Ultrastructural changes of Acanthamoeba cyst of clinical isolates after treatment with minimal cysticidal concentration of polyhexamethylene biguanide

1998 ◽  
Vol 36 (1) ◽  
pp. 7 ◽  
Author(s):  
H H Kong ◽  
D I Chung
Keyword(s):  
Clinical Isolates ◽  
Ultrastructural Changes ◽  
Polyhexamethylene Biguanide

scholarly journals Ultrastructural Changes in Clinical and Microbiota Isolates ofKlebsiella pneumoniaeCarriers of GenesblaSHV,blaTEM,blaCTX-M, orblaKPCWhen Subject toβ-Lactam Antibiotics

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Dyana Leal Veras ◽  
Ana Catarina de Souza Lopes ◽  
Grasielle Vaz da Silva ◽  
Gabriel Gazzoni Araújo Gonçalves ◽  
Catarina Fernandes de Freitas ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Residual Activity ◽  
Clinical Isolates ◽  
Ultrastructural Changes ◽  
Phenotypic Resistance ◽  
Cytoplasmic Material ◽  
Transmission Electron ◽  
Cell Alterations ◽  
Third Generation Cephalosporins

The aim of this study was to characterize the ultrastructural effects caused byβ-lactam antibiotics inKlebsiella pneumoniaeisolates. ThreeK. pneumoniaeclinical isolates were selected for the study with resistance profiles for third-generation cephalosporins, aztreonam, and/or imipenem and with different resistance genes for extended-spectrumβ-lactamases (ESBL) orKlebsiella pneumoniaecarbapenemase (KPC). TwoK. pneumoniaeisolates obtained from the microbiota, which were both resistant to amoxicillin and ampicillin, were also analyzed. In accordance with the susceptibility profile, the clinical isolates were subjected to subminimum inhibitory concentrations (sub-MICs) of cefotaxime, ceftazidime, aztreonam, and imipenem and the isolates from the microbiota to ampicillin and amoxicillin, for analysis by means of scanning and transmission electron microscopy. TheK. pneumoniaeisolates showed different morphological and ultrastructural changes after subjection toβ-lactams tested at different concentrations, such as cell filamentation, loss of cytoplasmic material, and deformation of dividing septa. Our results demonstrate thatK. pneumoniaeisolates harboring different genes that encode forβ-lactamases show cell alterations when subjected to differentβ-lactam antibiotics, thus suggesting that they possess residual activityin vitro, despite the phenotypic resistance presented in the isolates analyzed.

scholarly journals Morphological Сhanges of S. Aureus Cultivated in the Presence of Antibacterial Drugs

Medicina ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 31-49
Author(s):  
S. G. Andreevskaya ◽  
◽  
N. V. Shevlyagina ◽  
J. R. Pseunova ◽  
◽  
...  
Keyword(s):  
Biological Material ◽  
Reference Strain ◽  
Phenotypic Variability ◽  
Mechanisms Of Action ◽  
Growth Suppression ◽  
Clinical Isolates ◽  
Ultrastructural Changes ◽  
Bacterial Cells ◽  
Antibacterial Drugs ◽  
New Methods

The search for new methods for identifying the pathogen in biological material, including microscopic, remains relevant. The study of ultrastructural changes of microorganisms as a result of exposure to various groups of antibiotics is important, because the morphology of the bacterial cell varies considerably depending on the conditions of cultivation. The purpose of the study: 1. To identify the nature of changes in the ultrastructure of preserved bacterial cells of S. aureus, cultivated in the presence of antibiotics. 2. To determine the viability of that part of the population of S. aureus, which remained exposed to suppressive concentrations of antibacterial drugs. 3. To determine whether the ultrastructural changes of the reference strain S. aureus ATCC 25923 in the proposed conditions completely reflect the nature of these changes for strains isolated from clinical material. Materials and methods. Three strains of S. aureus isolated from biological material and the reference strain S. aureus ATCC 25923 were used to investigate the S. aureus ultrastructure. The analysis was carried out on the basis of data obtained using scanning electron microscopy (SEM). In the process of sample preparation, the technique of imprinting bacteria from agarized nutrient medium was applied. Results and conclusions. The most common feature for the strains of clinical isolates of S. aureus was the formation of a large number of bacterial cells of a specific disc-shaped form in zones of influence of bacteriostatic antibiotics. In terms of the use of bactericidal drugs, part of the population remained spherical, the other part had irregular contours. Changes in the size of bacterial cells in growth suppression zones were multidirectional. Cultivation of bacteria under conditions of exposure to suppressive concentrations of antibacterial drugs stimulated the production of exocellular matrix. The ultrastructural changes of phenotypic variability of the reference strain S. aureus ATCC 25923 did not fully correspond to changes in the morphology of the bacterial cells of the strains of clinical isolates. The viability of bacteria remaining in the zones of growth suppression has been confirmed in all cases of antibiotic exposure, except gentamicin. Thus, the study revealed the nature of changes in the ultrastructure of S. aureus as manifestations of phenotypic variability of microorganisms in response to the presence of antibacterial drugs with different mechanisms of action.

