Methicillin-resistant Staphylococcus Aureus Screening Research Articles

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.

Evaluating Methicillin-Resistant Staphylococcus aureus Polymerase Chain Reaction Nasal Screening as a Tool for Antimicrobial Stewardship

IntroductionInitiation of broad-spectrum empiric antibiotics is common when infection is suspected in hospitalized adults. The benefits of early utilization of effective antibiotics are well documented. However, the negative effects of inappropriate antibiotic use have led to antimicrobial stewardship mandates. Recent data demonstrate the utility of methicillin-resistant Staphylococcus aureus (MRSA) polymerase chain reaction (PCR) nasal screening to steward anti-MRSA empiric antibiotics in pneumonia. We hypothesize that MRSA PCR nasal swabs would also be effective to rule out other MRSA infection to effectively limit unnecessary antibiotics for any infectious source. MethodsWe performed a single-center retrospective chart review of all adult patient encounters from October 2019-July 2021 with MRSA PCR nasal testing. We then reviewed all charts to evaluate for the presence of infections based on source cultures results, as the gold standard. Sensitivity, specificity, negative predictive value, and positive predictive value were calculated from 2 × 2 contingency tables. ResultsAmong all patients with MRSA nasal screening, 1189 patients had any infection. Prevalence of MRSA nasal carriage among patients screened was 12%. Prevalence of MRSA infection among all infections was 7.5%. MRSA nasal swabs demonstrated a negative predictive value of 100% for MRSA urinary tract infection, 97.9% for MRSA bacteremia, 97.8% for MRSA pneumonia, 92.1% for MRSA wound infection, and 96.6% for other MRSA infections. Overall, MRSA PCR nasal swabs had a sensitivity of 68.5%, specificity of 90.1%, positive predictive value of 23.7%, and negative predictive value of 98.5% for any infections. ConclusionsMRSA PCR nasal swabs have a high negative predictive value for all infections. Our data support the use of MRSA PCR nasal swabs to rule out MRSA infection and thereby allow early de-escalation of MRSA coverage in hospitalized patients requiring empiric antibiotics. Implementation of MRSA screening could decrease antibiotic-associated morbidity, resistance, and costs. More studies should be conducted to validate these results and support these findings.

Development of a Real-Time Recombinase-Aided Amplification Method to Rapidly Detect Methicillin-Resistant Staphylococcus aureus.

Methicillin-resistant staphylococcus aureus (MRSA) is a major pathogen responsible for human hospital and community-onset diseases and severe invasive livestock infections. Rapid detection of MRSA is essential to control the spread of MRSA. Conventional identification methods and antibacterial susceptibility tests of MRSA are time-consuming. The commonly used qPCR assay also has the disadvantages of being complicated and expensive, restricting its application in resource-limited clinical laboratories. Here, a real-time fluorescent recombinase-assisted amplification (RAA) assay targeting the most conserved regions within the mecA gene of MRSA was developed and evaluated to detect MRSA. The detection limit of this assay was determined to be 10 copies/reaction of positive plasmids. The established RAA assay showed high specificity for MRSA detection without cross-reactivities with other clinically relevant bacteria. The diagnostic performance of real-time RAA was evaluated using 67 clinical S. aureus isolates from dairy farms, which were detected in parallel using the TaqMan probe qPCR assay. The results showed that 56 and 54 samples tested positive for MRSA by RAA and qPCR, respectively. The overall agreement between both assays was 97.01% (65/67), with a kappa value of 0.9517 (p &lt; 0.001). Further linear regression analysis demonstrated that the detection results between the two assays were significantly correlated (R2 = 0.9012, p &lt; 0.0001), indicating that this RAA assay possesses similar detection performance to the qPCR assay. In conclusion, our newly established RAA assay is a time-saving and convenient diagnostic tool suitable for MRSA detection and screening.

MRSA Prophylaxis in Spine Surgery Decreases Postoperative Infections.

