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@#Abstract: Objective To understand the situation of drug-resistant tuberculosis screening and epidemiological characteristics of multi-drug resistant tuberculosis (MDR-TB) and pre-extensively drug resistant tuberculosis (pre-XDR-TB) in Changsha, in order to provide a scientific basis for improving the quality of drug-resistant tuberculosis prevention and control in the city. Methods Demographic information and drug susceptibility date of etiologically positive pulmonary tuberculosis patients in Changsha from 2018 to 2021 were collected, the successful rate of resistance screening, incidence and tendency in MDR-TB and pre-XDR-TB in patients included in this study were statistically analyzed accordingly. Results From 2018 to 2021, the successful screening rates were 86.2%, 87.7%, 81.9% and 71.5% for MDR-TB and 82.2%, 84.8%, 76.9% and 68.2% for pre-XDR-TB, respectively. In each year, MDR-TB patients identified accounted for 7.6% (101/1 222), 6.5%(124/1 774), 6.6%(110/1 555) and 6.3%(99/1 478), and pre-XDR-TB patients identified accounted for 3.6%(46/1 219), 3.8%(69/1 766), 4.4%(69/1 495) and 4.6%(69/1 436), correspondingly. The incidence of MDR-TB showed a slowly downward trend, while the incidence of pre-MDR-TB showed a slowly upward trend, with neither decreasing nor increasing trends being statistically significant (（χ2=1.947，0.806，P>0.050). The incidence of MDR-TB in the retreatment failure population was 66.6% (2/3), and the others, failure initial treatment and recrudescence populations were 23.5% (19/81), 16.7% (2/12) and 15.2% (70/461), respectively. Similar to the incidence above, the incidence of pre-XDR-TB was 16.7% (2/12) among patients who failed in initial treatment, and 12.2% (9/74), 9.8% (43/439), and 4.5% (2/44) among the others, recrudescence and returned patients, respectively. The incidence rates of MDR-TB and pre-XDR-TB in different populations were significantly different (χ2=117.600，59.030，P<0.05). Conclusions There are still areas for improvement in tuberculosis drug resistance surveillance system in Changsha. On the premise of paying attention to patients in retreatment failure, other, initial treatment failure and relapse patients, high sensitivity molecular drug susceptibility testing, and scientifically efficient screening strategies must be explored.
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@#Abstract: Objective To analysis the genetic evolution characteristics of hemagglutinin (HA) gene of influenza A(H1N1)pdm virus in Changsha City from 2016-2023, to understand the trend of the HA genetic evolution and the mutations of the amino acid. It provides a scientific basis for the prevention and control of influenza epidemics, as well as the screening of vaccines under the new situation. Methods The A(H1N1)pdm09 virus strains from Changsha City from 2016 to 2023 were isolated using SPF chicken embryos, and then the HA genes were sequenced by MiSeq of Illumina Inc. The homology of HA gene was analyzed by MegAlign of the DNASTAR, and the phylogenetic tree was constructed using the Neighbor Joining (NJ) method in the Molecular Evolutionary Genetics Analysis version 11 (MEGA11). Results The homology of the HA gene of A(H1N1)pdm virus in Changsha from 2016 to 2023 was between 94.8%-99.9%, with the HA gene homology decreasing annually. The homology between the isolated strains of A(H1N1)pdm09 in Changsha City from 2016 to 2023 and the WHO recommended vaccine strain ranged from 96.8% to 99.0%, indicating a relatively good match between the flu isolates and the recommended vaccine strain. The phylogenetic tree of the HA gene of the A(H1N1)pdm09 influenza virus in Changsha City showed that the HA gene evolved into several different branches within the 6B branch, and it had currently evolved to 6B.1A.5a.2a branch. Constant mutations had occurred at the amino acid sites of the four antigenic determinant clusters of HA protein. Currently, amino acid mutations had occurred at 15 antigenic sites within the four antigenic determinant clusters, and the newly emerged A186T antigen mutant site in the isolates from 2023 was worth recent notice. The receptor-binding sites are relatively conserved in loop 130, minor amino acid mutations occurred in loop 220, whether the amino acid mutation site in loop 190 is becoming more stable needs to be further monitored. Taking A/California/07/2009 (CY121680) as the reference strain, most of the A(H1N1) pdm09 isolates in Changsha was increased 162 NQTY glycosylation site and was decreased 276 NTTC glycosylation site, and the glycosylation mutations at these two sites have become more stable recently. Conclusions The HA genes of influenza A(H1N1)pdm virus in Changsha are constantly evolving and mutating, suggesting influenza surveillance should be strengthened continuously.
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@#Abstract: Objective To investigate the molecular characteristic and evolutionary trends of full-genome sequences of coxsackievirus A2 (CV-A2) and A5 (CV-A5) in Changsha City. Methods The CV-A2 and CV-A5 strains were isolated and detected from patients with hand, foot and mouth disease (HFMD) cases. The full-genome sequences of CV-A2 and CV-A5 strains were obtained using NGS sequencing. Homology and phylogenetic tree analysis were performed, and the recombination regions of the strains were examined by SimPlot software. Results The full-genome sequences of CV-A2 and CV-A5 strains were obtained from routine surveillance cases of HFMD in Changsha in 2019. The CV-A2 strain was named S281/Changsha/CHN/2019 with the full-genome sequence of 7 422 bp long; the CV-A5 strain was named S272/Changsha/CHN/2019 with the full-genome sequence of 7 425 bp long. Homology analysis of the isolates by comparison with the nucleic acid sequences of CV-A2 and other CV-A2 strains in China showed that the non-structural protein region shared lower similarity than that of structural protein region. The CV-A2 showed 79.20% similarity with Fleetwood strain (NC038306), showed the highest similarity 95.60% with MN419014 strain from Hubei Province. The non-structural protein 3C and 3D region shared the lowest similarity with MN419014, 90.51 and 92.06%, respectively. Phylogenetic tree analysis showed that 3C and 3D regions were located in the CV-A4 branch. Amino acid mutation sites were found in non-structural protein region, and the amino acid sequence in structural protein region was conserved. SimPlot analysis showed that genetic recombination was found in the 3C and 3D region of CV-A2 strains. The full-genome sequence of CV-A5 showed 80.7% similarity with the Swartz (AY421763) and 97.43% similarity with the strain (MH111030) from Australian. Homology analysis showed that the non-structural protein region shared lower similarity than that of structural protein region, based on full-genome of CV-A5. Phylogenetic tree analysis showed that CV-A5 and MH111030 were in the same branch, indicating that CV-A5 strain not from local. The amino acid sequence of CV-A5 strain was conserved. Conclusions The CV-A2 strain in Changsha City shared genome sequence information with CV-A4, and the CV-A5 strain was imported from abroad. Our findings are expected to understand the molecular and recombination characteristics of CV-A2 and CV-A5, provided the data of evolution and genetic features of the coxsackievirus, and interrupt disease transmission in a timely and effective manner.