scholarly journals Risk factors associated with MRSA

2018 ◽  
Vol 33 (3) ◽  
pp. 76-79
Author(s):  
Sonal Gupta ◽  
Bibhabati Mishra ◽  
Archana Thankur ◽  
Vinita Dogra ◽  
Poonam S. Loomba ◽  
...  
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Antibiotic Therapy ◽  
Antimicrobial Agents ◽  
Treatment Options ◽  
Erythromycin Resistance ◽  
Methicillin Resistant ◽  
Hospitalised Patients ◽  
Mrsa Infection

Background: Methicillin-resistant Staphylococcus aureus (MRSA) infection is associated with increased morbidity and mortality compared with infections caused by methicillin-sensitive Staphylococcus aureus (MSSA). Treatment of MRSA infection is complicated by the fact that these organisms are resistant to multiple antimicrobial agents, so treatment options are limited. The aim of the present study is determine risk factors association with MRSA as compared with MSSA and to compare the minimum inhibitory concentrations (MICs) of vancomycin, teicoplanin, linezolid and erythromycin to MRSA and MSSA.Methods: A nine-month prospective study was carried out. Staphylococcus aureus strains with clinical correlation, isolated from hospitalised patients, were included in the study. MIC of vancomycin, teicoplanin, linezolid and erythromycin was determined by E-test (HIMEDIA). Risk factors such as immunosuppression, previous hospitalisation, surgical procedure done, invasive devices and antibiotic therapy were determined by a pre-set protocol.Results: A total of 62 S. aureus strains were included in the study. Some 40% of S. aureus strains were methicillin resistant. The risk factors, invasive devices, previous hospitalisation and comorbid illness were found to be significantly associated with MRSA. Borderline significant association was observed with immunosuppression and antibiotic therapy. Erythromycin resistance was observed in 56% of MRSA, while no resistance was observed in MSSA. Teicoplanin MIC50 values and mean MIC were found to be lowest in vitro among vancomycin and linezolid against both MRSA and MSSA. The efficacy of teicoplanin, in terms of clinical and microbiological cure, has not been proven to be superior to vancomycin, but it has a better toxicity profile and has demonstrated a reduced risk of adverse events. Conclusions: Minimising risk factors and attention to alternative antibiotics and infection control practices may ease the problem of management of infections with MRSA.

scholarly journals Synergism between a Novel Chimeric Lysin and Oxacillin Protects against Infection by Methicillin-Resistant Staphylococcus aureus

2010 ◽  
Vol 54 (4) ◽  
pp. 1603-1612 ◽  
Author(s):  
Anu Daniel ◽  
Chad Euler ◽  
Mattias Collin ◽  
Peter Chahales ◽  
Kenneth J. Gorelick ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Catalytic Domain ◽  
Specific Binding ◽  
Treatment Options ◽  
Current Treatment ◽  
Significant Treatment ◽  
Methicillin Resistant ◽  
Phage Lysin

ABSTRACT Staphylococcus aureus is the causative agent of several serious infectious diseases. The emergence of antibiotic-resistant S. aureus strains has resulted in significant treatment difficulties, intensifying the need for new antimicrobial agents. Toward this end, we have developed a novel chimeric bacteriophage (phage) lysin that is active against staphylococci, including methicillin-resistant S. aureus (MRSA). The chimeric lysin (called ClyS) was obtained by fusing the N-terminal catalytic domain of the S. aureus Twort phage lysin with the C-terminal cell wall-targeting domain from another S. aureus phage lysin (phiNM3), which displayed Staphylococcus-specific binding. ClyS was expressed in Escherichia coli, and the purified protein lysed MRSA, vancomycin-intermediate strains of S. aureus (VISA), and methicillin-sensitive (MSSA) strains of S. aureus in vitro. In a mouse nasal decolonization model, a 2-log reduction in the viability of MRSA cells was seen 1 h following a single treatment with ClyS. One intraperitoneal dose of ClyS also protected against death by MRSA in a mouse septicemia model. ClyS showed a typical pattern of synergistic interactions with both vancomycin and oxacillin in vitro. More importantly, ClyS and oxacillin at doses that were not protective individually protected synergistically against MRSA septic death in a mouse model. These results strongly support the development of ClyS as an attractive addition to the current treatment options of multidrug-resistant S. aureus infections and would allow for the reinstatement of antibiotics shelved because of mounting resistance.

