Unveiling the fructose metabolism system in Staphylococcus aureus: insights into the regulatory role of FruR and the FruRKT operon in bacterial fitness.

BACKGROUND: The utilization of fructose as a carbon source and energy provider plays a crucial role in bacterial metabolism. Additionally, fructose metabolism directly impacts the pathogenicity and virulence of certain pathogenic microorganisms. RESULTS: In this study, we report the discovery of a fructose phosphotransferase system (PTS) in S. aureus. This system comprises three genes, namely fruR, fruK, and fruT, which are co-located in an operon that is indispensable for fructose utilization in S. aureus. Our findings confirm that these three genes are transcribed from a single promoter located upstream of the fruRKT operon. The fruR gene encodes a DeoR-type transcriptional regulator, designated as FruR, which represses the expression of the fruRKT operon by direct binding to its promoter region. Significantly, our experimental data demonstrate that the fruRKT operon can be induced by fructose, suggesting a potential regulatory mechanism involving intracellular fructose-1-phosphate as a direct inducer. Furthermore, we conducted RNA-seq analysis to investigate the specificity of FruR regulation in S. aureus, revealing that the fruRKT operon is predominantly regulated by FruR. CONCLUSIONS: In summary, this study has uncovered a fructose phosphotransferase system (PTS) in S. aureus, highlighting the essential role of the fruR, fruK, and fruT genes in fructose utilization. We confirmed their co-location within an operon and established FruR as a key regulator by binding to the operon's promoter. Importantly, we demonstrated that fructose can induce this operon, possibly through intracellular fructose-1-phosphate. Our identification of this PTS system represents the initial characterization of a fructose metabolism system in S. aureus.

Efficacy and safety of traditional Chinese medicine in the treatment of menopause-like syndrome for breast cancer survivors: a systematic review and meta-analysis.

BACKGROUND: In recent years, breast cancer (BC) incidence and mortality have been the highest in females. Menopause-like syndrome (MLS), arising from hypoestrogenism caused by endocrine therapy, significantly affects the quality of life for females. Traditional Chinese Medicine (TCM) has advantages in ameliorating MLS, but the efficacy of TCM in patients with BC has not been systematically evaluated. METHODS: A comprehensive search was performed on PubMed, Web of Science, Embase, Ovid, Cochrane Library, China National Knowledge Infrastructure, Wanfang database, Chinese Scientific Journals Database, and Clinical Trial Registry from inception to September 4, 2023. The Cochrane Risk of Bias assessment tool was used for the quality evaluation of the randomized controlled trials (RCTs). Review Manager 5.4 software was used for statistical analysis, and the Grading of Recommendations Assessment, Development, and Evaluation was used for quality evaluation of the synthesized evidence. RESULTS: This review included 42 studies involving 3112 female patients with BC. The results showed that the TCM group was better at decreasing the Kupperman Menopausal Index (KMI) scores (standardized MD, SMD = - 1.84, 95% confidence interval, CI [- 2.21--1.46], Z = 9.63, P < 0.00001). Regarding the main symptoms of MLS, the TCM groups could significantly decrease the scores of hot flashes and night sweats (SMD = - 0.68, 95% CI [- 1.1--0.27], Z = 3.24, P = 0.001), paraesthesia (SMD = - 0.48, 95% CI [- 0.74--0.21], Z = 3.53, P = 0.0004), osteoarthralgia (SMD = - 0.41, 95% CI [- 0.6-0.21], Z = 4.09, P < 0.0001), anxiety (MD = - 0.85, 95% CI [- 1.13, - 0.58], Z = 6.08, P < 0.00001) and insomnia (MD = - 0.61, 95% CI [- 0.8, - 0.43], Z = 6.51, P < 0.00001). TCM can effectively improve the symptoms of MLS in patients with BC. Moreover, TCM could improve the objective response rate (ORR) by 50% (RR = 1.5, 95% CI [1.37-1.64], Z = 9.01, P < 0.00001). Follicle-stimulating hormone (FSH) and oestradiol (E2) had no significant difference compared with the control group (p = 0.81 and p = 0.87), and luteinizing hormone (LH) in the TCM group decreased significantly (MD = - 0.99, 95% CI [- 1.38, - 0.5], Z = 5.01, P < 0.00001). This means that the use of TCM does not negatively affect endocrine therapy and may even have a synergistic effect. The incidence of adverse events (AEs) was lower in the TCM groups than in the control groups. CONCLUSIONS: The meta-analysis stated that TCM could better improve the MLS of patients, alleviate related symptoms, and did not increase adverse drug reactions in BC survivors. This review brings more attention to MLS, and the present findings shed light on the potential applications of TCM in the treatment of MLS in BC survivors.

