Susceptibility of clinical Moraxella catarrhalis isolates in British Columbia to six empirically prescribed antibiotic agents

BACKGROUND:

Moraxella catarrhalis is a commensal organism of the respiratory tract that has emerged as an important pathogen for a variety of upper and lower respiratory tract infections including otitis media and acute exacerbations of chronic bronchitis. Susceptibility testing of M catarrhalis is not routinely performed in most diagnostic laboratories; rather, a comment predicting susceptibility based on the literature is attached to the report. The most recent Canadian report on M catarrhalis antimicrobial susceptibility was published in 2003; therefore, a new study at this time was of interest and importance.

OBJECTIVE:

To determine the susceptibility of M catarrhalis isolates from British Columbia to amoxicillin-clavulanate, doxycycline, clarithromycin, cefuroxime, levofloxacin and trimethoprimsulfamethoxazole.

METHODS:

A total of 117 clinical M catarrhalis isolates were isolated and tested from five Interior hospitals and two private laboratory centres in British Columbia between January and December 2012. Antibiotic susceptibility of M catarrhalis isolates was characterized using the Etest (E-strip; bioMérieux, USA) according to Clinical Laboratory Standards Institute guidelines.

RESULTS:

All isolates were sensitive to amoxicillin-clavulanate, doxycycline, clarithromycin, levofloxacin and trimethoprimsulfamethoxazole. One isolate was intermediately resistant to cefuroxime, representing a 99.15% sensitivity rate to the cephem agent. Cefuroxime minimum inhibitory concentrations (MICs) inhibiting 50% and 90% of organisms (MIC50 and MIC90) were highest among the antibiotics tested, and the MIC90 (3 μg/mL) of cefuroxime reached the Clinical Laboratory Standards Institute breakpoint of susceptibility.

DISCUSSION:

The antibiotic susceptibility of M catarrhalis isolates evaluated in the present study largely confirms the findings of previous surveillance studies performed in Canada. Cefuroxime MICs are in the high end of the sensitive range and the MIC50 and MIC90 observed in the present study are the highest ever reported in Canada.

CONCLUSION:

Although cefuroxime MICs in M catarrhalis are high, all agents tested showed antimicrobial activity, supporting their continued therapeutic and empirical use.     

Subacute bacterial endocarditis caused by Cardiobacterium hominis: A case report

Cardiobacterium hominis, a member of the HACEK group of organisms, is an uncommon but important cause of subacute bacterial endocarditis. First-line therapy is a third-generation cephalosporin due to rare beta-lactamase production. The authors report a case involving endovascular infection due to C hominis that initially tested resistant to third-generation cephalosporins using an antibiotic gradient strip susceptibility method (nitrocephin negative), but later proved to be susceptible using broth microdilution reference methods (a ‘major’ error). There are limited studies to guide susceptibility testing and interpretive breakpoints for C hominis in the medical literature, and the present case illustrates some of the issues that may arise when performing susceptibility testing for fastidious organisms in the clinical microbiology laboratory.     

Hypocholesterolemia in Patients with an Amebic Liver Abscess

Background/Aims

Many parasites induce changes in the lipid profiles of the host. Cholesterol increases the virulence of Entamoeba histolytica in animal models and in vitro culture. This study aimed to determine, in patients with an amebic liver abscess, the correlation between cholesterol and other features, such as the size and number of abscesses, standard hematological and serum chemistry profiles, liver tests, and duration of hospital stay.

Methods

A total of 108 patients with an amebic liver abscess and 140 clinically healthy volunteers were investigated. Cholesterol and triglycerides were measured in the sera. The data from medical observations and laboratory tests were obtained from the clinical records.

Results

A total of 93% of patients with an amebic liver abscess showed hypocholesterolemia not related to any of the studied parameters. Liver function tests correlated with the size of the abscess. The most severe cases of amebic liver disease or death were found in patients whose cholesterol levels continued to decrease despite receiving antiamebic treatment and hospital care.

