Decolonization Procedures Research Articles

Application of Octenidine into Nasal Vestibules Does Not Influence SARS-CoV-2 Detection via PCR or Antigen Test Methods.

The targeted or universal decolonization of patients through octenidine for nasal treatment and antiseptic body wash for 3 to 5 days prior elective surgery has been implemented in several surgical disciplines in order to significantly reduce surgical site infections (SSIs) caused by Staphylococcus aureus carriage. However, as most healthcare facilities also screen patients on admission for pilot infection, it is imperative that a prophylactic nasal decolonization procedure not yield a false negative SARS-CoV-2 status in otherwise positive patients. We assessed the effect of a commercially available octenidine-containing nasal gel on two different screening methods-antigen (Ag) detection based on colloidal gold immunochromatography and RT-PCR-in a prospective-type accuracy pilot study in asymptomatic SARS-CoV-2-positive inpatients. All patients still showed a positive test result after using the octenidine-containing nasal gel for about 3 days; therefore, its application did not influence SARS-CoV-2 screening, which is of high clinical relevance. Of note is that Ag detection was less sensitive, regardless of the presence of octenidine. From an infection prevention perspective, these results favor octenidine-based decolonization strategies, even during seasonal SARS-CoV-2 periods. As only asymptomatic patients are considered for elective interventions, screening programs based on RT-PCR technology should be preferred.

Limited Adaptation of Staphylococcus aureus during Transition from Colonization to Invasive Infection.

Staphylococcus aureus carriage is a risk factor for invasive infections. Unique genetic elements favoring the transition from colonizing to invasive phenotype have not yet been identified, and phenotypic adaptation traits are understudied. We therefore assessed phenotypic and genotypic profiles of 11 S. aureus isolate pairs sampled from colonized patients simultaneously suffering from invasive S. aureus infections. Ten out of 11 isolate pairs displayed the same spa and multilocus sequence type, suggesting colonization as an origin for the invasive infection. Systematic analysis of colonizing and invasive isolate pairs showed similar adherence, hemolysis, reproductive fitness properties, antibiotic tolerance, and virulence in a Galleria mellonella infection model, as well as minimal genetic differences. Our results provide insights into the similar phenotypes associated with limited adaptation between colonizing and invasive isolates. Disruption of the physical barriers of mucosa or skin was identified in the majority of patients, further emphasizing colonization as a major risk factor for invasive disease. IMPORTANCE S. aureus is a major pathogen of humans, causing a wide range of diseases. The difficulty to develop a vaccine and antibiotic treatment failure warrant the exploration of novel treatment strategies. Asymptomatic colonization of the human nasal passages is a major risk factor for invasive disease, and decolonization procedures have been effective in preventing invasive infections. However, the transition of S. aureus from a benign colonizer of the nasal passages to a major pathogen is not well understood, and both host and bacterial properties have been discussed as being relevant for this behavioral change. We conducted a thorough investigation of patient-derived strain pairs reflecting colonizing and invasive isolates in a given patient. Although we identified limited genetic adaptation in certain strains, as well as slight differences in adherence capacity among colonizing and invasive isolates, our work suggests that barrier breaches are a key event in the disease continuum of S. aureus.

Experience with Methicillin-Resistant Staphylococcus aureus in a Central London Tertiary Pediatric Hospital

Abstract Objective Methicillin-resistant Staphylococcus aureus (MRSA) infection is very serious, and thus, it is common practice, worldwide, to screen for MRSA colonization at admission and institute decolonization procedures. Our aim was to review adherence to local guidelines and sepsis risk in pediatric patients with a focus on surgical cases. Methods A retrospective case note review was conducted from January 2019 to October 2020 in a tertiary pediatric hospital. Data collected included demographics, incidence of sepsis, pediatric intensive care unit (PICU) admissions, and adherence to guidelines. The results were analyzed with an SPSS statistical package. Results MRSA screening was performed in all 47,904 admissions; 161/47,904 had MRSA colonization. All underwent topical decontamination; however, isolation guidelines were adhered in only 7.45%; 71/161 were surgical patients; 23/71 were admitted to the PICU. Irrespective of the class of wound, 4/71 surgical patients developed MRSA sepsis. Of these, 2/5 surgical patients did not receive MRSA appropriate preoperative antibiotics; 4/5 surgical patients who had sepsis were admitted to PICU. Standard preoperative World Health Organization (WHO) surgical checklists were completed in all surgical cases. There was no mention of MRSA status in these forms. Conclusion MRSA remains a risk for sepsis and PICU admissions despite a 100% compliance with screening and decontamination. Adherence to WHO checklist did not result in the administration of correct antibiotics. High risk of postoperative sepsis (6.8%), with 80% needing PICU, irrespective of class of wound, mandates a more robust approach to prevention. Changes need to be made to WHO local surgical checklists.

