Bakgrund: Utveckling av antibiotikaresistenta bakterier är ett globalt folkhälsoproblem. Meticillinresistenta Staphylococcus aureus (MRSA) är en av dom vanligaste antibiotikaresistenta bakterien och smittas vanligtvis via kontaktsmitta. I Sverige ses MRSA som en allmänfarlig sjukdom som kan innebära livshotande tillstånd samt lidande hos patienten. Smittspridning av MRSA kan minskas genom följsamhet av basala hygienrutiner. Sjuksköterskans ansvar är att arbeta smittförebyggande, patientsäkert, lindra lidande samt hålla sig uppdaterad med ny kunskap. Trots detta upplever sjuksköterskor kunskapsbrist gällande MRSA och rädsla över att själva bli smittade. Syfte: Studiens syfte är att belysa patienters upplevelser av att vårdas med MRSA inom slutenvården. Metod: Studien är gjord som en litteraturöversikt som baseras på 15 vetenskapliga artiklar med kvalitativ-, kvantitativ- och mixad metod. Datasökning har gjorts i databaserna CINAHL och PubMed. Resultat: I resultatet framkom tre teman där patienternas upplevelser av att vårdas med MRSA inom slutenvården belyses: Upplevelser av bemötande från vårdpersonal, Upplevelser av information samt kunskap hos vårdpersonal och Upplevelser av att vårdas i isoleringsrum. Resultatet visade att patienter med MRSA upplever stigmatisering, kränkning och oprofessionellt bemötande av vårdpersonal på grund av kunskapsbrist vilket medför psykiskt lidande hos patienterna. Det visade sig även att vårdande i isoleringsrum upplevs negativt och att den fysiska vårdmiljöns utformning har en betydande inverkan på upplevelse och välmående. Slutsats: Vårdpersonal behöver mer fortbildning för att öka kunskap om vårdandet av patienter med MRSA samt en god fysisk vårdmiljö i isoleringsrum skapar förutsättningar för att lindra lidande samt säkerhetsställa god och säker vård i vården av patienter med MRSA inom slutenvård. / Background: The development of antibiotic resistant bacteria is a global health problem. Methicillin-resistant Staphylococcus Aureus (MRSA) is one of the most common antibiotic resistant bacteria and is usually transmitted through contact infection. In Sweden MRSA is referred to as a dangerous disease that can cause life-threatening conditions as well as patient suffering. The spread of infection may be reduced by adherence to basic hygiene practices. The nurse’s responsibility involves infection prevention, patient safety, alleviation of suffering and maintaining current knowledge of the disease. Despite this, nurses may lack knowledge concerning MRSA and fear contracting it. Aim: The aim of this study is to highlight the patient’s experience during inpatient treatment of MRSA. Methods: The study was conducted as a literature review based on fifteen scientific articles with qualitative-, quantitative- and mixed method. The article search was conducted via the CINAHL and PubMed databases. Results: The result highlighted three themes involving patient experiences during isolated inpatient care of MRSA: Experience related to treatment by healthcare professionals, Experiences concerning the depth and correctness of information and knowledge by healthcare professionals and Experiences of being cared for in an isolation room. The result indicated that MRSA patients experience stigma experiences psychological distress as they felt stigmatized, violated and unprofessionally treated by healthcare professional due a lack of knowledge. Furthermore, it also showed that isolation room care was negatively experienced and that the care environment design significantly impacted the patient’s experiences and feelings of well-being. Conclusion: Healthcare professionals need further education to increase their knowledge of MRSA patient care and how the maintenance of a good care environment in isolation rooms is important for alleviation of suffering and ensuring the good and safe care of inpatient MRSA patients.