Conclusions

Our results show that the hypocholesterolemia observed in patients with an amebic liver abscess is not related to any of the clinical and laboratory features analyzed. This is the first study relating hypocholesterolemia to severity of hepatic amebiasis.     

Community-associated methicillin-resistant Staphylococcus aureus necrotizing pneumonia without evidence of antecedent viral upper respiratory infection

BACKGROUND:

USA300 community-associated (CA) methicillin-resistant Staphylococcus aureus (MRSA) strains causing necrotizing pneumonia have been reported in association with antecedent viral upper respiratory tract infections (URI).

METHODS:

A case series of necrotizing pneumonia presenting as a primary or coprimary infection, secondary to CA-MRSA without evidence of antecedent viral URI, is presented. Cases were identified through the infectious diseases consultation service records. Clinical and radiographic data were collected by chart review and electronic records. MRSA strains were isolated from sputum, bronchoalveolar lavage, pleural fluid or blood cultures and confirmed using standard laboratory procedures. MRSA strains were characterized by susceptibility testing, pulsed-field gel electrophoresis, spa typing, agr typing and multilocus sequence typing. Testing for respiratory viruses was performed by appropriate serological testing of banked sera, or nucleic acid testing of nasopharyngeal or bronchoalveloar lavage specimens.

RESULTS:

Ten patients who presented or copresented with CA necrotizing pneumonia secondary to CA-MRSA from April 2004 to October 2011 were identified. The median length of stay was 22.5 days. Mortality was 20.0%. Classical risk factors for CA-MRSA were identified in seven of 10 (70.0%) cases. Chest tube placement occurred in seven of 10 patients with empyema. None of the patients had historical evidence of antecedent URI. In eight of 10 patients, serological or nucleic acid testing testing revealed no evidence of acute viral coinfection. Eight strains were CMRSA-10 (USA300). The remaining two strains were a USA300 genetically related strain and a USA1100 strain.

CONCLUSION:

Pneumonia secondary to CA-MRSA can occur in the absence of an antecedent URI. Infections due to CA-MRSA are associated with significant morbidity and mortality. Clinicians need to have an awareness of this clinical entity, particularly in patients who are in risk groups that predispose to exposure to this bacterium.     

Incidence and Clinical Outcomes of Clostridium difficile Infection after Treatment with Tuberculosis Medication

Background/Aims

To determine the incidence and clinical characteristics of tuberculosis (TB) medication-associated Clostridium difficile infection.

Methods

This multicenter study included patients from eight tertiary hospitals enrolled from 2008 to 2013. A retrospective analysis was conducted to identify the clinical features of C. difficile infection in patients who received TB medication.

Results

C. difficile infection developed in 54 of the 19,080 patients prescribed TB medication, representing a total incidence of infection of 2.83 cases per 1,000 adults. Fifty-one of the 54 patients (94.4%) were treated with rifampin. The patients were usually treated with oral metronidazole, which produced improvement in 47 of the 54 patients (87%). Twenty-three patients clinically improved with continuous rifampin therapy for C. difficile infection. There were no significant differences in improvement between patients treated continuously (n=21) and patients in whom treatment was discontinued (n=26).

Conclusions

The incidence of C. difficile infection after TB medication was not low considering the relatively low TB medication dosage compared to other antibiotics. It may not be always necessary to discontinue TB medication. Instead, decisions concerning discontinuation of TB medication should be based on TB status.     

Disruption of the ASXL1 gene is frequent in primary, post-essential thrombocytosis and post-polycythemia vera myelofibrosis, but not essential thrombocytosis or polycythemia vera: analysis of molecular genetics and clinical phenotypes

Background

The myeloproliferative neoplasms, essential thrombocytosis, polycythemia vera and primary myelofibrosis, share the same acquired genetic lesion, but the concept of JAK2 V617F serving as the sole lesion responsible for these neoplasms is under question, and there has been interest in identifying additional mutations that may contribute to disease pathogenesis. Because ASXL1 lesions have been increasingly identified in myeloid neoplasms, we examined the relationships of ASXL1 mutation or deletion to both clinical phenotype and associated molecular features in 166 patients with myeloproliferative neoplasms.