Retrospective cohort study. To compare infection rates before and after the implementation of a quality improvement protocol focused on methicillin-resistant Staphylococcus aureus (MRSA) screening and decolonization in patients undergoing lumbar fusion and/or decompression. Prior studies have demonstrated MRSA infections comprise a sizable portion of SSIs. Additional studies are required to improve our understanding of the risks and benefits of MRSA decolonization with vancomycin prophylaxis. A retrospective cohort analysis was conducted on patients who underwent spinal fusion or laminectomy before (2008-2011) and after (2013-2016) the implementation of an MRSA screening and treatment protocol. Odds ratios for MRSA, methicillin-sensitive Staphylococcus aureus (MSSA), and Vancomycin-resistant Enterococcus (VRE) infection before and after screening was calculated. Multivariate analysis assessed demographic characteristics as potential independent predictors of infection. A total of 8425 lumbar fusion and 2558 lumbar decompression cases met inclusion criteria resulting in a total cohort of 10,983 patients. There was a significant decrease in the overall rate of infections ( P <0.001), MRSA infections ( P <0.001), and MSSA infections ( P <0.001) after protocol implementation. Although VRE infections after protocol implementation were not significantly different ( P =0.066), VRE rates as a percentage of all postoperative infections were substantially increased (0 vs. 3.36%, P =0.007). On multivariate analysis, significant predictors of the infection included younger age (OR=0.94[0.92-0.95]), shorter length of procedure (OR=1.00[0.99-1.00]), spinal fusion (OR=18.56[8.22-53.28]), higher ASA class (OR=5.49[4.08-7.44]), male sex (OR=1.61[1.18-2.20]), and history of diabetes (OR=1.58[1.08-2.29]). The implemented quality improvement protocol demonstrated that preoperative prophylactically treating MRSA colonized patients decreased the rate of overall infections, MSSA infections, and MRSA infections. In addition, younger age, male sex, diabetic status, greater ASA scores, and spinal fusions were risk factors for postoperative infection.

Methicillin resistance Staphylococcus aureus nasal carriage and its associated factors among HIV patients attending art clinic at Dessie comprehensive specialized hospital, Dessie, North East Ethiopia.

Globally the incidence of nosocomial infections and colonization due to methicillin resistant Staphylococcus aureus (MRSA) has become greater concern. The objective of the study was to determine the prevalence and associated factors of nasal carriage of MRSA with its antimicrobial susceptibility patter among HIV patients attending ART clinic. cross-sectional study was conducted from January 01 to May 30, 2020 at Dessie comprehensive specialized hospital, north east Ethiopia. A total of 206 HIV patients were recruited by applying systematic random sampling technique. Nasal specimen was collected from both anterior nares, and inoculated directly on mannitol salt agar, MacConkey, 5% blood agar. Screening of MRSA and methicillin susceptible Staphylococcus aureus (MSSA) strain was done by using cefoxitin antibiotic disc following modified Kirby-Bauer disc diffusion technique. Bivariable and multivariable logistic regression analyses were performed to assess the associated factors with S. aureus and MRSA. study participants were in the age range between 12 and 72 years and their mean (±SD) age was 41.52 (±11.2). The rate of S. aureus and MRSA colonization was 127/206 (61.7%) and 58/206 (28.2%), respectively. Having job close contact with human [AOR = 4.41; 95% CI = 1.5-13.02; p = 0.007], picking the nose [AOR = 4.38; 95% CI = 1.34-14.29; p = 0.014] and ART failure [AOR = 7.41; 95% CI = 2.08-26.41; p = 0.002] had statistically significant association with MRSA colonization. MRSA showed resistance for tetracycline (53.4%), erythromycin (84.5%), and trimethoprim-sulfamethoxazole (86.2%). Multi-Drug Resistance (MDR) was detected among 96.5% of MRSA and 20.3% of MSSA isolates. the rate of S. aureus and MRSA nasal colonization was high and it has associated with different factors. Understanding and managing MRSA among HIV patients is mandatory and stakeholders should find out the way how to decolonize the bacteria from nasal area.