The genetic variability, phylogeny and functional significance of E6, E7 and LCR in human papillomavirus type 52 isolates in Sichuan, China.

BACKGROUND: Variations in human papillomavirus (HPV) E6 and E7 have been shown to be closely related to the persistence of the virus and the occurrence and development of cervical cancer. Long control region (LCR) of HPV has been shown multiple functions on regulating viral transcription. In recent years, there have been reports on E6/E7/LCR of HPV-16 and HPV-58, but there are few studies on HPV-52, especially for LCR. In this study, we focused on gene polymorphism of the HPV-52 E6/E7/LCR sequences, assessed the effects of variations on the immune recognition of viral E6 and E7 antigens, predicted the effect of LCR variations on transcription factor binding sites and provided more basic date for further study of E6/E7/LCR in Chengdu, China. METHODS: LCR/E6/E7 of the HPV-52 were amplified and sequenced to do polymorphic and phylogenetic analysis. Sequences were aligned with the reference sequence by MEGA 7.0 to identify SNP. A neighbor-joining phylogenetic tree was constructed by MEGA 7.0, followed by the secondary structure prediction of the related proteins using PSIPRED 4.0. The selection pressure of E6 and E7 coding regions were estimated by Bayes empirical Bayes analysis of PAML 4.9. The HLA class-I and II binding peptides were predicted by the Immune Epitope Database server. The B cell epitopes were predicted by ABCpred server. Transcription factor binding sites in LCR were predicted by JASPAR database. RESULTS: 50 SNP sites (6 in E6, 10 in E7, 34 in LCR) were found. From the most variable to the least variable, the nucleotide variations were LCR > E7 > E6. Two deletions were found between the nucleotide sites 7387-7391 (TTATG) and 7698-7700 (CTT) in all samples. A deletion was found between the nucleotide sites 7287-7288 (TG) in 97.56% (40/41) of the samples. The combinations of all the SNP sites and deletions resulted in 12 unique sequences. As shown in the neighbor-joining phylogenetic tree, except for one belonging to sub-lineage C2, others sequences clustered into sub-lineage B2. No positive selection was observed in E6 and E7. 8 non-synonymous amino acid substitutions (including E3Q and K93R in the E6, and T37I, S52D, Y59D, H61Y, D64N and L99R in the E7) were potential affecting multiple putative epitopes for both CD4+ and CD8+ T-cells and B-cells. A7168G was the most variable site (100%) and the binding sites for transcription factor VAX1 in LCR. In addition, the prediction results showed that LCR had the high probability binding sites for transcription factors SOX9, FOS, RAX, HOXA5, VAX1 and SRY. CONCLUSION: This study provides basic data for understanding the relation among E6/E7/LCR mutations, lineages and carcinogenesis. Furthermore, it provides an insight into the intrinsic geographical relatedness and biological differences of the HPV-52 variants, and contributes to further research on the HPV-52 therapeutic vaccine development.

Preparation of Si quantum dots by phase transition with controlled annealing.

Silicon quantum dots (Si-QDs) are excellent luminescent material due to its unique optoelectronic properties and have huge application potential in the field of photodetection. Recently, there has been much research interests in developing low-cost, facile and environmentally friendly methods to prepare the nanomaterials in addition to yielding excellent performances. In this article, we developed a novel preparation method of producing Si-QDs film based on carbon-silicon composite. The film was synthesized by co-sputtering using magnetron sputtering technique and studied at different annealing temperatures. Upon annealing, the film was transformed from an amorphous state to a crystalline state leading to Si-QDs precipitation, which can be observed at a low temperature of 600 °C. A Si-QDs thin film/n-Si photodetector was then prepared and characterized. The device exhibited a high specific detection rate (D*) of 1.246 × 1012cm Hz1/2W-1under 940 nm (1.1 mW cm-2) infrared radiation at 5 V bias. It also demonstrated good responsiveness and stability.

Genetic variability, phylogeny and functional implication of the long control region in human papillomavirus type 16, 18 and 58 in Chengdu, China.

