Pair bonding and disruption impact lung transcriptome in monogamous Peromyscus californicus.

Social interactions affect physiological and pathological processes, yet their direct impact in peripheral tissues remains elusive. Recently we showed that disruption of pair bonds in monogamous Peromyscus californicus promotes lung tumorigenesis, pointing to a direct effect of bonding status in the periphery (Naderi et al., 2021). Here we show that lung transcriptomes of tumor-free Peromyscus are altered in a manner that depends on pair bonding and superseding the impact of genetic relevance between siblings. Pathways affected involve response to hypoxia and heart development. These effects are consistent with the profile of the serum proteome of bonded and bond-disrupted Peromyscus and were extended to lung cancer cells cultured in vitro, with sera from animals that differ in bonding experiences. In this setting, the species' origin of serum (deer mouse vs FBS) is the most potent discriminator of RNA expression profiles, followed by bonding status. By analyzing the transcriptomes of lung cancer cells exposed to deer mouse sera, an expression signature was developed that discriminates cells according to the history of social interactions and possesses prognostic significance when applied to primary human lung cancers. The results suggest that present and past social experiences modulate the expression profile of peripheral tissues such as the lungs, in a manner that impacts physiological processes and may affect disease outcomes. Furthermore, they show that besides the direct effects of the hormones that regulate bonding behavior, physiological changes influencing oxygen metabolism may contribute to the adverse effects of bond disruption.

Molecular genetic analysis of AKR1C2-4 and HSD17B6 genes in subjects 46,XY with hypospadias.

BACKGROUND: The formation of the male urethra depends to enzyme-mediated testosterone (T) conversion into 5α-dihydrotestosterone (DHT). Two metabolic pathways could be operating in the fetal testis to synthesize androgens: 1) the "classic" route (T→DHT) mediated by SRD5A2 and 2) a "backdoor" pathway in which DHT is synthesized by aldo-keto reductase family 1, member C2 (AKR1C2), AKR1C3, and AKR1C4 enzymes without formation of a T intermediate. OBJECTIVE: We studied four genes of the "backdoor" pathway in karyotypic males with hypospadias to ascertain whether gene defects in AKRs impair urethral DHT formation that result in hypospadias. DESIGN AND PATIENTS: The coding regions of the AKR1C2-4 and HSD17B6 genes were analyzed by PCR-SSCP and sequencing in a cohort of 25 Mexican patients (0.3-9 year-old-children) with 46,XY-hypospadias. Chi-squared tests was performed to evaluate the distribution of genotypes, alleles, and the Hardy-Weinberg (H-W) equilibrium. The effect of the genetic variants was investigated by in silico studies. RESULTS: Screening studies revealed distinct genotypic patterns at different exons of AKR1C2-4 whereas HSD17B6 presented a wild-type sequence. The DNA analyses detected two synonymous variants (c.327C>T, c.666T>C/unreported) in AKR1C2. The AKR1C3 had two variants (c.15C>G, c.230A>G), two unreported variants (c.538T>C, c.596G>A), and one silent variant (c.312G>A). Two variants (c.434C>G, c.931C>G) were identified in AKR1C4. All variants were in H-W equilibrium without structural changes. DISCUSSION: Hypospadias have been associated with defects that alter androgen biosynthesis in the human fetal testis, specifically 5α-DHT. We selected four candidate genes involved in the "backdoor" pathway for the formation of 5α-DHT. Molecular assays of the AKR1C2, AKR1C3, and AKR1C4 genes revealed a total of nine genetic single nucleotide variants. Several variants in the AKR1C genes have been associated with a variety of human pathologies. However, our studies suggest that active steroid biosynthesis via AKR1C might not be involved in hypospadias. Additionally, genetic research suggests a low involvement in the "backdoor" 5α-DHT pathway during human sexual development, specifically, the differentiation of male external genitalia. CONCLUSION: These results indicate that substitutions in AKR1C2-4 are polymorphisms and all genetic variants lacks deleterious significant association with hypospadias. The data suggest that inactivating mutations in the AKR1C2-4 and HSD17B6 genes are an infrequent cause of hypospadias, which might weaken the contribution of the "backdoor" pathway to embryonic urethral masculinization.

