Purulent pericardial effusion

A fatal case of purulent pericardial effusion in which the patient was treated with sulfadiazine and penicillin is presented.     

Antibody-mediated enhancement of community-acquired methicillin-resistant Staphylococcus aureus infection

Community-acquired infections caused by methicillin-resistant Staphylococcus aureus (MRSA) expressing the Panton-Valentine leukocidin (PVL) are rampant, but the contribution of PVL to bacterial virulence remains controversial. While PVL is usually viewed as a cytotoxin, at sublytic amounts it activates protective innate immune responses. A leukotoxic effect might predominate in high inoculum studies, whereas protective proinflammatory properties might predominate in settings with lower bacterial inocula that more closely mimic what initially occurs in humans. However, these protective effects might possibly be neutralized by antibodies to PVL, which are found in normal human sera and at increased levels following PVL⁺ S. aureus infections. In a low-inoculum murine skin abscess model including a foreign body at the infection site, strains deleted for the pvl genes replicated more efficiently within abscesses than isogenic PVL⁺ strains. Coinfection of mice at separate sites with isogenic PVL⁺ and PVL^- MRSA abrogated the differences in bacterial burdens, indicating a systemic effect on host innate immunity from production of PVL. Mice given antibody to PVL and then infected with seven different PVL⁺ strains also had significantly higher bacterial counts in abscesses compared with mice given nonimmune serum. Antibody to PVL had no effect on MRSA strains that did not produce PVL. In vitro, antibody to PVL incapacitated PVL-mediated activation of PMNs, indicating that virulence of PVL⁺ MRSA is enhanced by the interference of PVL-activated innate immune responses. Given the high rates of primary and recurring MRSA infections in humans, it appears that antibodies to PVL might contribute to host susceptibility to infection.     

Prostatic abscess due to community-acquired methicillin-resistant Staphylococcus aureus

We report what we believe to be the second case of a prostatic abscess due to community-acquired methicillin-resistant Staphylococcus aureus (MRSA). A previously healthy diabetic man presented with dysuria, fatigue, weight loss, a tender prostate, and leukocytosis. Computerized tomography of the abdomen and pelvis demonstrated a large prostatic abscess at the base of the bladder. Blood, urine, and pus obtained by percutaneous aspiration grew MRSA. Percutaneous drainage and prolonged therapy with intravenous vancomycin resulted in cure. Prostatic abscess is most often caused by Gram-negative organisms. Community-acquired MRSA, which usually causes skin and soft tissue infections, may also cause prostatic abscess. The mainstay of treatment of prostatic abscess is drainage, which can be accomplished either percutaneously or transurethrally. Gram stain and culture of the drainage will direct proper antibiotic selection.     

Treatment approaches for community-acquired methicillin-resistant Staphylococcus aureus infections

PURPOSE OF REVIEW: This review addresses therapeutic approaches to community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections, focusing on recently published data in the English-language medical literature dating from June 2004 to July 2005. RECENT FINDINGS: During the reviewed time period, the overall understanding of the epidemiology and virulence of community-acquired MRSA has continued to advance. This same period has also seen numerous works dealing with the newer and emerging anti-staphylococcal antimicrobial agents. Important clinical trials involving linezolid, daptomycin, tigecycline, dalbavancin, and telavancin have been completed. At the same time, owing to the cost of newer agents and the broad susceptibility pattern of community-acquired MRSA, many older antimicrobial agents (long-acting tetracyclines, fluoroquinolones, rifampin, trimethoprim-sulfamethoxazole, and clindamycin) have also been reexamined. SUMMARY: As data accumulates, the newer antimicrobial agents active against community-acquired MRSA continue to demonstrate their value. Despite the appeal and abundant publications involving newer agents, older antimicrobials certainly retain a therapeutic role. Considerable work needs to be done prospectively evaluating older agents for community-acquired MRSA disease. The most important therapeutic intervention for the majority of community-acquired MRSA infections is adequate drainage of purulent fluid collections. Antimicrobial selection for community-acquired MRSA infections should be governed by disease severity, susceptibility patterns (especially based on timely clinical specimen culture), clinical response to therapy, and cost.     

Treatment of community-acquired methicillin-resistant Staphylococcus aureus in children

PURPOSE OF REVIEW: The concept of methicillin-resistant Staphylococcus aureus (MRSA) associated with broad resistance, nosocomial acquisition, and known risk factors has recently been expanded. A new type of MRSA that is resistant to fewer antibiotics has emerged in pediatric practice since the mid-1990s. These isolates are community acquired and have been reported from diverse geographic regions. Awareness of these organisms is important for appropriate treatment of S. aureus infections in children. RECENT FINDINGS: Community-acquired MRSA (CA-MRSA) isolates are similar in many respects to community-acquired methicillin-susceptible S. aureus (CA-MSSA). There are usually no differences in risk factors between children with CA-MRSA infections and those with CA-MSSA infections or their household contacts. In one study, however, multivariate analysis showed that age greater than 1 year and health care contact in the preceding month were significant risk factors for CA-MRSA. Skin and soft tissue infections are the most common manifestations, although serious invasive infections and death may occur. Pneumonia has been reported more often in children with CA-MRSA than in those with CA-MSSA. Clindamycin is an effective therapy for CA-MRSA, but there is a risk for development of clindamycin resistance during treatment of a CA-MRSA that is clindamycin susceptible and inducibly erythromycin resistant. Trimethoprim-sulfamethoxazole is likely to be effective, and linezolid is a new option for treatment. SUMMARY: The appearance of CA-MRSA has important implications for therapy of infections caused by S. aureus in children. Three specific issues are the development of resistance during clindamycin therapy, insufficient data on the use of trimethoprim-sulfamethoxazole in serious CA-MRSA infections, and the appropriate role for newer antibiotics such as linezolid.     

