Methicillin-resistant Staphylococcus Aureus Group Research Articles

Molecular characteristics, risk factors, and clinical outcomes of methicillin-resistant Staphylococcus aureus infections among critically ill pediatric patients in Shanghai, 2016-2021.

Methicillin-resistant Staphylococcus aureus (MRSA) infection in children has been on the rise, which poses a serious threat to their health and life in China. The purpose of this study was to determine the molecular characteristics, risk factors, and clinical outcomes of MRSA infections among critically ill pediatric patients. A retrospective case-control study was performed in the pediatric intensive care unit (PICU) of a tertiary university teaching hospital. All children infected with culture-positive S. aureus in the PICU between January 2016 and December 2021 were included. Univariate and multivariable logistic regression analyses were used to identify potential risk factors for MRSA infection and clinical outcomes of S. aureus infection. All S. aureus isolates were characterized based on antimicrobial resistance, multilocus sequence typing (MLST) and Staphylococcal protein A (spa) typing. Of 3,974 patients admitted to the PICU, 280 were diagnosed with a S. aureus infection during the 6-year study period. Among them, 43.2% (121/280) were MRSA. All MRSA isolates showed significantly higher rates of resistance to penicillin, erythromycin, clindamycin and tetracycline than MSSA strains. The MRSA strains consisted of 45 spa types and 20 sequence types (STs) (20 clonal complexes), among which the most frequently represented were ST59-t437and ST398-t034. Multivariable logistic regression revealed vaginal delivery, respiratory failure, co-infection with a virus, C-reactive protein (CRP) > 8 mg/L as significant risk factors for MRSA infection. There was no significant difference in all-cause mortality during hospitalization between the MRSA group and the MSSA group. Furthermore, independent predictors for mortality in patients with S. aureus infections were the presence of hypoproteinemia, hematopathy, septic shock, respiratory failure, fever, and white blood cell (WBC) > 15.0 × 109/L. The study revealed a high proportion of MRSA infections among critically ill pediatric patients, and found significant risk factors for MRSA infection and poor prognosis of S. aureus infection. Methicillin resistance did not contribute to the mortality in the current study. These findings will provide evidence-based practices to make the strategies of prevention and rational use of antibiotics for pediatric patients with S. aureus infection in the ICU.

Predictors of Methicillin-resistant Staphylococcus aureus infection in children with acute osteomyelitis

BackgroundThis study aims to identify risk factors associated with Methicillin-resistant Staphylococcus aureus (MRSA) infection in children diagnosed with acute osteomyelitis (AO) and to elucidate the laboratory characteristics of these MRSA-infected children to enhance early targeted therapeutic interventions.MethodsWe conducted a retrospective analysis involving 123 children with acute osteomyelitis treated at our hospital. Upon admission, we measured white blood cell (WBC) counts, C-reactive protein (CRP) levels, erythrocyte sedimentation rates (ESR), and platelet counts. Patients were categorized into two groups: the non-MRSA group (n = 73) and the MRSA group (n = 50), with values assigned as follows (non-MRSA group = 0, MRSA group = 1).ResultsThe MRSA group had a significantly higher average age compared to the non-MRSA group (P < 0.05). Notably, the incidence of suppurative arthritis was significantly lower in the MRSA group (P < 0.05). At the time of admission, CRP levels in the MRSA group were markedly elevated compared to those in the non-MRSA group (P < 0.01). After three days of empirical therapy, both WBC and CRP levels remained significantly higher in the MRSA group compared to the non-MRSA group (P < 0.05).ConclusionsIn children newly admitted with acute osteomyelitis, a CRP level exceeding 73.23 µg/mL may indicate a high likelihood of MRSA infection. For children with AO who have been hospitalized for three days on empirical therapy, the presence of WBC > 10.95 × 10^9/L, CRP > 49.56 µg/mL, age > 3.5 years, and the absence of suppurative arthritis suggests a heightened risk of MRSA infection.

Comparison of bloodstream infections due to Corynebacterium striatum, MRSA, and MRSE

