scholarly journals Differential Abilities of Capsulated and Noncapsulated Staphylococcus aureus Isolates from Diverse agr Groups To Invade Mammary Epithelial Cells

2006 ◽  
Vol 75 (2) ◽  
pp. 886-891 ◽  
Author(s):  
Fernanda R. Buzzola ◽  
Lucía P. Alvarez ◽  
Lorena P. N. Tuchscherr ◽  
María S. Barbagelata ◽  
Santiago M. Lattar ◽  
...  

ABSTRACT Staphylococcus aureus is the bacterium most frequently isolated from milk of bovines with mastitis. Four allelic groups, which interfere with the regulatory activities among the different groups, have been identified in the accessory gene regulator (agr) system. The aim of this study was to ascertain the prevalence of the different agr groups in capsulated and noncapsulated S. aureus bacteria isolated from mastitic bovines in Argentina and whether a given agr group was associated with MAC-T cell invasion and in vivo persistence. Eighty-eight percent of the bovine S. aureus strains were classified in agr group I. The remainder belonged in agr groups II, III, and IV (2, 8, and 2%, respectively). By restriction fragment length polymorphism analysis after PCR amplification of the agr locus variable region, six agr restriction types were identified. All agr group I strains presented a unique allele (A/1), whereas strains from groups II, III, and IV exhibited more diversity. Bovine S. aureus strains defined as being in agr group I (capsulated or noncapsulated) showed significantly increased abilities to be internalized within MAC-T cells, compared with isolates from agr groups II, III, and IV. agr group II or IV S. aureus strains were cleared more efficiently than agr group I strains from the murine mammary gland. The results suggest that agr group I S. aureus strains are more efficiently internalized within epithelial cells and can persist in higher numbers in mammary gland tissue than S. aureus strains classified in agr group II, III, or IV.

2009 ◽  
Vol 7 (4) ◽  
pp. 423-430 ◽  
Author(s):  
Paulo de Tarso Camillo De Carvalho ◽  
Filipe Abdalla dos Reis ◽  
Ana Carulina Guimarães Belchior ◽  
Baldomero Antônio Kato da Silva ◽  
Daniel Martins Pereira ◽  
...  

The aims of this study were to determine whether S. aureus could be killed by toluidine blue-mediated photosensitization in vivo in an animal model. Twelve Wistar rats divided into three groups (n = 12): Group I: Control Group, the wounds were made and submitted to the application of the laser without the drug photosensitizing; Group II: The implementation of wounds received the toluidine blue, without application of laser; Group III: it was used toluidine blue, and application of laser-Indio phosphide Gallium-Aluminum (InGaAIP)  660nm power and density of 20 Joules/cm2. Statistical analysis of CFU by analysis of variance Kruskal-Wallis test shows significant intraoperative difference, photodynamic therapy group (p 0, 05), the Dunns post hoc test shows significant difference between Group I when compared to Group II treated with LLLT (p 0001). The results of this study show that photodynamic therapy with toluidine blue has reduced the number of Staphylococcus aureus in vivo.


2004 ◽  
Vol 48 (3) ◽  
pp. 1024-1027 ◽  
Author(s):  
Isabelle Verdier ◽  
Marie-Elisabeth Reverdy ◽  
Jerome Etienne ◽  
Gérard Lina ◽  
Michèle Bes ◽  
...  

ABSTRACT We used multiplex PCR to determine the agr group membership of 18 European glycopeptide heterointermediate and intermediate-resistant Staphylococcus aureus strains. Of the 15 agr group I strains, 13 were resistant and 2 were susceptible to methicillin. The remaining three strains, like the United States and Japanese control strains, belonged to agr group II.


