Adriana Lúcia Pires Ferreira

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.

Mupirocin for controlling methicillin-resistant Staphylococcus aureus: lessons from a decade of use at a university hospital.

BACKGROUND From 1990 to 1995 at Hospital Universitário Clementino Fraga Filho, patients colonized or infected with methicillin-resistant Staphylococcus aureus (MRSA) were treated with mupirocin to eliminate MRSA carriage. In 1995, 65% of MRSA patients at this hospital had mupirocin-resistant isolates. Starting in 1996, mupirocin use was restricted to patients colonized, but not infected, with MRSA. OBJECTIVES To describe the use of mupirocin for controlling MRSA over a decade and to analyze the molecular epidemiology of mupirocin-resistant MRSA infections at this hospital. SETTING A 490-bed, tertiary-care university hospital. METHODS The incidence densities of patients with MRSA and acquisition of mupirocin by the hospital were calculated for the period 1992-2001. S. aureus isolates from 1999-2000 were analyzed by pulsed-field gel electrophoresis. Mupirocin-resistant MRSA isolates from 1994-1995 and 1999-2000 were analyzed for ileS-2 gene background polymorphisms. RESULTS The incidence density of MRSA patients increased slightly over time, whereas the purchase of mupirocin decreased dramatically. Mupirocin-resistant MRSA infections decreased from 65% in 1994-1995 to 15% in 1999-2000. The MRSA Brazilian clone, detected in 1992, was still highly prevalent. The same ileS-2 encoding plasmid found in 1994-1995 persisted in three identical MRSA isolates from 1999-2000 belonging to the Brazilian clone. CONCLUSIONS After mupirocin use decreased, the ileS-2 encoding plasmid persisted in only a few Brazilian clone isolates. Our data on mupirocin-resistant MRSA incidence and mupirocin use strongly suggested that restricted use was related to decreased rates of mupirocin resistance at our hospital.

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).

Colonization with methicillin‐resistant Staphylococcus aureus after liver transplantation

Methicillin‐resistant Staphylococcus aureus (MRSA) is a frequent cause of infection after orthotopic liver transplantation (OLT). Colonization with MRSA is associated with a higher risk of infection. Previous studies have shown a high prevalence of MRSA colonization among OLT candidates. However, the risk of colonization with MRSA after OLT is still unclear. The objective of this study was to estimate the incidence and the factors associated with colonization with MRSA after OLT. This was a prospective cohort study including patients submitted to OLT between the years 2000 and 2002. Surveillance cultures of nasal swab specimens were performed within the 1st 72 hours of hospital admission and, subsequently, on weeks 2, 6, 13, and 26. Patients whose baseline cultures revealed nasal carriage of MRSA were excluded. A total of 60 patients were included in the study. The median follow‐up was 72 days. A total of 9 patients (15%) became colonized. In multiple logistic regression analyses, the use of a urinary catheter for ≥5 days (P = .006), postoperative bleeding at the surgical site (P = .009), and preoperative use of fluoroquinolones (P = .08) were associated with a higher risk of colonization. Patients without any of these risk factors did not become colonized. In conclusion, nasal carriage of MRSA is frequently acquired after OLT. Periodic postoperative screening for MRSA carriage should be an integral component in programs designed to reduce nosocomial MRSA transmission in these patients. Further studies are needed to set up and validate a predictive model that could allow targeting postoperative screening to high‐risk OLT recipients. (Liver Transpl 2005;11:203–209.)

The influence of carbapenem resistance on mortality in solid organ transplant recipients with Acinetobacter baumannii infection

BackgroundInfection with carbapenem-resistant Acinetobacter baumannii has been associated with high morbidity and mortality in solid organ transplant recipients. The main objective of this study was to assess the influence of carbapenem resistance and other potential risk factors on the outcome of A. baumannii infection after kidney and liver transplantation.MethodsRetrospective study of a case series of A. baumannii infection among liver and renal transplant recipients. The primary outcome was death associated with A. baumannii infection. Multivariate logistic regression was used to assess the influence of carbapenem resistance and other covariates on the outcome.ResultsForty-nine cases of A. baumannii infection affecting 24 kidney and 25 liver transplant recipients were studied. Eighteen cases (37%) were caused by carbapenem-resistant isolates. There were 17 (35%) deaths associated with A. baumannii infection. In unadjusted analysis, liver transplantation (p = 0.003), acquisition in intensive care unit (p = 0.001), extra-urinary site of infection (p < 0.001), mechanical ventilation (p = 0.001), use of central venous catheter (p = 0.008) and presentation with septic shock (p = 0.02) were significantly related to a higher risk of mortality associated with A. baumannii infection. The number of deaths associated with A. baumannii infection was higher among patients infected with carbapenem-resistant isolates, but the difference was not significant (p = 0.28). In multivariate analysis, the risk of A. baumannii-associated mortality was higher in patients with infection acquired in the intensive care unit (odds ratio [OR] = 34.8, p = 0.01) and on mechanical ventilation (OR = 15.2, p = 0.04). Appropriate empiric antimicrobial therapy was associated with significantly lower mortality (OR = 0.04, p = 0.03), but carbapenem resistance had no impact on it (OR = 0.73, p = 0.70).ConclusionThese findings suggest that A. baumannii-associated mortality among liver and kidney transplant recipients is influenced by baseline clinical severity and by the early start of appropriate therapy, but not by carbapenem resistance.

