Staphylococcus aureus Regulatory RNAs as Potential Biomarkers for Bloodstream Infections.

Staphylococcus aureus is a commensal bacterium and pathogen. Identifying biomarkers for the transition from colonization to disease caused by this organism would be useful. Several S. aureus small RNAs (sRNAs) regulate virulence. We investigated presence and expression of 8 sRNAs in 83 S. aureus strains from 42 patients with sepsis or septic shock and 41 asymptomatic colonized carriers. Small pathogenicity island sRNAs sprB and sprC were clade specific. Six sRNAs had variable expression not correlated with clinical status. Expression of RNAIII was lower in strains from septic shock patients than in strains from colonized patients. When RNAIII was associated with expression of sprD, colonizing strains could be discriminated from strains in patients with bloodstream infections, including patients with sepsis and septic shock. Isolates associated with colonization might have sRNAs with target expression different from those of disease isolates. Monitoring expression of RNAIII and sprD could help determine severity of bloodstream infections.

Effect of oropharyngeal povidone-iodine preventive oral care on ventilator-associated pneumonia in severely brain-injured or cerebral hemorrhage patients: a multicenter, randomized controlled trial.

OBJECTIVE: To evaluate the efficacy and safety of oral care with povidone-iodine on the occurrence of ventilator-associated pneumonia in a high-risk population. DESIGN: A multicenter, placebo-controlled, randomized, double-blind, two-parallel-group trial performed between May 2008 and May 2011. SETTING: Six ICUs in France. PATIENTS: One hundred seventy-nine severely brain-injured patients (Glasgow Coma Scale ≤ 8) or cerebral hemorrhage expected to be mechanically ventilated for more than 24 hours. INTERVENTIONS: Participants were randomly assigned to receive oropharyngeal care with povidone-iodine (n = 91) or placebo (n = 88) six times daily until mechanical ventilation withdrawal. MEASUREMENTS AND MAIN RESULTS: Primary endpoint was the rate of ventilator-associated pneumonia. Secondary endpoint included the rates of ventilator-associated tracheobronchitis and acute respiratory distress syndrome and patient's outcome. The number of patients evaluable for the primary endpoint (preplanned modified intention-to-treat population) was 150 (78 in the povidone-iodine group, 72 in the placebo group). Ventilator-associated pneumonia occurred in 24 patients (31%) in the povidone-iodine group and 20 (28%) in the placebo group (relative risk, 1.11 [95% CI, 0.67-1.82]; p = 0.69). There was no significant difference between the two groups for ventilator-associated tracheobronchitis: eight patients (10%) in the povidone-iodine group and five patients (7%) in the placebo group (relative risk, 1.48 [95% CI, 0.51-4.31]; p = 0.47). Acute respiratory distress syndrome occurred in five patients in the povidone-iodine group but not in the placebo group (p = 0.06). There was no difference between groups for ICU and hospital lengths of stay, as well as ICU and 90-day mortality. CONCLUSIONS: There is no evidence to recommend oral care with povidone-iodine to prevent ventilator-associated pneumonia in high-risk patients. Furthermore, this strategy seems to increase the rate of acute respiratory distress syndrome.

Short-term decline in all-cause acquired infections with the routine use of a decontamination regimen combining topical polymyxin, tobramycin, and amphotericin B with mupirocin and chlorhexidine in the ICU: a single-center experience.

