Embryo Mortality Research Articles

Genetic approach to select against embryo mortality caused by Enterococcus faecalis infection in laying hens

Selection to reduce susceptibility to Enterococcus faecalis infection in laying hens may contribute to the prevention of amyloid arthropathy since it is mainly induced by this bacterium. Therefore, the aim of the present study was to investigate the possibility to select more laying hens that are resistant against E. faecalis infection through the embryo lethality assay (ELA), which is proposed as an alternative model to replace the adult avian challenge assay. Ten-day-old embryos of 500 Lohmann Brown layers were inoculated into the allantoic cavity with an infectious dose of 2.5 colony-forming units (cfu)/mL of the avian E. faecalis strain K923/96 in 3 ELAs. The embryonic mortality rate (EMR) was determined by candling the eggs daily over a period of 4 d. The average EMR estimated during the 3 ELAs was 50% and the highest EMR occurred 3 to 4 d post inoculation. The estimated heritability for embryonic survivability to the infection was h2 = 0.12-0.14, calculated with the logistic and probit link function, respectively, indicating that the selection of more laying hens that are resistant to E. faecalis infection is feasible. A highly negative genetic correlation was estimated between embryonic survivability and laying performance at the peak of lay (rg = -0.22) and at the end of the production (rg = -0.65), as well as with breaking strength (rg = -0.30 to -0.37). A positive correlation was found between egg weight and the embryonic survivability (rg = +0.16), and no genetic correlation was found with body weight and dynamic stiffness. Therefore, although it was demonstrated that it is possible to breed for E. faecalis resistance, special care should be taken to monitor and to take all traits and their genetic correlations into account in order to achieve a balanced genetic progress. Besides, the ELA does not require that the hens are exposed to pathogens thereby saving labor and cost. Therefore, it could be feasible that ELA be implemented in selection programs.

Effect of adding anisum and Coriander to diet in some productive performance and the enteric ecosystem of quail

This study was conducted in one of the halls of Animal Production Department- College of Agriculture and Forestry / University of Mosul for the period 8/10/2017 until 31/12/2017 (84) day and aimed to know the effect of adding anisum seeds powder and Coriander in some productive performance and the enteric ecosystem of quail. The study was divided into two stages: The first stage (Growth stage)from the age (14 day) till the age of puberty. 288 Local quail birds were divided randomly into four treatments (72 birds/treatment),six replicates in each replicate 12 birds. The experimental treatments were First no addition (control) , Second treatment was added 2 % of anisum powder, Third added 2 % of coriander powder , and Forth added 2 % of anisum and 2 % of coriander powder to diet , birds reared until six weeks. Feed and water were Ad-Libitum and the water was provided free of additives. Statistic analysis of data showed a significantly increase in body weight, growth rate, improving in feed conversion ratio for third and fourth treatments. as compared with first and second treatments, weight gain for fourth treatment as compared with second. increasing in Number of Lactobacillus bacteria for third and fourth treatments as compared with control. Significantly decrease in feed consumption for third treatments decrease in number of Salmonella bacteria and E.coli bacteria for second, third, fourth treatments as compared with control. No significantly differences in relative weight of Edable organs, Length of digestive tracts, carcass weight, relative weight of chest, wings, back, neck, and dressing percentage for third treatment improvement in intestine tissue picture for forth treatment. Second stage (egg production) from the age seven weeks until twelfth weeks, statistic analysis of data showed significantly increase in egg production percentage,weight and high and diameter of yolk for second,third and forth treatments as compared with the control. Increasing in hatch ability percentage from fertility and total egg, fertility percentage for second treatment as compared with others treatments. No significant differences in body weight gain during production period. Significantly decrease in embryos mortality for second treatment.

