• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 4
  • 1
  • 1
  • Tagged with
  • 11
  • 4
  • 4
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

THE ROLE OF FOMITES IN THE TRANSMISSION OF NOROVIRUS

Fankem Mingo, Sonia Laure January 2008 (has links)
Introduction: Acute gastroenteritis is a common illness in humans. It has a high morbidity worldwide and in the United States (U.S); a sizeable mortality is reported in developing countries. Viruses are a common cause of acute gastroenteritis and noroviruses are the leading cause of non-bacterial gastroenteritis (1). Fomites play an important role in the infection cycle of norovirus. This study explored the comparability between a quantitative microbial risk assessment (QMRA) model to predict the probability of illness from norovirus due to environmental contamination with actual observed attack rates, the impact of appropriate cleaning procedures on fomites contamination, and the role of fomites in the transmission of norovirusMethod: Data from three different norovirus illness outbreaks occurring from 2004 to 2005 in Arizona in different venues were used. Questionnaires were used to determine demographics, symptoms associated with gastrointestinal illness, medical visits, and potential exposures such as food items consumed. When available, stool samples were collected from ill participants. Fomites samples were also gathered from the different venues; houseboats, college summer camp living spaces, and a restaurant. These samples were tested for norovirus using reverse transcriptase polymerase chain reaction (RT-PCR). Viral concentration on fomites was calculated using the most probable number methodology.Results: Norovirus was found on fomites from all three outbreaks. Improper cleaning of fomites increased the proportion of norovirus positive fomites from 40 percent to 70 percent in contrast, after cleaning and disinfection with 5000 mg/L free chloride, the proportion of norovirus positive fomites decreased to 33%. The predicted values from the quantitative microbial risk assessment model were consistent with the observed epidemiological attack rates.Conclusion: This study showed unequivocally that fomites play an important role in the transmission cycle of norovirus, and that improper cleaning and disinfection procedures only serve to spread the virus to previously uncontaminated fomites. In the case of outbreaks where people are not always available to answer questionnaires, QMRA should be considered as a worthwhile alternative to a full-scale epidemiological study.
2

Norovirus in Recreational Waters in Arizona

Jones, Ellen L. January 2006 (has links)
Noroviruses are the leading cause of gastroenteritis in the United States, causing an estimated 23 million illnesses, 50,000 hospitalizations and 300 deaths per year. This virus is transmitted via the fecal-oral route and infections can occur from drinking contaminated water or eating contaminated food, contact with contaminated fomites, inhalation of aerosolized vomitus, or person to person spread. Outbreaks of norovirus following exposure to contaminated recreational water have been documented, as swimmers and others engaged in water recreation often consume recreational water, either purposefully or accidentally, during their activities. In Arizona there have been several outbreaks of norovirus gastroenteritis among people using the recreational waters. In the past four years there have been four consecutive outbreaks of norovirus among rafters on the Colorado River, and in 2003 there was an outbreak of norovirus among a large group of houseboaters on Lake Powell.Norovirus is an emerging pathogen in the state of Arizona. In an effort to better understand its epidemiology, and with the aim of providing recommendations for prevention or minimization of future outbreaks, two investigations were undertaken: an investigation of the outbreak of norovirus among houseboaters on Lake Powell, and a survey of water quality and possible sources of norovirus in the Colorado River. Additionally, historical Colorado River water quality data was reviewed and outbreak epidemiology assessed. To better understand the role of viruses in waterborne recreational disease outbreaks, a review of the literature was conducted and an analysis of 48 recreational waterborne disease outbreaks was done.
3

The Transmission, Detection and Occurrence of Viruses on Indoor Environmental Fomites