234. Does nasal screening for methicillin resistant Staphylococcus aureus (MRSA) prevent deep surgical site infections for elective cervical spinal fusion?

<h3>BACKGROUND CONTEXT</h3> Preoperative MRSA screening and decolonization has demonstrated success for some orthopaedic subspecialties in prevention of surgical site infections (SSIs). Spine surgery, however, has seen varied results, potentially secondary to the anatomic and surgical heterogeneity of the patients included in prior studies. Given that prior research has demonstrated greater propensity for gram positive SSIs in the cervical spine, we sought to investigate if MRSA screening would be more impactful in the cervical spine. <h3>PURPOSE</h3> The purpose of this study was to determine the relationship between nasal MRSA testing and SSI rates specifically in the setting of primary posterior cervical instrumented spine surgery. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study. <h3>PATIENT SAMPLE</h3> Adult patients undergoing primary instrumented posterior cervical procedures from January 2015-December 2019 at two tertiary academic referral centers in an urban setting <h3>OUTCOME MEASURES</h3> Physiologic measures: subfascial presumed infected collection or abscess within 90 days of the index operation. <h3>METHODS</h3> Adult patients undergoing primary instrumented posterior cervical procedures from January 2015-December 2019 were reviewed for MRSA testing < 90-days before surgery, preoperative mupirocin, perioperative antibiotics and SSI defined as operative incision and drainage (I&D) < 90-days after surgery. Trauma, tumor and infection cases were excluded. Logistic regression modeling was used with SSI the primary outcome and MRSA screening the primary predictor with clinical and demographic factors as covariates. <h3>RESULTS</h3> This study included 668 patients, of whom MRSA testing was performed in 212 patients (31.7%) and 6 (2.8%) were colonized with MRSA. Twelve patients (1.8%) underwent an I&D. On adjusted analysis, preoperative MRSA testing was not associated with postoperative I&D risk. Perioperative vancomycin similarly had no association with postoperative I&D risk. Notably, six patients (50%) grew MSSA from intraoperative cultures, with no cases of MRSA. <h3>CONCLUSIONS</h3> There was no association between preoperative nasal MRSA screening and SSIs in primary posterior cervical instrumented procedures, nor was there any association between vancomycin or infection rate. Furthermore, there was a preponderance of gram-positive infections but none caused by MRSA. Given these findings, the considerable cost and effort associated with MRSA testing in the setting of primary posterior cervical instrumentation may not be justified. Further research should investigate if higher-risk scenarios demonstrate greater utility of preoperative testing. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Attitudes and Awareness of Cornea Specialists and Oculoplastic Surgeons toward Methicillin-Resistant Staphylococcus aureus Decolonization.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) decolonization is widely utilized in many medical subspecialities to reduce surgical site infections, but routine ophthalmic implementation has been limited. The aim of this study was to investigate the attitudes and actual practice of corneal specialists and oculoplastic surgeons toward MRSA decolonization as a preventive measure in ophthalmic surgery. Materials and Methods: A web-based survey was sent to cornea specialists and oculoplastic surgeons to assess their knowledge, beliefs, and practices regarding MRSA prophylaxis and the use of MRSA decolonization to prevent post-operative infections. Results: A total of 180 surgeons participated in this study: 71% of respondents agreed that MRSA colonization plays a role in post-operative infection of the eye and adnexal structures; 65% stated that MRSA decolonization could help prevent MRSA infection. Although 41% of respondents would change their management in response to a positive pre-operative MRSA screening result, only 18% performed pre-operative screening. Seventeen percent of respondents indicated that they offer pre-operative decolonization for MRSA-positive patients; the most frequently applied technique was the use of nasal antibiotic agents such as mupirocin, followed by antiseptic baths. Peri-operative MRSA prophylaxis was used by 18% of respondents; pre-operative MRSA decolonization was used in conjunction by 8.5 % of respondents. Conclusions: Although MRSA decolonization has been validated in fields outside of ophthalmology, there has not been widespread adoption of this practice among oculoplastic surgeons and cornea specialists. Prospective MRSA decolonization ophthalmic studies are necessary if evidence-based management guidelines are to be developed.

