RDRioMycobacterium tuberculosis strains associated with isoniazid resistance in Northern Mexico.

BACKGROUND: It has been established that the genomic background of Mycobacterium tuberculosis may influence disease progression, in particular for the Beijing family and the Latin American and Mediterranean (LAM)/RDRio strains. The purpose of this study was to evaluate the prevalence of the LAM/RDRio genotype in cases of tuberculosis from Mexico and their drug susceptibility profile. METHODS: Two hundred eighteen M. tuberculosis isolates were screened by 43-spacer spoligotyping. The LAM/RDRio genotype was confirmed by multiplex PCR, and the drug susceptibility testing was carried out in solid Löwenstein-Jensen media. RESULTS: Among the LAM strains identified, 24 (63.1%) were confirmed as M. tuberculosis RDRio. All RDRio strains shared the RD174 deletion, that was associated with isoniazid resistance (p=0.0264). CONCLUSIONS: We documented for the first time the isolation of the LAM/RDRio genotype in pulmonary cases of tuberculosis in Mexico, and we found resistance to the first-line anti-tuberculosis drug isoniazid in these strains.

Active Flavonoids from Colubrina greggii var. greggii S. Watson against Clinical Isolates of Candida spp.

Candida albicans is the most commonly implicated agent in invasive human fungal infections. The disease could be presented as minimal symptomatic candidemia or can be fulminant sepsis. Candidemia is associated with a high rate of mortality and high healthcare and hospitalization costs. The surveillance programs have reported the distribution of other Candida species reflecting the trends and antifungal susceptibilities. Previous studies have demonstrated that C. glabrata more frequently presents fluconazole-resistant strains. Extracts from Mexican plants have been reported with activity against pulmonary mycosis, among them Colubrina greggii. In the present study, extracts from the aerial parts (leaves, flowers, and fruits) of this plant were evaluated against clinical isolates of several species of Candida (C. albicans, C. glabrata, C. parapsilosis, C. krusei, and C. tropicalis) by the broth microdilution assay. Through bioassay-guided fractionation, three antifungal glycosylated flavonoids were isolated and characterized. The isolated compounds showed antifungal activity only against C. glabrata resistant to fluconazole, and were non-toxic toward brine shrimp lethality bioassay and in vitro Vero cell line assay. The ethyl acetate and butanol extracts, as well as the fractions containing the mixture of flavonoids, were more active against Candida spp.

Expression of recombinant protease MarP from Mycobacterium tuberculosis in Pichia pastoris and its effect on human monocytes.

OBJECTIVE: Mycobacterial acid-resistant protease (MarP) is a membrane-associated serine protease involved in the survival of Mycobacterium tuberculosis in macrophages; here we produced MarP in the yeast Pichia pastoris and study its involvement in macrophage immune modulation. RESULTS: Pichia pastoris vectors, harboring a full-length or a partial sequence of MarP, were constructed. GS115 clones were selected, and homologous recombination at the AOX1 locus was assessed by PCR. Protein was purified by nickel affinity chromatography, and its effect on the cytokine profile was tested in human monocytes. Only the partial MarP protein (121-397 a.a.) lacking the transmembrane domain was successfully expressed as an N-glycosylated proteolytically active protease. In vitro stimulation of THP-1 cells with MarP promoted the release of TNF-α and IL-10. CONCLUSION: Mycobacterial MarP was successfully expressed in P. pastoris, and it is capable of cytokine release in vitro.

RDRioMycobacterium tuberculosis strains associated with isoniazid resistance in Northern Mexico.

BACKGROUND: It has been established that the genomic background of Mycobacterium tuberculosis may influence disease progression, in particular for the Beijing family and the Latin American and Mediterranean (LAM)/RDRio strains. The purpose of this study was to evaluate the prevalence of the LAM/RDRio genotype in cases of tuberculosis from Mexico and their drug susceptibility profile. METHODS: Two hundred eighteen M. tuberculosis isolates were screened by 43-spacer spoligotyping. The LAM/RDRio genotype was confirmed by multiplex PCR, and the drug susceptibility testing was carried out in solid Löwenstein-Jensen media. RESULTS: Among the LAM strains identified, 24 (63.1%) were confirmed as M. tuberculosis RDRio. All RDRio strains shared the RD174 deletion, that was associated with isoniazid resistance (p=0.0264). CONCLUSIONS: We documented for the first time the isolation of the LAM/RDRio genotype in pulmonary cases of tuberculosis in Mexico, and we found resistance to the first-line anti-tuberculosis drug isoniazid in these strains.