BACKGROUND: Long control region (LCR) of human papillomavirus (HPV) has shown multiple functions on regulating viral transcription. The variations of LCR related to different lineages/sub-lineages have been found to affect viral persistence and cervical cancer progression differently. In this study, we focused on gene polymorphism of HPV16/18/58 LCR to assess the effect variations caused on transcription factor binding sites (TFBS) and provided more data for further study of LCR in Southwest China. METHODS: LCR of HPV16/18/58 were amplified and sequenced to do polymorphic and phylogenetic anlysis. Sequences of each type were aligned with the reference sequence by MEGA 6.0 to identify SNPs. Neighbor-joining phylogenetic trees were constructed using MEGA 6.0. Transcription factor binding sites were predicted by JASPAR database. RESULTS: The prevalence of these three HPVs ranked as HPV16 (12.8%) > HPV58 (12.6%) > HPV18 (3.5%) in Chengdu, Southwest China. 59 SNPs were identified in HPV16-LCR, 18 of them were novel mutations. 30 SNP were found in HPV18-LCR, 8 of them were novel. 55 SNPs were detected in HPV58-LCR, 18 of them were novel. Also, an insertion (CTTGTCAGTTTC) was detected in HPV58-LCR between position 7279 and 7280. As shown in the neighbor-joining phylogenetic trees, most isolates of HPV16/18/58 were clustered into lineage A. In addition, one isolate of HPV16 was classified into lineage C and 3 isolates of HPV58 were classified as lineage B. JASPAR results suggested that TFBS were potentially influenced by 7/6 mutations on LCR of HPV16/18. The insertion and 5 mutations were shown effects in LCR of HPV58. CONCLUSION: This study provides more data for understanding the relation among LCR mutations, lineages and carcinogenesis. It also helps performing further study to demonstrate biological function of LCR and find potential marker for diagnosis and therapy.

[Influence of Meteorological Factors on HFMD and Construction of Prediction Model in Sichuan Province].

OBJECTIVE: To analyze the epidemiological characteristics of hand, foot and mouth disease (HFMD) in Sichuan Province from 2013 to 2019. To study the correlation between meteorological factors and the incidence of HFMD and construct a prediction model. METHODS: The HMFD surveillance data and meteorological data from 2013 to 2019 in Sichuan Province were collected through the Chinese Center for Disease Control and Prevention and the China Meteorological data Network. Spearman correlation was used to analyze the relationship between HFMD incidence and meteorological factors. Multiple regression model and support vector regression (SVR) model were used to construct HFMD incidence prediction models respectively. RESULTS: A total of 615 840 cases of HFMD and 81 deaths were reported from 2013 to 2019. The average annual incidence rate was 107.31/105, and the mortality rate was 0.16/106. Spearman correlation analysis showed that the monthly incidence rate of HFMD was correlated with monthly average relative humidity (r=0.342), monthly average temperature (r=0.284), monthly average water vapor pressure (r=0.304) and monthly average days of precipitation (r=0.259). The prediction effect of the SVR model (R2=0.836) was better than the multiple regression model (R2=0.375). The SVR model provided a good fit to the monthly incidence of HFMD from 2013 to 2018, and can predict the peak incidence of HFMD in 2019. CONCLUSION: Relative humidity has the greatest influence on the incidence of HFMD. The fitting value of SVR model is in good agreement with the actual value, which is valuable in predicting the incidence of HFMD in Sichuan Province.

Divergent Total Synthesis of Euphoranginol†C, Euphoranginone†D, ent-Trachyloban-3ß-ol, ent-Trachyloban-3-one, Excoecarin†E, and ent-16α-Hydroxy-atisane-3-one.

A divergent synthetic approach to biogenetically related diterpenoids such as ent-kauranes, ent-trachylobanes, ent-beyerane, and ent-atisane has been developed. The unified synthetic route involves the De Mayo reaction to rapidly generate the bicyclo[3.2.1]-octane moiety of ent-kaurane. The key reactions also include bioinspired nucleophilic cyclopropanation generating the [3.2.1.02,7 ]-tricyclic core of ent-trachylobane and regioselective cyclopropane fragmentation furnishing ent-beyerane and ent-atisane through the nucleophilic attack and protonation of the cyclopropane ring. This strategy enables the asymmetric total syntheses of six diterpenoids from the commercially available geraniol.

