Development and Validation of UPLC Tandem Mass Spectrometry Assay for Ceftibuten and Sulbactam in Human Plasma.

A sensitive and rapid ultra-performance liquid chromatography coupled with -tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to determine ceftibuten (CTB) and sulbactam (SUL) in human plasma. An ACQUITY UPLC HSS T3 C18 (2.1 × 100 mm), 1.8 µm column with gradient elution of water (0.1% formic acid) and acetonitrile was used for separation at a flow rate of 0.2 mL/min. This method involves a simple sample preparation with acetonitrile. The calibration curves of CTB and SUL in plasma showed good linearity over the concentration range of 0.50-25 µg/mL and with a correlation coefficient (r2) >0.99. This method was validated in terms of selectivity, linearity, precision, accuracy and stability. High precision was obtained with coefficients of variation <15%. Excellent recovery in the range of 90-104% was achieved for CTB and SUL was 86-110%. The method has the potential utility to support pharmacometric modeling in clinical practice and biopharmaceutic studies.

miR-146a, miR-221, and miR-155 are Involved in Inflammatory Immune Response in Severe COVID-19 Patients.

COVID-19 infection triggered a global public health crisis during the 2020-2022 period, and it is still evolving. This highly transmissible respiratory disease can cause mild symptoms up to severe pneumonia with potentially fatal respiratory failure. In this cross-sectional study, 41 PCR-positive patients for SARS-CoV-2 and 42 healthy controls were recruited during the first wave of the pandemic in Mexico. The plasmatic expression of five circulating miRNAs involved in inflammatory and pathological host immune responses was assessed using RT-qPCR (Reverse Transcription quantitative Polymerase Chain Reaction). Compared with controls, a significant upregulation of miR-146a, miR-155, and miR-221 was observed; miR-146a had a positive correlation with absolute neutrophil count and levels of brain natriuretic propeptide (proBNP), and miR-221 had a positive correlation with ferritin and a negative correlation with total cholesterol. We found here that CDKN1B gen is a shared target of miR-146a, miR-221-3p, and miR-155-5p, paving the way for therapeutic interventions in severe COVID-19 patients. The ROC curve built with adjusted variables (miR-146a, miR-221-3p, miR-155-5p, age, and male sex) to differentiate individuals with severe COVID-19 showed an AUC of 0.95. The dysregulation of circulating miRNAs provides new insights into the underlying immunological mechanisms, and their possible use as biomarkers to discriminate against patients with severe COVID-19. Functional analysis showed that most enriched pathways were significantly associated with processes related to cell proliferation and immune responses (innate and adaptive). Twelve of the predicted gene targets have been validated in plasma/serum, reflecting their potential use as predictive prognosis biomarkers.

Diagnostic accuracy of antigen detection in urine and molecular assays testing in different clinical samples for the diagnosis of progressive disseminated histoplasmosis in patients living with HIV/AIDS: A prospective multicenter study in Mexico.

BACKGROUND: The progressive disseminated histoplasmosis (PDH) has been associated with severe disease and high risk of death among people living with HIV (PLWHIV). Therefore, the purpose of this multicenter, prospective, double-blinded study done in ten Mexican hospitals was to determine the diagnostic accuracy of detecting Histoplasma capsulatum antigen in urine using the IMMY ALPHA Histoplasma EIA kit (IAHE), clarus Histoplasma GM Enzyme Immunoassay (cHGEI IMMY) and MiraVista Histoplasma Urine Antigen LFA (MVHUALFA); as well as the Hcp100 and 1281-1283220SCAR nested PCRs in blood, bone-marrow, tissue biopsies and urine. METHODOLOGY/PRINCIPAL FINDINGS: We included 415 PLWHIV older than 18 years of age with suspicion of PDH. Using as diagnostic standard recovery of H. capsulatum in blood, bone marrow or tissue cultures, or histopathological exam compatible, detected 108 patients (26%, [95%CI, 21.78-30.22]) with proven-PDH. We analyzed 391 urine samples by the IAHE, cHGEI IMMY and MVHUALFA; the sensitivity/specificity values obtained were 67.3% (95% CI, 57.4-76.2) / 96.2% (95% CI, 93.2-98.0) for IAHE, 91.3% (95% CI, 84.2-96.0) / 90.9% (95% CI, 87.0-94.0) for cHGEI IMMY and 90.4% (95% CI, 83.0-95.3) / 92.3% (95% CI, 88.6-95.1) for MVHUALFA. The Hcp100 nested PCR was performed on 393, 343, 75 and 297, blood, bone marrow, tissue and urine samples respectively; the sensitivity/specificity values obtained were 62.9% (95%CI, 53.3-72.5)/ 89.5% (95%CI, 86.0-93.0), 65.9% (95%CI, 56.0-75.8)/ 89.0% (95%CI, 85.2-92.9), 62.1% (95%CI, 44.4-79.7)/ 82.6% (95%CI, 71.7-93.6) and 34.9% (95%CI, 24.8-46.2)/ 67.3% (95%CI, 60.6-73.5) respectively; and 1281-1283220SCAR nested PCR was performed on 392, 344, 75 and 291, respectively; the sensitivity/specificity values obtained were 65.3% (95% CI, 55.9-74.7)/ 58.8% (95%CI, 53.2-64.5), 70.8% (95%CI, 61.3-80.2)/ 52.9% (95%CI, 46.8-59.1), 71.4% (95%CI, 54.7-88.2)/ 40.4% (95%CI, 26.4-54.5) and 18.1% (95%CI, 10.5-28.1)/ 90.4% (95%CI, 85.5-94.0), respectively. CONCLUSIONS/SIGNIFICANCE: The cHGEI IMMY and MVHUALFA tests showed excellent performance for the diagnosis of PDH in PLWHIV. The integration of these tests in clinical laboratories will certainly impact on early diagnosis and treatment.