Effects of CRISPR/Cas9 dosage on TICAM1 and RBL gene mutation rate, embryonic development, hatchability and fry survival in channel catfish

The current study was conducted to assess the effects of microinjection of different dosages of guide RNA (gRNA)/Cas9 protein on the mutation rate, embryo survival, embryonic development, hatchability and early fry survival in channel catfish, Ictalurus punctatus. Guide RNAs targeting two of the channel catfish immune-related genes, toll/interleukin 1 receptor domain-containing adapter molecule (TICAM 1) and rhamnose binding lectin (RBL) genes, were designed and prepared. Three dosages of gRNA/Cas9 protein (low, 2.5 ng gRNA/7.5 ng Cas9, medium, 5 ng gRNA/15 ng Cas9 and high, 7.5 ng gRNA/22.5 ng Cas9) were microinjected into the yolk of one-cell embryos. Mutation rate increased with higher dosages (p < 0.05). Higher dosages increased the mutation frequency in individual embryos where biallelic mutations were detected. For both genes, microinjection procedures increased the embryo mortality (p < 0.05). Increasing the dosage of gRNA/Cas9 protein increased the embryo mortality and reduced the hatching percent (p < 0.05). Embryonic development was delayed when gRNAs targeting RBL gene were injected. Means of fry survival time were similar for different dosages (p > 0.05). The current results lay the foundations for designing gene editing experiments in channel catfish and can be used as a guide for other fish species.

Heterosymely and Accompanying Anomalies in the Spider Eratigena atrica (C. L. Koch, 1843) (Araneae: Agelenidae)

Abstract. Temperature changes are among the most powerful causes of disturbed embryogenesis in spiders. They are responsible for body deformities which impede development of these animals and lead to their death long before they reach sexual maturity. The main objective of this study was to show the relationship between the applied teratogenic factor and embryo mortality as well as morphological deformities in Eratigena atrica (C. L. Koch, 1843). Developmental abnormalities were induced by temperatures of 14 and 32°C, changed every 12 hours for the first 10 days of embryo development. As a result, we obtained 78 deformed specimens, including 8 with the fusion of a pedipalp and the first walking leg (heterosymely). Several spiders were additionally affected by oligomely (absence of legs) or schistomely (bifurcation of legs). Since we obtained a relatively large group of larvae with heterosymely of a pedipalp and the first walking leg (in different combinations) we aimed at showing the diversity of this deformity. The morphology of these individuals is described in detail and presented in figures.

Acute toxicity and teratogenicity of α-mangostin in zebrafish embryos.

α-Mangostin has been reported to have anticancer properties both in vitro and in vivo models. Although there are several studies that evaluated the toxicity of the compound in rodent models, we are the first to evaluate the teratogenicity of α-mangostin. In the present work, we found that α-mangostin induced mortality and malformations in zebrafish embryos. In addition, we exhibited that the compound also disrupted the reactive oxygen species and hemoglobin levels. These findings suggest that α-mangostin may possibly cause the same adverse effects on human health. The mechanisms of these toxicological effects of the compound will be further elucidated and the effects found in zebrafish embryos need to be verified in other animal models.

Biological impacts of organophosphates chlorpyrifos and diazinon on development, mitochondrial bioenergetics, and locomotor activity in zebrafish (Danio rerio)

The objectives of this study were to compare the biological responses in developing zebrafish to two organophosphate insecticides, chlorpyrifos (CPF) and diazinon (DZN). Zebrafish embryos were exposed to either solvent control (0.1% DMSO, v/v), or one dose of 0.1, 1.0, 10.0 and 25.0 μM CPF, as well as one dose of 0.1, 1.0, 10.0 and 100.0 μM DZN for 96 h. CPF at 10.0 and 25.0 μM caused 70–80% and 100% mortality in embryos after 96 h exposure, whereas embryos treated with 10.0 and 100.0 μM DZN showed 30–40% and 70–80% lethality. CPF at 10.0 μM significantly decreased cumulative hatching rate, whereas hatching rate was significantly reduced in embryos treated with 100.0 μM DZN. Spinal lordosis was primarily observed in larvae exposed to 1.0 and 10.0 μM CPF, whereas pericardial edema was mainly detected with 10.0 and 100.0 μM DZN exposure. Embryo exposed to 1.0, 10.0 and 25.0 μM CPF exhibited no mitochondrial dysfunction; exposure to 100.0 μM DZN significantly inhibited mitochondrial bioenergetics. To determine if CPF and DZN affected larval activity, dark photokinesis response was assessed in larvae following 7 days exposure to 0.1 and 1.0 μM CPF, as well as to 0.1 1.0, and 10.0 μM DZN. Larvae exposed to 1.0 μM CPF showed hypoactivity, whereas the activity in the dark was not overtly changed in larvae exposed to DZN. In summary, CPF showed higher developmental toxicity compared to DZN. Moreover, based on the types of morphological deformities noted, as well as differences in locomotor activity, we conclude that OPs have unique chemical-specific modes of action that can result in varied biological responses during early development.

