Community-acquired Methicillin-resistant Staphylococcus Aureus Pneumonia Research Articles

Molecular Epidemiology of Community-Acquired Methicillin-Resistant Staphylococcus aureus and Clinical Characteristics of Different Sites of Infection.

Since community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) was recognized, the molecular epidemiology of CA-MRSA in China has been diverse. It is unclear whether different sites of CA-MRSA infection differ in antimicrobial resistance and clinical characteristics. The purpose of this study was to identify the molecular types, virulence factors and antimicrobial resistance of CA-MRSA strains and to analyze the clinical characteristics of different sites of CA-MRSA infection. 26 CA-MRSA strains were screened from Beijing Chao-Yang Hospital from 2014 to 2022. SCCmec type, MLST type, spa type, Panton-Valentine leukocidin (PVL), hemolysin α (Hla), phenolic soluble regulatory protein α (PSMα), toxic shock syndrome toxin-1 (TSST-1), and enterotoxin (SE) A to E were detected by PCR and gene sequencing. Antimicrobial susceptibility tests and the clinical features of CA-MRSA infection cases were collected for statistical analysis. The predominant type of CA-MRSA was ST59-t437-IV. New non-epidemic types, SCCmec VII, were also found. PVL was seen in 65.4% of CA-MRSA strains and TSST-1 was only be detected in 3.8% of CA-MRSA strain which caused poor prognosis. There were three types of infections: pneumonia (61.5%), infective endocarditis (7.7%), and skin and soft tissue infections (SSTIs) (30.8%). CA-MRSA pneumonia cases were secondary to influenza infection (37.5%). Patients with CA-MRSA-associated infective endocarditis were more likely to have underlying cardiac diseases. Patients with CA-MRSA-associated SSTIs were more likely to have a history of diabetes mellitus, and strains in this group were more susceptible to erythromycin and clindamycin. ST59-t437-IV was the primary CA-MRSA type in our research and in China. We proposed that TSST-1 might be one of the indicators to predict the severity and prognosis of CA-MRSA infection. Different sites of CA-MRSA infection had difference in antibiotics susceptibility testing and underlying diseases of patients. It could provide a new perspective on treating different types of CA-MRSA infection.

Clinical characteristics of and risk factors for secondary bloodstream infection after pneumonia among patients infected with methicillin-resistant Staphylococcus aureus

PurposeTo investigate the clinical features and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) pneumonia (MP) with secondary MRSA bloodstream infections (MRSA-BSI) (termed MP-BSI) compared with MP alone and to study the incidence of MP-BSI among patients with MP. MethodsThis was a retrospective, single-center study with clinical data derived from previous medical records. The cases were divided into groups: MP alone and MP-BSI. The determination of independent risk factors for MP-BSI relied on logistic regression analysis. Additionally, the crude outcomes were compared. ResultsA total of 435 patients with MP were recruited, with 18.9% (82/435) having MP-BSI. The median age was 62 (interquartile range, 51,72) years, and 74.5% of the patients were male. Multivariate analysis revealed that immunosuppression, community-acquired MP (CA-MP), time from initial to targeted antibiotic use, high Sequential Organ Failure Assessment (SOFA) score, increased respiratory rate, and elevated γ-GT level (all p < 0.05) were independent risk factors for MP-BSI, while targeted treatment with linezolid was a protective factor. Patients with MP-BSI had a longer duration of hospitalization (median days, 27.5 vs. 19, p = 0.001), a higher 28-day mortality rate (24.4% vs. 11.0%, p = 0.001), and a higher in-hospital mortality rate (26.8% vs. 14.7%, p = 0.009) than those with MP alone. ConclusionSecondary MRSA-BSI among patients with MP is not rare. Immunosuppression, CA-MP, time from initial to targeted antibiotic use, high SOFA score, increased respiratory rate and elevated γ-GT level are all independent risk factors for MP-BSI; however, linezolid, as a targeted antibiotic, is a protective factor. Moreover, patients with MP may have worse clinical outcomes when they develop MRSA-BSI.

Community-acquired Methicillin-resistant Staphylococcus aureus Pneumonia and Parapneumonic Effusion in a Male Patient with Diabetes: A Case Report

Methicillin-resistant Staphylococcus aureus (MRSA) infections are a primary health concern. They are commonly differentiated as hospital-acquired methicillin-resistant Staphylococcus aureus (HA-MRSA) and community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections, based on their epidemiology, susceptibility findings, and molecular typing patterns. Therefore, appropriate contact precautions and isolation measures should be implemented. CA-MRSA mostly causes skin and soft-tissue infections, but the probability and incidence of it causing sepsis and invasive infections have increased dramatically in recent years. In this study, we report a case of CA-MRSA pneumonia with pan-pneumonic effusion in a 59-year-old male diabetic patient with preexisting comorbidities such as diabetic ketoacidosis and non-ST elevated myocardial infarction. The early reporting of the organism’s identity and its antimicrobial susceptibility, as well as timely initiation of antibiotic therapy, aided in the successful management and cure of the patient.

