Bacterial resistance to non-antibiotic agents is being increasingly studied. Plasmid-mediated resistance to cationic agents, which are important biocides, has been described in antibiotic-resistant Staphylococcus aureus. Multi-resistant Staphylococcus aureus (MRSA) are often found to express resistance to a range of cationic biocides including quaternary ammonium compounds (QACs), biguanides, diamidino compounds, cationic dyes and nuclear stains. Three resistance determinants, qacA, qacB and smr genes, have been identified that confer resistance to cationic biocides in staphylococci. These genes encode multi-drug efflux pumps that remove the cationic biocides from the cytoplasm using a membrane bound pumping mechanism dependent on the cell's proton-motive force (PMF). This prevents the build up of lethal concentrations of cationic compounds within the cytoplasm avoiding cell death.This research project has focused on the S. aureus strain WBG4364, a transcipient strain carrying the cationic biocide resistant plasmid pWBG1773. The plasmid encodes resistance to several QACs, including benzalkonium chloride and CTAB, and cationic dyes rhodamine 6G, crystal violet and safranin O but not to the dye ethidium bromide and therefore differing from other cationic biocide resistant plasmids previously identified in staphylococci (Emslie et al. 1986). This unique phenotype was further classified in this study alongside those strains carrying the qac gene families, qacA/B and smr.Plasmid pWBG1773 was cloned, sequenced and analysed to reveal a unique plasmid of 2,916 bp in length. Plasmid pWBG1773 was placed with the pC194 family of rolling-circle replicating plasmids. This family appear to be largely composed of interchangeable cassette structures.The plasmid was found to carry three ORFs, designated ORF1, ORF2 and ORF3. ORF1 was homologous to rep genes of small staphylococcal ++ / plasmids belonging to the pC194 rolling-circle replication family and has been redefined as repWBG1773. ORF2 was found to have no similarity to any proteins of known function in the GenBank database whereas ORF3 was found to have homology to the marR gene, a regulator of the multiple antibiotic resistance (mar) operon of Gram-negative organisms. MIC analysis of these ORFs found both ORF2 and ORF3 were essential for expression of resistance to cationic biocides. The exact ORF2 sequence required for resistance to be expressed was reduced to only 141 nt in size. This translated to a 47 aa sequence that contained a hydrophobic C-terminus indicating ORF2 to be a membrane-bound protein. The aa sequence of ORF3 contained a helix-turn-helix motif characteristic of the DNA binding domains of MarR-like proteins. Further analysis of pWBG1773 identified a putative 'marbox', a binding site for the homologous transcriptional activators of mar, within the ORF2 sequence. This indicated that ORF3 was binding to the 'marbox' sequence and activating transcription. Induction studies have not been able to ascertain any compounds capable of interacting with the ORF3 regulatory protein resulting in induction of cationic biocide resistance. Each ORF when analysed alone had no effect on the expression of cationic biocide resistance and it is thought that a efflux pump was not involved. This is further corroborated by the CCCP efflux experiments performed in an attempt to determine the mechanism of resistance. The unique ORFs of plasmid pWBG1773 appears to encode a novel cationic biocide resistance phenotype and mechanism.MRSA strains from all around the world were analysed to determine if they possessed sequences homologous to ORF2 and ORF3. Sequences sharing a high degree of homology to ORF2 and/or ORF3 were detected in several MRSA strains including strains sensitive to all cationic ++ / biocides tested. These findings suggest that the appearance of ORF2 and ORF3 sequences in MRSAs was not an isolated event and the fact that some MRSAs do not carry both ORF2 and ORF3 sequences simultaneously indicates that these genes have another role that does not involve expression of resistance to cationic biocides.Bacteria are noteworthy for their remarkable ability to adapt to changes in their environments and possess an impressive set of tools with which to adjust the blueprint of the cell to this change. The acquisition of a single system that may decrease a potential pathogenic organisms susceptibility to a wide range of cationic biocides, such as seen in pWBG1773, poses a clinical threat, one that needs to be thoroughly investigated.

