Jacyr Pasternak

A hospital-based matched case-control study to identify clinical outcome and risk factors associated with carbapenem-resistant Klebsiella pneumoniae infection.

BackgroundHealthcare-associated infections caused by Klebsiella pneumoniae isolates are increasing and few effective antibiotics are currently available to treat patients. We observed decreased carbapenem susceptibility among K. pneumoniae isolated from patients at a tertiary private hospital that showed a phenotype compatible with carbapenemase production although this group of enzymes was not detected in any sample. The aim of this study was to describe the epidemiology and clinical outcomes associated with carbapenem-resistant K. pneumoniae and to determine the antimicrobial resistance mechanisms.MethodsRisk factors associated with carbapenem-resistant K. pneumoniae infections were investigated by a matched case–control study from January 2006 through August 2008. A cohort study was also performed to evaluate the association between carbapenem resistance and in-hospital mortality. Bacterial identification and antimicrobial susceptibility were determined by Vitek 2 and Etest. Carbapenemase activity was detected using spectrophotometric assays. Production of beta-lactamases and alterations in genes encoding K. pneumoniae outer membrane proteins, OmpK35 and OmpK36, were analyzed by PCR and DNA sequencing, as well as SDS-Page. Genetic relatedness of carbapenem resistant isolates was evaluated by Pulsed Field Gel Electrophoresis.ResultsSixty patients were included (20 cases and 40 controls) in the study. Mortality was higher for patients with carbapenem-resistant K. pneumoniae infections compared with those with carbapenem-susceptible K. pneumoniae (50.0% vs 25.7%). The length of central venous catheter use was independently associated with carbapenem resistance in the multivariable analysis. All strains, except one, carried blaCTX-M-2, an extended-spectrum betalactamase gene. In addition, a single isolate also possessed blaGES-1. Genes encoding plasmid-mediated AmpC beta-lactamases or carbapenemases (KPC, metallo-betalactamases or OXA-carbapenemases) were not detected.ConclusionsThe K. pneumoniae multidrug-resistant organisms were associated with significant mortality. The mechanisms associated with decreased K. pneumoniae carbapenem susceptibility were likely due to the presence of cephalosporinases coupled with porin alterations, which resulted from the presence of the insertion sequences in the outer membrane encoding genes.

Ventilator associated pneumonia: comparison between quantitative and qualitative cultures of tracheal aspirates

IntroductionDeferred or inappropriate antibiotic treatment in ventilator-associated pneumonia (VAP) is associated with increased mortality, and clinical and radiological criteria are frequently employed to establish an early diagnosis. Culture results are used to confirm the clinical diagnosis and to adjust or sometimes withdraw antibiotic treatment. Tracheal aspirates have been shown to be useful for these purposes. Nonetheless, little is known about the usefulness of quantitative findings in tracheal secretions for diagnosing VAP.MethodsTo determine the value of quantification of bacterial colonies in tracheal aspirates for diagnosing VAP, we conducted a prospective follow-up study of 106 intensive care unit patients who were under ventilatory support. In total, the findings from 219 sequential weekly evaluations for VAP were examined. Clinical and radiological parameters were recorded and evaluated by three independent experts; a diagnosis of VAP required the agreement of at least two of the three experts. At the same time, cultures of tracheal aspirates were analyzed qualitatively and quantitatively (105 colony-forming units [cfu]/ml and 106 cfu/ml)ResultsQuantitative cultures of tracheal aspirates (105 cfu/ml and 106 cfu/ml) exhibited increased specificity (48% and 78%, respectively) over qualitative cultures (23%), but decreased sensitivity (26% and 65%, respectively) as compared with the qualitative findings (81%). Quantification did not improve the ability to predict a diagnosis of VAP.ConclusionQuantitative cultures of tracheal aspirates in selected critically ill patients have decreased sensitivity when compared with qualitative results, and they should not replace the latter to confirm a clinical diagnosis of VAP or to adjust antimicrobial therapy.

Scabies epidemic: price and prejudice.

Scabies epidemics are not unusual, and the recommended way of stopping them is by simultaneous treatment of everybody in the facility; this has been known since the last century, when Norwegian scabies was a problem in Norway. When this is not done, scabies epidemics can smolder for months. Scabies should not spread with good infection control measures, but we learned that a good infection control service is not enough. Efforts have to be done to educate everybody in the hospital, including laundry workers, and to improve work conditions.

SeptiFast for diagnosis of sepsis in severely ill patients from a Brazilian hospital

ABSTRACT Objective To test and validate a multiplex real-time polymerase chain reaction method for bloodstream infections, as well as to compare the results with conventional blood culture. Methods A total of 114 consecutive patients with clinical evidence of sepsis were submitted to blood culture and LightCycler™ SeptiFast tests. Results More positive specimens (23; 20.2%) were detected using the LightCycler™ SeptiFast than the blood culture (17; 14.9%), with an agreement of 86.8%. Discordant results were seen in four patients positive only to blood culture, ten positive only to LightCycler™ SeptiFast and one to different pathogens found by each test. Infections with microorganisms detected only using blood culture reassured the need to perform both tests. The mean time to results for blood culture was 5 days for negative and 3.5 days for positive results. LightCycler™ SeptiFast results were achieved in less than 8 hours. Conclusion LightCycler™ SeptiFast showed a high potential as a test to be carried out concomitantly with blood culture for sepsis diagnosis in severely ill patients. This test allowed a faster diagnosis of bacterial and fungal infections that helped to reduce hospital stay and to control the use of antibiotics. LightCycler™ SeptiFast can also eventually detect microorganism and infections that are hardly detected by blood culture, especially Candida non-albicans infections.