Surgical procedure versus medical treatment for infective endocarditis associated to mortality in Mexican population.

BACKGROUND: Early surgical procedures on patients with infective endocarditis (IE) have shown a clearly benefit to reduce embolization at the central nervous system. We conducted a retrospective cohort in Mexican population to evaluate mortality and clinical outcomes in patients with IE with or without surgical intervention. OBJECTIVES: Our aim was to evaluate factors associated with mortality in patients with IE and compare both groups with and without a surgical intervention. METHODS: We evaluated a retrospective cohort of patients who had been diagnosed with IE according to the Duke's criteria at our Institution in SLP, Mexico, from January 2001 to September 2016. We compared the risk factors associated to mortality of patients with or without surgery. Our primary outcome was mortality within 6 months of follow-up after the diagnosis. RESULTS: We included 105 patients, 51 (48.6%) were men, median age 46 [Q1 30, Q3 59] years, 36 patients (34.3%) received surgical treatment (STG), and 69 (65.7%) only medical treatment (MTG) group; 41 patients (39%) died during the study period; in the surgery group eight patients died (22%); and 33 in the MT group (47%) p = 0.049. Adjusted for APACHE II, surgery, creatinine levels and the size of vegetation, the surgery group had lower mortality than patients on MTG (HR 0.36, p = 0.047). CONCLUSION: As previously described in the literature, patients who underwent surgery had lower mortality than the patients who only received medical treatment; however, the Mexican population is different to other populations group, due to higher risk of diabetes mellitus (28%) versus (10%) in global risk of DM in the world and its complications and other chronic diseases as arterial systemic hypertension. Thus, surgical treatment must be elected as goal standard treatment in patient's whit IE and presence of vegetation.

Antecedentes: Los procedimientos quirúrgicos tempranos en pacientes con endocarditis infecciosa (EI) han mostrado un beneficio claro para reducir la embolización en el sistema nervioso central. Realizamos una cohorte retrospectiva en ­población mexicana para evaluar la mortalidad y los resultados clínicos en pacientes con EI con o sin intervención quirúrgica. Objetivos: Nuestro objetivo fue evaluar los factores asociados a la mortalidad en pacientes con endocarditis infecciosa y comparar ambos grupos con y sin intervención quirúrgica. Métodos: Evaluamos una cohorte retrospectiva de pacientes que habían sido diagnosticados de EI según los criterios de Duke en nuestra Institución en SLP, México, desde enero de 2001 a septiembre de 2016. Comparamos los factores de riesgo asociados a la mortalidad de pacientes con o sin cirugía. Nuestro resultado primario fue la mortalidad dentro de los 6 meses de seguimiento después del diagnóstico. Resultados: Se incluyeron 105 pacientes, 51 (48.6%) eran hombres, mediana de edad46 [Q1 30, Q3 59] años, 36 pacientes (34.3%) recibieron tratamiento quirúrgico (STG) y 69 (65.7%) solo grupo de tratamiento médico (MTG); 41 pacientes (39%) murieron durante el período de estudio; en el grupo de cirugía fallecieron 8 pacientes (22%) y en el grupo de MT (47%) 33 p = 0.049. Ajustado por APACHE II, cirugía, niveles de creatinina y tamaño de la vegetación, el grupo de cirugía tuvo menor mortalidad que los pacientes en MTG (HR 0.36, p = 0.047). Conclusión: Como se ha descrito anteriormente en la literatura, los pacientes que se sometieron a cirugía tuvieron menor mortalidad que los pacientes que solo recibieron tratamiento médico, sin embargo, la población mexicana es diferente a otros grupos poblacionales, debido a un mayor riesgo de diabetes mellitus (28%) vs (10%) en otros países y sus complicaciones y otras enfermedades crónicas como hipertensión arterial sistémica. Por tanto, el tratamiento quirúrgico debe ser elegido como principal método de tratamiento en pacientes con endocarditis infecciosa y presencia de vegetaciones.

