scholarly journals Biofilm-Related Infections in Gram-Positive Bacteria and the Potential Role of the Long-Acting Agent Dalbavancin

2021 ◽  
Vol 12 ◽  
Author(s):  
Alessandra Oliva ◽  
Stefania Stefani ◽  
Mario Venditti ◽  
Enea Gino Di Domenico
Keyword(s):  
Public Health Problem ◽  
Major Public Health Problem ◽  
Bacterial Cells ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Gram Positive Bacteria ◽  
Wide Range ◽  
Long Acting ◽  
Acting Agent ◽  
Biofilm Development

Infections caused by Gram-positive bacteria are a major public health problem due to their increasing resistance to antibiotics. Staphylococcus and Enterococcus species’ resistance and pathogenicity are enhanced by their ability to form biofilm. The biofilm lifestyle represents a significant obstacle to treatment because bacterial cells become highly tolerant to a wide range of antimicrobial compounds normally effective against their planktonic forms. Thus, novel therapeutic strategies targeting biofilms are urgently needed. The lipoglycopeptide dalbavancin is a long-acting agent for treating acute bacterial skin and skin structure infections caused by a broad range of Gram-positive pathogens. Recent studies have shown promising activity of dalbavancin against Gram-positive biofilms, including methicillin-resistant S. aureus (MRSA), methicillin-resistant S. epidermidis (MRSE), and vancomycin-susceptible enterococci. This review outlines the mechanisms regulating biofilm development in Staphylococcus and Enterococcus species and the clinical impact of biofilm-related infections. In addition, it discusses the clinical implications and potential therapeutic perspectives of the long-acting drug dalbavancin against biofilm-forming Gram-positive pathogens.

scholarly journals Isolation and Identification of Pathogenic Gram-Positive Bacteria from Egg Shell of Hen and to See Their Antimicrobial Susceptibility Pattern

2016 ◽  
Vol 6 (1) ◽  
pp. 15-18 ◽  
Author(s):  
Jannatul Fardows ◽  
Abu Bakar Siddique ◽  
Adneen Moureen ◽  
Tasmin Afroz Binte Islam ◽  
Nasrin Farhana ◽  
...  
Keyword(s):  
Public Health Problem ◽  
Major Public Health Problem ◽  
Isolation And Identification ◽  
Gram Positive ◽  
Medical College ◽  
Antimicrobial Susceptibility Pattern ◽  
Gram Positive Bacteria ◽  
Source Of Infection ◽  
Egg Shell ◽  
Staphylococcus Spp

Background: Food-borne disease is a major public health problem affecting developed as well as developing countries. Inaccurately treated eggs can be one of its causes. So we designed this study to observe the possibility of transmission of pathogenic Gram-positive bacteria from market eggs to the community.Objectives: To identify different Gram-positive bacteria in eggs and to observe their antimicrobial susceptibility.Materials and Methods: This observational study was conducted in the department of Microbiology, Dhaka Medical College, Dhaka. Shells of 150 eggs collected from different markets of Dhaka city were tested. Bacteria were isolated and identified by culture and relevant biochemical tests.Results: Out of 150 egg shells, 120 (80%) yielded growth of different bacteria. Of them, Staphylococcus spp. were 80 (66.67%), Streptococcus spp. 8 (6.67%), Bacillus subtilis 20 (16.67%) and Bacillus cereus 12 (10%). Out of 80 Staphylococcus spp., 30 (25%) were Staphylococcus aureus and 50 (41.67%) were Staphylococcus saprophyticus. Most of the Gram-positive bacteria were sensitive to ciprofloxacin, ceftriaxone and imipenem. No MRSA and VRSA were found.Conclusion: It can be concluded from this study that Gram-positive bacteria from market eggs may be an important source of infection to the community.J Enam Med Col 2016; 6(1): 15-18

scholarly journals Packed Like Sardines – How Surface Crowdedness Impacts Accessibility to Peptidoglycan of Staphylococcus aureus