Embryonic maternal interaction in cattle and its relationship with fertility.

Embryo mortality is a major contributor to poor reproductive efficiency and profitability in cattle production systems. While conception is achieved (i.e., the oocyte is fertilized) in the vast majority of cases if insemination is carried out correctly, a significant proportion of the resulting embryos fail to develop to term. Appropriate communication between the developing conceptus and the maternal endometrium is essential for the establishment and maintenance of pregnancy in all mammals. Up to the blastocyst stage, around Days 7-9, contact worth the female reproductive system is not required. However, the process of conceptus elongation after hatching and prior to implantation is entirely maternally driven and is essential to ensure that sufficient quantities of interferon-tau (IFNT) are secreted by the developing conceptus to abrogate the mechanisms that bring about luteolysis. While the importance of conceptus-derived IFNT in maternal recognition of pregnancy and prevention of luteolysis in cattle is unequivocal, many questions, such as the threshold level of IFNT required for pregnancy maintenance, remain unanswered. Furthermore, the precise role of IFNT-independent mechanisms in pregnancy establishment remains to be elucidated. Irrespective of this, failure of the conceptus to elongate undoubtedly results in embryonic loss and is thus believed to contribute greatly to reproductive failure in cattle. This review will address some of these answered questions and try to shed some light on those gaps in knowledge that could potentially contribute to improved embryo survival and reproductive efficiency.

Effect of Newcastle disease virus level of infection on embryonic length, embryonic death, and protein profile changes.

Background and Aim:Newcastle disease virus (NDV) is an obligate intracellular parasite. Virus can only live on living cells. The embryonated chicken eggs (ECEs) are one of the growth media of virus that is a cheap, easy to do, and accurate for showing patterns of virus change in the host. Higher virus titers indicate the higher number of viruses and more virulent to infect host. This research aimed to investigate the effect of different level of NDV titer infection in ECEs on protein profile, embryonic length, mortality, and pathological change.Materials and Methods:The study used a completely randomized design of six treatments and seven replications. The treatments were different level of NDV titer infection in allantoic fluid (AF) of 9-11 days ECEs, i.e., P1=20, P2=26, P3=27, P4=28, P5=29, and P6=210 hemagglutination unit (HAU). All samples were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Data were analyzed using one-way ANOVA with p=0.05 for length of the embryo and descriptive analysis for embryo mortality, pathology change, and protein band.Results:The result showed that protein profile of NDV-infected ECEs of all different levels is more complex than protein profile of no NDV-infected ECEs. NDV infected of all different levels showed longer size embryo, higher mortality embryo at the first 2 days, and higher occurrence of hemorrhagic in all part of bodies of embryo than those of no NDV infected.Conclusion:It was concluded that NDV infection of all different level decreased health conditions of chicken embryo of ECEs of 9-11 days old. Different level of NDV infection of ECEs of 9-11 days old showed no significantly different embryo profiles. However, all of the NDV-infected embryos were shorter, death on the 2nd day, and suffered more hemorrhage on all body surfaces than uninfected NDV embryos.

A Pilot Evaluation of the Toxicity of EarthTec® QZ on Invasive (Bithynia tentaculata) and Native (Physa gyrina) Snail Species from the Upper Mississippi River.

We used a comparative approach to investigate the effects of a copper-based pesticide (EarthTec® QZ) on embryos of an invasive snail (Bithynia tentaculata) and a native snail (Physa gyrina). Embryos were exposed to one of three treatments: control (0mg/L Cu2+), low-dose (0.1mg/L Cu2+), or high-dose (0.6mg/L Cu2+), which reflect manufacturer-recommended low and medium 4-day molluscicide treatment concentrations. Exposure to 0.6mg/L Cu2+ over 4days generated 100% mortality in both invasive and native snail embryos; however, reducing the exposure time from 4 to 1day resulted in 100% mortality in B. tentaculata but some hatching (7%) in P. gyrina. In contrast, embryos of both species exposed to 0.1mg/L Cu2+ treatment for 4days showed almost 100% survivorship. Further manipulations of Cu2+ concentrations and exposure times may yield regimes that maximize mortality in B. tentaculata while minimizing negative impacts on native species.

