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Abstract We subtyped 32 Salmonella enterica strains isolated from carcasses (n = 10), theenvironment (n = 14), head meat (n = 1) and viscera washing and chilling water (n = 7) in provin-cial abattoirs with no Hazard Analysis Critical Control Point (HACCP) system from Buenos Aires,Argentina, before and after implementing improvement actions. Pulsed-field gel electrophore-sis (PFGE) was carried out using the XbaI restriction enzyme. Strains belonged to six serovars,from which 10 restriction patterns were obtained (five unique patterns and five clusters). Wefound different clones of S. enterica serovars in the same abattoir by XbaI-PFGE. In addition topromoting good hygiene practices, the implementation of an HACCP plan is necessary to meetthe zero-tolerance criteria for Salmonella on beef.
Resumen Subtipificamos en total 32 cepas de Salmonella enterica aisladas de carcasas(n = 10), medio ambiente (n = 14), carne de cabeza (n = 1) y agua de lavado y enfriamientode vísceras (n = 7) en frigoríficos provinciales de Buenos Aires (Argentina) sin análisis de peli-gros y puntos críticos de control (hazard analysis critical control point [HACCP]); la toma demuestras se efectuó antes y después de implementar acciones de mejora. Se llevó a cabo elec-troforesis en gel de campo pulsado (PFGE) utilizando la enzima de restricción XbaI. Las cepaspertenecían a 6 serovares y presentaron 10 patrones de restricción (5 patrones únicos y 5 clus-ters). Demostramos la presencia de diferentes serovares de S. enterica en un mismo frigorífico.
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Small cell lung cancer accounts for about 15% of all lung cancers, and is a highly invasive neuroendocrine tumor. smoking is a major risk factor. SCLC grows rapidly, has a high metastasis rate and has a poor prognosis. For more than 30 years, the treatment of SCLC has progressed slowly, until the emergence of immunodrugs in recent years, which have achieved certain efficacy in a wide range of patients.
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Prostate cancer (PCa) exhibits epidemiological and molecular heterogeneity. Despite extensive studies of its phenotypic and genetic properties in Western populations, its molecular basis is not clear in Chinese patients. To determine critical molecular characteristics and explore correlations between genomic markers and clinical parameters in Chinese populations, we applied an integrative genetic/transcriptomic assay that combines targeted next-generation sequencing and quantitative real-time PCR (qRT-PCR) on samples from 46 Chinese patients with PCa. Lysine (K)-specific methyltransferase 2D (KMT2D), zinc finger homeobox 3 (ZFHX3), A-kinase anchoring protein 9 (AKAP9), and GLI family zinc finger 1 (GLI1) were frequently mutated in our cohort. Moreover, a clinicopathological analysis showed that RB transcriptional corepressor 1 (RB1) deletion was common in patients with a high risk of disease progression. Remarkably, four genomic events, MYC proto-oncogene (MYC) amplification, RB1 deletion, APC regulator of WNT signaling pathway (APC) mutation or deletion, and cyclin-dependent kinase 12 (CDK12) mutation, were correlated with poor disease-free survival. In addition, a close link between KMT2D expression and the androgen receptor (AR) signaling pathway was observed both in our cohort and in The Cancer Genome Atlas Prostate Adenocarcinoma (TCGA-PRAD) data. In summary, our results demonstrate the feasibility and benefits of integrative molecular characterization of PCa samples in disease pathology research and personalized medicine.