2020 ◽  
Author(s):  
Noel J. Ferraro ◽  
Marcos M. Pires
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Cell ◽  
Dense Layer ◽  
Bacterial Cells ◽  
Gram Positive ◽  
Teichoic Acids ◽  
Gram Positive Bacteria ◽  
Wide Range ◽  
Small Molecule Therapeutics ◽  
Live Bacterial Cells

AbstractBacterial cell walls are essential barriers that protect bacteria against the onslaught of potentially lethal molecules from the outside. Small molecule therapeutics, proteins from bacterial foes, and host immune proteins must navigate past a dense layer of bacterial biomacromolecules (e.g., capsular proteins, teichoic acids, and anchored proteins) to reach the peptidoglycan (PG) layer of Gram-positive bacteria. A subclass of molecules (e.g., antibiotics with intracellular targets) must also permeate through the PG (in a molecular sieving manner) to reach the cytoplasmic membrane. In the case of Staphylococcus aureus (S. aureus), teichoic acids are the major biopolymers that decorate bacterial cell surfaces. Despite the biological and therapeutic importance of surface accessibility, systematic analyses in live bacterial cells have been lacking. We describe a novel live cell fluorescence assay that reports on the permeability of molecules to and within the PG scaffold. The assay has robust reproducibility, is readily adoptable to any Gram-positive organism, and is compatible with high-throughput sample processing. Analysis of the factors controlling permeability to S. aureus and the methicillin resistant MRSA revealed that molecular flexibility plays a central role in molecular permeability. Moreover, teichoic acids impeded permeability of molecules of a wide range of sizes and chemical composition.

scholarly journals Antimicrobial Nodule-Specific Cysteine-Rich Peptides Induce Membrane Depolarization-Associated Changes in the Transcriptome of Sinorhizobium meliloti

2013 ◽  
Vol 79 (21) ◽  
pp. 6737-6746 ◽  
Author(s):  
Hilda Tiricz ◽  
Attila Szűcs ◽  
Attila Farkas ◽  
Bernadett Pap ◽  
Rui M. Lima ◽  
...  
Keyword(s):  
Stress Responses ◽  
Sinorhizobium Meliloti ◽  
Antimicrobial Agents ◽  
Cellular Functions ◽  
Gram Positive ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Peptide Family ◽  
Wide Range ◽  
Natural Target

ABSTRACTLeguminous plants establish symbiosis with nitrogen-fixing alpha- and betaproteobacteria, collectively called rhizobia, which provide combined nitrogen to support plant growth. Members of the inverted repeat-lacking clade of legumes impose terminal differentiation on their endosymbiotic bacterium partners with the help of the nodule-specific cysteine-rich (NCR) peptide family composed of close to 600 members. Among the few tested NCR peptides, cationic ones had antirhizobial activity measured by reduction or elimination of the CFU and uptake of the membrane-impermeable dye propidium iodide. Here, the antimicrobial spectrum of two of these peptides, NCR247 and NCR335, was investigated, and their effect on the transcriptome of the natural targetSinorhizobium melilotiwas characterized. Both peptides were able to kill quickly a wide range of Gram-negative and Gram-positive bacteria; however, their spectra were only partially overlapping, and differences were found also in their efficacy on given strains, indicating that the actions of NCR247 and NCR335 might be similar though not identical. Treatment ofS. meliloticultures with either peptide resulted in a quick downregulation of genes involved in basic cellular functions, such as transcription-translation and energy production, as well as upregulation of genes involved in stress and oxidative stress responses and membrane transport. Similar changes provoked mainly in Gram-positive bacteria by antimicrobial agents were coupled with the destruction of membrane potential, indicating that it might also be a common step in the bactericidal actions of NCR247 and NCR335.

scholarly journals In Vitro and In Vivo Activities of DA-7867, a New Oxazolidinone, against Aerobic Gram-Positive Bacteria

2005 ◽  
Vol 49 (6) ◽  
pp. 2498-2500 ◽  
Author(s):  
Eun Jeong Yoon ◽  
Yeong Woo Jo ◽  
Sung Hak Choi ◽  
Tae Ho Lee ◽  
Jae Keol Rhee ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Gram Positive Bacteria ◽  
Vancomycin Resistant Enterococci ◽  
Infection Models ◽  
Vancomycin Resistant

