Abstract Long-chain polyunsaturated fatty acids (LC-PUFAs) are critical for infant growth and development, particularly arachidonic acid (ARA, C20:4n-6) and docosahexaenoic acid (DHA, C22:6n-3). ARA and DHA are components of cell membrane phospholipids and play an important role in cell division, differentiation, and signaling; and DHA is the n-3 fatty acid predominant in the developing brain and retina. During the third trimester of pregnancy, LC-PUFAs increase substantially in fetal circulation, and a “biomagnification” process in the fetal brain is observed. Moreover, LC-PUFAs are precursors of eicosanoids and metabolites, which modulate the intensity and duration of the immune response. LC-PUFA synthesis implies complex desaturation and elongation processes on their principal precursors, linoleic acid (LA) (18:3 n-6) (series n-6) and α-linolenic acid (LNA) (20:3 n-3) (series n-3), where fatty acid desaturases (FADS) and elongases (ELOVL) are competing. It is important to notice that during the first months of life, as a consequence of low enzymatic activity, LC-PUFA synthesis from LA and LNA is reduced, especially in those infants carrying variations in the FADS and ELOVL genes, which are involved in LC-PUFA synthesis, and so they are unable to supply their own DHA and ARA needs. Homozygote infants for FADS haplotype A (97 % of the Latinoamerican population) show low levels of ARA (only 43 %) and DHA (only 24 %) when compared to those carrying haplotype D (more prevalent in Europe, Africa and Asia). Human milk is the only source of LA, LNA, ARA, and DHA for the neonate and infant till complementary feeding (CF) is introduced. Infants fed with infant formulas must receive enough amounts of LA, LNA, ARA, and DHA to cover their nutritional requirements. The new guidelines by the European Food Safety Authority (EFSA) (2016) recommend that infant formulas and follow-on formulas must contain 20-50 mg of DHA/100 kcal (0.5-1 % of total fatty acids, which is higher than in human milk and the majority of infant formulas in the market), and it is not necessary to add ARA. This new regulation, which is already applicable since February 2020, has resulted in profound controversy because there is no scientific evidence about its appropriateness and safety for healthy children. Then, different international expert groups have revised the research already published about the effects of ARA and DHA addition to infant formulas, and discussed different emerging questions from this European directive. The expert group led from the University of Granada (Spain) recommends the addition of ARA in similar or higher concentrations than those of DHA, at least equal to those present in human milk (0.3 % of total fatty acids), although preferably 0.5 % and up to around 0.64 % of total fatty acids, since new studies confirm the optimal intake of ARA and DHA during the different developmental stages. This recommendation could be of particular importance for infants carrying the haplotype A of FADS.

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Abstract Objectives: To evaluate the effect of azithromycin (AZM) on biofilm formation and composition in multidrug resistant (MDR) Acinetobacter baumannii. Material and methods: Ninety-six A. baumannii isolates were studied. Antimicrobial susceptibility and sub-minimum inhibitory concentration (sub-MIC) were determined by the broth microdilution method. Carbapenemase genes were detected by polymerase chain reaction and clonal diversity by pulsed-field gel electrophoresis (PFGE). Biofilm formation without AZM and AZM sub-MIC were determined by crystal violet staining. AZM-free biofilm composition and AZM sub-MIC were determined by detachment assays. Results: The selected A. baumannii were MDR; 93.8 % were carbapenem-resistant and 24 were OXA-24-positive. PFGE showed predominance of clones A (53 %), B (34.7 %) and C (12.5 %). Biofilm production at AZM sub-MICs decreased in 53.1 %, increased in 34.7 % and showed no differences in 12.5 % of isolates, in comparison with biofilm production without AZM. Conclusion: AZM sub-MIC can reduce biofilm production in A. baumannii MDR isolates with decreased protein and DNA in the biofilm. Our results may be useful in synergy studies for new therapeutic alternatives.