O063 Use of MRSA screening to discontinue teicoplanin on a tertiary vascular surgical firm

Abstract Introduction The aim of this study was to determine whether the implementation of new educational interventions could reduce the use of teicoplanin in Diabetic Foot Infections (DFI) on a Vascular surgical firm and prevent potential toxicity. Local trust guidelines state that DFI should be treated with piperacillin-tazobactam and teicoplanin. Following a groin/nasal swab, teicoplanin can then be withdrawn if the patient has a negative screen for MRSA (methicillin-resistant Staphylococcus aureus). Methods Interventions were undertaken to reduce overuse of teicoplanin. These consisted of Ward Pharmacist teaching, updating the Vascular Doctor Handbook and sending an email to the Ward Juniors explaining current antibiotic guidelines. Alongside these interventions was the pre-existing weekly microbiology Consultant-led ward rounds. Teicoplanin prescribing was compared in patient groups identified pre (n=44) and post intervention (n=36). Inclusion criteria were diabetes/ prediabetes, no allergies to penicillin or teicoplanin and no prosthetic material grafts in situ. Results The mean number of excess doses of teicoplanin decreased from 4.84 (pre-intervention) to 1.00 (post-intervention). Largest excess doses received by one patient was reduced from 11 to 6. One 400 mg teicoplanin vial costs £9.30, resulting in an average saving of £35.71 per patient. Conclusion The described interventions reduced the number of excess teicoplanin doses for DFI on the Vascular firm. This resulted in a more cost-effective practice, drug administration rounds becoming more time efficient and resulting in less waste thus facilitating more sustainable practice. Future research could further explore the impact on sustainability by calculating carbon emissions of antibiotic usage on the ward. Take-home message Educational interventions have helped reduce excess use of teicoplanin in Diabetic Foot Infections for patients under the care of a vascular surgical firm. This has led to a reduction in time and expenses, thus promoting a more sustainable practice.

Does Nasal Screening for Methicillin-Resistant Staphylococcus aureus (MRSA) Prevent Deep Surgical Site Infections for Elective Cervical Spinal Fusion?

Retrospective cohort study. The objective of this study was to determine the relationship between nasal methicillin-resistant Staphylococcus aureus (MRSA) testing and surgical site infection (SSI) rates in the setting of primary posterior cervical instrumented spine surgery. Preoperative MRSA screening and decolonization has demonstrated success for some orthopedic subspecialties in prevention of SSIs. Spine surgery, however, has seen varied results, potentially secondary to the anatomic and surgical heterogeneity of the patients included in prior studies. Given that prior research has demonstrated greater propensity for gram positive SSIs in the cervical spine, we sought to investigate if MRSA screening would be more impactful in the cervical spine. Adult patients undergoing primary instrumented posterior cervical procedures from January 2015 to December 2019 were reviewed for MRSA testing <90 days before surgery, preoperative mupirocin, perioperative antibiotics, and SSI defined as operative incision and drainage (I&D) <90 days after surgery. Logistic regression modeling used SSI as the primary outcome, MRSA screening as primary predictor, and clinical and demographic factors as covariates. This study included 668 patients, of whom MRSA testing was performed in 212 patients (31.7%) and 6 (2.8%) were colonized with MRSA. Twelve patients (1.8%) underwent an I&D. On adjusted analysis, preoperative MRSA testing was not associated with postoperative I&D risk. Perioperative vancomycin similarly had no association with postoperative I&D risk. Notably, 6 patients (50%) grew methicillin sensitive Staphylococcus aureus from intraoperative cultures, with no cases of MRSA. There was no association between preoperative nasal MRSA screening and SSIs in primary posterior cervical instrumented procedures, nor was there any association between vancomycin or infection rate. Furthermore, there was a preponderance of gram positive infections but none caused by MRSA. Given these findings, the considerable cost and effort associated with MRSA testing in the setting of primary posterior cervical instrumentation may not be justified. Further research should investigate if higher-risk scenarios demonstrate greater utility of preoperative testing.

