First-generation fluoroquinolone use and subsequent emergence of multiple drug-resistant bacteria in the intensive care unit

Risk Factors for Post-Operative Multi-Drug-Resistant Organism Bacterial Infection in Patients With Stanford Acute Type A Aortic Dissection

Background: To explore the risk factors for multi-drug-resistant organism (MDRO) infection in patients with Stanford acute type A aortic dissection (ATAAD). We conducted a retrospective cohort study using the data of post-operative patients with ATAAD in our hospital. Patients and Methods: This study included 82 post-operative patients with ATAAD in the past decade. They were divided into a MDRO group (n = 31) and a non-MDRO group (n = 51) according to whether they had acquired multi-drug-resistant (MDR) bacterial infection. Multivariable logistic regression was used to analyze the risk factors for MDR infections in patients with ATAAD. Results: The incidence of multi-drug-resistant bacterial infection was 37.80%. Seventeen factors, including hospital stay (p = 0.007), utilization of third-generation cephalosporins (p = 0.0068), antibiotic species of exposure (p = 0.0002), leukocyte-depleted red blood cell suspension dosage (p < 0.0001), fresh frozen plasma dosage (p < 0.0001), application of blood purification (p = 0.0493), and the total antibiotic days of exposure (p = 0.0001) diverged between the two groups (all p < 0.05). The logistic regression analysis revealed that the utilization of third-generation cephalosporins (odds ratio [OR], 2.32; 95% confidence interval [CI], 1.01-5.33; p = 0.0478), antibiotic species of exposure (OR, 5.76; 95% CI, 1.45-22.83; p = 0.0128), leukocyte-depleted red blood cell suspension dosage (OR, 12.43; 95% CI, 2.71-57.07; p = 0.0012), and fresh frozen plasma dosage (OR, 5.05; 95% CI, 1.18-21.56; p = 0.0286) were independent variables for MDRO infections. Among the 23 drug-resistant bacteria detected, Acinetobacter baumannii was the main pathogen. Conclusions: Our study shows that the utilization of third-generation cephalosporins, antibiotic species of exposure, leukocyte-depleted red blood cell suspension dosage, and fresh frozen plasma dosage were independent risk factors for post-operative multi-drug-resistant infection in patients with ATAAD. Acinetobacter baumannii occupied the largest share of resistant bacteria that induce infection in post-operative patients with ATAAD.

The effects of Peptide Mel4-coated titanium plates on infection rabbits after internal fixation of open fractures

INTRODUCTION

Infection after internal fixation surgery is an orthopedic serious complication which affect the fracture healing. The primary objective of this study was to verify the effects of a Peptide Mel4-coated titanium plate applied in the treatment of infection after internal fixation of open fracture.

MATERIALS AND METHODS

Eighty-eight rabbits were intravenously inoculated with Staphylococcus aureus or Pseudomonas aeruginosa suspensions. Bacterial cultures were obtained from titanium plates at 1st, 3rd, 5th, 7th and 9th days. Blood samples were collected at 1st, 3rd, 5th, 7th and 9th days after the infection.

RESULTS

Mel4-coated titanium plates have significant inhibitory effects on Staphylococcus aureus and Pseudomonas aeruginosa (P < 0.05), and there are significant differences in serum IL-1 and TNF-α levels (P < 0.05).

CONCLUSION

We suggest that the use of Mel4-coated titanium plates may be a promising way to control postoperative infection of open fracture in vivo.

Evolution of fluoroquinolone-resistant Escherichia coli in the gut after ciprofloxacin treatment

BACKGROUND

Three healthy volunteers carried similar quinolone-resistant E. coli (QREC) (pulsed field gel electrophoresis profiles) in their gut before and after 14 days ciprofloxacin treatment. Given the intensity of the selective pressure and the mutagenic properties of quinolones, we determined whether these strains had evolved at the phenotypic and/or genomic levels.

MATERIAL AND METHODS

Commensal QREC from before day-0 (D0), and a month after 14 days of ciprofloxacin (D42) were compared in 3 volunteers. Growth experiments were performed; acetate levels, mutation frequencies, quinolone MICs and antibiotic tolerance were measured at D0 and D42. Genomes were sequenced and single nucleotide polymorphisms (SNPs) between D0 and D42 were analyzed using DiscoSNP and breseq methods. Cytoplasmic proteins were extracted, HPLC performed and proteins identified using X!tandem software; abundances were measured by mass spectrometry using the Spectral Counting (SC) and eXtraction Ion Chromatograms (XIC) integration methods.

RESULTS

No difference was found in MICs, growth characteristics, acetate concentrations, mutation frequencies, tolerance profiles, phylogroups, O-and H-types, fimH alleles and sequence types between D0 and D42. No SNP variation was evidenced between D0 and D42 isolates for 2/3 subjects; 2 SNP variations were evidenced in one. At the protein level, very few significant protein abundance differences were identified between D0 and D42.

CONCLUSION

No fitness, tolerance, metabolic or genomic evolution of commensal QREC was observed overtime, despite massive exposure to ciprofloxacin in the gut. The three strains behaved as if they had been unaffected by ciprofloxacin, suggesting that gut may act as a sanctuary where bacteria would be protected from the effect of antibiotics and survive without any detrimental effect of stress.

Risk Factors of Multidrug Resistant Pathogens Induced Infection in Severe Acute Pancreatitis

Purpose:

A retrospective study was first performed to assess the multidrug resistant (MDR) pathogen in severe acute pancreatitis (SAP) patients who were treated using the step-up approach. We aim to assess the risk factors between MDR pathogen and potential covariates in SAP patients.

Methods:

The clinical data of 51 SAP patients who were treated from June, 2013 to December, 2016 were retrospectively collected. A total of 23 patients in the MDR group and 28 patients in the non-MDR group were reviewed. The risk factors for MDR pathogen-induced infections in SAP patients were analyzed.

Results:

Hyperlipidemia was the leading cause of SAP in our study. The mean duration of hospital stay was significantly longer in the patients with MDR pathogen infections (P=0.0135). The hospitalization expenses of MDR group were much higher than those in non-MDR group. The mortality of MDR group (56.5%) was higher than that in non-MDR group (28.6%) (P=0.0436). Gram-negative isolates (63.8%) were commonly detected in SAP patients. Acinetobacter baumannii was the most common MDR pathogens. Systemic disease (P = 0.0136), initial use of carbapenem (P = 0.0438), and open necrosectomy (P = 0.0002) were the potential risk factors for MDR pathogen-induced infections in SAP. Furthermore, the logistic regression analysis revealed that open necrosectomy was the independent variable for MDR infections (OR: 15.6, 95% CI: 2.951–82.469, P = 0.0012).