Imported and Intensive Care Unit-Born Acinetobacter baumannii Clonal Complexes: One-Year Prospective Cohort Study in Intensive Care Patients

The main objective of this study was to assess the frequency and possible sources of colonization and infection by Acinetobacter in the intensive care unit (ICU) of a university hospital in Rio de Janeiro, Brazil, and characterize the isolates for relatedness to internationally and locally disseminated lineages. Patients consecutively admitted to the ICU from April 2007 to April 2008 were screened for colonization and infection. Species were identified by rpoB sequencing. The presence of acquired and intrinsic carbapenemase genes was assessed by polymerase chain reaction (PCR). Strains were typed by random amplification of polymorphic DNA (RAPD)-PCR, pulsed-field gel electrophoresis, and multilocus sequence typing (MLST) using the schemes hosted at the University of Oxford (UO) and Institut Pasteur (IP). Of 234 patients, 98 (42%) had at least one specimen positive for the Acinetobacter isolate, and 24 (10%) had infection. A total of 22 (92%) infections were caused by Acinetobacter baumannii and one each (4%) by Acinetobacter nosocomialis and Acinetobacter berezinae. A. baumannii isolates from 60 patients belonged to RAPD types that corresponded to MLST clonal complexes (CCs) 109/1 (UO/IP scheme, known as International Clone I), CC 110/110 (UO/IP), CC 113/79 (UO/IP), and CC 104/15 (UO/IP). Most CCs were carbapenem resistant and carried the bla(OXA-23)-like gene. Strains were introduced by patients transferred from other wards of the same hospital (11 patients, 18%) or acquired from cross-transmission within the ICU (49 patients, 82%). A. nosocomialis lineage sequence type 260 colonized 10% of the whole study population. A. baumannii have become established in this hospital as a part of a global epidemic of successful clones. Once introduced into the hospital, such clones have become entrenched among patients in the ICU.

Oral involvement in autoimmune bullous diseases

The oral mucosa is frequently involved by autoimmune bullous diseases and often this is the first site of manifestation. In this site the lesions are very similar, making the clinical diagnosis difficult; therefore, the definition of the immunohistopathologic characteristics of each one becomes essential for a differential diagnosis. The authors review the clinical-pathological and therapeutic aspect of these oral injuries in order to help in the diagnosis, treatment and prognosis of the oral conditions of those diseases.

Surveillance for vancomycin‐resistant enterococci colonization among patients of a liver transplant program

The emergence and spread of multiple-drug resistant enterococci [vancomycin-resistant enterococci (VRE)] has been a worldwide cause of concern [1]. Different studies showed that liver transplant recipients are at increased risk for colonization and infection with these pathogens [2–6]. Other risk factors for VRE acquisition include hospital factors [location in an intensive care unit (ICU), proximity to a VRE colonized patient, extended length of stay in the hospital], antimicrobial use and host characteristics, such as the presence of a hematologic malignancy [1]. Colonization with these pathogens, predominantly of the gastrointestinal tract, usually precedes infection. Surveillance for enteric VRE colonization among liver transplant recipients and other high-risk patients may allow the early identification of colonized patients and the timely adoption of other interventions designed to prevent person-to-person transmission of VRE [1]. In Brazil, acquisition of VRE has been documented in different centers since the first isolation in this country in 1996 [7–11]. In the city of Rio de Janeiro, outbreaks of VRE occurred in different hospitals since 2000. Nevertheless, there are scarce data on the frequency of VRE colonization of high-risk patients in this area. We describe the results of surveillance for enteric colonization with VRE among patients with cirrhosis who were admitted for liver transplantation at a university hospital in Rio de Janeiro, Brazil. This study was prospectively carried out at Hospital Universitário Clementino Fraga Filho, a teaching hospital affiliated to Universidade Federal do Rio de Janeiro. By the time this study began, VRE had not been isolated in any clinical specimen from infected patients admitted to this hospital and routine surveillance for VRE was not implemented. However, candidates for liver transplantation program were frequently admitted to other hospitals. This fact raised the concern about the possibility of nosocomial acquisition of VRE by these patients in other medical facilities. Cirrhotic patients admitted for liver transplantation between October 2000 and December 2002 were eligible for the study. Patients were included in this study only after signing an informed consent. Rectal swab specimens were collected within the first 72 h after admission for transplantation. In part of this population, follow-up rectal swab or stool specimens were collected at postoperative weeks 2, 6 and 13. Perioperative antimicrobial prophylaxis consisted of ampicillin plus sulbactam for 48 h. Selective bowel decontamination was not used in any case after transplantation. Additional data were collected in each case by non-structured interviews or review of medical charts. Demographic and preoperative data included: age, sex, Child-Pugh-Turcotte and model for end-stage liver disease (MELD) scores at the time of surgery, hospital admissions and the antibiotics used within the previous 6 months, the occurrence of spontaneous bacterial peritonitis, the diagnosis of liver disease, the presence of diabetes mellitus or renal failure (defined by serum creatinine persistently above 2.5 mg percent at the time of surgery), time spent in the waiting list and invasive procedures that had been carried out before transplantation. The postoperative data variables that were assessed included the antibiotics that were used for at least 72 h, the need for hemodialysis or for a new laparotomy, the length of stay in the ICU and the total length of hospital stay. Swab and stool specimens were inoculated onto Enterococcosel agar (Becton Dickinson, Cockeysville, MD, USA) containing vancomycin (8 lg/ml). Plates were incubated at 37 C for up to 3 days. Each morphologically different colony resembling Enterococcus was further characterized by means of standard biochemical tests (bile-esculin test, salt tolerance test in 6.5% NaCl brain-heart infusion (BHI), hydrolysis of arginine), observation of motility in semisolid motility medium and pigment production on Mueller Hinton agar [12]. Vancomycin susceptibility was tested by the disc diffusion method according to National Committee for Clinical and Laboratory Standards (NCCLS) guidelines. This study was approved by the Institutional Research Board. Eighty-two subjects were included in the study. Forty (49%) of them were men. The median age was 51 years (interquartile range: 42–59). The most common diagnoses of liver disease were: chronic hepatitis C (n 1⁄4 33, 40%), hepatocellular carcinoma (n 1⁄4 13, 16%), primary sclerosing cholangitis (n 1⁄4 9, 11%), auto-immune hepatitis

