Methicillin-resistant Staphylococcus Aureus Screening Research Articles

Molecular Determination of Resistance Gene in Methicillin Resistant Staphylococcus aureus (MRSA) Isolated from Skin and Wound

The wide spread use of antibiotic resulted in the development of resistance to antibiotics through acquisition of the mobile cassette chromosome carrying the Methicillin-resistant gene mecA. The study was aimed to characterize the resistance gene in Methicillin resistant Staphylococcus aureus (MRSA) isolated from skin and wound samples in Kano Metropolis, Northwestern, Nigeria. A total of 235 S. aureus isolates were identified and subjected to MRSA screening. MRSA were phenotypically identified by antibiotic susceptibility testing using agar disc diffusion method. The suspected MRSA were subjected to polymerase chain reaction (PCR). The PCR products were subjected to gel electrophoresis and a DNA ladder were loaded into the gel wells. The gel was examined for the presence of specific amplicons of the expected size for mecA, which is 192bp. Out of a total of 235 isolates of Staphylococcus aureus, only 11 (4.7%) strains were found to be Methicillin resistant Staphylococcus aureus (MRSA). Five out of the 11 isolates show the presence of DNA bands of the expected size for MecA gene which indicated the presence of the resistance genes in the bacterial isolates. It is concluded that MecA gene is one of the gene responsible for methicillin resistance in MRSA.

Addition of vancomycin to cefazolin is often unnecessary for preoperative antibiotic prophylaxis during total joint arthroplasties

PurposeThe gold standard to decrease total joint arthroplasty (TJA) periprosthetic joint infection (PJI) is preoperative antibiotic prophylaxis. Despite substantial prevention efforts, rates of PJIs are increasing. While cefazolin is the drug of choice for preoperative prophylaxis, adjunctive vancomycin therapy has been used in methicillin-resistant Staphylococcus aureus (MRSA) endemic areas. However, studies examining these combinations are lacking. Therefore, we sought to examine complications among vancomycin plus cefazolin and cefazolin-only recipients prior to primary TJA in a single institutional sample and specifically assessed: (1) microbiological aspects, including periprosthetic joint and surgical site infections, microbes cultured from the infection, and frequency of microbes cultured from nasal swab screening; (2) 30-day emergency department (ED) visits and re-admissions; as well as (3) associated risk factors for infection.MethodsA total of 2,907 patients (1,437 receiving both cefazolin and vancomycin and 1,470 given cefazolin only) who underwent primary TJA between 1 January 2014 and 31 May 2021 were identified. SSI and PJI as well as rates of cultured microbes rates were obtained through one year, those with prior nasal swab screening and 30-day re-admission were identified. Subsequently, multiple regression analyses were performed to investigate potential independent risk factors for PJIs.ResultsThere was no significant difference in the rates of SSI (P = 0.089) and PJI (P = 0.279) between the groups at one year after operation. Commonly identified organisms included Staphylococcus and Streptococcus species. The VC cohort did have a greater reduction of MRSA in the previously nasal swab-screened subset of patients. Multiple regression analyses demonstrated emergency as well as inpatient admissions as risk factors for PJI.ConclusionsAdjunctive vancomycin therapy offers increased protection against MRSA in previously screened individuals. However, those negative for MRSA screening do not require vancomycin and have similar protection to infection compared to recipients of cefazolin only in a high-powered single institution analysis in an MRSA endemic area.

Assessing the Concordance of MRSA Carriage Screening With MRSA Infections.

