scholarly journals Complete Killing of Agar Lawn Biofilms by Systematic Spacing of Antibiotic-Loaded Calcium Sulfate Beads

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4052 ◽  
Author(s):  
Devendra H. Dusane ◽  
Jacob R. Brooks ◽  
Devin Sindeldecker ◽  
Casey W. Peters ◽  
Anthony Li ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Calcium Sulfate ◽  
Chronic Infections ◽  
Replica Plating ◽  
Joint Infections ◽  
Single Bead ◽  
Causative Agents ◽  
Biofilm Bacteria ◽  
Adequate Coverage ◽  
And Staphylococcus Aureus

Background: Pseudomonas aeruginosa (PA) and Staphylococcus aureus (SA) are the major causative agents of acute and chronic infections. Antibiotic-loaded calcium sulfate beads (ALCSB) are used in the management of musculoskeletal infections such as periprosthetic joint infections (PJI). Methods: To determine whether the number and spatial distribution of ALCSB are important factors to totally eradicate biofilms, ALCSBs containing vancomycin and tobramycin were placed on 24 h agar lawn biofilms as a single bead in the center, or as 16 beads placed as four clusters of four, a ring around the edge and as a group in the center or 19 beads evenly across the plate. Bioluminescence was used to assess spatial metabolic activity in real time. Replica plating was used to assess viability. Results: For both strains antibiotics released from the beads completely killed biofilm bacteria in a zone immediately adjacent to each bead. However, for PA extended incubation revealed the emergence of resistant colony phenotypes between the zone of eradication and the background lawn. The rate of biofilm clearing was greater when the beads were distributed evenly over the plate. Conclusions: Both number and distribution pattern of ALCSB are important to ensure adequate coverage of antibiotics required to eradicate biofilms.

scholarly journals d-Amino Acids Enhance the Activity of Antimicrobials against Biofilms of Clinical Wound Isolates of Staphylococcus aureus and Pseudomonas aeruginosa

2014 ◽  
Vol 58 (8) ◽  
pp. 4353-4361 ◽  
Author(s):  
Carlos J. Sanchez ◽  
Kevin S. Akers ◽  
Desiree R. Romano ◽  
Ronald L. Woodbury ◽  
Sharanda K. Hardy ◽  
...  
Keyword(s):  
Amino Acids ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Clinical Isolates ◽  
Chronic Infections ◽  
Content Type ◽  
Log Reduction ◽  
Viable Bacteria ◽  
Biofilm Bacteria

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.

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 Non-Antimicrobial Adjuvant Strategies to Tackle Biofilm-Related Staphylococcus aureus Prosthetic Joint Infections

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1060
Author(s):  
Narayan Pant ◽  
Damon P. Eisen
Keyword(s):  
Staphylococcus Aureus ◽  
Joint Infection ◽  
Treatment Strategies ◽  
Chronic Infections ◽  
Biochemical Processes ◽  
Hospital Acquired Infections ◽  
Joint Infections ◽  
Prosthetic Joint ◽  
Prosthetic Joint Infections ◽  
Hospital Acquired

Staphylococcus aureus frequently causes community- and hospital-acquired infections. S. aureus attachment followed by biofilm formation on tissues and medical devices plays a significant role in the establishment of chronic infections. Staphylococcal biofilms encase bacteria in a matrix and protect the cells from antimicrobials and the immune system, resulting in infections that are highly resistant to treatment. The biology of biofilms is complex and varies between organisms. In this review, we focus our discussion on S. aureus biofilms and describe the stages of their formation. We particularly emphasize genetic and biochemical processes that may be vulnerable to novel treatment approaches. Against this background, we discuss treatment strategies that have been successful in animal models of S. aureus biofilm-related infection and consider their possible use for the prevention and eradication of biofilm-related S. aureus prosthetic joint infection.

scholarly journals Genotypic and Phenotypic Characteristics of Staphylococcus aureus Prosthetic Joint Infections: Insight on the Pathogenesis and Prognosis of a Multicenter Prospective Cohort

2020 ◽  
Vol 7 (9) ◽  
Author(s):  
Irene Muñoz-Gallego ◽  
Esther Viedma ◽  
Jaime Esteban ◽  
Mikel Mancheño-Losa ◽  
Joaquín García-Cañete ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Joint Infection ◽  
Genotypic Diversity ◽  
Symptom Duration ◽  
Chronic Infections ◽  
Phenotypic Characteristics ◽  
Joint Infections ◽  
Prosthetic Joint ◽  
Microbiological Characteristics ◽  
Prosthetic Joint Infections

