Clofoctol-Induced Ultrastructural Changes In Staphylococcus Aureus

1999 ◽  
Vol 5 (S2) ◽  
pp. 1138-1139
Author(s):  
Beverly E. Maleeff ◽  
Stewart C. Pearson ◽  
David J. Payne ◽  
Timothy K. Hart
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Ultrastructural Changes ◽  
Upper Respiratory Tract ◽  
Butyl Phenol ◽  
Dividing Cells ◽  
Life Threatening ◽  
In Vitro Effects ◽  
Tract Infections

Clofoctol [2-(2,4-dichlorobenzyl)-4-(tetramethyl-l,l,3,3-butyl) phenol] is a synthetic antibacterial compound with activity against both Gram-positive1 and Gram-negative2 microorganisms. Although the specific mechanism of Clofoctol action has not been fully elucidated, it is reported to alter the permeability of the cytoplasmic membrane in Bacillus subtilis, and is used clinically to treat upper respiratory tract infections in humans. Staphylococcus aureus is a major human Grampositive pathogen that causes a variety of human diseases ranging from localized skin suppuration and food poisoning to life threatening presentations such as septicemia and endocarditis. Several clinical isolates of S. aureus have recently been identified that are resistant to all currently available antibacterial therapies. Consequently, the identification of new antimicrobial targets in this organism is of paramount importance. The purpose of this study was to investigate the in vitro effects of Clofoctol on S. aureus.Ultrastructural examination of S. aureus revealed a population of actively dividing cells.

scholarly journals Human urine alters methicillin-resistant Staphylococcus aureus virulence and transcriptome

2021 ◽  
Author(s):  
Santosh Paudel ◽  
Kamal Bagale ◽  
Swapnil Patel ◽  
Nicholas J. Kooyers ◽  
Ritwij Kulkarni
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Human Urine ◽  
Molecular Mechanisms ◽  
Methicillin Resistant ◽  
Life Threatening ◽  
Tract Infections

Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) is an emerging cause of hospital-associated urinary tract infections (UTI), especially in catheterized individuals. Despite being rare, MRSA UTI are prone to potentially life-threatening exacerbations such as bacteremia that can be refractory to routine antibiotic therapy. To delineate the molecular mechanisms governing MRSA urinary pathogenesis, we exposed three S. aureus clinical isolates, including two MRSA strains to human urine for 2h and analyzed virulence characteristics and changes in gene expression. The in vitro virulence assays showed that human urine rapidly alters adherence to human bladder epithelial cells and fibronectin, hemolysis of sheep RBCs, and surface hydrophobicity in a staphylococcal strain-specific manner. In addition, RNA-Seq analysis of uropathogenic strain MRSA-1369 revealed that 2h-long exposure to human urine alters MRSA transcriptome, by modifying expression of genes encoding enzymes catalyzing metabolic pathways, virulence factors, and transcriptional regulators. In summary, our results provide important insights into how human urine specifically and rapidly alters MRSA physiology and facilitates MRSA survival in the nutrient-limiting and hostile urinary microenvironment. Importance: Methicillin-resistant Staphylococcus aureus (MRSA) is an uncommon cause of urinary tract infections (UTI) in the general population. However, it is important to understand MRSA pathophysiology in the urinary tract because isolation of MRSA in urine samples often precedes potentially life-threatening MRSA bacteremia. In this report, we describe how exposure to human urine alters MRSA global gene expression and virulence. We hypothesize that these alterations may aid MRSA in acclimating to the nutrient-limiting, immunologically hostile conditions within the urinary tract leading to MRSA-UTI.

scholarly journals Could Chlamydia Pneumoniae Be Considered an Infectious Risk Factor for Inflammatory Diseases Such as Atherosclerosis ?

