[Epidemiological surveillance cultures in antimicrobial-resistant bacteria causing nosocomial infection].

Implementation of surveillance culture programs and molecular typing are important contributions of Clinical Microbiology to the control of nosocomial infections. This document provides information on collection, transport, preservation, and processing of samples for surveillance culture, as well as the criteria for interpreting and reporting the results of relevant etiologic agents in nosocomial infection. This includes methicillin-resistant Staphylococcus aureus (MRSA), glycopeptide-resistant Enterococcus spp.

Comparison of different culture media and growth conditions for recognition of Arcanobacterium haemolyticum.

Detection of Arcanobacterium haemolyticum is based upon typical beta-hemolysis and colony morphology, but it may go undetected if only conventional sheep blood agar media for detection of beta-hemolytic streptococci are used. The influence of different culture media, atmospheres, and times of incubation for the recognition of colonies of 47 isolates of A. haemolyticum was studied.

Activity of Tigecycline against Coryneform Bacteria of Clinical Interest and Listeria monocytogenes.

The activities of tigecycline and eight other agents were evaluated against 220 coryneform bacteria and 42 Listeria monocytogenes isolates. All strains were inhibited by tigecycline at 0.5 mug/ml, except for 11 Corynebacterium striatum strains that were inhibited at 1 mug/ml.

Impact of antibiotic resistance and of adequate empirical antibiotic treatment in the prognosis of patients with Escherichia coli bacteraemia.

Background: Escherichia coli is the most frequent Gram-negative organism causing bacteraemia. There are few data about prognostic factors of bloodstream infections due to E. coli.

[Recommendations for selecting antimicrobial agents for in vitro susceptibility studies using automatic and semiautomatic systems].

The number of clinical microbiology laboratories that have incorporated automatic susceptibility testing devices has increased in recent years. The majority of these systems determine MIC values using microdilution panels or specific cards, with grouping into clinical categories (susceptible, intermediate or resistant) and incorporate expert systems to infer resistance mechanisms. This document presents the recommendations of a group of experts designated by Grupo de Estudio de los Mecanismos de Acción y Resistencia a los Antimicrobianos (GEMARA, Study group on mechanisms of action and resistance to antimicrobial agents) and Mesa Española de Normalización de la Sensibilidad y Resistencia a los Antimicrobianos (MENSURA, Spanish Group for Normalizing Antimicrobial Susceptibility and Antimicrobial Resistance), with the aim of including antimicrobial agents and selecting concentrations for the susceptibility testing panels of automatic systems.

Isolation of Mycoplasma hominis in critically ill patients with pulmonary infections: clinical and microbiological analysis in an intensive care unit.

Objective: Mycoplasma hominis is a well recognized extragenital pathogen. However, it is an uncommon cause of respiratory infections in critically ill patients admitted to the intensive care unit (ICU).

Design And Setting: Prospective clinical investigation in a 21-bed ICU in a university hospital.

Comparative in vitro activity of ertapenem against extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolated in Spain.

The in vitro activity of ertapenem was tested against extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae isolated in Spain. Ertapenem activity was similar to that of imipenem and meropenem and better than that of the other antimicrobials tested. No differences in activity were observed regarding the origin of the isolates or type of ESBL produced.

In vivo selection of Enterobacter aerogenes with reduced susceptibility to cefepime and carbapenems associated with decreased expression of a 40 kDa outer membrane protein and hyperproduction of AmpC beta-lactamase.

The mechanism(s) of resistance or decreased susceptibility to cefepime (FEP) and/or imipenem (IMP) in three consecutive isolates of Enterobacter aerogenes (Ea1, Ea2 and Ea3) cultured from bronchial aspirates of the same patient after treatment with ceftriaxone and FEP were studied. Identification was performed with the VITEK 2 system. All three isolates showed identical pulsed-field gel electrophoresis patterns and were resistant (minimum inhibitory concentrations (MICs)) to cefoxitin (MIC, >1024 mg/L), cefotaxime (CTX; MIC, 32-128 mg/L) and ceftazidime (CAZ; MIC, 32-128 mg/L) but susceptible to meropenem (MIC, View Article and Find Full Text PDF

[Prevalence of the tetA and tetB genes as mechanisms of resistance to tetracycline and minocycline in Acinetobacter baumannii clinical isolates].

Introduction: Two hundred twenty-one Acinetobacter baumannii clinical strains were collected from 25 hospitals in Spain. The aim of this study was to analyze the prevalence of the tetA and tetB genes in a collection of A. baumannii strains that were not epidemiologically related.

