scholarly journals Antibiotic Susceptibility Study Of Metal-Gentamicin Complexes Against Staphylococcus Aureus Biofilms

2017 ◽  
Vol 16 (2) ◽  
Author(s):  
Intan Azura Shahdan ◽  
Fatimah Zahrah Mohd Sobri ◽  
Mohammad Faiz Hizzuan Hanapi ◽  
Hanani Ahmad Yusof ◽  
Fiona N.-F. How
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Susceptibility ◽  
Bacterial Species ◽  
Dental Biofilm ◽  
Planktonic Bacteria ◽  
Metal Contents ◽  
Susceptibility Study ◽  
Biofilm Bacteria ◽  
Dental Plaques ◽  
Conventional Antibiotics

Introduction: Dental plaque is a structurally and functionally organized biofilm. Modern molecular biological techniques have identified about 1000 different bacterial species in the dental biofilm, twice as many as can be cultured. Inherent resistance of biofilm bacteria to conventional antibiotics is alarming. It induces antibiotic resistance to an order of three or more in magnitude greater than those displayed by planktonic bacteria. Staphylococcus aureus is the most dominant bacterial species isolated from the saliva and dental plaques. One of the reasons for its pathogenicity is its ability to form biofilms. In this study, the resistance of S. aureus biofilms against a eries of metal-antibiotics, an alternative to the conventional antibiotics, was investigated. Materials and Methods: A series of metal-antibiotic complexes derived from gentamicin was synthesized to give metal-gentamicin complexes. The metal contents of all the compounds were determined using Atomic Absorption Spectroscopy (AAS). Antibiotic susceptibility testing of the gentamicin-antibiotic complexes against several strains of S. aureus biofilms was conducted using broth microdilution assay. Results: The results showed that S. aureus is susceptible against Co(II) and Fe(II) gentamicin complexes; all were tested at 0.25 to 1 mmol concentrations. Conclusion(s): Co(II) and Fe(II)-gentamicin complexes demonstrated antimicrobial activity.

scholarly journals Antibiotic susceptibility study of metal-gentamicin complexes against Pseudomonas aeruginosa biofilms

2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Intan Azura Shahdan ◽  
Fatimah Zahrah Mohd Sobri ◽  
Mohammad Faiz Hizzuan Hanapi ◽  
Hanani Ahmad Yusof ◽  
Fiona N.-F. How
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Susceptibility ◽  
High Morbidity ◽  
Chronic Infections ◽  
Planktonic Bacteria ◽  
Metal Contents ◽  
Susceptibility Study ◽  
Biofilm Bacteria ◽  
Conventional Antibiotics ◽  
Hospital Acquired

Introduction: Inherent resistance of biofilm bacteria to conventional antibiotics is alarming because biofilms induce antibiotic resistance to an order of three or more in magnitude greater than those displayed by planktonic bacteria. Pseudomonas aeruginosa is an infectious organism that causes the hallmark of chronic infections including hospital acquired infections that leads to high morbidity and mortality. One of the reasons for the occurrence of resistance is its ability to form biofilms. In this study, the resistance of P. aeruginosa biofilms against a series of metal-antibiotics, an alternative to the conventional antibiotics, was investigated. Methods: A series of metal-antibiotic complexes derived from gentamicin was synthesized to give metal-gentamicin complexes. The metal contents of all the compounds were determined using Atomic Absorption Spectroscopy (AAS). Antibiotic susceptibility testing of the gentamicin-antibiotic complexes against the biofilms was conducted using broth microdilution assay. Results: The results showed that P. aeruginosa is susceptible against all the metal-gentamicin complexes, which include, Ni(II), Fe(II), Cu(II), Zn(II) and Co(II) complexes; all were tested at 0.25 to 1 mmol concentrations. Conclusions: The results show that all metal-gentamicin complexes have higher antimicrobial activity than gentamicin (0.25 to 1 mmol) on its own. Finally, mechanisms of P. aeruginosa biofilms resistance to these metal-antibiotics are also proposed.

scholarly journals Function-adaptive clustered nanoparticles reverse Streptococcus mutans dental biofilm and maintain microbiota balance