Abstract Background Staphylococcus aureus is the leading cause of prosthetic joint infection (PJI). Beyond the antibiogram, little attention has been paid to the influence of deep microbiological characteristics on patient prognosis. Our aim was to investigate whether microbiological genotypic and phenotypic features have a significant influence on infection pathogenesis and patient outcome. Methods A prospective multicenter study was performed, including all S. aureus PJIs (2016–2017). Clinical data and phenotypic (agr functionality, β-hemolysis, biofilm formation) and genotypic characteristics of the strains were collected. Biofilm susceptibility to antimicrobials was investigated (minimal biofilm eradication concentration [MBEC] assay). Results Eighty-eight patients (39.8% men, age 74.7 ± 14.1 years) were included. Forty-five had early postoperative infections (EPIs), 21 had chronic infections (CPIs), and 19 had hematogenous infections (HIs). Twenty (22.7%) were caused by methicillin-resistant S. aureus. High genotypic diversity was observed, including 16 clonal complexes (CCs), with CC5 being the most frequent (30.7%). agr activity was greater in EPI than CPI (55.6% vs 28.6%; P = .041). Strains causing EPI were phenotypically and genotypically similar, regardless of symptom duration. Treatment failure (36.5%) occurred less frequently among cases treated with implant removal. In cases treated with debridement and implant retention, there were fewer failures among those who received combination therapy with rifampin. No genotypic or phenotypic characteristics predicted failure, except vancomycin minimal inhibitory concentration ≥1.5 mg/L (23.1% failure vs 3.4%; P = .044). MBEC50 was >128 mg/L for all antibiotics tested and showed no association with prognosis. Conclusions S. aureus with different genotypic backgrounds is capable of causing PJI, showing slight differences in clinical presentation and pathogenesis. No major microbiological characteristics were observed to influence the outcome, including MBEC.

Incidence of Foodborne Diseases in The Netherlands: Annual Summary 1982 and an Overview from 1979 to 1982

1988 ◽  
Vol 51 (4) ◽  
pp. 327-334 ◽  
Author(s):  
H. J. BECKERS
Keyword(s):  
Staphylococcus Aureus ◽  
Campylobacter Jejuni ◽  
Monosodium Glutamate ◽  
Meat Products ◽  
Foodborne Diseases ◽  
Foodborne Disease ◽  
Causative Agents ◽  
Fish And Shellfish ◽  
And Staphylococcus Aureus ◽  
Epidemiological Information

Data on the incidence of foodborne disease in 1982 are presented. A total of 319 incidents affecting 1376 ill persons was analyzed. In 86 incidents (553 cases), the etiology was established. Microorganisms appeared to be the main causative agents: Bacillus cereus was responsible for 17 of these incidents (53 cases), Salmonella for 15 (83 cases), Campylobacter jejuni and Staphylococcus aureus for 11 (220 and 51 cases, respectively). Clostridium perfringens for 10 (96) and Yersinia enterocolitica for 1 (3). In 2 outbreaks (7 cases), several bacterial agents were detected without being able to discover which one had caused the symptoms. In 7 episodes (13 cases), illness resulted from ingestion of food contaminated with scombrotoxin. In one incident (4 cases), food had been contaminated with an excess of nutmeg and in 9 (20 cases) with monosodium glutamate. Two episodes (3 cases) were attributed to spoiled food. Cases of foodborne disease recorded by the Chief Medical Inspectorate, but not analyzed due to a lack of epidemiological information, included infections from Salmonella (6795), C. jejuni (1728) and Y. enterocolitica (274). Meat and meat products (24 incidents), fish and shellfish (25), snacks (21) and Dutch meals (23), but especially Chinese foods (132) were associated with incidents most frequently. About 70% of the incidents involved places where food is prepared for immediate consumption. Examples of outbreaks are presented.

scholarly journals Trends in microbiological profiles and antibiotic resistance in periprosthetic joint infections

2021 ◽  
Vol 49 (3) ◽  
pp. 030006052110027
Author(s):  
Lifeng Hu ◽  
Jun Fu ◽  
Yonggang Zhou ◽  
Wei Chai ◽  
Guoqiang Zhang ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibiotic Resistance ◽  
Joint Infection ◽  
Coagulase Negative Staphylococcus ◽  
Antibiotic Resistance Profile ◽  
Joint Infections ◽  
Chi Squared ◽  
And Staphylococcus Aureus ◽  
Gram Positive Cocci ◽  
Over Time

