Are Pathogenic Leptospira Species Agents of Community-Acquired Pneumonia? Case Reports of Leptospirosis Presenting as Pneumonia.

We report four Indonesian cases meeting the clinical and radiological criteria for community-acquired pneumonia and other findings suggestive of leptospirosis. Quantitative PCR (qPCR) analyses of serum and urine samples and serology confirmed the diagnosis of leptospirosis in each. Results of qPCR analysis of throat swabs were concordant with those obtained with acute-phase serum samples, which suggests its potential for use as a noninvasive diagnostic tool for leptospirosis.

Viruses and Gram-negative bacilli dominate the etiology of community-acquired pneumonia in Indonesia, a cohort study.

OBJECTIVE: Knowledge about the etiology of community-acquired pneumonia (CAP) is essential for adequate management. Presently, few studies about CAP are available from Southeast Asia. This study aimed to investigate the etiology, severity, and outcome of CAP in the most populous Southeast Asia country, Indonesia. METHODS: From October 2007 to April 2009, adult patients admitted with CAP to two hospitals in Semarang, Indonesia, were included to detect the etiology of CAP using a full range of diagnostic methods. The severity of disease was classified according to the Pneumonia Severity Index (PSI). The outcome was assessed as 30-day mortality. RESULTS: In total, 148 consecutive patients with CAP were included. Influenza virus (18%), Klebsiella pneumoniae (14%), and Streptococcus pneumoniae (13%) were the most common agents identified. Other Gram-negative bacilli, Mycobacterium tuberculosis, Chlamydia pneumoniae each accounted for 5%. The bacteria presented wild type antibiotic susceptibility profiles. Forty-four percent of subjects were high-risk patients (PSI class IV-V). The mortality rate (30%) was significantly associated with disease severity score (P<0.001), and with failure to establish an etiological diagnosis (P=0.027). No associations were found between etiology and underlying diseases, PSI class, nor mortality. CONCLUSIONS: Viruses and Gram-negative bacilli are dominant causes of CAP in this region, more so than S. pneumoniae. Most of the bacteria have wild type susceptibility to antimicrobial agents. Patients with severe disease and those with unknown etiology have a higher mortality risk.

Development of quality indicators to evaluate antibiotic treatment of patients with community-acquired pneumonia in Indonesia.

OBJECTIVE: To develop an instrument for evaluating the quality of antibiotic management of patients with community-acquired pneumonia (CAP) applicable in a middle-income developing country. METHOD: A previous study and Indonesian guidelines were reviewed to derive potential quality of care indicators (QIs). An expert panel performed a two-round Delphi consensus procedure on the QI's relevance to patient recovery, reduction of antimicrobial resistance and cost containment. Applicability in practice, including reliability, feasibility and opportunity for improvement, was determined in a data set of 128 patients hospitalised with CAP in Semarang, Indonesia. RESULTS: Fifteen QIs were selected by the consensus procedure. Five QIs did not pass feasibility criteria, because of inappropriate documentation, inefficient laboratory services or patient factors. Three QIs provided minor opportunity for improvement. Two QIs contradicted each other; one of these was considered not valid and excluded. A final set of six QIs was defined for use in the Indonesian setting. CONCLUSION: Using the Delphi method, we defined a list of QIs for assessing the quality of care, in particular antibiotic treatment, for CAP in Indonesia. For further improvement, a modified Delphi method that includes discussion, a sound medical documentation system, improvement of microbiology laboratory services, and multi-center applicability tests are needed to develop a valid and applicable QI list for the Indonesian setting.

Nasopharyngeal carriage of Streptococcus pneumonia in pneumonia-prone age groups in Semarang, Java Island, Indonesia.

INTRODUCTION: Streptococcus pneumoniae is a worldwide occurring pathogen Nasopharyngeal carriage of Streptococcus pneumoniae precedes pneumonia and other pneumococcal diseases in the community. Little is known about S. pneumoniae carriage in Indonesia, complicating strategies to control pneumococcal diseases. We investigated nasopharyngeal carriage of S. pneumoniae in Semarang, Indonesia. METHODS: A population-based survey was performed in Semarang, Indonesia. Nasopharyngeal swabs and questionnaires were taken from 496 healthy young (6-60 month-old) children and 45-70 year-old adults. RESULTS: Forty-three percent of children aged 6-60 months and 11% of adults aged 45-75 years carried S. pneumoniae. Determinants of carriage were being a child (OR 7.7; 95% CI = 4.5-13.0), passive smoking (OR 2.1; 95% CI = 1.3-3.4), and contact with toddler(s) at home (OR 3.0; 95% CI = 1.9-4.7). The most frequent serotypes found were 6A/B and 15B/C. The current commercially available vaccines cover <50% serotypes found in children. Twenty-four percent of S. pneumoniae strains were penicillin non-susceptible, and 45% were resistant to cotrimoxazol. CONCLUSIONS: The limited coverage of commercially available vaccines against the serotypes found in this population, and the high proportion of non-susceptibility to penicillin and cotrimoxazol suggest the need for region-specific information and strategies to control S. pneumoniae.