Design and Methods

Exon 12 of ASXL1 was amplified from neutrophil genomic DNA and bidirectionally sequenced in 77 patients with myelofibrosis (including patients with primary and post-essential thrombocytosis or post-polycythemia myelofibrosis), 42 patients with polycythemia vera, 41 with essential thrombocytosis and 6 with post-myelofibrosis acute myeloid leukemia. Pyrosequencing assays were designed to determine the allele percentages of JAK2 V617F (G5073770T), ASXL1 2475dupA, and ASXL1 2846_2847del in neutrophil genomic DNA samples. Clinical and laboratory characteristics of patients with wild-type and ASXL1 mutations were then compared.

Results

We identified nonsense mutations or hemizygous deletion of ASXL1 in 36% of the patients with myelofibrosis, but very rarely among those with polycythemia vera or essential thrombocytosis. Among the patients with myelofibrosis, those with ASXL1 lesions were not distinguished from their wild-type counterparts with regard to JAK2 V617F status, exposure to chemotherapy or evolution to leukemia. Myelofibrosis patients with ASXL1 lesions were more likely to have received anemia-directed therapy compared to those without lesions [15/26 (58%) versus 11/39 (23%); P=0.02]. Using serial banked samples and quantitative ASXL1 mutant allele burden assays, we observed the acquisition and accumulation of ASXL1 mutations over time in two patients with post-essential thrombocytosis myelofibrosis.

Conclusions

ASXL1 haploinsufficiency is associated with a myelofibrosis phenotype in the context of other known and unknown lesions, and disruption of ASXL1 function may contribute to the disease pathogenesis of myelofibrosis.     

A Caenorhabditis elegans host model correlates with invasive disease caused by Staphylococcus aureus recovered during an outbreak in neonatal intensive care

BACKGROUND:

Caenorhabditis elegans has previously been used as a host model to determine the virulence of clinical methicillin-resistant Staphylococcus aureus isolates. In the present study, methicillin-susceptible S aureus (MSSA) strains associated with an outbreak in a neonatal intensive care unit (NICU) were investigated using the C elegans model.

METHODS:

Two distinct outbreak clones, MSSA type-C and MSSA type-G, were identified by pulsed-field gel electrophoresis in a MSSA outbreak during a seven-month period in the NICU of the Sunnybrook Health Sciences Centre (Toronto, Ontario). MSSA type-C was associated with severe infection, while type-G was associated with less invasive disease. Four representative type-C isolates, three type-G and three infant-colonized isolates unrelated to the outbreak, were sent to Calgary (Alberta), for the double-blinded virulence tests in the C elegans host model and for further molecular characterization.

RESULTS:

The invasive outbreak strains (type-C) demonstrated highly nematocidal activity, the noninvasive outbreak strains (type-G) an intermediate virulence, and the outbreak-unrelated colonization isolates demonstrated avirulence or low virulence in the C elegans model, with mean killing rates of 93.0%, 61.0% and 14.4% by day 9, respectively, for these three group strains. Different group MSSA strains had their own unique genetic profiles and virulence gene profiles, but all isolates within the same group (type-C or type-G) shared identical genetic characteristics and virulence gene patterns.

CONCLUSIONS:

The present blinded evaluation demonstrated that the nematocidal activities of MSSA strains correlated well with the clinical manifestation in an MSSA outbreak in the NICU, supporting C elegans as a robust host model to study the pathogenesis of S aureus.     

