Correlation of MRSA polymerase chain reaction (PCR) nasal swab in ventilator-associated pneumonia, lung abscess, and empyema.

Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen empirically covered in pulmonary infections. Limited studies evaluate the relationship between the MRSA PCR nasal swab assays and clinically diagnosed ventilator-associated pneumonia (VAP), lung abscess, and empyema. This retrospective, single-center study included 161 patients, which aimed to validate the clinical utility of MRSA PCR nasal swabs in VAP, lung abscess, and empyema through sensitivity, specificity, positive predictive value (PPV), and negative predicative value (NPV) analysis. VAP had a 100% sensitivity, 89% specificity, 67% PPV, and 100% NPV.  Lung abscess had a 0% sensitivity, 90% specificity, 0% PPV, 90% NPV. Empyema had a 80% sensitivity, 84% specificity, 42% PPV, and 97% NPV. The study results demonstrate that the MRSA PCR nasal swab assay has the potential to be a vital tool in de-escalating antimicrobial therapy in VAP, lung abscess, and empyema.

Correlation of MRSA polymerase chain reaction (PCR) wound swab testing and wound cultures in skin and soft tissue infections.

Methicillin-resistant Staphylococcus aureus is a considerable pathogen in the setting of skin and soft tissue infections (SSTIs). MRSA PCR swab testing is widely used in the setting of respiratory tract infections, however little data exists relating to the use of MRSA PCR swab testing in SSTIs. Three thousand, nine hundred and ninety-five patients were included in this retrospective study that aimed to validate the clinical correlation of MRSA PCR wound swab testing in SSTIs through sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) analysis. From this review, MRSA PCR wound swabs were found to have a sensitivity of 97.6% (97.5-98.5), a specificity of 94.9% (94.3-95.7), a PPV of 92.3% (91.4-93.2), and a NPV of 98.4% (98.0-98.8). The study results demonstrate that the MRSA SSTI PCR assays have a high NPV and the potential to be a vital tool in de-escalating antimicrobial therapy associated with SSTIs.

Evaluation of a pharmacy-driven methicillin-resistant Staphylococcus aureus surveillance protocol in pneumonia.

Background Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of pneumonia and clinicians must determine when empiric antimicrobial therapy directed toward MRSA is needed. Objective To evaluate the effect of a pharmacy-driven protocol utilizing the nasal swab MRSA polymerase chain reaction (PCR) test to discontinue vancomycin on duration of vancomycin therapy and clinical outcomes in patients with suspected community-acquired pneumonia (CAP) or healthcare-associated pneumonia (HCAP). Setting A teaching hospital in Huntington, WV, USA. Methods This retrospective study included adult patients who received at least one dose of vancomycin for suspected CAP or HCAP. The pre-intervention group consisted of patients prior to the addition of the nasal swab MRSA PCR test to the CAP/HCAP order set. The post-intervention group consisted of patients after the addition of the nasal swab MRSA PCR test to the CAP/HCAP order set. Main outcome measure The primary outcome was vancomycin hours of therapy. Results Of the 196 patients included in the study, 121 patients were in the pre-intervention group and 75 patients were in the post-intervention group. The median duration of vancomycin therapy was significantly shorter in the post-intervention group than the pre-intervention group (49 vs. 18 h, p < 0.001). There were no statistically significant differences in the secondary outcomes including hospital length of stay, 30-day readmission rate, and in-hospital all-cause mortality. Conclusion The addition of a pharmacy-driven protocol utilizing the nasal swab MRSA PCR test was associated with shorter duration of empiric vancomycin therapy by approximately 31 h per patient without increasing adverse clinical outcomes.

Clinical utility of a nasal swab methicillin-resistant Staphylococcus aureus polymerase chain reaction test in intensive and intermediate care unit patients with pneumonia.

This retrospective study aimed to validate the concordance between nasal swab methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) test and respiratory culture and to determine the number of potentially preventable days of anti-MRSA therapy in patients with pneumonia. Two hundred adult inpatients in the intensive and intermediate care units were included. The nasal swab MRSA PCR test was positive in 55 (27.5%) patients. MRSA was isolated from respiratory culture in 21 (10.5%) patients. The nasal swab MRSA PCR test demonstrated 90.5% sensitivity, 79.9% specificity, 34.5% positive predictive value, and 98.6% negative predictive value. Anti-MRSA therapy was initiated in 168 (84%) patients. Patients in the study received a combined 782days of anti-MRSA therapy; 300days were considered potentially preventable. This study suggests that the nasal swab MRSA PCR test may be used to guide discontinuation of anti-MRSA antibiotics in patients with clinically confirmed pneumonia in the intensive or intermediate care units.