Clonal spread of carbapenem-resistant Acinetobacter baumannii in a neonatal intensive care unit.

Acinetobacter baumannii has often been associated with colonization and/or infection in neonatal intensive care units (NICU). This study describes a clonal spread of carbapenem-resistant A. baumannii (CRAB) isolates in an NICU. In total, 21 CRAB isolates were collected from premature newborns. Only polymyxin B was active against such isolates. Nineteen CRAB isolates were clonally related (Cluster C, which belonged to worldwide-disseminated ST1). All newborns had peripheral access and had received ß-lactam therapy previously. The implementation of strict infection control measures was of fundamental importance to eradicate the clonal type in the study hospital.

Rates of serum level determinations of antiepileptic drugs in accord with guidelines: A clinical study at a tertiary center.

OBJECTIVE: To compare our rates of appropriate therapeutic drug monitoring (TDM) with those defined in the French guidelines for measuring drug levels of antiepileptic drugs (AEDs) during the pre- and post-medical/pharmaceutical interventional periods. METHODS: This study was prospectively carried out at a tertiary center (epilepsy unit of the Pitié-Salpêtrière Hospital in Paris) between 2013 and 2016 over three time periods. Criteria for appropriateness were those stated in the current French guidelines. The main outcome measure was the percentage of drug level measurements with an appropriate indication, while a second outcome measure was the impact of education on clinical practice. RESULTS: Of the 698 AED level measurements requested, 84% overall were found to have appropriate indications ranging from 75% to 90%, according to French guideline criteria. Rates of appropriate indications for the three most commonly used individual AEDs-valproate, carbamazepine and lamotrigine-were 79.6%, 77.3% and 90.7%, respectively, whereas the requests considered to not have an appropriate indication involved the majority (63.5%) of cases of routine drug monitoring. In addition, dedicated education seems to substantially increase rates of appropriateness. CONCLUSION: At our center, 84% of AED level determinations had an appropriate indication according to a priori defined and reliable criteria. Moreover, it was noted that a specific educational intervention substantially increased rates of appropriateness. Thus, it appears to be crucial to ensure that medical and paramedical staff are aware of the official recommendations to avoid taking unnecessary drug level measurements.

Survival of vancomycin-intermediate Staphylococcus aureus on hospital surfaces.

BACKGROUND: Contaminated surfaces play an important role in the transmission of certain pathogens that are responsible for healthcare-associated infections. Although previous studies have shown that meticillin-resistant Staphylococcus aureus (MRSA) can survive on dry surfaces at room temperature, no published data regarding vancomycin-intermediate S. aureus (VISA) are available to date. AIM: To compare the survival time on different types of surfaces, cell-surface hydrophobicity, adherence to abiotic surfaces and biofilm formation of meticillin-susceptible S. aureus (MSSA), MRSA and VISA. METHODS: Survival of the S. aureus strains was tested on latex, cotton fabric, vinyl flooring and formica. Cell-surface hydrophobicity was determined using the hydrocarbon interaction affinity method. Adhesion to abiotic surfaces was tested on granite, latex (gloves), glass, vinyl flooring and formica. Biofilm formation was evaluated at 6, 12, 24 and 48 h. FINDINGS: All of the samples survived on the vinyl flooring and formica for at least 40 days. VISA survived on both surfaces for more than 45 days. All of the strains were highly hydrophobic. VISA adhered to latex, vinyl flooring and formica. Biofilm formation increased for all of the tested strains within 6-24 h. CONCLUSION: VISA present high survival, adherence and cell-surface hydrophobicity. Therefore, as the treatment of patients with VISA is a significant challenge for clinicians, greater care with cleaning and disinfection of different types of surfaces in healthcare facilities is recommended because these may become important reservoirs of multi-resistant pathogens.

Unusual association of NDM-1 with KPC-2 and armA among Brazilian Enterobacteriaceae isolates.

We report the microbiological characterization of four New Delhi metallo-ß-lactamase-1 (blaNDM-1)-producing Enterobacteriaceae isolated in Rio de Janeiro, Brazil. blaNDM-1 was located on a conjugative plasmid and was associated with Klebsiella pneumoniae carbapenemase-2 (blaKPC-2) or aminoglycoside-resistance methylase (armA), a 16S rRNA methylase not previously reported in Brazil, in two distinct strains of Enterobacter cloacae. Our results suggested that the introduction of blaNDM-1 in Brazil has been accompanied by rapid spread, since our isolates showed no genetic relationship.

