Biofilm demolition and antibiotic treatment to eradicate resistant Helicobacter pylori: a clinical trial.

BACKGROUND & AIMS: Helicobacter pylori attaches to gastric mucosa and grows as a biofilm. This constitutes protection from antimicrobial agents. We assessed the role of a pretreatment with n-acetylcysteine in destroying biofilm and overcoming H pylori antibiotic resistance. METHODS: In an open-label, randomized controlled trial, 40 subjects with a history of at least 4 H pylori eradication failures were evaluated for biofilm presence, antibiotic susceptibility, and H pylori genotypes. Subjects were assigned randomly to receive (group A) or not (group B) n-acetylcysteine before a culture-guided antibiotic regimen. The primary end point was the H pylori eradication rate as assessed by (13)C-labeled urea breath testing. RESULTS: H pylori was eradicated in 13 of 20 (both per-protocol and intention-to-treat analyses, 65%; 95% confidence interval, 44%-86%) group A participants and 4 of 20 (both per-protocol and intention-to-treat analyses, 20%; 95% confidence interval, 3%-37%) group B participants (P < .01). Biofilms persisted only in unsuccessfully treated participants. H pylori genotypes did not influence treatment outcome. CONCLUSIONS: N-acetylcysteine pretreatment before a culture-guided antibiotic regimen is effective in overcoming H pylori antibiotic resistance.

Endotracheal lidocaine in preventing endotracheal suctioning-induced changes in cerebral hemodynamics in patients with severe head trauma.

INTRODUCTION: In patients with severe head trauma, endotracheal suctioning can result in adverse reactions including cough, systemic hypertension, increased intracranial pressure, and reduced cerebral perfusion pressure. The aim of this prospective, blinded clinical trial in mechanically ventilated patients with severe head trauma whose cough reflexes were still intact was to assess the effectiveness of endotracheally instilled lidocaine in preventing endotracheal suctioning-induced changes in cerebral hemodynamics (increase in intracranial pressure and reduced cerebral perfusion pressure) after a single endotracheal suctioning. METHODS AND RESULTS: Ten minutes after lidocaine instillation into the endotracheal tube, secretions were suctioned for <30 s through a standard closed endotracheal suctioning circuit. Heart rate, arterial pressure, intracranial pressure, and cerebral perfusion pressure were continuously monitored. The first patient studied received an endotracheal lidocaine dose of 2.0 mg/kg. The dose for the next study patient was titrated upwards or downwards in 0.5 mg/kg steps according to, whether the intracranial pressure reached the predefined threshold of > or =20 mmHg. A total of 41 patients were studied. Lidocaine instillation into the endotracheal tube had no effect on hemodynamic and ventilatory variables. In 21 patients lidocaine dose instilled into the endotracheal tube effectively prevented the endotracheal suctioning-induced intracranial pressure increase behind the predefined threshold of > or =20 mmHg and cerebral perfusion pressure remained unchanged. In the remaining 20, although intracranial pressure rose significantly cerebral perfusion pressure remained constant. CONCLUSIONS: In mechanically ventilated patients with severe head trauma endotracheal lidocaine instillation effectively and dose-dependently prevents the endotracheal suctioning-induced intracranial pressure increase and cerebral perfusion pressure reduction.

TAFI deficiency in liver cirrhosis: relation with plasma fibrinolysis and survival.

INTRODUCTION: TAFI (thrombin-activatable fibrinolysis inhibitor) is a potent anti-fibrinolytic and anti-inflammatory factor of liver origin. It is markedly reduced in liver cirrhosis but its effect on fibrinolysis remains controversial and no data are available on its prognostic value. We evaluated the relationship of TAFI level with plasma fibrinolysis and survival in cirrhotic patients. PATIENTS AND METHODS: Sixty-five patients with liver cirrhosis were studied. TAFI antigen, plasma fibrinolysis and other laboratory variables were assayed at study entry and their association with mortality was assessed during a 3-year follow-up. RESULTS: TAFI level and fibrinolysis time were markedly reduced in liver cirrhosis as compared to healthy subjects (p<0.0001) and TAFI deficiency was strongly correlated with fibrinolysis time (p=0.0002). TAFI level at entry, but not fibrinolysis time, was significantly lower in non-survivors (n=25) than in survivors (n=40, p=0.0001). By Cox regression analysis, after adjustment for possible confounding factors, TAFI, but not fibrinolysis time, was identified as an independent predictor of mortality. TAFI assay, moreover, showed a clinically relevant accuracy in assessing patients' survival (ROC curve analysis, p<0.0001) achieving a sensitivity of 92%, a specificity of 55%, and a negative predictive value of 91.7%. CONCLUSIONS: Our data indicate that TAFI deficiency in liver cirrhosis is associated with enhanced plasma fibrinolysis. Moreover, they suggest that TAFI, but not fibrinolysis time, is a strong predictor of survival and thus TAFI assay might prove useful to select candidates for liver transplantation.

Rapid detection of clarithromycin resistance in Helicobacter pylori using a PCR-based denaturing HPLC assay.