Conclusions:

MDR pathogen-induced infections were common in SAP patients and Acinetobacter baumannii was the main pathogen. Meanwhile, open necrosectomy was the independent risk factor for the infection of MDR pathogen.

Collaborative Antimicrobial Stewardship for Surgeons

Antimicrobial stewardship efforts that include surgeons rely on healthy and open communications between surgeons, infectious diseases specialists, and pharmacists. These efforts most frequently are related to surgical prophylaxis, the management of surgical infections, and surgical critical care. Policy should be based on best evidence and timely interactions to develop consensus on how to develop appropriate guidelines and protocols. Flexibility on all sides leads to increasingly strong relationships over time.

Detection of the Novel optrA Gene Among Linezolid-Resistant Enterococci in Barcelona, Spain

The purpose of this study was to describe the presence of the novel optrA gene among clinical isolates of enterococci in a Spanish teaching hospital (May 2016-April 2017). optrA and cfr genes were screened by PCR in all isolates showing linezolid minimal inhibitory concentration (MIC) ≥4 mg/L. The genetic relatedness of the isolates, the presence of resistance and virulence genes, and the genetic environment of optrA were assessed by whole-genome sequencing (WGS). Six of 1,640 enterococci had linezolid MIC ≥4 mg/L. Among them, the optrA gene was detected in five Enterococcus faecalis isolated from unrelated patients. Although none of them had received linezolid or chloramphenicol, all had antecedents of recent quinolone consumption. WGS analysis revealed the existence of two different genotypes: ST585 and ST474. cfr was not detected in any of the isolates. No mutations were detected among the 23S ribosomal RNA and the ribosomal proteins L3, L4, and L22. Both genotypes also carried genes related to aminoglycoside, lincosamide, macrolide, phenicol, and tetracycline resistance. Detection of optrA in a setting with low linezolid consumption and among patients without antecedents of oxazolidinone therapy is of concern.

Fluoroquinolone Restriction as an Effective Antimicrobial Stewardship Intervention

PURPOSE OF REVIEW

Fluoroquinolones are a commonly prescribed antibiotic class that has come under scrutiny in recent years due to mounting evidence of association between adverse drug events, C. difficile infection and isolation of antibiotic-resistant bacteria.

RECENT FINDINGS

Inpatient antimicrobial stewardship (AMS) programs have a toolbox of potential interventions to curb inappropriate antibiotic use, prevent antibiotic-associated adverse drug events, and avoid unnecessary costs of care. Fluoroquinolone restriction policies in the acute care setting have demonstrated beneficial effects, including decreased rates of C. difficile infection and ESBL-producing Enterobacteriaceae. However, a simple blanket restriction policy may "squeeze the antibiotic balloon" and will likely be insufficient if not implemented in conjunction with other AMS interventions. There is a growing body of evidence to support formulary restriction of fluoroquinolones in the acute care setting to decrease rates of C. difficile infection and development of ESBL-producing organisms. Data on how to best implement these restrictions or how to implement outside of acute care settings is limited.

Antimicrobial strategy for severe community-acquired legionnaires' disease: a multicentre retrospective observational study

Background

Legionnaires' disease (LD) is an important cause of community-acquired pneumonia with high mortality rates in the most severe cases.

Objectives

To evaluate the effect of antimicrobial strategy on ICU mortality.

Methods

Retrospective, observational study including patients admitted to 10 ICUs for severe community-acquired LD over a 10 year period (2005-15) and receiving an active therapy within 48 h of admission . Patients were stratified according to the antibiotic strategy administered: (i) fluoroquinolone-based versus non-fluoroquinolone-based therapy; and (ii) monotherapy versus combination therapy. The primary endpoint was in-ICU mortality. A multivariable Cox model and propensity score analyses were used.

Results

Two hundred and eleven patients with severe LD were included. A fluoroquinolone-based and a combination therapy were administered to 159 (75%) and 123 (58%) patients, respectively. One hundred and forty-six patients (69%) developed acute respiratory distress syndrome and 54 (26%) died in the ICU. In-ICU mortality was lower in the fluoroquinolone-based than in the non-fluoroquinolone-based group (21% versus 39%, P  =   0.01), and in the combination therapy than in the monotherapy group (20% versus 34%, P  =   0.02). In multivariable analysis, a fluoroquinolone-based therapy, but not a combination therapy, was associated with a reduced risk of mortality [HR = 0.41, 95% CI 0.19-0.89; P  =   0.02].

Conclusions

Patients with severe LD receiving a fluoroquinolone-based antimicrobial regimen in the early course of management had a lower in-ICU mortality, which persisted after adjusting for significant covariates.

Managing the oncologic patient with suspected pneumonia in the intensive care unit

INTRODUCTION

Solid cancer patients are frequently admitted in intensive care units for critical events. Improving survival rates in this setting is considered an achievable goal today. Respiratory failure is the main reason for admission, representing a primary target for research.

AREAS COVERED

This review presents a diagnostic and therapeutic algorithm for pneumonia and other severe respiratory events in the solid cancer population. It aims to increase awareness of the risk factors and the different etiologies in this changing scenario in which neutropenia no longer seems to be a decisive factor in poor outcome. Bacterial pneumonia is the leading cause, but opportunistic diseases and non-infectious etiologies, especially unexpected adverse effects of radiation, biological drugs and monoclonal antibodies, are becoming increasingly frequent. Options for respiratory support and diagnostics are discussed and indications for antibiotics in the management of pneumonia are detailed. Expert commentary: Prompt initiation of critical care to facilitate optimal decision-making in the management of respiratory failure, early etiological assessment and appropriate antibiotic therapy are cornerstones in management of severe pneumonia in oncologic patients.

Dissimilar Fitness Associated with Resistance to Fluoroquinolones Influences Clonal Dynamics of Various Multiresistant Bacteria

Fitness cost associated with resistance to fluoroquinolones was recently shown to vary across clones of methicillin-resistant Staphylococcus aureus and extended-spectrum β-lactamase-producing Klebsiella pneumoniae. The resulting dissimilar fitness should have influenced the clonal dynamics and thereby the rates of resistance for these pathogens. Moreover, a similar mechanism was recently proposed for the emergence of the H30 and H30R lineages of ESBL-producing E. coli and the major international clone (ribotype 027) of Clostridium difficile. Furthermore, several additional international clones of various multiresistant bacteria are suspect to have been selected by an analogous process. An ability to develop favorable mutations in the gyrase and topoisomerase IV genes seems to be a prerequisite for pathogens to retain fitness while showing high-level resistance to fluoroquinolones. Since, the consumption of other "non-fluoroquinolone" groups of antibiotics have also contributed to the rise in resistance rates a more judicious use of antibiotics in general and of fluoroquinolones in particular could ameliorate the international resistance situation.

