Background: Methicillin-resistant S. aureus (MRSA) is known to cause frequent and severe infections in community living centers, potentially resulting in significant mortality for elderly patients. More research is needed to understand how to utilize genomic and epidemiological data to understand characteristics that may lead to increased transmission. We hypothesized that combining genomic and epidemiological information to sample patients and their environments during long-term stays, we will be able to capture a diverse set of MRSA strains. Method: This work included genome sequencing of patient and environmental samples from 11 patients within the VA Ann Arbor Healthcare System from May 4, 2021- November 16, 2022. All 11 patients tested positive for MRSA during their stay (mean days = 31). Patient and environmental samples were taken throughout their stays, screened for MRSA, and whole-genome sequenced. Single nucleotide variants (SNVs) were identified by mapping reads and calling variants against strain-specific reference genomes. We used ape v5.6-2 in R v4.2.2 to analyze and infer evolution, acquisition, and transmission events based on pairwise SNV distances. Genomic clusters were determined using stats v3.6.2, with a SNV distance threshold of 20. Result: Samples that were collected from patient bodily sites were able to reveal 20 distinct genomic clusters of MRSA (patient hands: n = 10, nares: n = 7, groin: n = 3). Environmental samples from patient environments also revealed distinct genomic MRSA clusters (tv remote: n = 9, toilet seat and bed rail: n = 6, table top, bed control, and call button: n = 5, bed curtain: n = 4, pulse ox = 2, cell phone, tray, pulse ox, mat, body hoist wrap, and bed: n = 1). Conclusion: The identification of various genomic clusters from patients and their environmental reservoirs suggests intrahost variation that can only be captured by using a more holistic approach of integrating epidemiology and genomic sequencing. Developing studies that incorporate genomic data, various environmental sources, and multiple isolates over time within community living centers can increase our understanding of strains that are more likely to transmit, survive on living and non-living surfaces and therefore lead to improved recommendation for infection prevention interventions and drivers of endemicity.

Disclosure: Lona Mody: NIH, VA, CDC, Kahn Foundation; Honoraria: UpToDate; Contracted Research: Nano-Vibronix

Background: Nursing homes (NHs) have high prevalence of multi-drug resistant organisms (MDROs) with rates exceeding those in hospitals. This study proposes quantifying patients’ risk of MDRO colonization and creating a risk profile for the NH patient populations to assist in reducing MDRO burden in health care facilities. Methods: We assessed a risk classification model using data from a prospective cohort study (2018 Pathways study). Patient sample included 783 newly admitted patients followed for up to 180 days and 9,587 samples collected from patients during 2,089 visits. Individual risk factors of MDRO colonization were assessed using unadjusted logistic regression, and patients were risk classified based on number of risk factors. Multivariate regression was performed to obtain odds of MDRO colonization for patient risk groups adjusting for patient age, sex, race, and length of NH stay (LOS). The risk classification tool developed using Pathways data was also tested among a sample of NH residents from Veterans Administration (N=190). Results: The patient sample (Pathways data) was 43.2% male, 37.2% Black with a mean age 74 years. 69.3% were colonized with a MDRO during the study. In unadjusted regression, recent antibiotic use (p<.001), open wounds (p<.05), use of urinary catheter or feeding tube (p<.001), functional disability (p<.001), diabetes (p<.01), and preadmission hospital stay over 14 days (p<.001) were associated with colonization, while Charlson comorbidity score, age, sex, and race were not. In adjusted analysis (c-statistic=0.75), a patient’s colonization risk increased with the number of risk factors (Figure 1), with 47.2% expected colonization among patients with none of the risk factors and 86.7% expected colonization among patients with four or more risk factors. The risk classification model had similar performance among male and female patients, and among Black and White patients (Figure 2). Secondary analysis using data obtained from separate, Veterans Administration facilities provided preliminary validation of the risk scoring tool. The model had acceptable fit (c-statistic=0.71). Veterans with four or more risk factors had 87.8% expected probability of MDRO colonization compared with 39.6% colonization among those without any risk factors. Veterans with less than four risk factors also had higher colonization, but these differences were not statistically significant. Conclusions. Despite system-wide efforts to reduce MDRO burden, prevalence of MDRO colonization remains high in NHs. The risk classification tool can assist in early identification of most vulnerable NH patients to direct targeted interventions such as education, enhanced environmental cleaning, and active surveillance.