Objective This study examined the trends in demographics, the distribution of microorganisms, and antibiotic resistance in patients with periprosthetic joint infection (PJI). Methods We conducted a retrospective study of 231 consecutive patients diagnosed with PJI in our hospital from January 2006 to December 2015 (93 and 138 patients diagnosed in 2006–2010 and 2011–2015, respectively). The linear-by-linear chi-squared test was used to assess the trends in demographics, the distribution of microorganisms, and antibiotic resistance. Results Gram-positive cocci accounted for 63.9% of all pathogens, and coagulase-negative Staphylococcus (CoNS) accounted for 38.1% of all isolates. The proportion of isolates identified as methicillin-resistant CoNS significantly increased over the study period (39.0% vs. 61.8%). In addition, the proportions of levofloxacin-resistant CoNS (4.9% vs. 21.8%) and Staphylococcus aureus (6.3% vs. 45.0%) isolates significantly increased over the study period. By contrast, the proportions of penicillin-resistant CoNS (82.9% vs. 40.0%) and S. aureus (75.0% vs. 30.0%) isolates decreased over the study period. Conclusion Our research revealed changes in the distribution of microorganisms and antibiotic resistance profile of the pathogens responsible for PJI over time, which could complicate treatment. These findings may serve as a reference for strategies to prevent and empirically treat PJI in China.

scholarly journals Leukocidins and the Nuclease Nuc Prevent Neutrophil-Mediated Killing of Staphylococcus aureus Biofilms

2020 ◽  
Vol 88 (10) ◽  
Author(s):  
Mohini Bhattacharya ◽  
Evelien T. M. Berends ◽  
Xuhui Zheng ◽  
Preston J. Hill ◽  
Rita Chan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Innate Immune ◽  
Human Neutrophils ◽  
Chronic Infections ◽  
Content Type ◽  
Persistent Infections ◽  
Biofilm Bacteria ◽  
Key Aspects ◽  
Neutrophil Response ◽  
Insight Into

ABSTRACT Bacterial biofilms are linked with chronic infections and have properties distinct from those of planktonic, single-celled bacteria. The virulence mechanisms associated with Staphylococcus aureus biofilms are becoming better understood. Human neutrophils are critical for the innate immune response to S. aureus infection. Here, we describe two virulence strategies that converge to promote the ability of S. aureus biofilms to evade killing by neutrophils. Specifically, we show that while neutrophils exposed to S. aureus biofilms produce extracellular traps (NETs) and phagocytose bacteria, both mechanisms are inefficient in clearance of the biofilm biomass. This is attributed to the leukocidin LukAB, which promotes S. aureus survival during phagocytosis. We also show that the persistence of biofilm bacteria trapped in NETs is facilitated by S. aureus nuclease (Nuc)-mediated degradation of NET DNA. This study describes key aspects of the interaction between primary human neutrophils and S. aureus biofilms and provides insight into how S. aureus evades the neutrophil response to cause persistent infections.

scholarly journals Surfaceome and Exoproteome Dynamics in Dual-Species Pseudomonas aeruginosa and Staphylococcus aureus Biofilms

2021 ◽  
Vol 12 ◽  
Author(s):  
Inés Reigada ◽  
Paola San-Martin-Galindo ◽  
Shella Gilbert-Girard ◽  
Jacopo Chiaro ◽  
Vincenzo Cerullo ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Quantitative Proteomics ◽  
Single Species ◽  
Pigment Production ◽  
Bacterial Biofilms ◽  
Label Free ◽  
Host Defenses ◽  
Chronic Infections ◽  
And Staphylococcus Aureus

Bacterial biofilms are an important underlying cause for chronic infections. By switching into the biofilm state, bacteria can evade host defenses and withstand antibiotic chemotherapy. Despite the fact that biofilms at clinical and environmental settings are mostly composed of multiple microbial species, biofilm research has largely been focused on single-species biofilms. In this study, we investigated the interaction between two clinically relevant bacterial pathogens (Staphylococcus aureus and Pseudomonas aeruginosa) by label-free quantitative proteomics focusing on proteins associated with the bacterial cell surfaces (surfaceome) and proteins exported/released to the extracellular space (exoproteome). The changes observed in the surfaceome and exoproteome of P. aeruginosa pointed toward higher motility and lower pigment production when co-cultured with S. aureus. In S. aureus, lower abundances of proteins related to cell wall biosynthesis and cell division, suggesting increased persistence, were observed in the dual-species biofilm. Complementary phenotypic analyses confirmed the higher motility and the lower pigment production in P. aeruginosa when co-cultured with S. aureus. Higher antimicrobial tolerance associated with the co-culture setting was additionally observed in both species. To the best of our knowledge, this study is among the first systematic explorations providing insights into the dynamics of both the surfaceome and exoproteome of S. aureus and P. aeruginosa dual-species biofilms.

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