High Fecundity, Rapid Development and Selfing Ability in Three Species of Viviparous Land Snails Phaedusinae (Gastropoda: Stylommatophora: Clausiliidae) from East Asia.

Anna Sulikowska-Drozd, Takahiro Hirano, Shu-Ping Wu, and Barna Páll-Gergely (2018) Life history traits are important yet understudied aspects of ecological diversification in land snail faunas. To acquire information for comparative analysis of gastropod life cycles, we conducted experimental breeding of three viviparous clausiliids from Japan and Taiwan. Under laboratory conditions, Tauphaedusa sheridani (Pfeiffer, 1866), T. tau (O. Boettger, 1877) and Stereophaedusa (Breviphaedusa) jacobiana (Pilsbry, 1902) featured similar times to complete shell growth (12-16 weeks), age of first reproduction (23-24 weeks) and annual fecundity (143- 173 neonates per pair of snails). The maximum number of eggs retained in genital tract reaches nine for T. sheridani, 11 for T. tau, and seven for S. jacobiana. The ratio between average shell height of neonate and adult varied between 13.5% for T. tau, 13.9% for T. sheridani, and 16.7% for S. jacobiana. All species were able to self-fertilize. Exposure to long drought affects intrauterine embryo development in all species; additionally, it results in parent and embryo mortality in S. jacobiana. Observed differences in the structure of the egg envelope among studied species point to greater than expected differentiation of developmental processes in viviparous Phaedusinae of East Asia.

Deletion of accessory genes 3a, 3b, 5a or 5b from avian coronavirus infectious bronchitis virus induces an attenuated phenotype both in vitro and in vivo.

Avian coronavirus infectious bronchitis virus (IBV) infects domestic fowl, resulting in respiratory disease and causing serious losses in unprotected birds. Its control is mainly achieved by using live attenuated vaccines. Here we explored the possibilities for rationally attenuating IBV to improve our knowledge regarding the function of IBV accessory proteins and for the development of next-generation vaccines with the recently established reverse genetic system for IBV H52 based on targeted RNA recombination and selection of recombinant viruses in embryonated eggs. To this aim, we selectively removed accessory genes 3a, 3b, 5a and 5b individually, and rescued the resulting recombinant (r) rIBV-Δ3a, rIBV-Δ3b, rIBV-Δ5a and rIBV-Δ5b. In vitro inoculation of chicken embryo kidney cells with recombinant and wild-type viruses demonstrated that the accessory protein 5b is involved in the delayed activation of the interferon response of the host after IBV infection. Embryo mortality after the inoculation of 8-day-old embryonated chicken eggs with recombinant and wild-type viruses showed that rIBV-Δ3b, rIBV-Δ5a and rIBV-Δ5b had an attenuated phenotype in ovo, with reduced titres at 6 h p.i. and 12 h p.i. for all viruses, while growing to the same titre as wild-type rIBV at 48 h p.i. When administered to 1-day-old chickens, rIBV-Δ3a, rIBV-Δ3b, rIBV-Δ5a and rIBV-Δ5b showed reduced ciliostasis in comparison to the wild-type viruses. In conclusion, individual deletion of accessory genes in IBV H52 resulted in mutant viruses with an attenuated phenotype.

Injection of an SV40 transcriptional terminator causes embryonic lethality: a possible zebrafish model for screening nonhomologous end-joining inhibitors.