Disclosure: Lona Mody: NIH, VA, CDC, Kahn Foundation; Honoraria: UpToDate; Contracted Research: Nano-Vibronix

Background: Veterans Health Administration (VHA) community living centers (CLCs) provide postacute and long-term care. CLC veterans visit myriad locations outside their rooms (eg, rehabilitation, dialysis). Pathogen transmission during out-of-room visits is unknown. Methods: We recruited newly admitted veterans at 3 CLCs. After obtaining informed consent, we cultured nares, groin, hands, and 7 surfaces in the patient rooms. We accompanied veterans to up to 5 out-of-room visits and cultured patients’ hands and surfaces they touched. We tested for multidrug-resistant organisms (MDROs) including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and quinolone, carbapenem, and/or ceftazidime-resistant gram-negative bacteria (R-GNB). We defined transmission as a positive culture following an initial negative culture during the same visit. Results: We enrolled 137 veterans (median follow-up, 29 days; mean, 5.9 visits); 97% were postacute patients. We conducted 539 patient-room sampling visits (mean, 3.9 per veteran; 5,490 swabs) and accompanied 97 veterans to 266 out-of-room sampling visits (mean, 2.7 per veteran; 2,360 swabs). Of 137 patients, 47 (35%) were colonized with an MDRO at enrollment and 74 (58%) of 128 patients were colonized on any follow-up patient-room visits. Of 133 patients, 55 (41%) acquired a new MDRO, most often VRE (31 of 97, 32%). In patient rooms, toilet seats [114 (21%) of 538], curtains [101 (19%) of 530] and bedrails [98 (18%) of 539] were most frequently contaminated. Among 266 out-of-room visits, 17% had surfaces contaminated with MDROs, most commonly involving dialysis [4 (31%) of 13], radiology [2 (25%) of 8], and rehabilitation therapy [29 (18%) of 159] (Fig. 1).Transmission of MDROs during out-of-room visits was common and occurred in 18% of visits with 8% (9 MRSA and 12 VRE) acquiring a new MDRO on their hands and 12% (9 MRSA and 23 VRE) of MDRO transmission occurring from hands to a surface that the patient touched (Fig. 1). In 18 (58%) of 31 cases, the organism transmitted to a surface was on patient hands at the start of the visit. Transmission was most common during visits to dialysis (3 to patients and 2 to surfaces), radiology (1 to a patient and 2 to surfaces), and rehabilitation therapy (13 to patients and 21 to surfaces) (Fig. 2). Conclusions: New MDRO acquisition during VHA CLC stay was common, and nearly one-fifth of out-of-room visits resulted in MDRO transmission. Our analyses suggest that veterans’ hands may shed MDROs (MRSA and VRE) to surfaces. Interventions to reduce MDRO transmission during visits for rehabilitation, dialysis, and other therapies are needed.