Nasal microbiome disruption and recovery after mupirocin treatment in Staphylococcus aureus carriers and noncarriers

Nasal decolonization procedures against the opportunistic pathogen Staphylococcus aureus rely on topical antimicrobial drug usage, whose impact on the nasal microbiota is poorly understood. We examined this impact in healthy S. aureus carriers and noncarriers. This is a prospective interventional cohort study of 8 S. aureus carriers and 8 noncarriers treated with nasal mupirocin and chlorhexidine baths. Sequential nasal swabs were taken over 6 months. S. aureus was detected by quantitative culture and genotyped using spa typing. RNA-based 16S species-level metabarcoding was used to assess the living microbial diversity. The species Dolosigranulum pigrum, Moraxella nonliquefaciens and Corynebacterium propinquum correlated negatively with S. aureus carriage. Mupirocin treatment effectively eliminated S. aureus, D. pigrum and M. nonliquefaciens, but not corynebacteria. S. aureus recolonization in carriers occurred more rapidly than recolonization by the dominant species in noncarriers (median 3 vs. 6 months, respectively). Most recolonizing S. aureus isolates had the same spa type as the initial isolate. The impact of mupirocin-chlorhexidine treatment on the nasal microbiota was still detectable after 6 months. S. aureus recolonization predated microbiota recovery, emphasizing the strong adaptation of this pathogen to the nasal niche and the transient efficacy of the decolonization procedure.

Patient compliance and satisfaction with topical benzoyl peroxide gel prior to shoulder surgery.

BackgroundCutibacterium acnes is a common pathogen leading to postoperative shoulder infections. Many centers are utilizing 5% topical benzoyl peroxide (BPO) gel to decrease cutibacterium acnes bioburden prior to surgery. The purpose of this study was to evaluate patient compliance, tolerance, and side effects of applying BPO to the shoulder prior to surgery. Our hypothesis was that BPO would be well tolerated with few, minor side effects, and patients would comply with a regimen of 5 treatments spanning 48 hours prior to surgery.MethodsAll patients undergoing operative intervention, either open or arthroscopic, about the shoulder from August 7, 2020, through July 15, 2021, by a single surgeon were instructed to apply BPO to the shoulder after showering, on dry skin, in the morning and evening, starting 48 hours before their surgical date. Patients were instructed to apply a half-dollar-sized quantity for each treatment. There were a total of 5 topical applications. On the day of surgery, patients were given a 6-question survey regarding side effects experienced, BPO treatments missed, ease of treatment, and a scenario question. Demographic information was collected, and a satisfaction survey was administered upon study completion.ResultsA total of 183 patients out of a possible 284 eligible patients (64.4%) completed the survey. The median (interquartile range) age at surgery was 59.9 years. Sixty-four participants (35%) in the study cohort were female. One-hundred thirteen (61.7%) had an arthroscopic surgical approach, whereas 70 (38.3%) underwent open shoulder surgery. Most patients (N = 152, 83.5%) experienced no side effects from the topical 5% BPO gel treatments. Twenty-two (12.0%) patients missed 1 treatment, 10 (5.5%) missed 2 treatments, 1 (0.5%) missed 3 treatments, 3 (1.6%) missed 4 treatments, and 4 (2.2%) missed all 5 treatments. The majority of patients, 143 (78.1%), completed all 5 treatments. When prompted to choose between serial skin preparation treatments at home leading up to surgery or a single light-based decolonization procedure in the preoperative holding area on the day of surgery, 111 (60.7%) preferred to undergo antimicrobial treatment at home and arrive for surgery as otherwise scheduled.ConclusionSerial preoperative applications of topical 5% BPO gel are well tolerated by the majority of patients. Over 20% of patients missed at least one application of BPO. Most patients prefer home-based antimicrobial treatments compared with arriving earlier on the day of surgery for a single light-based antimicrobial treatment.

Modeling Interventions to Reduce the Spread of Multidrug-Resistant Organisms Between Health Care Facilities in a Region