Subject(s)
Adult , Aged , Humans , Male , Middle Aged , A Kinase Anchor Proteins/genetics , Biomarkers, Tumor/genetics , China , Cytoskeletal Proteins/genetics , DNA-Binding Proteins/genetics , Gene Amplification , High-Throughput Nucleotide Sequencing , Homeodomain Proteins/genetics , Mutation , Neoplasm Proteins/genetics , Prostatic Neoplasms/pathology , Proto-Oncogene Mas , Receptors, Androgen/genetics , Signal Transduction/genetics , Zinc Finger Protein GLI1/geneticsABSTRACT
Prostate cancer (PCa) exhibits epidemiological and molecular heterogeneity. Despite extensive studies of its phenotypic and genetic properties in Western populations, its molecular basis is not clear in Chinese patients. To determine critical molecular characteristics and explore correlations between genomic markers and clinical parameters in Chinese populations, we applied an integrative genetic/transcriptomic assay that combines targeted next-generation sequencing and quantitative real-time PCR (qRT-PCR) on samples from 46 Chinese patients with PCa. Lysine (K)-specific methyltransferase 2D (KMT2D), zinc finger homeobox 3 (ZFHX3), A-kinase anchoring protein 9 (AKAP9), and GLI family zinc finger 1 (GLI1) were frequently mutated in our cohort. Moreover, a clinicopathological analysis showed that RB transcriptional corepressor 1 (RB1) deletion was common in patients with a high risk of disease progression. Remarkably, four genomic events, MYC proto-oncogene (MYC) amplification, RB1 deletion, APC regulator of WNT signaling pathway (APC) mutation or deletion, and cyclin-dependent kinase 12 (CDK12) mutation, were correlated with poor disease-free survival. In addition, a close link between KMT2D expression and the androgen receptor (AR) signaling pathway was observed both in our cohort and in The Cancer Genome Atlas Prostate Adenocarcinoma (TCGA-PRAD) data. In summary, our results demonstrate the feasibility and benefits of integrative molecular characterization of PCa samples in disease pathology research and personalized medicine.
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Intratumor heterogeneity within a single tumor mass is one of the hallmarks of malignancy and has been reported in various tumor types. The molecular characterization of intratumor heterogeneity in breast cancer is a significant challenge for effective treatment. Using single-cell RNA sequencing (RNA-seq) data from a public resource, an ERBB pathway activated triple-negative cell population was identified. The differential expression of three subtyping marker genes (ERBB2, ESR1, and PGR) was not changed in the bulk RNA-seq data, but the single-cell transcriptomes showed intratumor heterogeneity. This result shows that ERBB signaling is activated using an indirect route and that the molecular subtype is changed on a single-cell level. Our data propose a different view on breast cancer subtypes, clarifying much confusion in this field and contributing to precision medicine.
Subject(s)
Breast Neoplasms , Population Characteristics , Precision Medicine , Sequence Analysis, RNA , Transcriptome , Triple Negative Breast NeoplasmsABSTRACT
Objective: To investigate the correlations between parameters of histograms of the apparent diffusion coefficient (ADC) with multi-b-value diffusion-weighted imaging (DWI) at 3.0T MRI and prognostic factors and molecular subtypes of breast cancer, to evaluate the diagnostic performance of ADC histograms at different b values. Methods: A total of 114 patients (116 lesions) with inva-sive ductal carcinomas confirmed by surgical pathology who underwent breast magnetic resonance imaging from March 2015 to Janu-ary 2016 in Tianjin Medical University Cancer Institute and Hospital were analyzed retrospectively. The histograms of ADC with b val-ues of 0, 500, 800, 1000, and 1,500 s/mm2 were generated using Image J software. Various parameters were calculated: for example, the minimum, mean, mode, skewness, and kurtosis. Different groups were based on the molecular subtypes, tumor size (T1 vs . T2-3), histologic grade (high vs. low), and lymph node status (positive vs. negative) that were recorded. Mann-Whitney U tests were used to compare the differences in ADC histogram parameters between two different groups. Receiver operating characteristic curves (ROC) were constructed. Results: The skewness was lower in Luminal tumors than that in non-Luminal tumors with b values of 500, 800, 1, 000, and 1,500s/mm2 (P<0.05). The ADCmin was higher in human epidermal growth factor receptor-2 (HER-2) over-expression than in non-HER-2 over-expression (P<0.05). The kurtosis was lower in stage T1 tumors than stage T2-3 tumors (P<0.05), and kurtosis was cor-related with tumor size (P<0.05). ADCmode and ADCmean were different between different histological subtypes with a b value of 500 s/mm2 (P<0.05). Under different b values, there were no significant differences in terms of areas under the curve for each histogram pa-rameter, which had statistically significant differences (P>0.05). Conclusions: Multi-b-value DWI ADC histogram analysis, as a quantita- tive method to characterize tumor heterogeneity, can reflect the biological behavior and prognosis of breast cancer to some extent, and the diagnostic performance of ADC histograms showed no significant differences in differentiating molecular types and prognostic factors of breast cancer at different b values.