Disclosures: None

Background and objectives: Patients with functional disabilities are at higher risk of adverse outcomes, including infections. Although healthcare worker hand contamination has long been recognized as an important source of pathogen acquisition, the role of patient hands has been less clearly defined. We sought to determine whether the presence of functional disabilities is correlated with patient hand contamination by multidrug-resistant organisms (MDROs) and thus a potential target for patient hand hygiene (PHH) interventions. Methods: Case–control study of hand contamination with methicillin-resistant S. aureus, vancomycin-resistant enterococci, and gram-negative bacilli resistant to cephalosporins, fluoroquinolones, and/or carbapenems in 2 acute-care hospitals in southeastern Michigan. Cases (n = 40) and controls (n = 359) were defined as patients with or without hand contamination by MDROs, respectively. We assigned 3 exposure categories based on Katz activities of daily living scores: no functional disabilities (independent, reference group), 1–3 functional disabilities (partially dependent), and 4+ functional disabilities (dependent). We used stepwise logistic regression to identify confounding variables. Logistic regression was then used to establish the relationship between a patient’s functional dependence level and their hand contamination by MDROs. Results: The distribution of hand contamination of each target MDRO by level of patient dependence is shown in the Table. Overall, methicillin-resistant Staphylococcus aureus (MRSA) was the most represented, followed by resistant gram-negatives and vancomycin-resistant enterococci (VRE). Hospital site, sex, and history of MDROs were included in the model based on stepwise regression. The odds ratio (OR) of MRSA hand contamination in the dependent category was 3.19 (95% CI, 1.18–5.54) compared to the independent category, and for any MDRO the OR was 2.77 (95% CI, 1.22–6.32) (Fig. 1). The OR of MRSA hand contamination in the partially dependent category was 1.38 (95% CI, 0.27–7.07) compared to the independent group, and for any MDRO the OR was 0.86 (95% CI, 0.24–3.10) (Fig. 1). Feeding dependence had the highest single association with hand contamination (OR, 3.79, 95% CI, 1.26–11.43), with dressing dependence having the second highest association with hand contamination (OR, 2.82; 95% CI, 1.31–6.05) (Fig. 2). Conclusions: Patients with more functional dependencies were more likely to have MDRO hand contamination. This finding suggests a need for targeted PHH interventions in patients with functional disabilities to help prevent the spread of MDROs in the acute-care setting.

Disclosures: None

Background: Persistent colonization with resistant gram-negative bacteria (R-GNB) increases risk of clinical infection and intra-facility transmission among nursing home (NH) patients. Limited data exist on the roles of age and function on duration of R-GNB colonization. Methods: Secondary data analysis was performed from a cohort study of patients admitted to 6 Michigan NHs between November 2013 and May 2018. Swabs obtained upon enrollment, day 14, day 30, then monthly until NH discharge from 6 anatomical sites were cultured for GNB. R-GNB were defined as resistant to ciprofloxacin, ceftazidime, or imipenem. Positive R-GNB culture from a single visit followed by negative cultures for the same organism from ≥2 subsequent visits were defined as transient R-GNB colonization. All other patients with positive R-GNB cultures from multiple visits were considered persistently colonized. Demographic data, antibiotic use, device use, and physical self-maintenance scales (PSMSs) were obtained upon enrollment. Characteristics were compared between patients with transient versus persistent R-GNB and uncolonized patients using multinomial logistic regression. Results: We recruited 896 patients (median age, 75 years; 41% male; 46% nonwhite) and followed them for 2,437 total visits. Of 896 patients, 407 (45.4%) were colonized with ≥1 R-GNB during their stay. Of 171 patients with ≥ 2 follow-up visits after R-GNB detection, 94 (55%) remained persistently colonized with the same R-GNB (Table 1). Escherichia coli (30%) and Proteus mirabilis (22%) were the most frequently identified R-GNB. The most common anatomical colonization sites were perirectal (368 [24.3%] of 1,147) groin (340 [14.3%] of 2,046), and hands (115 [4.8%] of 2283). Compared to uncolonized patients, patients with persistent (1.09; 95% CI, 1.00–1.19, P = .048) and transient R-GNB colonization (1.13; 95% CI, 1.04–1.23; P = .003) had lower PSMS (Tables 2 and 3). Compared to uncolonized and transiently colonized patients, patients with persistent R-GNB colonization had prolonged lengths of NH stay (1.01; 95% CI, 1.00–1.01; P = .003). Conclusions: R-GNB colonization in vulnerable NH patients is common (407 [45.5%] of 896 and often persistent (94 [55%] of 171 patients with sufficient follow-up to assess persistence). Patients with persistent R-GNB had lower functional status, longer LOS, and higher readmission rates than those without. R-GNB decolonization should be investigated as a strategy to potentially improve outcomes among NH patients.