OBJECTIVES: In a multicenter, placebo-controlled, randomized, double-blind trial, we showed that acquired infections in intubated patients were reduced by the combination of topical polymyxin plus tobramycin and nasal mupirocin plus chlorhexidine body wash. Because intubated patients are particularly at risk for acquired infections, we reassessed the impact of this protocol as a routine procedure to control acquired infections in the ICU. DESIGN: Nonrandomized study comparing acquired infections in ICU patients during two 1-year periods: the last year before (group A, n = 925) and the first year after the implementation of the protocol (group B, n = 1,022). Acquired infections were prospectively recorded. SETTING: Polyvalent medical ICU at a university-affiliated hospital. PATIENTS: All patients admitted to the ICU. INTERVENTIONS: Administration of polymyxin/tobramycin/amphotericin B in the oropharynx and the gastric tube plus a mupirocin/chlorhexidine regimen in intubated patients and standard care in the other patients. MEASUREMENTS AND MAIN RESULTS: The comparison of acquired infection rates between groups was adjusted for differences at baseline. Infection rates were lower in group B compared with group A (5.3% vs 11.0%; p < 0.001), as were the incidence rates of total acquired infections (9.4 vs 23.6 per 1,000 patient-days; p < 0.001), intubation-related pneumonia (5.1 vs 17.1 per 1,000 ventilator-days; p < 0.001), and catheter-related bloodstream infections (1.0 vs 3.5 per 1,000 catheter-days; p = 0.03). There were fewer acquired infections caused by ceftazidime-resistant Enterobacteriaceae (0.8‰ vs 3.6‰; p < 0.001), ciprofloxacin-resistant Enterobacteriaceae (0.8‰ vs 2.5‰; p = 0.02), ciprofloxacin-resistant Pseudomonas aeruginosa (0.5‰ vs 1.6‰; p = 0.05), and colistin-resistant Gram-negative bacilli (0.7‰ vs 1.9‰; p = 0.04). Fewer patients got acquired infections due to multidrug-resistant aerobic Gram-negative bacilli (p = 0.008). CONCLUSIONS: In intubated patients, the use of topical polymyxin/tobramycin/amphotericin B plus mupirocin/chlorhexidine was associated with the reduction of all-cause ICU-acquired infections. Long-term emergence of multidrug-resistant organisms deserves further investigation.

CC9 livestock-associated Staphylococcus aureus emerges in bloodstream infections in French patients unconnected with animal farming.

We report 4 bloodstream infections associated with CC9 agr type II Staphylococcus aureus in individuals without animal exposure. We demonstrate, by microarray analysis, the presence of egc cluster, fnbA, cap operon, lukS, set2, set12, splE, splD, sak, epiD, and can, genomic features associated with a high virulence potential in humans.

Forecasting Staphylococcus aureus Infections Using Genome-Wide Association Studies, Machine Learning, and Transcriptomic Approaches.

Staphylococcus aureus is a major human and animal pathogen, colonizing diverse ecological niches within its hosts. Predicting whether an isolate will infect a specific host and its subsequent clinical fate remains unknown. In this study, we investigated the S. aureus pangenome using a curated set of 356 strains, spanning a wide range of hosts, origins, and clinical display and antibiotic resistance profiles. We used genome-wide association study (GWAS) and random forest (RF) algorithms to discriminate strains based on their origins and clinical sources. Here, we show that the presence of sak and scn can discriminate strains based on their host specificity, while other genes such as mecA are often associated with virulent outcomes. Both GWAS and RF indicated the importance of intergenic regions (IGRs) and coding DNA sequence (CDS) but not sRNAs in forecasting an outcome. Additional transcriptomic analyses performed on the most prevalent clonal complex 8 (CC8) clonal types, in media mimicking nasal colonization or bacteremia, indicated three RNAs as potential RNA markers to forecast infection, followed by 30 others that could serve as infection severity predictors. Our report shows that genetic association and transcriptomics are complementary approaches that will be combined in a single analytical framework to improve our understanding of bacterial pathogenesis and ultimately identify potential predictive molecular markers. IMPORTANCE Predicting the outcome of bacterial colonization and infections, based on extensive genomic and transcriptomic data from a given pathogen, would be of substantial help for clinicians in treating and curing patients. In this report, genome-wide association studies and random forest algorithms have defined gene combinations that differentiate human from animal strains, colonization from diseases, and nonsevere from severe diseases, while it revealed the importance of IGRs and CDS, but not small RNAs (sRNAs), in anticipating an outcome. In addition, transcriptomic analyses performed on the most prevalent clonal types, in media mimicking either nasal colonization or bacteremia, revealed significant differences and therefore potent RNA markers. Overall, the use of both genomic and transcriptomic data in a single analytical framework can enhance our understanding of bacterial pathogenesis.

Galleria mellonella as a Suitable Model of Bacterial Infection: Past, Present and Future.