Nosocomial infections with metallo-beta-lactamase-producing Pseudomonas aeruginosa: molecular epidemiology, risk factors, clinical features and outcomes.

BACKGROUND: Metallo-ß-lactamases (MBLs) have emerged as one of the most important bacterial resistance mechanisms because of their ability to hydrolyse virtually all ß-lactam agents. MBL-producing Pseudomonas aeruginosa (MBL-PA) are an important cause of nosocomial infections, particularly in intensive care units (ICUs), where they are associated with serious infections and present a significant clinical risk. AIM: To assess the molecular epidemiology, risk factors and outcomes of nosocomial infections caused by MBL-PA in a teaching hospital in Southern Brazil. METHODS: From January 2001 to December 2008, 142 carbapenem-resistant P. aeruginosa strains were isolated from distinct clinical samples from hospitalized patients. These isolates were screened for MBLs, and underwent polymerase chain reaction, sequencing and pulsed-field gel electrophoresis (PFGE). Patients infected with carbapenem-resistant MBL-PA were considered as cases, and patients infected with non-MBL-PA were considered as controls. FINDINGS: Eighty-four of 142 patients with positive carbapenem-resistant P. aeruginosa cultures met the criteria of the Centers for Disease Control and Prevention for infection. Fifty-eight patients were infected with MBL-PA (69%) and 26 patients were infected with non-MBL-PA (31%). Multi-variate analysis revealed that ICU stay [P = 0.003, odds ratio (OR) 4.01, 95% confidence interval (CI) 1.15-14.01] and urinary tract infection (P = 0.001, OR 9.67, 95% CI 1.72-54.48) were important risk factors for MBL-PA infection. Patients infected with MBL-PA showed faster onset of infection (P = 0.002) and faster progression to death (P = 0.04). CONCLUSIONS: These results showed the severity of MBL-PA infections, and demonstrated the urgent need for strategies to improve infection control measures to prevent an increase in these nosocomial infections.

Dual roles of hemidesmosomal proteins in the pancreatic epithelium: the phosphoinositide 3-kinase decides.

Given the failure of chemo- and biotherapies to fight advanced pancreatic cancer, one major challenge is to identify critical events that initiate invasion. One priming step in epithelia carcinogenesis is the disruption of epithelial cell anchorage to the basement membrane which can be provided by hemidesmosomes (HDs). However, the existence of HDs in pancreatic ductal epithelium and their role in carcinogenesis remain unexplored. HDs have been explored in normal and cancer pancreatic cells, and patient samples. Unique cancer cell models where HD assembly can be pharmacologically manipulated by somatostatin/sst2 signaling have been then used to investigate the role and molecular mechanisms of dynamic HD during pancreatic carcinogenesis. We surprisingly report the presence of mature type-1 HDs comprising the integrin α6ß4 and bullous pemphigoid antigen BP180 in the human pancreatic ductal epithelium. Importantly, HDs are shown to disassemble during pancreatic carcinogenesis. HD breakdown requires phosphoinositide 3-kinase (PI3K)-dependent induction of the matrix-metalloprotease MMP-9, which cleaves BP180. Consequently, integrin α6ß4 delocalizes to the cell-leading edges where it paradoxically promotes cell migration and invasion through S100A4 activation. As S100A4 in turn stimulates MMP-9 expression, a vicious cycle maintains BP180 cleavage. Inactivation of this PI3K-MMP-9-S100A4 signaling loop conversely blocks BP180 cleavage, induces HD reassembly and inhibits cell invasion. We conclude that mature type-1 HDs are critical anchoring structures for the pancreatic ductal epithelium whose disruption, upon PI3K activation during carcinogenesis, provokes pancreatic cancer cell migration and invasion.

Risk factors for hospital-acquired pneumonia caused by imipenem-resistant Pseudomonas aeruginosa in an intensive care unit.