Community-acquired methicillin-resistant Staphylococcus aureus pneumonia in a children's hospital. Our ten-year experience.

Community-acquired methicillinresistant Staphylococcus aureus (CA-MRSA) infections have increased in recent years. CAMRSA necrotizing pneumonia and empyema are now more common in children. To determine the prevalence of CA-MRSA pneumonia and its clinical and epidemiological characteristics compared to Streptococcus pneumoniae (SP) pneumonia in the same population. Descriptive, observational, cross-sectional study of patients hospitalized due to CA-MRSA pneumonia at Hospital de Niños Víctor J. Vilela (period: January 2008-December 2017). Out of 54 Staphylococcus aureus pneumonia cases, 46 (85 %) corresponded to CA-MRSA. The rate of CA-MRSA pneumonia ranged from 4.9/10 000 (2008) to 10/10 000 hospital discharges (2017). Sepsis/septic shock was observed in 41 %; empyema, in 96 %; pneumothorax, in 35 %; 90 % of cases required pleural drainage and 55 %, surgical debridement. Also, 65 % of patients were admitted to the intensive care unit (ICU); half of them required assisted mechanical ventilation. Two patients died. Strain resistance: 17 %, gentamicin; 13 %, erythromycin; and 11 %, clindamycin. Compared to SP pneumonia, CAMRSA pneumonia showed a higher risk for sepsis (95 % confidence interval; relative risk: 7.38; 3.32- 16.38) and admission to the ICU (RR: 4.29; 2.70- 6.83). No patient died due to SP pneumonia. The prevalence of CA-MRSA pneumonia doubled in the past decade. Compared to SP pneumonia, CA-MRSA pneumonia was more commonly accompanied by sepsis and septic shock, admission to the ICU, and ventilatory support requirement.

Successful rescue combination of extracorporeal membrane oxygenation, high-frequency oscillatory ventilation and prone positioning for the management of severe methicillin-resistant Staphylococcus aureus pneumonia complicated by pneumothorax: a case report and literature review

BackgroundTo describe the experience of combination therapy with extracorporeal membrane oxygenation(ECMO), high-frequency oscillatory ventilation(HFOV) and prone positioning in treating severe respiratory failure caused by community acquired methicillin resistant Staphylococcus aureus(CA-MRSA).Case presentationA 30-year-old female presented with fever and dyspnea for 3 days. She was diagnosed CA-MRSA pneumonia complicated by severe respiratory failure, pneumothorax and neutropenia. Venovenous ECMO was applied within 8 h of the pneumothorax diagnosis. For amelioration of ventilator-induced lung injury, HFOV and prone positioning were combined with ECMO. The patient’s condition improved considerably. ECMO was weaned on day 19, and she was discharged on day 48 with good lung recovery.ConclusionsTo the best of our knowledge, this was the first case in which ECMO was combined with HFOV and prone positioning to treat severe necrotic CA-MRSA pneumonia complicated with pneumothorax. This combination therapy may provide safe respiratory support, may minimize the risk of barotrauma, and provide better drainage of secretions in patients with necrotizing pneumonia.

Multiple Pneumatoceles in a 6-Week-Old Infant

Methicillin-resistant Staphylococcus aureus (MRSA) usually causes skin and soft tissue infections in children and is occasionally associated with hospital-acquired pneumonias, but in recent years, there has been an increase in the incidence of community-acquired MRSA pneumonia. We report a case of community-acquired Panton-Valentine leukocidin secreting MRSA necrotizing pneumonia in a previously well 6-week-old infant, who presented with multiple pneumatoceles. This case highlights the possibility of emerging community-acquired MRSA pneumonia in healthy infants.

