Cu-doped Fe3O4 nanoparticles for efficient detoxification of epsilon toxin: Toward substituting magnetically recyclable detoxifying agent for formaldehyde

This research presents the synthesis and characterization of Cu-doped Fe3O4 (Cu-Fe3O4) nanoparticles as a magnetically recoverable and reusable detoxifying agent for the efficient and long-lasting neutralization of bacterial toxins. The nanoparticles were synthesized using the combustion synthesis method and characterized through SEM, XRD, BET, TGA, and VSM techniques. The detoxification potential of Cu-Fe3O4 was compared with traditional formaldehyde (FA) in detoxifying epsilon toxin (ETx) from Clostridium perfringens Type D, the causative agent of enterotoxemia in ruminants. In vivo residual toxicity tests revealed that Cu-Fe3O4 could detoxify ETx at a concentration of 2.0 mg mL-1 within 4 days at room temperature (RT) and 2 days at 37 °C, outperforming FA (12 and 6 days at RT and 37 °C, respectively). Characterization studies using dynamic light scattering (DLS) and circular dichroism (CD) highlighted lower conformational changes in Cu-Fe3O4-detoxified ETx compared to FA-detoxified ETx. Moreover, Cu-Fe3O4-detoxified ETx exhibited exceptional storage stability at 4 °C and RT for 6 months, maintaining an irreversible structure with no residual toxicity. The particles demonstrated remarkable reusability, with the ability to undergo five continuous detoxification batches. This study provides valuable insights into the development of an efficient and safe detoxifying agent, enabling the production of toxoids with a native-like structure. The magnetically recoverable and reusable nature of Cu-Fe3O4 nanoparticles offers practical advantages for easy recovery and reuse in detoxification reactions.

Effect of formalin percentage, incubation time and temperature on Clostridium chauvoei culture inactivation and immunogenicity

OBJECTIVES

In order to find the optimal inactivation conditions for Clostridium chauvoei culture, different factors were investigated and the immunogenicity of inactivated cultures was studied.

METHODS

C. chauvoei was cultured with different formalin percentages (0.3, 0.5 or 0.7% V/V), inactivation temperatures (37 °C or room temperature) and incubation times (one or two weeks). Sterility tests were performed and residual formaldehyde and pH were measured. Rabbits were immunized twice with inactivated cultures and sera were used for detection of immune response.

RESULTS

In the one-week experiment, 0.5 and 0.7% formalin inactivated the bacteria after one week, and the percentage of 0.3 inactivated after three weeks. The residual formaldehyde at weeks 1 and 8 was not significantly different. In the two-week experiment, cultures treated with 0.3 and 0.5% formalin were inactivated after four weeks, and those with 0.7% formalin were inactivated after three weeks. Residual formaldehyde at week 8 differed significantly from that of week 1. Residual formaldehyde was affected by incubation temperature since it was lower at 37 °C than in room temperature. Also, a significant effect was observed for formalin on pH, as higher formalin contents led to lower pH values of the cultures. ELISA showed the lowest antibody titer achieved by 0.7% formalin group. Antibody titer was not different between 0.3 and 0.5% formalin.

CONCLUSIONS

The best condition for inactivation of C. chauvoei was considered as one-week incubation with 0.5% formalin at 37 °C, leading to a high antibody response.

Diagnosis of Pebrine Disease in Silkworm Using Molecular Methods

Since pebrine disease, as the most important and dangerous disease in silkworms, spreads horizontally through the spores and vertically through the eggs, combating the disease and eliminating it completely from livestock production has been associated with numerous problems. This project aimed to identify the molecular cause of pebrine disease in silkworms using a sensitive, specific, and accurate method. To this purpose, a 136 bp fragment was selected based on the Nosema bombycis partial SSU rDNA sequence, and a pair of primers was designed. Afterward, using the conventional polymerase chain reaction (PCR) method, the target fragment was amplified and sequenced. After that, to determine the detection sensitivity, using the Real-Time PCR method, 5-fold serial dilutions of N. bombycis DNA were prepared, and the last dilution that produced a fluorescent signal was considered the minimum detection limit. All tests were performed in duplicates. Based on the results of the sensitivity test, the standard curve including Ct values ​​and DNA concentration was used for analysis. Moreover, 80 unknown samples examined by light microscope were evaluated using conventional PCR and Real-Time PCR. Both PCR results showed no amplification for the negative control samples. The findings demonstrated that the lowest detection limit for N. bombycis was less than 6 pg of DNA, while, this amount was 8 ng for conventional PCR. Out of 80 samples examined, 55, 60, and 62 samples were positive for light microscope, conventional PCR, and Real-Time PCR methods, respectively. The findings suggested that the Real-Time PCR method had a higher ability to detect the causative agent of pebrine disease than the conventional PCR method, and both methods were superior to light microscopy. Therefore, due to the fewer steps and higher accuracy of Real-Time PCR, it can be introduced as a suitable method for diagnosing pebrine disease.