Boone, Stephanie January 2005 (has links)
Viruses cause 60% of human infections and are probably the most common cause of infectious disease acquired indoors. Rapid spread of viral illness in indoor establishments facilitates disease morbidity and mortality. The goal of this dissertation is to clarify the role of fomites in the viral infection cycle. Research methods include investigation of published literature, and the use of polymerase chain reaction (PCR) for viral detection. The Appendix A study reviewed published literature to assess the significance of fomites in the transmission of ten common respiratory and enteric viruses (rhinovirus, respiratory syncytial virus (RSV), influenza A, parainfluenza 1 (HPIV1), coronavirus, rotavirus, calicivirus, hepatitis A virus (HAV), astrovirus and adenovirus). Results suggest that fomites play an important role in the transmission of common viral pathogens, and the use of disinfectants may limit the spread of viral disease. The Appendix B study examined PCR primer detection limits by determining the time length viruses can be isolated on fomites. Results indicated that poliovirus 1 and hepatitis A virus could be detected for up to 60 days. Parainfluenza 1 virus isolation yielded detection at 30 days and 50 days. Norovirus isolation yielded detection at 20 days and 30 days. Influenza virus isolation results were inconsistent, yielding no initial detection and detection up to 20 days. Appendix C assessed the occurrence of human parainfluenza 1 virus (HPIV1) on surfaces in office settings. HPIV1 was detected on 37% of fomites. HPIV1 was detected most on desktops (47%), and least on light switches (19%). Study results indicated a statistically significant difference between positive fomites in different buildings (Chi-square p < 0.011), and between building cubicles and conference room fomites (Chi-square p < 0.011). Appendix D evaluated the prevalence of influenza A virus on surfaces in day care and home settings. Influenza A was isolated on 23% of fall day care fomites and 53% of spring day care fomites. Influenza was isolated on 59% of home fomites sampled during March, and no influenza was detected on home fomites sampled during the summer. Overall, Influenza A virus was isolated on over 50% of fomites in homes and day care centers.
4

The role of mobile phones as a possible pathway for pathogen movement, a cross-sectional microbial analysis

Tajouri, L., Campos, M., Olsen, M., Lohning, A., Jones, P., Moloney, S., Grimwood, K., Ugail, Hassan, Mahboub, B., Alawar, H., McKirdy, S., Alghafri, R. 20 March 2022 (has links)
Yes / Introduction: Mobile phones are used the world over, including in healthcare settings. This study aimed to investigate the viable microbial colonisation of mobile phones used by healthcare personnel. Methods: Swabs collected on the same day from 30 mobile phones belonging to healthcare workers from three separate paediatric wards of an Australian hospital were cultured on five types of agar plate, then colonies from each phone were pooled, extracted and sequenced by shotgun metagenomics. Questionnaires completed by staff whose phones were sampled assisted in the analysis and interpretation of results. Results and discussion: All phones sampled cultured viable bacteria. Overall, 399 bacterial operational taxonomic units were identified from 30 phones, with 1432 cumulative hits. Among these were 58 recognised human pathogenic and commensal bacteria (37 Gram-negative, 21 Gram-positive). The total number of virulence factor genes detected was 347, with 1258 cumulative hits. Antibiotic resistance genes (ARGs) were detected on all sampled phones and overall, 133 ARGs were detected with 520 cumulative hits. The most important classes of ARGs detected encoded resistance to beta-lactam, aminoglycoside and macrolide antibiotics and efflux pump mediated resistance mechanisms. Conclusion: Mobile phones carry viable bacterial pathogens and may act as fomites by contaminating the hands of their users and indirectly providing a transmission pathway for hospital-acquired infections and dissemination of antibiotic resistance. Further research is needed, but meanwhile adding touching mobile phones to the five moments of hand hygiene is a simple infection control strategy worth considering in hospital and community settings. Additionally, the implementation of practical and effective guidelines to decontaminate mobile phone devices would likely be beneficial to the hospital population and community at large.
5

Validación de una escala para evaluar contaminación de alimentos en el hogar, estudio en la zona rural de Perú