ABSTRACT In vitro and in vivo activities of DA-7867 were assessed against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin-resistant Streptococcus pneumoniae. All isolates were inhibited by DA-7867 at ≤0.78 μg/ml, a four-times-lower concentration than that of inhibition by linezolid. For murine infection models, DA-7867 also exhibited greater efficacy than linezolid against all isolates tested.

scholarly journals Biogenic Synthesis of Silver Nanoparticles with Antimicrobial Properties

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Evangelia A Pavlatou
Keyword(s):  
Silver Nanoparticles ◽  
Antimicrobial Properties ◽  
Public Health Problem ◽  
Integrated Approach ◽  
Synthetic Methods ◽  
Synthesis Process ◽  
Major Public Health Problem ◽  
Biogenic Synthesis ◽  
Wide Range ◽  
Bacteria And Fungi

The transmission of a wide range of diseases, related to the infection by pathogenic microorganisms is a major public health problem that daily endangers the safety of human population. Silver has been thoroughly studied and used against bacteria due to its antimicrobial properties. Nanostructured silver gathers all the advantages of the silver itself, as well as the advanced performance of the nanomaterials. Thus, currently, silver nanoparticles constitute the most widely used kind of nanoparticles in biomedicine, due to their attractive antimicrobial properties. A variety of physical and chemical methods are employed for the AgNPs synthesis. However, many of them include the use of toxic reagents or require large amounts of energy, during the synthesis process. For this reason, many eco-friendly methods are proposed in order to synthesize AgNPs. Hence, biogenic synthesis of AgNPs, utilizing biological resources opens a novel route for the development of alternative production processes.These methods seem to have significant advantages, as the extracts contribute positively to the formation and enhancement of the antimicrobial activity of AgNPs, also acting as protective agents of the produced particles. In this review an integrated approach of AgNPs bio-synthetic methods using microorganisms, such as bacteria and fungi, plants and plant extracts, as well as several templates, like DNA and viruses is discussed, shedding light on the comparative advantages of them.

scholarly journals Understanding the social determinants of TB and HIV in South Asia

2014 ◽  
Author(s):  
Bishwajit Ghose ◽  
Cheng Zhaohui ◽  
He Zhifei
Keyword(s):  
South Asia ◽  
Healthcare System ◽  
Social Determinants ◽  
Social Life ◽  
Public Health Problem ◽  
Asian Population ◽  
Major Public Health Problem ◽  
South Asian Population ◽  
Wide Range ◽  
Mdr Tb

South Asian population suffer a particularly wide range of infectious diseases among which TB and HIV appear to produce most profound influence across various dimensions of social life, healthcare and the economy. Although the countries in this region have a relatively lower prevalence of HIV/AIDS compared to other developing regions until now, the future looks rather bleak in terms of preparedness for emerging healthcare realities. Tuberculosis on the other hand, has always been a major public health problem plaguing the healthcare system and the economy for decades. Moreover, the emergence of the drug resistant (MDR-TB & XDR-TB) strains are making the existing intervention and prevention strategies less effective and posing ever-growing threats to the underdeveloped healthcare infrastructure. Understanding the underlying social-determinants of these diseases can prove crucial to design more comprehensive intervention approaches. This article aims to clarify why the healthcare system in South Asia needs to adopt a social-determinants-of-health (SDOH) approach as a long-term strategy for more efficient prevention and control of TB and HIV infection.

scholarly journals A Pilot Study of Bacteriological Population Changes through Potable Water Treatment and Distribution

2000 ◽  
Vol 66 (1) ◽  
pp. 268-276 ◽  
Author(s):  
Cheryl D. Norton ◽  
Mark W. LeChevallier
Keyword(s):  
Pilot Study ◽  
Biologically Active ◽  
Plate Count ◽  
Identification System ◽  
Population Changes ◽  
Gram Positive ◽  
Pipe Surface ◽  
Treated Water ◽  
Gram Positive Bacteria ◽  
Biofilm Development

