Could past Chlamydial vascular infection promote the dissemination of Chlamydia pneumoniae to the brain?

Chlamydia pneumoniae, a pathogen responsible for respiratory tract infections, has been associated with atherosclerosis which, along with hypertension, hyperlipidemia, cardiovascular and/or cerebrovascular ischemia and stroke, is a risk factor for chronic neurological disorders. Several studies have demonstrated the ability of C. pneumoniae to disseminate from lungs to arteries through peripheral blood mononuclear cells. Once inside the vascular tissue, C. pneumoniae infection may disseminate via peripheral monocytes to the brain over the intact blood-brain barrier, and contribute to the development of chronic neurological disorders. The aim of our study was to evaluate whether past C. pneumoniae vascular infection may promote the dissemination of this microorganism to the brain, therefore we investigated the presence of C. pneumoniae in post-mortem brain tissue specimens of patients with past chlamydial vascular infection. Seventy six post-mortem brain tissue specimens from 19 patients with past chlamydial vascular infection were investigated for the presence of C. pneumoniae by immunohistochemistry, polymerase chain reaction, in situ polymerase chain reaction and in situ reverse transcription polymerase chain reaction. As control, 28 brain tissue specimens were taken from 7 age and sex matched subjects without chlamydial infection. C. pneumoniae was detected in 16 (84.2%) out of 19 patients with chlamydial vascular infection whereas it was not detected in control subjects (p= 0.0002). In conclusion, the main result of our study is the evidence that a chlamydial vascular infection can disseminate to the brain. It will be important for current and future researches to perform large-scale prospective studies on cardiovascular patients with chlamydial vascular infection in order to evaluate the long-term pathological alterations of the brain.

Purity and stability of online-prepared hemodiafiltration fluid after storage.

BACKGROUND/AIMS: Previous studies have suggested that online hemodiafiltration (OL-HDF) fluid can be used as dialysate for continuous renal replacement therapies, and thus HDF costs can be reduced. The aims of this study were to determine the purity of OL-HDF fluid and to verify the stability of the electrolyte composition and acid-base balance during its storage. METHODS: OL-HDF fluid was collected in 70 individual bags and stored for up to 7 days. The following tests were performed daily in 10 bags: natural visible precipitation (macrocrystallization), sample collection for chemical analysis and fluid culture, limulus amebocyte lysate endotoxin test, standard culture of NALGENE® filters after passing of the fluid, and molecular analysis of bacterial DNA. RESULTS: The values of pH and pCO(2) showed a significant change starting at 24 h (p < 0.001); after 72 h, their values were beyond the measurable range. Coefficient of variation for pCO(2) was as high as 25.7%. Electrolyte composition (Na(+), K(+), Cl(-), Ca(2+) and glucose) showed a statistically significant difference over time (p < 0.05); however, their coefficients of variation were low (1.7, 1.4, 0.6, 2.3 and 0.9%, respectively), which might not be considered clinically significant. Negative results were obtained at all points by fluid and filter cultures, endotoxin test and molecular analysis. No macrocrystallization was observed at any time point. CONCLUSIONS: We demonstrate the microbiological purity of OL-HDF fluid stored for up to 7 days. The electrolyte composition was stable, except for a relevant change in pCO(2) and consequently in pH (first noted at 24 h), emphasizing the need to reassess the acid-base balance in multilayer plastic bags in future studies.

Septic shock, pneumonia, and soft tissue infection due to Myroides odoratimimus: report of a case and review of Myroides infections.

The genus Myroides comprises aerobic, yellow-pigmented, non-motile, non-fermenting gram-negative rods formerly classified as Flavobacterium odoratum. Members of the genus are widely distributed in the environment, especially in water, and usually behave as low-grade opportunistic pathogens, having been found to cause urinary tract infection, endocarditis, ventriculitis, and cutaneous infections in severely immunocompromised patients. We report a case of soft tissue infection, septic shock, and pneumonia due to M. odoratimimus in an immunocompetent male. To our knowledge, this is the first description of life-threatening infection caused by this organism in an immunocompetent host. We have also reviewed the medical literature on the genus Myroides.

Chlamydia pneumoniae infection as a risk factor for accelerated atherosclerosis in hemodialysis patients.

