Emergence of Fosfomycin Resistance by Plasmid-Mediated fos Genes in Uropathogenic ESBL-Producing E. coli Isolates in Mexico.

Fosfomycin is currently a viable option against urinary tract infections, particularly against extended-spectrum ß-lactamases (ESBL)-producing E. coli, due to its unique mechanism of action and its low resistance among bacteria. The objective of this study was to investigate two of the three most common mechanisms of resistance against this antibiotic among 350 ESBL-producing E. coli strains isolated from the urine of Mexican patients. The prevalence of fosfomycin resistance in our study was 10.9% (38/350). Of all resistant isolates analyzed, 23 (60.5%) were identified as fos-producing organisms, with 14 strains carrying fosA3 and 9, fosA1. Additionally, 11 (28.9%) fosfomycin-resistant isolates presented resistance due to impaired antibiotic transport and 8 (21.0%) both mechanisms. No resistance mechanism investigated in the study was found on 12 strains. All 38 confirmed ESBL-producing isolates carried a blaCTX-M subtype, 36 (94.5%) belonged to the O25b-ST131 clone, and all of them were able to transfer the fosfomycin resistance trait to recipient strains horizontally. This is the first study in Mexico demonstrating a plasmid-mediated fosfomycin resistance mechanism among clinical E. coli strains. Since our results suggest a strong association among fos and blaCTX-M genes and ST131 clones in uropathogenic E. coli, plasmid-mediated fosfomycin resistance should be closely monitored.

Drug resistance phenotypes and genotypes in Mexico in representative gram-negative species: Results from the infivar network.

AIM: This report presents phenotypic and genetic data on the prevalence and characteristics of extended-spectrum ß-lactamases (ESBLs) and representative carbapenemases-producing Gram-negative species in Mexico. MATERIAL AND METHODS: A total of 52 centers participated, 43 hospital-based laboratories and 9 external laboratories. The distribution of antimicrobial resistance data for Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae complex, Acinetobacter baumannii complex, and Pseudomonas aeruginosa in selected clinical specimens from January 1 to March 31, 2020 was analyzed using the WHONET 5.6 platform. The following clinical isolates recovered from selected specimens were included: carbapenem-resistant Enterobacteriaceae, ESBL or carbapenem-resistant E. coli, and K. pneumoniae, carbapenem-resistant A. baumannii complex, and P. aeruginosa. Strains were genotyped to detect ESBL and/or carbapenemase-encoding genes. RESULTS: Among blood isolates, A. baumannii complex showed more than 68% resistance for all antibiotics tested, and among Enterobacteria, E. cloacae complex showed higher resistance to carbapenems. A. baumannii complex showed a higher resistance pattern for respiratory specimens, with only amikacin having a resistance lower than 70%. Among K. pneumoniae isolates, blaTEM, blaSHV, and blaCTX were detected in 68.79%, 72.3%, and 91.9% of isolates, respectively. Among E. coli isolates, blaTEM, blaSHV, and blaCTX were detected in 20.8%, 4.53%, and 85.7% isolates, respectively. For both species, the most frequent genotype was blaCTX-M-15. Among Enterobacteriaceae, the most frequently detected carbapenemase-encoding gene was blaNDM-1 (81.5%), followed by blaOXA-232 (14.8%) and blaoxa-181(7.4%), in A. baumannii was blaOXA-24 (76%) and in P. aeruginosa, was blaIMP (25.3%), followed by blaGES and blaVIM (13.1% each). CONCLUSION: Our study reports that NDM-1 is the most frequent carbapenemase-encoding gene in Mexico in Enterobacteriaceae with the circulation of the oxacillinase genes 181 and 232. KPC, in contrast to other countries in Latin America and the USA, is a rare occurrence. Additionally, a high circulation of ESBL blaCTX-M-15 exists in both E. coli and K. pneumoniae.

The Evolution of Antimicrobial Resistance in Mexico During the Last Decade: Results from the INVIFAR Group.