Resumen Objetivos: Evaluar el efecto de la azitromicina (AZM) en la formación y composición de biopelículas en Acinetobacter baumannii resistente a múltiples fármacos (MDR). Material y métodos: Se estudiaron 96 aislamientos de A. baumannii. La susceptibilidad antimicrobiana y la concentración inhibitoria submínima (sub-MIC) se determinaron por el método de microdilución del caldo. Los genes carbapenemasa fueron detectados por reacción en cadena de la polimerasa y la diversidad clonal por electroforesis en gel de campos pulsados (PFGE). La formación de biopelículas sin AZM y la sub-MIC de AZM por tinción de cristal violeta. La composición de la biopelícula sin AZM y la sub-MIC de AZM se determinaron mediante ensayos de desprendimiento. Resultados: Los A. baumannii seleccionados fueron MDR; el 93.8% resistentes al carbapenem y 24 OXA-24 positivos. El PFGE demostró predominancia en los clones A (53%), B (34.7%) y C (12.5%). La producción de biopelículas en sub-MIC de AZM disminuyó en un 53.1%, aumentó en un 34.7% y no mostró diferencias en un 12.5% de los aislamientos, comparado con la producción de biopelículas sin AZM. Conclusión: La sub-MIC de AZM puede reducir la producción de biopelículas en aislamientos de A. baumannii MDR con disminución de proteínas y el ADN en la biopelícula. Nuestros resultados pueden ser útiles en estudios de sinergia para nuevas alternativas terapéuticas.

Abstract Objective: To describe the causal agents, prevalence of antimicrobial resistance, and risk factors associated with extended spectrum beta-lactamase (ESBL)-producing agents in urinary tract infections (UTIs). Materials and methods: A retrospective study was conducted at a tertiary care hospital in Monterrey, Mexico. Inclusion criteria were patients that clinically presented with a UTI and had a positive urine culture, within the time frame of March to October 2017. The association with ESBL-producing agents was determined through the Χ2 test for categorical variables. Statistical significance was set at a p <0.05, utilizing SPSS version 20.0 software. Results: A total of 353 positive urine cultures were confirmed. ESBL production was found in 21.5% of the strains. There was a high level of resistance (>50%) to amoxicillin-clavulanate, ciprofloxacin, levofloxacin, fosfomycin, and trimethoprim-sulfamethoxazole and moderate resistance (10-50%) to gentamicin and ceftriaxone. Amikacin, ertapenem, nitrofurantoin, and colistin had the lowest resistance rates (<10%). The ESBL-producing agents were associated with complicated UTI (p≤0.0001). The comorbidities associated with ESBL-positive UTIs were diabetes mellitus (p=0.02) and immunodeficiency (p=0.008), as was having undergone radiotherapy (p=0.025) and previous antibiotic use (p≤0.001). Limitations: The clonal relationship of isolates, especially of E. coli, was not analyzed. We could not establish whether there was a high level of genetic diversity between the isolates or whether independent acquisition or cross-transmission occurred. Value: We evaluated the epidemiologic characteristics of the ESBL-producing agents in UTIs at a Mexican tertiary care hospital. Conclusions: One out of every five UTIs was caused by ESBLs in our study population. There was a high level of resistance to the antibiotics used as first-line empiric therapy in the patients studied.

