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النتائج 241 - 250 من 586
Vaccine potential of an attenuated Pasteurella multocida that expresses only the N-terminal truncated fragment of P. multocida toxin in pigs النص الكامل
2012
Kim, Taejung | Son, Changho | Lee, Jaeil | Kim, Kwanghyun
Previously we described the development of an attenuated Pasteurella multocida mutant that expresses only the N-terminal truncated fragment of P. multocida toxin (N-PMT) and its protective effects in a mouse model. This paper details our evaluation of the vaccine potential of this mutant strain in pigs. Pigs vaccinated with the mutant showed significantly higher rates of antibody induction and lower nasal conchal (turbinate) scores for atrophic rhinitis than controls, which suggests that this mutant strain may be a good candidate for a live attenuated vaccine.
اظهر المزيد [+] اقل [-]Expression of interleukin-8 and intercellular cell adhesion molecule-1 in the synovial membrane and cranial cruciate ligament of dogs after rupture of the ligament النص الكامل
2012
El-Hadi, Mustafa | Charavaryamath, Chandarshekhar | Aebischer, Andrea | Smith, C Wayne | Shmon, Cindy | Balajīta Siṅgha.
This cross-sectional clinical study compared inflammation, including expression of the chemokine interleukin (IL)-8 and intercellular cell adhesion molecule-1 (ICAM-1), in the stifle joints of 4 control dogs and 23 dogs with cranial cruciate ligament rupture (CCLR). The CCL, synovial membrane, meniscus, cartilage, and synovial fluid from the affected stifle joints of all the dogs were examined. Inflammatory cell counts were performed on the synovial fluid, and the tissues were processed for histologic study and immunohistochemical detection of IL-8 and ICAM-1. The synovial fluid from the stifle joints of the dogs with CCLR had an increased percentage of neutrophils (P = 0.054) and a decreased percentage of lymphocytes (P = 0.004) but not macrophages compared with the fluid from the control dogs. There was accumulation of inflammatory cells and increased expression of IL-8 and ICAM-1 in the vascular endothelium of the synovial membrane and the CCL of the dogs with CCLR. The increase in inflammatory cells in the stifle joints of dogs with CCLR may therefore be due to increased expression of IL-8 and ICAM-1 in the synovial membrane and the CCL after the injury. These data may help in understanding the mechanisms of inflammation associated with CCLR.
اظهر المزيد [+] اقل [-]Effect of a zinc l-carnosine compound on acid-induced injury in canine gastric mucosa ex vivo النص الكامل
2012
Hill, Tracy L. | Blikslager, Anthony T.
Objective: To examine whether a zinc l-carnosine compound used for treatment of suspected gastric ulcers in dogs ameliorates acid-induced injury in canine gastric mucosa. Sample: Gastric mucosa from 6 healthy dogs. Procedures: Mucosa from the gastric antrum was harvested from 6 unadoptable shelter dogs immediately after euthanasia and mounted on Ussing chambers. The tissues were equilibrated for 30 minutes in neutral Ringer's solution prior to incubation with acidic Ringer's solution (HCl plus Ringer's solution [final pH, 1.5 to 2.5]), acidic Ringer's solution plus zinc l-carnosine compound, or zinc l-carnosine compound alone. Tissues were maintained for 180 minutes in Ussing chambers, during which permeability was assessed by measurement of transepithelial electrical resistance. After the 180-minute treatment period, tissues were removed from Ussing chambers and labeled with immunofluorescent anti–active caspase-3 antibody as an indicator of apoptosis. Results: Permeability of the gastric mucosa was significantly increased in a time-dependent manner by addition of HCl, whereas control tissues maintained viability for the study period. Change in permeability was detected within the first 15 minutes after acid application and progressed over the subsequent 150 minutes. The zinc l-carnosine compound had no significant effect on this increase in permeability. Apoptosis was evident in acid-treated tissues but not in control tissues. The zinc l-carnosine compound did not protect against development of apoptosis. Conclusions and Clinical Relevance: Addition of HCl caused a dose-dependent increase in gastric permeability over time and apparent induction of apoptosis as determined on the basis of immunofluorescence. However, there was no significant protective effect of a zinc l-carnosine compound. Nonetheless, results suggested the utility of this method for further studies of canine gastric injury.
اظهر المزيد [+] اقل [-]Respiratory mechanics and results of cytologic examination of bronchoalveolar lavage fluid in healthy adult alpacas النص الكامل
2012
Pacheco, Ana P. | Bedenice, Daniela | Mazan, Melissa R. | Hoffman, Andrew M.