Minimally invasive approach in symptomatic aberrant right subclavian artery treatment

INTRODUCTION AND IMPORTANCE

Anomalous right subclavian artery (ARSA) represents an uncommon anatomical deviation concerning the genesis of the right subclavian artery. As the predominant embryological irregularity of the aortic arch, it is clinically recognized as arteria lusoria (AL).

CASE PRESENTATION

This study, describe the instance of a 22-year-old female exhibiting a non-aneurysmal, symptomatic anomalous right subclavian artery (ARSA) coursing posteriorly to the esophagus, as evidenced by thoracic computed tomography (CT) imaging.

CLINICAL DISCUSSION

As an attractive option, a minimally invasive surgical method was used to treat the patient, and the anomalous vessel was closed from the closest location to its origin in the aortic arch during a short time thoracoscopic surgery.

DISCUSSION, CONCLUSION

Compared to the common surgical methods to treat this anomaly, the complications and morbidity resulting from this method are much less and the length of stay in the hospital is shorter and the results are acceptable.

Virulence genes and antibiotic resistance profiles of Staphylococcus aureus isolated from bovine mastitis milk samples

Background

The increasing importance of antibiotic resistance shows the need for determining indices of the epidemiology of infection.

Aims

This study aimed to determine the virulence genes and antibiotic resistance profiles of Staphylococcus aureus isolated from bovine mastitis cases.

Methods

A total of 200 cattle were selected based on California Mastitis Test (CMT) results, and the samples were cultured in the laboratory. Grown colonies were examined by conventional phenotypic methods and confirmed using PCR amplification of 16S rRNA gene. The prevalence of the virulence genes was also defined. The results of phenotypic and molecular tests were compared using SPSS software by McNemar test. Then, the confirmed isolates were tested for antibiotic susceptibility using the disc diffusion method.

Results

Of the 200 positive CMT cattle, 24 animals were positive for S. aureus and confirmed using 16S rRNA gene amplification. Statistical analysis showed that the phenotypic and genotypic tests of hemolysin genes were not significantly different (P>0.01). PCR analysis revealed the presence of coa and clfa genes in more than half of the cases. Overall, nine genetic profiles of virulence factors were found among S. aureus isolates. The highest and lowest resistance rates were against penicillin and gentamicin, respectively.

Conclusion

Our findings showed a high rate of antibiotic resistance. So, accurate and fast diagnosis and antimicrobial susceptibility tests should be considered before prescribing the drugs.

Major pathogenic Clostridia in human and progress toward the clostridial vaccines

The Clostridium genus is composed of a large spectrum of heterogeneous bacteria. They are Gram-positive, mostly mesophilic, and anaerobic spore-forming strains. Clostridia are widely distributed in oxygen-free habitats. They are found principally in the soil and intestines of ruminants as normal flora, but also are the cause of several infections in humans. The infections produced by important species in humans include botulism, tetanus, pseudomembranous colitis, antibiotics-associated diarrhea, and gas gangrene. Immunization with toxoid or bacterin-toxoid or genetically modified or other vaccines is a protective way against clostridial infection. Several experimental or commercial vaccines have been developed worldwide. Although conventional vaccines including toxoid vaccines are very important, the new generation of vaccines is an effective alternative to conventional vaccines. Recent advances have made it possible for new vaccines to increase immunogenicity. This review discusses briefly the important species of clostridia in humans, their toxins structure, and vaccine development and usage throughout the world.

Molecular Characterization of a New Nosema bombycis Strain Detected in Iranian Silkworm Farms

PURPOSE

Pebrine as the most dangerous disease of silkworm mostly caused by Nosema species has caused huge economic losses. There is no information on the species and the genomic sequences of the pebrine-causing microsporidia in Iran.

METHODS

In the present research, we tried to determine the sequences of two regions of rDNA using molecular methods. First, infected larvae and mother moths were collected from several farms in the north of Iran for identification and molecular characterization of microsporidian isolates. After extracting the spores and genomic DNA from the collected samples, two fragments of internal transcribed spacer (ITS) rDNA and small subunit (SSU) rDNA were amplified and sequenced, and registered in NCBI database and then, the phylogenetic tree was drawn.