Resumen Objetivo: Describir los agentes causales, la prevalencia de resistencia a antibióticos y determinar factores de riesgo asociados con agentes productores de betalactamasa de espectro extendido (BLEE) en las infecciones del tracto urinario (ITU). Materiales y métodos: Realizamos una cohorte retrospectiva en un hospital de III Nivel en Monterrey, México. Se incluyeron pacientes con clínica de ITU de marzo a octubre del 2017 con urocultivo positivo. Se determinó la asociación con agentes productores de BLEE, utilizando la prueba Χ2 para variables categóricas y la prueba T para variables continuas. La significancia estadística se estableció en p <0.05 utilizando SPSS versión 20.0. Resultados: 353 urocultivos positivos fueron recabados. La producción de BLEE se encontró en 21.5%. Altas resistencias a amoxicilina-clavulanato (75%) y moderada resistencia a gentamicina, aztreonam, ceftriaxona, ciprofloxacina, levofloxacina, fosfomicina y trimetoprima-sulfametoxazol fueron encontradas. Los agentes BLEE se asociaron con ITU complicada (p = <0.0001) y se asociaron con DM2 (p = 0.02), inmunodeficiencia (p = 0.008), radioterapia (p = 0.025) y uso previo de antibióticos (p = <0.001). Limitaciones: La relación clonal de los aislamientos, especialmente de E. coli, no se analizó. No podemos establecer si hubo diversidad genética entre los aislamientos y si ocurrió adquisición independiente o transmisión cruzada. Valor: Evaluamos las características epidemiológicas de los agentes productores de BLEE en ITU en un hospital de III Nivel de México. Conclusiones: Una de cada cinco ITU es causada por agentes BLEE en nuestra población. Existe una alta resistencia a los antibióticos usados como terapia empírica en nuestra población.

The aim of this study was to assess the risk factors and clinical and microbiological characteristics of community-acquired pneumonia (CAP) in adult patients in Mexico. Streptococcus pneumoniae classified as the causative agent of CAP in adult patients and patients with invasive S. pneumoniae isolates presented to three tertiary teaching hospitals during the 15-year study period were selected. Serotyping and susceptibility testing were performed for all included isolates. Clinical and demographic data were recorded. A total of 96 patients infected with S. pneumoniae (71 with CAP, 25 with invasive disease) were included. The CAP group involved more males (74.6%) than the invasive disease group (p = 0.03). Head trauma was more common in the CAP group (21.1%) than in the invasive disease group (4.0%; p = 0.03). The most prevalent serotype was 19A, followed by serotypes 3 and 23F. After the introduction of the heptavalent conjugated pneumococcal vaccine (PCV7), the prevalence of included serotypes declined significantly; no such change was found after the introduction of the PCV13 vaccine, including in the prevalence of serotype 19A. Susceptibility to all antimicrobials tested except vancomycin declined over the study period. In conclusion, head trauma was the most common comorbidity in the CAP group. The most prevalent serotype was 19A. Decreased susceptibility to most antimicrobials tested was observed.

El objetivo de este estudio fue evaluar los factores de riesgo y las características clínicas y microbiológicas de la neumonía adquirida en la comunidad (NAC) en pacientes adultos en México. Se seleccionaron pacientes adultos con NAC con Streptococcus pneumoniae como agente causal y pacientes con aislamientos invasivos de S. pneumoniae que concurrieron a tres hospitales de enseñanza de tercer nivel durante el período de estudio de 15 anos (2000-2015). Se realizaron pruebas de serotipificación y sensibilidad con todos los aislados incluidos. Se colectaron los datos clínicos y demográficos. Se incluyeron en total 96 pacientes infectados con S. pneumoniae (71 con NAC y 25 con enfermedad invasiva). El grupo con NAC incluía más varones (74,6%) que el grupo de enfermedad invasiva (p = 0,03). El traumatismo craneoencefálico fue más frecuente en el grupo NAC (21,1%) queen el grupo con enfermedad invasiva (4,0%; p = 0,03). El serotipo más frecuente fue 19A, seguido de los serotipos 3 y 23F. Después de la introducción de la vacuna antineumocócica conjugada heptavalente (PCV7), la prevalencia de los serotipos incluidos en aquella disminuyó significativamente; no sucedió lo mismo después de la introducción de la PCV13, incluso en relación con la prevalencia del serotipo 19A. La sensibilidad a todos los antimicrobianos evaluados, excepto la vancomicina, disminuyó durante el período de estudio. En conclusión, el traumatismo craneoencefálico fue la comorbilidad más frecuente en el grupo con NAC. El serotipo más frecuente fue el 19A, y se observó disminución de la sensibilidad a la mayoría de los antimicrobianos probados a lo largo del período considerado.

