ObjectiveTo analyze the evolutionary characteristics and genetic variations of the HA (hemagglutinin) and NA (neuraminidase) genes of influenza A(H1N1) viruses in Shanghai during 2024, to investigate their transmission patterns, and to evaluate their potential impact on vaccine effectiveness. MethodsFrom January to October 2024, throat swab specimens were collected from influenza like illness (ILI) patients at 4 hospitals in Shanghai. Real-time fluorescence ploymerase chain reaction (RT-PCR) was used for virus detection and isolation of H1N1 influenza viruses. Forty influenza A(H1N1) virus strains were sequenced using Illumina NovaSeq 6000 platform, followed by phylogenetic analyses, genetic distance analysis, and amino acid variation analyses of HA and NA genes. ResultsPhylogenetic tree of the HA and NA genes revealed that the 40 influenza A(H1N1) virus strains circulating in Shanghai in 2024 exhibited no significant geographic clustering, with a broad origin of strains and complex transmission chains. Genetic distance analyses demonstrated that the average intra-group genetic distances of HA and NA genes among the Shanghai strains were 0.005 1±0.000 6 and 0.004 6±0.000 6, respectively, which were comparable to or higher than those observed in global surveillance strains. Both HA and NA genes displayed frequent mutations. Compared to the 2023‒2024 and 2024‒2025 Northern Hemisphere A(H1N1) vaccine strains (WHO-recommended), the HA proteins of 40 Shanghai strains exhibited amino acid substitutions at positions 120, 137, 142, 169, 216, 223, 260, 277, 356 and 451, with critical mutations at positions 137 and 142 located within the Ca2 antigenic determinant. Furthermore, mutations in the NA protein were observed at positions 13, 50, 200, 257, 264, 339 and 382. ConclusionThe genetic background of the 2024 Shanghai influenza A(H1N1) virus strains is complex and diverse, and antigenic variation may affect vaccine effectiveness. Therefore, it is recommended to enhance genomic surveillance of influenza viruses, evaluate vaccine suitability, and implement more targeted prevention and control strategies against imported influenza viruses.

Toll-like receptor 4 (TLR4) is a key regulator of innate and adaptive immune response. The role of TLR4 in pancreatic diseases is a research hotspot in recent years, and a large number of studies have shown that TLR4 is closely associated with pancreatic cancer. This article mainly discusses the abnormal expression and regulation mechanism of TLR4 in pancreatic cancer and its potential in cancer treatment, so as to provide new ideas for the pathogenesis and treatment of pancreatic cancer.

Common bile duct stones are a common of digestive system disease, and as one of the long-term complications after Billroth II subtotal gastrectomy, it has attracted more and more attention from clinicians. Common bile duct stones after Billroth II subtotal gastrectomy have a complex pathogenesis, including neurological, humoral, and mechanical factors. Even though there are many methods to remove stones, there are still controversies over the selection of digestive endoscopy, surgical operation, or percutaneous transhepatic approach. Clinicians should fully evaluate the specific conditions of patients and formulate individualized treatment regimens to achieve the best treatment outcome.

OBJECTIVETo analyze horizontal transmission patterns of Streptococcus mutans among caries-active preschool children for early interventions of dental caries.

METHODSPlaque samples obtained from 20 caries-active preschool children between 4 and 5 years of age were cultured under anaerobic conditions for isolating S. mutans, which were identified by morphological and biochemical analyses and PCR using primers homologous to the surface protein glucosyltransferase B (gtfB). The genotypes of the isolated S. mutans strains were determined by arbitrarily primed PCR (AP-PCR).

RESULTSOf the 200 S. mutans isolates obtained, 19 were excluded by biochemical analysis, and the remaining 181 isolates were identified as S. mutans by PCR with primers of gtfB, showing 37 different genotypes as identified by AP-PCR. Six children were found to carry S. mutans of a single genotype, 11 carried 2 genotypes, 2 had 3 genotypes, and 1 had 4 genotypes; 2 children from different classes were found to carry S. mutans of the same single genotype.

CONCLUSIONWe identified 37 genotypes of S. mutans in these caries-active preschool children, among whom horizontal transmissions of the strains were not found.

Child, Preschool ; Dental Caries ; microbiology ; Dental Plaque ; Genotype ; Glucosyltransferases ; Humans ; Polymerase Chain Reaction ; Streptococcal Infections ; transmission ; Streptococcus mutans ; classification

Objective To analyze horizontal transmission patterns of Streptococcus mutans among caries-active preschool children for early interventions of dental caries. Methods Plaque samples obtained from 20 caries-active preschool children between 4 and 5 years of age were cultured under anaerobic conditions for isolating S. mutans, which were identified by morphological and biochemical analyses and PCR using primers homologous to the surface protein glucosyltransferase B (gtfB). The genotypes of the isolated S. mutans strains were determined by arbitrarily primed PCR (AP-PCR). Results Of the 200 S. mutans isolates obtained, 19 were excluded by biochemical analysis, and the remaining 181 isolates were identified as S. mutans by PCR with primers of gtfB, showing 37 different genotypes as identified by AP-PCR. Six children were found to carry S. mutans of a single genotype, 11 carried 2 genotypes, 2 had 3 genotypes, and 1 had 4 genotypes;2 children from different classes were found to carry S. mutans of the same single genotype. Conclusion We identified 37 genotypes of S. mutans in these caries-active preschool children, among whom horizontal transmissions of the strains were not found.