Lozada Urbano, Michelle, Rivera, Roger, Miranda, Doris, Gallegos Vergara, Clara, Reyes Villegas, María Ysabel, Xirinachs Salazar, Yanira 02 December 2014 (has links)
Objetivos: validar una escala para evaluar la contaminación de alimentos en el hogar y, medir la validez y confiabilidad. Métodos: se encuestaron madres o cuidadoras con niños menores a 5 años, en San Juan de Lurigancho en Lima Perú. La escala fue previamente sometida a una calificación de jueces expertos. Se realizó el análisis de factores con componentes principales, la consistencia interna fue medida con Kuder–Richardson Formula 20 (KR-20) y la validez de la prueba con el coeficiente Kaiser-Meyer-Olkin (KMO) y el test de esfericidad de Barlet. Resultados: la muestra tuvo 194 cuidadoras. Se definieron tres componentes (prácticas de limpieza, prácticas de almacenaje y contaminación del niño) con un total de 10 ítems. El ítem Prácticas de limpieza tuvo un KR-20=0.722 prácticas de almacenaje y contaminación de alimentos 0.518 y 0.5 respectivamente. La validez de la prueba tuvo un KMO = 0.549 y un test de Barlet 591.678 , gl =136, (p<0.05). Conclusiones: esta escala puede contribuir a la planificación de intervenciones en el aspecto de contaminación en el hogar y por lo tanto reducir episodios de infecciones en los niños. / Objectives: To validate a scale to assess contamination of food at home and measure the validity and reliability. Methods: mothers or caregivers with children under 5 years were surveyed in San Juan de Lurigancho in Lima Peru. The scale was previously subject to a rating of expert judges. Factor analysis with principal components was performed; the internal consistency was measured with Kuder-Richardson Formula 20 (KR-20) and the validity of the test with the coefficient Kaiser-Meyer-Olkin (KMO) and the sphericity test Barlet. Results: The sample was 194 caregivers. Three components (Practices cleaning, storage practices and pollution of the child) with a total of 10 items were identified. The item Cleaning Practices had a KR-20 = 0.722 storage practices and food contamination 0.518 and 0.5 respectively. The validity of the test was KMO = 0.549 and 591,678. Barlet test, df = 136, (p <0.05). Conclusions: This scale can contribute to the planning of interventions in the aspect of pollution in the home and thus reduce episodes of infections in children.
6

The Occurrence and Control of Pathogens on Fomites

Sexton, Jonathan D. January 2013 (has links)
Microbes survive for an extended period of time on fomites. With new strains of pathogens constantly emerging, it is important to understand their survival and spread and to evaluate the efficiency of new disinfection methods. The purpose of this study was to determine the occurrence of pathogens on fomites, and evaluate different disinfection methods (household bleach and steam vapor). Fomites were sampled in a variety of environments for the presence of pathogens including methicillin intermediate- and resistant- Staphylococcus aureus, Clostridium difficile, Penecillium brevi-compactum, Alternaria alternata and novel H1N1 influenza A. Samples were assayed using both cultural and genetic techniques to determine the microbial occurrence. In disinfection studies, samples were collected before and after disinfectant application. Steam vapor was effective at reducing microbial occurrence by>90% with a minimal contact time of 10-20 seconds on hospital fomites. The material and shape of the surface had an effect on the reduction rate, due to access of the disinfecting agent. In addition, low levels of initial contamination limited the reduction rate. Many surfaces had a starting contamination level of less than 3 log10 and after disinfection the contamination levels, in 69% of the samples, were at or near the limit of detection. This suggests a higher reduction is feasible. Household bleach reduced the presence of mold spores and mycelium by >99% on gypsum-wall board. Reduction rates were influenced by the growth stage of mold, with the mycelium requiring additional disinfectant application to achieve the 99% reduction rate. Novel H1N1 influenza A was not recovered on any surfaces in day care facilities and elementary schools. This is consistent with previous studies looking at H1N1 influenza occurrence in similar environments, though it is different from H3N2 influenza A studies. Survival differences among varying influenza strains are expected to have an impact on pathogen spread and human health risks. Differences can be quantitatively evaluated and used to develop more advanced risk assessment models. Steam vapor and household bleach are effective at reducing risks of pathogens in the environment and are critical interventions in an overall strategy to minimize exposure and prevent disease.
7

Prevalência e caracterização molecular de bastonetes Gram negativos isolados do sistema de transporte público coletivo do município de Goiânia-Go / Molecular epidemiology of Gram negative rods from collective public Transport system in the central region of Brazil

