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Gram-negative Bacilli (gram-negative + bacillus)
Selected AbstractsRisk factors of mortality for nosocomial pneumonia: importance of initial anti-microbial therapyINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 1 2005S-C Lee Summary Nosocomial pneumonia is a common nosocomial infection and has high mortality rate. Risk factors of mortality of nosocomial pneumonia were studied in 132 hospitalised patients who developed nosocomial pneumonia. The overall mortality rate was 64/132, 48.5%. Of the 11 risk factors univariately associated with mortality due to nosocomial pneumonia, only the inappropriate initial anti-microbial therapy, high simplified acute physiology score and multiple organ failures remained significant after stepwise logistic regression. Gram-negative bacilli were still the most pre-dominant causative microbiologic agents of nosocomial pneumonia with Pseudomonas aeruginosa (20.3%), Acinetobacter baumannii (18.6%) and Escherichia coli (5.9%) being the three most predominant pathogens. A. baumannii were significantly more predominant among non-survivors than survivors (13.56 vs. 5.08%, p = 0.0418). The incidence rate of methicillin-resistant Staphylococcus aureus was 19.5% higher than previous reports. We conclude that inappropriate initial anti-microbial therapy for nosocomial pneumonia is associated with the mortality rate of nosocomial pneumonia, and appropriate anti-microbial therapy improves outcome of nosocomial pneumonia. [source] Risk factors and outcome of community-acquired pneumonia due to Gram-negative bacilliRESPIROLOGY, Issue 1 2009Miquel FALGUERA Background and objective: Several sets of guidelines have advocated initial antibiotic treatment for community-acquired pneumonia due to Gram-negative bacilli in patients with specific risk factors. However, evidence to support this recommendation is scarce. We sought to identify risk factors for community-acquired pneumonia due to Gram-negative bacilli, including Pseudomonas aeruginosa, and to assess outcomes. Methods: An observational analysis was carried out on prospectively collected data for immunocompetent adults hospitalized for community-acquired pneumonia in two acute-care hospitals. Cases of pneumonia due to Gram-negative bacilli were compared with those of non-Gram-negative bacilli causes. Results: Sixty-one (2%) of 3272 episodes of community-acquired pneumonia were due to Gram-negative bacilli. COPD (odds ratio (OR) 2.4, 95% confidence interval (CI): 1.2,5.1), current use of corticosteroids (OR 2.8, 95% CI: 1.2,6.3), prior antibiotic therapy (OR 2.6, 95% CI: 1.4,4.8), tachypnoea ,30 cycles/min (OR 2.1, 95% CI: 1.1,4.2) and septic shock at presentation (OR 6.1, 95% CI: 2.5,14.6) were independently associated with Gram-negative bacilli pneumonia. Initial antibiotic therapy in patients with pneumonia due to Gram-negative bacilli was often inappropriate. These patients were also more likely to require admission to the intensive care unit, had longer hospital stays, and higher early (<48 h) (21% vs 2%; P < 0.001) and overall mortality (36% vs 7%; P < 0.001). Conclusions: These results suggest that community-acquired pneumonia due to Gram-negative bacilli is uncommon, but is associated with a poor outcome. The risk factors identified in this study should be considered when selecting initial antibiotic therapy for patients with community-acquired pneumonia. [source] Sputum bacteriology in hospitalized patients with acute exacerbation of chronic obstructive pulmonary disease in Taiwan with an emphasis on Klebsiella pneumoniae and Pseudomonas aeruginosaRESPIROLOGY, Issue 1 2007Sheng-Hsiang LIN Background and objective: Bacterial infection is one of the major causes of acute exacerbation of COPD (AECOPD). This study was undertaken to investigate the microbiology of AECOPD. Methods: Medical records from 494 episodes of AECOPD in patients admitted to the National Taiwan University Hospital from January 2000 to June 2004 were reviewed. Severity of COPD was classified according to the 2003 Global Initiative for Chronic Obstructive Lung Disease guideline. Results: Potential pathogenic microorganisms were isolated from patients in 328 (66.4%) episodes of AECOPD. The predominant bacteria were Klebsiella pneumoniae (19.6%), Pseudomonas aeruginosa (16.8%) and Haemophilus influenzae (7.5%), followed by Acinetobacter baumannii (6.9%), Enterobacter species (6.1%) and Staphylococcus aureus (6.1%). The incidence of Streptococcus pneumoniae