Multidrug-resistant organisms (MDROs) can spread across health care facilities in a region. Because of limited resources, certain interventions can be implemented in only some facilities; thus, decision-makers need to evaluate which interventions may be best to implement. To identify a group of target facilities and assess which MDRO intervention would be best to implement in the Shared Healthcare Intervention to Eliminate Life-threatening Dissemination of MDROs in Orange County, a large regional public health collaborative in Orange County, California. An agent-based model of health care facilities was developed in 2016 to simulate the spread of methicillin-resistant Staphylococcus aureus (MRSA) and carbapenem-resistant Enterobacteriaceae (CRE) for 10 years starting in 2010 and to simulate the use of various MDRO interventions for 3 years starting in 2017. All health care facilities (23 hospitals, 5 long-term acute care hospitals, and 74 nursing homes) serving adult inpatients in Orange County, California, were included, and 42 target facilities were identified via network analyses. Increasing contact precaution effectiveness, increasing interfacility communication about patients' MDRO status, and performing decolonization using antiseptic bathing soap and a nasal product in a specific group of target facilities. MRSA and CRE prevalence and number of new carriers (ie, transmission events). Compared with continuing infection control measures used in Orange County as of 2017, increasing contact precaution effectiveness from 40% to 64% in 42 target facilities yielded relative reductions of 0.8% (range, 0.5%-1.1%) in MRSA prevalence and 2.4% (range, 0.8%-4.6%) in CRE prevalence in health care facilities countywide after 3 years, averting 761 new MRSA transmission events (95% CI, 756-765 events) and 166 new CRE transmission events (95% CI, 158-174 events). Increasing interfacility communication of patients' MDRO status to 80% in these target facilities produced no changes in the prevalence or transmission of MRDOs. Implementing decolonization procedures (clearance probability: 39% in hospitals, 27% in long-term acute care facilities, and 3% in nursing homes) yielded a relative reduction of 23.7% (range, 23.5%-23.9%) in MRSA prevalence, averting 3515 new transmission events (95% CI, 3509-3521 events). Increasing the effectiveness of antiseptic bathing soap to 48% yielded a relative reduction of 39.9% (range, 38.5%-41.5%) in CRE prevalence, averting 1435 new transmission events (95% CI, 1427-1442 events). The findings of this study highlight the ways in which modeling can inform design of regional interventions and suggested that decolonization would be the best strategy for the Shared Healthcare Intervention to Eliminate Life-threatening Dissemination of MDROs in Orange County.

Skin infections due to Panton-Valentine leukocidin (PVL)-producing S. aureus-Cost effectiveness of outpatient treatment.

IntroductionSkin and soft tissue infections (SSTI) caused by Panton-Valentine leukocidin (PVL)-producing strains of Staphylococcus aureus (PVL-SA) are associated with recurrent skin abscesses. Secondary prevention, in conjunction with primary treatment of the infection, focuses on topical decolonization. Topical decolonization is a standard procedure in cases of recurrent PVL-SA skin infections and is recommended in international guidelines. However, this outpatient treatment is often not fully reimbursed by health insurance providers, which may interfere with successful PVL-SA decolonization.AimOur goal was to estimate the cost effectiveness of outpatient decolonization of patients with recurrent PVL-SA skin infections. We calculated the average cost of treatment for PVL-SA per outpatient decolonization procedure as well as per in-hospital stay.MethodsThe study was conducted between 2014 and 2018 at a German tertiary care university hospital. The cohort analyzed was obtained from the hospital’s microbiology laboratory database. Data on medical costs, DRG-based diagnoses, and ICD-10 patient data was obtained from the hospital’s financial controlling department. We calculated the average cost of treatment for patients admitted for treatment of PVL-SA induced skin infections. The cost of outpatient treatment is based on the German regulations of drug prices for prescription drugs.ResultsWe analyzed a total of n = 466 swabs from n = 411 patients with recurrent skin infections suspected of carrying PVL-SA. PVL-SA was detected in 61.3% of all patients included in the study. Of those isolates, 80.6% were methicillin-susceptible, 19.4% methicillin-resistant. 89.8% of all patients were treated as outpatients. In 73.0% of inpatients colonized with PVL-SA the main diagnosis was SSTI. The median length of stay was 5.5 days for inpatients colonized with PVL-SA whose main diagnosis SSTI; the average cost was €2,283. The estimated costs per decolonization procedure in outpatients ranged from €50-€110, depending on the products used.ConclusionOur data shows that outpatient decolonization offers a highly cost-effective secondary prevention strategy, which may prevent costly inpatient treatments. Therefore, health insurance companies should consider providing coverage of outpatient treatment of recurrent PVL-SA skin and soft tissue infections.

Staphylococcus aureus nasal decolonization before cardiac and orthopaedic surgeries: first descriptive survey in France

The objective was to describe French hospital nasal screening and decolonization procedures before clean surgery procedures. Information for participants was sent to the French Society for Infection Control members in June 2018. Seventy hospitals participated in the survey; 40% (N= 28) declared having institutional decolonization procedures: 64% (N= 18) in orthopaedic and 56% (N= 15) in cardiac surgeries. All hospitals used mupirocin for nasal decolonization and body decolonization with chlorhexidine (N= 16) or povidone iodine (N= 10). This study is the first to be performed in France giving information in this field. Screening/decolonization procedures are heterogeneous and the evaluation of their clinical impact remains complex.