Objective To analyze horizontal transmission patterns of Streptococcus mutans among caries-active preschool children for early interventions of dental caries. Methods Plaque samples obtained from 20 caries-active preschool children between 4 and 5 years of age were cultured under anaerobic conditions for isolating S. mutans, which were identified by morphological and biochemical analyses and PCR using primers homologous to the surface protein glucosyltransferase B (gtfB). The genotypes of the isolated S. mutans strains were determined by arbitrarily primed PCR (AP-PCR). Results Of the 200 S. mutans isolates obtained, 19 were excluded by biochemical analysis, and the remaining 181 isolates were identified as S. mutans by PCR with primers of gtfB, showing 37 different genotypes as identified by AP-PCR. Six children were found to carry S. mutans of a single genotype, 11 carried 2 genotypes, 2 had 3 genotypes, and 1 had 4 genotypes;2 children from different classes were found to carry S. mutans of the same single genotype. Conclusion We identified 37 genotypes of S. mutans in these caries-active preschool children, among whom horizontal transmissions of the strains were not found.

OBJECTIVETo screen of high cariogenicity Streptococcus mutans (S. mutans) strains isolated from clinical specimens preliminary.

METHODSAcidogenicity, aciduricity, extracellular polysaccharide production and adhesion of 41 strains of S. mutans isolated from clinical specimens were investigated to screen high cariogenicity S. mutans strains.

RESULTSThere were different cariogenicity among 41 strains of S. mutans, in which 3 strains of S. mutans had all high ability to produce extracellular polysaccharide, adhere to the saliva-coated hydroxyapatite, produce acid and tolerate acid, indicated there were 3 strains with high cariogenicity S. mutans strains isolated from clinical specimens. Another 3 strains of S. mutans with all low ability to produce extracellular polysaccharide, adhere to the saliva-coated hydroxyapatite, produce acid and tolerate acid indicated they were low cariogenicity S. mutans strains isolated from clinical specimens.

CONCLUSIONWe may have obtained high cariogenicity S. mutans strains isolated from clinical specimens.

Dental Caries ; Durapatite ; Humans ; Saliva ; Streptococcus mutans

OBJECTIVETo identify Streptococcus mutans (S. mutans) strains from clinical samples.

METHODSPlaque samples from caries-active and caries-free sites on enamel surfaces were obtained and cultivated for S. mutans isolation. Morphology, biochemistry, automatic microorganism analysis system and polymerase chain reaction using primers homologous to surface protein antigen I/II (spaP), glucosyltransferase B (gtfB) and dextranase (dexA) were used to identify S. mutans. Genotype of isolated S. mutans was determined by arbitrarily primed polymerase chain reaction.

RESULTSForty-six strains of S. mutans were obtained from the 32 subjects and were identified as S. mutans by biochemistry, automatic microorganism analysis system and polymerase chain reaction. Five identical genotypes were found by arbitrarily primed polymerase chain reaction.

CONCLUSIONForty-one strains of S. mutans with different genotype were obtained from clinical samples.

Dental Caries ; Dental Plaque ; Genotype ; Glucosyltransferases ; Humans ; Polymerase Chain Reaction ; Streptococcus mutans

OBJECTIVETo select and identify ssDNA aptamers specific to Streptococcus mutans strains with different cariogenicity isolated from clinical specimens.

METHODSSubtractive SELEX technology targeting the whole intact cells was used to screen for ssDNA aptamers specific to the clinical isolates Streptococcus mutans strains with different cariogenicity. Radioactive isotope, flow cytometry, gene cloning and sequencing, MEME online software and RNA structure analysis software were employed to analyze the first and secondary structures of the aptamers and identify the screened aptamers.

RESULTSDetection by radioactive isotope showed sufficient pool enrichment after 9 rounds of subtractive SELEX. Flow cytometry showed that the selected aptamers H1, H16, H4, L1, L10 and H19 were capable of binding specifically with highly cariogenic Streptococcus mutans strains but not with strains with a low cariogenicity. The aptamer H19 had the strongest binding capacity to highly cariogenic Streptococcus mutans strains, with a dissociation constant of 69.45∓38.53 nmol/L.

CONCLUSIONWe have obtained the ssDNA aptamers specific to the clinical isolates of highly cariogenic Streptococcus mutans strains.

Aptamers, Nucleotide ; genetics ; Cloning, Molecular ; DNA Primers ; Dental Caries ; microbiology ; Gene Library ; Humans ; Nucleic Acid Conformation ; SELEX Aptamer Technique ; Species Specificity ; Streptococcus mutans ; classification ; genetics ; isolation & purification