was 2.4%. Spirometry results obtained within 1 year of the exacerbation were available in 186 cases. K. pneumoniae was more frequently isolated in stage I COPD (39.1%) than stage II (16.6%), III (13.8%) and IV (9.4%). No glucose non-fermentative Gram-negative bacilli were isolated in stage I patients. Multivariate logistic regression analysis revealed that P. aeruginosa (odds ratio (OR) 3.19; 95% confidence interval (CI): 1.21,8.38), intubation (OR 14.81; 95% CI: 5.08,43.12) and age (OR 1.1; 95% CI: 1.03,1.17) were independent risk factors for mortality. Conclusions: Klebsiella pneumoniae and P. aeruginosa are the most common sputum pathogens in hospitalized patients with AECOPD in Taiwan, with the former being more commonly isolated from mild COPD and the latter associated with poor clinical outcome. These results should be considered when deciding which antibiotics should initially be used to treat patients with AECOPD. [source] Evaluation of the VITEK 2 cards for identification and antimicrobial susceptibility testing of non-glucose-fermenting Gram-negative bacilliAPMIS, Issue 4 2009WEN-SHYANG HSIEH We evaluated VITEK 2 cards (NGNC and AST-GN10) for the accuracy of identification (ID) and antimicrobial susceptibility testing (AST) of non-glucose-fermenting Gram-negative bacilli (NGF-GNB). In a total of 201 strains, 190 strains (94.5%) were correctly identified, seven strains (3.5%) showed low discrimination, four strains (2.0%) had discrepancies, and no strain remained unidentified. Reference AST of amikacin, aztreonam, cefepime, cefotaxime, ceftazidime, ciprofloxacin, imipenem, levofloxacin, piperacillin-tazobactam, and trimethoprim-sulfamethoxazole was performed by the agar dilution method. Approximately 82.5% of ID and 72.9% of AST were completed within 7 and 14 h, respectively. For NGF-GNB, other than Pseudomonas aeruginosa, Acinetobacter spp., Stenotrophomonas maltophilia, and the Burkholderia cepacia group, essential agreements (EAs) were 93.6,100.0%. Severe disagreements (resistant by the reference method to susceptible by AST-GN10) were observed for amikacin (0.9%), cefepime (1.8%), cefotaxime (1.8%), imipenem (0.9%), and piperacillin-tazobactam (0.9%). One major disagreement (susceptible to resistant) was observed for ceftazidime (0.1%). For P. aeruginosa, EAs were 85.7,100%, with severe disagreements observed for cefepime (4.8%) and piperacillin-tazobactam (4.8%). For Acinetobacter spp., EAs were 86.4,100% without disagreements. The VITEK 2 cards appear to be promising for rapid ID and reliable AST for most species of NGF-GNB. [source] Oral ciprofloxacin plus colistin: prophylaxis against bacterial infection in neutropenic patients.BRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2001A strategy for the prevention of emergence of antimicrobial resistance Following a 2-year study, the combination of oral ciprofloxacin and colistin has been used continuously for 10 years without the emergence of resistance. During a 2-year period (1987,1989), we compared ciprofloxacin + colistin (CIP + COL) with neomycin + colistin (NEO + COL) in a randomized trial , combinations chosen because of the potential for prophylaxis of Gram-negative infection by ciprofloxacin, with colistin given to reduce the risk of emergence of resistance. Sixty-four patients with similar demographics in each arm were evaluable for efficacy analysis. Patients on CIP + COL had a significantly lower proportion of neutropenic days with fever (P < 0·001) and neutropenic days on intravenous antibiotics (P < 0·001) than patients on NEO + COL. A total of 54 (15 bacteriologically documented) pyrexial episodes occurred in patients on CIP + COL and 77 (41 bacteriologically documented) in patients on NEO + COL. Only two Gram-negative bacterial infections occurred in the CIP + COL arm compared with 16 in the NEO + COL arm. No Staphylococcus aureus infections occurred in the CIP + COL group compared with 10 in the other patients. Two CIP-resistant Gram-negative bacilli were isolated from patients on CIP + COL compared with 13 NEO-resistant Gram-negative bacilli from patients on NEO + COL. Following a subsequent decade of unchanged use of this prophylactic strategy in neutropenic patients, a 2-year follow-up study between 1 January 1998 and 31 December 1999 showed 66 significant infections during 350,400 neutropenic episodes. Eight of the 111 (7·2%) isolates were with ciprofloxacin-resistant organisms, involving 2% of the neutropenic episodes, indicating that the strategy of