Mutational analysis of SRD5A2: From gene to functional kinetics in individuals with steroid 5α-reductase 2 deficiency.

Human steroid 5α-reductase 2 (SRD5A2) plays a determinative role in the masculinization of external genitalia. To date, approximately 114 different mutations of the SRD5A2 gene have been reported; however, little information is available about their impact on catalytic function or their three-dimensional (3D) structures. We determined the effect of point mutations on the testosterone-depend kinetic constants (Km,app and Vmax,app) and structural characteristics of SRD5A2 from Mexican patients with 46,XY-steroid 5α-reductase 2 deficiency. PCR-SSCP assays identified ten distinct gene variants and sequencing analysis identified missense mutations [p.V3I, p.S14R, p.A52T, p.F118L, p.R145W, p.R171S, p.L226P, p.F229S, p.S245Y, and p.A248V]. Mutations were re-created by site-directed mutagenesis and expressed in HEK293 cells. Functional studies demonstrated that 8 variants led to partial (Km,app = 0.16-2.6 µM; Vmax,app = 224-2640 pmol/mg P/min) or complete losses of activity compared to the wild-type enzyme (Km,app = 0.7 µM; Vmax,app = 4044 pmol/mg P/min). All the mutations were assessed using multiple software tools and the results predicted that all of the mutations were associated with disease or damage. Mapping mutations on the model of a 3D structure of SRD5A2 demonstrated alterations in contact sites with their proximal amino acids. Our data show that mutations affect the catalytic efficiency (Vmax/Km) or result in residual enzymatic activity, which could be due to erroneous interactions between amino acid residues, the substrate testosterone, or NADPH.

Corrigendum to "isolation and sex steroid effects on the expression of the ATP-binding cassette transporter ABCB6 in Harderian glands of hamster (Mesocricetus auratus)" [Comparative Biochemistry and Physiology, Part A 232 (2019) 40-46].

ATP-Binding Cassette, subfamily B, member 6 (ABCB6) is a transporter that is upregulated by elevated intracellular porphyrin concentrations. In the Harderian gland (HG), the synthesis of porphyrins appears to be under the influence of gonadal steroids and to exhibit a dimorphic pattern. To explore whether ABCB6 is also influenced by sex steroids, we isolated its specific cDNA sequence and investigated its mRNA levels in the HGs of hamsters. ABCB6's cDNA sequence presents an open reading frame (ORF) of 2529 bp that encodes a predicted 842-amino acid (aa) protein with a molecular weight of 93 kDa. Multiple sequence alignments showed that ABCB6's aa sequence is highly conserved and shares the highest homology (93%) with mouse ABCB6. RT-qPCR analysis indicated that ABCB6 is expressed in all the tissues examined, exhibiting high expression levels in the liver, adrenal glands, and testis. The mRNA concentrations of ABCB6 in HGs were very similar between males and in females; similarly, gonadectomy and treatment with sex steroids appear to scarcely affect ABCB6 mRNA levels. The intraglandular content of ABCB6 mRNA showed discrete, though non-significant, variations through the estrous cycle. The results provide evidence that gonadal steroids have a minimal physiological role on the regulation of ABCB6 expression and might indicate that this transporter has a small effect on porphyrin trafficking in the HGs of hamsters. The authors would like to apologise for any inconvenience caused.

Isolation and sex steroid effects on the expression of the ATP-binding cassette transporter ABCB6 in Harderian glands of hamster (Mesocricetus auratus).