Hyperoxemia as a risk factor for ventilator-associated pneumonia

Background

Consequences of hyperoxemia, such as acute lung injury, atelectasis, and reduced bacterial clearance, might promote ventilator-associated pneumonia (VAP). The aim of our study was to determine the relationship between hyperoxemia and VAP.

Methods

This retrospective observational study was performed in a 30-bed mixed ICU. All patients receiving invasive mechanical ventilation for more than 48 hours were eligible. VAP was defined using clinical, radiologic, and quantitative microbiological criteria. Hyperoxemia was defined as PaO₂ > 120 mmHg. All data, except those related to hyperoxemia, were prospectively collected. Risk factors for VAP were determined using univariate and multivariate analysis.

Results

VAP was diagnosed in 141 of the 503 enrolled patients (28 %). The incidence rate of VAP was 14.7 per 1000 ventilator days. Hyperoxemia at intensive care unit admission (67 % vs 53 %, OR = 1.8, 95 % CI (1.2, 29), p <0.05) and number of days spent with hyperoxemia were significantly more frequent in patients with VAP, compared with those with no VAP. Multivariate analysis identified number of days spent with hyperoxemia (OR = 1.1, 95 % CI (1.04, 1.2) per day, p = 0.004), simplified acute physiology score (SAPS) II (OR = 1.01, 95 % CI (1.002, 1.024) per point, p < 0 .05), red blood cell transfusion (OR = 1.8, 95 % CI (1.2, 2.7), p = 0.01), and proton pomp inhibitor use (OR = 1.9, 95 % CI (1.03, 1.2), p < 0.05) as independent risk factors for VAP. Other multiple regression models also identified hyperoxemia at ICU admission (OR = 1.89, 95 % CI (1.23, 2.89), p = 0.004), and percentage of days with hyperoxemia (OR = 2.2, 95 % CI (1.08, 4.48), p = 0.029) as independent risk factors for VAP.

Conclusion

Hyperoxemia is independently associated with VAP. Further studies are required to confirm our results.

Comparison of equal doses of continuous venovenous haemofiltration and haemodiafiltration on ciprofloxacin population pharmacokinetics in critically ill patients

OBJECTIVES

Whilst commonly performed in ICUs, renal replacement therapies (RRTs) differ in their solute clearances. There is a paucity of data on ciprofloxacin clearances in different RRT techniques. The aim of this study was to compare the population pharmacokinetics of ciprofloxacin during equal doses of continuous venovenous haemofiltration (CVVHF) and continuous venovenous haemodiafiltration (CVVHDF) in septic patients.

METHODS

Patients receiving 400 mg of ciprofloxacin intravenously 8 or 12 hourly and undergoing either CVVHF or CVVHDF were eligible. Up to 10 blood samples were collected over one dosing interval and analysed by a validated chromatographic method. Population pharmacokinetic analysis and Monte Carlo simulation was undertaken using Pmetrics.

RESULTS

Eighteen sampling intervals were included (8 CVVHDF and 10 CVVHF) from 11 patients (6 patients having sampling during both RRT modes). A two-compartment linear model best described the data. Increasing patient weight was the only covariate associated with increasing drug clearance. The mean (SD) parameter estimates were: clearance, 10.7 (5.3) L/h; volume of distribution of the central compartment, 21.3 (11.3) L; rate constant for drug distribution from the central compartment to the peripheral compartment, 10.9 (4.3) L/h; and rate constant for drug distribution from the peripheral compartment to the central compartment, 2.3 (1.8) L/h. After accounting for patient weight, the mean ciprofloxacin clearance was not statistically different between CVVHF and CVVHDF [11.8 (9.9) and 10.3 (7.4) L/h, respectively, P = 0.43].

CONCLUSIONS

The present study indicates a high pharmacokinetic variability of ciprofloxacin during CVVHF and CVVHDF with no significant differences in clearance apparent. Based on patient weight, higher ciprofloxacin dosing regimens should be used in critically ill patients when difficult-to-treat pathogens are suspected.

Comparative dynamics of the emergence of fluoroquinolone resistance in staphylococci from the nasal microbiota of patients treated with fluoroquinolones according to their environment

Fluoroquinolone-resistant staphylococci (FQRS) are primarily selected in the nasal microbiota during fluoroquinolone (FQ) treatment. To gain insight into the dynamics of the emergence of FQRS, 49 hospitalised patients (HPs) and 62 community patients (CPs) treated with FQs were studied. Nasal swabs were collected before (T0), at the end of (T1) and 1 month after (T2) FQ treatment. FQRS were identified by mass spectrometry. Antibiotic resistance was determined. Pre- and post-exposure staphylococci populations were compared phenotypically and by MLST to determine the origin of FQRS. At T0, 33/49 HPs (67%) and 24/62 CPs (39%) carried FQRS (OR=3.3, 95% CI: 1.4-7.9; P<0.001). Among patients with no FQRS at T0, 15/16 HPs (94%) and 16/38 CPs (42%) had FQRS detected at T1 and/or T2 (OR=19.6, 95% CI: 2.5-902; P<0.001). Among FQRS having emerged, co-resistance to meticillin was detected in 87% and 82% of HPs and CPs, respectively. No selection of resistance emerging from the initial microbiota was evidenced. FQRS showed decreased species diversity in favour of Staphylococcus haemolyticus and Staphylococcus epidermidis. As a consequence of FQ treatment, acquisition of FQRS in the nasal microbiota is frequent in the community and almost inevitable in hospitals. Acquisition from extranasal sites prevails. A restriction in species diversity in favour of more pathogenic and resistant species occurs. This highlights the major impact of FQ treatment on nasal microbiota, the role of the ecological environment in the emergence of FQRS, and the high-risk of dissemination of resistant staphylococci.

Mechanisms of antimicrobial resistance in Gram-negative bacilli

The burden of multidrug resistance in Gram-negative bacilli (GNB) now represents a daily issue for the management of antimicrobial therapy in intensive care unit (ICU) patients. In Enterobacteriaceae, the dramatic increase in the rates of resistance to third-generation cephalosporins mainly results from the spread of plasmid-borne extended-spectrum beta-lactamase (ESBL), especially those belonging to the CTX-M family. The efficacy of beta-lactam/beta-lactamase inhibitor associations for severe infections due to ESBL-producing Enterobacteriaceae has not been adequately evaluated in critically ill patients, and carbapenems still stands as the first-line choice in this situation. However, carbapenemase-producing strains have emerged worldwide over the past decade. VIM- and NDM-type metallo-beta-lactamases, OXA-48 and KPC appear as the most successful enzymes and may threaten the efficacy of carbapenems in the near future. ESBL- and carbapenemase-encoding plasmids frequently bear resistance determinants for other antimicrobial classes, including aminoglycosides (aminoglycoside-modifying enzymes or 16S rRNA methylases) and fluoroquinolones (Qnr, AAC(6′)-Ib-cr or efflux pumps), a key feature that fosters the spread of multidrug resistance in Enterobacteriaceae. In non-fermenting GNB such as Pseudomonas aeruginosa, Acinetobacter baumannii and Stenotrophomonas maltophilia, multidrug resistance may emerge following the sole occurrence of sequential chromosomal mutations, which may lead to the overproduction of intrinsic beta-lactamases, hyper-expression of efflux pumps, target modifications and permeability alterations. P. aeruginosa and A. baumannii also have the ability to acquire mobile genetic elements encoding resistance determinants, including carbapenemases. Available options for the treatment of ICU-acquired infections due to carbapenem-resistant GNB are currently scarce, and recent reports emphasizing the spread of colistin resistance in environments with high volume of polymyxins use elicit major concern.