combining colistin with ciprofloxacin has been effective in the prevention of Gram-negative sepsis in neutropenic patients without the emergence of significant resistance despite widespread concurrent hospital and community use of the quinolones. [source] Children with Bacterial Meningitis Presenting to the Emergency Department during the Pneumococcal Conjugate Vaccine EraACADEMIC EMERGENCY MEDICINE, Issue 6 2008Lise E. Nigrovic MD Abstract Background:, The epidemiology of bacterial meningitis in children in the era of widespread heptavalent conjugate pneumococcal vaccination (PCV7) is unknown. Objectives:, The objective was to describe the epidemiology of bacterial meningitis in children presenting to the emergency department (ED) during the era of widespread PCV7 vaccination. Methods:, The authors retrospectively reviewed the medical records of all children aged 1 month to 19 years with bacterial meningitis who presented to the EDs of 20 U.S. pediatric centers (2001,2004). Bacterial meningitis was defined by a positive cerebrospinal fluid (CSF) culture for a bacterial pathogen or CSF pleocytosis (CSF white blood cell [WBC] count ,10 cells/mm3) in association with either a positive blood culture or a CSF latex agglutination study. Results:, A total of 231 children with bacterial meningitis were identified. The median age was 0.6 years (interquartile range [IQR] = 0.2,4.2). Eight patients (3% of all patients) died. The following bacterial pathogens were identified: Streptococcus pneumoniae (n = 77; 33.3%), Neisseria meningitidis (67; 29.0%), Group B Streptococcus (42; 18.2%), Escherichia coli (17; 7.4%), nontypeable Haemophilus influenzae (10; 4.3%), other Gram-negative bacilli (7; 3.0%), Listeria monocytogenes (5; 2.2%), Group A Streptococcus (5; 2.2%), and Moraxella catarrhalis (1; 0.4%). S. pneumoniae serotypes were determined in 37 of 77 patients; of these, 62% were due to nonvaccine serotypes (including 19A). Conclusions:, Although now a rare infectious disease in United States, bacterial meningitis still causes substantial morbidity in affected children. Despite the introduction of PCV7, S. pneumoniae remains the most common cause of bacterial meningitis in U.S. children, with approximately half of cases due to nonvaccine serotypes. [source] Tigecycline: in-vitro performance as a predictor of clinical efficacyCLINICAL MICROBIOLOGY AND INFECTION, Issue 4 2007P. Hawkey Abstract The incidence of nosocomial disease caused by Gram-negative pathogens is increasing, and infections caused by Enterobacter, Klebsiella, Acinetobacter, Escherichia coli and Pseudomonas aeruginosa are more commonly refractive to traditional antimicrobial agents, including aminoglycosides, fluoroquinolones and broad-spectrum cephalosporins. The most important mechanism of resistance to ,-lactam antibiotics among Gram-negative bacilli involves the production of ,-lactamases. Extended-spectrum ,-lactamases are particularly worrisome, since they are often associated with multidrug resistance phenotypes, which can pose a significant therapeutic challenge. Novel agents for the treatment of Gram-negative infections are uncommon, as recent emphasis has been placed on the development of agents targeting drug-resistant strains of Gram-positive bacteria, e.g., streptococci, enterococci and staphylococci. Tigecycline, a semi-synthetic derivative of minocycline, has a unique and novel mechanism of action, which not only allows this agent to overcome the well-known tet gene-encoded resistance mechanisms, but also maintains its activity against Gram-negative pathogens producing a broad array of extended-spectrum ,-lactamases. Tigecycline is the first example of a new class of glycylcyclines with activity against a wide range of clinically important Gram-negative pathogens. Tigecycline has potent antimicrobial activity, and has been associated with an excellent therapeutic response in animal infection models and recently reported clinical trials, which reflect the effectiveness of tigecycline against pathogens causing intra-abdominal, skin and soft-tissue infections, including susceptible or multidrug-resistant strains of most Enterobacteriaceae, as well as anaerobic pathogens. [source] Severe strongyloidiasis in corticosteroid-treated patientsCLINICAL MICROBIOLOGY AND INFECTION, Issue 10 2006L. Fardet Abstract Severe strongyloidiasis, caused by Strongyloides stercoralis, is a preventable life-threatening disease that can occur in any corticosteroid-treated patient who has travelled to a country