BackgroundCorynebacterium striatum (C. striatum), a common skin and mucosal colonizer, is increasingly considered as an opportunistic pathogen causing bloodstream infections (BSIs). This study aims to investigate the clinical features and outcomes of C. striatum-BSI.MethodsWe included hospitalized cases with C. striatum-positive blood cultures from January 2014 to June 2022 and classified them into C. striatum-BSI group and contamination group; Clinical characteristics, treatments, and outcomes were compared between the C. striatum-BSI group and contamination group, Methicillin-resistant Staphylococcus aureus (MRSA)-BSI and Methicillin-resistant Staphylococcus epidermidis (MRSE)-BSI.ResultsFifty-three patients with positive C. striatum blood cultures were identified. Among them, 25 patients were classified as C. striatum-BSI, with 21 as contamination cases. And 62 cases of MRSA-BSI and 44 cases of MRSE-BSI were identified. Compared to the contaminated group, the C. striatum-BSI group had a shorter time to positivity of blood cultures (27.0 h vs. 42.5 h, P = 0.011). C. striatum-BSI group had a longer time to positivity (27 h) when compared to both the MRSA (20 h) and MRSE groups (19 h) (p < 0.05). Appropriate therapy within 24 h of BSI onset was significantly lower in the C. striatum group (28%) compared to the MRSA (64.5%) and MRSE (65.9%) groups (p < 0.005). The 28-day mortality was higher in the C. striatum group (52.0%) compared to the MRSA (25.8%) and MRSE (18.2%) groups. ConclusionsGiven the distinct characteristics of C. striatum-BSI, including a longer time to positivity than other Gram-positive bacteria and higher mortality rates, we suggest prescribing early appropriate antibiotics if C. striatum-BSI is suspected.

Curcumin-Polyethylene Glycol Loaded on Chitosan-Gelatin Nanoparticles Enhances Infected Wound Healing.

The aim of the present study was to evaluate effects of curcumin-polyethylene glycol loaded on chitosan-gelatin nanoparticles (C-PEG-CGNPs) on healing of methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds in rat as a model study. Forty male Wistar rats were randomized into 5 groups of 8 animals each. In CNTRL group, no infected/no treated wounds were covered with sterile saline 0.9% solution (0.1 mL). In MRSA group, MRSA-infected wounds were only treated with sterile saline 0.9% solution (0.1 mL). In MRSA/CP group, 0.1 mL curcumin nanoparticles (1 mg/mL) was applied topically to treat MRSA-infected wounds. In MRSA/CG group, 0.1 mL CG (1 mg/mL) was applied topically to treat MRSA-infected wounds. In MRSA/CP-CG group, 0.1 mL CP-CG (1 mg/mL) was applied topically to treat MRSA-infected wounds. Microbiological examination; planimetric, biochemical, histological, morphometric studies, angiogenesis, hydroxyproline levels, and reverse transcription polymerase chain reaction for caspase 3, Bcl-2, and p53 showed significant difference between rats in MRSA/CP-CG group in comparison with other groups (P < .05). Accelerated and improved healing in wounds infected with MRSA were observed in animals treated with C-PEG-CGNPs. Via increasing solubility of curcumin in C-PEG-CGNP, this harmless and easily available composition could be considered to be topically applied in infected wounds.

Risk factors, antimicrobial susceptibility, and outcome of methicillin-resistant Staphylococcus aureus bacteremia in critically ill children with sepsis in a tertiary hospital in Egypt

Background Staphylococcus aureus bacteremia (SAB) and methicillin-resistant Staphylococcus aureus (MRSA) infection are associated with unfavorable outcomes. Aim To reveal the risk factors, sensitivity to antibiotics, and outcome of MRSA bacteremia in infants and children with sepsis. Settings and design A prospective observational cross-sectional study was performed in Mansoura University Children’s Hospital from March 2023 to January 2024. Patients and methods The study involved infants and children diagnosed with sepsis and confirmed SAB on blood culture. Demographic data and blood culture with antibiotics sensitivity were recorded. Risk factors for MRSA bacteremia, antibiotic susceptibility, and mortality are the study outcomes. Statistical analysis used Multivariate analysis was done to assess the predictors of MRSA infection. Results A total of 319 patients were admitted with sepsis. SAB was isolated from 133 patients, 99 (74.4%) with methicillin-sensitive Staphylococcus aureus and 34 (25.6%) with MRSA. Risk factors for the development of MRSA infection are the presence of hospital-acquired infection (adjusted odds ratio=6.95), prolonged mechanical ventilation, presence of shock, and decreased body weight. Mortality was higher in the MRSA group (20.6 vs. 6.1%, P=0.014) with prolonged median duration of pediatric intensive care unit admission (19.5 vs. 14 days; P=0.040). Linezolid and teicoplanin were the most efficient antibiotics used in MRSA with 100% sensitivity in-vitro cultures, whereas resistance to erythromycin (90.9%) was documented. Conclusion MRSA poses a significant threat in pediatric sepsis. The presence of hospital-acquired infection and prolonged mechanical ventilation are the chief predictors of MRSA infection. Linezolid and teicoplanin are the most sensitive antibiotics used in MRSA management.

