Characterization of a novel carbapenem-hydrolysing ß-lactamase OXA-1041 in Escherichia coli.

BACKGROUND: We found a carbapenem-resistant Escherichia coli without known carbapenemase-encoding genes and performed a study to identify the possible new carbapenemase. METHODS: The production of carbapenemase was examined using the modified carbapenem inactivation method. The strain was subjected to short- and long-read genome sequencing and the complete genome was obtained by hybrid assembly. The gene encoding a potential new OXA-type carbapenemase was cloned. The enzyme was purified and was then subjected to kinetic assays. Molecular docking analysis of the enzyme was performed using the MOE software suite. Mating experiments were attempted to obtain the plasmid carrying the corresponding gene. RESULTS: We identified and characterized a novel class D carbapenem-hydrolysing ß-lactamase, OXA-1041, in a carbapenem-resistant E. coli clinical strain. OXA-1041 had 89.77% (237/264) amino acid identity with OXA-427, a known carbapenemase. By cloning in an E. coli laboratory strain, blaOXA-1041 was found to reduce susceptibility to ertapenem by 16 times (MIC 0.25 versus 0.016 mg/L) and meropenem by four times (MIC 0.06 versus 0.016 mg/L) but did not significantly reduce susceptibility to imipenem and doripenem. Enzyme kinetic measurement of purified OXA-1041 showed that OXA-1041 could hydrolyse ertapenem and meropenem with a turnover number (kcat)/Michaelis constant (KM) of 8.57 and 3.63 mM-1s-1, respectively. The complete genome contained a single plasmid (223 341 bp, IncF, containing five replicons), which was self-transmissible. blaOXA-1041 was downstream of insertion sequence ISCR1 and there were three tandem copies of ISCR1-blaOXA-1041-creDΔ (encoding an envelope protein) on this plasmid. CONCLUSIONS: The above findings suggest OXA-1041 is a new plasmid-encoded carbapenemase with preferential activity against ertapenem.

Clinical characteristics of liver injury induced by immune checkpoint inhibitors in patients with advanced biliary tract carcinoma.

Immune-related liver injuries are closely associated with the liver's fundamental state. Patients with advanced biliary tract carcinoma (BTC) have poor liver function. We evaluated the clinical data of immune-related liver injury in patients with advanced BTC and gastric cancer (GC) during immune checkpoint inhibitor (ICI) treatment between February 2019 and July 2022 at Peking University First Hospital. Twenty-five patients with advanced BTC were identified. Fifteen patients (60%) experienced immune-related liver injury during ICI treatment. We also evaluated the clinical status of patients with GC in another group receiving immunotherapy. The results demonstrated that the incidence of immune-related liver injury was higher in patients with BTC than in GC cancer (p=0.040). Multivariate analysis suggested that the type of malignant tumor and baseline liver function status were high-risk factors for grade 2 and higher immune-related liver injuries. Two patients were diagnosed with immune-related cholangitis. Both biliary enzymes can be decreased to a certain degree by corticosteroid and ursodeoxycholic acid (UDCA) therapy but are difficult to reduce to normal levels. Liver function normalized, and symptoms improved after local treatment for cholestasis (stent implantation or PTBD). We observed a higher incidence of immune-related liver injury after ICI treatment in patients with advanced BTC. Effect of baseline liver function on the incidence of liver injury associated with immunotherapy. Interventional therapy provides rapid relief from cholestasis and is an indispensable and effective approach to the treatment of immune-related cholangitis.

A rare class A carbapenemase FRI-11 in Enterobacter clinical strain.

We found a carbapenem-resistant Enterobacter clinical strain which was susceptible to cefotaxime and ceftazidime. This unusual susceptibility profile promoted the investigation. This strain had blaFRI-11, a rare carbapenemase-encoding gene, on a 93,864-bp plasmid containing two replicons of IncFII(pECLA) and IncFIA(HI1). FRI-11, FRI-2, FRI-3, FRI-4, FRI-6, FRI-7, and FRI-9 belong to the same group of FRI ß-lactamases based on the amino acid sequence similarity and their encoding genes are carried by plasmids containing an IncFII(pECLA) replicon. Awareness should be raised towards FRI carbapenemases that are plasmid-encoded and confer an unusual carbapenem-resistant but 3rd-generation-cephalosporin-susceptible resistance profile.

Clinical features and prognostic factors of brain metastases from colorectal cancer: a single center experience.

