Acquisition and spread of Acinetobacter baumannii and Stenotrophomonas maltophilia in intensive care patients

Microbial Evolution in Artisanal Pecorino-like Cheeses Produced from Two Farms Managing Two Different Breeds of Sheep (Comisana and Lacaune)

"Pecorino" is a typical semi-hard cheese obtained with raw or heat-treated sheep milk using procedures to valorize the raw material's chemical and microbiological properties. In the present study, using a high-throughput method of 16S rRNA gene sequencing, we assessed the evolution of the microbiome composition from milk to Pecorino-like cheese in artisanal processes using milk from Comisana and Lacaune sheep breeds. The comparative analysis of the bacterial community composition revealed significant differences in the presence and abundance of specific taxa in the milk microbiomes of the Comisana and Lacaune breeds. Next-Generation Sequencing (NGS) analysis also revealed differences in the curd microbiomes related to dairy farming practices, which have a relevant effect on the final structure of the Pecorino cheese microbiome.

Clonal spread of trimethoprim-sulfamethoxazole-resistant Stenotrophomonas maltophilia isolates in a tertiary hospital

Aim

The aims of this study were to: (i) determine antibiotic susceptibility of clinical Stenotrophomonas maltophilia isolates, (ii) investigate the presence of different classes of integrons and sul genes responsible for sulphonamide resistance, (iii) assess the molecular epidemiology of the isolates by determining their clonal relatedness, and (iv) investigate the potential sources of infection by collecting environmental samples when necessary.

Methods

99 S. maltophilia isolates from clinical specimens of hospitalized patients were screened by PCR for sul1, sul2, sul3 genes, and integron-associated integrase genes: intI1, intI2, and intI3. PFGE was used to determine the clonal relatedness of the isolates.

Results

Susceptibility rates for trimethoprim-sulfamethoxazole, levofloxacin, and ceftazidime were 90.9%, 91.9%, and 53.5% respectively. All trimethoprim-sulfamethoxazole-resistant isolates were positive for intI1 and sul1. PFGE analysis revealed that 24 of the isolates were clonally related, clustering in seven different clones. Five of the nine trimethoprim-sulfamethoxazole-resistant isolates were clonally related. The first isolate in this clone was from a wound sample of a patient in the infectious diseases clinic, and the other four were isolated from the bronchoalveolar lavage samples of patients in the thoracic surgery unit. The patient with the first isolate neither underwent bronchoscopy nor stayed in the thoracic surgery unit. Although clustering was observed in bronchoalveolar lavage samples, no S. maltophilia growth was detected in environmental samples.

Conclusion

The findings demonstrated that the sul1 gene carried by class 1 integrons plays an important role in trimethoprim-sulfamethoxazole resistance in S. maltophilia isolates. PFGE analysis revealed a high degree of genetic diversity. However, detection of clonally related isolates suggests the acquisition from a common source and/or cross-transmission of this microorganism between the patients.

Stenotrophomonas maltophilia outbreak originating from a pull-out faucet in a pediatric intensive care unit in Turkey: Insights from clinical records and molecular typing

BACKGROUND

Nosocomial Stenotrophomonas maltophilia-related cases are rising and pose a threat to immunocompromised patients. Twelve patients from our pediatric intensive care unit (PICU) presented with S maltophilia-associated bloodstream infection.

METHODS

This outbreak investigation includes 12 patients from PICU between the ages of 2 months and 4 years (mean 16 months, 7 male). To identify the origin, samples from all possible sources throughout the hospital were collected and ran through DNA isolation and Pulse Field Gel Electrophoresis.

RESULTS

120 samples were collected during the outbreak. 31 samples (26%) were positive for S maltophilia. 30 S maltophilia isolates were analyzed, 10 different genotypes were identified. Clustering isolates were grouped into 3 different clusters (tolerance and optimization 1.0, cutoff 90%). The largest cluster was genotype 1, which included 19 isolates, those belong to patients' samples and a sample from a pull-out faucet inside the PICU. The Pull-out faucet was the origin of the bloodstream infection.

DISCUSSION

Pull-out faucets allow biofilm production, due its structure. Pulse Field Gel Electrophoresis identifies the transmission dynamics of the outbreak, with its high discriminatory power.

CONCLUSIONS

Water sources should be monitored on a regular basis. Pull-out faucets enable bacterial overgrowth; therefore, we recommend water surveillance during outbreak investigations.