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is a multidrug-resistant bacterium that causes serious infections. Specific measures to prevent the spread of MRSA are required within health care, and insufficient knowledge and lack of compliance to these measures have been identified in healthcare professionals. The need to adhere to special guidelines in order to prevent the spread of infection have been shown to create negative feelings for carriers of multidrug-resistant bacterium. Aim: The aim of this study was to investigate different aspects of living and being cared for with known carriage of MRSA. The fist aspect aimed to investigate how people experience their knowledge and the information they receive from the healthcare. The second aspect aimed to investigate their feelings and existence in relation to their carriage. The third aspect aimed investigate their experiences and encounters with health care. Method: Literature study with systematic approach and inductive method. The results were analysed with inspiration from thematic synthesis and based on ten qualitative original articles.  Results: Getting MRSA was shocking and shameful, and many blamed the health care for contracting MRSA. Living with MRSA had a negative impact on daily life. Life felt lonely and isolated, and people were scared to infect others. Being cared for with MRSA was described with experiences of lack knowledge from the health care professionals, inconsistencies in adherence to hygiene measures and unprofessional behaviour. Being cared for in isolation had a negative impact on the persons’ independence, their relations with the health care professionals and the quality of care. Conclusion: Getting MRSA is perceived as stigmatising and frightening, and the health care fails to provide adequate information to counteract these feelings. People feel sadness, abandonment and uncertainty about the future. The behaviour of health care professionals and their compliance with hygiene measures is inconsistent. This results in people feeling extradited to health care, which contributes to enhanced feelings of shame and stigmatisation, and people with MRSA do not receive health care on equal terms. / Bakgrund: Meticillinresistenta Staphylococcus aureus (MRSA) är en multiresistent bakterie som orsakar allvarliga infektioner. För att förhindra spridning av MRSA krävs särskilda hygienrutiner inom vården, och otillräcklig kunskap och bristande följsamhet till dessa har identifierats hos vårdpersonal. För att inte sprida smitta behöver personer med bärarskap av multiresistenta bakterier förhålla sig till särskilda riktlinjer, vilket har visat sig skapa negativa känslor för personerna. Syfte: Syftet var att undersöka olika aspekter av att leva och vårdas med känt bärarskap av MRSA. Den första aspekten syftade till att undersöka hur personerna upplever sin kunskap och informationen de får från vården. Den andra aspekten syftade till att undersöka deras känslor och tillvaro i relation till bärarskapet. Den tredje aspekten syftade till att undersöka deras erfarenheter och upplevelser av mötet med vården. Metod: Litteraturstudie med systematisk ansats och induktiv metod. Resultatet analyserades med inspiration av tematisk syntes och baseras på tio kvalitativa originalartiklar. Resultat: Att få MRSA var chockartat och skamfyllt, och många beskyllde vården för att ha fått MRSA. Att leva med MRSA påverkade vardagen negativt. Livet kändes begränsat, ensamt och isolerat och personerna var rädda för att smitta andra. Att vårdas med MRSA beskrevs med upplevelser av bristande kunskap hos vårdpersonalen, inkonsekvens i följsamhet till hygienrutiner och oprofessionellt bemötande. Att vårdas under isolering för MRSA inverkade negativt på personernas upplevelse av självständighet, relationen till vårdpersonalen och kvaliteten på omvårdnaden. Slutsats: Att få MRSA upplevs stigmatiserande och skrämmande och vården misslyckas med att ge adekvat information för att motverka dessa känslor. Personerna känner sorg, övergivenhet och framtiden känns osäker. Vårdpersonalens beteende och följsamhet till hygienrutiner är inkonsekvent, vilket gör att personerna känner sig utlämnade till vården. Detta bidrar till förstärkta känslor av skam och stigmatisering, och personer med MRSA får inte vård på lika villkor.