Evaluación de MALDI-TOF MS para la identificación de levaduras patógenas oportunistas de muestras clínicas / Evaluation of MALDI-TOF MS for the identification of opportunistic pathogenic yeasts of clinical samples

Resumen La espectrometría de masas MALDI-TOF MS es una técnica rápida y sencilla para identificar microorganismos por análisis proteico. Se estudiaron 304 aislados de levaduras procedentes de micosis superficiales y profundas, con el objetivo de comparar tres métodos: convencional (bioquímico y morfológico), MALDI-TOF MS, y reacción en cadena de la polimerasa (RPC, método de referencia). Se estudiaron 24 especies con predominio de Candida spp y Cryptococcus spp. La identificación por método convencional fue de 258/304 cepas, mientras que por MALDI-TOF MS fue de: 277/304 cepas (84,8 versus 91,2%, p = no significativo). El coeficiente Kappa entre el MALDI-TOF MS y la RPC reportó una excelente concordancia (0,99). La sensibilidad y la especificidad de MALDI-TOF MS para la identificación de levaduras patógenas oportunistas de muestras clínicas fueron de 94,6% y 99%; respectivamente. MALDI-TOF MS demostró ser una herramienta de alta precisión para la identificación de levaduras patógenas.

MALDI-TOF MS mass spectrometry is a rapid and straightforward technique to identify microorganisms by protein analysis. The study was performed in 304 yeast isolates from superficial and deep mycoses, in order to compare three methods: conventional (biochemical and morphological), MALDI-TOF MS, and polymerase chain reaction (PCR, reference). We included 24 species with predominance of Candida spp and Cryptococcus spp. The identification by conventional methods was 258/304 strains, while by MALDI-TOF MS was: 277/304 strains (84.8% versus 91.2%, P = not significant). The Kappa coefficient comparing MALDI-TOF-MS with PCR reported excellent concordance (0.99). The sensitivity and specificity of MALDI-TOF MS for the diagnosis of opportunistic pathogenic yeasts of clinical samples were 94.6% and 99% respectively. MALDI-TOF MS is a simple, fast and reliable tool for pathogenic yeasts.

Candida albicans and non-albicans Isolates from Bloodstream Have Different Capacities to Induce Neutrophil Extracellular Traps.

Neutrophils activated with pathogens or their products induce formation of extracellular traps (NETs), but if this constitutes a general response against all pathogenic species in a single genus or intrageneric differences exist remains unknown, yet this is of great importance for the establishment of effective treatments. To determine this, we analyzed neutrophil extracellular traps formation after the stimulation with bloodstream isolates from different Candida species (Candida albicans, C. tropicalis, C. parapsilosis, and C. glabrata), and found that each species has a different capacity to induce DNA extrusion, which is independent of their morphology (yeast or hyphae). We observed that phospholipase producer's strains and their secretion products were able to induce NETs, a property not observed with phospholipase deficient strains, with exception of some Candida glabrata sensu stricto isolates, which showed no NETs induction although they did show phospholipase production. To further analyze this, we extended our study to include Candida glabrata cryptic species (C. bracarensis and C. nivariensis) and no extracellular traps formation was observed. Here, we contribute to the understanding of how neutrophils initiate NETs, and we found that certain strains may have a differential capacity to trigger these structures, which may explain the high mortality of some isolates.

[Evaluation of MALDI-TOF MS for the identification of opportunistic pathogenic yeasts of clinical samples]. / Evaluación de MALDI-TOF MS para la identificación de levaduras patógenas oportunistas de muestras clínicas.