Molecular Typing and Resistance Profile of Acinetobacter baumannii Isolates during the COVID-19 Pandemic: Findings from the "EPIRADIOCLINF" Project

Due to the COVID-19 pandemic, there has been a shift in focus towards controlling the spread of SARS-CoV-2, which has resulted in the neglect of traditional programs aimed at preventing healthcare-associated infections and combating antimicrobial resistance. The present work aims to characterize the colonization or infection with Acinetobacter baumannii of COVID-19 patients and to identify any clonality between different isolates. Specifically, data and resistance profiles of A. baumannii isolates were prospectively collected from patients recruited by the EPIRADIOCLINF project. Pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) were used for molecular typing. Overall, we analyzed 64 isolates of A. baumannii from 48 COVID-19 patients. According to our analysis, we have identified the spread of a clonally related isolate, referred to as B. The PFGE pattern B includes four subtypes: B1 (consisting of 37 strains), B2 (11), B3 (5), and B4 (2). Furthermore, in the isolates that were examined using MLST, the most observed sequence type was ST/281. In terms of resistance profiles, 59 out of the total isolates (92.2%) were found to be resistant to gentamicin, carbapenems, ciprofloxacin, and tobramycin. The isolation and identification of A. baumannii from COVID-19 patients, along with the high levels of transmission observed within the hospital setting, highlight the urgent need for the implementation of effective prevention and containment strategies.

Upraising Stenotrophomonas maltophilia in Critically Ill Patients: A New Enemy?

Stenotrophomonas maltophilia (S. maltophilia), an important pathogen in immuno-compromised patients, has recently gained attention in patients admitted in intensive care units (ICU). We sought to investigate clinical features of infections caused by S. maltophilia in ICU patients and identify risk factors for mortality. We conducted a retrospective study in two multivalent non-COVID-19 ICUs of tertiary-teaching hospitals in Greece and Spain, including patients with isolated S. maltophilia from at least one clinical specimen along with clinical signs of infection. A total of 103 patients (66% male) were analyzed. Median age was 65.5 (54–73.3) years and mean APACHE II and SOFA scores upon ICU admission were 18.36 (±7.22) and 18.17 (±6.95), respectively. Pneumonia was the predominant clinical syndrome (72.8%), while 22% of cases were among hemato/oncology patients. Crude 28-day mortality rate was 54.8%, even though, 14-day clinical and microbiological response was 96%. Age, APACHE II on ICU admission, hemato-oncologic disease, and multi-organ failure were initially identified as potential predictors of mortality. In the multivariable analysis, only increasing age and hemato-oncologic disease were shown to be independent risk factors for 28-day mortality. High all-cause mortality was observed in critically ill patients with predominantly respiratory infections by S. maltophilia, despite initial clinical and laboratory response after targeted treatment. The study elucidates a potentially worrisome emerging pathogen in the ICU.

Colonization of the central venous catheter by Stenotrophomonas maltophilia in an ICU setting: An impending outbreak managed in time

BACKGROUND

Stenotrophomonas maltophiliacauses opportunistic infections in immunocompromised and patients in intensive care units (ICUs). An outbreak of S. maltophilia in ICU is described which highlights the importance of the risk of infection from contaminated medical devices and suction fluids in ventilated patients.

METHODS

The investigation of the outbreak was carried out. Environmental sampling was done. This was followed by MALDI-TOF MS typing and recA gene-based-phylogeny.

RESULTS

In February, S. maltophilia was reported from the central line blood of six patients from ICU within a span of two weeks. The peripheral line blood cultures were sterile in all patients. Relevant environmental sampling of the high-touch surface and fluids revealed S. maltophilia strains in normal saline used for suction and in the inspiratory circuit of two patients. The isolated strains from patients and environment (inspiratory fluid) showed a minimum of 95.41% recA gene sequence identity between each other. Strict cleaning and disinfection procedures were followed. Continuous surveillance was done and no further case of S. maltophilia was detected. Timely diagnosis and removal of central line prevented development of central-line associated blood stream infection.

CONCLUSION

This outbreak report illustrates that environmental sources like suction fluid and normal saline could be the source of S. maltophilia in ICU patients.

The "Obiettivo Antibiotico" Campaign on Prudent Use of Antibiotics in Sicily, Italy: The Pilot Phase

The issue of antimicrobial resistance (AMR) is a focus of the World Health Organization, which proposes educational interventions targeting the public and healthcare professionals. Here, we present the first attempt at a regionwide multicomponent campaign in Sicily (Italy), called "Obiettivo Antibiotico", which aims to raise the awareness of prudent use of antibiotics in the public and in healthcare professionals. The campaign was designed by an interdisciplinary academic team, and an interactive website was populated with different materials, including key messages, letters, slogans, posters, factsheets, leaflets, and videos. The campaign was launched in November 2018 and, as of 21 December 2018, the website had a total of 1159 unique visitors, of which 190 became champions by pledging to take simple actions to support the fight against AMR. Data from social media showed that the audience was between 18 and 54 years of age, with a high proportion of female participants (64%). Interestingly, the LinkedIn page received more than 1200 followers, and Facebook 685 followers. The number of actions taken (pledges) by the audience was 458, evenly divided between experts (53%) and the general public (47%). Additional efforts are needed to reach more people, thus future efforts should focus on further promotion within the Sicilian region to sustain the engagement with the campaign.