Methicillin-resistant staphylococcus aureus (MRSA) has become resistant to antibiotics. The purpose of this quantitative, retrospective cohort study was to examine the relationship between length of hospitalization and invasive MRSA infection rates among different racial and ethnic groups in the 8 service planning areas (SPAs) of Los Angeles County. Cane, O'Connor, and Michie's theoretical domain framework was used. Secondary data from the Healthcare-Associated (HA) Infections Program of the California Department of Public Health were analyzed. For the first research question, a Pearson correlation analysis was conducted to assess the relationships between length of hospitalization and invasive HA-MRSA infection rates and counts. Length of hospital stay was not correlatedwith HA-MRSA infection rates; however, it was strongly and positively correlated with HA-MRSA infection counts. For the second research question, a one-way ANOVA was conducted on the infection count rate data, with SPA as the between-subjects factor. The results were statistically significant, indicating that HA-MRSA infection counts varied among the 8 SPAs. The findings might help medical professionals better understand the risk factors associated with MRSA infections. In doing so, findings may relieve some of the burden on the U.S. health care system and improve the overall quality of life of the patients involved.

Syfte: Syftet med denna litteraturstudie är att undersöka vad som publicerats angående vilka metoder sjuksköterskan kan använda sig av för att förhindra spridning av meticillinresistenta Staphylococcus aureus (MRSA) i sjukhusmiljöer.Bakgrund: Infektioner orsakade av MRSA gör MRSA till en av de största utmaningarna i modern sjukhusmiljö runt om i världen. Dominerande är att smittan sprids från patient till patient genom vårdpersonalens händer eller förorenade handskar. I enlighet med gällande riktlinjer är sjuksköterskan skyldig att förebygga smitta.Metod: Litteraturstudie med artiklar från primärkällor. Dessa granskades med Willmans granskningsmall.Resultat: Totalt identifierades och beskrevs fyra olika teman. 1. Vårdpersonalens hygienrutiner, 2. Vårdpersonalens kunskap, 3. Patienthygien och 4. Barriärvård.Slutsats: De flesta studierna som undersökte metoder för att minska spridning av MRSA i vården visade sig ha fokus på handhygien. Alkoholbaserad handdesinfektion var den mest effektiva metoden för att minska spridning av MRSA. Det visade sig att kunskap var viktigt för att vårdpersonalen skulle följa hygien rutinerna. Då sjuksköterskan är ansvarig för omvårdnadsarbetet kring patient, är det viktigt att de har kunskap om MRSA och hur det sprids. / Aim: The aim of this literature review was to investigate what has been published regarding the methods nurses can apply to reduce the spread of Methicillin-resistant Staphylococcus aureus (MRSA) in hospital settings.Background: Infections caused by MRSA make MRSA are one of the greatest challenges worldwide in modern hospital setting. The dominating route of transmission between patients is through the hands of health care personnel and contaminated gloves. According to current guidelines the nurses are obligated to prevent contagion.Method: Literature review with articles from primary sources. Articles were reviewed following the review template by Willman.Result: Four themes were identified and described: 1. Hygiene routines by health care staff. 2. Knowledge by health care staff. 3. Patient hygiene. 4. Barrier nursing.Outcome: A majority of the articles, studying methods to reduce spread of MRSA, had focus on hand hygiene. Alcohol based hand disinfection proved to be the most effective method to reduce spread of MRSA. Knowledge also proved to be an important predictor for the compliance to hand hygiene. Since nurses are responsible for the nursing around the patient it is important they have knowledge about MRSA and the routes of its spread.

