ABSTRACT
Purpose To explore the molecular features of diffuse large B-cell lymphoma(DLBCL)with high expression of MYC.Methods The clinical data of 45 cases of DLBCL were collected.Immunohistochemical EnVision method was used to classify the patients into the group with high expression of MYC and the group with low expression of MYC.All samples were subjected to DNA targeted sequencing and molecular typing was performed using the LymphGen online tool.Cellular origin was determined by using the Lymph2Cx method.The correlation be-tween MYC overexpression and clinicopathological parameters was analyzed by the x2 test and Fisher precise test.Survival curves were drawn and survival-related factors were analyzed u-sing Cox univariate and multivariate regression.ResultsCases were classified into DLBCL with high expression of MYC(n=17)and DLBCL with low expression of MYC(n=28).Com-pared to the group with low expression of MYC,the group with high expression of MYC had more PIM1,MYD88,CD79B,CD58 and PRDM1 mutations(76.5％vs 28.6％,70.6％vs 32.1％,58.8％vs28.6％,29.4％vs3.6％,29.4％vs 3.6％,P＜0.05),MCD were more frequently found(58.8％vs 10.7％,P=0.001),GCB were rarely found(17.6％vs 50.0％,P=0.030).Overall survival was significantly shorter in DLBCL with high expression of MYC(P＜0.05).Cox multi-factorial analysis showed that age was an independent prognostic factor for DLBCL(P＜0.05).Conclusion Patients with high expression of MYC were frequently characterized as MCD and ABC,and PIM1,MYD88,CD79B,CD58 and PRDM1 muta-tions were common.Patients with high expression of MYC had a poorer prognosis.
ABSTRACT
Purpose To investigate the relationship be-tween the level of tumor abnormal protein(TAP)and the molec-ular subtypes and clinicopathological features of breast cancer,and to analyze the value of TAP in breast cancer screening,di-agnosis and prognosis prediction.Methods The clinical data of 357 breast cancer patients were collected,and the elbow venous blood was collected to detect the TAP condensate area.Immuno-histochemical(IHC)EnVision two-step method was used to de-tect the expression of AR,ER,PR,HER2,p53 and Ki67,and FISH to detect HER2 gene.The relationship between TAP ex-pression and clinicopathological features,molecular subtypes and clinical stages of breast cancer was analyzed,and the rele-vant literature was reviewed.Results Among 357 breast cancer patients,9 cases(2.52％)were TAP negative,36 cases(10.08％)were weakly positive,312 cases(87.40％)were strongly positive,and the positive rate of TAP was 97.48％.AR was positive in 321 cases and negative in 36 cases,ER was pos-itive in 256 cases and negative in 101 cases,PR was positive in 214 cases and negative in 143 cases,HER2 was strongly posi-tive in 98 cases,weakly positive in 214 cases and negative in 45 cases,p53 was positive in 146 cases and negative in 211 cases,Ki67 index was ≥20％in 276 cases and＜20％in 81 case.A total of 155 cases of IHC HER2(2+)breast cancer were tested by FISH:140 cases were negative and 15 cases were positive.The expression level of TAP in patients of ≥50 years old expres-sionas significantly higher than that in patients of＜50 years old(P＜0.05).The expression level of TAP in patients with high Ki67 proliferation index was significantly higher than that in pa-tients with low Ki67 proliferation index(P＜0.05).There was a significant difference in TAP expression between patients with different molecular subtypes(P＜0.05).Tap expression was higher in triple-negative breast cancer patients than in non-tri-ple-negative breast cancer patients(P＜0.05),and it was high-er in Luminal B breast cancer patients than in non-Luminal B breast cancer patients(P＜0.05).There was a significant difference in TAP expression between patients with different clin-ical stages(P＜0.05),and TAP expression level was positively correlated with clinical stage in breast cancer.Conclusion TAP detection can improve the diagnostic accuracy of breast cancer,and has a certain correlation with the survival rate and prognosis of breast cancer patients.