1997 ◽  
Vol 36 (08) ◽  
pp. 259-264
Author(s):  
N. Topuzović

Summary Aim: The purpose of this study was to investigate the changes in blood activity during rest, exercise and recovery, and to assess its influence on left ventricular (LV) volume determination using the count-based method requiring blood sampling. Methods: Forty-four patients underwent rest-stress radionuclide ventriculography; Tc-99m-human serum albumin was used in 13 patients (Group I), red blood cells was labeled using Tc-99m in 17 patients (Group II) in vivo, and in 14 patients (Group III) by modified in vivo/in vitro method. LV volumes were determined by a count-based method using corrected count rate in blood samples obtained during rest, peak exercise and after recovery. Results: In group I at stress, the blood activity decreased by 12.6 ± 5.4%, p <0.05, as compared to the rest level, and increased by 25.1 ± 6.4%, p <0.001, and 12.8 ± 4.5%, p <0.05, above the resting level in group II and III, respectively. This had profound effects on LV volume determinations if only one rest blood aliquot was used: during exercise, the LV volumes significantly decreased by 22.1 ± 9.6%, p <0.05, in group I, whereas in groups II and III it was significantly overestimated by 32.1 ± 10.3%, p <0.001, and 10.7 ± 6.4%, p <0.05, respectively. The changes in blood activity between stress and recovery were not significantly different for any of the groups. Conclusion: The use of only a single blood sample as volume aliquot at rest in rest-stress studies leads to erroneous estimation of cardiac volumes due to significant changes in blood radioactivity during exercise and recovery.


1994 ◽  
Vol 72 (05) ◽  
pp. 745-749 ◽  
Author(s):  
Elza Chignier ◽  
Maud Parise ◽  
Lilian McGregor ◽  
Caroline Delabre ◽  
Sylvie Faucompret ◽  
...  

SummaryP-selectin, also known as CD62P, GMP140 or PADGEM, is present in platelet a-granules and endothelial cell Weibel-Palade bodies and is very rapidly expressed on the surface of these cells on activation. In this study, an anti P-selectin monoclonal antibody (LYP20) was used, in tandem with flow cytometry, to identify activated platelets at the site of induced vascular trauma or in peripheral blood. Moreover, electron microscopy was performed to characterize sites of vascular trauma and quantify the number of adhering platelets. The same induced vascular trauma was observed to result into animals responding in 2 different ways (Group I, Group II) following the degree of platelet activation. Five rats, out of 14 with induced vascular trauma, had more than half of their circulating platelets expressing P-selectin when drawn at the site of the trauma (67.4% ± 3.44) or in peripheral blood (78.5% ± 2.5) (Group I). In the remaining 9 animals a much smaller proportion of circulating platelets expressed P-selectin when assayed from trauma sites (18% ± 3.34) or in peripheral blood (18.0% ± 4.30) (Group II). Enhanced P-selectin expression by circulating platelets in Group I, compared to Group II, appears to be linked to the degree of activated platelets adhering at sites of trauma (171 ± 15 × 103 platelets versus 48 ± 31 × 103 platelets per mm2). In the 5 control animals, that were not operated on, platelets expressing P-selectin when drawn at the site of a mock trauma (7.0% ± 1.84) or in the peripheral blood (11.2% ± 3.30) showed little activation. In addition, no platelet adhesion was seen on the vascular bed of these animals. Results from this study show that analysis of P-selectin (CD62P) expression, in circulating platelets, is a valuable and rapid marker of platelet activation following severe vascular trauma induced in rats. However, activated platelets were not detected to the same extent in the peripheral blood of all animals having undergone vascular trauma. It is conceivable that platelets, depending on the degree of activation, may be actively sequestered in organs and prevented from circulating. Alternatively, P-selectin may be rapidly endocytosed, or not expressed, by activated circulating platelets depending on the type of agonists implicated in vivo activation.


2018 ◽  
Author(s):  
Dr Malathi Dayalan ◽  
Dr Sudeshna Sharma ◽  
Dr Shweta Poovani ◽  
Dr Saher Altaf