Background: Surveillance of antimicrobial resistance (AMR) requires an international approach with national and local strategies. Our aim was to summarize a retrospective 10-year report of antibiotic resistance of gram-positive and gram-negative bacteria in Mexico. Methods: A total of 46 centers from 22 states of Mexico participated. Databases of AMR from January 2009 to December 2018 were included for most species. The 10-year period was divided into five 2-year periods. Results: For Staphylococcus aureus, a decrease in resistance in all specimens was observed for erythromycin and oxacillin (p < 0.0001 for each). For Enterobacter spp., resistance to meropenem increased for urine specimens (p = 0.0042). For Klebsiella spp., increased drug resistance in specimens collected from blood was observed for trimethoprim/sulfamethoxazole, gentamicin, tobramycin (p < 0.0001 for each), meropenem (p = 0.0014), and aztreonam (p = 0.0030). For Acinetobacter baumannii complex, high drug resistance was detected for almost all antibiotics, including carbapenems, except for tobramycin, which showed decreased resistance for urine, respiratory, and blood isolates (p < 0.0001 for each), and for amikacin, which showed a decrease in resistance in urine specimens (p = 0.0002). An increase in resistance to cefepime was found for urine, respiratory, and blood specimens (p < 0.0001 for each). For Pseudomonas aeruginosa, aztreonam resistance increased for isolates recovered from blood (p = 0.0001). Conclusion: This laboratory-based surveillance of antibiotic resistance shows that resistance is increasing for some antibiotics in different bacterial species in Mexico and highlights the need for continuous monitoring of antibiotic resistance.

A snapshot of antimicrobial resistance in Mexico. Results from 47 centers from 20 states during a six-month period.

AIM: We aimed to assess the resistance rates of antimicrobial-resistant, in bacterial pathogens of epidemiological importance in 47 Mexican centers. MATERIAL AND METHODS: In this retrospective study, we included a stratified sample of 47 centers, covering 20 Mexican states. Selected isolates considered as potential causatives of disease collected over a 6-month period were included. Laboratories employed their usual methods to perform microbiological studies. The results were deposited into a database and analyzed with the WHONET 5.6 software. RESULTS: In this 6-month study, a total of 22,943 strains were included. Regarding Gram-negatives, carbapenem resistance was detected in ≤ 3% in Escherichia coli, 12.5% in Klebsiella sp. and Enterobacter sp., and up to 40% in Pseudomonas aeruginosa; in the latter, the resistance rate for piperacillin-tazobactam (TZP) was as high as 19.1%. In Acinetobacter sp., resistance rates for cefepime, ciprofloxacin, meropenem, and TZP were higher than 50%. Regarding Gram-positives, methicillin resistance in Staphylococcus aureus (MRSA) was as high as 21.4%, and vancomycin (VAN) resistance reached up to 21% in Enterococcus faecium. Acinetobacter sp. presented the highest multidrug resistance (53%) followed by Klebsiella sp. (22.6%) and E. coli (19.4%). CONCLUSION: The multidrug resistance of Acinetobacter sp., Klebsiella sp. and E. coli and the carbapenem resistance in specific groups of enterobacteria deserve special attention in Mexico. Vancomycin-resistant enterococci (VRE) and MRSA are common in our hospitals. Our results present valuable information for the implementation of measures to control drug resistance.

Abordaje supra-cerebeloso trans-tentorial para la resección de MAV del lóbulo temporal mesial posterior / Supra-cerebellar trans-tentorial approach for the resection of AVM of the posterior mesial temporal lobe