MALDI-TOF MS mass spectrometry is a rapid and straightforward technique to identify microorganisms by protein analysis. The study was performed in 304 yeast isolates from superficial and deep mycoses, in order to compare three methods: conventional (biochemical and morphological), MALDI-TOF MS, and polymerase chain reaction (PCR, reference). We included 24 species with predominance of Candida spp and Cryptococcus spp. The identification by conventional methods was 258/304 strains, while by MALDI-TOF MS was: 277/304 strains (84.8% versus 91.2%, P = not significant). The Kappa coefficient comparing MALDI-TOF-MS with PCR reported excellent concordance (0.99). The sensitivity and specificity of MALDI-TOF MS for the diagnosis of opportunistic pathogenic yeasts of clinical samples were 94.6% and 99% respectively. MALDI-TOF MS is a simple, fast and reliable tool for pathogenic yeasts.

One-domain approach for studying multiphase transport phenomena in biofilm growing systems.

The one-domain approach (ODA) was used as an alternative to solve fluid-biofilm interfacial behavior in a 2-D model for diffusion-reaction-convection coupled with prediction of irregular growth of biofilms via a cellular automaton strategy. The simulations exhibited errors of <7% compared with the porosity of a previously reported capillary experimental system. Additionally, biofilm surface geometrical aspects were satisfactorily compared with reports of experimental and similar rigorously simulated benchmark systems. The method developed was applied to simulate typical biofilm systems predicting recirculation flow patterns, interface concentration profiles, and clogging of the inlet section of the capillary tube, which are phenomena that affect the efficiency of diverse biotechnological applications, including membrane bioreactors and biofilters. The ODA method applied to the governing equations of momentum and mass transfer combined with a cellular automaton algorithm is a suitable and straightforward approach for modeling solid-state fermentation at different sophistication levels.

Nivel de conocimiento sobre cáncer bucal en un sector de la población / Level of knowledge on oral cancer in a sector of the population

Introducción: el conocimiento por parte de la población del cáncer bucal es de vital importancia para actuar sobre los factores de riesgo a padecer cáncer bucal y disminuir su incidencia. Objetivo: evaluar el nivel de conocimiento de la población objeto de estudio sobre los factores de riesgo del cáncer bucal, los factores protectores para prevenir el cáncer bucal y los signos bucales de alarma relacionados con el cáncer bucal. Materiales y Métodos: se realizó un estudio experimental de intervención educativa para aumentar el nivel de conocimiento y la percepción del riesgo ante el cáncer bucal, en el territorio atendido por el Hospital General Docente “Julio Aristegui Villamil” de Cárdenas. Resultados: se diagnosticó bajo nivel de conocimiento en el 78,5 % de la población estudiada sobre el cáncer bucal, se diseñó y ejecutó una estrategia de intervención educativa para aumentar la percepción del riesgo ante el cáncer bucal en la población según las necesidades de aprendizaje. El nivel de conocimiento luego de la intervención educativa resultó satisfactorio en el 94,2 % de la población. Conclusiones: el nivel de conocimiento sobre cáncer bucal inicial resultó ser insatisfactorio en la mayoría, mientras que luego de aplicar la intervención educativa fue satisfactorio en casi su totalidad. La intervención educativa resultó ser un método idóneo de la educación para la salud respecto al cáncer bucal en la población estudiada (AU).

Introduction: knowledge of oral cancer in all the population is very important, that permit to act over factors of risk to suffer Oral cancer and to diminish the morbidity in this illness. Objective: to describe the level knowledge about factors of risk of Oral cancer in the population studied, the protective factors to prevent the Oral cancer and the alarm signs related with the Oral cancer; as well as to evaluate the level of knowledge before and after the application of the educational strategy to the population. Materials and methods: was carried out an experimental study of educational intervention to increase the perception of risk about Oral cancer, in the territory assisted by the General Hospital "Julio Aristegui Villamil" of Cárdenas. The level of knowledge about Oral cancer was studied in 450 patients. Results: low level of knowledge was diagnosed in population´s studied (78,5 %). Then was designed and executed a Strategy of Educational Intervention to increase the perception of the risk about Oral cancer in the population according to the learning necessities. The level of knowledge after the educational intervention was Satisfactory in the 94,2 % of the population. Conclusions: at first most of population have a not satisfactory level of knowledge about Oral cancer, but it turned out to be Satisfactory in almost totally, after applying the educational intervention. This educational intervention turned out to be a suitable method for the health´s education regarding Oral cancer in the studied population (AU).