OBJECTIVES: We evaluated a new approach for the rapid detection of clarithromycin resistance in Helicobacter pylori, based on PCR and denaturing HPLC (DHPLC). METHODS: A 180 bp fragment of the 23S rRNA gene was amplified using DNA from 81 clinical H. pylori isolates (51 isolates were shown to be resistant to clarithromycin by Etest), and, directly, from 101 gastric biopsies from patients with digestive diseases, who were infected with H. pylori as assessed by a 13C-urea breath test, histology and/or culture. DHPLC was used to detect mutations in all the PCR products. RESULTS: DHPLC profiles for the 30 susceptible isolates all showed homoduplex peaks; the resistant isolates consistently generated heteroduplex peaks that were easily distinguishable from the wild-type H. pylori reference strain. Sequencing revealed point mutations in all the resistant isolates. Overall, five different mutations were detected. Four of these mutations (A2142G, A2142C, A2143G and T2182C) are known to be associated with clarithromycin resistance; the remaining mutation (C2195T) has not been previously described. This novel single-base substitution was found in combination with the common mutation A2143G. Of the biopsies tested, 25 specimens generated heteroduplexes due to sequence alterations (mutation A2142G, A2142C or A2143G). In one of these specimens, A2143G was found together with the novel mutation T2221C; in another, a mixture of wild-type and mutant (A2143G) sequences was detected. For 20 culture-positive out of the 25 biopsies DHPLC results confirmed the presence of clarithromycin resistance. CONCLUSIONS: Our results suggest that the PCR-DHPLC assay is a valid tool for rapid assessment of clarithromycin resistance in H. pylori and that in the future it could be used directly on biopsy specimens, avoiding the need for culture-based methods.

High levels of dual resistance to clarithromycin and metronidazole and in vitro activity of levofloxacin against Helicobacter pylori isolates from patients after failure of therapy.

Current treatment for Helicobacter pylori infections generally includes two or more antimicrobials (amoxicillin, clarithromycin, nitroimidazoles, tetracycline, etc.), but treatment fails in 10-20% of all cases, often because of drug resistance. Levofloxacin has been proposed as an alternative for these refractory infections. We examined 67 H. pylori isolates from patients unsuccessfully treated with amoxicillin, clarithromycin, metronidazole and levofloxacin. Minimum inhibitory concentrations determined with the epsilometer test revealed clarithromycin and metronidazole resistance in 91 and 82.1% of the isolates, respectively; 52 (77.6%) were resistant to both drugs. All 67 isolates were susceptible to amoxicillin and tetracycline. Fifty-two isolates had levofloxacin MICs of 0.01-2 mg/l; the remaining 15 (22.4%), all clarithromycin- and metronidazole-resistant, had MICs >/= 8 mg/l. Levofloxacin may be an option for refractory H. pylori infections, but the choice should be based on in vitro susceptibility data, and physicians should consider local resistance patterns when treating these infections empirically.

High-dose versus low-dose clarithromycin in 1-week triple therapy, including rabeprazole and levofloxacin, for Helicobacter pylori eradication.

GOALS: To compare high-dose versus low-dose clarithromycin in 1-week triple therapy including rabeprazole and levofloxacin. BACKGROUND: Regimens containing rabeprazole and levofloxacin have proved to be effective against H. pylori infection. STUDY: One-hundred H. pylori-positive patients were randomly assigned to one of the following 1-week regimens: rabeprazole 20 mg o.d. plus levofloxacin 500 mg o.d. and clarithromycin 250 mg b.d. (RLC-1 group); rabeprazole 20 mg o.d. plus levofloxacin 500 mg o.d. and clarithromycin 500 mg b.d. (RLC-2 group). H. pylori status was assessed at entry and after the treatment. Patients who experienced treatment failure underwent antibiotic susceptibility testing. RESULTS: Forty-two patients in RLC-1 group (both PP and ITT analysis: 84%; 95%CI: 71-93%) and 47 in RLC2 group (both PP and ITT analysis: 94%; 95% CI: 83-98%) became H. pylori negative. Clarithromycin resistance was detected in all of 8 (100%) RLC-1 failures and in 1 out of 3 (33%) RLC-2 failures. Side effects occurred in 8% of patients in RLC-1 group and in 12% in RLC-2. CONCLUSIONS: Regimens tested are competitive with other PPI-based treatments. One-week triple therapy containing rabeprazole plus, levofloxacin, and high-dose clarithromycin yielded a higher eradicating rate than the one containing low-dose clarithromycin and may be considered as a first-line therapy option.

[Epidemiological monitoring of legionellosis: a case-control study in an university general hospital]. / La sorveglianza epidemiologica della Legionellosi in un Policlinico Universitario: risultati di un anno di attività.

The authors report the early results of a case-control study carried out about the risk of legionellosis. During the first year, they have tested urine samples from patients with unknown pneumonia, using a legionella-sensitive test for the detection of its antigen. Out of 171 samples, 9 have turned out to be positive (5.3%). Lifestyles, predisposing factors, possible sources of infection and stressful events were investigated.