This study was conducted to determine if alternative heating times and slower cooling times, other than those defined by FSIS, could be utilized and still comply with FSIS performance standards. Large (10.43 to 12.25 kg), cured bone-in hams (n = 190) and large (greater than or equal to 9.07 kg), uncured beef inside rounds (n = 180) were utilized in a two-phase study. Phase 1 of the study investigated the effect of alternative lethality parameters on toxin production of Staphylococcus aureus and log reduction of Salmonella Typhimurium and coliforms. Both the hams and roast beef were subjected to 1 of 10 treatments defined by varying final internal product temperatures (48.9 degrees C, 54.4 degrees C, 60.0 degrees C, 65.6 degrees C, or 71.1 degrees C) and smokehouse relative humidities (50% or 90%). Phase 2 investigated the effect of alternative stabilization parameters on log growth of Clostridium perfringens. Stabilization treatments extended the times taken to reduce internal product temperature from 54.4 degrees C to 26.7 degrees C and from 26.7 degrees C to 7.2 degrees C (ham) or 4.5 degrees C (beef), independently. Further, a control treatment following current FSIS, Appendix B guidelines was conducted for ham, and a "worst case" scenario was assessed for both products. The "worst case" treatment evaluated the effects of cooling products at room temperature (approximately 22.8 degrees C) in place of normal cooling procedures in a temperature controlled environment. Results of the study showed at least a 6.5-log10 reduction in S. Typhimurium across all lethality treatments for both products. Further, coliform counts also were reduced significantly, and S. aureus toxin kits returned negative results for toxin production for all treatments of ham and roast beef. Stabilization showed less than 1-log growth of C. perfringens for any treatment, with the exception of the "worst case" scenario for roast beef. As expected, > 1 log growth of C. perfringens was found for uncured roast beef maintained at room temperature for cooling. This study supports that there are multiple time and temperature combinations, other than those currently provided by FSIS, which may be utilized for cooking and cooling large roast beef and bone-in ham products while still meeting FSIS lethality and stabilization microbiological performance standards.

Clinical S. aureus strains were gathered from four hospitals, two in Turkey (Hacettepe hospital 200 strains and Ankara Hospital 106 strains) and the other two from Libya (Aljalla Hospital 88 strains and Jamahyria Hospital 62 strains). The clinical specimens were collected form different sources including blood, urine, wound, pus, burn, sputum, semen, catheter and aspiration. Patients were aged between 0 to 84 years and from both sexes. Resistance to Methicillin was determined by measuring the Oxacillin MIC / this was done by using the oxacillin E-test, with resistance defined as an MIC of &gt / 2 &micro / g ml. In this study all isolates displayed an Oxacillin MIC of &amp / #8805 / 256&micro / g/ml. The MRSA strains were (56%) in Turkish hospitals, and (59%) in Libyan hospitals. The percentage of the VRSA and VISA in Libyan hospitals was (7%) and (26%) respectively, although the percentage of VRSA in Turkish hospitals was only 2% and there were no intermediately susceptible Staphylococcus aureus (VISA). Besides the MRSA isolates, Coagulase Negative Staphylococcus showing Methicillin resistance was collected from clinical isolates in thirteen patients in Turkish hospitals. In both countries, the majority MRSA isolates were multiresistant to more than five classes of antibiotics including / Ampicillin, Amoxicillin, Tetracycline, Erythromycin and Ciprofloxacin. Most of the MRSA isolates were from blood (68%), wounds (57%) and pus (50%).The results of genetic investigations indicated that the mecA gene was present in the majority of isolates in both countries / the community acquired MRSA type (ccr-BIV) was present in three samples out of thirty in Turkish hospitals and in one case out of twenty in Libyan hospitals / There was no case out of fifty specimens that carry the hospitals acquired MRSA type (ccr-BI, II, III) in both countries. Besides the Methicillin resistance gene, the incidence of Tetracycline resistance gene was quite high (tetM and tetK 50%) in Turkish hospitals isolates, and the prevalence of Panton-Valentine Leukocidin gene was high (PVL 70%) in Libyan hospitals specimens.