The increasing interest for Galleria mellonella larvae as an infection model is evidenced by the number of papers reporting its use, which increases exponentially since the early 2010s. This popularity was initially linked to limitation of conventional animal models due to financial, technical and ethical aspects. In comparison, alternative models (e.g. models using Caenorhabditis elegans, Drosophila melanogaster or G. mellonella) were cheap, simple to use and not limited by ethical regulation. Since then, similar results have been established with G. mellonella model comparatively to vertebrates, and it is more and more often used as a robust model per se, not only as an alternative to the murine model. This review attempts to summarize the current knowledge supporting the development of this model, both on immunological and microbiological aspects. For that, we focus on investigation of virulence and new therapies for the most important pathogenic bacteria. We also discuss points out directions for standardization, as well as recent advances and new perspectives for monitoring host-pathogen interactions.

Galleria mellonella Larvae as an Infection Model to Investigate sRNA-Mediated Pathogenesis in Staphylococcus aureus.

Small regulatory RNAs (sRNAs) are key players in bacterial regulatory networks. Monitoring their expression inside living colonized or infected organisms is essential for identifying sRNA functions, but few studies have looked at sRNA expression during host infection with bacterial pathogens. Insufficient in vivo studies monitoring sRNA expression attest to the difficulties in collecting such data, we therefore developed a non-mammalian infection model using larval Galleria mellonella to analyze the roles of Staphylococcus aureus sRNAs during larval infection and to quickly determine possible sRNA involvement in staphylococcal virulence before proceeding to more complicated animal testing. We began by using the model to test infected larvae for immunohistochemical evidence of infection as well as host inflammatory responses over time. To monitor sRNA expression during infection, total RNAs were extracted from the larvae and invading bacteria at different time points. The expression profiles of the tested sRNAs were distinct and they fluctuated over time, with expression of both sprD and sprC increased during infection and associated with mortality, while rnaIII expression remained barely detectable over time. A strong correlation was observed between sprD expression and the mortality. To confirm these results, we used sRNA-knockout mutants to investigate sRNA involvement in Staphylococcus aureus pathogenesis, finding that the decrease in death rates is delayed when either sprD or sprC was lacking. These results demonstrate the relevance of this G. mellonella model for investigating the role of sRNAs as transcriptional regulators involved in staphylococcal virulence. This insect model provides a fast and easy method for monitoring sRNA (and mRNA) participation in S. aureus pathogenesis, and can also be used for other human bacterial pathogens.

Constipation in long-term ventilated patients: associated factors and impact on intensive care unit outcomes.

OBJECTIVES: To characterize the factors associated with delayed defecation in long-term ventilated patients and to examine the relationship between delayed defecation and logistic organ dysfunction scores, acquired bacterial infections, and mortality in the intensive care unit. DESIGN: Prospective observational cohort study. SETTING: A 21-bed polyvalent intensive care unit in a university hospital. PATIENTS: A total of 609 adult patients admitted over a 41-month period who underwent mechanical ventilation for ≥ 6 days. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Three hundred fifty-three patients (58%) passed stools ≥ 6 days after they were admitted to the intensive care unit ("late" defecation). Patients with early and late defecation had similar general characteristics when admitted to the intensive care unit and had similar logistic organ dysfunction scores on the first day of mechanical ventilation. Several variables were independently associated with a delay in defecation: a Pao2/Fio2 ratio of less than 150 mm Hg (adjusted hazard ratio 1.40; 95% confidence interval: 1.06-1.60; p = .0073), a systolic blood pressure between 70 and 89 mm Hg (adjusted hazard ratio 1.48; 95% confidence interval: 1.17-1.79; p = .002), and systolic blood pressure < 68 mm Hg (adjusted hazard ratio 1.29; 95% confidence interval: 1.01-1.60; p = .03). Logistic organ dysfunction scores were significantly higher on the fourth and ninth days of mechanical ventilation in patients with late defecation than in those with early defecation. The crude intensive care unit mortality rate was 18% in patients with early defecation and 30% in patients with late defecation (p < .001). Acquired bacterial infections at any site occurred in 34% of patients with early defecation and 66% of patients with late defecation (p < .001). CONCLUSION: A Pao2/Fio2 ratio of < 150 mm Hg and systolic blood pressure of < 90 mm Hg during the first 5 days of mechanical ventilation were independently associated with a delay in defecation. Our results suggest that constipation is associated with adverse outcomes in long-term ventilated patients.

