Synergistic activity between beta-lactams and igy antibodies against Pseudomonas aeruginosa in vitro.

Multi-drug resistant Pseudomonas aeruginosa is a gram-negative bacillus responsible for nosocomial infections. Immunoglobulin Y (IgY) is a chicken immunoglobulin used for research, immunodiagnosis, and immunotherapy. IgY presents antimicrobial properties and it is under investigation for use as an adjunct to prophylactic therapies. The current study aimed to assess the synergistic action between anti-P aeruginosa IgY and the beta-lactams ceftazidime, imipenem, and meropenem. IgY antibodies were obtained from laying hens immunized with SPM-1 producing P. aeruginosa (Pa48spm-1+) or VIM-2 producing P. aeruginosa (Pa23vim-2 +). The antimicrobial activity of IgY antibodies was evaluated by the growth inhibition test, and the synergistic effect was assessed by determination of the fractional inhibitory concentration index. Anti-Pa48spm-1+ IgY shows antimicrobial activity at 1.25 mg/ml and anti-Pa23vim-2+ IgY shows antimicrobial activity at 2.5 mg/ml. The fractional inhibitory concentration indices of anti-Pa48spm-1+ IgY and ceftazidime, or imipenem, or meropenem at 72 h of experiment were 0.189, 0.209, and 0.440, respectively. For anti-Pa23vim-2+ IgY, the fractional inhibitory concentration indices were 0.440 with ceftazidime, 0.453 with imipenem, and 0.441 with meropenem at 72 h. We conclude that there is a synergistic action between anti-P. aeruginosa IgY and the antimicrobials tested. Further studies are necessary to investigate the mechanisms associated with this action.

Evolução da resistência de Klebsiella pneumoniae no Hospital Universitário de Londrina no período de 2000 a 2011 / Evolution of resistance of Klebsiella pneumoniae in Londrina University Hospital from 2000 to 2011

O presente estudo teve como objetivo avaliar a evolução da resistência a antimicrobianos em isolados clínicos de Klebsiella pneumoniae, no período de 2000 a 2011, no Hospital Universitário da Universidade Estadual de Londrina (HU-UEL). Foi realizada uma análise retrospectiva de 2.318 testes de sensibilidade aos antimicrobianos de K. pneumoniae, a partir de um banco de dados do setor de Microbiologia do Laboratório Clínico do HU. No período de 2000 a 2009, o principal mecanismo de resistência aos antimicrobianos β-lactâmicos observado foi a produção de β-lactamases do tipo ESBL (β-lactamase de espectro ampliado),que pode ser verificado pelo aumento da resistência de K. pneumoniae às cefalosporinas de 3a. e 4a. geração. No entanto, a partir de 2009 apareceram as primeiras cepas de K. pneumoniae produtoras de carbapenemase, comprometendo a eficácia dos carbapenêmicos. Os índices de resistência ao ertapenem variaram de 16%,em 2005, para 40%, em 2011. Outra classe de antimicrobianos comprometida foi a das fluoroquinolonas; para ciprofloxacina, os índices de resistência variaram de 13% a 62%, em 2001 e 2011, respectivamente.Os aminoglicosídeos tiveram oscilações de resistência durante o período estudado, chegando, em 2011,a valores de 56% e 30% para gentamicina e amicacina, respectivamente. Enquanto isso, sulfametoxazol/trimetoprim e piperacilina/tazobactam alcançaram índices de resistência de 60%, nesse mesmo período. O aumento de resistência em K. pneumoniae neste hospital evidencia a necessidade de adequação do tratamento de infecções por este agente e de adoção o de medidas apropriadas que visem ao controle de infecções, bem como ao uso adequado dessas drogas.

The present study aimed to evaluate the evolution of antibiotic resistance in clinical isolates of Klebsiella pneumoniae in the period of 2000 to 2011, at the University Hospital of Londrina (HU-UEL). A retrospective analysis of 2,318 antimicrobial susceptibility tests of Klebsiella pneumoniae was performed from a database of the Clinical Laboratory of Microbiology of the University Hospital. In the period of 2000 to 2009, the main mechanism of resistance observed to β-lactam antimicrobials was due to the production of ESBL β-lactamase type (β-lactamase wide spectrum), which can be verified by the increased resistance of Klebsiella pneumoniae to 3rd generation cephalosporins and cefepime. However, the first strains of Klebsiella pneumoniae carbapenemase-producing appeared in 2009, compromising the efficacy of carbapenems. The rates of resistance to ertapenem ranged from 16%, in 2005, to 40% in 2011. Another class of committed antibiotics was the fluoroquinolones; for ciprofloxacin, resistance rates ranged from 13% to 62%, in 2001 and 2011, respectively. Aminoglycosides exhibited oscillations of resistance during the period studied, reaching,in 2011, values of 56% and 30% for gentamicin and amikacin, respectively. Meanwhile, trimethoprim/sulfamethoxazole and piperacillin/tazobactam reached about 60%, in the same period. Therefore, knowing the antimicrobial resistance of Klebsiella pneumoniae strains is essential for proper treatment of patients and adoption of appropriate measures that aims infection control, and proper use of these drugs.

