Rosmari Hörner

Suscetibilidade antimicrobiana entre amostras de Enterococcus isoladas no Hospital Universitário de Santa Maria

Members of the genus Enterococcus have emerged as the most important nosocomial pathogens worldwide.In the present study, the occurrence of enterococcal infections by species and site of infection was analyzed. Enterococcus faecalis was the predominant enterococci species among all clinical isolates. A total of 233 enterococci isolates obtained from patients of Hospital Universitario de Santa Maria were studied. Antimicrobial susceptibility to a variety of agents was also evaluated.

Composição e atividade antibacteriana dos óleos essenciais de Senecio crassiflorus var. crassiflorus

The essential oils of leaves, aerial and underground stems of Senecio crassiflorus var. crassiflorus were extracted by hydrodistillation and their analyses were performed by GC/MS. Qualitative and quantitative differences have been found between the analyzed parts. The main compounds of the essentials oils of the leaves were found to be oxygenated sesquiterpenes, while the oils from the aerial and underground stems showed sesquiterpene hydrocarbons as major constituents. Furthermore, the essential oils were tested against Staphylocccus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus cereus. The essential oil of the leaves was shown to be the most active.

Interference in the Limulus amebocyte lysate assay for endotoxin determination in peritoneal dialysis fluids and concentrates for hemodialysis.

The interference of the saline concentration of fluids for peritoneal dialysis and concentrates for hemodialysis on the Limulus amebocyte lysate (LAL) assay for endotoxins was investigated. The experiments were carried out individually with each substance that compose fluids for hemodialysis, to determine the possible inhibition or enhancement effects that they could cause on the LAL assay. The compositions were also assayed to investigate the possibility of synergistic effect. They were assayed by the gel-clot method from two different suppliers, and the samples that showed inhibition effect were also assayed by the chromogenic method. The samples were analysed at successive dilutions, with different LAL sensitivities, to satisfy the endotoxin limits of 5 EU/ml for the concentrate and 0.25 EU/ml for the fluid for dialysis peritoneal. The results showed that the major interference on the gel-clot assay occurs in presence of acetic acid and in concentrates containing acid acetic, even the pH being adjusted between 6.5 and 7.5. However, the test, after an adequate dilution, could be validating for all samples. Chromogenic test can be used for peritoneal dialysis fluids considering a limit of 0.25 EU/ml and sample dilution of eight times, but it cannot be used for concentrates for hemodialysis without further dilution. Considering the results and that the chromogenic is a more time-consuming method, endotoxins in fluids for hemodialysis can be satisfactorily assayed by the gel-clot method.

In vitro evaluation of triazenes: DNA cleavage, antibacterial activity and cytotoxicity against acute myeloid leukemia cells

). The observation of intermolecular hydrogen bonding in the solid state of compound 3, based on the structural analysis by X-ray crystallography, as well as the results of IR and UV-Vis spectroscopic analyses of compounds 1, 2 and 3 are discussed in the present work.

Bacteriological analysis of platelets and cases of septic reactions associated with transfusion of contaminated samples.

INTRODUCTIONnFor years, platelet transfusion therapy has been playing an important role in controlling patients with hematological and oncological diseases. However, platelet transfusion represents a serious risk for bacterial sepsis. This study aimed to verify the bacterial contamination index in platelet concentrates (PCs) obtained from the Blood Center of the State of Rio Grande do Sul (HEMORGS).nnnMETHODSnAll 612 samples of PCs from HEMORGS were analyzed in August 2009 and January 2010. We used a qualitative methodology which was modified manually in order to detect bacterial contamination. The patients who received the platelet units with confirmed positive cultures had their medical records analyzed. After the prospective study, a retrospective analysis of the samples of PCs checked by the bacteriological control from HEMORGS since its foundation (2008) until 2010 was made.nnnRESULTSnFour hundred and eighty samples (10 monthly samples of plateletpheresis and 10 of whole blood-derived platelets) were analyzed in order to compare the contamination index for both studies. Of 1092 samples, 15 were found to be contaminated (6 of retrospective analysis and 9 of prospective). In prospective study, isolated microorganisms were nine Staphylococcus epidermidis, but in retrospective two Staphylococcus sp., two glucose non-fermenting gram negative bacilli, one Streptococcus sp. and one Proteus mirabilis. We report 3 feasible cases of bacterial sepsis associated with the transfusion of CPs analyzed by prospective study.nnnCONCLUSIONnBacterial sepsis associated with platelet transfusion is today the most frequent infectious complication of transfusion medicine. Although complex, it is important to recognize transfusion sepsis in patients to reduce morbidity and mortality.