Risk factors for multidrug-resistant bacteria in patients with post-operative peritonitis requiring intensive care.

OBJECTIVES: This prospective non-interventional study investigated the risk factors for multidrug-resistant bacteria (MDRB) in patients with post-operative peritonitis (POP), to provide guidance for empirical antimicrobial therapy. METHODS: All consecutive patients, >15 years old, admitted to a surgical intensive care unit (ICU) between September 2006 and January 2009 for a first episode of POP were included. Antibiotic susceptibilities of microorganisms recovered from blood cultures and peritoneal fluid were determined by disc diffusion. Amoxicillin/clavulanic acid, ticarcillin/clavulanic acid, piperacillin/tazobactam, cefotaxime, ceftazidime, cefepime, imipenem, gentamicin, amikacin and ciprofloxacin were tested against Gram-negative bacteria, and oxacillin, amoxicillin, vancomycin, gentamicin and erythromycin were tested against aerobic Gram-positive bacteria. Results were reported as susceptible or resistant. RESULTS: MDRB were isolated from 20/115 (17%) patients. In univariate analysis, use of antimicrobial therapy during the 3 months prior to hospitalization and a long duration between hospital admission or first operation and relaparotomy were significantly associated with MDRB recovery. In multivariate analysis, only antimicrobial treatment in the 3 months preceding hospitalization and duration between first operation and relaparotomy were independent risk factors for MDRB [odds ratio (OR) = 5.80, 95% confidence interval (95% CI) = 1.99-16.91 and OR = 1.10, 95% CI = 1.02-1.19, respectively]. No MDRB were found when the delay between the first operation and relaparotomy was <5 days. POP severity, non-surgical and surgical complications, hospital and ICU length of stay, and mortality were similar in patients with and without MDRB. CONCLUSIONS: Our results suggest that broad-spectrum antibiotics should be used in ICU patients with POP who have received antimicrobial therapy in the 3 months prior to hospitalization, or with >5 days between the first operation and relaparotomy.

Adhesion of Staphylococcus aureus to epithelial cells: an in vitro approach to study interactions within the nasal microbiota.

Introduction. Staphylococcus aureus is a skin and mucous commensal bacterium of warm-blooded animals. In humans, the nose is the main ecological niche of S. aureus, and nasal carriage is a risk factor for developing an endogenous infection. S. aureus nasal colonization is a multifactorial process, involving inter-species interactions among the nasal microbiota.Aims. The objectives of this study were to characterize the microbiota of carriers and non-carriers of S. aureus and to demonstrate the importance of inter-species relationships in the adhesion of S. aureus, a key step in nasal colonization.Methodology. First, we characterized the nasal microbiota from 30 S. aureus carriers and non-carriers by a culturomic approach. We then evaluated the adhesion of S. aureus, first alone and then along with other bacteria of the nasal microbiota. To do that, we used an in vitro model to measure the interactions among bacteria in the presence of epithelial cells.Results. Analysis of the nasal microbiota of the carriers and non-carriers of S. aureus made it possible to observe that each microbiota has specific features in terms of composition. However, this composition differs significantly between carriers and non-carriers mainly through two bacterial groups: coagulase-negative staphylococci and corynebacteria. In a second part, adhesion of S. aureus to epithelial cells showed competition between S. aureus and these bacteria, suggesting a limitation of nasal colonization by S. aureus.Conclusion. These findings demonstrate the existence of a negative correlation between S. aureus and other species which inhibits adhesion and could limit nasal colonization.

Plasma and peritoneal concentration following continuous infusion of cefotaxime in patients with secondary peritonitis.