2005 ◽  
Vol 3 (3) ◽  
pp. 109-112
Author(s):  
R. Sessa ◽  
M. Di Pietro ◽  
G. Schiavoni ◽  
I. Santino ◽  
M. Del Piano
Keyword(s):  
Risk Factor ◽  
Chlamydia Pneumoniae ◽  
Direct Detection ◽  
Inflammatory Diseases ◽  
Cell Types ◽  
Chronic Inflammatory Disease ◽  
Upper Respiratory Tract ◽  
Infectious Risk ◽  
Tract Infections

Chlamydia pneumoniae, a Gram-negative intracellular obligate bacteria, is recognised as a common cause of upper respiratory tract infections, and accounts for ∼10% of community-acquired pneumonia. In recent years, chronic and persistent infection with C. pneumoniae has been implicated in the pathogenesis of atherosclerosis. Atherosclerosis is regarded as a chronic inflammatory disease that results from complex interactions between a variety of cell types such as endothelial cells, vascular smooth muscle cells, monocytes/macrophages and inflammatory mediators. Involvement of C. pneumoniae in the pathogenesis of atherosclerosis has been supported by findings from seroepidemiologic studies, direct detection of chlamydial DNA, experimental animal and in vitro studies, and antibiotic intervention trials. The spectrum of cell biological, animal, and human clinical data suggests that C. pneumoniae may be considered an infectious risk factor for atherosclerosis but further studies are needed to clarify the etiopathogenetic role of C. pneumoniae in atherosclerotic vessel walls.

scholarly journals The Antimicrobial Peptide Temporin G: Anti-Biofilm, Anti-Persister Activities, and Potentiator Effect of Tobramycin Efficacy Against Staphylococcus aureus

2020 ◽  
Vol 21 (24) ◽  
pp. 9410
Author(s):  
Bruno Casciaro ◽  
Maria Rosa Loffredo ◽  
Floriana Cappiello ◽  
Guendalina Fabiano ◽  
Luisa Torrini ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Human Keratinocytes ◽  
Skin Infections ◽  
Positive Bacterium ◽  
Persister Cells ◽  
Dividing Cells ◽  
Adverse Environmental Conditions ◽  
Bacterial Skin Infections ◽  
First Time

Bacterial biofilms are a serious threat for human health, and the Gram-positive bacterium Staphylococcus aureus is one of the microorganisms that can easily switch from a planktonic to a sessile lifestyle, providing protection from a large variety of adverse environmental conditions. Dormant non-dividing cells with low metabolic activity, named persisters, are tolerant to antibiotic treatment and are the principal cause of recalcitrant and resistant infections, including skin infections. Antimicrobial peptides (AMPs) hold promise as new anti-infective agents to treat such infections. Here for the first time, we investigated the activity of the frog-skin AMP temporin G (TG) against preformed S. aureus biofilm including persisters, as well as its efficacy in combination with tobramycin, in inhibiting S. aureus growth. TG was found to provoke ~50 to 100% reduction of biofilm viability in the concentration range from 12.5 to 100 µM vs ATCC and clinical isolates and to be active against persister cells (about 70–80% killing at 50–100 µM). Notably, sub-inhibitory concentrations of TG in combination with tobramycin were able to significantly reduce S. aureus growth, potentiating the antibiotic power. No critical cytotoxicity was detected when TG was tested in vitro up to 100 µM against human keratinocytes, confirming its safety profile for the development of a new potential anti-infective drug, especially for treatment of bacterial skin infections.

scholarly journals Nitrofurantoin Combined With Amikacin: A Promising Alternative Strategy for Combating MDR Uropathogenic Escherichia coli

2020 ◽  
Vol 10 ◽  
Author(s):  
Zi-Xing Zhong ◽  
Ze-Hua Cui ◽  
Xiao-Jie Li ◽  
Tian Tang ◽  
Zi-Jian Zheng ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Resistance ◽  
Galleria Mellonella ◽  
Synergistic Effects ◽  
Promising Alternative ◽  
Poor Patient Compliance ◽  
Life Threatening ◽  
Tract Infections ◽  
Time Kill

Urinary tract infections (UTI) are common infections that can be mild to life threatening. However, increased bacterial resistance and poor patient compliance rates have limited the effectiveness of conventional antibiotic therapies. Here, we investigated the relationship between nitrofurantoin and amikacin against 12 clinical MDR uropathogenic Escherichia coli (UPEC) strains both in vitro and in an experimental Galleria mellonella model. In vitro synergistic effects were observed in all 12 test strains by standard checkerboard and time-kill assays. Importantly, amikacin or nitrofurantoin at half of the clinical doses were not effective in the treatment of UPEC infections in the G. mellonella model but the combination therapy significantly increased G. mellonella survival from infections caused by all 12 study UPEC strains. Taken together, these results demonstrated synergy effects between nitrofurantoin and amikacin against MDR UPEC.