Characterization, antibiofilm and biocompatibility properties of chitosan hydrogels loaded with silver nanoparticles and ampicillin: an alternative protection to central venous catheters.

The purpose of this study was to generate novel chitosan hydrogels (CHs) loaded with silver nanoparticles (AgNPs) and ampicillin (AMP) to prevent early formation of biofilms. AgNPs and CHs were characterized by UV-Vis, DLS, TEM, rheology, FT-IR, Raman, and SEM. The antibiofilm effect of the formulations was investigated against four multidrug-resistant and extensively drug-resistant pathogens using a colony biofilm, a high cell density and gradients model. Also, their hemostatic properties and cytotoxic effect were evaluated. Rheology results showed that CHs with AgNPs and AMP are typical non-Newtonian pseudoplastic fluids. The CH with 25 ppm of AgNPs and 50 ppm AMP inhibited the formation of biofilms of Acinetobacter baumannii, Enterococcus faecium and Staphylococcus epidermidis, while a ten-fold increase of the antimicrobial's concentration was needed to inhibit the biofilm of the ß-lactamase positive Enterobacter cloacae. Further, CH with 250 ppm of AgNPs and 500 ppm AMP showed anticoagulant effect, and it was shown that all formulations were biocompatible. Besides to previous reports that described the bioadhesion properties of chitosan, these results suggest that AgNPs and AMP CHs loaded could be used as prophylactic treatment in patients with central venous catheter (CVC), inhibiting the formation of biofilms in their early stages, in addition to their anticoagulant effect and biocompatibility, those properties could keep the functionality of CVC helping to prevent complications such as sepsis and thrombosis.

A population approach of rifampicin pharmacogenetics and pharmacokinetics in Mexican patients with tuberculosis.

The aim of this study was to develop a population pharmacokinetic model of rifampicin (RMP) in Mexican patients with tuberculosis (TB) to evaluate the influence of anthropometric and clinical covariates, as well as genotypic variants associated with MDR1 and OATP1B1 transporters. A prospective study approved by Research Ethics Committee was performed at Hospital Central in San Luis Potosí, Mexico. TB patients under DOTS scheme and who signed informed consent were consecutively included. Anthropometric and clinical information was retrieved from medical records. Single nucleotide polymorphisms in MDR1 (C3435T) and SLCO1B1 (A388G and T521C) genes were evaluated. RMP plasma concentrations and time data were assessed with NONMEM software. A total of 71 Mexican TB patients from 18 to 72 years old were included for RMP quantification from 0.3 to 12 h after dose; 329 and 97 plasma concentrations were available for model development and validation, respectively. Sequential process includes a typical lag time of 0.25 h prior to absorption start with a Ka of 1.24 h-1 and a zero-order absorption of 0.62 h to characterize the gradual increase in RMP plasma concentrations. Final model includes total body weight in volume of distribution (0.7 L/kg, CV = 26.8%) and a total clearance of 5.96 L/h (CV = 38.5%). Bioavailability was modified according to time under treatment and generic formulation administration. In conclusion, a population pharmacokinetic model was developed to describe the variability in RMP plasma concentrations in Mexican TB patients. Genetic variants evaluated did not showed significant influence on pharmacokinetic parameters. Final model will allow therapeutic drug monitoring at early stages.

Population pharmacokinetics of isoniazid and dose recommendations in Mexican patients with tuberculosis.

