Bacilli In Intensive Care Unit Research Articles

The problem of multi-resistance in gram-negative bacilli in intensive care units: Treatment and prevention strategies

The rise of infections caused by multi-resistant gram-negative bacilli (MR-GNB), which includes carbapenems, represents one of the major current challenges worldwide. These MR-GNB include extended spectrum β-lactamase-producing Enterobacterales, derepressed AmpC-producing or carbapenemase-producing Enterobacterales as well as non-fermenting Gram-negative bacilli such as Pseudomonas aeruginosa or Acinetobacter baumannii. P. aeruginosa predominantly exhibits other resistance mechanisms different to β-lactamases such as expulsion pumps or loss of porins. A. baumannii frequently presents several of these resistance mechanisms. Mortality is high especially if empirical treatment is inadequate. In this review, treatment strategies are revised, describing the tools available to identify patients in whom empirical antibiotic treatment would be justified to cover MR-GNB, the importance of optimizing the administration of these antibiotics, as well as prevention strategies to avoid its spread from patients colonized or infected by a MR-GNB.

High Prevalence of Antimicrobial Resistance Among Gram-Negative Isolated Bacilli in Intensive Care Units at a Tertiary-Care Hospital in Yucatán Mexico.

Background and Objectives: Antimicrobial resistance (AMR) is increasing worldwide and imposes significant life-threatening risks to several different populations, especially to those in intensive care units (ICU). The most commonly isolated organisms in ICU comprise gram-negative bacilli (GNB), and these represent a leading cause of serious infections. This study was conducted to describe the prevalence of resistance in GNB isolated from patients in adults, pediatric, and neonatal ICU in a tertiary-care hospital in Mérida, Mexico. Materials and Methods: A retrospective study was done on samples collected in Neonatal (NICU), Pediatric (PICU) and Adult (AICU) ICU of Unidad Médica de Alta Especialidad, Instituto Mexicano del Seguro Social in Mérida, México. The identification of isolates and antimicrobial susceptibility testing were performed using an automated system. Results: A total of 517 GNB strains were isolated. The most common positive culture was bronchial secretions. Pseudomonas aeruginosa was the prevalent pathogen in NICU and PICU, whereas Escherichia coli was common in the AICU. Overall, GNB exhibited a high resistance rates for Ampicillin (95.85%), Cefuroxime (84.17%), Piperacillin (82.93%), Cefotaxime (78.07%), Ceftriaxone (77.41%), Aztreonam (75.23%), Cefazolin (75.00%), and Ceftazidime (73.19%). There are significant differences in the resistance rates of GNB from different ICUs for penicillins, cephalosporins, carbapenems and fluoroquinolones drugs. Escherichia coli (multidrug-resistant [MDR] = 91.57%, highly resistant microorganisms [HRMO] = 90.36%) and Acinetobacter baumannii (MDR = 86.79%, HRMO = 83.02%) exhibited the highest percentage of MDR and HRMO profiles. The prevalence of the extended-spectrum beta-lactamases (ESBL)-producing isolates was 83.13% in E. coli, 78.84% in Klebsiella pneumoniae, and 66.67% in Proteus mirabilis, respectively. Conclusions: The high resistance rates to drugs were exhibited by our GNB isolates. Continuous surveillance and control of the use of antimicrobials are urgently needed to reduce the emergence and spreading of MDR, HRMO, and/or ESBL-producing bacilli.

Occurrence of unusual non-fermentative gram negative bacilli in intensive care units of a university hospital, Egypt

