Describing vancomycin serum levels in pediatric intensive care unit (ICU) patients: are expected goals being met.

BACKGROUND: In the pediatric population, infections by methicillin-resistant Staphylococcus aureus (MRSA) are associated with significant morbidity and hospital costs. Vancomycin is a glycopeptide antibiotic, widely used for the treatment of serious infections by Gram-positive microorganisms, especially MRSA. It is recommended to keep the serum level of vancomycin between 10 and 20 mg/L, that correlates with AUC/MIC > 400 in adults. This pharmacodynamic target is extrapolated to pediatric patients despite the lack of similar evidence. However, recent studies suggest that serum levels between 7 and 10 mg/L are predictive of reaching the pharmacodynamic target in this population. In spite of widespread use, ideal information about dosage for the pediatric population remains limited. METHODS: A retrospective study was conducted in patients admitted to the Pediatric Intensive Care Unit during the period between January 01, 2008 to December 31, 2014. We investigated variables such as age, positive fluid balance and use of vasoactive drugs on the ability of these patients to achieve the proposed recommended serum level target and the vancomycin serum levels. RESULTS: Our study showed that only 26% of children reached the 10-20 mg/L serum level whereas the 7-20 mg/L serum level was reached by 51% of patients. CONCLUSIONS: We observed no evidence of a significant association between the inadequacy of serum level and age. The positive fluid balance also had no influence on the vancomycin serum level but patients using vasoactive drugs had a greater serum level adequacy than patients not using vasoactive drugs.

Racionalização de antimicrobianos em ambiente hospitalar / Antimicrobial stewardship program in hospitals

Foi feita uma revisão sobre o uso racional de antimicrobianos em ambiente hospitalar, pois este é um dos principais desafios encontrados na terapia de infecções em ambiente hospitalar. Foram abordados os principais fatores que nos levam ao atual panorama global em relação à resistência antimicrobiana, bem como as principais estratégias para o uso racional dos antimicrobianos, de modo a garantir melhor terapêutica e menor incidência de resistência aos antimicrobianos. A racionalização de antimicrobianos é um componente-chave de uma abordagem multifacetada para a prevenção de resistência antimicrobiana. A boa gestão de antimicrobianos envolve a seleção do medicamento apropriado, otimizando sempre a dose e a duração do tratamento, utilizando bem os parâmetros de farmacodinâmica e farmacocinética, minimizando a toxicidade e as condições para a seleção de cepas bacterianas resistentes e garantindo, assim, sucesso terapêutico. Com o uso racional de antimicrobianos, podemos obter um melhor desempenho no tratamento de doenças infecciosas. Nesta revisão foi demonstrada a existência de várias estratégias de racionalização de antimicrobianos. Portanto, cabe a cada instituição estudar e analisar quais métodos devem ser implantados. Também é de fundamental importância que o prescritor analise as opções terapêuticas disponíveis e busque a individualização do tratamento, sempre visando à otimização terapêutica.(AU)

A review on antimicrobial stewardship was performed, because this is one of the leading challenges found in infectious diseases therapy in hospital settings. The major factors leading to the current global picture regarding antimicrobial resistance, and the main strategies for antimicrobial stewardship, to ensure the best treatment and lower incidence of antimicrobial resistance were discussed. Antimicrobial stewardship is a multifaceted approach considered a key component in the prevention of antimicrobial resistance. The best antimicrobial stewardship program involves selecting the appropriate medication, always optimizing its dose and duration of treatment using pharmacodynamics and pharmacokinetics parameters, minimizing toxicity and the conditions for selecting resistant bacterial strains, and ensuring treatment success. The rational use of antimicrobials can lead to more success in the treatment of infectious diseases. This review shows several strategies for antimicrobial stewardship. Therefore, it is up to each institution to study and analyze which method should be implemented. It is also crucial that the prescriber reviews the therapeutic options available to seek individualization of treatment, always aiming at therapy optimization.(AU)

Noções sobre parâmetros farmacocinéticos/farmacodinâmicos e sua utilização na prática médica / Notions of pharmacokinetic and pharmacodynamic parameters, and their use in medical practice

