1.Complete cfb gene deletion in Streptococcus agalactiae: molecular mechanism of qPCR false negatives
Xiu Wang ; Guiyun Leng ; Yunsi Yang ; Wei Tang ; Qiang Zhou ; Jie Yao
Acta Universitatis Medicinalis Anhui 2025;60(9):1624-1630
Objective :
To investigate the causes of false negative results in the detection of Streptococcus agalactiae using fluorescent quantitative PCR(qPCR) targeting the CAMP factor gene(cfb),and to perform a comprehensive analysis of the associated molecular mechanisms.
Methods:
A total of 76 vaginal secretion samples were evaluated using both qPCR based on cfb gene and bacterial culture methods. Four suspicious strains exhibiting negative qPCR results but positive culture findings were identified using matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS),latex agglutination antigen detection,and the CAMP test. Whole genome analysis was conducted utilizing the MGI DNBSEQ-T7 and Nanopore-PromethION 48 sequencing platforms. Phylogenetic and circular evolutionary trees were constructed using the 16S rRNA gene for strain verification. Multilocus sequence typing(MLST) was conducted,and cfb sequences were aligned and analyzed based on spliced sequences and original data. Specific primers targeting the cfb gene were designed for full-length amplification,followed by verification through agarose gel electrophoresis.
Results:
The four strains identified as suspicious were classified as S. agalactiae through MALDI-TOF MS,antigen detection,and 16S rRNA gene analysis,with MLST typing indicating ST-862. Phenotypic analysis revealed a negative CAMP test. Whole genome sequence alignment failed to detect the cfb gene or any homologous sequences,and molecular testing confirmed the absence of cfb gene PCR amplification products,thereby confirming its complete deletion.
Conclusion
This deletion is identified as the molecular mechanism responsible for the false negative qPCR detection of S. agalactiae when targeting this specific gene.It is recommended that the qPCR detection targeting a single cfb gene has limitation,and this may impact clinical diagnosis and treatment decisions. This limitation warrants carefulconsideration.
2.Hemolytic phenotype analysis of Staphylococcus aureus clinical isolates
Ju Gao ; Shengnan Weng ; Guiyun Leng ; Xin Li ; Jie Yao ; Qiang Zhou ; Wei Tang
Acta Universitatis Medicinalis Anhui 2025;60(7):1312-1319
Objective:
To investigate the hemolytic phenotypes of Staphylococcus aureus clinical isolates.
Methods:
The hemolytic phenotypes of 105 Staphylococcus aureus isolates were analyzed and summarized using the three-point inoculation method.Real-time fluorescence quantitative PCR was used to measure the mRNA expression levels of four hemolysin genes (hla,hlb,hlc,and hld) ; The VITEK 2 GP639 antimicrobial susceptibility card was used to detect resistance to commonly used antibiotics ; DNA gel electrophoresis was performed to determine the prevalence of the mecA,sea,tst,and pvl genes ; The microtiter plate crystal violet staining method was used to assess biofilm formation ability ; The CCK-8 assay was used to evaluate cytotoxicity against macrophages.
Results:
Seven hemo- lytic phenotypes were identified among the Staphylococcus aureus clinical isolates. Differences were found among Staphylococcus aureus clinical isolates with different hemolytic phenotypes in terms of mRNA expression levels of he- molysin genes,antibiotic resistance,virulence gene prevalence,biofilm formation ability,and cytotoxicity to mouse macrophages (P <0. 05 ) .
Conclusion
Staphylococcus aureus clinical isolates exhibit diverse hemolytic pheno- types,which should be a focus across multiple dimensions,including microbiological testing,clinical treatment, and nosocomial infection prevention and control.