OBJECTIVES: The aim of this study was to determine the steady-state plasma and peritoneal concentrations of cefotaxime and its metabolite desacetyl-cefotaxime administered by continuous infusion to critically ill patients with secondary peritonitis. PATIENTS AND METHODS: In 11 patients, a continuous infusion of 4 g/24 h of cefotaxime following a bolus of 2 g was evaluated. Plasma and peritoneal levels of cefotaxime and desacetyl-cefotaxime were measured at steady state on days 2 and 3 (plasma) and on day 3 (peritoneal) by HPLC. Results are expressed as means +/- SD. RESULTS: Total and unbound plasma levels of cefotaxime were 24.0 +/- 21.5 and 20.3 +/- 19.8 mg/L on day 2 and 22.1 +/- 20.7 and 18.9 +/- 19.2 mg/L on day 3, respectively. Total and unbound levels of cefotaxime in the peritoneal fluids were 16.2 +/- 11.5 and 14.3 +/- 10.4 mg/L, respectively. The unbound fraction of plasma cefotaxime was 81.8 +/- 5.9% on day 2 and 82.6 +/- 7.7% on day 3, and the unbound fraction at the peritoneal site was 87.0 +/- 5.5% on day 3. Total and unbound plasma levels of desacetyl-cefotaxime were 9.0 +/- 8.1 and 8.4 +/- 8.1 mg/L on day 2 and 7.6 +/- 7.6 and 7.2 +/- 7.6 mg/L on day 3, respectively. Total and unbound levels of desacetyl-cefotaxime in the peritoneal fluids were 11.9 +/- 11.5 and 10.9 +/- 10.8 mg/L, respectively. The MICs for the enterobacteria recovered ranged from 0.016 to 0.25 mg/L. CONCLUSIONS: Continuous infusion of 4 g/24 h of cefotaxime provided a peritoneal concentration >5x MIC for the recovered Enterobacteriaceae and the susceptibility breakpoint of cefotaxime for facultative Gram-negative bacilli.

Late-onset ventilator-associated pneumonia in nontrauma intensive care unit patients.

BACKGROUND: Most studies designed to determine the factors associated with the acquisition of late-onset ventilator-associated pneumonia (VAP) were performed in critically ill trauma patients. The impact of enteral nutrition (EN) on the risk of acquiring VAP has been discussed. In this study, we assessed factors associated with late-onset VAP in nontrauma patients and determined whether nutrition provided early was associated with development of late-onset VAP in this population. METHODS: We performed a prospective observational cohort study in a 21-bed polyvalent intensive care unit in a university hospital. RESULTS: Three hundred sixty-one intubated adult patients with a duration of mechanical ventilation (MV) of 6 days or more were admitted over a 28-mo period. Late-onset VAP was confirmed in 76 patients (21%) by the presence of at least one microorganism at a concentration >or=10(4) colony-forming units/mL on the bronchoalveolar lavage. Gram-negative bacilli represented 75% and Staphylococcus aureus 21% of recovered organisms. Factors independently associated with late-onset VAP by multivariate analysis included a high simplified acute physiology score II score (odds ratio: 1.021; 95% confidence interval [CI]: 1.005-1.038; P = 0.01), development of acute respiratory distress syndrome during the first 5 days of MV (odds ratio: 1.98; 95% CI: 1.05-3.67; P = 0.04), and size of the endotracheal tube >or=7.5 (odds ratio: 2.06; 95% CI: 1.88-3.90; P = 0.03). EN started within 48 h of MV onset was not associated with a higher risk for late-onset VAP. CONCLUSION: In our nontrauma patient population, early EN was not associated with development of late-onset VAP. In this population, severity of the disease during the first 5 days of MV seemed to be associated with late-onset VAP. In addition, our results suggest that the risk of late-onset VAP is higher in patients with a tube size >or=7.5 than in patients with a tube size <7.5.

At-risk drinkers are at higher risk to acquire a bacterial infection during an intensive care unit stay than abstinent or moderate drinkers.