Optical sensor systems that integrate Long-Period-Gratings (LPG) as the detection arm have been proven to be highly sensitive and reliable in many applications. With increasing public recognition of threats from bacteria-induced diseases and their potential outbreak among densely populated communities, an intrinsic, low-cost biosensor device that can perform quick and precise identification of the infection type is in high demand to respond to such challenging situations and control the damage those diseases could possibly cause. This dissertation describes the development of a biosensor platform that utilizes polymer thin films, known as ionic self-assembled multilayer (ISAM) films, to be the sensitivity- enhancing medium between an LPG fiber and specific, recognition layer. With the aid of cross- linking reactions, monoclonal antibodies (IgG) or DNA probes are immobilized onto the surface of the ISAM-coated fiber, which form the core component of the biosensor. By immersing such biosensor fiber into a sample suspension, the immobilized antibody molecules will bind the specific antigen and capture the target cells or cell fragments onto the surface of the fiber sensor, resulting in increasing the average thickness of the fiber cladding and changing the refractive index of the cladding. This change occurring at the surface of the fiber results in a decrease of optical power emerging from the LPG section of the fiber. By comparing the transmitted optical power before and after applying the sample suspension, we are able to determine whether or not certain bacterial species have attached to the surface of the fiber, and as a consequence, we are able to determine whether or not the solution contains the targeted bacteria. This platform has the potential for detection of a wide range of bacteria types. In our study, we have primarily investigated the sensitivity and specificity of the biosensor to methicillin- resistant Staphlococcus aureus (MRSA). The data we obtained have shown a sensitive threshold at as low as 102 cfu/ml with pure culture samples. A typical MRSA antibody-based biosensor assay with MRSA sample at this concentration has shown optical power reduction of 21.78%. In a detailed study involving twenty-six bacterial strains possessing the PBP2a protein that enables antibiotic resistance and sixteen strains that do not, the biosensor system was able to correctly identify every sample in pure culture samples at concentration of 104 cfu/ml. Further studies have also been conducted on infected mouse tissues and clinical swab samples from human ears, noses, and skin, and in each case, the system was in full agreement with the results of standard culture tests. However, the system is not yet able to correctly distinguish MRSA and non-MRSA infections in clinical swab samples taken from infected patient wounds. It is proposed that nonspecific binding due to insufficient blocking methods is the key issue. Other bacterial strains, such as Brucella and Francisella tularensis have also been studied using a similar biosensor platform with DNA probes and antibodies, respectively, and the outcomes are also promising. The Brucella DNA biosensor is able to reflect the existence of 3 Brucella strains at 100 cfu/ml with an average of 12.2% signal reduction, while negative control samples at 106cfu/ml generate an average signal reduction of -2.1%. Similarly, the F. tularensis antibodies biosensor has shown a 25.6% signal reduction to LVS strain samples at 100 cfu/ml, while for negative control samples at the same concentration, it only produces a signal reduction of 0.05%. In general, this biosensor platform has demonstrated the potential of detecting a wide range of bacteria in a rapid and relatively inexpensive manner. / Ph. D.

The thesis describes over-expression, purification and crystallization of three proteins from Staphylococcus aureus (S. aureus). S. aureus is an important human pathogen and methicillin-resistant S. aureus (MRSA) is a serious problem in hospitals nowadays. The crystal structure of 3-Methyladenine DNA glycosylase I (TAG) was determined by single-wavelength anomalous diffraction (SAD) method. TAG is responsible for DNA repair and is an essential gene for both MRSA and methicilin-susceptible S. aureus (MSSA). The structure was also determined in complex with 3-methyladenine (3-MeA) and was solved using molecular replacement (MR) method. An assay was carried out and the molecular basis of discrimination between 3-MeA and adenosine was determined. The native crystal structure of fructose 1-phosphate kinase (PFK) from S. aureus was determined to 2.30 Å and solved using molecular replacement method. PFK is an essential enzyme involved in the central metabolism of MRSA. Despite extensive efforts no co-complex was determined, although crystals were obtained they diffracted poorly. An assay which can be used to test for inhibitors has been developed. Mevalonate Kinase (MK) is another essential enzyme in MRSA and is a key drug target in the mevalonate pathway. Native data diffracting to 2.2 Å was collected. The structure was solved using multiple isomorphorus replacement (MIR) method. A citrate molecule was bound at the MK active site, arising from the crystallization condition. The citrate molecule indicates how substrate might bind. The protein was kinetically characterized. A thermodynamic analysis using fluorescence-based method was carried out on each protein to investigate binding interactions of potential fragments and thus a drug design starting point.