Objective-To evaluate respiratory mechanical function and bronchoalveolar lavage (BAL) cytologic results in healthy alpacas. Animals-16 client-owned adult alpacas. Procedures-Measurements of pulmonary function were performed, including functional residual capacity (FRC) via helium dilution, respiratory system resistance via forced oscillatory technique (FOT), and assessment of breathing pattern by use of respiratory inductive plethysmography (RIP) in standing and sternally recumbent alpacas. Bronchoalveolar lavage was performed orotracheally during short-term anesthesia. Results-Mean +/- SD measurements of respiratory function were obtained in standing alpacas for FRC (3.19 +/- 0.53 L), tidal volume (0.8 +/- 0.13 L), and respiratory system resistance at 1 Hz (2.70 +/- 0.88 cm H2O/L/s), 2 Hz (2.98 +/- 0.70 cm H2O/L/s), 3 Hz (3.14 +/- 0.77 cm H2O/L/s), 5 Hz (3.45 +/- 0.91 cm H2O/L/s), and 7 Hz (3.84 +/- 0.93 cm H2O/L/s). Mean phase angle, as a measurement of thoracoabdominal asynchrony, was 19.59 +/- 10.06°, and mean difference between nasal and plethysmographic flow measurements was 0.18 +/- 0.07 L/s. Tidal volume, peak inspiratory flow, and peak expiratory flow were significantly higher in sternally recumbent alpacas than in standing alpacas. Cytologic examination of BAL fluid revealed 58.52 +/- 12.36% alveolar macrophages, 30.53 +/- 13.78% lymphocytes, 10.95 +/- 9.29% neutrophils, 0% mast cells, and several ciliated epithelial cells. Conclusions and Clinical Relevance-Pulmonary function testing was tolerated well in nonsedated untrained alpacas. Bronchoalveolar lavage in alpacas yielded samples with adequate cellularity that had a greater abundance of neutrophils than has been reported in horses.
اظهر المزيد [+] اقل [-]Antimicrobial susceptibility and molecular subtypes of Staphylococcus aureus isolated from pig tonsils and cow’s milk in China النص الكامل
2012
Zhang, Chunping | Song, Li | Chen, Huijuan | Liu, Yang | Ning, Yibao | Qin, Yuling
This study investigated and compared the antimicrobial resistance patterns and ribotypes of Staphylococcus aureus isolated from pig tonsils and cow’s milk in China. A total of 90 isolates of S. aureus was included: 42 strains were isolated from tonsils of pigs and 48 from half-udder milk. The broth microdilution method and the double-disc diffusion test (D test) were used for antimicrobial susceptibility testing. The mecA gene for methicillin-resistant S. aureus (MRSA) and the ermA, ermB, ermC, and msrA genes for erythromycin-resistant strains were detected by polymerase chain reaction (PCR). The isolates were ribotyped with the Riboprinter system. The highest frequency of resistance was observed with clindamycin (91.1%), followed by penicillin (90.0%), and erythromycin (85.6%). All strains were susceptible to vancomycin and trimethoprim-sulfamethoxazole. The D test showed that 54.5% (42/77) of erythromycin-resistant isolates had the constitutive resistance phenotype and 45.5% (35/77) had the inducible resistance phenotype to clindamycin. A higher proportion of resistance to cephalosporins, macrolides, fluoroquinolones, and pleuromutilins was observed in pig isolates than in milk isolates (P < 0.05). The mecA gene was detected in all MRSA isolates; 89.6% of erythromycin-resistant strains harbored the ermC gene and 16.9% harbored the ermB gene. A total of 35 different ribogroups was found among the isolates investigated; 83.3% of pig strains belonged to 1 cluster with a similarity coefficient of 0.84. In contrast, 3 main clusters were observed among 68.8% of milk strains, which indicates a high degree of host specificity.