Funding: None

Disclosures: None

Background: Face masks have been worn universally and for long periods of time by healthcare personnel during the COVID-19 pandemic. They are frequently touched or adjusted with the hands and may come in contact with various surfaces and high-touch sites when taken off and on even briefly. These activities present opportunities for face masks to become contaminated with microorganisms. Nursing homes have high rates of multidrug-resistant bacteria and low PPE compliance; therefore, contamination of face masks in this setting may be of great interest. We investigated bacterial colonization status on used face masks in healthcare personnel, including assessing the presence of clinically important and multidrug-resistant bacteria. Methods: At a nursing home serving mostly post–acute-care patients, we collected 69 face masks from personnel at the end of the user’s work shift. Information about the mask and the user was also collected via a self-reported survey. Face masks were incubated in BHI broth overnight at 36°C and 10 μL was then plated on selective and differential plates. Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and gram-negative bacteria (GNB) resistant to several antibiotic classes were identified using standard microbiological methods. Resistance testing for cefoxitin (S. aureus), ciprofloxacin, meropenem, tetracycline, erythromycin, gentamicin, trimethoprim–sulfamethoxazole, and ceftazidime with and without clavulanic acid (gram-negative bacteria) was performed using the disc diffusion technique on Mueller-Hinton plates (Kirby Bauer). Results: The job categories of face mask users were competency-evaluated nursing assistant or nursing assistant (22.73%), nurse (12.12%), and other or administrative (37.88%). Overall face mask contamination rates for MRSA (0%) and VRE (3.3%) were low; however, methicillin-susceptible S. aureus was found on 11 masks (15.9%). High contamination and resistance rates were found for gram-negative bacteria, with 113 isolates. Among them, 69 (60.9%) were resistant to at least 1 antibiotic, most commonly was erythromycin (59.4%). Additionally, higher rates of clinically important pathogenic gram-negative bacteria were identified: 14.3% of masks were contaminated with Klebsiella pneumoniae, 13.0% were contaminated with Enterobacter spp, and 4.2% were contaminated with Escherichia coli. Importantly, there were no significant differences in the total number of isolates of potential clinical significance recovered from masks worn >6 hours versus those worn <6 hours. Conclusions: Among nursing-home healthcare workers, face masks were often contaminated with multiple organisms, including potentially pathogenic bacteria and antibiotic-resistant gram-negative organisms. This contamination may pose a risk for transmission if face masks are not properly used and/or disposed of after wearing. Prolonged duration of face-mask wearing, however, was not associated with increased contamination rates.

Funding: None

Disclosures: None

Background: Transmission of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) is of special concern among frail patients in nursing homes. To understand environmental contamination patterns in this setting, we screened a suitable section of a nursing home over time and assessed MRSA and VRE prevalence in patients and their rooms. We were especially interested in assessing whether MRSA and VRE strains persist in rooms during changes of occupancy after patient discharge. Methods: We conducted a prospective cohort study of MRSA and VRE colonization and contamination among successive patients in a cluster of 9 single-occupancy rooms. Using flocked swabs, 5 high-touch surfaces were screened 3 times a week for 34 weeks. Patients were also screened (ie, nares, groin, and hands), if they agreed to participate. Whole-genome sequencing was performed on 67 nonredundant MRSA and VRE strains. Single-nucleotide polymorphism heatmaps and similarity trees were generated to evaluate strain diversity and persistence the facility. Results: Overall, 146 distinct occupancy events were captured during the study (16.5 average per room; range, 11–22), with 387 study visits and 4,670 total swabs collected. All rooms were contaminated with VRE, and 8 of 9 were contaminated with MRSA at least once during the study period. New contamination of a room with MRSA or VRE was observed in 43 (23%) of 185 opportunities, with potential persistence during occupancy changes in 25 (32.9%) of 76 opportunities. Sequencing of 67 nonredundant isolates identified at least 6 enterococcal clades and 10 MRSA clades (6 USA100 and 4 USA300), indicating a high degree of diversity and probably multiple introductions in the facility during the study time. In 3 separate cases, whole-genome sequencing confirmed persistence of a specific MRSA strain during a change of room occupancy, including 1 case of a MRSA strain persisting in a clean room before admission of the next patient. For VRE, 2 cases of persistence during room occupancy changes were confirmed, along with 6 cases of possible persistence (contamination across noncontiguous room occupancy events). Conclusions: Active surveillance screening and a recurring evaluation of terminal cleaning procedures should be considered due to high levels of circulation and persistence of MRSA and VRE in the nursing home setting.