Imipenem-resistant Pseudomonas aeruginosa is a leading cause of hospital-acquired pneumonia. Aiming to determine the risk factors associated for hospital-acquired pneumonia due to imipenem-resistant Pseudomonas aeruginosa, we undertook a retrospective case-case-control study. Patients admitted to a 14-bed medical-surgical intensive care unit from a university-affiliated hospital with hospital-acquired pneumonia caused by imipenem-resistant Pseudomonas aeruginosa strains and by imipenem-susceptible Pseudomonas aeruginosa strains were matched to control patients by time under risk and comorbidities. A total of 58 resistant cases, 47 susceptible cases and 237 controls were evaluated. The risk factors independently associated to hospital-acquired pneumonia caused by imipenem-resistant Pseudomonas aeruginosa were: duration of hospitalisation, Acute Physiological and Chronic Health Evaluation II score, male gender receipt of haemodialysis, receipt of piperacillin-tazobactam and receipt of third-generation cephalosporins.

Low interleukin-10 production by monocytes of patients with a self-limiting hepatitis C virus infection.

Host factors seem to be crucial for the spontaneous clearance of hepatitis C virus (HCV). Monocytes play a pivotal role in innate immunity and help regulate adaptive responses. This study assesses the characteristics of monocytes from patients with self-limiting HCV infections. We studied 35 consecutive patients [11 with a self-limiting HCV infection, 16 chronically infected with HCV and sustained virological responders (SVR) following antiviral therapy, and eight chronically infected HCV but untreated] and eight healthy donors (HD). The production of interleukin (IL)-10, tumour necrosis factor-alpha (TNF-alpha) and IL-12p40 by monocytes stimulated with lipopolysaccharides(LPS) or HCV Core protein was measured by enzyme-linked immunoassay. Monocyte surface markers were analysed by flow cytometry. LPS and Core protein triggered IL-10 and TNF-alpha production, but monocytes from self-limiting infection patients produced significantly less IL-10 and TNF-alpha than those of SVR, chronically infected or HD (P < 0.05), while IL-12p40 production was unchanged. This cytokine production profile did not appear to be due to expansion of the CD14(+) CD16(+) monocyte subset or to a classical or alternative activation monocyte profile. Monocytes from self-limiting infection patients had more CCR7 than those from SVR or chronically infected patients (P < 0.05). Monocytes of self-limiting infection patients appear to produce little IL-10 and TNF-alpha in response to viral or unspecific stimulation and to have a higher CCR7 expression. This profile seems to be independent to a particular monocyte subset or activation state. Low IL-10 production may help establish an effective immune response and spontaneous HCV clearance.

Prevalence and genetic characterization of blaCTX-M among Klebsiella pneumoniae isolates collected in an intensive care unit in Brazil.

Thirteen (44.8%) CTX-M-2-producing K. pneumoniae clinical isolates were identified among 29 strains collected from single patients with serious infection hospitalized in an intensive care unit of a tertiary hospital located in São Paulo, Brazil. These isolates belonged to 9 different typing clusters and showed great diversity of plasmid content. Their bla(CTX-M-2)was carried in an ISCR1/sul1-type integron structure located in transferable plasmids of different sizes or in the chromosome.

In vitro evaluation of the antimicrobial activity of meropenem in combination with polymyxin B and gatifloxacin against Pseudomonas aeruginosa and Acinetobacter baumannii.

The antimicrobial activity of meropenem combined with either polymyxin B or gatifloxacin was evaluated by the checkerboard method against Pseudomonas aeruginosa (10 strains) and Acinetobacter baumannii (10 strains). In addition, the triple combination of polymyxin B, gatifloxacin, and meropenem was also studied as well as the polymyxin B and gatifloxacin combination. A partial synergism interaction between meropenem and polymyxin B was observed for 80% of the A. baumannii strains. In contrast, this combination showed an indifferent effect for 80% of the P. aeruginosa strains tested. The combination of meropenem and gatifloxacin showed synergism only for two strains of A. baumannii, and partial synergism and additive effect for seven strains and indifference for four strains of both species. For the strains of P. aeruginosa, the double combination of polymyxin B and gatifloxacin and the triple combination of meropenem, polymyxin B and gatifloxacin were indifferent for the majority of the strains tested, that is, 90 and 80% respectively.

An outbreak of catalase-negative methicillin-resistant Staphylococcus aureus.