Antibiotic Consumption and Resistance during a 3-Year Period in Sicily, Southern Italy

Antimicrobial resistance (AMR) is one of the biggest issues facing global public health. In 2017, Italy adopted its first National Action Plan on Antimicrobial Resistance 2017-2020, which works through the synergy between national, regional, and local levels. In the framework of a Regional Action Plan on healthcare-associated infections and AMR prevention, the Sicilian Health Authority of the Sicilian Region, Southern Italy, has implemented a surveillance system of antibiotic consumption in hospitals, in the community, and of resistance rates (RRs) in hospital settings. Data on antibiotic consumption and on antibiotic RRs have been collected from 2015 to 2017 from pharmacies and laboratories of participating hospitals and from community, respectively. Data on antibiotic consumption showed that the most consumed antibiotics in hospitals were fluoroquinolones in 2015, penicillin in 2016, and beta-lactams in 2017. From 2015 to 2017, data on Klebsiella pneumoniae showed significant increasing RRs to all antibiotic classes, except to carbapenems. RRs of third-generation cephalosporins and carbapenems Escherichia coli showed significant decreasing trends. RRs of the other microorganisms did not change significantly during the study period. The results from the present study show that in Sicily, the use of antibiotics and RRs for selected microorganisms are at a high level. Immediate strategies are needed to decrease the inappropriate usage of antibiotics and control the spread of AMR.

Preventable proportion of intubation-associated pneumonia: Role of adherence to a care bundle

Objective

The aim of the present study was to estimate the preventable proportion of Intubation-Associated Pneumonia (IAP) in the Intensive Care Units (ICUs) participating in the Italian Nosocomial Infections Surveillance in ICUs (SPIN-UTI) network, taking into account differences in intrinsic patients’ risk factors, and additionally considering the compliance with the European bundle for IAP prevention.

Methods

A prospective patient-based survey was conducted and all patients staying in ICU for more than 2 days were enrolled in the surveillance. Compliance with the bundle was assessed using a questionnaire for each intubated patient. A twofold analysis by the parametric g-formula was used to compute the number of infections to be expected if the infection incidence in all ICUs could be reduced to that one of the top-tenth-percentile-ranked ICUs and to that one of the ICU with the highest compliance to all five bundle components.

Results

A total of 1,840 patients and of 17 ICUs were included in the first analysis showing a preventable proportion of 44% of IAP. In a second analysis on a subset of data, considering compliance with the European bundle, a preventable proportion of 40% of IAP was shown. A significant negative trend of IAP incidences was observed with increasing number of bundle components performed (p<0.001) and a strong negative correlation between these two factors was shown (r = -0.882; p = 0.048).

Conclusions

The g-formula controlled for time-varying factors is a valuable approach for estimating the preventable proportion of IAP and the impact of interventions, based entirely on an observed population in a real-world setting. However, both the study design that cannot definitively prove a causative relationship between bundle compliance and IAP risk, and the small number of patients included in the care bundle compliance analysis, may represent limits of the study and further and larger studies should be conducted.

Acinetobacter baumannii strains isolated from patients in intensive care units in Goiânia, Brazil: Molecular and drug susceptibility profiles

Resistance to antimicrobial agents is increasing worldwide and imposes significant life-threatening risks to several different populations, especially those in intensive care units (ICUs). Bacteria can quickly develop or acquire resistance to antimicrobial drugs, and combined with their intrinsic potential to cause disease in humans, these bacteria can become deadly. Among Gram-negative bacteria, Acinetobacter baumannii is notorious as a frequent opportunistic pathogen associated with critically ill patients, and understanding the genetic basis of A. baumannii resistance to beta-lactams among patients in ICUs will result in better protocols to prevent the development of resistance as well as improved treatment regimens. In this study, we assessed 1333 patients in five ICUs, 56 of whom developed A. baumannii infections. Most of the A. baumannii isolates were resistant to beta-lactam antimicrobial drugs, specifically, 3rd- and 4th-generation cephalosporins and carbapenems, and 91.1% of the isolates were multi-drug resistant (MDR). The most frequent OXA gene present was OXA-23 (55.1%), which is significantly associated with MDR strains. Most of the A. baumannii isolates (76.8%) were capable of forming a biofilm. The antimicrobial drug classes that were effective against most of these isolates were polymyxins and tigecycline. The molecular profile of the isolates allowed detection of 12 different clusters comprising 2 to 8 isolates each. In conclusion, our data indicate a high incidence of resistance to carbapenems as well as MDR strains among the observed A. baumannii isolates, most of which exhibited a high prevalence of OXA-23 gene expression. Only a few selective drugs were effective, reinforcing the notion that bacterial resistance is an emerging problem that should be prioritized in every healthcare facility.