Mycobacterium haemophilum: Emerging or Underdiagnosed in Brazil?

To the Editor: Mycobacterium haemophilum was first described in 1978 by Sompolinsky et al. (1) as the cause of cutaneous infections in a patient with Hodgkin disease. Since then, fewer than 100 cases have been reported worldwide, mostly among immunocompromised patients (2), although M. haemophilum infection has also been described in immunocompetent patients as the cause of cervical, submandibular, and perihilar lymphadenopathy in children and of pulmonary nodules in an adult (3–5). Cases have been reported from United States, Australia, Canada, France, Israel, and the United Kingdom, but to date no reports have originated in South America.

Reliability of hsp65-RFLP analysis for identification of Mycobacterium species in cultured strains and clinical specimens.

The purpose of this study was to evaluate the reliability of an amplification restriction analysis based method (hsp65-RFLP) to detect and identify mycobacterial species in clinical samples and cultures with low number of bacilli. We examined 247 clinical specimens and 88 culture vials, comparing hsp65-RFLP results with conventional culture/biochemical tests. The analytical sensitivity of the method was assessed with cerebrospinal fluid (CSF), broncho-alveolar lavage (BAL), sputum, water, and 12B medium containing defined amounts of mycobacterial chromosome. We detected the equivalent of 10(3) cells per ml in all samples, except sputum, the most common source of clinical sample for mycobacterial testing, which presented inhibition throughout. We investigated two purification procedures to overcome inhibition of DNA amplification: DNAzol and phenol/chloroform. The former was superior, eliminating inhibition in 93.7% of the clinical samples. The technique was effective for bacterial cultures, including those with very low growth indices (GIs), substantially abbreviating time for diagnosis, but showed low sensitivity (25%) when applied to clinical samples, an issue that has never been extensively assessed by other researchers.

Evaluation of a new rapid test for carbapenemase detection in carbapenem resistant Enterobacteriaceae.

We evaluated a new phenotypic test for carbapenemase detection. A total of 100 Enterobacteriaceae isolates were selected. The test was compared with conventional PCR for bla(KPC) and bla(NDM) detection. We found 100% sensitivity and specificity, suggesting that this test may be a feasible alternative for rapid carbapenemase detection.

Fecal microbiota transplant by push enteroscopy to treat diarrhea caused by Clostridium difficile

ABSTRACT Clostridium difficile is the major etiological agent of pseudomembranous colitis and is found in up to 20% of adult inpatients. The recommended treatment is antibiotic therapy with metronidazole and/or vancomycin. However, the recurrence rate may reach up to 25% and it increases in each episode. The newest alternative to treat diarrhea due to recurrent Clostridium difficile is fecal microbiota transplantation. The procedure was performed in 12 patients, with a 6-month follow-up on 10 of them. Of the ten cases, bacterial recurrence was diagnosed in only one patient, after a course of antibiotic to treat urinary tract infection, without presenting with diarrhea. The particularity of our study, besides being an unprecedented event in South America, is the way to perform the infusion of fecal microbiota by enteroscopy.

Evaluation of Two Methods for Determination of CD64 as a Diagnostic Marker of Infection in Critically Ill Adults

Objectives. Diagnostic markers of infection have had little innovation over the last few decades. CD64, a marker expressed on the surface of neutrophils, may have utility for this purpose. Methods. This study was conducted in an adult intensive care unit (ICU) in São Paulo, Brazil, with 89 patients. We evaluated CD64 in patients with documented or clinically diagnosed infection (infection group) and controls (patients without any evidence of infection) by two different methodologies: method #1, an in house assay, and method #2, the commercial kit Leuko64 (Trillium Diagnostics). Results. CD64 displayed good discriminating power with a 91.2% sensitivity (95% CI 90.7–91.6%) for detecting infection. The commercial kit (Leuko64) demonstrated higher specificity (87.3%) compared with method #1 as well as better accuracy (88.8%). Conclusions. CD64 seems to be a promising marker of infection in the intensive care setting, with Leuko64 showing a slight advantage.

Performance of the dipstick screening test as a predictor of negative urine culture

RESUMO Objetivo Verificar se a triagem de urina por fitas reativas e capaz de predizer a cultura de urina. Metodos Estudo retrospectivo realizado entre janeiro e dezembro de 2014 com 8.587 pacientes, com solicitacao medica de triagem de urina (fita), sedimento urinario e cultura de urina. Foram analisados sensibilidade, especificidade, valor preditivo positivo, valor preditivo negativo e curva ROC. Resultados Foram positivas 17,5% das culturas. O nitrito apresentou sensibilidade de 28% e especificidade de 99%. O valor preditivo positivo foi [...]