Topical Therapy for Methicillin-Resistant Staphylococcus aureus Colonization Impact on Infection Risk

2009 ◽  
Vol 30 (7) ◽  
pp. 623-632 ◽  
Author(s):  
Ari Robicsek ◽  
Jennifer L. Beaumont ◽  
Richard B. Thomson ◽  
Geetha Govindarajan ◽  
Lance R. Peterson
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Antimicrobial Agents ◽  
Topical Therapy ◽  
Care Facility ◽  
Term Care ◽  
Methicillin Resistant ◽  
Mrsa Infection ◽  
Independent Risk Factors ◽  
The Impact

Objective.We evaluated the usefulness of topical decolonization therapy for reducing the risk of methicillin-resistant Staphylococcus aureus (MRSA) infection among MRSA-colonized inpatients.Design.Retrospective cohort study.Setting and Intervention.Three hospitals with universal surveillance for MRSA; at their physician's discretion, colonized patients could be treated with a 5-day course of nasal mupirocin calcium 2%, twice daily, plus Chlorhexidine gluconate 4% every second day.Patients and Methods.MRSA carriers were later retested for colonization (407 subjects; study 1) or followed up for development of MRSA infection (933 subjects; study 2). Multivariable methods were used to determine the impact of decolonization therapy on the risks of sustained colonization (in study 1) and MRSA infection (in study 2).Results.Independent risk factors for sustained colonization included residence in a long-term care facility (odds ratio [OR], 1.8 [95% confidence interval {CI}, 1.1–3.2]) and a pressure ulcer (OR, 2.3 195% CI, 1.2–4.4]). Mupirocin at any dose decreased this risk, particularly during the 30-60-day period after therapy; mupirocin resistance increased this risk (OR, 4.1 [95% CI, 1.6–10.7]). Over a median follow-up duration of 269 days, 69 (7.4%) of 933 patients developed infection. Independent risk factors for infection were length of stay (hazard ratio [HR], 1.2 per 5 additional days [95% CI, 1.0–1.4]), chronic lung disease (HR, 1.7 [95% CI, 1.0–2.8]), and receipt of non-MRSA-active systemic antimicrobial agents (HR, 1.8 [95% CI, 1.1–3.1]). Receipt of mupirocin did not affect the risk of infection, although there was a trend toward delayed infection among patients receiving mupirocin (median time to infection, 50 vs 15.5 days; P = .06).Conclusions.Mupirocin-based decolonization therapy temporarily reduced the risk of continued colonization but did not decrease the risk of subsequent infection.

scholarly journals Methicillin-resistant Staphylococcus aureus bloodstream infection: risk factors and clinical outcome in non-intensive-care units

2012 ◽  
Vol 45 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Karinne Spirandelli Carvalho Naves ◽  
Natália Vaz da Trindade ◽  
Paulo Pinto Gontijo Filho
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Bloodstream Infection ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistance ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Staphylococcus Aureus Bloodstream Infection

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is spread out in hospitals across different regions of the world and is regarded as the major agent of nosocomial infections, causing infections such as skin and soft tissue pneumonia and sepsis. The aim of this study was to identify risk factors for methicillin-resistance in Staphylococcus aureus bloodstream infection (BSI) and the predictive factors for death. METHODS: A retrospective cohort of fifty-one patients presenting bacteraemia due to S. aureus between September 2006 and September 2008 was analysed. Staphylococcu aureus samples were obtained from blood cultures performed by clinical hospital microbiology laboratory from the Uberlândia Federal University. Methicillinresistance was determined by growth on oxacillin screen agar and antimicrobial susceptibility by means of the disk diffusion method. RESULTS: We found similar numbers of MRSA (56.8%) and methicillin-susceptible Staphylococcus aureus (MSSA) (43.2%) infections, and the overall hospital mortality ratio was 47%, predominantly in MRSA group (70.8% vs. 29.2%) (p=0.05). Age (p=0.02) was significantly higher in MRSA patients as also was the use of central venous catheter (p=0.02). The use of two or more antimicrobial agents (p=0.03) and the length of hospital stay prior to bacteraemia superior to seven days (p=0.006) were associated with mortality. High odds ratio value was observed in cardiopathy as comorbidity. CONCLUSIONS: Despite several risk factors associated with MRSA and MSSA infection, the use of two or more antimicrobial agents was the unique independent variable associated with mortality.

