Improvement and optimization of the classical gastric biopsy culture technique for Helicobacter pylori diagnosis using trypsin.

Helicobacter pylori infection represents a key factor in the aetiology of various gastrointestinal diseases. H. pylori infection diagnosis is generally achieved using both invasive (e.g. biopsy of the gastric epithelium) and non-invasive methods. Therefore, cultivation on a growth medium becomes complex. Trypsin is a proteinase enzyme that plays a role in an early stage of tissue digestion. In this study, we used trypsin in order to improve the diagnostic sensitivity of the H. pylori cultivation technique. We used 46 duplicate antrum biopsy specimens, divided into trypsin-treated and non-treated groups. The tissues were seeded on a selective H. pylori growth agar medium. We demonstrated that the classic H. pylori culture technique misses the growth of a large number of H. pylori colonies. Significantly more colonies were found in the trypsin-treated specimens group.

Catheter-associated candiduria: Risk factors, medical interventions, and antifungal susceptibility.

BACKGROUND: Catheter-associated candiduria is a common clinical finding in hospitalized patients, especially in the intensive care unit. The objective of this study was to obtain demographic and clinical data regarding the prevalence of Candida spp in catheterized in-patients and the medical interventions provided to these patients in a northern Israeli hospital between 2011 and 2013. METHODS: Isolation and identification of microorganisms were performed on 1,408 urine culture samples 48 hours after catheter insertion. Antifungal Etest susceptibility tests were carried out on every Candida-positive urine sample. Demographic and clinical data were gathered to determine risk factors and medical interventions. RESULTS: Candiduria was detected in 146 catheterized in-patients out of the 1,408 patients included in this study. C albicans was detected in most cases (69.1%). Fever was observed in 52 (35.61%) patients, and leukocyturia was observed in 48 cases (32.87%). Diabetes mellitus was associated with C albicans candiduria. There were 93 patients (63.69%) who did not receive any medical intervention for their candiduria. CONCLUSION: Candida is the second leading pathogen causing catheter-associated urinary tract infection or asymptomatic colonization, whereas previous studies showed Candida as the third leading pathogen. Clinical signs and symptoms, such as fever and laboratory tests, cannot distinguish between asymptomatic colonization and infection. Because the management of catheter-associated candiduria is still controversial, additional studies should be carried out.

An efficiency comparison between three invasive methods for the diagnosis of Helicobacter pylori infections: Culture from stomach biopsy, rapid urease test (CUTest(®)), and histologic examination of gastric biopsy.

BACKGROUND: Helicobacter pylori is one of the most prevalent pathogenic bacteria in the world, and humans are its principal reservoir. There are several available methods to diagnose H. pylori infection. Disagreement exists as to the best and most efficient method for diagnosis. METHODS: In this paper, we report the results of a comparison between three invasive methods for H. pylori diagnosis among 193 patients: culture, biopsy for histologic examination, and rapid urease test (CUTest(®)). RESULTS: We found that all three methods have a high sensitivity and specificity for the diagnosis of infections caused by H. pylori. However, the culture method, which is not used routinely, also showed high sensitivity, probably due to biopsies' seeding within 30 minutes, using warm culture media, non-selective media, and longer incubation. CONCLUSIONS: Although not a routine test, culture from biopsy can be meaningful in identification of antibiotic-resistant strains of H. pylori and should therefore be considered a useful diagnostic tool.

Susceptibility of Helicobacter pylori to Levofloxacin and Rifampicin in Israel.

The aim of this study was to assess the resistance level of Helicobacter pylori to levofloxacin and rifampicin from samples collected from pediatric and adult Israeli patients from 2012 to 2013. A total of 117 isolate samples of H. pylori were collected between 2012 and 2013. Isolates were cultured from stomach antrum biopsies and identified by the microbiology laboratory. Isolates were considered susceptible to levofloxacin and rifampicin by an Etest. Out of 117 isolates, 105 were found susceptible and 12 resistant to levofloxacin. For rifampicin, 104 isolates were susceptible and 13 were resistant. Study results estimate an alarming resistance rate, which reiterates the need for prudent use of alternative antibiotics to prevent further spread of resistant strains. Therefore, we suggest subjecting cultures from biopsy samples to susceptibility testing for the purpose of identification of strains resistant to levofloxacin and rifampicin among other antibiotic agents. This will allow for successful monitoring of microbial resistance and will assure prudent use of antimicrobial modalities.

Resistance of Helicobacter pylori to tetracycline, amoxicillin, clarithromycin and metronidazole in Israeli children and adults.

The aim of this study was to examine Helicobacter pylori-resistance rate to different antibiotics: tetracycline, amoxicillin, clarithromycin and metronidazole, and to compare eradication rates in adults and children in Israel. The study was based on the hypothesis of high-resistance rates to clarithromycin and metronidazole especially in adults and overall low-resistance rates to tetracycline and amoxicillin. One seventy six biopsies from patients with dyspeptic symptoms were cultured of which 100 were from adults (19-79 years) and 76 from children (7-17 years). All positive cultures were examined by Epsilometer test for MIC determination against tetracycline, amoxicillin, clarithromycin and metronidazole. 48.3% (85 out of 176) were H. pylori positive, of which 44% were from adults and 54% from children. Antibiotic resistance was seen in 31 out of 44 (70.5%) for metronidazole, 1 out of 44 (2.3%) for amoxicillin, 10 out of 44 (22.3%) for clarithromycin and 1 out of 44 (2.3%) for tetracycline among adults. Antibiotic resistance was seen in 10 out of 41 (24.4%) for metronidazole, 5 out of 41 (12.2%) for amoxicillin, 10 out of 41 (24.4%) for clarithromycin and 1 out of 41 (2.4%) for tetracycline among children. High rates of H. pylori resistance to metronidazole and clarithromycin was found especially among adults. Therefore, to increase the success rate of anti-H. pylori treatment, other classes of antibiotics need to be considered.