Nasopharyngeal carriage of Klebsiella pneumoniae and other Gram-negative bacilli in pneumonia-prone age groups in Semarang, Indonesia.

Gram-negative bacilli (GNB) cause many cases of pneumonia in Indonesia. We investigated nasopharyngeal carriage of GNB in Semarang, Indonesia. Klebsiella pneumoniae carriage in adults (15%) was higher than in children (7%) (P = 0.004), while that of other GNB was comparable. Poor food and water hygiene are determinants of carriage of these bacteria.

Appropriate use of indwelling urethra catheters in hospitalized patients: results of a multicentre prevalence study.

BACKGROUND: Although indwelling urethra catheterization is a medical intervention with well-defined risks, studies show that approximately 14-38% of the indwelling urethra catheters (IUCs) are placed without a specific medical indication. In this paper we describe the prevalence of IUCs, including their inappropriate use in the Netherlands. We also determine factors associated with inappropriate use of IUCs in hospitalized patients. METHODS: In 28 Dutch hospitals, prevalence surveys were performed biannually in 2009 and 2010 within the PREZIES-network. All patients admitted to a participating hospital and who had an IUC in place at the day of the survey were included. Pre-determined criteria were used to categorize the indication for catheterization as appropriate or inappropriate. RESULTS: A total of 14,252 patients was included and 3020 (21.2%) of them had an IUC (range hospitals 13.4-27.3). Initial catheter placement was inappropriate in 5.2% of patients and 7.5% patients had an inappropriate indication at the day of the survey. In multivariate analyses inappropriate catheter use at the time of placement was associated with female sex, older age, admission on a non-intensive care ward, and not having had surgery. Inappropriate catheter use at the time of survey showed comparable associated factors. CONCLUSIONS: Although lower than in many other countries, inappropriate use of IUC is present in Dutch hospitals. To reduce the inappropriate use of IUCs, recommended components of care (bundle for UTI), including daily revision and registration of the indication for catheterization, should be introduced for all patients with an IUC. Additionally, an education and awareness campaign about appropriate indications for IUC should be available.

Urinary catheter policies for long-term bladder drainage.

BACKGROUND: People requiring long-term bladder draining commonly experience catheter-associated urinary tract infection and other problems. OBJECTIVES: To determine if certain catheter policies are better than others in terms of effectiveness, complications, quality of life and cost-effectiveness in long-term catheterised adults and children. SEARCH METHODS: We searched the Cochrane Incontinence Group Specialised Trials Register (searched 28 September 2011). Additionally, we examined all reference lists of identified trials. SELECTION CRITERIA: All randomised and quasi-randomised trials comparing catheter policies (route of insertion and use of antibiotics) for long-term (more than 14 days) catheterisation in adults and children. DATA COLLECTION AND ANALYSIS: Data were extracted by two reviewers independently and compared. Disagreements were resolved by discussion. Data were processed as described in the Cochrane Handbook. If the data in trials had not been fully reported, clarification was sought from the authors. When necessary, the incidence-density rates (IDR) and/or the incidence-density differences (IDD) within a certain time period were calculated. MAIN RESULTS: Eight trials met the inclusion criteria involving 504 patients in four cross-over and four parallel-group randomised controlled trials. Only two of the pre-stated six comparisons were addressed in these trials. Four trials compared antibiotic prophylaxis with antibiotics when clinically indicated. For patients using intermittent catheterisation, there were inconsistent findings about the effect of antibiotic prophylaxis on symptomatic urinary tract infection (UTI). Only one study found a significant difference in the frequency of UTI favouring prophylaxis. For patients using indwelling urethral catheterisation, one small trial reported fewer episodes of symptomatic UTI in the prophylaxis group.Four trials compared antibiotic prophylaxis with giving antibiotics when microbiologically indicated. For patients using intermittent catheterisation, there was limited evidence that receiving antibiotics reduced the rate of bacteriuria (asymptomatic and symptomatic). There was weak evidence that prophylactic antibiotics were better in terms of fewer symptomatic bacteriuria. AUTHORS' CONCLUSIONS: No eligible trials were identified that compared alternative routes of catheter insertion. The data from eight trials comparing different antibiotic policies were sparse, particularly when intermittent catheterisation was considered separately from indwelling catheterisation. Possible benefits of antibiotic prophylaxis must be balanced against possible adverse effects, such as development of antibiotic resistant bacteria. These cannot be reliably estimated from currently available trials.

