scholarly journals Pseudomonas aeruginosaincreases the sensitivity of biofilm-grownStaphylococcus aureusto membrane-targeting antiseptics and antibiotics

2019 ◽  
Author(s):  
Giulia Orazi ◽  
Kathryn L. Ruoff ◽  
George A. O’Toole

AbstractPseudomonas aeruginosaandStaphylococcus aureusoften cause chronic, recalcitrant infections in large part due to their ability to form biofilms. The biofilm mode of growth enables these organisms to withstand antibacterial insults that would effectively eliminate their planktonic counterparts. We found thatP. aeruginosasupernatant increased the sensitivity ofS. aureusbiofilms to multiple antimicrobial compounds, including fluoroquinolones and membrane-targeting antibacterial agents, including the antiseptic chloroxylenol. Treatment ofS. aureuswith the antiseptic chloroxylenol alone did not decrease biofilm cell viability; however, the combination of chloroxylenol andP. aeruginosasupernatant led to a 4-log reduction inS. aureusbiofilm viability compared to exposure to chloroxylenol alone. We found that theP. aeruginosa-produced small molecule 2-n-heptyl-4-hydroxyquinoline N-oxide (HQNO) is responsible for the observed heightened sensitivity ofS. aureusto chloroxylenol. Similarly, HQNO increased the susceptibility ofS. aureusbiofilms to other compounds, including both traditional and non-traditional antibiotics, which permeabilize bacterial membranes. Genetic and phenotypic studies support a model whereby HQNO causes an increase inS. aureusmembrane fluidity, thereby improving the efficacy of membrane-targeting antiseptics and antibiotics. Importantly, our data show thatP. aeruginosaexoproducts can enhance the ability of various antimicrobial agents to kill biofilm populations ofS. aureusthat are typically difficult to eradicate, providing a path for the discovery of new biofilm-targeting antimicrobial strategies.ImportanceThe thick mucus in the airways of cystic fibrosis (CF) patients predisposes them to frequent, polymicrobial respiratory infections.Pseudomonas aeruginosaandStaphylococcus aureusare frequently co-isolated from the airways of individuals with CF, as well as from diabetic foot ulcers and other wounds. Both organisms form biofilms, which are notoriously difficult to eradicate and promote chronic infection. In this study, we have shownP. aeruginosasecreted factors can increase the efficacy of compounds that alone have little or no bactericidal activity againstS. aureusbiofilms. In particular, we discovered thatP. aeruginosaexoproducts can potentiate the anti-staphylococcal activity of phenol-based antiseptics and other membrane-active drugs, including non-traditional antibiotics. Our findings illustrate that polymicrobial interactions can dramatically increase antibacterial efficacyin vitro, and may guide new approaches to target persistent infections, such as those commonly found in respiratory tract infections and in chronic wounds.

mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Giulia Orazi ◽  
Kathryn L. Ruoff ◽  
George A. O’Toole