ABSTRACT
Objective To observe the value of radiomics models and nomogram model based on two-dimensional ultrasound and automated breast volume scanning(ABVS)for predicting molecular types of breast cancer.Methods Data of 326 female patients of single breast cancer confirmed by pathology were analyzed retrospectively.The patients were randomly divided into training set(n=260)or validation set(n=66)at the ratio of 8∶2,and further divided into Luminal subgroup and non-Luminal subgroup.Radiomics features were extracted based on two-dimensional ultrasound of breast and ABVS imaging,then model2DUS,modelABVS and modelcombined radiomics were constructed,respectively.Univariate analysis and multivariate logistic regression analysis were used to screen independent factors for predicting molecular types of breast cancer,and nomogram model(modelnomogram)was constructed combined with independent factors and radiomics Radscores.The receiver operating characteristic(ROC)curve was used to evaluate the efficacy of each model for molecular type of breast cancer.Results The maximum diameter of tumor(OR=1.029)and the retraction phenomenon(OR=0.408)were both independent predictive factors for molecular type of breast cancer(both P＜0.05).The area under the curve(AUC)of model2DUS,modelABVS.modelcombined radiomics and modelnomogram for predicting molecular type of breast cancer in validation set was 0.67,0.75,0.84 and 0.83,respectively.No significant difference of AUC of modelcombined radiomics and modelnomogram was found(P＞0.05),which were both higher than AUC of model2DUs and modelABVS(all P＜0.05).Conclusion Combined radiomics model and nomogram model based on two-dimensional ultrasound and ABVS could effectively predict molecular type of breast cancer.
ABSTRACT
Objective To understand the serotype, drug resistance and pulsed field gel electrophoresis (PFGE) typing of Salmonella isolated from meat products in Hengyang from 2020 to 2022, so as to provide scientific data for the prevention and control of food-borne Salmonella infection in our city. Methods All 101 Salmonella isolated from meat products were serotyped, drug sensitivity tests were performed with micro broth dilution method, molecular typing was performed using PFGE, clustering analysis was performed with BioNumerics software, and statistical analysis was performed using SPSS 18.0 software. Results The total detection rate of Salmonella from meat sources in Hengyang City from 2020 to 2022 was 38.55% (101/262). Totally 23 different serotypes were detected in the 101 strains of Salmonella among which S. London (21.78%, 22/101),was the dominant serotypes. Seventy nine Salmonella strains showed different levels of drug resistance, with a multi drug resistance rate of 42.57% (43/101). Eighty nine different PFGE bands were found in the 101 strains of Salmonella, with a similarity of approximately 55% to 100%. Conclusion Different Salmonella Serotype are widely distributed, and the antibiotic resistance rate is very high. The PFGE map are polymorphic, and the homology of PFGE bands in Salmonella from different sources is relatively low.
ABSTRACT
Peripheral T-cell lymphoma (PTCL) is a group of heterogeneous malignant tumors with poor prognosis, with a lack of standard treatment regimen and poor efficacy of traditional chemotherapy. Therefore, finding new and more effective therapeutic targets to improve the efficacy of PTCL is an urgent clinical problem. In recent years, as the exploration of PTCL at the genetic and molecular levels has intensified, novel therapeutic targets based on gene alterations and molecular typing have been identified. This article summarizes the research progress of main gene alterations and molecular typing of PTCL in recent years.
ABSTRACT
Objective:To learn about the genotyping of human Brucella isolated from Sichuan Province. Methods:BCSP31-PCR and AMOS-PCR were used to identify the genus and biotype of the 66 strains isolated from confirmed human brucellosis cases in Sichuan Province from 2014 to 2020, respectively. The isolated strains were genotyped by multi-locus sequence typing (MLST)-9. The sequence type (ST) was compared trough the online MLST database. A minimum spanning tree (MST) was constructed to cluster the newly discovered and known ST using the BioNumerics software version 7.6.Results:The 66 strains isolated from human cases of brucellosis in Sichuan Province from 2014 to 2020 were Brucella, and 65 of them were Brucella melitensis while one strain was Brucella abortus. The MLST method identified three known STs (ST-8, ST-39 and ST-2) and one newly type (ST-101). Among them, ST-8 was the main ST in Sichuan Province (90.91%, 60/66), another 4 strains of Brucella melitensis were ST-39, and 1 strain of Brucella abortus was ST-2. The newly type ST-101 was isolated from Leshan City in 2019, belonging to the Brucella melitensis and closely related to the evolution of ST-8. Conclusion:Brucella melitensis is the main epidemic Brucella strain in Sichuan Province, ST-8 is predominant genotype, with a small amount of ST-39, ST-101 and ST-2.