Prevalence of Multidrug-Resistant Methicillin-Resistant Staphylococcus aureus in Northeastern Saudi Hospitals

Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for serious threats to human health, causing various syndromes worldwide. Here, our purpose was to estimate the prevalence of nosocomial MRSA among isolates from King Khalid Hospital (KKH) and Maternity and Children Hospital (MCH) at Hafar Al-Batin Governorate, Saudi Arabia, and to determine the resistance of these isolates to common antibiotics used for treatment. One-hundred clinical specimens were collected from admitted patients during a six month period, and subjected to MRSA screening using traditional microbiological techniques. Antimicrobial susceptibility testing (AST) was also performed and confirmed by the VITEK2 automated system. Among the 37 S. aureus strains isolated from KKH, 23 (62.16%) were identified as MRSA. In MCH, 38 (60.31%) out 63 isolated strains were identified as MRSA. According to AST, few MRSA strains were resistant to teicoplanin, fosfomycin, linezolid, and mupirocin in both hospitals. Vancomycin resistance was not detected in any of the MRSA strains. Twelve MRSA strains from KKH and 17 strains from MCH were considered multidrug resistant (MDR). In conclusion, prevention is critical to reduce the high prevalence of MRSA.

Prospective surveillance of colonization and disease by methicillin-resistant Staphylococcus aureus (MRSA) at a European pediatric cancer center

PurposeChildren and adolescents undergoing treatment for cancer or allogeneic hematopoietic cell transplantation are at increased risk for methicillin-resistant Staphylococcus aureus (MRSA). We therefore examined the occurrence and outcome of MRSA colonization and infection in patients of a large European pediatric cancer center.MethodsIn a prospective observational cohort study conducted between 2007 and 2018, nasopharyngeal swabs for culture of MRSA were obtained from all admitted patients. The primary endpoint of the study was the colonization rate over time. Secondary endpoints included genetic relatedness of isolates, time burden of isolation measures, and results of decolonization efforts.ResultsDuring the study period, MRSA screening identified 34 colonized patients (median age: 10 years; range: 0–21) without trends over time. MRSA colonization was associated with the presence of classical risk factors. There was no molecular evidence of patient-to-patient transmission. A standard MRSA eradication regimen led to a lasting eradication of the organism in 26 of 34 patients. MRSA infection occurred in two patients with no associated fatalities.ConclusionProspective monitoring revealed low rates of MRSA colonization and infection at our center. These low rates and the absence of patient-to-patient transmission support the effectiveness of the management bundle of MRSA identification, isolation, and decolonization.

Prevalence of Methicillin Resistant Staphylococcus aureus and its Associated SCCmec Types among Healthcare workers and Patient Visitors from Western Maharashtra, India

Staphylococcus aureus is one of the major pathogen causing infections in human ranging from mild to severe life-threatening conditions. Methicillin-Resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen with high morbidity and mortality in both hospital and community settings. Total 600 nasal swabs were collected from patient visitors and Healthcare workers. Of these, 184 S.aureus (30.66%) were isolated. All S.aureus isolates screened for MRSA and 73 (39.67%) isolates showed MRSA by Cefoxitin disc diffusion method and PCR. 21 (28.76%) isolates detected pvl gene of the 73 isolated MRSA i.e., CA-MRSA. All MRSA isolates were typed into SCCmec element (I to V). Of these SCCmec type III was found more prevalent than other SCCmec types and 3 isolates were not typeable. MRSA still remains a significant problem in public Healthcare settings. Screening of MRSA among Healthcare Workers and patient visitors is mandatory to prevent the spread of CA-MRSA in hospitals.