ABSTRACT Pseudomonas aeruginosa and Staphylococcus aureus often cause chronic, recalcitrant infections in large part due to their ability to form biofilms. The biofilm mode of growth enables these organisms to withstand antibacterial insults that would effectively eliminate their planktonic counterparts. We found that P. aeruginosa supernatant increased the sensitivity of S. aureus biofilms to multiple antimicrobial compounds, including fluoroquinolones and membrane-targeting antibacterial agents, including the antiseptic chloroxylenol. Treatment of S. aureus with the antiseptic chloroxylenol alone did not decrease biofilm cell viability; however, the combination of chloroxylenol and P. aeruginosa supernatant led to a 4-log reduction in S. aureus biofilm viability compared to exposure to chloroxylenol alone. We found that the P. aeruginosa-produced small molecule 2-n-heptyl-4-hydroxyquinoline N-oxide (HQNO) is responsible for the observed heightened sensitivity of S. aureus to chloroxylenol. Similarly, HQNO increased the susceptibility of S. aureus biofilms to other compounds, including both traditional and nontraditional antibiotics, which permeabilize bacterial membranes. Genetic and phenotypic studies support a model whereby HQNO causes an increase in S. aureus membrane fluidity, thereby improving the efficacy of membrane-targeting antiseptics and antibiotics. Importantly, our data show that P. aeruginosa exoproducts can enhance the ability of various antimicrobial agents to kill biofilm populations of S. aureus that are typically difficult to eradicate. Finally, our discovery that altering membrane fluidity shifts antimicrobial sensitivity profiles of bacterial biofilms may guide new approaches to target persistent infections, such as those commonly found in respiratory tract infections and in chronic wounds. IMPORTANCE The thick mucus in the airways of cystic fibrosis (CF) patients predisposes them to frequent, polymicrobial respiratory infections. Pseudomonas aeruginosa and Staphylococcus aureus are frequently coisolated from the airways of individuals with CF, as well as from diabetic foot ulcers and other wounds. Both organisms form biofilms, which are notoriously difficult to eradicate and promote chronic infection. In this study, we have shown that P. aeruginosa-secreted factors can increase the efficacy of compounds that alone have little or no bactericidal activity against S. aureus biofilms. In particular, we discovered that P. aeruginosa exoproducts can potentiate the antistaphylococcal activity of phenol-based antiseptics and other membrane-active drugs. Our findings illustrate that polymicrobial interactions can dramatically increase antibacterial efficacy in vitro and suggest that altering membrane physiology promotes the ability of certain drugs to kill bacterial biofilms—knowledge that may provide a path for the discovery of new biofilm-targeting antimicrobial strategies.


2020 ◽  
Vol 202 (18) ◽  
Author(s):  
Giulia Orazi ◽  
Fabrice Jean-Pierre ◽  
George A. O’Toole

ABSTRACT The thick mucus within the airways of individuals with cystic fibrosis (CF) promotes frequent respiratory infections that are often polymicrobial. Pseudomonas aeruginosa and Staphylococcus aureus are two of the most prevalent pathogens that cause CF pulmonary infections, and both are among the most common etiologic agents of chronic wound infections. Furthermore, the ability of P. aeruginosa and S. aureus to form biofilms promotes the establishment of chronic infections that are often difficult to eradicate using antimicrobial agents. In this study, we found that multiple LasR-regulated exoproducts of P. aeruginosa, including 2-heptyl-4-hydroxyquinoline N-oxide (HQNO), siderophores, phenazines, and rhamnolipids, likely contribute to the ability of P. aeruginosa PA14 to shift S. aureus Newman norfloxacin susceptibility profiles. Here, we observe that exposure to P. aeruginosa exoproducts leads to an increase in intracellular norfloxacin accumulation by S. aureus. We previously showed that P. aeruginosa supernatant dissipates the S. aureus membrane potential, and furthermore, depletion of the S. aureus proton motive force recapitulates the effect of the P. aeruginosa PA14 supernatant on shifting norfloxacin sensitivity profiles of biofilm-grown S. aureus Newman. From these results, we hypothesize that exposure to P. aeruginosa PA14 exoproducts leads to increased uptake of the drug and/or an impaired ability of S. aureus Newman to efflux norfloxacin. Surprisingly, the effect observed here of P. aeruginosa PA14 exoproducts on S. aureus Newman susceptibility to norfloxacin seemed to be specific to these strains and this antibiotic. Our results illustrate that microbially derived products can alter the ability of antimicrobial agents to kill bacterial biofilms. IMPORTANCE Pseudomonas aeruginosa and Staphylococcus aureus are frequently coisolated from multiple infection sites, including the lungs of individuals with cystic fibrosis (CF) and nonhealing diabetic foot ulcers. Coinfection with P. aeruginosa and S. aureus has been shown to produce worse outcomes compared to infection with either organism alone. Furthermore, the ability of these pathogens to form biofilms enables them to cause persistent infection and withstand antimicrobial therapy. In this study, we found that P. aeruginosa-secreted products dramatically increase the ability of the antibiotic norfloxacin to kill S. aureus biofilms. Understanding how interspecies interactions alter the antibiotic susceptibility of bacterial biofilms may inform treatment decisions and inspire the development of new therapeutic strategies.