RESULTS

Results showed the obtained sequences (ITS rDNA: Accession No. MZ322002 and SSU rDNA: Accession No. MZ314703) represent a new strain of Nosema bombycis, which differs from the sequences deposited in the NCBI.

CONCLUSION

The new N. bombycis strain identified in our study will help in control and management of the pebrine disease by specific detection of the infectious agent.

Comparison of flagellin and an oil-emulsion adjuvant in inactivated Newcastle disease vaccine in stimulation of immunogenic parameters

The present study was designed to investigate the potential application of native (N) and recombinant (truncated modified [tmFliC] and full-length [flFliC]) flagellin proteins along with inactivated Newcastle disease virus (NDV). Fifty six SPF chickens were immunized twice with PBS (control), inactivated NDV (Ag), inactivated NDV/flFliC (AgF), inactivated NDV/tmFliC (AgT), inactivated NDV/N (AgN), commercial vaccine containing Montanide (Vac) and Vac/N (VacN), with a two-week interval. Blood was collected weekly and spleens were harvested after chickens were sacrificed. Interleukin-6 (IL-6) and tumor necrotic factor-α (TNF-α) gene expression in peripheral blood mononuclear cells were analyzed by Real-Time PCR. Antibody response was assessed by haemagglutination inhibition (HI). Cellular activity was quantified by MTT assay. Results showed that the most IL-6 and TNF-α gene expression was observed in AgF group (P < 0.01). The lowest gene expression among vaccinated groups was observed in Ag group for IL-6 and Ag and Vac group for TNF-α. The highest HI titer was observed in Vac, VacN, AgF and AgT groups. The AgF group showed the highest cellular activity (P < 0.01). In conclusion, flagellin-adjuvanted groups showed a pro-inflammatory effect and acted similarly to or better than the Vac group. Hence, flagellin can be proposed as a potential adjuvant for ND vaccine.

Are Epitopic Sites of 3AB and 3D Nonstructural Proteins Sufficient for Detection of Foot and Mouth Disease?

An efficient method for detection of foot and mouth disease (FMD) and, particularly, differentiation of vaccinated from infected animals is the use of nonstructural (NS) proteins as antigens in Enzyme-Linked Immunosorbent Assay (ELISA) Kits. In this study, only epitopic regions of 3AB and 3D NS proteins were used for recombinant protein production, as a cost-effective method instead of peptide synthesis, for application in in-house ELISA diagnostic kits. Specific primers were designed according to the antigenic regions of 3AB (C-terminus of 3A and the whole 3B) and 3D (N-terminus) proteins, and the polymerase chain reaction (PCR) amplification was performed. Purified amplicons were cloned into pET21a (+) vectors and then transformed into Escherichia coli (BL21). Thereafter, bacteria were induced with 1 mM isopropyl β-d-1-thiogalactopyranoside (IPTG) for expression of antigenic proteins. Antigenic 3AB protein was expressed in soluble form, but 3D protein was extracted from the bacterial lysate. Protein expression was confirmed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analyses. An indirect ELISA was developed for each protein, and the diagnostic sensitivity and specificity were determined. The 3AB-ELISA showed higher sensitivity and specificity than 3D-ELISA (95.24% and 100%, compared with 90.48% and 88.71%, respectively). The epitopic 3AB-ELISA developed here can be used for detection and differentiation of FMD infected from vaccinated animals, but the epitopic 3D-ELISA showed lower efficiency in screening for FMD status.

The effect of cytoplasmic crude extracts of Trichophyton verrucosum on cell mediated immunity

OBJECTIVE

Trichophyton verrucosum is a slow growing dermatophyte responsible for a number of skin diseases such as ringworm, and is characterized by patches of hair loss and thick crusts on the host skin in domestic animals. In this study, we examined the immunomodulatory effects of crude extract of Trichophyton verrucosum (TV)cytoplasm in a mouse model.

METHODS

The TV variate was cultured on Sabouraud dextrose agar and the mycelium was grinded by mechanical force. The purified protein was obtained from crude extract of the fungus, and protein concentration was measured by BradFord assay. Six to eight week-female BALB/c mice were divided into three groups: test group, receiving cytoplasmic crude extract plus defibrinated sheep blood; control group, receiving defibrinated sheep blood; and normal group, receiving normal saline. Injections were performed on days 0, 3, 5, 7 and 9 and the mice were sacrificed four days after the last injection. T lymphocyte metabolic activity was examined by methyl thiazol tetrazolium (MTT) assay, and also interleukin-4 (IL-4) and interferon-γ (IFNγ) levels were evaluated by enzyme-linked immunosorbent assay (ELISA).