Three-dimensional human skin equivalent as a tool to study Acinetobacter baumannii colonization.

Acinetobacter baumannii can colonize body surfaces of hospitalized patients. From these sites, invasion into the host and spread to other patients and the hospital environment may occur. The eradication of the organism from the patient's skin is an important infection control strategy during epidemic and endemic episodes. In this study, a three-dimensional (3D), air-exposed human epidermal skin equivalent was exploited to study Acinetobacter skin colonization. We characterized the adherence of A. baumannii ATCC 19606(T) and Acinetobacter junii RUH2228(T) to and biofilm formation on the skin equivalent and the responses to these bacteria. Furthermore, we assessed the ability of the disinfectant chlorhexidine to decolonize the skin equivalents. The results revealed that both strains replicated on the stratum corneum for up to 72 h but did not invade the epidermis. A. baumannii, in contrast to A. junii, formed large biofilms on the stratum corneum. Bacterial colonization did not affect keratinocyte activation, proliferation, or differentiation, nor did it induce a strong inflammatory response. Disinfection with chlorhexidine solution resulted in complete eradication of A. baumannii from the skin, without detrimental effects. This 3D model is a promising tool to study skin colonization and to evaluate the effects of novel disinfectant and antimicrobial strategies.

Pleconaril revisited: clinical course of chronic enteroviral meningoencephalitis after treatment correlates with in vitro susceptibility.

BACKGROUND: Human enteroviruses (HEVs) can cause severe infections, especially in patients with a deficient humoral immune response, such as X-linked agammaglobulinemia. In this patient group, chronic enteroviral meningitis (CEMA) is feared because of extensive morbidity and high fatality rate. Treatment options consist of intravenous immunoglobulin (IVIG), with various outcomes. Pleconaril is an antiviral agent with in vitro activity against HEVs that has been used in the treatment of HEV infections. METHODS: The efficacy of pleconaril and IVIG against HEV isolated from the patients was assessed in vitro in two patients with CEMA. RESULTS: Echovirus 11 was found in the cerebrospinal fluid (CSF) of case 1. Treatment with high-dose IVIG and pleconaril did not provide any clinical improvement and HEV PCR in CSF remained positive. Case 2 (echovirus 13 positive in CSF) was also treated with IVIG and pleconaril. The patient recovered completely and HEV PCR in CSF became negative. Recent IVIG batches contained low titres of neutralizing antibodies against the patient strains. Echovirus 11 (case 1) was resistant to pleconaril in vitro, whereas echovirus 13 (case 2) was susceptible, in accordance with virological response after treatment and subsequent clinical results. CONCLUSIONS: This is the first report that evaluates efficacy of antiviral treatment in CEMA patients in relation to in vitro susceptibility of clinical virus isolates. Since pleconaril is no longer available for compassionate use we strongly propagate that new drugs should be developed against these potential life threatening HEV infections.

Differences in Acinetobacter baumannii strains and host innate immune response determine morbidity and mortality in experimental pneumonia.

Despite many reports documenting its epidemicity, little is known on the interaction of Acinetobacter baumannii with its host. To deepen our insight into this relationship, we studied persistence of and host response to different A. baumannii strains including representatives of the European (EU) clones I-III in a mouse pneumonia model. Neutropenic mice were inoculated intratracheally with five A. baumannii strains and an A. junii strain and at several days morbidity, mortality, bacterial counts, airway inflammation, and chemo- and cytokine production in lungs and blood were determined. A. baumannii RUH875 and RUH134 (EU clone I and II, respectively) and sporadic strain LUH8326 resulted in high morbidity/mortality, whereas A. baumannii LUH5875 (EU clone III, which is less widespread than clone I and II) caused less symptoms. A. baumannii type strain RUH3023(T) and A. junii LUH5851 did not cause disease. All strains, except A. baumannii RUH3023(T) and A. junii LUH5851, survived and multiplied in the lungs for several days. Morbidity and mortality were associated with the severity of lung pathology and a specific immune response characterized by low levels of anti-inflammatory (IL-10) and specific pro-inflammatory (IL-12p40 and IL-23) cytokines at the first day of infection. Altogether, a striking difference in behaviour among the A. baumannii strains was observed with the clone I and II strains being most virulent, whereas the A. baumannii type strain, which is frequently used in virulence studies appeared harmless.