ATP-Binding Cassette, subfamily B, member 6 (ABCB6) is a transporter that is upregulated by elevated intracellular porphyrin concentrations. In the Harderian gland (HG), the synthesis of porphyrins appears to be under the influence of gonadal steroids and to exhibit a dimorphic pattern. To explore whether ABCB6 is also influenced by sex steroids, we isolated its specific cDNA sequence and investigated its mRNA levels in the HGs of hamsters. ABCB6's cDNA sequence presents an open reading frame (ORF) of 2529 bp that encodes a predicted 842-amino acid (aa) protein with a molecular weight of 93 kDa. Multiple sequence alignments showed that ABCB6's aa sequence is highly conserved and shares the highest homology (93%) with mouse ABCB6. RT-qPCR analysis indicated that ABCB6 is expressed in all the tissues examined, exhibiting high expression levels in the liver, adrenal glands, and testis. The mRNA concentrations of ABCB6 in HGs were very similar between males and in females; similarly, gonadectomy and treatment with sex steroids appear to scarcely affect ABCB6 mRNA levels. The intraglandular content of ABCB6 mRNA showed discrete, though non-significant, variations through the estrous cycle. The results provide evidence that gonadal steroids have a minimal physiological role on the regulation of ABCB6 expression and might indicate that this transporter has a small effect on porphyrin trafficking in the HGs of hamsters.

[Management of the chronic compartment syndrome of the leg in athletes. Presentation of 2 cases and review of literature]. / Manejo del síndrome compartimental crónico de la pierna en atletas. Presentación de dos casos y revisión de la literatura.

A problem commonly undiagnosed, severe and diffi cult to treat is chronic compartment syndrome in athletes. This pathology in its acute phase requires a diagnosis and treatment early to avoid muscle necrosis and neurological injury. Also, in chronic cases, the diagnosis is mainly clinical and the complete liberation of all compartments of the leg is essential. I review the literature of management of this pathology and two cases with specific treatment are presented. The objective is to provide evidence-based guidance for both chronic and acute treatment of chronic compartment syndrome in athletes to reduce the delay in the diagnosis and implement effective therapeutic measures for the improvement of the athletes and to avoid as much as possible the presentation of complications and sequelae in this group of patients.

Un problema comúnmente no diagnosticado, grave y difícil de tratar es el síndrome compartimental crónico en atletas (SCCA), patología que cuando se agudiza requiere un diagnóstico y tratamiento temprano para evitar necrosis musculares y lesiones neurológicas. Asimismo, en los casos crónicos el diagnóstico es principalmente clínico y la liberación completa de todos los compartimientos de la pierna es esencial. Se revisa la literatura del manejo de esta patología, se presentan dos casos y su tratamiento específico. El objetivo es ofrecer una guía con base en evidencia para el tratamiento del síndrome compartimental tanto crónico como agudo en atletas, con el fin disminuir el retraso en el diagnóstico, implementar medidas terapéuticas efectivas y cronológicamente adecuadas en beneficio de los deportistas y evitar en lo posible la presentación de complicaciones y secuelas en este grupo de pacientes.

Manejo del síndrome compartimental crónico de la pierna en atletas. Presentación de dos casos y revisión de la literatura / Management of the chronic compartment syndrome of the leg in athletes. Presentation of 2 cases and review of literature

Resumen: Un problema comúnmente no diagnosticado, grave y difícil de tratar es el síndrome compartimental crónico en atletas (SCCA), patología que cuando se agudiza requiere un diagnóstico y tratamiento temprano para evitar necrosis musculares y lesiones neurológicas. Asimismo, en los casos crónicos el diagnóstico es principalmente clínico y la liberación completa de todos los compartimientos de la pierna es esencial. Se revisa la literatura del manejo de esta patología, se presentan dos casos y su tratamiento específico. El objetivo es ofrecer una guía con base en evidencia para el tratamiento del síndrome compartimental tanto crónico como agudo en atletas, con el fin disminuir el retraso en el diagnóstico, implementar medidas terapéuticas efectivas y cronológicamente adecuadas en beneficio de los deportistas y evitar en lo posible la presentación de complicaciones y secuelas en este grupo de pacientes.