RESULTS

MTT assay showed that the TV extract stimulated lymphocyte metabolic activity. ELISA results showed that despite increase in the level of IFNγ, no changes were observed in IL-4 level.

CONCLUSIONS

Results indicated that crude extract of TV cytoplasm may probably act as an immune modulator, which affects Th₁ responses. The TV crude extract may be an appropriate agent to induce cellular immunity for combating dermatophytosis infection in animals; and therefore, TV extract may have some potential applications in vaccine/adjuvant technology.

Effect of flagellin on inhibition of infectious mechanisms by activating opsonization and salmonella flagellum disruption

Some serovars of salmonella cause huge global diseases such as enteric fever and invasive non typhoidal Salmonella disease. Flagellin as a key antigenic component of salmonella, can induce humoral and cellular immunity responses. In this research, we performed an opsonophagocytic killing assay (OPKA) as an important mechanism of the host-defense system, for salmonella to study the activity of anti-sera of native FliC, truncated modified recombinant FliC (tmFliC) and full length recombinant FliC proteins (flFliC). Also, the potency of antibodies for inhibiting bacterial movement was evaluated by traditional and newly-designed motility inhibition assay methods. Results showed both recombinant FliC anti-sera and native FliC (nFliC) anti-serum had the ability to opsonize Salmonella typhimurim, which led to bacterial clearance by mice macrophages. Also, inhibition of bacterial motility was observed for all anti-sera. Anti-nFliC and anti-flFliC sera showed higher effects on Salmonella typhimurim motility than that of tmFliC. In traditional method, about 88%, 86% and 80% inhibition were observed by using 5% nFliC, anti-flFliC and anti-tmFliC sera, respectively. In the newly-designed method using SIM (Sulfide indole motility) medium, results confirmed the traditional method for motility inhibition. Our findings suggest that salmonella fliC as a protective antigen may disrupt the flagellum apparatus activity.

Immunostimulatory effects of truncated and full-length flagellin recombinant proteins

Problems regarding purification efficacy in recombinant technologies is due to the protein structure. Experimental manipulation of genes and the subsequent proteins may overcome this issue. In order to improve production efficacy and maintain immunestimulatory effect of flagellin, the Toll-like Receptor 5 (TLR5) ligand and a potent adjuvant, we performed a bioinformatic study to find the best model for FliC manipulation. Truncated modified FliC (tmFliC) and full length FliC (flFliC) genes were cloned and expressed in pET-21a vector and protein purification was carried out using an improved His-Tag method. Polyclonal antibodies were generated against flFliC and tmFliC in New Zealand white rabbits. IgG response to the recombinant proteins was determined by ELISA. Cross-reactivity assay was performed by ELISA for all proteins and bacteria. Immunogenicity of tmFliC and flFliC was evaluated in chicken cells, and expression level of tumor necrotic factor-α (TNF-α) and interleukin-6 (IL-6) were relatively analyzed by Real-Time-PCR. Results showed high purification efficacy for tmFliC. Antibody titer of tmFliC was significantly higher than that of flFliC. In addition, the cross-reactivity assay for both proteins and Salmonella was positive which indicates similar epitopic regions. Stimulation of both FliCs significantly increased TNF-α and IL-6 expression in peripheral blood mononuclear cells (PBMCs) and splenocytes, with higher effect observed with flFliC. IL-8 protein level increased after 6 and 24 h stimulation with different concentrations of tmFliC and flFliC. These results suggest that the aimed gene modification in fliC gene produces a bioactive immunostimulant type of flagellin which upregulates TLR5 downstream genes as well as in flFliC.

Effect of purmorphamine on the mRNA expression of Sonic Hedgehog signaling downstream molecules in ovine embryo