Community-Acquired MRSA Pneumonia in an Urban Community Hospital: Risk Factors, Presentation, and Outcomes

Community-Acquired MRSA Pneumonia in an Urban Community Hospital: Risk Factors, Presentation, and Outcomes

A Case of Community-Acquired Methicillin-ResistantStaphylococcus aureusPneumonia

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has received considerable attention in recent years as the cause of infections in individuals in the community who do not have traditional risk factors for MRSA infection, such as hospitalization or contact with healthcare services. CA-MRSA strains have different molecular and antimicrobial susceptibilities, as compared to hospital-associated MRSA. Although CA-MRSA strains are primarily associated with skin and soft tissue infections, they can cause more invasive infections, such as severe community-acquired pneumonia. Reports on CA-MRSA pneumonia in Korea are sparse. Therefore, we report a case of CA-MRSA pneumonia with molecular typing of the MRSA isolate. (Korean J Med 2013;84:728-732)

Community acquired methicillin resistant Staphylococcus aureus pneumonia presenting along with multiple subcutaneous abscesses

Community onset necrotizing pneumonia due to community acquired methicillin resistant Staphylococcus aureus (CA-MRSA) is an emerging clinical entity, especially, following a viral infection, with substantial morbidity and mortality and survivors, have long-term pulmonary complications requiring treatment. The infectious diseases society of America guidelines has recently addressed the issue of MRSA as a possible pathogen that warrants empiric antibiotic therapy for community-acquired pneumonia (CAP) in patients requiring inpatient intensive care unit treatment, recommending the use of vancomycin or linezolid, with linezolid having an advantage due to its documented suppression of panton valentine leukocidin toxin production in CA-MRSA. We report a case of a child presenting with pyothorax and multiple subcutaneous absceses over the deltoid region. The pus from the abscesses and pyothorax and the expectorated sputum showed the growth of MRSA. The case was diagnosed as CA-MRSA pneumonia and was successfully treated with vancomycin but the patient required pulmonary decortications and long-term physiotherapy. The case highlights the importance of considering CA-MRSA in the initial empirical therapy for severe CAP and the long-term morbidity associated with this otherwise fatal disease.

Community‐acquired methicillin‐resistant Staphylococcus aureus pneumonia: A clinical audit

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) strains are primarily associated with skin and soft tissue infections; however, they are increasingly causing more invasive infections including severe community-acquired pneumonia. The objective of this study was to describe the clinico-pathological characteristics of community-acquired MRSA pneumonia. A retrospective analysis of case records from January 2002 to August 2008 was performed on patients admitted with community-acquired MRSA pneumonia to two large teaching hospitals. Sixteen patients with community-acquired MRSA pneumonia were identified. Their age ranged from 11 months to 86 years (median age; 30 years). Duration of symptoms before hospital presentation ranged from one to 21 days. Most patients had productive cough, fever and dyspnoea. The most common radiological presentation included multilobar consolidation (8/16), necrotizing consolidation (7/16) and empyema (5/16). Seven patients required intensive care support; four required ionotropic support and five required mechanical ventilation for a mean duration of 53 h and 6.6 days, respectively. Six patients underwent surgery (VATS or open thoracotomy). There was a mean delay of approximately 69 h (range; 18 h to 11 days) after presentation before appropriate MRSA antimicrobial treatment was initiated. Three patients died of complications from pneumonia, all within 72 h of presentation. Among survivors, the average length of hospital stay was 23.8 days (range; 10-49 days). Majority of survivors were left with mild residual radiological changes. Community-acquired MRSA pneumonia is increasing and should be suspected in patients with severe community-acquired pneumonia. There was a delay in initiation of appropriate antimicrobial treatment that could have lead to increased morbidity.

A 24-Year-Old Man With Cough, Rhabdomyolysis, and Pneumomediastinum

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) frequently causes severe necrotizing pneumonia in young patients. We present the case of a 24-year-old male, who was brought to the emergency department with persistent fevers, confusion, and severe cough. He was found to have necrotizing pneumonia, pneumomediastinum, and rhabdomyolysis with renal failure. Cultures were positive for influenza A and CA-MRSA. After a prolonged intensive care unit (ICU) stay, he made a complete recovery. Community-acquired MRSA pneumonia is a growing health threat that typically presents in young adults after, or in conjunction with, a flu-like illness. It is characterized by a rapidly progressive deteriorating clinical course.

Clinical Presentation of Community-Acquired MRSA Pneumonia

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections present as skin abscesses or — rarely — as severe pneumonia. In the

Expanded Clinical Presentation of Community-Acquired Methicillin-Resistant Staphylococcus aureus Pneumonia