Occurrence of Stenotrophomonas maltophilia in agricultural soils and antibiotic resistance properties

The occurrence of Stenotrophomonas maltophilia was monitored in organic amendments and agricultural soils from various sites in France and Tunisia. S. maltophilia was detected in horse and bovine manures, and its abundance ranged from 0.294 (±0.509) × 10(3) to 880 (±33.4) × 10(3) CFU (g drywt)(-1) of sample. S. maltophilia was recovered from most tested soil samples (104/124). Its abundance varied from 0.33 (±0.52) to 414 (±50) × 10(3) CFU (g drywt)(-1) of soil and was not related to soil characteristics. Antibiotic resistance properties of a set of environmental strains were compared to a clinical set, and revealed a high diversity of antibiotic resistance profiles, given both the numbers of resistance and the phenotypes. Manure strains showed resistance phenotypes, with most of the strains resisting between 7 and 9 antibiotics. While French soil strains were sensitive to most antibiotics tested, some Tunisian strains displayed resistance phenotypes close to those of clinical French strains. Screening for metal resistance among 66 soil strains showed a positive relationship between antibiotic and metal resistance. However, the prevalence of antibiotic resistance phenotypes in the studied sites was not related to the metal content in soil samples.

First multicenter study on multidrug resistant bacteria carriage in Chinese ICUs

Background

The importance of multidrug-resistant organisms (MDRO) in Chinese hospitals is not clearly delineated. Thus we sought to assess the prevalence of MDRO in Chinese intensive care units (ICUs).

Methods

Prospective study of inpatients admitted consecutively to eight ICUs in four Chinese cities in 2009–10. Admission and weekly screenings were performed by using selective media for methicillin resistant Staphylococcus aureus, extended-spectrum beta-lactamase-producing Enterobacteriaceae, Acinetobacter and Pseudomonas aeruginosa. For the two latters, resistance to ceftazidime defined MDRO. Backward logistic regression models were designed to assess factors independently associated with MDRO carriage on admission and MDRO acquisition within ICUs.

Results

686 patients were included, and the MDRO prevalence rate on admission was 30.5 % (32.7 % for ESBL-positive Enterobacteriaceae, 3.2 % for MRSA). Antibiotic treatment prior to ICU admission was independently associated with carriage on admission (OR: 1.4) in multivariate analysis. A total of 104 patients acquired ≥1 MDRO in ICU (overall attack rate: 23.7 %; 14.9 % for ESBL-positive Enterobacteriaceae, and 5.1 % for MRSA). The MDRO attack rate increased from 13.2 % in the first week to 82.1 % for ICU stay > 3 weeks. Duration of antibiotic exposure (OR: 1.16; 1.1–1.2) and prior antibiotic treatment before ICU (OR: 2.1; 1.1–3.3) were associated with MDRO acquisition in multivariate analysis. The MDRO prevalence rate on ICU discharge was 51.2 % and the global prevalence density rate 71 per 1000 hospital-days.

Conclusion

More than one out of two patients was MDRO carrier on ICU discharge in Chinese hospitals. This is the result of the combination of a high MDRO prevalence rate on ICU admission and a high MDRO acquisition rate within ICU.

The role of systemic antibiotics in acquiring respiratory tract colonization with gram-negative bacteria in intensive care patients: a nested cohort study

OBJECTIVE

Colonization of the respiratory tract with Gram-negative bacteria in intensive care patients increases the risk of subsequent infections. Application of systemic antibiotics may prevent colonization with Gram-negative bacteria, but this effect has never been quantified. The objective of this study was to determine associations between systemic antibiotic use and acquisition of respiratory tract colonization with Gram-negative bacteria in ICUs.

DESIGN

A nested cohort study.

SETTING

A university hospital and a teaching hospital.

PATIENTS

Patients with ICU stay of more than 48 hours and absence of respiratory tract colonization with Gram-negative bacteria on ICU admission.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Acquisition was determined through protocolized surveillance. Associations were investigated with Cox regression models with antibiotics as a time-dependent covariate. In all, 250 of 481 patients (52%) acquired respiratory tract colonization with Gram-negative bacteria after a median of 5 days (interquartile range, 3-8 d) (acquisition rate, 77.1/1,000 patient-days at risk). Antibiotic exposure during ICU admission was present in 78% and 72% of the patients with and without acquired Gram-negative bacteria colonization, respectively. In Kaplan-Meier curve analysis, the median times to acquisition of Gram-negative bacteria were 9 days (95% CI, 7.9-10.1) and 6 days (95% CI, 4.8-7.2) in patients receiving and not receiving antibiotics, respectively. In time varying Cox regression analysis, however, the association between acquired colonization and systemic antibiotics was not statistically significant (hazard ratio, 0.90; 95% CI, 0.70-1.16).

CONCLUSIONS

Among patients not colonized with Gram-negative bacteria in the respiratory tract at admission to ICU, systemic antibiotics during ICU stay were not associated with a reduction in acquisition of Gram-negative bacteria carriage in the respiratory tract during the ICU stay.