ABSTRACT
Objective:To investigate the value of qualitative characteristics of contrast-enhanced ultrasound (CEUS) and VueBox quantitative parameters in the evaluation of pathological molecular typing of breast cancer.Methods:A retrospective analysis was performed on 133 patients with pathologically confirmed breast cancer who underwent CEUS examination in the People′s Hospital of Guangxi Zhuang Autonomous Region from January 2020 to July 2022. The patients were divided into Luminal A type, Luminal B type, human epidermal growth factor receptor-2(HER-2) type and triple negative type according to the results of immunohistochemistry. The differences of qualitative characteristics and quantitative parameters of CEUS in different molecular subtypes of breast cancer were analyzed. The ROC curve was used to evaluate the diagnostic efficacy of CEUS in the differentiation of molecular subtypes of breast cancer.Results:There were significant differences in enhancement intensity, post-enhancement boundary, filling defect and peripheral radial convergence among different molecular subtypes of breast cancer(all P<0.05), while there was no significant difference in enhancement uniformity ( P>0.05). Peak enhancement (PE), wash-in and wash-out areas under the curve (WiWoAUC), and wash-in ratio (WiR) of HER-2 type and triple-negative type breast cancer were higher than Luminal A type and Luminal B type (all P<0.05). ROC curve analysis showed that PE and radial convergence had reasonable diagnostic efficiency in Luminal A type, and the areas under the curve were 0.849 and 0.780, sensitivity was 0.711 and 0.889, specificity was 0.909 and 0.671, accuracy was 0.842 and 0.744, respectively. The areas under the curve of PE in diagnosing Luminal B type was 0.852, the sensitivity, specificity, and accuracy were 0.825, 0.763 and 0.782, respectively. The area under the curve of WiWoAUC and filling defect in diagnosing HER-2 type were 0.912 and 0.898, the sensitivity was 0.903 and 0.903, the specificity was 0.853 and 0.892, and the accuracy was 0.865 and 0.895, respectively. The area under the curve of clear boundary after enhancement in diagnosing triple negative type was 0.919, and the sensitivity, specificity and accuracy were 0.941, 0.897 and 0.902, respectively. Conclusions:There are differences in the qualitative characteristics and quantitative parameters of contrast-enhanced ultrasound in different molecular types of breast cancer. CEUS is suggested as a noninvasive modality for preoperative prediction of molecular subtypes of breast cancer.
ABSTRACT
The incidence of breast cancer currently ranks first among malignant tumors in women.Breast cancer exhibits high heterogeneity and can be classified into four molecular subtypes:luminal A,luminal B,human epidermal growth factor receptor 2(HER2)overexpression and triple-negative.However,previous molecular subtype classifications have limited treatment options for patients with HER2 low expression.In recent years,with the rapid development of antibody-drug conjugates(ADCs),new treatment options have emerged for breast cancer patients with HER2 low expression.This has also led to updates in the criteria for determining HER2 expression status in both domestic and international guidelines,based on immunohistochemistry(IHC)and in situ hybridization(ISH)testing,categorizing HER2 expression as HER2-positive(IHC 3+ or IHC 2+/ISH+),HER2 low expression(IHC 1+ or IHC 2+/ISH-),and HER2-negative(IHC 0).ADCs are immunotherapeutics composed of a linker that conjugates a monoclonal antibody with a cytotoxic payload.In the field of breast cancer,several large clinical trials have demonstrated clinical benefits of ADCs targeting HER2,such as trastuzumab emtansine(T-DM1),trastuzumab deruxtecan(T-DXd)and sacituzumab govitecan targeting trophoblast cell surface antigen 2(TROP2),in various molecular subtypes of breast cancer.With the phaseⅢ DESTINY-Breast03 trial and others,T-DXd has been found to have superior efficacy compared to T-DM1 in advanced HER2-positive breast cancer patients(approximately two times higher complete response rate,and four times longer median progression-free survival).T-DXd has now replaced T-DM1 as the recommended second-line therapy for HER2-positive breast cancer and as a second-line treatment option after local treatment for brain metastasis.The phase Ⅲ DESTINY-Breast04 trial confirmed that breast cancer patients with HER2 low expression can also benefit from T-DXd,further reshaping the treatment landscape for advanced breast cancer and supporting the need to redefine molecular subtypes of HER2-negative breast cancer.The phase Ⅲ ASCENT trial demonstrated that sacituzumab govitecan significantly improved survival and quality of life in triple-negative breast cancer(TNBC)patients,and the phase Ⅱ NeoSTAR study suggested its potential as neoadjuvant therapy in TNBC.Based on evidence,T-DM1,T-DXd and sacituzumab govitecan have been approved for marketing in both foreign and Chinese markets.Other ADC drugs,such as HER3-DXd,Dato-DXd and China-developed RC48,are also undergoing extensive clinical trials in the field of breast cancer and other tumors.Furthermore,there are several other ADCs targeting different molecular targets in active development.This article aimed to review the new advances related to ADCs therapy for breast cancer patients with different molecular subtypes and discuss the clinical application value of ADCs in breast cancer.