Lamaro, Luana 09 June 2017 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-11-07T17:03:10Z No. of bitstreams: 2 Dissertação - Luana Lamaro - 2017.pdf: 3263118 bytes, checksum: d0e16b39616bfde882a20ec1ff2e5c54 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-11-08T10:02:25Z (GMT) No. of bitstreams: 2 Dissertação - Luana Lamaro - 2017.pdf: 3263118 bytes, checksum: d0e16b39616bfde882a20ec1ff2e5c54 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-11-08T10:02:25Z (GMT). No. of bitstreams: 2 Dissertação - Luana Lamaro - 2017.pdf: 3263118 bytes, checksum: d0e16b39616bfde882a20ec1ff2e5c54 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-06-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Objects contaminated with microorganisms are denominated fomites. A number of studies have reported fomites as sources of microorganism dissemination. This study aimed to isolate and identify Gram Negative Bacilli (GNB) from a collective public transport line in the city of Goiânia, GO, to characterize by phenotypic and genotypic methods in the antimicrobial susceptibility profile and to analyze the macrorrestricity profile of the isolated. As samples of the fixed bars surfaces of the buses and ratchets of the platforms and terminals of “Leste-Oeste” line were collected with swab and sent to the Laboratory of Applied Bacteriology of the IPTSP-UFG. After the GNB culture, as species were identified by PCR and submitted to the Antimicrobial Susceptibility Test (AST). The plasmid DNA of the strains resistant to beta-lactams was extracted for the search of genes encoding beta-lactamases by PCR. The macrorrestriction profile of P. mirabilis strains was performed by PFGE using the XbaI enzyme. A total of 852 swabs were collected representing a prevalence of 46.0% of GNB in the evaluated surfaces. The species identified were A. baumannii (40.8%), H. alvei (30.9%), P. mirabilis (26.1%) and E. coli (2.2%). The AST revealed 31 (7.9%) multidrug resistant isolates. The blaTEM and blaCTX genes were detected. We observed a presence of eight clusters and three clones among the species P. mirabilis. This study proves that the surfaces present in the collective public transport system can be sources of resistant multi-drug GNB and these bacteria have the potential of dispersion and permanence in different community environments. / Objetos contaminados por micro-organismos são denominados fômites. Vários estudos relacionam fômites como fontes de disseminação de micro-organismos. Este estudo objetivou isolar e identificar Bastonetes Gram Negativos (BGN) de uma linha de transporte público coletivo da cidade de Goiânia – GO, caracterizar por métodos fenotípicos e genotípicos o perfil de suscetibilidade aos antimicrobianos e analisar o perfil de macrorrestrição dos isolados. As amostras das superfícies das barras fixas dos ônibus e as catracas das plataformas e terminais da linha Leste-Oeste foram coletadas com swab e enviadas para o Laboratório de Bacteriologia Aplicada do IPTSP-UFG. Após o cultivo dos BGN, as espécies foram identificadas por PCR e submetidas ao Teste de Suscetibilidade aos Antimicrobianos (TSA). O DNA plasmidial das cepas resistentes aos betalactâmicos foi extraído para a pesquisa dos genes codificadores de betalactamases por PCR. O perfil de macrorrestrição das cepas de P. mirabilis foi realizado por PFGE utilizando a enzima XbaI. Foram coletados 852 swabs representando uma prevalência de 46,0% de BGN nas superfícies avaliadas. As espécies identificadas foram: A. baumannii (40,8 %), H. alvei (30,9 %), P. mirabilis (26,1 %) e E. coli (2,2 %). O TSA revelou 31 (7,9 %) isolados multidroga resistentes. Foram detectados os genes blaTEM e o gene blaCTX. Observamos a presença de oito clusters e três clones entre as espécies P. mirabilis. Este estudo comprova que as superfícies presentes no sistema de transporte público coletivo podem ser fontes de BGN multidroga resistentes e que essas bactérias possuem potencial de dispersar e permanecer em diferentes ambientes comunitários.
8

Transfer of Microorganisms from Fomites to Hands and Risk Assessment of Contaminated and Disinfected Surfaces