Foram revisados os parâmetros ou índices farmacocinéticos e farmacodinâmicos, com o objetivo de enfatizar sua importância como ferramenta de otimização da terapia antimicrobiana na prática médica. Destacam-se a ligação proteica, o clearance e o volume de distribuição da droga como parâmetros farmacocinéticos fundamentais, que podem ser alterados pelas características dos pacientes e da infecção. Foram apresentados ainda os parâmetros farmacodinâmicos (concentração máxima/concentração inibitória mínima, tempo > concentração inibitória mínima e área sob a curva/concentração inibitória mínima), que representam a relação dose-resposta e são determinantes para a eficácia terapêutica das drogas anti-infecciosas, considerando a dinâmica bactericida/bacteriostática dos diferentes grupos farmacológicos. Discutiu-se ainda o modelo matemático preditor de resultados prováveis para desfechos de tratamentos, como o método de Monte Carlo. Para finalizar, os índices farmacocinéticos e farmacodinâmicos foram apontados como estratégia de racionalização de antimicrobianos e redução da resistência bacteriana.(AU)

The pharmacokinetic and pharmacodynamic parameters were reviewed with the objective to emphasise their importance as tools for optimizing antimicrobial therapies in medical practice. The protein binding, clearance and drug distribution volume are highlighted as fundamental pharmacokinetic parameters that can be altered according to the characteristics of the patient or infection. We present the pharmacodynamic parameters (maximum concentration/minimal inhibitory concentration, time > minimal inhibitory concentration, and area under the curve/minimal inhibitory concentration) that represent the dose-response ratio and are determinants for the therapeutic efficacy of the antimicrobial drugs, considering the bactericidal/ bacteriostatic dynamics of the different pharmacological groups. We also commented on the predictive mathematical model for probable results for treatment outcomes, such as Monte Carlo method. Finally, the pharmacokinetic and pharmacodynamics indexes were shown as a strategy for antimicrobial rationalization and reduction of bacterial resistance.(AU)

Microbiological and epidemiological study of infectious keratitis in children and adolescents.

PURPOSE:: To analyze epidemiological and microbiological aspects of microbial keratitis in children and adolescents. METHODS:: This retrospective cohort study was conducted at the Department of Ophthalmology and Visual Science, Escola Paulista de Medicina, Universidade Federal de São Paulo, between July 15, 1975, and December 31, 2010. We analyzed corneal samples from 859 patients with clinical suspicion of infectious keratitis, comparing epidemiological and microbiological characteristics of bacterial keratitis with those of non-bacterial and non-viral keratitis. We also compared Gram-positive and Gram-negative pathogens in patients with bacterial keratitis. We created a susceptibility profile of the bacterial microorganisms studied. RESULTS:: Of the 859 patients, 346 (40.3%) showed positive culture results for non-viral microorganisms. Teenagers (13-18 years) made up the group with the highest number of patients with keratitis (164, 47.4%). The most frequent risk factors for keratitis were trauma (33.5%) and previous ocular surgery (24.9%). Gram-positive bacteria (71.8%) were the most often isolated, with coagulase-negative Staphylococcus (23.8%) the most prevalent microorganism. Logistic regression analysis showed age (p=0.002), topical antimicrobial drug use (p=0.01), and trauma due to non-chemical burns (p=0.005) were risk factors for non-bacterial keratitis. Age (p=0.01) was also a risk factor for Gram-negative bacterial keratitis. CONCLUSION:: Our study showed that in the age range studied, the prevalence of keratitis caused by Gram-negative bacteria or by the non-viral microorganisms evaluated increases with age. Previous use of topical antimicrobial drug and trauma due to non-chemical burns are associated with non-bacterial keratitis. Knowledge of the risk factors and the microorganisms involved may help improve treatment of keratitis in children and adolescents and minimize visual impairment.