BACKGROUND Masticatory system is a complex functional unit, primarily engaged in chewing, swallowing and breathing functions, and some parts are involved in taste recognition and determination of food consistency. Sophisticated functional performances of speech and emotional expressions are specifically human qualities. Irregularities in occlusion appears to be the precipitating factor in the pathogenesis of myofascial pain dysfunction syndrome. Tek- Scan III records the bite length, number, distribution, timing, duration and the relative force of each tooth contact. It also records the sequence of occlusal contacts in terms of time and the associated force with each occlusal contact. The aim of this study was to treat masticatory muscle disorders with occlusal equilibration, and compare the efficacy of treatment outcomes between selective grinding and stabilization splints using Tek-Scan III. OBJECTIVE Objective of this study was to compare the efficacy of occlusal equilibration achieved through selective griding and stabilization splints using Tek-Scan III. METHODS In this in vivo study, 40 patients with masticatory muscle disorders were selected based on the inclusion and exclusion criteria. The occlusal discrepancies were analyzed using Tek-Scan III. The selected 40 subjects were then randomly divided into 2 groups based on the treatment they recieved; Group I – Selective grinding group (20) and Group II – Stabilization splint group (20). Comparison of pre-treatment and post treatment results were evaluated in terms of pain, mouth opening, left and right side force percentage as recorded through Tek-Scan III and reduction of disclusion time. Statistical analysis was carried out with Kolmogorov Smirnov test, Wilcoxon matched pair test and Mann-Whitney U test. RESULTS Wilcoxon matched pairs test demonstrated that there was statistically significant results ( p = 0.0007) in both the groups for reduction of disclusion time, elimination of pain and improved mouth opening. Patients in Group I showed better results as compared to Group II in terms of disclusion time, pain and mouth opening. CONCLUSIONS Occlusal equilibration brought about by reducing the disclusion time using the Tek- Scan III reduced the symptoms of pain in masticatory muscles. Patients in group I (Selective grinding) however showed better results when compared to patients in group II (Stabilization splints).


2013 ◽  
Vol 4 (3) ◽  
Author(s):  
Poppy M Lintong ◽  
Carla F Kairupan ◽  
Priska L N Sondakh

Abstract: Gentamycin, a frequently used aminoglycoside antibiotics, has a nephrotoxic effect to human beings and animals. The purpose of this research was to find out the microscopic changes of wistar rat kidneys after gentamycin induction. This was an experimental study, using five adult wistar rats, divided into three groups. Group I was the control group; group II consisted of two rats, injected with gentamycin 0,3 ml/day (dose of 60 mg/kg body weight/day) intraperitoneally for seven days; and group III consisted of two rats, injected with gentamycin 0,3 ml/day intraperitoneally for 10 days. Group I and II were terminated at day-8, and group III at day-11. Their kidneys were processed for microscopic slides, stained with hematoxylin eosin and Periodic Acid Schiff. In microscopic evaluation, group II and III showed oedema, necrosis, apoptosis, and basal membrane destruction of tubular epithelial cells. Group III also showed fat vacuoles in these epithelial cells (macrovesicular fatty changes). Conclusion: wistar rats injected with gentamycin 60 mg/kg body weight/day for 7 and 10 days showed oedema, necrosis, apoptosis, and basal membrane destruction of tubular epithelial cells; and macrovesicular fatty changes after 10 days of gentamycin.Key words: gentamycin, necrosis tubular epithelial cells, fatty changesAbstrak: Gentamisin termasuk antibiotik golongan aminoglikosida berspektrum luas yang bersifat nefrotoksik terhadap manusia dan hewan. Tujuan penelitian ini untuk melihat perubahan mikroskopik struktur ginjal tikus Wistar setelah diberikan gentamisin. Metode penelitian eksperimental dengan menggunakan lima ekor tikus Wistar dewasa yang dibagi atas tiga kelompok. Kelompok I tanpa perlakuan; kelompok II terdiri dari dua ekor tikus perlakuan yang diinjeksi dengan gentamisin 0,3 ml/hari (dosis 60 mg/kgBB/hari) secara intraperitonial selama tujuh hari; dan kelompok III terdiri dari dua ekor tikus perlakuan yang diinjeksi dengan gentamisin 0,3 ml/hari secara intraperitonial selama 10 hari. Tikus Wistar kelompok I dan II diteminasi hari ke-8, sedangkan kelompok III diterminasi hari ke-11. Ginjal tikus kelompok I -III kemudian dibuat preparat histopatologik dengan pengecatan rutin hematoksilin eosin dan Periodic Acid Schiff (PAS). Hasil penelitian menunjukkan tikus Wistar perlakuan yang diberikan gentamisin 0,3 ml/hari selama 7 sampai 10 hari secara mikroskopik memperlihatkan pembengkakan, nekrosis, apoptosis, dan destruksi membrana basalis sel epitel tubulus; dan pada hari ke-10 terlihat vakuol-vakuol lemak pada sel epitel sehingga inti terdesak ke tepi (perlemakan makrovesikuler). Simpulan: pemberian gentamisin pada tikus Wistar dengan dosis 60 mg/kg BB/hari selama 7-10 hari menunjukkan pembengkakan, nekrosis, apoptosis sel epitel tubulus, dan membrana basalis tubulus rusak; dan setelah hari ke-10 juga terlihat perlemakan makrovesikuler.Kata kunci: gentamisin, nekrosis sel epitel tubulus, perlemakan makrovesikuler


