Complete substitution of the Brazilian endemic clone by other methicillin-resistant Staphylococcus aureus lineages in two public hospitals in Rio de Janeiro, Brazil

Abstract Staphylococcus aureus is an important cause of bloodstream infections. Therefore, the main purpose of this work was to characterize a collection of 139 S. aureus isolates from bloodstream infections in two public hospitals in relation to their antimicrobial susceptibility profile, staphylococcal cassette chromosome mec types, and clonal relationship. Methicillin resistance and resistance to other 12 agents were accessed by the disk diffusion test. Minimum inhibitory concentration to mupirocin was also determined. The SCCmec types were accessed by multiplex PCR, and the clonal relationship was determined by pulsed field gel electrophoresis method and restriction modification system characterization. Besides, multilocus sequence typing was performed for representative methicillin-resistant S. aureus isolates. The military hospital showed a dissemination of the New York/Japan (USA100/ST5/CC5/SCCmecII) lineage associated to multidrug resistance, including mupirocin resistance, and the teaching hospital presented polyclonal and non-multidrug resistant MRSA isolates. Complete substitution of the Brazilian endemic clone by other lineages was found in both hospitals. These findings can highlight differences in policy control and prevention of infections used in the hospitals and a change in the epidemiological profile of MRSA in Brazilian hospitals, with the replacement of BEC, a previously well-established clone, by other lineages.

Preparation of mupirocin-loaded polymeric nanocapsules using essential oil of rosemary

Abstract The purpose of this study was to prepare and characterize mupirocin-loaded polymeric nanocapsules using two different oils and to develop and validate an analytical method for quantitative determination by high performance liquid chromatography. The mean size of the nanoparticles was 233.05 nm and 275.03 nm for nanocapsules with a rosemary oil like oily core and caprylic/capric triglyceride, respectively, and a good polydispersity index below 0.25 for both formulations. The nanocapsules showed good stability when stored at 40 ºC and room temperature for 30 days. The quantitative method was performed with a mobile phase consisting of ammonium ammonium acetate (0.05 M adjusted to pH 5.0 with acetic acid) and acetonitrile 60:40 (v/v); the flow rate was 0.8 mL/min, UV detection at 230 nm. The analytical method was linear in the range of 5.0-15.0 µg/mL, specific for both oils, accurate, precise (intermediate precision RSD = 1.68% and repeatability RSD = 0.81%) and robust under the evaluated conditions. Therefore, this method can be performed for quantification of mupirocin in polymeric nanocapsules containing both oils.

Staphylococcus aureus resistance to topical antimicrobials in atopic dermatitis

Abstract: Background: Topical antimicrobial drugs are indicated for limited superficial pyodermitis treatment, although they are largely used as self-prescribed medication for a variety of inflammatory dermatoses, including atopic dermatitis. Monitoring bacterial susceptibility to these drugs is difficult, given the paucity of laboratory standardization. Objective: To evaluate the prevalence of Staphylococcus aureus topical antimicrobial drug resistance in atopic dermatitis patients. Methods: We conducted a cross-sectional study of children and adults diagnosed with atopic dermatitis and S. aureus colonization. We used miscellaneous literature reported breakpoints to define S. aureus resistance to mupirocin, fusidic acid, gentamicin, neomycin and bacitracin. Results: A total of 91 patients were included and 100 S. aureus isolates were analyzed. All strains were methicillin-susceptible S. aureus. We found a low prevalence of mupirocin and fusidic acid resistance (1.1% and 5.9%, respectively), but high levels of neomycin and bacitracin resistance (42.6% and 100%, respectively). Fusidic acid resistance was associated with more severe atopic dermatitis, demonstrated by higher EASI scores (median 17.8 vs 5.7, p=.009). Our results also corroborate the literature on the absence of cross-resistance between the aminoglycosides neomycin and gentamicin. Conclusions: Our data, in a southern Brazilian sample of AD patients, revealed a low prevalence of mupirocin and fusidic acid resistance of S. aureus atopic eczema colonizer strains. However, for neomycin and bacitracin, which are commonly used topical antimicrobial drugs in Brazil, high levels of resistance were identified. Further restrictions on the use of these antimicrobials seem necessary to keep resistance as low as possible.

