Negative Nasal Methicillin-Resistant Staphylococcus aureus (MRSA) Polymerase Chain Reaction Rules Out Future MRSA Infections in Severely Injured Trauma Patients

Abstract

Introduction:

Studies have shown that methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) swabs aid in de-escalating and decreasing the duration of antibiotic use in respiratory infections. However, the utility of MRSA PCR swabs is unknown for severely injured trauma patients. The aim of this study is to determine if negative MRSA PCR nasal swabs are associated with future MRSA infections in trauma patients admitted to the intensive care unit (ICU).

Methods:

Trauma patients admitted to the ICU that had a nasal MRSA PCR from July 2022 to March 2024 were evaluated. Demographics, as well as complication rates (including myocardial infarction, stroke, venous thromboembolism, acute respiratory distress syndrome, acute kidney injury), number and site of cultures obtained, days from MRSA PCR to culture, and positivity of a MRSA infection in those cultures, were evaluated.

Results:

In the study period, 65 severely injured patients were identified with an infection and nasal MRSA PCR. Most patients were male (74%), suffered a blunt mechanism (85%), and had a 28-day mortality rate of 36.9%. The median injury severity score was 26. Of the 65 injured patients, 7 (10.8%) had a positive MRSA PCR. There were 142 cultures obtained. No patient that had a negative PCR had a positive MRSA infection. The performance characteristics of a MRSA PCR swab included sensitivity (100%), specificity (92%), positive predictive value (29%), and negative predictive value (NPV, 100%).

Conclusion:

The incidence of MRSA-positive infections in trauma patients is low with a negative MRSA PCR swab, NPV of 100%. On the basis of these findings, there should be consideration of withholding empiric MRSA coverage in trauma ICU patients with a negative MRSA PCR. This may aid in reducing unnecessary antibiotic initiation and healthcare costs. Larger studies are needed to validate these findings and help delineate patients for which empiric MRSA coverage can be withheld.

Antibiotic resistance and adverse events related to antibiotic therapy are two considerable concerns in healthcare settings.¹ Thus, finding ways to avoid unnecessary antibiotic therapies is crucial in reducing antibiotic resistance and overall healthcare costs. Methicillin-resistant Staphylococcus aureus (MRSA) colonization and infections are a concern in patients regardless of duration of hospitalization.^2–5 However, studies have shown that MRSA infections were more likely with longer hospital stays (mean 33 vs. 22 d, p < 0.001 in one study).⁶ MRSA polymerase chain reaction (PCR) nasal swabs have a high negative predictive value (NPV) and can be beneficial in determining if MRSA coverage is needed for empiric antibiotic coverage. The NPV for MRSA nasal swabs is >98% in several studies identifying MRSA pneumonia.^7–9 They have also been shown to have high NPV for other sites of infection, including blood (98%), urine (100%), and wounds (92%).⁷ Studies show appropriate de-escalation of empiric antibiotic agents for MRSA coverage with resulting negative MRSA PCR nasal swabs.¹⁰ In surgical patients and those with extended hospital stays, identifying MRSA colonization early is important to prevent further infections and health-related complications. Early detection of nasal colonization along with treatment can reduce the risk of MRSA infections in these patients.¹¹

Recent studies have shown that MRSA PCR swabs aid in de-escalating antibiotic agents, decreasing the duration of antibiotic use, or even discontinuing antibiotic agents.^10,12,13 This has been associated with a reduced risk of antibiotic-related side effects through earlier cessation of anti-MRSA coverage and reduction in complications associated with anti-MRSA coverage, which may include Clostridium difficile infections, diarrhea, elevated liver enzymes, myelosuppression associated with linezolid use, and vancomycin-associated acute kidney injury.^7,10,13–15 Furthermore, reducing anti-MRSA antimicrobial coverage would decrease the need for laboratories or tests aimed at antibiotic monitoring.^7,10,13–15 MRSA coverage is guided by Infectious Disease Society of America guidelines and is not necessarily unique or specific to injured patients.¹⁶ Current data show the benefit of using MRSA PCR swabs for antibiotic guidance in mixed intensive care unit (ICU) patient populations.^7,17–19 Severely injured patients are known to have high prevalence of MRSA colonization²⁰ and may be at increased risk of MRSA infections.²¹ A few studies have evaluated MRSA colonization in trauma patients or rates of ventilator-associated pneumonia compared with non-trauma ICU patients, but no studies have evaluated the use of MRSA PCR swabs to rule out future MRSA infections in severely injured patients.^21,22