‘Bobo-Newton syndrome’: An unwanted gift from man’s best friend

Capnocytophaga canimorsus is a facultative Gram-negative bacillus that is typically a constituent of the oral flora of dogs and cats. It was first isolated by Bobo and Newton in 1976 from a man presenting with meningitis following a dog bite. Transmission to humans follows various animal-related injuries, which may be gross or subtle. C canimorsus can cause a spectrum of syndromes ranging from skin and soft tissue infection to invasive disease such as meningitis or endocarditis. The present article reports a case of C canimorsus meningitis in a patient with the classic risk factor of alcoholic liver cirrhosis. Clinical suspicion was confirmed by culture and genetic identification of the blood isolate. The present article reviews the Capnocytophaga genus, the clinical syndromes most commonly associated with this zoonotic organism, its laboratory identification and treatment.     

Incidence and clinical features of endoscopic ulcers developing after gastrectomy

AIM: To determine the precise incidence and clinical features of endoscopic ulcers following gastrectomy.METHODS: A consecutive series of patients who underwent endoscopic examination following gastrectomy between 2005 and 2010 was retrospectively analyzed. A total of 78 patients with endoscopic ulcers and 759 without ulcers following gastrectomy were enrolled. We analyzed differences in patient age, sex, size of the lesions, method of operation, indications for gastric resection, and infection rates of Helicobacter pylori (H. pylori) between the nonulcer and ulcer groups.RESULTS: The incidence of endoscopic ulcers after gastrectomy was 9.3% and that of marginal ulcers was 8.6%. Ulcers were more common in patients with Billroth II anastomosis and pre-existing conditions for peptic ulcer disease (PUD). Infection rates of H. pyloridid not differ significantly between the two groups. The patients who underwent operations to treat PUD had lower initial levels of hemoglobin and higher rates of hospital admission.CONCLUSION: H. pylori was not an important factor in ulcerogenesis following gastrectomy. For patients who underwent surgery for PUD, clinical course of marginal ulcers was more severe.     

On deaf ears,Mycobacterium avium paratuberculosis in pathogenesis Crohn’s and other diseases

The historic suggestion that Mycobacterium avium subsp. paratuberculosis (Map) might be a zoonotic pathogen was based on the apparent similarity of lesions in the intestine of patients with Crohn’s disease (CD) with those present in cattle infected with Map, the etiological agent of Johne’s disease. Reluctance to fully explore this possibility has been attributed to the difficulty in demonstrating the presence of Map in tissues from patients with CD. Advances in technology have resolved this problem and revealed the presence of Map in a significant proportion of patients with CD and other diseases. The seminal finding from recent investigations, however, is the detection of Map in healthy individuals with no clinical signs of disease. The latter observation indicates all humans are susceptible to infection with Map and lends support to the thesis that Map is zoonotic, with a latent stage of infection similar to tuberculosis, where infection leads to the development of an immune response that controls but does not eliminate the pathogen. This clarifies one of the reasons why it has been so difficult to document that Map is zoonotic and associated with the pathogenesis of CD and other diseases. As discussed in the present review, a better understanding of the immune response to Map is needed to determine how infection is usually kept under immune control during the latent stage of infection and elucidate the triggering events that lead to disease progression in the natural host and pathogenesis of CD and immune related diseases in humans.     

Necrotizing pneumonia and empyema caused by Neisseria flavescens infection

Neisseria flavescens is an uncommon pathogen of human infection, pneumonia and empyema caused by N. flavescens is rarely reported. Herein, we report a 56-year-old diabetic patient presenting necrotising pneumonia and empyema due to N. flavescens infection. The main clinical manifestation of this patient was high fever, sticky pus and gradually aggravating dyspnea. The chest computed tomography (CT) scan showed there are mass of high density areas around hilus of the left lung, hollow sign with inflammation also appeared. A biopsy specimen was taken from the left principal bronchus by lung puncture biopsy and showed necrosis and inflammation. Microscopic examination of direct smear and culture of sticky pus, much more gram-negative diplococcus was present, pathogen was further identified by Vitek NH card, Vitek MS and confirmed as N. flavescens by 16S rRNA gene sequencing finally. Anti-infection therapy following the antimicrobial susceptibility test results was effectively. To our knowledge, this is the first report of pulmonary infection caused by N. flavescens.     