OBJECTIVES: To determine whether excessive alcohol consumption increases the risk for intensive care unit (ICU)-acquired bacterial infection, especially ventilator-associated pneumonia (VAP), in nontrauma patients. DESIGN: Prospective observational cohort study. SETTING: A 21-bed polyvalent ICU in a university hospital. PATIENTS: A total of 358 adult patients admitted over a 1-yr period who had an ICU stay > or = 3 days and in whom alcohol consumption could be assessed. INTERVENTIONS: None. MEASUREMENTS AND MEAN RESULTS: Thirty-one percent of the patients (111 of 358) were identified as at-risk drinkers according to the National Institute on Alcohol Abuse and Alcoholism criteria. Among these, 61 had a daily intake of five or more drinks per day and 73 had Simplified Michigan Alcohol Short Test scores > or = 3. ICU-acquired bacterial infections were diagnosed in 88 patients, and 69 patients had one or more VAPs. Forty (36%) at-risk drinkers acquired bacterial infections vs. 48 (19%) not-at-risk drinkers (p < .001). Among at-risk drinkers, the proportion of patients who developed bacterial infection was higher in at-risk drinkers consuming five or more drinks per day compared with at-risk drinkers consuming fewer than five drinks per day (p = .048). After adjustment for age, gender, Simplified Acute Physiology Score II, length of hospital stay before ICU admission, prior antibiotic administration within 24 hrs before ICU admission, type of admission, immunosuppression, duration of mechanical ventilation, and central venous and urinary catheter exposure, at-risk drinking remained significantly associated with the acquisition of bacterial infection at any site (hazard ratio 1.92; 95% confidence interval, 1.17-3.14; p = .009) and of VAP (hazard ratio 1.76; 95% confidence interval, 1.05-3.06; p = .04). CONCLUSIONS: At-risk drinking was a significant risk factor for acquisition of ICU-acquired bacterial infection.

Genotypic characterization of Porphyromonas gingivalis isolated from subgingival plaque and blood sample in positive bacteremia subjects with periodontitis.

AIM: The objective of this study was to investigate clonal relationship among Porphyromonas gingivalis isolated from subgingival plaque and blood samples in positive transient bacteremia subjects with periodontitis. MATERIAL AND METHODS: Unrelated patients with general chronic periodontitis or general aggressive periodontitis requiring scaling and root planing (SRP) were included in the study. Genotyping of each isolate was performed using pulsed field gel electrophoresis technique. Genetic relatedness of strains isolated within an individual or between different patients was determined by dendogram analysis. RESULTS: Following SRP, from 16 patients, seven patients showed positive P. gingivalis bacteremia and nine were negative. Thirty-two strains were isolated from subgingival plaque and blood samples before and during induced transient bacteremia. The majority of the patients harboured one clonal type. Two patients showed different clones in plaque and blood samples suggesting that more than one clone can be found in subgingival plaque. P. gingivalis isolates from periodontitis patients after transient bacteremia following SRP, revealed a high heterogeneity among isolates. CONCLUSION: In 6/16 subjects the same P. gingivalis isolate was found in the blood and in oral cavity. P. gingivalis heterogeneity suggests no association of a unique clonal type with transient bacteremia.

Simplification of first-line antibacterial regimen for complicated appendicitis in children is associated with better adherence to guidelines and reduced use of antibiotics.

Acute appendicitis in children requires early surgery and short-course antibiotics active against Enterobacteriaceae and anaerobes. Although an aminoglycoside-containing three-drug regimen has been used successfully for decades, simpler regimens with similar efficacy are increasingly used. This study evaluated the impact of a switch from the combination of cefotaxime, metronidazole and gentamicin (regimen 1) to piperacillin/tazobactam (regimen 2) as first-line regimen for complicated acute appendicitis in children. In total, 171 children were enrolled [median (IQR) age, 10 (6-13) years], treated with regimen 1 (n = 80) or regimen 2 (n = 91) following surgery for complicated acute appendicitis. The two groups were comparable except for surgical approach (through laparoscopy in 46% vs. 88% for regimens 1 and 2, respectively; P < 0.001). Post-operative complications and duration of hospital stay were similar. Deviations from antibacterial treatment protocol decreased from 36% (29/80) to 14% (13/91) (P < 0.001), with a dramatic reduction in antibacterial treatment duration from median (IQR) of 15 (12-16) days to 5 (5-8) days (P < 0.001). Post-operative intra-abdominal abscess developed in 32 children (18.7%). Female sex (OR = 2.76, 95% CI 1.18-6.48; P = 0.02) and sepsis/septic shock on admission (OR = 4.72, 95% CI 1.12-19.97; P = 0.035) were independently associated with post-operative intra-abdominal abscess, but not antibacterial regimen. This study shows that simplification of first-line antibacterial regimen for complicated appendicitis in children was associated with reduced protocol deviation, reduced duration of antibiotics, and similar outcomes (post-operative complications and duration of hospital stay).