Abstract In the first nine weeks of implementation of a Zika Virus Preparedness Plan in a Mexican Public Hospital, we cared for 221 pregnant women with any signal or symptom suggesting Zika virus infection and 99 (44.8%) patients were found to be positive for Zika virus.The median age of patients was 25.3 years (range 13-49). Symptoms in PCR-positive patients were rash (91.4%) followed by headache (53.1%), myalgia (46.9%), arthralgia (45.7%), pruritus (35.8%), retroocular pain (29.6%), conjunctivitis (21%), and fever (21%). The women's epidemiologic exposure history indicates local transmission and a community outbreak.

Abstract Introduction The epidemiology of Clostridium difficile infection (CDI) has changed in the last two decades. There is a lack of information regarding incidence and severity of CDI, especially in the developing world. Methods This was a retrospective and observational study from four hospitals of three Mexican cities. Patients were diagnosed with CDI when presented with loose stools and had at least one of the following tests positive: toxins assay, real-time PCR, or an endoscopic image compatible with pseudomembranous colitis. CDI was classified according to international guidelines. Demographic and clinical data as well as information regarding total hospital admissions, total length-of-hospital stay, and other variables related to hospitalization were gathered from the epidemiology and administration departments of each hospital. Results A total of 2050 hospital beds were analyzed with 288,171 patients hospitalized accumulating 1,576,446 days of hospitalization during the study period. The average rate of CDI per 1000 hospital-days was lower than the rates reported in the US and Europe, although in 2015 CDI rates were almost persistently above the mean rate for the study period. More than half of PCR positive patients were ribotype 027. Conclusion Hospital rates of CDI are increasing in Mexican hospitals with a predominance of infections caused by ribotype 027.

Abstract: This research - a case study - was conducted in two schools at the basic education stage (educación básica) and 54 educators - 45 from primary and 9 from preschool education - participated. The purpose was to study how the Practice Community (PC) introduced in Technical School Board (TSB) meetings would benefit the analysis of learning assessment practices from collaborative work. Each school held four video-recorded meetings of approximately two hours in duration. It was found that teachers identified opportunity areas for improving practice through collaborative work, which led to a stronger, more open relationship between them and reflection on their assessment practices.

Resumen: La presente investigación (estudio de caso) se desarrolló en dos escuelas de Educación Básica. En ella participaron 54 educadores: 45 de educación primaria y 9 de preescolar. El propósito fue estudiar cómo la Comunidad de Práctica (CoP) implementada en las reuniones de Consejo Técnico Escolar (CTE) propiciaría el análisis de las prácticas de evaluación de aprendizajes a partir del trabajo colaborativo. En cada escuela se desarrollaron cuatro reuniones de aproximadamente dos horas que fueron registradas en video. Se encontró que los profesores identificaron áreas de oportunidad para mejorar la práctica mediante el trabajo colaborativo, fortaleciendo una relación de apertura entre ellos y reflexionando sobre sus prácticas evaluativas.

Abstract The mechanisms contributing to persistence of coagulase-negative staphylococci are diverse; to better understanding of their dynamics, the characterization of nosocomial isolates is needed. Our aim was to characterize phenotypic and molecular characteristics of Staphylococcus epidermidis and Staphylococcus haemolyticus human blood isolates from two tertiary care hospitals in Mexico, the Hospital Universitario in Monterrey and the Hospital Civil in Guadalajara. Antimicrobial susceptibility was determined. Biofilm formation was assessed by crystal violet staining. Detection of the ica operon and Staphylococcal Cassette Chromosome mec typing were performed by PCR. Clonal relatedness was determined by Pulsed-fiel gel electrophoresis and Multi locus sequence typing. Methicillin-resistance was 85.5% and 93.2% for S. epidermidis and S. haemolyticus, respectively. Both species showed resistance >70% to norfloxacin, clindamycin, levofloxacin, trimethoprim/sulfamethoxazole, and erythromycin. Three S. epidermidis and two S. haemolyticus isolates were linezolid-resistant (one isolate of each species was cfr+). Most isolates of both species were strong biofilm producers (92.8% of S. epidermidis and 72.9% of S. haemolyticus). The ica operon was amplified in 36 (43.4%) S. epidermidis isolates. SCCmec type IV was found in 47.2% of the S. epidermidis isolates and SCCmec type V in 14.5% of S. haemolyticus isolates. No clonal relatedness was found in either species. Resistance to clindamycin, levofloxacin, erythromycin, oxacillin, and cefoxitin was associated with biofilm production for both species (p < 0.05). A G2576T mutation in 23S rRNA gene was detected in an S. haemolyticus linezolid-resistant isolate. All linezolid-resistant S. epidermidis isolates belonged to ST23; isolate with SCCmec type IV belonged to ST7, and isolate with SCCmec type III belonged to ST2. This is the first report of ST7 in Mexico. There was a high genetic diversity in both species, though both species shared characteristics that may contibute to virulence.