Caracterización del Cáncer Bucal. Estudio de 15 años / Characterization of oral cancer. Study of 15 years

Introducción: La región bucal es una de las diez localizaciones más frecuentes de incidencia del cáncer en Cuba y en el mundo, su estudio en nuestro medio es de vital importancia para mejorar su prevención y curación. Objetivo: identificar distribución de morbilidad por año del cáncer bucal en el territorio de Cárdenas y su tasa por 100 000 habitantes, características sociodemográficas de los pacientes diagnosticados con cáncer bucal en la región y periodo objetos de estudio y determinar el comportamiento del cáncer bucal según localización anatómica y presencia de factores de riesgo. Materiales y Métodos: se realizó un estudio descriptivo retrospectivo de 15 años en pacientes con diagnóstico histopatológico de cáncer bucal atendidos en el Hospital General Docente ¨Julio M Aristegui Villamil¨ de Cárdenas, en el periodo comprendido entre enero de 2000 y diciembre de 2014. Resultados: se pudo constatar un incremento de pacientes afectados en el referido territorio al elevarse la tasa de 4,5 X 100 000 habitantes en el 2000 a 15,4 en el 2013 y 12,5 en el 2014. Hubo mayor incidencia en el grupo de edad de 51-60 años (24,6 %), el sexo masculino (78,5 %), el color de piel blanca (94,1 %), el labio inferior (44,5 %). Los factores de riesgo con mayores valores fueron el tabaquismo (94,6 %) y alcoholismo (64,8 %). Conclusiones: El cáncer bucal tiene una tendencia al incremento en el municipio estudiado, predominando en individuos masculinos, de piel blanca y con adicciones como tabaquismo y alcoholismo. Es necesario realizar actividades de promoción de salud y prevención del cáncer bucal por el incremento de esta enfermedad (AU).

Introduction: oral region is one of the ten more frequent localizations of the cancer in our country and in the world, so to study oral cancer in our context is very important to improve prevention and cure. Objective: describing the distribution of the morbidity for year of the Oral cancer in Cárdenas and their rate for 100 000 inhabitants, as well as the demographic characteristics of the patients diagnosed with Oral cancer in the anatomical region and period studied and factors of risk in those patients. Materials and methods: was carried out a descriptive and retrospective study of 15 year in patient with histopathologic diagnosis of Oral cancer assisted in the General Hospital ¨Julio M Aristegui Villamil¨ of Cárdenas, since January, 2000 to December, 2014. Results: was verified an increase of patients affected by Oral cancer in the referred territory and was raising the rate of since 4,5 X 100 000 inhabitants in the 2000 to 15,4 in the 2013 and 12,5 in the 2014. There was bigger incidence in the group of 51-60 year-old age (24,6 %), the masculine sex (78,5 %), the white skin color (94,1 %) and the inferior lip area (44,5 %). The higher factors of risk were Tabaco addiction (94,6 %) and alcoholism (64,8 %). Conclusions: it becomes necessary to carry out activities of promotion of health and prevention of Oral cancer because the growth of this illness in our context (AU).

Intervención educativa sobre el programa de detección del cáncer bucal en estomatólogos generales / Educative intervention on the program of oral cancer detection in general dentists

