Abstract Our study aimed to evaluate the chemical composition of the essential oil from the leaves of Eugenia pyriformis Cambess., belonging to the Myrtaceae family and native to the Brazilian Atlantic forest. The volatile compounds in the essential oil were extracted by hydrodistillation and analyzed using GC-MS; 36 compounds accounted for 78.80% of the total oil content. The major compounds were β-caryophyllene, bicyclogermacrene, globulol, and (δ-cadinene. We evaluated their antimicrobial potential of the essential oil and toxicity to Artemia salina. The antimicrobial activity of the essential oil was evaluated against 12 microorganisms using the broth microdilution method. Our results showed moderate inhibition of Staphylococcus aureus and methicillin-resistant S. aureus (MIC, 250 and 125 μg.mL-1, respectively) and toxicity to A. salina (LC50, 125.64 μg.mL-1). Our results establish the biological activity of the essential oil obtained from E. pyriformis.

Abstract Ralstonia mannitolilytica, a Gram-negative bacterium, is rarely isolated in clinical laboratories. It has been associated with outbreaks due to its ability to survive in liquid media and hospital devices. We describe three cases of bacteremia caused by R. mannitolilytica in a neonatal intensive care unit in Curitiba, Southern Brazil. All isolates presented the same PFGE profile. The common source of infection was undetected in surveillance cultures for the outbreak survey. All patients received antimicrobial treatment and were discharged from the maternity. Due to the characteristics of the microorganism, clinicians and microbiologists should pay attention to the emergence of Ralstonia spp. infections.

Abstract INTRODUCTION: Bloodstream infections can be fatal, and timely identification of the etiologic agent is important for treatment. METHODOLOGY: An alternative method, consisting of direct identification and susceptibility testing of blood culture bottles using the automated VITEK 2® system, was assessed. RESULTS: All 37 of the Gram-negative bacilli (GNB) identifications and 57.1% of the 28 Gram-positive cocci (GPC) identifications matched those obtained with standard methods. In susceptibility testing, the agreement was greater than 90%. CONCLUSIONS: This alternative methodology may assist in the early identification and susceptibility testing of GNB. Further research is necessary to develop appropriate methods for GPC.

Introdução:A infecção do trato urinário é bastante frequente em ambiente hospitalar, e a cultura de urina é padrão-ouro para o diagnóstico dessa doença, pois permite a identificação bacteriana e a realização do teste de suscetibilidade aos antimicrobianos. Amostras de urina de pacientes com forte suspeita de infecção que resultam em cultura negativa podem ocorrer devido à atividade de resíduos de antimicrobianos, os quais podem interferir no crescimento bacteriano in vitro e gerar resultados falso negativos.Objetivo:Verificar a ocorrência de culturas de urina falso negativas devido à presença de resíduos de antimicrobianos em amostras de pacientes internados no Hospital de Clínicas da Universidade Federal do Paraná.Material e métodos:Um total de 188 amostras de urina de pacientes internados foi selecionado aleatoriamente, durante o período de julho a dezembro de 2012. Todas as amostras foram avaliadas quanto ao resultado da cultura de urina, da bacteriúria e da pesquisa da atividade de resíduos de antimicrobianos por meio das técnicas manual e automatizada.Resultados:Quarenta e quatro (23,4%) apresentaram cultura de urina positiva, 121 (64,4%), cultura negativa e 23 (12,2%), crescimento de várias espécies. Em 14 amostras foi observada cultura negativa associada à presença de bactérias e pesquisa da atividade de resíduos de antimicrobianos (PRA) positiva.Conclusão:A técnica automatizada apresentou melhor desempenho quando comparada com a técnica manual, apresentando sensibilidade de 92,8% e 71,4%, respectivamente. A presença de resíduos de antimicrobianos pode comprometer a recuperação de bactérias na urina, gerando resultado falso negativo.