Lopez, Gerardo Urquijo January 2013 (has links)
It is now widely accepted that surface contamination plays an important role in the transmission of both respiratory and gastrointestinal infections in the domestic environment and community setting. The efficiency of transfer of a pathogen to the hand from a fomite is important in modeling transmission in microbial risk assessment models. The objective of this study was to use published literature to assess the role of fomites and hands in disease transmission, and to conduct fomite-to-finger transfer studies from various porous and nonporous fomites under different relative humidity condition using non-pathogenic strains of Escherichia coli, Staphylococcus aureus, MS2 coliphage, Bacillus thuringiensis spores, and poliovirus 1; to evaluate the persistence of bacteria and viruses on surfaces; to examine bacteria and virus transfer from treated surfaces; and to conduct a foodborne quantitative microbial risk assessment using Campylobacter jejuni from the data obtained in these studies. It was found that numerous factors influence the transfer efficiency of microorganisms, with moisture being the most important, with greater transfer under humid conditions. Other factors influencing transfer include drying time, contact time, pressure, friction, type of material, and porosity of the fomite. Percent transfer was greater under high relative humidity for both porous and nonporous surfaces. Most organisms on average had greater transfer under high relative humidity (40 - 65%) compared to low relative humidity (15 - 32%). Relative humidity and fomite type influenced the survival of all studied organisms; survival was greater on nonporous surfaces than those for porous surfaces. Test organisms were reduced up to 99.997% on the fomites after the surfaces were wiped with a disinfectant wipe. Microbial fomite-to-finger transfer from disinfectant wipe-treated surfaces were, lower than from non-treated surfaces. The disinfectant-wipe intervention reduced the risk of Campylobacter infection, illness, and death by 2 to 3 orders on all fomites. The disinfectant-wipe intervention reduced the annual risk of illness below the reported national average of diagnosed Campylobacteriosis cases 1.3E-04. This risk assessment demonstrates that the use of disinfectant wipes to decontaminate surface areas after chicken preparation reduces the risk of C. jejuni infections up to 99.2%.
9

Staphylococcus haemolyticus e Staphylococcus epidermidis isolados de fômites de origem hospitalar: perfis de resistência aos agentes antimicrobianos e produção de biofilme / Staphylococcus haemolyticus and Staphylococcus epidermidis isolated from fomites hospital origin: profiles of antimicrobial resistance and biofilm production

