scholarly journals 712. Activity of Exebacase (CF-301) Against Methicillin-Resistant Staphylococcus aureus (MRSA) Biofilms on Orthopedic Kirschner Wires

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S320-S320
Author(s):  
Melissa J Karau ◽  
Suzannah Schmidt-Malan ◽  
Jayawant Mandrekar ◽  
Dario Lehoux ◽  
Raymond Schuch ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bactericidal Activity ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Kirschner Wires ◽  
Carrier Solution ◽  
Time Points ◽  
Significant Difference ◽  
Peptidoglycan Cell Wall ◽  
The Media ◽  
K Wires

Abstract Background Orthopedic foreign body-associated infection can be difficult to treat due to the formation of biofilms protecting microorganisms from both antimicrobials and the immune system. Exebacase (EXE) is a phage-derived lysin which acts as a direct lytic agent by hydrolyzing the peptidoglycan cell wall of Staphylococcus aureus. In this study, the activity of EXE was evaluated in comparison to daptomycin against MRSA biofilms on orthopedic Kirschner wires (K-wires). Methods MRSA strain IDRL-6169 was studied; it has a MIC of 0.5 µg/mL for both daptomycin (DAP) and EXE. Biofilms were formed in 1 mL of 106 cfu/mL tryptic soy broth on 0.5x0.1 mm threaded stainless steel K-wires for 10 hours, after which the wires were removed from the media and placed into 0.04 mL of either DAP or EXE at 0 (vehicle only), 0.098, 0.98, or 9.8 mg/mL. DAP+EXE was also tested, each at 0.098 mg/mL. Bacteria were quantified after 0, 2, 4, 8, and 12 hours of incubation at 37ºC. Testing was performed in triplicate. Results were reported as log10 cfu/K-wire reduction relative to vehicle alone. A 3-log10 cfu/K-wire reduction was considered bactericidal. P-values were calculated using Kruskal–Wallis. Results The bacterial burden of vehicle alone ranged from 5.49- to 6.33-log10 cfu/K-wire at all time points. Bacterial reductions for each treatment compared with carrier solution are shown in the table. DAP showed no bactericidal activity. EXE showed bactericidal activity at all concentrations at all time points studied except 0.098 mg/mL at 8 hours. There was no significant difference between EXE at 0.098 and 0.98 mg/mL at any time point but EXE at 9.8 mg/mL did show superiority over the lower concentrations. DAP+EXE 0.098 mg/mL was bactericidal at all time points. Conclusion EXE showed a rapid effect against MRSA biofilms on orthopedic K-wires apparent within the first 2 hours of exposure and was more active than daptomycin alone at the same concentrations. Disclosures All authors: No reported disclosures.

scholarly journals The basis of α-hemolysis Negative Methicillin-resistant Staphylococcus Aureus Isolates from Beijing Children’s Hospital

2021 ◽  
Author(s):  
Lijuan Wang ◽  
Chen Sun ◽  
Suyun Qian ◽  
Yingchao Liu ◽  
Kaihu Yao ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Clonal Complex ◽  
Common Mutation ◽  
Rna Expression ◽  
Single Mutation ◽  
Methicillin Resistant ◽  
Significant Difference ◽  
Important Virulence Factor

Abstract Background. Methicillin-resistant Staphylococcus aureus (MRSA) Clonal Complex 59 (CC59) clone has spread among Chinese children, resulting in many Staphylococcus aureus infections. α-hemolysin (Hlα) is an important virulence factor of Staphylococcus aureus, but little research has been done on CC59 isolates with negative α-hemolysis. Results. During the 4 periods (2009-2011, 2012-2013, 2016, 2017), 291 MRSA isolates were collected. Isolates with β and δ hemolysis accounted for 60.47% among the MRSA isolates in 2009-2011; 56.41% in 2012-2013; 77.14% in 2016; and 56.25% in 2017. most ST59 isolates (94.38%), 9 ST338 isolates (100%) showed β and δ hemolysis, both ST59 and ST338 clone belong to CC59 clone. Twenty-two ST239 isolates (73.33%), 8 ST88 isolates (80%), 4 ST5 isolates (100%), 13 ST22 isolates (92.86%) and 6 ST398 isolates (85.71%) showed α and δ hemolysis. α hemolysin in most clinical isolates is highly conservative, each showed one amino acid locus variation, the most common mutation was threonine at position 275 instead of isoleucine, then glutamic acid replaced aspartic acid at 208. Seventeen ST59 and 2 ST338 isolates had no mutation, 3 ST59 isolates showed single mutation (C448G), and only one ST59 isolate showed multilocus mutation. Other ST typing, such as ST1, ST5, ST88, ST20, ST239 and ST398, all had multilocus mutations, sites were from 3 to 8, no conservative sequence was found among isolates with the same ST typing. The carrying rates of RNA III, Rot, agrA, SarR, SarU and SigB were all over 93%, the carrying rates of SarZ and SarA genes were 41.86% and 34.88% respectively. Trancriptional levels of hlα in isolates showed α and δ hemolysis and β and δ hemolysis were equal. USA300 and R23 produced Hlα, R23 didn’t showed α hemolysis phenotype.Conclusions. Most clinical CC59 isolates from children in China were α hemolysis negative. There was no statistically significant difference in hlα gene and RNA expression, they produced the protein. The reason for the phenotypic deletion probably related to β hemolysin (Hlβ).