Oxacillin-resistant coagulase-negative Staphylococci bacteremia at a teaching hospital in Santa Maria, State of Rio Grande do Sul, Brazil

INTRODUCTIONnThis study aimed to characterize the prevalence and susceptibility profile to oxacillin-resistant Coagulase-negative Staphylococci strains isolated from blood cultures in a teaching hospital, located in Santa Maria, RS. In addition, different methodologies for phenotypic characterization of mecA-mediated oxacillin resistance were compared with genotypic reference testing.nnnMETHODSnAfter identification (MicroScan - Siemens), the isolates were tested for antimicrobial sensitivity using disk diffusion and automation (MicroScan - Siemens). The presence of mecA gene was identified by the polymerase chain reaction molecular technique.nnnRESULTSnThe most common species was Staphylococcus epidermidis (n=40, 67%). The mecA gene was detected in 54 (90%) strains, while analysis of the sensitivity profiles revealed a high rate of resistance to multiple classes of antimicrobial drugs. However, all isolates were uniformly sensitive to vancomycin and tigecycline. The cefoxitin disk was the phenotypic method that best correlated with the gold standard.nnnCONCLUSIONSnAnalysis of the clinical significance of CoNS isolated from hemocultures and the precise detection of oxacillin resistance represent decisive factors for the correct choice of antibiotic therapy. Although vancomycin constitutes the normal treatment in most Brazilian hospitals, reduction in its use is recommended.

Composição química, atividade antibacteriana in vitro e toxicidade em Artemia salina do óleo essencial das inflorescências de Ocimum gratissimum L., Lamiaceae

The essential oil obtained by hydrodistillation of the inflorescences of Ocimum gratissimum L. was analyzed by GC/MS. The main constituents were eugenol (81.94%) and γ-muurolene (12.58%). Antibacterial activity was shown against all assayed strains by the broth microdilution method. Its worth noting the activity against resistant strains of Enterococcus faecalis, Staphylococcus aureus and Escherichia coli. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values ranged between 0.5-2 mg/mL and 1-4 mg/mL, respectively. Preliminary toxicity assayed by the brine-shrimp (Artemia salina L.) test showed LC50 values of 233.8 (200.7 - 272.0) µg/mL and 186.1 (144.1 - 228.5) µg/mL, respectively for the essential oil and eugenol (positive control).

