BACTEC™ FX system as a tool for culturing gastric biopsies and Helicobacter pylori diagnosis

Prevalence of Multidrug-Resistant Bacteria in Healthcare-Associated Bloodstream Infections at Hospitals in Riyadh, Saudi Arabia

Bloodstream infection (BSI) prevalence in hospitalized patients has increased owing to the spread of antibiotic-resistant pathogens; moreover, antimicrobial resistance in bacteria is a global problem. Here, BSIs are investigated in several patients at a hospital in Saudi Arabia, and the resistance of bacterial isolates to widely used drugs is determined. Throughout 2020, bacteria isolated from patients were identified and subjected to antibiotic susceptibility testing. In total, 1125 bacterial isolates were obtained from 1039 patients; among them, gram-positive bacteria were significantly more abundant than gram-negative bacteria. The most prevalent bacteria were Staphylococcus epidermidis and Klebsiella pneumoniae. Notably, gram-negative bacteria were mainly isolated from adult patients, and 20.63% of the gram-positive isolates were from pediatric patients, which was significantly higher than the corresponding percentages in elders and adults. The gram-positive isolates were mainly resistant to cephalothin, oxacillin, amoxicillin-clavulanate, and erythromycin and susceptible to penicillin, gentamicin, ciprofloxacin, and vancomycin. Additionally, the gram-negative isolates were mainly resistant to ampicillin, cephalothin, and amoxicillin-clavulanate and susceptible to amikacin, ertapenem, aztreonam, colistin, and trimethoprim-sulfamethoxazole. Consequently, the high prevalence of infective multidrug-resistant bacteria may account as a significant health issue; it is considered a hazard in Riyadh hospitals and must be prevented at all costs.

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.

Diagnosis of Helicobacter pylori infection

The present manuscript focuses on the new information that was published in the field of diagnosis of Helicobacter pylori this past year. While there is little news about the invasive tests, more data are coming concerning the endoscopic features of H. pylori infection. Major efforts were also done to improve molecular detection of the mutations involved in antibiotic resistance. New antibody-based tests (stool antigen test or indirect antibody tests) were also developed.