Atherosclerotic cardiovascular disease is the main cause of morbidity and mortality for end-stage renal disease patients undergoing chronic haemodialysis (HD). Several studies in recent years have identified Chlamydia pneumoniae, a respiratory pathogen, as risk factor for cardiovascular diseases in the general population. The aim of our study is to evaluate chlamydial load, in peripheral blood mononuclear cells (PBMC) of HD patients. Furthermore, the correlation between DNA chlamydial load and markers of inflammation was also examined. PBMC specimens isolated from 49 HD patients and 46 blood donors were analyzed for the presence of C. pneumoniae DNA by real-time PCR and ompA nested touchdown PCR. In HD patients, plasma levels of several inflammatory markers were also determined. A significantly higher rate of C. pneumoniae DNA was found in HD patients (44.9 percent) than in blood donors (19.6 percent) (p=0.016); HD patients were also more likely to have a significantly high chlamydial load (p=0.0004). HD patients with atherosclerotic cardiovascular diseases have a significantly greater chlamydial load than HD patients without cardiovascular diseases (p= 0.006). A significantly higher value of C-reactive protein, IL-6 and advanced oxidative protein products was found in HD patients with a greater chlamydial load (p less than 0.05). Likewise, a significantly lower monocyte HLA-DR percentage (p=0.011) as well as a lower monocyte HLA-DR expression were found in such patients (p= 0.007). In conclusion, our results show that HD patients are at high risk of C. pneumoniae infection correlated with chronic inflammatory response which in turn can lead to accelerated atherosclerosis and other long-term clinical complications such as myocardial infarction and stroke.

Clustering and risk factors of methicillin-resistant Staphylococcus aureus carriage in two Italian long-term care facilities.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a well-recognized agent of health care-associated infections in long-term care facilities, but few data about the circulation of MRSA in this setting in Italy are available. The aim of the study is to determine the prevalence and risk factors for MRSA carriage in nursing home residents in Vicenza (northeastern Italy). PATIENTS AND METHODS: A point prevalence survey was conducted in two long-term care facilities (subdivided into 15 wards) from 12 June 2006 to 6 July 2006. Anterior nasal swabs were obtained from residents and laboratory screening for MRSA was performed; full antibiotic susceptibility was assessed in MRSA isolates. Macrorestriction analysis of chromosomal DNA was carried out by pulsed field gel electrophoresis (PFGE). For each subject, demographic data, length of stay, dependency, cognitive function, presence of medical devices, comorbidities, current and previous antibiotic treatment, previous hospital admission and presence of infection were assessed on the day of sample collection. Factors that were found to be significantly associated with MRSA carriage at univariate analysis were introduced into multilevel logistic regression models in order to estimate the odds ratios (OR) with 95% confidence intervals (CI) for the risk of MRSA colonization, taking into account the clustering of patients within wards. RESULTS: Nasal swabs were obtained in 551 subjects; overall 43 MRSA carriers were detected (7.8%; CI = 5.7-10.4%). The rate of nasal carriers was very similar in the two institutions, and varied from 0% (0/36) to 18% (7/39) between wards. Only two out of 15 wards were found to have no MRSA carriers; overall, three pairs of colonized roommates were detected. Upon multilevel logistic regression, the risk of MRSA carriage was increased in patients with cancer (OR = 6.4; CI = 2.5-16.4), in those that had undergone recent hospitalization (OR = 2.2; CI = 1.0-4.4), and it reached OR = 4.0 (CI = 1.7-9.9) in those with three or more antibiotic treatments in the previous year; about 10% of the variability in MRSA carriage could be attributed to differences between wards. Pulsed field gel electrophoresis analysis permitted the definition of six clusters; two of these comprised 78.6% of the studied isolates and were quite similar, with one being more strongly represented among subjects hospitalized in the previous 12 months. All of the MRSA strains were resistant to ciprofloxacine; nevertheless, the majority were susceptible to most other non-betalactam antibiotics. CONCLUSION: The study suggests that nursing homes are a significant reservoir for MRSA. Statistical and PFGE analyses indicate a scenario where MRSA seems to be endemic and individual risk factors, namely recent hospitalizations and repeated antibiotic treatments, play a major role in the selection of drug-resistant organisms. Infection control measures should be coordinated among different health care settings, and the appropriate use of antibiotics has emerged as an important issue for improving the quality of care.