Hard-to-heal ulcers are resource intensive due to the fact that they are difficult to treat and especially vulnerable to bacterial invasion. The bacterial culture contaminating these wounds often consist of several different bacterial organisms that originate from endogenous sources. Necrotic material in ischemic ulcers provide nutrition which support bacterial reproduction, increasing the risk of infection. Determining causative pathogen in infected ulcers proves to be difficult when culturing swab samples, however Staphylococcus aureus and hemolytic streptococci generally act as primary pathogens.     The aim of the study was to investigate if the detection rate increased for S. aureus and hemolytic streptococci when culturing swab samples from ulcers on Columbia CNA; a media selective for gram-positive bacteria. In the experimental procedure the inhibitory action of CNA upon gram-negative bacterial growth was evaluated, using simulated ulcer samples (n=6) containing bacterial quality control strains in arbitrary concentrations. Additionally, patient samples (n=51) were cultured and screened for primary pathogens to investigate differences in the detection rate for CNA and the current culture media; Blood agar, Chocolate agar, Gentian violet blood agar and CLED agar.    Results from simulated ulcer samples showed excellent inhibitory function regarding the antibiotic substances of the CNA agar. Culturing patient samples from lower leg- and pressure ulcers on CNA, provided indications of diverse circumstances yielding higher respectively lower detection rate concerning S. aureus and hemolytic streptococci. Samples containing mixed flora with gram-negative bacteria generated higher detection rate and samples containing S. aureus yielded a lower detection rate when culturing on CNA, compared with that of the routine method.

Bacterial infections are becoming progressively more difficult to treat due to antibiotic resistance and the decreasing rate at which new antibiotics are brought to market. The Turos laboratory has attempted to tackle this problem for the last 15 years with the discovery of N-thiolated β-lactams leading to the design of polyacrylate nanoparticles to deliver these and other drugs. Chapter 1 discusses many reported instances of utilizing different types of polymeric nanoparticles to deliver antibiotics. Poly(lactic-co-glycolic acid) (PLGA), poly(alkyl cyanoacrylate) (PACA), poly(styrene-co-butylacrylate), and chitosan are the main polymers used to make nanoparticles. Chapter 2 describes the synthesis, antibacterial activity, and mechanism of action of N-acyl ciprofloxacins, which have demonstrated in vitro bioactivity against Staphyloccocus aureus, methicillin-resistant Staphylococcus aureus, Bacillus anthracis, Enterococcus faecalis, Bartonella, and E. coli. Antimicrobial activity was found to diminish with increasingly lipophilic acyl groups of the derivatives. The N-acyl ciprofloxacins were found to utilize the same mechanism of action as the parent drug, ciprofloxacin, however, several exhibited lower mutation frequencies. Chapter 3 discusses the use of the N-acyl ciprofloxacins as probes for experimentation on the poly(vinyl benzoate) nanoparticles. These compounds were incorporated into poly(vinyl benzoate) nanoparticles, also designed in the Turos laboratory, to determine the effects of the lipophilic acyl groups on drug loading and drug release. N-acyl ciprofloxacins with higher lipophilicities (predicted logP values) experienced higher drug loading than the less lipophilic counterparts. However, the nanoparticles were unable to release large amounts of entrapped drug. N-acyl ciprofloxacins with increased hydrophilicity were found to either not be incorporated at all, or in incredibly small amounts. Drug release studies of these drugs indicate that possible the hydrophobic compounds that were associated with the nanoparticles were done so via adsorption onto the surface resulting in a burst release of drug. The work is concluded in Chapter 4, followed by experimental procedures and spectral data in Chapters 5 and 6.

Staphylococcus aureus has long been recognized as a leading cause of nosocomial infection. However, several recent publications have demonstrated this pathogen as the cause of community-acquired severe wound infections and necrotizing pneumonia in otherwise healthy individuals. These highly virulent endemic clones have been reported in several locations in the United States and Canada. The rapid spread of the organism, the ability of certain clones to cause serious infection, and the antibiotic resistance of the endemic clones, illustrates the importance of infection control measures. In this study we examined three S. aureus typing techniques; pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and Staphylococcal protein A (spa) sequencing for subspeciation of community-acquired methicillin-resistant S. aureus (CA-MRSA). It is hypothesized that PFGE will result in a higher level of discrimination among the strains, while MLST and spa typing will result in highly portable data that lacks the discriminatory power of PFGE. Thirty CA-MRSA isolates that were obtained from Florida and Washington State were characterized by molecular typing methods. Whole genome restriction analysis was performed by PFGE using the SmaI enzyme. Sequence-based typing analyses, MLST and spa typing, were performed by polymerase chain reaction (PCR) followed by sequencing. PFGE data was analyzed using the BioNumerics® software package and sequence-based data was analyzed using DNAstar®. MLST Alleles were assigned using the online MLST database (www.mlst.net) and spa types were assigned using the Ridom SpaServer (www.ridom.de/spaserver). Molecular characterization of the 30 isolates resulted in 21 pulsotypes, four MLST sequence types (STs), and six spa types. Combining data from both MLST and spa typing resulted in only seven strain categories, many of which grouped isolates that are not epidemiologically linked. These data demonstrate that techniques such as MLST and spa typing are not well suited for tracking isolates with limited evolutionary diversity such as the CA-MRSA epidemic clones.