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has been documented to cause community-acquired pneumonias (CAP), notable for necrotizing features. The frequency of occurrence, risk factors, and optimal treatment of CA-MRSA CAP are unclear. This was a retrospective analysis of patients admitted to Northwestern Memorial Hospital from January 2005 to April 2007 with initial clinical presentation of pneumonia and respiratory or blood culture positive for CA-MRSA. Definition of CA-MRSA was based on sensitivity to trimethoprim/sulfamethoxazole and clindamycin. Fifteen patients with CA-MRSA CAP were identified during the 28-month period. Only one of the 14 patients tested had evidence of preceding influenza, and no seasonal pattern was seen. Seven patients were never admitted to the ICU. Eight of 14 with chest CT scans had evidence of lung necrosis. Nine of 15 had evidence of pleural effusions early in their hospital course, and five of nine required at least one pleural drainage procedure. Seven of 15 were immunocompromised (three HIV, one acute lymphocytic leukemia [ALL], one high-dose steroids, and two immunoglobulin deficiency) with an additional three patients with diabetes. Mortality was only 13% (two of 15); both deaths occurred in patients with severe immunocompromise (ALL post chemotherapy and AIDS). Fourteen of 15 patients were treated with antimicrobials that inhibit exotoxin production (clindamycin or linezolid). CA-MRSA pneumonia is not necessarily a post-influenza infection. Despite necrotizing features in many, the mortality of CA-MRSA pneumonia in our series is lower than previously reported, and patients do not routinely require ICU care. Treatment with antibiotics that inhibit exotoxin production and/or nontoxigenic strains may explain this improved outcome.

Community‐acquired, methicillin‐resistant Staphylococcus aureus isolated from children with community‐onset pneumonia in China

Community-acquired, methicillin-resistant Staphylococcus aureus (CA-MRSA) has been associated with morbidity and mortality in various countries. In this study, we characterized the molecular and clinical features of pediatric CA-MRSA pneumonia in China. Between June 2006 and February 2008, 55 previously healthy children confined in eight hospitals countrywide were found to be afflicted with CA-MRSA pneumonia. A total of 55 strains collected from these children were analyzed by multilocus sequence typing (MLST), Staphylococcus cassette chromosome mec (SCCmec) typing, and spa typing. The Panton-Valentine leukocidin (PVL) gene was also detected. Overall, nine STs were obtained, with ST59 (40.4%) established to be the most prevalent type. We first registered the new ST1409 from a child with necrotizing pneumonia. SCCmecIVa was the most predominant type, followed by SCCmec type V. Twelve spa types were identified, of which one new spa type, t5348, was first detected and registered. One typical livestock-associated spa type, t034, was found in a 4-month-old girl living in the countryside. We also found that 40% of those isolates were PVL-positive. In addition, the median age of the children in this study was 10 months. A total of 69% (38/55) of the children with community-acquired pneumonia (CAP) had preceding influenza or influenza-like illness, and three ST910-MRSA-IV strains (PVL gene-positive) were associated with severe necrosis. The results indicated that the recent CA-MRSA found in Chinese children with CAP was largely associated with the spread of the ST59-MRSA-IV clone, and most of the PVL-positive strains in this study did not cause necrotic cases.

Pneumonia due to methicillin-resistant Staphylococcus aureus: clinical features, diagnosis and management

The review highlights the clinical findings and the management of community-acquired, health-care associated and nosocomial pneumonia due to methicillin-resistant Staphylococcus aureus (MRSA). Although previously considered as a purely nosocomial event, community-acquired MRSA pneumonia is underestimated and is spreading worldwide. A retrospective study showed that almost half of patients with nonnosocomial MRSA pneumonia admitted to a large teaching hospital did not present established criteria for healthcare-associated infections. Recent data show that MRSA ventilator-associated pneumonia is associated with significantly higher mortality than ventilator-associated pneumonia caused by methicillin-susceptible Staphylococcus aureus. Therefore, prompt and appropriate therapy is essential. The optimal therapy for MRSA pneumonia has not been fully elucidated. Although vancomycin has been considered the gold standard for the treatment of MRSA infections, clinical failures have also been reported in the presence of in-vitro susceptibility. Linezolid may provide improved outcomes compared with vancomycin in patients with MRSA pneumonia, but validation in a prospective trial is currently lacking. Recently licensed tigecycline and dalbavancin, a drug in phase III trial, look promising. Animal models showed that immunization against a cytolytic toxin secreted by most Staphylococcus aureus strains protects against lethal pneumonia. Rapid recognition of possible staphylococcal infection in patients with severe pneumonia is essential. The treatment of MRSA pneumonia must be prompt and effective in order to allow a fast microbiological clearance and to successfully manage the infection.