Background The standardized doses of isoniazid in therapy against tuberculosis are determined based on total body weight, without considering genetic polymorphisms of the metabolic enzyme N-acetyltransferase-2 that contribute to the wide pharmacokinetic variability of isoniazid. Objective The aim of this work was to build a population pharmacokinetic model of isoniazid in Mexican patients with tuberculosis to characterize typical estimates of pharmacokinetics, as well as inter-individual and residual variability of isoniazid considering the genetic factors associated with the N-acetyltransferase-2 enzyme. Setting A prospective study was conducted at the Department of Internal Medicine in Hospital Central, San Luis Potosí, México. Methods Plasma concentrations of isoniazid were measured by high performance liquid chromatography. The acetylator phenotype was predicted through single nucleotide polymorphisms in the N-acetyltransferase-2 gene. Genetic, anthropometric and clinical covariates were used to develop a pharmacokinetic model. Main outcome measure Isoniazid plasma concentration. Results A total of 69 patients with tuberculosis were included. Blood samples were drawn from 20 min to 12 h post dose to determinate the isoniazid plasma concentration. Typical pharmacokinetics parameters were characterized through two-compartment open model with first-order absorption and linear elimination. Clearance was different for each predicted N-acetyltransferase-2 phenotype being 11.4, 19.2 and 27.4 L/h for slow, intermediate and rapid acetylators, respectively. Central volume of distribution was determined as 1.5 * body mass index (L). Through the application of the model, external validation was performed and initial dose regimen of isoniazid is proposed based on stochastic simulations. Conclusion A validated population pharmacokinetic model of isoniazid was developed in Mexican patients with tuberculosis. Through the application of the final model, initial dose recommendations were provided considering body mass index and N-acetyltransferase-2 phenotype.

[Prevalence and genotypic characterization of methicillin-resistant strains of Staphylococcus aureus isolated in a Mexican regional hospital]. / Prevalencia y caracterización genotípica de cepas de Staphylococcus aureus resistente a meticilina aisladas en un hospital regional mexicano.

BACKGROUND: Staphylococcus aureus is one of most prevalent pathogens in the world associated with a high mortality rate and a rapid development of resistance to antibiotics. Despite its pathogenicity, epidemiological monitoring in Mexico is scarce. AIM: To analyze the local molecular epidemiology and determine the clonal origin of methicillin-resistant (MR) strains isolated from patients admitted to Hospital "Dr. Ignacio Morones Prieto". METHODS: A cross-sectional prospective study was carried out from July to December 2016. The characterization of the strains was carried out by Spa genotyping, frequency of specific virulence genes by PCR and antibiogram. RESULTS: The prevalence of MRSA was 25.7%, highlighting the presence of the Spa type t895 in 76% of the resistant strains and a similar pattern of susceptibility to antibiotics. CONCLUSION: The results of this study indicate that the regional prevalence of MRSA has not changed in the last 10 years and provide valuable information on the clonal origin and the virulence factors of the strains of S. aureus isolated in the region.

Population Pharmacokinetics of Amikacin Administered Once Daily in Patients with Different Renal Functions.

The aim of this work was to evaluate the pharmacokinetics of amikacin in Mexican patients with different renal functions receiving once-daily dosing regimens and the influence of clinical and demographical covariates that may influence the optimization of this antibiotic. A prospective study was performed in a total of 63 patients with at least one determination of amikacin plasma concentration. Population pharmacokinetic (PK) parameters were estimated by nonlinear mixed-effects modeling; validations were performed for dosing recommendation purposes based on PK/pharmacodynamic simulations. The concentration-versus-time data were best described by a one-compartment open model with proportional interindividual variability associated with amikacin clearance (CL) and volume of distribution (V); residual error followed a homoscedastic trend. Creatinine clearance (CLCR) and ideal body weight (IBW) demonstrated significant influence on amikacin CL and V, respectively. The final model [CL (liters/h) = 7.1 × (CLCR/130)0.84 and V (liters) = 20.3 × (IBW/68)2.9] showed a mean prediction error of 0.11 mg/liter (95% confidence interval, -3.34, 3.55) in the validation performed in a different group of patients with similar characteristics. There is a wide variability in amikacin PK parameters in Mexican patients. This leads to inadequate dosing regimens, especially in patients with augmented renal clearance (CLCR of >130 ml/min). Optimization based on the final population PK model in Mexican patients may be useful, since reliability and clinical applicability have been demonstrated in this study.