IntroductionDNA repair by the nonhomologous end joining (NHEJ) pathway promotes tumor recurrence after chemotherapy and radiotherapy. Discovery of rapid and high-throughput techniques to screen for an effective NHEJ inhibitor drug is imperative for the suppression of NHEJ during tumor treatment. However, traditional screening methods are too cumbersome to meet the current need. Zebrafish is an ideal model for drug screening due to the specificity of its early embryonic development and similarity of tumor cell generation. By exploiting the high frequency of NHEJ in early embryonic development, we established a model that uses a transcriptional terminator signal fragment from the Simian virus 40 (SV40) to cause embryonic lethality. SV40 fragment-induced embryonic lethality was alleviated by 5,6-bis ((E)-benzylideneamino)-2-mercaptopyrimidin-4-ol or C18H14N4OS (SCR7), an NHEJ inhibitor.Materials and methodsA 122 bp SV40 terminator fragment (10 ng/µL) was microinjected into zebrafish zygotes. SV40 fragment integration into the zebrafish embryonic genome was detected by Southern blot using a DNA probe for the SV40 terminator. Embryonic lethality rates were observed 24 and 48 h after microinjection. A nonhomologous recombinant inhibitor, SCR7 (5 µM), was used to alleviate embryonic lethality.ResultsMicroinjection of zebrafish embryos with the SV40 terminator fragment (10 ng/µL) caused a progressive increase in mortality over time. Using Southern blots, we confirmed that SV40 terminator sequences were integrated into the zebrafish embryonic genome. This phenomenon was effectively alleviated by addition of SCR7.ConclusionInjection of an SV40 terminator into zebrafish embryos may cause embryonic lethality due to NHEJ during early zebrafish development. The high mortality of zebrafish embryos could be alleviated by using the NHEJ inhibitor, SCR7. The zebrafish model presented here is simpler and more convenient than traditional methods of screening for NHEJ inhibitors and can be utilized in large-scale drug screens for NHEJ inhibitors and for the development of novel anticancer drugs.

Oxidative stress and NF-κB signaling are involved in LPS induced pulmonary dysplasia in chick embryos

ABSTRACTInflammation or dysbacteriosis-derived lipopolysaccharides (LPS) adversely influence the embryonic development of respiratory system. However, the precise pathological mechanisms still remain to be elucidated. In this study, we demonstrated that LPS exposure caused lung maldevelopment in chick embryos, including higher embryo mortality, increased thickness of alveolar gas exchange zone, and accumulation of PAS+ immature pulmonary cells, accompanied with reduced expression of alveolar epithelial cell markers and lamellar body count. Upon LPS exposure, pulmonary cell proliferation was significantly altered and cell apoptosis was inhibited as well, indicating a delayed progress of pulmonary development. LPS treatment also resulted in reduced CAV-1 expression and up-regulation of Collagen I, suggesting increased lung fibrosis, which was verified by Masson staining. Moreover, LPS induced enhanced Nrf2 expression in E18 lungs, and the increased reactive oxygen species (ROS) production was confirmed in MLE-12 cells in vitro. Antioxidant vitamin C restored the LPS induced down-regulation of ABCA3, SP-C and GATA-6 in MLE-12 cells. Furthermore, LPS induced activation of NF-κB signaling in MLE-12 cells, and the LPS-induced decrease in SP-C expression was partially abrogated by blocking NF-κB signaling with Bay-11–7082. Bay-11–7082 also inhibited LPS-induced increases of ROS and Nrf2 expression. Taken together, we have demonstrated that oxidative stress and NF-κB signaling are involved in LPS induced disruption of pulmonary cell development in chick embryos.

Immunogenicity and safety of a live Riemerella anatipestifer vaccine and the contribution of IgA to protective efficacy in Pekin ducks

Riemerella anatipestifer (RA) infections cause major economic losses in the duck industry.In this study, we developed an RA vaccine to control virulent serotype 1 and 2 RA, which predominate in worldwide prevalence. We established a strategy for vaccine candidate screening, and selected strains D15-RDA-92 (serotype 1) and D14-RDA-8 (serotype 2). These strains were characterized by ≤50% embryo mortality and <3.0 serum resistance assay values in in vitro screening. We evaluated the protective efficacy of live bivalent RA vaccines against virulent homologous serotype RA. Ducklings received two oral immunizations with the bivalent vaccine and showed significant protection against two virulent strains (serotypes 1 and 2) at 21 days post-immunization. No death or clinical signs of diarrhea, tremors, or limb swelling were observed in the immunized ducks. In a safety evaluation, ducks immunized with 100 times higher doses showed no clinical signs, mortality, gross lesions, or histological lesions, and body weight of the ducks showed no significant difference compared to that of negative controls. In addition, IgA analysis showed a significant increase in secretory IgA antibodies generated in the trachea and duodenum of orally immunized ducks at 28 days of age. The IgA might be involved in one of the major immune responses to RA and contributes to protecting against virulent RA. In this study, we developed monovalent and bivalent RA vaccines that were safe in ducks and provided significant protective efficacy against virulent homologous RA strains.

