scholarly journals Rapid Detection of Methicillin-Resistant Staphylococcus aureus Directly from Blood for the Diagnosis of Bloodstream Infections: A Mini-Review

Diagnostics ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 830
Author(s):  
Anna Rita Buonomini ◽  
Elisabetta Riva ◽  
Giovanni Di Bonaventura ◽  
Giovanni Gherardi

Staphylococcus aureus represents a major human pathogen able to cause a number of infections, especially bloodstream infections (BSI). Clinical use of methicillin has led to the emergence of methicillin-resistant S. aureus (MRSA) and MRSA-BSI have been reported to be associated with high morbidity and mortality. Clinical diagnosis of BSI is based on the results from blood culture that, although considered the gold standard method, is time-consuming. For this reason, rapid diagnostic tests to identify the presence of methicillin-susceptible S. aureus (MSSA) and MRSA isolates directly in blood cultures are being used with increasing frequency to rapidly commence targeted antimicrobial therapy, also in the light of antimicrobial stewardship efforts. Here, we review and report the most common rapid non-molecular and molecular methods currently available to detect the presence of MRSA directly from blood.

Author(s):  
Gaby Scheunemann ◽  
Bruna N. Fortes ◽  
Nilton Lincopan ◽  
Kelly Ishida

Infections by microorganisms resistant to antimicrobials is a major challenge that leads to high morbidity and mortality rates and increased time and cost with hospitalization. It was estimated that 27 to 56% of bloodstream infections by C. albicans are polymicrobial, with S. aureus being one of the microorganisms commonly coisolated worldwide.


Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 395
Author(s):  
Katarina Pomorska ◽  
Vladislav Jakubu ◽  
Lucia Malisova ◽  
Marta Fridrichova ◽  
Martin Musilek ◽  
...  

Staphylococcus aureus is one of the major causes of bloodstream infections. The aim of our study was to characterize methicillin-resistant Staphylococcus aureus (MRSA) isolates from blood of patients hospitalized in the Czech Republic between 2016 and 2018. All MRSA strains were tested for antibiotic susceptibility, analyzed by spa typing and clustered using a Based Upon Repeat Pattern (BURP) algorithm. The representative isolates of the four most common spa types and representative isolates of all spa clonal complexes were further typed by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. The majority of MRSA strains were resistant to ciprofloxacin (94%), erythromycin (95.5%) and clindamycin (95.6%). Among the 618 strains analyzed, 52 different spa types were detected. BURP analysis divided them into six different clusters. The most common spa types were t003, t586, t014 and t002, all belonging to the CC5 (clonal complex). CC5 was the most abundant MLST CC of our study, comprising of 91.7% (n = 565) of spa-typeable isolates. Other CCs present in our study were CC398, CC22, CC8, CC45 and CC97. To our knowledge, this is the biggest nationwide study aimed at typing MRSA blood isolates from the Czech Republic.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S143-S144
Author(s):  
Michelle Vu ◽  
Kenneth Smith ◽  
Sherrie L Aspinall ◽  
Cornelius J Clancy ◽  
Deanna Buehrle

Abstract Background Methicillin-resistant Staphylococcus aureus bloodstream infections (MRSAB) cause significant mortality and often require extended antibiotic therapy. Vancomycin, the most common initial MRSAB treatment, carries significant monitoring burden and nephrotoxicity risks. We compared cost-effectiveness of vancomycin and other antibiotic regimens as MRSAB treatment. Methods We estimated cost-effectiveness of intravenous antibiotics (vancomycin, daptomycin, linezolid, ceftaroline/daptomycin, dalbavancin) for Veterans Health Administration (VA) patients with MRSAB using an exploratory decision-tree model. Primary effectiveness outcome was composite of microbiological failure and adverse drug event (ADE)-related discontinuation at 7-days. Results In base-case analyses, linezolid and daptomycin were less expensive and had fewer treatment failures than other regimens at 4 and 6-weeks. Compared to linezolid, daptomycin incremental cost-effectiveness ratios were ~$45,000 (4-weeks) and ~$61,000 (6-weeks) per composite failure avoided, respectively. In one-way sensitivity analyses, daptomycin (4-weeks) was favored over linezolid if linezolid microbiological failure or ADE-related discontinuation rates were >14.8% (base case: 14.0%) or >14.3% (base case: 14.0%), respectively, assuming a willingness to pay (WTP) threshold of $40,000/ composite treatment failure avoided. Vancomycin was favored if its microbiological failure risk was < 16.4% (base case: 27.2%). In two-way sensitivity analyses, daptomycin was favored if linezolid microbiological failure and ADE-related discontinuation rates were >19% and > 16%, respectively. Linezolid, daptomycin and vancomycin were favored in 47%, 39%, and 11% of 4-week probabilistic iterations, respectively, at $40,000 WTP. Conclusion Daptomycin or linezolid are likely less expensive and more effective than vancomycin or other initial regimens for MRSAB. More data are needed to support safety of linezolid in MRSAB patients. Disclosures Cornelius J. Clancy, MD, Astellas (Consultant, Grant/Research Support)Cidara (Consultant, Research Grant or Support)Melinta (Grant/Research Support)Merck (Consultant, Grant/Research Support)Needham Associates (Consultant)Qpex (Consultant)Scynexis (Consultant)Shionogi (Consultant)


