Efficacy of mupirocin, neomycin and octenidine for nasal Staphylococcus aureus decolonisation: a retrospective cohort study

Background Periprosthetic joint infection (PJI) causes significant morbidity. Methicillin sensitive Staphylococcus aureus (MSSA) is the most frequent organism, and the majority are endogenous. Decolonisation reduces PJIs but there is a paucity of evidence comparing treatments. Aims; compare 3 nasal decolonisation treatments at (1) achieving MSSA decolonisation, (2) preventing PJI. Methods Our hospital prospectively collected data on our MSSA decolonisation programme since 2013, including; all MSSA carriers, treatment received, MSSA status at time of surgery and all PJIs. Prior to 2017 MSSA carriers received nasal mupirocin or neomycin, from August 2017 until August 2019 nasal octenidine was used. Results During the study period 15,958 primary hip and knee replacements were performed. 3200 (20.1%) were MSSA positive at preoperative screening and received decolonisation treatment, 698 mupirocin, 1210 neomycin and 1221 octenidine. Mupirocin (89.1%) and neomycin (90.9%) were more effective at decolonisation than octenidine (50.0%, P < 0.0001). There was no difference in PJI rates (P = 0.452). Conclusions Mupirocin and neomycin are more effective than octenidine at MSSA decolonisation. There was poor correlation between the MSSA status after treatment (on day of surgery) and PJI rates. Further research is needed to compare alternative MSSA decolonisation treatments.

783. Impact of Universal Decolonization on Intensive Care Unit Bloodstream Infections

Background Interventions used to reduce the incidence of hospital-acquired infections (HAIs) include hand hygiene, isolation, and decolonization. The routine use of chlorhexidine gluconate (CHG) and nasal mupirocin ointment has been shown to be an effective universal decolonization option to reduce bacterial transmission and prevent HAIs. The objective of this study is to compare the pre- and post-intervention of universal decolonization among ICU patients at Desert Regional Medical Center, an acute care Level II trauma center. Methods The first part of this study is a retrospective chart review of all ICU patients from June 2020 to August 2020. The second part of this research is a prospective study from December 2020 to March 2021. The prospective study will include all patients admitted to the ICU who completed the decolonization regimen of mupirocin for 5 days and daily CHG baths. In the intervention phase, all ICUs patients will be decolonized with nasal mupirocin twice daily for 5 days and CHG baths daily for the entire ICU stay. The primary outcome is the number of ICU bloodstream infections (BSIs). Secondary outcomes include the number of ICU-related central line associated bloodstream infections (CLABSI), catheter-associated urinary tract infections (CAUTI), and ventilator associated pneumonia (VAP). An infection attributed to ICU stay is defined as an infection onset occurring more than 48 hours after ICU admission. Fisher’s exact and chi square test was used for the statistical analysis. Results A total of 130 patients were included in this study. Universal decolonization resulted in a reduction in overall ICU infections in the baseline group vs intervention group using a p-value of 0.05 (ICU-BSI 5 vs 4, p=0.73; CLABSI 2 vs 1, p=0.56; CAUTI 4 vs 2, p=0.41; VAP 23 vs 17, p=0.25). Conclusion Patients in the intervention group had a lower incidence of ICU infections compared to the baseline group. These findings suggest that universal decolonization may be an effective strategy in reducing ICU incidence rates of BSI, CLABSI, CAUTI, and VAP. Further studies need to be conducted to validate this finding with a greater population enrolled to achieve adequate power. Disclosures All Authors: No reported disclosures

The impact of site-specific clearance on Methicillin-resistant Staphylococcus aureus decolonization

Methicillin-resistant Staphylococcus aureus (MRSA) colonizes multiple body sites, and carriage is an important risk factor for MRSA infection. Successful decolonization reduces disease incidence; however, decolonization protocols vary in the number of body sites targeted, and the impact of site-specific treatments is not well understood. Here, we used data from a randomized controlled trial (RCT) of MRSA decolonization using chlorhexidine body and mouth wash and nasal mupirocin to quantify the contribution of each treatment component to the success of the protocol. We estimated mouthwash as the least effective treatment component and the combined effect of MRSA clearance at the nares, skin, and wound as 93% (90% credible interval 85%-99%) of the full decolonization. Our model can estimate the effectiveness of hypothetical treatments in silico and shows enhancing MRSA clearance at nares will achieve the largest gains. This study demonstrates the use of machine learning to go beyond what is typically achieved by RCTs, facilitating evidence-based decision-making to streamline clinical protocols.