[Methylobacterium radiotolerans bacteremia in hemodialysis patients]. / Batteriemie da methylobacterium radiotolerans in pazienti emodializzati.

Central venous catheters (CVCs) play an important role in replacement therapy for patients with acute and chronic renal failure. Secondary infections due to central venous access are responsible for 48-73% of bacteremia in hemodialysis patients and are an important cause of morbidity and increased health costs for these patients. Episodes of unexplained fever were noted in hemodialysis patients in our center starting in October 2006. An investigation for causative microorganisms was conducted from October 2006 to April 2007. Bacterial DNA was extracted and amplified using universal primers for bacterial 16S. Amplification by multiple PCR was performed on the samples and the subsequent sequencing led to the identification of the microorganism of interest as belonging to Methylobacterium radiotolerans. We report the largest cluster of dialysis catheter-related bloodstream infections caused by M. radiotolerans, and describe the difficulties in the prompt and correct identification of these bacteria. Thirty-seven patients had positive cultures for M. radiotolerans from blood (2.7%) or CVC (29.7%) or both (67.6%). After removal and replacement of CVCs and antibiotic therapy and the strict application of an infection management protocol, there were no more fever episodes or cultures positive for M. radiotolerans.

Residual of bacterial DNA in hemodialyzers: the proof of subclinical infection sustaining chronic inflammation.

BACKGROUND AND PURPOSE: Inflammation and infection seem to be important causes of morbidity and mortality in Chronic Kidney Disease (CKD) patients. Subclinical infections have been proposed as an important cause of inflammatory syndrome but to date this hypothesis remains speculative. In this investigation, we developed a method for molecular detection of the presence of bacterial DNA in a population of chronic kidney disease patients in order to correlate molecular data with the degree and level of inflammation and to evaluate the usefulness of the method in the diagnosis of subclinical infection. DESIGN: The study was divided into two phases: the study of a population of 81 CKD patients for prevalence and level of inflammation and infection; and the molecular evaluation of a subgroup of 38 patients without evident clinical causes of inflammation for molecular evaluation of subclinical infection. RESULTS: Patients hemoculture negative turned out positive for the presence of bacterial DNA when molecular methods were used. We found a trend of correlation with the presence of bacterial DNA and the increase in hs-CRP, IL-6 and oxidative stress (AOPP) levels and a reduction in MFI DR+. Hemodialyzer membranes seem to have properties that are 'sticky' to bacteria/bacterial DNA and work as concentrators. Moreover our data suggest that DNA can traverse hemodialysis membranes. CONCLUSIONS: Molecular methods have turned out to be far more sensitive than standard methods in detecting subclinical infection. The presence of bacterial DNA seems to influence the variation of some parameters of inflammation and immunity. Apart from the limitations and pitfalls, a molecular method could be useful for the screening of subclinical infection and diagnosis of sepsis when the hemoculture is negative. The identification of the microorganism involved, however, must be done with species-specific primers. These results are preliminary and more investigations will have to be performed in order to confirm our results.

ß-Cyclodextrin-based supramolecular poly(N-isopropylacrylamide) hydrogels prepared by frontal polymerization.

Frontal polymerization (FP) was successfully applied to the synthesis of poly(N-isopropylacrylamide)-grafted-acryloyl-ß-cyclodextrin supramolecularly crosslinked hydrogels. It was established that acryloyl-ß-cyclodextrin (AßCD) allowed performing successful frontal polymerizations with N-isopropylacrylamide even in the absence of any covalent crosslinker, which is something generally required. It was found that the swelling properties of the resulting hydrogels can be tuned by varying the amount of AßCD. Namely, when little amounts of this non-covalent crosslinker were used, superabsorbent hydrogels were obtained. Hydrogels containing also a covalent crosslinker were also prepared for comparison. These latter exhibited swelling ratios that are much lower than the others.

Impact of liver steatosis on virological response in [corrected] Italian patients with chronic hepatitis C treated with peg-interferon alpha-2b plus ribavarin.