Introducción: los estomatólogos generales constituyen la primera línea de educación para la salud y prevención del cáncer bucal, por ello su nivel de conocimiento y su percepción del riesgo poblacional de padecer cáncer bucal resultan de gran importancia para su prevención en la atención primaria de salud. Objetivos: evaluar el nivel de conocimiento inicial que presentaron los estomatólogos generales objeto de estudio. Aplicar una intervención educativa para elevar el nivel de conocimiento sobre cáncer bucal en la población de profesionales estudiados. Evaluar los resultados de la intervención educativa aplicada a los estomatólogos participantes. Materiales y Métodos: con la participación de 60 estomatólogos que prestan servicio en los municipios de Cárdenas, Martí y el Consejo Popular de Máximo Gómez y durante el periodo de septiembre 2011 a junio del 2012, se diseñó y ejecutó un estudio experimental de intervención educativa y desarrollo tecnológico sobre el Programa de Detección del Cáncer Bucal (PDCB), con el propósito de aumentar la percepción del riesgo ante el cáncer bucal. Resultados: el nivel de conocimiento resultó inadecuado en el 56.6% de los estomatólogos en los acápites relacionados a: PDCB, características clínicas del cáncer bucal, factores de riesgo, factores protectores y signos de alarma. Luego de aplicada la estrategia educativa se elevó el nivel de conocimiento a un 98,3 % de estomatólogos evaluados de satisfactorio. Conclusiones: elevar en los estomatólogos generales el nivel de conocimiento sobre cáncer bucal y la forma de prevenirlo, permite potenciar los objetivos propuestos por el PDCB (AU).

Introduction: general dentists are the first line of the education for health and oral cancer prevention; so their level of knowledge and their perception of the risk the population are at of suffering oral cancer has great importance for oral cancer prevention in the primary health care. Objectives: to assess the initial level of knowledge the studied general dentist had. To apply an educative intervention for improving the level of knowledge on oral cancer among the studied population of professionals. To assess the outcomes of the educative intervention applied to dentists who participated. Materials and Methods: an experimental study of educative intervention and technological development on the Program of Oral Cancer Detection (PDCB en Spanish) was designed and carried out with the participation of 60 dentists working in the municipalities of Cardenas, Marti and the Popular Council Máximo Gómez during the period from September 2011 to June 2012, aimed to the increment of their perception of oral cancer risk. Results: the level of knowledge was inadequate in 56,6 % of the dentists in items related with: Program of Oral Cancer Detection, oral cancer clinical characteristics, risk factors, protecting factors and alarming signs. After the application of the educative intervention, the level of knowledge improved up to 97,3 % of the dentists evaluated as satisfactory. Conclusions: improving the level of knowledge the general dentists have on oral cancer and the forms of preventing it allows potentiating the aims proposed by the Program of Oral Cancer Detection (AU).

Tumor del cuerpo carotídeo. A propósito de un caso / Tumor of the carotid body.Concerning a case

Los tumores del cuerpo carotídeo son relativamente infrecuentes y raramente se diagnostican antes de la exposición quirúrgica, su diagnóstico es benigno, pero suelen ser muy vasculares por lo que su extirpación quirúrgica muchas veces resulta difícil. Estos tumores son de crecimiento lento y pueden evolucionar durante años. El objetivo de este estudio es presentar un caso con un tumor del cuerpo carotídeo en región lateral derecha del cuello. Clínicamente se observó un aumento de volumen de aproximadamente 4 cm, no doloroso a la palpación, de tipo gomoso y adherido a planos profundos, asintomático, tratado en nuestra institución durante el año 2014. Se le realizó exéresis simple de la lesión, y el departamento de Anatomía Patológica reportó el diagnóstico de referencia. La evolución de la paciente después de 17 meses ha sido satisfactoria (AU).

The tumors of the carotid body are relatively uncommon and rarely diagnosed before the surgical exeresis, their diagnosis is benign, but they are usually very vascular and its extirpation is very difficult. These tumors have a slow growth and it can evolve during years. The aim of this study is to present a case with a tumor of the carotid body in the right lateral region of the neck. An increase of volume was observed of approximately 4 cm, not painful, of gummy type and stuck to deep, asymptomatic plans, treaty in our institution during the year 2014. It was carried out exeresis of the lesion, and the department of Pathological Anatomy reported the reference diagnosis. The patient's evolution after 17 months has been satisfactory (AU).

Characterization of phenotypic and genotypic drug resistance patterns of Mycobacterium tuberculosis isolates from a city in Mexico.

