细化搜索
结果 131-140 的 449
Characterisation of South African field Ehrlichia ruminantium using multilocus sequence typing
2023
Zinathi Dlamkile | Luis Neves | Darshana Morar-Leather | Christopher Brandt | Alri Pretorius | Helena Steyn | Junita Liebenberg
Heartwater, one of the major tick-borne diseases of some domestic and wild ruminants in Africa, is caused by Ehrlichia ruminantium. The genetic diversity of E. ruminantium isolates renders the available vaccine ineffective against certain virulent isolates. To better understand the E. ruminantium genotypes in South Africa, a total of 1004 Amblyomma hebraeum tick deoxyribonucleic acid (DNA) samples from cattle in three South African provinces were tested by pCS20 Sol1 real-time polymerase chain reaction (qPCR) and characterised by multilocus sequence typing (MLST) using five housekeeping genes. Out of 1004 samples tested, 222 (22%) were positive for E. ruminantium. The occurrence of E. ruminantium in Mpumalanga, KwaZulu-Natal and Limpopo provinces was 19%, 22% and 27%, respectively. The E. ruminantium positive samples were screened for housekeeping genes and sequenced. Phylogenetic analysis revealed three main lineages: clade 1 made up of worldwide isolates (eastern, southern Africa, and Caribbean isolates), clade 2 comprised only West African isolates and clade 3 consisted of Omatjenne, Kümm2 and Riverside. Some study sample sequences were not identical to any of the reference isolates. However, they could all be grouped into the worldwide clade. Genetic variation in the sequenced regions was observed in the form of single nucleotide polymorphisms (SNPs). Using MLST to characterise E. ruminantium field isolates allowed the South African genotypes to be clearly distinguished from the distinct West African isolates. Contribution: Characterisation of E. ruminantium field isolates is important for the control of heartwater and contributes to preliminary knowledge required for the development of a more practical vaccine against heartwater.
显示更多 [+] 显示较少 [-]Approaches to increase recovery of bacterial and fungal abortion agents in domestic ruminants
2023
Jonker, Annelize(University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases) | Thompson, Peter N.(University of Pretoria Faculty of Veterinary Science Department of Production Animal Studies) | Michel, Anita L.(University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases)
Abortions in domestic ruminants cause significant economic losses to farmers. Determining the cause of an abortion is important for control efforts, but it can be challenging. All available diagnostic methods in the bacteriology laboratory should be employed in every case due to the many limiting factors (autolysis, lack of history, range of samples) that complicate the investigation process. The purpose of this study was to determine whether the recovery of diagnostically significant isolates from domestic ruminant abortion cases could be increased through the use of a combination of the existing aerobic culture and Brucella selective method with methods that are commonly recommended in the literature reporting abortion investigations. These methods are examination of wet preparations and impression smears stained by the modified Ziehl-Neelsen method, anaerobic, microaerophilic, Leptospira, Mycoplasma and fungal culture. Samples of placenta and aborted foetuses from 135 routine clinical abortion cases of cattle (n = 88), sheep (n = 25) and goats (n = 22) were analysed by the new combination of methods. In 46 cases, bacteria were identified as aetiological agents and in one case a fungus. Isolation of Brucella species increased to 7.4% over two years compared with the previous 10 years (7.3%), as well as Campylobacter jejuni (n = 2) and Rhizopus species (n = 1). Salmonella species (5.9%) and Trueperella pyogenes (4.4%) were also isolated more often. In conclusion, the approach was effective in removing test selection bias in the bacteriology laboratory. The importance of performing an in-depth study on the products of abortion by means of an extensive, combination of conventional culture methods was emphasised by increased isolation of Brucella abortus and isolation of C. jejuni. The combination of methods that yielded the most clinically relevant isolates was aerobic, microaerophilic, Brucella and fungal cultures.
