Evaluation of gastroenteritis causative agents in the 0-17 age group using the multiplex PCR method

This study aimed to evaluate viral, bacterial, and parasitic agents in children with acute diarrhea by combining microscopic and macroscopic examinations with immunochromatographic rapid tests, culture-based classical methods, and molecular techniques, and to determine the distribution frequencies of these agents. Stool samples were collected from 101 pediatric patients aged 0-17 years presented with diarrhea to the Microbiology Laboratory of Gaziantep University Şahinbey Research and Practice Hospital. Samples were assessed macroscopically and microscopically. The presence of Rotavirus, enteric Adenovirus, Cryptosporidium spp., Giardia lamblia, and Entamoeba histolytica was investigated using immunochromatographic rapid antigen tests. Bacteriological cultures were performed, and samples were additionally analyzed by multiplex PCR for viral, bacterial, and parasitic pathogens. The frequency of infections was similar between genders. Although all patients in the 3-5-year age group had at least one detected pathogen, the small subgroup size warrants cautious interpretation of this finding. According to multiplex PCR results, bacterial pathogens were identified in 83.2%, viral agents in 47.5%, and protozoal pathogens in 11.9% of the patients. Among viral agents, Rotavirus was the most frequently detected, followed by Adenovirus and Norovirus. Among bacterial targets detected by multiplex PCR, diarrheagenic Escherichia coli pathotypes were the most frequently identified molecular findings. For protozoal agents, Cryptosporidium spp. and G. lamblia (2%) were the most frequently detected parasites. Cases requiring antibiotic treatment are primarily caused by Shigella spp. and parasitic agents. Multiplex PCR substantially increased pathogen detection compared with culture and immunochromatographic methods. However, interpretation of molecular positivity, particularly for diarrheagenic Escherichia coli pathotypes, requires caution because PCR detection may reflect colonization, prolonged shedding, or asymptomatic carriage rather than active disease. Conventional methods continue to provide valuable complementary information, especially when combined with clinical assessment.