3.TCMKD:From ancient wisdom to modern insights-A comprehensive platform for traditional Chinese medicine knowledge discovery
Wenke XIAO ; Mengqing ZHANG ; Danni ZHAO ; Fanbo MENG ; Qiang TANG ; Lianjiang HU ; Hongguo CHEN ; Yixi XU ; Qianqian TIAN ; Mingrui LI ; Guiyang ZHANG ; Liang LENG ; Shilin CHEN ; Chi SONG ; Wei CHEN
Journal of Pharmaceutical Analysis 2025;15(6):1390-1402
Traditional Chinese medicine(TCM)serves as a treasure trove of ancient knowledge,holding a crucial position in the medical field.However,the exploration of TCM's extensive information has been hindered by challenges related to data standardization,completeness,and accuracy,primarily due to the decen-tralized distribution of TCM resources.To address these issues,we developed a platform for TCM knowledge discovery(TCMKD,https://cbcb.cdutcm.edu.cn/TCMKD/).Seven types of data,including syndromes,formulas,Chinese patent drugs(CPDs),Chinese medicinal materials(CMMs),ingredients,targets,and diseases,were manually proofread and consolidated within TCMKD.To strengthen the integration of TCM with modern medicine,TCMKD employs analytical methods such as TCM data mining,enrichment analysis,and network localization and separation.These tools help elucidate the molecular-level commonalities between TCM and contemporary scientific insights.In addition to its analytical capabilities,a quick question and answer(Q&A)system is also embedded within TCMKD to query the database efficiently,thereby improving the interactivity of the platform.The platform also provides a TCM text annotation tool,offering a simple and efficient method for TCM text mining.Overall,TCMKD not only has the potential to become a pivotal repository for TCM,delving into the pharmaco-logical foundations of TCM treatments,but its flexible embedded tools and algorithms can also be applied to the study of other traditional medical systems,extending beyond just TCM.
4.Identification and resistance characteristics of CAMP-negative Streptococcus agalactiae
Xiu Wang ; Guiyun Leng ; Wei Tang ; Qiang Zhou
Acta Universitatis Medicinalis Anhui 2025;60(1):142-146
Objective:
To explore identification and resistance characteristics of CAMP-negativeStreptococcus agalactiae.
Methods :
Using matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS) and the CAMP assay, 33 presumptive strains ofStreptococcus agalactiaewere identified. The CAMP-negative strains were further validated through 16S rDNA, while the CAMP factor encoding gene(cfb) was detected using real-time fluorescence quantitative polymerase chain reaction(qPCR). Antimicrobial susceptibility testing was conducted using the microbroth dilution method, and the resistance rates of CAMP-negative and CAMP-positive strains were compared.
Results :
Based on MALDI-TOF MS identification, all 33 strains were classified asStreptococcus agalactiae. Among them, 7 strains tested negative for CAMP were subsequently confirmed asStreptococcus agalactiaethrough 16S rDNA. The qPCR results indicated that, only 1 strain showedcfbpresence. The CAMP-negative and CAMP-positive strains were sensitive to penicillin G, cefepime, cefotaxime, vancomycin, and linezolid. The resistance rates of the former to chloramphenicol and tetracycline(28.57%, 85.71%) were slightly higher than the latter(15.38%, 57.69%), while the resistance rates to moxifloxacin, levofloxacin, and erythromycin(14.29%, 14.29%, 42.86%) were slightly lower than the latter(34.62%, 34.62%, 57.69%), but was not significant.
Conclusion
Drug risistance of CAMP-negativeStreptococcus agalactiaeis the same as CAMP-positive strains, but traditional CAMP assay andcfb-targeted qPCR can result in missed detections. MALDI-TOF MS offers a quick, simple, and accurate identification method that merits wider adoption.
5.Study on the antagonistic activity of Lactococcus garvieae SHAMU-LG6 against Staphylococcus
Shengnan Weng ; Guiyun Leng ; Ying Liu ; Yawu Wang ; Xin Li ; Jie Yao ; Qiang Zhou ; Wei Tang
Acta Universitatis Medicinalis Anhui 2025;60(2):195-200
Objective :
To investigate the antagonistic activity of Lactococcus garvieae SHAMU-LG6 against Staphy- lococcus .
Methods :
VITEK 2 GP identification card , Microflex LT MALDI-TOF mass spectrometer and 16S rDNA amplification sequencing were used to identify the strain species . The antagonistic activity of L. garvieae SHAMU- LG6 against different Staphylococcus was detected by Oxford cup method for bacterial inhibition ; the antimicrobial active components were preliminarily isolated and purified by adsorption on XAD16 nonionic macroporous resin , gradient ethanol elution and rotary evaporation drying.