PURPOSE: The study aimed to investigate the clinical characteristics, prognostic factors, survival times, and therapy outcomes of brain metastases (BM) from colorectal cancer (CRC). METHODS: The clinical characteristics of 25 patients with BM from CRC were retrospectively analyzed. The time of the occurrence of BM after diagnosis of CRC was recorded. Meanwhile, the time from the occurrence of lung, bone, liver, and other extracranial metastases to the occurrence of BM was also recorded. We evaluate the time factors affecting the length of the occurrence of BM and the potential prognostic factors after BM diagnosis. The influences of patients undergoing surgery-based comprehensive treatment, radiotherapy-based comprehensive treatment, and co-medication were also assessed. RESULTS: In patients with BM from CRC, lung metastases (13/25) occurred at a higher frequency than liver metastases (8/25) and bone metastases (6/25). The median time to the development of BM was much shorter (3.7 vs. 25.3 months, p = 0.027), with the brain being the origin site for the metastasis. The median overall survival reached 9.9 months. The interval between diagnosis of BM and bone, liver, and lung metastasis remains 3, 6.5, and 11 months, respectively. The brain lesions of patients with BM alone had higher rates in supratentorial (88.9%), while those with extracranial metastasis had a 62.5% incidence of infratentorial metastasis. The difference was statistically significant (p < 0.05). The time of occurrence of BM in patients aged 67 years and younger was 16.1 and 30.1 months, respectively. The differences between them were statistically significant (p = 0.043). The BM time for left- and right-sided colon cancer were 26.5 and 7.8 months, representing a statistically significant difference (p = 0.015). The time to onset of BM for patients with and without the resection of primary lesions was 25.4 and 4.5 months. Statistically significant differences are shown (p = 0.007). Univariate analysis demonstrated that the prognosis of patients was related to the KPS score, the number of BM, the treatment methods, and the occurrence of lung metastasis (p < 0.05). The multivariate analysis revealed that the treatment modality and lung metastasis were independent prognostic factors for CRC patients with BM. Right-sided CRC patients with BM have a poor prognosis (8.1 vs. 10.2 months, p = 0.31). Although median survival time was not significantly different between patients with and without bevacizumab combination therapy, bevacizumab therapy is associated with a better survival time (9.9 vs. 7.1 months, p = 0.27). CONCLUSION: Patients with left-sided CRC, especially those with lung metastases, are prone to brain metastases, and patients with brain metastases as the first metastatic site have a higher rate of supratentorial metastases. Young patients with right hemicolon cancer and patients who have not undergone primary lesion resection have a shorter time for the occurrence of BM. Patients with colorectal lung metastases, especially those young with right-sided CRC, require close imaging surveillance of BM. The prognosis of CRC patients with BM and lung metastases is poor, and comprehensive treatment based on surgery could significantly prolong patients' survival time.

Resistance to aztreonam-avibactam due to a mutation of SHV-12 in Enterobacter.

Aztreonam-avibactam is an important option against Enterobacterales producing metallo-ß-lactamases (MBLs). We obtained an aztreonam-avibactam-resistant mutant of an MBL-producing Enterobacter mori strain by induced mutagenesis. Genome sequencing revealed an Arg244Gly (Ambler position) substitution of SHV-12 ß-lactamase in the mutant. Cloning and susceptibility testing verified that the SHV-12 Arg244Gly substitution led to significantly reduced susceptibility to aztreonam-avibactam (MIC, from 0.5/4 to 4/4 mg/L) but with the loss of resistance to cephalosporins as tradeoff. Arg244 of SHV involves in the binding of avibactam by forming an arginine-mediated salt bridge and is a critical residue to interact with ß-lactams. Molecular modeling analysis demonstrated that the Arg244Gly substitution hindered the binding of avibactam to SHV with higher binding energy (from - 5.24 to -4.32 kcal/mol) and elevated inhibition constant Ki (from 143.96 to 677.37 µM) to indicate lower affinity. This substitution, however, resulted in loss of resistance to cephalosporins as tradeoff by impairing substrate binding. This represents a new aztreonam-avibactam resistance mechanism.

Enterobacter pseudoroggenkampii sp. nov. carrying quinolone-resistant gene qnrE recovered from clinical samples in China.