Bruna Pinto Ribeiro Sued 14 June 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os Staphylococcus coagulase-negativos (SCN) são encontrados na pele e mucosas de seres humanos e outros animais, já que algumas espécies são parte constituinte da microbiota normal destes mesmos sítios, e podem constituir um reservatório para SCN. A espécie Staphylococcus epidermidis, é reconhecida como grande oportunista e agente de graves infecções nosocomiais e comunitárias, além de associado com infecções em pacientes submetidos a implantes com dispositivos médicos, e a espécie Staphyloccus haemolyticus é a segunda espécie mais isolada de hemoculturas humanas, sendo uma das espécies que apresenta elevada resistência aos antimicrobianos. O presente estudo teve como objetivo principal investigar a presença de SCN em fômites (estetoscópios, termômetros e esfigmomanômetros) no ambiente hospitalar, identificar as espécies S. haemolyticus e S. epidermidis e correlacionar seus perfis de resistência aos antimicrobianos com a capacidade de produção de biofilme. A técnica de multiplex-mPCR foi empregada na determinação das espécies e a fenotipagem foi realizada pelos testes fenotípicos convencionais. Os perfis de resistência aos antimicrobianos foram verificados através do teste de disco-difusão, determinação da CIM (oxacilina e vancomicina), determinação da CBM e presença do gene mecA. A capacidade de produção de biofilme foi investigada pelos testes do Ágar Vermelho do Congo e ensaios de aderência em superfícies abióticas (poliestireno e vidro) na presença e ausência de oxacilina e vancomicina, além da PCR para o gene icaAD. Os resultados demonstraram que pelos testes bioquímicos convencionais, a espécie mais encontrada foi S. epidermidis (43,5%). Após a confirmação pela técnica de PCR, 29 amostras (82%) foram identificadas como S. epidermidis, e 6 amostras (18%) foram identificadas como S. haemolyticus. Todas as amostras foram multirresistentes, oxacilina resistentes e vancomicina sensíveis, sendo que apenas 5 amostras S. epidermidis (17,2%) foram tolerantes a oxacilina. A presença do gene mecA foi detectada em 71,4% das amostras. Apesar da maioria das amostras ter apresentado capacidade de produzir slime e/ou biofilme não foi observada total correlação com a presença do gene icaAD enfatizando a natureza multifatorial da produção de biofilme. As amostras aderiram melhor ao esfigmomanômetro, e também, neste fômites, foi encontrado a maior porcentagem de amostras positivas para a produção de slime. Para aderência ao vidro e aderência ao poliestireno não foi encontrada correlação com os fômites. Foram isoladas amostras S. epidermidis de todos os sítios hospitalares estudados e S. haemolyticus só não foi encontrado em Enfermaria de Clínica Médica. Em relação aos fômites, S. epidermidis foi encontrado em todos os fômites estudados, e S. haemolyticus, apenas foi encontrado em esfigmomanômetro e em outros fômites. Os fômites estão servindo como fontes de transmissão e disseminação de micro-organismos, sendo necessário maiores estudos a respeito. / Coagulase-negative staphylococci ( SCN ) are found in the skin and mucous membranes of humans and other animals , since some species are a constituent part of the normal flora of these same sites, which may constitute a reservoir for SCN. Staphylococcus epidermidis species, is recognized as a major opportunistic infections and serious nosocomial and community staff, as well as associated with infections in patients undergoing implants with medical devices, and Staphylooccus haemolyticus is the second species most frequent species of human blood cultures, one of species that has a high antimicrobial resistance. The present study aimed to investigate the presence of SCN on fomites (stethoscopes, thermometers and sphygmomanometers) in the hospital environment, identify the species S. haemolyticus and S. epidermidis and correlate their antimicrobial resistance profiles with the ability to produce biofilm. The technique of multiplex mPCR was used in the determination of the species and phenotyping was performed by conventional phenotypic tests. The antimicrobial resistance profiles were checked by the disk diffusion test, MIC determination (oxacillin and vancomycin), determination of MBC and the presence of the mecA gene. The capacity of the biofilm was investigated by testing the Congo Red agar and adhesion assays abiotic surfaces (glass and polystyrene) in the presence and absence of oxacillin and vancomycin in addition to the PCR icaAD gene. The results demonstrated that the conventional biochemical tests, it was found more species S. epidermidis (43,5%). After confirmation by PCR , 29 samples (82%) were identified as S. epidermidis, and 6 samples (18%) were identified as S. haemolyticus. All samples were multiresistant, oxacillin-resistant and vancomycin-sensitive, and only 5 samples S. epidermidis (17,2%) were tolerant to oxacillin. The presence of the mecA gene was detected in 71,4% of samples. Although most of the samples have shown the ability to produce slime and/or biofilm not fully correlate with the presence of the gene was observed icaAD emphasizing the multifactorial nature of biofilm production. Samples adhered better to the sphygmomanometer, and that too, in this fomites, found the highest percentage of samples positive for slime production. For adhesion to glass and adherence to polystyrene was found no correlation with fomites. S. epidermidis samples of all hospital sites studied, and S. haemolyticus were isolated not only found in Infirmary Medical Clinic. Regarding fomites, S. epidermidis was found in all studied fomites, and S. haemolyticus, have been found only on sphygmomanometer and other fomites. The fomites are serving as sources of transmission and spread of microorganisms, and further study concerning necessary.
10

Staphylococcus haemolyticus e Staphylococcus epidermidis isolados de fômites de origem hospitalar: perfis de resistência aos agentes antimicrobianos e produção de biofilme / Staphylococcus haemolyticus and Staphylococcus epidermidis isolated from fomites hospital origin: profiles of antimicrobial resistance and biofilm production