Community-associated methicillin-resistant Staphylococcus aureus infection of diabetic foot ulcers in an eastern diabetic foot center in a tertiary hospital in China: a retrospective study

BackgroundDiabetic foot concerns are a major public health problem. Methicillin-resistant Staphylococcus aureus (MRSA) plays a significant role in diabetic foot ulcers. Community-associated MRSA has become notorious for skin and skin soft tissue infections over the last two decades. This study investigated MRSA infection in diabetic foot patients at a tertiary hospital, focusing on the epidemiology and characteristics of community-associated MRSA.MethodsA total of 149 patients with diabetic foot infection whose culture results indicated Staphylococcus aureus as the source were selected. Epidemiological investigations, clinical characteristics, laboratory index records, antibiotic susceptibility analysis, and clinical outcome tracking were performed in all cases. Based on oxacillin resistance using the Vitek Compact 2 system, cases were divided into methicillin-sensitive Staphylococcus aureus and MRSA groups. Subgroup analysis of the MRSA group was performed in accordance with the Centers for Disease Control definition: community-associated MRSA and hospital-associated MRSA.ResultsThe MRSA group (n = 41, 27.5%) had a longer duration of ulcers and hospital stay and higher hospitalization costs than the methicillin-sensitive Staphylococcus aureus group (n = 108, 72.5%). According to the classification criteria of Infectious Diseases Society of America, the severity of infection in the community-associated MRSA group was higher than that in the hospital-associated MRSA group. The analysis of antimicrobial susceptibility of 41 MRSA isolates showed that the resistance rates to erythromycin, clindamycin, quinolone, gentamicin, tetracycline, and rifampicin were 78.0%, 68.3%, 31.7%, 17.1%, 9.8%, and 2.4%, respectively. All the MRSA strains were sensitive to linezolid, tigecycline, and vancomycin. The resistance rates to quinolones and gentamycin in the community-associated MRSA group (both 0%) were lower than those in the hospital-associated MRSA group.ConclusionEmergence of MRSA in diabetic foot ulcer was associated with a prolonged wound duration and increased consumption of medical resources. Community-associated MRSA strains predominated among MRSA isolates from diabetic foot wounds and caused more severe infections.

Comparison of diagnosis and treatment of MSSA and MRSA osteomyelitis in children: a case–control study of 64 patients

BackgroundWe aimed to compare the clinical characteristics of acute osteomyelitis caused by methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) in children.MethodsWe retrospectively analyzed the data of 64 children treated between September 2017 and June 2021. Based on the bacterial culture results, they were divided into MRSA and MSSA infection groups. Both groups were treated with debridement and vacuum-assisted closure for negative pressure drainage. Parameters including clinical manifestations, number of operations, length of hospital stay, inflammatory indicators, and concurrent arthritis were compared between the two groups.ResultsIn the MRSA infection group, there was one case each of residual joint stiffness and pathological fracture. Conversely, the MSSA group had two cases of residual joint stiffness. The MRSA infection group was more prone to high fever (t = 3.61, P = 0.001), white blood cell count elevation (t = 2.41, P = 0.022), arthritis (X2 = 7.48, P = 0.013), metastatic abscess (X2 = 4.78, P = 0.042), and a shorter length of progression from onset to admission (t = − 2.04, P = 0.046); however, it required more surgeries (t = 2.68, P = 0.009) and longer hospital stay (t = 2.04, P = 0.045).ConclusionsPediatric acute osteomyelitis caused by MRSA is more prone to cause high fever and markedly elevated of white blood cell count, and is often accompanied with suppurative infection of adjacent joints and metastatic abscesses, thus requiring more surgeries and longer hospital stay.

A retrospective analysis of clinical characteristics and prognostic factors for 152 cases of Staphylococcus aureus bloodstream infection

To understand the clinical characteristics of Staphylococcus aureus bloodstream infection and the main risk factors affecting clinical prognosis, providing a reference for clinical prevention and control of Staphylococcus aureus bloodstream infection. In this study, the clinical data of 152 patients with Staphylococcus aureus bloodstream infection admitted to Guangdong Provincial People's Hospital from January 2019 to December 2021 were retrospectively analyzed by reviewing the electronic medical record system, including underlying diseases, clinical characteristics, risk factors, and bacterial resistance. Statistical methods such as Chi-Squared Test and t Test were used to analyze the related risk factors that may affect the clinical characteristics and prognosis of patients with Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection, then the variables with P<0.05 in univariate analysis were included in the multivariate logistic regression model to analyze the independent risk factors of poor prognosis. The results showed among 152 patients with Staphylococcus aureus bloodstream infection, 50 patients (32.89%) were infected with MRSA. In comparison, 102 patients (67.11%) were infected with methicillin-sensitive Staphylococcus aureus (MSSA). Except for rifampicin, the resistance rate of MRSA to commonly used antibiotics was all higher than that of MSSA, and the difference was statistically significant (Chi-square values were 8.272, 11.972, 4.998, 4.776, respectively;all P-values are less than 0.05). Strains resistant to vancomycin, linezolid, and quinupristin/dalfopristin were not found. In the MRSA group, indwelling catheter and drainage tube, carbapenems, and β-lactamase inhibitor treatment were significantly higher than the MSSA group. The difference was statistically significant (P<0.05). The incidence of poor prognosis of bloodstream infection in the MRSA group was higher than that in the MSSA group (34.00% vs 13.73%), and the difference was statistically significant (χ2=8.495, P<0.05). No independent risk factors associated with poor prognosis were found in the included patients with MRSA bloodstream infection.Multivariate Logistic regression model analysis showed that solid malignant tumors (OR=13.576, 95%CI: 3.352-54.977, P<0.05), mechanical ventilation (OR=7.468, 95%CI: 1.398-39.884, P<0.05) were the most important independent risk factors for poor prognosis in patients with Staphylococcus aureus bloodstream infection. In summary, the poor prognosis rate of MRSA bloodstream infection is higher than that of MSSA. The clinical evaluation of related risk factors should be strengthened, targeted prevention and control interventions should be taken to improve the prognosis of patients with Staphylococcus aureus bloodstream infection, and the use of antibiotics should be rational and standardized, to control bacterial infection and drug resistance effectively.

