Simone A. Nouér

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.

Polyclonal presence of non-multiresistant methicillin-resistant Staphylococcus aureus isolates carrying SCCmec IV in health care-associated infections in a hospital in Rio de Janeiro, Brazil

Change in epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) was observed because of the emergence of infections by non-multiresistant MRSA (nMRSA) in our hospital in Rio de Janeiro, Brazil. Clinical characterization and molecular analysis of 20 nMRSA isolates recovered from 17 patients, between February 2005 and March 2006, were performed. The analysis included SCCmec (staphylococcal cassette chromosome mec), pulsed field gel electrophoresis (PFGE), multilocus restriction fragment, and multilocus sequence typing. MICs for oxacillin and vancomycin and presence of Panton-Valentine leukocidin (PVL) genes were also investigated. All but 1 of the 20 isolates presented SCCmec type IV. PFGE clustered all isolates into 9 genotypes. MIC < or = 16 microg/mL to oxacillin was found for 65% of the isolates, whereas 80% exhibited MIC of 2 microg/mL for vancomycin. PVL-encoding genes were observed in 3 isolates. Polyclonal presence of nMRSA SCCmec IV was observed in our institution, including community and health care-associated isolates, which belonged to the sequence types (STs) 1 (clonal complex [CC1]), ST5 (CC5), ST8 and ST72 (CC8), ST97 (CC97), and 2 ST singletons (SLV5 and SLV30).

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.

Ciprofloxacin prophylaxis in high risk neutropenic patients: effects on outcomes, antimicrobial therapy and resistance

BackgroundThe use of quinolone prophylaxis in high-risk neutropenic patients is considered standard of care but the development of resistance is a concern. Previous studies have focused mainly on quinolone resistance among patients receiving prophylaxis, with very few data reporting its impact on the hospital microbial epidemiology.MethodsWe analyzed a cohort of 329 episodes of chemotherapy-induced neutropenia in adults, and compared two periods: 2005 (period 1, no prophylaxis, n=110) and 2006-2008 (period 2, ciprofloxacin prophylaxis, n=219). Outcomes analyzed were the frequency of febrile neutropenia, bacteremia, duration of antibiotic therapy and hospitalization, and antimicrobial resistance to ciprofloxacin and extended-spectrum beta-lactamase [ESBL] production. We analyzed resistance rates (by patients-day) in the cohort, as well as in other patients (neutropenic and non-neutropenic, 11,975 patients-day) admitted to the hematology unit in the same period, taking into consideration the general resistance patterns in the hospital.ResultsQuinolone prophylaxis (period 2) resulted in fewer episodes of febrile neutropenia (159/219 [73%] vs. 102/110 [93%], Chi-square 18.09, p = 0.00002), and bacteremia (49/219 [22] vs. 36/110 [33%], Chi-square 4.10, p = 0.04), shorter duration of antibiotic therapy (p = 0.0002) and hospitalization (p = 0.002), but more frequent use of carbapenems (79/219 [36%] vs. 15/110 [14%], Chi-square 18.06, p = 0.0002). In addition, period 2 was associated with higher rates of quinolone resistance (6.77 vs. 3.02 per 1,000 patients-day, p = 0.03). The rate of ESBL-producing enterobacteria in the two periods was slightly higher in patients receiving quinolone prophylaxis (1.27 vs. 0.38 per 1,000 patients-day, p = 0.26) as well as in the hematology unit overall (1.59 vs. 0.53 per 1,000 patients-day, p = 0.08), but remained stable in the whole hospital (0.53 vs. 0.56 per 1,000 patients-day, p = 0.74).ConclusionsCiprofloxacin prophylaxis was beneficial in high risk neutropenic patients, but important modifications in the prescription of carbapenems and on antimicrobial resistance patterns of isolates were observed. The importance of hospital or ward ecology must be taken into account when deciding for quinolone prophylaxis in high-risk neutropenic patients.

