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Purpose: This study was designed to identify the phenotypic and genotypic characteristics of pyrazinamide (PZA) resistance among multidrug-resistant Mycobacterium tuberculosis (MDR-TB) from Henan and to evaluate the efficacy of pncA, rpsA, and panD mutations in predicting PZA resistance. Materials and Methods: A total of 152 MDR strains were included in this study. The Bactec MGIT system was used to determine PZA susceptibility for all strains. The pncA, rpsA, and panD genes were sequenced to identify any mutations, and the sequences were then aligned with the sequence of standard strain H37Rv. Moreover, the correlations between PZA-resistant phenotypes and treatment outcomes were analysed. Results: Of the152 strains, 105 had a PZA-resistant phenotype, and 102 harboured the pncA mutation. The PZA resistance rate was higher in the strains with resistance to all four first-line drugs and those that were pre-extensively drug-resistant (pre-XDR) and extensively drug-resistant (XDR). A total of 100 different pncA mutation patterns were identified, including 80 point mutations and 20 insertions/deletions, and 32 new pncA mutation patterns were detected. In this study, 13 strains had multiple mutations. Of the11 PZA-resistant strains without pncA mutations, two harboured the rpsA mutation, and one harboured the panD mutation. With PZA susceptibility results as the reference, single-gene pncA sequencing had sensitivity of 89.52% and specificity of 89.36%. With the combination of rpsA and panD, the sensitivity increased to 92.38%, and the specificity remained the same. No significant differences were observed in the sputum smear/culture conversion rate between PZA-resistant patients and PZA-sensitive patients. However, PZA resistance was related to the time to sputum smear/culture conversion (P = 0.018). Conclusion: The combination of pncA, rpsA, and panD was beneficial for the timely diagnosis of PZA resistance and could provide a laboratory basis for customizing treatment regimens for MDR-TB patients. [ABSTRACT FROM AUTHOR]

Background: The World Health Organization End TB Strategy meant that compared with 2015 baseline, the reduction in pulmonary tuberculosis (PTB) incidence should be 20 and 50% in 2020 and 2025, respectively. The case number of PTB in China accounted for 9% of the global total in 2018, which ranked the second high in the world. From 2007 to 2019, 854 672 active PTB cases were registered and treated in Henan Province, China. This study was to assess whether the WHO milestones could be achieved in Henan Province. Methods: The active PTB numbers in Henan Province from 2007 to 2019, registered in Chinese Tuberculosis Information Management System were analyzed to predict the active PTB registration rates in 2020 and 2025, which is conductive to early response measures to ensure the achievement of the WHO milestones. The time series model was created by monthly active PTB registration rates from 2007 to 2016, and the optimal model was verified by data from 2017 to 2019. The Ljung-Box Q statistic was used to evaluate the model. The statistically significant level is α = 0.05. Monthly active PTB registration rates and 95% confidence interval (CI) from 2020 to 2025 were predicted. Results: High active PTB registration rates in March, April, May and June showed the seasonal variations. The exponential smoothing winter's multiplication model was selected as the best-fitting model. The predicted values were approximately consistent with the observed ones from 2017 to 2019. The annual active PTB registration rates were predicted as 49.1 (95% CI: 36.2–62.0) per 100 000 population and 34.4 (95% CI: 18.6–50.2) per 100 000 population in 2020 and 2025, respectively. Compared with the active PTB registration rate in 2015, the reduction will reach 23.7% (95% CI, 3.2–44.1%) and 46.8% (95% CI, 21.4–72.1%) in 2020 and 2025, respectively. Conclusions: The high active PTB registration rates in spring and early summer indicate that high risk of tuberculosis infection in late autumn and winter in Henan Province. Without regard to the CI, the first milestone of WHO End TB Strategy in 2020 will be achieved. However, the second milestone in 2025 will not be easily achieved unless there are early response measures in Henan Province, China. [ABSTRACT FROM AUTHOR]

Porcine circovirus 4 (PCV4) is a recently discovered circovirus that was first reported in 2019 in several pigs with severe clinical disease in Hunan province of China, and also identified in pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV). To further investigate the epidemic profile and genetic characteristics of the two viruses, 150 clinical samples were collected from 9 swine farms in Shaanxi and Henan provinces of China, and a SYBR Green I-based duplex quantitative real-time polymerase chain reaction (qPCR) was developed for detecting PCV4 and PRRSV simultaneously. The results showed the limits of detection were 41.1 copies/μL and 81.5 copies/μL for PCV4 and PRRSV, respectively. The detection rates of PCV4 and PRRSV were 8.00% (12/150) and 12.00% (18/150) respectively, and a case of co-infection with PCV4 and PRRSV was found in the lung tissue of a suckling pig with respiratory symptom. Subsequently, the complete genomic sequences of five PCV4 strains were obtained, of which one PCV4 strain (SX-ZX) was from Shaanxi province, and these strains were 1770 nucleotides in length and had 97.7%−99.4% genomic identity with 59 PCV4 reference strains. The genome characteristic of the SX-ZX strain was evaluated from three aspects, a "stem-loop" structure, ORF1 and ORF2. As essential elements for the replication, the 17-bp iterative sequence was predicted as the stem structure, in which three non-tandem hexamers were found at downstream with H1/H2 (12-CGGCACACTTCGGCAC-27) as the minimal binding site. Three of the five PCV4 strains were clustered into PCV4b, which was composed of Suidae, fox, dairy cow, dog and raccoon dog. Phylogenetic analysis revealed that seven PRRSV strains from the present study were clustered into the PRRSV-2 genotype. Collectively, these data extend our understanding of the genome characteristic of PCV4 as well as the molecular epidemiology and the genetic profile of PCV4 and PRRSV. • A duplex qPCR assay was developed for the simultaneous detection of PCV4 and PRRSV. • Limits of detection were 41.1 copies/μL and 81.5 copies/μL for PCV4 and PRRSV, respectively. • A case of co-infection with PCV4 and PRRSV was found in lung tissue of a suckling pig with respiratory symptom. • The 17-bp iterative sequence was predicted as the stem structure. [ABSTRACT FROM AUTHOR]