An effective and biocompatible antibiofilm coating for central venous catheter.

The aim of this study was to investigate the in vitro and in vivo efficacy and the tissue reaction of an antibiofilm coating composed of xylitol, triclosan, and polyhexamethylene biguanide. The antimicrobial activity was analyzed by a turbidimetric method. Scanning electron microscopy was used to evaluate the antiadherent property of central venous catheter (CVC) fragments impregnated with an antibiofilm coating (I-CVC) in comparison with noncoated CVC (NC-CVC) fragments. Two in vivo assays using subcutaneous implantation of NC-CVC and I-CVC fragments in the dorsal area of rats were performed. The first assay comprised hematological and microbiological analysis. The second assay evaluated tissue response by examining the inflammatory reactions after 7 and 21 days. The formulation displayed antimicrobial activity against all tested strains. A biofilm disaggregation with significant reduction of microorganism's adherence in I-CVC fragments was observed. In vivo antiadherence results demonstrated a reduction of early biofilm formation of Staphylococcus aureus ATCC 25923, mainly in an external surface of the I-CVC, in comparison with the NC-CVC. All animals displayed negative hemoculture. No significant tissue reaction was observed, indicating that the antibiofilm formulation could be considered biocompatible. The use of I-CVC could decrease the probability of development of localized or systemic infections.

Clonal complexes 104, 109 and 113 playing a major role in the dissemination of OXA-carbapenemase-producing Acinetobacter baumannii in Southeast Brazil.

Carbapenem resistance among Acinetobacter baumannii strains isolated from clinical settings in Brazil has increased dramatically in the last 10 years due to the emergence and dissemination of OXA-type carbapenemase encoding genes. This study aimed to characterize the presence of carbapenem-hydrolyzing class D ß-lactamases (CHDL)-encoding genes and clonal complexes playing a major role in the dissemination of OXA-carbapenemase-producing A. baumannii in Southeast Brazil. A total of 74 A. baumannii strains isolated from patients admitted to 4 hospitals in Southeast Brazil were analyzed. Molecular characterization of strains revealed that 67 strains carried blaOXA-23 (72%), blaOXA-143 (25%) or both genes (3%). PFGE analysis identified 12 PFGE clusters, grouping 26 pulsotypes. Two PFGE clusters were predominant, comprising more than 66% of OXA-producing A. baumannii isolates. Among 23 representative strains characterized by MLST-UO (Multilocus Sequence Typing Scheme - University of Oxford, http://pubmlst.org/abaumannii/), 14 different STs were identified, of which six were confirmed as novel sequence types (designated as STs 402-407). Most of these isolates belonged to clonal complexes CC104,CC109 or CC113, whereas three STs were singletons (ST339, 403 and 407). In conclusion, the presence of blaOXA-23- and blaOXA-143-like genes was not related to specific ST/CC, suggesting that the dissemination of OXA-carbapenemase-encoding genes may involve different STs, in which the spread of OXA-23-like is most likely due to mobile elements (i.e., plasmids). In this regard, CC104, CC109 and CC113 played a major role as predominant CDHL-carrying clones, instead of CC92, which was not identified.

In vitro inhibition of Pseudomonas aeruginosa adhesion by Xylitol

This study evaluated, in vitro, the antimicrobial activity and the anti-adherent property of xylitol (0.5, 2.5 and 5.0 percent, w/v) on two Pseudomonas aeruginosa strains (ATCC 9027 and clinical). The assay of antimicrobial activity was performed to determine a minimum inhibitory concentration (MIC) and the adhesion test was performed, by which the parameters regarding, growth in the culture medium, number of colony forming units (CFUs) released and slide evaluation by scanning electron microscopy (SEM) were analyzed. The Statistical Package for the Social Sciences (SPSS) was employed for statistical analysis. Results showed that xylitol had no antimicrobial activity on these strains; however, the inhibition of bacterial adherence was observed in microphotographs obtained by SEM. These results indicated that xylitol could be a future alternative to combat bacterial colonization.

In vitro inhibition of adhesion of Escherichia coli strains by Xylitol

The present study aimed to evaluate xylitol's antimicrobial and anti-adherence activities on Escherichia coli (ATCC 8739) and on another clinical strain enteropathogenic E. coli (EPEC). In vitro minimum inhibitory concentration (MIC) test and adhesion assays were performed using 0.5, 2.5 and 5.0 percent xylitol. It was found that xylitol did not have antimicrobial properties on these strains. The scanning electron microscopy (SEM) demonstrated that the slides treated with xylitol had a significant reduction in the number of bacilli and the inhibition of microbial adhesion was probably the xylitol's mechanism of action. Xylitol could be a possible alternative on the control of E. coli infections.