2014 ◽  
Vol 58 (8) ◽  
pp. 4353-4361 ◽  
Author(s):  
Carlos J. Sanchez ◽  
Kevin S. Akers ◽  
Desiree R. Romano ◽  
Ronald L. Woodbury ◽  
Sharanda K. Hardy ◽  
...  

ABSTRACTWithin wounds, microorganisms predominantly exist as biofilms. Biofilms are associated with chronic infections and represent a tremendous clinical challenge. As antibiotics are often ineffective against biofilms, use of dispersal agents as adjunctive, topical therapies for the treatment of wound infections involving biofilms has gained interest. We evaluatedin vitrothe dispersive activity ofd-amino acids (d-AAs) on biofilms from clinical wound isolates ofStaphylococcus aureusandPseudomonas aeruginosa; moreover, we determined whether combinations ofd-AAs and antibiotics (clindamycin, cefazolin, oxacillin, rifampin, and vancomycin forS. aureusand amikacin, colistin, ciprofloxacin, imipenem, and ceftazidime forP. aeruginosa) enhance activity against biofilms.d-Met,d-Phe, andd-Trp at concentrations of ≥5 mM effectively dispersed preformed biofilms ofS. aureusandP. aeruginosaclinical isolates, an effect that was enhanced when they were combined as an equimolar mixture (d-Met/d-Phe/d-Trp). When combined withd-AAs, the activity of rifampin was significantly enhanced against biofilms of clinical isolates ofS. aureus, as indicated by a reduction in the minimum biofilm inhibitory concentration (MBIC) (from 32 to 8 μg/ml) and a >2-log reduction of viable biofilm bacteria compared to treatment with antibiotic alone. The addition ofd-AAs was also observed to enhance the activity of colistin and ciprofloxacin against biofilms ofP. aeruginosa, reducing the observed MBIC and the number of viable bacteria by >2 logs and 1 log at 64 and 32 μg/ml in contrast to antibiotics alone. These findings indicate that the biofilm dispersal activity ofd-AAs may represent an effective strategy, in combination with antimicrobials, to release bacteria from biofilms, subsequently enhancing antimicrobial activity.


Author(s):  
Rajanikanth Garapati ◽  
N. Ramesh

Objective: In vitro investigated the potential of methanol extracts of micro-propagated C. orchiodes in the antimicrobial property against the three gram-negative bacteria, two gram-positive and one fungal filament.Methods: The micro propagated callus methanol extract was examined against Escherichia coli, Proteus vulgaris, Salmonella typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus and Candida albicans. The zone of inhibitions are determined at 10 mg/ml concentration of methanol extracts of callus on agar well plate and MIC against tested microorganism.Results: The highest antibacterial activity recorded in Staphylococcus aureus Bacillus cereus and followed by Candida albicans. Antibacterial activity of leaf extracts of A. reticulata was also significant against the tested microorganisms Escherichia coli, Salmonella typhi, Proteus vulgaris, Pseudomonas aeruginosa compared to ciprofloxacin.Conclusion: Based on the above observations, these extracts were further evaluated for their effect on microorganisms causing infections like typhoid fever, urinary tract infections, septicemia, toxic shock syndrome, skin infection, nosocomial infection, arthritis and diarrhoea. The results also suggest that these plants serve a therapeutic purpose in the treatment bacterial infections.


2017 ◽  
Vol 61 (4) ◽  
Author(s):  
M. A. Pfaller ◽  
H. S. Sader ◽  
P. R. Rhomberg ◽  
R. K. Flamm

ABSTRACT The in vitro activities of delafloxacin and comparator antimicrobial agents against 6,485 bacterial isolates collected from medical centers in Europe and the United States in 2014 were tested. Delafloxacin was the most potent agent tested against methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus, Streptococcus pneumoniae, viridans group streptococci, and beta-hemolytic streptococci and had activity similar to that of ciprofloxacin and levofloxacin against certain members of the Enterobacteriaceae. Overall, the broadest coverage of the tested pathogens (Gram-positive cocci and Gram-negative bacilli) was observed with meropenem and tigecycline in both Europe and the United States. Delafloxacin was shown to be active against organisms that may be encountered in acute bacterial skin and skin structure infections, respiratory infections, and urinary tract infections.