This study focused on children with confirmed methicillin-resistant Staphylococcus aureus (MRSA) infections to determine MRSA screening utility in guiding empirical anti-MRSA treatment of children without history of MRSA infection. We examined the concordance of screens to assess differences by infection type and used statistical analysis to determine significant contributors to concordance. Pediatric hospital patients admitted from 2002 through 2022 were included. Subjects had MRSA infections subsequent to MRSA surveillance screens performed the preceding year. Statistical analysis identified associations between MRSA screens and infections. Number needed to treat analysis calculated the utility of rescreening. Among 246 subjects, 39.0% had concordant screens; 151 (61.4%) screens were obtained in the 2 weeks preceding infection. Sensitivity for bacteremia was 50.0% (n = 42), for endotracheal/respiratory 44.4% (n = 81), and 29.4% (n = 102) for skin and soft-tissue infection. For children aged younger than 6 months, sensitivity was 35.9% (n = 78). Multivariable analysis significantly associated days since screening with decreasing likelihood of concordance. Regression modeled the probability of concordance to drop below 50.0% for all infections after 4 days, after 6 days for bacteremia specifically, and 12 days for endotracheal/respiratory infections. The concordance of screens was far lower than negative predictive values found previously; earlier studies were possibly impacted by low prevalence and exclusion of children at high risk to inform high negative predictive values. We suggest that negative MRSA screens should not invalidate reasonable suspicion for MRSA infection in patients with high pretest probabilities.

Prevalence of Methicillin Resistant Staphylococcus aureus Colonisation in Patients undergoing Total Joint Arthroplasty: A Retrospective Observational Study

Introduction: Methicillin Resistant Staphylococcus aureus (MRSA) presents a significant, yet preventable, complication in Total Joint Arthroplasties (TJAs). Surgical Site Infections (SSIs) of prosthetic joints resulting from MRSA lead to substantial patient morbidity, mortality, and impose a significant burden on healthcare budgets. One method to mitigate these risks is to screen for MRSA colonisation prior to elective surgeries. The prevalence of MRSA colonisation in nasal mucosa ranges from 0.18-7.2% in different patient populations, with a nosocomial prevalence of 1.7%. Aim: To determine the prevalence of MRSA colonisation in all patients undergoing elective TJA, including Total Hip Replacement (THR) or Total Knee Replacement (TKR). Materials and Methods: A retrospective observational study was conducted on a total of 407 patients scheduled for elective TJAs. Data from 407 patients who underwent elective TJA between January 2020 and December 2022 (a period of three years) were selected for the study. Data compilation and analysis of the study subjects were performed retrospectively until March 2023 at the Sanjay Gandhi Institute of Trauma and Orthopaedics, a tertiary care Orthopaedic centre in Bengaluru, Karnataka, India. The study subjects were screened for MRSA colonisation through nasal swab culture and sensitivity. Patients with positive MRSA culture results were treated with decolonisation therapy, which involved the local application of 2% mupirocin and chlorhexidine body wash for five days. Descriptive data analytics were employed in the study, and tables were generated using Microsoft Word 2010 and Microsoft Excel 2010 (Microsoft Corp, Redmond, WA, USA). Results: The prevalence rates of MRSA nasal colonisation were n1=8 (8.42%), n2=2 (2%), and n3=16 (7.55%) for the years 2020 (n1), 2021 (n2), and 2022 (n3), respectively, at the centre. The period prevalence rate of MRSA colonisation in the nasal mucosa over three years was N=26 (6.4%). Conclusion: The present study revealed a high period prevalence of MRSA colonisation (6.4%) in patients undergoing TJAs. Therefore, all elective TJAs should undergo MRSA screening and decolonisation using 2% intranasal mupirocin and daily chlorhexidine body wash for five days as a successful treatment modality for all patients with MRSA-positive nasal colonisation. This approach helps prevent postoperative SSIs caused by MRSA.

Evaluation of PhenoMATRIX and PhenoMATRIX PLUS for the screening of MRSA from nasal and inguinal/perineal swabs using chromogenic media.