Results :
L. garvieae SHAMU-LG6 exhibited potent antago- nistic effect against methicillin-resistant Staphylococcus aureus , methicillin-susceptible S. aureus , S. epidermidis , S. saprophyticus , S. lugdunensis , S. hominis , S. capitis and S. warneri , with inhibitory indices of 3 . 3 , 3 . 0 , 4. 3 , 2. 0 , 4. 0 , 3 . 5 , 3 . 8 , and 3 . 5 , respectively. The antimicrobial active components produced by L. garvieae SHAMU-LG6 were mainly present in 70% and 80% ethanol eluates .
Conclusion
L. garvieae SHAMU-LG6 ex- hibits a potent antagonistic effect on Staphylococcus , and the antimicrobial active components produced by it are ex- pected to be a lead compound for the development of novel antimicrobial agents .
6.Whole genome sequencing analysis of four strains of CAMP negative Streptococcus agalactiae
Xiu Wang ; Jie Yao ; Guiyun Leng ; Wei Tang ; Qiang Zhou
Acta Universitatis Medicinalis Anhui 2025;60(4):707-711
Objective :
To explore the molecular characteristics of four CAMP negativeStreptococcus agalactiae(S.agalactiae) in whole genome sequencing.
Methods :
The identification of suspicious bacterial strains was conducted using matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF MS). For the strains confirmed asS.agalactiaethrough identification, further CAMP experiments were conducted. For CAMP negative strains, whole genome sequencing was performed using MGI DNBSEQ-T7 and MinION Flow Cell sequencing platforms. Subsequently, multi-locus sequence typing(MLST), virulence genes and resistance genes of the strains were compared and analyzed using various databases. Phoenix M50 fully automatic drug sensitivity analyzer was employed to determine the sensitivity of the bacterial strains to commonly used antibiotics.
Results:
Four CAMP-negativeS.agalactiaestrains were included. Whole-genome sequencing analysis revealed that all four CAMP-negativeS.agalactiaestrains belonged to the ST862 type. These strains harbored 22 virulence genes associated with capsular polysaccharides, β-hemolysin, and hyaluronidase, as well as seven resistance genes linked to macrolides, lincosamides, polypeptides, and aminoglycosides. Antimicrobial susceptibility testing revealed that CAMP-negativeS.agalactiaewas susceptible to penicillin G, cefepime, cefotaxime, and vancomycin. However, three strains exhibited resistance to erythromycin, and one strain demonstrated resistance to clindamycin.
Conclusion
Four CAMP negativeS.agalactiaeof the ST862 type possess multiple virulence and drug resistance genes, showing high resistance to erythromycin, warranting clinical attention.
7.TCMKD: From ancient wisdom to modern insights-A comprehensive platform for traditional Chinese medicine knowledge discovery.
Wenke XIAO ; Mengqing ZHANG ; Danni ZHAO ; Fanbo MENG ; Qiang TANG ; Lianjiang HU ; Hongguo CHEN ; Yixi XU ; Qianqian TIAN ; Mingrui LI ; Guiyang ZHANG ; Liang LENG ; Shilin CHEN ; Chi SONG ; Wei CHEN
Journal of Pharmaceutical Analysis 2025;15(6):101297-101297
Traditional Chinese medicine (TCM) serves as a treasure trove of ancient knowledge, holding a crucial position in the medical field. However, the exploration of TCM's extensive information has been hindered by challenges related to data standardization, completeness, and accuracy, primarily due to the decentralized distribution of TCM resources. To address these issues, we developed a platform for TCM knowledge discovery (TCMKD, https://cbcb.cdutcm.edu.cn/TCMKD/). Seven types of data, including syndromes, formulas, Chinese patent drugs (CPDs), Chinese medicinal materials (CMMs), ingredients, targets, and diseases, were manually proofread and consolidated within TCMKD. To strengthen the integration of TCM with modern medicine, TCMKD employs analytical methods such as TCM data mining, enrichment analysis, and network localization and separation. These tools help elucidate the molecular-level commonalities between TCM and contemporary scientific insights. In addition to its analytical capabilities, a quick question and answer (Q&A) system is also embedded within TCMKD to query the database efficiently, thereby improving the interactivity of the platform. The platform also provides a TCM text annotation tool, offering a simple and efficient method for TCM text mining. Overall, TCMKD not only has the potential to become a pivotal repository for TCM, delving into the pharmacological foundations of TCM treatments, but its flexible embedded tools and algorithms can also be applied to the study of other traditional medical systems, extending beyond just TCM.