Abstract: A problem commonly undiagnosed, severe and difficult to treat is chronic compartment syndrome in athletes. This pathology in its acute phase requires a diagnosis and treatment early to avoid muscle necrosis and neurological injury. Also, in chronic cases, the diagnosis is mainly clinical and the complete liberation of all compartments of the leg is essential. I review the literature of management of this pathology and two cases with specific treatment are presented. The objective is to provide evidence-based guidance for both chronic and acute treatment of chronic compartment syndrome in athletes to reduce the delay in the diagnosis and implement effective therapeutic measures for the improvement of the athletes and to avoid as much as possible the presentation of complications and sequelae in this group of patients.

Mutational analysis of the androgen receptor (NR3C4) gene in patients with 46,XY DSD.

Androgen insensitivity syndrome (AIS) is an X-linked disorder caused by mutations in the NR3C4 gene, which encodes the androgen receptor (AR). In this study, we performed mutational analyses to identify AR molecular defects, in individuals with 46,XY disorders of sex development (46,XY DSD) and a presumptive diagnosis of AIS. Eighteen different gene mutations, including seven previously unreported new variants, were detected in 26 unrelated cases. These included two deletion mutations (P49fs*185 and E308f*320) in exon 1 and five substitution mutations (p.S792P, p.D829G, p.R832P, p.L839F, and p.K906E) located in the steroid-binding domain. Expression analyses of mutants generated by site-directed mutagenesis indicated that these new gene variants impaired AR function by affecting its binding activity. Seventeen of 18 mutations likely lead to reduced or absent responses to androgens, which may in turn account for the different degrees of undermasculinization observed. Our study provides insight into the functional consequences of these mutations.

Hamster SRD5A3 lacks steroid 5α-reductase activity in vitro.

According to current knowledge, two steroid 5α-reductases, designated type 1 (SRD5A1) and type 2 (SRD5A2), are present in all species examined to date. These isozymes play a central role in steroid hormone physiology by catalyzing the reduction of 3-keto-4-ene-steroids into more active 5α-reduced derivatives, including the conversion of testosterone (T) to dihydrotestosterone (DHT). A third 5α-reductase (SRD5A3, -type 3), which is overexpressed in hormone-refractory prostate cancer cells, has been identified; however, its enzymatic characteristics are practically unknown. Here, we isolated a cDNA encoding hamster Srd5a3 (hSrd5a3) and performed functional metabolic assays to investigate its biochemical properties. The cloned cDNA encodes a 330 amino acid protein that is 87% identical to the homologous protein in mice and 78% to that in humans. However, hSrd5a3 exhibits low sequence homology with its counterparts hSrd5a1 (19%) and hSrd5a2 (17%). A fusion protein consisting of hSrd5a3 and green fluorescent protein provided evidence for cytoplasmic localization in transfected mammalian cells. Real-time PCR analysis revealed that, Srd5a3 mRNA was present in nearly all hamster tissues, with high expression in the cerebellum, Harderian gland and testis. Functional assays expressing hSrd5a3 cDNA in HEK-293 cells revealed that this isozyme is unable to reduce T into DHT. Further expression assays confirmed that similar to testosterone, progesterone, androstenedione and corticosterone are not reduced by hSrd5a3 or human SRD5A3. Together, these results indicate that hSrd5a3 lacks the catalytic activity to transform 3-keto-4-ene-compounds; therefore 5α-reductase type 3 may not be involved in 5α-reduction of steroids.

N alpha methyl histamine versus propranolol in migraine prophylaxis.