1224. The incidence of severe C. striatum hospital-acquired pneumonia sharply increased and was associated with a high mortality rate

Abstract Background The clinical information on patients with severe C. striatum pneumonia who require intensive care unit admission is currently limited. Methods We investigated the incidence and characteristics of severe Corynebacterium striatum pneumonia during a 6-year period at Asan Medical Center in comparison with severe pneumonia associated with MRSA. Results Between 2014 and 2019, there were 27 adult cases of severe C. striatum pneumonia. The majority of the cases (70.4%) were hospital-acquired pneumonia (HAP), and about half of the patients (51.9%) were immunocompromised. The incidence of C. striatum HAP significantly increased from 1.0% (2/200) in 2014-2015 to 5.4% (10/185) in 2018-2019 (P &amp;lt; 0.001), while the incidence of severe methicillin-resistant Staphylococcus aureus (MRSA) HAP significantly decreased from 12.0% to 2.7% during the same period. Of the 75 HAP cases whose bacterial pathogens were identified in 2018–2019, C. striatum was responsible for 13.3% of the cases. The 90-day mortality rates were similarly high in the C. striatum and MRSA groups (59.3% vs. 50.5%, P = 0.42). Conclusion In conclusion, C. striatum was a major pathogen of recent severe HAP and was associated with a substantially high mortality rate. Disclosures All Authors: No reported disclosures.

Severe Pneumonia Caused by Corynebacterium striatum in Adults, Seoul, South Korea, 2014-2019.

We investigated the proportion and characteristics of severe Corynebacterium striatum pneumonia in South Korea during 2014-2019. As part of an ongoing observational study of severe pneumonia among adult patients, we identified 27 severe C. striatum pneumonia cases. Most (70.4%) cases were hospital-acquired, and 51.9% of patients were immunocompromised. C. striatum cases among patients with severe hospital-acquired pneumonia (HAP) increased from 1.0% (2/200) during 2014-2015 to 5.4% (10/185) during 2018-2019, but methicillin-resistant Staphylococcus aureus (MRSA) infections among severe HAP cases decreased from 12.0% to 2.7% during the same timeframe. During 2018-2019, C. striatum was responsible for 13.3% of severe HAP cases from which bacterial pathogens were identified. The 90-day mortality rates were similarly high in the C. striatum and MRSA groups. C. striatum was a major cause of severe HAP and had high mortality rates. This pathogen is emerging as a possible cause for severe pneumonia, especially among immunocompromised patients.

Analysis of clinical features and poor prognostic factors of acute hematogenous osteomyelitis in children