A field experiment demonstrating risk on the seafloor for planktonic embryos

AbstractMost solitary marine eggs are shed into the plankton. Presumably the seafloor is more dangerous than the plankton for small solitary embryos, but estimates of benthic mortality of solitary embryos are few. To assess risk, we introduced suspensions of sinking, early stage embryos into conical chambers whose basal surfaces differed in mesh size and distance of mesh from the sediment surface. Surviving embryos hatched as blastulae and swam upward into an apical collection tube, later removed for counting. Test embryos were of a clypeasteroid echinoid. The two test sites, within a coastal lagoon in the NE Pacific, differed in sediments. At both sites, mean proportion of embryos retrieved was 0 and near 0 in chambers floored with 0.9 mm and 0.08 mm meshes at the sediment surface, but greater in chambers floored with a 0.08 mm mesh about 6 cm above the sediment (0.40 and 0.42) and also with a different chamber design with finer (0.055 mm) mesh at the sediment (0.42). Mean proportion retrieved was still greater (0.68 and 0.67) with chambers floored with a complete barrier at the sediment surface and similar to retrieval with chambers in laboratory aquaria without sediment. Estimated mortality rates for embryos on the sediment exceeded published estimates from the plankton. The results support the hypothesis that solitary eggs are released to the plankton because of benthic risks. This method can be used at varied sites on the seafloor, with varied embryos, and with varied protective barriers to test the generality of these results.

Toxic effects of cyhalofop-butyl on embryos of the Yellow River carp (Cyprinus carpio var.): alters embryos hatching, development failure, mortality of embryos, and apoptosis.

As a universal environmental contaminant, the herbicide cyhalofop-butyl is considered to have infested effects on the embryonic development of aquatic species. The present study focused on an assessment of the impacts of cyhalofop-butyl on Yellow River carp embryos. It was found that cyhalofop-butyl inhibited the hatching of the embryos, and the hatching rate decreased with higher concentrations of the herbicide. The mortality rate was increased on exposure to cyhalofop-butyl and was significantly higher in the 1.6 and 2mg/L treatment groups over 48h. All of the embryos of the 2mg/L treatment group died within the 48h post-hatching stage. And the transcription of several embryos related to apoptosis was also influenced by cyhalofop-butyl exposure. Further, cyhalofop-butyl exposure leads to a series of morphological changes (pericardial edema, tail deformation, and spine deformation) in embryos, which were consistent with significant modifications in the associated genes. These results provided a scientific basis for further studies into the effects of cyhalofop-butyl on aquatic organisms.

INFLUENCE OF WEIGHT OF MEAT-TYPE HYBRID HATCHING EGGS ON INCUBATION RESULTS

The aim of study was to examine the values of the incubation parameters(weight loss, fertilization, hatchability of placed and fertilized eggs, total, early,middle and late embryonic mortality) of eggs of different weights in brolier hybridCobb 500. In total, 600 eggs were divided into four equal groups (n = 150 each)according to their weight: 57.5-62.5 g (S); 62.6-67.5 g (M); 67.6-72.5 g (L) and 72.6-77.50 g (XL). Values of incubation parameters were determined and statisticallyprocessed by standard methods. The weight of eggs significantly influenced the lossof egg weight during incubation (p&lt;0.05), with this loss being higher in smaller eggs(group S 11.10% and group M 11.40%) compared to larger eggs (group L 10.42%and group XL 10.31%). Hatchability of all eggs in groups S, M, L and XL was 76.0;75.3; 78.7 and 66.0%, respectively, and for fertilized it was 82.0; 81.3; 82.5 and71.7%, respectively, with no significant difference (p&gt;0.05). The weight of eggs didnot significantly affected the difference in embryo mortality values, although in theXL egg group a higher value of total, early and late mortality was found, comparedto other groups. The results of this study indicate lower hatchability and highermortality of embryos in eggs of extremely large weight, compared to other groups,which indicates that special attention should be given to the selection of hatchingeggs in terms of their weight.