Prevalencia y caracterización genotípica de cepas de Staphylococcus aureus resistente a meticilina aisladas en un hospital regional mexicano / Prevalence and genotypic characterization of methicillin-resistant strains of Staphylococcus aureus isolated in a Mexican regional hospital

Resumen Introducción: Staphylococcus aureus es uno de los patógenos con mayor prevalencia en el mundo, asociado a una alta tasa de mortalidad y un rápido desarrollo de resistencia a los antimicrobianos. A pesar de su patogenicidad, su seguimiento epidemiológico en México es escaso. Objetivo: Analizar la epidemiología molecular local y determinar el origen clonal de cepas resistentes a meticilina (RM) aisladas de pacientes internados en el Hospital Central "Dr. Ignacio Morones Prieto". Métodos: Se llevó a cabo un estudio prospectivo de corte transversal, de julio a diciembre de 2016. La caracterización de las cepas se realizó mediante genotipificación Spa, la determinación por RPC punto final de la frecuencia de genes de virulencia específicos y su antibiograma. Resultados: A partir de estos datos, se obtuvo que la prevalencia de S. aureus RM fue de 25,7%, destacando la presencia del tipo Spa t895 en 76% de las cepas resistentes y un patrón similar de susceptibilidad a antimicrobianos. Conclusión: Los resultados de este estudio indican que la prevalencia regional de SARM no se ha modificado en los últimos 10 años y proporcionan información valiosa del origen clonal y los factores de virulencia de las cepas de S. aureus aisladas en la región.

Abstract Background: Staphylococcus aureus is one of most prevalent pathogens in the world associated with a high mortality rate and a rapid development of resistance to antibiotics. Despite its pathogenicity, epidemiological monitoring in Mexico is scarce. Aim: To analyze the local molecular epidemiology and determine the clonal origin of methicillin-resistant (MR) strains isolated from patients admitted to Hospital "Dr. Ignacio Morones Prieto". Methods: A cross-sectional prospective study was carried out from July to December 2016. The characterization of the strains was carried out by Spa genotyping, frequency of specific virulence genes by PCR and antibiogram. Results: The prevalence of MRSA was 25.7%, highlighting the presence of the Spa type t895 in 76% of the resistant strains and a similar pattern of susceptibility to antibiotics. Conclusion: The results of this study indicate that the regional prevalence of MRSA has not changed in the last 10 years and provide valuable information on the clonal origin and the virulence factors of the strains of S. aureus isolated in the region.

Glycerophospholipid Metabolism Alterations in Patients with Type 2 Diabetes Mellitus and Tuberculosis Comorbidity.

Type-2 Diabetes (T2D) is a predisposing cause for developing tuberculosis (TB) in low- and middle-income countries. TB-T2D comorbidity worsens clinical control and prognosis of the affected individuals. The underlying metabolic alterations for this infectious-metabolic disease are still largely unknown. Possible mediators of the increased susceptibility to TB in diabetic patients are lipids levels, which are altered in individuals with T2D. To evaluate the modulation of glycerophospholipids in patients with TB-T2D, an untargeted lipidomic approach was developed by means of ultra-performance liquid chromatography (UPLC) coupled to electrospray ionization/quadrupole time-of-flight mass spectrometry (ESI-QToF). In addition, tandem mass spectrometry was performed to determine the identity of the differentially expressed metabolites. We found that TB infected individuals with or without T2D share a common glycerophospholipid profile characterized by a decrease in phosphatidylcholines. A total of 14 glycerophospholipids were differentially deregulated in TB and TB-T2D patients and could potentially be considered biomarkers. It is necessary to further validate these identified lipids as biomarkers, focusing on the anticipate diagnosis for TB development in T2D predisposed individuals.

Anthropometric and Genetic Factors Associated With the Exposure of Rifampicin and Isoniazid in Mexican Patients With Tuberculosis.