Patients with inflammatory or infectious conditions such as periodontitis, peri-implantitis, osteomyelitis, rheumatoid arthritis, septic arthritis and loosened joint prosthesis display varying severity of destruction in the adjacent bone tissue. Bone loss in inflammatory diseases is considered a consequence of cytokine induced RANKL and subsequent enhanced osteoclast formation. Hence, osteotropic cytokines and their receptors have been suggested to be important for the pathogenesis of inflammation-induced osteolysis. It is, here, suggested that bacterial components, so called “pathogen associated molecular patterns=PAMPs”, may also be involved. Varieties of cells express receptors for PAMPs, including Toll-like receptors (TLRs) which are the first line of defence in the innate immune system. LPS (lipopolysaccharide), fimbria and lipoproteins from pathogenic bacteria such as P. gingivalis, S. aureus are ligands for TLR2 and flagellin from pathogenic flagellated bacteria like S. typhimurium is a ligand for TLR5.   Since the susceptibility to, or the severity of inflammation-associated bone diseases are likely related to differences in the tissue response, and the mechanisms by which PAMPs interact with bone cells are not fully understood, we aimed to elucidate the importance of different TLRs for inflammation induced bone loss by conducting in vitro and in vivo investigations. Activation of TLR2 and TLR5 in organ cultured mouse parietal bones increased bone resorption in a time- and concentration-dependent manner by a process inhibited by OPG and bisphosphonate, showing the crucial role of RANKL-induced osteoclast formation. In addition, the number of osteoclasts, expression of osteoclastic genes and osteoclastogenic transcription factors were increased. In the bones and in osteoblasts isolated from the bones, TLR2 agonists increased the expression of RANKL without affecting OPG, while TLR5 activation resulted in enhanced RANKL and decreased OPG. Activation of both TLR2 and TLR5 stimulated the expression in both bones and osteoblasts of prostaglandins and pro-inflammatory cytokines, known to stimulate RANKL. By blocking the cytokines and prostaglandin, we showed that TLR2 and TLR5 induced bone resorption and RANKL expression are independent of these molecules. Activation of TLR2, but not TLR5, in mouse bone marrow macrophage cultures inhibited RANKL-induced osteoclast formation, an effect not observed in committed pre-osteoclasts. Local administration in vivo of TLR2 and TLR5 agonists on the top of mouse skull bones enhanced local and systemic osteoclast formation and bone resorption. Using knockout mice, we showed that the effects by LPS from P. gingivalis (used as TLR2 agonist) and flagellins (used as TLR5 agonists) are explicit for TLR2 and TLR5 ex vivo and in vivo, respectively. These data show that stimulation of TLR2 and TLR5 results in bone resorption in vitro and in vivo mediated by increased RANKL in osteoblasts and thus may be one mechanism for developing inflammatory bone loss. Interestingly, histological analyses of skull bones of mice treated locally with TLR2 and TLR5 agonists revealed that the bones not only reacted with locally increased osteoclastogenesis (osteoclast formation), but also with locally increased new bone formation. This was observed on both periosteal and endosteal sides of the bones, as well as in the bone marrow compartment. The formation of new bone was seen close to osteoclasts in some parts, but also in other areas, distant from these cells. The response was associated with active, cuboidal osteoblasts, extensive cell proliferation and increased expression of genes coding for bone matrix proteins and osteoblastic transcription factors. In conclusion, activation of TLR2 and TLR5 in osteoblasts results in bone loss associated with enhanced osteoclast formation and bone resorption, as well as with increased osteoblast differentiation and new bone formation, indicating that inflammation causes bone modeling. The data provide an explanation why LPS from P. gingivalis and flagellin from flagella-expressing bacteria can stimulate bone loss. Since TLR2 and TLR5 can be activated not only by bacterial components, but also by endogenous ligands produced in inflammatory processes, the data also contribute to the understanding of inflammation induced bone loss in autoimmune diseases. Hopefully, these findings will contribute to the development of treatment strategies for inflammation induced bone loss.