The objective of this study was to assess the clinical performances of PhenoMATRIX and PhenoMATRIX PLUS for the screening of methicillin-resistant Staphylococcus aureus (MRSA) from nasal and inguinal/perineal ESwabs using chromogenic media. The automated performances were compared to the manual reading. Additionally, we evaluated PhenoMATRIX PLUS for the automatic release of the negative results to the Laboratory Information System (LIS) and the automatic discharge of the negative plates from the incubators. A total of 6,771 non-duplicate specimens were used by PhenoMATRIX as a machine learning model. The validation of these settings was performed on 17,223 non-duplicate specimens. The MRSA positivity rate was 5% (866/17,223). Validated settings were then used by PhenoMATRIX PLUS on another 1,409 non-duplicate specimens. The sensitivities of PhenoMATRIX and PhenoMATRIX PLUS were 99.8% [95% confidence interval (CI), 99.2%-99.9%] and 100% (95% CI, 92.1%-100%), respectively. The specificities of PhenoMATRIX and PhenoMATRIX PLUS were 99.1% (95% CI, 99.0%-99.2%) and 95.2% (95% CI, 93.8%-96.1%), respectively. All the 1,297 MRSA-negative specimens analyzed by PhenoMATRIX PLUS were automatically released and sent to the LIS immediately after availability of the culture image on the WASPLab (100% accuracy). All negative media plates were automatically discarded. PhenoMATRIX PLUS decreases the time spent by technologists on negative plates and ensures optimal usage of the incubators' capacity.

Nasal Methicillin-Resistant Staphylococcus aureus Culture Screens in the Setting of Universal Decolonization

Introduction The negative predictive value (NPV) of nasal methicillin-resistant Staphylococcus aureus (MRSA) screens has been compromised by universal decolonization practices. We aimed to determine the reliability of the nasal MRSA culture screen to deescalate antibiotic therapy in the setting of decolonization with ethyl alcohol. Methodology A retrospective observational cohort study was conducted using 62% ethanol solution intranasally per protocol. Patients were divided into 2 groups based on whether they received decolonization. Data were analyzed to determine NPV of the nasal MRSA culture screen with and without decolonization. Results A total of 505 cases were screened, and 128 subjects were included. One hundred two received decolonization, whereas 26 did not. Baseline characteristics were well balanced. Overall MRSA infection prevalence was 31.25%. The NPV was 73% in the decolonized group compared with 80% in the group without. Positive predictive value was 63% in the group receiving decolonization compared with 100% in the group without. There was also a higher specificity but lower sensitivity of the nasal MRSA culture screen in the decolonization group. Nine patients in the decolonization group required reescalation of antibiotics compared with nil in the other group. Conclusions Culture-based nasal MRSA screens are less accurate than PCR tests, as ethyl alcohol leads to false-negative results. A lower NPV in the decolonization group predisposes to increased false negative results, leading to inappropriate antibiotic deescalation and often requiring reinitiation. Nasal MRSA culture screen is less reliable if alcohol has already been administered for decolonization and cannot be used as an appropriate tool to guide antibiotic deescalation.

1703. Pseudo-Outbreak of Methicillin-Resistant Staphylococcus aureus in a Neonatal Intensive Care Unit: Implications for Surveillance

Abstract Background We conduct weekly surveillance screening for methicillin-resistant Staphylococcus aureus (MRSA) in our neonatal intensive care unit (NICU). In September 2021, we noted an increase in positive MRSA screening results and identified 2 patients with MRSA wound infection. We conducted an investigation to explore the possibility of in-unit transmission. Methods We launched a multi-pronged investigation that included additional patient screening. Surveillance isolates were assessed for the presence of MRSA using chromogenic agar. Additional antimicrobial sensitivity testing was performed on an automated bacterial identification system if chromogenic agar results were inconclusive, fig 1 & 2. We also conducted audits of staff hand hygiene, enhanced cleaning and disinfection of shared patient-care equipment, implemented standardized chlorhexidine gluconate (CHG) scrub use for NICU staff upon unit entry, and added new CHG bathing for certain patients. Positive control chromogenic agar plate Ambiguous chromogenic agar results Results Over the course of a 6-week long investigation, 18 neonates were found to be MRSA-positive on surveillance swabs using chromogenic agar. In the first 2 weeks of the investigation, PFGE showed that 9 MRSA isolates were genetically distinct. Over the next weeks, additional MRSA-positive surveillance swabs were collected and ultimately 15 isolates underwent whole genome sequencing at the Mass. State Public Health Laboratory. Only 2 pairs of isolates appeared related. Antimicrobial resistance genes were identified and revealed only 6 of the 15 isolates contained the mecA gene consistent with MRSA. As a result, all 18 positive surveillance swabs obtained during the investigation underwent full identification and sensitivity testing confirming only 6 samples contained MRSA and 12 contained methicillin-sensitive Staphylococcus aureus (MSSA). Testing discordance with breakthrough MSSA growth was reported to the chromogenic agar manufacturer. Conclusion Our investigation identified that an increase in MRSA-positive surveillance swabs was a pseudo-outbreak due to false-positive MSSA growth on MRSA selective media. At the conclusion of this investigation, the need for ongoing surveillance swabs was re-evaluated and ultimately discontinued. Clinical NICU specimens are now monitored in real-time by Infection Control. Disclosures James Kirby, MD, D(ABMM), Abbott Molecular: Educational Grant