BACKGROUND: Whether liver steatosis affects sustained virological response in patients with chronic hepatitis C is still under discussion. AIM: To evaluate the impact of liver steatosis in patients treated (for chronic hepatitis C) with combination therapy. METHODS: We evaluated 97 (male/female 82/15, mean age 41.1 years) consecutive naive patients treated with pegylated interferon alpha-2b plus ribavirin. RESULTS: Prevalence and severity of liver steatosis were significantly associated with genotype 3a [grade 3-4 in 14 of 32 patients (44%) vs. 8 of 65 patients (12%) with other genotypes; P = 0.001], while steatosis grade 1 (<10% of hepatocytes affected) was more frequently associated with genotype 1a/1b [9/39 (23%) vs. 4/57 (7%); P = 0.02]. Overall, sustained virological response was 62.8%, and was statistically uninfluenced by the presence/absence of liver steatosis. On the contrary, the following variables were independently associated with sustained virological response at logistic regression analysis: genotype other than 1a/1b, positive association, (odds ratio 3.4, P < 0.04), and low-grade liver steatosis, negative association, (odds ratio 9.0, P = 0.009), whereas sustained virological response was unaffected by severe liver steatosis, which was mainly associated with genotypes 2 and 3 [steatosis grade 2, 18/29 (62%); grade 3, 10/12 (83%); grade 4, 7/10 (70%)]. CONCLUSIONS: Only low-grade liver steatosis negatively affects the outcome of combination therapy, with peginterferon alpha-2b plus ribavirin, while severe steatosis (which is virus-related in most cases) has no impact on virological response.

Demonstration of Chlamydia pneumoniae in atherosclerotic arteries from various vascular regions.

Chlamydia pneumoniae (CP) has been reported to be a pathogenic agent in the mechanism leading to atherosclerosis. The majority of available data is focused mainly on coronary artery disease whereas the distribution of CP in different areas, associated with atherosclerotic disorders, has not been completely clarified. In this study we investigated the presence of CP in atheromasic plaques from five different vascular areas (basilary artery, coronary artery, thoracic aorta, abdominal aorta, renal arteries) using nested polymerase chain reaction (PCR) and immunohistochemical staining (IHC), in order to establish the putative association of CP with atherosclerotic disease. The same atheromasic plaques were also tested for the presence of Helicobacter pylori (HP) and cytomegalovirus (CMV), other putative agents of atherosclerosis, using a nested PCR technique. Our data indicate that the presence of CP can be demonstrated in 100% of patients tested, considering globally the five areas of analysis. On the other hand the presence of HP has been demonstrated in four out of 18 patients (22.2%), and CMV only in three out of 18 (16.6%). Our results strongly suggest an association between CP and atherosclerosis and highlight the need for the detection of CP in multiple vascular areas of the same patient.

Interferon alfa-2b alone or in combination with ketoprofen as treatment for interferon-naive chronic hepatitis C patients.

BACKGROUND: Non-steroidal anti-inflammatory drugs may amplify the anti-viral effect of alpha-interferon in vitro but in vivo data are still controversial. AIM: : To test the hypothesis that ketoprofen may increase the rate of response to alpha-interferon of chronic hepatitis C patients. METHODS: Fifty patients with chronic hepatitis C who had never received alpha-interferon were randomly assigned to receive 3-8 MU of alpha2b-interferon, three times weekly for 6 months, alone or in association with ketoprofen at a dose of 200 mg/day five times weekly. The virological response to treatment (undetectable HCV RNA in serum) was evaluated after 3 months and at the end of treatment, and 6 and 12 months after therapy withdrawal. RESULTS: One patient under combination therapy stopped the ketoprofen for persisting epigastric pain. Complete response under treatment was observed in 15 out of 24 (62.5%) patients receiving alpha2b-interferon alone and in 14 out of 26 (53.8%) patients under combination therapy (P=N.S.). One year after the end of treatment, a sustained response was seen in 4 out of 24 (16.2%) patients treated with alpha2b-interferon and in 5 out of 26 (19.2%) patients having received the combination (P=N.S.). CONCLUSION: Administration of ketoprofen does not increase either the primary or the sustained response to alpha2b-interferon therapy of interferon-naive chronic hepatitis C patients.

The effect of antibiotic resistance on the outcome of three 1-week triple therapies against Helicobacter pylori.