In some hospitals, MRSA PCR nasal swabs are obtained upon patient admission to the ICU, and understanding the use of initial MRSA PCR results is important for antibiotic use tactics. However, data are lacking regarding MRSA PCR swabs used to assist with guiding de-escalation, discontinuation, or avoidance of initiation of specific antibiotic agents aimed at targeting MRSA in severely injured trauma patients. Therefore, we aimed to determine the utility of MRSA PCR screening swabs in predicting future MRSA infections in severely injured trauma patients admitted to the ICU.

Patients and Methods

Trauma patients admitted to the Trauma Intensive Care Unit (TICU) that had a nasal MRSA swab from July 2022 to March 2024 and who received a diagnosis of a subsequent infection or healthcare-associated infection at our American College of Surgeons (ACS)-verified Level 1 trauma center were included. The nasal MRSA swab is a PCR test that takes about 60 minutes to run from time of test initiation. Patients that presented to the hospital with an active infection such as a community-acquired pneumonia were not included. Patients were excluded if they did not have a nasal MRSA swab obtained at the time of TICU admission or if an infection did not develop in them. The primary outcome of the study was any infection following admission to the TICU in injured patients. Cultures (blood, wound, respiratory, or urine) were obtained on the basis of clinical suspicion of an infection by the treating clinical team.

Clinical data were abstracted from our institutional trauma registry and electronic medical records. Demographic data collected included age, gender, Glasgow Coma Scale (GCS) on arrival in the emergency department (ED), systolic blood pressure on arrival to ED, heart rate on arrival to ED, mechanism of injury, abbreviated injury scale, injury severity score (ISS), complications during hospitalization, including myocardial infarction, stroke, venous thromboembolism, acute respiratory distress syndrome, and acute kidney injury, nasal MRSA swab status, and culture results. Rates of MRSA colonization from 2022 to 2024 were obtained from our infection control group specifically for the TICU.

IBM SPSS Statistics version 27 (IBM; Armonk, NY) and GraphPad Prism version 10.0.2 (GraphPad Software, Inc; La Jolla, CA) were used for statistical analysis. All tests were two-tailed with significance set at p < 0.05. The Mann-Whitney U test was used for continuous variables. The Chi-square test was used for categorical variables. Fisher exact test was utilized for 2 × 2 tables, in which the value in the cells was less than five. Non-normally distributed data are presented as median and interquartile (IQR) ranges. Multi-variable regression was used to identify parameters that remained substantial predictors of outcomes. Parameters with a p value of 0.2 or less, or those that were believed to be of clinical significance, were included in the multiple variable regression. Goodness of fit of multi-linear regression models used R squared statistics. Sensitivity, specificity, NPV, and positive predictive value for nasal MRSA swabs to predict a subsequent MRSA infection were calculated. The study was approved by the institutional review board.

Results

In the study period, 65 injured patients were identified with a MRSA PCR and an infection following admission. These patients were severely injured with a median ISS of 26. Most patients were male (74%), suffered a blunt mechanism (85%), and had a 28-day mortality rate of 36.9% (Table 1). At the time of admission, 55.4% (n = 36) of these severely injured patients were intubated. Of the 65 severely injured patients, 32% (n = 21) of them had a culture obtained after they had obtained a tracheostomy. The monthly rates of MRSA colonization on admission to the TICU ranged from 0.0% to 25.0% from February 2022 to December 2024. The yearly rate of MRSA colonization on admission to the TICU ranged from 7.5% to 9.6%.