INTRODUCTION: The emergence of multidrug-resistant (MDR) Mycobacterium tuberculosis strains has become a worldwide health care problem, making treatment of tuberculosis difficult. The aim of this study was to determine phenotypic resistance and gene mutations associated with MDR of clinical isolates of Mycobacterium tuberculosis from Guadalajara, Mexico. METHODS: One hundred and five isolates were subjected to drug susceptibility testing to first line drugs using the proportion and Mycobacteria Growth Indicator Tube (MGIT) methods. Genes associated with isoniazid (inhA, katG, ahpC) and rifampicin (rpoB) resistance were analyzed by either pyrosequencing or PCR-RFLP. RESULTS: Resistance to any drug was detected in 48.6% of isolates, of which 40% were isoniazid-resistant, 20% were rifampicin-resistant and 19% were MDR. Drug-resistant isolates had the following frequency of mutations in rpoB (48%), katG (14%), inhA (26%), ahpC (26%). Susceptible isolates also had a mutation in ahpC (29%). CONCLUSIONS: This is the first analysis of mutations associated with MDR of M. tuberculosis in Guadalajara. Commonly reported mutations worldwide were found in rpoB, katG and inhA genes. Substitution C to T in position -15 of the ahpC gene may possibly be a polymorphism.

Carcinoma adenoquístico de glándula sublingual. A propósito de un caso / Adenocystic carcinoma of the sublingual gland. On the purpose of a case

Los tumores de glándulas salivales son relativamente infrecuentes, constituyendo el 1% de los tumores de cabeza y cuello, siendo aún más raros los tumores de glándulas sublinguales, aunque frecuentemente su diagnóstico es maligno. El propósito de este trabajo es la presentación de un caso clínico que presentó un carcinoma adenoquístico de glándula sublingual en suelo de boca lado izquierdo. Clínicamente apareció una lesión alargada, sobre el trayecto del conducto de Wharton, con una coloración normal, lisa, brillante y asintomática. Se le realizó exéresis simple de la lesión y el Departamento de Anatomía Patológica confirmó el diagnóstico. Se procedió a revisar la bibliografía nacional e internacional sobre estas lesiones encontrándose escasas referencias debido a su rareza. La evolución de la paciente después de 16 meses ha sido satisfactoria.

The salivary gland tumors are relatively infrequent, being only 1 % of the head and neck tumors; the sublingual gland tumors are even more unusual, although their diagnosis is frequently malignant. The purpose of the current work is presenting a clinical case carrying a sublingual gland adenocystic carcinoma on the left side of the mouth bottom. Clinically, there it was a long lesion, over the course of the Wharton’s duct, with an asymptomatic, normal, brilliant and smooth color. The lesion was simply removed and the Department of Pathologic Anatomy confirmed the diagnosis. We reviewed the national and international literature on these lesions, finding scarce references because of its unusualness. The patient’s evolution is satisfactory when 16 months have passed from the surgery.

Chemical compositions and antimicrobial and antioxidant activities of the essential oils from Magnolia grandiflora, Chrysactinia mexicana, and Schinus molle found in northeast Mexico.

The essential oils from Magnolia grandiflora and Chrysactinia mexicana leaves, and from Schinus molle leaves and fruit, were characterized by gas chromatography/flame-ionization detection and gas chromatography/mass spectrometry. Twenty-eight compounds from M. grandiflora leaves were identified (representing 93.6% of the total area of the gas chromatogram), with the major component being bornyl acetate (20.9%). Colorless and yellow oils were obtained from the C. mexicana leaves with 18 (86.7%) and 11 (100%) compounds identified, respectively. In both fractions, the principal component was sylvestrene (36.8% and 41.1%, respectively). The essential oils ofS. molle leaves and fruit were each separated into colorless and yellow fractions, in which 14 (98.2) and 20 (99.8%) compounds were identified. The main component was alpha-phellandrene in all fractions (between 32.8% and 45.0%). The M. grandiflora oil displayed antifungal activity against five dermatophyte strains. The oils from S. molle and M. grandiflora leaves had antimicrobial activity against Staphylococcus aureus and Streptococcus pyogenes, which cause skin infections that potentially may lead to sepsis. However, the antioxidant activities of all oils were small (half maximal effective concentration values >250 microg/mL).