ABSTRACT This pilot study compares the compositions of bacterial biofilms in pipe networks supplied with water containing either high levels of biodegradable organic matter (BOM) or low levels of BOM (conventionally or biologically treated, respectively). The Microbial Identification System for fatty acid analysis was utilized in this study to identify a large number of organisms (>1,400) to determine population changes in both conventionally and biologically treated water and biofilms. Data generated during this study indicated that suspended bacteria have little impact on biofilms, and despite treatment (conventional or biological), suspended microbial populations were similar following disinfection. Prechlorination with free chlorine resulted not only in reduced plate count values but also in a dramatic shift in the composition of the bacterial population to predominately gram-positive bacteria. Chlorination of biologically treated water produced the same shifts toward gram-positive bacteria. Removal of assimilable organic carbon by the biologically active filters slowed the rate of biofilm accumulation, but biofilm levels were similar to those found in conventionally treated water within several weeks. Iron pipes stimulated the rate of biofilm development, and bacterial levels on disinfected iron pipes exceeded those for chlorinated polyvinyl chloride pipes. The study showed that the iron pipe surface dramatically influenced the composition, activity, and disinfection resistance of biofilm bacteria.

scholarly journals Activities of Oxadiazole Antibacterials against Staphylococcus aureus and Other Gram-Positive Bacteria

2018 ◽  
Vol 62 (8) ◽  
Author(s):  
Sara Ceballos ◽  
Choon Kim ◽  
Derong Ding ◽  
Shahriar Mobashery ◽  
Mayland Chang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Vancomycin Resistant Enterococci ◽  
Vancomycin Resistant ◽  
Mrsa Strains

ABSTRACT The activities of four oxadiazoles were investigated with 210 methicillin-resistant Staphylococcus aureus (MRSA) strains. MIC50 and MIC90 values of 1 to 2 and 4 μg/ml, respectively, were observed. We also evaluated the activity of oxadiazole ND-421 against other staphylococci and enterococci and in the presence of oxacillin for selected MRSA strains. The MIC for ND-421 is lowered severalfold in combination with oxacillin, as they synergize. The MIC90 of ND-421 against vancomycin-resistant enterococci is ≤1 μg/ml.

scholarly journals Comparative Surveillance Study of Telavancin Activity against Recently Collected Gram-Positive Clinical Isolates from across the United States

2008 ◽  
Vol 52 (7) ◽  
pp. 2383-2388 ◽  
Author(s):  
Deborah C. Draghi ◽  
Bret M. Benton ◽  
Kevin M. Krause ◽  
Clyde Thornsberry ◽  
Chris Pillar ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Clinical Isolates ◽  
Surveillance Study ◽  
Coagulase Negative Staphylococci ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Serious Infections ◽  
Wide Range ◽  
Vancomycin Resistant

ABSTRACT Telavancin is an investigational, rapidly bactericidal lipoglycopeptide antibiotic that is being developed to treat serious infections caused by gram-positive bacteria. A baseline prospective surveillance study was conducted to assess telavancin activity, in comparison with other agents, against contemporary clinical isolates collected from 2004 to 2005 from across the United States. Nearly 4,000 isolates were collected, including staphylococci, enterococci, and streptococci (pneumococci, beta-hemolytic, and viridans). Telavancin had potent activity against Staphylococcus aureus and coagulase-negative staphylococci (MIC range, 0.03 to 1.0 μg/ml), independent of resistance to methicillin or to multiple agents. Telavancin activity was particularly potent against all streptococcal groups (MIC90s, 0.03 to 0.12 μg/ml). Telavancin had excellent activity against vancomycin-susceptible enterococci (MIC90, 1 μg/ml) and was active against VanB strains of vancomycin-resistant enterococci (MIC90, 2 μg/ml) but less active against VanA strains (MIC90, 8 to 16 μg/ml). Telavancin also demonstrated activity against vancomycin-intermediate S. aureus and vancomycin-resistant S. aureus strains (MICs, 0.5 μg/ml to 1.0 μg/ml and 1.0 μg/ml to 4.0 μg/ml, respectively). These data may support the efficacy of telavancin for treatment of serious infections with a wide range of gram-positive organisms.

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