BACKGROUND: Tuberculosis (TB) remains a critical infectious, contagious disease worldwide with high prevalence and mortality rate. The directly observed treatment short-course therapy includes rifampicin (RMP) and isoniazid (INH) for at least 6 months. The purposes of this scheme are to interrupt the transmissibility of the Mycobacterium tuberculosis complex and to avoid secondary complications. Low plasma concentrations of these anti-TB drugs have been associated with extended treatment duration, therapeutic failure, and relapse. The determination of anthropometric, genetic, and clinical variables that may affect plasma concentrations of RMP and INH might facilitate the detection of patients at increased risk of therapeutic failure. METHODS: A prospective observational study was performed in patients with TB diagnosis. A fixed-dose combined formulation was administered following clinical guidelines, and 12 venous blood samples were collected within 24 hours after dose for the quantification of plasma levels of RMP and INH by high-performance liquid chromatography-ultraviolet. The plasma concentrations versus time for each drug in each patient were assessed by a noncompartmental approach to obtain Cmax, and the area under the concentration-time curve to the last observation point (AUC0-24 h) was calculated by the linear trapezoidal rule. Genetic polymorphisms of the enzyme involved in INH metabolism (NAT2) and proteins involved in RMP transport (glycoprotein-P and OATP1B1) were determined. RESULTS: A total of 34 patients aged between 18 and 72 years with the diagnosis of TB were included in the current study. A multivariate analysis was performed to determine the anthropometric and genetic characteristics that modified the Cmax and AUC0-24 h of RMP and INH. Results indicated that RMP Cmax and AUC0-24 h were affected by sex, dose/weight, and single nucleotide polymorphism of MDR1. In addition, age, body mass index, and NAT2 acetylator genotype were shown to determine the Cmax and AUC0-24 h for INH. CONCLUSIONS: Anthropometric, genetic, and dosage characteristics of Mexican patients with TB are an important source of risk for subtherapeutic plasma concentrations of anti-TB drugs. Factors such as lower-than-recommended RMP dose, male patients with TB, and MDR1 3435 genotype, in addition to age group, body mass index, and INH acetylator phenotype based on NAT2 genotype, should be considered during treatment.

"Differential risk of hospitalization among single virus infections causing influenza-like illnesses".

BACKGROUND: Acute respiratory infections are a major cause of morbidity in children and are often caused by viruses. However, the relative severity of illness associated with different viruses is unclear. The objective of this study was to evaluate the risk of hospitalization from different viruses in children presenting with an influenza-like illness (ILI). METHODS: Data from children 5 years old or younger participating in an ILI natural history study from April 2010 to March 2014 was analyzed. The adjusted odds ratio for hospitalization was estimated in children with infections caused by respiratory syncytial virus (RSV), metapneumovirus, bocavirus, parainfluenza viruses, rhinovirus/enterovirus, coronavirus, adenovirus, and influenza. RESULTS: A total of 1486 children (408 outpatients and 1078 inpatients) were included in this analysis. At least one virus was detected in 1227 (82.6%) patients. The most frequent viruses detected as single pathogens were RSV (n = 286), rhinovirus/enterovirus (n = 251), parainfluenza viruses (n = 104), and influenza A or B (n = 99). After controlling for potential confounders (age, sex, recruitment site, days from symptom onset to enrollment, and underlying illnesses), children with RSV and metapneumovirus infections showed a greater likelihood of hospitalization than those infected by parainfluenza viruses (OR 2.7 and 1.9, respectively), rhinovirus/enterovirus (OR 3.1 and 2.1, respectively), coronaviruses (OR 4.9 and 3.4, respectively), adenovirus (OR 4.6 and 3.2, respectively), and influenza (OR 6.3 and 4.4, respectively). CONCLUSIONS: Children presenting with ILI caused by RSV and metapneumovirus were at greatest risk for hospitalization, while children with rhinovirus/enterovirus, parainfluenza, coronavirus, adenovirus, and influenza were at lower risk of hospitalization.

Diagnostic accuracy cohort study and clinical value of the Histoplasma urine antigen (ALPHA Histoplasma EIA) for disseminated histoplasmosis among HIV infected patients: A multicenter study.

BACKGROUND: The Histoplasma urine antigen (HUAg) is the preferred method to diagnose progressive disseminated histoplasmosis (PDH) in HIV patients. In 2007, IMMY ALPHA Histoplasma EIA was approved for clinical for on-site use, and therefore useful for regions outside the United States. However, ALPHA-HUAg is considered inferior to the MVista-HUAg which is only available on referral. We aim to evaluate the diagnostic accuracy of ALPHA-HUAg. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a multicenter, prospective, diagnostic test study in two secondary and eight tertiary-care facilities in Mexico. We included HIV patient with PDH suspicion and evaluated ALPHA-HUAg diagnostic accuracy using as reference standard the Histoplasma capsulatum growth on blood, bone marrow, and tissue cultures or compatible histopathologic exam (PDH-proven). We evaluated the results of 288 patients, 29.5% (85/288; 95% confidence interval [CI], 24.3-35.1) had PDH. The sensitivity of ALPHA-HUAg was 67.1% (95% CI, 56-76.8%) and the specificity was 97.5% (95% CI, 94.3%-99.1%). The positive likelihood ratio was 27.2 (95% CI; 11.6-74.4). In 10.5% of the PDH-proven patients, a co-existing opportunistic infection was diagnosed, mostly disseminated Mycobacterium avium complex infection. CONCLUSIONS/SIGNIFICANCE: We observed a high specificity but low sensitivity of IMMY-HUAg. The test may be useful to start early antifungals, but a culture-based approach is necessary since co-infections are frequent and a negative IMMY-HUAg result does not rule out PDH.