Neonatal Crohn's disease with Oral ulcer as the first symptom caused by a compound heterozygote mutation in IL-10RA: a case report.

OBJECTIVE: To investigate the clinical and genetic characteristics of neonatal Crohn's disease (CD), improve recognition of neonatal CD, and reduce the number of patients that are missed or misdiagnosed. METHODS: A 10-day-old Chinese girl with oral ulcers was admitted to the Department of Neonatology. She later developed a rash and perianal disease, but without diarrhea and stool abnormalities. The patient and her parents underwent next-generation sequencing. RESULTS: The results showed that the patient carries a compound heterozygous mutation in the interleukin-10 receptor A (IL-10RA) (NM_001558.3) gene. One heterozygous mutation was c.301 c > T, P. (Arg 101 Trp) in exon 3 of IL-10RA (a missense mutation), and the other was c. 537G > A, P. (Thr 179 =) in exon 4 of IL 10RA (a synonymous mutation). The patient's father also carries the c.301 c > T, P. (Arg 101 Trp) heterozygous mutation in exon 3 of IL-10RA, whereas her mother carries the c.537G > A, P. (Thr 179 =) heterozygous mutation in exon 4 of IL-10RA. CONCLUSIONS: The results show that a compound heterozygous mutation in IL-10RA is associated with neonatal CD. Oral ulcers with a rash and perianal disease may be an early symptom of neonatal CD; therefore, such patients should undergo genetic identification as soon as possible.

Correlation between protein expression of FOXP3 and level of FOXP3 promoter methylation in recurrent spontaneous abortion.

AIM: The aim of this study was to investigate the level of Forkhead box P3 (FOXP3) promoter methylation and protein expression in recurrent spontaneous abortion and to elucidate the pathogenesis of unexplained recurrent spontaneous abortion (URSA). METHODS: We assessed a total of 56 URSA patients with a normal embryo, 24 recurrent spontaneous abortion (RSA) patients with an abnormal embryo (as control group 1), and 39 normal pregnant women (as control group 2). The expression of FOXP3 protein in deciduas was assessed through Western blot, and the level of FOXP3 promoter methylation was detected using bisulfite-assisted genomic sequencing polymerase chain reaction. RESULTS: The expressing quantity of FOXP3 protein in the URSA group was significantly lower than that in control groups 1 and 2, both with a P-value < 0.05. By contrast, no statistical difference was observed in the expressing quantity of FOXP3 protein of the two control groups (P = 0.212). The FOXP3 promoter methylation level in the URSA group was significantly higher than that in the two control groups, both of which exhibited a statistical difference of P-values < 0.05. Meanwhile, no statistical difference was observed in the FOXP3 promoter methylation level of the two control groups (P = 0.141). A negative correlation was found between the FOXP3 promoter methylation level and the expressing quantity of FOXP3 protein (r = -0.861, P < 0.05). CONCLUSION: Increasing FOXP3 promoter methylation levels may cause abnormal immune tolerance through the downregulation expression of the FOXP3 protein, which in turn leads to URSA.

[Association of polymorphisms in signal transducer and activator of transcription 4 gene and the susceptibility to unexplained recurrent spontaneous abortions].

OBJECTIVE: To investigate the association between the polymorphisms of signal transducer and activator of transcription 4 (STAT4) gene and the susceptibility to unexplained recurrent spontaneous abortion(URSA). METHODS: PCR-restriction fragment length polymorphism (PCR-RFLP) was used to detect genotype 3 loca (rs7574865 G/T, rs10181656 C/G and rs16833431 C/T) polymorphism of STAT4 in 246 URSA cases (URSA group) and 183 normal controls (control group) . RESULTS: (1)The frequencies of rs7574865 were genotype G/G of 36.2% (89/246) in URSA group and 46.4% (85/183) in control group, genotype G/T of 47.2% (116/246) in URSA group and 45.4% (83/183) in control group, and genotype T/T of 16.7% (41/246) in URSA group and 8.2% (15/183) in control group, which reached statistical difference (P < 0.05). The frequencies of rs10181656 were genotype CC of 36.6% (90/246) in URSA group and 46.4% (85/183) in control group, genotype C/G of 48.0% (118/246) in URSA group and 44.8% (82/183) in control group, and genotype G/G of 15.4% (38/246) in URSA group and 8.7% (16/183) in control group, which reached statistical difference (P < 0.05). The carriers of rs7574865 T allele and rs10181656 G allele increased the risk of URSA (OR = 1.51, 1.44, all P < 0.05).(2) There was no different distribution in 3 genotypes (C/C, C/T, T/T) and 2 alleles (C and T) of rs16833431 C/T between URSA patients and normal controls (P = 0.43,0.48). (3) Timated haplotype frequency distribution of rs7574865 G/T and rs10181656 C/G showed haplotype G-T conferring the susceptibility to URSA (OR = 1.49, P < 0.01), but haplotype C-G could provide protection on URSA (OR = 0.68, P < 0.01). CONCLUSION: Polymorphisms of STAT4 gene might confer the susceptibility to URSA by altering STAT4 function and (or) its expression.