Objective: To analyze the clinical characteristics, pathogenic bacteria, complications and risk factors of prognosis of acute hematogenous osteomyelitis in children. Methods: The clinical manifestations, laboratorg tests, etiological charateristics and clinical data of 107 patients with acute hematogenous osteomyelitis admitted to Beijing Children's Hospital from January 2017 to December 2020 were retrospectively analyzed. According to the drug sensitivity results of Staphylococcus aureus, the group was divided into methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA) group; according to the presence or absence of complications, the group was divided into the group with and without complications; according to the prognosis of the follow-up children, the group was divided into good prognosis and poor prognosis. The χ2 test or Mann-Whitney U test used for comparison between groups, and Logistic regression was used to analyze the risk factors for complications and prognosis. Results: Of the 107 patients, 62 were males and 45 were females. The age of presentation was 5.6 (1.7, 10.0) years, including 5 patients (4.7%) age from >28 days to 3 months, 46 patients (43.0%) age from >3 months to 5 years, 43 patients (40.2%)>5-12 years of age, and 13 patients (12.1%)>12-18 years of age. The first symptoms were acute fever in 35 patients (32.7%), limb pain in 24 patients (22.4%), and fever with limb pain in 23 patients (21.5%). Pathogen culture was positive in 75 patients (70.1%), Streptococcus pyogenes, Salmonella enterica and Escherichia coli in 1 case (1.4%) each, and Staphylococcus aureus in 72 cases (96.0%), among them, 47 cases were MSSA, 22 cases were MRSA, and 3 cases had positive reports of Staphylococcus aureus from other hospitals without drug-sensitive tests. The proportion of infected children living in rural areas and receiving surgical treatment was higher in the MRSA group than in the MSSA group (14 cases (63.6%) vs. 18 cases (38.3%) and 21 cases (95.5%) vs. 33 cases (70.2%), χ2=3.87, 4.23, both P<0.05). Sixty-five children had no complications while 42 children (39.3%) suffered from complications. Common complications consisted of 19 cases (17.8%) of sepsis, 17 cases (15.9%) of septic arthritis, and 12 cases (11.2%) of venous thrombosis. The group with complications showed higher mental changes, decreased appetite and (or) weakness, positive pathogenic cultures, and time from admission to surgery than the group without complications (18 cases (42.9%) vs. 9 cases (13.8%), 20 cases (47.6%) vs. 12 cases (18.5%), 34 cases (81.0%) vs. 41 cases (63.1%), 3.5 (2.0, 6.0) vs. 2.0 (1.0, 4.0) d,χ2=11.38, 10.35, 3.89, Z=2.21, all P<0.05). The poor prognosis group had more comorbidities, combined local complications, and positive aureus than the good prognosis group (10/15 vs. 34.9% (30/86), 7/15 vs. 17.4% (15/86), 14/15 vs. 61.6% (53/86), χ2=5.39, 6.40, 4.42, all P<0.05). Multifactorial Logistic regression analysis showed that acute phase C-reactive protein (CRP) was both an independent risk factor for complications (OR=1.01, 95%CI 1.01-1.02) and an independent risk factor for poor prognosis (OR=1.01, 95%CI 1.00-1.02). Conclusions: The first symptoms of acute hematogenous osteomyelitis are acute fever, limb pain, and fever with limb pain are most common. Staphylococcus aureus is the most common pathogenic organism. Those with loss of appetite and (or) weakness, mental changes, positive pathogenic cultures, and longer time between admission and surgery are prone to complications. Those with complications, combined local complications, and positive for Staphylococcus aureus had a poor prognosis. Elevated CRP is an independent risk factor not only for complications but for poor prognosis as well.

Role of Bioaerosols on the Short-Distance Transmission of Multidrug-Resistant Methicillin-Resistant Staphylococcus aureus (MRSA) in a Chicken Farm Environment.

Methicillin-resistant Staphylococcus aureus (MRSA) is a dynamic and tenacious pathogenic bacterium which is prevalent in livestock farming environments. This study investigated the possibility of MRSA spread via bioaerosol transmission from an indoor chicken farm environment to outdoors downwind (up to 50 m). The concentration of total airborne bacteria colony formation units (CFUs) was decreased with increasing sampling distance ranging from 9.18 × 101 to 3.67 × 103 per air volume (m3). Among the 21 MRSA isolates, 15 were isolated from indoor chicken sheds and exposure square areas, whereas 6 were isolated from downwind bioaerosol samples. Molecular characterization revealed that all of them carried the staphylococcal cassette chromosome mec (SCCmec) VIII, and they were remarkably linked with the hospital-associated MRSA group. Spa typing analysis determined that all MRSA isolates belonged to spa type t002. Virulence analysis showed that 100% of total isolates possessed exfoliative toxin A (eta), whereas 38.09% and 23.80% strains carried exfoliative toxin B (etb) and enterotoxin A (entA). Additionally, all of these MRSA isolates carried multidrug resistance properties and showed their resistance against chloramphenicol, ciprofloxacin, clindamycin, tetracycline, and erythromycin. In addition, chi-squared statistical analysis displayed a significant distributional relationship of gene phenotypes between MRSA isolates from chicken farm indoor and downwind bioaerosol samples. The results of this study revealed that chicken farm indoor air might act as a hotspot of MRSA local community-level outbreak, wherein the short-distance dispersal of MRSA could be supported by bioaerosols.