The wide dissemination of a major epidemic methicillin-resistant Staphylococcus aureus (MRSA) clone in Brazilian hospitals (Brazilian clone) limits the value of molecular typing techniques such as pulsed-field gel electrophoresis (PFGE) for outbreak investigation. We report the first outbreak of a catalase-negative strain of MRSA, which was initially detected by the unusual result of this phenotypical test. The outbreak occurred in the Hospital Sanatorinhos de Carapicuíba, a 237-bed secondary hospital located in São Paulo, Brazil. From May to August 2002, a total of 11 MRSA isolates were recovered from four patients in the intensive care unit. All the isolates were catalase negative and susceptible only to vancomycin and linezolid. Three of the four patients eventually died. Molecular typing demonstrated an indistinguishable PFGE pattern among the 11 isolates, with similarities to the Brazilian clone and the hospital's usual MRSA strain. This report emphasizes the importance of an uncommon phenotypical result as a marker for initiating an outbreak investigation and should encourage clinical laboratories to recognize and report such isolates.

Global assessment of the antimicrobial activity of polymyxin B against 54 731 clinical isolates of Gram-negative bacilli: report from the SENTRY antimicrobial surveillance programme (2001-2004).

In total, 54 731 Gram-negative bacilli isolated worldwide between 2001 and 2004 from diverse sites of infection were tested for susceptibility to polymyxin B by the broth reference microdilution method, with interpretation of results according to CLSI (formerly NCCLS) guidelines. Polymyxin B showed excellent potency and spectrum against 8705 Pseudomonas aeruginosa and 2621 Acinetobacter spp. isolates (MIC50, < or = 1 mg/L and MIC90, 2 mg/L for both pathogens). Polymyxin B resistance rates were slightly higher for carbapenem-resistant P. aeruginosa (2.7%) and Acinetobacter spp. (2.8%), or multidrug-resistant (MDR) P. aeruginosa (3.3%) and Acinetobacter spp. (3.2%), when compared with the entire group (1.3% for P. aeruginosa and 2.1% for Acinetobacter spp.). Among P. aeruginosa, polymyxin B resistance rates varied from 2.9% in the Asia-Pacific region to only 1.1% in Europe, Latin America and North America, while polymyxin B resistance rates ranged from 2.7% in Europe to 1.7% in North America and Latin America among Acinetobacter spp. Polymyxin B also demonstrated excellent activity (MIC90, < or = 1 mg/L; > 98% susceptible) against Citrobacter spp., Escherichia coli and Klebsiella spp., but activity was more variable against Enterobacter spp. (MIC50, < or = 1 mg/L; 83.3% susceptible) and Stenotrophomonas maltophilia (MIC50, < or = 1 mg/L; 72.4% susceptible), and was very limited (MIC50, > 8 mg/L) against Burkholderia cepacia (11.8% susceptible), Serratia spp. (5.4% susceptible), indole-positive Proteus spp. (1.3% susceptible) and Proteus mirabilis (0.7% susceptible).

Antimicrobial activity of dalbavancin tested against Gram-positive clinical isolates from Latin American medical centres.

The activity of dalbavancin, a new semi-synthetic lipoglycopeptide antibiotic, was evaluated in comparison with other antibacterial agents against 1229 Gram-positive organisms collected from medical centres in Latin America. Dalbavancin was the most potent compound tested against isolates of Staphylococcus aureus (MIC(50), 0.06 mg/L) and coagulase-negative staphylococci (MIC(50), 0.03 mg/L), independently of methicillin susceptibility. Dalbavancin inhibited all Streptococcus pneumoniae isolates at /= 8 mg/L. Dalbavancin exhibited excellent activity against isolates of Corynebacterium spp. and Listeria spp. Dalbavancin may provide an important therapeutic option for Gram-positive infections, excluding those caused by enterococci with VanA-type resistance.

IMPs, VIMs and SPMs: the diversity of metallo-beta-lactamases produced by carbapenem-resistant Pseudomonas aeruginosa in a Brazilian hospital.

Pseudomonas aeruginosa isolates (n=183), collected from bacteraemic patients hospitalised in Sao Paulo Hospital (Brazil) during 2000-2001, were screened for susceptibility to antimicrobial agents. The polymyxins were the most active compounds (100% susceptibility), followed by amikacin and cefepime (59.0%), meropenem (57.4%), and imipenem and gentamicin (55.2%). Imipenem-resistant isolates were ribotyped and screened for production of metallo-beta-lactamases (MBLs) by PCR with primers for bla(IMP), bla(VIM) and bla(SPM). MBL production was detected in 36 isolates (19.7% of the entire collection; 43.9% of the imipenem-resistant isolates) and the MBLs included SPM-1-like (55.6%), VIM-2-like (30.6%) and IMP-1-like (8.3%) enzymes.