with infested soil, even if the contact occurred up to 30 years previously. This diagnosis should be considered in corticosteroid-treated patients who experience either unusual gastrointestinal or pulmonary symptoms, or who suffer from unexplained sepsis caused by Gram-negative bacilli. Peripheral eosinophilia is not observed systematically and, even if present, is moderate in most cases. Ivermectine is the best prophylactic and therapeutic option, and thiabendazole should no longer be used. However, guidelines for the prevention and management of S. stercoralis infection in such patients have not yet been established. [source] Intravenous catheter infections associated with bacteraemia: a 2-year study in a University HospitalCLINICAL MICROBIOLOGY AND INFECTION, Issue 5 2004M. Paragioudaki Abstract The aim of this retrospective study was to assess the incidence and aetiology of central and peripheral venous catheter (C/PVC) infections during a 2-year period (1999,2000) and to determine the susceptibility of isolated microorganisms to various antimicrobial agents. Catheter tips were processed using the semiquantitative method and blood cultures were performed with the BacT/Alert automated system. Antibiotic susceptibilities were performed by disk agar diffusion and MICs were determined by Etest, according to NCCLS standards. During the study period, samples from 1039 C/PVC infections were evaluated, yielding 384 (37.0%) positive cultures. Blood cultures were also available from 274 patients, of which 155 (56.6%) yielded the same microorganism as from the catheter. No bloodstream infections were detected in 104 C/PVC-positive cases. Methicillin-resistant coagulase-negative staphylococci were the most frequent isolates, followed by Gram-negative bacteria, especially Pseudomonas aeruginosa. Resistance to glycopeptides among staphylococci and enterococci was not detected, whereas 60% of Gram-negative bacilli were resistant to ,-lactams. [source] Enterobacter sakazakii infection in the newbornACTA PAEDIATRICA, Issue 3 2001B Bar-Oz Enterobacter sakazakii, a Gram-negative bacillus, previously known as "yellow pigmented Enterobacter cloacae," is a rare cause of neonatal infection. We describe the detailed clinical presentation of two cases in whom E. sakazakii was isolated in our neonatal service during the course of 1 mo. These include one case of sepsis and meningitis complicated by cerebral infarction, and one case of sepsis. In addition, three cases of intestinal colonization were identified. The source of the organism was thoroughly sought and was found to be a blender in the milk kitchen that was used for preparation of the reconstituted powdered milk formula. Conclusion: Our paper adds clinical and laboratory information about the disease spectrum caused by this relatively rare organism and emphasizes the importance of a thorough search for the source of the infection. [source] Microbial and clinical determinants of time-to-positivity in patients with bacteraemiaCLINICAL MICROBIOLOGY AND INFECTION, Issue 7 2007J. A. Martínez Abstract Time-to-positivity is useful in the diagnosis of catheter-related bacteraemia and as a predictor of an endovascular source in patients with Staphylococcus aureus bacteraemia. However, this parameter has been evaluated for only a limited number of microorganisms. In the present study, time-to-positivity was recorded for 1872 episodes of significant monomicrobial bacteraemia diagnosed at a teaching hospital during a 2-year period, and the associated microbial and clinical variables were investigated. According to multivariate analysis, Streptococcus pneumoniae, ,-haemolytic streptococci, Escherichia coli, Klebsiella, Enterobacter, Citrobacter and Aeromonas were characterised by fast growth, with an endovascular source, shock, liver cirrhosis and neutropenia also predicting a short time-to-positivity. For patients not receiving appropriate antibiotics, detection of Gram-positive cocci in clusters within 14 h was predictive of Staph. aureus; a time-to-positivity of >21 h ruled out the possibility that a Gram-positive organism in chains was a ,-haemolytic streptococcus or Strep. pneumoniae, and a time-to-positivity of ,12 h meant that it was very unlikely that a Gram-negative bacillus was a non-fermenter. A time-to-positivity of ,8 h was predictive of a non-urinary tract source in patients with E. coli bacteraemia, and detection of growth within 13 h predicted an endovascular source in those with Staph. aureus bacteraemia. In