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-20T23:20:39Z No. of bitstreams: 1 EmmanuellaDeOliveiraMoura_DISSERT.pdf: 52497880 bytes, checksum: 1629d2ecbbd9990511f15a23f34329a5 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-24T22:10:14Z (GMT) No. of bitstreams: 1 EmmanuellaDeOliveiraMoura_DISSERT.pdf: 52497880 bytes, checksum: 1629d2ecbbd9990511f15a23f34329a5 (MD5) / Made available in DSpace on 2017-03-24T22:10:14Z (GMT). No. of bitstreams: 1 EmmanuellaDeOliveiraMoura_DISSERT.pdf: 52497880 bytes, checksum: 1629d2ecbbd9990511f15a23f34329a5 (MD5) Previous issue date: 2016-03-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O aumento na demanda mundial por leite e seus derivados de qualidade ? um tema recorrente quando se decide investir em agrega??o de valor, por consequ?ncia, a aquisi??o de alimentos saud?veis e seguros por parte dos consumidores. Dentre as diferentes esp?cies leiteiras, a bubalina aparece como alternativa para a disponibilidade de alimentos de alto valor biol?gico, por?m semelhantes ?s outras esp?cies, possuem problemas sanit?rios como as mastites, mesmo tendo como caracter?stica maior resist?ncia contra infec??es. O agente patog?nico de maior relev?ncia ? o Staphyloccocus aureus, que al?m de est? envolvido diretamente com a sa?de de gl?ndula mam?ria, produzem toxinas que causam riscos a sa?de dos que ingerem produtos contaminados. Assim, objetivou-se com esse estudo avaliar o perfil microbiol?gico e celular do leite para um diagn?stico mais preciso de mastite subcl?nica em b?falas leiteiras, analisando fatores ambientais e fisiol?gicos, bem como a detec??o de genes codificadores de enterotoxinas de S. aureus. Para o estudo foram escolhidos aleatoriamente 30 b?falas da ra?a Murrah pertencente 15 ao grupo de maior produ??o e 15 do grupo de menor produ??o, submetidos ? ordenha mec?nica. Na primeira etapa, foram analisadas nas amostras de leite os par?metros microbiol?gicos de identifica??o das esp?cies, contagem padr?o em placas (CPP), perfil de resist?ncia a antimicrobianos por discos-difusores, contagem de c?lulas som?ticas (CCS), condutividade el?trica do leite (CEL), quantifica??o de lactoferrina (Lfe) e a identifica??o dos fatores de risco associados ? mastite subcl?nica como o grau de hiperqueratose, higieniza??o de teteiras atrav?s de swabs para an?lise microbiol?gica e observa??o do local. Na etapa seguinte realizou-se o isolamento de Staphylococcus aureus para detec??o de genes de 8 enterotoxinas (EEA-EEI). No exame microbiol?gico, as bact?rias mais frequentes foram Staphylococcus spp, Streptococcus spp e Corynebacterium spp. No teste de sensibilidade aos antimicrobianos 17 antibi?ticos testados, 10 (58,82%) foram sens?veis a todos os isolados, entre os resistentes encontrou-se que Streptococcus uberis e dysgalactiae foram resistentes a cefalexina, gentamicina e neomicina, o S. haemolyticus foi resistente a ampicilina+colistina e o E.coli a oxacilina, amoxacilina e novobiocina+ penicilinaG. Observou-se ainda que as teteiras e sala de espera dos animais encontravam-se com higieniza??o deficiente. Na an?lise do perfil de celularidade em rela??o ao exame microbiol?gico observou-se que, para o rebanho, os valores de refer?ncia para o diagn?stico de mastite foram de animais com CCS m?dia ?537.000 mil c?lulas/mL e a CEL com m?dia ?3,0 mS/mL e positivos no exame microbiol?gico, al?m disto, nos isolados de S.aureus, foi poss?vel identificar em 12 animais os genes enterotoxig?nicos sea, seh e sei, com maior freq??ncia para os dois ?ltimos.