scholarly journals In VitroPharmacodynamics of Human Simulated Exposures of Ceftaroline and Daptomycin against MRSA, hVISA, and VISA with and without Prior Vancomycin Exposure

2013 ◽  
Vol 58 (2) ◽  
pp. 672-677 ◽  
Author(s):  
Amira A. Bhalodi ◽  
Mao Hagihara ◽  
David P. Nicolau ◽  
Joseph L. Kuti
Keyword(s):  
Staphylococcus Aureus ◽  
Body Weight ◽  
Sequential Therapy ◽  
Free Drug ◽  
Pharmacodynamic Model ◽  
Prior Exposure ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mrsa Infection

ABSTRACTThe effects of prior vancomycin exposure on ceftaroline and daptomycin therapy against methicillin-resistantStaphylococcus aureus(MRSA) have not been widely studied. Humanized free-drug exposures of vancomycin at 1 g every 12 h (q12h), ceftaroline at 600 mg q12h, and daptomycin at 10 mg/kg of body weight q24h were simulated in a 96-hin vitropharmacodynamic model against three MRSA isolates, including one heteroresistant vancomycin-intermediateS. aureus(hVISA) isolate and one VISA isolate. A total of five regimens were tested: vancomycin, ceftaroline, and daptomycin alone for the entire 96 h, and then sequential therapy with vancomycin for 48 h followed by ceftaroline or daptomycin for 48 h. Microbiological responses were measured by the changes in log10CFU during 96 h from baseline. Control isolates grew to 9.16 ± 0.32, 9.13 ± 0.14, and 8.69 ± 0.28 log10CFU for MRSA, hVISA, and VISA, respectively. Vancomycin initially achieved ≥3 log10CFU reductions against the MRSA and hVISA isolates, followed by regrowth beginning at 48 h; minimal activity was observed against VISA. The change in 96-h log10CFU was largest for sequential therapy with vancomycin followed by ceftaroline (−5.22 ± 1.2,P= 0.010 versus ceftaroline) and for sequential therapy with vancomycin followed by ceftaroline (−3.60 ± 0.6,P= 0.037 versus daptomycin), compared with daptomycin (−2.24 ± 1.0), vancomycin (−1.40 ± 1.8), and sequential therapy with vancomycin followed by daptomycin (−1.32 ± 1.0,P> 0.5 for the last three regimens). Prior exposure of vancomycin at 1 g q12h reduced the initial microbiological response of daptomycin, particularly for hVISA and VISA isolates, but did not affect the response of ceftaroline. In the scenario of poor vancomycin response for high-inoculum MRSA infection, a ceftaroline-containing regimen may be preferred.

Nemonoxacin enhances antibacterial activity and anti-resistant mutation ability of vancomycin against methicillin-resistant Staphylococcus aureus in an in vitro dynamic pharmacokinetic/pharmacodynamic model

2021 ◽  
Author(s):  
Junchen Huang ◽  
Siwei Guo ◽  
Xin Li ◽  
Fang Yuan ◽  
You Li ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Bactericidal Activity ◽  
Pharmacodynamic Model ◽  
Methicillin Resistant ◽  
Mutant Prevention Concentration ◽  
Mrsa Infection ◽  
Independent Risk Factors ◽  
Resistant Mutation

Reduced susceptibility and emergence of resistance to vancomycin in methicillin-resistant Staphylococcus aureus (MRSA) have led to the development of various vancomycin based combinations. Nemonoxacin is a novel nonfluorinated quinolone with antibacterial activity against MRSA. The present study aimed to investigate the effects of nemonoxacin on antibacterial activity and the anti-resistant mutation ability of vancomycin for MRSA and explore whether quinolone resistance genes are associated with a reduction in the vancomycin minimal inhibitory concentration (MIC) and mutant prevention concentration (MPC) when combined with nemonoxacin. Four isolates, all with a vancomycin MIC of 2 μg/mL, were used in a modified in vitro dynamic pharmacokinetic/pharmacodynamic model to investigate the effects of nemonoxacin on antibacterial activity (M04, M23 and M24) and anti-resistant mutation ability (M04, M23 and M25, all with MPC ≥19.2 μg/mL) of vancomycin. The mutation sites of gyrA , gyrB , parC , and parE of 55 clinical MRSA isolates were sequenced. We observed that in M04 and M23, the combination of vancomycin (1g q12h) and nemonoxacin (0.5g qd) showed a synergistic bactericidal activity and resistance enrichment suppression. All clinical isolates resistant to nemonoxacin harbored gyrA (S84→L) mutation; gyrA (S84→L) and parC (E84→K) mutations were the two independent risk factors for the unchanged vancomycin MPC in combination. Nemonoxacin enhances the bactericidal activity and suppresses resistance enrichment ability of vancomycin against MRSA with a MIC of 2 μg/mL. Our in vitro data support the combination of nemonoxacin and vancomycin for the treatment of MRSA infection with a high MIC.