Multidrug-resistant Acinetobacter baumannii in veterinary clinics, Germany.

An increase in prevalence of multidrug-resistant Acinetobacter spp. in hospitalized animals was observed at the Justus-Liebig-University (Germany). Genotypic analysis of 56 isolates during 2000-2008 showed 3 clusters that corresponded to European clones I-III. Results indicate spread of genotypically related strains within and among veterinary clinics in Germany.

Eradication of carriage with methicillin-resistant Staphylococcus aureus: determinants of treatment failure.

BACKGROUND: Using data from an observational study in which the effectiveness of a guideline for eradication of methicillin-resistant Staphylococcus aureus (MRSA) carriage was evaluated, we identified variables that were associated with treatment failure. METHODS: A multivariate logistic regression model was performed with subgroup analyses for uncomplicated and complicated MRSA carriage (the latter including MRSA infection, skin lesions, foreign-body material, mupirocin resistance and/or exclusive extranasal carriage) and for those treated according to the guideline (i.e. mupirocin nasal ointment and chlorhexidine soap solution for uncomplicated carriage, in combination with two oral antibiotics for complicated carriage). RESULTS: Six hundred and thirteen MRSA carriers were included, of whom 333 (54%) had complicated carriage; 327 of 530 patients (62%) with known complexity of carriage were treated according to the guideline with an absolute increase in treatment success of 20% (95% confidence interval 12%-28%). Among those with uncomplicated carriage, guideline adherence [adjusted odds ratio (OR(a)) 7.4 (1.7-31.7)], chronic pulmonary disease [OR(a) 44 (2.9-668)], throat carriage [OR(a) 2.9 (1.4-6.1)], perineal carriage [OR(a) 2.2 (1.1-4.4)] and carriage among household contacts [OR(a) 5.6 (1.2-26)] were associated with treatment failure. Among those with complicated carriage, guideline adherence was associated with treatment success [OR(a) 0.2 (0.1-0.3)], whereas throat carriage [OR(a) 4.4 (2.3-8.3)] and dependence in activities of daily living [OR(a) 3.6 (1.4-8.9)] were associated with failure. CONCLUSIONS: Guideline adherence, especially among those with complicated MRSA carriage, was associated with treatment success. Adding patients with extranasal carriage or dependence in daily self-care activities to the definition of complicated carriage, and treating them likewise, may further increase treatment success.

Eradication of carriage with methicillin-resistant Staphylococcus aureus: effectiveness of a national guideline.

BACKGROUND: We evaluated the effectiveness of eradication of methicillin-resistant Staphylococcus aureus (MRSA) carriage in the Netherlands after the introduction of a guideline in 2006. The guideline distinguishes complicated (defined as the presence of MRSA infection, skin lesions, foreign-body material, mupirocin resistance and/or exclusive extranasal carriage) and uncomplicated carriage (not meeting criteria for complicated carriage). Mupirocin nasal ointment and chlorhexidine soap solution are recommended for uncomplicated carriers and the same treatment in combination with two oral antibiotics for complicated carriage. METHODS: A prospective cohort study was performed in 18 Dutch centres from 1 October 2006 until 1 October 2008. RESULTS: Six hundred and thirteen MRSA carriers underwent one or more decolonization treatments during the study period, mostly after hospital discharge. Decolonization was achieved in 367 (60%) patients with one eradication attempt and ultimately 493 (80%) patients were decolonized, with a median time until decolonization of 10 days (interquartile range 7-43 days). Three hundred and twenty-seven (62%) carriers were treated according to the guideline, which was associated with an absolute increase in treatment success of 20% [from 45% (91/203) to 65% (214/327)]. CONCLUSIONS: Sixty percent of MRSA carriers were successfully decolonized after the first eradication attempt and 62% were treated according to the guideline, which was associated with an increased treatment success.

[Sterile gloves are necessary in minor surgery]. / Steriele handschoenen wél nodig bij kleine chirurgie.

