Floristher Elaine Carrara-Marroni

Detection of OXA-231, a new variant of blaOXA-143, in Acinetobacter baumannii from Brazil: a case report

Department of Microbiology, Universidade Estadual de Londrina, Londrina, Paraná, Brazil; Department of Science Pathological, Universidade Estadual de Londrina, Londrina, Paraná, Brazil; Laboratório ALERTA, Division of Infectious Diseases, Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil; Department of Pathology, Clinical and Toxicological Analysis, Hospital Universitário de Londrina, Universidade Estadual de Londrina, Londrina, Paraná, Brazil

In vitro activity of polymyxins in combination with β-lactams against clinical strains of Pseudomonas aeruginosa

The emergence of multidrug-resistant (MDR) strains has made it difficult to treat infections caused by Pseudomonas aeruginosa. In order to develop new alternative therapies for the treatment of MDR P. aeruginosa infections, the antimicrobial activities of different antibiotic combinations have been studied in vitro and in vivo. In this study, the in vitro antimicrobial activities of six different combinations of polymyxins and β-lactams against 34 clinical isolates of P. aeruginosa were evaluated. For the combinations tested by the checkerboard method, an indifferent effect was observed for all strains. However, 27 strains (19 MDR) showed reductions in their minimal inhibitory concentration (MIC) for at least one of the antibiotics in the combinations evaluated. Combination with polymyxins resulted in reductions of the β-lactam MICs, with a change in the resistance category to susceptible in eight MDR strains. These results from the in vitro evaluation suggest that combinations of polymyxins and β-lactams may significantly reduce the MICs of the antibiotics tested. These combinations require further evaluation for use in medical practice.

Strategies for the treatment of polymyxin B-resistant Acinetobacter baumannii infections

In this study, the activity of meropenem (MEM), fosfomycin (FOF) and polymyxin B (PMB), alone and in combination, was analysed. In addition, optimisation of the pharmacodynamic index of MEM and FOF against six isolates of OXA-23-producing Acinetobacter baumannii (including three resistant to PMB) that were not clonally related was assessed. Antimicrobial combinations were evaluated by chequerboard analysis and were considered synergistic when the fractional inhibitory concentration index (FICI) was ≤0.5. Pharmacodynamic analyses of the MEM and FOF dosing schemes were performed by Monte Carlo simulation. The target pharmacodynamic index (%ƒT>MIC) for MEM and FOF was ≥40% and ≥70%, respectively, and a probability of target attainment (PTA) ≥0.9 was considered adequate. Among the PMB-resistant isolates, combinations of PMB+MEM and PMB+FOF+MEM showed the highest synergistic activity (FICI ≤0.125); isolates that were previously PMB-resistant were included in the susceptible category using CLSI interpretive criteria. Pharmacodynamic evaluation found that for a FOF minimum inhibitory concentration (MIC) of ≤16μg/mL, treatment both by bolus dosing and prolonged infusion achieved adequate PTA, whilst for MIC=32μg/mL only infusion achieved adequate PTA. For a MEM MIC of 4μg/mL, only the bolus treatment scheme with 1.5g q6h and the infusion schemes with 1.0g q8h, 1.5g q6h and 2.0g q8h achieved PTA ≥0.9. Results of antimicrobial and pharmacodynamic analyses can assist in treating infections caused by multidrug-resistant A. baumannii. However, in vivo clinical studies are essential to evaluate the true role of these compounds, including intravenous antimicrobial FOF therapy.

Detection of blaVIM-7 in an extensively drug-resistant Pseudomonas aeruginosa isolate belonging to ST1284 in Brazil

We described for the first time an extensively drug-resistant Pseudomonas aeruginosa isolate belonging to ST1284 carrying a plasmid-mediated blaVIM-7 in Brazil. The blaVIM-7 was harbored by an integron that also carried aacA4 and blaOXA-46. Multiple virulence factors were also detected.