A colonização nasal por Staphylococcus aureus e a infecção pelo HIV representam problemas de saúde pública de preocupação mundial. O objetivo geral foi identificar os fatores de risco para a colonização nasal por Staphylococcus aureus em pessoas vivendo com HIV/aids. Para tanto, foi realizado um estudo tipo caso-controle, com pessoas vivendo com HIV/aids internadas nas unidades especializadas na assistência às doenças infecciosas de um hospital de ensino no interior paulista. A coleta de dados ocorreu de janeiro/2013 a fevereiro/2015, por meio de entrevista individual contemplando dados sociodemográficos e clínicos, além da coleta da secreção nasal com auxílio do swab em meio Stuart, ambos nas primeiras 24 horas de internação. As amostras foram encaminhadas e processadas pelo Laboratório de Microbiologia da própria instituição. Os critérios de inclusão foram: ter idade acima de 18 anos, ser soropositivo ao HIV, estar internado. Nas análises estatísticas foram realizados os testes qui-quadrado de Pearson, Exato de Fisher, t-Student, Wilcoxon e Regressão Logística Univariada e Multivariada, por meio do software SAS®. Os dados estão apresentados em tabelas e figuras. O presente estudo foi aprovado pelo Comitê de Ética em Pesquisa da Escola de Enfermagem de Ribeirão Preto (No CAAE 38990114.5.0000.5393) e pela instituição co-participante (No CAAE 38990114.5.3001.5440). Participaram do estudo 240 pessoas vivendo com HIV/aids, sendo 120 Casos e 120 Controles, houve predominância do sexo masculino em 65,0% dos Casos e 55,0% dos Controles, 35,8% dos Casos estavam na faixa etária de 30 a 39 anos e 45,8% dos Controles tinham idade de 40 a 49 anos, a etnia predominante foi a branca para Casos e Controles, 74,2% e 64,2%, respectivamente. Os grupos foram homogêneos entre si em relação ao sexo, etnia e escolaridade. A média do tempo de diagnóstico foi de 9 anos para Casos e 8,8 anos para Controles. O modelo final de regressão logística evidenciou como fatores de risco associados à colonização nasal por Staphylococcus aureus em pessoas vivendo com HIV/aids, ser da etnia branca, p=0,05 (OR:1,85; IC95% 1,00 - 3,57); ter carga viral >40 cópias/mL, p= 0,03 (OR: 2,90; IC95% 1,15 - 7,30); estar com contagem de LT-CD4+ <200 células/mm3 p=0,001 (OR: 2,71; IC95% 1,53 - 4,81); e apresentar doença oportunista p=0,014 (OR: 2,09; IC95% 1,20 - 3,67). Além disso, foi evidenciado como fator de proteção para a colonização nasal pelo Staphylococcus aureus em pessoas vivendo com HIV/aids o uso de antirretroviral p=0,008 (OR: 0,45; IC95% 0,25 - 0,81). Concluímos que a colonização nasal por Staphylococcus aureus nas pessoas vivendo com HIV/aids foi associada aos fatores: etnia, carga viral, contagem de LT-CD4+ , infecção oportunista e uso de antirretroviral / Staphylococcus aureus nasal colonization and HIV infection represent public health problems of global concern. The overall objective was to identify the risk factors for nasal colonization by Staphylococcus aureus in people living with HIV / AIDS. Therefore, a case-control study was conducted, with people living with HIV / AIDS hospitalized at the units specialized in infectious disease care at a teaching hospital in the interior of São Paulo. Data were collected from January / 2013 to February / 2015 by means of an individual interview, including sociodemographic and clinical data, as well as the collection of nasal secretions with the aid of swab in Stuart\'s medium, both during the first 24 hours of hospitalization. The samples were sent and processed by the Laboratory of Microbiology of the institution itself. The inclusion criteria were: to be over 18 years of age, to be known as infected HIV, to be hospitalized. Statistical analyzes were performed