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The breast cancer is a usual and serious malignant tumor which threatens the women′s health.Molecular subtyping bases on the molecular level, and provides a new classification method for the breast cancer pathology classification, and plays an important guidance significance for the clinical treatment.At present, the breast cancer molecular subtyping is mainly divided into the following subtypes: the Luminal A type and Luminal B type, HER-2 overexpression and the triple negative breast cancer.Different molecular subtyping has different characteristics in treatment reaction, prognosis and the clinical application situation.
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IN post-human genomic era, the concept of precision medicine has provided opportunities for “reinterpretation” and “new orientation” for cancer therapy including prostate cancer. Prostate cancer is the leading cause of cancer-related death in men, and its traditional treatment meets bottleneck and needs broken through, while the concept of precision medicine is starting to have positive effect. Precision medicine has potential values in optimizing the clinical reclassification of patients, androgen deprivation therapy (ADT), chemotherapy, and radiation therapy strategies for prostate cancer. When traditional treatment of prostate cancer gradually loses efficacy, the prostate cancer molecular subtyping map and the development of targeted therapies are expected to bring new breakthrough. At the same time, precision medicine also prompts new therapeutic concepts for prostate cancer, such as reconstruction of the immune environment, tumor-specific neoantigens prediction, and organoid culture system. The future of precision medicine has been widely embraced and it will have promising application in the diagnosis and treatment of prostate cancer. However, currently the benefit of precision treatment of cancer is still far below the public expectations. Like for many emerging concepts, the potentially huge market behind precision medicine inevitably breeds overheated commercial propaganda. Full communication and cooperation of scientific researchers with clinical doctors and patients, and standardization and guidance of health administration are the keys to ensure that precision medicine benefits for human health.
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Translational medicine is characterized by its close association with precision medicine in the field of colorectal cancer.In particular,the studies of life histology promote the prevention and treatment of colorectal cancer entered the stage of precision medicine.Accurate molecular typing of colorectal cancer has been used to guide clinical practice is an important breakthrough in the field of colorectal cancer translational medicine in recent years,and its clinical value has been verified.As an important tool for the effective integration of clinical data and life histology data,the biomedical big data platform is expected to contribute to the continued breakthrough of translational medicine in precision molecular typing.New treatment methods,such as liquid biopsy technology with non-invasive,flexible features can be dynamically detected as soon as possible to find the state of somatic mutations.Among them,circulating tumor DNA has a good detection sensitivity and specificity,highlighting the value of early recurrence monitoring.In addition,new therapeutic strategies,such as immunological checkpoints and chimeric antigen receptor genetically modified T-cell therapy,are under intense study in the field of colorectal cancer.Based on the biomedical big data analysis in the context of the precise molecular typing,dynamic liquid biopsy monitoring technology,new immunotherapy and other fields will be the future of colorectal cancer translational medicine research hot and breakthrough direction.
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Objective:To investigate the prognostic value of estrogen receptor (ER), progesterone receptor (PR), and Ki-67 in breast can-cer patients receiving neoadjuvant chemotherapy (NAC) and explore the association of chemotherapy regimens and cycles with the outcome of NAC. Methods:Clinical data of cancer patients receiving NAC were retrospectively analyzed. All the patients were admit-ted in Tianjin Medical University Cancer Institute and Hospital from January 2015 to December 2015. All statistical analyses were per-formed using SPSS version 19.0. The relationship among the outcome of NAC, molecular subtype, expression levels of ER, PR, and Ki-67, and chemotherapy regimens and cycles was investigated. Results:Only five HER-2(+) patients accepted the addition of trastuzum-ab in treatment, and few cases were excluded from the statistical analysis based on the effect of chemotherapy regimens. The effec-tiveness of NAC was positively correlated with the expression of Ki-67 whereas negatively correlated with the expression levels of ER and PR (P<0.05). In patients receiving NAC, the patients with Luminal subtype had worse outcome than those with non-Luminal sub-type (P=0.033). The invalid efficacy of pathologic evaluations of Luminal and non-Luminal NAC were 10.1%and 1.3%, respectively. No significant difference was found in the outcome among patients receiving TE, TEC, or EC-T;however, patients who received more than four cycles of NAC had better outcome than others (P=0.016). The outcome was statistically significant when the cut-off value of Ki-67 was 25%. Conclusion:Ki-67 proliferative index could be used as a prognostic marker to NAC in breast cancer patients. The cut-off value of Ki-67 should be determined on the basis of the data of each cancer patient. The curative effect of NAC was poor, and Luminal pa-tients with chemotherapy were insensitive and could be considered for surgical treatment. Patients who received less than four cycles of NAC had worse outcome than others, and prompt NAC foot treatment could improve the efficiency.