Metabolomics applied to the discovery of tuberculosis and diabetes mellitus biomarkers.

Tuberculosis (TB) and diabetes mellitus Type 2 (DM2) are two diseases as ancient as they are harmful to human health. The outcome for both diseases in part depends on immune and metabolic individual responses. DM2 is increasing yearly, mainly due to environmental, genetic and lifestyle habits. There are multiple evidence that DM2 is one of the most important risk factor of becoming infected with TB or reactivating latent TB. Mass spectrometry-based metabolomics is an important tool for elucidating the metabolites and metabolic pathways that influence the immune responses to M. tuberculosis infection during diabetes. We provide an up-to-date review highlighting the importance and benefit of metabolomics for identifying biomarkers as candidate molecules for diagnosis, disease activity or prognosis.

Adhesion forces of biofilms developed in vitro from clinical strains of skin wounds.

A biofilm is a very complex consortium formed by a mix of different microorganisms, which have become an important health problem, because its formation is a resistance mechanism used by bacteria against antibiotics or the immune system. In this work, we show differences between some physicochemical properties of biofilms in mono- and multi-species, formed by bacteria from clinical samples of infected chronic wounds. Of the most prevalent bacteria in wounds, two mono- and one multi-species biofilms were developed in vitro by Drip Flow Reactor: one biofilm was developed by S. aureus, other by P. aeruginosa, and a third one by the mix of both strains. With these biofilms, we determined microbial growth by plate counting, and their physicochemical characterization by Atomic Force Microscopy, Raman Micro-Spectroscopy and Scanning Electron Microscopy. We found that the viability of S. aureus was less than P. aeruginosa in multi-species biofilm. However, the adhesion force of S. aureus is much higher than that of P. aeruginosa, but it decreased while that of P. aeruginosa increased in the multi-species biofilm. In addition, we found free pyrimidines functional groups in the P. aeruginosa biofilm and its mix with S. aureus. Surprisingly, each bacterium alone formed single layer biofilms, while the mix bacteria formed a multilayer biofilm at the same observation time. Our results show the necessity to evaluate biofilms from clinically isolated strains and have a better understanding of the adhesion forces of bacteria in biofilm multispecies, which could be of prime importance in developing more effective treatments against biofilm formation.

Analysis of transcription factors, microRNAs and cytokines involved in T lymphocyte differentiation in patients with tuberculosis after directly observed treatment short-course.

Tuberculosis (Tb) is an infectious disease in which the immune system plays an important role. MicroRNAs are involved in the development and maintenance of CD4 + T lymphocyte subpopulations. miR-326 regulates the differentiation to Th17 cells and miR-29 correlates with the Th1 response. The aim of this study was to determine the role of microRNAs, Transcription Factors, and cytokines in Th differentiation before and after the directly observed treatment short-course (DOTS). Peripheral blood mononuclear cells and serum from Tb patients were collected at times 0 (before therapy), 2 (after the intensive phase), and 6 months (after the holding phase). The cells were cultivated in presence or absence of ESAT-6 (10 µg/ml) and CFP-10 (10 µg/ml). Transcription Factor and microRNA expressions were analyzed by qPCR and cytokine production in both serum and culture supernatant using ELISA. A decrease in Th1 response with a diminishing in the relative expression of TBET and miR-29a at 2 and 6 months after the anti-Tb therapy (p < 0.01) were found. The miR-326 levels decreased after the intensive phase of the DOTS scheme. However, subdivision of the Tb patients according to gender, showed increased levels of miR-29a and miR-155 in females after the intensive phase of the therapeutic treatment when compared to time 0 and similar increased levels of miR-326 at time 6 versus time 0. In contrast, we observed a decrease in miR-326 levels in males at 6 months when compared to before therapy (time 0). In addition, high production of IL-17 in the culture supernatant was found at 2 and 6 months (p < 0.05) while in serum IL-17 was decreased. A positive correlation between IL-17 and RORC2 at time 6 was detected (p = 0.0202, r = 0.7880). In conclusion, these data suggest a reduction in Th1 and an induction of Th17 response after the anti-Tb therapy.

Clinical characteristics of asthmatic patients with influenza-like illness and risk of severe exacerbations in Mexico.

