Flávia Lúcia Piffano Costa Pellegrino

Occurrence of a Multidrug-Resistant Pseudomonas aeruginosa Clone in Different Hospitals in Rio de Janeiro, Brazil

ABSTRACT Multidrug-resistant Pseudomonas aeruginosa nosocomial infections are increasingly recognized worldwide. The existence of metallo-β-lactamase- and extended-spectrum β-lactamase-producing isolates exhibiting resistance to most β-lactam antimicrobial agents greatly complicates the clinical management of patients infected with such isolates. Since 1998, P. aeruginosa isolates resistant to all commercially available antimicrobial agents have been detected at a university-affiliated public hospital in Rio de Janeiro, Brazil. The present study was designed to characterize the antimicrobial resistance profiles and the genetic diversity of the P. aeruginosa strains isolated at this hospital and four private hospitals in Rio de Janeiro. Between April 1999 and March 2000, 200 consecutive isolates were obtained and analyzed for antimicrobial resistance. The genetic diversity of a selected number of them was evaluated by pulsed-field gel electrophoresis and PCR with the ERIC-2 primer. A predominant genotype, designated genotype A, was identified among isolates from four of the five hospitals evaluated. Eighty-four ceftazidime-resistant isolates were evaluated for metallo-β-lactamase production, which was detected in 20 (91%) of 22 genotype A isolates and 11 (18%) of 62 isolates belonging to other genotypes (P < 0.05). Two metallo-β-lactamase-producing genotype A isolates also produced an extended-spectrum β-lactamase. The occurrence of multidrug-resistant P. aeruginosa strains belonging to a unique genotype in different hospitals in Rio de Janeiro underscores the importance of the contribution of a single clone to the increase in the incidence of multidrug-resistant P. aeruginosa nosocomial infections.

Risk Factors for Acquisition of Multidrug-Resistant Pseudomonas aeruginosa Producing SPM Metallo-β-Lactamase

ABSTRACT To evaluate risk factors for colonization or infection due to multidrug-resistant Pseudomonas aeruginosa (MDRPa) carrying the blaSPM gene (SPM-MRDPa) among hospitalized patients, we undertook a case control study at a 480-bed, tertiary-care university hospital. Two different case definitions were used. In the first definition, a case patient (SPM case patient) was defined as a patient who had at least one isolate of SPM-MDRPa (14 patients). In the second, a case patient (non-SPM case patient) was defined as a patient who had at least one isolate of non-SPM-MDRPa (18 patients). For each case patient, we selected two controls, defined as a patient colonized and/or infected by a non-MDRPa isolate during the same study period and with the closest duration of hospitalization until the isolation of P. aeruginosa as cases. The use of quinolones was the single independent predictor of colonization and/or infection by blaSPM MDRPa (odds ratrio [OR] = 14.70, 95% confidence interval [95% CI] = 1.70 to 127.34, P = 0.01), whereas the use of cefepime was the single predictor of colonization and/or infection by non-blaSPM MDRPa (OR = 8.50, 95% CI = 1.51 to 47.96, P = 0.01). The main risk factor for MDRPa was a history of antibiotics usage. Stratification of risk factor analysis by a precise mechanism of resistance led us to identify a specific antibiotic, a quinolone, as a predictor for SPM-MDRPa.

Severe infection in a lung transplant recipient caused by donor-transmitted carbapenem-resistant Acinetobacter baumannii

We describe a case of proven donor transmission of carbapenem‐resistant Acinetobacter baumannii, which resulted in severe infectious complications after lung transplantation. A single blaOXA‐23 positive strain, belonging to a new multilocus sequence type (ST231), was isolated from donor and recipient, who died 65 days after transplantation. This report highlights the current challenges associated with the potential transmission of multidrug‐resistant infections through organ transplantation.

Clonal composition of Escherichia coli causing community-acquired urinary tract infections in the State of Rio de Janeiro, Brazil.

Recent studies from North America and Europe have demonstrated community-wide clonal spread of uropathogenic Escherichia coli (UPEC). To investigate if a similar pattern of spread occurs in Brazil, we characterized UPEC from women with community-acquired urinary tract infection (UTI) in Rio de Janeiro. E. coli isolates from women with UTI in one public outpatient clinic were evaluated for antibiotic susceptibility, E. coli phylogenetic grouping, enterobacterial repetitive intergenic consensus (ERIC) 2 PCR and pulsed-field gel electrophoresis fingerprinting, and multilocus sequence typing. From March 2005 to November 2006, 344 patients were studied. Of these, 186 (54%) had confirmed UTI, 118 (63.4%) of which were caused by E. coli. More than 50% of these isolates were resistant to ampicillin and trimethoprim/sulfamethoxazole. Of these, 96 (81%) belonged to 19 ERIC2 clonal groups. The largest group included 15 isolates, all belonging to multilocus sequence typing group ST69 and phylogenetic group D; they had pulsed-field gel electrophoresis patterns sharing at least 89% similarity compared with the CgA reference strain ATCC BAA-457. CgA strains have been found to be widespread in the United States in the early 2000s. Clonal group E. coli strains accounted for a large proportion (52%) of all UTIs and 82% of the trimethoprim/sulfamethoxazole-resistant E. coli UTIs. Thus, as in North America and Europe, UPECs that cause UTI in Rio de Janeiro also show clonal distribution, and a substantial proportion of drug-resistant UTI is caused by a small set of genetically related E. coli strains.