Risk factors associated with extended-spectrum ß-lactamase-producing Enterobacteriaceae nosocomial bloodstream infections in a tertiary care hospital: a clinical and molecular analysis.

AIM: To describe the risk factors and molecular epidemiology of nosocomial bloodstream infections caused by extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae in a tertiary care hospital. METHODS: Patients with enterobacteria-positive blood cultures were included. ESBL expression in the isolates was detected using the combination disk method. Antimicrobial susceptibility testing was performed using the disk diffusion method. bla(SHV), bla(TEM), and bla(CTX-M) genes were identified in the isolated strains by PCR and sequencing. Klebsiella pneumoniae isolates were genotyped by PFGE. RESULTS: Of the 90 isolates recovered, half were found to express ESBLs. Twenty-eight (62%) of these isolates were K. pneumoniae, 8 (18%) were Escherichia coli, 6 (13%) were Enterobacter cloacae, and 3 (7%) were Serratia marcescens. Multivariate logistic regression analysis showed that the only independent risk factor associated with infection by ESBL-producing strains was use of broad-spectrum cephalosporins. None of the isolates was resistant to imipenem. The bla(SHV5) gene was detected in 84% of isolates, followed by bla(CTX-M15) (27%), bla(SHV2) (9%), and bla(SHV12) (7%). PFGE identified six clones among the 28 ESBL-producing K. pneumoniae isolates. CONCLUSIONS: ESBL-producing K. pneumoniae clones were detected throughout the hospital. Use of broad-spectrum cephalosporins is the most important risk factor associated with the proliferation of ESBL-producing strains.

Molecular identification of coccidioides isolates from Mexican patients.

Molecular studies of the genome of the fungus Coccidioides have demonstrated two nearly identical, but well-identified species, Coccidioides immitis and C. posadasii, known as "California" and "non-California" species, respectively. The objective of this study was to determine, through molecular methods, whether both species of Coccidioides are present in Mexican patients with coccidioidomycosis and to estimate, their geographical distribution in Mexico. We analyzed 56 clinical isolates of Coccidioides spp. from Mexican patients. Molecular identification of each strain was done by means of real time PCR using TaqMan(R) probes to amplify single nucleotide polymorphisms (SNPs) in four target sequences, loci, named proline 157, proline 174, hexokinase 149 and glucose-synthase 192. SNP analysis identified two of the 56 isolates as Coccidioides immitis and the remaining 54 as C. posadasii. The dual probe assay that included proline 157, proline 174 and glucose-synthase 192 gave consistent results on SNP differentiation between the two species. In contrast, the template matching hexokinase 149 gave negative results for any species in 34 samples. Our results did not show geographical overlap of the species, and they also confirmed that C. posadasii is the most frequent species in Mexico. A vast majority of C. posadasii strains were localized in the north-central region of the country.

Inmunoensayo enzimático (ELISA) para la detección de enterotoxinas B y C de S. aureus en leche / Enzimatic inmunoessay for the detection of entrotoxins B and C of S. aureus in milk

Se utilizaron las cepas 243 y6 361 de S. aureus para la obtención de las enterotoxinas B y C. Se estandarizó la técnica inmunoenzimática cualitativa y cuantitativamente. Se contaminaron artificialmente leches y las enterotoxinas fueron determinadas del extracto demostrándose su presencia al nivel de nanogramos. Esta técnica inmunoenzimática ELISA implementada poor nosostros con las condiciones operativas de nuestro medio, resultó de fácil manejo, corto tiempo de elaboración, bajo costo y con una gran sensibilidad diagnóstica

Staphylococcus aureus enterotoxins B and C, were obtained from strains 243 and 361 respectively. An immunoenzimatic technique was standariced both quantitative and qualitativly. We were able to detect enterotoxin to nanogram level on extracts from artificially contaminated milk. This ELISA immunoenzimatic technique implemented by us under the operative conditions of our working environment, resulted to be easy to handle, consumes only a short time, has a low cost and great diagnostic sensitivity.