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．

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 .

Objective To explore the antimicrobial activity of the bacteriocin(tentatively named garvicin LG6)se-creted by Lactococcus garvieae(L.garvieae)SHAMU-LG6 against Staphylococcus aureus(S.aureus)of different hemolytic phenotypes.Methods S.aureus isolated from clinical patients in a hospital of Anhui from 2021 to 2023 were collected.The hemolytic phenotypes of S.aureus were detected by three-point inoculation method.S.aureus of different hemolytic phenotypes were further categorized into methicillin-sensitive S.aureus(MSSA)and methi-cillin-resistant S.aureus(MRSA)according to antimicrobial susceptibility testing results.The antagonistic activity of L.garvieae SHAMU-LG6 against S.aureus of different hemolytic phenotypes was assayed by Oxford cup me-thod.The whole-genome sequencing of L.garvieae SHAMU-LG6 was performed.Biosynthetic gene cluster of gar-vicin LG6 was searched by online databases antiSMASH 7.0 and BAGEL4.Through macroporous resin adsorption,ethanol gradient elution,rotary evaporation,and dried material reconstitution,antimicrobial activity of garvicin LG6 crude extract against S.aureus was detected by the inhibitory testing of Oxford cup method.Results L.garvieae SHAMU-LG6 could significantly antagonize MSSA and MRSA of different hemolytic phenotypes.Biosynthetic gene cluster of garvicin LG6 was present on the chromosomal genome of L.garvieae SHAMU-LG6.The antimicrobial activity of garvicin LG6 secreted by a single colony or 6 mL fermentation fluid of L.garvieae SHAMU-LG6 were at least equal to that of antibiotic disc of 30 pg cefoxitin.Conclusion Garvicin LG6 can efficiently kill MSSA and MR-SA of different hemolytic phenotypes,and has the potential to be developed into a novel antimicrobial agent,which has great prospects for clinical application.

Objective To explore the antimicrobial activity of the bacteriocin(tentatively named garvicin LG6)se-creted by Lactococcus garvieae(L.garvieae)SHAMU-LG6 against Staphylococcus aureus(S.aureus)of different hemolytic phenotypes.Methods S.aureus isolated from clinical patients in a hospital of Anhui from 2021 to 2023 were collected.The hemolytic phenotypes of S.aureus were detected by three-point inoculation method.S.aureus of different hemolytic phenotypes were further categorized into methicillin-sensitive S.aureus(MSSA)and methi-cillin-resistant S.aureus(MRSA)according to antimicrobial susceptibility testing results.The antagonistic activity of L.garvieae SHAMU-LG6 against S.aureus of different hemolytic phenotypes was assayed by Oxford cup me-thod.The whole-genome sequencing of L.garvieae SHAMU-LG6 was performed.Biosynthetic gene cluster of gar-vicin LG6 was searched by online databases antiSMASH 7.0 and BAGEL4.Through macroporous resin adsorption,ethanol gradient elution,rotary evaporation,and dried material reconstitution,antimicrobial activity of garvicin LG6 crude extract against S.aureus was detected by the inhibitory testing of Oxford cup method.Results L.garvieae SHAMU-LG6 could significantly antagonize MSSA and MRSA of different hemolytic phenotypes.Biosynthetic gene cluster of garvicin LG6 was present on the chromosomal genome of L.garvieae SHAMU-LG6.The antimicrobial activity of garvicin LG6 secreted by a single colony or 6 mL fermentation fluid of L.garvieae SHAMU-LG6 were at least equal to that of antibiotic disc of 30 pg cefoxitin.Conclusion Garvicin LG6 can efficiently kill MSSA and MR-SA of different hemolytic phenotypes,and has the potential to be developed into a novel antimicrobial agent,which has great prospects for clinical application.

Background and purpose:Tumor budding is a poor prognostic factor in colorectal cancer. In this study, we studied the tumor budding by counting the actual number in 10 high power fields and evaluated itsclinical application in predicting lymph node metastasis of T1 colorectal cancer.Methods:Tissue specimens from 307 patients with histologically conifrmed T1 colorectal cancer were enrolled. The clinicopathological characteristics including tumor budding were evaluated for their predictive value in lymph node metastasis. A formula was created to calculate the risk score for prediction of lymph node metastasis which was validated by 14 new cases.Results:In the multivariate analysis, it showed that tumor grade, lymphovascular invasion and the number of tumor budding were signiifcantly associated with lymph node metastasis. The probability of lymph node metastasis was calculated using the following equations:Z=1.571×(lymphovascular state: invasion, 1; no invasion, 0)+2.661×(tumor grade: high grade, 1; low grade, 0)+0.024×(budding counts)-3.885; Probability=1/1+e-Z. The high scores were correlated with the lymph node metastasis in the validations.Conclusion:We can accurately assess the risk of lymph node metastasis by counting the number of tumor budding in 10 high power fields. Therefore tumor budding could potentially assist treatment decision making in T1 colorectal cancer patients with high-risk lymph node metastasis.