Bioresorbable  implants vs. Kirschner-wires in the treatment of severely displaced distal paediatric radius and forearm fractures – a retrospective multicentre study

2021 ◽  
Author(s):  
Marcell Varga
Keyword(s):  
Surgical Intervention ◽  
Complication Rates ◽  
Distal Forearm ◽  
Forearm Fractures ◽  
Kirschner Wires ◽  
Paediatric Patients ◽  
Fractures In Children ◽  
Significant Difference ◽  
K Wires ◽  
Wire Osteosynthesis

Abstract BackgroundDistal radius fractures are very common in paediatric patients. Severely displaced fractures may require surgical intervention. The gold standard surgical method is percutaneous K-wire osteosynthesis followed by immobilisation. Metal implants can be removed with a second intervention; however, these extra procedures can cause further complications. Several studies confirm the benefits of bioabsorbable implants for paediatric patients. The aim of this retrospective study was to compare the complication rates of displaced distal metaphyseal radius and forearm fractures in children operated on with K-wires versus a novel technique with bioresorbable implants.MethodsWe retrospectively reviewed 94 patients in three paediatric trauma centres who underwent operations due to severely displaced distal forearm or metaphyseal radial fractures between January 2019 and January 2020. The mean age was 8.23 (ranging from 5-12). 30 patients (bioresorbable group, BR-group) were treated with biodegradable PLGA implants (Bioretec®, ActivaPin®), 40 patients with one or two stainless steel Kirschner-wires (K-wires, Sanatmetal®) which were buried under the skin (KW I-group) and 30 children with K-wires left outside the skin. (KWII. Group). We examined the number of minor and major complications as well as the need for repeated interventions. Follow-up was at least one year.ResultsThere was no significant difference between the complication rates at the two KW groups (p = 0.241; Cramer’s V = 0.211), while the complication rate of the BR group was significantly lower. (p = 0.049; Cramer’s V = 0.293 and p = 0.002; Cramer’s V = 0.418 respectively). No later than half a year after the injury, no difference was observed between the functional outcomes of the patients in each group. One and a half years after the injury, no signs of growth disturbance were found in any of the children. No second surgical intervention was required in the BR group.ConclusionsSurgeries with bioresorbable intramedullary implants may have fewer complications than K- wire osteosynthesis in the treatment of severely displaced distal forearm fractures. The benefits are most pronounced in the first six weeks after surgery, reducing the number of outpatient visits and increasing the child's sense of comfort. As no second intervention is required, this can lead to significant cost savings. After half a year, there is no difference in the outcomes between the different surgical treatment strategies.

scholarly journals PREPARATION OF COLD CREAM AGAINST CLINICAL PATHOGEN USING CARALLUMA ADSCENDENS VAR. ATTENUATA

2020 ◽  
pp. 120-123
Author(s):  
SUNDAR MADASAMY ◽  
SURESH SUNDAN ◽  
LINGAKUMAR KRISHNASAMY
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Positive Control ◽  
Diffusion Method ◽  
Methicillin Resistant ◽  
Cold Cream ◽  
Significant Difference ◽  
Vancomycin Resistant