OBJETIVO: El propósito de los autores es mostrar los beneficios del abordaje Supra-Cerebeloso Trans-Tentorial (SCTT) para lesiones que se localizan en la región del lóbulo temporal mesial posterior, y la posibilidad técnica de realizar este procedimiento. INTRODUCCIÓN: El abordaje SCTT para alcanzar la región del lóbulo temporal mesial ha sido muy bien descripto en la última década, y ampliamente utilizado por algunos grupos neuroquirúrgicos internacionales durante los últimos dos años, para la resección de patologías vasculares (MAV, aneurismas, cavernomas), lesiones neoplásicas de distintas estirpes y para la resección de estructuras encefálicas relacionadas con la epilepsia. INTERVENCIÓN: Los autores han practicado esta vía de abordaje en una paciente de 58 años, que presentó una hemorragia intracraneana (HSA, hematoma temporal posterior profundo derecho, hemoventrículos), hemiparesia moderada izquierda y estado de obnubilación; a la que se le realiza el diagnóstico por RMN y angiografía digital, de MAV en la región del lóbulo temporal mesial posterior derecho. DISCUSIÓN: El abordaje SCTT a la región del lóbulo temporal mesial posterior no sólo con la apertura del tentorio sino con la resección total o parcial del mismo, ofrece la posibilidad única de acceder a lesiones vasculares, neoplásicas y/o funcionales que se localizan en esta zona, sin la necesidad de realizar una retracción cerebral excesiva que se torna prácticamente mandatoria al practicar la vía subtemporal, ampliamente difundida para el tratamiento quirúrgico de las patologías que se asientan en esta ubicación. CONCLUSIÓN: El abordaje SCTT para la exéresis de patologías que se encuentran en la región del lóbulo temporal mesial posterior, es una alternativa que presenta un valor excepcional a la hora de elegir una estrategia quirúrgica, evitando por completo la retracción del lóbulo temporal y, por lo tanto, las consecuencias que se asocian a esta maniobra. Si bien este abordaje ha sido bien descripto por varios autores extranjeros, no es de amplia utilización en nuestro medio

Microbial contamination in 20-peso banknotes in Monterrey, Mexico.

The authors' aim was to isolate and identify bacteria or yeast that may be present on the surface of 20-peso banknotes from the metropolitan area of Monterrey, Mexico. They randomly studied a total of 70 20-peso banknotes for the presence of bacteria and species of Candida by conventional methods. Out of the 70 banknotes, 48 (69%) were found to be contaminated. The most prevalent species observed was Candida kruseii (19 bills, 27%) followed by Burkholderia cepacia (9 bills, 13%); 22 (31%) bills showed no growth. Of the 48 contaminated bills, four (5.7%) yielded bacteria considered pathogenic and the other 44 bills (63%) yielded bacteria considered potentially pathogenic. Eleven bills showed more than one microbial species. The results of the authors' study show that contamination occurs on paper currency in the metropolitan area of Monterrey. The authors' findings provide evidence that currency banknotes may represent a threat to human health.

En-bloc craniotomy for the pre-sigmoid infra- and supratentorial approach: technical note.

INTRODUCTION: The combined supra-infratentorial approach as described some 30 years ago is to date considered a standard procedure for skull base procedures. Several variants have been devised, including preservation of the mastoid process. We herein present the cosmetically most sophisticated and fastest solution. OBJECTIVES: The authors describe an en bloc supra- and infratentorial pre-sigmoid combined approach. This variant of surgical technique involves a one-piece bone flap (temporal-suboccipital-mastoideal flap). We present another variant of craniotomy for the combined supra- and infratentorial pre-sigmoid approach that preserves the mastoid process and thus appears to be cosmetically much more acceptable. MATERIALS AND METHODS: Eight dry cadaveric skulls were used to develop an ideal one-piece excision of the cranial vault across the transverse sinus, including portions of the mastoid. Our aim was that no further drilling of the basal skull was needed. The procedure thereafter was practiced on a fresh prepared cadaveric specimen where its feasibility was again confirmed and was then applied to a patient suffering from a huge petroclival meningioma. It was very well tolerated and produced an excellent long-term cosmetic result. DISCUSSION: The combined supra- and infratentorial pre-sigmoid approach offers the possibility of resecting complex petroclival lesions. The variant presented herein is less time consuming than previously described methods and probably offers the best possible cosmetic result. CONCLUSION: The en-bloc cranioplastic approach with preservation of the mastoid process is a new, interesting variant of a classical technique that is easy to perform and has the intention of achieving the best possible cosmetic result.