887. Implementation of a Surgical Site Infection (SSI) Prevention Bundle: Patient Compliance and Experience

Background An evidence-based preoperative bundle including chlorhexidine gluconate (CHG) bathing, screening for S. aureus nasal carriage and decolonizing carriers with mupirocin was the standard of care for patients having total joint arthroplasty (TJA) at a VA medical center. We aimed to assess patient compliance with mupirocin and CHG, and characterize patient perceptions of barriers and facilitators to compliance. Compliance with CHG Bathing & Mupirocin By Methicillin-resistant S. aureus (MRSA) or Methicillin-susceptible S. aureus (MSSA) Colonization Status Methods The bundle for S. aureus colonized patients having TJA included nasal mupirocin ointment twice daily and daily CHG bathing for 5 days before surgery. The bundle for non-carriers included CHG bathing the day before and the morning of surgery. From 7/2018-10/2019, inpatients completed a 31-item survey following their TJA. Results 73 patients completed the survey (~29% of the TJA population). 17 patients (23%) carried S. aureus & 56 patients (77%) were non-carriers. Patients reported high compliance with home use of CHG for the full number of days directed (88% when prescribed for 2 days; 71% when prescribed for 5 days; overall 85% used as prescribed; Figure). 7 (10%) patients reported CHG side effects, including burning or itchy/dry skin. 99% of patients reported willingness to use the CHG before a future surgery. Compliance with home use of mupirocin was lower (53% used as prescribed). Reported side effects included stinging, itching or dryness (N=2, 12%), unpleasant taste (N=2, 12%) & runny or stuffy nose (N=3, 18%). 100% of patients reported willingness to use mupirocin before a future surgery. Barriers to patient compliance with the bundle included forgetfulness and difficulty bathing daily. Facilitators to patient compliance included high facility compliance with S. aureus screening (100% patients reported), patient education regarding CHG and mupirocin use (95% patients recalled), and access to prescribed medications (100% patients received). Most patients (93%) reported no financial burden for mupirocin and 95% of patients reported no financial burden for CHG. Conclusion Patients reported high willingness to use the prevention bundle, yet mupirocin compliance was sub-optimal. Replacing patient-applied home mupirocin with nurse-applied day-of-surgery decolonization should be assessed in order to facilitate increased compliance. Disclosures All Authors: No reported disclosures

Siblings’ Precautions and Parents’ Decolonization to Control Methicillin-Resistant Staphylococcus aureus in a Neonatal Intensive Care Unit (NICU)