2008 ◽  
Vol 53 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Jose L. del Pozo ◽  
Mark S. Rouse ◽  
Jayawant N. Mandrekar ◽  
Marta Fernandez Sampedro ◽  
James M. Steckelberg ◽  
...  

ABSTRACT Bacterial biofilms are resistant to conventional antimicrobial agents. Prior in vitro studies have shown that electrical current (EC) enhances the activities of aminoglycosides, quinolones, and oxytetracycline against Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus epidermidis, Escherichia coli, and Streptococcus gordonii. This phenomenon, known as the bioelectric effect, has been only partially defined. The purpose of this work was to study the in vitro bioelectric effect on the activities of 11 antimicrobial agents representing a variety of different classes against P. aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), and S. epidermidis. An eight-channel current generator/controller and eight chambers delivering a continuous flow of fresh medium with or without antimicrobial agents and/or EC to biofilm-coated coupons were used. No significant decreases in the numbers of log10 CFU/cm2 were seen after exposure to antimicrobial agents alone, with the exception of a 4.57-log-unit reduction for S. epidermidis and trimethoprim-sulfamethoxazole. We detected a statistically significant bioelectric effect when vancomycin plus 2,000 microamperes EC were used against MRSA biofilms (P = 0.04) and when daptomycin and erythromycin were used in combination with 200 or 2,000 microamperes EC against S. epidermidis biofilms (P = 0.02 and 0.0004, respectively). The results of these experiments indicate that the enhancement of the activity of antimicrobial agents against biofilm organisms by EC is not a generalizable phenomenon across microorganisms and antimicrobial agents.


2014 ◽  
Vol 82 (11) ◽  
pp. 4718-4728 ◽  
Author(s):  
Stephanie DeLeon ◽  
Allie Clinton ◽  
Haley Fowler ◽  
Jake Everett ◽  
Alexander R. Horswill ◽  
...  

ABSTRACTIn individuals with polymicrobial infections, microbes often display synergistic interactions that can enhance their colonization, virulence, or persistence. One of the most prevalent types of polymicrobial infection occurs in chronic wounds, wherePseudomonas aeruginosaandStaphylococcus aureusare the two most common causes. Although they are the most commonly associated microbial species in wound infections, very little is known about their interspecies relationship. Evidence suggests thatP. aeruginosa–S. aureuscoinfections are more virulent than monoculture infection with either species; however, difficulties in growing these two pathogens togetherin vitrohave hampered attempts to uncover the mechanisms involved. Here we describe a simple and clinically relevantin vitrowound model that supported concomitant growth ofP. aeruginosaandS. aureus. We observed that the ability ofP. aeruginosaandS. aureusto survive antibiotic treatment increased when they were grown together in planktonic cocultures and that antibiotic tolerance was further enhanced when they were grown together in the wound model. We attributed this enhanced tolerance to both the “host-derived” and “bacterium-derived” matrix components. Taken together, our data indicate thatP. aeruginosaandS. aureusmay benefit each other by coinfecting wounds and that the host-derived matrix may serve as important a role as the bacterium-derived matrix in protecting bacteria from some antibiotics.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
B. A. Baviskar ◽  
S. S. Khadabadi ◽  
S. L. Deore

A new series ofN-{4-methyl-5-[4-(4-oxo-2-phenyl(1,3-thiazolidin-3-yl)]-5-sulfanyl(1,2,4-triazol-3-yl)-1,3-thiazol-2-yl }acetamide (7a-l) was synthesized in order to determine their antimicrobial activity and feasible structure–activity relationships. The compounds were synthesized in good yield and the structures of all newly synthesized compounds were established on the basis of their IR,1HNMR, and elemental analysis. The synthesized compounds were testedin vitroantibacterial activity againstStaphylococcus aureus,Escherichia coli,Pseudomonas aeruginosaandSalmonella typhiand antifungal activity againstAspergillus niger,Candida albicansby measuring the zone of inhibition in mm.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S858-S858
Author(s):  
Monica Maria Rojas Rojas ◽  
Catalina López ◽  
Jaime Ruiz ◽  
Jacquleine Pavía ◽  
Jose Oñate ◽  
...  