Pneumonia Caused by Methicillin‐ResistantStaphylococcus aureus

A recent increase in staphylococcal infections caused by methicillin-resistant Staphylococcus aureus (MRSA), combined with frequent, prolonged ventilatory support of an aging, often chronically ill population, has resulted in a large increase in cases of MRSA pneumonia in the health care setting. In addition, community-acquired MRSA pneumonia has become more prevalent. This type of pneumonia historically affects younger patients, follows infection with influenza virus, and is often severe, requiring hospitalization and causing the death of a significant proportion of those affected. Ultimately, hospital-acquired MRSA and community-acquired MRSA are important causes of pneumonia and present diagnostic and therapeutic challenges. Rapid institution of appropriate antibiotic therapy, including linezolid as an alternative to vancomycin, is crucial. Respiratory infection-control measures and de-escalation of initial broad-spectrum antibiotic regimens to avoid emergence of resistant organisms are also important. This article reviews the clinical features of, diagnosis of, and therapies for MRSA pneumonia.

Community-acquired methicillin-resistant Staphylococcus aureus pneumonia

Community-acquired methicillin-resistant Staphylococcus aureus is increasingly recognized as an important pathogen causing skin and soft tissue infections. We report a case of severe necrotizing pneumonia caused by community-acquired methicillin-resistant S. aureus in a peripartum woman. This case illustrates that community-acquired methicillin-resistant S. aureus must be considered as a potential pathogen in severe community-acquired pneumonia.

Necrotizing pneumonia caused by community-acquired methicillin-resistant Staphylococcus aureus: an increasing cause of “mayhem in the lung”

Although long recognized as a nosocomial organism, methicillin-resistant Staphylococcus aureus (MRSA) has been noted to have an increasing incidence in both immunocompromised and otherwise healthy people in the community. Community-acquired MRSA (CA-MRSA) is genetically distinct from hospital-acquired MRSA and frequently expresses the Panton-Valentine leukocidin toxin, which confers an aggressive necrotizing phenotype and is accompanied by a poor prognosis. We present a case of CA-MRSA pneumonia with the aim to alert the radiologist of the radiographic manifestations of this increasingly encountered and frequently fatal disease.

Community-acquired Methicillin-resistant Staphylococcus aureus Pneumonia

The aim of our study was to review the radiologic findings of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) pneumonia. The hospital infection control computer database was used to identify patients who had a CA-MRSA infection with organisms isolated from blood, bronchoalveolar lavage fluid, or pleural fluid samples. Criteria for CA-MRSA pneumonia were consolidation seen on chest radiography or computed tomography (CT), growth of MRSA from sputum and/or sterile pulmonary site, clinical complaints of cough and/or shortness of breath. Chest radiographs and CT scans for 9 patients (5 men, mean age 45 y, range 35 to 71 y) were retrospectively reviewed by 2 chest radiologists. The most common chest radiographic finding was consolidation, which was bilateral in 7 patients and unilateral in 2 patients. The consolidation was patchy and nonsegmental in 5 and segmental in 4 patients. Two patients had cavitation evident on the chest radiograph. The most common CT scan findings were bilateral (n=8), often symmetric (n=5) consolidation, bilateral septal lines (n=7), and multiple nodules (n=5). Cavitation was present in 5 patients, either in regions of consolidation (n=5) or in large nodules (n=3). Five patients with CA-MRSA pneumonia had rapid clinical deterioration requiring ventilatory support. Two patients died. CA-MRSA pneumonia is characterized by extensive bilateral consolidation and frequent cavitation and is commonly associated with rapid progression and clinical deterioration. CT is superior to radiography in demonstrating the presence of cavitation.

The Modified APACHE II Score Outperforms Curb65 Pneumonia Severity Score as a Predictor of 30-Day Mortality in Patients With Methicillin-Resistant Staphylococcus aureus Pneumonia

To compare the predictive accuracy for 30-day mortality of the CURB65 score adopted by the British Thoracic Society and the simpler CRB65 score to APACHE (acute physiology and chronic health evaluation) II in patients with methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. A retrospective, single-center, observational cohort study. Barnes-Jewish Hospital, a 1,200-bed urban teaching hospital. Adult patients requiring hospitalization identified to have MRSA pneumonia. Retrospective data collection from automated hospital, microbiology, and pharmacy databases. Two hundred eighteen patients with MRSA pneumonia were identified over a 3-year period. Forty-four patients (20.2%) died during hospitalization. All three prediction rules had high negative predictive values but relatively low positive predictive values at most cut-off points examined. APACHE II had the greatest area under the receiver operating characteristic curve (0.805; 95% confidence interval [CI], 0.743 to 0.866) compared to CURB65 (0.634; 95% CI, 0.541 to 0.727) and CRB65 (0.643; 95% CI, 0.546 to 0.739) [p < 0.05 for both comparisons]. Similar results were obtained when the subgroups of community-acquired MRSA pneumonia and health-care-associated MRSA pneumonia were examined separately. APACHE II outperformed CURB65 and CRB65 for initial prognostic assessment in MRSA pneumonia.