Abstract: Objective: To determine the frequency of nine sexually transmitted pathogens, coinfections and risk factors in patients attending obstetrics and gynecology clinics in Jalisco, Mexico. Materials and methods: Samples from 662 patients attending obstetrics and gynecology clinics were analyzed. Treponema pallidum, HIV, and HCV were detected by serology. HPV was detected by Polimerase Chain Reaction (PCR), and its genotype was determined by Restriction Fragment Length Polymorphism (RFLP). Trichomonas vaginalis, HSV-1, HSV-2, Mycoplasma genitalium, Neisseria gonorrhoeae and T. pallidum were detected by multiplex PCR. Results: By serology, HIV frequency was 6.8%, T. pallidum was 2.26%, and HCV was 0.15%. By PCR, HPV frequency was 13.9%, (more frequent genotype was 16, 33.7%), followed by T. vaginalis (14.2%), HSV-1 (8.5%), M. genitalium (2,41%), N. gonorrhoeae (2.11%), HSV-2 (1.8%), and T. pallidum (1.05%). Patients infected with T. vaginalis were more likely to have multiple coinfections (p = 0.01). Conclusion: The frequency of HPV, HVS-1, HSV-2, M. genitalium and T. vaginalis was lower than that reported. However, a high frequency of HIV, T. pallidum, and N. gonorrhoeae was detected.

Resumen: Objetivo: Determinar la frecuencia de nueve patógenos de transmisión sexual, coinfecciones y factores de riesgo en pacientes que acudieron a una consulta de ginecología y obstetricia en Jalisco, México. Material y métodos: Se analizaron muestras de 662 pacientes que asistieron a la consulta de ginecología y obstetricia. Se detectaron Treponema pallidum, VIH y VHC mediante serología. Se detectó VPH por Reacción de Cadena de Polimerasa (PCR) y sus genotipos se detectaron por Polimorfismos de Longitud de Fragmentos de Restricción (RFLP). Se detectaron Trichomonas vaginalis, VHS-1,VHS-2, Mycoplasma genitalium, Neisseria gonorrhoeae y T. pallidum por PCR múltiple. Resultados: Por serología, la frecuencia deVIH fue 6.8%, de T. pallidum fue 2.26% y deVHC fue 0.15%. Por PCR, la frecuencia más alta fue deVPH (13.9%, el genotipo más frecuente fue el 16, 33.7%), seguida deT. vaginalis (14.2%), VHS-1 (8.5%), M. genitalium (2.41%), N. gonorrhoeae (2.11%), VHS-2 (1.8%) y T. pallidum (1.05%). Los pacientes infectados con T. vaginalis presentaron más probabilidades de tener múltiples coinfecciones (p = 0.01). Conclusiones: La frecuencia de infección por VPH, VHS-1,VHS-2, M.genitalium y T. vaginalis fue menor a lo reportado. Sin embargo, se detectó una alta frecuencia de VIH, T. pallidum, y N. gonorrhoeae.