1301. Risk Factors for Methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa in Community Acquired Pneumonia

Abstract Background The 2019 American Thoracic Society and Infectious Diseases Society of America Community-Acquired Pneumonia (CAP) guidelines concluded that the major risk factors for methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PsA) include prior isolation of these organisms and previous hospitalization with IV antibiotic use within 90 days. However, the guidelines recognized that results may vary by region and recommended local validation of risk factors. The primary objective of this study was to determine which potential risk factors are associated with MRSA and Pseudomonas aeruginosa in CAP in our institution. This study also evaluated appropriateness of antibiotics used for empiric CAP therapy. Methods This was a single-center, retrospective cohort study performed in an urban academic medical center in Cleveland, OH. Adults hospitalized for CAP who had a respiratory culture performed between January 2016 and September 2020 were included. Patients were randomized in a 1:1:1 ratio into MRSA, PsA, and non-resistant CAP (NR-CAP) groups. Patients with bacterial co-infections or resistant pathogens other than MRSA or PsA were excluded. Results The study included 111 patients with 37 patients in each group. The median age was 61 years (IQR 52-70), and 58.6% of patients were male. There were no independent risk factors for MRSA (Table 1). Independent risk factors for PsA included prior isolation and enteral feeding (Table 2). MRSA risk factors as defined by the 2019 CAP guidelines were found in 48.6% of patients with MRSA CAP (Figure 1). Guideline-defined PsA risk factors were found in 56.8% of patients with PsA CAP (Figure 2). In NR-CAP, 62.2% received empiric MRSA coverage while only 27% had a guideline-defined risk factor; PsA coverage was administered in 78.4% of NR-CAP patients, but risk factors were found in only 24.3% of this cohort. MRSA and P. aeruginosa Risk Factor Analyses Empiric MRSA and P. aeruginosa Coverage and Guideline-Defined Risk Factors Conclusion Our findings were consistent with the risk factors identified in the 2019 CAP guidelines, but additional risk factors may be present in our patient population. Empiric coverage for MRSA and PsA was disproportionately high relative to the rate of recovery. This study encourages local validation of risk factors; however, further analyses are needed to determine the impact on empiric therapy. Disclosures All Authors: No reported disclosures

Clinical characteristics of lactational breast abscess caused by methicillin-resistant Staphylococcus aureus: hospital-based study in China

BackgroundThis study aimed to identify the differences in clinical characteristics, puncture efficacy, antibiotic use, treatment duration, breastfeeding post-illness, and recurrence of patients with breast abscesses caused by methicillin-resistant Staphylococcus aureus (MRSA) or methicillin-susceptible Staphylococcus aureus (MSSA) infection during lactation.MethodsThe clinical data of patients with breast abscesses during lactation who were treated from January 2014 to February 2017 at Haidian Maternal and Child Health Hospital, Beijing, were reviewed. According to bacterial culture results, they were divided into MRSA (n = 260) and MSSA (n = 962) groups. Hospitalization (whether or not the patients were hospitalized), postpartum period, maternal age, location of abscess cavities, number of abscess cavities, amount of pus, frequency of needle aspiration, failure of needle aspiration, antibiotic use, treatment duration, cessation of breastfeeding and recurrence were compared between the two groups using a t-test and a chi-squared test.ResultsWe noted that only the cessation of breastfeeding was statistically significantly different between the two groups (P = 0.018). Hospitalization, postpartum period, maternal age, location of abscess cavities, number of abscess cavities, amount of pus, number of needle aspiration, failure of needle aspiration, antibiotic use, treatment duration and recurrence showed no statistically significant differences (P = 0.488, P = 0.328, P = 0.494, P = 0.218, P = 0.088, P = 0.102, P = 0.712, P = 0.336, P = 0.512, P = 0.386 and P = 0.359, respectively).ConclusionsThere was no difference in clinical characteristics between breast abscesses infected by MRSA and those infected by MSSA. Ultrasound-guided needle aspiration could be the first choice for MRSA-infected breast abscess treatment. There is no need to increase antibiotic use because of MRSA infection, unless it is necessary. The reason why more patients with MRSA infected breast abscesses terminated breastfeeding is unclear from this study.

De novo methicillin-resistant Staphylococcus aureus vs. methicillin-sensitive Staphylococcus aureus infections of the spine, similar clinical outcome, despite more severe presentation in surgical patients.

Vertebral osteomyelitis (VO) is a severe infection of the vertebral body and the adjacent disc space, where Staphylococcus aureus is most commonly isolated. The objective of this retrospective study was to determine risk factors for and compare outcome differences between de novo methicillin-resistant Staphylococcus aureus (MRSA) VO and methicillin-sensitive Staphylococcus aureus (MSSA) VO. A retrospective cohort study was performed by review of the electronic medical records of 4541 consecutive spine surgery patients. Among these 37 underwent surgical treatment of de novo MRSA and MSSA spinal infections. Patient demographics, pre- and postoperative neurological status (ASIA impairment score), surgical treatment, inflammatory laboratory values, nutritional status, comorbidities, antibiotics, hospital stay, ICU stay, reoperation, readmission, and complications were collected. A minimum follow-up (FU) of 12months was required. Among the 37 patients with de novo VO, 19 were MRSA and 18 were MSSA. Mean age was 52.4 and 52.9years in the MRSA and MSSA groups, respectively. Neurological deficits were found in 53% of patients with MRSA infection and in 17% of the patients with MSSA infection, which was statistically significant (p < 0.05). Chronic renal insufficiency and malnutrition were found to be significant risk factors for MRSA VO. Preoperative albumin was significantly lower in the MRSA group (p < 0.05). Patients suffering from spinal infection with chronic renal insufficiency and malnutrition should be watched more carefully for MRSA. The MRSA group did not show a significant difference with regard to final clinical outcome despite more severe presentation.