Stenotrophomonas maltophilia infection among young children in a cardiac intensive care unit: a single institution experience

Stenotrophomonas maltophilia can present as bacteremia, respiratory tract infection, urinary tract infection, soft tissue and wound infections, bone and joint infections, meningitis, and endocarditis especially in immunosuppressed patients and those with underlying medical conditions. The incidence and impact of S. maltophilia in young children with heart disease are poorly defined. A single center retrospective observational study was conducted in infants <180 days of age with positive S. maltophilia cultures over a period of 5 years. The overall incidence for S. maltophilia infection was 0.8 % (n = 32/3656). Among 32 identified infants, there were 47 episodes of S. maltophilia infection 66 % of infants had prior exposure to broad spectrum antibiotics. 97 % of positive isolates were susceptible to trimethoprim/sulfamethoxazole and 91 % to levofloxacin as well as ticarcillin/clavulanate. Ventilator-free days and absolute lymphocyte count prior to acquiring infection were significantly lower in non-survivors than in survivors. 100 % of survivors had clearance of positive cultures compared to 50 % in non-survivors (p < 0.05). The crude all-cause mortality rate was 37.5 %. All non-survivors had increased length of ICU stay and duration of mechanical ventilation and had delayed clearance of infection and required longer duration of treatment.

A review of 11 years of Stenotrophomonas maltophilia blood isolates at a tertiary care institute in Canada

BACKGROUND

Stenotrophomonas maltophilia has emerged as a significant nosocomial pathogen with increasing resistance to trimethoprim/sulphamethoxazole (TMP/SMX), the current drug of choice for treatment.

OBJECTIVES

To describe the microbiological and clinical characteristics of S maltophilia bloodstream infections (BSIs) over an 11-year period at a tertiary care centre in Canada.

METHODS

All adult S maltophilia BSIs from 1999 to 2009 in a 750-bed tertiary care teaching hospital (University of Alberta Hospital, Edmonton, Alberta) were identified through the infection control nosocomial infection surveillance program. Demographic and clinical data were extracted from the infection control database and from patient charts. Microbiological data were confirmed through the laboratory information system.

RESULTS

Twenty-five episodes of S maltophilia BSI (0.9% of all BSIs) involving 24 patients were identified between 1999 and 2009. The patient age range was 18 to 83 years (average 45.7 years). The majority were men (14 of 24 [58.3%]). The mean length of hospital stay was 83.3 days (range eight to 310 days). The rate of S maltophilia BSIs per 1000 admissions ranged from 0.04 to 0.22 (average 0.09). Greater than one-half of the episodes (13 of 25 [52%]) were admitted to the intensive care unit before BSI onset. Laboratory data were available for 24 of the 25 isolates. Polymicrobial infections were present in 11 of 24 (45.8%) patients. Resistance to TMP/SMX occurred in 8.3% of all infections. Fifteen per cent of isolates were resistant to ticarcillin/clavulanate. Mortality attributed to bacteremia was 16.7%.

CONCLUSIONS

In the University of Alberta Hospital, the rate of S maltophilia BSI remains low and constant, and TMP/SMX remains the drug of choice for treatment.

Stenotrophomonas maltophilia in Malaysia: molecular epidemiology and trimethoprim-sulfamethoxazole resistance

OBJECTIVES

Stenotrophomonas maltophilia is a recently identified nosocomial pathogen in Malaysia. Despite limited pathogenicity, its rate of isolation has increased in recent years. The aim of this study was to investigate the antibiotic susceptibility patterns, antibiotic resistance determinants, and the epidemiology of S. maltophilia at the largest tertiary care hospital in Malaysia.

METHODS

This study was carried out from January to December 2008. Sixty-four S. maltophilia isolates were investigated for their antibiotic susceptibility patterns by disk diffusion test and E-test. The antibiotic resistance mechanism for trimethoprim-sulfamethoxazole (TMP-SMX) was assessed by PCR for sul1, sul2, qac/smr, and class 1 integrons in general. Epidemiological relatedness among isolates was determined by pulsed-field gel electrophoresis (PFGE).

RESULTS

The highest number of S. maltophilia infections was observed in the intensive care unit (ICU) (n=13; 20.3%), while the lowest number of infections was seen in the neurology, psychiatric, and dermatology wards (each n=1; 1.6%). All isolates were susceptible to minocycline. One isolate was resistant to TMP-SMX with a minimum inhibitory concentration (E-test) >32 mg/l. The strain carried the sul1 gene and class 1 integron. None of the isolates were positive for the qac/smr genes. Although the data suggest the potential for patient to patient transmission, most of the S. maltophilia strains showed unrelated PFGE patterns and were considered to be genetically diverse.

CONCLUSION

The increasing number of S. maltophilia isolates seen in the ICU, their resistance to mainstay antibiotics, their genetically diverse nature, and possible cross-transmission within the hospital, strongly underscores the need for continuous surveillance for S. maltophilia in the hospital setting.