Surgical infection prophylaxis prior to left ventricular assist device implantation: A survey of clinical practice

Short duration, antimicrobial prophylaxis that includes antistaphylococcal activity is recommended at the time of left ventricular assist device (LVAD) implantation to reduce infection-related complications. There continues to be wide variability in surgical infection prophylaxis (SIP) regimens among implantation centers. The aim of this study is to characterize current SIP regimens at different LVAD centers. A survey study was conducted from 26 September 2017 to 25 October 2017. Surveys were distributed electronically to LVAD coordinators and infectious diseases specialists at 75 US medical centers identified as having an LVAD program. Data collection included information about antimicrobial selection, duration, Staphylococcus aureus screening, and decolonization procedures. We received 29 survey responses. The majority of surveys were completed by infectious diseases physicians (72.4% [21 out of 29]). Most responding centers reported LVAD programs established for greater than 10 years (20 out of 29 [69%]). Cardiac transplantation was performed in 28 out of 29 (96%) centers. Of centers reporting a defined SIP regimen for non-penicillin allergic patients (96% [28 out of 29]), 17.9% (5 out of 28) reported a four-drug regimen, 35.7% (10 out of 28) reported a three-drug regimen, and 46.4% (13 out of 28) reported a two-drug regimen, while no centers reported a single-drug regimen. Empiric fluconazole was common (50% [14 out of 28]) and 96.4% (27 out of 28) of regimens included vancomycin. Duration of antimicrobial prophylaxis (24 hours to 5 days), S. aureus screening, decolonization procedures, and alterations due to drug allergies varied across participating centers. Our survey results indicate wide variation in SIP regimens among participating LVAD centers. These results highlight the need for studies evaluating the implications of SIP regimens, and whether clinical factors that prolong antimicrobial duration impact postoperative infection rates.

Methicillin-Resistant Staphylococcus aureus Eradication and Decolonization in Children Study (Part 1): Development of a Decolonization Toolkit With Patient and Parent Advisors.

BackgroundCommunity-acquired methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections affect many healthy children. A significant number of these children are hospitalized and require surgical incision and drainage (I&D). Once sent home, these children and families are asked to complete burdensome home decolonization and hygiene procedures in an effort to prevent the high rate of recurrent infections.ObjectiveThis component of the Methicillin-resistant Staphylococcus aureus Eradication and Decolonization in Children (MEDiC) study aimed to develop a toolkit to assist MEDiC study participants in completing MRSA decolonization and hygiene procedures at home (the MEDiC kit).MethodsIn all, 5 adolescents (aged 10-18 years) who had undergone an I&D procedure for a skin infection and 11 parents of children who had undergone an I&D procedure for a skin infection were engaged in a 4-hour group workshop using a human-centered design approach. The topics covered in this workshop and analyzed for this paper were (1) attitudes about MRSA decolonization procedures and (2) barriers to the implementation of MRSA decolonization and hygiene procedures. The team analyzed the audio and artifacts created during the workshop and synthesized their findings to inform the creation of the MEDiC kit.ResultsThe workshop activities uncovered barriers to successful completion of the decolonization and hygiene procedures: lack of step-by-step instruction, lack of proper tools in the home, concerns about adverse events, lack of control over some aspects of the hygiene procedures, and general difficulty coordinating all the procedures. Many of these could be addressed as part of the MEDiC kit. In addition, the workshop revealed that effective communication about decolonization would have to address concerns about the effects of bleach, provide detailed information, give reasons for the specific decolonization and hygiene protocol steps, and include step-by-step instructions (preferably through video).ConclusionsThrough direct engagement with patients and families, we were able to better understand how to support families in implementing MRSA decolonization and hygiene protocols. In addition, we were able to better understand how to communicate about MRSA decolonization and hygiene protocols. With this knowledge, we created a robust toolkit that uses patient-driven language and visuals to help support patients and families through the implementation of these protocols.Trial RegistrationClinicalTrials.gov NCT02127658; https://clinicaltrials.gov/ct2/show/NCT02127658

Methicillin-Resistant Staphylococcus aureus Eradication and Decolonization in Children Study (Part 2): Patient- and Parent-Centered Outcomes of Decolonization.