Early diagnosis of invasive pulmonary aspergillosis in hematologic patients: an opportunity to improve the outcome

Invasive pulmonary aspergillosis (IPA) is the leading invasive fungal disease in high-risk hematologic patients, including those with acute myeloid leukemia (AML) receiving chemotherapy for induction of remission, and allogeneic hematopoietic cell transplant (HCT) recipients.[1][1],[2][2] Studies

A cluster of Listeria monocytogenes infections in hospitalized adults

BACKGROUND Listeriosis occurs mainly in persons at extremes of age and with immunocompromising conditions. It is believed that most cases of listeriosis are acquired in the community. A cluster of listeriosis in hospitalized patients prompted the present investigation. METHODS We conducted a case series study of listeriosis from August 21, 2006, to June 1, 2007, in a hospital in the city of Rio de Janeiro, Brazil. RESULTS Six patients with Listeria monocytogenes infection were identified: 5 during hospitalization and 1 at a day clinic. By the time the infection was diagnosed, 5 patients had been in the hospital for a mean of 9 days. All patients were elderly (median age, 80 years) and had immunocompromising conditions. Five (83%) patients died. Four patients developed bloodstream infections, 3 caused by serotype 1/2b. Two patients had peritonitis: one caused by serotype 3b and another by serotype 1/2b. Four L monocytogenes isolates belonged to a single pulse-field gel electrophoresis genotype, suggesting a common source. An epidemiologic investigation pointed to the hospital kitchen as the possible contamination. CONCLUSION Data suggest a health care-associated outbreak of listeriosis and highlight the importance of developing guidelines for prevention and treatment of health care-associated foodborne diseases, especially in hospitals with immunocompromised adult patients.

Discontinuation of empirical antifungal therapy in ICU patients using 1,3-β-d-glucan

BACKGROUND Empirical antifungal therapy in high-risk ICU patients is an attractive strategy, but overuse of antifungal agents is a potential problem. OBJECTIVES We evaluated if ICU patients at high risk to develop candidaemia identified by a prediction rule could discontinue empirical antifungal therapy on the basis of repeatedly negative 1-3-β-d-glucan (BDG) tests. METHODS We conducted a multicentre cohort study in 85 ICU patients receiving antibiotics or with central venous catheter plus two additional factors (dialysis, parenteral nutrition, surgery, pancreatitis or receipt of corticosteroids or other immunosuppressive agents) plus either fever, hypothermia, hypotension, acidosis, elevated C-reactive protein or leucocytosis. Blood cultures (days 1 and 2) and BDG (days 1-3, baseline period) were performed and anidulafungin was given. On day 4, patients with negative blood cultures and BDG discontinued antifungal therapy. Registered in ClinicalTrials.gov (NCT01734525). RESULTS The incidence of candidaemia was 8.2% in patients selected versus 0.5% in patients without entry criteria (16.9 times higher). Sixty-four patients (75.3%) had baseline positive BDG, including 7 with candidaemia. All 21 patients with baseline negative BDG discontinued anidulafungin on day 4. None developed candidaemia until day 30. CONCLUSIONS Early discontinuation of empirical echinocandin therapy in high-risk ICU patients based on consecutive negative BDG tests may be a reasonable strategy, with great potential to reduce the overuse of echinocandins in ICU patients. Prospective studies with a higher number of patients are needed.

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.

Methicillin-resistant Staphylococcus lugdunensis carrying SCCmec type V misidentified as MRSA

Staphylococcus lugdunensis is a rare cause of severe infections and clinical manifestations are similar to those related to S. aureus infection. We describe a hospital-acquired bacteremia due to methicillin-resistant Staphylococcus lugdunensis, misidentified as methicillin-resistant S. aureus. The oxacillin MIC was 16 µg/mL and the mecA gene and SCCmec type V were determined by PCR. Although treatment had been appropriated, the patient died after rapid progressive respiratory failure and another nosocomial sepsis. It is important not only to identify S. lugdunensis in view of its clinical course, but also to determine its susceptibility to oxacillin by detecting the mecA gene or its product.