Introduction:Urinary tract infection is quite frequent in a hospital environment, and the urine culture is the gold standard for diagnosis of this disease, because it allows bacterial identification and performing antimicrobial susceptibility testing. Culturenegative urine samples result of patients with strong suspicion of infection may occur due to the activity of antimicrobial residues, which can interfere with bacterial growth in vitro and produce false-negative results.Objective:Verify the occurrence of falsenegative urine cultures due to the presence of antimicrobial residues in samples of patients admitted to the Clinical Hospital of Paraná Federal University.Material and methods:A total of 188 urine samples from hospitalized patients were randomly selected, during the period from July to December 2012. All samples were evaluated on the result of the urine culture, bacteriuria, and research on residues of antimicrobial activity by manual and automated techniques.Results:44 (23.4%) presented positive urine culture, 121 (64.4%) negative urine culture, and 23 (12.2%) presented growth of many species. In 14 samples, negative urine cultures associated with the presence of bacteria and were positive for the research on antimicrobial residues activity (RARA), were observed.Conclusion:Automated technique showed better performance when compared to manual technique, with sensitivity of 92.8% and 71.4%, respectively. The presence of antimicrobial residues may affect the recovery of bacteria in the urine, producing a false-negative result.

Prevalence of H. pylori infection was determined using cultures of gastric biopsy samples of patients attended at the academic hospital of the Federal University of Paraná, Curitiba, Paraná, Brazil. Molecular methods were used to characterize the cagA and vacA genes from bacterial isolates associated with different diseases presented by patients. Out of a total of 81, forty-two gastric biopsy samples tested were positive for H. pylori, with a prevalence of 51.9%. No significant difference was found with regard to the gender (p=0.793) and age (p=0.183) of the patients. Genotype s1m1 vacA gene was found in 67% of the cases of peptic ulcer investigated (p=1.0), despite the limited number of patients with this disease (n=3). A correlation between the presence of less virulent strains (s2m2) and reflux esophagitis was found in the majority of the cases (45%), but without statistical significance. An association between the prevalence of cagA gene, found in 92% of isolates, and peptic ulcer was not observed (p=1.0), suggesting that this gene cannot be considered a specific marker of severity in our environment. The results reinforce the importance of conducting regional studies and the need to characterize H. pylori virulence genes associated with different diseases.

The antibacterial activity of plant extracts obtained from Bixa orellana L., Chamomilla recutita L., Ilex paraguariensis A. St.-Hil., Malva sylvestris L., Plantago major L. and Rheum rhaponticum L. has been evaluated against two reference strains and eleven clinical isolates of Helicobacter pylori. All the plant species chosen are used in popular Brazilian cuisine and folk medicine in the treatment of gastrointestinal disorders. Initial screening was made by the disk diffusion test and then minimum inhibitory concentration was determined by the agar dilution method. The results presented in this work demonstrated that among the plant preparations analyzed, B. orellana L., C. recutita L., I. paraguariensis A. St.-Hil. and M. sylvestris L. were capable of inhibiting the in vitro growth of H. pylori.

Production of extended-spectrum beta-lactamases (ESBL) by enterobacteria is an important resistance mechanism against antimicrobial beta-lactamics. We tested 498 bacterial strains isolated from two tertiary-care teaching hospitals for ESBL production, using screening breakpoints for aztreonam and third generation cephalosporins, according to CLSI recommendations. Among these isolates, 155 were positive for the ESBL screening test, and 121 (78%) were confirmed by the clavulanic acid combination disk method. We found a high frequency of ESBL (24%) among Enterobacteriaceae, with a frequency of 57.4% for Klebsiella pneumoniae, 21.4% for Klebsiella oxytoca, and 7.2% for E. coli. In other members of Enterobacteriaceae, non-Klebsiella and non-E. coli, the prevalence was 21.6%. Ceftriaxone and cefotaxime showed a higher sensitivity in the screening test (99.2%) when compared to ceftazidime, aztreonam and cefpodoxime. However, cefotaxime/cefotaxime plus clavulanic acid showed a higher sensitivity in the confirmatory test (96.7%).

Isolation and identification of etiological agents found in body fluids can be of critical importance for the recovery of patients suffering from potentially-severe infections, which are often followed by serious sequels. Eighty-two samples of different body fluids were analyzed using two different methods: (1) the conventional culture method (agar plating) and (2) the enrichment culture technique, using the Bact/Alert® blood culture bottle. The number of positive cultures increased on average from 9.7% to 23.1% with the enrichment culture technique. Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus were the most frequently isolated bacteria. The enrichment method could provide a more accurate means the identifying etiological agents.