Abstract: Objective: To determine the frequency of nine sexually transmitted pathogens, coinfections and risk factors in patients attending obstetrics and gynecology clinics in Jalisco, Mexico. Materials and methods: Samples from 662 patients attending obstetrics and gynecology clinics were analyzed. Treponema pallidum, HIV, and HCV were detected by serology. HPV was detected by Polimerase Chain Reaction (PCR), and its genotype was determined by Restriction Fragment Length Polymorphism (RFLP). Trichomonas vaginalis, HSV-1, HSV-2, Mycoplasma genitalium, Neisseria gonorrhoeae and T. pallidum were detected by multiplex PCR. Results: By serology, HIV frequency was 6.8%, T. pallidum was 2.26%, and HCV was 0.15%. By PCR, HPV frequency was 13.9%, (more frequent genotype was 16, 33.7%), followed by T. vaginalis (14.2%), HSV-1 (8.5%), M. genitalium (2,41%), N. gonorrhoeae (2.11%), HSV-2 (1.8%), and T. pallidum (1.05%). Patients infected with T. vaginalis were more likely to have multiple coinfections (p = 0.01). Conclusion: The frequency of HPV, HVS-1, HSV-2, M. genitalium and T. vaginalis was lower than that reported. However, a high frequency of HIV, T. pallidum, and N. gonorrhoeae was detected.

Resumen: Objetivo: Determinar la frecuencia de nueve patógenos de transmisión sexual, coinfecciones y factores de riesgo en pacientes que acudieron a una consulta de ginecología y obstetricia en Jalisco, México. Material y métodos: Se analizaron muestras de 662 pacientes que asistieron a la consulta de ginecología y obstetricia. Se detectaron Treponema pallidum, VIH y VHC mediante serología. Se detectó VPH por Reacción de Cadena de Polimerasa (PCR) y sus genotipos se detectaron por Polimorfismos de Longitud de Fragmentos de Restricción (RFLP). Se detectaron Trichomonas vaginalis, VHS-1,VHS-2, Mycoplasma genitalium, Neisseria gonorrhoeae y T. pallidum por PCR múltiple. Resultados: Por serología, la frecuencia deVIH fue 6.8%, de T. pallidum fue 2.26% y deVHC fue 0.15%. Por PCR, la frecuencia más alta fue deVPH (13.9%, el genotipo más frecuente fue el 16, 33.7%), seguida deT. vaginalis (14.2%), VHS-1 (8.5%), M. genitalium (2.41%), N. gonorrhoeae (2.11%), VHS-2 (1.8%) y T. pallidum (1.05%). Los pacientes infectados con T. vaginalis presentaron más probabilidades de tener múltiples coinfecciones (p = 0.01). Conclusiones: La frecuencia de infección por VPH, VHS-1,VHS-2, M.genitalium y T. vaginalis fue menor a lo reportado. Sin embargo, se detectó una alta frecuencia de VIH, T. pallidum, y N. gonorrhoeae.

Background: For clinicians, a practical bedside tool for severity assessment and prognosis of patients with Clostridium difficileinfection is a highly desirable unmet medical need.Setting: Two general teaching hospitals in northeast Mexico.Population: Adult patients with C. difficileinfection.Methods: Prospective observational study.Results: Patients included had a median of 48 years of age, 54% of male gender and an average of 24.3 days length of hospital stay. Third generation cephalosporins were the antibiotics most commonly used prior to C. difficileinfection diagnosis. Patients diagnosed with C. difficileinfection had a median ATLAS score of 4 and 56.7% of the subjects had a score between 4 and 7 points. Patients with a score of 8 through 10 points had 100% mortality.Conclusion: The ATLAS score is a potentially useful tool for the routine evaluation of patients at the time of C. difficileinfection diagnosis. At 30 days post-diagnosis, patients with a score of ≤3 points had 100% survival while all of those with scores ≥8 died. Patients with scores between 4 and 7 points had a greater probability of colectomy with an overall cure rate of 70.1%.