using the Pearson chi-square test, Fisher\'s exact test, Student t-test, Wilcoxon test, and Univariate and Multivariate logistic regression using the SAS® software. The data are presented in tables and figures. The present study was approved by the Research Ethics Committee of the Ribeirão Preto College of Nursing (CAAE 38990114.5.0000.5393) and by the co- participating institution (CAAE 38990114.5.3001.5440). A total of 240 people living with HIV / AIDS participated in the study, of which 120 were Cases and 120 Controls; 65.0% of Cases and 55.0% of Controls were male: 35.8% of Cases were in the age group of 30 at 39 years and 45.8% of the Controls were aged from 40 to 49 years, the predominant ethnicity was white for Cases and Controls, 74.2% and 64.2%, respectively. The groups were homogeneous among themselves in relation to gender, ethnicity and schooling. The mean time of diagnosis was 9 years for Cases and 8.8 years for Controls. The final logistic regression model showed that the risk factors associated with Staphylococcus aureus nasal colonization in people living with HIV / AIDS were white, p = 0.05 (OR: 1.85, 95% CI: 1.00 - 3.57); having viral load> 40 copies / mL, p = 0.03 (OR: 2.90; IC95% 1.15 - 7.30); being with LT-CD4+ <200 cells / mm3 p = 0.001 (OR: 2.71; IC95% 1.53 - 4.81); and present opportunistic disease p = 0.014 (OR: 2,09; IC95% 1,20 - 3,67). In addition, it was also obtained by the final regression final model that the use of antiretroviral therapy is a protection factor of p = 0.008 (OR: 0.45; 95% CI 0.25 - 0.81) for nasal colonization by Staphylococcus aureus. We conclude that nasal colonization by Staphylococcus aureus in people living with HIV/AIDS was associated with factors: ethnicity, viral load, LT-CD4+ count, opportunistic infection, and antiretroviral use

MRSA é um importante agente de colonização e infecção em pacientes hepatopatas e transplantados de fígado. Este estudo tem como objetivo avaliar a clonalidade e a virulência de isolados MRSA de pacientes hepatopatas atendidos no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. De agosto de 2010 a janeiro de 2012, foram coletados swabs nasais e inguinais de 190 pacientes (126 pré-transplante e 64 de pós-transplante). Isolados de MRSA foram identificados fenotipicamente e foi realizada detecção de genes de virulência, caracterização do tipo de SCCmec, análise de polimorfismo genômico por PFGE e técnica de microarranjo. Além disso, determinou-se a CIM para dez antimicrobianos pelo método de microdiluição em caldo. MRSA foi detectado em 20% dos pacientes pelo método de cultura e em 82% por PCRs. Apenas três pacientes colonizados desenvolveram infecção após o transplante. Entre os 69 isolados de MRSA, 42,0% (29/69) apresentaram SCCmec tipo II, 20,3% (14/69) SCCmec tipo I, 20,3% (14/69) SCCmec tipo III, 13,0% (9/69) SCCmec tipo IVa, 2,9% (2/69) SCCmec tipo IV e 1,5% (1/69) SCCmec tipo V. O gene tst foi detectado em 5,8% (4/69) dos isolados MRSA e todos eles foram definidos como SCCmec tipo I. Outros genes identificados por PCR foram: lukD (89,9%; 62/69), lukE (89,9%; 62/69), clf (91,3%; 63/69) e fnbA (89,9%; 62/69). A análise por PFGE dos 69 isolados mostrou a presença de um clone predominante chamado cluster A em 36,2% (25/69) e este cluster apresentou 84,6% de similaridade com o clone NewYork/Japan (BK2464). O dendrograma demonstrou também a presença de um cluster relacionado com BEC (Clone Endêmico Brasileiro) HSJ216. Atualmente o tipo de SCCmec mais prevalente em nosso hospital é o tipo II. Neste estudo, observou-se a presença de isolados virulentos tanto em pacientes hepatopatas como em pacientes transplantados. Nossos resultados mostraram que o clone predominante (cluster A) apresentou