conclusion, time-to-positivity depended on the microorganism, original source and clinical variables involved. Although this measurement may provide some early clues concerning the microorganisms involved and the source of bacteraemia, its clinical impact remains to be defined. [source] A pilot study evaluating the safety and microbiologic efficacy of an economically viable antimicrobial lozenge in patients with head and neck cancer receiving radiation therapyHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 1 2002FRCPC, Samy El-Sayed MD Abstract Background Mucositis occurs in almost all radiotherapy-treated head and neck cancer patients, in approximately 75% of patients receiving hematopoietic marrow transplantation, and in approximately 40% of all patients who receive chemotherapy. Mucositis is painful, may affect all oral functions, and is a dose- and rate-limiting toxicity of therapy for cancer. Radiation-associated mucositis (onset, intensity, and duration) has been shown in recent clinical trials to be modified by the use of antibacterial/antifungal lozenges. Purpose The aim of this collaborative two-center phase II study was to assess the toxicity and microbiologic efficacy of an economically viable antimicrobial lozenge in the management of patients receiving radiation therapy for head and neck cancer. Materials and Methods Seventeen patients scheduled to receive radical or postoperative radiotherapy were provided with bacitracin, clotrimazole, and gentamicin (BCoG) lozenges (one lozenge dissolved in the mouth qid from day 1 of radiotherapy until completion). Ease of use and palatability of the lozenges, patients' symptoms (swallowing and pain), and quantitative and qualitative microbiologic evaluation of an oral rinse collection was conducted at least once weekly during radiation therapy. Results No significant side effects were reported from the use of the lozenges. The lozenges were well tolerated at the beginning of treatment by all patients, with some minor difficulty associated with oral discomfort toward the end of the treatment. Microbiologic evaluation showed consistent elimination of yeast organisms in all patients. In four patients there was no growth of gram-negative bacilli on culture, whereas in two patients, fluctuating counts were seen, and one patient had increased counts. The remaining patients had significant reduction in the gram-negative bacilli counts. Conclusions This study demonstrated that the BCoG lozenge is tolerable and microbiologically efficacious, achieving elimination of Candida in all patients and reduction in gram-negative flora in most patients. A phase III study is underway to evaluate the clinical efficacy of this lozenge. © 2002 John Wiley & Sons, Inc. Head Neck 24: 6,15, 2002. [source] Antimicrobial Resistance and Aging: Beginning of the End of the Antibiotic Era?JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 2002Thomas T. Yoshikawa MD Throughout the history of mankind, infectious diseases have remained a major cause of death and disability. Although industrialized nations, such as the United States, have experienced significant reductions in infection-related mortality and morbidity since the beginning of the "antibiotic era," death and complications from infectious diseases remain a serious problem for older persons. Pneumonia is the major infection-related cause of death in older persons, and urinary tract infection is the most common bacterial infection seen in geriatric patients. Other serious and common infections in older people include intra-abdominal sepsis, bacterial meningitis, infective endocarditis, infected pressure ulcers, septic arthritis, tuberculosis, and herpes zoster. As a consequence, frequent prescribing of antibiotics for older patients is common practice. The large volume of antibiotics prescribed has contributed to the emergence of highly resistant pathogens among geriatric patients, including methicillin-resistant Staphylococcus aureus, penicillin-resistant Streptococcus pneumoniae, vancomycin-resistant enterococci, and multiple-drug-resistant gram-negative bacilli. Unless preventive strategies coupled with newer drug development are established soon, eventually clinicians will be encountering infections caused by highly resistant pathogens for which no effective antibiotics will be available. Clinicians could then be experiencing the same frustrations of not being able to treat infections effectively as were seen in the "pre-antibiotic era." [source] | ||||||||||