[Epidemiology, clinical features and prognosis of infections due to Stenotrophomonas maltophilia].

Introduction: Stenotrophomonas maltophilia is a multiresistant pathogen that is being isolated with increasing frequency from patients with predisposing factors. Few studies have assessed the epidemiology and clinical relevance of this pathogen in various types of patients from general hospitals.

Methods: This is a prospective study performed in the cohort of patients with infection due to S.

Efficacy of cefepime and imipenem in experimental murine pneumonia caused by porin-deficient Klebsiella pneumoniae producing CMY-2 beta-Lactamase.

Previous studies have shown decreased in vitro activity of zwitterionic cephalosporins and carbapenems against porin-deficient Klebsiella pneumoniae expressing a plasmid-mediated AmpC-type beta-lactamase (PACBL). The in vitro and in vivo activities of cefepime and imipenem were evaluated against the porin-deficient strain K. pneumoniae C2 and its CMY-2-producing derivative [K.

Relationship between mutations in the gyrA gene and quinolone resistance in clinical isolates of Corynebacterium striatum and Corynebacterium amycolatum.

Quinolone susceptibility was analyzed in 17 clinical isolates of Corynebacterium striatum and 9 strains of Corynebacterium amycolatum by the E-test method in Mueller-Hinton agar plates. The C. striatum ATCC 6940 strain was used as a control strain.

Emergence of plasmid-mediated quinolone resistance in Escherichia coli in Europe.

Although quinolone resistance results mostly from chromosomal mutations, it may also be mediated by a plasmid-encoded qnr gene in members of the family Enterobacteriaceae. Thus, 297 nalidixic-acid resistant strains of 2,700 Escherichia coli strains that had been isolated at the Bicetre Hospital (Le Kremlin-Bicetre, France) in 2003 were screened for qnr by PCR. A single E.

Clinical features and epidemiology of Acinetobacter baumannii colonization and infection in Spanish hospitals.

Objective: To investigate the clinical features and the epidemiology of Acinetobacter baumannii in Spanish hospitals.

Design: Prospective multicenter cohort study.

Setting: Twenty-seven general hospitals and one paraplegic center in Spain.

Use of positive blood cultures for direct identification and susceptibility testing with the vitek 2 system.

In order to further decrease the time lapse between initial inoculation of blood culture media and the reporting of results of identification and antimicrobial susceptibility tests for microorganisms causing bacteremia, we performed a prospective study in which specially processed fluid from positive blood culture bottles from Bactec 9240 (Becton Dickinson, Cockeysville, Md.) containing aerobic media were directly inoculated into Vitek 2 system cards (bio-Mérieux, France). Organism identification and susceptibility results were compared with those obtained from cards inoculated with a standardized bacterial suspension obtained following subculture to agar; 100 consecutive positive monomicrobic blood cultures, consisting of 50 gram-negative rods and 50 gram-positive cocci, were included in the study.

[Clonal diversity and antimicrobial susceptibility of Acinetobacter baumannii isolated in Spain. A nationwide multicenter study: GEIH-Ab project (2000)].

Introduction: A nationwide multicenter study was performed in Spain to evaluate the clonal diversity and antimicrobial susceptibility of Acinetobacter baumannii clinical isolates.

Methods: A total of 221 consecutive A. baumannii isolates recovered from clinical samples from 25 Spanish hospitals during November 2000 were studied.

[Resistance to quinolones and beta-lactams in Salmonella enterica due to mutations in topoisomerase-encoding genes, altered cell permeability and expression of an active efflux system].

Background: The mechanisms of resistance to fluoroquinolones and beta-lactams were studied in isolates of Salmonella enterica resistant to both antimicrobial groups, isolated over time from two patients treated with fluoroquinolones.

Methods: The clonal relationships among the various strains was established by serotyping and pulsed-field gel electrophoresis. MICs for beta-lactams, quinolones, chloramphenicol and tetracycline were determined.

Epidemiology and clinical features of infections caused by extended-spectrum beta-lactamase-producing Escherichia coli in nonhospitalized patients.

Infections due to extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBLEC) in nonhospitalized patients seem to be emerging in different countries. Their incidence, epidemiology, and clinical impact in the community have not been studied. We describe the epidemiology and clinical features of infections caused by ESBLEC in nonhospitalized patients in Spain and the results of a case-control study performed to investigate the risk factors associated with the acquisition of these organisms.