Characterization of Antibacterial Proanthocyanidins of Dalbergia monetaria, an Amazonian Medicinal Plant, by UHPLC-HRMS/MS

Planta Medica ◽  
2020 ◽  
Vol 86 (12) ◽  
pp. 858-866
Author(s):  
Patricia Homobono Brito de Moura ◽  
Amaryllis Almeida de Sousa ◽  
Andrea Porzel ◽  
Ludger A. Wessjohann ◽  
Ivana Correa Ramos Leal ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Neutral Loss ◽  
Antibacterial Activities ◽  
Quinone Methide ◽  
In Vitro Assays ◽  
Fragmentation Pattern ◽  
Bacterial Strains ◽  
Tract Infections

Abstract Dalbergia monetaria is an Amazonian plant whose bark is widely used to treat urinary tract infections. This paper describes a bio-guided study of ethanolic extracts from the bark and leaves of D. monetaria, in a search for metabolites active against human pathogenic bacteria. In vitro assays were performed against 10 bacterial strains, highlighting methicillin-sensitive Staphylococcus aureus and methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa. Fractioning of the extracts was performed using instrumental and classical techniques, and samples were characterized by UHPLC-HRMS/MS. Ethyl acetate fractions from bark and leaves showed similar antibacterial activities. EAFB is enriched in isoflavone C-glucosides and EAFL enriched in proanthocyanidins. Subfractions from EAFL presented higher activity and showed a complex profile of proanthocyanidins constructed by (epi)-cassiaflavan and (epi)-catechin units, including dimers, trimers and tetramers. The fragmentation pattern emphasized the neutral loss of cassiaflavan units by quinone-methide fission. Fraction SL7-6, constituted by (ent)-cassiaflavan-(ent)-cassiaflavan-(epi)-catechin isomers, showed the lowest MIC against the S. aureus and P. aeruginosa with values corresponding to 64 and 32 µg/mL, respectively. Cassiaflavan-proanthocyanidins have not been found previously in another botanical genus, except in Cassia, and the traditional medicinal use of D. monetaria might be related to the antibacterial activity of proanthocyanidins characterized in the species.

In Vitro Effects of Isobutyl Cyanoacrylate on Four Types of Bacteria

1971 ◽  
Vol 50 (6) ◽  
pp. 1557-1558 ◽  
Author(s):  
John Jandinski ◽  
Stephen Sonis
Keyword(s):  
Staphylococcus Aureus ◽  
Growth Inhibition ◽  
Petri Dishes ◽  
In Vitro Effects ◽  
Streptococcus A ◽  
Polymer Application

Isobutyl cyanoacrylate produced varying degrees of growth inhibition when applied to freshly plated Petri dishes of Staphylococcus aureus, Gaffkya, Neisseria catarrhalis, and a-Streptococcus. A biproduct or diffusible substance produced by the polymer was implicated as the cause. Destruction of growing colonies was observed only with a-Streptococcus after polymer application. The mechanism for this was not determined.

The myelotoxicity of chloramphenicol: in vitro and in vivo studies: I. In vitro effects on cells in culture

1997 ◽  
Vol 16 (10) ◽  
pp. 570-576 ◽  
Author(s):  
DE Holt ◽  
TA Ryder ◽  
A. Fairbairn ◽  
R. Hurley ◽  
D. Harvey
Keyword(s):  
Progenitor Cells ◽  
Aplastic Anaemia ◽  
Monkey Kidney ◽  
In Vivo Studies ◽  
Patient Treatment ◽  
Morphological Effect ◽  
Dividing Cells ◽  
In Vitro Effects