Table 1.

Characteristics of Severely Injured Patients Who Were Admitted to the Traumatic Intensive Care Unit and had Nasal Methicillin-Resistant Staphylococcus aureus Polymerase Chain Reaction Swab Obtained

Demographics	n = 65
Age (y)	52 (32–71)
Male Sex	73.8%
Blunt Mechanism	84.6%
Systolic Blood Pressure (mmHg)	114 (96–130)
Heart Rate (bpm)	93 (82–114)
Respiratory Rate	20 (18–25)
Oxygen Saturation (%)	97 (95–100)
GCS	14 (3–15)
Hgb (g/dL)	12.4 (10.9–13.7)
WBC (10*3/uL)	11.7 (9.2–17.6)
Lactate (mmol/L)	2.8 (1.7–5.1)
INR	1.1 (1.0–1.2)
AIS Head/Neck	3 (0–4)
AIS Face	0 (0–0)
AIS Chest	2 (0–3)
AIS Abdomen/Pelvis	2 (0–3)
AIS Extremities	2 (0–3)
ISS	26 (15–38)
Ventilatory Days	7 (0–13)
ICU LOS (d)	10 (4–14)
Hospital LOS (d)	18 (11–32)
AKI	44.6%
ARDS	23.0%
MI	0%
Stroke	6.6%
VTE	10.8%
28-Day Mortality	36.9%

Data are presented as median and interquartile range.

Hgb = hemoglobin; WBC = white blood cell; GCS = Glasgow Coma Scale; INR = international normalized ratio; AIS = abbreviated injury scale; ISS = injury severity score; ICU = intensive care unit; LOS = length of stay; AKI = acute kidney injury; ARDS = acute respiratory distress syndrome; MI = myocardial infarction; VTE = venous thromboembolism.

Of these 65 severely injured patients, 7 (10.8%) had a positive nasal MRSA PCR screen. Patients with a positive and negative nasal MRSA swab were compared with in Table 2. Compared with patients with a negative PCR, those with a positive nasal MRSA PCR swab had fewer ventilator days, shorter ICU length of stay, and shorter overall hospital length of stay on uni-variable analysis (Table 2). However, on multi-variable regression (including age, gender, GCS, hemoglobin concentration, lactate concentration, ISS, and MRSA PCR status), a positive nasal MRSA swab did not influence the number of ventilator days (R² = 0.1277), ICU length of stay (R² = 0.1348), or overall hospital length of stay (R² = 0.1051).

Table 2.

Comparison of Severely Injured Patients with Negative and Positive Nasal Methicillin-Resistant Staphylococcus aureus Swabs

Demographics	Nasal MRSA− (n = 58)	Nasal MRSA+ (n = 7)	p value
Age	49 (32–69)	61 (52–82)	0.14
Male Sex	77.6%	42.8%	0.07
Blunt Mechanism	82.8%	100.0%	0.58
Systolic Blood Pressure	115 (96–130)	111 (108–138)	0.67
Heart Rate	94 (83–115)	89 (76–98)	0.35
Respiratory Rate	20 (18–25)	17 (15–24)	0.22
Oxygen Saturation	97 (95–99)	98 (95–100)	0.59
GCS	13 (3–15)	15 (14–15)	0.10
Hgb	12.6 (11–13.7)	11.8 (8.6–12.6)	0.13
WBC	12 (9.1–17.8)	11 (10.6–17.1)	0.82
Lactate	2.9 (1.7–5.4)	1.8 (0.8–4.9)	0.18
INR	1.1 (1.0–1.2)	1.1 (1.0–1.1)	0.39
AIS Head/Neck	3 (0–5)	0 (0–0)	0.08
AIS Face	0 (0–1)	0 (0–0)	0.20
AIS Chest	2 (0–3)	2 (0–3)	0.58
AIS Abdomen/Pelvis	2 (0–3)	0 (0–2)	0.09
AIS Extremities	2 (0–3)	3 (2–4)	0.06
ISS	26 (17–40)	13 (13–29)	0.12
Ventilatory Days	9 (2–14)	0 (0–2)	0.00
ICU LOS (d)	11 (6–16)	3 (0–6)	0.00
Hospital LOS (d)	20 (12–34)	10 (3–18)	0.04
AKI	44.8%	42.8%	>0.99
ARDS	25.8%	0.0%	0.19
MI	0.0%	0.0%	>0.99
Stroke	6.9%	0.0%	>0.99
VTE	12.1%	0.0%	>0.99
28-Day Mortality	39.7%	14.3%	0.25