Non-fermentative Gram-negative bacilli (NFGNB) other than Pseudomonas and Acinetobacter species have emerged as nosocomial pathogens. No much data is currently available concerning the occurrence of these types of bacteria in Zagazig University Hospitals (ZUHs). In this study, the occurrence as well as the antimicrobial susceptibility pattern of unusual NFGNB obtained from clinical samples collected from intensive care units (ICUs) of ZUHs was assessed. Additionally, the genetic relatedness among the most prevalent unusual NFGNB species was studied.Results: Out of 516 non-repeated clinical sample, 97 NFGNB (18.7%) were isolated. Among them, 17 unusual NFGNB were identified by API 20NE, accounting for 17.5% of NFGNB and 3.3% of all tested samples. Within the unusual NFGNB, Burkholderiacepaciacomplex (Bcc) was the most prevalent species accounting for 94.1% of NFGNB and 3.1% of total samples. This was followed by Burkholderia pseudomallei (B. pseudomallei) which accounted for 5.9% of NFGNB and 0.2% of all obtained specimens. Tigecycline antibiotic was the most effective antibiotic against Bcc isolates (68.8% susceptibility) in disc diffusion method. After random amplified polymorphic DNA (RAPD) testing, the obtained Bcc isolates were found to be genetically diverse. This highlights Bcc as an emerging nosocomial pathogen in ICUs of ZUHs. Continuous monitoring of the occurrence of Bcc in ICU as well as in other hospital wards is warranted.Keywords: ʺUnusualʺ, ʺNon-fermentativeʺ, ʺgram-negative bacilliʺ, ʺintensive care unitʺ

Genetic diversity of common environmental Enterobacteriaceae bacilli in intensive care units of hospitals from central Iran

Genetic diversity of common environmental Enterobacteriaceae bacilli in intensive care units of hospitals from central Iran

Acquisition of carbapenem-resistant Gram-negative bacilli in intensive care unit: Predictors and molecular epidemiology

ObjectivesWe had for aim to determine the risk factors for acquiring carbapenem-intermediate or -resistant Gram-negative bacilli (CR-GNB) in an intensive care unit (ICU) and to identify the resistance mechanisms involved. Patients and methodsWe conducted an observational prospective cohort study during 6 months in medical and surgical ICUs of the Besançon Teaching Hospital. Patients with acquired CR-GNB were patients whose cultures (screening or diagnosis) became positive more than 48h after admission to the ICU. The risk factors for ICU-acquired CR-GNB were determined by multivariate logistic regression. CR-GNB isolates were typed by pulsed-field gel electrophoresis (PFGE) and screened for resistance mechanisms with phenotypic and genotypic tests. ResultsTwenty-three of the 347 included patients had acquired a CR-GNB. The multivariate analysis revealed significant associations between this acquisition and the duration of previous treatments with piperacillin-tazobactam (adjusted odds ratio [aOR], 1.13, P=0.02) and aminoglycosides (aOR, 1.62; P=0.005), but not with carbapenems. The CR-GNB strains were identified as Pseudomonas aeruginosa (n=10), Stenotrophomonas maltophilia (n=7), and Enterobacter cloacae (n=6). No acquired carbapenemase-producing strain was identified. PFGE typing identified 1 multiple clone among P. aeruginosa isolates (4 patients), whereas for the other bacteria, all the strains were different. ConclusionOur study results suggest that the strategy to prevent the emergence and spread of CR-GNB should not be limited to the sole restriction of carbapenem use in ICU settings.

Clinicians' knowledge, attitudes, and practices regarding infections with multidrug-resistant gram-negative bacilli in intensive care units.

To assess how healthcare professionals caring for patients in intensive care units (ICUs) understand and use antimicrobial susceptibility testing (AST) for multidrug-resistant gram-negative bacilli (MDR-GNB). A knowledge, attitude, and practice survey assessed ICU clinicians' knowledge of antimicrobial resistance, confidence interpreting AST results, and beliefs regarding the impact of AST on patient outcomes. Sixteen ICUs affiliated with NewYork-Presbyterian Hospital. Attending physicians and subspecialty residents with primary clinical responsibilities in adult or pediatric ICUs as well as infectious diseases subspecialists and clinical pharmacists. Participants completed an anonymous electronic survey. Responses included 4-level Likert scales dichotomized for analysis. Multivariate analyses were performed using generalized estimating equation logistic regression to account for correlation of respondents from the same ICU. The response rate was 51% (178 of 349 eligible participants); of the respondents, 120 (67%) were ICU physicians. Those caring for adult patients were more knowledgeable about antimicrobial activity and were more familiar with MDR-GNB infections. Only 33% and 12% of ICU physicians were familiar with standardized and specialized AST methods, respectively, but more than 95% believed that AST improved patient outcomes. After adjustment for demographic and healthcare provider characteristics, those familiar with treatment of MDR-GNB bloodstream infections, those aware of resistance mechanisms, and those aware of AST methods were more confident that they could interpret AST results and/or request additional in vitro testing. Our study uncovered knowledge gaps and educational needs that could serve as the foundation for future interventions. Familiarity with MDR-GNB increased overall knowledge, and familiarity with AST increased confidence interpreting the results.