BackgroundSkin and soft tissue infections (SSTIs) due to community-acquired methicillin-resistant Staphylococcus aureus (MRSA) can lead to a number of significant known medical outcomes including hospitalization, surgical procedures such as incision and drainage (I&D), and the need for decolonization procedures to remove the bacteria from the skin and nose and prevent recurrent infection. Little research has been done to understand patient and caregiver-centered outcomes associated with the successful treatment of MRSA infection.ObjectiveThis study aimed to uncover MRSA decolonization outcomes that are important to patients and their parents in order to create a set of prototype measures for use in the MRSA Eradication and Decolonization in Children (MEDiC) study.MethodsA 4-hour, human-centered design (HCD) workshop was held with 5 adolescents (aged 10-18 years) who had experienced an I&D procedure and 11 parents of children who had experienced an I&D procedure. The workshop explored the patient and family experience with skin infection to uncover patient-centered outcomes of MRSA treatment. The research team analyzed the audio and artifacts created during the workshop and coded for thematic similarity. The final themes represent patient-centered outcome domains to be measured in the MEDiC comparative effectiveness trial.ResultsThe workshop identified 9 outcomes of importance to patients and their parents: fewer MRSA outbreaks, improved emotional health, improved self-perception, decreased social stigma, increased amount of free time, increased control over free time, fewer days of school or work missed, decreased physical pain and discomfort, and decreased financial burden.ConclusionsThis study represents an innovative HCD approach to engaging patients and families with lived experience with MRSA SSTIs in the study design and trial development to determine meaningful patient-centered outcomes. We were able to identify 9 major recurrent themes. These themes were used to develop the primary and secondary outcome measures for MEDiC, a prospectively enrolling comparative effectiveness trial.Trial RegistrationClinicalTrials.gov NCT02127658; https://clinicaltrials.gov/ct2/show/NCT02127658

Does Preoperative Decolonization Reduce Surgical Site Infections in Elective Orthopaedic Surgery? A Prospective Randomized Controlled Trial.

Surgical site infections (SSIs) after elective orthopaedic surgery are very stressful for patients due to frequent rehospitalizations with reoperations and poorer functional outcomes. Prevention of such events is therefore crucial. Although an evidence-based consensus is still lacking, preoperative decolonization could decrease SSI. Specifically, more information is needed about the effect of a preoperative decolonization procedure on SSI proportions in both Staphylococcus aureus carriers and non-S. aureus carriers after general orthopaedic surgery. Our study addressed the following questions: (1) Does preoperative decolonization reduce the risk of SSI after general elective orthopaedic surgery in patients colonized with S. aureus? (2) Does preoperative decolonization reduce the risk of SSI among patients who are not colonized with S. aureus? In this prospective, randomized, single-blinded trial, we recruited patients undergoing general elective orthopaedic surgery in one tertiary care center in Switzerland. Between November 2014 and September 2017, 1318 of 1897 screened patients were enrolled. Patients were allocated into either the S. aureus carrier group (35%, 465 of 1318 patients) or the noncarrier group (65%, 853 of 1318 patients) according to screening culture results. In the S. aureus group, 232 patients were allocated to the intervention arm and 233 were allocated to the control arm. Intervention was 5 days of daily chlorhexidine showers and mupirocin nasal ointment twice a day. Of the 853 noncarriers, 426 were allocated to the intervention arm and 427 were allocated to the control arm. All patients in both groups were analyzed in an intention-to-treat manner. The primary endpoint was SSI occurrence at 90 days postoperative and the secondary endpoint was SSI occurrence at 30 days postoperative.The initial sample size calculation was made for the S. aureus carrier group. Based on the literature review, a 4% proportion of SSI was expected in the control group. Thus, 726 carriers would have been needed to detect a relative risk reduction of 80% with a power of 80% at a two-sided α-error of 0.048 (adjusted for interim analysis). Assuming carrier prevalence of 27%, 2690 patients would have been needed in total. An interim analysis was performed after including half of the targeted S. aureus carriers (363 of 726). Based on the low infection rate in the control group (one of 179), a new sample size of 15,000 patients would have been needed. This was deemed not feasible and the trial was stopped prematurely. Among carriers, there was no difference in the risk of SSI between the intervention and control arms (decolonized SSI risk: 0.4% [one of 232], control SSI risk: 0.4% [one of 233], risk difference: 0.0% [95% CI -1.2% to 1.2%], stratified for randomization stratification factors; p > 0.999). For noncarriers, there was no difference in risk between the intervention and control arms (decolonized SSI risk: 0.2% [one of 426], control SSI risk: 0.2% [one of 247], stratified risk difference: -0.0% [95% CI -0.7 to 0.6]; p = 0.973). We found no difference in the risk of SSI between the decolonization and control groups, both in S. aureus carriers and noncarriers. Because of the low event numbers, no definite conclusion about efficacy of routine preoperative decolonization can be drawn. The results, however, may be helpful in future meta-analyses. Level II, therapeutic study.