Bacteria drug resistance profile affects knee and hip periprosthetic joint infection outcome with debridement, antibiotics and implant retention

BackgroundEvaluate the effect of bacteria drug resistance profile on the success rates of debridement, antibiotics and implant retention.MethodsAll early acute periprosthetic infections in hip and knee arthroplasties treated with DAIR at our institution over the period from 2011 to 2015 were retrospectively analyzed. The success rate was evaluated according to the type of organism identified in culture: multidrug-sensitive (MSB), methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Gram-negative bacteria (MRB) and according to other risk factors for treatment failure. The data were analyzed using univariate and multivariate statistics.ResultsFifty-seven patients were analyzed; there were 37 in the multidrug-sensitive bacteria (MSB) group, 11 in the methicillin-resistant Staphylococcus aureus (MRSA) group and 9 in the other multidrug-resistant Gram-negative bacteria (MRB) group. There was a statistically significant difference (p < 0.05) in the treatment failure rate among the three groups: 8.3% for the MSB group, 18.2% for the MRSA group and 55.6% for the MRB group (p = 0.005). Among the other risk factors for treatment failure, the presence of inflammatory arthritis presented a failure rate of 45.1 (p < 0.05).ConclusionDAIR showed a good success rate in cases of early acute infection by multidrug-sensitive bacteria. In the presence of infection by multidrug-resistant bacteria or association with rheumatic diseases the treatment failure rate was higher and other surgical options should be considered in this specific population. The MRSA group showed intermediate results between MSB and MRB and should be carefully evaluated.

Curcumin Nanoparticles Improved Diabetic Wounds Infected With Methicillin-Resistant Staphylococcus aureus Sensitized With HAMLET

Accurately orchestrated course of events normally observed in healing are not followed in diabetic wounds, and bacterial colonization/infection further messes up the process. Novel therapeutic options for treatment of infections caused by multidrug-resistant Staphylococcus aureus are urgently needed. HAMLET (human α-lactalbumin made lethal to tumor cells) has been reported to be able to sensitize bacterial pathogens to traditional antimicrobial agents. The aim was to assess the wound healing activity of curcumin nanoparticles in diabetic wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) sensitized with HAMLET. Fifty male rats were randomized into 5 groups of 10 animals each. In CONTROL group, 0.1-mL sterile saline 0.9% solution was added to the wounds with no infection. In MRSA group, the wounds were infected with MRSA and only treated with 0.1-mL sterile saline 0.9% solution. In MRSA/HAMLET group, infected wounds were treated with HAMLET (100 µg). In MRSA/CNP group, animals with infected wounds were treated with 0.1 mL topical application of 1 mg/mL curcumin nanoparticles. In MRSA/CNP/HAMLET group, animals with infected wounds were treated with topical application of 0.1 mL solution of curcumin nanoparticles (1 mg/mL) and HAMLET (100 µg). All test formulations were applied for 10 days, twice a day, starting from first treatment. Microbiological examination; planimetric, biochemical, histological, and quantitative morphometric studies; immunohistochemical staining for angiogenesis; determination of hydroxyproline levels; and reverse transcription polymerase chain reaction for caspase 3, Bcl-2, and p53 showed that there was significant difference between animals in MRSA/CNP/HAMLET group compared with other groups (P < .05). Curcumin nanoparticles improved diabetic wounds infected with MRSA sensitized with HAMLET and had the potential to offer more attention to this safer agent for topical use in infected diabetic wounds.

Clinical and economic impact of methicillin-resistant Staphylococcus aureus: a multicentre study in China

Methicillin-resistant Staphylococcus aureus (MRSA) has become a serious threat to global health. In China, the proportion of S. aureus isolates that were MRSA was 44.6% in 2014. The clinical and economic impact of MRSA in China remains largely uninvestigated. This study aims to compare the differences in hospital costs, length of hospital stay, and hospital mortality rate between MRSA and methicillin-susceptible S. aureus (MSSA) colonization or infection and between MRSA cases and those without an S. aureus infection. A retrospective and multicentre study was conducted in four tertiary hospitals in China between 2013 and 2015. Inpatient characteristics and hospital costs were collected from electronic medical records. We conducted propensity score matching (PSM) to eliminate selection bias by balancing the potential confounding variables between the two groups. The main indicators included hospital costs, length of hospital stay, and hospital mortality rate. A total of 1,335 inpatients with MRSA, 1,397 with MSSA, and 33,606 without an S. aureus infection were included. PSM obtained 954 and 1,313 pairs between the MRSA and MSSA groups and between the MRSA and S. aureus-free groups, respectively. After PSM, MRSA colonization or infection is associated with an increased total hospital cost ranging from $3,220 to $9,606, an excess length of hospital stay of 6 days–14 days, and an attributable hospital mortality rate of 0–3.58%. Between the MRSA and MSSA groups, MRSA colonization or infection was significantly associated with a higher total hospital cost and longer length of hospital stay among survivors but not among non-survivors; however, there were no differences in the hospital mortality rate between these two groups. Between the MRSA and the S. aureus-free groups, MRSA colonization or infection was significantly associated with an increased total hospital cost, a prolonged length of hospital stay and a higher hospital mortality rate among both survivors and non-survivors. It is critical to quantify the clinical and economic impact of MRSA to justify resource allocation for the development of strategies to improve clinical outcomes and to reduce the economic burden.