BACKGROUND: Resistance of Helicobacter pylori to antibiotics may be a major reason for treatment failure. AIM: To evaluate the effect of primary H. pylori resistance to antibiotics on the cure rates of three anti-H. pylori 1-week triple therapies. METHODS: One hundred and sixteen consecutive patients diagnosed H. pylori-positive by gastric histology, rapid urease test and culture were enrolled. Activity of tested antibiotics was determined by means of the E-test. Patients were treated for 7 days with: (i) pantoprazole 40 mg o.d. plus amoxycillin 1 g b.d. and metronidazole 250 mg q.d.s. (PAM); (ii) pantoprazole 40 mg o.d. plus clarithromycin 250 mg b.d. and metronidazole 250 mg q.d.s. (PCM); or (iii) pantoprazole 40 mg o.d. plus amoxycillin 1 g b.d. and clarithromycin 250 mg b.d. (PAC). Two months after completion of therapy, endoscopy and gastric biopsies were repeated. RESULTS: Primary resistance rates to metronidazole, clarithromycin and amoxycillin were 17.2, 6.9 and 0%, respectively. Overall H. pylori cure rates expressed as intention-to-treat and per protocol analyses were, respectively, 79% and 86% with PAM, 82% and 89% with PCM, and 85% and 85% with PAC. Significantly lower cure rates were observed in metronidazole-resistant patients treated with PAM (56% vs. 96%, P = 0.01) or PCM (50% vs. 97%, P = 0.01). A trend towards lower H. pylori cure rates was observed in clarithromycin-resistant patients treated with PCM (67% vs. 91%, P = 0.74) or PAC (50% vs. 87%, P = 0.68). CONCLUSION: Primary resistance to metronidazole influences the H. pylori cure rate of anti-H. pylori proton pump inhibitor-based triple therapies which include this antibiotic. A similar trend exists for primary clarithromycin resistance.

Cure of Helicobacter pylori infection in elderly patients: comparison of low versus high doses of clarithromycin in combination with amoxicillin and pantoprazole.

BACKGROUND: Advancing age may influence clarithromycin's pharmacokinetics. No studies have yet compared the effects of different dosages of clarithromycin in combination with a proton pump inhibitor and amoxicillin in elderly patients. AIM: To compare the efficacy and tolerability of clarithromycin 250 mg vs. clarithromycin 500 mg twice daily (b.d.) in combination with pantoprazole and amoxicillin in elderly patients. METHODS: One hundred and fifty-four elderly patients with H. pylori-associated ulcer disease or chronic gastritis were consecutively randomized to receive pantoprazole 40 mg daily plus amoxicillin 1 g, and either clarithromycin 250 mg b.d. (PAC 250) or clarithromycin 500 mg b.d. (PAC 500). Two months after therapy, endoscopy and gastric biopsies were repeated. RESULTS: The cure rates of H. pylori infection in the PAC 250 and PAC 500 groups were, respectively, 83% and 79% (ITT analysis) and 94% and 88% (PP analysis) (P=N.S.). Significant decreases in chronic gastritis activity both in the body (P < 0.00001) and the antrum (P < 0.0001) of the stomach were found in H. pylori-cured patients, independently of clarithromycin dosage. Four patients in PAC 250 (5%) and seven in PAC 500 (9%) reported adverse events (P=N.S.). One patient in PAC 250 (25%) and three in PAC 500 (43%) discontinued the study because of these drug-related side-effects (P=N.S.). CONCLUSIONS: In elderly patients, 1-week triple therapy with a proton pump inhibitor, amoxicillin and clarithromycin is a highly effective and well tolerated anti-H. pylori treatment. With this combination, clarithromycin at the lower dose of 250 mg b.d. achieved excel- lent cure rates and minimized adverse events and costs.

Cellular uptake of phosphonylmethoxyalkylpurine derivatives.

The cellular uptake of the phosphonylmethoxyalkylpurine derivatives HPMPA and PMEA has been studied in H9 cells. The two compounds exhibited an identical pattern of permeation in this cell line. Uptake did not occur via the nucleoside transport system, but through a different mechanism which, for its slow kinetics and temperature-dependence, is compatible with an endocytosis-like process. The amount of cell-associated drug increased up to one hour post-incubation.

Relevance of DNA binding to the mechanism of anti-herpesvirus activity of benzhydrazone.

