Community-associated methicillin-resistant Staphylococcus aureus infective endocarditis with Panton-Valentine leukocidin gene in an injection drug user with HIV infection

Invasive community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) infection in children: case series and literature review

The majority of CA-MRSA infections present as skin and soft tissue infections such as abscesses or cellulitis. However, CA-MRSA can cause invasive infections such as joint infections, necrotizing pneumonia or septicemia. Here we describe five cases with CA-MRSA bacteremia complicated with osteoarticular infection, necrotizing pneumonia, and infective endocarditis. We report these case series to outline the spectrum of invasive CA-MRSA diseases and to demonstrate clinical outcome. Early proper intervention with regular revisiting the empirical treatment based on local susceptibility data is crucial. More data on the risk factors for acquiring and spread of CA-MRSA in children are required.

Infective Endocarditis Caused by Panton-Valentine Leukocidin-producing Methicillin-susceptible Staphylococcus aureus Identified by the Broad-range PCR Method

A 76-year-old man was admitted to a community hospital due to a persistent high fever. He became afebrile after the administration of broad-spectrum antibiotics, but developed heart failure due to progressive aortic and mitral valve insufficiency and was transferred to our hospital. Although sequential blood cultures were negative, a broad-range polymerase chain reaction targeting the bacterial 16S-rRNA gene followed by the direct sequencing of whole blood revealed spa(+), mecA(-) and Panton-Valentine leukocidin (PVL)(+). He was finally diagnosed with infective endocarditis (IE) caused by PVL-producing methicillin-susceptible Staphylococcus aureus (MSSA), and underwent cardiac surgery. This is the first reported case of IE due to MSSA producing PVL.

Emergence of a strain of methicillin-resistant Staphylococcus aureus with decreased susceptibility to vancomycin 7 months after treatment with glycopeptide antibiotics

This case report describes a methicillin-resistant Staphylococcus aureus isolated repeatedly from the blood of a patient with community-acquired endocarditis who developed a four-fold increase in the minimal inhibitory concentration of vancomycin and daptomycin 7 months after his last exposure to glycopeptide antibiotics. This is contrary to the expected situation in which antimicrobial resistance tends to decrease after a patient is no longer exposed to vancomycin.

Infective endocarditis caused by community-associated methicillin-resistant Staphylococcus aureus in a previously healthy preschool child

Community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) has been increasingly reported recently and has become an emerging pathogen of infective endocarditis (IE) in adults, but still rarely reported in children. A previously healthy preschool child without any heart anomaly developed IE and pneumonia with pleural effusion. Blood cultures repeatedly yielded MRSA and did not become negative until 13 days after a teicoplanin-containing regimen was administered. In total, a 4-week intravenous antibiotic therapy and an additional 8-week oral antibiotic therapy were given. The patient recovered uneventfully. All five MRSA blood isolates were molecularly characterized and shared common characteristics, which were consistent with those of the endemic CA-MRSA clone in Taiwan. This case highlights that physicians should be aware of the growing role of CA-MRSA in childhood IE and should meticulously choose an appropriate empiric antibiotic regimen for such a severe disease.

Methicillin-resistant Staphylococcus aureus in HIV-infected patients

Concordant with the emergence of methicillin-resistant Staphylococcus aureus (MRSA) in the community setting, colonization and infections with this pathogen have become a prevalent problem among the human immunodeficiency virus (HIV)-positive population. A variety of different host- and, possibly, pathogen-related factors may play a role in explaining the increased prevalence and incidence observed. In this article, we review pathophysiology, epidemiology, clinical manifestations, and treatment of MRSA in the HIV-infected population.

Community-associated methicillin-resistant Staphylococcus aureus: epidemiology and clinical consequences of an emerging epidemic

Staphylococcus aureus is an important cause of skin and soft-tissue infections (SSTIs), endovascular infections, pneumonia, septic arthritis, endocarditis, osteomyelitis, foreign-body infections, and sepsis. Methicillin-resistant S. aureus (MRSA) isolates were once confined largely to hospitals, other health care environments, and patients frequenting these facilities. Since the mid-1990s, however, there has been an explosion in the number of MRSA infections reported in populations lacking risk factors for exposure to the health care system. This increase in the incidence of MRSA infection has been associated with the recognition of new MRSA clones known as community-associated MRSA (CA-MRSA). CA-MRSA strains differ from the older, health care-associated MRSA strains; they infect a different group of patients, they cause different clinical syndromes, they differ in antimicrobial susceptibility patterns, they spread rapidly among healthy people in the community, and they frequently cause infections in health care environments as well. This review details what is known about the epidemiology of CA-MRSA strains and the clinical spectrum of infectious syndromes associated with them that ranges from a commensal state to severe, overwhelming infection. It also addresses the therapy of these infections and strategies for their prevention.