Abstract INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen causing healthcare-associated infections. Owing to the restricted use of beta-lactams in MRSA infections, non-beta-lactam antimicrobials are required for treatment. However, MRSA can develop resistance mechanisms to non-beta-lactam antimicrobials, which reduces viable treatment options. Here, we evaluated the antimicrobial susceptibility and resistance genes of MRSA isolated from hospitalized patients in South Brazil. METHODS: The antimicrobial susceptibilities of hospital MRSA (217) isolates were determined by disk diffusion or microdilution methods. Additionally, the presence of 14 resistance genes and SCCmec typing was performed by PCR. RESULTS: Among the antimicrobials tested, we observed high erythromycin (74.2%), ciprofloxacin (64.5%), and clindamycin (46.1%) resistance rates and complete susceptibility to linezolid and vancomycin. Seventeen different patterns of MRSA antimicrobial resistance were observed, of which 42.9% represented multidrug resistance. Among erythromycin-resistant MRSA, 53.4%, 45.3%, 37.9%, 13.0%, and 6.8% carried ermA, msrA, msrB, ermC, and ermB genes, respectively. Among clindamycin-resistant MRSA, 83%, 17%, 10%, 4%, and 2% carried ermA, ermC, ermB, linA, and linB genes, respectively. Among gentamicin-resistant MRSA, 96.8%, 83.9%, and 9.7% carried aac(6')/aph(2''), aph(3’)-IIIa, and ant(4’)-Ia genes, respectively. Among tetracycline-resistant MRSA, 6.5% and 93.5% carried tetK and tetM genes, respectively. Lastly, among trimethoprim/sulfamethoxazole-resistant MRSA, 13.3% and 100% carried dfrA and dfrG genes, respectively. The SCCmec type IV isolates were detected more frequently, whereas the SCCmec type III isolates exhibited higher multidrug resistance. CONCLUSIONS: The study data provides information regarding the MRSA resistance profile in South Brazil that is associated with the clinical conditions of patients and can contribute to clinical decision-making.

Abstract INTRODUCTION: The pathogenic versatility of Staphylococcus aureus is attributed to various virulence genes, including enterotoxins and hemolysins. METHODS: Here, the virulence genes in 177 nosocomial MRSA strains in Porto Alegre, Brazil were detected by PCR. RESULTS: The overall prevalence rates were as follows: sea, 4.5%; pvl, 18.6%; tst, 27.7%; hla, 87.6%; and hld, 90.4%. No strain contained all tested genes. However, there was frequent coexistence of tst with pvl and hla with hld (40.7% and 26.6%, respectively). CONCLUSIONS: Horizontal transfer of virulence genes is very common in S. aureus, as suggested by the frequent coexistence of several virulence genes.

ABSTRACT Rapid identification of vancomycin-resistant enterococci (VRE) can assist in choosing the appropriate treatment and preventing VRE spread. The performance of chromIDTM VRE agar was evaluated using 184 clinical isolates of Enterococcus spp. and reference strains. The test had a sensitivity of 95.52% but a low specificity of 30%.

A dermatite atópica é uma doença inflamatória crônica da pele que afeta um grande número de crianças e adultos. A doença resulta da interação entre predisposição genética, fatores ambientais, defeitos da barreira cutânea e fatores imunológicos. Um dos grandes fatores agravantes associados à dermatite atópica é a presença de microorganismos na superfície cutânea desses pacientes. Staphylococcus aureus e Streptococcus pyogenes, por exemplo, podem exacerbar a inflamação crônica da pele. Como resultado, antimicrobianos são prescritos para controlar a fase aguda da doença. O constante crescimento da resistência bacteriana aos antimicrobianos tem tornado a escolha do mais adequado medicamento uma difícil decisão para os dermatologistas. Na presença de dermatite disseminada com infecção secundaria, antibióticos sistêmicos necessitam ser prescritos; no entanto, o tratamento deve ser individualizado, de forma a encontrar o antimicrobiano mais eficaz e com menores efeitos colaterais. Além disso, esse medicamento deve ser utilizado pelo menor tempo possível, a fim de minimizar a resistência bacteriana.

Atopic Dermatitis is a chronic inflammatory skin disease that affects a large number of children and adults. The disease results from an interaction between genetic predisposition, host environment, skin barrier defects, and immunological factors. A major aggravating factor associated with Atopic Dermatitis is the presence of microorganisms on the patient's skin surface. Staphylococcus aureus and Streptococcus pyogenes, for instance, can exacerbate chronic skin inflammation. As a result, antimicrobials have often been prescribed to control the acute phase of the disease. However, increased bacterial resistance to antimicrobial agents has made it difficult for dermatologists to prescribe appropriate medication. In the presence of disseminated dermatitis with secondary infection, systemic antibiotics need to be prescribed; however, treatment should be individualized, in an attempt to find the most effective antibiotic with fewer side effects. Also, the medication should be used for as short as possible in order to minimize bacterial resistance.

Staphylococcus aureus é uma bactéria responsável por uma ampla variedade de enfermidades infecciosas. A grande preocupação está relacionada, principalmente, com os isolados resistentes à meticilina (MRSA), que, tradicionalmente, estavam limitados aos hospitais. Nos últimos anos, infecções causadas por MRSA associadas ou adquiridas na comunidade (CA-MRSA) têm sido relatadas com frequência crescente em todo o mundo. Algumas características fenotípicas e genéticas são distintas entre a forma de infecção hospitalar e a comunitária. Atualmente, verifica-se um perfil de sensibilidade reduzido para diferentes antimicrobianos; sendo assim faz-se necessário um alerta aos profissionais da saúde, particularmente aos dermatologistas, para a importância da distinção entre as formas de infecções, evitando uma terapia empírica incorreta e sem sucesso.

Staphylococcus aureus is responsible for a broad variety of infectious diseases. The main concern is about methicillin-resistant isolates (MRSA), which are usually limited to hospitals. In recent years, community associated or acquired MRSA infections (CA-MRSA) have been frequently reported and emerged in the world. Some phenotypic and genotypic characteristics are distinct between hospital and community infection. Currently, there is reduced sensibility profile to different antimicrobials, reason why it is necessary to issue an alert to healthcare professionals, dermatologists in particular, about the importance of knowing the differences between the infections, preventing wrong and unsuccessful empirical therapy.