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Inactivation of the gene encoding zinc-binding lipoprotein 103 impairs the infectivity of Streptococcus suis Texto completo
2012
Aranda, Jesus | Teixido, Laura | Fittipaldi, Nahuel | Cortés, Pilar | Llagostera, Montserrat | Gottschalk, Marcelo | Barbe, Jordi
The Streptococcus suis 103 gene product is an immunogenic and protective lipoprotein that is a component of an ATP-binding cassette transporter implicated in zinc uptake. Belonging to the same transcriptional unit and downstream of the 103 gene is a gene that encodes a homologue of the pneumococcal histidine triad (Pht) protein Pht309. In an intraperitoneal mouse model the virulence of a mutant lacking the 103 gene was more than 50 times lower than that of the wild-type (WT) parent strain, S. suis serotype 2 strain P1/7. In addition, the immunogenicity of this mutant was dramatically decreased. In striking contrast, the virulence and immunogenicity of a P1/7 mutant lacking the Pht309 gene were similar to those of the parent strain. These results demonstrate that the 103 lipoprotein is strongly involved in S. suis virulence and support the hypothesis that this lipoprotein might be an excellent candidate for vaccines aiming to achieve broad protection against streptococci.
Mostrar más [+] Menos [-]Increased expression of vascular endothelial growth factor in neo-vascularized canine brain tissue Texto completo
2012
Yu, Chi-Ho | Yhee, Ji-Young | Kim, Jong-Hyuk | Im, Keum-Soon | Kim, Na-Hyun | Kwon, So-Young | Hur, Tai-Young | Sur, Jung-Hyang
This retrospective study was done to characterize the levels of vascular endothelial growth factor (VEGF) and hypoxia inducible factor 1 (HIF-1α) in dog brains with neo-vascularization in the cerebral cortex of frontal, temporal, and parietal lobe by using immunohistochemistry (IHC) and Western blot. In neo-vascularized (NV) brains, we analyzed the number and area of blood vessels and the expression of VEGF and HIF-1α. The IHC results showed that the number and area of blood vessels, as assessed by immunolabeling for von Willebrand factor, was higher in the NV brain than in the control brain. The Western blot results showed that the level of VEGF was increased, predominantly in NV brain of the cerebral cortex relative to the clinically normal cerebral cortex, whereas the expression of HIF-1α in NV brains was not different from the control brains. Our study showed that dilatation of vessels and development of new vessels in the cerebral cortex were observed in cases of canine CNS disease and found increased expression of VEGF in canine brains with neo-vascularization.
Mostrar más [+] Menos [-]Comparison of bone marrow aspiration at the sternum and the tuber coxae in middle-aged horses Texto completo
2012
Delling, Uta | Lindner, Katrin | Ribitsch, Iris | Julke, Henriette | Brehm, Walter
The objective of this study was to compare bone marrow (BM) aspirates from the sternum and the tuber coxae of middle-aged horses. Bone marrow was obtained from the sternum and both tubera coxae of 12 healthy, 13-year-old geldings. Two different puncture techniques were used for the tuber coxae. The 2 syringes used for sternal sampling were evaluated separately. The mononuclear cell (MNC) fraction of the BM was isolated and the mesenchymal stem cells (MSCs) were culture-expanded. At the sternum, BM aspiration was always possible. Bone marrow aspiration at the tuber coxae required straight and deep needle penetration combined with high negative pressure. With this technique a median sample amount of 11.0 mL with large individual variation was obtained. A median of 3.06 × 10(6) MNC/mL BM (1st syringe) and 2.46 × 10(6) MNC/mL BM (2nd syringe) was isolated from sternal samples. In contrast, the tuber coxae yielded a median of 0.27 × 10(6) MNC/mL BM. The first passage yielded a median of 2.19 × 10(6) MSC (1st syringe) and 1.13 × 10(6) MSC (2nd syringe) from sternal samples, compared to a significantly lower median number of MSC from tuber coxae BM (0.06 × 10(6) MSC). The number of MNC and MSC obtainable from the BM aspirates taken from the tuber coxae is significantly lower than that obtained from the sternal BM aspirates. Autologous BM for the equine athlete is particularly clinically relevant at an advanced age. Based on our findings, the tuber coxae cannot be recommended for BM aspiration in middle-aged horses.
Mostrar más [+] Menos [-]Vaccine potential of an attenuated Pasteurella multocida that expresses only the N-terminal truncated fragment of P. multocida toxin in pigs Texto completo
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.
Mostrar más [+] Menos [-]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 Texto completo
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.
Mostrar más [+] Menos [-]Effect of a zinc l-carnosine compound on acid-induced injury in canine gastric mucosa ex vivo Texto completo
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.
Mostrar más [+] Menos [-]Respiratory mechanics and results of cytologic examination of bronchoalveolar lavage fluid in healthy adult alpacas Texto completo
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.
Mostrar más [+] Menos [-]Antimicrobial susceptibility and molecular subtypes of Staphylococcus aureus isolated from pig tonsils and cow’s milk in China Texto completo
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.
Mostrar más [+] Menos [-]One Health: Towards safeguarding the health, food security and economic welfare of communities Texto completo
2012
Nabarro, David(the United Nations Food Security and Nutrition)
Bartonella spp. in human and animal populations in Gauteng, South Africa, from 2007 to 2009 Texto completo
2012
Trataris, Anastasia N(National Health Laboratory Service) | Rossouw, Jennifer(National Health Laboratory Service) | Arntzen, Lorraine(National Health Laboratory Service) | Karstaedt, Allan(National Health Laboratory Service) | Frean, John(National Health Laboratory Service)
Bartonellae are highly adaptive organisms that have the ability to evade the host immune system and cause persistent bacteraemia by occupying the host's erythrocytes. Bartonella spp. is under-studied and health care professionals often misdiagnose Bartonella-related infections. The aim of this study was to investigate the carriage of Bartonella spp. circulating in human and animal populations in Gauteng using culturing and polymerase chain reaction (PCR) detection. A total of 424 human, 98 cat, 179 dog, and 124 wild rodent blood samples were plated onto specialised media and incubated for 7-21 days at 37 °C in CO2. Culture isolates morphologically similar to Bartonella control strains were confirmed by PCR and sequenced to determine species. Deoxyribonucleic acid (DNA) was extracted from all blood samples and tested by nested PCR. Bartonella could only be cultured from the cat and rodent specimens. Cat isolates were > 99% similar to Bartonella henselae URBHLIE 9, previously isolated from an endocarditis patient, and rat isolates were > 98% similar to either RN24BJ (candidus 'Bartonella thailandensis') or RN28BJ, previously isolated from rodents in China. The PCR prevalences were 22.5% in HIV-positive patients, 9.5% in clinically healthy volunteers, 23.5% in cats, 9% in dogs and 25% in rodents. Findings of this study have important implications for HIV-positive patients.
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