Microbiological and epidemiological study of infectious keratitis in children and adolescents / Estudo microbiológico e epidemiológico da ceratite infecciosa em crianças e adolescentes

ABSTRACT Purpose: To analyze epidemiological and microbiological aspects of microbial keratitis in children and adolescents. Methods: This retrospective cohort study was conducted at the Department of Ophthalmology and Visual Science, Escola Paulista de Medicina, Universidade Federal de São Paulo, between July 15, 1975, and December 31, 2010. We analyzed corneal samples from 859 patients with clinical suspicion of infectious keratitis, comparing epidemiological and microbiological characteristics of bacterial keratitis with those of non-bacterial and non-viral keratitis. We also compared Gram-positive and Gram-negative pathogens in patients with bacterial keratitis. We created a susceptibility profile of the bacterial microorganisms studied. Results: Of the 859 patients, 346 (40.3%) showed positive culture results for non-viral microorganisms. Teenagers (13-18 years) made up the group with the highest number of patients with keratitis (164, 47.4%). The most frequent risk factors for keratitis were trauma (33.5%) and previous ocular surgery (24.9%). Gram-positive bacteria (71.8%) were the most often isolated, with coagulase-negative Staphylococcus (23.8%) the most prevalent microorganism. Logistic regression analysis showed age (p=0.002), topical antimicrobial drug use (p=0.01), and trauma due to non-chemical burns (p=0.005) were risk factors for non-bacterial keratitis. Age (p=0.01) was also a risk factor for Gram-negative bacterial keratitis. Conclusion: Our study showed that in the age range studied, the prevalence of keratitis caused by Gram-negative bacteria or by the non-viral microorganisms evaluated increases with age. Previous use of topical antimicrobial drug and trauma due to non-chemical burns are associated with non-bacterial keratitis. Knowledge of the risk factors and the microorganisms involved may help improve treatment of keratitis in children and adolescents and minimize visual impairment.

RESUMO Objetivos: Descrever o perfil epidemiológico e microbiológico de ceratite microbiana em crianças e adolescentes. Métodos: Estudo retrospectivo tipo coorte, utilizando fichas laboratoriais de pacientes, atendidos no Departamento de Oftalmologia e Ciências Visuais - Escola Paulista de Medicina - Universidade Federal de São Paulo, entre 15 de julho de 1975 a 31 de dezembro de 2010. Foram comparados pacientes com ceratite bacteriana e não bacteriana (não viral). Entre os pacientes com ceratite bacteriana, foram comparados aqueles em que a ceratite foi causada por bactérias Gram positivas e Gram negativas. O perfil de sensibilidade dos microrganismos bacterianos aos antimicrobianos também foi estudado. Resultados: Foram analisadas amostras corneanas de 859 pacientes com suspeita clínica de ceratite infecciosa, na faixa etária estudada. Destes, 346 (40,3%) apresentaram resultados de culturas positivas para microrganismos não virais. Adolescentes (13 a 18 anos) compuseram o grupo com maior número de pacientes com ceratite (164-47,4%). Os principais fatores de risco foram trauma (33,5%) e cirurgias oculares prévias (24,9%). Bactérias Gram positivas foram isoladas com maior frequência (71,8%), sendo prevalente o patógeno Staphylococcus coagulase negativo (23,8%). De acordo com a análise de regressão logística, idade (p=0,002), uso tópico de drogas antimicrobianas (p=0,01) e trauma por queimadura não química (p=0,005) foram fatores predisponentes para ceratite não bacteriana. Idade (p=0,01) também foi fator de risco para ceratite causada por bactérias Gram negativas. Conclusões: Nosso estudo mostrou que quanto maior a idade, na faixa etária estudada, maior a probabilidade da ceratite ser causada por bactérias Gram negativas e/ou por outros microrganismos não virais avaliados. O uso tópico de drogas antimicrobianas prévias e trauma devido à queimadura não química predispõe à ceratite não bacteriana. O conhecimento dos fatores de risco e dos microrganismos envolvidos resultarão em tratamento específico da ceratite em crianças e adolescentes, com menores danos visuais.

Successful treatment of lower urinary tract infections with oral fosfomycin: a report of three cases.

Infections due to multidrug-resistant organisms continue to increase, and therapeutic options remain scarce. Given this challenge, it has become necessary to use older antimicrobials for treatment of these pathogens. We report three patients with lower urinary tract infections caused by Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae who were successfully treated with a seven-day course of oral fosfomycin monotherapy.

