Etiological Diagnostics of Postdiarheal Hemolytic Uremic Syndrome in Children Using TaqMan Array Cards
Introduction. Applying of microfluidic TaqMan Array Cards (TAC cards) has become one of the innovative directions in microbiology of the last two decades, allowing simultaneous detection of a wide range of enteropathogens (bacteria, viruses, protozoa, helminths). Purpose. Identification of the aetiology of diarrhoea in children with postdiarrheal hemolytic uremic syndrome (HUS) using real-time PCR based on TAC cards. Materials and methods. A total of 54 patients aged 9 months to 10 years with HUS hospitalized at the 2nd City Children’s Clinical Hospital in Minsk in 2021 were included in the study. Results. Genes of enteropathogens responsible for diarrheal syndrome were identified in 39 (72.2%) of 54 examined children: genes of bacterial pathogens (diarrheal E. coli, Campylobacter, Clostridium difficile, Bacteroides fragilis) - in 23 (42.6%), viral pathogens (Rota-, Noro-, Adeno-, Sapoviruses) - in 11 (20.4%); in 2 children (3.7%) genes of the protozoan (Cryptosporidium) were detected, and in 3 children (5.6%) - genes of both viral and bacterial pathogens. Among 25 children diagnosed with diarrheagenic E. coli, 20 (80.0%) had shigatoxin-producing E. coli (STEC). In all 20 cases shigatoxin type 2 (stx2) was detected, in 8 of them both shigatoxin types 1 and 2 were present. In 6 cases, only STEC was detected, whereas enterohemorrhagic E. coli (STEC/EHEC) in 8 cases and hybrid variants in 6 cases (STEC/EAEC and STEC/EHEC/EAEC). 92.6% of children received antibacterial or intestinal antimicrobials at the time of admission to the nephrology center. STEC were detected after 7 (5; 9) days, with a maximum of 13 days from the onset of diarrhea to fecal collection. Conclusions. The data obtained using TAC cards confirm the role of STEC as the main etiological agent of HUS. The role of other E. coli (non-shiga toxin-producing strains), as well as other pathogens, in the development of HUS requires further study. It is advisable to expand the algorithm for HUS etiological diagnosis of and genetic analysis of detected hybrid variants of diarrheal E. coli.