Prevalence and antimicrobial susceptibility profile of Streptococcus agalactiae in pregnant women seen at the University Hospital of Londrina, Paraná, Brazil

1 Mestranda do Programa de Pós-Graduação em Microbiologia da Universidade Estadual de Londrina, Londrina, Paraná, Brasil. Departamento de Microbiologia do Centro de Ciências Biológicas da Universidade Estadual de Londrina, Londrina, Paraná, Brasil. 2 Doutoranda em Microbiologia pela Universidade Estadual de Londrina, Londrina, Paraná, Brasil. Departamento de Microbiologia do Centro de Ciências Biológicas da Universidade Estadual de Londrina, Londrina, Paraná, Brasil. 3 Doutorado em Doenças Infecciosas e Parasitárias pela Universidade de São Paulo, São Paulo, Brasil. Professor associado do Laboratório de Análises Clínicas, Setor de Microbiologia do Hospital Universitário da Universidade Estadual de Londrina, Londrina, Paraná, Brasil. 4 Mestrado em Microbiologia pela Universidade Estadual de Londrina, Londrina, Paraná, Brasil. Departamento de Patologia, Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Estadual de Londrina, Londrina, Paraná, Brasil. 5 Doutorado em Microbiologia pela Universidade Estadual de Londrina, Londrina, Paraná, Brasil. Professor adjunto do Departamento de Patologia, Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Estadual de Londrina, Londrina, Paraná, Brasil. 6 Doutorado em Microbiologia pela Universidade Estadual de Londrina, Londrina, Paraná, Brasil. Departamento de Patologia, Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Estadual de Londrina, Londrina, Paraná, Brasil. 7 Doutorado em Educação pela Universidade Estadual Paulista Júlio de Mesquita Filho, Marília, São Paulo, Brasil. Departamento de Enfermagem, Centro de Ciências da Saúde da Universidade Estadual de Londrina, Londrina, Paraná, Brasil. 8 Doutorado em Microbiologia pela Universidade Estadual de Londrina, Londrina, Paraná, Brasil. Professor adjunto do Departamento de Enfermagem do Centro de Ciências da Saúde da Universidade Estadual de Londrina, Londrina, Paraná, Brasil. 9 Doutorado em Ciências da Saúde pela Universidade Estadual de Londrina, Londrina, Paraná, Brasil. Departamento de Clínica Médica do Centro de Ciências da Saúde da Universidade Estadual de Londrina, Londrina, Paraná, Brasil. 10 Doutorado em Imunologia Básica e Aplicada pela Universidade de São Paulo, Ribeirão Preto, São Paulo, Brasil. Departamento de Microbiologia do Centro de Ciências Biológicas da Universidade Estadual de Londrina, Londrina, Paraná, Brasil. 11 Doutorado em Biologia Celular e Molecular pela Fundação Oswaldo Cruz, Curitiba, Paraná, Brasil. Departamento de Microbiologia do Centro de Ciências Biológicas da Universidade Estadual de Londrina, Londrina, Paraná, Brasil. E-mail: ogatta@uel.br DOI: 10.5433/1679-0367.2018v39n1p77 Um estudo retrospectivo foi realizado com gestantes atendidas no Hospital Universitário de Londrina, Paraná, Brasil para determinar a prevalência de colonização vaginal-retal por estreptococos do Grupo B (EGB) e o perfil de sensibilidade de EGB aos antimicrobianos utilizados para a antibioticoterapia profilática intraparto. Swabs vaginais-retais foram coletados de 2.901 mulheres entre a 35a e 37a semana de gestação. Destes, 527 (18,2%) apresentaram cultura positiva para EGB, e 0,4%, 10,2% e 10% dos ARTIGOS / ARTICLES C ÊN C AS IO LÓ G IC AS E D A AÚ D E A retrospective study of pregnant women seen at the University Hospital of Londrina, Paraná, Brazil was performed to determine the prevalence of Group B Streptococcus (GBS) vaginal-rectal colonization, and the GBS susceptibility for antimicrobials used in intrapartum antibiotic prophylaxis. A vaginal-rectal swab was collected from 2,901 women between 35 and 37 weeks of gestation. Of these, 527 (18.2%) had a positive culture for GBS, and 0.4%, 10.2% and 10% of the isolates were resistant to penicillin, erythromycin and clindamycin, respectively. These results highlight the importance of continuous surveillance of GBS colonization in pregnant women for preventing GBS infections in neonates. Resumo