Successful treatment of lower urinary tract infections with oral fosfomycin: a report of three cases

Infections due to multidrug-resistant organisms continue to increase, and therapeutic options remain scarce. Given this challenge, it has become necessary to use older antimicrobials for treatment of these pathogens. We report three patients with lower urinary tract infections caused by Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae who were successfully treated with a seven-day course of oral fosfomycin monotherapy.

Healthcare worker adherence to follow-up after occupational exposure to blood and body fluids at a teaching hospital in Brazil.

Healthcare workers (HCWs) are at a high risk for exposure to pathogens in the workplace. The objective of this study was to evaluate HCW adherence to follow-up after occupational exposure to blood and body fluids at a tertiary care university hospital in the city of São Paulo, Brazil. Data were collected from 2102 occupational exposures to blood and body fluids reports, obtained from the Infection Control Division of the Universidade Federal de São Paulo/Escola Paulista de Medicina/Hospital São Paulo, in São Paulo, Brazil, occurring between January of 2005 and December of 2011. To evaluate adherence to post-exposure follow-up among the affected HCWs, we took into consideration follow-up visits for serological testing. For HCWs exposed to materials from source patients infected with human immunodeficiency virus (HIV), hepatitis B virus (HBV), or hepatitis C virus (HCV), as well as from source patients of unknown serological status, follow-up serological testing was scheduled for 3 and 6 months after the accident. For those exposed to materials from source patients co-infected with HIV and HCV, follow-up evaluations were scheduled for 3, 6, and 12 months after the accident. During the study period, there were 2056 accidental exposures for which data regarding the serology of the source patient were available. Follow-up evaluation of the affected HCW was recommended in 612 (29.8%) of those incidents. After the implementation of a post-exposure protocol involving telephone calls and official letters mailed to the affected HCW, adherence to follow-up increased significantly, from 30.5 to 54.0% (P = 0.028). Adherence was correlated positively with being female (P = 0.009), with the source of the exposure being known (P = 0.026), with the source patient being HIV positive (P = 0.029), and with the HCW having no history of such accidents (P = 0.047). Adherence to the recommended serological testing was better at the evaluation scheduled for 3 months after the exposure (the initial evaluation) than at those scheduled for 6 and 12 months after the exposure (P = 0.004). During the study period, there was one confirmed case of HCW seroconversion to HCV positivity. The establishment of a protocol that involves the immediate supervisor of the affected HCWs, in the formal summoning of those HCWs is necessary in order to increase the rate of adherence to post-exposure follow-up.

Historical trends in the epidemiology of candidaemia: analysis of an 11-year period in a tertiary care hospital in Brazil.

Candida species are an important cause of bloodstream infections (BSI). To evaluate the epidemiological, clinical and microbiological aspects of two cohorts {1994-1999 [period 1 (P1) ]; 2000-2004 [period 2 (P2) ]} of candidaemic patients, we performed a retrospective analysis from a laboratory-based survey. A total of 388 candidaemias were identified, with an incidence of 0.20/1,000 patient-days and a significant increase in P2 vs. P1 (0.25 vs. 0.15, p = 0.04). Cancer and prior antibiotic use were frequent and Candida albicans was the most prevalent species found (42.4%). Resistance to fluconazole was found in 2.47% of the strains. No differences were observed in the species distribution of Candida during the study periods. In the P2 cohort, there were higher prevalence of elderly individuals, cardiac, pulmonary and liver diseases, renal failure, central venous catheters and antibiotic therapy. In P1, there were higher prevalence of neurological diseases and chemotherapy. The crude mortality was 55.4%. In conclusion, our incidence rates remained high. Furthermore, the distribution pattern of Candida species and the fluconazole resistance profile remained unchanged. Moreover, we found a clear trend of higher prevalence of candidaemia among the elderly and among patients with comorbidities. Finally, it is necessary to discuss strategies for the prevention and control of Candida BSI in Brazil.