Benzhydrazone (1H-benz(f)indene-1,3(2H)-dione bis (amidino-hydrazone) (BH) is a synthetic compound with selective anti-herpesvirus activity. Its selectivity seems to stem from the inhibition of viral protein glycosylation and several hypotheses have been formulated to explain such an effect. Data presented here demonstrate that DNA binding is a prominent feature of BH. Interaction is taking place with a relatively high affinity constant and is more efficient for GC-rich viral sequences. Experiments with the cloned DNA fragments from a BH-resistant virus strain indicate that BH-DNA complex formation is drastically reduced as compared to BH-sensitive virus. The occurrence of the resistant phenotype in HEp-2 cells but not in Vero cells could be explained by differences in BH cytotoxicity. Changes in drug uptake and accumulation by cells following infection, in addition to GC preference, may also account for the degree of antiviral selectivity shown by BH.

Noninvasive diagnosis of Helicobacter pylori infection in older subjects: comparison of the 13C-urea breath test with serology.

BACKGROUND: The potential influence of cognitive status, physical activities, comorbidity and cotreatments on the feasibility and diagnostic accuracy of two noninvasive diagnostic tests for Helicobacter pylori (Hp) infection, i.e., the 13C-urea breath test (13C-UBT) and serology (immunoglobulin G [IgG] anti-Hp antibodies), in older subjects is not known. METHOD: The study involved 100 consecutive symptomatic elderly subjects (mean age, 78.3 years; range, 65-96 years), who had undergone an upper gastrointestinal endoscopy. Patients were considered Hp positive if at least two of the three invasive methods, i.e. histology, culture, and/or the rapid urease test were positive for Hp infection. Patients were considered Hp negative if all three invasive methods were negative. The 13C-UBT was performed according to the European standard method and the assaying of IgG anti-Hp antibodies by enzyme-linked immunosorbent assay. Cognitive status and functional activities were determined by the Mini-Mental State Examination (MMSE), the activities of daily living (ADLs) and instrumental ADLs (IADLs). RESULTS: According to invasive methods, 49 patients were Hp positive and 47 were Hp negative (4 subjects were excluded from the study). Hp-positive patients demonstrated a significantly higher prevalence of peptic ulcers (p =.02) and activity of chronic gastritis (p<.0001) than Hp-negative subjects. The 13C-UBT demonstrated a sensitivity of 100%, a specificity of 95.7%, and a diagnostic accuracy of 97.9%. Serology had significantly lower sensitivity (74.4%), specificity (59%), and diagnostic accuracy (67%, p<.001) than the 13C-UBT. The feasibility and the diagnostic accuracy of the 13C-UBT were not altered by the cognitive status (MMSE) and functional activities (ADL, IADL) of the patients, their drug consumption, or the prevalence of concomitant diseases. CONCLUSIONS: In older subjects, the 13C-UBT had a significantly higher diagnostic accuracy than serology without influence of cognitive function, disability, comorbidity and cotreatments. This method may be considered an excellent, clinically useful, noninvasive test for the diagnosis of Hp infection in older subjects.

Polymerase chain reaction amplification and restriction enzyme typing as an accurate and simple way to detect and identify human papillomaviruses.

A simple and economic method for the detection and identification of human papillomaviruses (HPV) is described. The method has been developed with cloned HPV DNA and DNA from clinical samples. Genomic fragments were obtained from several different HPV types, including the ones most frequently encountered in the genital tract by polymerase chain reaction (PCR) amplification directed by degenerate general primers. The amplification fragments were identified by a form of miniature fingerprinting, with a set of restriction enzymes that gave a unique digestion pattern for each HPV type. Different strategies are proposed, based on PCR and restriction analysis, and this approach to identification was compared with more classic methods such as Southern hybridisation.

Prevalence of Helicobacter pylori resistance to antibiotics in Northeast Italy: a multicentre study. GISU. Interdisciplinary Group for the Study of Ulcer.