OBJECTIVES: To compare the efficacy and tolerability of the subcutaneous administration of N alpha methyl histamine versus oral propranolol in the treatment of migraine prophylaxis. BACKGROUND: N alpha methyl histamine has a selective affinity for H3 receptors and could constitute a new therapeutic drug in migraine prophylaxis. METHODS: Sixty patients with migraine were selected and enrolled in a 12-week double-blind controlled clinical trial to evaluate the efficacy of subcutaneous administration of N-alpha methyl histamine (1 to 3 ug twice a week ) n=30, compared to administration of 120 mg/day of oral propranolol n=30. the variables were: headache intensity, frequency of attacks, duration of migraine attacks and analgesic intake. RESULTS: fifty five patients completed the study. the data collected during the 4th week of treatment revealed that N alpha methyl histamine and propranolol caused a significantly (p<0.01) greater reduction between the basal values and final values of every variable studied. CONCLUSIONS: Both N alpha methyl histamine and propranolol are similarly effective in reducing or eliminating the headache in migraine prophylaxis. low doses of N-alpha methyl histamine injected subcutaneously may represent a novel and effective therapeutic alternative in migraine patients and may lay the clinical and pharmacological groundwork for the use of H3 receptor agonist in migraine prophylaxis.

[Biceps tendon rupture in athletes. Diagnosis and management modalities. Report of three cases]. / Ruptura del tendón del bíceps en atletas: diagnóstico y modalidades de manejo, presentación de 3 casos.

OBJECTIVE: To help the orthopedic surgeon become familiar with this type of injuries in athletes; to mention the difficulty to perform the clinical and imaging diagnosis; to emphasize the diagnostic need of arthroscopy in the injury of the proximal or long tendon; to present the current treatment modalities and, in the distal injury, suggest the use of a single incision, as well as biodegradable material for fixation purposes. CONCLUSIONS: The diagnosis of biceps tendon injuries in athletes is mainly a clinical one, assisted by imaging; however, the arthroscopic confirmation of proximal injuries is essential. Current techniques for proximal tendon fixation are variable, but, same as in the distal aspect, early fixation with biodegradable screws is a biomechanically stable option and promotes the athlete's full rehabilitation.

[Clinical practice guidelines on the diagnosis and treatment of infectious acute diarrhea in children Peru - 2011]. / Guía de práctica clínica sobre el diagnóstico y tratamiento de la diarrea aguda infecciosa en pediatría Perú - 2011.

The Clinical Practice Guidelines cover the Diagnosis and Treatment of Acute Diarrhea in Pediatric Infectious is a consice information about definition, inclusion and exclusion criteria; epidemiology and etiology of infectious diarrhea. The guidelines cover aspects of diagnosis and treatment (dehydration, antibiotics, supportive therapy), nutritional support and other aspects of transferences and prevention.

Guía de práctica clínica sobre el diagnóstico y tratamiento de la diarrea aguda infecciosa en pediatría Perú - 2011 / Clinical practice guidelines on the diagnosis and treatment of infectious acute diarrhea in children Peru - 2011

Guía de Práctica Clínica sobre el Diagnóstico y Tratamiento de la Diarrea Aguda Infecciosa en Pediatría del Perú es una información resumida sobre la definición criterios de inclusión y exclusión epidemiología y etiología de la diarrea infecciosa; considerando aspectos en el dignóstico y tratamiento (desidratación, tratamiento antibiótico, tratamientos de apoyo), soporte nutricional criterios de transferencias y alta y aspectos de prevención.

The Clinical Practice Guidelines cover the Diagnosis and Treatment of Acute Diarrhea in Pediatric Infectious is a consice information about definition, inclusion and exclusion criteria; epidemiology and etiology of infectious diarrhea. The guidelines cover aspects of diagnosis and treatment (dehydration, antibiotics, supportive therapy), nutritional support and other aspects of transferences and prevention.

[Orthotopic liver transplantation. Experience in the University Hospital of Monterrey, N.L]. / Trasplante hepático ortotpico. Experiencia en el Hospital Universitario de Monterrey, N.L.