Background: Following the first reports of the emergence of methicillin-resistant Staphylococcus aureus (MRSA) in the 1970s, several measures to prevent its transmission were introduced in hospitals. However, controversy continues regarding the best approach to prevent and control MRSA, especially in neonatal intensive care units (NICUs). Objective: To report the reduction of colonization and primary central venous catheter–related bloodstream infection (CRBSI) caused by MRSA through surveillance, decolonization, and adoption of best practices in intravenous catheter care. Methods: Quasi-experimental, nonrandomized, before-and-after intervention study conducted in a 70-bed NICU in a private maternity hospital in Brazil. Period studied comprehended between August 2018 and May 2019 (period 1 - preintervention) and June to December 2019 (period II - postintervention). At the end of period 1, several measures were implanted to control and prevent colonization and CRBSI in the unit. The following measures were implemented: incentive to hand hygiene; best practices training on medication preparation and central catheter manipulation; systematic screening of colonized patients with nasal and umbilical swabs; contact precautions for colonized newborn (NB); contact precautions for twins of a colonized NB even when they had a negative swab; decolonization of patients with nasal mupirocin and chlorohexidine (oral preparation) for oral hygiene; concurrent linen change at the end of the patient’s decolonization; decolonization of parents of colonized siblings with chlorohexidine bath and nasal mupirocin; environmental organization; intensification of cleaning and disinfection of equipment and articles; cohort of patients and workers; isolation and precautions compliance audit; professional investigation and decolonization and universal chlorhexidine bath for newborns. Results: In periods I and II, the positivity rates of the collected swabs were 4.14% and 0.75% (P < .0001), respectively, with a peak of positivity of 11.8% in January. Also, 12 episodes of CRBSI were documented in period I (incidence, 2.9%) versus no episode in period 2, with a significant difference in incidence rate between the 2 periods (P = .002). Conclusion: The innovative measures were effective for eradicating the outbreak when instituted together with recognized good practices. In an outbreak scenario is difficult to define the isolated impact of each measure, although, parents’ decolonization to prevent the colonization of other siblings and contact precautions for twins of colonized NB seemed to improve the results.Funding: NoneDisclosures: None

Evaluation of effectiveness and compliance with the mupirocin nasal ointment part of Staphylococcus aureus decolonization in real life using UPLC-MS/MS mupirocin quantification

Background Preoperative decolonization is recommended in Staphylococcus aureus nasal carriers scheduled for cardiac surgery. We aimed to evaluate the effectiveness of and compliance with mupirocin use in nasal S. aureus carriers in a real-life setting. Methods Prospective study including consecutive patients scheduled for cardiac surgery screened for S. aureus nasal carriage at preoperative consultation. Carriers were prescribed mupirocin nasal ointment, chlorhexidine shower and mouthwash. Effectiveness of decolonization was evaluated with a postoperative nasal sample. Compliance was evaluated objectively by determination of nasal mupirocin concentration using UPLC-MS/MS and self-reported by questionnaire. Results Over 10 months, 361 patients were included, 286 had preoperative screening, 75 (26.2%) were S. aureus nasal carriers and 19 of them (25.3%) failed to be effectively decolonized. No resistance to mupirocin was documented. Preoperative and postoperative strains were identical in all cases. Declared good compliance was associated with decolonization success (OR = 24; 95% CI 4–143, P &lt; 0.0001). Mupirocin detection was significantly associated with the level of compliance. Mupirocin was detected in 52.2% (24/46) of patients effectively decolonized and in 12.5% (2/16) of patients with decolonization failure (P &lt; 0.01). In 2/19 patients, failure of decolonization was not associated with a compliance issue. Postoperative carriage was associated with an increased risk of S. aureus infection (OR = 9.8; 95% CI 1.8–53, P &lt; 0.01). Conclusions In real life, decolonization is not always effective, hence there is a persisting risk of S. aureus endogenous infection. Mupirocin concentration measurement may help to understand compliance issues and failures in decolonization.

1238. Alcohol-Based Nasal Antiseptic as Part of a Bundle to Reduce the Incidence of Contact Precautions and Surgical Site Infections

