Tipos de clones e perfis de resistência antimicrobiana de Staphylococcus aureus resistentes à meticilina isolados de hospitais no sul do Brasil

In the present study were evaluated the DNA macrorestriction profile and SCCmec types for nine multi-resistant MRSA selected. Also antimicrobial susceptibility testing by disk diffusion method was evaluated for 68 MRSA isolates against 12 antimicrobial agents. The isolates were recovered from blood culture collected from hospitalized patients in three hospitals of Porto Alegre, Brazil. PFGE and PCR for mecA and SCCmec I, II, III, IV types genes were done on selected nine isolates with susceptibility only to vancomycin, teicoplanin and linezolid. Two clone profiles, with five subtypes, were demonstrated among multi-resistant MRSA analyzed. Eight isolates showed harbor SCCmec type III and one isolate was not typeable. The knowledge of SCCmec type, clone and antimicrobial profiles among S. aureus is essential mainly to prevention and control of dissemination of the antimicrobial resistance.No presente estudo foram avaliados o perfil de macrorrestrição do DNA e tipos de SCCmec para nove MRSA multirresistentes selecionados. Além disso, susceptibilidade a 12 agentes antimicrobianos pelo teste de disco-difusão foi avaliada para 68 isolados de MRSA. Os isolados foram obtidos de hemoculturas de pacientes hospitalizados de três hospitais de Porto Alegre, Brasil. PFGE e PCR para detecção do gene mecA e para os tipos genéticos SCCmec I, II, III e IV foram realizados em nove isolados selecionados que apresentaram susceptibilidade somente a vancomicina, teicoplanina e linezolida. Dois perfis clonais, com cinco subtipos, foram demonstrados entre os isolados analisados. Oito isolados apresentaram SCCmec tipo III e um isolado não foi caracterizado quanto ao tipo de SCCmec. O conhecimento do tipo de SCCmec bem como dos perfis clonais e de susceptibilidade aos antimicrobianos entre isolados de S. aureus é essencial, principalmente, para a prevenção e controle da disseminação da resistência antimicrobiana

Biofilm and MBL production among imipenem resistant Pseudomonas aeruginosa and Acinetobacter species

Pseudomonas aeruginosa and Acinetobacter species are the primary cause of nosocomial infections. The advent of Metallo-beta-lactamase (MBL) and biofilm-producing bacterial strains poses a serious threat to reserve drugs such as carbapenem. The objective of this study was to determine the rate of MBL and biofilm production among imipenem resistant P. aeruginosa (IRPA) and imipenem resistant Acinetobacter spp. (IRAS) isolates. A total of 79 P. aeruginosa and 117 Acinetobacter spp. were isolated from various clinical specimens of patients from July 2016 to January 2017 at Manipal Teaching Hospital, Pokhara. MBL in IRPA and IRAS isolates were detected by Combined disc test and E-test. Biofilm production in imipenem resistant isolates was carried out by Microtitre plate assay. Fifteen (19%) P. aeruginosa and 57 (48.7%) Acinetobacter spp. were imipenem resistant isolates. MBL producers were found among 53.3% of IRPA and 38.6% of IRAS, whereas 100% of IRPA and 82.5% of IRAS were biofilm producers. All the biofilm producer IRPA isolates were Extensively Drug-Resistant (XDR), and a larger proportion of XDR IRAS strains were of high biofilm-producing phenotype. However, the majority of imipenem resistant (80% of IRPA and 49.1% of IRAS) and MBL producing (63%) isolates were weak biofilm formers. The study demonstrated the high capability of IRPA and IRAS to form a biofilm, which was strongly related to higher drug resistance. Nonetheless, imipenem resistant and MBL producer isolates showed an analogous association with the degree of biofilm formation. These MBL cum biofilm producer isolates were better susceptible to polymyxin B and ampicillin-sulbactam. DOI: http://dx.doi.org/10.5281/zenodo.419547

Evaluation of tests to predict metallo-B-lactamase in cystic fibrosis (CF) and non-(CF) Pseudomonas

Double disks synergy test (DDST) and combined disks test (CD) were evaluated to predict the presence of metallo-β-lactamase in 70 Pseudomonas aeruginosa isolates recovered from cystic fibrosis and non-cystic fibrosis patients. DDSTCAZ-EDTA 1 cm and CDIMP-EDTA tests showed the best accuracy (94.3%). Furthermore, for other combinations, accuracy unsatisfactory was obtained

Rhizobium radiobacter recovered from blood of a pediatric patient with stem cell transplantation: a case report and characterization of antimicrobial susceptibility profile

Rhizobium radiobacter is an uncommon agent of infection and has been associated with indwelling intravascular devices such as catheter in immunocompromised patients. Here, we report a case of R. radiobacter recovered from blood cultures in stem cell transplantation in a pediatric patient and present an extensive characterization of its antimicrobial susceptibility profile. The isolate presented low MICs to many antimicrobial agents, but high MICs to ceftazidime, piperacillin-tazobactam, aztreonam, and fosfomycin

Rhizobium radiobacter recovered from blood of a pediatric patient with stem cell transplantation : a case report and characterization of antimicrobial susceptibility profile

Rhizobium radiobacter is an uncommon agent of infection and has been associated with indwelling intravascular devices such as catheter in immunocompromised patients. Here, we report a case of R. radiobacter recovered from blood cultures in stem cell transplantation in a pediatric patient and present an extensive characterization of its antimicrobial susceptibility profile. The isolate presented low MICs to many antimicrobial agents, but high MICs to ceftazidime, piperacillintazobactam, aztreonam, and fosfomycin

Susceptibility profiles and correlation with pneumococcal serotypes soon after implementation of the 10-valent pneumococcal conjugate vaccine in Brazil

SummaryObjectivesTo evaluate the susceptibility patterns among Streptococcus pneumoniae recovered during the years 2010–2012 and to correlate these with serotypes.MethodsPneumococci from invasive sites were serotyped by sequential multiplex PCR and/or Quellung reaction. Etest strips were used to determine the minimal inhibitory concentrations, and the Clinical and Laboratory Standards Institute (CLSI) guidelines were used for interpretation. Genetic determinants of macrolide resistance were assessed by PCR, and the occurrence of the D phenotype was analyzed following the recommendations of the CLSI.ResultsOne hundred fifty-nine S. pneumoniae were studied; most were recovered from blood and were associated with serotypes 14, 3, 4, 23F, 20, 7F, 12F, 19A, and 19F. Pneumococcal conjugate vaccine PCV7, PCV10, and PCV13 and 23-valent polysaccharide vaccine serotypes represented 38.2%, 48.7%, 64.5%, and 85.5%, respectively. β-Lactam non-susceptibility (non-meningitis) was basically related to serotype 19A. For meningitis, it was observed in 21.4% (serotypes 14, 3, 9V, 23F, and 24F). Resistance to erythromycin occurred in 8.2% and mefA was the most common macrolide genetic determinant. One isolate was resistant to levofloxacin. Non-susceptibility to trimethoprim–sulfamethoxazole was 37.7% and to tetracycline was 22.0%.ConclusionsOur population of pneumococci represents a transition era, soon after the introduction of PCV10. Non-susceptible patterns were found to be associated with classical PCV serotypes (especially serotype 14), which is still highly prevalent, and non-PCV10 ones (19A), which may disseminate, occupying the biological niche left by the vaccine serotypes