INTRODUCTION: Several programs of organ and tissues transplantation have been developed for over a decade at the University Hospital. OBJECTIVE: To describe long term complications and survival in the liver transplant program at the University Hospital, UANL. MATERIAL AND METHODS: The long term complications and survival were analyzed in the liver transplant program at the University Hospital Dr. José Eleuterio González in the period between 1991 and 2011. RESULTS: Ninety six liver transplants were performed during this period, four of them received one re-transplant and one patient received 2 retransplants. Most common long term complications were metabolic 62%, bony 31% and infectious 28%. Median survival was 78 months. CONCLUSIONS: Liver transplant program at the University Hospital UANL has grown, being the most active in the state of Nuevo Leon, with 1-, 5- and 10-years survival of 66.1, 53.3 and 46.2%, respectively.

Análisis de una experiencia de consultoría ético clínica en cuidado intensivo / Analysis of a clinical ethics consultation experience in intensive care

Background: Very few patients are presented to ethics committees, and individual ethics consultations are a response to this situation. At the intensive care unit (ICU) in Clínica Alemana, Santiago Chile, an ethics consultation system was organized coordinated with the ethics committee. Aim: To report an evaluation of this ethics consultation system. Material and Methods: Analysis of the frst 50 cases analyzed in the consultation system. Analysis of the responses of intensive care physicians to a questionnaire about the main ethical problems that they face in their work. Results: The consultation system is mainly required by the ICU staff, and reports to the ethics committee. Fifty four percent of patients subjected to consultation were aged over 80 years. The main diagnoses were neurological, oncological or cardiopulmonary problems. The ethical problems identifed were treatment limitation (62 percent), proportionality or futility (42 percent), need of a peaceful death (36 percent), lack of anticipated decisions (28 percent), disagreement between physicians and patient’s family (24 percent), undefined subrogation (14 percent), and abuse of public resources (14 percent). Twenty six of 31 ICU physicians answered the questionnaire, using a 1 (min) to 7 (max.) scale. They found that consultation is helpful for decision making (6.3), useful for improving ethical perception (6.0), supportive for staff (6.5), good for patients (6.3), supportive for families (6.7), and timely performed (5.2). Conclusions: As a complement for the ethics committee’s work, consultation is a valid alternative for ethics counselling and a support for physicians and patient’s families. Its implementation depends on the particularities of each health institution.

Comparación de los modelos pronósticos APACHE II y Score Salvador en sepsis abdominal / Comparison of APACHE II and Score Salvador models of prediction in abdominal sepsis

La evolución y pronóstico de la sepsis abdominal están determinados por la rapidez con que se efectúa el diagnóstico, intervención apropiada y la eficacia y oportunidad del tratamiento antibiótico. Los estudios clínicos han identificado algunos factores de mal pronóstico, entre los cuales se encuentran el puntaje APACHE II elevado. Nosotros realizamos un estudio retrospectivo en la Unidad de Cuidados Intensivos del Hospital del Salvador, comparando el Score Apache II con un Score local, denominado Score del Salvador, en los pacientes con diagnóstico de sepsis abdominal. Resultados: Hubo 2.158 ingresos en la UCI del Hospital del Salvador, correspondiendo a 7,6% (n =164) de los casos a sepsis abdominal. Las principales causas de infección abdominal fueron perforación intestinal, colangitis, obstrucción intestinal y pancreatitis aguda. La comparación de las curvas receptor-operador del Score del Salvador y el índice pronóstico Apache II, evidencia que no existen diferencias significativas en el área bajo la curva de ambos índices pronósticos en pacientes con sepsis abdominal. Conclusión: Ambos índices pronósticos fueron comparables plenamente. Dado el escaso número de pacientes enrolados y la gravedad de ellos el valor predictivo es limitado lo que sugiere necesario aumentar el tamaño de la muestra y diversificar la gravedad.