ABSTRACT
ObjectiveTo understand the presence of virulence genes， molecular typing characteristics， and antibiotic sensitivity of enteroaggregative Escherichia coli （EAEC） in children with diarrhea in Shanghai， so as to provide a scientific basis for EAEC monitoring and standardized treatment of EAEC infection. MethodsEAEC strains isolated from children （≤5 years old） with diarrhea in six districts of Shanghai were collected as the study subjects. EAEC virulence genes were detected by real-time fluorescence quantitative PCR， molecular typing was performed by pulsed-field gel electrophoresis （PFGE）， and drug susceptibility tests were conducted using the microbroth dilution method. χ2 test and two independent samples t-test were used to compare the differences in virulence genes and antibiotic resistance between suburban and urban EAEC strains. ResultsFrom 2019 to 2021， the overall detection rates of gene aggR， pic and astA of 59 EAEC were 30.5%， 50.8%， and 57.6%， respectively. There was no significant difference in the detection rates of virulence genes between suburban and urban EAEC strains （P>0.05）. PFGE analysis revealed that only two EAEC strains belonged to the same PFGE pattern and were collected from the same hospital， and the overall PFGE patterns were polymorphic. EAEC showed susceptibility to imipenem and colistin E， and the resistance rates to sulfamethoxazole （SXT）， ampicillin （AMP）， nalidixic acid （NAL）， and tetracycline （93.1%， 79.3%， 63.8%， and 58.6%， respectively） were higher than 50.0%. The antibiotic resistance rates of cefazolin （CFZ）， cefotaxime （CTX）， and ciprofloxacin （CIP） were significantly different between EAEC strains from suburban and urban areas （P<0.05）. A total of 47 strains exhibited multi-drug resistance， with the most common resistance spectrum being AMP-SXT-NAL. There was no statistically significant difference in the number of multidrug-resistant EAEC strains between suburban and urban areas （P>0.05）. ConclusionThe EAEC virulence gene assemblages in children with diarrhea in the six districts of Shanghai are diverse， and the molecular typing patterns are relatively scattered， indicating possible cross-infection of homologous strains. Multi-drug resistance in EAEC strains is relatively common， and there is a statistically significant difference in the resistance rates of CFZ， CTX and CIP between urban and suburban EAEC strains. Attention should be given to standardizing the use of clinical antibiotics to effectively control the dissemination of multidrug-resistant EAEC strains.