Impact of fluoroquinolones on human microbiota. Focus on the emergence of antibiotic resistance

The aggregate of microorganisms residing on the surface of the skin, in the oropharynx and in the GI tract, known as the human microbiota, play a major role as natural reservoirs for bacterial resistance to antibiotics. Fluoroquinolones (FQ) are among the most prescribed antibiotics and a major increase in FQ resistance is occurring worldwide. High concentrations of FQ are found in microbial ecosystems explaining their profound effect on the clinically relevant bacteria that compose them. Yet, because of different local pharmacokinetics, distinct selective pressures occur in the different microbiota. Here we review the qualitative and quantitative impact of FQ on the three main human microbiota and their consequences, particularly in terms of emergence of antibiotic resistance. Finally, we review potential actions that could decrease the impact of FQs on microbiota.

Strategies to reduce curative antibiotic therapy in intensive care units (adult and paediatric)

Emerging resistance to antibiotics shows no signs of decline. At the same time, few new antibacterials are being discovered. There is a worldwide recognition regarding the danger of this situation. The urgency of the situation and the conviction that practices should change led the Société de Réanimation de Langue Française (SRLF) and the Société Française d'Anesthésie et de Réanimation (SFAR) to set up a panel of experts from various disciplines. These experts met for the first time at the end of 2012 and have since met regularly to issue the following 67 recommendations, according to the rigorous GRADE methodology. Five fields were explored: i) the link between the resistance of bacteria and the use of antibiotics in intensive care; ii) which microbiological data and how to use them to reduce antibiotic consumption; iii) how should antibiotic therapy be chosen to limit consumption of antibiotics; iv) how can antibiotic administration be optimized; v) review and duration of antibiotic treatments. In each institution, the appropriation of these recommendations should arouse multidisciplinary discussions resulting in better knowledge of local epidemiology, rate of antibiotic use, and finally protocols for improving the stewardship of antibiotics. These efforts should contribute to limit the emergence of resistant bacteria.

Has the use of fluoroquinolones facilitated the widespread dissemination of methicillin-resistant Staphylococcus aureus and extended-spectrum β-lactamase-producing Klebsiella pneumoniae in the healthcare setting?

Our group recently demonstrated that diverse fitness cost associated with resistance to fluoroquinolones allowed the extensive dissemination of the major international clones of both methicillin-resistant Staphylococcus aureus (MRSA) and multiresistant Klebsiella pneumoniae in the healthcare setting. The mechanism described by us was subsequently confirmed by British authors investigating the dynamics of MRSA clones in England. Our results imply that the use of fluoroquinolones should impact the incidence for both MRSA and multiresistant K. pneumoniae. A review of the related clinical studies mostly support this notion and shows that changes in the consumption of fluoroquinolone type antibiotics and the rates for both MRSA and multiresistant ESBL-producing K. pneumoniae remain usually in accordance. Though the association seems strong and the mechanism behind it unequivocal the use of fluoroquinolones should not be abandoned; a more judicious application can be recommended.

Antibiotic stewardship in the intensive care unit

The rapid emergence and dissemination of antimicrobial-resistant microorganisms in ICUs worldwide constitute a problem of crisis dimensions. The root causes of this problem are multifactorial, but the core issues are clear. The emergence of antibiotic resistance is highly correlated with selective pressure resulting from inappropriate use of these drugs. Appropriate antibiotic stewardship in ICUs includes not only rapid identification and optimal treatment of bacterial infections in these critically ill patients, based on pharmacokinetic-pharmacodynamic characteristics, but also improving our ability to avoid administering unnecessary broad-spectrum antibiotics, shortening the duration of their administration, and reducing the numbers of patients receiving undue antibiotic therapy. Either we will be able to implement such a policy or we and our patients will face an uncontrollable surge of very difficult-to-treat pathogens.

Risk factors for hospital-acquired pneumonia caused by carbapenem-resistant Gram-negative bacteria in critically ill patients: a multicenter study in Korea

We performed a case-control study to identify risk factors of carbapenem-resistant Gram-negative bacteria (CRGNB) as an increasing cause of hospital-acquired pneumonia (HAP). The study included critically ill adult patients with HAP whose microbial etiology was identified at eight tertiary centers in Korea between June 2008 and December 2009. Eighty two patients with 86 isolates of CRGNB (62 Acinetobacter baumannii, 14 Pseudomonas aeruginosa, and 10 Stenotrophomonas maltophilia) were included in the case group, and 122 patients with carbapenem-susceptible Gram-negative bacteria were included in the control group. Diabetes mellitus (adjusted odds ratio [aOR] 2.82, 95% confidence interval [95% CI] 1.25-6.38), radiologic score ≥5 (aOR 4.56, 95% CI 2.36-8.81), prior fluoroquinolone (aOR 2.39. 95% CI = 1.07-5.35), or carbapenem usage (aOR 2.82, 95% CI 1.75-17.83) were found to be independent risk factors. Fluoroquinolone and carbapenem should be cautiously used to avoid HAP caused by CRGNB.

Nosocomial pneumonia: lessons learned

Nosocomial pneumonia remains a significant cause of hospital-acquired infection, imposing substantial economic burden on the health care system worldwide. Various preventive strategies have been increasingly used to prevent the development of pneumonia. It is now recognized that patients with health care-associated pneumonia are a heterogeneous population and that not all are at risk for infection with nosocomial pneumonia pathogens, with some being infected with the same organisms as in community-acquired pneumonia. This review discusses the risk factors for nosocomial pneumonia, controversies in its diagnosis, and approaches to the treatment and prevention of nosocomial and health care-associated pneumonia.