Two Enterobacter strains 155092T and 170,225 were isolated from clinical samples, pus and sputum, from two hospitalised patients separately, in China. Preliminary identification using Vitek II microbiology system assigned the strains to the Enterobacter cloacae complex. The two strains were subjected to genome sequencing and genome-based taxonomy analysis with type strains of all Enterobacter species and those within closely related genera Huaxiibacter, Leclercia, Lelliottia, and Pseudoenterobacter. The average nucleotide identity (ANI) and in silico DNA-DNA hybridisation (isDDH) values between the two strains were 98.35% and 89.4%, respectively, suggesting that they belong to one species. The two strains had the highest ANI (95.02% and 95.04%) with the type strain of Enterobacter quasiroggenkampii. Their highest isDDH values, also seen with the type strain of E. quasiroggenkampii, were 59.5% and 59.8%, well below the 70% cutoff to define species. The two strains were also characterised for morphological and biochemical features by a set of experiments and observations. The abilities of metabolising gelatin and L-rhamnose could differentiate the two strains from all currently known Enterobacter species. Collectively, the two strains represent a novel Enterobacter species, for which we propose Enterobacter pseudoroggenkampii sp. nov. as the species name. The type strain of this novel species is155092T (= GDMCC 1.3415T = JCM 35646T). The two strains also carried multiple virulence factors comprising aerobactin-encoding iucABCD-iutA and salmochelin-encoding iroN. The two strains also had chromosomally located qnrE, a gene associated with reduced susceptibility to quinolones, suggesting that this species is a potential reservoir of qnrE genes.

Real-world outcomes of regorafenib combined with immune checkpoint inhibitors in patients with advanced or metastatic microsatellite stable colorectal cancer: A multicenter study.

BACKGROUND: Treatment strategies are limited for patients with chemotherapy refractory microsatellite stable (MSS) colorectal cancer. We aim to evaluate the efficacy and safety of immune checkpoint inhibitors (ICIs) combined with regorafenib in this population in routine clinical practice. METHODS: We retrospectively analyzed patients with advanced or metastatic colorectal cancer who received at least one dose of ICIs combined with regorafenib in 14 Chinese medical centers. The primary outcome was objective response rate (ORR). This study was registered at ClinicalTrials.gov on February 2020 (NCT04771715). RESULTS: Eighty-four patients received ICIs combined with regorafenib from January 2019 to January 2021. Most patients (91%) received two or more systemic treatment lines before the study treatment. Seventy-six patients (90%) had confirmed MSS status. At a median follow-up of 5.5 months, four patients achieved partial response (5%) and 37 patients achieved stable disease (45%) as the best response. The median progression-free survival (PFS) was 3.1 months, and the median overall survival was 17.3 months. Eleven patients (13%) remained progression-free for more than 6 months. Baseline liver metastasis (HR 1.98, 95%CI 1.07-3.69, P = 0.03) and neutrophil-lymphocyte ratio (NLR) of ≥ 1.5 (HR 2.83, 95%CI 1.00-7.98, P = 0.05) were associated with shorter PFS in multivariate analysis. Grade 3 or higher treatment-related adverse events (TRAEs) occurred in 16 patients (19%). CONCLUSION: The combination of ICIs with regorafenib can be a valuable treatment option for a proportion of patients with chemotherapy refractory MSS colorectal cancer. Patients with no liver metastasis and a low NLR at baseline may derive most benefit from this strategy.

Huaxiibacter chinensis gen. nov., sp. nov., recovered from human sputum.

Strain 155047T was recovered from human sputum in China in 2021. Preliminary species identification based on limited phenotypic tests assigned the strain to the genus Enterobacter of the family Enterobacteriaceae. The genome sequence of the strain was obtained and had ≤84.43 % average nucleotide identity (ANI) and ≤26.3 % in silico DNA-DNA hybridization (isDDH) values with the genomes of type strains of known Enterobacteriaceae species. The highest ANI and isDDH matches were with Lelliottia nimipressuralis and Enterobacter asburiae, respectively. The ANI and isDDH values support that the strain belongs to a novel species of the family Enterobacteriaceae. Phylogenomic analysis based on core genes revealed that strain 155047T was located in the Enterobacter-Leclercia-Lelliottia-Pseudenterobacter lineage. The highest ANI and average amino acid identity values between 155047T and any species of the Enterobacter-Leclercia-Lelliottia-Pseudenterobacter lineage were 84.43 % and 90.21 %, respectively, lower than the maximum inter-genus pairwise values. This indicates that 155047T belongs to a novel species of a novel genus in the lineage. Strain 155047T could be differentiated from Enterobacter, Lelliottia, Leclercia and Pseudenterobacter species by a negative reaction for ß-galactosidase and the ability to produce acid from l-fucose but not from sucrose. The names Huaxiibacter gen. nov. and Huaxiibacter chinensis sp. nov. are proposed for the novel genus and species, respectively. The type strain is 155047T (= GDMCC 1.2980T=JCM 35262T).