Prenatal and perinatal outcomes of twin pregnancy discordant for one fetus with nuchal translucency above the 95th percentile.

OBJECTIVE: To compare prenatal and perinatal outcomes of twin pregnancies in which one twin the nuchal translucency (NT) was above the 95th percentile in dichorionic twins (DCT) and monochorionic twins (MCT). METHOD: In this retrospective study, 93 twin pregnancies (186 fetuses) in which one twin the NT was above the 95th percentile and the co-twin had normal NT were analyzed. Results of of G-banding and Chromosomal microarray (CMA), ultrasound findings and pregnancy outcomes were reviewed. RESULTS: Totally, 57 pregnancies (114 fetuses) were DCT and 36 pregnancies (72 fetuses) were MCT. Karyotyping and CMA results shown that clinically significant chromosomal abnormalities were found in 16 fetuses, including 13 aneuploidies, 2 chromosomal mosaic and 1 pathological Copy number variations (CNVs) (14 were DCT and 2 were MCT). Overall, the incidence of fetal chromosomal abnormalities was 12.3% (14/114) in DCT and 2.8%(2/72) in MCT (χ2 = 3.932, p = 0.047). Among the cases with normal prenatal diagnosis result, structural abnormalities were found in four fetuses (4.0%, 4/100) in DCT and two fetuses (2.9%, 2/70) in MCT (p > 0.999). There were one intrauterine fetal demises (IUFD) and two miscarry in DCT. One IUFD, three subsequently developed Twin-to-Twin Transfusion Syndrome (TTTS) and four developed selective intrauterine growth restriction (sIUGR) in MCT. Totally, the overall fetal survival rate was 85.1% (97/114) in DCT and 80.6% (58/72) in MCT (χ2 = 0.653, p = 0.419). CONCLUSION: Compared to MCT, the incidence of chromosomal abnormalities in DCT discordant for one fetus with NT above the 95th percentile was higher. The risk of structural abnormalities and the rate of fetal survival for both MCT and DCT was similar.

Analysis of amino acids and acylcarnitines profiles in small, appropriate, and large for gestational age neonates.

OBJECTIVE: To identify the amino acid (AA) and acylcarnitines (ACs) profiles in dry blood spot (DBS) of small, appropriate and large for gestational age neonates, and to investigate the difference AA and AC profiles in groups. METHODS: Eight thousand nine hundred and fourteen healthy singleton newborns were divided into three groups: small for gestational age (SGA) (n = 713), appropriate for gestational age (AGA) (n = 7866), and LGA (n = 335). Electrospray ionization tandem mass spectrometry was taken to evaluate the concentrations of 11 AAs and 31 ACs in DBS specimens obtained from all enrolled neonates. RESULTS: Compared with the AGA neonates, except propionylcarnitine, the concentrations of SGA neonatal most AAs and AC in the newborn were higher, while those of the newborns in the LGA group were lower. CONCLUSION: Different concentrations of AAs and ACs in the three groups suggest that SGA may be associated with under anabolic metabolism, while LGA may be associated with over anabolic metabolism.

A cohort study of the perinatal outcome of radiofrequency ablation in complicated monochorionic multiple pregnancies based on a different needle insert angle.