scholarly journals Characterizing clinical isolates of Acanthamoeba castellanii with high resistance to polyhexamethylene biguanide in Taiwan

2017 ◽  
Vol 50 (5) ◽  
pp. 570-577 ◽  
Author(s):  
Fu-Chin Huang ◽  
Min-Hsiu Shih ◽  
Kai-Fei Chang ◽  
Jian-Ming Huang ◽  
Jyh-Wei Shin ◽  
...  
Keyword(s):  
High Resistance ◽  
Acanthamoeba Castellanii ◽  
Clinical Isolates ◽  
Polyhexamethylene Biguanide

Ultrastructural Changes on Clinical Isolates ofTrichophyton rubrum,Trichophyton mentagrophytes, andMicrosporum gypseumCaused bySolanum chrysotrichumSaponin SC-2

Planta Medica ◽  
2009 ◽  
Vol 75 (14) ◽  
pp. 1517-1520 ◽  
Author(s):  
Edgar López-Villegas ◽  
Armando Herrera-Arellano ◽  
María de los Ángeles Martínez-Rivera ◽  
Laura Álvarez ◽  
Magally Cano-Nepauseno ◽  
...  
Keyword(s):  
Trichophyton Mentagrophytes ◽  
Clinical Isolates ◽  
Ultrastructural Changes

Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

1974 ◽  
Vol 32 ◽  
pp. 54-55
Author(s):  
S. Phyllis Steamer ◽  
Rosemarie L. Devine
Keyword(s):  
Structural Changes ◽  
Radiation Treatment ◽  
Arterial Stenosis ◽  
Ultrastructural Changes ◽  
Vascular Effects ◽  
Microvascular Changes ◽  
Surrounding Connective Tissue ◽  
Fission Neutrons ◽  
Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

Basal Lamina Formation in DMBA Induced Mammary Carcinoma

1977 ◽  
Vol 35 ◽  
pp. 534-535
Author(s):  
I. Russo ◽  
J. Saby ◽  
J. Russo
Keyword(s):  
Mammary Carcinoma ◽  
Virgin Female ◽  
Mammary Glands ◽  
Sesame Oil ◽  
Female Rats ◽  
Ultrastructural Changes ◽  
Post Inoculation ◽  
Intermediate Type ◽  
Sprague Dawley ◽  
Intercellular Spaces

It has been previously demonstrated that DMBA-induced rat mammary carcinoma originates in the terminal end bud (TEB) of the mammary gland by proliferation of intermediate type cells (1). The earliest lesion identified is the intraductal proliferation (IDP), which gives rise to intraductal carcinomas. These evolve to cribriform, papillary and comedo types (2). In the present work, we report the ultrastructural changes that take place in the IDP for the formation of a cribriform pattern.Fifty-five-day-old Sprague Dawley virgin female rats were inoculated intra- gastrically with 20 mg 7,12-dimethylbenz(a)anthracene (DMBA) in 1 ml sesame oil. Non-inoculated, age-matched females were used as controls. Mammary glands from both control and experimental rats were removed weekly from the time of inoculation until 86 days post-inoculation. The glands were fixed and processed for electron microscopy (2).The first change observed in IDP's was the widening of intercellular spaces and the secretion of an electron dense material into these spaces (Fig. 1).

Ultrastructural Changes of the Symbiotic Chlorella-Like Alga Isolated from Hydra Viridis

1982 ◽  
Vol 40 ◽  
pp. 320-321
Author(s):  
K.W. Lee ◽  
R.H. Meints ◽  
D. Kuczmarski ◽  
J.L. Van Etten
Keyword(s):  
Time Course ◽  
Reciprocal Cross ◽  
Ultrastructural Level ◽  
Ultrastructural Changes ◽  
Symbiotic Relationship ◽  
Cell Recognition ◽  
Green Hydra ◽  
Different Strains ◽  
Hydra Viridis

The physiological, biochemical, and ultrastructural aspects of the symbiotic relationship between the Chlorella-like algae and the hydra have been intensively investigated. Reciprocal cross-transfer of the Chlorellalike algae between different strains of green hydra provide a system for the study of cell recognition. However, our attempts to culture the algae free of the host hydra of the Florida strain, Hydra viridis, have been consistently unsuccessful. We were, therefore, prompted to examine the isolated algae at the ultrastructural level on a time course.