Early use of imipenem/cilastatin and vancomycin followed by de-escalation versus conventional antimicrobials without de-escalation for patients with hospital-acquired pneumonia in a medical ICU: a randomized clinical trial

Introduction

Although early use of broad-spectrum antimicrobials in critically ill patients may increase antimicrobial adequacy, uncontrolled use of these agents may select for more-resistant organisms. This study investigated the effects of early use of broad-spectrum antimicrobials in critically ill patients with hospital-acquired pneumonia.

Methods

We compared the early use of broad-spectrum antimicrobials plus subsequent de-escalation (DE) with conventional antimicrobial treatment (non-de-escalation, NDE) in critically ill patients with hospital-acquired pneumonia (HAP). This open-label, randomized clinical trial was performed in patients in a tertiary-care center medical intensive care unit (MICU) in Korea. Patients (n = 54) randomized to the DE group received initial imipenem/cilastatin plus vancomycin with subsequent de-escalation according to culture results, whereas patients randomized to the NDE group (n = 55) received noncarbapenem, nonvancomycin empiric antimicrobials.

Results

Between November 2004 and October 2006, 109 MICU patients with HAP were enrolled. Initial antimicrobial adequacy was significantly higher in the DE than in the NDE group for Gram-positive organisms (100% versus 14.3%; P < 0.001), but not for Gram-negative organisms (64.3% versus 85.7%; P = 0.190). Mean intensive care unit (ICU) stay, and 14-day, 28-day, and overall mortality rates did not differ in the two groups. Among culture-positive patients, mortality from methicillin-resistant Staphylococcus aureus (MRSA) pneumonia was higher in the DE group, even after early administration of vancomycin. Multidrug-resistant organisms, especially MRSA, were more likely to emerge in the DE group (adjusted hazard ratio for emergence of MRSA, 3.84; 95% confidence interval, 1.06 to 13.91).

Conclusions

The therapeutic advantage of early administration of broad-spectrum antimicrobials, especially with vancomycin, was not evident in this study.

Stenotrophomonas maltophilia in the respiratory tract of medical intensive care unit patients

The purpose of this study was to investigate characteristics of critically ill patients with Stenotrophomonas maltophilia (S. maltophilia) isolated from the respiratory tract, to identify risk factors for S. maltophilia-pneumonia and intensive care unit (ICU) mortality and to analyze antibiotic susceptibility of S. maltophilia. This was a retrospective analysis of 64 medical ICU patients with S. maltophilia in the respiratory tract. Thirty-six patients fulfilled the criteria for diagnosis of pneumonia. A significantly higher lung injury score (LIS) was observed in patients with pneumonia compared to patients with colonization (p=0.010). Independent risk factors for S. maltophilia-pneumonia were higher Sequential Organ Failure Assessment (SOFA) score (p=0.009) and immunosuppression (p=0.014). Patients with S. maltophilia-pneumonia had higher ICU mortality within a 28-day follow-up (p=0.040) and higher hospital mortality (p=0.018) than patients with colonization. The highest antibiotic susceptibility rates were observed to trimethoprim-sulfamethoxazole, tigecycline, and moxifloxacin. Higher SOFA score when S. maltophilia was isolated (p=0.001) and development of renal failure (p=0.021) were independent risk factors for ICU mortality. Higher SOFA score and immunosuppression are independent risk factors for S. maltophilia-pneumonia. Patients with S. maltophilia-pneumonia have a significantly higher ICU mortality within a 28-day follow-up, hospital mortality and LIS compared to patients with S. maltophilia-colonization.

Antibacterial effects of theaflavin and synergy with epicatechin against clinical isolates of Acinetobacter baumannii and Stenotrophomonas maltophilia

Stenotrophomonas maltophilia and Acinetobacter baumannii are recognised as important nosocomial pathogens; however, due to their intrinsic resistance to multiple antibiotics, treatment options are limited. Polyphenols from black tea have been shown to possess antibacterial action. In this study, the antibacterial effects of various concentrations of theaflavin as well as combinations of theaflavin and epicatechin were determined using the disk diffusion assay. The results showed strong antibacterial activity of theaflavin against eight clinical isolates of S. maltophilia and A. baumannii. Significant synergy (P≤0.05) was also observed between theaflavin and epicatechin against all isolates. Although the mechanisms for this activity and synergy are not well understood, the clinical potential is clear and further research is recommended to determine the modes of action.