1995 ◽  
Vol 29 (7-8) ◽  
pp. 694-697 ◽  
Author(s):  
Sherrie L Aspinall ◽  
David M Friedland ◽  
Victor L Yu ◽  
John D Rihs ◽  
Robert R Muder

Objective: To report on a patient with recurrent methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis and bacteremia successfully treated with combination antibiotic therapy. Case Summary: Two sets of blood cultures from a 55-year-old man with fever, malaise, and low back pain grew MRSA. Radiologic studies of the spine showed bony changes consistent with osteomyelitis. Soon after completing 6 weeks of vancomycin, the patient experienced a recurrence of back pain. Laboratory values included an increase in the sedimentation rate to 53 mm/h and positive blood cultures for MRSA. Vancomycin, gentamicin, and rifampin were administered for 8 weeks. Serum inhibitory and bactericidal titers were more than 1:1024 for both the peak and trough concentrations. Radiologic studies of the spine showed healing osteomyelitis. Two years after completion of antibiotic therapy, the infection has not recurred. Discussion: Antibiotic therapy alone was attempted because the patient was considered a risky surgical candidate. Serum inhibitory and bactericidal titers documented the high in vivo activity of the vancomycin, gentamicin, and rifampin combination. Initiation of vancomycin therapy led to disappearance of the fever and back pain. Cure was documented by sustained normalization of the erythrocyte sedimentation rate and radiologic evidence of healing. Conclusions: Combination antibiotic therapy with vancomycin, rifampin, and low-dose gentamicin (1 mg/kg q12h) may be useful for deep-seated tissue infection caused by MRSA.


Author(s):  
Evan J Zasowski ◽  
Trang D Trinh ◽  
Kimberly C Claeys ◽  
Abdalhamid M Lagnf ◽  
Sahil Bhatia ◽  
...  

Abstract Background Observational data suggest ceftaroline may be effective for methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSI) but comparative data with standard of care are limited. This analysis compares the outcomes of MRSA BSI treated with ceftaroline or daptomycin. Methods Multicenter, retrospective, observational cohort study of adult patients with MRSA BSI from 2010 to 2017. Patients treated with ≥ 72 hours of ceftaroline or daptomycin were included. Those clearing BSI before study drug and those with a pneumonia source were excluded. The primary outcome was composite treatment failure, defined as 30-day mortality, BSI duration ≥ 7 days on study drug, and 60-day MRSA BSI recurrence. Inverse probability of treatment weighted risk difference in composite failure between daptomycin and ceftaroline groups was computed and 15% non-inferiority margin applied. Results Two hundred seventy patients were included; 83 ceftaroline and 187 daptomycin. Ceftaroline was non-inferior to daptomycin with respect to composite failure [39% daptomycin, 32.5% ceftaroline; weighted risk difference (95% CI) 7.0% (-5.0 – 19.0%)]. No differences between treatment groups was observed for 30-day mortality or other secondary efficacy outcomes. Creatine phosphokinase elevation was significantly more common among daptomycin patients (5.3% vs 0%, P = 0.034). Rash was significantly more common among ceftaroline patients (10.8 vs 1.1%, P = 0.001). Conclusions No difference in treatment failure or mortality was observed between MRSA BSI treated with ceftaroline or daptomycin. These data support future study of ceftaroline as a primary MRSA BSI treatment and current use of ceftaroline when an alternative to vancomycin and daptomycin is required.


2019 ◽  
Vol 71 (5) ◽  
pp. 1142-1148 ◽  
Author(s):  
Kari A Mergenhagen ◽  
Kaitlyn E Starr ◽  
Bethany A Wattengel ◽  
Alan J Lesse ◽  
Zarchi Sumon ◽  
...  

Abstract Background Treatment of suspected methicillin-resistant Staphylococcus aureus (MRSA) is a cornerstone of many antibiotic regimens; however, there is associated toxicity. The Department of Veterans Affairs (VA) hospitals screen each patient for MRSA nares colonization on admission and transfer. The objective was to determine the negative predictive value (NPV) of MRSA screening in the determination of subsequent positive clinical culture for MRSA. High NPVs with MRSA nares screening may be used as a stewardship tool. Methods This was a retrospective cohort study across VA medical centers nationwide from 1 January 2007 to 1 January 2018. Data from patients with MRSA nares screening were obtained from the VA Corporate Data Warehouse. Subsequent clinical cultures within 7 days of the nares swab were evaluated for the presence of MRSA. Sensitivity, specificity, positive predictive values, and NPVs were calculated for the entire cohort as well as subgroups for specific culture sites. Results This cohort yielded 561 325 clinical cultures from a variety of anatomical sites. The sensitivity and specificity for positive MRSA clinical culture were 67.4% and 81.2%, respectively. The NPV of MRSA nares screening for ruling out MRSA infection was 96.5%. The NPV for bloodstream infections was 96.5%, for intraabdominal cultures it was 98.6%, for respiratory cultures it was 96.1%, for wound cultures it was 93.1%, and for cultures from the urinary system it was 99.2%. Conclusion Given the high NPVs, MRSA nares screening may be a powerful stewardship tool for deescalation and avoidance of empirical anti-MRSA therapy.


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