Helicobacter pylori infection and atopic diseases: Is there a relationship? A systematic review and meta-analysis

AIM: To review and conduct a meta-analysis of the existing literature on the relationship between Helicobacter pylori (H. pylori), atopy and allergic diseases.METHODS: Studies published in English assessing the prevalence of atopy and/or allergic diseases in patients with H. pylori infection and the prevalence of H. pylori infection in patients with atopy and/or allergic diseases were identified through a MEDLINE search (1950-2014). Random-effect model was used for the meta-analysis.RESULTS: Pooled results of case-control studies showed a significant inverse association of H. pylori infection with atopy/allergic disease or with exclusively atopy, but not with allergic disease, whereas pooled results of cross-sectional studies showed only a significant association between allergic disease and H. pylori infection.CONCLUSION: There is some evidence of an inverse association between atopy/allergic diseases and H. pylori infection, although further studied are needed.     

Empyema caused by Clostridium bifermentans: A case report

A case of pneumonia with associated empyema caused by Clostridium bifermentans is described. C bifermentans is an anaerobic, spore-forming, Gram-positive bacillus. This organism is infrequently reported as a cause of infection in humans, and older publications tended to regard it as nonpathogenic. However, in more recent reports, C bifermentans has been documented as a cause of septic arthritis, osteomyelitis, soft tissue infection, abdominal infections, brain abscess, bacteremia and endocarditis. The present case is the third reported case of empyema caused by C bifermentans, and it serves to further define the spectrum of illness due to this uncommon organism.     

High Frequency of A2143G Mutation in Clarithromycin-Resistant Helicobacter pylori Isolates Recovered from Dyspeptic Patients in Iran

Background/Aim:

Resistance to clarithromycin in H. pylori isolates is accepted as a main cause of treatment failure in developing countries. We aimed to determine the prevalence of clarithromycin-resistant strains isolated from dyspeptic patients in northern Iran, furthermore we aimed to assess the relationship between clinical outcomes of infection with point mutations.

Materials and Methods:

A total of 147 consecutive patients infected with H. pylori were included for determining the status of resistant H. pylori strains. With upper gastroscopy, three antral biopsies were taken from each patient, first section for rapid urea test, second for pathology and third section was used for bacterial culture in microbiologic lab. The antimicrobial susceptibility tests in this examination were agar dilution, in accordance with clinical and laboratory standards institue guidelines. Restriction fragment length polymorphism-PCR (RFLP-PCR) method was applied to determine the frequency of point mutations in 23s rRNA gene. Statistical analysis was performed using SPSS software (15.0) (SPSS, Inc., Chicago, Ill). Chi-square and Fisher''s exact tests were applied to our analysis. A P value less than 5% was considered as statistically significant.

Results:

Our results showed that there was no point mutation in clarithromycin-susceptible strains of H. pylori.

Conclusion:

The important findings in our study indicate that A2143G is the most prevalent point mutation (30/32: 93.7%) attributed in clarithromycin resistance among the H. pylori strains. The current study concluded that clarithromycin could still be involved in the empirical treatment of H. pylori infection, although a high frequency of A2143G mutation may increase the concerns regarding treatment failure.     

A case of Clostridium difficile infection complicated by acute respiratory distress syndrome treated with fecal microbiota transplantation

Acute respiratory distress syndrome is a life-threatening disorder caused mainly by pneumonia. Clostridium difficile infection (CDI) is a common nosocomial diarrheal disease. Disruption of normal intestinal flora by antibiotics is the main risk factor for CDI. The use of broad-spectrum antibiotics for serious medical conditions can make it difficult to treat CDI complicated by acute respiratory distress syndrome. Fecal microbiota transplantation is a highly effective treatment in patients with refractory CDI. Here we report on a patient with refractory CDI and acute respiratory distress syndrome caused by pneumonia who was treated with fecal microbiota transplantation.     