Stenotrophomonas maltophilia: emerging disease patterns and challenges for treatment

Stenotrophomonas maltophilia is a ubiquitous organism associated with opportunistic infections. In the immunocompromised host, increasing prevalence and severity of illness is observed, particularly opportunistic bloodstream infections and pneumonia syndromes. In this article, the classification and microbiology are outlined, together with clinical presentation, outcomes and management of infections due to S. maltophilia. Although virulence mechanisms and the genetic basis of antibiotic resistance have been identified, a role for standardized and uniform reporting of antibiotic sensitivity is not defined. Infections due to S. maltophilia have traditionally been treated with trimethoprim-sulfamethoxazole, ticarcillin-clavulanic acid, or fluoroquinolone agents. The use of combination therapies, newer fluoroquinolone agents and tetracycline derivatives is discussed. Finally, measures to prevent transmission of S. maltophilia within healthcare facilities are reported, especially in at-risk patient populations.

Rapid control of a hospital-wide outbreak caused by extensively drug-resistant OXA-72-producing Acinetobacter baumannii

Extensively drug-resistant Acinetobacter baumannii (XDRAb) emerges as an important pathogen of health care-associated infections and outbreaks worldwide. During January and February 2006, there was a hospital-wide outbreak of XDRAb at a medical center in Taiwan. Without limiting the usage of carbapenems or the closure of any ward, this outbreak was effectively controlled. We investigated the molecular epidemiology and reported the infection control experiences. XDRAb is defined as A baumannii that is resistant to multiple antibiotics but susceptible to tigecycline and polymyxin B. During the outbreak, the clinical and environmental XDRAb isolates were collected and studied by antimicrobial susceptibility testing, pulsed-field gel electrophoresis, and polymerase chain reaction for Verona integron-encoded metallo-beta-lactamases, imipenemases, and oxacillinases (OXA). Our measures to control the outbreak included private room isolation of patients until there were three successive negative cultures, reinforcement of contact precautions, daily environmental cleansing with room-dedicated cleaning tools and sodium hypochlorite, and careful auditing of adherence. During the outbreak, 32 clinical XDRAb isolates came from 13 patients who were hospitalized in four intensive care units and three wards. Most (7 of 13, 53.8%) cases were associated with a surgical intensive care unit. The results from pulsed-field gel electrophoresis study indicated that all isolates were of one genotype. All 32 isolates harbored ISAba1-bla(OxA-51-like) and bla(OxA-72) genes. After this outbreak till August 2010, further incidences of XDRAb were sporadic cases of XDRAb with different clones and did not reach the level of outbreak. To our knowledge, this is the first reported hospital-wide outbreak caused by OXA-72 carbapenemase-producing A baumannii in the Asia-Pacific region, with successful and sustained control. Although the source or vehicle of the outbreak was not identified, our results suggest that a hospital-wide outbreak can be successfully managed with strict infection control measures, and that the limitation of the use of carbapenems and closure of wards may not be necessary.

Interventions to improve hand hygiene compliance in patient care

BACKGROUND

Health care-associated infection is a major cause of morbidity and mortality. Hand hygiene is regarded as an effective preventive measure.

OBJECTIVES

To update the review done in 2007, to assess the short and longer-term success of strategies to improve hand hygiene compliance and to determine whether a sustained increase in hand hygiene compliance can reduce rates of health care-associated infection.

SEARCH STRATEGY

We conducted electronic searches of: the Cochrane Central Register of Controlled Trials; the Cochrane Effective Practice and Organisation of Care Group specialised register of trials; MEDLINE; PubMed; EMBASE; CINAHL; and the BNI. Originally searched to July 2006, for the update databases were searched from August 2006 until November 2009.

SELECTION CRITERIA

Randomised controlled trials, controlled clinical trials, controlled before and after studies, and interrupted time series analyses meeting explicit entry and quality criteria used by the Cochrane Effective Practice and Organisation of Care Group were eligible for inclusion. Studies reporting indicators of hand hygiene compliance and proxy indicators such as product use were considered. Self-reported data were not considered a valid measure of compliance. Studies to promote hand hygiene compliance as part of a care bundle approach were included, providing data relating specifically to hand hygiene were presented separately. Studies were excluded if hand hygiene was assessed in simulations, non-clinical settings or the operating theatre setting.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed data quality.

MAIN RESULTS

Four studies met the criteria for the review: two from the original review and two from the update. Two studies evaluated simple education initiatives, one using a randomized clinical trial design and the other a controlled before and after design. Both measured hand hygiene compliance by direct observation. The other two studies were both interrupted times series studies. One study presented three separate interventions within the same paper: simple substitutions of product and two multifaceted campaigns, one of which included involving practitioners in making decisions about choice of hand hygiene products and the components of the hand hygiene program. The other study also presented two separate multifaceted campaigns, one of which involved application of social marketing theory. In these two studies follow-up data collection continued beyond twelve months, and a proxy measure of hand hygiene compliance (product use) was recorded. Microbiological data were recorded in one study. Hand hygiene compliance increased for one of the studies where it was measured by direct observation, but the results from the other study were not conclusive. Product use increased in the two studies in which it was reported, with inconsistent results reported for one initiative. MRSA incidence decreased in the one study reporting microbiological data.