Zebrafish embryo bioassays for a comprehensive evaluation of microalgae efficiency in the removal of diclofenac from water

This work deals with a preliminary study aimed at evaluating the efficiency of three different microalgae strains, namely Chlorella sorokiniana, Chlorella vulgaris and Scenedesmus obliquus in the bioremediation of diclofenac contaminated water. For this purpose, microalgae were cultured in bubbling column photobioreactors (PBRs) under batch operation until the end of the exponential growth phase. For the three strains, the concentration of diclofenac in the PBRs aquatic medium decreased along microalgae growing, which pointed to biodegradation as the main removal mechanism. Among the three strains, S. obliquus was the most capable to reduce diclofenac concentration (99% removal from an initial concentration of 25,000 μg l−1). However, such a large removal does not guarantee an efficient treatment since transformation products (TPs) exceeding the concentration and/or toxicity of the parent compound may be generated during biodegradation of diclofenac. Thus, for a comprehensive evaluation of the microalgae treatments efficiency, the final effluents from the PBRs were tested for their effects on the embryonic development of zebrafish. Again, the S. obliquus treatment was the most efficient in the reduction of toxicity, with the corresponding effluents having no effects on the embryo's mortality or abnormalities incidence (at 80 h post fertilization). In any case, for the three strains, the toxicity effects of effluents were equal or lower than those determined for diclofenac solutions with the same concentration. Therefore, it may be stated that, at the end of the batch culture, the removal of diclofenac by the considered strains did not involve the generation of toxic TPs to zebrafish embryos.

Assessment of the Toxic and Teratogenic Effects of Kamagong (Diospyros discolor Willd.) Leaves Extract to the Developing Embryo of Zebrafish (Danio rerio)

This work highlighted the embryo-toxic and teratogenic effects of D. discolor leaves extract to the embryo of D. rerio, a model. Apparently, 100% mortality of embryos was observed in 5% and 10% treatment concentration at 12 hpta. Meanwhile, mortality in lower concentrations increases as time of exposure is prolonged and as the amount of treatment concentration increases. Coagulation was the toxic effect of the plant water extract. On the other hand, heartbeat and hatchability rate decreases as the amount of treatment concentration increases. In terms of teratogenicity, tail malformation was the most marked teratogenic effect of the plant extract. Moreover, growth retardation, head malformation, yolk deformities and abdominal edema were observed. Altogether, D. discolor leaves water extract exhibit toxic and teratogenic effects against D. rerio embryo. Thus, this plant contains active phytochemical components that can be developed as anticancer drugs.

Virulence of Escherichia coli Isolates Obtained from Layer Chickens with Colibacillosis Associated with Pericarditis, Perihepatitis, and Salpingitis in Experimentally Infected Chicks and Embryonated Eggs.

To evaluate the virulence of avian pathogenic Escherichia coli (APEC) isolates obtained from colibacillosis cases associated with pericarditis, perihepatitis, and salpingitis, the embryo lethality assay and experimental infection model in chicks were used in this study. According to the established criteria based on mortality in the embryo lethality assay for evaluating the virulence of E. coli isolates, 23 of the 26 APEC isolates associated with pericarditis and perihepatitis and 8 of the 20 isolates associated with salpingitis were found to be virulent. Isolate D137, which had been obtained from a case with pericarditis and perihepatitis and had an embryo mortality of 92%, and isolate D445, which had been obtained from a case with pericarditis and perihepatitis and had an embryo mortality of 17%, were used for the experimental infection. Four of the five 11-day-old chickens inoculated through the air sac with isolate D137 died 1 day postinoculation, and the challenge strain was recovered from the air sac, pericardial sac, or liver; however, colibacillosis lesions were found in only one of the five birds postmortem. All five chicks inoculated with isolate D445 survived for 7 days postinoculation and exhibited airsacculitis or pericarditis lesions at 7 days postinoculation; the challenge strain was not recovered from the lesions postmortem. The results obtained in this study suggest that the different APEC isolates tested cause illness in chickens through distinct pathogenesis.