显示更多 [+] 显示较少 [-]Th1 and Th2 epitopes of Cowdria polymorphic gene 1 of Ehrlichia ruminantium
2023
Ngoepe, Tlou A.(Agricultural Research Council-Onderstepoort Veterinary Research Department of Immunology ,University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases,University of Pretoria Faculty of Health Sciences Department of Immunology) | Pretorius, Alri(Agricultural Research Council-Onderstepoort Veterinary Research Department of Immunology ,University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases) | Steyn, Helena C.(Agricultural Research Council-Onderstepoort Veterinary Research Department of Immunology) | van Kleef, Mirinda(Agricultural Research Council-Onderstepoort Veterinary Research Department of Immunology ,University of Pretoria Faculty of Veterinary Science Department of Veterinary Tropical Diseases)
Cowdria polymorphic gene 1 (cpg1, Erum2510, ERUM_RS01380) has been shown to induce 30% and 100% protection in sheep immunised by deoxyribonucleic acid (DNA) prime combined with DNA boost and DNA prime combined with protein boost, respectively, against heartwater infection via needle challenge. To localise its antigenic regions for inclusion in a multi-epitope DNA vaccine against heartwater, Erum2510 was cleaved into five overlapping subfragments. These subfragments were expressed individually in an Escherichia coli host expression system and evaluated for their ability to induce proliferative responses, Th1 and Th2 cytokines (interferon gamma [IFN-γ] and interleukin 4 [IL-4]) via enzyme-linked immunospot (ELISpot), quantitative real time polymerase chain reaction (qRT-PCR) and flow cytometry. Recombinant (r)proteins 3 and 4 were shown to induce immunodominant Th1 and Th2 immune responses characterised by the secretion of effector cytokines IFN-γ and IL-4 in addition to differential messenger ribonucleic acid (mRNA) expression of tumour necrosis factor (TNF), IL-2, IL-1, IL-18, IL-10, transforming growth factor (TGF), granulocyte-macrophage colony-stimulating factor (GM-CSF) and inducible nitric oxide synthase (iNOS). Thirty-seven overlapping synthetic peptides (16 mer) spanning the lengths of these immunodominant rproteins were synthesised and assayed. A peptide pool comprising p9 and p10 derived from rprotein 3 induced a Th1-biased immune response. A peptide pool comprising p28 and p29 derived from rprotein 4 induced a mixed Th1 and Th2 immune response characterised by secretion of IFN-γ and differential mRNA expression of IL-1, IL-2, IL-10, IL-12, iNOS, TGF, TNF and GM-CSF. Only one of the peptides (p29) induced secretion of IL-4. Phenotypic analysis showed significant activation of cluster of differentiation 8+ (CD8+), cluster of differentiation 4+ (CD4+) and B+ lymphocyte populations. Findings suggest that Erum2510 rproteins and synthetic peptides can induce both cellular and humoral immune responses, thereby implicating their importance in protection against heartwater. CONTRIBUTION: This study will facilitate the design of an effective multi-epitope DNA vaccine against heartwater that will contribute to control this economically important disease in sub-Saharan Africa and beyond.
显示更多 [+] 显示较少 [-]Chemical composition and antibacterial activity of bee venom against multi-drug resistant pathogens
2023
Gökmen, Tülin G.(Cukurova University Ceyhan Veterinary Faculty Department of Microbiology) | Yazgan, Hatice(Cukurova University Ceyhan Veterinary Faculty Department of Food Hygiene and Technology) | Özdemir, Yıldız(Adana City Hospital Microbiology Laboratory) | Sevin, Sedat(Ankara University Veterinary Faculty Department of Pharmacology and Toxicology) | Turut, Nevin(Veterinary Control Institute Microbiology Laboratory) | Karahan, Şifa(Veterinary Control Institute Microbiology Laboratory) | Eşki, Funda(Cukurova University Veterinary Faculty Department of Obstetrics and Gynecology) | Kıvra, İbrahim(Koçman University Mugla Vocational School Department of Chemistry and Chemical Processing Technologies) | Sezer, Osman(Veterinary Control Institute Parasitology Laboratory) | Ütük, Armağan E(Cukurova University Ceyhan Veterinary Faculty Department of Parasitology)
Bee venom with an antimicrobial effect is a powerful natural product. One of the most important areas where new antimicrobials are needed is in the prevention and control of multi-drug resistant pathogens. Today, antibacterial products used to treat multi-drug resistant pathogen infections in hospitals and healthcare facilities are insufficient to prevent colonisation and spread, and new products are needed. The aim of the study is to investigate the antibacterial effect of the bee venom (BV), a natural substance, on the species of Methicillin resistant Staphylococcus aureus, Vancomycin resistant Enterococcus faecalis, Carbapenem resistant Escherichia coli, Carbapenem resistant Klebsiella pneumoniae and Carbapenem resistant Acinetobacter baumannii. As a result of this study, it was found that MIC90 and MBC90 values ranged from 6.25 μg/mL - 12.5 μg/mL and numbers of bacteria decreased by 4-6 logs within 1-24 h for multi-drug resistant pathogens. In particular, Vancomycin resistant Enterococcus faecalis isolate decreased 6 log cfu/mL at 50 μg/mL and 100 μg/mL concentrations in the first hour. The effective bacterial inhibition rate of bee venom suggests that it could be a potential antibacterial agent for multi-drug resistant pathogens. CONTRIBUTION: The treatment options of antibiotic-resistant pathogens are a major problem in both veterinary and human medicine fields. We have detected a high antibacterial effect against these agents in this bee venom study, which is a natural product. Apitherapy is a fashionable treatment method all over the world and is used in many areas of health. Bee venom is also a product that can be used as a drug or disinfectant raw material and can fill the natural product gap that can be used against resistant bacteria.