AIMS: To evaluate prevalence of primary Helicobacter pylori antibiotic resistances in Northeast Italy and to identify risk factors associated with this resistance. MATERIALS AND METHODS: A total of 248 patients undergoing upper gastrointestinal endoscopy were enrolled from 19 Endoscopy Units over a 6-month period. From each patient, 4 gastric biopsies were taken for histology and 2 were sent to the Central Referral Microbiological Laboratory for culture and determination of antibiotic activity against Helicobacter pylori by means of E-test. Strains were considered resistant when minimum inhibitory concentration was >8 microg/ml for metronidazole and >1 microg/ml for clarithromycin. No cut-off value was predefined for amoxycillin. RESULTS: Culture of Helicobacter pylori was successfully performed in 167 patients. Primary resistance to metronidazole, clarithromycin or amoxycillin was 14.9%, 1.8% and 0%, respectively Patients infected with Helicobacter pylori strains resistant to antibiotics were more frequently females than males (70.3% vs 41.4%), had a significantly lower coffee intake (66.6% vs 86.6%) and lower body mass index (23.7+/-2.6 vs 25.3+/-3.6) than patients with susceptible Helicobacter pylori strains. Age, smoking, alcohol use, family history of Helicobacter pylori infection, concomitant diseases and treatments, endoscopic diagnoses, Helicobacter pylori density and histological activity of chronic gastritis were not associated with antibiotic resistance. Multivariate analysis confirmed that female gender (odds ratio = 2.74, 95% confidence interval = 1.03-7.27) was the only significant risk factor associated with antibiotic resistance. CONCLUSIONS: In this population, primary Helicobacter pylori resistance to metronidazole was higher than resistance to clarithromycin, and female gender was significantly associated with this resistance. The low prevalence of resistance to metronidazole, clarithromycin and amoxycillin identified in this geographical area suggests that proton pump inhibitor-based triple regimens including these antibiotics may still be used as first line therapies against Helicobacter pylori infection.

Incidence of secondary Helicobacter pylori resistance to antibiotics in treatment failures after 1-week proton pump inhibitor-based triple therapies: a prospective study.

BACKGROUND: Antibiotic-resistant Helicobacter pylori strains are becoming increasingly prevalent, although it is not clear to what extent the new resistant organisms will spread. AIM: To evaluate the incidence of secondary Helicobacter pylori resistance to metronidazole, clarithromycin and/or amoxycillin after one-week proton pump inhibitor based triple therapy failure in patients who were, before therapy infected with Helicobacter pylori strains susceptible to these antibiotics. PATIENTS AND METHODS: Enrolled in the study were 97 consecutive Helicobacter pylori-positive subjects infected by Helicobacter pylori strains susceptible to metronidazole, clarithromycin and amoxycillin. Activity of tested antibiotics was determined by means of the E-test. Patients were treated for seven days with a proton pump inhibitor, omeprazole 20 mg twice daily or pantoprazole 40 mg once daily, plus clarithromycin 250 mg twice daily and metronidazole 250 mg four times daily; or with a proton pump inhibitor plus amoxycillin 1 g twice daily and clarithromycin 500 mg twice daily. Two months after completion of therapy, endoscopy and gastric biopsies for histology, rapid urease test and culture were repeated. RESULTS: Four patients were dropped from the study Overall Helicobacter pylori cure rates expressed as both intention-to-treat and per-protocol analyses, were, respectively 80% (40/50) and 81.6% (40/49) with proton pump inhibitor, clarithromycin and metronidazole and 76.6% (36/47) and 81.8% (36/44) with proton pump inhibitor amoxycillin and clarithromycin. No significant differences were observed between the two treatments. Subjects in whom treatment failed were significantly younger and had less active ulcer than cured patients. Of treatment failures, 70.6% (12 out of 17 subjects) de veloped a secondary resistance to metronidazole (35.33% and/or clarithromycin (64.7%). Secondary antibiotic resistance occurred in 77. 8% of treatment failures treated with proton pump inhibitor, clarithromycin and metronidazole and in 62.5% of those treated with proton pump inhibitor, amoxycillin and clarithromycin. Considering all patients treated, the overall incidence of secondary metronidazole and/or clarithromycin resistance after therapy was reported in 12.9% of subjects (12 out of 93 treated patients). CONCLUSIONS: Secondary Helicobacter pylori resistances to metronidazole and/or clarithromycin occurred in large percentages in patients with treatment failure after the one-week proton pump inhibitor-based triple therapies, proton pump inhibitor, clarithromycin and metronidazole and proton pump inhibitor, amoxycillin and clarithromycin. It is likely that new antibiotics or treatment strategies will be needed in the near future to successfully treat Helicobacter pylori infection.