Subtilase cytotoxin-encoding subAB operon found exclusively among Shiga toxin-producing Escherichia coli strains.

The presence of subAB was investigated for 3,453 Escherichia coli strains of various pathogenic categories. The occurrence of other virulence genes in subAB-positive strains was investigated. The subAB operon was detected among some Shiga toxin-producing E. coli (STEC) serotypes devoid of eae and carrying ehxA. Most subAB-positive strains also harbored stx2, iha, saa, and lpfA(O113).

Diversity of virulence profiles of Shiga toxin-producing Escherichia coli serotypes in food-producing animals in Brazil.

The prevalence, serotypes and virulence profiles of Shiga toxin-producing Escherichia coli (STEC) were investigated in 205 healthy beef and dairy cattle, and 106 goats reared in the southeastern region of Minas Gerais State, Brazil. The prevalence of STEC was 57.5% (61/106) in goats, 39.2%, (40/102) in beef cattle and 17.5% (18/103) in dairy cattle. Among the 514 STEC isolates, 40 different serotypes were found and some of them were identified in a specific host. STEC isolates harboring stx1 corresponded to 15.6% (28/180), 26.7% (16/60) and 24.1% (66/274) in beef cattle, dairy cattle and goats, respectively. stx2 was found in 30% (54/180), 53.3% (32/60) and 34.7% (95/274) of beef and dairy cattle, and goats. stx1 plus stx2 sequences were harbored by 54.4% (98/180), 20% (12/60) and 41.2% (113/274) of beef cattle, dairy cattle and goats, respectively. The eae sequence was found in 15% (9/60) and 0.6% (1/180) of STEC isolates from dairy and beef cattle, respectively, and the toxB gene was found only in one O157:H7 strain isolated from beef cattle. Strains with the genetic profiles stx2 ehxA iha saa and stx1 stx2 ehxA iha saa were the most prevalent among STEC isolates from cattle. Profiles stx1 stx2 ehxA iha, stx2, and stx1 iha accounted for 75.5% (207 /274) of the STEC isolates from goats. While STEC strains carrying either stx2 alone or associated with stx1 were found more frequently in cattle, those harboring sequences stx1c and stx2d alone or associated with stx1c predominated in goats. Our data show a diversity of STEC strains in food-producing animals, most of them carrying genes linked to severe forms of human diseases.

Perfil epidemiológico das pielonefrites agudas no Hospital Universitário da UFJF / Epidemiological profile of acute pyelonephritis in the university hospital of Universidade Federal de Juiz de Fora

Infecção do trato urinário é o tipo mais comum de infecção bacteriana e se apresenta sob a forma de várias entidades clínicas. Destaca-se entre elas a pielonefrite aguda (PNA) por apresentar maior morbidade. Dados referentes à epidemiologia desta condição são indispensáveis para correta suspeita diagnóstica e definição da sua terapêutica, que é empírica e baseada nas características peculiares de cada população. Objetivos: no presente estudo, buscamos traçar o perfil epidemiológico e microbiológico das pielonefrites agudas no Hospital Universitário da Universidade Federal de Juiz de Fora (HU-UFJF). Métodos: análise retrospectiva dos prontuários de pacientes internados com PNA de 01/1999 a 07/2003, que tinham urocultura positiva. Resultados: PNA corresponderam a 1,63% das internações no período. Encontramos preponderância do sexo feminino e, na maioria dos casos, os quadros clínicos e laboratoriais típicos de PNA. Os critérios de sepse estavam presentes em 22% e as bactérias Gram-negativas foram os agentes etiológicos na esmagadora maioria dos casos. Conclusão: encontramos o quadro clínico característico de PNA na nossa população, o que permite que facilmente se chegue à suspeita e ao diagnóstico desta patologia potencialmente grave.