Variant RH alleles and Rh immunisation in patients with sickle cell disease

Background

Alloimmunisation is a major complication in patients with sickle cell disease (SCD) receiving red blood cell (RBC) transfusions and despite provision of Rh phenotyped RBC units, Rh antibodies still occur. These antibodies in patients positive for the corresponding Rh antigen are considered autoantibodies in many cases but variant RH alleles found in SCD patients can also contribute to Rh alloimmunisation. In this study, we characterised variant RH alleles in 31 SCD patients who made antibodies to Rh antigens despite antigen-positive status and evaluated the clinical significance of the antibodies produced.

Materials and methods

RHD and RHCE BeadChip™ from BioArray Solutions and/or amplification and sequencing of exons were used to identify the RH variants. The serological features of all Rh antibodies in antigen-positive patients were analysed and the clinical significance of the antibodies was evaluated by retrospective analysis of the haemoglobin (Hb) levels before and after transfusion; the change from baseline pre-transfusion Hb and the percentage of HbS were also determined.

Results

We identified variant RH alleles in 31/48 (65%) of SCD patients with Rh antibodies. Molecular analyses revealed the presence of partial RHD alleles and variant RHCE alleles associated with altered C and e antigens. Five patients were compound heterozygotes for RHD and RHCE variants. Retrospective analysis showed that 42% of antibodies produced by the patients with RH variants were involved in delayed haemolytic transfusion reactions or decreased survival of transfused RBC.

Discussion

In this study, we found that Rh antibodies in SCD patients with RH variants can be clinically significant and, therefore, matching patients based on RH variants should be considered.     

Rabeprazole,clarithromycin, and amoxicillin Helicobacter pylori eradication therapy: Report of an efficacy study

AIM:To investigate the efficacy of a standard triple therapy(comprising rabeprazole,clarithromycin,and amoxicillin)for Helicobacter pylori(H.pylori)eradication,noting factors that influence the outcome and documenting any adverse events.METHODS:Following institutional ethical approval,fifty consecutive and consenting symptomatic patients with evidence of H.pylori infection by either a positive urea breath test(UBT)and/or a campylobacter-like organism test who presented to the Gastroenterology clinic of Lagos State University Teaching Hospital between 2012 and 2013 were recruited into the study.Patients were openly randomized to either a 7-d or a 10-d regimen of amoxicillin 1 g,clarithromycin 500mg and rabeprazole 20 mg twice daily.The extent of symptom resolution was noted following the treatment,and at the end of one month after the completion oftreatment,a repeat UBT was performed in each patient to document the eradication of the infection.All data(demographics,symptoms,and eradication rates)were collated and analyzed with SPSS version 18.RESULTS:Forty-seven patients completed the study(three were excluded from the analysis for breaching the study protocol).The patients included 18 males and 29 females within the age range of 13-80 years(mean 43.7,SD 16.8).The clinical features of the study subjects were dyspepsia,reflux symptoms and features of gastrointestinal bleeding.The average eradication rate was 87.2%.Eighteen subjects were enrolled in the 7-d arm,while 29 were in the 10-d arm.There was no statistically significant difference in the age or sex distributions of the two arms.There was no significant advantage of the 10-d treatment duration over the 7-d duration(P=0.78),and the eradication outcomes were not influenced by the gender or age of the subjects.No adverse effects were reported in either arm.CONCLUSION:The triple therapy regime,employing a combination of amoxicillin,clarithromycin and rabeprazole,showed great efficacy and safety in the eradication of H.pylori,and this outcome was not influenced by gender or age.No difference was observed between the 7-d and 10-d regimens.     