1 Chloramphenicol is used extensively in non-industria lized countries for the treatment of life-threatening infections because it is cheap and effective, despite its known hemotoxicity and linkage to fatal aplastic anaemia. It is important to define the mechanism of toxicity so that means can be devised to ameliorate the toxic effects in order to produce safer usage. 2 Chloramphenicol, at concentrations from 5 mM to 2 mM initiated apoptosis in dividing cells from a monkey kidney-derived cell line and in haematopoie tic progenitor cells from human neonatal cord blood. 3 Growth of progenitor cells was suppressed at concen trations of chloramphenicol which would be consid ered less than therapeutic during patient treatment. 4 These effects could be ameliorated in progenitor cells by co-culture with the antioxidant mercaptoethyla mine and in monkey kidney cells by co-culture with vitamin C. 5 This is the first report of apoptosis in chloramphenicol toxicity and suggests a possible link between a metabolic event i.e. the production of free radicals; a morphological effect, apoptosis; and a clinical effect, bone marrow suppression and aplastic anaemia.

scholarly journals Effects of Sauropus androgynus extract and its combination with ampicillin against Methicillin-resistant Staphylococcus aureus: An in vitro study

2020 ◽  
Vol 6 (2) ◽  
pp. 128-133
Author(s):  
Asih Rahayu ◽  
Chylen Setiyo Rini ◽  
Yos Adi Prakoso ◽  
Bagus Uda Palgunadi ◽  
Muhammad Aris Munandar
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Synergistic Effects ◽  
In Vitro Study ◽  
Latex Agglutination ◽  
Herbal Extract ◽  
Ultrastructural Changes ◽  
Methicillin Resistant

Background and Aim: The massive utilization of antibiotics has increased resistant genes produced by bacteria. Many bacteria, including Methicillin-resistant Staphylococcus aureus (MRSA), have become resistant against ampicillin (AMP). The combination of an herbal extract with AMP is expected to generate synergistic effects and may restore the susceptibility of MRSA against AMP. This study aimed to analyze the potency of Sauropus androgynous extract (SAE) as a single extract and combination with AMP against MRSA. Materials and Methods: Sauropus androgynous was extracted using 60% ethanol. SAE biochemical compounds were analyzed qualitatively and quantitatively. SAE, AMP, and SAE+AMP were tested against MRSA isolates to determine the minimum inhibitory concentration and fractional inhibitory concentration. The inhibition of penicillin-binding proteins 2a (PBP2a) was analyzed using a latex agglutination test. Further, the disruptive membrane effects of SAE, AMP, and SAE+AMP were analyzed using a scanning electron microscope. The analysis of data was conducted using SPSS version 16 with p=0.01. Results: SAE contained bioactive compounds such as phenolics and flavonoids. Further, 2 mg/mL of SAE could be used as the potential concentration against MRSA isolates in vitro. In addition, the utilization of SAE+AMP generated synergistic effects, restored the susceptibility of isolates against AMP, decreased the synthesis of PBP2a by the MRSA, and induced ultrastructural changes in the bacterial membrane. Conclusion: This study indicated that the utilization of SAE potentially inhibits the growth of MRSA through decreasing of PBP2a expression, disruption of the MRSA membrane, while the combination of SAE+AMP showed synergistic effects against MRSA.

scholarly journals Nanosilver Colloid Inhibits Toxoplasma gondii Tachyzoites and Bradyzoites in Vitro

2019 ◽  
Author(s):  
Saeedeh SHOJAEE ◽  
Nima FIROUZEH ◽  
Hussein KESHAVARZ ◽  
Sanaz JAFARPOUR AZAMI ◽  
Mahboobeh SALIMI ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Structural Changes ◽  
Protozoan Parasite ◽  
Blue Dye ◽  
Type I ◽  
Worldwide Distribution ◽  
Life Threatening ◽  
Strain Type ◽  
In Vitro Effects