Historical trends in the epidemiology of candidaemia: analysis of an 11-year period in a tertiary care hospital in Brazil

Candida species are an important cause of bloodstream infections (BSI). To evaluate the epidemiological, clinical and microbiological aspects of two cohorts {1994-1999 [period 1 (P1) ]; 2000-2004 [period 2 (P2) ]} of candidaemic patients, we performed a retrospective analysis from a laboratory-based survey. A total of 388 candidaemias were identified, with an incidence of 0.20/1,000 patient-days and a significant increase in P2 vs. P1 (0.25 vs. 0.15, p = 0.04). Cancer and prior antibiotic use were frequent and Candida albicans was the most prevalent species found (42.4%). Resistance to fluconazole was found in 2.47% of the strains. No differences were observed in the species distribution of Candida during the study periods. In the P2 cohort, there were higher prevalence of elderly individuals, cardiac, pulmonary and liver diseases, renal failure, central venous catheters and antibiotic therapy. In P1, there were higher prevalence of neurological diseases and chemotherapy. The crude mortality was 55.4%. In conclusion, our incidence rates remained high. Furthermore, the distribution pattern of Candida species and the fluconazole resistance profile remained unchanged. Moreover, we found a clear trend of higher prevalence of candidaemia among the elderly and among patients with comorbidities. Finally, it is necessary to discuss strategies for the prevention and control of Candida BSI in Brazil.

Impact of the introduction of an automated microbiologic system on the clinical outcomes of bloodstream infections caused by Enterobacteriaceae strains.

INTRODUCTION: Enterobacteriaceae strains are a leading cause of bloodstream infections (BSI). The aim of this study is to assess differences in clinical outcomes of patients with BSI caused by Enterobacteriaceae strains before and after introduction of an automated microbiologic system by the microbiology laboratory. METHODS: We conducted a retrospective cohort study aimed to evaluate the impact of the introduction of an automated microbiologic system (Phoenix(tm) automated microbiology system, Becton, Dickinson and Company (BD) - Diagnostic Systems, Sparks, MD, USA) on the outcomes of BSIs caused by Enterobacteriaceae strains. The study was undertaken at Hospital São Paulo, a 750-bed teaching hospital in São Paulo, Brazil. Patients with BSI caused by Enterobacteriaceae strains before the introduction of the automated system were compared with patients with BSI caused by the same pathogens after the introduction of the automated system with regard to treatment adequacy, clinical cure/improvement and 14- and 28-day mortality rates. RESULTS: We evaluated 90 and 106 patients in the non-automated and automated testing periods, respectively. The most prevalent species in both periods were Klebsiella spp. and Proteus spp. Clinical cure/improvement occurred in 70% and 67.9% in non-automated and automated period, respectively (p = 0.75). 14-day mortality rates were 22.2% and 30% (p = 0.94) and 28-day mortality rates were 24.5% and 40.5% (p = 0.12). There were no significant differences between the two testing periods with regard to treatment adequacy, clinical cure/improvement and 14- and 28-day mortality rates. CONCLUSIONS: Introduction of the BD Phoenix(tm) automated microbiology system did not impact the clinical outcomes of BSIs caused by Enterobacteriaceae strains in our setting.

Pharmacokinetics and pharmacodynamics of antimicrobial drugs in intensive care unit patients.

Inappropriate use of antimicrobial drugs is responsible for therapeutic failures, increased mortality rates, and the emergence of resistance. Antimicrobial activity is determined by intrinsic pharmacokinetics/pharmacodynamics concepts. In critically ill patients, an inappropriate dosing regimen can be caused by the inability of an antimicrobial drug to reach adequate concentrations at the infection site owing to alterations in the drug's pharmacokinetics caused by pathophysiological changes. Understanding these concepts and changes in PK-PD parameters that occur in intensive care unit patients is crucial for the optimization of antimicrobial therapy in these patients.

Prevalence and clinical outcomes of episodes of ventilator-associated pneumonia caused by SPM-1-producing and non-producing imipenem-resistant Pseudomonas aeruginosa.