The use of sterile gloves as part of asepsis during surgery goes back to the end of the nineteenth century, but now the preventive value of this measure during minor surgery is questioned. One randomized study showed no difference in wound infection rates whether sterile or nonsterile gloves were used for repair of uncomplicated lacerations of the skin. An observational and a retrospective study in minor dermatological surgery confirm that the use of sterile or nonsterile gloves makes no difference for excisions of tumours as long as no reconstructions of the skin are performed. However, in more complicated minor dermatological surgery, 80% less wound infections were observed when sterile gloves were used. In conclusion, the available evidence is too limited to change the recommendation to use sterile gloves for minor surgery.

An evidence-based recommendation on bed head elevation for mechanically ventilated patients.

INTRODUCTION: A semi-upright position in ventilated patients is recommended to prevent ventilator-associated pneumonia (VAP) and is one of the components in the Ventilator Bundle of the Institute for Health Care Improvement. This recommendation, however, is not an evidence-based one. METHODS: A systematic review on the benefits and disadvantages of semi-upright position in ventilated patients was done according to PRISMA guidelines. Then a European expert panel developed a recommendation based on the results of the systematic review and considerations beyond the scientific evidence in a three-round electronic Delphi procedure. RESULTS: Three trials (337 patients) were included in the review. The results showed that it was uncertain whether a 45° bed head elevation was effective or harmful with regard to the occurrence of clinically suspected VAP, microbiologically confirmed VAP, decubitus and mortality, and that it was unknown whether 45° elevation for 24 hours a day increased the risk for thromboembolism or hemodynamic instability. A group of 22 experts recommended elevating the head of the bed of mechanically ventilated patients to a 20 to 45° position and preferably to a ≥ 30° position as long as it does not pose risks or conflicts with other nursing tasks, medical interventions or patients' wishes. CONCLUSIONS: Although the review failed to prove clinical benefits of bed head elevation, experts prefer this position in ventilated patients. They made clear that the position of a ventilated patient in bed depended on many determinants. Therefore, given the scientific uncertainty about the benefits and harms of a semi-upright position, this position could only be recommended as the preferred position with the necessary restrictions.

Cross-sectional study of availability and pharmaceutical quality of antibiotics requested with or without prescription (Over The Counter) in Surabaya, Indonesia.

BACKGROUND: Antimicrobial resistance is an increasing problem in developing countries and antibiotic use is widespread. Our previous surveys in Java, Indonesia, revealed that most antibiotic use was probably unnecessary or ineffective. The aim of this study was to explore a potential connection between resistance and substandard antibiotics sold in the area. METHODS: A cross-sectional field study using the simulated client method was conducted in Surabaya. Five first-line antibiotics were requested with or without prescription (OTC). A certified laboratory analysed the drug content using validated methods. Possible determinants of substandard quality were explored. RESULTS: In total, 104 samples from 75 pharmacies, ten drug stores and 39 roadside stalls (kiosks) were obtained. Pharmacy employees filled all OTC requests. Three quarters of kiosks sold antibiotics. Antibiotics were dispensed as single blister strips or repackaged (16%) without label. Ninety five percent of samples carried the label of 14 Indonesian manufacturers. The pharmaceutical quality did not meet BP standards for 18% of samples. Deviations (less active ingredient) were small. There was no association between low content and type of outlet, sold with or without prescription, registration type, price or packaging. Median retail prices of products carrying the same label varied up to 20 fold. CONCLUSIONS: Antibiotics were available OTC in all visited pharmacies and sold in the streets of an Indonesian city. Most samples contained an active ingredient. We urge to increase enforcement of existing regulations, including legislation that categorizes antibiotics as prescription-only drugs for all types of medicine outlets, to limit further selection of antimicrobial resistance.

How much time should long-term care and geriatric rehabilitation facilities (nursing homes) spend on infection control?

BACKGROUND: For hospitals, standards for the required number of infection control personnel are outdated and disputed. Such standards are not even available for long-term care and geriatric rehabilitation facilities (ie, nursing homes). This study addressed the question of how much time nursing homes should spend on infection control. METHODS: Through group discussions and individual sessions, experienced infection control practitioners, medical microbiologists, and nursing home doctors evaluated the time needed to perform infection control activities in a model nursing home. RESULTS: The number of hours needed was estimated as 513 per 100 beds, or 154 per 10,000 care-days per year. CONCLUSION: Given that significant differences can be expected among the various facilities identified as nursing homes, long-term care facilities, or geriatric rehabilitation centers, as well as among countries, the standard that we propose for The Netherlands will not be generally applicable. However, the method we have used to determine this standard can be easily applied in other countries and settings.