scholarly journals 1230. Epidemiology and Risk Factors for Recurrent Invasive Methicillin-Resistant Staphylococcus aureus Infection: nine US States, 2006–2013

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S373-S374
Author(s):  
Ian Kracalik ◽  
Kelly Jackson ◽  
Joelle Nadle ◽  
Wendy Bamberg ◽  
Susan Petit ◽  
...  
Keyword(s):  
Risk Factors ◽  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Infection Type ◽  
The United States ◽  
Emerging Infections ◽  
Methicillin Resistant ◽  
Initial Infection ◽  
Joint Infections ◽  
Mrsa Infection

Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA) causes >70,000 invasive infections annually in the United States, and recurrent infections pose a major clinical challenge. We examined risk factors for recurrent MRSA infections. Methods We identified patients with an initial invasive MRSA infection (isolation from a normally sterile body site) from 2006 to 2013, through active, population-based surveillance in selected counties in nine states through the Emerging Infections Program. Recurrence was defined as invasive MRSA isolation >30 days after initial isolation. We used logistic regression with backwards selection to evaluate adjusted odds ratios (aOR) associated with recurrence within 180 days, prior healthcare exposures, and initial infection type, controlling for patient demographics and comorbidities. Results Among 24,478 patients with invasive MRSA, 3,976 (16%) experienced a recurrence, including 61% (2,438) within 180 days. Risk factors for recurrence were: injection drug use (IDU) (aOR; 1.38, 95% confidence interval [CI]: 1.15–1.65), central venous catheters (aOR; 1.35, 95% CI: 1.22–1.51), dialysis (aOR; 2.00, 95% CI: 1.74–2.31), and history of MRSA colonization (aOR; 1.35, 95% CI: 1.22–1.51) (figure). Recurrence was more likely for bloodstream infections (BSI) without another infection (aOR; 2.08, 95% CI: 1.74–2.48), endocarditis (aOR; 1.46, 95% CI: 1.16–1.55), and bone/joint infections (aOR; 1.38, 95% CI: 1.20–1.59), and less likely for pneumonia (aOR: 0.75, 95% CI: 0.64–0.89), compared with other initial infection types. When assessed separately, the presence of a secondary BSI with another infection increased the odds of recurrence over that infection without a BSI (aOR: 1.96, 95% CI: 1.68–2.30). Conclusion Approximately one in six persons with invasive MRSA infection had recurrence. We identified potential opportunities to prevent recurrence through infection control (e.g., management and early removal of central catheters). Other possible areas for preventing recurrence include improving the management of patients with BSI and bone/joint infections (including both during and after antibiotic treatment) and mitigating risk of infection from IDU. Disclosures All authors: No reported disclosures.

scholarly journals Adjunctive ceftaroline in combination with daptomycin or vancomycin for complicated methicillin-resistant Staphylococcus aureus bacteremia after monotherapy failure

2019 ◽  
Vol 6 ◽  
pp. 204993611988650 ◽  
Author(s):  
Joseph Patrik Hornak ◽  
Seher Anjum ◽  
David Reynoso
Keyword(s):  
Staphylococcus Aureus ◽  
Combination Therapy ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Treatment Options ◽  
Source Control ◽  
Optimal Timing ◽  
Methicillin Resistant ◽  
Staphylococcus Aureus Bacteremia ◽  
Persistent Bacteremia

