Comparison of a rapid cytomegalovirus pp65 antigenemia assay revealed by immunofluorescence to an in-house assay revealed by immunoperoxidase for diagnosis in solid organ transplant recipient patients

Cytomegalovirus (CMV) antigenemia is still one of the two major assays available for diagnosis and monitoring of CMV infections. A commercial rapid test recently available in Brazil for quantification of human cytomegalovirus pp65 antigenemia revealed by immunofluorescence technique was compared with the original in-house method revealed by immunoperoxidase in patients receiving solid organ transplants. Of 80 blood samples tested for CMV antigenemia, 34 (42.5%) were positive: commercial assay detected 33 (97%) and in-house assay detected 20 (58.8%) samples. The numbers of positive cells in the two assays were different, with a median of 4.5 and 12 positive cells obtained by in-house and commercial kit, respectively. Discrepancies between assays occurred in 15 specimens from patients with low-grade antigenemia (median 6 positive cells). The assay-time was reduced in approximately 50% compared to in-house methodology. In conclusion, besides comparable results obtained for both assays, the commercial antigenemia assay provides more rapid and sensitive results.Hospital Albert Einstein Clinical Laboratory Microbiology SectionUNIFESP Infectious Diseases Department Clinical Virology LaboratoryUNIFESP, Infectious Diseases Department Clinical Virology LaboratorySciEL

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

Background: Healthcare-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.Methods: Risk 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.Results: Sixty 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 bla(CTX-M-2), an extended-spectrum betalactamase gene. in addition, a single isolate also possessed bla(GES-1). Genes encoding plasmid-mediated AmpC beta-lactamases or carbapenemases (KPC, metallo-betalactamases or OXA-carbapenemases) were not detected.Conclusions: the 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.Instituto Israelita de Ensino e Pesquisa Israelita Albert EinsteinHosp Israelita Albert Einstein, Infect Control Unit, BR-05652000 São Paulo, BrazilHosp Israelita Albert Einstein, Microbiol Lab, BR-05651901 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP EPM, Div Infect Dis, BR-04024002 São Paulo, BrazilHosp Israelita Albert Einstein, Intens Care Unit, BR-05651901 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP EPM, Div Infect Dis, BR-04024002 São Paulo, BrazilInstituto Israelita de Ensino e Pesquisa Israelita Albert Einstein: 449.08Web of Scienc

Rotavirus infection in children and adult patients attending in a tertiary Hospital of São Paulo, Brazil

During the period of January 2003 to December 2005, 3,768 stool samples were received in the Microbiology Laboratory for rotavirus antigen detection from outpatients and inpatients of Albert Einstein Hospital, SP. Fresh stool samples from children and adults were analyzed by two methodologies: during 2003 and 2004 by latex agglutination (Slidex Rotavirus, Biomerieux) and 2005 by an immunochromatographic assay for the combined detection of rotavirus and adenovirus (Vikia Rota-Adeno, Biomerieux). Rotavirus group A was detected in 755 (20%) samples. The annual prevalence was 19.8% in 2003, 21.7% in 2004, and 18.7% in 2005. Rotavirus was detected every month during the period of the study, with peak of positivity between June and August (>35%). The prevalence in hospitalized patients was 26.1% (352/1,350) and in outpatients was 16.7% (403/2,418). For hospitalized patients most of the rotavirus infections were diagnosed in Pediatric setting, age range of 0 to 10 years (prevalence of 55.3%, 295/534). Overall positivity was up to 30% in patients between six months and five years of age (67% of all positive patients), all other age groups had at least 10% positive tests. Rotavirus infection is common in Sao Paulo, and besides the expected higher frequency in children it is also frequent in adults

A hospital-based matched case–control study to identify clinical outcome and risk factors associated with carbapenem-resistant <it>Klebsiella pneumoniae</it> infection

Abstract Background Healthcare-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. Methods Risk 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. Results Sixty 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. Conclusions The 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.</p