551 Age Does Not Predict Admission Culture Positivity

IntroductionBurn patients are susceptible to wound infections, urinary tract infections, pneumonia, and bloodstream infections. With rising rates of community colonization with multidrug-resistant organisms (MDRO), the colonization of wounds with commensal organisms is more concerning than ever, which is particularly true in patients with recent hospital admissions, advanced age, or institutional living situations. The purpose of this study was to examine if age was a factor in obtaining admission cultures and if older patients were more likely to have positive cultures.MethodsA retrospective chart review was conducted involving burn patients admitted at three ABA verified burn centers from January 2016 - December 2017. Data collected included demographics, burn injury, and cultures obtained within 24 hours of admission. Patients were divided into 10-year age increments from 20 to ≥ 80 years old. Data analysis was conducted using Chi-square, Fisher Exact, and Kruskal-Wallis tests.ResultsA total of 1615 patients (mean age 45.9± 17.7 years, 1145 males (70.9%), mean burn size (TBSA) 9.6± 14.2%) were analyzed. Admission cultures obtained were: 656 (40.6%) wound cultures, 196 (12.1%) urine cultures, 139 (8.6%) blood cultures, and 1445 (89.5%) Methicillin-Resistant Staphylococcus Aureus (MRSA) screen. In all age groups, there were no significant differences between patients who had wound cultures (p = 0.97), blood cultures (p = 0.39), or MRSA screening (p = 0.9). As patients aged, they were more likely to have urine cultures obtained (p=0.01); - 23% of patients >80 years old had urine cultures ordered at admission compared to 8.6-16.9% of younger patients. Positive results by age group: wound cultures (p= 0.09), urine cultures (p= 0.16), blood cultures (0.10), MRSA screen (p=0.98). In looking at increased exposure to MDROs prior to admission by age groups, patients in the 61–70year (8.33%), 71–80-year (5.68%), and >80-year (6.67%) age groups were more likely to have a recent (within 30 days) hospitalization (p = 0.02), but there was no significant difference in pre-hospital institutionalization (i.e., prison, skilled nursing facility) by age group (p = 0.06). With a recent hospitalization, MRSA screening was more likely to be positive (11.3% vs. 4.9%, p = 0.05).ConclusionsAll burn patients are susceptible to infections. Urine cultures were more likely to be obtained in older burn injured patients who are 80 years of age or older. There was no significant difference in culture positivity by age. Apart from MRSA screen positivity, there was no increased risk of urine, wound, or blood culture positivity with recent hospitalization or institutionalization. The utility of screening all patients for MDROs on admission should be considered for patients 20 years of age and older.

120 The Association of Admission Cultures with Burn Outcomes

IntroductionBurn patients are susceptible to infections. It is thought that burn wounds are initially sterile and become colonized by commensal and environmental microorganisms. Many burn centers have protocols to routinely screen patients for infection on admission. The ability of culture results to predict outcomes in burn patients has not been examined. In this study, we aim to examine the relationship between admission cultures and burn outcomes. We hypothesize that patients who have positive cultures on admission will have increased mortality and length of stay (LOS).MethodsA retrospective chart review was conducted using electronic medical records for all adult patients admitted to three ABA verified burn centers from January 2016 -December 2017. Data collected included patient demographics, burn injury, burn outcomes, and cultures obtained within the first 24 hours of admission. Data analysis was conducted using Chi-square, Fisher Exact, Spearman Correlation, Wilcoxon 2-sample, and Kruskal-Wallis tests.ResultsA total of 1615 patients (mean age 45.87±17.65 years, 1145 males [70.9%]) were analyzed. Mean total body surface area burn (TBSA) was 9.6±14.2% and 10% had inhalation injuries. In this study population, the median LOS was 7 days (Interquartile range [IQR] = 12) and 72 patients (4.5%) expired. Older patients (p < .0001), those with higher scores on the 11-factor modified frailty index (mFI-11) (p < 0.0001), a higher TBSA (p< .0.0001) and inhalation injury (p < 0.0001) had a higher mortality rate. In examining the effect of admission cultures on mortality, there was no significant difference in mortality based on wound culture (p 0.14), Clostridium difficile (C. diff) (p 0.25), or urine culture (p=0.79) results. Patients with positive Methicillin-Resistant Staphylococcus Aureus (MRSA) screening (p 0.04) and those with positive blood cultures (p 0.01) were more likely to die from their injuries. Older patients (r= 0.14, p < 0.0001), those with a larger TBSA (r=0.49, p < 0.0001), and a higher MFI-11 score (r=0.12, p < 0.0001) had and increased LOS.. There was no association between LOS and positive wound cultures (p 0.08), or blood cultures (p 0.49) upon admission. Patients with positive MRSA results (p 0.003) and urine cultures (p 0.01) upon admission had a longer LOS while those with positive C. diff results had a shorter LOS (p 0.01).ConclusionsMortality is associated with standard predictors of outcomes (age, burn size, inhalation injuries, frailty scores) and positive MRSA screens and blood cultures. Patients with larger burns (define larger burn-maybe use the degree scale), a positive MRSA and negative C. diff had a longer LOS. Based on these results, cultures should be considered in all patients upon admission to the hospital as they are predictive of burn outcomes.