The evolution and presage of the abdominal sepsis are determined by the speed with which it is made the diagnosis, appropriate intervention and the effectiveness and opportunity of the antibiotic treatment. The clinical studies have identified some factors of bad presage, among which are the high score APACHE II. We carry out a retrospective study in the Intensive Care Unit of the Salvador’s Hospital, comparing the Apache Score II with a local score, denominated Score of the Salvador to the patients with the diagnose of abdominal sepsis. Results: There were 2.158 revenues in the ICU of the Salvador’s Hospital, corresponding 7,6% (n =164) of the cases to abdominal sepsis. The main causes of abdominal infection were intestinal perforation, colangitis, intestinal obstruction, and sharp pancreatitis. The comparison of the curves receiver-operator of the Salvador’s Score and the index Apache II, it evidences that significant differences don’t exist in the area under the curve of both index in patient with abdominal sepsis. Conclusion: Both scores were comparable fully. Given the scarce number of signed up patients and the graveness of them, the predictive value is limited what suggests necessary to increase the size of the sample and to diversify the graveness.

Elaboración de un sazonador a base de harina de cabezas de camarón de cultivo (Penaeous sp) / Elaboration of a seasoning from a crop shrimp (Penaeus sp) heads flour

La harina del camarón es el desperdicio de camarón seco molido, con buenas características de conservación, que se obtiene a partir de cabezas, abdomen o el camarón entero, según las características químicas del producto. Se elabora un sazonador a base de harinas de cabezas de camarón de cultivo (Penaeus sp) mediante un proceso de mezclado a pequeña escala, realizado en el Instituto de Ciencia y Tecnología Alimentaría, Medellín, con el fin de proporcionar una alternativa para darles valor agregado a los subproductos de empresas camaroneras. Se preparan tres formulaciones con 10, 20 y 30 por ciento p/p de harina de cabezas de camarón, adicionándoles condimentos y aditivos. De acuerdo al análisis sensorial, realizado por panelistas entrenados, la mejor formulación es la preparada con 30 por ciento p/p de harina de cabezas de camarón.

Viabilidad de Escherichia coli en presencia de diferentes contaminantes / Escherichia coli viability in the presence of different contaminants

La contaminación en ríos condiciona la presencia de microorganismos adaptados al ecosistema entre ellos a patógenosde importancia en salud pública. Objetivo: Determinar la viabilidad de Escherichia coli en presencia de nitratode plata, carbonato de amonio, fenol y formaldehído. Materiales y métodos: Se tomaron muestras de agua del ríoAlseseca, que luego se sembró en medios de cultivo selectivos para enterobacterias, seleccionándose las coloniasdel género Escherichia, las cuales fueron sembradas en el medio de orientación CHROMagar ECC. Las muestrasde E. coli se evaluaron en presencia de nitrato de plata, carbonato de amonio, fenol y formaldehído. Resultados: Elgrupo experimental presentó viabilidad en presencia de los cuatro compuestos, el grupo control positivo presentó nulaviabilidad, la comparación entre los grupos mostró diferencia significativa (p< 0,05). Conclusión: Los aislamientos deE. coli mostraron viabilidad, implicando riesgos para el ecosistemas y la salud, ya que el río Alseseca atraviesa por elmunicipio de Puebla donde existen núcleos poblacionales importantes.

River contamination conditions the presence of microorganisms adapted to different ecosystems, particularly for pathogens important from public health’s point of view. Objective: To determine Escherichia coli viability in the presence of silver nitrate, ammonium carbonate, phenol and formaldehyde. Materials and methods: Water samples from Alseseca river were taken, which later were placed in selective culture media for enterobacteriaceae, and Escherichia colonies were selected, which, were then placed in orienting CHROMagar ECC medium. E. coli samples were assessed in the presence of silver nitrate, ammonium carbonate, and formaldehyde. Results: The experimental group showed viability in presence of the four compounds tested, control group showed null viability, and the comparison between the two groups showed a statistically significant difference (p<0,05). Conclusion: E. coli isolates showed viability under the conditions tested, which implies risks for the ecosystem and for health, since Alseseca river goes through Puebla town, where there are important population nuclei.