Overview of Nosocomial Infections Caused by Gram-Negative Bacilli

We analyzed data from the National Nosocomial Infections Surveillance (NNIS) System from 1986-2003 to determine the epidemiology of gram-negative bacilli in intensive care units (ICUs) for the most frequent types of hospital-acquired infection: pneumonia, surgical site infection (SSI), urinary tract infection (UTI), and bloodstream infection (BSI). We analyzed >410,000 bacterial isolates associated with hospital-acquired infections in ICUs during 1986-2003. In 2003, gram-negative bacilli were associated with 23.8% of BSIs, 65.2% of pneumonia episodes, 33.8% of SSIs, and 71.1% of UTIs. The percentage of BSIs associated with gram-negative bacilli decreased from 33.2% in 1986 to 23.8% in 2003. The percentage of SSIs associated with gram-negative bacilli decreased from 56.5% in 1986 to 33.8% in 2003. The percentages pneumonia episodes and UTIs associated with gram-negative bacilli remained constant during the study period. The proportion of ICU pneumonia episodes associated with Acinetobacter species increased from 4% in 1986 to 7.0% in 2003 (P<.001, by the Cochran-Armitage chi2 test for trend). Significant increases in resistance rates were uniformly seen for selected antimicrobial-pathogen combinations. Gram-negative bacilli are commonly associated with hospital-acquired infections in ICUs. The proportion of Acinetobacter species associated with ICU pneumonia increased from 4% in 1986 to 7.0% in 2003.

Nosocomial Antibiotic Resistance in GNB at the ICUs

In Brief Over the last decade, bacterial resistance has increased alarmingly among nosocomial gram-negative bacilli (GNB) in intensive care units (ICUs). In Pseudomonas aeruginosa imipenem-resistance (R) was 18%, quinolone-R 27%, cephalosporin-R 26%, extended spectrum β-lactamase (ESBL)–producing Klebsiella pneumoniae >10%, and third-generation cephalosporin-resistant Enterobacter spp 35% (National Nosocomial Infection Surveillance data 2000). In addition, ICU outbreaks caused by multiresistant Acinetobacter baumannii have increasingly been reported worldwide. The role of cephalosporin overuse has been noted in numerous nosocomial outbreaks due to ESBL-producing K. pneumoniaes. Most ICUs face the challenge of managing patients with endemic P. aeruginosa infections, in whom antibiotic therapy seems to play a decisive role selecting bacterial flora. P. aeruginosa pneumonia should always be considered in late ventilator-associated pneumonia (VAP) and in early VAP with previous antibiotic therapy. Nowadays, many strains of A. baumannii are highly resistant to modern β-lactams, aminoglycosides, and fluoroquinolones; of great concern, resistance to carbapenems has already emerged worldwide. Reinforcement of cleaning procedures, handwashing, and isolation methods remain the cornerstone of control programs in A. baumannii outbreaks. Attributed mortality of these infections is a controversial issue but probably low. Because of that, acute clinical judgment in selecting the patients who really need antibiotics is essential. Overall, multiresistant GNB infections in ICUs make their correct therapeutic antimicrobial management a real challenge for physicians. The risk of mortality in patients with life-threatening infections is substantially increased if initial antibiotic therapy is inadequate. However, excessive antibiotic use has been linked with the development of resistance. There is a general consensus that an early broad-spectrum empirical antibiotic therapy with a high probability of covering the likely pathogens should be used for serious VAP or other life-threatening infections. Appropriate general guidelines may be useful to establish a rational antibiotic policy, but their application should take into account the local organism ecology and resistance patterns. Over the last decade, bacterial resistance has increased alarmingly among nosocomial gram-negative bacilli in intensive care unit patients, including multiresistant Pseudomonas aeruginosa and Acinetobacter baumannii, extended spectrum β-lactamase–producing Klebsiella pneumoniae and derepressed Enterobacter spp. These infections make their correct therapeutic antimicrobial management a real challenge for physicians. Appropriate general guidelines may be useful to establish a rational antibiotic policy, but their application should take into account the local organism ecology and resistance patterns.