Prevalence of methicillin resistant staphylococcus aureus (MRSA) colonization in pregnant females visiting at tertiary care hospital in Northern Mumbai

Methicillin resistant s (MRSA) screening is a routine practice at many hospitals for high-risk patients. However, its incidence and clinical significance in expectant mothers are poorly understood. Hence, the purpose of the current study was to look at MRSA colonization rates in our obstetric population.Prospective study was conducted for three months from December 2019 to February 2020. MRSA screening samples from pregnant women at 32-34 weeks of gestation were collected after informed consent. All screening samples underwent standard microbiological analysis. Women who tested positive for MRSA received a decolonization program and their care was monitored.Total 78 mothers were included in the study. The rate of MRSA colonisation was 2.5% at 32 – 34 week of gestation. Decolonization protocol was advised for MRSA carriers.Our obstetric population has a low colonization rate for MRSA. Infections could be decreased with targeted antenatal MRSA screening and decolonization in women at high risk. Continued monitoring of MRSA infections in obstetric population and their infants is required.

IMPACT OF ACTIVE SURVEILLANCE SCREENING OF MRSA ON SURGICAL SITE INFECTION RATES- A PROSPECTIVE INTERVENTIONAL STUDY

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common cause of surgical site infections. Different methods are employed to reduce nosocomial spread including application of Isolation precautions, admission screening cultures and MRSA decolonization 3,4,5,6,7. Preoperative MRSA screening in patients undergoing cardiac surgeries can reduce the risk of surgical site infections. To evaluate the significance of preoperative MRSA screening on rates of surgical site infections in cardiac surgery patients Material and Methods: This was a prospective interventional study, conducted at the National Institute of Cardiovascular diseases, Karachi from 1st February 2022- 31st July 2022. Preoperative MRSA screening in patients undergoing cardiac surgeries was performed at the Microbiology Laboratory. Patients identified as colonized were isolated and decolonized with chlorhexidine baths prior to surgeries. Surgical site infections (SSIs) rates were recorded by Infection control nurse through active surveillance for the screening period. SSI rates for a prescreening period of 6 months (August 2021- January 2022) was retrieved through electronic medical records for comparison. Results: Total 359 patients were screened from 1st February 2022- 31st July 2022, out of which 20 were colonized with MRSA. None of the patients who screened positive for MRSA developed SSI. 11 SSIs with MRSA were reported from August 2021- January 2022 and 4 SSIs were reported from February 2022-July 2022 (p value < 0.05). Conclusion: It can be concluded that active MRSA screening and subsequent implementation of decolonization policy would decrease the percentage of SSI in cardiac surgery Keywords: MRSA, Screening, Surgical site infection, Surveillance

Using Methicillin-Resistant Staphylococcus aureus Nasal Screens to Rule Out Methicillin-Resistant S aureus Pneumonia in Surgical Intensive Care Units