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Fatemeh Ostadhossein ◽  
Parikshit Moitra ◽  
Esra Altun ◽  
Debapriya Dutta ◽  
Dinabandhu Sar ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Ex Vivo ◽  
Bacterial Species ◽  
Reactive Oxygen Species Generation ◽  
Biofilm Inhibition ◽  
16S Rrna Analysis ◽  
Dental Biofilm ◽  
Dental Plaques

AbstractDental plaques are biofilms that cause dental caries by demineralization with acidogenic bacteria. These bacteria reside inside a protective sheath which makes any curative treatment challenging. We propose an antibiotic-free strategy to disrupt the biofilm by engineered clustered carbon dot nanoparticles that function in the acidic environment of the biofilms. In vitro and ex vivo studies on the mature biofilms of Streptococcus mutans revealed >90% biofilm inhibition associated with the contact-mediated interaction of nanoparticles with the bacterial membrane, excessive reactive oxygen species generation, and DNA fragmentation. An in vivo examination showed that these nanoparticles could effectively suppress the growth of S. mutans. Importantly, 16S rRNA analysis of the dental microbiota showed that the diversity and richness of bacterial species did not substantially change with nanoparticle treatment. Overall, this study presents a safe and effective approach to decrease the dental biofilm formation without disrupting the ecological balance of the oral cavity.

scholarly journals Use of Confocal Microscopy To Analyze the Rate of Vancomycin Penetration through Staphylococcus aureus Biofilms

2005 ◽  
Vol 49 (6) ◽  
pp. 2467-2473 ◽  
Author(s):  
Kimberly K. Jefferson ◽  
Donald A. Goldmann ◽  
Gerald B. Pier
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Confocal Scanning Laser Microscopy ◽  
Planktonic Bacteria ◽  
Transcriptional Changes ◽  
Confocal Scanning ◽  
Biofilm Bacteria ◽  
Confocal Scanning Laser ◽  
Reduced Rate

ABSTRACT When bacteria assume the biofilm mode of growth, they can tolerate levels of antimicrobial agents 10 to 1,000 times higher than the MICs of genetically equivalent planktonic bacteria. The properties of biofilms that give rise to antibiotic resistance are only partially understood. Inhibition of antibiotic penetration into the biofilm may play a role, but this has not been proven directly. In this report, penetration of the glycopeptide antibiotic vancomycin into viable Staphylococcus aureus biofilms was analyzed by confocal scanning laser microscopy using a fluorescently labeled derivative of the drug. We found that while vancomycin bound to free-floating bacteria in water within 5 min, it took more than 1 h to bind to cells within the deepest layers of a biofilm. These results indicate that the antibiotic is transported through the depth of the biofilm but that the rate is significantly reduced with respect to its transport through flowing water. This suggests that, whereas planktonic bacteria were rapidly exposed to a full bolus of vancomycin, the bacteria in the deeper layers of the biofilm were exposed to a gradually increasing dose of the drug due to its reduced rate of penetration. This gradual exposure may allow the biofilm bacteria to undergo stress-induced metabolic or transcriptional changes that increase resistance to the antibiotic. We also investigated the role of poly-N-acetylglucosamine, an important component of the S. aureus biofilm matrix, and found that its production was not involved in the observed decrease in the rate of vancomycin penetration.

scholarly journals Antibiotic susceptibility of Staphylococcus aureus with different degrees of biofilm formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hyo-Jung Shin ◽  
Sungtae Yang ◽  
Yong Lim
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Resistance Mechanisms ◽  
Minimal Bactericidal Concentration ◽  
Chronic Infections ◽  
Planktonic Bacteria ◽  
Growth Modes ◽  
Biofilm Bacteria ◽  
Biofilm Development

AbstractStaphylococcus aureus is one of the most common pathogens in biofilm-associated chronic infections. S. aureus living within biofilms evades the host immune response and is more resistant to antibiotics than planktonic bacteria. In this study, we generated S. aureus with low and high levels of biofilm formation using the rbf (regulator of biofilm formation) gene and performed a BioTimer assay to determine the minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of various types of antibiotics. We showed that biofilm formation by S. aureus had a greater effect on MBC than MIC, probably due to the different growth modes between planktonic and biofilm bacteria. Importantly, we found that the MBC for biofilm S. aureus was much higher than that for planktonic cells, but there was little difference in MBC between low and high levels of biofilm formation. These results suggest that once the biofilm is formed, the bactericidal activity of antibiotics is significantly reduced, regardless of the degree of S. aureus biofilm formation. We propose that S. aureus strains with varying degrees of biofilm formation may be useful for evaluating the anti-biofilm activity of antimicrobial agents and understanding antibiotic resistance mechanisms by biofilm development.