Antibiotic Consumption and Development of Resistance among Gram-Negative Bacilli in Intensive Care Units in Oman

Antibiotic Consumption and Development of Resistance among Gram-Negative Bacilli in Intensive Care Units in Oman

Colonization with broad-spectrum cephalosporin-resistant gram-negative bacilli in intensive care units during a nonoutbreak period: prevalence, risk factors, and rate of infection.

To define the epidemiology of broad-spectrum cephalosporin-resistant gram-negative bacilli in intensive care units (ICUs) during a nonoutbreak period, including the prevalence, the risk factors for colonization, the frequency of acquisition, and the rate of infection. Prospective cohort study. Tertiary care hospital. Consecutive patients admitted to two surgical ICUs. Serial patient surveillance cultures screened for ceftazidime (CAZ) resistance, antibiotic and hospital exposure, and infections. Of the 333 patients enrolled, 60 (18%) were colonized with CAZ-resistant gram-negative bacilli (CAZ-RGN) at admission. Clinical cultures detected CAZ-RGN in only 5% (3/60) of these patients. By using logistic regression, CAZ-RGN colonization was associated with duration of exposure to cefazolin (odds ratio, 10.3; p < or = .006) and to broad-spectrum cephalosporins/penicillins (odds ratio, 2; p < or = .03), Acute Physiology and Chronic Health Evaluation III score (odds ratio, 1.2; p < or = .008), and previous hospitalization (odds ratio, 3.1; p < or = .006). Of the 100 patients who remained in the surgical ICU for > or = 3 days, 26% acquired a CAZ-RGN. Of the 14 infections caused by CAZ-RGN, 11 (79%) were attributable to the same species present in surveillance cultures at admission to the surgical ICU. Colonization with CAZ-RGN was common and was usually not recognized by clinical cultures. Most patients colonized or infected with CAZ-RGN had positive surveillance cultures at the time of admission to the surgical ICU, suggesting that acquisition frequently occurred in other wards and institutions. Patients exposed to first-generation cephalosporins, as well as broad-spectrum cephalosporins/penicillins, were at high risk of colonization with CAZ-RGN. Empirical treatment of nosocomial gram-negative infections with broad-spectrum cephalosporins, especially in the critically ill patient, should be reconsidered.

Conclusion: Fourth-generation cephalosporins: new hopes and new duties.

Conclusion: Fourth-generation cephalosporins: new hopes and new duties.

Antibiotic susceptibility among aerobic gram-negative bacilli in intensive care units in 5 European countries. French and Portuguese ICU Study Groups.

Surveillance of antibiotic resistance is especially important in intensive care units (ICUs) because the infection rates are much higher there than in other hospital wards and most epidemics with multiresistant bacteria originate in ICUs. To evaluate the incidence of decreased antibiotic susceptibility among aerobic gram-negative bacilli isolated from patients in ICUs. Consecutive specimens collected on clinical indications from ICU patients were cultured and tested. Minimum inhibitory concentrations for amikacin, ceftazidime, ceftriaxone, ciprofloxacin, gentamicin, imipenem, piperacillin, and piperacillin-tazobactam were determined using E test. Eighteen hospitals in Belgium, 40 in France, 20 in Portugal, 30 in Spain, and 10 in Sweden. A total of 9166 gram-negative strains were initially isolated from 7308 patients between June 1994 and June 1995. The incidence of decreased susceptibility, defined as the sum of resistant and intermediate categories with use of the minimum inhibitory concentration break points recommended by the National Committee for Clinical Laboratory Standards. The most frequently isolated organisms were Enterobacteriaceae (59%) followed by Pseudomonas aeruginosa (24%). The main sources were respiratory tract (42%), urine (26%), blood (14%), abdomen (11%), and skin and soft tissue (7%). Decreased antibiotic susceptibility across all species and drugs was highest in Portuguese ICUs followed by French, Spanish, Belgian, and Swedish ICUs. The highest incidence of resistance was seen in all countries among P aeruginosa (up to 37% resistant to ciprofloxacin in Portuguese ICUs and 46% resistant to gentamicin in French ICUs), Enterobacter species, Acinetobacter species, and Stenotrophomonas maltophilia, and in Portugal and France among Klebsiella species. The high incidence of reduced antibiotic susceptibility among gram-negative bacteria in these ICUs suggests that more effective strategies are needed to control the selection and spread of resistant organisms.