IntroductionThe methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) has a high negative predictive value (NPV). We aimed to understand if there was a difference in the NPV of the MRSA screen in surgical intensive care units (ICUs) and to determine its role in antibiotic de-escalation. MethodsWe performed a single-center, retrospective cohort study of adults with a positive respiratory culture and MRSA nasal PCR admitted to a surgical ICU from 2016 to 2019. Patients were stratified by surgical ICU: cardiothoracic/cardiovascular intensive care unit (CVICU) or transplant/acute care surgery intensive care unit (ACS-ICU). Our primary outcome was the NPV of MRSA screen. Secondary outcome was the duration of empiric MRSA-targeted therapy. ResultsWe analyzed 61 patients: 42.6% (n = 26) ACS-ICU and 57.4% (n = 35) CVICU. There were no differences in age, comorbidities, prior MRSA infection, recent antibiotic use, immunocompromised status, or renal replacement therapy. At pneumonia diagnosis, more patients in the ACS-ICU were hospitalized ≥5 d (65.4% versus 8.6%, P < 0.0001) and more patients in the CVICU were in septic shock (88.6% versus 34.5%, P < 0.0001) and thrombocytopenic (40% versus 11.5%, P = 0.02). NPV of the PCR was similar (ACS-ICU: 0.92 [0.75-0.98], CV-ICU 0.89 [0.73-0.96]). On multivariable linear regression, the CVICU was associated with longer empiric therapy (β 1.5, 95% CI 0.8-2.3, P < 0.0001), as was hospitalization for ≥5 d (β 0.73, 95% CI 0.06-1.39, P = 0.03). ConclusionsThe MRSA nasal PCR screen has a high NPV for ruling out MRSA pneumonia in critically ill surgical patients. However, patients in the CVICU and patients hospitalized ≥5 d had a longer time to de-escalation of MRSA-targeted therapy, potentially due to higher clinical risk profile.

Whole-Genome Sequencing-Based Screening of MRSA in Patients and Healthcare Workers in Public Hospitals in Benin.

Methicillin-resistant Staphylococcus aureus (MRSA) constitutes a serious public health concern, with a considerable impact on patients' health, and substantial healthcare costs. In this study, patients and healthcare workers (HCWs) from six public hospitals in Benin were screened for MRSA. Strains were identified as MRSA using conventional microbiological methods in Benin, and confirmed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in Belgium. Whole-genome sequencing (WGS) was used on the confirmed MRSA isolates, to characterize their genomic content and study their relatedness. Amongst the 305 isolates (304 wound swabs and 61 nasal swabs) that were collected from patients and HCWs, we detected 32 and 15 cases of MRSA, respectively. From this collection, 27 high-quality WGS datasets were obtained, which carried numerous genes and mutations associated with antimicrobial resistance. The mecA gene was detected in all the sequenced isolates. These isolates were assigned to five sequence types (STs), with ST8 (55.56%, n = 15/27), ST152 (18.52%, n = 5/27), and ST121 (18.52%, n = 5/27) being the most common. These 27 isolates carried multiple virulence genes, including the genes encoding the Panton-Valentine leukocidin toxin (48.15%, n = 13/27), and the tst gene (29.63%, n = 8/27), associated with toxic shock syndrome. This study highlights the need to implement a multimodal strategy for reducing the risk of the cross-transmission of MRSA in hospitals.

Screening for Methicillin-Resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) has become less common in Germany in recent years. In this paper, we report data from the MRSA module of the Hospital Infection Surveillance System (Krankenhaus-Infektionen- Surveillance-System, KISS) for the years 2006-2021. We also describe the association of MRSA rates with the frequency of patient screening for MRSA and discuss the findings. Participation in the MRSA KISS module is voluntary. Once a year, the participating hospitals submit structural data, information on cases in which MRSA was detected (both colonizations and infections; both detected on admission and nosocomially acquired), and the number of nasal swabs taken for the detection of MRSA to the German National Reference Center for the Surveillance of Nosocomial Infections. Statistical analyses were performed with R software. The number of hospitals participating in the MRSA module rose from 110 in 2006 to 525 in 2021. From 2006 onward, the overall MRSA prevalence in German hospitals increased, reaching a maximum of 1.04 cases per 100 patients in 2012. The prevalence on admission fell by 44% from 0.96 in 2016 to 0.54 in 2021. The incidence density of nosocomial MRSA fell by an average of 12% per year, from 0.27 per 1000 patient-days in 2006 to 0.06 in 2021, while MRSA screening frequency increased sevenfold by 2021. The nosocomial incidence density was stable, independently of the screening frequency. MRSA rates in German hospitals fell markedly from 2006 to 2021, reflecting a general trend. The incidence density was no higher in hospitals with a low or moderate screening frequency than in those with a high one. Thus, a targeted, riskadapted MRSA screening strategy on hospital admission can be recommended.

