). In both experiments, a standard Medium with gentamicin and an antimicrobial‐free Medium were maintained as positive and negative controls, respectively. In the first experiment, in the hydrolate‐supplemented Medium fewer E. larvarum completed egg‐to‐adult development than in the standard Medium, but significantly more parasitoids developed from egg to adult compared to the antimicrobial‐free Medium. No significant difference was found between the numbers of eggs laid by the females obtained from the standard Medium vs. those from the hydrolate‐supplemented Medium. In the second experiment, the hydrolate‐saturated air significantly decreased E. larvarum egg hatching, puparium formation, and female fecundity compared to the standard Medium. In perspective, M. fistulosa hydrolate supplemented to the Artificial media for E. larvarum may be considered as a promising candidate to replace the gentamicin solution, as suggested also by the microbiological analyses of the media, performed at various growth stages of the parasitoid in a separate trial. Conversely, the hydrolate‐saturated air treatment was deemed unsuitable.
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In vitro rearing of the tachinid parasitoid Exorista larvarum with exclusion of the host insect for more than one generation
2008Co-Authors: Elisa Marchetti, Piero Baronio, Maria Luisa DindoAbstract:We tested the possibility to eliminate the host insect from the line of production of Exorista larvarum (L.), a larval parasitoid of Lepidoptera, for more than one generation. Galleria mellonella (L.) larvae or a plastic sheet were provided as oviposition substrates either to parental or 1 st generation females. The eggs/female laid in 45 min were dramatically fewer on the plastic sheet compared to host larvae and decreased from the parental to the 1 st generation. Both the 1 st and 2 nd generation eggs (respectively laid by parental and 1 st generation females) were removed from the oviposition substrates (host larvae or plastic sheet) and placed on a skimmed milk-based Artificial Medium. The percentages of hatched eggs were not significantly affected by the oviposition substrate, but the generation effect was significant and fewer eggs hatched in the 2 nd than in the 1 st generation. The percentages of puparia and adults were not significantly influenced either by the oviposition substrate or generation. All the 2 nd generation adults obtained from eggs laid on the plastic sheet died 1-2 days after emergence, before the females oviposited, whereas the 2 nd generation adults obtained from eggs removed from the host integument survived. After mating, the females laid eggs on G. mellonella larvae. The results confirmed that, for one generation, the out-of-host eggs are competitive with those removed from G. mellonella larvae to rear E. larvarum on an Artificial Medium. The quality of the in vitro-cultured tachinids however decreases over generations, especially if the host is completely excluded from their line of production, i.e. not even used for collecting eggs. Moreover, several factors need to be investigated for E. larvarum to be stimulated to lay more eggs on Artificial substrates.
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In Vitro Rearing of the Parasitoid Exorista larvarum (Diptera: Tachinidae) from Eggs Laid Out of Host
Journal of Economic Entomology, 2007Co-Authors: Maria Luisa Dindo, Elisa Marchetti, Piero BaronioAbstract:We evaluated the possibility of using the eggs laid out of host to rear Exorista larvarum (L.) (Diptera: Tachinidae), a larval parasitoid of Lepidoptera, on Artificial media. In a first experiment, eggs oviposited on a plastic sheet (either by inexperienced or experienced females) showed the same in vitro hatching capability as those removed from the larvae of the factitious host Galleria mellonella L. Subsequently, eggs laid on the host integument or out of host, either by inexperienced or experienced females, were removed from the oviposition substrate and placed on a skimmed milkbased Artificial Medium. The percentages of hatched eggs, of puparia and adults, as well as the puparial weights did not differ significantly among the three treatments. These findings suggested that E. larvarum may be successfully reared in vitro with a total exclusion of the host insect. In a further test, no difference for the in vitro hatching time was found between the eggs oviposited either on a plastic sheet or on G. mellonella larvae in the same length of time (60 min). This result suggested that at oviposition the out-of-host eggs were unincubated, similarly to those that had been laid on the host larvae.
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In Vitro Rearing of the Parasitoid Exorista larvarum (Diptera: Tachinidae) from Eggs Laid Out of Host
2007Co-Authors: Maria Luisa Dindo, Elisa Marchetti, Piero BaronioAbstract:We evaluated the possibility of using the eggs laid out of host to rear Exorista larvarum (L.), a larval parasitoid of Lepidoptera, on Artificial media. In a first experiment, eggs oviposited on a plastic sheet (either by inexperienced or experienced females) showed the same in vitro hatching capability as those removed from the larvae of the factitious host Galleria mellonella L. Subsequently, eggs laid on the host integument (1) or out of host, either by inexperienced (2) or experienced (3) females, were removed from the oviposition substrate and placed on a skimmed milk-based Artificial Medium. The percentages of hatched eggs, of puparia and adults, as well as the puparial weights did not differ significantly among the three treatments. These findings suggested that E. larvarum may be successfully reared in vitro with a total exclusion of the host insect. In a further test, no difference for the in vitro hatching time was found between the eggs oviposited either on a plastic sheet or on G. mellonella larvae in the same lenght of time (60 mins) . This result suggested that at oviposition the out-of-host eggs were unincubated, similarly to those that had been laid on the host larvae
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rearing of exorista larvarum diptera tachinidae simplification of the in vitro technique
2003Co-Authors: Maria Luisa Dindo, Elisa Marchetti, Giovanna Galvagni, Piero BaronioAbstract:The tachinid Exorista larvarum (L.) was developed in vitro from egg to adult using absorbent cotton in replacement of more expensive agar as a physical support of the Artificial Medium. Puparial yields and adult emergence did not differ significantly between agar-containing and cotton absorbed diets. The heaviest puparia (mg 66-69 for males and 59-60 for females) were obtained when 15 mg cotton were used to absorb 0.4 ml diet. With this ratio of absorbent mass to volume of absorbed liquid, puparial yields reached as high as 61% and over 92% of puparia emerged as adults. Subsequently a comparison was made of in vitro rearing procedure conducted in or out of a laminar flow hood with a cotton absorbed diet devoid of antifungal agents. When the procedure was conducted out of a laminar flow hood no significant increase of mould contamination or decrease of adult yields occurred. The weights of male puparia were significantly lighter than the weights of puparia reared in a laminar flow hood. Both male and female puparia obtained out of a laminar flow hood however weighed more than those previously cultured in vivo from monoparasitized G. mellonella larvae.