Abordaje cosmético supra/infratentorial pre-sigmoideo en bloque: técnica original / Cosmetic supra/infratentoral presigmoid approach: original technique

Objetivo: presentar una variante original del abordaje supra/infratentorial presigmoideo que preserva la apófisis mastoidea. Material y método: se practicó este abordaje en ocho cráneos secos, dos procedimientos por espécimen y posteriormente fue realizado en un preparado fresco. Posteriormente se realizó esta técnica quirúrgica en una paciente que presentaba una lesión compatible con un meningioma petroclivalen las imágenes de IRM. Discusión: el abordaje supra/ifratentorial pre-sigmoideo ofrece la posibilidad de resecar lesiones complejas de la región petroclival. Desde su popularización han sido diversas las variantes descriptivas sobre esta técnica quirúrgica con el objetivo de obtener un buen resultado cosmético postoperatorio. Conclusión: el abordaje supra/infratentorial pre-sigmoideo con preservación de la porción mastoidea en una sola pieza es una variante interesante del procedimiento clásico que tiene el propósito de lograr un buen resultado cosmético.

Spatial and temporal variations and mobile source emissions of polycyclic aromatic hydrocarbons in Quito, Ecuador.

Motor vehicles are a major source of air pollution in Quito, Ecuador; however, little work has been done to characterize spatial and temporal variations in traffic-related pollutants, or to measure pollutants in vehicle emissions. We measured PAH continuously for one year at two residential sites in Quito, and PAH and traffic patterns for one week near a busy roadway. Morning rush-hour traffic and temperature inversions caused daily PAH maxima between 06:00 and 08:00. SO2, NOx, CO, and PM(2.5) behaved similarly. At the residential sites PAH levels during inversions were 2-3-fold higher than during the afternoon, and 10-16-fold higher than 02:00-03:00 when levels were lowest. In contrast, at the near-roadway site, PAH concentrations were 3-6-fold higher than at the residential sites, and the effects of inversions were less pronounced. Cars and buses accounted for >95% of PAH at the near-roadway site. Near-roadway PAH concentrations were comparable to other polluted cities.

Manifestaciones usuales e inusuales de la neurocisticercosis / Usual and unusual manifestations of the neurocisticercosis

Propósito: Caracterizar las diferentes formas de presentación de la neurocisticercosis y sus diagnósticos diferenciales. Materiales y métodos: Se evaluaron 12 pacientes, con edades comprendidas entre 1 y 65 años (media de 43 años), con resonancia magnética (RM) encefálica y espinal (1.5T Magnetom Symphony, Siemens, Erlangen, Alemania), previa y posterior a la administración de gadolinio (Gadoversetamida, Mallinckrodt Inc). Resultados: De los doce pacientes estudiados, siete presentaron compromiso parenquimatoso encefálico exclusivo en diferentes estadios evolutivos; cuatro, compromiso mixto encefálico y subaracnoideo; uno, compromiso mixto espinal, intraventricular y subaracnoideo. Conclusión: La neurocisticercosis es la infección parasitaria más frecuente del SNC en países en vías de desarrollo. Si bien la afección intraparenquimatosa se presenta en más del 50 por ciento de los casos y sus características han sido bien descritas en la bibliografía, la resonancia magnética constituye una herramienta de gran valor en el análisis de sus manifestaciones inusuales y el médico radiólogo debe poder reconocerlas a fin de facilitar su diagnóstico y tratamiento oportuno y así evitar eventuales complicaciones.

[Stereotactic radiosurgery with linear accelerator (LINAC). Report of the technical experience in 100 cases treated at the Mexico General Hospital]. / Radiocirugía estereotáxica con acelerador lineal (LINAC). Informe de la experiencia técnica en el manejo de 100 casos en el Hospital General de México.