Urinary tract infection is the most common type of bacterial infection, presenting as a variety of clinical entities. Acute pyelonephritis (AP) stands out for its morbidity. Data referring to this condition's epidemiology are essential for correct diagnostic suspicion and definition of its therapy, which is empirical and based on patterns peculiar to each population. Objective: in this study we aimed to determine the epidemiological and microbiological profiles of acute pyelonephritis in the University Hospital of the Federal University of Juiz de Fora. Methods: retrospective analysis of the records of inpatients diagnosed with AP through a positive result of urine culture, seen from January 1999 to July 2003. Results: AP accounted for 1.63% of all hospitalizations. AP predominantly occurred in females and in most cases the typical clinical and laboratory findings were found. Sepsis criteria were present in 22% and gram-negative bacteria were isolated in the great majority of the cases. Conclusion: We found the characteristic clinical profile of AP in our population, making it easy to suspect the diagnosis of this potential life-threatening condition.

Avaliaçäo bacteriológica da açäo do glutaraldeído utilizado como desinfetante em esofagogastroduodenofibroscopia / Bacteriological evaluation of the action of glutaraldehyde used as disinfecting agent in esophagogastroduodescopy

Foi estudado o efeito bacteriológico do glutaraldeído a 2 por cento, usado como desinfetante, em um esofagogastroduodenofibroscópio modelo Olympus GIFXQ. Realizaram-se culturas do material colhido na superfície externa e no canal operatório, antes do início da jornada de trabalho, imediatamente após uso no paciente e após limpeza e desinfecçao. Concluiu-se que, quando imerso em glutaraldeído a 2 por cento por dez minutos, fazendo-se também a aspiraçao do desinfetante pelo canal de biópsias e enxaguadura com soro fisiológico, nao houve crescimento bacteriano nem na superfície externa nem no canal operatório do aparelho, constituindo-se em procedimento eficaz para limpeza e desinfecçao.

Acinetobacter species in clinical isolates and detection of a new biotype of acinetobacter baumannii

As infecçöes por Acinetobacter tem despertado interesse face ao aumento de sua frequência, gravidade e dificuldade terapêutica. No entanto, estudos epidemiológicos sempre foram dificultados em razäo da incerta posiçäo taxonômica do gênero. Um total de 255 cepas de Acinetobacter, isoladas de material clínico de pacientes hospitalizados e näo hospitalizados, foram identificadas através de 28 testes fenotípicos constantes de recente reorganizaçäo taxonômica. A.baumannii foi a espécie mais frequentemente encontrada (81,6 por cento), seguida de A. genoespécie 3 (4,3 por cento), A. haemolyticus e A. junii (2,3 por cento); 5 outras espécies foram isoladas em menor número, enquanto 5,5 por cento das cepas näo foram isoladas em menor número, enquanto 5,5 por cento das cepas näo foram identifiacadas. Um sistema de biotipagem para A. baumannii basedo na utilizaçäo de 6 fontes de carbono nos levou à identificaçäo de 13 dentre 19 biotipos determinados. Houve o predomínio dos biotipos 2 (42 por cento), 6 (20,2 por cento) e 9 (18,3 por cento), isolados, em sua maioria, de secreçöes do trato respitatório dos pacientes de ambas origens. Um novo biotipo, caracterizado pela utilizaçäo somente do L-tartarato, foi descrito e denominado biotipo 20. A combinaçäo dos esquemas de identificaçäo de espécies de Acinobacter e de biotipagem de A. baumannii nos permitiu evidenciar a prevalência, na área e período analisados, da espécie A. baumannii biotipo 2, demonstrando a aplicabilidade desses métodos para fins epidemiológicos

Ocorrência de bactérias enteropatogênicas em crianças com diarréia no município de Juiz de Fora, Minas Gerais, Brasil / Enteropathogenic bacteria occurrence in diarrheic children living in Juiz de Fora Municipality, Minas Gerais, Brazil

A ocorrência de bactérias enteropatogênicas e sua resistência a antimicrobianos säo analisadas no Município de Juiz de Fora, MG, Brasil. Em 187 espécies fecais provenientes de crianças diarréicas, na faixa etária de 0a 5 anos, foram isolados 64 enteropatógenos, destacando-se o gênero Shigella -31 amostras- das quais 29 pertenceram ao subgrupo B, sendo 25 do sorotipo B2, EPEC, ETEC e Salmonella foram recuperados em 8,0%, 6,9% e 2,6% dos casos, respectivamente. Näo foi isolada nenhuma amostra de EIEC. Observou-se elevada resistência aos antimicrobianos, notadamente entre as shigella. Säo discutidos aspectos referentes ao saneamento básico das áreas estudadas