Somatic molecular changes and histo-pathological features of colorectal cancer in Tunisia

AIM:To determine correlations between family history,clinical features and mutational status of genes involved in the progression of colorectal cancer(CRC).METHODS:Histo-pathological features and molecular changes[KRAS,BRAF and CTNNB1 genes mutations,microsatellite instability(MSI)phenotype,expression of mismatch repair(MMR)and mucin(MUC)5AC proteins,mutation and expression analysis of TP53,MLH1promoter hypermethylation analysis]were examined in a series of 51 unselected Tunisian CRC patients,10 of them had a proven or probable hereditary disease,on the track of new tumoral markers for CRC susceptibility in Tunisian patients.RESULTS:As expected,MSI and MMR expression loss were associated to the presence of familial CRC(75%vs 9%,P<0.001).However,no significant associations have been detected between personal or familial cancer history and KRAS(codons 12 and 13)or TP53(exons 4-9)alterations.A significant inverse relationship has been observed between the presence of MSI and TP53 accumulation(10.0%vs 48.8%,P=0.0335)in CRC tumors,suggesting different molecular pathways to CRC that in turn may reflect different environmental exposures.Interestingly,MUC5AC expression was significantly associated to the presence of MSI(46.7%vs 8.3%,P=0.0039),MMR expression loss(46.7%vs8.3%,P=0.0039)and the presence of familial CRC(63%vs 23%,P=0.039).CONCLUSION:These findings suggest that MUC5AC expression analysis may be useful in the screening of Tunisian patients with high risk of CRC.     

Typical and atypical symptoms of gastro esophageal reflux disease: Does Helicobacter pylori infection matter?

AIM: To analyze whether the presence of Helicobacter pylori(H. pylori) infection could affect the quality of symptoms in gastro-esophageal reflux disease(GERD) patients. METHODS: one hundred and forty-four consecutive patients referred to our Unit for suspected GERD were recruited for the study. All patients underwent esophageal p H-metric recording. For those with a positive test, C13 urea breath test was then performed to assess the H. pylori status. GERD patients were stratified according to the quality of their symptoms and classified as typical, if affected by heartburn and regurgitation, and atypical if complaining of chest pain, respiratory and ears, nose, and throat features. H. pylori-negative patients were also asked whether they had a previous diagnosis of H. pylori infection. If a positive response was given, on the basis of the time period after successful eradication, patients were considered as "eradicated"(E) if H. pylori eradication occurred more than six months earlier or "recently eradicated" if the therapy had been administered within the last six months. Patients without history of infection were identified as "negative"(N). χ2 test was performed by combining the clinical aspects with the H. pylori status.RESULTS: one hundred and twenty-nine of the 144 patients, including 44 H. pylori-positive and 85 H. pylori-negative(41 negative, 21 recently eradicated, 23 eradicated more than 6 mo before), were eligible for the analysis. No difference has been found between H. pylori status and either the number of reflux episodes(138 ± 23 vs 146 ± 36, respectively, P = 0.2, not significant) or the percentage of time with pH values 4(6.8 ± 1.2 vs 7.4 ± 2.1, respectively, P = 0.3, not significant). The distribution of symptoms was as follows: 13 typical(30%) and 31 atypical(70%) among the 44 H. pylori-positive cases; 44 typical(52%) and 41 atypical(48%) among the 85 H. pylori-negative cases,(P = 0.017 vs H. pylori +; OR = 2.55, 95%CI: 1.17-5.55). Furthermore, clinical signs in patients with recent H. pylori eradication were similar to those of H. pylori-positive(P = 0.49; OR = 1.46, 95%CI: 0.49-4.37); on the other hand, patients with ancient H. pylori eradication showed a clinical behavior similar to that of H. pylori-negative subjects(P = 0.13; OR = 0.89, 95%CI: 0.77-6.51) but different as compared to the H. pylori-positive group(P 0.05; OR = 3.71, 95%CI: 0.83-16.47).CONCLUSION: Atypical symptoms of GERD occur more frequently in H. pylori-positive patients than in H. pylori-negative subjects. In addition, atypical symptoms tend to decrease after H. pylori eradication.