اظهر المزيد [+] اقل [-]Filoviral haemorrhagic fevers: A threat to Zambia? النص الكامل
2012
Katendi Changula | A.S. Mweene
Filoviral haemorrhagic fevers (FVHF) are caused by agents belonging to Filoviridae family, Ebola and Marburg viruses. They are amongst the most lethal pathogens known to infect humans. Incidence of FVHF outbreaks are increasing, with affected number of patients on the rise. Whilst there has been no report yet of FVHF in Zambia, its proximity to Angola and Democratic Republic of Congo, which have recorded major outbreaks, as well as the open borders, increased trade and annual migration of bats between these countries, puts Zambia at present and increased risk. Previous studies have indicated bats as potential reservoir hosts for filoviruses. An increasing population with an increasing demand for resources has forced incursion into previously uninhabited land, potentially bringing them into contact with unknown pathogens, reservoir hosts and/or amplifying hosts. The recent discovery of a novel arenavirus, Lujo, highlights the potential that every region, including Zambia, has for being the epicentre or primary focus for emerging and re-emerging infections. It is therefore imperative that surveillance for potential emerging infections, such as viral haemorrhagic fevers be instituted. In order to accomplish this surveillance, rapid detection, identification and monitoring of agents in patients and potential reservoirs is needed. International co-operation is the strategy of choice for the surveillance and fight against emerging infections. Due to the extensive area in which filoviral infections can occur, a regional approach to surveillance activities is required, with regional referral centres. There is a need to adopt shared policies for the prevention and control of infectious diseases. There is also need for optimisation of currently available tests and development of new diagnostic tests, in order to have robust, highly sensitive and specific diagnostic tests that can be used even where there are inadequate laboratories and diagnostic services.
اظهر المزيد [+] اقل [-]Vector competence of <i>Glossina austeni</i> and <i>Glossina brevipalpis</i> for <i>Trypanosoma congolense</i> in KwaZulu-Natal, South Africa النص الكامل
2012
Makhosazana Motloang | Justin Masumu | Barend Mans | Peter van den Bossche | Abdalla Latif
Tsetse-transmitted trypanosomosis (nagana) has been the cause of stock losses in the recent past and still presents a major problem to livestock owners in certain areas of KwaZulu- Natal, South Africa. Over 10 000 cattle mortalities were reported in the 1990 nagana outbreak. Although information on the distribution and abundance of the tsetse flies Glossina brevipalpis and Glossina austeni in KwaZulu-Natal exists, data on their vector competence are lacking. This study aimed to determine the rate of natural Trypanosoma congolense infection by field-collected as well as colony-reared flies of these species. A total of 442 field-collected G. brevipalpis and 40 G. austeni flies were dissected immediately after collection to determine their infection rates, whilst 699 G. brevipalpis and 49 G. austeni flies were fed on susceptible animals in 10 and four batches, respectively, for use in xenodiagnosis experiments. Teneral colony flies were fed on infected animals and dissected 21 days post infection to confirm their infectivity testing. Glossina austeni harboured 8% immature and mature infections. In G. brevipalpis, the infection with the immature stages was lower (1%) and no mature infections were observed. Although all four batches of G. austeni transmitted T. congolense to four susceptible animals, no transmission resulted from 10 batches of G. brevipalpis fed on susceptible cattle. Colony-derived G. austeni (534) and G. brevipalpis (882) were fed on four bovines infected with different T. congolense isolates. Both G. austeni and G. brevipalpis acquired trypanosome infection from the bovines, with immature infection ranges of 20% – 33% and 1% – 4%, respectively. Parasites, however, only matured in G. austeni (average = 4%). Glossina austeni plays a larger role in the epidemiology of animal trypanosomosis in KwaZulu-Natal than G. brevipalpis and therefore more focus should be aimed at the former when control measures are implemented.
اظهر المزيد [+] اقل [-]Leptospirosis in South Africa النص الكامل
2012
Adrienne Saif | John Frean | Jenny Rossouw | Anastasia N. Trataris
Leptospirosis is a common zoonosis worldwide. It has a ubiquitous distribution and causes a wide spectrum of disease. Leptospirosis therefore has a broad reservoir host range, and many infected species of animals excrete leptospires in their urine, which leads to contamination of soil and water. Typical descriptions of the disease include a biphasic (anicteric form) and fulminant disease in the icterohaemorrhagic form. Only a few local case reports of human leptospirosis have been published, the most recent one being in 1974. A rodent-related zoonosis study (RatZooMan) was conducted from 2003 until 2006 in three provinces (Limpopo, KwaZulu-Natal and the Eastern Cape). Of the people sampled in Cato Crest (Durban, KwaZulu-Natal Province), 43/217 (19.8%) were seropositive for leptospirosis. Of the clinical samples sent to the Special Bacterial Pathogens Reference Unit from all over the country for testing in 2009, 16/176 (9%) were IgM positive; in 2010 and January 2011 to May 2011, 14/215 (6.5%) and 12/96 (12.5%), respectively, were IgM positive. The apparent incidence of leptospirosis in the South African population is moderately high based on the detected positives in suspected cases; it is thought that the circulating infection rate may be even higher when looking at the RatZooMan results. This may be due to underreporting and undiagnosed cases. Communities in informal settlements in urban areas are especially at risk as infected rodent populations are a continuous source of transmission.