Abstract. Sonic Hedgehog (SHH) is a signaling pathway mediated through a receptor system which seems to have effects on oocyte maturation and embryonic development. Purmorphamine is an SHH agonist that performs a crucial role in the regulation of the activity of SHH receptors and downstream transcription factors. The aim of this study was to analyze the effect of purmorphamine on the mRNA expression of SHH signaling downstream molecules (Patched1, Glioma-Associated Oncogene1, Smoothened, Histone Deacetylase1, Histone Deacetylase2 and Histone Deacetylase3) in ovine two-cell embryo. Ovaries were obtained from a slaughterhouse, and cumulus–oocyte complexes were aspirated and cultured in maturation media containing 0, 250 or 500 ng mL−1 purmorphamine. Then, oocytes were fertilized and cultured in a CR1 culture medium and after 24 h, two-cell embryos were collected for RNA extraction. Gene expression was evaluated by real-time polymerase chain reaction (PCR). Results indicated that in 250 ng mL−1 purmorphamine, Smo, Ptch1 and Hdac3 expression reduced, Hdac1 expression increased, and Gli1 and Hdac2 expression levels did not change. In 500 ng mL−1 purmorphamine, Gli1 and Smo transcripts increased, while Ptch1, Hdac2 and Hdac3 transcripts decreased. Regarding to the presence of SHH signaling molecules in two-cell embryos and their response to purmorphamine, it can be suggested that SHH signaling is probably active before embryonic genome activation in ovine embryos.

Expressional and Bioinformatic Analysis of Bovine Filia/Ecat1/Khdc3l Gene: A Comparison with Ovine Species

Maternal effect genes have highly impressive effects on pre-implantation development. Filia/Ecat1/Khdc3l is a maternal effect gene found in mouse oocytes and embryos, loss of which causes a 50% decrease in fertility. In the present study, we investigated Filia mRNA expression in bovine oviduct, 30- to 40-day fetus, liver, heart, lung, and oocytes (as a positive control), by RT-PCR and detected it only in oocytes. A 443 bp fragment was amplified only in oocytes and was sequenced as a part of bovine predicted Filia mRNA. We analyzed bovine and ovine Filia N-terminal peptide sequence in PHYRE2, and a KH domain was predicted. Protein alignment using ClustalW indicated a highly identical N-terminal extention between the 2 species. Immunohistochemical analysis using anti-bovine Filia antibody showed the expression of Filia protein in the zone surrounding the nuclear membrane, and in the subcortex of ovine oocytes of primary and antral follicles. However, in the bovine, Filia has been found through the oocyte cytoplasm of antral follicles, and here it is further confirmed in the primary follicles. Our data suggests a difference in Filia expression pattern between cow and sheep, although the sequence is highly conserved.

Quantitative analysis of RNA abondance for CTCF during reprogramming of bovine embryo from oocyte to blastocyst

Abstract. CTCF is a highly conserved protein among eukaryotes and it is involved in many of regulatory functions including, transcriptional repression and activation, chromatin insulation, imprinting, X chromosome inactivation, higher-order chromatin organization, and alternative splicing. Studies performed on mouse embryos indicate that CTCF can be a maternal-effect gene, and is essential for normal development of embryos. CTCF can be used as a molecular effector for the proper epigenetic establishment of embryonic development. The aim of this study was to determine changes in transcript levels of the CTCF gene in bovine preimplantation embryos. RNA was extracted from immature and mature oocytes and embryos at various developmental stages (two-cell, four-cell, eight-cell, and blastocysts). Results showed that the amounts of CTCF transcripts decreased in mature oocyte in comparison with immature oocytes, but this change was not significant. In addition, the amount of CTCF transcript in embryos at two-cell, four-cell, eight-cell, and blastocyst stages significantly increased in comparison with immature oocytes. These data show that CTCF expression in bovine embryo begins at minor embryonic genome activation.

Expression of bovine Ecat1 gene in immature and in vitro matured oocytes as well as during early embryonic development

Ecat1 is a maternal effect gene that is exclusively expressed in oocytes and embryonic stem cells, and has an important role in pre-implantation development. This study was designed to investigate the expression of bovine Ecat1 gene in immature and in vitro matured oocytes as well as during early embryonic development, and also Ecat1 protein localization. Samples were obtained from slaughtered animals. RNA extractions were carried out from ovary, immature and in vitro matured oocytes and also different stages of embryonic development (2-, 4-, 8- to 16-cell stages and blastocysts). RT-PCR analysis revealed the expression of Ecat1 in ovary, oocytes and embryos. Analysis in FGENESH online tool predicted three exons and one transcription start site (TSS) in Ecat1 gene, and the 3' RACE-PCR result showed that just one splice variant was amplified. By quantitative real-time PCR technique, we showed that Ecat1 transcript increased at 8- to 16-cell-stage embryos and decreased in blastocyst stage (p < 0.05). Immunofluorescence analysis showed cytoplasmic localization of Ecat1 protein in bovine oocytes. Results demonstrated bovine Ecat1 expression at protein level and also indicated that Ecat1 has a significant higher embryonic expression at 8- to 16-cell stage. This embryonic expression is probably required for further developmental stages.