diferentes genes de virulência (genes fnbA, clf e lukD-lukE) e foi resistente a pelo menos seis diferentes drogas, além de ser caracterizado como HA-MRSA SCCmec tipo II. Em conclusão, a técnica de microarranjo permite a genotipagem e detecção de genes estafilocócicos clinicamente relevantes, e pode, na maioria dos casos, ser utilizada como uma importante ferramenta para a triagem da virulência e resistência a antimicrobianos em isolados de MRSA / MRSA is an important agent of colonization and infection in patients with liver disease and liver transplant. This study aims to evaluate clonality and virulence of MRSA isolates from liver diseases patients treated at Hospital of Clinics Faculty of Medicine from University of Sao Paulo. From August 2010 to January 2012, we collected nasal and groin swabs from 190 patients (126 pre-liver and 64 post-liver). MRSA isolates were identified phenotypically and the detection of virulence genes, characterization of SCCmec type, microarray and genomic polymorphism analysis by PFGE were done. In addition, it was determined the MIC for ten antibiotics by broth microdillution method. MRSA was detected in 20% patients by culture method and 82% by PCR. Only three patients colonized developed infection post-transplantation. Among the 69 MRSA isolates, 42.0% (29/69) had type II SCCmec, 20.3% (14/69) SCCmec type I, 20.3% (14/69) SCCmec type III, 13.0% (9/69) SCCmec type IVa, 2.9% (2/69) SCCmec type IV and 1.5% (1/69) SCCmec type V. The tst gene was detected in 5.8% (4/69) of MRSA isolates and all of them were defined as SCCmec type I. Other genes were identified by PCR: lukD (89.9%; 62/69), lukE (89.9%; 62/69), clf (91.3%; 63/69) and fnbA (89.9%; 62/69). The PFGE analysis of 69 isolates showed the presence of a predominant cluster named cluster A in 36.2% (25/69) and this cluster had 84.6% similarity with New York/Japan clone (BK2464). Dendrogram also demonstrated presence of one cluster related with BEC (Brazilian Endemic Clone) HSJ216. Currently the most prevalent SCCmec type in our hospital is type II. In this study, we observed virulent isolates in pre and post-transplantation patients. Our results showed that the predominant clone (cluster A) had different virulence genes (genes fnbA, clf and lukD-lukE) and was resistant to at least six different drugs, in addition to being characterized as HA-MRSA SCCmec type II. In conclusion, microarray profiling allows genotyping and detection of clinically relevant staphylococcal genes, and can, in most cases, be used as an important tool to screening virulence and antibiotic resistance genes in MRSA isolates

S.aureus resistente à meticilina(SARM) é um problema em centros de fibrose cística(FC). Foi desenvolvido um multiplex PCR(mPCR) para detecção do SARM em secreção respiratória de 106 pacientes com FC. Foram usados 3 pares de primers para amplificar os genes: mecA, coa, 16S rRNA. O mPCR detectou até 0,25pg de DNA de SARM e identificou 70/106(66,0%) pacientes com S.aureus e 28/106(26,4%) com SARM. O mPCR mostrou especificidade, sensibilidade, valores preditivos positivo e negativo de 87,8%, 84,4%, 50% e 97,5%, considerando a cultura como padrão-ouro. Os resultados discordantes foram testados com outros primers, confirmando os obtidos pelo mPCR em 82/84. O mPCR mostrou-se método rápido e confiável para detecção de SARM / Methicillin-resistant S.aureus(MRSA) is a significant concern in cystic fibrosis(CF) centers. A multiplex PCR(MPCR) was developed to detect MRSA in respiratory secretion of 106 CF patients. Three pairs of primers were used for amplification of genes: mecA, coa, 16S rRNA. MPCR detected 0.25pg of MRSA DNA and identified 70/106(66.0%) of patients with S.aureus and 28/106(26.4%) with MRSA. MPCR showed specificity, sensitivity, positive and negative predicted values at 87.8%, 84.4%, 50% and 97.5%, considering culture as the gold standard. Discrepant results were retested using different primers, and confirmed MPCR results in 82/84. The developed MPCR was found to be a rapid and reliable method for MRSA detection