The family's role as a support network for people living with HIV/AIDS: a review of Brazilian research into the theme / A família como rede de apoio às pessoas que vivem com HIV/AIDS: uma revisão na literatura brasileira

The study of HIV transmission and the implementation of AIDS prevention actions recognize the importance of social networks in the transmission of the disease, the adherence to treatment and the quality of life of those infected. For this relevance there was a review of articles on social support networks to people living with HIV /AIDS available in the Virtual Health Library (VHL) were published in Brazil between 2002 and 2012. In this study 31 articles were used from journals covering the following áreas: Nursing (n = 15), Psychology (n = 6) and Science Health / Biomedica (n = 6), were included, which some principal authors were affiliated to higher education public institutions (n = 17). In relation to the methodology used, priority wasgiven to conducting: qualitative research (n = 18), cross-sectional studies (n = 19) and studies that involved talking to people living with HIV/AIDS (n = 13). Particular importance was placed on analytic categories related to: adherence to treatment (n = 6), the family (n = 4), vulnerability (n = 3) and support from social networks (n = 5). Within this paper we argue for more investments into studies that focus on the family, carers and their households, as well as deepening the theoretical study of the themes discussed and the use of developed theories for the analysis of Social Networks.

O estudo da transmissão do HIV e a implementação de ações de prevenção da AIDS reconhece a importância das redes sociais na contaminação, adesão ao tratamento e qualidade de vida das pessoas infectadas. Por tal relevância, realizou-se uma revisão de artigos sobre redes sociais de apoio às pessoas que vivem com HIV/ AIDS, disponíveis na Biblioteca Virtual em Saúde (BVS) e publicados no Brasil no período de 2002 a 2012. Encontraram-se 31 artigos em revistas de Enfermagem (n = 15), Psicologia (n = 6) e Ciências da Saúde/Biomédicas (n = 6), produzidos por primeiros autores associados a Instituições de Ensino Superior públicas (n = 17). Quanto à metodologia, priorizou-se o método qualitativo (n = 18), estudos transversais (n = 19) e a participação exclusiva de pessoas que vivem com HIV/AIDS (n = 13). Houve predomínio de categorias analíticas relacionadas à adesão ao tratamento (n = 6), família (n = 4), vulnerabilidade (n = 3) e apoio/suporte social/ rede de apoio (n = 5). Discute-se a necessidade de investimento em estudos que privilegiem familiares e cuidadores como participantes e seus domicílios como lócus de investigação, bem como maior aprofundamento teórico nos estudos das temáticas abordadas e utilização de teorias desenvolvidas para análise de Redes Sociais.

The detection of mupirocin resistance and the distribution of methicillin-resistant Staphylococcus aureus at the University Hospital of the West Indies, Jamaica / Detección de la resistencia a la mupirocina y distribución de Staphylococcus aureus resistente a la meticilina en el Hospital Universitario de West Indies, Jamaica

OBJECTIVES: The objectives of this study were to determine the susceptibility of Methicillin Resistant Staphylococcus aureus (MRSA) isolates to Mupirocin and other antimicrobial agents and to record the prevalence and distribution of this organism at the University Hospital of the West Indies (UHWI). METHODS: MRSA isolates collected between January 1, 2008 and December 31, 2008, were tested for low and high level resistance to Mupirocin. Susceptibility testing to other antibiotics including cotrimoxazole, minocycline, tetracycline, clindamycin, erythromycin, gentamicin and vancomycin was also done. Laboratory records for all patients from whom MRSA was recovered were reviewed and data on type and source of isolates, clinical diagnosis, history of previous hospitalization and use of mupirocin were extracted. In addition, the laboratory records for 2004 and 2005 were also reviewed to determine prevalence during these periods. RESULTS: Seven per cent of Staphylococcus aureus isolates were resistant to methicillin (MRSA) and of these, 30% and 24% showed low level and high level resistance to mupirocin, respectively. Ninety-four per cent of MRSA strains were resistant to erythromycin while 52% showed resistance to clindamycin. Resistance to tetracycline, co-trimoxazole and minocycline was 27%, 12% and 6%, respectively, while about one-third ofthe isolates were resistant to gentamicin. There was no resistance to vancomycin. More than half (58%) of the isolates were from skin and soft tissue specimens while isolates from respiratory and urinary tracts and the bloodstream accounted for 19%, 13% and 4%, respectively. There has been a steady increase in prevalence from 4% in 2004 to 5% in 2007 and 7% in 2008. CONCLUSION: Resistance of MRSA to mupirocin appears to be an emerging problem at the UHWI and must be monitored carefully. There is also significant resistance to commonly used antimicrobial agents and strict adherence to antibiotic policy is required to preserve the usefulness of these agents.