Mechanisms of carbapenem resistance in endemic Pseudomonas aeruginosa isolates after an SPM-1 metallo-β-lactamase producing strain subsided in an intensive care unit of a teaching hospital in Brazil.

Carbapenem-resistance mechanisms are a challenge in the treatment of Pseudomonas aeruginosa infections. We investigated changes in P. aeruginosa carbapenem-resistance determinants over a time period of eight years after the emergence of São Paulo metallo-β-lactamase in a university hospital in Rio de Janeiro, Brazil. Patients admitted to the intensive care unit (ICU) were screened for P. aeruginosa colonisation and followed for the occurrence of infections from April 2007 to April 2008. The ICU environment was also sampled. Isolates were typed using random amplified polymorphic DNA, pulsed-field gel electrophoresis and multilocus sequence typing. Antimicrobial susceptibility was determined by disk diffusion and E-test, production of carbapenemases by a modified-CarbaNP test and presence of carbapenemase-encoding genes by polymerase chain reaction. Non-carbapenemase resistance mechanisms studied included efflux and AmpC overexpression by PAβN and cloxacillin susceptibility enhancement, respectively, as well as oprD mutations. From 472 P. aeruginosa clinical isolates (93 patients) and 17 isolates from the ICU environment, high genotypic diversity and several international clones were observed; one environment isolate belonged to the blaSPM-1 P. aeruginosa epidemic genotype. Among isolates from infections, 10 (29%) were carbapenem resistant: none produced carbapenemases, three exhibited all non-carbapenemase mechanisms studied, six presented a combination of two mechanisms, and one exclusively displayed oprD mutations. Carbapenem-resistant P. aeruginosa displayed a polyclonal profile after the SPM-1 epidemic genotype declined. This phenomenon is connected with blaSPM-1 P. aeruginosa replaced by other carbapenem-resistant pathogens.

A promising antibiotic, synergistic and antibiofilm effects of Vernonia condensata Baker (Asteraceae) on Staphylococcus aureus

Vernonia condensata Baker is traditionally used to treat several inflammatory and infectious processes. So, this study evaluated the antibiotic, synergistic and antibiofilm effects, and the mode of action of ethyl acetate fraction from V. condensata leaves (Vc-EAF) against Staphylococcus aureus. Five S. aureus ATCC® and five methicillin-resistant S. aureus (MRSA) routine strains were used to determine Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration. The combinatory effect was evaluated by checkerboard and time kill methods; the mode of action through the bacterial cell viability and leakage of compounds absorbing at 280 nm; and the antibiofilm action by quantifying the percentage of adhesion inhibition. Vc-EAF was active against S. aureus (ATCC® 6538™), (ATCC® 25923™), (ATCC® 29213™), (ATCC® 33591™), (ATCC® 33592™), MRSA 1485279, 1605677, 1664534, 1688441 and 1830466, with MIC of 625 μg/mL for ATCC®, and 1250, 1250, >2500, 2500 and 2500 μg/mL for MRSA, in this order, with bacteriostatic effect for both ATCC® and MRSA strains. Vc-EAF plus ampicillin revealed a total synergic effect on MRSA 1485279, and Vc-EAF combined with chloramphenicol, a partial synergic action against S. aureus (ATCC® 29213™) and (ATCC® 25923™). The time kill data agreed with checkerboard results, and the treated cells number was reduced with release of bacterial content. An expressive bacterial adhesion inhibition for S. aureus (ATCC® 25923™) and MRSA 1485279 was detected. These results showed that V. condensata is a promising natural source of active substances against S. aureus, including multiresistant strains, interfering with their antibacterial growth and hampering their adhesion to surfaces.