Background: Toxoplasma gondii, the coccidian protozoan parasite with worldwide distribution, is the agent of toxoplasmosis. The disease is life threatening in congenital form and in immunocompromised patients. The present study was carried out in 2016 to evaluate the in vitro effects of nanosilver colloid on tachyzoites and bradyzoites of T. gondii, RH and Tehran strains. Methods: Different concentrations (5, 10 , 20 ppm) of  nanosilver colloid were added to tachyzoites of T. gondii , RH strain (type I) and bradyzoites and tissue cysts of T. gondii , Tehran strain (type II) and incubated for 30, 60, 90 and 120 minutes. The mortality rates of tachyzoites and bradyzoites were evaluated by trypan blue dye and MTT assay. Then SEM carried out to show the changes between control and exposed parasites. Results: The greatest mortality rate was seen in 20 ppm concentration and after 120 minutes of exposure. By electron microscopy, the structural changes were seen in tachyzoites of RH and tissue cyst of Tehran strain in comparison with control groups. Conclusion: Nanosilver colloid was effective on both tachyzoites and bradyzoites of T. gondii, RH and Tehran strains.

scholarly journals The Effects of Turmeric Infusion and Turmeric Juice (Curcuma Domestica) on The Staphylococcus Aureus Growth in Vitro

2021 ◽  
Vol 2 (2) ◽  
pp. 54-60
Author(s):  
Renny Novi Puspitasari ◽  
Handayani Handayani ◽  
Ratna Sofaria
Keyword(s):  
Staphylococcus Aureus ◽  
Pearson Correlation ◽  
Food Poisoning ◽  
Average Growth ◽  
Phenol Derivatives ◽  
Group I ◽  
The One ◽  
Insect Bites ◽  
Growth Of Bacteria

Background: Turmeric is a plant that grows in tropical areas and functions as medicine. The chemical compounds contained in turmeric have a role as antioxidants, antimicrobials, anti-cancer, indigestion, smallpox, insect bites. The curcumin content in turmeric has antibacterial activity against various types of Gram negative, Gram positive, antiviral and anti-tumor bacteria. Essential oils can be used as antibacterial because they contain hydroxyl and carbonyl functional groups which are phenol derivatives. Flavonoids can interfere with cell wall formation with peptidoglycan transpeptidase activity which will break down cell walls and damage cell membranes so that important components such as proteins, nucleic acids, nucleotides will be lysis. Staphylococcus bacteria are normal flora on the skin, respiratory tract, and digestive tract of food in humans. These bacteria can cause disease when they reach 1,000,000 or 106 per gram, an amount sufficient to produce the toxin. S. aureus bacteria can cause various types of infections ranging from minor skin infections, food poisoning to systemic infections. The aim of our study was to analyze the effects of infusion and turmeric juice (Curcuma domestica val) on the growth of bacteria Staphylococcus aureus through invitro. Method: This study is a laboratory experimental study with the aim of analyzing turmeric infusion (Curcuma domestica val) and turmeric juice effect on the growth of staphylococcus aureus by invitro. This research was conducted in an integrated laboratory, FK UNUSA. The samples in this study were 4 replications per treatment. The independent variables in this study were turmeric infusion and turmeric juice (with a concentration of 10%, 30%, 50% while the dependent variable in this study was the growth of Staphylococcus aureus bacteria. Data analysis used was the one way ANOVA test and Pearson correlation to determine the effect of giving turmeric infusion and turmeric juice on the growth of bacteria staphylococcus aureus through invitro. Result: The average growth of bacteria in the turmeric infusion in group I (control), 10%, 30% and 50% of turmeric infusion was 4.89 ± 0.4425 log CFU / ml, 3.07 ± 0.61330 log CFU / ml, 2.99 ± 0.63986 log CFU. / ml and 3.02 ± 0.22650 log CFU / ml. The average growth of this bacteria in giving turmeric juice in group I (control), giving 10%, 30% and 50% turmeric infusion was 4.89 ± 0.04425 log CFU / ml, 4.40 ± 0.18355log CFU / ml, 3.10 ± 0.58926 log CFU / ml and 3.02 ± 0.38206 log CFU / ml. Conclusion: In this study, found that there was an effect of giving turmeric infusion and turmeric juice (Curcuma domestica val) on Staphylococcus aureus growth and there was an effect of giving multilevel doses of turmeric infusion and turmeric juice (Curcuma domestica val) on Staphylococcus aureus growth through invitro.

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