Comparison of cefoxitin disc diffusion test, HiCrome rapid MRSA agar and PCR for&lt;em&gt; mec&lt;/em&gt;A, PVL and &lt;em&gt;fem&lt;/em&gt;B genes for detection of methicillinresistant &lt;em&gt;Staphylococcus aureus&lt;/em&gt; (MRSA)

This study evaluates the effectiveness of cefoxitin disk diffusion as a method to detect methicillin-resistant Staphylococcus aureus (MRSA), comparing with HiCrome MRSA screening agar and PCR-based mecA gene detection. Both PCR and the cefoxitin disk diffusion test exhibited 100% sensitivity and specificity, while HiCrome agar showed slightly lower sensitivity (90%) and specificity (95.24%) out of 72 Staphylococcus aureus isolates. The MRSA detection rate was found to be 41.66%, with femB and PVL genes present in 86.6% and 13.3% of MRSA isolates, respectively. Cefoxitin could serve as a reliable substitute marker for MRSA detection, particularly in settings with limited resources.

Hiding in Plain Sight: Benefit of Abrasion and Laceration Swabs in Identification of Panton-Valentine Leucocidin (PVL)-Meticillin Resistant Staphylococcus aureus (MRSA) Colonisation in Military Personnel.

Background Outbreaks of Panton-Valentine Leucocidin (PVL)-producing methicillin-resistantStaphylococcus aureus(MRSA) skin and soft tissue infections (SSTIs) are a recurrent challenge for the Royal Marines at the Commando Training Centre (CTCRM). The intensity of commando training, its impact on skin integrity, and persistent colonisation reservoirs within the training centre have thwarted attempts to prevent these outbreaks. Aim To present an outbreak of PVL-producing MRSA SSTIs at a military training centre, demonstrating the benefit of additional abrasion and laceration swabs on the identification of colonised personnel and showing the effectiveness of a 10-day decolonisation regime. Method Following the identification of the outbreak of PVL-producing MRSA, all 36 members of the Recruit Troop underwent nasal MRSA screening to identify MRSA carriers. The screening was repeated on day 16 after completing an enhanced 10-day decolonisation regime. A third screening was conducted on the 110th day after a second peak of infection was identified. Various infection control measures, such as enhanced cleaning, restriction of movement and adjustments to the military training serials, were introduced to prevent further spread through the training centre. Results In this outbreak, two-thirds (eighteen) of the Recruit Troop suffered MRSA-PVL skin infections requiring antibiotic therapy and three required hospital admission for surgical management of their abscesses. The outbreak lasted 130 days, with two spikes in infections 10 weeks apart. The outbreak was successfully confined to one troop. Conclusion With concerns about low identification rates of carriers using nasal screening for MRSA, in this outbreak, we improved the identification of asymptomatic carriage with the simple step of additional culture swabs for all cuts and abrasions. Improved identification of colonised recruits, along with an enhanced decolonisation regime and rigid infection control practices, prevented the further spread of the clone through the training centre. In a population with constant ongoing skin trauma, such as the military, contact sport athletes and iIV drug users, our results show that a culture of suitable abrasions/lacerations will improve the identification of MRSA colonisation compared with nasal swabs alone. Despite ongoing skin trauma and the logistical difficulties in delivering effective decolonisation during military training, decolonisation was successful in 79% of recruits after one decolonisation and 87% after the second 10-day decolonisation.

A Simple and Rapid Methicillin-Resistant Staphylococcus aureus (MRSA) Screening Test Using a Mannose-Binding Lectin (MBL)-Conjugated Gold Nanoparticle Probe.