Approaching zero: temporal effects of a restrictive antibiotic policy on hospital-acquired Clostridium difficile, extended-spectrum β-lactamase-producing coliforms and meticillin-resistant Staphylococcus aureus

A restrictive antibiotic policy banning routine use of ceftriaxone and ciprofloxacin was implemented in a 450-bed district general hospital following an educational campaign. Monthly consumption of nine antibiotics was monitored in defined daily doses (DDDs) per 1000 patient-occupied bed-days (1000 pt-bds) 9 months before until 16 months after policy introduction. Hospital-acquired Clostridium difficile, meticillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL)-producing coliform cases per month/1000 pt-bds were identified and reviewed throughout the hospital. Between the first and final 6 months of the study, average monthly consumption of ceftriaxone reduced by 95% (from 46.213 to 2.129 DDDs/1000 pt-bds) and that for ciprofloxacin by 72.5% (109.804 to 30.205 DDDs/1000 pt-bds). Over the same periods, hospital-acquisition rates for C. difficile reduced by 77% (2.398 to 0.549 cases/1000 pt-bds), for MRSA by 25% (1.187 to 0.894 cases/1000 pt-bds) and for ESBL-producing coliforms by 17% (1.480 to 1.224 cases/1000 pt-bds). Time-lag modelling confirmed significant associations between ceftriaxone and C. difficile cases at 1 month (correlation 0.83; P<0.005), and between ciprofloxacin and ESBL-producing coliform cases at 2 months (correlation 0.649; P=0.002). An audit performed 3 years after the policy showed sustained reduction in C. difficile rates (0.259 cases/1000 pt-bds), with additional decreases for MRSA (0.409 cases/1000 pt-bds) and ESBL-producing coliforms (0.809 cases/1000 pt-bds). In conclusion, banning two antibiotics resulted in an immediate and profound reduction in hospital-acquired C. difficile, with possible longer-term effects on MRSA and ESBL-producing coliform rates. Antibiotic stewardship is fundamental in the control of major hospital pathogens.

Elderly patients with community-acquired pneumonia: optimal treatment strategies

Community-acquired pneumonia (CAP) is a common infectious disease that still causes substantial morbidity and mortality. Elderly people are frequently affected, and several issues related to care of this condition in the elderly have to be considered. This article reviews current recommendations of guidelines with a special focus on aspects of the care of elderly patients with CAP. The most common pathogen in CAP is still Streptococcus pneumoniae, followed by other pathogens such as Haemophilus influenzae, Mycoplasma pneumoniae, Chlamydophila pneumoniae and Legionella species. Antimicrobial resistance is an increasing problem, especially with regard to macrolide-resistant S. pneumoniae and fluoroquinolone-resistant strains. With regard to β-lactam antibacterials, resistance by H. influenzae and Moraxella catarrhalis is important, as is the emergence of multidrug-resistant Staphylococcus aureus. The main management decisions should be guided by the severity of disease, which can be assessed by validated clinical risk scores such as CURB-65, a tool for measuring the severity of pneumonia based on assessment of confusion, serum urea, respiratory rate and blood pressure in patients aged ≥65 years. For the treatment of low-risk pneumonia, an aminopenicillin such as amoxicillin with or without a β-lactamase inhibitor is frequently recommended. Monotherapy with macrolides is also possible, although macrolide resistance is of concern. When predisposing factors for special pathogens are present, a β-lactam antibacterial combined with a β-lactamase inhibitor, or the combination of a β-lactam antibacterial, a β-lactamase inhibitor and a macrolide, may be warranted. If possible, patients who have undergone previous antibacterial therapy should receive drug classes not previously used. For hospitalized patients with non-severe pneumonia, a common recommendation is empirical antibacterial therapy with an aminopenicillin in combination with a β-lactamase inhibitor, or with fluoroquinolone monotherapy. With proven Legionella pneumonia, a combination of β-lactams with a fluoroquinolone or a macrolide is beneficial. In severe pneumonia, ureidopenicillins with β-lactamase inhibitors, broad-spectrum cephalosporins, macrolides and fluoroquinolones are used. A combination of a broad-spectrum β-lactam antibacterial (e.g. cefotaxime or ceftriaxone), piperacillin/tazobactam and a macrolide is mostly recommended. In patients with a predisposition for Pseudomonas aeruginosa, a combination of piperacillin/tazobactam, cefepime, imipenem or meropenem and levofloxacin or ciprofloxacin is frequently used. Treatment duration of more than 7 days is not generally recommended, except for proven infections with P. aeruginosa, for which 15 days of treatment appears to be appropriate. Further care issues in all hospitalized patients are timely administration of antibacterials, oxygen supply in case of hypoxaemia, and fluid management and dose adjustments according to kidney function. The management of elderly patients with CAP is a challenge. Shifts in antimicrobial resistance and the availability of new antibacterials will change future clinical practice. Studies investigating new methods to detect pathogens, determine the optimal antimicrobial regimen and clarify the duration of treatment may assist in further optimizing the management of elderly patients with CAP.

Colonization with antibiotic-susceptible strains protects against methicillin-resistant Staphylococcus aureus but not vancomycin-resistant enterococci acquisition: a nested case-control study

Introduction

Harboring sensitive strains may prevent acquisition of resistant pathogens by competing for colonization of ecological niches. Competition may be relevant to decolonization strategies that eliminate sensitive strains and may predispose to acquiring resistant strains in high-endemic settings. We evaluated the impact of colonization with methicillin-sensitive Staphylococcus aureus (MSSA) and vancomycin-sensitive enterococci (VSE) on acquisition of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), respectively, when controlling for other risk factors.

Methods

We conducted a nested case-control study of patients admitted to eight ICUs performing admission and weekly bilateral nares and rectal screening for MRSA and VRE, respectively. Analyses were identical for both pathogens. For MRSA, patients were identified who had a negative nares screen and no prior history of MRSA. We evaluated predictors of MRSA acquisition, defined as a subsequent MRSA-positive clinical or screening culture, compared to those with a subsequent MRSA-negative nares screen within the same hospitalization. Medical records were reviewed for the presence of MSSA on the initial MRSA-negative nares screen, demographic and comorbidity information, medical devices, procedures, antibiotic utilization, and daily exposure to MRSA-positive patients in the same ward. Generalized linear mixed models were used to assess predictors of acquisition.

Results

In multivariate models, MSSA carriage protected against subsequent MRSA acquisition (OR = 0.52, CI: 0.29, 0.95), even when controlling for other risk factors. MRSA predictors included intubation (OR = 4.65, CI: 1.77, 12.26), fluoroquinolone exposure (OR = 1.91, CI: 1.20, 3.04), and increased time from ICU admission to initial negative swab (OR = 15.59, CI: 8.40, 28.94). In contrast, VSE carriage did not protect against VRE acquisition (OR = 1.37, CI: 0.54, 3.48), whereas hemodialysis (OR = 2.60, CI: 1.19, 5.70), low albumin (OR = 2.07, CI: 1.12, 3.83), fluoroquinolones (OR = 1.90, CI: 1.14, 3.17), third-generation cephalosporins (OR = 1.89, CI: 1.15, 3.10), and increased time from ICU admission to initial negative swab (OR = 15.13, CI: 7.86, 29.14) were predictive.