Identification and characteristics of drug resistance and genotypes of methicillin-resistant Staphylococcus aureus isolated from intensive care units at obstetrics &amp; gynaecology departments: a retrospective analysis

Background: The aim of this study was to investigate the prevalence and characteristics of SCCmec genotypes and drug resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolated from intensive care units (ICU) at obstetrics &amp; gynaecology departments in a tertiary hospital. Methods: MRSA obtained from patients admitted to the ICU were isolated and identified by using the Vitek 2 Compact System with GP21 342 cards. Antimicrobial susceptibility profiles and MRSA screening were determined by using the broth microdilution method according to CLSI guidelines. Determination of resistant genes and SCCmec genotypes were performed by multiplex PCR. Results: Of the 283 patients evaluated, 120 (42.4%) isolates were phenotypically and genotypically confirmed to be MRSA. Among 120 strains, 15 (12.5%) strains were SCCmec type II, 96 (80%) strains were SCCmec type III and 9 (7.5%) strains were undifferentiated type. All MRSA strains were recognized as multidrug resistant, exhibiting 100% resistance to cefoxitin and oxacillin, followed by erythromycin and levofloxacin (more than 80% and 90% respectively). Different SCCmec genotypes in MRAS isolates showed distinct antimicrobial agent patterns. SCCmec type II was highly resistant to clindamycin (93.3%) with lower resistance to tetracycline (26.7%) with SCCmec type III being highly resistant to gentamicin (91.7%). Undifferentiated strains were resistant to Cotrimoxazole (77.8%). There was a statistical difference among type II, type III and Undifferentiated strains (P &lt; 0.05). Of interest, a high prevalence of resistance to rifampicin (more than 75%) was also noted in the hospital. With different SCCmec genotypes, MRSA isolates were sensitive to minocycline, quinupristin, teicoplanin, vancomycin and nitrofurantoin. Conclusions: Our data indicate that SCCmec type II and SCCmec type III of MRSA are circulating in the ICU and constitute a major source for the infection spread. It is necessary to increase surveillance of MRSA in the ICU and develop adequate infection prevention strategies.

Frequency and Molecular Characterization of Staphylococcus aureus from Placenta of Mothers with Term and Preterm Deliveries.