Risk factors and characteristics of bacterial infection during first-line chemotherapy for metastatic gastric or gastroesophageal junction adenocarcinoma.

PURPOSE: Chemotherapy-related bacterial infection is a common side effect in patients receiving chemotherapy. The purpose of this study was to determine the risk factors and characteristics of bacterial infection in metastatic gastric or gastroesophageal junction (GEJ) adenocarcinoma patients treated with combined chemotherapy. METHODS: Patients with metastatic gastric or GEJ adenocarcinoma were followed up from 2013 to 2016 at Peking University First Hospital in China. Patients were treated with multiple cycles of combined chemotherapy. The incidence rate of bacterial infection and patients' clinical data were manually reviewed. RESULTS: A total of 154 patients were eligible and were enrolled in this study. A median of 6 chemotherapy cycles were administered (range, 1-14 cycles). Chemotherapy-related bacterial infections were observed in 36 of 154 patients (23.4%). Pulmonary is the most common site of infections. Ninety-four percent of patients with bacterial infection during chemotherapy received broad-spectrum antibiotics. The independent risk factors for chemotherapy-related bacterial infection identified by multivariable analysis were Nutritional Risk Screening 2002 (NRS2002) ≥ 3 (P = 0.008), ≥ grade 3 neutropenia (P = 0.028), and Eastern Cooperative Oncology Group Performance Status (ECOG PS) ≥ 2 (P = 0.042). CONCLUSIONS: Nearly a quarter of patients with metastatic gastric or GEJ adenocarcinoma who received combined chemotherapy had bacterial infection in this study. The proportion of broad-spectrum antibiotics used in patients with infection is very high. Improving nutritional status may help reduce the incidence of bacterial infection.

Controlling Nutritional Status score predict the individualized survival of patients with gastric cancer.

BACKGROUND AND OBJECTIVES: The present study aimed to determine the correlation between Controlling Nutritional Status (CONUT) score and prognosis in gastric cancer patients undergoing total gastrectomy. METHODS AND STUDY DESIGN: The clinical data of 245 gastric cancer patients who underwent total gastrectomy in Peking University, First Hospital between January1st 2005 and December 30th 2015 were retrospectively collected. According to the CONUT level, they were divided into high CONUT (>3) group and low CONUT (≤3) group. The relationship between CONUT and the disease-free survival (DFS) and overall survival (OS) were analyzed by statistical analysis. RESULTS: The results showed that the optimal cutoff value for CONUT to predict the 5-year survival was 3 and CONUT had a higher area under the ROC curve (AUC) for 5-year disease free survival (DFS) and overall survival (OS) prediction. Additionally, when age was considered as a stratified factor, univariate analyses demonstrated that high CONUT correlated with shorter DFS in non-elderly (<65) patients and shorter DFS and OS in elderly (≥65) patients. CONCLUSIONS: High CONUT was significantly correlated with older age, advanced TNM-stage, higher Ki-67 and pathological subtype. Patients with high pre-operative high CONUT levels should be given more observation and constant follow-up after surgery.

Retrospective comparison of stereotactic body radiotherapy versus intensity-modulated radiotherapy for stage III ultra-central squamous non-small-cell lung cancer.

Aim: To analyze the efficacy and toxicity of stereotactic body radiotherapy (SBRT) versus intensity-modulated radiotherapy (IMRT) in stage III patients with ultra-central squamous non-small-cell lung cancer (sqNSCLC). Methods: Forty-four stage III patients with ultra-central sqNSCLC receiving SBRT (n = 15) or IMRT (n = 29) between December 2014 and August 2017 were reviewed. Results: At a median follow-up of 16.5 months, the 1-year local control rate of SBRT and IMRT was 60.8 and 37.5%, respectively (p = 0.23); the median overall survival was 17 versus 18 months (p = 0.48); ≥3 grade toxicity was 20 versus 24.1% (p = 0.83). Conclusion: SBRT is effective and patient friendly for stage III patients with ultra-central sqNSCLC. Toxicity might be tolerable with a moderate dose five to six fraction regimen. However, more prospective studies are warranted.