INTRODUCTION: Pseudomonas aeruginosa is a leading cause of ventilator-associated pneumonia (VAP) and exhibits high rates of resistance to several antimicrobial drugs. The carbapenens are usually the drugs of choice against this microorganism. However, the carbapenem resistance has increased among these strains worldwide. The presence of metallo-ß-lactamases (MBL) has been pointed out as a major mechanism of resistance among these strains. No previous study addressed outcomes of respiratory infections caused by these strains. METHODS: Our group sought to analyze the epidemiology and clinical outcomes of patients with VAP caused by imipenem-resistant P. aeruginosa. A total of 29 clinical isolates of carbapenem-resistant Pseudomonas aeruginosa were screened for metallo-ß-lactamase (MBL) genes. RESULTS: Demographic and clinical variables were similar between the SPM-1-producing and non-SPM-1-producing group. Five (17.2%) isolates were positive for blaSPM-1. No other MBL gene was found. All patients were treated with polymyxin B. The infection-related mortality was 40% and 54.2% for SPM-1-producing and -non-producing isolates, respectively. CONCLUSIONS: There were no differences in epidemiological and clinical outcomes between the two groups.

Prevalence and clinical outcomes of episodes of ventilator-associated pneumonia caused by SPM-1-producing and non-producing imipenem-resistant Pseudomonas aeruginosa / Prevalência e evolução clínica de episódios de pneumonia associada à ventilação mecânica causada por Pseudomonas aeruginosa resistente a imipenem produtoras e não-produtoras de SPM-1

INTRODUCTION: Pseudomonas aeruginosa is a leading cause of ventilator-associated pneumonia (VAP) and exhibits high rates of resistance to several antimicrobial drugs. The carbapenens are usually the drugs of choice against this microorganism. However, the carbapenem resistance has increased among these strains worldwide. The presence of metallo-β-lactamases (MBL) has been pointed out as a major mechanism of resistance among these strains. No previous study addressed outcomes of respiratory infections caused by these strains. METHODS: Our group sought to analyze the epidemiology and clinical outcomes of patients with VAP caused by imipenem-resistant P. aeruginosa. A total of 29 clinical isolates of carbapenem-resistant Pseudomonas aeruginosa were screened for metallo-β-lactamase (MBL) genes. RESULTS: Demographic and clinical variables were similar between the SPM-1-producing and non-SPM-1-producing group. Five (17.2 percent) isolates were positive for blaSPM-1. No other MBL gene was found. All patients were treated with polymyxin B. The infection-related mortality was 40 percent and 54.2 percent for SPM-1-producing and -non-producing isolates, respectively. CONCLUSIONS: There were no differences in epidemiological and clinical outcomes between the two groups.

INTRODUÇÃO: Pseudomonas aeruginosa é uma importante causa de pneumonia associada à ventilação mecânica (PAV) e exibe altas taxas de resistência a vários antimicrobianos. Os carbapenens são usualmente as drogas de escolha para esse microorganismo. Contudo, a resistência a carbapenens tem crescido entre essas amostras em todo o mundo. A presença de metalo- β-lactamase (MBL) tem sido apontado como um importante mecanismo de resistência nessas cepas. Nenhum estudo prévio avaliou desfechos clínicos de infecções respiratórias causadas por essas amostras MÉTODOS: Nosso grupo analisou a epidemiologia e evolução clínica de episódios de PAV causada por P. aeruginosa resistente a imipenem. Um total de vinte e nove isolados clínicos de Pseudomonas aeruginosa resistente a carbapenem foram avaliados quanto à presença de genes para metalo-β-lactamase (MBL). RESULTADOS: Variáveis clínicas e demográficas foram similares entre o grupo produtor de SPM-1 e o não-produtor. Cinco (17,2 por cento) isolados foram positivos para blaSPM-1. Nenhum outro gene para MBL foi encontrado. Todos os pacientes foram tratados com polimixina B. A mortalidade relacionada à infecção foi de 40 por cento e 50 por cento respectivamente para os isolados produtores de SPM-1 e não-produtores de SPM-1. CONCLUSÕES: Nao houve diferença entre os dados epidemiológicos e a evolução clínica entre os dois grupos.