8.Assessing distribution characteristics and clinical significance of vertebral fractures in patients with osteoporosis based on whole spine MRI
Jiajun ZHOU ; Fei MA ; Yebo LENG ; Shicai XU ; Baoqiang HE ; Yang LI ; Yehui LIAO ; Qiang TANG ; Chao TANG ; Qing WANG ; Dejun ZHONG
Chinese Journal of Tissue Engineering Research 2025;29(9):1883-1889
BACKGROUND:Osteoporotic vertebral fractures are the most common complication in patients with osteoporosis.As a new imaging technique,spine magnetic resonance imaging(MRI)is much more sensitive than X-ray film in the diagnosis of osteoporotic vertebral fractures.However,total spine MRI is costly and takes a long time to scan.Therefore,there is no consensus on whether all patients with osteoporotic vertebral fractures need to undergo total spine MRI scan and which patients need to undergo total spine MRI. OBJECTIVE:To analyze the distribution characteristics of vertebral fractures and explore their clinical significance by observing the whole spine MRI data of osteoporotic vertebral fractures patients. METHODS:Data of cases and MRI images of all patients diagnosed with fresh osteoporotic vertebral fractures who visited the Department of Orthopedics,Affiliated Hospital of Southwest Medical University from August 2018 to September 2022 were retrospectively analyzed.903 patients were included in the study based on inclusion and exclusion criteria.General information(age,gender,and body mass index),medical history characteristics(duration of illness,history of trauma surgery,percussion pain area,and pain score)were collected.The characteristics of vertebral fractures were analyzed through whole spine magnetic resonance imaging.Firstly,based on the number of vertebral fractures in patients,they were divided into the single vertebral fracture group(484 cases)and the multi-vertebral fracture group(419 cases),and the differences were analyzed between the two groups.Then,based on whether the farthest interval between the fractured vertebrae was greater than or equal to 5,the multi vertebral fracture group was further divided into two subgroups.Among them,Group A(the farthest interval between the fractured vertebrae was less than 5)contained 306 cases;Group B(with the farthest interval between fractured vertebral bodies greater than 5)included 113 cases.The differences were analyzed between two subgroups. RESULTS AND CONCLUSION:(1)Among 903 patients,419 patients(46.4%)had more than two fractured vertebrae.There were 654 patients(72.4%)with thoracolumbar fractures,and 54 patients(6%)with fractures in the thoracic plus lumbar region and the entire thoracic to lumbar region.In group B,96.5%of patients had multiregional percussion pain.(2)Compared with the patients in the single vertebral fracture group and the multi-vertebral fracture group,there were significant differences in bone mineral density,whether the medical history was greater than or equal to 1 month,the history of low energy injury,and the distribution and number of axial percussion pain areas in the spine during physical examination between the two groups(P<0.05).Age,gender,body mass index,whether there was underlying disease,pain visual analog scale score,whether there was a history of elderly thoracolumbar fracture,and whether there was a history of thoracolumbar surgery,and the number of fractured vertebrae had no statistical significance(P>0.05).(3)There were statistically significant differences between the Groups A and B in bone mineral density,the distribution and quantity of percussion pain area,and the history of low energy injury(P<0.05).There were no significant differences in age,gender,history of old fractures,visual analog scale score,body mass index,whether the medical history was longer than or equal to 1 month,history of underlying diseases,and history of thoracolumbar surgery between the two groups(P>0.05).(4)Patients with multiple low-energy trauma history,history of more than 1 month,multiple percussion pain,and the lower bone mineral density should be alert to the occurrence of multiple vertebral fracture and jump fracture.We recommend the whole spinal MRI for these patients.