The antibacterial activity of tramadol against bacteria associated with infectious complications after local or regional anesthesia.

BACKGROUND: Tramadol is a synthetic analog of codeine with opioid and local anesthetic properties. It is used as a central-acting analgesic, and recently, in subcutaneous or intradermal injections, as a local anesthetic. We investigated in vitro the antibacterial activity of tramadol in the absence of any local anesthetics against Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa pathogens that can cause infectious complications after local or regional anesthesia. METHODS: Bacterial cultures were grown for 18 h, diluted in sterile physiological saline, and incubated for 6 or 24 h at 37 degrees C with 6.25, 12.5, or 25 mg/mL tramadol. The mixtures were then plated onto blood agar and colony counts were recorded after 24 h incubation at 37 degrees C. RESULTS: Tramadol had bactericidal activity against E. coli and S. epidermidis compared with controls: at 25 mg/mL for 6 h or at 12.5 mg/mL for 24 h, tramadol decreased by approximately 7 log(10) (P < 0.001) the colony counts of E. coli (100% kill). Similar results were obtained with S. epidermidis, with approximately 6 log(10) reduction (100% kill) when tramadol was used at 25 mg/mL for 24 h (P < 0.001). The antibacterial effect of 25 mg/mL tramadol was lower against S. aureus and P. aeruginosa, reducing the growth of these strains by approximately 3log(10) after 24 h (P < 0.001). CONCLUSIONS: Tramadol has dose- and time-dependent bactericidal activity against E. coli and S. epidermidis, as well as antibacterial activity against S. aureus and P. aeruginosa. The antibacterial properties of tramadol may be useful for reducing the risk of bacterial infection after local or regional anesthesia.

[Endoscopic and pathological aspect of small bowel and colonic involvement in Whipple's disease: a case report]. / Aspect endoscopique et pathologique de l'atteinte intestinale et colique de la maladie de Whipple. A propos d'un cas.

We describe a case of Whipple's disease confirmed by clinical, histological, bacteriological and molecular criteria. The duodenal involvement was associated with the presence of an endoscopic and histological enterocolitis. Final diagnosis of small bowel and colonic involvement by Whipple's disease was confirmed by histology and molecular biology. We review the literature on extra duodenal involvement. We underline the fact that enterocolitis in Whipple's disease is non-specific. We also discuss the other causes of intestinal mucosal infiltration by macrophages.

Clostridium difficile infections: do we know the real dimensions of the problem?

Clostridium difficile infection (CDI) is the primary cause of nosocomial diarrhoea in industrialised countries, usually occurring as a complication of antibiotic therapy in elderly patients. Landmark events contributed to boosting interest in CDI over the last 10 years, including the emergence of unusually severe and recurrent CDI due to the NAP1/BI/027 strain, as well as reports suggesting that CDI is also significantly encountered in patients previously considered at no risk, such as community-acquired CDI in patients with no recent antibiotic use, or CDI during pregnancy. Despite this growing interest from the medical community, we do not know the real dimensions of the disease for the following reasons: (i) despite comprehensive guidelines published in Europe and in the USA, most laboratories still use diagnostic tests with suboptimal sensitivity as a 'rule-out' test, hence a significant proportion of CDIs remain undiagnosed; (ii) use of PCR as a stand-alone test by others will probably overestimate the real incidence of CDI and jeopardise any comparison between institutions with different diagnostic procedures; and (iii) transversal studies, with optimum design and diagnostic tests, are rapidly outdated due to the dramatic changes in CDI epidemiology that may occur from one year to another. To get an accurate picture of the real dimensions of the CDI issue, we need more systematic use of an adequate and homogeneous diagnostic strategy in the field as well as the implementation of continuous monitoring of CDI incidence through surveillance programmes.

Whole-Genome Sequences of Staphylococcus aureus ST398 Strains of Animal Origin.

Staphylococcus aureus sequence type 398 (ST398) was originally associated with animal infections. We announce the complete genome sequences of two ST398 methicillin-susceptible S. aureus strains from the livestock environment. These genome sequences assist in the characterization of interesting ST398 features relying on host tropism and epidemiological settings.