Submitted by Etelvina Domingos (etelvina.domingos@ufpe.br) on 2015-04-09T19:51:49Z No. of bitstreams: 2 DISSERTAÇÃO Fábio José dos Santos Aguiar.pdf: 859548 bytes, checksum: 26707ed652529cbd3f3d6a6142b5b0dd (MD5) license_rdf: 9 bytes, checksum: 42dd12a06de379d3ffa39b67dc9c7aff (MD5) / Made available in DSpace on 2015-04-09T19:51:49Z (GMT). No. of bitstreams: 2 DISSERTAÇÃO Fábio José dos Santos Aguiar.pdf: 859548 bytes, checksum: 26707ed652529cbd3f3d6a6142b5b0dd (MD5) license_rdf: 9 bytes, checksum: 42dd12a06de379d3ffa39b67dc9c7aff (MD5) Previous issue date: 2014 / O objetivo deste estudo foi avaliar a ação sinérgica entre o ácido úsnico extraído de Cladonia substellata Vainio e cinco agentes antimicrobianos (ciprofloxacino, gentamicina, oxacilina e penicilina) sobre dez cepas de Staphylococcus aureus com fenótipo de resistência previamente definido. Cinco destas cepas de S. aureus (ATCC 33591, AM 13, AM 18, AM 20, AM 21) apresentaram resistência a todos os agentes antimicrobianos avaliados e desta forma foram selecionadas para o estudo do sinergismo entre o ácido úsnico e os agentes antimicrobianos através do método do tabuleiro de xadrez (checkerboard method). Os critérios utilizados para avaliar a atividade sinérgica foram definidos pelo Índice da Concentração Inibitória Fracionada (FICI). Todas as cepas de S. aureus foram suscetíveis ao ácido úsnico, determinado pelo método de microdiluição. O FICI variou de 0,25 – 1,0, sugerindo uma interação sinérgica frente as cepas de S. aureus MRSA. A associação do ácido úsnico com o ciprofloxacino apresentou efeito sinérgico sobre todas as cepas S. aureus MRSA. A oxacilina apresentou sinergismo em associação com ácido úsnico sobre as cepas de S. aureus ATCC 33591, AM 13, AM18 e AM24 e exibiu os menores valores FICI. A associação do ácido úsnico com a gentamicina foi sinérgica sobre as cepas AM18, AM21 e AM24. A associação do ácido úsnico com a penicilina apresentou-se indiferente para todas as cepas exceto para S. aureus AM13. Este estudo demonstrou que o ácido úsnico, quando associado à antimicrobianos fluoroquinolônicos, betalactâmicos e aminoglicosídeos pode agir sinergicamente, inibindo cepas de S. aureus MRSA.

Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2017-03-24T17:22:23Z No. of bitstreams: 1 Deutsch, Gabriela [Dissertação, 2014].pdf: 1124546 bytes, checksum: 4c2efe5d127b5965bea25e458da2afc4 (MD5) / Made available in DSpace on 2017-03-24T17:22:23Z (GMT). No. of bitstreams: 1 Deutsch, Gabriela [Dissertação, 2014].pdf: 1124546 bytes, checksum: 4c2efe5d127b5965bea25e458da2afc4 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A balneoterapia é um importante procedimento realizado diariamente em pacientes queimados. Esta prática consiste na limpeza mecânica com fricção manual sobre as áreas lesionadas pela queimadura utilizando antisséptico. Poucas são as evidências de que sua prática seja efetiva na higienização das feridas e na prevenção de infecção cruzada entre pacientes que utilizam o mesmo tanque. Neste projeto, buscou-se estudar a influência da balneoterapia na descolonização da superfície corporal queimada (SCQ) de pacientes internados em um centro de tratamento de queimaduras (CTQ), quanto à presença de cepas de Staphylococcus aureus e Pseudomonas aeruginosa. Swabs foram coletados durante a realização da balneoterapia de 18 pacientes por 14 semanas. A água utilizada também foi avaliada. Testes fenotípicos e genotípicos foram utilizados para identificação de S. aureus e P. aeruginosa. A susceptibilidade a antimicrobianos e biocidas foi verificada segundo os critérios do Clinical and Laboratory Standards Institute (CLSI). Pulsed-field gel electrophoresis (PFGE) foi utilizado para avaliar a diversidade genômica. Análise exploratória das variáveis envolvidas no processo da balneoterapia foi determinado pela estatística descritiva e testes estatísticos não paramétricos foram utilizados na análise dos fatores de risco. Trezentos e cinquenta e dois swabs foram coletados dos quais 214 (61%) da SCQ, 60 (17%) da cavidade nasal e 78 (22%) da mesa onde ocorreu a balneoterapia. Detectou-se 13 cepas de S. aureus e 39 de P. aeruginosa. A concentração mínima inibitória (CMI) para sulfadiazina de prata foi ≥32μg/mL para as cepas de S. aureus enquanto