Cavernous sinus thrombosis and meningitis from community-acquired methicillin-resistant Staphylococcus aureus infection

Septic cavernous sinus thrombosis is an uncommon clinical syndrome with a high morbidity and mortality. The commonest bacterial pathogen is Staphylococcus aureus. We describe the study of a patient with cavernous sinus thrombosis and meningitis caused by community-acquired methicillin-resistant S. aureus (CA-MRSA) infection. The isolate was genotyped as the ST93 (Queensland) clone of CA-MRSA and carried the Panton-Valentine leucocidin genes. Cure was obtained following prolonged antimicrobial therapy with vancomycin, rifampicin, cotrimoxazole and linezolid. Given the high morbidity and mortality of cavernous sinus thrombosis and the worldwide recent emergence of CA-MRSA, clinicians treating patients with this infection should consider early empirical coverage for CA-MRSA with an antimicrobial agent, such as vancomycin or linezolid, particularly in the presence of suspected facial staphylococcal skin infections. If vancomycin is used, we emphasize that high doses may be required to achieve even low levels in the cerebrospinal fluid.     

社区获得性耐甲氧西林金黄色葡萄球菌耐药性及毒力的分子基础

目前社区获得性耐甲氧西林金黄色葡萄球菌在世界范围流行,其耐药性和毒力与医院获得性耐甲氧西林金黄色葡萄球菌不同.社区获得性耐甲氧西林金黄色葡萄球菌能分泌多种毒素,在疾病的发生发展过程中起重要作用.     

The emergence of severe, community-acquired methicillin-resistant Staphylococcus aureus infections

The number of community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infections is rapidly increasing. Most CA-MRSA infections are localized soft tissue infections; however, severe life-threatening infections have been occasionally described. This report serves to increase the awareness of severe CA-MRSA infections by presenting a fulminant CA-MRSA infection with sepsis, endocarditis, septic pulmonary emboli, and extensive soft tissue and bone destruction. A review of the literature revealed 14 cases of severe CA-MRSA infections with a median age of 13 y; 93% had no underlying medical condition. Only 1 case was initially treated with antibiotics effective for MRSA. The fatality rate was 64%, and 40% of patients who survived had significant disabilities.     

社区获得性耐甲氧西林金黄色葡萄球菌肺炎临床分析

目的 探讨社区获得性耐甲氧西林金黄色葡萄球菌肺炎的临床特点.方法 对16例确诊病例的临床资料进行回顾性研究.结果 16例确诊病例,13例无基础性疾病,9例合并休克,7例合并急性呼吸窘迫综合征,4例死亡;死亡者从出现症状入院至死亡平均时间为(5.9±6.1)d,生存者平均住院时间为(21.6±11.1)d;8例有流感样症状,7例有咯血,5例有白细胞减少,16例C-反应蛋白明显升高,平均为(211.1±121.9) mg/L,13例有多肺叶病变,9例有胸腔积液.结论 社区获得性耐甲氧西林金黄色葡萄球菌肺炎病情凶险,应提高对其临床特点的认识,优化综合治疗方案.     

Purulent pericarditis due to methicillin-resistant Staphylococcus aureus. A case report.

Purulent pericarditis is an infrequent complication of infections originating in another body location. Symptoms and signs are often absent; a high index of awareness is required for its diagnosis. A patient recovering from extensive necrotic-hemorrhagic pancreatitis presented with tamponade due to methicillin-resistant Staphylococcus aureus (MRSA) purulent pericarditis, further complicated by MRSA endocarditis. Treatment included pericardectomy, IV vancomycin and teicoplanin.     

Implications of methicillin-resistant Staphylococcus aureus as a community-acquired pathogen in pediatric patients

Methicillin-resistant Staphylococcus aureus is now an established community pathogen in many areas of the United States and the world. Community-acquired methicillin-resistant S aureus infections have changed several aspects of staphylococcal infections in children. This article discusses epidemiology, clinical manifestations, laboratory diagnosis, treatment, and prevention.     

Penile cellulitis due to community-acquired methicillin-resistant Staphylococcus aureus in an HIV-positive man

This is a study of aggressive penile cellulitis in an HIV-positive man due to community-acquired methicillin-resistant Staphylococcus aureus. Discussion focuses on the importance of recognizing this pathogen in the sexual health setting and possible causes of penile cellulitis.