Rapid diagnosis of methicillin-resistant Staphylococcus aureus (MRSA) is essential for guiding clinical treatment and preventing the spread of MRSA infections. Herein, we present a simple and rapid MRSA screening test based on the aggregation effect of mannose-binding lectin (MBL)-conjugated gold nanoparticles (AuNP), called the MRSA probe. Recombinant MBL protein is a member of the lectin family and part of the innate immune system. It can recognize wall teichoic acid (WTA) on the membrane of MRSA more specifically than that of methicillin-sensitive Staphylococcus aureus (MSSA) under optimized salt conditions. Thus, the MRSA probe can selectively bind to MRSA, and the aggregation of the probes on the surface of the target bacteria can be detected and analyzed by the naked eye within 5 min. To demonstrate the suitability of the method for real-world application, we tested 40 clinical S. aureus isolates (including 20 MRSA specimens) and recorded a sensitivity of 100%. In conclusion, the MRSA probe-based screening test with its excellent sensitivity has the potential for successful application in the microbiology laboratory.

Identification of Risk Factors for Nasal Colonization of Methicillin-resistant Staphylococcus aureus and Vancomycin-resistant Staphylococcus aureus in Health Workers at a Tertiary Hospital, Indonesia

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-resistant S. aureus (VRSA) frequently cause nosocomial infections yearly. During the COVID-19 pandemic, the potential for excessive use of antibiotics is a global threat to the increasing incidence of multiresistant bacteria. AIM: This study aimed to determine MRSA and VRSA colonization and identify factors associated with the risk of MRSA and VRSA nasal colonization in health workers at Dr. Soemarno Sosroatmodjo General Hospital, Kuala Kapuas, as one of the type C hospitals in Indonesia. METHODS: This cross-sectional analytic study at Dr. Soemarno Sosroatmodjo General Hospital, a tertiary hospital in Indonesia. A 128 health workers’ subjects had undergone nasal swab screening for MRSA and VRSA colonization examinations. Then, they were asked to complete a questionnaire concerning the risk factors of MRSA and VRSA infections. RESULTS: Nasal swab results obtained as many as 30 (23.5%) MRSA positive subjects and 6 (4.7%) subjects with positive VRSA. The most common risk factors that led to MRSA colonization included a history of positive MRSA in the previous hospital (60%), a history of ear, nose, and throat infection (41.7%), and did not do hand rub/handwash (36.7%). In comparison, the most risk factors for VRSA colonization were having pigs farm at home (33.3%), a history of positive MRSA in the previous hospital (20%), and a history of hospitalization in the past 6–12 months (16.7%). The results of multivariate analysis showed the most powerful and statistically significant risk factors in influencing nasal MRSA colonization were a history of positive MRSA in the previous hospital (OR 13.69, 95% confidence intervals [CI]: 1.34–140.25, p = 0.028) and did not do hand rub/handwash (OR 2.95, 95% CI: 1.167–7.49, p = 0.023). Meanwhile, marital status (OR 0.160, 95% CI: 0.02–1.06), p = 0.058) and home care service (OR 6.10, 95% CI: 0.79–46.96, p = 0.082) were the strongest risk factors for nasal colonization of VRSA but not statistically significant. CONCLUSION: As many as, 23.5% and 4.7% of healthcare workers’ subjects were found with nasal colonization of MRSA and VRSA, respectively. Accordingly, strict policies are needed to minimize the transmission of these organisms from the hospital setting to the community.

SG-APSIC1170: Reduction of hospital-onset MRSA bacteremia with chlorhexidine baths among MRSA-colonized patients

Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is a major concern for hospitalized patients in Singapore. Hospital-onset (HO) MRSA bacteremia is monitored at the national level as an indicator of hospital quality. Patients who have colonized with methicillin-resistant Staphylococcus aureus (MRSA) are more likely to develop an MRSA infection in the future. A topical antiseptic solution or cloth called chlorhexidine gluconate (CHG) is effective against several gram-positive and gram-negative bacteria, including MRSA. Methods: The following control measures were present before and throughout the study period: (1) active screening of MRSA upon admission; (2) initiation of contact precaution once MRSA is detected; and (3) emphasis on strict hand hygiene. In January 2021, an intervention was for routine application of CHG bathing as follows: (1) training materials were developed; (2) train-the-trainer sessions were organized; (3) compliance regarding the application of CHG baths was monitored; and (4) the postimplementation process was reviewed. Results: There was no change of hand hygiene rate before and after implementation. In 2020, 17 cases of MRSA bacteremia occurred in the hospital, with an infection incidence of 0.54 per 10,000 patient days. In 2021, there were 10 cases of HO-MRSA bacteremia infection, with an overall rate of was 0.30 per 10,000 patient days. Conclusions: Daily bathing with chlorhexidine reduced the risk of MRSA acquisition and of hospital-acquired bacteremia.