Determinants of carriage of resistant Staphylococcus aureus among S. aureus carriers in the Indonesian population inside and outside hospitals.

SUMMARY OBJECTIVES: To identify determinants of carriage of resistant Staphylococcus aureus in both hospitalized patients and individuals from the community in two urban centres in Indonesia. METHODS: Staphylococcus aureus cultures and data on recent antibiotic use, demographic, socioeconomic, disease-related and healthcare-related variables were collected from 3995 community dwellers and hospitalized persons. Nasal S. aureus carriage was found in 362 persons (9.1%). Logistic regression analysis was performed to identify which variables were independently associated with carriage of resistant S. aureus. RESULTS: The penicillins were the most frequently used antibiotics both in the community and in hospitalized patients. In the community, admission to a hospital was associated with carriage of S. aureus resistant to any of the tested antibiotics [odds ratio (OR) 2.5, 95% confidence interval (95% CI) 1.3-4.9] and any tetracycline resistance (OR 2.4, 95% CI 1.1-5.1). Having no symptoms was associated with less carriage of S. aureus with resistance to any of the tested antibiotics (OR 0.5, 95% CI 0.3-0.9) and any tetracycline resistance (OR 0.5, 95% CI 0.3-0.9). Crowding (OR 4.5, 95% CI 1.2-4.9) and low income (OR 8.9, 95% CI 1.8-43.9) were associated with multidrug resistance. In hospitalized patients, the use of penicillins was associated with resistance to any of the tested antibiotics (OR 3.9, 95% CI 1.4-11.6) and any tetracycline resistance (OR 3.7, 95% CI 1.1-12.0). CONCLUSIONS: Antibiotic policies including proper diagnosis, treatment and drug delivery process should be made by healthcare providers in Indonesia to help limit the emergence of antibiotic resistance.

Should in-line filters be used in peripheral intravenous catheters to prevent infusion-related phlebitis? A systematic review of randomized controlled trials.

BACKGROUND: In this systematic review, we assessed the effect of in-line filters on infusion-related phlebitis associated with peripheral IV catheters. The study was designed as a systematic review and meta-analysis of randomized controlled trials. We used MEDLINE and the Cochrane Controlled Trial Register up to August 10, 2009. METHODS: Two reviewers independently assessed trial quality and extracted data. Data on phlebitis were combined when appropriate, using a random-effects model. The impact of the risk of phlebitis in the control group (baseline risk) on the effect of in-line filters was studied by using meta-regression based on the bivariate meta-analysis model. The quality of the evidence was determined by using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) method. RESULTS: Eleven trials (1633 peripheral catheters) were included in this review to compare the effect of in-line filters on the incidence of phlebitis in hospitalized patients. Baseline risks across trials ranged from 23% to 96%. Meta-analysis of all trials showed that in-line filters reduced the risk of infusion-related phlebitis (relative risk, 0.66; 95% confidence interval, 0.43-1.00). This benefit, however, is very uncertain, because the trials had serious methodological shortcomings and meta-analysis revealed marked unexplained statistical heterogeneity (P < 0.0000, I(2) = 90.4%). The estimated benefit did not depend on baseline risk. CONCLUSION: In-line filters in peripheral IV catheters cannot be recommended routinely, because evidence of their benefit is uncertain.

Do biofilm formation and interactions with human cells explain the clinical success of Acinetobacter baumannii?

BACKGROUND: The dramatic increase in antibiotic resistance and the recent manifestation in war trauma patients underscore the threat of Acinetobacter baumannii as a nosocomial pathogen. Despite numerous reports documenting its epidemicity, little is known about the pathogenicity of A. baumannii. The aim of this study was to obtain insight into the factors that might explain the clinical success of A. baumannii. METHODOLOGY/PRINCIPAL FINDINGS: We compared biofilm formation, adherence to and inflammatory cytokine induction by human cells for a large panel of well-described strains of A. baumannii and compared these features to that of other, clinically less relevant Acinetobacter species. Results revealed that biofilm formation and adherence to airway epithelial cells varied widely within the various species, but did not differ among the species. However, airway epithelial cells and cultured human macrophages produced significantly less inflammatory cytokines upon exposure to A. baumannii strains than to strains of A. junii, a species infrequently causing infection. CONCLUSION/SIGNIFICANCE: The induction of a weak inflammatory response may provide a clue to the persistence of A. baumannii in patients.