UNLABELLED: Stereotactic radiosurgery consists of the release and high dose radiation inside the intracraneal, small, well defined and stereotactic localized injury. OBJECTIVE: In this study we describe the technical aspects, clinical results and dose radiation levels used in 100 patients treated with LINAC. METHODS: One hundred patients received treatment with LINAC stereotactic radiosurgery, 34 AVM, 22 meningiomas, 18 astrocytomas, 11 pituitary adenomas, 5 cavernous malformations, 3 acoustic neuromas, 3 craniopharyngiomas, 2 cases of epilepsy, one brain metastasis and one ependymoma. The radiation dose changed in each case. Studied variables: response of the injury, toxicity, in target dose, number of isocenters, number of treatment arcs, number o fcollimators, dose of risk organ, homogeneity of target, margin of error, target, diameter of collimator and location of target. We applied the chi2 test with statistical significance of p < 0.05. RESULTS: The median follow-up was 17.7 months. We had 3 cases of minor toxicity. We confirmed that for a greater target volume, greater number of treatment arcs were necessary, with greater margins of errors and greater number of isocenters. CONCLUSIONS: Radiosurgery is a safe and reliable technique to treat benign and malignant intracraneal lesions.

Radiocirugía estereotáxica con acelerador lineal (LINAC): Informe de la experiencia técnica en el manejo de 100 casos en el Hospital General de México / Stereotactic radiosurgery with linear accelerator (LINAC): Report of the technical experience in 100 cases treated at the Mexico General Hospital

La radiocirugía estereotáxica consiste en la liberación de una dosis única y grande de radiación a una lesión intracraneal, pequeña, bien definida y localizada estereotáxicamente. Objetivo: El objetivo de este estudio es detallar las consideraciones técnicas y correlacionarlas con los resultados clínicos, así como reportar los márgenes de dosis utilizados. Métodos: Fueron tratados 100 pacientes mediante radiocirugía estereotáxica con LINAC. Treinta y cuatro casos de malformaciones arteriovenosas, 22 meningiomas, 18 astrocitomas, 11 adenomas hipofisiarios, 5 angiomas cavernosos, 3 neurinomas del acústico, 3 craneofaringiomas, 2 casos de epilepsia, una metástasis cerebral y un ependimoma. Las dosis de radiación utilizadas variaron en cada caso. Variables estudiadas: respuesta de la lesión, toxicidad, dosis al volumen blanco, número de isocentros, número de arcos de tratamiento, número de colimadores, dosis a órganos riesgo, homogeneidad volumen blanco, margen de error, volumen blanco, diámetro de colimadores y localización del volumen blanco. Se realizó la prueba x² con significancia estadística p <0.05. La media seguimiento fue de 17.7 meses. Resultados: Se presentaron tres casos de toxicidad menor. Se confirmó que a mayor volumen blanco tratado será necesario mayor número de arcos de tratamiento, con amplio margen de error y mayor número de isocentros. Conclusión: La radiocirugía es un método seguro y confiable para el manejo de entidades patológicas benignas y malignas intracraneales.

Stereotactic radiosurgery consists of the release and high dose radiation inside the intracraneal, small, well defined and stereotactic localized injury. Objective: In this study we describe the technical aspects, clinical results and dose radiation levels used in 100 patients treated with LINAC. Methods: One hundred patients received treatment withe LINAC stereotactic radiosurgery, 34 AVM, 22 meningiomas, 18 astrocytomas, 11 pituitary adenomas, 5 cavernous malformations, 3 acoustic neuromas, 3 craniopharyngiomas, 2 cases of epilepsy, one brain metastases and one ependymoma. The radiation dose changed in each case. Studied variables: response of the injury, toxicity, in target dose, number of isocenters, number of treatment arcs, number of collimators, dose of risk organ, homogeneity of target, margin of error, target, diameter of collimator and location of target. We applied the %2 test with statistical significance of p < 0.05. Results: The median follow up was 17.7 months. We had 3 cases of minor toxicity. We confirmed that for a greater target volume, greater number oftreatment arcs were necessary, with greater margins of errors and greater number of isocenters. Conclusions: Radiosurgery is a safe and reliable technique to treat benign and malignant intracranial lesions.

Acute respiratory diseases and carboxyhemoglobin status in school children of Quito, Ecuador.