Conclusions

MSSA carriage reduced the odds of MRSA acquisition by 50% in ICUs. In contrast, VSE colonization was not protective against VRE acquisition. Studies are needed to evaluate whether decolonization of MSSA ICU carriers increases the risk of acquiring MRSA when discharging patients to high-endemic MRSA healthcare settings. This may be particularly important for populations in whom MRSA infection may be more frequent and severe than MSSA infections, such as ICU patients.

An evaluation of ciprofloxacin pharmacokinetics in critically ill patients undergoing continuous veno-venous haemodiafiltration

Background

The study aimed to investigate the pharmacokinetics of intravenous ciprofloxacin and the adequacy of 400 mg every 12 hours in critically ill Intensive Care Unit (ICU) patients on continuous veno-venous haemodiafiltration (CVVHDF) with particular reference to the effect of achieved flow rates on drug clearance.

Methods

This was an open prospective study conducted in the intensive care unit and research unit of a university teaching hospital. The study population was seven critically ill patients with sepsis requiring CVVHDF.

Blood and ultrafiltrate samples were collected and assayed for ciprofloxacin by High Performance Liquid Chromatography (HPLC) to calculate the model independent pharmacokinetic parameters; total body clearance (TBC), half-life (t_1/2) and volume of distribution (Vd). CVVHDF was performed at prescribed dialysate rates of 1 or 2 L/hr and ultrafiltration rate of 2 L/hr. The blood flow rate was 200 ml/min, achieved using a Gambro blood pump and Hospal AN69HF haemofilter.

Results

Seventeen profiles were obtained. CVVHDF resulted in a median ciprofloxacin t_1/2 of 13.8 (range 5.15-39.4) hr, median TBC of 9.90 (range 3.10-13.2) L/hr, a median V_dss of 125 (range 79.5-554) L, a CVVHDF clearance of 2.47+/-0.29 L/hr and a clearance of creatinine (Cl_cr) of 2.66+/-0.25 L/hr. Thus CVVHDF, at an average flow rate of ~3.5 L/hr, was responsible for removing 26% of ciprofloxacin cleared. At the dose rate of 400 mg every 12 hr, the median estimated C_pmax/MIC and AUC_0-24/MIC ratios were 10.3 and 161 respectively (for a MIC of 0.5 mg/L) and exceed the proposed criteria of >10 for C_pmax/MIC and > 100 for AUC_0-24/MIC. There was a suggestion towards increased ciprofloxacin clearance by CVVHDF with increasing effluent flow rate.

Conclusions

Given the growing microbial resistance to ciprofloxacin our results suggest that a dose rate of 400 mg every 12 hr, may be necessary to achieve the desired pharmacokinetic - pharmacodynamic (PK-PD) goals in patients on CVVHDF, however an extended interval may be required if there is concomitant hepatic impairment. A correlation between ciprofloxacin clearance due to CVVHDF and creatinine clearance by the filter was observed (r² = 0.76), providing a useful clinical surrogate marker for ciprofloxacin clearance within the range studied.

Trial Registration

Current Controlled Trials ISRCTN52722850

Relationship between inhaled β₂-agonists and ventilator-associated pneumonia: a cohort study

OBJECTIVE

To determine the impact of aerosolized bronchodilators on ventilator-associated pneumonia.

DESIGN

Prospective cohort study.

SETTING

A 30-bed medical and surgical intensive care unit.

METHODS

All intubated patients requiring mechanical ventilation for >48 hrs were eligible during a 13-month period. Nebulized β2-agonists were administered at the intensive care unit physician's discretion. Ventilator-associated pneumonia definition included clinical and quantitative microbiological criteria. Only first ventilator-associated pneumonia episodes were analyzed. Risk factors for ventilator-associated pneumonia were determined using univariate and multivariate analyses. The influence of inhaled β2-agonists on ventilator-associated pneumonia occurrence was also adjusted for confounding factors using Cox's proportional-hazards model.

RESULTS

Ventilator-associated pneumonia was diagnosed in 137 (31%) of the 439 enrolled patients. Ventilator-associated pneumonia was early-onset in 14 (10%) patients. The incidence rate of ventilator-associated pneumonia was 20 per 1,000 ventilator days. Ventilator-associated pneumonia was polymicrobial in 16 (11%) patients, and related to multidrug-resistant bacteria in 42 (28%) patients. Most cases of ventilator-associated pneumonia were caused by Gram-negative bacteria. Inhaled β2-agonists were significantly more frequently used in patients with ventilator-associated pneumonia compared with those without ventilator-associated pneumonia (49% vs. 34%, odds ratio [95% confidence interval] = 1.9 [1.2-2.8], p = .003). Multivariate analysis identified aerosolized β2-agonists (odds ratio [95% confidence interval] = 1.7 [1.1-2.6], p = .012), Simplified Acute Physiology Score II at intensive care unit admission (odds ratio [95% confidence interval] = 1.01 [1.001-1.02] per point, p = .031), and red blood cell transfusion (odds ratio [95% confidence interval] = 2 [1.3-3.1], p = .001) as independent risk factors for ventilator-associated pneumonia. Cox's proportional-hazards model also identified inhaled β2-agonists as a risk factor for ventilator-associated pneumonia (odds ratio [95% confidence interval] = 1.52 [1.06-2.19], p = .021).

CONCLUSION

Use of aerosolized bronchodilators in intensive care unit mechanically ventilated patients is an independent risk factor for ventilator-associated pneumonia.

Multi-drug-resistant gram-negative bacterial infection in surgical patients hospitalized in the ICU: a cohort study

We sought to identify risk factors for postoperative infections, caused by multi-drug-resistant gram-negative bacteria (MDR-GNB) in surgical patients. This was a retrospective cohort study among patients hospitalized in the intensive care unit (ICU) for more than 5 days, following general surgical operations. Comparison of patients who developed infection caused by MDR-GNB with the remainder of the cohort showed that every minute of operative time, use of special treatments during hospitalization (antineoplastic, immunosuppressive or immunomodulating therapies), every day of metronidazole, and every day of carbapenems use, increased patients' odds to acquire an infection caused by MDR-GNB by 0.7%, 8.9 times, 9%, and 9%, respectively [OR (95% CI): 1.007 (1.003-1.011), p = 0.001; 8.9 (1.8-17.3), p = 0.004; 1.09 (1.04-1.18), p = 0.039; 1.09 (1.01-1.18), p = 0.023, respectively]. The above were adjusted in the multivariable analysis for the confounder of time distribution of infections caused by MDR-GNB. Finally, the secondary comparison, with patients that did not develop any infection, showed that patients who had received antibiotics, within 3 months prior to admission, had 3.8 times higher odds to acquire an infection caused by MDR-GNB [OR (95% CI): 3.8 (1.07-13.2), p = 0.002]. This study depicts certain, potentially modifiable, risk factors for postoperative infections in patients hospitalized in the ICU for more than 5 days.