Data are presented as median and interquartile range.

Between these 65 patients with a nasal MRSA swab, a total of 142 cultures were obtained. Of these cultures, 84 (59.2%) cultures were obtained while the patient was mechanically ventilated, and 35 (24.6%) cultures were obtained after the patient had undergone a tracheostomy. Only 29 (20.4%) of the total cultures were collected while the patient was on the regular hospital ward, with the remainder being collected while the patient was in the TICU or Step-down Unit (an extension of the TICU). The total number of cultures included 65 blood cultures (46%), 20 wound cultures (14%), 55 respiratory cultures (39%), and 2 urine cultures (1%). The organisms that grew of the cultures obtained in our severely injured patient population are included in Table 3. The median days from admission to culture was 8 IQR: 4–13 days. Cultures were obtained on days ranging from day zero of hospitalization to day 65 of hospitalization. Two cultures resulted in a positive MRSA infection, both of which occurred in patients with a positive nasal MRSA PCR swab. One culture was obtained as a quantitative respiratory culture obtained by tracheal aspirate in a patient with a tracheostomy on the ventilator. The other MRSA positive culture was from a blood culture believed to be secondary to post-operative surgical site infection. No patient had a negative PCR and then a subsequent positive MRSA infection. Table 4 shows the predictive characteristics of a nasal MRSA PCR swab for identifying any future MRSA infection.

Table 3.

Organisms Isolated from Respiratory, Blood, Wound, and Urine Cultures in Patients Who Had a Nasal Methicillin-Resistant Staphylococcus aureus Polymerase Chain Reaction Swab Obtained at the Time of Traumatic Intensive Care Unit Admission

Respiratory (55 cultures)	Blood (65 cultures)	Wound (20 cultures)	Urine (2 cultures)
Acinetobacter bereziniae - 1	Bacteroides thetaiotaomicron - 2	Bacteroides thetaiotaomicron - 1	Escherichia coli - 2
Citrobacter koseri - 1	Candida Albicans - 1	Candida Albicans - 2
Acinetobacter baumannii complex - 2	Candida dubliniensis - 1	Citrobacter freundii complex - 1
Achromobacter xylosoxidans - 1	Candida tropicalis - 1	Clostridium bifermentans - 1
Chryseobacterium indologenes - 1	Klebsiella oxytoca - 2	Clostridium sporogenes - 1
Enterobacter aerogenes - 5	Enterobacter aerogenes - 1	Clostridium tertium - 1
Enterobacter cloacae complex - 7	Enterobacter cloacae complex - 2	Enterococcus faecalis - 2
Escherichia coli - 4	Enterococcus faecalis - 2	Enterococcus faecium - 2
Group A Streptococcus - 1	Escherichia coli - 1	Enterobacter cloacae complex - 5
Haemophilus influenzae - 5	Micrococcus luteus - 1	Escherichia coli - 2
Klebsiella oxytoca - 2	Pseudomonas aeruginosa - 1	Klebsiella aerogenes - 1
Proteus mirabilis - 2	Pseudomonas putida - 1	Morganella morganii - 1
Pseudomonas aeruginosa - 2	Prevotella species - 1	Pseudomonas aeruginosa - 3
Serratia marcescens - 5	Serratia marcescens - 1	Prevotella melaninogenica - 1
Staphylococcus aureus (MRSA) - 1	Staphylococcus aureus (MRSA) - 1	Staphylococcus aureus (MRSA) - 1
Staphylococcus aureus (MSSA) - 7	Staphylococcus aureus (MSSA) - 4	Streptococcus intermedius - 1
Stenotrophomonas maltophilia - 3	Staphylococcus capitis - 1	Serratia marcescens - 3
Streptococcus pneumoniae - 2	Staphylococcus epidermidis - 3	Sphingobacterium multivorum - 1
	Staphylococcus hominis - 2	Streptococcus anginosus - 1
	Streptococcus anginosus - 1	Streptococcus constellatus - 1
	Streptococcus mitis - 1
	Streptococcus pneumoniae - 1