اظهر المزيد [+] اقل [-]Immunogeno: Protective mechanism for Rift Valley fever in the Democratic Republic of Congo النص الكامل
2012
Georges Tshilenge
Rift Valley fever (RVF) is an acute, fever causing viral disease that affects domestic animals and humans. In Democratic Republic of Congo (DRC), this pathology is not well documented. No epidemic of the RVF has not been reported but sera samples collected in six provinces surveyed from 2005 to 2006 revealed 14% of apparent prevalence and, high apparent prevalence (20%) of antibodies against RVF virus was reported in Katanga Province during the same survey; this serological evidence was associated with abortions cases in Cattle (Mulumba et al. 2009). Livestock immunisation is important for control of Rift Valley fever virus (RVFV) epidemics; however immunisation of susceptible domestic animals in endemic countries does not protect animals against the clinical disease but prevents the propagation of virus to human population through reduction of the amplification degree in host animals. The humoral immunity is sufficient for protection for animals as well as for humans. The infection caused by RVFV leads to neutralisation of the immunity of the animal (Barnard 1979). Various immunological studies have been made on the characterisation of immune response during RVFV epidemics but, until now several studies have been concentrated on the response of the innate immune particularly based on signal interferon system than the response of the adaptive immune and cell mediated humoral immune. The available information on the immune response related to RVFV does not seem to provide enough information on various mechanisms of the response immune system. The aim of the study is based on mechanism of immune response system including protective effect of immunisation against RVFV. In addition, epidemiological and molecular studies will be assessed. As a matter of fact, following studies will be conducted: • evaluation of the immunological protection against Rift Valley fever in vaccinated and non- vaccinated cattle using IgG and IgM ELISAs in Katanga Province • assessment of cellular response to Rift Valley fever disease in vaccinated and naturally infected cattle • molecular characterisation of RVFV strains circulating in vaccinated and non vaccinated cattle • assessment of protective effect related to vaccinal strains in cattle, using a longitudinal survey. The studies will be carried out Northern Katanga Province within two areas, one with historyof circulation of RVFV and other without history RVFV circulation. Whole blood, spleen, liver, lymph node will be collected as target tissues from cattle carcasses. In addition, goats and sheeps samples will be collected alongside from each area in order to clarify the disease situation. Serological tests based on the detection of Ig M and Ig G will be used. DIVA tests, LAMP, and IHC techniques will be used. Within previously vaccinated areas in the above mentioned areas and those that are not vaccinated, the collected samples will be analysed using RT-PCR/RT-LAMP. In vitro experimental studies systems will be carried out using animal PMBCs that will be infected with wild type of RVF virus as well as with vaccinal strains, such as clones 13 and MP12 to characterise various cell types such as CD4 T cells, CD8 T cells, B-cells, NK cells and, macrophages will be studied with regard to activation and apoptosis signals on various post – infection days, using flow cytometry. A pool of animals will be vaccinated with the Clone 13 and another with the MP12 to determine the traceability. The monitoring of the immune response will be done through the measurement of immunoglobulin G (Ig G) and immunoglobulin M (Ig M). RT-PCR, spectrophotometer or Facs methods will be used for the dosage of cells T CD4 + and Cell T CD8+.
اظهر المزيد [+] اقل [-]‘One Health’ infectious diseases surveillance in Tanzania: Are we all on board the same flight? النص الكامل
2012
Erasto V. Mbugi | Kim A. Kayunze | Bugwesa Z. Katale | Sharon Kendall | Liam Good | Gibson S. Kibik | Julius D. Keyyu | Peter Godfrey-Faussett | Paul van Helden | Mecky I. Matee
Infectious diseases account for nearly 40% of the burden of human mortality and morbidity in low-income countries, of which 7% is attributable to zoonoses and 13% to recently emerging diseases from animals. One of the strategic approaches for effective surveillance, monitoring and control of infectious diseases compromising health in both humans and animals could be through a combination of multiple disciplines. The approach can be achieved through a joint effort from stakeholders comprising health professionals (medical and veterinary), social, economic, agricultural, environmental and other interested parties. With resource scarcity in terms of number of staff, skills and facility in low-income countries, participatory multi- sectoral and multidisciplinary approaches in limiting the burden of zoonotic diseases could be worthwhile. We review challenging issues that may limit the ‘One Health’ approach for infectious diseases surveillance in Tanzania with a focus on Health Policy and how best the human and animal health systems could be complemented or linked to suit the community in need for disease control under the theme’s context.
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