Is there a higher prevalence of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) colonization in patients with antibiotic allergy labels?

A penicillin allergy label has been associated with significantly higher rates of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) colonization, and correspondingly poorer clinical outcomes. However, there are limited data examining the association between any antibiotic label and colonization rates. We sought to evaluate if there is a relationship between patients with an antibiotic allergy label and prevalence of MRSA or VRE colonization. We retrospectively reviewed all patients with an MRSA surveillance culture between December 15, 2014 and January 31, 2015, or a VRE surveillance culture between January 1, 2013 and January 31, 2015, at a tertiary community-based teaching hospital. Our primary objective was to evaluate the prevalence of MRSA or VRE colonization among patients with and without antibiotic allergies. Bivariate analyses included the χ² test and the Student t test to determine statistical significance for categorical and continuous variables, respectively. We included a total of 1,053 unique patients screened for MRSA, and 290 unique patients screened for VRE. The rate of MRSA and VRE colonization was 5.8% (62 of 1,053) and 32.4% (94 of 290), respectively, in our cohort. Antibiotic allergies were documented in approximately 1 out of 3 patients, 337 (32%) for the MRSA group and 94 (32%) for VRE group. There was a significant difference in MRSA colonization between patients with and without an antibiotic allergy, 28 of 337 (8.3%) versus 34 of 716 (4.7%) (P = .025), respectively. In contrast, there was no significant difference in antibiotic allergy rates with and without VRE colonization, 34 of 94 (36.2%) versus 92 of 196 (46.9%) (P = .10), respectively. An antibiotic allergy label was associated with significantly higher rates of MRSA colonization but no statistical difference with VRE colonization.

Risk Factors And Clinical Outcomes Of Hospital-Acquired MRSA Infections In Chongqing, China.

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen of hospital infection with multi-drug resistant characteristics. Its spread and epidemic pose great challenges to nosocomial infection control. This study was aimed to identify risk factors for hospital-acquired MRSA (HA-MRSA) infections and investigate its clinical outcome, developing infection control strategies and improving patient outcomes.MethodsA retrospective case-case-control study was conducted to compare patients in Southwest Hospital, Chongqing, People's Republic of China from January 2018 to December 2018 with control patients. In this study, 251 patients with MRSA nosocomial infection, 339 patients with methicillin-sensitive Staphylococcus aureus strains (MSSA) nosocomial infection, and 300 patients with non-Staphylococcus aureus infection were included.ResultsMultivariate analysis showed that presence of central venous catheters (odds ratio [OR], 1.932; 95% confidence interval [CI], 1.074–3.477; P=0.028), sputum suction (OR, 2.887; 95% CI, 1.591–5.240; p<0.001), and total hospital stays more than 30 days (OR, 3.067; 95% CI, 2.063–4.559; P<0.001) were independent risk factors for HA-MRSA. Renal insufficiency (OR, 2.744; 95% CI, 1.089–6.914; P=0.032) and receipt of immunosuppressors (OR, 3.140; 95% CI, 1.284–7.678; P=0.012) were independent predictors of poor prognosis of MRSA nosocomial infection. Moreover, empirical use of antibiotics (OR, 0.514; 95% CI, 0.282–0.935; P=0.029) was a protective factor for poor prognosis of MRSA nosocomial infection. In-hospital mortality in the MRSA group was not statistically significant compared with the other two groups; however, the rate of poor prognosis in the MRSA group was higher than that of the MSSA group (27.5% vs 17.1%, χ2=9.200, P=0.002) and the control group (27.5% vs 16.0%, χ2=19.190, P=0.001).ConclusionOur results have shown presence of central venous catheters, sputum suction, and total hospital stays more than 30 days were associated with nosocomial MRSA infection. Patients with renal insufficiency and immunosuppressive therapy were more likely to cause poor prognosis with MRSA infection, and the empirical use of antibiotics can effectively reduce the adverse clinical outcomes caused by MRSA infection. Based on above findings, strategies to control MRSA infection should emphasize more attention to these patients and appropriate empirical use of antibiotics.