Impact of bloodstream infections on outcome and the influence of prophylactic oral antibiotic regimens in allogeneic hematopoietic SCT recipients

This study aimed to determine the impact of blood stream infections (BSIs) on outcome of allogeneic hematopoietic SCT (HSCT), and to examine the influence of old (non-levofloxacin-containing) and new (levofloxacin-based) prophylactic antibiotic protocols on the pattern of BSIs. We retrospectively enrolled 246 allogeneic HSCT recipients between January 1999 and June 2006, dividing patients into BSI (within 6 months post-HSCT, n=61) and non-BSI groups (n=185). We found that Gram-negative bacteria (GNB) predominated BSI pathogens (54%). Multivariate analyses showed that patients with a BSI, compared with those without, had a significantly greater 6-month mortality (hazard ratio, 1.75; 95% confidence interval, 1.09-2.82; P=0.021) and a significantly increased length of hospital (LOH) stay (70.8 vs 55.2 days, P=0.014). Moreover, recipients of old and new protocols did not have a significantly different 6-month mortality and time-to-occurrence of BSIs. However, there were significantly more resistant GNB to third-generation cephalosporins and carbapenem in recipients of levofloxacin-based prophylaxis. Our data suggest that BSIs occur substantially and impact negatively on the outcome and LOH stay after allogeneic HSCT despite antibiotic prophylaxis. Levofloxacin-based prophylaxis, albeit providing similar efficacy to non-levofloxacin-containing regimens, may be associated with increased antimicrobial resistance.

Independent behavior of commensal flora for carriage of fluoroquinolone-resistant bacteria in patients at admission

The important role of commensal flora as a natural reservoir of bacterial resistance is now well established. However, whether the behavior of each commensal flora is similar to that of other floras in terms of rates of carriage and risk factors for bacterial resistance is unknown. During a 6-month period, we prospectively investigated colonization with fluoroquinolone-resistant bacteria in the three main commensal floras from hospitalized patients at admission, targeting Escherichia coli in the fecal flora, coagulase-negative Staphylococcus (CNS) in the nasal flora, and α-hemolytic streptococci in the pharyngeal flora. Resistant strains were detected on quinolone-containing selective agar. Clinical and epidemiological data were collected. A total of 555 patients were included. Carriage rates of resistance were 8.0% in E. coli, 30.3% in CNS for ciprofloxacin, and 27.2% in streptococci for levofloxacin; 56% of the patients carried resistance in at least one flora but only 0.9% simultaneously in all floras, which is no more than random. Risk factors associated with the carriage of fluoroquinolone-resistant strains differed between fecal E. coli (i.e., colonization by multidrug-resistant bacteria) and nasal CNS (i.e., age, coming from a health care facility, and previous antibiotic treatment with a fluoroquinolone) while no risk factors were identified for pharyngeal streptococci. Despite high rates of colonization with fluoroquinolone-resistant bacteria, each commensal flora behaved independently since simultaneous carriage of resistance in the three distinct floras was uncommon, and risk factors differed. Consequences of environmental selective pressures vary in each commensal flora according to its local specificities (clinical trial NCT00520715 [http://clinicaltrials.gov/ct2/show/NCT00520715]).

[Hospital fluoroquinolone prescription habits in northern France]

OBJECTIVE

The aim of the study was to assess the good use organization and fluoroquinolone prescription habits in cases of bone and joint, urinary, pulmonary, and digestive infections.

DESIGN

A declarative survey was made (questionnaire for the hospital and for the prescriber).

RESULTS

Thirty percent (44/145) of hospitals participated with 274 prescribers. Eighty percent had prescription protocols, 71 % of clinicians had access to epidemiologic data. A percentage of 30.7 (853/2,771) of prescriptions included a fluoroquinolone, 44.5 % (380/853) among these had not been recommended. The excessive prescription reached 24.4 % (116/474) in case of bone and joint infection, 14.6 % (107/731), and 20 % (157/779) in cases of digestive and respiratory infection respectively. Prescriptions for urinary infection were adequate in 47.6 % (375/787) of cases. Inadequate prescriptions were made because of bad knowledge of bacteria resistance epidemiology and pharmacology (insufficient dose, monotherapy at risk of selection), and non-application of good practice recommendations.

CONCLUSION

This study justifies the rationalization of antibiotic prescription.

Previous ciprofloxacin exposure is associated with resistance to beta-lactam antibiotics in subsequent Pseudomonas aeruginosa bacteremic isolates

BACKGROUND

Pseudomonas aeruginosa cross-resistance to ceftazidime, imipenem, meropenem, piperacillin, and fluoroquinoles has been shown in experimental studies, but information regarding its impact in the clinical setting is scarce and inconsistent. The aim of this study was to assess whether previous exposure to ciprofloxacin influences on the sensitivity of those antibiotics in subsequent P aeruginosa bacteremic isolates.

METHODS

Patients with P aeruginosa bacteremia were recorded from a blood culture surveillance program (1997-2007). Demographic characteristics, underlying diseases, setting of the infection, source of infection, previous antibiotic exposure, and antibiotic sensitivity were analyzed.

RESULTS

We studied 572 cases of P aeruginosa bacteremia. There were 327 men (57.2%), and the mean age was 61.2 +/- 18 years. The bacteremia was nosocomial in 62.4% of episodes. Resistance rates of P aeruginosa isolates were 15.5% for ceftazidime, 16.7% for imipenem, 11.2% for meropenem, 12.3% for piperacillin-tazobactam, and 23.1% for ciprofloxacin. Exposure to ciprofloxacin during the previous 30 days was an independent predictor of resistance to ceftazidime (odds ratio [OR], 3; 95% confidence interval [CI]: 1.7-5.3; P < .001), imipenem (OR, 2; 95% CI: 1.1-3.7; P = .02), meropenem (OR, 2.7; 95% CI: 1.4-5.3; P = .004), piperacillin-tazobactam (OR, 2.4; 95% CI: 1.3-4.7; P = .007), ciprofloxacin (OR, 2.9; 95% CI: 1.7-4.9; P < .001), and multidrug resistance (OR, 2.5; 95% CI: 1.2-5.2; P = .02).

CONCLUSION

P aeruginosa bacteremic isolates from patients who have been exposed to ciprofloxacin during the 30 days prior to the development of bacteremia have an increased risk of being resistant to ceftazidime, imipenem, meropenem, piperacillin-tazobactam, or ciprofloxacin and to have multidrug resistance.

Carbapenems and subsequent multiresistant bloodstream infection: does treatment duration matter?