Background: Methicillin-resistant Staphylococcus aureus bacteremia (MRSA-B) may fail to improve with standard monotherapy, particularly in patients with multifocal infection, incomplete source control, or persistent bacteremia. Synergy observed in vitro between ceftaroline (CPT) and daptomycin (DAP) or vancomycin (VAN) may translate into clinical benefit. Here, we describe our experience with DAP/CPT and VAN/CPT for complicated MRSA-B after monotherapy failure. Methods: Single-center, retrospective review of consecutive patients treated with DAP/CPT or VAN/CPT for MRSA-B after monotherapy failure from 1 January 2016 to 30 November 2018. Results: We identified 11 instances of combination therapy in 10 patients (DAP/CPT = 6, VAN/CPT = 5) with 1 patient receiving VAN/CPT followed by DAP/CPT. Rates of multifocal infection, incomplete source control, persistent bacteremia, and infective endocarditis were high (100%, 80%, 60%, and 60%, respectively). Combination therapy was initiated most commonly for persistent bacteremia (60%). When patients were persistently bacteremic, median preceding duration was 13 days and median time to clearance was 3 days. Total microbiologic cure rate was 100%. There were zero instances of bacteremia relapse at 30 days (30D) or 60 days (60D). All-cause 30D and 60D mortality rates were 11.1% and 33.3%, respectively. Conclusions: Combination therapy demonstrated success in diverse cases of refractory MRSA-B, including instances of persistent bacteremia paired with incomplete source control. Optimal timing and therapeutic cadence for combination therapy remain unclear. Our findings suggest that DAP/CPT and VAN/CPT can be considered for complicated MRSA bacteremia when other treatment options fail or are unavailable. We propose persistent bacteremia with incomplete source control to be a clinical niche particularly worthy of further investigation.

scholarly journals Combination of Tedizolid and Daptomycin against Methicillin-Resistant Staphylococcus aureus in an In Vitro Model of Simulated Endocardial Vegetations

2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Jordan R. Smith ◽  
Juwon Yim ◽  
Seth Rice ◽  
Kyle Stamper ◽  
Razie Kebriaei ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Treatment Options ◽  
Antagonistic Activity ◽  
Exact Nature ◽  
Once Daily ◽  
Methicillin Resistant ◽  
Content Type ◽  
Vitro Model

ABSTRACT Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen responsible for health care-associated infections, and treatment options are limited. Tedizolid (TZD) is a novel oxazolidinone antibiotic with activity against MRSA. Previously, daptomycin (DAP) has demonstrated synergy with other antibiotics against MRSA. We sought to determine the efficacy of the combination of TZD and DAP against MRSA in an in vitro model of simulated endocardial vegetations (SEVs). TZD simulations of 200 mg once daily and DAP simulations of 6 mg/kg of body weight and 10 mg/kg once daily were tested alone and in the combinations TZD plus DAP at 6 mg/kg or DAP at 10 mg/kg against two clinical strains of MRSA, 494 and 67. These regimens were tested in SEV models over 8 days to determine the antibacterial activity of the regimens and whether synergy or antagonism might be present between the agents. Against both strains 494 and 67 and at both DAP dose regimens, the combination of TZD and DAP was antagonistic at 192 h. In all cases, DAP alone was statistically superior to DAP plus TZD. When the combination was stopped after 96 h, transitioning to DAP at 6 mg/kg or DAP at 10 mg/kg alone resulted in better antibacterial activity than either of the TZD-plus-DAP combinations, further demonstrating antagonistic effects. Against MRSA, we demonstrated that TZD and DAP have antagonistic activity that hinders their overall antimicrobial efficacy. The exact nature of this antagonistic relationship is still undetermined, but its presence warrants further study of the potentially harmful grouping of the two antibiotics in clinical use.

scholarly journals In vitro activities of oxazolidinone compounds U100592 and U100766 against Staphylococcus aureus and Staphylococcus epidermidis.

1996 ◽  
Vol 40 (3) ◽  
pp. 799-801 ◽  
Author(s):  
G W Kaatz ◽  
S M Seo
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Inhibitory Activity ◽  
Antimicrobial Agents ◽  
Methicillin Resistant ◽  
Clinical Strains ◽  
Time Kill

The new oxazolidinone antimicrobial agents U100592 and U100766 demonstrated good in vitro inhibitory activity against clinical strains of Staphylococcus aureus and Staphylococcus epidermidis regardless of methicillin susceptibility. Both agents appeared bacteriostatic by time-kill analysis. Stable resistance to low multiples of the MIC of either drug could be produced only in methicillin-resistant S. aureus.

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