显示更多 [+] 显示较少 [-]Monitoring the genetic variation of some Escherichia coli strains in wild birds and cattle
2023
Ibrahim, Ghada A.(Animal Health Research Institute Agriculture Research Center Bacteriology Department) | Salah-Eldein, Ahmed M.(Suez Canal University Faculty of Veterinary Medicine Wildlife and Zoo Department) | Al-zaban, Mayasar l.(Princess Nourah bint Abdulrahman University College of Science Department of Biology) | El-Oksh, Amal S.A.(Animal Health Research Institute Agriculture Research Center Biotechnology Department, Reference Lab of Quality Control of Poultry Production) | Ahmed, Elsayyad M.(Agricultural Research Center Animal Health, Research Institute Department of Virology) | Farid, Doaa S.(Arish University Faculty of Environmental Agricultural Sciences Department of Environmental Protection) | Saad, Enas M.(Suez Canal University Faculty of Veterinary Medicine Wildlife and Zoo Department)
To date, there is limited data about the genetic relationship of Escherichia coli between wild birds and cattle because these birds act as silent vectors for many zoonotic bacteria. This study aimed to elucidate the role of rooming wild birds in the vicinity of cattle farm in transmission of the same pathogenic E. coli variants, identifying their virulence, resistance traits and genetic similarities of fimH virulence gene. About 240 faecal/cloacal swabs were collected from both species and examined bacteriologically. Escherichia coli was yielded in 45.8% and 32.5%, respectively, of examined cattle and wild birds. The most prevalent detected E. coli serovar was O26. High tetracycline and chloramphenicol resistance were recorded; however, gentamycin and ciprofloxacin exhibited the highest sensitivity rates. Polymerase chain reaction (PCR) conserved genotypic resistance (tetA and blaCTX-M) and virulence attributes (fimH, stx1, eaeA and ompA) of E. coli isolates were discussed in detail. The fimH gene revealed 100% sequence similarity when comparing with different E. coli isolates globally and locally. Finally, a close genetic association of E. coli with both wild birds and cattle was detected, thus strengthening its role in the dissemination of the infection via environment. Prevention and conservative policy should be carried as E. coli constitute enormous significant zoonotic risks to livestock and animal workers. Also, further studies to the whole genome sequencing of fimH, other virulence and resistance genes of E. coli are recommended trying to limit the possibilities of co-infection and transfer among different species. CONTRIBUTION: The current study recorded updated data about the critical infectious role of wild birds to livestock, including cattle farms in Egypt. It also delivered some recommendations for good hygienic practices in cattle farms which must be implemented for handling animal manure.
显示更多 [+] 显示较少 [-]Spontaneous closure of perimembranous ventricular septal defect in a cat
2023
Park, S.Y. | Jeong, H.S. | Lee, S.G.
We discuss the case of a 5-month-old male British Shorthair cat referred to our hospital following the detection of a heart murmur during a routine vaccination appointment. Two-dimensional echocardiography revealed a 1.18 mm ventricular septal defect (VSD) located immediately below the aortic valve, without signs of secondary cardiac remodeling. Given the absence of cardiac dysfunction, no treatment was administered, and the cat was periodically monitored over the next 2 years. Echocardiography at 29 months of age revealed no signs of the VSD. Future studies are needed to increase the evidence base for spontaneous VSD closure in small animals.
显示更多 [+] 显示较少 [-]Treatment of canine CD3+/CD21+/CD45- T-zone lymphoma with chlorambucil and prednisolone in two dogs: case reports
2023
Park, H.T. | Lee, J.M. | Bae, H.A. | Yu, D.H. | Jung, D.I. | Song, K.H. | Song, J.H.