ABSTRACT
ObjectiveIn this paper， the cause of an outbreak of foodborne disease in Huzhou City was analyzed， which may help avoid the recurrence of such incidents. MethodsThrough the field epidemiological investigation， the case definition was formulated and the questionnaire survey was carried out in the case group and the control group. In addition， the chi-square test and logistic regression method were used to identify the factors affecting the outbreak. The patient stool samples， food samples， environmental samples and water samples were collected and used for the laboratory test. The PFGE molecular typing was conducted on the isolated positive strains. ResultsThe number of people exposed during the same period was 410， and the number of possible cases was 18， with an incidence of 4.39%. Generally， the main symptoms were abdominal pain and diarrhea， accompanied by nausea， fatigue， fever and others. For case-control analysis， 17 of the 18 patients were included in the case group， and 19 non-patients were into control group. The results suggested that the risk factors were blanched deep-water shrimp（OR=19.42， 95%CI=1.06‒357.02， P=0.046）and steamed Ao Long （Australian lobster） with garlic and vermicelli （OR=22.01， 95%CI=1.24‒390.70， P=0.035）. According to the laboratory test results Vibrio parahaemolyticus （VP） was positive in 5 cases， and the serum type was is O10∶K4. In the reserved food， VP was positive in the samples of steamed Australian lobster with garlic vermicelli and lamb chops. The serum type was O5∶Kut. ConclusionThis incident was an outbreak of foodborne disease caused by the consumption of wedding food contaminated by VP. The dinner was served by Hotel B on September 17. Moreover， the suspicious foods include the blanched deep-water shrimp and steamed lobster with garlic vermicelli.
ABSTRACT
@#Abstract: Objective To understand the contamination status, drug resistance, virulence gene carrying status, and molecular typing characteristics of Vibrio parahaemolyticus (VP) in aquatic products sold in Nanchang City. Methods A total of 170 commercial crayfishes, freshwater fish frogs and related smears samples were collected from various farmers' markets in Nanchang from March to September 2021. The strains of V. parahaemolyticus were detected and isolated from the samples. Antibiotic resistance test, virulence gene test, and pulsed-field gel electrophoresis (PFGE) molecular typing analysis were carried out. Results Among the collected samples, V.parahaemolyticus was only isolated from crayfish and crayfish smear samples, with a total of 35 strains of VP isolated. No V.parahaemolyticus strain was isolated from other freshwater fish, frogs, and their smear samples. Among the 17 common antibiotics tested, only two trains showed resistance to ampicillin, and one strain to streptomycin, , and all were sensitive to other antibiotics; all 35 strains of V. parahaemolyticus carried the gene, but only one strain carried the heat-resistant related hemolysin gene trh, and no direct heat-resistant hemolysin gene tdh positive strain was found; PFGE pattern clustering showed that there was no strain with the same PFGE pattern, and there was no obvious dominant cluster among these strains, and their genetic relationship was relatively distant. Conclusions The contamination of V. parahaemolyticus in small and medium-sized crayfish sold in the market in Nanchang City is relatively serious. The V. parahaemolyticus isolates in these polluted crayfish generally do not carry key virulence genes such as tdh, are sensitive to common antibiotics, and only have low-level resistance to ampicillin and streptomycin. PFGE pattern clustering showed that V. parahaemolyticus does not have no obvious dominant cluster, and these strains have rich genetic diversity, indicating that they may have different sources.
ABSTRACT
This study explored three molecular typing methods for Vibrio parahaemolyticus(VP)in Liaoning Province in 2020,to assess the correlation among the three methods and the genetic relationships among between strains;analyze the epi-demic trends and distribution patterns of VPin Liaoning Province;and provide reliable technical support for the prevention and control of foodborne diseases.Serum typing,PFGE,REP-PCR,and ERIC-PCR molecular typing and cluster analysis were performed on 44 VP isolates from Liaoning Province in 2020.A total of 44 isolated strains were divided into 15 serotypes,and 8 isolated strains could not be classified.The serotypes were primarily O3 group,O1 group,and O2 group.Clinical isolates had high molecular similarity,whereas food isolates had low molecular similarity.The resolution(DI)of PFGE was 0.986,that of REP-PCR was 0.947,and that of ERIC-PCR was 0.935.The molecular similarity between serotype O3 and O1 group strains was high.The epidemic serotypes of isolated VP strains in Liaoning Province in 2020 were consistent with those from the past 5 years.The resolution of the PFGE typing method was better than that of REP-PCR and ERIC-PCR;moreover,REP-PCR had better resolution than ERIC-PCR.These three typing methods showed good intercorrelation.The O3 group strains are likely to originate from the O1 group strains.When a foodborne disease outbreak is caused by VP,laboratories with conditions can apply these three methods to trace the source of the pathogenic bacteriaquickly and effectively.