Background A 145-bed hospital embarked on a 12-month project to reduce contact precautions (CP) for colonized methicillin-resistant Staphylococcus aureus (MRSA) patients, and to reduce surgical site infections (SSI) for orthopedic patients. Prior to the project all high-risk patients were screened using nasal polymerase chain reaction (PCR) test for MRSA, and if positive, placed on CP. Orthopedic surgical patients were also screened for MRSA, and if positive, received preoperative chlorhexidine (CHG) bath and nasal mupirocin. Methods Starting in January 2017, all high-risk patients received twice-daily alcohol-based nasal antiseptic and a daily chlorhexidine (CHG) bath, in place of targeted screening and CP. In addition, an SSI prevention bundle was instituted, comprised of alcohol-based nasal antiseptic in place of mupirocin, retraining perioperative staff on skin preparation, and UV-C disinfection added to manual cleaning in the operating room. Preoperative CHG bathing was already in place and was continued. During this period, there was a total of 868 orthopedic surgery patients. Patients who remained in the hospital post-operatively received twice-daily nasal antiseptic and daily CHG bathing. Results There was a reduction in the incidence of CP from 16% to 10% per day, while maintaining a rate of zero MRSA bacteremia. Reduction of gloves, gowns and nasal PCR tests, resulted in an estimated total cost reduction of $200,000. Additionally, there was a statistically significant reduction in total hip SSI from a 2016 baseline of 1.15 infections per 100 procedures to 0.017 infections per 100 procedures (98% reduction, P = 0.014.), and the rate of zero SSI in total knee replacement patients was maintained. Conclusion Universal decolonization in place of targeted screening and CP for colonized MRSA patients, reduced costs without increasing MRSA bacteremia. Replacement of mupirocin with a nasal alcohol-based antiseptic, as one component of an SSI prevention bundle, resulted in a marked reduction in SSI after total hip procedures. Disclosures All authors: No reported disclosures.

591. Mupirocin and Chlorhexidine Resistance in Staphylococcus aureus Isolated from Children in South Korea

Background Increasing prevalence of mupirocin-resistant Staphylococcus aureus have been reported, and chlorhexidine resistance has become an issue. This study aimed to investigate the prevalence of mupirocin and chlorhexidine resistance in both colonized and infection causing Staphylococcus aureus in children, and find factors associated with increased virulence. Methods Staphylococcus aureus, isolated from children <18 years old admitted at a single center, were collected prospectively from August 2017 to July 2018. The isolates underwent multilocus sequence typing and were screened for genes causing chlorhexidine resistance (qac A/B), quaternary ammonium resistance (smr), mupirocin resistance (ileS mutation, Mup A, MupB), and Pantone Valentine Leucocidin (pvl) toxin. Results During the study period, a total of 49 non-duplicate isolates were included, of which 69.4% (n = 34) were Methicillin-resistant Staphylococcus aureus (MRSA). Of the colonizers (n = 25), the most common sequence type was ST 72 (68.0%), whereas among pathogens (n = 24), ST 72 (29.2%) and ST 89 (29.2%) were most prevalent. Pathogens in this study caused abscess formation (n = 3), sepsis (n = 4), and skin infections such as cellulitis and omphalitis (n = 17). Mupirocin resistance was found in 16.0% among colonizers vs. 45.8% among pathogens (P = 0.023). High-level mupirocin resistance was more common (n = 3/25, 12.0%) than low-level mupirocin resistance (n = 1/25, 4.0%) in colonizers, whereas, pathogens had similar rates of low-level (25.0%) and high-level (n = 20.8%) mupirocin resistance. PVL toxin gene was more frequently found in colonizers than pathogens (64.0% vs. 33.3%, P = 0.032), and all isolates had quaternary ammonium resistance genes. Chlorhexidine resistance gene was found in only 3 MRSA isolates colonized in the nares of preterm infants. All were SCCmec type 4, however, two were ST 72, spa type t1054, which had high -level mupirocin resistance and PVL toxin gene. Conclusion A PVL toxin gene-positive MRSA which had genes causing mupirocin and chlorhexidine resistance were found in the nasal carriages of preterm infants. These stains may cause failure of MRSA eradication in hospital settings, using conventional methods of nasal mupirocin application and chlorhexidine bathing. Disclosures All authors: No reported disclosures.

Nasal Decolonisation of MRSA

The recent demonstration for the first time of urinary monic acid A as a clinical urinary biomarker of exposure to intra-nasal mupirocin during medication for methicillin-resistant Staphylococcus aureus (MRSA) offers a way of verifying adherence to the regimen. However, absence of the biomarker in some patients needs explanation, to ensure that efficient decolonisation has not been compromised by confounding circumstances, and that additional resistance to mupirocin has not unwittingly been encouraged.