MRSA = Methicillin-Resistant Staphylococcus aureus; MSSA = Methicillin-sensitive Staphylcoccus aureus.

Table 4.

Predictive Performance of Nasal Methicillin-Resistant Staphylococcus aureus Polymerase Chain Reaction Swab for Predicting a Future MRSA Infection in Severely Injured Patients Admitted to the Intensive Care Unit

MRSA testing	Any infection	95% confidence interval
Sensitivity	100%	1.00–1.00
Specificity	92%	0.85–0.99
Positive Predictive Value	29%	0.00–0.62
Negative Predictive Value	100%	1.00–1.00

MRSA = Methicillin-Resistant Staphylococcus aureus.

Discussion

In our study, we noted a relatively low MRSA colonization rate (<11%), which was consistent with our historical unit colonization rate. On the basis of our results, in severely injured patients admitted to the trauma ICU, a negative MRSA PCR nasal swab has excellent predictive capacity to rule out a future MRSA infection. This adds to the growing data of the utility of MRSA PCR nasal swabs to predict the need for anti-MRSA coverage.

Much of the recent research surrounding MRSA infections is the identification of MRSA colonization that may allow de-escalation, discontinuation, or avoidance of initiation of antimicrobial agents that target MRSA, ultimately with the goal of reducing future antimicrobial resistance.^7,10,13–15 Like our study, these studies have identified a negative MRSA PCR nasal swab as having a high NPV for MRSA infection. However, these studies have primarily focused on medical populations, whereas only one recent study had a large population of surgical patients included.⁷ Only few studies have focused specifically on trauma patients, and none has evaluated a severely injured ICU population.^21–23

We focused specifically on severely injured patients that were admitted to the trauma ICU. Although there were small differences in outcomes between patients with positive and negative MRSA PCR (Table 2), following multi-variable regression, a positive MRSA PCR did not appear to affect patient outcomes compared with those that had a negative MRSA PCR. Our results support the findings of previous studies evaluating the use of MRSA PCR swabs and de-escalation of antibiotic agents. We found that MRSA PCR swabs, obtained at the time of ICU admission, had a strong NPV (100%) regarding future MRSA infections (Table 4). This included patients that were also ultimately transferred to the regular hospital ward and not just those that remained admitted to the ICU. In one study of mixed ICU populations, MRSA PCR swabs had a good NPV of 100% as well.⁷ Like that study, our data resulted in a subpar ability to predict the presence of future MRSA infections.⁷ Although the positive predictive value and specificity of nasal MRSA PCR swabs to predict future infection are poor, the strength in the test appears to be in its ability to rule out future infections. This would suggest that patients with negative tests at the time of ICU admission may not need MRSA coverage if a future infection develops in them.