Activity of mupirocin and 14 additional antibiotics against staphylococci isolated from Latin American hospitals: report from the SENTRY antimicrobial surveillance program.

A total of 1,346 Staphylococcus aureus (SA) and 498 coagulase-negative staphylococcal (CoNS) strains isolated from 11 Latin American medical centers between 2000 and 2001 were tested against mupirocin and other antimicrobial agents by reference broth microdilution method as part of the SENTRY Antimicrobial Surveillance Program. Oxacillin resistance (OR) was detected in 38.6% of S. aureus and in 78.1% of CoNS. The overall resistance rate to mupirocin was low among S. aureus (3.1%; MIC > or =8 microd/ml) but significantly higher among ORSA compared to oxacillin-susceptible SA (5.4% versus 1.7%; p <0.001). Mupirocin-resistant S. aureus strains were detected in 9 of 11 centers, with individual center rates varying between 1.8 and 15.7%. Mupirocin resistance rates were high among CoNS (27.5%) and varied widely (10.0 to 48.9%) among the monitored Latin American medical centers. Mupirocin resistance rates appear to be increasing and routine monitoring for potential resistance seems prudent.

Antimicrobial susceptibility of Streptococcus pneumoniae in Latin America: results from five years of the SENTRY Antimicrobial Surveillance Program.

A total of 1561 pneumococcal isolates were collected in 1997-2001, mainly from patients with community-acquired respiratory tract infections, and susceptibilities were tested by reference broth microdilution against 29 antimicrobial agents. In general, 69.3% of strains were considered susceptible (MIC < or = 0.06 mg/L) to penicillin. Resistance to penicillin (MIC > or = 2 mg/L) and cefotaxime (MIC > or = 4 mg/L) was found in 11.9% and 0.4% of isolates, respectively. The fluoroquinolones gatifloxacin (MIC90, 0.5 mg/L) and levofloxacin (MIC90, 1 mg/L) were active against > 99% of the isolates tested. Among the other non-beta-lactam drugs tested, the rank order of susceptibility was chloramphenicol (95.6%) > clindamycin (94.5%) > azithromycin (88.5%) > clarithromycin (87.5%) >tetracycline (79.5%) > trimethoprim + sulphamethoxazole (60.5%). The penicillin-non-susceptible isolates presented higher rates of resistance to other antimicrobial agents. The rank order of penicillin resistance rates among the seven participating countries was Mexico (25.0%) > Uruguay (19.2%) > Chile (18.3%) > Colombia = Argentina (9.9%) > Brazil (3.9%) > Venezuela (2.8%). The regional rate of penicillin resistance did not vary significantly over the years studied (p 0.339). Screening for the ermB and mefA genes by multiplex rapid cycle PCR on 23 erythromycin-resistant isolates collected during the year 2001 showed that 43.5% and 56.5%, respectively, were positive for ermB and mefA. Overall, the results indicated that antimicrobial susceptibilities of Streptococcus pneumoniae vary significantly among Latin American countries. Regional and local surveillance programmes are necessary to guide empirical therapy of pneumococcal infection in Latin American countries.

Screening of antibacterial extracts from plants native to the Brazilian Amazon Rain Forest and Atlantic Forest.

More than 20% of the world's biodiversity is located in Brazilian forests and only a few plant extracts have been evaluated for potential antibacterial activity. In the present study, 705 organic and aqueous extracts of plants obtained from different Amazon Rain Forest and Atlantic Forest plants were screened for antibacterial activity at 100 microg/ml, using a microdilution broth assay against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and Escherichia coli. One extract, VO581, was active against S. aureus (minimum inhibitory concentration (MIC)=140 microg/ml and minimal bactericidal concentration (MBC)=160 microg/ml, organic extract obtained from stems) and two extracts were active against E. faecalis, SM053 (MIC=80 microg/ml and MBC=90 microg/ml, organic extract obtained from aerial parts), and MY841 (MIC=30 microg/ml and MBC=50 microg/ml, organic extract obtained from stems). The most active fractions are being fractionated to identify their active substances. Higher concentrations of other extracts are currently being evaluated against the same microorganisms.