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Purpose To detect the expression of CD90 in invasive ductal breast carcinoma with different molecular subtypes and to explore its clinical significance.Methods The expression of CD90,ER,PR,Ki-67 and HER-2 were detected in 80 cases of invasive ductal breast carcinoma tissue and 20 cases of breast benign lesion with immunohistochemical method.The relationship between CD90 and clinicopathological parameters were analyzed.Results The positive expression rate of CD90 in invasive ductal breast carcinoma and breast benign lesion tissues were 62.5％ and 20.0％,respectively (P ＜0.001).The expression of CD90 in invasive ductal breast carcinoma was correlated with lymph node metastasis (P ＜ 0.05),but not with age,tumor size,TNM staging and histological grade (P ＞ 0.05).Among different molecular subtypes,CD90 expression level in Luminal A type was the lowest (40.0％),and the level in triple negative type was the highest (82.4％) (P ＜0.05).CD90 expression level was negatively correlated with ER (r=-0.342,P＜0.05) orPR (r=-0.374,P＜0.05) expression level,but not with Ki-67 (r =0.084,P ＞ 0.05).Condusion The over-expression of CD90 is related with molecular subtypes of breast carcinoma,and its high expression suggests a poor prognosis.
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With the advance of genomics research, there have been a new breakthrough in the molecular classification of gliomas. Glioblastoma (WHO grade Ⅳ) could be subtyped to proneural, neural, classical, and mesochymal according to the mRNA expression. Lower grade gliomas (WHO grade Ⅱ and Ⅲ) could be divided into 5 types using 1p/19q co-deletion, isocitrate dehydrogenase(IDH) mutation, and TERTp (promotor region) mutation. In 2016, a new classification of tumors of the central nervous system was proposed, and some new markers such as IDH1 mutation were introduced into the diagnosis of gliomas. Genotype and phenotype were integrated to diagnose gliomas. In the meantime, precision treatment for gliomas has also been vigorously developed. This article reviewed recent studies on the molecular diagnosis, precise chemotherapy, targeted therapy, and immunotherapy for gliomas to provide new ideas and strategies for precise diagnosis and treatment of gliomas.
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Triple-negative breast cancer (TNBC) is a heterogeneous disease. Recently, the development of a gene expression profile fa-cilitated the re-classification of TNBC into six new subtypes, which show varied sensitivities to different therapies. In the era of preci-sion medicine, precision therapy may be directed at various potentially actionable molecular mutations in different subtypes of TNBC.