que para a P. aeruginosa a maioria das cepas apresentou CMI de 128μg/mL. Com relação a clorexidina, as cepas de S.aureus apresentaram um CMI variando de 2 a 8g/mL enquanto para P. aeruginosa a variação foi de 16 a 64μg/mL. Cinco amostras foram identificadas como S. aureus resistentes a meticilina (MRSA) e nove como P. aeruginosa resistentes a carbapenêmicos. A análise do perfil de fragmentação do DNA total (PFGE) nas cepas de P. aeruginosa demonstrou a existência de 10 clones entre 35 cepas analisadas. O tipo A foi o mais prevalente, com 23 cepas distribuídas em 8 subtipos. Estes estavam presentes na SCQ coletada antes e após o banho e nas superfícies da mesa de banho, sugerindo que há contaminação cruzada de um indivíduo para o outro, de uma área queimada para outra no mesmo indivíduo, da mesa da balneoterapia para indivíduos e finalmente do indivíduo para mesa. Os resultados não se mostraram estatisticamente significativos, no entanto, quatro pacientes que não apresentaram contaminação antes do banho se tornaram positivos após este procedimento, e 10 pacientes que apresentaram contaminação antes do banho, assim permaneceram. Conclui-se que o procedimento de descontaminação não está sendo eficaz uma vez que houve similaridade clonal entre as cepas de P. aeruginosa coletadas em vários pontos e momentos / Balneotherapy is an important procedure usually performed in burn patients. This practice consists on a mechanical cleaning with manual friction on the damaged areas using an antiseptic. There is little evidence that this practice is effective to clean the wounds and avoid cross infection between patients using the same table. In this project, we study the influence of hydrotherapy in the decolonization of burned body surface area (BSA) of patients admitted to a burn center (BC) for the presence of Staphylococcus aureus and Pseudomonas aeruginosa isolates. Thus, swabs were used to collect bacteria from 18 patients submitted to balneotherapy during 14 weeks. The material from bath table and the water used were also evaluated. Genotypic and phenotypic tests were used to identify S. aureus and P. aeruginosa. Susceptibility to antimicrobials and biocides has been verified according to the criteria of the Clinical and Laboratory Standards Institute (CLSI). Genomic diversity was assessed by pulsed-field gel electrophoresis (PFGE). Descriptive statistics were used in the exploratory analysis of the variables involved in the balneotherapy and non-parametric statistical tests were used in process analysis of risk factors. Three hundred fifty-two swabs were collected of which 214 (61%) were from BSA, 60 (17%) from nasal cavity and 78 (22%) from table where balneotherapy occurred. Thirteen isolates were identified as S. aureus and 39 as P. aeruginosa. Minimum inhibitory concentration (MIC) for silver sulfadiazine was ≥ 32μg/mL for S. aureus isolates and 128μg/mL for P. aeruginosa. It is possible that the increased MIC to silver sulfadiazine has occurred by the constant use of this antimicrobial in balneotherapy. However, MIC to chlorhexidine for S. aureus isolates range from 2 to 8mg/mL and for P. aeruginosa range from 16 to 64μg/mL. Furthermore, five S. aureus isolates were identified as methicillin-resistant Staphylococcus aureus (MRSA) and nine as P. aeruginosa resistant to carbapenems. A profile analysis of total P. aeruginosa DNA fragmentation showed 10 clones among 35 strains analyzed. Type A was the most prevalent, with 23 isolates distributed into eight subtypes. These subtypes were present in BSA collected before and after the bath and on the surfaces of the bath table, suggesting that there is cross-contamination from one individual to another, from a burned area to another in the same individual, from the balneotherapy table to an individual and finally from the individual to the table. The results were not statistically significant, however, four patients who were not contaminated before bathing became positive after this procedure, and 10 patients who were contaminated before bathing, remained so. Thus, it is possible to conclude that the procedure is not efficient for the decontamination because there was similarity between the clonal isolates of P. aeruginosa collected at various points and times