1176. Antibiotic Prophylaxis Strategies Prior to Left Ventricular Assist Device Implantation: A Survey of Practice

BackgroundShort duration, single-agent antimicrobial prophylaxis with anti-staphylococcal activity is recommended at the time of left ventricular assist device (LVAD) placement to prevent infection-related complications. Despite consensus guidelines, there continues to be wide variability in antimicrobial regimens among implantation centers. The aim of this study was to characterize current peri-operative antimicrobial prophylactic strategies at different LVAD implantation centers.MethodsA survey study was conducted from September 26, 2017 to October 25, 2017. Surveys were distributed electronically to both LVAD coordinators and infectious diseases specialists at 75 US medical centers identified as having an LVAD program. Data collection included information about antimicrobial selection, duration, MRSA screening and decolonization procedures.ResultsWe received 29 survey responses. The majority of surveys were completed by infectious diseases physicians [72.4% (21/29)]. Most responding centers reported LVAD programs established for >10 years [20/29 (69%)]. Cardiac transplantation was performed in 28/29 (96%) centers. Of centers reporting a defined antimicrobial prophylaxis regimen for nonpenicillin allergic patients [97% (28/29)], 17.9% (5/28) reported a four-drug regimen, 35.7% (10/28) reported a three-drug regimen, and 46.4% (13/28) reported a two-drug regimen, while no centers reported a single-drug regimen. Empiric fluconazole was common [50% (14/28)] and 96.4% (27/28) of regimens included Vancomycin. Duration of antimicrobial prophylaxis (24 h-5 d), MRSA screening, decolonization procedures, and alterations due to drug allergies varied significantly across participating centers.ConclusionOur survey results indicate a wide variation in the peri-operative antimicrobial prophylaxis regimens among participating LVAD centers. These results highlight the need for further studies evaluating the utility, toxicity, and stewardship implications of multi-drug regimens and whether specific clinical factors that prolong antimicrobial duration impact post-operative LVAD-related infection rates.DisclosuresRachel Miller, MD, Synexis: Research Grant.

Staphylococcus aureus Infecting and Colonizing Experimental Animals, Macaques, in a Research Animal Facility.

An outbreak of methicillin-resistant Staphylococcus aureus (MRSA) infections on the skin and soft tissues of experimental macaques in the vivarium of The Rockefeller University, New York, triggered this observational and interventional study. We screened 14 macaques in the colony (samples from head, nares, and rectum) and their housing (40 environmental surfaces) four times in 1 year, for S. aureus colonization or contamination, while implementing enhanced decolonization and decontamination procedures. A total of 114 isolates of S. aureus were recovered and characterized (antibiograms, spa typing, multilocus sequence typing, pulsed-field gel electrophoresis [PFGE], mecA, Panton-Valentine Leukocidin, and arginine catabolic mobile element). Based on these results, six strains of S. aureus were identified: two MRSA strains (t16708/ST3862/PFGE-A, t16709/ST3862/PFGE-C) and one methicillin-sensitive S. aureus (t8397/ST3884/PFGE-D) were characterized for the first time in this study; strains belonging to spa types t189 and t4167 have been identified in primates in previous studies. None of these strains was common to the neighboring New York City human community. Thus, it seems probable that the animals were already colonized upon arrival to the University. We suggest screening primates for S. aureus carriage upon arrival to University vivaria and possible implementation of extensive decolonization procedures before any surgical interventions.

160. Reduction in the Spread of Hospital-Associated Infections Among Pediatric Oncology Patients in an Animal-Assisted Intervention Program from a Canine Decolonization Procedure

BackgroundAnimal-assisted interventions (AAI), the use of animals as a complementary therapy in holistic patient care, has shown many positive outcomes. However, therapy animals can serve as mechanical vectors of hospital-associated infections (HAI), e.g., methicillin-resistant Staphylococcus aureus (MRSA). This pilot study assessed for transmission of HAIs among therapy animals, patients, and the hospital environment. We tested the effectiveness of a novel decolonization protocol for therapy dogs to reduce the risk of transmission of HAIs and enhance AAI program sustainability. Our hypothesis was that HAI transmission occurs from positive child to child, with the dog as an intermediary fomite.MethodsBefore and after child–animal interaction, we sampled patients, dogs, and the environment, and collected vital statistics and survey data from patients. MRSA was detected in samples by culture and molecular testing. Therapy dog handlers performed normal pre-visit practices for 2 control visits, then switched to a decolonization protocol (chlorhexidine-based shampoo prior to the visit, and chlorhexidine wipes on the fur during the visit) for 2 intervention visits.ResultsWe evaluated 45 children and 4 therapy dogs over 13 visits. Children had decreased blood pressure and heart rate, and reported improved mental health scores post visit. MRSA conversion was identified from 10.2% of the children and 38.5% of the dogs, while 93% of the environmental samples were MRSA positive both pre and post. Patients that interacted closely with the dog had 8.01 times higher odds (95% CI 1.1–15.2) of MRSA conversion compared with patients who barely interacted with the dog. When stratified by intervention group, the MRSA conversation odds ratio of close interaction was 0.93 (95% CI 0.1–10.8) when the dog was decolonized versus 9.72 (0.9–99) when not decolonized.ConclusionThis study showed the potential for AAI visits to improve physiological and mental health of pediatric outpatients. A risk of HAI exposure to patients from interaction with the dog was found, but this effect was nullified by the decolonization procedure. Future research is needed to increase the safety of this valuable alternative therapy.Disclosures All authors: No reported disclosures.