Funding: None

Disclosures: None

Perianal screening can be intrusive. The sensitivities of multianatomical, nonperianal surveillance were 92.3% for methicillin-resistant Staphylococcus aureus (MRSA), 58.7% for vancomycin-resistant enterococci (VRE), and 54.9% for resistant Gram-negative bacilli (R-GNB). Sensitivities improved upon adding environmental surveillance (95.5%, 82.9%, and 67.9%, respectively). Multianatomical, nonperianal screening and room environment surveillance may replace perianal screening and reduce healthy participant bias in nursing homes.

Background: Although active surveillance for multidrug-resistant organism (MDRO) colonization permits timely intervention, obtaining cultures can be time-consuming, costly, and uncomfortable for patients. We evaluated clinical differences between patients with and without attainable perianal cultures, and we sought to determine whether environmental surveillance could replace perianal screening. Methods: We collected active surveillance cultures from patient hands, nares, groin, and perianal area upon enrollment, at day 14, and monthly thereafter in 6 Michigan nursing homes. Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and resistant gram-negative bacilli (RGNB) were identified using standard methods. Patient characteristics were collected by trained research professionals. This substudy focused on visits during which all body sites were sampled. To determine the contribution of perianal screening to MDRO detection, site of colonization was categorized into 2 groups: perianal and non-perianal. We evaluated the utility of multisite surveillance (eg, type 1 and type 2 error) using nonperianal sites and environment surveillance. To evaluate characteristics associated with the acquisition of perianal cultures (eg, selection bias), we compared clinical characteristics, overall patient colonization, and room environment contamination of patients in whom all body sites were sampled during a study visit (533 patients; 1,026 visits) to patients with all body sites except the perianal culture sampled during a study visit (108 patients; 168 visits). Results: Of 651 patients, 533 met the inclusion criteria; average age was 74.5 years, 42.6% were male, and 60.8% were white. Of 1,026 eligible visits, 620 visits detected MDRO colonized patients; 155 MRSA, 363 VRE, and 386 RGNB (Table 1). If perianal cultures were not collected, nonperianal surveillance misses 7.7%, 41.3%, and 45.1% of MRSA, VRE, and RGNB colonized visits, respectively. The addition of environmental surveillance to non-perianal screening detected 95.5%, 82.9%, and 67.9% of MRSA, VRE, and RGNB colonized visits, respectively. The specificity of environmental screening was 85.3%, 72.7%, and 73.4% for MRSA, VRE, and RGNB, respectively. Patients without attainable perianal cultures had significantly more comorbidities, worse functional status, shorter length of stay, and higher baseline presence of wounds than patients with attainable perianal cultures; introducing potential selection bias to surveillance efforts (Table 2). No significant differences in overall patient colonization and room contamination were noted between patients with and without attainable perianal cultures. Conclusion: Perianal screening is important for the detection of VRE and RGNB colonization. Infection prevention must be cognizant of the tradeoff between reducing type 2 error and the selection bias that occurs with required attainment of perianal cultures. In the absence of perianal cultures, environmental surveillance improves MDRO detection while introducing type 1 error.