Canine T-zone lymphoma (TZL) is an indolent form of T-cell lymphoma. Conservative management is usually recommended; however, chemotherapy may be considered for symptomatic or progressive cases. Herein, we describe two dogs with generalized peripheral lymphadenopathy and peripheral blood lymphocytosis at presentation. One dog presented with gross lesions on the tongue. Flow cytometric immunophenotyping and cytological examinations demonstrated findings consistent with those of TZL. Chemotherapy with chlorambucil and prednisolone was administered, which resulted in improvement of the condition without any adverse events. Chemotherapy with chlorambucil may be considered as an appropriate choice for treating canine TZL.
显示更多 [+] 显示较少 [-]Testicular granular cell tumor of two rabbits: case reports
2023
Lee, N.Y. | Lee, J.S. | Yu, B.H. | Kim, J.H. | Kim, D.Y. | Woo, G.H.
Granular cell tumor was described in the testis of two rabbits. Testis from each rabbit was surgically removed and submitted for histopathological diagnosis. Both testes were about 2.0 cm in diameter, firm, and tan. Microscopically, testicular mass consisted of compact sheets of round to polygonal and occasional spindle-shaped cells. The neoplastic cells contain a large amount of eosinophilic granular material in the cytoplasm. The cytoplasmic eosinophilic granules were positive for periodic acid Schiff stain. Immunohistochemically, the neoplastic cells were immunoreactive to Melan-A and vimentin. Based on these results, the testicular mass was diagnosed as a granular cell tumor.
显示更多 [+] 显示较少 [-]Alleviation of γ-enolase decrease by the chlorogenic acid administration in the stroke animal model
2023
Kang, J.B. | Shah, M.A. | Ko, M.S. | Koh, P.O.
Stroke is a major cause of death and long-term disability. Chlorogenic acid is a phenolic compound with a potent neuroprotective effect. γ-enolase is a phosphopyruvate hydratase found in mature neurons and plays an important role in neuronal survival. This study investigated whether chlorogenic acid regulates the expression of γ-enolase during cerebral ischemia. Middle cerebral artery occlusion (MCAO) was performed to induce cerebral ischemia. Adult male rats were used and chlorogenic acid (30 mg/kg) or phosphate buffered saline (PBS) was injected intraperitoneally 2 hours after MCAO surgery. Cerebral cortical tissues were collected 24 hours after MCAO surgery. Our proteomic approach identified the reduction of γ-enolase caused by MCAO damage and the mitigation of this reduction by chlorogenic acid treatment. Results of reverse transcription-polymerase chain reaction and Western blot analyses showed a decrease in γ-enolase expression in the PBS-treated MCAO group. However, chlorogenic acid treatment attenuated this decrease. Results of immunofluorescence staining showed the change of γ-enolase by chlorogenic acid treatment. These results demonstrated that chlorogenic acid regulates the γ-enolase expression during MCAO-induced ischemia. Therefore, we suggest that chlorogenic acid mediates the neuroprotective function by regulating the γ-enolase expression in cerebral ischemia and may be used as a therapeutic agent for brain diseases including stroke.
显示更多 [+] 显示较少 [-]Developmental competence of chimeric porcine embryos through the aggregation of parthenogenetic embryos and somatic cell nuclear transfer embryos
2023
Lee, J.H. | Cai, L. | Kim, M.R. | Choi, H.R. | Oh, D.J. | Jawad, A | Lee, E.S. | Hyun, S.H.
The efficiency of somatic cell nuclear transfer (NT) in pigs is low and requires enhancement. We identified the most efficient method for zona pellucida (ZP) removal and blastomere aggregation in pigs and investigated whether the aggregation of NT and parthenogenetic activation (PA) of blastomeres could reduce embryonic apoptosis and improve the quality of NT-derived embryos by investigating. Embryonic developmental competence after ZP removal using acid Tyrode’s solution or protease (pronase E). The embryonic developmental potential of NT-derived blastomeres was also investigated using well-of-the-well or phytohemagglutinin-L. We analyzed apoptosis in aggregate-derived blastocysts. The aggregation rate of protease-treated embryos was lower than that of Tyrode’s solution-treated embryos (69.2% vs. 88.3%). No significant difference was observed between phytohemagglutinin-L and well-of-the-well (35.7%–38.5%). However, 2P1N showed a higher number of blastocysts compared to 3N (73.8% vs. 24.3%) and an increased blastocyst diameter compared to the control and 1P2N (274 μm vs. 230–234 μm). In blastomeres aggregated using phytohemagglutinin-L, the apoptotic cell ratio was significantly higher in 1P2N and 3N than in 3P (5.91%–6.46% vs. 2.94%, respectively). Our results indicate that aggregation of one NT embryo with two PA embryos improved the rate of blastocysts with increased blastocyst diameter.
显示更多 [+] 显示较少 [-]