scholarly journals Improving the Efficacy of Antimicrobials against Biofilm-Embedded Bacteria Using Bovine Hyaluronidase Azoximer (Longidaza®)

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1740
Author(s):  
Elena Trizna ◽  
Diana Baidamshina ◽  
Anna Gorshkova ◽  
Valentin Drucker ◽  
Mikhail Bogachev ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Immune System ◽  
Side Effects ◽  
Klebsiella Pneumoniae ◽  
Chronic Infection ◽  
Bacterial Species ◽  
Biofilm Bacteria ◽  
Biofilm Structure

While in a biofilm, bacteria are extremely resistant to both antimicrobials and the immune system, leading to the development of chronic infection. Here, we show that bovine hyaluronidase fused with a copolymer of 1,4-ethylenepiperazine N-oxide and (N-carboxymethyl) -1,4-ethylenepiperazinium bromide (Longidaza®) destroys both mono- and dual-species biofilms formed by various bacteria. After 4 h of treatment with 750 units of the enzyme, the residual biofilms of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae preserved about 50–70% of their initial mass. Biomasses of dual-species biofilms formed by S. aureus and the four latter species were reduced 1.5-fold after 24 h treatment, while the significant destruction of S. aureus–P. aeruginosa and S. aureus–K. pneumoniae was also observed after 4 h of treatment with Longidaza®. Furthermore, when applied in combination, Longidaza® increased the efficacy of various antimicrobials against biofilm-embedded bacteria, although with various increase-factor values depending on both the bacterial species and antimicrobials chosen. Taken together, our data indicate that Longidaza® destroys the biofilm structure, facilitating the penetration of antimicrobials through the biofilm, and in this way improving their efficacy, lowering the required dose and thus also potentially reducing the associated side effects.

scholarly journals Antibiofilm Peptides: Potential as Broad-Spectrum Agents

2016 ◽  
Vol 198 (19) ◽  
pp. 2572-2578 ◽  
Author(s):  
Daniel Pletzer ◽  
Robert E. W. Hancock
Keyword(s):  
Broad Spectrum ◽  
Bacterial Species ◽  
Antibiofilm Activity ◽  
Promising Alternative ◽  
Content Type ◽  
Bacterial Diseases ◽  
Novel Approach ◽  
Recent Developments ◽  
Biofilm Bacteria ◽  
Conventional Antibiotics

The treatment of bacterial diseases is facing twin threats, with increasing bacterial antibiotic resistance and relatively few novel compounds or strategies under development or entering the clinic. Bacteria frequently grow on surfaces as biofilm communities encased in a polymeric matrix. The biofilm mode of growth is associated with 65 to 80% of all clinical infections. It causes broad adaptive changes; biofilm bacteria are especially (10- to 1,000-fold) resistant to conventional antibiotics and to date no antimicrobials have been developed specifically to treat biofilms. Small synthetic peptides with broad-spectrum antibiofilm activity represent a novel approach to treat biofilm-related infections. Recent developments have provided evidence that these peptides can inhibit even developed biofilms, kill multiple bacterial species in biofilms (including the ESKAPE [Enterococcus faecium,Staphylococcus aureus,Klebsiella pneumoniae,Acinetobacter baumannii,Pseudomonas aeruginosa, andEnterobacterspecies] pathogens), show strong synergy with several antibiotics, and act by targeting a universal stress response in bacteria. Thus, these peptides represent a promising alternative treatment to conventional antibiotics and work effectively in animal models of biofilm-associated infections.

scholarly journals Assessment of indoor air bacterial load and antibiotic susceptibility profile of bacteria from some hospitals in Dutse, Jigawa State