Outdoor carbon monoxide comes mainly from vehicular emissions, and high concentrations occur in areas with heavy traffic congestion. CO binds to hemoglobin, forming carboxyhemoglobin (COHb), and reduces oxygen delivery. We investigated the link between the adverse effects of CO on the respiratory system using COHb as a marker for chronic CO exposure. We examined the relationship between acute respiratory infections (ARIs) and COHb concentrations in school-age children living in urban and suburban areas of Quito, Ecuador. We selected three schools located in areas with different traffic intensities and enrolled 960 children. To adjust for potential confounders we conducted a detailed survey. In a random subsample of 295 children, we determined that average COHb concentrations were significantly higher in children attending schools in areas with high and moderate traffic, compared with the low-traffic area. The percentage of children with COHb concentrations above the safe level of 2.5% were 1, 43, and 92% in low-, moderate-, and high-traffic areas, respectively. Children with COHb above the safe level are 3.25 [95% confidence interval (CI), 1.65-6.38] times more likely to have ARI than children with COHb < 2.5%. Furthermore, with each percent increase in COHb above the safety level, children are 1.15 (95% CI, 1.03-1.28) times more likely to have an additional case of ARI. Our findings provide strong evidence of the relation between CO exposure and susceptibility to respiratory infections.

Tratamiento quirúrgico del desequilibrio patelofemoral / Surgical treatment of patellofemoral unbalance

Se realizó un estudio retrospectivo y descriptivo en 38 pacientes operados con desequilibrios patelofemorales durante los años 2001-2002 en el Complejo Científico Ortopédico Internacional "Frank País". El intervalo de edad más frecuente en el que se observaron los desequilibrios fue entre 20 y 29 años, predominó el sexo femenino en el 68,1 por ciento; eran trabajadores el 52,6 por ciento de los pacientes. La luxación recidivante de rótula fue la entidad nosológica más frecuentemente observada. La liberación del retináculo lateral por artroscopia se practicó en el 34,2 por ciento y se obtuvieron resultados excelentes en el 76,9 por ciento de la muestra estudiada. La sinovitis de rodilla fue la complicación más frecuente

Tratamiento quirúrgico del desequilibrio patelofemoral / Surgical treatment of patellofemoral unbalance

Se realizó un estudio retrospectivo y descriptivo en 38 pacientes operados con desequilibrios patelofemorales durante los años 2001-2002 en el Complejo Científico Ortopédico Internacional "Frank País". El intervalo de edad más frecuente en el que se observaron los desequilibrios fue entre 20 y 29 años, predominó el sexo femenino en el 68,1 por ciento; eran trabajadores el 52,6 por ciento de los pacientes. La luxación recidivante de rótula fue la entidad nosológica más frecuentemente observada. La liberación del retináculo lateral por artroscopia se practicó en el 34,2 por ciento y se obtuvieron resultados excelentes en el 76,9 por ciento de la muestra estudiada. La sinovitis de rodilla fue la complicación más frecuente(AU)

Hemorragia subaracnoidea perimesencefálica de origen venoso / Subarachnoid mesencephalic hemorrhage

Se presenta el caso de un paciente de sexo masculino de 57 años de edad que consulta por cefalea aguda sin signos de irritación meníngea ni de foco neurológico. La tomografía computada inicial evidenció una hemorragia subaracnoidea perimesencefálica. Se realizaron posteriormente resonancia magnética de encéfalo y angiografía digital, interpretándose el sangrado como secundario a una alteración en el estado hemodinámico provocado por trombosis venosa cerebral

Hemorragia subaracnoidea perimesencefálica de origen venoso / Subarachnoid mesencephalic hemorrhage

Se presenta el caso de un paciente de sexo masculino de 57 años de edad que consulta por cefalea aguda sin signos de irritación meníngea ni de foco neurológico. La tomografía computada inicial evidenció una hemorragia subaracnoidea perimesencefálica. Se realizaron posteriormente resonancia magnética de encéfalo y angiografía digital, interpretándose el sangrado como secundario a una alteración en el estado hemodinámico provocado por trombosis venosa cerebral (AU)