Rapid detection of Vancomycin-Resistant Enterococci (VRE) in rectal samples from patients admitted to intensive care units

The reduction in time required to identify vancomycin-resistant enterococci (VRE) has gained increased importance during hospital outbreaks. In the present study, we implemented a laboratory protocol to speed up the VRE screening from rectal samples. The protocol combines a medium for selective VRE isolation (VREBAC®, Probac, São Paulo) and a multiplex PCR for detection and identification of vanA and vanB resistance genes. The screening performance was analyzed in 114 specimens collected from four intensive care units. The swabs were collected at two periods: (1) during a VRE outbreak (February 2006, n=83 patients) and (2) at the post-outbreak period, after adoption of infection control measures (June 2006, n=31 patients). Forty-one/83 VRE (49.4 percent) and 3/31(9.7 percent) VRE were found at the first and second period, respectively. All isolates harbored the vanA gene. In both periods, detection of the gene vanA parallels to the minimum inhibitory concentration values of >256 µg/mL and >48 µg/mL for vancomycin and teicoplanin, respectively. Multiplex PCR and conventional methods agreed in 90.2 percent for enterococci identification. Besides this accuracy, we also found a remarkable reduction in time to obtain results. Detection of enterococcal species and identification of vancomycin resistance genes were ready in 29.5 hours, in comparison to 72 hours needed by the conventional methods. In conclusion, our protocol identified properly and rapidly enterococci species and vancomycin-resistance genes. The results strongly encourage its adoption by microbiology laboratories for VRE screenning in rectal samples.

Rapid detection of vancomycin-resistant enterococci (VRE) in rectal samples from patients admitted to intensive care units.

The reduction in time required to identify vancomycin-resistant enterococci (VRE) has gained increased importance during hospital outbreaks. In the present study, we implemented a laboratory protocol to speed up the VRE screening from rectal samples. The protocol combines a medium for selective VRE isolation (VREBAC(R), Probac, São Paulo) and a multiplex PCR for detection and identification of vanA and vanB resistance genes. The screening performance was analyzed in 114 specimens collected from four intensive care units. The swabs were collected at two periods: (1) during a VRE outbreak (February 2006, n=83 patients) and (2) at the post-outbreak period, after adoption of infection control measures (June 2006, n=31 patients). Forty-one/83 VRE (49.4%) and 3/31(9.7%) VRE were found at the first and second period, respectively. All isolates harbored the vanA gene. In both periods, detection of the gene vanA parallels to the minimum inhibitory concentration values of >256 microg/mL and >48 microg/mL for vancomycin and teicoplanin, respectively. Multiplex PCR and conventional methods agreed in 90.2% for enterococci identification. Besides this accuracy, we also found a remarkable reduction in time to obtain results. Detection of enterococcal species and identification of vancomycin resistance genes were ready in 29.5 hours, in comparison to 72 hours needed by the conventional methods. In conclusion, our protocol identified properly and rapidly enterococci species and vancomycin-resistance genes. The results strongly encourage its adoption by microbiology laboratories for VRE screening in rectal samples.

Intravenous polymyxin B for the treatment of nosocomial pneumonia caused by multidrug-resistant Pseudomonas aeruginosa.

Nosocomial pneumonia caused by multidrug-resistant (MDR) Pseudomonas aeruginosa is becoming increasingly prevalent throughout the world. The use of polymyxins to treat these infections has greatly increased. We analysed 74 patients with nosocomial pneumonia caused by MDR P. aeruginosa who were treated with polymyxin B. A favourable outcome was observed in 35 patients (47.3%). A case-control study was performed to assess the variables associated with an unfavourable outcome. The presence of acute respiratory distress syndrome (odds ratio (OR)=11.29, 95% confidence interval (CI) 2.64-48.22; P=0.001) and septic shock (OR=4.81, 95% CI 1.42-16.25; P=0.01) were independently associated with an unfavourable outcome in patients with nosocomial pneumonia due to MDR P. aeruginosa. Our study demonstrated that polymyxin B is a reliable antimicrobial drug, but only as salvage therapy, for nosocomial pneumonia caused by MDR P. aeruginosa.