Na última década, Staphlylococcus aureus resistentes à meticilina não multidroga resistente (NM-MRSA) tem sido descrito como um importante agente de infecção de corrente sanguínea em nosso serviço. Este estudo de coorte prospectivo, realizado entre fevereiro de 2009 e janeiro de 2010 na unidade neonatal, avaliou 403 recém-nascidos (RN), suas 382 mães e 148 profissionais da área da saúde (PS). Duzentos e dezessete NB (54%), 187 mães (48%) e 87 PS (59%) foram colonizados por S. aureus (SA). A colonização por S. aureus resistente à meticilina (MRSA) foi maior entre RN (15%) do que entre mães (4.7%) e PS (3.4%). Embora a transmissão da mãe para seu RN tenha ocorrido, na maior parte dos casos, a mãe não foi a responsável pela colonização do RN. Houve dois padrões predominantes de polimorfismo do DNA por eletroforese em campo pulsado (PFGE) entre os RN, e algumas mães e PS foram colonizados por eles. Fatores estatisticamente associados com colonização por MRSA foram baixo nível de escolaridade materna (fator de risco - OR: 2.99; 95%CI: 1.10-8.07) e rinossinusite materna (fator protetor - OR: 0.33; 95%CI: 0.12-0.88). Entre os Rn que permaneceram hospitalizados mais do que 72 horas, o aleitamento materno foi protetor (OR: 0.22; 95%CI: 0.05-0.98). Todos os isolados foram NM-MRSA, portavam poucos fatores de virulência e Staphylococcal Cassete Chromossome mec (SCCmec) tipos IVa e IVd predominaram. Embora não tenham ocorrido casos de infecção, a transmissão nosocomial de MRSA claramente ocorreu na unidade neonatal e aponta para a necessidade de implementação de práticas de controle de infecção, como higienização das mãos para prevenção de infecção cruzada. Outras práticas de promoção à saúde, básicas, mas abrangentes, podem ser fundamentais, como educação e aleitamento materno / In the last decade non-multiresistant methicillin-resistant S. aureus (NM-MRSA) has been described as an important agent in bloodstream infections in our hospital. This prospective cohort study, conducted from February 2009 through January 2010 in the neonatal unit, evaluated 403 newborns (NB), their 382 mothers and 148 health care workers (HCW). 217 NB (54%), 187 mothers (48%) and 87 HCW (59%) were colonized by S. aureus (SA). Methicillin-resistant S. aureus (MRSA) colonization was greater among NB (15%) than mothers (4.7%) and HCW (3.4%). Although mother-to-NB transmission occurred, in most cases mothers were not responsible for NB colonization. There were two predominant PGFE patterns among the NB and some mothers and HCW became colonized by them. Factors significantly associated with MRSA carriage by NB were lower level of maternal schooling (risk factor: OR: 2.99; 95%CI: 1.10-8.07) and maternal rhinosinusitis (protective factor: OR: 0.33; 95%CI: 0.12-0.88). Among NB who remained hospitalized for more than 72 hours, breast feeding was protective (OR: 0.22; 95%CI: 0.05-0.98). All the isolates were NM-MRSA, carried few virulence factors and Staphylococcal Cassete Chromossome mec (SCCmec) types IVa and type IVd predominated. Although there were no cases of infection, nosocomial transmission of MRSA clearly occurred in the neonatal unit and this highlights the need for infection control practices such as hand hygiene to prevent cross-dissemination. Other healthcare practices, which are very basic but also ample in scope, may play a role, such as general education of women and breast feeding