2021 ◽  
Vol 12 (2) ◽  
pp. 57-66
Author(s):  
B. Mohammed ◽  
I. Haruna
Keyword(s):  
Staphylococcus Aureus ◽  
General Hospital ◽  
Teaching Hospital ◽  
Indoor Air ◽  
Antibiotic Susceptibility ◽  
Bacterial Species ◽  
Bacterial Load ◽  
Medical Ward ◽  
Health Care Centre ◽  
Bacterial Counts

Indoor air microbial communities play significant roles on the increase in hospitals acquired infections globally. In view of the importance of indoor air bacterial quality in the transmission of nosocomial infections, a study was conducted to assess the air bacterial load and antibiotic susceptibility profile of bacteria from some hospitals in Dutse, Jigawa State. A total of 114 air samples were collected and analyzed using standard procedures from wards and units of Rasheed Shekoni Teaching Hospital Dutse, General Hospital Dutse and Primary Health Care Centre Shuwarin. Settling platetechnique was employed and sampling was done twice daily (Morning and Afternoon). Aerobic mesophilic bacterial counts were conducted. Isolates were identified according to standard methods. The Medical Surgical Ward (MSW) revealed the highest airborne bacterial count (2.770x103 CFU/m3). General Hospital Dutse was found to have a higher indoor bacterial load than Rasheed Shekoni Teaching Hospital and Primary Healthcare Centre Shuwarin. Airborne Gram positive cocci were the most frequently detected (100%) in all the indoor environments. Staphylococcus aureus, Klebsiella pneumoniae, Proteus mirabilis and Escherichia coli were the bacterial species identified in the study. It was observed that the bacterial isolates were more susceptible to gentimicin. The findings revealed the presence of five (5) methicillin resistant staphylococcus aureus isolates (MRSA) 60% in Male Medical Ward (MMW), 20% in Female Medical Ward (FMW), and 20% in Post-natal Ward (PNW). In conclusion, 84.2% of the hospitals’ units were having aerobic mesophilic bacterial counts within the acceptable limits. It is recommended that disinfection of male, female and post-natal wards should be intensified.

Staphylococcus aureus nasal colonization among Vietnamese adults: prevalence, risk factors and antibiotic susceptibility profile

MedPharmRes ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 21-31
Author(s):  
Nguyen Phan ◽  
Hien Pham ◽  
Thuc Nguyen ◽  
Hoai Nguyen
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Antibiotic Susceptibility ◽  
Nasal Carriage ◽  
Resistance Rate ◽  
High Rate ◽  
Weight History ◽  
Potential Risk Factors ◽  
History Of ◽  
Vietnamese Community

Staphylococcus aureus (S. aureus) has long been recognized as an important human pathogen causing many severe diseases. It is also a part of human normal flora with its ecological niche in the human anterior nares. This study focused on screening S. aureus nasal carriage in community and its relationship to human physiological and pathological factors which have not been studied in Vietnam previously. Two hundred and five volunteers in Ho Chi Minh City from 18 to 35 and over 59 years old both male and female participated in the study. Result showed that the prevalence of S. aureus nasal carriage in southern Vietnamese community was relatively low, only 11.2% (23/205), much lower than that in other international reports on human S. aureus. In addition, nasal carriage of the older age group (> 59 years old, 13.7%) was higher than that of younger age (18-35 years old, 10.4%). Other potential risk factors such as gender, career, height, weight, history of antibiotic usage, daily nasal wash, use of nasal medication sprays, acne problems, smoking and nasal problems showed no significant impact on S. aureus carriage. The obtained S. aureus nasal isolates were all sensitive to vancomycin. Lincomycin and tetracycline had low resistance rate with 4.3 % and 17.4 %, respectively. However, the isolates showed particularly high rate of multidrug resistance (54.2%) In summary, our data provided researchers an overview on S. aureus nasal carriage and antibiotic susceptibility profile of the community- isolated S. aureus in Vietnam. This would serve as valuable information on assessing risk of community-acquired S. aureus infections.

A Survey of Staphylococcus aureus Contamination and Antibiotic Susceptibility in Retail Meat

2008 ◽  
Vol 37 (4) ◽  
pp. 528-533 ◽  
Author(s):  
Jung-Im Yang ◽  
Sun-Min Lee ◽  
Gil Lee ◽  
Hwan-Ju Lee ◽  
Min-Kyu Kim ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Susceptibility ◽  
Retail Meat
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