ABSTRACT
Single nucleotide polymorphisms(SNPs),third generation molecular genetic markers,have attracted extensive attention because of their importance in research on genetic diseases,gene evolution,adaptation,species,medicine and other fields.SNPs are found in large numbers,with a wide distribution,stable genetics and high throughput.Moreover,SNPs are suitable for rapid and large-scale screening.These genetic markers have been widely used in molecular typing for a variety of bacteria.Herein,the current status of SNP technology is discussed and compared with other typing methods,and its applica-tions in bacterial molecular typing are reviewed.
ABSTRACT
MicroRNA (miRNA) plays an important role in the development of diffuse large B-cell lymphoma (DLBCL) by binding to the 3′ non-coding region of the target gene mRNA to regulate gene expression after transcription. The expression level of miRNA is closely related to the clinical staging, typing, prognosis assessment, and therapeutic effect of DLBCL. miRNA has a great potential as that of DLBCL-related biomarkers, and because of the close link between the two, miRNA-based therapies are expected to lead to new treatment options for DLBCL patients.
ABSTRACT
Molecular typing of leukemia is the basis of risk assessment and treatment options. NUTM1 gene (15q14) rearrangement is a novel molecular type of acute B lymphoblastic leukemia (B-ALL), which is mainly found in children (≥1 year old) and infants (< 1 year old). The number of patients is slightly more in children than infants. However, in infantile ALL, NUTM1 rearrangement is the second most common molecular abnormality. These children respond well to conventional chemotherapy regimens and with a good prognosis. The number of leukemia patients with NUTM1 gene rearrangement is still small, and there is no relevant study or case report in China. NUT protein encoded by NUTM1 gene is a chromatin regulator, which is related to histone acetylation regulation and chromatin remodeling. This article aims to introduce the clinicopathological features, detection methods, possible tumorigenic mechanisms and therapeutic prospects of leukemia with NUTM1 gene rearrangement, to increase the understanding of this type of leukemia and provide reference for the precise molecular subtyping and treatment.
ABSTRACT
Endometrial cancer has been identified by The Cancer Genome Atlas program with four molecular subtypes by genome sequence analysis. Clinical trials to select suitable immunotherapeutic agents based on the different immune characteristics of each subtype have been conducted in several countries and have made important progress. The main clinical applications of immune checkpoint inhibitors include anti-programmed cell death protein-1/programmed death-ligand 1 antibodies and poly ADP-ribose polymerase inhibitors. Optimizing drug selection and drug combination based on the target characteristics of different immune checkpoint inhibitors may provide new opportunities for immunotherapy of endometrial cancer and bring new light to improve survival rates.
ABSTRACT
Objective:To determine the molecular characteristics of Streptococcus suis type 2 (SS2) in Zhejiang Province. Methods:Twenty-nine SS2 sporadic human isolates in Zhejiang Province from Januery 2005 to July 2021 were genotyped by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and minimum core genome (MCG) sequence typing.Results:Among 29 strains, 10 PFGE patterns and three main clusters were obtained by PFGE. Twenty-one (72.41%) of the strains were divided into two main branch groups and the remaining eight (27.59%) showed genetic diversity with the similarity ranging from 49.7% to 94.7%. Three sequence types were obtained from 29 strains by MLST, including ST7 (86.21%(25/29)), ST1 (10.34%(3/29)) and ST25 (3.45%(1/29)). In addition, three genotypes were obtained from 29 strains by MCG, including genotype E (41.38%(12/29)), genotype group 1 (55.17%(16/29)) and genotype group 4 (3.45%(1/29)).Conclusions:Two large clonal groups of highly pathogenic strains of SS2 have been prevalent in Zhejiang Province. A few strains display genetic diversity, indicating genetic variation may exist during transmission.