Our study has several limitations. The retrospective nature of this study is a limitation, and as such, the data are only as accurate as trauma registry collection. Statistical adjustment for potential confounders was limited by the low rate of MRSA nasal swab positivity in our trauma ICU patient population. Furthermore, our protocol for routinely obtaining MRSA PCR swabs in TICU admissions was established in July/August of 2022 limiting the amount of time for data collection. Similarly, patients that boarded in the Emergency Room (ER), had an immediate procedural intervention (operating room or interventional radiology suit), or were admitted to the ICU following an admission to the ward may not have had a PCR obtained. Unfortunately, given this limitation and available data, we are not able to determine why patients may not have had an MRSA PCR obtained, potentially leading to a degree of selection bias.

Conclusions

MRSA PCR nasal swabs may be used to help predict MRSA positivity in future infections in severely injured patients admitted to the ICU. If negative at the time of admission, MRSA PCR swabs provide exceptional discrimination to rule out a future MRSA infection in severely injured patients admitted to the TICU. Larger prospective studies are needed to validate our findings, as well as quantify reductions in complications associated with reduced antibiotic exposure, cost savings, and potential reductions in development of antibiotic-resistant organisms.

Footnotes

Authors’ Contributions

G.R.S., K.M., S.G., K.A.R., and A.M.N. implemented the study, interpreted data, drafted, and critically revised the article. S.G., K.A.R., and A.M.N. were principal investigators and were responsible for study conception and design, implementation of study, completion of study, interpretation of data, article drafting, and critical revision.

Funding Information

The authors declare no sources of funding.

Author Disclosure Statement

The authors have no disclosures.

References

Chinemerem Nwobodo

, Ugwu

, Oliseloke Anie

, et al. Antibiotic resistance: The challenges and some emerging strategies for tackling a global menace. J Clin Lab Anal, 2022; 36(9):e24655; doi: 10.1002/jcla.24655

Algammal

, Hetta

, Elkelish

, et al. Methicillin-Resistant Staphylococcus aureus (MRSA): One health perspective approach to the bacterium epidemiology, virulence factors, antibiotic-resistance, and zoonotic impact. Infect Drug Resist, 2020; 13:3255–3265; doi: 10.2147/IDR.S272733

Kock

, Becker

, Cookson

, et al. Methicillin-resistant Staphylococcus aureus (MRSA): burden of disease and control challenges in Europe. Euro Surveill, 2010; 15(41):19688; doi: 10.2807/ese.15.41.19688-en

Moran

, Krishnadasan

, Gorwitz

, et al. Methicillin-resistant S. aureus infections among patients in the emergency department. N Engl J Med, 2006; 355(7):666–674; doi: 10.1056/NEJMoa055356

Turner

, Sharma-Kuinkel

, Maskarinec

, et al. Methicillin-resistant Staphylococcus aureus: An overview of basic and clinical research. Nat Rev Microbiol, 2019; 17(4):203–218; doi: 10.1038/s41579-018-0147-4

Huang

, Platt

. Risk of methicillin-resistant Staphylococcus aureus infection after previous infection or colonization. Clin Infect Dis, 2003; 36(3):281–285; doi: 10.1086/345955

Bono

, Caceda

, Zhai

, et al. Evaluating methicillin-resistant Staphylococcus aureus polymerase chain reaction nasal screening as a tool for antimicrobial stewardship. J Surg Res, 2023; 283:1047–1052; doi: 10.1016/j.jss.2022.11.054

Dangerfield

, Chung

, Webb

, et al. Predictive value of methicillin-resistant Staphylococcus aureus (MRSA) nasal swab PCR assay for MRSA pneumonia. Antimicrob Agents Chemother, 2014; 58(2):859–864; doi: 10.1128/AAC.01805-13

Tilahun

, Faust

, McCorstin

, et al. Nasal colonization and lower respiratory tract infections with methicillin-resistant Staphylococcus aureus. Am J Crit Care, 2015; 24(1):8–12; doi: 10.4037/ajcc2015102

10.