Triazenos e atividade antibacteriana

Fifteen triazenes compounds were studied concerning their antibacterial activity by broth microdilution method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) was determined with E. coli ATCC 25922, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, Acinetobacter baumannii, Acinetobacter lwoffii, Ralstonia pickettii, Bordetella bronchiseptica, Micrococcus sp., Enterococcus sp., Staphylococcus epidermidis, Staphylococcus saprophyticus, Streptococcus agalactiae, Bacillus cereus, Corynebacterium sp., Rhodococcus sp., Salmonella sp., Serratia marcescens, Morganella morganii, Enterobacter cloacae, Shigella flexneri, Shigella sonnei, Shigella sp., Klebsiella pneumoniae, ESBL Klebsiella oxytoca 14, ESBL Klebsiella pneumoniae 23, ESBL Klebsiella pneumoniae 24, ESBL Klebsiella pneumoniae 25, ESBL Escherichia coli 26, ESBL Klebsiella pneumoniae 27, ESBL Klebsiella pneumoniae 31, ESBL Escherichia coli 32, ESBL Klebsiella pneumoniae 37 e ESBL Escherichia coli 38. The highest effect was evidenced by the compound 1-methyl-3-(p-carboxyphenyl)triazene 1-oxide (2) against Streptococcus agalactiae (MIC = 16 µg/mL and MBC = 32 µg/mL). The compounds 1-phenyl-3-(4-nitrophenyl)triazene-1-oxide (9), 1-(4-nitrophenyl)-3-(4-carboxyphenyl)triazene (10) e 1-(4-acethyl amine phenyl)-3-(4-carboxyphenyl)triazene (11) presented MIC between 32 and 64 µg/mL against S. edipermidis, S. saprophyticus, Rhodococcus sp. and E. cloacae. The compounds 1-methyl-3-phenyltriazene-1-oxide (1) , bis-1,3-(4-acethyl oxime)triazene (3), bis-1,3 (4-acethyl phenyl)triazene (4), 1-(2-fluorophenyl)-3-(4-acethylphenyl)triazene (5), 1,3-(3-hydroxy-diphenyltriazenide)(piridil)(bis-oxo-vanadium) (12), 1-(3-nitrophenyl)-3-phenyltriazene (14), 1-(4-nitrophenyl)-3-benzyltriazene (15) presented MIC of the 128 µg/mL against S. aureus ATCC 25923, P. aeruginosa ATCC 27853, A. lwoffii, Micrococcus sp., S. epidermidis, S. saprophyticus, Corynebacterirum sp., E. cloacae, S. flenneri e S. sonnei. The compounds 1-phenyl-3-(4-acethylphenyl)triazene (6), 1,3-bis-(4-ethoxycarbonylphenyl) triazene (7), and 3-(4-carboxylatephenyl)-1-methyltriazene 1-oxide of potassium tetrahydrate (13) presented MICs equals or highest than 128 µg/mL. The results have demonstrated the potential biological activity of these compounds against Gram-positive and Gram-negative bacteria.

Uma revisão sobre metalo-β-lactamases

A emergencia e disseminacao da resistencia aos antimicrobianos sao problemas de grande importância mundial, particularmente entre patogenos nosocomiais de importância clinica como os bacilos Gram negativos nao fermentadores e membros da familia Enterobacteriaceae. O principal mecanismo de resistencia desses patogenos e a producao de β-lactamases, que sao enzimas que hidrolisam o anel β-lactâmico impedindo assim a acao dos antimicrobianos β-lactâmicos. As β-lactamases foram dividas em quatro classes de acordo com a sua estrutura primaria e podem tambem ser classificadas dentro de dois grupos com base no seu mecanismo catalitico, isto e, serina-β-lactamases (Classes A, C e D) e metalo-β-lactamases (Classe B). As metalo-β-lactamases (MβL) utilizam ions divalentes, comumente zinco, como co-fator para sua atividade catalitica e sao atualmente uma das classes que mais merece destaque, devido a sua capacidade de hidrolisar todos os antimicrobianos β-lactâmicos, incluindo os carbapenens. Estes antimicrobianos sao utilizados no tratamento de infeccoes causadas por bacterias Gram-negativas multirresistentes e conseguem se manter estaveis frente as serina-β-lactamases. A deteccao de microrganismos produtores de MβL tem por finalidade auxiliar a Comissao de Controle de Infeccao Hospitalar (CCIH) na prevencao da disseminacao desse mecanismo de resistencia no ambiente hospitalar e impedir que ele chegue ate a comunidade, bem como enfatizar o uso racional dos antimicrobianos disponiveis para uso clinico, pois, atualmente,ha poucos investimentos da industria farmaceutica na pesquisa de novos agentes antimicrobianos.

Spontaneous bacterial peritonitis caused by Streptococcus bovis: case report and review of the literature

Spontaneous bacterial peritonitis (SBP) is a frequent and severe complication that occurs in patient with cirrhosis and ascites. It occurs in 10% to 30% of patients admitted to hospital. The organisms that cause SBP are predominantly enteric. Escherichia coli is the most frequent recovered pathogen, and Gram-positive bacteria, mainly Staphylococcus spp., are being considered an emerging causative agent of SBP. Streptococcus bovis that may be found as part of the commensal bowel flora in about 10% of healthy adults constitute an uncommon cause of peritonitis that was first reported in 1994. We describe the first case of SBP at the University Hospital of Santa Maria (HUSM) caused by S. bovis, resistant to the antibiotics erythromycin and clindamycin (inducible clindamycin resistance detected by disk diffusion test using the D-zone test).