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Objective ] To study the molecular characteristics and antibiotic resistance of Salmonella diarrhea cases in sentinel hospitals through active surveillance system conducted by public health laboratory. [ Methods] Two sentinel hospitals were chosen for collection of stool specimens from food-borne infectious diarrhea cases and for Salmonella separation and detection immediately following serotyping and antimicrobial susceptible test ( AST ) on those isolates .Moreover , pulsed field gel electrophoresis ( PFGE) was used for the genetic homology analysis . [ Results] A total of 2 579 diarrhea specimens were collected and analyzed from 2010 to 2012, with 185 Salmonella isolates, covering 23 different serotypes (annual positive rates were 9.1%, 6.8%, 5.1%, with an average 7.2%).Salmonella enterica serovar Enteritidis(S.Enteritidis) and Typhimurium(S.Typhimurium) were the most common serotypes, of which 68.9% cases were seen in those aged 21 to 60 and 21.4% cases in those over 60 years old. 27.7%-96.9%S.Enteritidis and 2.6%-63.2% S.Typhimurium(P all <0.05) proved resistant to Nalidixic acid, Sultisoxazole, Streptomycin, Sulfamethoxydiazine, Gentamicinand Tetracycline. PFGE analysis on 22 S.Enteritidis strains showed 11 different clusters , while 20 S.Typhimurium strians showed 6. [Conclusion] S.Enteritidis and S.Typhimurium are the most common Salmonella serotypes, and molecular typing indicates the existence of clustering and sporadic outbreaks caused by dominance clones . We should be alert to early warnings on potential outbreaks of multiple-drug-resistant ( MDR ) S.Enteritidis.Active surveillance system based on public health laboratory should play an important role in the control of food-borne infectious diseases .
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To establish a new method for PFGE fingerprint analysis , which is easy-to-operate , inexpensive , software-low-dependent and readily-exchangeable . [ Methods ] A group of 44 vibrio parahaemolyticus was subtyped according to PulseNet standardized PFGE protocol .The fingerprint was analyzed with new gel-partition bands counting method and BioNumerics clustering separately and then the results by the two methods were compared with type number , cluster number and Simpson ’ s Index of Diversity ( DI) . [ Results] The 44 isolates could be typed into 32 types and 5 clusters were found by gel-partition bands counting method ( DI=97.6%) .BioNumerics could type the same isolates into 29 types and 4 clusters were found ( DI=95.5%) .The difference in the ability of finding clusters between the two methods was not statistically significant . [ Conclusion] Gel-partition bands counting method is based on the bands distribution among finger print and greatly reduces the number of visually observed spectrum , which is easy-to-operate, inexpensive , software-low-dependent and readily-exchangeable .
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Triple negative breast cancer (TNBC) is characterized by the lack of expression of hormone receptors, as well as human epidermal growth factor receptor 2 and displays special biological and clinicopathological characteristics. This subtype is aggressive in nature with high histological grade. Besides invasive ductal carcinoma,several special histological types have also been found. The features of the TNBC subgroup roughly parallel those of the basal-like subgroup. Due to the lack of molecular targets, this subgroup has no chance of endocrine treatment and target therapy. Currently, the treatment of TNBC is dominated by chemotherapy based on anthracycline with suboptimal efficacy. Overall, the prognosis has remained quite poor. Emerging evidence indicates that patients regimens with triple negative breast cancer usually displays high rate of early recurrence and distant metastasis. Both the diseasefree survival and overall survival rates are low. Although this subtype which shows same immunohistologic pattern, great heterogeneity still exists within the group causing distinctions in morphology, prognosis, and more importantly, drastically different reactions to same treatment protocol. In recent years, TNBC has been widely concerned by both clinician and pathologist. Several targeted drugs for corresponding signal pathway as well as the subtype of triple negative breast cancer have been widely studied. This article focused on the advances in clinicopathological characteristics, new subtypes and treatment of triple negative breast cancer.