ABSTRACT
Objective:Analysis of the antibiotic resistance profiles and molecular typing of Salmonella typhimurium ( S. typhimurium) isolated in Wuxi city from 2011 to 2018. Methods:A total of 109 S. typhimurium isolates were detected from different types monitoring samples in Wuxi city from 2011 to 2018. Microbroth dilution method was used to test antimicrobial susceptibility of S. typhimurium for 17 antimicrobial agents. Pulsed field gel electrophoresis (PFGE) was used to conduct molecular typing. Statistical analysis was carried out using Chi-square test. Results:Tetracycline-resistance and ampicillin-resistance were most frequency in 109 S. typhimurium isolates, 69.72% (76/109) and 68.81% (75/109), respectively. For compound sulfamethoxazole, chloramphenicol, ciprofloxacin, ampicillin/sulbactam, azithromycin, nitrofurantoin, cefotaxime and aztreonam, the resistance rates were 23.85%(26/109), 22.02%(24/109), 11.93%(13/109), 4.59%(5/109), 3.67%(4/109), 3.67%(4/109), 0.92%(1/109), 0.92%(1/109), respectively. All isolates were susceptible to amikacin, ertapenem, imipenem, meropenem, ceftazidime and ceftazidime-avibactam. Azithromycin-resistance isolates were decreasing year by year gradually. The aztreonam and cefotaxime-resistant isolates were found since 2018, while chloramphenicol and compound sulfa-resistant isolates showed upward trend simultaneously. Conclusions:S. typhimurium in Wuxi city exhibited highly resistant to tetracycline and ampicillin. The significant variability existed between genotype and phenotype of S. typhimurium.
ABSTRACT
ObjectiveTo determine the pathogenic cause in a foodborne diseases outbreak of Salmonella enteritidis in a company in Suzhou City， and provide evidence for epidemiological investigation and guidance for clinical treatment. MethodsRelevant specimens were examined for Salmonella， Shigella， Staphylococcus aureus and Vibrio parahaemolyticus. Furthermore， for the isolated Salmonella enteritidis， a micro broth dilution method was used for antimicrobial susceptibility testing， and pulsed field gel electrophoresis （PFGE） was used for molecular typing. ResultsA total of 44 strains of Salmonella enteritidis were detected from 43 anal swabs of the patients in the outbreak， 7 anal swabs of canteen employees， 31 retained food specimens and 6 environmental specimens. A total of 15 antimicrobial susceptibility testings showed that the 44 strains had the same antimicrobial resistance spectrum， which was 100% resistant to cefazolin， ampicillin， ampicillin/sulbactam， polymyxin E and nalidixic acid， suggesting a multi-drug resistance to more than three antibiotics. PFGE cluster analysis showed that the 44 strains had a 100% of genetic similarity. ConclusionThe outbreak is caused by the consumption of food contaminated with Salmonella enteritidis. The isolated strains have multi-drug resistance， which could guide appropriate antimicrobial treatment based on the antimicrobial susceptibility testing.
ABSTRACT
Objective:To investigate the molecular epidemiological characteristics and antibiotic resistance of Clostridioides difficile ( Cd) in hospitalized diarrhea patients in a tertiary hospital in Shaanxi Province. Methods:This study collected 425 stool samples of hospitalized diarrhea patients from October 2018 to December 2021 for isolation and identification of Cd. Toxin genes carried by the isolates were detected. Multilocus sequence typing (MLST) was performed to analyze the phylogenetic profile. Antibiotic susceptibility was analyzed by E-test. Results:Forty-nine strains of Cd were isolated from the 425 samples, including 37 strains of toxigenic Cd (75.5%, 37/49). The detection rate of Cd was 14.0% (25/179) in diarrhea patients aged ≥65 years old and 36.4% (4/11) in Nephrology Department. In the 37 toxigenic Cd strains, A -B + CDT -Cd, A + B + CDT -Cd and A + B + CDT +Cd accounted for 18.9% (7/37), 78.4% (29/37) and 2.7% (1/37), respectively. There were 24 ST types, among which ST2, ST3 and ST54 were the predominant types, each accounting for 12.2% (6/49). All strains were sensitive to metronidazole and vancomycin, with a high resistance rate of 93.9% (46/49) to ciprofloxacin and a low resistance rate of 12.2% (6/49) and 10.2% (5/49) to rifampicin and meropenem, respectively. Conclusions:The main type of toxigenic strains was A + B + CDT -. ST2, ST3 and ST54 were the predominant types and the distribution of ST types was scattered. All isolates were sensitive to metronidazole and vancomycin and most of them were resistant to ciprofloxacin.