OBJETIVOS: Los objetivos de este estudio fueron determinar la susceptibilidad de aislados de Staphylococcus aureus resistentes (MRSA) frente a la mupirocina y otros agentes antimicrobianos, y grabar la prevalencia y distribución de este organismo en el Hospital Universitario de West Indies (UHWI). MÉTODOS: Aislados de MRSA recogidos entre el 1ero. de enero de 2008 y el 31 de diciembre de 2008, fueron sometidos a prueba a fin de determinar sus niveles bajo y alto de resistencia a la mupirocina. También se investigó la susceptibilidad frente a otros antibióticos tales como co-trimoxazol, minociclina, tetraciclina, clindamicina, eritromicina, gentamicina y vancomicina. Se revisaron las historias de laboratorio de todos los pacientes de quienes de recobró MRSA, y se extrajeron datos sobre el tipo y fuente de los aislados, el diagnóstico clínico, la historia de hospitalización previa, y el uso de mupirocina. Además, se revisaron las historias clínicas de laboratorio de 2004 y 2005 a fin de determinar la prevalencia durante estos periodos. RESULTADOS: Setenta por ciento de los ailados de estafilococo dorado era resistente a la meticilina (MRSA) y de éstos, 30% y 24% mostraron un bajo nivel y un alto nivel de resistencia a la mupirocina, respectivamente. Noventa y cuatro por ciento de las cepas de MRSA eran resistentes a la eritromicina, mientras que el 52% mostró resistencia a la clindamicina. La resistencia a la tetraciclina, el cotrimoxazol, y la minociclina fue de 27%, 12% y 6%, respectivamente, mientras que aproximadamente un tercio de los aislados eran resistentes a la gentamicina. No hubo resistencia a la vancomicina. Más de la mitad (58%) de los aislados procedían de especimenes de tejido blando y de la piel, mientras que los aislados de las vías respiratorias y urinarias así como del torrente sanguíneo constituyeron el 19%, 13% y 4%, respectivamente. Ha habido un aumento constante de la prevalencia de 4% en 2004 a 5% en 2007 y 7% en 2008. CONCLUSIÓN: La resistencia de MRSA a la mupirocina parece ser un problema emergente en el HUWI y debe monitorearse cuidadosamente. Hay también una resistencia significativa a los agentes antimicrobianos normalmente usados y se requiere una adhesión estricta a la política antibiótica a fin de preservar la utilidad de estos agentes.

Molecular Analysis of Isoleucyl-tRNA Synthetase Mutations in Clinical Isolates of Methicillin-Resistant Staphylococcus aureus with Low-Level Mupirocin Resistance

Emergence and spread of low-level mupirocin resistance in staphylococci have been increasingly reported in recent years. The aim of this study was to characterize missense mutations within the chromosomal isoleucyl-tRNA synthetase gene (ileS) among clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) with low-level mupirocin resistance. A total of 20 isolates of MRSA with low-level mupirocin resistance (minimal inhibitory concentration, 16-64 microgram/mL) were collected from 79 patients in intensive care units for six months. The isolates were analyzed for isoleucyl-tRNA synthetase (IleS) mutations that might affect the binding of mupirocin to the three-dimensional structure of the S. aureus IleS enzyme. All isolates with low-level mupirocin resistance contained the known V588F mutation affecting the Rossman fold, and some of them additionally had previously unidentified mutations such as P187F, K226T, F227L, Q612H, or V767D. Interestingly, Q612H was a novel mutation that was involved in stabilizing the conformation of the catalytic loop containing the KMSKS motif. In conclusion, this study confirms that molecular heterogeneity in ileS gene is common among clinical MRSA isolates with low-level mupirocin resistance, and further study on clinical mutants is needed to understand the structural basis of low-level mupirocin resistance.