2019 ◽  
Vol 6 (1) ◽  
pp. 21-32
Author(s):  
Jeevan R. Dash ◽  
Tapas K. Sar ◽  
Rinku Buragohain ◽  
Indranil Samanta ◽  
Rahul Nanotkar

Background: Mammary gland tissue (left half) revealed the presence of excess proliferation of fibrous tissue with disorganization of alveolar structures and the right half showed extensive fibrous tissue proliferation of mammary gland following intramammary inoculation of 2000 c.f.u. of Staphylococcus aureus. However, oral dosing of Bauhinia variegata L. bark powder at 6 gm/kg for 7 days and 3 gm/kg for another 7 days exhibited reduction of fibrous tissue in chronic mastitis. Objective: The fibrolytic effect of one week oral dosing of Bauhinia purpurea L. bark powder was studied in chronic mastitis with induced fibrosis as Bauhinia variegate L. is rarely available in plain land. Methods: Chronic mastitis with fibrosis was induced by intramammary inoculation of coagulase positive Staphylococcus aureus in group III and IV goats. Group I and III goats were injected with a single dose of ceftriaxone at 20 mg/kg intravenously, whereas group II and IV goats were orally administered Bauhinia purpurea L. bark powder at 6 g/kg for 7 days with a single dose of ceftriaxone at 20 mg/kg intravenously. Results: The t1/2β of ceftriaxone with Bauhinia purpurea L. stem bark powder in chronic mastitis increased significantly. Ceftizoxime was detected in plasma from 1 h to 48 h post dosing (pd) in group III and from 1 h to 96 h pd in group IV, respectively. Conclusion: Bark powder of Bauhinia purpurea L. at 6g/kg orally once daily increased the bioavailability of ceftriaxone and or ceftizoxime in milk due to its fibrolytic effect which was not reported earlier. Therefore, the Bauhinia purpurea L. bark powder having fibrolytic effect has the potential to reduce development of cancer.


2014 ◽  
Vol 304 (2) ◽  
pp. 177-187 ◽  
Author(s):  
Henrike Pförtner ◽  
Marc S. Burian ◽  
Stephan Michalik ◽  
Maren Depke ◽  
Petra Hildebrandt ◽  
...  

2002 ◽  
Vol 13 (10) ◽  
pp. 3521-3531 ◽  
Author(s):  
Marisa M. Faraldo ◽  
Marie-Ange Deugnier ◽  
Sylvie Tlouzeau ◽  
Jean Paul Thiery ◽  
Marina A. Glukhova

To study the mechanism of β1-integrin function in vivo, we have generated transgenic mouse expressing a dominant negative mutant of β1-integrin under the control of mouse mammary tumor virus (MMTV) promoter (MMTV-β1-cyto). Mammary glands from MMTV-β1-cyto transgenic females present significant growth defects during pregnancy and lactation and impaired differentiation of secretory epithelial cells at the onset of lactation. We report herein that perturbation of β1-integrin function in involuting mammary gland induced precocious dedifferentiation of the secretory epithelium, as shown by the premature decrease in β-casein and whey acidic protein mRNA levels, accompanied by inactivation of STAT5, a transcription factor essential for mammary gland development and up-regulation of nuclear factor-κB, a negative regulator of STAT5 signaling. This is the first study demonstrating in vivo that cell–extracellular matrix interactions involving β1-integrins play an important role in the control of milk gene transcription and in the maintenance of the mammary epithelial cell differentiated state.


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