Tendência de resistência entre isolados clínicos de Staphylococcus aureus em um hospital universitário do norte do Paraná de 2002 a 2011 / Trends in antimicrobial resistance among clinical isolates of Staphylococcus aureus in a university hospital of the north of Paraná from 2002 through 2011

Staphylococcus aureus são patógenos com alta ocorrência em infecções hospitalares e comunitárias e têm grande capacidade de adquirir resistência. O objetivo deste estudo foi determinar o perfil de resistência aos antimicrobianos de S. aureus isolados no Hospital Universitário de Londrina de janeiro de 2002 a dezembro de 2011. A análise retrospectiva de 3.494 S. aureus foi realizada a partir de um banco de dados do setor de Microbiologia do Laboratório Clínico do Hospital Universitário de Londrina (HUL). Resistência aos antimicrobianos foi determinada de acordo com os critérios recomendados pelo Clinical Laboratory Standard Institute (CLSI-2011). Os maiores percentuais de resistência foram verificados para eritromicina (49,4%), oxacilina, clindamicina (41,8%) e ciprofloxacina (36,5%). Adicionalmente, ocorreu redução significativa nas taxas de resistência à gentamicina, e a sulfametoxazol-trimetoprim. Todas as cepas analisadas foram sensíveis à linezolide. Verificou-se que 40% apresentaram susceptibilidade reduzida à vancomicina. Estes dados revelaram uma provável mudança na epidemiologia de S. aureus na nossa região, o que pode trazer impacto no tratamento e controle da infecção por este agente etiológico.

Staphylococcus aureus are pathogens with high incidence of nosocomial infections and community and has great ability to acquire resistance. The objective of this study was to determine susceptibility to antimicrobial profiles of S. aureus isolated in Londrina University Hospital, from January 2002 through December 2011. The retrospective analysis of 3,494 S. aureus performed from a database of Clinical Laboratory Microbiology HU sector. Antibiotic resistance was judged according to the criteria recommended by the Clinical Laboratory Standards Institute. The highest percentages of resistance was founding to erythromycin (49.4%), clindamycin and oxacillin (41.8%) and ciprofloxacin (36.5%). In addition, there was a significant reduction in gentamicin resistance rates, and trimethoprim-sulfamethoxazol. All strains studied were susceptible to linezolid. We found that 40% showed reduced susceptibility to vancomycin. These data indicate a possible change in the epidemiology of S. aureus in our region, which can bring impact on the treatment and control of infection by this agent.

Enterococcus spp. resistentes à vancomicina: características clínicas efatores de risco / Vancomycin-resistant Enterococcus spp: clinical characteristics and risk factors

Enterococcus spp. resistentes à vancomicina (ERV) têm emergido como um patógeno multirresistente relevante e de etiologia potencialmente letal nas infecções associadas à assistência em saúde ao redor do mundo. Este estudo pretende mostrar epidemiologia e características clínicas de pacientes com ERV em um hospital do sul do Brasil. Um estudo retrospectivo foi conduzido no período de janeiro de 2005 a novembro de 2007 no Hospital Universitário de Londrina. Todos os pacientes com cultura clínica com ERV foram identificados e seu prontuário médico revisado. A presença de colonização foi avaliada através de culturas de swab retal e a identificação das amostras clínicas foi realizada pelo método automatizado MicroScan®. A média de idade dos pacientes foi de 54 anos. Trato urinário (68,0%) e corrente sanguínea (23,8%) foram os sítios mais frequentes, e a UTI apresentou se como setor de maior ocorrência (49,2%) das culturas positivas. E. faecium foi a espécie predominante, em 82,8% dos casos. Os fatores de risco observados foram a duração da internação (média de 58,2 dias), uso de antimicrobianos prévios e realização de procedimento invasivos, como o uso de cateter venoso central, sonda vesical e ventilação mecânica. Medidas de controle e culturas de vigilância são imprescindíveis no controle da disseminação do ERV. Os resultados obtidos no presente trabalho contribuem para uma melhor compreensão da dinâmica epidemiológica das infecções e da disseminação do ERV no Hospital Universitário de Londrina.

Vancomycin-resistant Enterococci (VRE) have emerged as a relevant multidrug-resistant pathogen and potencially lethal etiology of healthcare associated infections worldwide. This study intends to show the epidemiology and clinical characteristics of patients with VRE in a Hospital in South Brazil. A retrospective study was conducted from January 2005 to November 2007. A total of 122 VRE were identified in this period at the University Hospital of Londrina. All patients with VRE clinical culture have identified and their medical records have reviewed. The presence of colonization was evaluated through rectal swab cultures, and the species identification of clinical samples was performed by automated method MicroScan®. The mean age of patients was 54 years. Urinary tract (68.0%) and blood (23.8%) were the most frequent sites, and ICU was the largest sector of occurrence (49.2%). E. faecium was the predominant species, in 82.8% of cases.The risk factors presents were length of hospitalization (mean 58.2 days), previous use of antimicrobials and invasive procedure, such as use of central venous catheter, urinary catheter and mechanical ventilation. Control barriers and surveillance cultures are essential to prevent the VRE spread. The results obtained in this study contribute to a better understanding of the epidemiological dynamics of infections and the spread of VRE in University Hospital of Londrina.

Can ampicillin/sulbactam resistance in Acinetobacter baumannii be predicted accurately by disk diffusion?

The objective of this study was to compare the performance of disk diffusion and agar dilution for the determination of susceptibility to ampicillin/sulbactam (SAM), ceftazidime, cefepime, imipenem, meropenem, polymyxin B and tigecycline of 121 Acinetobacter baumannii clinical isolates. The antimicrobial susceptibility testing methods were performed as recommended by the Clinical and Laboratory Standards Institute (CLSI). For SAM, in addition the Etest method was performed according to the manufacturer's instructions. The error rates for the antimicrobial agents for 121 isolates tested were within the acceptable ranges established by the CLSI, with the exception of SAM and polymyxin B. For polymyxin B, there were 1.7% very major errors and for SAM there were 15% comparing disk diffusion with agar dilution. The very major error rate of SAM comparing the Etest with agar dilution was 10%. These high observed rates of very major error cast doubt on the disk diffusion and Etest techniques as appropriate methods for detecting resistance to SAM.