Ultrastructural Changes in Patients With Heat Stroke

1970 ◽  
Vol 28 ◽  
pp. 210-211
Author(s):  
O. T. Minick ◽  
M. C. Kew
Keyword(s):  
Liver Damage ◽  
Heat Stroke ◽  
Free State ◽  
Ultrastructural Changes ◽  
Gold Mines

The effects of heat stroke on hepatic structure were studied in 32 Bantu patients who worked underground in the Transvaal and Orange Free State Gold Mines.Judging from biochemical and morphologic findings, liver damage is an invariable complication of heat stroke. In the milder cases (90 per cent) raised enzyme levels, bromsulphalein retention, and increased prothrombin times were the most common abnormalities.

Fine Structural Alterations in Thyroid Follicular Cells (FC) and Changes in Serum Thyroxine Produced by Feeding Polychlorinated Biphenyl (PCB) to Rats

1977 ◽  
Vol 35 ◽  
pp. 498-499
Author(s):  
W.T. Collins ◽  
Charles C. Capen ◽  
Louis Kasza
Keyword(s):  
Feed Efficiency ◽  
Polychlorinated Biphenyl ◽  
Serum Proteins ◽  
Skin Lesions ◽  
Hepatic Necrosis ◽  
Ultrastructural Changes ◽  
Lymphoid Tissues ◽  
Heat Transfer Fluids ◽  
Thyroid Follicular Cells ◽  
Peripheral Metabolism

The widespread contamination of the environment with PCB, a compound used extensively by industry in hydraulic and heat transfer fluids as well as plasticizers and solvents in adhesives and sealants, has resulted in detectable tissue levels in a large portion of the human population, domestic animals, and wildlife. Intoxication with PCB produces severe hepatic necrosis, degeneration of lymphoid tissues and kidney, skin lesions, decreased reproductive performance, reduced feed efficiency, and decreased weight gain. PCB also has been reported to reduce the binding of thyroid hormone to serum proteins and enhance the peripheral metabolism of thyroxine with increased excretion of thyroxine-glucuronide in the bile (Bastomsky, Endocrinology 95: 1150-1155, 1974).The objectives of this investigation were (1) to investigate the histopathologic, histochemical, and ultrastructural changes in thyroid FC produced by the acute (4 week) and chronic (12 week) administration of low (50 ppm) and high (500 ppm) doses of PCB to rats, (2) to correlate these alterations to changes in serum immunoreactive thyroxine concentration, and (3) to investigate the persistence of the effects of PCB on the thyroid gland.

Effects of renovascular hypertension on rat adrenal zona glomerulosa

1978 ◽  
Vol 36 (2) ◽  
pp. 582-583
Author(s):  
G. Mazzocchi ◽  
P. Rebuffat ◽  
C. Robba ◽  
P. Vassanelli ◽  
G. G. Nussdorfer
Keyword(s):  
Renovascular Hypertension ◽  
Left Kidney ◽  
Renin Angiotensin System ◽  
Plasma Renin ◽  
Zona Glomerulosa ◽  
Ultrastructural Changes ◽  
Albino Rats ◽  
Left Renal Artery ◽  
Angiotensin System ◽  
And Control

It is well known that the rat adrenal zona glomerulosa steroidogenic activity is controlled by the renin-angiotensin system. The ultrastructural changes in the rat zona glomerulosa cells induced by renovascular hypertension were described previously, but as far as we are aware no correlated biochemical and morphometric investigations were performed.Twenty adult male albino rats were divided into 2 experimental groups. One group was subjected to restriction of blood flow to the left kidney by the application of a silver clip about the left renal artery. The other group was sham-operated and served as a control. Renovascular hypertension developed in about 10 days: sistolic blood pressure averaged 165 ± 6. 4 mmHg, whereas it was about 110 ± 3. 8 mmHg in the control animals. The hypertensive and control rats were sacrificed 20 days after the operation. The blood was collected and plasma renin activity was determined by radioimmunological methods. The aldosterone concentration was radioimmunologically assayed both in the plasma and in the homogenate of the left capsular adrenal gland.

Sign in / Sign up

Export Citation Format

Share Document