Objective: A simple formulation of cold cream from methanolic extract Caralluma adscendens var. attenuata (MECA) and their antimicrobial activity was tested against various clinical pathogens, namely, Escherichia coli, methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus faecium, and Candida albicans. Methods: Methanol extract of these plant extract was prepared by the Soxhlet method. We analyzed phytochemical nature of theses plant, and subsequently, a cream was formulated cold-cream C. adscendens var. attenuata (FCA) different concentration such as FCA 50 mg, FCA 100 mg, and FCA 200 mg. In the present study, aimed to the antimicrobial activity of cold cream was measured by agar well diffusion method, and standard antibiotic Neosporin (market available) cream was used as positive control and dummy cold cream (without-MECA) were used as the negative control. Results: Phytochemical screening showed that the plant extracts were found a rich source of secondary metabolites. For more, the efficacy of cold cream from MECA extracts to against the clinical pathogen. Positive control Neosporin and 200 mg FCA cream was a highly significant difference in the zone of inhibition when compared to dummy cream. The 200 mg FCA was activity against Escherichia coli, methicillin-resistant Staphylococcus aureus, vancomycin-resistant E. faecium, and C. albicans highly significantly difference (p<0.05) compared FCA 50 mg and FAC 100 mg creams. Conclusion: The results from this study suggested that the cold cream form base of MECA crude had antimicrobial activity in the different clinical pathogen. They could be used as an alternative source to conventional antimicrobial agents for the treatment of pathological infection.

scholarly journals Novel Use of Rifabutin and Rifapentine to Treat Methicillin-Resistant Staphylococcus aureus in a Rat Model of Foreign Body Osteomyelitis

2020 ◽  
Vol 222 (9) ◽  
pp. 1498-1504
Author(s):  
Melissa J Karau ◽  
Suzannah M Schmidt-Malan ◽  
Mariana Albano ◽  
Jayawant N Mandrekar ◽  
Christina G Rivera ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Foreign Body ◽  
Rat Model ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Joint Infection ◽  
Kirschner Wire ◽  
Methicillin Resistant ◽  
Joint Infections ◽  
Single Animal ◽  
K Wires

Abstract Background Owing to patient intolerance or drug interactions, alternative agents to rifampin are needed for management of staphylococcal periprosthetic joint infection. In the current study, we evaluated rifabutin, rifapentine and rifampin, with and without vancomycin, in a rat model of foreign body osteomyelitis. Methods Proximal tibiae were inoculated with methicillin-resistant Staphylococcus aureus (MRSA) and a Kirschner wire (K-wire) implanted in each. After 4 weeks of infection, rifampin, rifabutin, or rifapentine were administered, alone or with vancomycin. Tibiae and K-wires were cultured, and medians were reported as log10 colony-forming units (CFUs) per gram of bone or log10 CFUs per K-wire, respectively. Results Rifampin, rifabutin or rifapentine administered with vancomycin yielded less MRSA from bones (0.10, 3.02, and 0.10 log10 CFUs/g, respectively) than did no treatment (4.36 log10 CFUs/g) or vancomycin alone (4.64 log10 CFUs/g) (both P ≤ .02). The K-wires of animals receiving no treatment or vancomycin monotherapy recovered medians of 1.76 and 2.91 log10 CFUs/g per K-wire, respectively. In contrast, rifampin, rifabutin and rifapentine administered with vancomycin yielded medians of 0.1 log10 CFUs per K-wire, respectively. Rifampin resistance was detected in a single animal in the rifampin monotherapy group. Conclusions Rifabutin or rifapentine with vancomycin were as active as rifampin with vancomycin against MRSA in rat foreign body osteomyelitis, suggesting that rifabutin and/or rifapentine may be alternatives to rifampin in the clinical management of staphylococcal periprosthetic joint infections.

scholarly journals ComparativeIn VitroActivities of Oritavancin, Dalbavancin, and Vancomycin against Methicillin-Resistant Staphylococcus aureus Isolates in a Nondividing State

2016 ◽  
Vol 60 (7) ◽  
pp. 4342-4345 ◽  
Author(s):  
Adam Belley ◽  
David Lalonde Seguin ◽  
Francis Arhin ◽  
Greg Moeck
Keyword(s):  
Staphylococcus Aureus ◽  
Bactericidal Activity ◽  
Antibacterial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistant ◽  
Content Type ◽  
Skin Structure ◽  
Persistent Infections ◽  
Time Kill

ABSTRACTAntibacterial agents that kill nondividing bacteria may be of utility in treating persistent infections. Oritavancin and dalbavancin are bactericidal lipoglycopeptides that are approved for acute bacterial skin and skin structure infections in adults caused by susceptible Gram-positive pathogens. Using time-kill methodology, we demonstrate that oritavancin exerts bactericidal activity against methicillin-resistantStaphylococcus aureus(MRSA) isolates that are maintained in a nondividing statein vitro, whereas dalbavancin and the glycopeptide vancomycin do not.

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