Bruna Pinto Ribeiro Sued 14 June 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os Staphylococcus coagulase-negativos (SCN) são encontrados na pele e mucosas de seres humanos e outros animais, já que algumas espécies são parte constituinte da microbiota normal destes mesmos sítios, e podem constituir um reservatório para SCN. A espécie Staphylococcus epidermidis, é reconhecida como grande oportunista e agente de graves infecções nosocomiais e comunitárias, além de associado com infecções em pacientes submetidos a implantes com dispositivos médicos, e a espécie Staphyloccus haemolyticus é a segunda espécie mais isolada de hemoculturas humanas, sendo uma das espécies que apresenta elevada resistência aos antimicrobianos. O presente estudo teve como objetivo principal investigar a presença de SCN em fômites (estetoscópios, termômetros e esfigmomanômetros) no ambiente hospitalar, identificar as espécies S. haemolyticus e S. epidermidis e correlacionar seus perfis de resistência aos antimicrobianos com a capacidade de produção de biofilme. A técnica de multiplex-mPCR foi empregada na determinação das espécies e a fenotipagem foi realizada pelos testes fenotípicos convencionais. Os perfis de resistência aos antimicrobianos foram verificados através do teste de disco-difusão, determinação da CIM (oxacilina e vancomicina), determinação da CBM e presença do gene mecA. A capacidade de produção de biofilme foi investigada pelos testes do Ágar Vermelho do Congo e ensaios de aderência em superfícies abióticas (poliestireno e vidro) na presença e ausência de oxacilina e vancomicina, além da PCR para o gene icaAD. Os resultados demonstraram que pelos testes bioquímicos convencionais, a espécie mais encontrada foi S. epidermidis (43,5%). Após a confirmação pela técnica de PCR, 29 amostras (82%) foram identificadas como S. epidermidis, e 6 amostras (18%) foram identificadas como S. haemolyticus. Todas as amostras foram multirresistentes, oxacilina resistentes e vancomicina sensíveis, sendo que apenas 5 amostras S. epidermidis (17,2%) foram tolerantes a oxacilina. A presença do gene mecA foi detectada em 71,4% das amostras. Apesar da maioria das amostras ter apresentado capacidade de produzir slime e/ou biofilme não foi observada total correlação com a presença do gene icaAD enfatizando a natureza multifatorial da produção de biofilme. As amostras aderiram melhor ao esfigmomanômetro, e também, neste fômites, foi encontrado a maior porcentagem de amostras positivas para a produção de slime. Para aderência ao vidro e aderência ao poliestireno não foi encontrada correlação com os fômites. Foram isoladas amostras S. epidermidis de todos os sítios hospitalares estudados e S. haemolyticus só não foi encontrado em Enfermaria de Clínica Médica. Em relação aos fômites, S. epidermidis foi encontrado em todos os fômites estudados, e S. haemolyticus, apenas foi encontrado em esfigmomanômetro e em outros fômites. Os fômites estão servindo como fontes de transmissão e disseminação de micro-organismos, sendo necessário maiores estudos a respeito. / Coagulase-negative staphylococci ( SCN ) are found in the skin and mucous membranes of humans and other animals , since some species are a constituent part of the normal flora of these same sites, which may constitute a reservoir for SCN. Staphylococcus epidermidis species, is recognized as a major opportunistic infections and serious nosocomial and community staff, as well as associated with infections in patients undergoing implants with medical devices, and Staphylooccus haemolyticus is the second species most frequent species of human blood cultures, one of species that has a high antimicrobial resistance. The present study aimed to investigate the presence of SCN on fomites (stethoscopes, thermometers and sphygmomanometers) in the hospital environment, identify the species S. haemolyticus and S. epidermidis and correlate their antimicrobial resistance profiles with the ability to produce biofilm. The technique of multiplex mPCR was used in the determination of the species and phenotyping was performed by conventional phenotypic tests. The antimicrobial resistance profiles were checked by the disk diffusion test, MIC determination (oxacillin and vancomycin), determination of MBC and the presence of the mecA gene. The capacity of the biofilm was investigated by testing the Congo Red agar and adhesion assays abiotic surfaces (glass and polystyrene) in the presence and absence of oxacillin and vancomycin in addition to the PCR icaAD gene. The results demonstrated that the conventional biochemical tests, it was found more species S. epidermidis (43,5%). After confirmation by PCR , 29 samples (82%) were identified as S. epidermidis, and 6 samples (18%) were identified as S. haemolyticus. All samples were multiresistant, oxacillin-resistant and vancomycin-sensitive, and only 5 samples S. epidermidis (17,2%) were tolerant to oxacillin. The presence of the mecA gene was detected in 71,4% of samples. Although most of the samples have shown the ability to produce slime and/or biofilm not fully correlate with the presence of the gene was observed icaAD emphasizing the multifactorial nature of biofilm production. Samples adhered better to the sphygmomanometer, and that too, in this fomites, found the highest percentage of samples positive for slime production. For adhesion to glass and adherence to polystyrene was found no correlation with fomites. S. epidermidis samples of all hospital sites studied, and S. haemolyticus were isolated not only found in Infirmary Medical Clinic. Regarding fomites, S. epidermidis was found in all studied fomites, and S. haemolyticus, have been found only on sphygmomanometer and other fomites. The fomites are serving as sources of transmission and spread of microorganisms, and further study concerning necessary.

Page generated in 0.0512 seconds