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Objective: The aim of this study was to explore the association of different molecular subtypes with the clinicopathologic features and the prognosis in breast cancer patients with axillary lymph node metastasis. Methods: The clinicopathologic information of 181 operable breast cancer patients with axillary lymph node metastasis was retrospectively analyzed. These patients were classified into different groups according to molecular subtyping. All patients were followed-up with a median of 58 months (range: 44-68 months). The multivariate analysis was performed to evaluate the prognostic indicators among the potential factors including age, primary tumor size, number of metastatic axillary lymph nodes and molecular subtype. Results: Of all 181 patients, 58.0% (105/181) were luminal subtype, 24.3% (44/181) were basal-like subtype, and 17.7% (32/181) were HER-2 overexpression subtype. HER-2 overexpression was closely associated with increased tumor size and more positive lymph nodes. The relapse rates of luminal, basal-like and HER-2 overexpression subtypes were 17.1% (18/105), 31.8% (14/44) and 37.5% (12/32), respectively (P = 0.026); the death rates of luminal, basal-like and HER-2 overexpression subtypes were 6.7% (7/105), 13.6% (6/44) and 18.8% (6/32), respectively (luminal vs non-luminal, P = 0.048). The five-year disease-free survival rate of patients with luminal subtype was much higher than those of the patients with HER-2 overexpression and basal-like subtypes (log-rank test, P = 0.025); the five-year overall survival rate of patients with luminal subtype was also much higher than that of patients with HER-2 overexpression subtype (log-rank test, P = 0.039). COX proportional hazards model revealed that primary tumor size and the number of metastatic axillary lymph nodes were both independent prognostic indicators (P > 0.05). Conclusion: In axillary lymph node-positive breast cancer patients not receiving targeted molecular therapy, the subtype of HER-2 overexpression has the worst prognosis while the subtype of luminal has the best. The primary tumor size and the number of metastatic axillary lymph nodes were both independent prognostic indicators for breast cancer patients. Copyright © 2013 by TUMOR.
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Objective To investigate the relationship between molecular subtypes of breast cancer and postoperative loco-regional recurrence (LR) in early breast cancer patients with 1-3 positive axillary lymph nodes (pN1) and to improve the individualized indications for post-mastectomy radiotherapy (PMRT)in these patients.Methods A total of 547 patients with pT1-2 N1M0 breast cancer,who received mastectomy between December 1998 and December 2009 in Sun Yat-sen University Cancer Center,were retrospectively analyzed.None of them received adjuvant radiotherapy after mastectomy.The patients were divided into luminal A group,luminal B group,HER-2-overexpressing group,and triple-negative group according to the molecular subtypes of breast cancer determined by immunohistochemistry and fluorescence in situ hybridization.The patients in different groups were compared in terms of LR rate (LRR) and LR-free survival (LRFS),and the risk factors for LR were analyzed in combination with clinical and pathological features.The Kaplan-Meier method was adopted to calculate LRR and LRFS;the Logrank test was used for survival difference analysis and univariate prognostic analysis.The Cox proportional hazards model was used for multivariate prognostic analysis.Results The luminal A group,luminal B group,HER-2-overexpressing group,and triple-negative group accounted for 30.0％,48.6％,9.3％,and 12.1％,respectively,of all the patients.The follow-up rate was 97.1％ ;334 patients were followed up for at least 5 years,and 127 were followed up for at least 10 years.Univariate analysis showed that,compared with the luminal A group,the HER-2-overexpressing group and triple-negative group had significantly higher 5-year LRRs (19.0％ vs 5.3％,x2 =4.28,P =0.026; 14.9％ vs 5.3％,x2 =5.02,P =0.015) and significantly lower LRFSs (73.5％ vs 91.1％,x2=7.27,P=0.005;80.6％ vs 91.1％,x2=4.77,P=0.021).Multivariate analysis revealed that HER-2 overexpression,triple-negative phenotype,age of ≤ 35 years,and stage pT2 were poor prognostic factors for survival (LRR and LRFS) (x2 =2.29,2.08,18.22,and 6.86,P =0.020,0.016,0.001,and 0.005;x2 =1.90,1.41,8.58,and 3.94,P=0.006,0.025,0.002,and 0.039).The 10-year LRRs of patients with 0,1,and ≥2 of the above risk factors were 4.3％,14.1％,and 31.9％,respectively (x2 =28.03,P =0.000).Conclusions Molecular subtyping is helpful for individualized evaluation of LR risk in early breast cancer patients with 1-3 positive axillary lymph nodes (pN1).PMRT should be recommended for the patients with 2 or more risk factors for LR.