MRSA carriage among healthcare workers in a Vietnamese intensive care unit: a prospective cohort study.

Background: Little is known about the magnitude and patterns of methicillin-resistant Staphylococcus aureus (MRSA) carriage among intensive care unit (ICU) healthcare workers (HCWs), especially in lower-middle-income countries like Vietnam. Materials and methods: A prospective cohort study was conducted on HCWs working in the adult ICU of the Hospital for Tropical Diseases in Vietnam between October 28 and December 20, 2019. These HCWs included physicians, nurses, and nursing assistants who were responsible for all essential medical activities and basic patient care. A questionnaire was used to collect participants’ information, including age, sex, profession, ICU working time, and underlying diseases. Hand and nasal swabs were collected weekly for 8 consecutive weeks for MRSA screening. Staphylococcal isolates were checked for catalase and coagulase and, for methicillin resistance using cefoxitin disk diffusion, then rechecked on the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Results: Among 55 HCWs, 16 (29.1%) carried MRSA in their noses or hands. MRSA intermittent hand carriage was documented in 2 (3.6%) HCWs. Among 53 HCWs undertaking nasal swabs, 13 (24.5%) were MRSA persistent and 3 (5.6%) were intermittent carriers. The MRSA carriage rate was highest among nursing assistants (50%, 4/8). More HCWs with underlying diseases were found to be MRSA carriers (31.8%, 7/22) compared with those without comorbidities (27.3%, 9/33). Conclusion: MRSA carriage among HCWs is not rare. The findings highlight an urgent need to review and update the local infection prevention and control measures to prevent MRSA transmission from HCWs to patients.

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.

1287: METHICILLIN-RESISTANT STAPHYLOCOCCUS AUREUS NARES SCREEN LEADS TO VANCOMYCIN DE-ESCALATION IN TRAUMA

Introduction: Methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) nares swab is a proven screening tool to de-escalate vancomycin therapy due to its high negative predictive value in pneumonia and other infections. However, data are lacking on the utility of this test in the critically ill trauma population, which is at high risk for hospital-acquired infections. This study evaluated the impact of empiric MRSA PCR nares screening on de-escalation of vancomycin therapy in critically ill trauma patients. Methods: This is a single center, pre-post observational cohort study conducted at an academic, level I trauma center. Adult patients who were admitted for trauma and received empiric vancomycin therapy for suspected infection in the trauma intensive care unit were included. Patients were grouped by whether they were included 6 months before (pre-cohort) and 6 months after (post-cohort) the implementation of empiric rapid MRSA PCR nares screening in September 2021. The primary outcome was duration of vancomycin therapy. Secondary outcomes included rate of acute kidney injury (AKI), positive MRSA screen or cultures, ICU length of stay (LOS), hospital LOS, and mortality. Results: One-hundred fifty-eight patients were included: 82 in the pre-cohort group and 76 in the post-cohort group. Ninety vancomycin initiation orders were observed in the pre-cohort versus 80 orders in the post-cohort. Baseline demographics were similar between groups. There was a significantly higher rate of MRSA PCR orders in the post-cohort group (75%) compared to (21%) in the pre-cohort (p< 0.001). The pre-cohort group had higher rates of positive MRSA screens (26 vs. 13%, p=0.18) and MRSA positive cultures (17 vs. 9%, p=0.22) compared to post-cohort. There were no reported instances of positive MRSA cultures with a negative PCR. Vancomycin duration was significantly shorter in the post-cohort group (2.55 days vs. 3.5, p=0.02). Hospital and ICU LOS, rates of AKI, and mortality were not different between groups. Conclusions: Implementation of empiric rapid MRSA nares screening led to a shorter overall duration of vancomycin therapy by nearly one day in critically ill trauma patients. Further study is required to evaluate the potential cost savings of empiric MRSA screening in critically ill trauma patients.