Marine Pseudomonas putida: a potential source of antimicrobial substances against antibiotic-resistant bacteria

Bacteria isolated from marine sponges found off the coast of Rio de Janeiro, Brazil, were screened for the production of antimicrobial substances. We report a new Pseudomonas putida strain (designated P. putida Mm3) isolated from the sponge Mycale microsigmatosa that produces a powerful antimicrobial substance active against multidrug-resistant bacteria. P. putida Mm3 was identified on the basis of 16S rRNA gene sequencing and phenotypic tests. Molecular typing for Mm3 was performed by RAPD-PCR and comparison of the results to other Pseudomonas strains. Our results contribute to the search for new antimicrobial agents, an important strategy for developing alternative therapies to treat infections caused by multidrug-resistant bacteria.

Acinetobacter soli as a Cause of Bloodstream Infection in a Neonatal Intensive Care Unit

ABSTRACT Acinetobacter soli is a new bacterial species described from forest soil. Five cases of bloodstream infection caused by A. soli clonal isolates are reported here for the first time. The patients were neonates admitted to an intensive care unit. This is a new neonatal pathogen with the potential to cause outbreaks.

Pseudomonas aeruginosa Epidemic Strain Carrying bla SPM Metallo-Beta-Lactamase Detected in Rio de Janeiro, Brazil

Abstract The present study was designed to characterize β-lactamase genes and evaluate polymerase chain reaction (PCR) typing for multidrug-resistant Pseudomonas aeruginosa pulsed-field gel electrophoresis (PFGE) genotype A isolates from Rio de Janeiro, Brazil, collected between April 1999 and March 2000 and one additional isolate collected in June 2002. As reported previously, all of the genotype A isolates produced non-characterized metallo-β-lactamase. These isolates (22) were screened for the bla SPM gene by PCR and dot-blotting. Isolates were typed by PCR fingerprinting with primers RAPD-1, 272, 208, 1290, ERIC-1 and ERIC-2. The bla SPM gene was detected in 18 (82%) of the 22 isolates. PCR fingerprinting gave results that correlated with PFGE, except with primer 1290. In Rio de Janeiro and other Brazilian states, nearly all SPM -producing P. aeruginosa isolates belong to a single PFGE type accounting for a large proportion of drug-resistant P. aeruginosa hospital infections. RAPD PCR fingerprinting may be a useful technique to screen for an epidemic multidrug-resistant strain in Brazil.

A carbapenem-susceptible Pseudomonas aeruginosa strain carrying the blaSPM gene

We studied a carbapenem-susceptible Pseudomonas aeruginosa strain that does not produce carbapenemase but carries the metallo-beta-lactamase gene bla(SPM) identical in sequence to the gene of other fully carbapenem-resistant isolates. Carbapenem-susceptible isolates may be silent reservoirs of the bla(SPM) gene.

Ralstonia pickettii Bloodstream Infections at a Brazilian Cancer Institution

We describe a series of Ralstonia pickettii bloodstream infections (BSI) that occurred in 19 oncohematologic patients admitted to a hospital for patients with cancer, in the city of Rio de Janeiro, from July 1999 to February 2006. Fifty-four R. pickettii isolates were recovered from blood and catheter-tip specimens (1–5 isolates per patient). Two patients eventually died of causes unrelated to R. pickettii BSI. Eight pulsed-field gel electrophoresis genotypes were resolved (A–H), with two detected in more than 1 patient: genotype B, in 2 patients (1.5%), and E, in 12 patients (63.2%). R. pickettii emerged as a new pathogen at our institution, causing at least one outbreak. Cross-transmission of the pathogen, infusion of a putative contaminated intravenous solution, and persistent colonization of medical devices were the likely sources of R. pickettii BSI.

blaGES carrying Pseudomonas aeruginosa isolates from a public hospital in Rio de Janeiro, Brazil

Previous analysis of Pseudomonas aeruginosa class-1 integrons from Rio de Janeiro, Brazil, revealed the blaGES gene in one isolate. We screened isolates of two widespread PFGE genotypes, A and B, at a public hospital in Rio, for the presence of blaGES. The gene was detected in all seven P. aeruginosa isolates belonging to genotype B. Three of the seven genotype-B isolates were resistant to amikacin, aztreonam, ceftazidime, cefepime, ciprofloxacin, gentamicin, imipenem, meropenem, piperacillin-tazobactam and ticarcillin-clavulanic acid. The other four isolates were resistant to all these agents, except gentamicin, imipenem, meropenem and piperacillin-tazobactam. A synergistic effect between ceftazidime and imipenem or clavulanic acid suggested the production of GES-type ESBL.