Baby

, Faust

, Smith

, et al. Nasal methicillin-resistant Staphylococcus aureus (MRSA) PCR testing reduces the duration of MRSA-targeted therapy in patients with suspected MRSA pneumonia. Antimicrob Agents Chemother, 2017; 61(4); doi: 10.1128/AAC.02432-16

11.

Bode

, Kluytmans

, Wertheim

, et al. Preventing surgical-site infections in nasal carriers of Staphylococcus aureus. N Engl J Med, 2010; 362(1):9–17; doi: 10.1056/NEJMoa0808939

12.

Gentges

, El-Kouri

, Rahman

, et al. Use of nares swab to de-escalate vancomycin for patients with suspected methicillin-resistant Staphylococcus aureus. Antimicrob Steward Healthc Epidemiol, 2023; 3(1):e167; doi: 10.1017/ash.2023.444

13.

Raush

, Betthauser

, Shen

, et al. Prospective nasal screening for methicillin-resistant Staphylococcus aureus in critically Ill patients with suspected pneumonia. Open Forum Infect Dis, 2022; 9(1):ofab578; doi: 10.1093/ofid/ofab578

14.

Liu

, Holubar

. Should a MRSA nasal swab guide empiric antibiotic treatment? NEJM Evid, 2022; 1(12):EVIDccon2200124; doi: 10.1056/EVIDccon2200124

15.

Bridwell

, Bajaj

, Gress

, et al. Impact of MRSA polymerase chain reaction (PCR) wound swabs on antibiotic de-escalation in skin and soft tissue infections. Diagn Microbiol Infect Dis, 2022; 103(3):115722; doi: 10.1016/j.diagmicrobio.2022.115722

16.

Liu

, Bayer

, Cosgrove

, et al. Clinical practice guidelines by the infectious diseases society of America for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children. Clin Infect Dis, 2011; 52(3):e18-55–e55; doi: 10.1093/cid/ciq146

17.

Buckley

, Kobic

, Yerondopoulos

, et al. Comparison of methicillin-resistant Staphylococcus aureus nasal screening predictive value in the intensive care unit and general ward. Ann Pharmacother, 2023; 57(9):1036–1043; doi: 10.1177/10600280221145152

18.

Marinucci

, Louzon

, Carr

, et al. Pharmacist-Driven methicillin-resistant S. aureus polymerase chain reaction testing for pneumonia. Ann Pharmacother, 2023; 57(5):560–569; doi: 10.1177/10600280221121144

19.

Sarikonda

, Micek

, Doherty

, et al. Methicillin-resistant Staphylococcus aureus nasal colonization is a poor predictor of intensive care unit-acquired methicillin-resistant Staphylococcus aureus infections requiring antibiotic treatment. Crit Care Med, 2010; 38(10):1991–1995; doi: 10.1097/CCM.0b013e3181eeda3f

20.

Walley

, Bridgman

, Davis

, et al. N. Methicillin resistant Staphylococcus Aureus (MRSA) is not walways caught on the orthopaedic ward. Acta Orthopaedica Belgica, 2009; 75(2):245–251.

21.

Croft

, Mejia

, Barker

, et al. Methicillin-resistant Staphylococcus aureus in a trauma population: Does colonization predict infection? Am Surg, 2009; 75(6):458–462. discussion 461-2.

22.

Agbaht

, Lisboa

, Pobo

, et al. Management of ventilator-associated pneumonia in a multidisciplinary intensive care unit: Does trauma make a difference? Intensive Care Med, 2007; 33(8):1387–1395; doi: 10.1007/s00134-007-0729-5

23.

Shaw

, Whalen

, Mitchell

, et al. Methicillin-Resistant Staphylococcus aureus carrier rate in orthopaedic trauma patients: A prospective cohort study. J Orthop Trauma, 2020; 34(1):1–7; doi: 10.1097/BOT.0000000000001630