Intracellular activity of antimicrobial compounds used for Staphylococcus aureus nasal decolonization.

Staphylococcus aureus is able to invade mammalian cells during infection and was recently observed inside nasal mucosa of healthy carriers. To determine the intracellular activity of antimicrobial compounds used for decolonization procedures using a cell model mimicking S. aureus nasal epithelium invasion. HaCaT cells and human nasal epithelial cells (HNECs) recovered from nasal swabs of S. aureus carriers were visualized by confocal laser scanning microscopy to detect intracellular S. aureus cells. An HaCaT cell model, mimicking S. aureus internalization observed ex vivo in HNECs, was used to assess the intracellular activity against S. aureus of 21 antimicrobial compounds used for nasal decolonization, including mupirocin and chlorhexidine. HaCaT cells and HNECs were found to internalize S. aureus with the same focal pattern. Most antimicrobial compounds tested on HaCaT cells were shown to have weak activity against intracellular S. aureus. Some systemic antimicrobials, including fusidic acid, clindamycin, linezolid, minocycline, ciprofloxacin, moxifloxacin, rifampicin and levofloxacin, reduced S. aureus intracellular loads by 0.43-1.66 log cfu/106 cells compared with the control (P < 0.001). By contrast, mupirocin and chlorhexidine reduced the S. aureus intracellular load by 0.19 and 0.23 log cfu/106 cells, respectively. These data indicate that most of the antimicrobial compounds used for nasal decolonization, including mupirocin and chlorhexidine, exhibit weak activity against intracellular S. aureus using the HaCaT cell model. This work emphasizes the need to better understand the role of the S. aureus intracellular reservoir during nasal colonization in order to improve decolonization procedures.

MRSA colonization and infection rates among cardiovascular thoracic surgical patients

Background: Infection due to Staphylococcus aureus is a common complication of cardiovascular and thoracic surgery (CVTS). Infections due to methicillin-resistant S aureus (MRSA), results in even greater morbidity and mortality than infections from methicillin-sensitive S aureus (MSSA) strains. To prevent such consequences, implementation of MRSA screening to identify MRSA carriers, followed by decolonization protocol is becoming a norm for cardiothoracic centres. Methods & Materials: We retrospectively studied the clinical and microbiological data of all cardiovascular thoracic surgical (CVTS) patients who were admitted for their procedure at Faculty of Medicine, University Teknologi MARA, Malaysia. The study period was five years, starting from November 2012 to October 2017. Inclusion criteria for the cases were screened for MRSA colonization upon admission, underwent appropriate decolonization procedure following detection of MRSA and remained with cardiothoracic follow-up post-surgery, for at least a month after the surgical procedure. Decolonization protocol practised by our infection control unit was the application of mupirocin ointment for nasal colonization and chlorhexidine bath for axilla and groin colonization. Results: Three hundred and fifty-eight CVTS patients were admitted for procedures during the five-year study. We identified six MRSA carriers, pre-operatively colonized at either their nose, groin or axilla. This gives an overall MRSA carrier rate of 1.7%. The majority of them, which were four patients or 67% of MRSA carriers, were colonized at their nasal sites. One patient was colonized at groin and the other one at axilla. All carriers had single-site colonization, none with multiple-sites colonization. They all successfully underwent decolonizing procedure as per protocol. Consecutively, none of the carriers developed surgical site infection (SSI) due to MRSA within a month following surgery, giving an MRSA infection rate of 0%. Conclusion: Our centre's MRSA carrier rate of less than 2% among the CVTS patients is generally lower than that reported from other similar cohorts of patients from various institutions. This, coupled with an effective decolonization protocol, appeared to have contributed to the absence of SSI due to MRSA in these patients for the past five years. The application of this ‘MRSA search and destroy’ strategy contributes not only to life-saving, but also financial saving in the long run.

2080 Implementing and evaluating an evidence-based intervention from the intensive care unit (ICU) setting into primary care using promotoras to reduce CA-MRSA recurrence and household transmission