OBJECTIVE: To compare the pregnancy outcomes of radiofrequency ablation (RFA) for complicated multiple pregnancies between fetal abdominal and dorsal needle insertion angles. METHODS: We performed a historical cohort study of patients who underwent selective reduction using RFA through different needle insertion angles from 2015 to 2018 at a local hospital. Dorsal needle insertion cases were consecutively selected and abdominal needle insertion cases were selectively enrolled. The Cox proportional hazards model was constructed to identify predictors of fetal survival time with different needle insertion angles. RESULTS: The RFA procedure was performed in 28 women through an abdominal insertion angle and in 28 women through a dorsal insertion angle. There were no significant differences in perinatal outcomes between the two groups. The overall live birth rate after RFA in the two groups was 73.5% and the mean gestation was 31.6 ± 6.5 weeks. The Cox model showed that gestational age at RFA was a predictor of the duration of the period between RFA and delivery. CONCLUSION: RFA conducted through the dorsal insertion angle is technically feasible for selective reduction in complex monochorionic multiple pregnancies. Gestational age at this procedure is an independent risk factor for the duration of pregnancy post-RFA.

Prenatal diagnosis of fetal right ventricular diverticulum with massive pericardial effusion in one of monochorionic diamniotic twins: a case report with a favorable outcome following in utero pericardiocentesis.

BACKGROUND: Congenital ventricular diverticulum is a rare abnormality that may occur as an isolated malformation. Most cases are accompanied by pericardial effusion. Prenatal counseling can be difficult because the prognosis is uncertain and there is no consensus approach to prenatal management.Case presentation: We describe a case of congenital cardiac diverticulum complicated by large pericardial effusion in one of monochorionic diamniotic twins. The case was diagnosed by ultrasonography at 21 weeks of gestation. Therapeutic pericardiocentesis at 22 weeks resulted in complete resolution of the effusion and led to a favorable fetal outcome. We summarize the interventions and pregnancy outcomes in cases of cardiac diverticula reported in the literature. CONCLUSIONS: Better awareness of clinical features, in utero therapies, and pregnancy outcomes could help define and improve prenatal management of congenital ventricular diverticula.

Characterisation of two unusual cases of haemoglobin Bart's hydrops foetalis caused by -SEA and large novel α-globin gene cluster deletions.

BACKGROUND: We describe 2 unusual haemoglobin (Hb) Bart's hydrops cases that could not be explained by traditional factors.Case presentation: Two families with a diagnosis or history of foetal hydrops were enrolled. A suspension-array system was used to detect the 23 most frequent mutations in southern China. Multiplex ligation-dependent probe amplification (MLPA) was used to screen for possible deletions. Precise characterisation of the breakpoints of the novel variants and uniparental disomy analysis were performed using a single nucleotide polymorphism (SNP) array. Quantitative fluorescence PCR was used to eliminate maternal cell contamination and nonpaternity. In case 1, the suspension-array system indicated a maternal heterozygous (-SEA/) deletion, and the paternal sample was negative. The foetal hydrops was caused by the maternal (-SEA/) deletion and a de novo α-globin gene deletion (-193). In case 2, the paternal sample had a heterozygous (-SEA/) deletion, and MLPA and SNP array analysis revealed a large maternal deletion (-227) that encompassed the α-globin gene, which explained the history of Hb Bart's foetal hydrops. CONCLUSIONS: Our cases describe 2 new α0-thalassaemia deletions and illustrate the importance of using a combination of methods to detect rare types of α-thalassaemia.

Genetic variability and lineage phylogeny of human papillomavirus type 45 based on E6 and E7 genes in Southwest China.

The current study investigated nucleotide variability and phylogeny in high-risk HPV45 collected from Chinese women. Fifty-one samples positive for single infections of HPV45 were collected for DNA extraction and HPV typing. The E6 and E7 genes of HPV45 were sequenced, and then the phylogenetic tree was reconstructed by the maximum likelihood method implemented in IQ-TREE under the HKY nucleotide substitution model. The selection pressures of the E6 and E7 genes were estimated using PAML software. Eleven nucleotide polymorphism sites were observed in the HPV45 E6 sequences, with 6 synonymous (C134T, T163C, A284C, T341C, T482C, A497G) and 5 non-synonymous (A124C, C157T, T162A, G259T, G487A) mutations. Six nucleotide polymorphism sites were observed in the E7 sequences, with 5 non-synonymous (G600A, A603C, A769C, G808T, G832T) and 1 synonymous (A718C) mutation. Our investigation suggests that B2 was the most frequent HPV45 sublineage in Southwest China, followed by A2; no A1 or A3 variants were detected. Selective pressure analysis showed that these mutations could reflect positive selection in HPV45 E6 and E7 genes.