Low BMI is correlated with increased TGF-ß and IL-10 mRNA levels in the peripheral blood of breast cancer patients.

Transforming growth factor-ß (TGF-ß), interleukin-10 (IL-10), and forkhead box P3 (Foxp3) have important roles in breast cancer development. Previous studies confirmed a correlation between these immune molecules and tumor characteristics, but their association with nutritional status in breast cancer is largely unknown. We aimed to investigate the association between body mass index (BMI), hemoglobin, total protein, albumin, globulin (GLB), albumin/GLB ratio (AGR), pre-albumin, prognostic nutritional index, and TGF-ß, IL-10, and Foxp3 mRNA expression in patients with breast cancer. Quantitative real-time PCR was used to detect the mRNA expression of TGF-ß, IL-10, and Foxp3 in the peripheral blood of 107 patients with breast cancer and 21 healthy controls. We found that TGF-ß mRNA levels were 2.6-fold, 3.2-fold, and 2.3-fold higher in patients with low BMI (<23), low AGR, and high GLB, respectively, than in their counterparts (P < 0.05). In addition, IL-10 mRNA expression levels in patients with normal BMI (<23) were 2.8-fold and 3.5-fold higher than in those who were overweight (23≤ BMI <25) and obese (BMI ≥ 25), respectively (P < 0.05). In addition, TGF-ß, IL-10, and Foxp3 mRNA levels were significantly higher in patients with breast cancer than in healthy controls (P < 0.05). In summary, our results suggest that nutritional status, especially BMI, may strongly affect systematic immune function in patients with breast cancer. © 2018 IUBMB Life, 70(3):237-245, 2018.

Effect of Metal Ions on the Formation of Trichloronitromethane during Chlorination of Catechol and Nitrite.

Catechol, nitrite, and dissolved metals are ubiquitous in source drinking water. Catechol and nitrite have been identified as precursors for halonitromethanes (HNMs), but the effect of metal ions on HNM formation during chlorination remains unclear. The main objective of this study was to investigate the effect of metal ions (Fe, Ti, Al) on the formation of trichloronitromethane (TCNM) (the most representative HNM species in disinfected water) on chlorinating catechol and nitrite. Trichloronitromethane was extracted by methyl tert-butyl ether and detected by gas chromatography. The results show that metal ions promoted the formation of TCNM and that the enhancement efficiency followed the order of Fe > Ti > Al. Trichloronitromethane formation increased greatly within 2 h, and a basic condition (pH 8-9) favored TCNM formation more than acidic or neutral conditions. The conjoint effect of the metal-ion mixtures was shown to be similar to that of the single metal ion having the highest promoting effect on TCNM formation. Our results strongly suggest that metal ions play a significant role in enhancing TCNM formation.

[Establish and analyze the predictive model of early stage brain metastases in patients with breast cancer].

OBJECTIVE: To investigate the risk factors of cerebral metastasis of breast cancer and to provide guidance for the early diagnosis and treatment of brain metastases. METHODS: Clinical data of postoperative patients with breast cancer were collected in our hospital from 2005 to 2009. All the patients were divided into two groups, with or without brain metastasis. The risk factors of brain metastases of patients with breast cancer were analyzed by the logistic regression. RESULTS: Eight hundred and twenty four early postoperative patients with breast cancer were enrolled. The median follow-up time was 68 months and 199 cases had brain metastasis. The univariate logistic regression results showed that higher grade of tumor, <35 years, premenopausal, clinical stage Ⅲ, HER-2 positive and ER negative, no adjuvant chemotherapy, no adjuvant normal therapy were the risk factors of brain metastasis. The multivariate logistic regression result showed that higher grade of tumor, <35 years, premenopausal, clinical stage Ⅲ, HER-2 positive, ER negative were the risk factors. The mathematical model was used to predict the probability of occurrence of brain metastasis. ROC curve were draw by the value of predict probability as test variable and the brain metastasis status as state variables. The AUC value of this predictive model was 0.743±0.018. The specificity and sensitivity are relative high. CONCLUSION: Age<35 years, premenopausal, clinical stage Ⅲ, HER-2 positive and ER negative were independent risk factors for brain metastases. This model has the predictive value for the occurrence of brain metastases from breast cancer.