Globally, prematurity is the leading cause of neonatal mortality (babies in the first four weeks of life) and now the second leading cause of mortality after pneumonia in children under age five. The neonatal gut microbial colonization is crucial in the human life cycle. Placental microbiota transmits from the gut microbiota plays a significant role in association with kinship. Simultaneously, this transition is being made from mother to infant. This comparative study explored the diversity of microbiota associated with term and preterm neonates by evaluating the placental samples. The study found that 16/68 (23.5%) full-term placental samples were positive for S. aureus; on the other hand, 4/16 (25%) preterm placental samples confirmed culture growth for S. aureus. Antimicrobial susceptibility patterns showed that Staphylococcus aureus (S. aureus) isolates from both types of samples were resistant to Ofloxacin, Trimethoprim-sulfamethoxazole, Oxacillin, and Cefoxitin. However, Methicillin-Resistant Staphylococcus aureus (MRSA) detection was 43.75% in full-term and 75% in preterm placental samples. Moreover, two isolates were positive for both mecA and PVL virulent genes, and the rest were positive only for the mecA gene. Interestingly few isolates lacked both characteristic MRSA genes, mecA and PVL. Notably, resistances were more inclined towards preterm samples for antimicrobial susceptibility and MRSA screening. It may be concluded that there is a significant presence of S. aureus in the placenta of mothers with term and preterm deliveries which might be responsible for preterm deliveries. Therefore, judicious use of antibiotics during pregnancies may help prevent preterm births.

Comparative Genomics of Borderline Oxacillin-Resistant Staphylococcus aureus Detected during a Pseudo-outbreak of Methicillin-Resistant S. aureus in a Neonatal Intensive Care Unit.

ABSTRACTActive surveillance for methicillin-resistant Staphylococcus aureus (MRSA) is a component of our neonatal intensive care unit (NICU) infection prevention efforts. Recent atypical trends prompted review of 42 suspected MRSA isolates. Species identification was confirmed by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS), and methicillin resistance was reevaluated by PBP2a lateral flow assay, cefoxitin/oxacillin susceptibility testing, mecA and mecC PCR, and six commercially available MRSA detection agars. All isolates were confirmed S. aureus, but only eight were MRSA (cefoxitin resistant, PBP2a positive, mecA positive, growth on all MRSA screening agars). One MRSA isolate was cefoxitin susceptible but PBP2a and mecA positive, and the remaining 33 were cefoxitin susceptible, PBP2a negative, and mecA negative; interestingly, these isolates grew inconsistently across MRSA screening agars and had susceptibility profiles consistent with that of borderline oxacillin-resistant S. aureus (BORSA). Comparative genomic analyses found these BORSA isolates to be phylogenetically diverse and not representative of clonal expansion or shared gene content, though clones of two NICU strains were infrequently observed over 8 months. We identified 6 features—substitutions and truncations in PBP2, PBP4, and GdpP and beta-lactamase hyperproduction—that were used to generate a random forest classifier to distinguish BORSA from methicillin-susceptible S. aureus (MSSA) in our cohort. Our model demonstrated a robust ability to predict the BORSA phenotype among isolates collected across two continents (validation area under the curve [AUC], 0.902). Taking these findings together, we observed an unexpected prevalence of BORSA in our NICU, BORSA misclassification by existing MRSA screening methods, and markers that are together discriminatory for BORSA and MSSA within our cohort. This work has implications for epidemiological reporting of MRSA rates for centers using different screening methods.

The application of the loop-mediated isothermal amplification method for rapid detection of methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is an important problem associated with significant mortality and morbidity and well known as a predominant bacterial pathogen. The aim of this study was to identify MRSA strains. In this study (June 2018 to June 2019) isolates of S. aureus were obtained from patients referred to teaching hospitals of Ahvaz, Iran. All isolates were confirmed by conventional microbiological methods. In following, antimicrobial susceptibility testing (AST), MRSA screening, PCR detection of MRSA and LAMP assay were performed. Out of a total of 156 staphylococcal isolates, 126 isolates were identified as MRSA. Seventy-two (57.1%) MRSA isolates were recovered from wound. All MRSA isolates were sensitive to vancomycin, linezolid, teicoplanin, quinupristin-dalfopristin, and tigecycline. The results of LAMP showed 100% agreement with PCR. Sensitivity and specificity of the LAMP assays for the mecA genes were 100% and 100%, respectively. The LAMP assay is a rapid and simple method for the identifications of MRSA. Because of its performance without the need for specific instrumentation, this method can be easily employed in medical centers for the detection of mecA.