9.Correlation Between the Spinopelvic Parameters and Morphological Characteristics of Pedicle-Facet Joints in Different Lumbar Spondylolisthesis
Baoqiang HE ; Yebo LENG ; Shicai XU ; Yang LI ; Jiajun ZHOU ; Min KANG ; Yehui LIAO ; Minghao TIAN ; Qiang TANG ; Fei MA ; Qing WANG ; Chao TANG ; Dejun ZHONG
Neurospine 2025;22(1):231-242
Objective:
Based on spinopelvic parameters and biomechanical principles, the pedicle-facet joint (PFJ) morphological characteristics of isthmic and degenerative spondylolisthesis were analyzed, and the mechanism of their onset and progression was discussed.
Methods:
This retrospective cross-sectional study included 194 patients with L5 spondylolysis or L5–S1 low-grade isthmic spondylolisthesis (IS group), 172 patients with L4–5 degenerative spondylolisthesis (DS group), and 366 patients with nonlumbar spondylolysis (NL group). The spinopelvic parameters and PFJ morphological parameters of the patients were measured, the differences in these parameters among and within the 3 groups were compared, and the correlations were analyzed.
Results:
Sacral slope (SS) and lumbar lordosis (LL) were the highest in the IS group, the second highest in the DS group, and the lowest in the NL group. Among the 3 groups, the L4 facet joint angle (FJA) was the largest in the IS group, the second largest in the NL group, and the smallest in the DS group. The L4 pedicle-facet joint angle (PFA) was the largest in the DS group, the second largest in the IS group, and the smallest in the NL group. Pearson correlation analysis showed that within each group, SS and LL were negatively correlated with FJA and positively correlated with PFA.
Conclusion
This study found a correlation between the PFJ morphological characteristics of patients with lumbar spondylolisthesis and spinopelvic parameters, suggesting that the morphological characteristics of PFJs may be caused by varying stresses under different spinopelvic morphologies.
10.Correlation Between the Spinopelvic Parameters and Morphological Characteristics of Pedicle-Facet Joints in Different Lumbar Spondylolisthesis
Baoqiang HE ; Yebo LENG ; Shicai XU ; Yang LI ; Jiajun ZHOU ; Min KANG ; Yehui LIAO ; Minghao TIAN ; Qiang TANG ; Fei MA ; Qing WANG ; Chao TANG ; Dejun ZHONG
Neurospine 2025;22(1):231-242
Objective:
Based on spinopelvic parameters and biomechanical principles, the pedicle-facet joint (PFJ) morphological characteristics of isthmic and degenerative spondylolisthesis were analyzed, and the mechanism of their onset and progression was discussed.
Methods:
This retrospective cross-sectional study included 194 patients with L5 spondylolysis or L5–S1 low-grade isthmic spondylolisthesis (IS group), 172 patients with L4–5 degenerative spondylolisthesis (DS group), and 366 patients with nonlumbar spondylolysis (NL group). The spinopelvic parameters and PFJ morphological parameters of the patients were measured, the differences in these parameters among and within the 3 groups were compared, and the correlations were analyzed.
Results:
Sacral slope (SS) and lumbar lordosis (LL) were the highest in the IS group, the second highest in the DS group, and the lowest in the NL group. Among the 3 groups, the L4 facet joint angle (FJA) was the largest in the IS group, the second largest in the NL group, and the smallest in the DS group. The L4 pedicle-facet joint angle (PFA) was the largest in the DS group, the second largest in the IS group, and the smallest in the NL group. Pearson correlation analysis showed that within each group, SS and LL were negatively correlated with FJA and positively correlated with PFA.
Conclusion
This study found a correlation between the PFJ morphological characteristics of patients with lumbar spondylolisthesis and spinopelvic parameters, suggesting that the morphological characteristics of PFJs may be caused by varying stresses under different spinopelvic morphologies.


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