Autologous hematopoietic stem cell transplantation in chemotherapy-sensitive lymphoblastic lymphoma: treatment outcome and prognostic factor analysis.

OBJECTIVE: The study evaluated the effectiveness of autologous hematopoietic stem cell transplantation (AHSCT) in the treatment of lymphoblastic lymphoma (LL). METHODS: We retrospectively analyzed the data from 41 patients with chemotherapy-sensitive LL who underwent hematopoietic stem cell transplantation (HSCT) from December 1989 to December 2009 in a single institution. RESULTS: HSCT was conducted as first-line consolidation therapy and salvage therapy in 36 and 5 patients, respectively. The median follow-up was 97.1 months (range, 24.6-173.1 months). The 5-year overall survival (OS) and event-free survival (EFS) rate were 64% and 47% for the initially treated patients, respectively, and were both 20% for the relapsed ones. Bone marrow (BM) involvement and chemotherapy cycles prior to transplantation were identified as significant prognostic factors for EFS in multivariate analysis. CONCLUSIONS: These results confirm that AHSCT is a reasonable option for chemotherapy-sensitive LL patients in first complete remission (CR1).

[Clinical observations of ductal carcinoma in situ and early stage breast cancer with invasive depth less than 1 cm].

OBJECTIVE: To explore the clinical characteristics and prognosis of ductal carcinoma in situ (DCIS) and early stage ductal breast cancer with invasive depth ≤ 1 cm. METHODS: Follow-up analyses were performed for the clinical data of 57 patients with DCIS, 46 with pT(1mic) and 74 with pT(1a-b) breast cancer treated or consulted at our hospital. Single factor analysis was used to examine their prognostic factors. RESULTS: Among them, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2(HER-2) positive rate and visual tumor size (2.0(0.1-7.0) vs 2.0(0.5-10.0) vs 2.0(0.3-10.0) cm)had no statistical differences between 3 groups (all P > 0.05). After median follow-up periods of 63, 38, 59 months, 12 patients suffered recurrence and metastasis and the rate of each group had no statistical differences. For pT(1a-b) patients with positive hormone receptor, endocrine therapy markedly reduced the risk of recurrence and metastasis (P = 0.024) . pT(1mic), pT(1a-b) patients on chemotherapy had higher or comparable recurrence rate versus those without. And DCIS patients on chemotherapy had a much higher recurrence rate (P = 0.016) . In pT(1a-b) group, HER-2 positive patients had higher recurrence and metastasis rates. Yet there was a decreasing tendency after Herceptin treatment. CONCLUSIONS: Chemotherapy without proper indications may not improve the prognosis of DCIS, pT(1mic) and pT(1a-b) patients. Endocrine therapy is the crucial prognostic factor of patients with positive hormone receptor. Use of Herceptin for HER-2-positive patients is probably significant.

[Serum HER2 ECD level and its clinical significance in advanced breast cancer patients with different molecular subtypes].

OBJECTIVE: To evaluate the serum HER2 ECD level and its significance in advanced breast cancer patients with different molecular subtypes. METHODS: A total of 322 advanced breast cancer patients were enrolled. The serum HER2 ECD concentrations were quantitatively detected by enzyme-linked immunosorbent assay(ELISA). Its relationship with clinicopathological characteristics and clinical significance were analyzed. RESULTS: It was found that 55.9% (19/34)Luminal A, 42.7% (44/103) Luminal B-HER2(-), 70.6% (60/85) Luminal B-HER2(+), 73.8% (45/61)HER2-enriched and 23.1% (9/39) triple-negative patients had serum concentrations of HER2 ECD at least 15 ng/ml respectively. The prevalence of elevated ECD level in patients of different molecular subtypes differed significantly (P < 0.001). Tissue HER2 status, number of metastatic sites, visceral metastasis, CA15-3 and carcinoembryonic antigen(CEA) levels exhibited statistically significant correlations with the prevalence of elevated serum HER2 ECD level. The serum concentrations of HER2 ECD decreased after effective targeted therapy in tissue HER2-positive patients. CONCLUSION: The prevalence of elevated serum levels of HER2 ECD differed significantly in advanced breast cancer patients with different molecular subtypes. The serum HER2 ECD level may reflect both histological HER2 status and tumor load. And the dynamic changes of ECD concentrations are somewhat correlated with the efficacies of targeted treatment.

[Detection of circulating tumor cells and its clinical value for different stages and various subtypes of breast cancer].