Funding: None

Disclosures: None

Background: Methicillin-resistant Staphylococcus aureus (MRSA) colonization of patients and contamination of their immediate environmental surfaces is common in the acute care setting, but there is much to be learned about the dynamics of MRSA transmission over a short period of time. Methods: A prospective, observational time-motion qualitative study was conducted at 2 hospitals: 1 in Michigan (hospital 1) and 1 in Zurich, Switzerland (hospital 2)—between November 2018 and July 2019. Hospitalized patients with a MRSA infection or colonization were enrolled. Microbiologic cultures for MRSA were collected from patient nares, axilla, groin and hands and several high-touch surfaces in their room (bed controls, call button, tray table, etc) at the first visit, and patient hands and high-touch surfaces continued to be swabbed every 90 minutes over the course of 5 hours. Patient hands and environment were disinfected after each swabbing. Clinical data were collected from patient’s medical chart. Results: We recruited 10 MRSA colonized or infected patients for the study with 50 hours of observation and obtained 360 patient and environmental swabs. Most were women (7 of 10); the average age was 52.8 years (Table 1). At the first visit, 8 (80%) patients were MRSA-colonized (at 1 or more body sites) and 5 (50%) rooms were MRSA-contaminated (at 1 or more surfaces). Also, 6 patients (60%) had an active MRSA infection and were actively receiving an anti-MRSA agent (eg, Vancomycin). Among those 6 patients receiving an anti-MRSA agent, 4 patients (67%) and 2 rooms (33%) were contaminated at the first visit. Among those 4 patients not receiving an anti-MRSA agent, all 4 patients (100%) and 3 rooms (75%) were contaminated at the baseline visit. Acquisitions (ie, MRSA recovered from a site it was not previously recovered from) occurred on 3 of 7 patient hands (43%) and on 6 occasions in the room (among 5 patients), most commonly at the toilet seat (2 of 6 times). MRSA prevalence on patient and room surfaces for the 5 patients enrolled at hospital 2 are illustrated in Figure 1, which shows colonization of patient and contamination of environment as well as activities performed by the patient in between culturing. Conclusions: We evaluated transmission of MRSA over brief periods of time; our results show that transmission of MRSA depended on patient activity in the room. Furthermore, degree of patient colonization is reflected by environmental contamination and supports the notion of constant transmission of MRSA from patients to environment.

Funding: None

Disclosures: None

OBJECTIVES/GOALS: We investigated the association between gut microbiota features in newly admitted nursing facility (NF) patients and the acquisition of vancomycin-resistant Enterococcus (VRE) and/or resistant Gram-negative bacteria (rGNB) within 14 days. METHODS/STUDY POPULATION: Patients were recruited at 6 Michigan NFs from 09/16-08/18. VRE or rGNB colonization status was determined by culture swabs collected from multiple body sites at enrolment, day 7, and day 14. Our analysis focused on patients with no colonization at baseline, a perirectal swab collected at baseline, and at least one follow-up visit. The V4 hypervariable region of the 16S rRNA gene from bacterial DNA in each sample was PCR-amplified and sequenced on the MiSeq platform. Sequencing results were then processed with the mothur bioinformatics pipeline to classify bacterial taxa present in each sample. Taxa typically associated with the skin microbiota were removed. The primary outcome was acquisition of VRE and/or rGNB within 14 days. Exposures of interest included patient and microbiota characteristics. RESULTS/ANTICIPATED RESULTS: Among 61 patients, 18 (30%) acquired AROs within 14 days of enrolment (3 VRE, 13 rGNB, 2 both) (Table 1). The baseline microbiota features differed significantly in those who acquired a new ARO. Of the major 8 phyla found across samples, patients who acquired an ARO were depleted in the number of phyla present (5.74 ± 1.20 vs 5.06 ± 1.43; p = 0.037) (Fig. 1). The log10-transformed relative abundance of Enterococcus was enriched in patients who acquired an ARO (−0.32 ± 1.47) compared to those who did not (−1.68 ± 1.76; p = 0.021) (Fig. 2). Patients who did not acquire an ARO tended to harbour more butyrate-producing bacterial taxa and strict anaerobes, although the differences were not statistically significant (relative abundance of butyrate producer: 29.49 ± 22.09 vs 22.05 ± 17.76; anaerobes: 64.78 ± 23.54 vs 53.68 ± 27.61). DISCUSSION/SIGNIFICANCE OF IMPACT: Microbiota metrics calculated from perirectal samples are predictive of ARO acquisition. The clinical utility of perirectal samples thus warrants further assessment.

The role of demographic characteristics, such as sex and race, as risk factors for colonization with multidrug-resistant organisms, has not been established in the nursing home setting. We demonstrate significantly higher prevalence overall in male patients, and sex differences are dependent on organism of interest and body site.