Abstract: Objective　To understand the contamination status, drug resistance, virulence gene carrying status, and molecular typing characteristics of Vibrio parahaemolyticus (VP) in aquatic products sold in Nanchang City. Methods　A total of 170 commercial crayfishes, freshwater fish frogs and related smears samples were collected from various farmers' markets in Nanchang from March to September 2021. The strains of V. parahaemolyticus were detected and isolated from the samples. Antibiotic resistance test, virulence gene test, and pulsed-field gel electrophoresis (PFGE) molecular typing analysis were carried out. Results　Among the collected samples, V.parahaemolyticus was only isolated from crayfish and crayfish smear samples, with a total of 35 strains of VP isolated. No V.parahaemolyticus strain was isolated from other freshwater fish, frogs, and their smear samples. Among the 17 common antibiotics tested, only two trains showed resistance to ampicillin, and one strain to streptomycin, , and all were sensitive to other antibiotics; all 35 strains of V. parahaemolyticus carried the gene, but only one strain carried the heat-resistant related hemolysin gene trh, and no direct heat-resistant hemolysin gene tdh positive strain was found; PFGE pattern clustering showed that there was no strain with the same PFGE pattern, and there was no obvious dominant cluster among these strains, and their genetic relationship was relatively distant. Conclusions　The contamination of V. parahaemolyticus in small and medium-sized crayfish sold in the market in Nanchang City is relatively serious. The V. parahaemolyticus isolates in these polluted crayfish generally do not carry key virulence genes such as tdh, are sensitive to common antibiotics, and only have low-level resistance to ampicillin and streptomycin. PFGE pattern clustering showed that V. parahaemolyticus does not have no obvious dominant cluster, and these strains have rich genetic diversity, indicating that they may have different sources.

Objective To investigate the prevalence of Cryptosporidium infection and the distribution of parasite species and genotypes among HIV-positive individuals in Jiangxi Province. Methods HIV-positive individuals' sociodemographic and clinical data were collected from three AIDS designated hospitals in Jiangxi Province from January 2022 to March 2023. Subjects' stool samples were collected, and genomic DNA was extracted from stool samples. Nested PCR assay was performed based on the small subunit ribosomal RNA (SSU rRNA) gene of Cryptosporidium, and Cryptosporidium gp60 gene was amplified in stool samples positive for the SSU rRNA gene. The second-round PCR amplification product was checked with 1.5% agarose gel electrophoresis, and the products of suspected positive amplifications were sequenced, followed by sequence alignment. The phylogenetic tree was created using the Neighbor-Joining method with the software MEGA 11.0, to characterize the species, genotypes and sub-genotypes of Cryptosporidium. Results A total of 382 HIV-positive individuals were enrolled, with two cases identified with Cryptosporidium infection (0.52% prevalence), and both cases had no abdominal pain or diarrhea. Following sequencing and sequence alignment, the gene sequences of these two Cryptosporidium isolates shared 99.76% and 99.88% similarity with the gene sequence of C. meleagridis isolates. Phylogenetic analysis based on the Cryptosporidium SSU rRNA gene sequence identified the species of these two Cryptosporidium-positive stool samples as C. meleagridis. Following nested PCR amplification of the Cryptosporidium gp60 gene, sequencing and sequence alignment, the two C. meleagridis isolates were characterized as III eA17G2R1 and III bA25G1R1a sub-genotypes, and the sub-genotype III bA25G1R1a was firstly described in humans. Conclusion The prevalence of Cryptosporidium is low among HIV-positive individuals in Jiangxi Province. The likelihood of Cryptosporidium infection cannot be neglected among HIV-positive individuals without diarrhea.