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<p><b>OBJECTIVE</b>To optimize the performance of Pulsed-Field Gel Electrophoresis (PFGE) for the comparison of inter-laboratory results and information exchange of Borrelia burgdorferi subtyping.</p><p><b>METHODS</b>A panel of 34 strains of B. burgdorferi were used to optimize PFGE for subtyping. In order to optimize the electrophoretic parameters (EPs), all 34 strains of B. burgdorferi were analyzed using four EPs, yielding different Simpson diversity index (D) values and the epidemiological concordance was also evaluated.</p><p><b>RESULTS</b>The EP of a switch time of 1 s to 25 s for 13 h and 1 s to 10 s for 6 h produced the highest D value and was declared to be optimal for MluI and SmaI PFGE of B. burgdorferi. MluI and SmaI were selected as the first and second restriction enzymes for PFGE subtyping of B. burgdorferi according to discrimination and consistency with epidemiological data.</p><p><b>CONCLUSION</b>PFGE can be used as a valuable test for routine genospecies identification of B. burgdorferi.</p>
Subject(s)
Animals , Humans , Rats , Bacterial Proteins , Metabolism , Bacterial Typing Techniques , Borrelia burgdorferi , Classification , Genetics , DNA, Bacterial , Metabolism , Deoxyribonucleases, Type II Site-Specific , Metabolism , Electrophoresis, Gel, Pulsed-Field , IxodesABSTRACT
El objetivo de este trabajo fue confirmar por Electroforesis de Campo Electrico Pulsado (PFGE) que la Salmonella aislada del alimento implicado en el brote (queso blanco) fue la responsable del evento.La muestra de queso blanco presento elevado recuento de coliformes, E. coli y S. aureus,ademas, presencia de Salmo nella spp., lo que indico condiciones sanitarias inadecuadas y posible contaminacion de origen fecal. Para la confirmacion de las cepas sospechosas de Sal monella spp, aisladas de los pacientes y del alimento, se utilizaron tecnicas bioquimicas convencionales, la serotipificacion se realizo siguiendo el esquema de White-kauffmann-LeMinor y la sensibilidad a los antimicrobianos (Ampicilina, Trimetroprim-Sulfametoxazole, Ciprofloxacina, Amoxicilina, Ac.Clavulanico, Cloranfenicol, Ceftriaxone y Tetraciclina) por la tecnica kirby-Bauer. Las cepas bacterianas de Salmonella spp aisladas fueron identificadas como Salmonella Javiana [1,9,12:l, z28:1,5] y resultaron sensibles a todos los antibioticos probados.La Tipificacion Molecular de las cepas, se realizo por PFGE, se gun protocolo estandarizado de PulseNet para Salmonella y el analisis de los patrones se estudio utilizando el programa BioNumerics, version 4.0, lo cual mostro que los aisla dos de Salmonella Javiana procedentes tanto de pacientes como del alimento tenian identico patron de restriccion, en tamano y numero de fragmentos. La ocurrencia de un patron unico de PFGE (Coeficiente de similitud 100%) entre los aislados permitio demostrar que el queso contaminado con Salmonella Javiana fue el responsable del brote familiar.
The aim of this work was confirmation through Pulse Field Gel Electrophoresis (PFGE) that Salmonella isolated from the food implicated in the outbreak (white cheese) was responsible for the event. The white cheese sample showed a high count of Coli orms,f E. coli and S. aureus. Moreover, Salmonella was pre ent,s which indicated inadequate sanitary conditions and possible fecal contamination. The suspected Salmonella strains isolated from patients and the food sample, were confirmed using conventional biochemical techniques, serotyping according to the White-kauffmann-Le Minor scheme and antibiotics sensibility (Am picillin, Trimetroprim-Sulfametoxazole, Ciprofloxacin, Amoxicillin, Clavulanic Acid, Cloranfenicol, Ceftriaxone and tetraciclin) following kirby-Bauers technique. The Salmonella strains were identified as Salmonella Javiana [1,9,12:I, z28:1,5]and were sensitive to all the antibiotics tested. The molecular typing of the strains was performed using PFGE, according to the PulseNet standardized protocol for Salmonella. The pattern analysis was studied using Bionunella merics program, version 4.0, which showed that the Sal monella Javiana isolates from patients as the food sample had an identical restriction pattern in size and fragments number. The incidence of a unique pattern of PFGE (similarity coefficient 100%) between isolates demonstrated that the cheese contaminated with Salmonella Javiana was responsible for the family outbreak.