AUTHORS' CONCLUSIONS

The quality of intervention studies intended to increase hand hygiene compliance remains disappointing. Although multifaceted campaigns with social marketing or staff involvement appear to have an effect, there is insufficient evidence to draw a firm conclusion. There remains an urgent need to undertake methodologically robust research to explore the effectiveness of soundly designed and implemented interventions to increase hand hygiene compliance.

[Stenotrophomonas maltophilia and Pseudomonas aeruginosa water-associated microbiologic risk assessment in Amiens' University Hospital Centre]

BACKGROUND

Pseudomonas aeruginosa (Psa) and Stenotrophomonas maltophilia (Smalto) are major opportunistic waterborne pathogens causing hospital-acquired infections. This study aimed to assess the biocontamination level of cold water used in Amiens' university hospital wards, from March to June 2008.

METHODS

We cultivated 122 pairs of cold water first jet and taps cotton-swabs on Cetrimide agar for Psa, on Stenotrophomonas maltophilia selective medium with coloured indicator (SM2i) for Smalto, on Mueller Hinton agar used as isolation medium reference for both, 48h at 30 degrees C. Data analysed with Epi-Info 6.04dFr were compared with chi(2) test, significant at p<.05.

RESULTS

Psa and Smalto were isolated in 26.2 and 14.8% of water samples and in 21.3 and 10.7% of swab samples respectively. They were associated in 11.5% of water samples and 5% of swab samples. Psa was alone in 13.1% of water samples and 7.4% of swab samples whereas Smalto was found in 6.6% of water and 2.5% of swabs. Psa and Smalto were isolated from 14.8% of water samples and 8.2% of swab samples of the same tap. Finally, respectively 35.2 and 17.2% of the cold water taps were biocontaminated by Psa and Smalto. In fact, microbiologic water taps contamination risk was two-fold higher for Psa than for Smalto, p<.001, without variation between wards.

CONCLUSION

Sm2i and Cetrimide are suited and efficient medium respectively for Smalto and Psa isolation. Cold-water samples are sufficient for waterborne pathogens biocontamination risk appraisal. Our results urged healthcare workers on efficient water fittings microbiologic risk control to prevent healthcare associated waterborne infections, notably due to Psa and Smalto.

[A sensitive, specific and predictive isolation medium developed for Stenotrophomonas maltophilia study in healthcare settings]

BACKGROUND

Stenotrophomonas maltophilia (Smalto) is a prominent nosocomial pathogen, commonly isolated in the hospital environment. Multiple Smalto nosocomial outbreaks have been linked to contaminated water sources. This study aimed to develop a medium able to ease healthcare environment Smalto isolation.

METHODS

Financed, from March 2007 to June 2008, by a university hospital of Amiens' clinical research program, this study allowed Stenotrophomonas maltophilia selective medium with coloured indicator (SM2i) development. SM2i is constituted of Mueller Hinton agar (MH), maltose, DL-methionine, bromothymol blue. The mixture sterilized is refreshed at 50 degrees C, its pH adjusted to 7.1, and render selective by addition of vancomycin, imipenem and amphotericin B. Then, SM2i agar is sunk into 90 cm diameter Petri dish dated and stored at 4 degrees C for 4 weeks. SM2i is developed using Pasteur Institute culture type collection (CIP) strains of Smalto, Burkholderia cepacia, Pseudomonas aeruginosa (Psa) and a Smalto strain of our hygiene laboratory collection. It was validate on Psa imipenem-resistant and Enterococcus faecium vancomycin-resistant strains, then, tested on cold water first jet and faucet cotton-swabs samples. SM2i tests were made in comparison with the MH agar, MH agar plus four paper disks loaded 10 microg of imipenem and Cetrimed agar. Its sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, accuracy, likehood-ratio (LR) and Youden index have been determined.

RESULTS

SM2i agar is better in culturing Smalto test-strains. On SM2i, Smalto colonies are smooth, round, greeny, olive or lime green, have a green olive centre with a peripheral lighter or a dark green centre with an olive green suburb surrounded by a blue halo. SM2i is a selective, specific, predictive, accurate medium to search for Smalto in healthcare environment. In 122 pairs of cold water first jet and taps cotton-swabs samples, Smalto was isolated from 14.8% of water samples, 10.7% of cotton-swabs samples. It was isolated alone in 6.6% of water samples and 2.5% of swab samples. Thus, smalto has biocontaminated 17.2% of cold water taps. Compared to MH agar, SM2i sensitivity, specificity, PPV, NPV, accuracy, LR were 100, 100, 100, 100, 100% and infinity, and 87.5, 100, 100, 98.1, 98.4% and infinity for water and cotton-swabs samples respectively.

CONCLUSION

SM2i is a selective, specific, predictive medium which can allow easily isolating and identifying accurately Smalto in environmental samples. Its evaluation on clinical samples is on going.