It has been proposed that initial empirical broad-spectrum antibiotic therapy will result in better clinical outcomes and that shorter courses will reduce the 'collateral damage' of promoting antibiotic resistance. There are few data from Intensive Care Units (ICUs) that support this latter conclusion. A prospective observational study was undertaken at the National University Hospital, Singapore, to examine the relationship between duration of carbapenem therapy and subsequent nosocomial multidrug-resistant (MDR) bloodstream infection (BSI). Over a 2-year period, 415 ICU patients receiving empirical carbapenem therapy were prospectively followed. MDR BSI occurred on 35 occasions in 31 patients, comprising 21 carbapenem-resistant Acinetobacter baumannii, 3 carbapenem-resistant Pseudomonas aeruginosa and 11 meticillin-resistant Staphylococcus aureus (MRSA). There was no difference in the duration of carbapenems for those who developed MDR BSI compared with those who did not [median duration 8 days (range 3-23 days) vs. 9 days (range 3-59 days); P=0.78]. On multivariate analysis using the Cox proportional hazard model the hazard ratio was 0.935 (P=0.070). In this cohort of critically ill patients, a shorter duration of carbapenem therapy was not shown to protect against subsequent development of MDR BSI. Strategies that depend primarily on reducing broad-spectrum antibiotic duration may be inadequate in preventing the emergence of MDR organisms.

Ventilator-associated pneumonia and oral care: a successful quality improvement project

BACKGROUND

Ventilator-associated pneumonia (VAP) is a nosocomial pneumonia that develops in patients on mechanical ventilation for >or=48 hours. VAP develops at an estimated rate of 1% to 3% per day of mechanical ventilation.

METHODS

Quality improvement project. Mechanically ventilated patients received the following oral care every 4 hours: the teeth were brushed with cetylpyridinium chloride (changed to 0.12% chlorhexidine gluconate in 2007) using a suction toothbrush, the oral cavity was cleansed with suction swabs treated with hydrogen peroxide, a mouth moisturizer was applied, deep oropharyngeal suctioning was performed, and suction catheters were used to control secretions. The primary efficacy variable was a diagnosis of VAP in patients mechanically ventilated for >or=48 hours.

RESULTS

The historical average rate of VAP in 2004 was 12.6 cases/1000 ventilator-days. After the inception of the quality improvement project, VAP rates decreased to 4.12 (VAP cases/days of ventilation x 1000) for May to December 2005, to 3.57 for 2006, and to 1.3 for 2007.

CONCLUSION

The use of an oral care protocol intervention and ventilator bundle led to an 89.7% reduction in the VAP rate in mechanically ventilated patients from 2004 to 2007.

Detection of point mutations associated with antibiotic resistance in Pseudomonas aeruginosa

Excessive use of broad-spectrum antibiotics in hospitals has led to the emergence of highly resistant strains of Pseudomonas aeruginosa. To reduce the selection pressure for resistance, it is important to determine the antibiotic susceptibility pattern of bacteria so that hospital patients can be treated with more narrow-spectrum and target-specific antibiotics. This study describes the development of a technique for detecting point muations in the fluoroquinolone resistance-determining region of the gyrA and parC genes as well as the efflux regulatory genes mexR, mexZ and mexOZ that are associated with fluoroquinolone and aminoglycoside resistance. The assay is based on a short DNA sequencing method using multiplex-fast polymerase chain reaction (PCR) and Pyrosequencing for amplification and sequencing of the selected genes. Fifty-nine clinical isolates of P. aeruginosa were examined for mutations in the abovementioned genes. Mutations related to antibiotic resistance were detected in codons 83 and 87 of gyrA and codon 126 of the mexR regulatory gene. Results of this study suggest Pyrosequencing as a substitute for traditional methods as it provides a rapid and reliable technique for determining the antibiotic resistance pattern of a given bacterial strain in <1 h.

Determinação da resistência antimicrobiana associada em isolados clínicos de Staphylococcus aureus e Pseudomonas aeruginosa em um hospital público de Goiânia, Estado de Goiás

Este estudo avaliou a resistência antimicrobiana associada de Pseudomonas aeruginosa e Staphylococcus aureus a um agente antimicrobiano com outras drogas. A resistência antimicrobiana associada foi calculada através do risco relativo. Houve uma relação óbvia entre resistência à oxacilina e a outros agentes antimicrobianos entre os isolados de Staphylococcus aureus resistentes à oxacilina (68,5%) superior a 32%, com exceção da linezolida (6,7%). Resistência associada pronunciada entre drogas foi observada para isolados de Pseudomonas aeruginosa, particularmente entre ciprofloxacina e os carbapenens (59,6% a 60,7%), entre aminoglicosídeos e carbapenens (66,3% a 67,7%) e os demais β-lactâmicos (52,3% a 85,8%). O presente trabalho enfatiza a importância da cultura diagnóstica e do teste de suscetibilidade na seleção de um correto agente antimicrobiano com relação ao impacto clínico no aumento da multirresistência e na seleção de resistência antimicrobiana associada.

Does nonadherence to local recommendations for empirical antibiotic therapy on admission to the intensive care unit have an impact on in-hospital mortality?

Objective

1/ To evaluate if empirical antibiotic prescription on admission to our intensive care unit (ICU) respects the local recommendations for antibiotic prescription and to identify predictors of nonadherence to these guidelines. 2/ To assess whether nonadherence to the guidelines is associated with increased in-hospital mortality due to the initial infection.

Materials and methods

This was a prospective six-month observational study performed in a 14-bed medical ICU. Patients were included if they received curative antibiotic therapy on admission. Respect of the local treatment recommendations was evaluated according to adherence to the local empirical guidelines defined in a 80-page booklet which is given in our hospital to every physician.

Results

Among 132 antibiotic prescriptions, 21 (16%) were unjustified (absence of infection), 17 (13%) were microbiologically documented at admission, and nine (7%) were given for infections from unknown origin. Among the 85 (64%) empirical prescriptions that could be evaluated for adherence to local recommendations, nine (11%) were inappropriate and 76 (89%) appropriate. In univariate analysis hospital-acquired infection was the sole predictor of inappropriate treatment (p = 0.0475). Independent predictors of in-hospital mortality due to the initial infection were inappropriate empirical treatment (odds ratio [OR] = 14.64, 95% confidence interval [CI]: 2.17–98.97; p = 0.006), prescription of fluoroquinolones (OR = 8.22, 95% CI: 1.88–35.95; p = 0.005) and a higher Simplified Acute Physiology Score II score (per one-point increment (OR = 1.04, 95% CI: 1.01–1.07; p = 0.02).

Conclusion

Nonadherence to local empirical antibiotic therapy guidelines was associated with increased in-hospital mortality due to the initial infection.