OBJECTIVES/SPECIFIC AIMS: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) skin and soft tissue infections (SSTIs) recurrence ranges from 16% to 43% and presents significant challenges to clinicians, patients, and families. This comparative effectiveness research study aims to disseminate, implement and evaluate whether an existing intervention, consisting of decolonization and decontamination procedures, which has been determined to be effective in hospital intensive care unit settings, can be implemented by Community Health Workers (CHWs) or “promotoras” conducting home visits prevent recurrence of CA-MRSA and transmission within their households for patients presenting to primary care with SSTIs. METHODS/STUDY POPULATION: In partnership with 3 Community Health Centers and 4 community hospitals in NYC, this study will recruit patients (n=278) with confirmed MRSA SSTIs and their household members. Participants are randomized to receive either a CHW/Promotora-delivered decolonization-decontamination intervention or usual care, which includes hygiene education. The highly engaged stakeholder team meets monthly to review interim results, identify areas for refinement and new research questions, and develop and implement strategies to improve participant engagement and retention. RESULTS/ANTICIPATED RESULTS: MRSA and MSSA were found in 19% and 21.1% of wound cultures, respectively. 59.5% with MRSA+ wound culture had one or more MRSA+ surveillance culture; 67.8% with MSSA+ wound culture had one or more MSSA+ surveillance culture. The “warm handoff” approach, developed and implemented by the stakeholder team to engage patients from their initial consent to return of lab results and scheduling of the home visits, helped improve completion of baseline home visits by 14%, from 45% to 59% of eligible participants. Home visits have demonstrated that 60% of households had at least one surface contaminated with S. aureus. Of the surfaces that tested positive in the households, nearly 20% were MRSA and 81% were MSSA; 32.5% of household members had at least one surveillance culture positive for S. aureus (MRSA: 7.7%, MSSA: 92.3%). DISCUSSION/SIGNIFICANCE OF IMPACT: This study aims to understand the systems-level, patient-level, and environmental-level factors associated with SSTI recurrence and household transmission, and to examine the interactions between bacterial genotypic and clinical/phenotypic factors on decontamination, decolonization, SSTI recurrence and household transmission. This study will evaluate the barriers and facilitators of implementation of home visits by CHWs in underserved populations, and aims to strengthen the weak evidence base for implementation of strategies to reduce SSTI recurrence and household transmission.

Determinants of the Nasal Microbiome: Pilot Study of Effects of Intranasal Medication Use.

IntroductionA role for bacteria and other microbes has long been suspected in the chronic inflammatory sinonasal diseases. Recent studies utilizing culture-independent, sequence-based identification have demonstrated aberrant shifts in the sinus microbiota of chronic rhinosinusitis subjects, compared with ostensibly healthy controls. Examining how such microbiota shifts occur and the potential for physician-prescribed interventions to influence microbiota dynamics are the topics of the current article.MethodsThe nasal cavity microbiota of 5 subjects was serially examined over an 8-week period using pan-bacterial 16S rRNA gene sequencing. Four of the subjects were administered topical mometasone furoate spray, while 1 subject underwent a mupirocin decolonization procedure in anticipation of orthopedic surgery.ResultsMeasures of microbial diversity were unaffected by intranasal treatment in 2 patients and were markedly increased in the remaining 3. The increase in microbial diversity was related to clearance of Moraxella spp. and a simultaneous increase in members of the phylum Actinobacteria. Both effects persisted at least 2 weeks beyond cessation of treatment. Transient changes in the relative abundance of several bacterial genera, including Staphylococcus and Priopionibacteria, were also observed during treatment.ConclusionsThe effects of intranasal steroids on the sinonasal microbiome are poorly understood, despite their widespread use in treating chronic sinonasal inflammatory disorders. In this longitudinal study, administration of intranasal mometasone furoate or mupirocin resulted in shifts in microbial diversity that persisted to some degree following treatment cessation. Further characterization of these effects as well as elucidation of the mechanism(s) underlying these changes is needed.

Comparing a single-day swabbing regimen with an established 3-day protocol for MRSA decolonization control

ObjectivesSuccess of methicillin-resistant Staphylococcus aureus (MRSA) decolonization procedures is usually verified by control swabs of the colonized body region. This prospective controlled study compared a single-day regimen with a well-established 3-day scheme for noninferiority and adherence to the testing scheme. MethodsTwo sampling schemes for screening MRSA patients of a single study cohort at a German tertiary-care hospital 2 days after decolonization were compared regarding their ability to identify MRSA colonization in throat or nose. In each patient, three nose and three throat swabs were taken at 3- to 4-hour intervals during screening day 1, and in the same patients once daily on days 1, 2 and 3. Swabs were analysed using chromogenic agar and broth enrichment. The study aimed to investigate whether the single-day swabbing scheme is not inferior to the 3-day scheme with a 15% noninferiority margin. ResultsOne hundred sixty patients were included, comprising 105 and 101 patients with results on all three swabs for decolonization screening of the nose and throat, respectively. Noninferiority of the single-day swabbing scheme was confirmed for both pharyngeal and nasal swabs, with 91.8% and 89% agreement, respectively. The absolute difference of positivity rates between the swabbing regimens was 0.025 (−0.082, 0.131) for the nose and 0.006 (−0.102, 0.114) (95% confidence interval) for the pharynx as calculated with McNemar's test for matched or paired data. Compliance with the single-day scheme was better, with 12% lacking second-day swabs and 27% lacking third-day swabs from the nostrils. ConclusionsThe better adherence to the single-day screening scheme with noninferiority suggests its implementation as the new gold standard.