OBJECTIVE: To explore the prognostic value of applying a semi-automated detection system for detecting circulating tumor cells (CTC) for different stages and various subtypes of breast cancer. METHODS: Immunomagnetic separation and immunofluorescent staining were employed to detect the expressions of CTC and CTC HER-2. Chi-square test, univariate and multivariate analyses were used to examine the correlations between CTC and clinical characteristics. RESULTS: CTC was detected in 57.5% (138/240) of metastatic breast cancer (MBC). CTC enumeration, HER-2 status, number of metastasis and bone metastasis were relevant (P < 0.05). CTC was detected in 23.1% (6/26) of early-stage breast cancer (EBC). CTC enumeration, pathological type, estrogen receptor (ER), progesterone receptor (PR), Ki-67, tumor size and lymph node metastasis were irrelevant (P > 0.05). HER-2-positive MBC detected less CTC than HER-2-negative (χ(2) = 12.296, P < 0.001) . CTC HER-2 expression was different between HER-2-positive and negative patients in 99 MBC cases (χ(2) = 8.082, P = 0.004). CONCLUSION: CTC enumeration is different for various stages and different subtypes of breast cancer. CTC enumeration and bone metastasis are relevant. CTC detection in EBC may predict tumor relapse. And CTC HER-2 expression is different between HER-2-positive and negative MBC patients.

Two novel Enterobacter species, Enterobacter chinensis sp. nov. and Enterobacter rongchengensis sp. nov., recovered from clinical samples carrying multiple virulence factors.

Two Enterobacter strains 170198T and 170250T were isolated from clinical blood samples from distinct patients in a hospital in Chengdu, China, in 2022. These isolates were subjected to whole-genome sequencing. A phylogenomic tree based on 2,096 concatenated core genes showed that the two strains were clustered within the genus Enterobacter. The average nucleotide identity (ANI) and in silico DNA-DNA hybridization (isDDH) values between each of the two strains and type strains of all currently known Enterobacter species were determined. The two strains belonged to two novel species as the highest ANI and isDDH values with type strains of all currently known Enterobacter species below the cutoff for species demarcation (96% for ANI and 70% for isDDH). Then the physiological and biochemical studies demonstrated that biochemical features and the profile of whole fatty acids of strains 170198T and 170250T were largely consistent with those known Enterobacter species. Nevertheless, the two novel species can be differentiated from all other Enterobacter species by certain biochemical characteristics. In conclusion, 170198T and 170250T represent two novel species of the genus Enterobacter, for which we propose Enterobacter chinensis sp. nov. and Enterobacter rongchengensis sp. nov., as the species names. The type strains of Enterobacter chinensis sp. nov., and Enterobacter rongchengensis sp. nov. are 170198T (=GDMCC 1.3549T=JCM 35826T) and 170250T (=GDMCC 1.3670T=JCM 36189T), respectively. The two novel species have clinical significance with the ability to cause bloodstream infections.IMPORTANCEEnterobacter is a group of bacteria comprising several common opportunistic pathogens and has a complicated taxonomy. Here, we reported two novel Enterobacter species. We demonstrated that the two novel species can be differentiated from other Enterobacter species by certain phenotypic characteristics and therefore provide information for designing tests for identification. We also showed that strains of the two novel species are able to cause human bloodstream infections and carry multiple virulence factors and therefore are of clinical significance. We highlight that the virulence of Enterobacter is less studied and warrants further exploration. We believe that the findings here are valuable for enhancing the appreciation toward Enterobacter, an important pathogen.

T-cell infiltration and its regulatory mechanisms in cancers: insights at single-cell resolution.

Tumor-infiltrating T cells recognize, attack, and clear tumor cells, playing a central role in antitumor immune response. However, certain immune cells can impair this response and help tumor immune escape. Therefore, exploring the factors that influence T-cell infiltration is crucial to understand tumor immunity and improve therapeutic effect of cancer immunotherapy. The use of single-cell RNA sequencing (scRNA-seq) allows the high-resolution analysis of the precise composition of immune cells with different phenotypes and other microenvironmental factors, including non-immune stromal cells and the related molecules in the tumor microenvironment of various cancer types. In this review, we summarized the research progress on T-cell infiltration and the crosstalk of other stromal cells and cytokines during T-cell infiltration using scRNA-seq to provide insights into the mechanisms regulating T-cell infiltration and contribute new perspectives on tumor immunotherapy.