BACKGROUND: Patients with chronic inflammatory lung diseases, such as asthma, are at higher risk for influenza-like illness (ILI) complications. Viral infections are known to trigger asthma exacerbations, but a thorough description of the clinical characteristics of ILI-associated asthma exacerbations and the role of viruses as a risk factor for severe exacerbation (SE) in ILI has not been published yet. OBJECTIVE: To investigate risk factors for SE in patients with ILI and asthma. METHODS: Patients with ILI symptoms were recruited from 6 hospitals of Mexico (LaRed sites) during 2010 to 2014. Those with a previous asthma diagnosis and ILI symptoms and who were 5 years or older were included. Patients were assigned as cases or controls based on symptoms reported. SE was defined when participants presented with wheezing or dyspnea and required hospitalization. RESULTS: A total of 486 patients with ILI and a diagnosis of asthma were included. There were no differences in the proportion, number, or type of viral illness among those with and without SE. Those with SE were less likely to report ILI symptoms. Muscle pain and nasal drip were predictors for patients not progressing to SE. A delay in seeking medical care was associated with SE (odds ratio, 2.93; 95% CI, 1.46-5.88). CONCLUSION: The presence of a particular virus did not predict SE. ILI symptoms in asthma patients are not associated with severe exacerbation. Patients with asthma should be encouraged to seek early medical care when ILI symptoms are first noticed to prevent serious complications.

Outbreak Caused by blaOXA-72-Producing Acinetobacter baumannii ST417 Detected in Clinical and Environmental Isolates.

We characterized an outbreak of imipenem-resistant Acinetobacter baumannii with clinical and environmental isolates from a tertiary care hospital in San Luis Potosi, Mexico. During a 4-month period, a total of 32 nonrepetitive imipenem-resistant clinical isolates of A. baumannii were collected. All isolates were susceptible to colistin and tigecycline and resistant to cefepime, ceftazidime, ceftriaxone, imipenem, and meropenem. Genotyping by pulsed-field gel electrophoresis showed a major clone (A). Multilocus sequence type (MLST) analysis was performed, revealing sequence type (ST) 417 (ST417) and 208 (ST208). The blaIMP-, blaVIM-, blaGIM-, blaSIM-, blaNDM-type, and blaOXA-type (blaOXA-23-like, blaOXA-24-like, blaOXA-51-like, and blaOXA-58-like) genes were screened and showed that the blaOXA-51-like and blaOXA-24-like genes were present in all isolates. Sequencing and southern hybridization were performed, confirming the presence of the blaOXA-72 gene and its plasmid-borne nature. In addition, the blaOXA-72-XerC/XerD-like association was identified. These findings indicate that a clonal spread of blaOXA-72-producing A. baumannii ST417 had occurred throughout the hospital. The ST417 corresponded with a previous ST described in the United States.

Diabetes and Other Risk Factors for Multi-drug Resistant Tuberculosis in a Mexican Population with Pulmonary Tuberculosis: Case Control Study.

BACKGROUND AND AIMS: Multidrug resistant tuberculosis (MDR-TB) poses problems in treatment, costs and treatment outcomes. It is not known if classically described risk factors for MDR-TB in other countries are the same in Mexico and the frequency of the association between diabetes mellitus (DM) and MDR-TB in our country is not clear. We undertook this study to analyze risk factors associated with the development of MDR-TB, with emphasis on DM. METHODS: A case-control study in the state of San Luis Potosi (SLP), Mexico was carried out. All pulmonary MDR-TB patients diagnosed in the state of SLP between 1998 and 2013 (36 cases) evaluated at a state pharmacoresistant tuberculosis (TB) clinic and committee; 139 controls were randomly selected from all pulmonary non-multidrug-resistant tuberculosis (non-MDR-TB) cases identified between 2003 and 2008. Cases and controls were diagnosed and treated under programmatic conditions. RESULTS: Age, gender, malnutrition, being a health-care worker, HIV/AIDS status, and drug abuse were not significantly different between MDR-TB and non-MDR-TB patients. Significant differences between MDR-TB and non-MDR-TB patients were DM (47.2 vs. 28.1%; p = 0.028); previous anti-TB treatments (3 vs. 0, respectively; p <0.001), and duration of first anti-TB treatment (8 vs. 6 months, respectively; p <0.001). CONCLUSIONS: MDR-TB and DM are associated in 47.2% of MDR TB cases (17/36) in this study. Other recognized factors were not found to be significantly different in MDR-TB compared to non-MDR-TB in this study. Cost-feasible strategies must be implemented in the treatment of DM-TB in order to prevent the selection of MDR-TB.