Abstract Background The Study for Monitoring Antimicrobial Resistance Trends (SMART) is a worldwide initiative to monitor in vitro susceptibility of clinical Gram-negative isolates to several antimicrobial agents. Surveillance initiatives are essential to provide real-world evidence to support local guidelines development. Colombia has participated since 2012 with isolates from complicated intrabdominal infections (cIAI), complicated urinary tract infections (cUTI) and respiratory tract infections (RTI). This study describes resistant patterns of Escherichia coli (Eco), Klebsiella pneumoniae (Kpn) and Pseudomonas aeruginosa (Pae) clinical isolates collected in Colombian hospitals in a 2 years period (2017–2018). Methods Isolates from patients with cIAI, cUTI and RTI were collected. Identification confirmation was done in central laboratory. Minimum inhibitory concentrations (MIC) were performed by broth microdilution and interpreted according to 2018 CLSI guidelines, same criteria for Extended-spectrum β-lactamase (ESBL) classification. The antimicrobial activity was evaluated for aztreonam (ATM), ceftolozane/tazobactam (C/T), ceftazidime (CAZ), colistin (COL), ertapenem (ETP), cefepime (FEP), imipenem (IMP), meropenem (MEM) and piperacillin–tazobactam (TZP). Results During 2017–2018, 1492 isolates were collected. The main organism was Eco (51%) followed by Kpn (29%) and Pae (20%). In vitro susceptibility activity is presented in Table 1. COL, C/T, ETP, MEM and IPM exhibited over 95% susceptibility in Eco. ESBL prevalence was 18% for Eco (53/314) and 22% for Kpn (36/165). COL and C/T were the most active agents against Pae isolates. For Kpn, MIC50/90 values were: MEM (0.12 / 8), C/T (0.5 / 8) and for TZP (8 / > 64), meanwhile for Pae were MEM (0.5 / 32), C/T (0.5 / 32) and for TZP (8 / > 64). Conclusion Continued antimicrobial resistance surveillance initiatives are critical to guide the empiric treatments decision in a multidrug resistance era. This study shows that Ceftolozane/Tazobactam, MEM and COL have the best susceptibility profile against Eco, Kpn and Pae of cIAI, cUTI and RTI cases in Colombia. The C/T susceptibility rates and low MIC distribution provide evidence to support its use as a non-carbapenem therapeutic alternative for Gram-negative infections. Disclosures All authors: No reported disclosures.


Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 62
Author(s):  
Grzegorz Krasowski ◽  
Adam Junka ◽  
Justyna Paleczny ◽  
Joanna Czajkowska ◽  
Elżbieta Makomaska-Szaroszyk ◽  
...  

Chronic wounds complicated with biofilm formed by pathogens remain one of the most significant challenges of contemporary medicine. The application of topical antiseptic solutions against wound biofilm has been gaining increasing interest among clinical practitioners and scientific researchers. This paper compares the activity of polyhexanide-, octenidine- and hypochlorite/hypochlorous acid-based antiseptics against biofilm formed by clinical strains of Candida albicans, Staphylococcus aureus and Pseudomonas aeruginosa. The analyses included both standard techniques utilizing polystyrene plates and self-designed biocellulose-based models in which a biofilm formed by pathogens was formed on an elastic, fibrinous surface covered with a fibroblast layer. The obtained results show high antibiofilm activity of polihexanide- and octenidine-based antiseptics and lack or weak antibiofilm activity of hypochlorite-based antiseptic of total chlorine content equal to 80 parts per million. The data presented in this paper indicate that polihexanide- or octenidine-based antiseptics are highly useful in the treatment of biofilm, while hypochlorite-based antiseptics with low chlorine content may be applied for wound rinsing but not when specific antibiofilm activity is required.


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